This disclosure relates to an automatic driving device and a radar device.
According to the related art (for example, Japanese Patent Application Laid-open No. 2019-206339), when a driver of a vehicle falls into a situation in which the driver has difficulty in driving, a travel control apparatus automatically stops the vehicle in a pull-over area on behalf of the driver based on information received from a camera and a radar.
For radars, roadside objects such as guardrails are highly reflective objects, while humans are low reflective objects. Therefore, for example, when a vehicle is to be pulled over to a pull-over area, it may be difficult for a radar to detect a human present near a roadside object. Thus, there is a fear in that such a related-art travel control apparatus as described above may cause a decrease in accuracy of object detection by a radar.
This disclosure has been made in order to solve the above-mentioned problem, and has an object to provide an automatic driving device and a radar device that suppress a decrease in accuracy of object detection by a radar device.
According to at least one embodiment of this disclosure, there is provided an automatic driving device including a vehicle controller configured to control driving of a vehicle based on information received from a radar device mounted to the vehicle, wherein driving modes of the vehicle to be used by the vehicle controller include a separation mode, wherein the vehicle controller has a control target monitoring area set therefor, the control target monitoring area being an area on a front side in a traveling direction of the vehicle, wherein the vehicle controller is configured to control the driving of the vehicle in the separation mode so that an object assumed to be present in the control target monitoring area and a detected object that is different from the object are separately detected by the radar device, and wherein the detected object is at least one of a structure outside the vehicle or an indirect wave from the object via the structure.
According to the automatic driving device and the radar device of the at least one embodiment of this disclosure, it is possible to suppress a decrease in accuracy of object detection by the radar device.
Now, embodiments of this disclosure are described with reference to the drawings. In the following description, like components are denoted by like reference numerals.
The driver monitor 30 monitors a state of a driver of the vehicle 10, and determines whether or not the driver can continue to drive. The driver monitor 30 monitors, for example, a heart rate of the driver, an eye movement of the driver, a driving behavior of the driver.
The object detection device 40 acquires obstacle information and road information. The obstacle information is information relating to a position of an obstacle present in a periphery of the vehicle 10. The road information is information including a change of a road in a traveling direction of the vehicle 10.
The object detection device 40 includes an object detector 41, a camera 42 serving as a sensor, a radar device 43, an ultrasonic sensor 44 and a locator 45.
The object detector 41 acquires pieces of information detected by the camera 42, the radar device 43, the ultrasonic sensor 44, and the locator 45, and integrates the acquired pieces of information to output the integrated information to the vehicle controller 60. The camera 42 includes a camera for photographing a front side in the traveling direction of the vehicle 10 and a camera for photographing the periphery of the vehicle 10.
The radar device 43 is mounted to a front portion of the vehicle 10. The radar device 43 emits electromagnetic waves toward the front side in the traveling direction of the vehicle 10, and detects reflected waves thereof, to thereby output a relative distance, a relative velocity, and an angle of an obstacle with respect to the vehicle 10. The radar device 43 may be provided not only to the front portion of the vehicle 10 but also to each of left and right rear portions of the vehicle 10 to output a relative distance, a relative velocity, and an angle of an obstacle of an object behind the vehicle 10 with respect thereto.
The ultrasonic sensor 44 emits ultrasonic waves, and detects reflected waves thereof, to thereby output the relative distance of the obstacle with respect to the vehicle 10. For example, the object detector 41 integrates information relating to the object detected by the camera 42 and information relating to the object detected by the radar device 43, to thereby generate more reliable information.
The object detector 41 also integrates information received from a sensor for monitoring the front side of the vehicle 10 and information received from a sensor for monitoring the periphery of the vehicle 10 to generate information relating to the entire periphery of the vehicle 10. Further, the object detector 41 determines in which lane another vehicle in the periphery of the vehicle 10 is present based on the information on white lines detected by the camera 42. Such integration of pieces of information received from a plurality of sensors to generate more reliable information is also called “sensor fusion.”
The vehicle state detector 50 acquires, as vehicle state information, information including a vehicle speed being a speed of the vehicle 10, an acceleration of the vehicle 10, an azimuth angle of the vehicle 10, and an angular velocity of the vehicle 10. The vehicle state detector 50 includes a steering angle sensor, a steering torque sensor, a yaw rate sensor, a speed sensor, and an acceleration sensor.
The vehicle controller 60 controls driving of the vehicle 10 based on information received from the radar device 43. Driving modes of the vehicle 10 to be selected by the vehicle controller 60 include a separation mode. A control target monitoring area is set for the vehicle controller 60. The control target monitoring area is an area on the front side in the traveling direction of the vehicle 10. In the separation mode, the vehicle controller 60 controls the driving of the vehicle 10 so that a peripheral structure serving as a structure and an object assumed to be present in the control target monitoring area are separately detected by the radar device 43. The peripheral structure is a detected object that is different from the object assumed to be present in the control target monitoring area.
The peripheral structure is a structure outside the vehicle 10. For example, the peripheral structure is a stationary object such as a guardrail. The peripheral structure is detected by the object detection device 40. For example, the peripheral structure may be detected based on the information received from the radar device 43, or may be detected based on positional information on the vehicle 10 and map information that are received from the locator 45.
The “separation” as used herein represents that the radar device 43 can correctly detect two objects as separate objects. As a plurality of control modes, the vehicle controller 60 has a manual driving compatible mode and an automatic driving compatible mode. The manual driving compatible mode is a mode to be selected when a driving entity of the vehicle 10 is a driver. The automatic driving compatible mode is a mode to be selected when the driving entity of the vehicle 10 is the vehicle controller 60.
The vehicle controller 60 includes a driving support controller 61 and an actuator controller 62. The driving support controller 61 is also called “advanced driver-assistance systems electronic control unit (ADAS-ECU).” The driving support controller 61 includes a roadside pull-over controller 70. The roadside pull-over controller 70 executes control for automatically stopping the vehicle 10 on the roadside when the driver of the vehicle 10 has difficulty in driving in the automatic driving compatible mode.
The roadside pull-over controller 70 includes a pull-over path determiner 71 and a vehicle motion limiter 72. The pull-over path determiner 71 determines a travel path and a future vehicle speed of the vehicle 10 based on physical restrictions, road signs, ride comfort, positional relationships of the vehicle 10 with respect to structures in the periphery of the vehicle 10, and positional relationships between the vehicle 10 and other vehicles in the periphery of the vehicle 10. The physical restrictions include the vehicle speed, an acceleration and a deceleration of the vehicle 10, and a steering angle.
The vehicle motion limiter 72 limits motion of the vehicle 10 based on a resolution of the radar device 43, a position of the vehicle 10, the vehicle speed, and the azimuth angle serving as the traveling direction of the vehicle 10. The resolution of the radar device 43 includes a range resolution and a relative velocity resolution.
The pull-over path determiner 71 determines the travel path and the vehicle speed of the vehicle 10 based on parameters regarding the motion of the vehicle 10 determined by the vehicle motion limiter 72, that is, within a limit range set by the vehicle motion limiter 72.
The actuator controller 62 controls a plurality of actuators of the vehicle 10 so that pull-over control of the vehicle 10 is achieved. The actuator controller 62 includes, for example, an electric power steering ECU, a power train ECU, and a brake ECU.
The transmission circuit 433 includes a voltage generation circuit 435, a voltage-controlled oscillator 436, and a distribution circuit 437. The reception circuit 434 includes mixers 438 to 441, filter circuits 442 to 445, and analog-to-digital converters (ADCs) 446 to 449.
The voltage generation circuit 435 generates a voltage waveform in accordance with a control timing of the radar controller 432. The voltage-controlled oscillator 436 oscillates a transmission signal based on the voltage waveform generated by the voltage generation circuit 435. The distribution circuit 437 amplifies the oscillated transmission signal. The distribution circuit 437 outputs the amplified transmission signal to the transmission antenna Tx1 and to the mixers 438 to 441 in the reception circuit 434 as well.
An electromagnetic wave serving as the transmission signal radiated from the transmission antenna Tx1 is reflected by a target object outside the vehicle 10. Reflected electromagnetic waves are received by the reception antennas Rx1 to Rx4. The electromagnetic waves received by the reception antennas Rx1 to Rx4 are input to the reception circuit 434 as reception signals. The reception signal received from the reception antenna Rx1 is input to the mixer 438. The reception signal received from the reception antenna Rx2 is input to the mixer 439. The reception signal received from the reception antenna Rx3 is input to the is input to the mixer 440. The reception signal received from the reception antenna Rx4 is input to the mixer 441.
The mixer 438 mixes the reception signal received by the reception antenna Rx1 and the transmission signal received from the distribution circuit 437 to output a beat signal being a mixed signal to the filter circuit 442. The mixer 439 mixes the reception signal received by the reception antenna Rx2 and the transmission signal received from the distribution circuit 437 to output a beat signal to the filter circuit 443. The mixer 440 mixes the reception signal received by the reception antenna Rx3 and the transmission signal received from the distribution circuit 437 to output a beat signal to the filter circuit 444. The mixer 441 mixes the reception signal received by the reception antenna Rx4 and the transmission signal received from the distribution circuit 437 to output a beat signal to the filter circuit 445.
The filter circuits 442 to 445 each include a band-pass filter and an amplifier circuit. The band-pass filter is a filter for extracting a signal in a specific frequency band. The amplifier circuit is a circuit for amplifying the signal extracted by the band-pass filter.
The filter circuit 442 extracts a signal in a specific frequency band from the beat signal received from the mixer 438 and amplifies the extracted signal to output the amplified signal to the ADC 446. The filter circuit 443 extracts a signal in a specific frequency band from the beat signal received from the mixer 439 and amplifies the extracted signal to output the amplified signal to the ADC 447. The filter circuit 444 extracts a signal in a specific frequency band from the beat signal received from the mixer 440 and amplifies the extracted signal to output the amplified signal to the ADC 448. The filter circuit 445 extracts a signal in a specific frequency band from the beat signal received from the mixer 441 and amplifies the extracted signal to output the amplified signal to the ADC 449.
The ADC 446 converts the analog voltage signal received from the filter circuit 442 into digital voltage data in accordance with the control timing of the radar controller 432 to output the digital voltage data to the radar controller 432. The ADC 447 converts the analog voltage signal received from the filter circuit 443 into digital voltage data in accordance with the control timing of the radar controller 432 to output the digital voltage data to the radar controller 432. The ADC 448 converts the analog voltage signal received from the filter circuit 444 into digital voltage data in accordance with the control timing of the radar controller 432 to output the digital voltage data to the radar controller 432. The ADC 449 converts the analog voltage signal received from the filter circuit 445 into digital voltage data in accordance with the control timing of the radar controller 432 to output the digital voltage data to the radar controller 432.
The pieces of digital voltage data input to the radar controller 432 are stored in a memory (not shown) included in the radar controller 432.
The radar controller 432 calculates a distance between the radar device 43 and a target object and a relative velocity between the radar device 43 and the target object from the digital voltage data corresponding to four channels. A principle of calculating a distance and a relative velocity in the FCM method is publicly known, and is described in, for example, Japanese Patent Application Laid-open No. 2016-3873.
The number of samples per chirp is represented by Nsample, the number of fast Fourier transform (FFT) points in a range direction is represented by NRFFT, and the number of FFT points in a relative velocity direction is represented by NVFFT. It is assumed that the number Nsample of samples per chirp and the number NRFFT of FFT points in the range direction are equal to each other and the number Nchirp of chirps and the number NVFFT of FFT points in the relative velocity direction are equal to each other. In this case, as a waveform obtained after FFT processing in the range direction and FFT processing in the relative velocity direction, a two-dimensional power spectrum having NRFFT/2 bins in the range direction and NVFFT bins in the relative velocity direction is obtained. The range direction means a chirp direction, and the relative velocity direction means a chirp sequence direction.
Now, a range resolution ΔR and a relative velocity resolution ΔV of the radar device 43 are expressed by the following expressions.
ΔR=c/(2×B) (1)
ΔV=λ/(2×Tcs) (2)
In the expressions, “c” represents the speed of light, B represents a frequency modulation width, and Tcs represents a chirp sequence time. The chirp sequence time Tcs is a time required for one chirp sequence. In addition, a wavelength λ is expressed by the following expression.
λ=c/fc (3)
In the expression, fc represents a center frequency of the chirp having the frequency modulation width B in
When the routine of
Step S101: The radar controller 432 executes two-dimensional FFT on the obtained digital voltage data corresponding to four channels to generate a two-dimensional power spectrum.
Step S102: The radar controller 432 executes peak detection on the obtained two-dimensional power spectrum to extract a peak from the two-dimensional power spectrum. Examples of a method of extracting a peak include a publicly known constant false alarm (CFAR) method.
Step S103: The radar controller 432 calculates a distance from the target object and a relative velocity with respect to the target object corresponding to the extracted peak, based on the principle of the publicly known FCM method.
Step S104: The radar controller 432 measures an azimuth angle of the target object corresponding to the extracted peak. As a method of measuring an azimuth angle, for example, a beamformer method is used. This single routine corresponds to the chirp sequence that is repeated at a processing cycle period set in advance.
To describe the processing step of Step S101 more specifically, the radar controller 432 first executes first FFT processing on the digital voltage data in each chirp to generate a power spectrum. For example, as the distance between the radar device 43 and the target object becomes longer, a time delay of the reception signal with respect to the transmitted signal becomes longer. Therefore, the frequency of the beat signal is proportional to the distance between the radar device 43 and the target object.
In the first FFT processing, intensity information on the reception signal and phase information on the reception signal are extracted for each of frequency points set at regular intervals. The frequency point is called “range bin.” As a result of the first FFT processing, a peak appears in a range bin for a frequency corresponding to the distance. That is, the distance from the target object can be obtained by detecting a peak frequency in the first FFT processing. The first FFT processing is executed on the beat signal. Therefore, the first FFT processing is repeated as often as the number of beat signals, namely, the number of chirps.
When second FFT processing is performed with frequency power spectra obtained by the first FFT processing being arranged in time series, a frequency power spectrum in which a peak appears in a frequency bin for the beat frequency is obtained. The frequency bin for the beat frequency is called “relative velocity bin.” In this manner, a two-dimensional power spectrum having the range bin and the relative velocity bin as axes thereof is obtained. For example, when two objects having mutually different distances or two objects having mutually different relative velocities are detected by the radar device 43, two peaks appear on the two-dimensional power spectrum.
As illustrated in
The radar device 43 includes a plurality of control modes relating to the range resolution. The plurality of control modes relating to the range resolution include the manual driving compatible mode and the automatic driving compatible mode. The radar controller 432 controls the radar main body 431 in the plurality of control modes relating to the range resolution.
A first range resolution is higher than a second range resolution. The first range resolution is a range resolution to be used in the automatic driving compatible mode. The second range resolution is a range resolution to be used in the manual driving compatible mode. As indicated in Expression (1), a method of increasing the frequency modulation width B is conceivable as means for increasing the range resolution.
The radar device 43 also includes a plurality of control modes relating to the relative velocity resolution. The plurality of control modes relating to the relative velocity resolution include the manual driving compatible mode and the automatic driving compatible mode. The radar controller 432 controls the radar main body 431 in the plurality of control modes relating to the relative velocity resolution.
A first relative velocity resolution is higher than a second relative velocity resolution. The first relative velocity resolution is a relative velocity resolution to be used in the automatic driving compatible mode. The second relative velocity resolution is a relative velocity resolution to be used in the manual driving compatible mode. As indicated in Expression (2), a method of increasing the chirp sequence time Tcs is conceivable as means for increasing the relative velocity resolution. In addition, as a result of increasing the chirp sequence time Tcs, a time during which radio waves are transmitted becomes longer than in the manual driving compatible mode, and hence this case may be handled by correspondingly increasing the processing cycle period.
The radar device 43 selects, from among the plurality of control modes, a control mode in which at least one of the range resolution or the relative velocity resolution is set higher as the vehicle speed becomes lower.
Further, the radar device 43 selects, from among the plurality of control modes, a control mode in which at least one of the range resolution or the relative velocity resolution is set higher as the distance between the vehicle 10 and the peripheral structure is shorter.
For the sake of simplification, the description has been made on the premise that a height of a reflection point on the peripheral structure 81 and a height of a reflection point on the target object 82 are the same as a height of the radar device 43. However, the same results can be obtained even when the heights of the respective reflection points are different from the height of the radar device 43.
Next, roadside pull-over control to be performed by the driving support controller 61 is described. In the following description, the following control is assumed: while the vehicle 10 is traveling in a leftmost lane, the driver of the vehicle 10 falls into a situation in which the driver has difficulty in driving, and the driving support controller 61 automatically decelerates the vehicle 10 to stop the vehicle 10 at a roadside edge on the left side. However, this roadside pull-over control is applicable to the vehicle 10 irrespective of which lane the vehicle 10 is traveling in or whether the roadside is located on the left side or the right side of the vehicle 10.
When the routine of
Meanwhile, when the driver of the vehicle 10 is in a situation in which the driver has difficulty in driving, the driving support controller 61 determines in Step S202 whether or not presence of a control target has been confirmed based on the information received from the object detection device 40. When the presence of a control target has been confirmed, the driving support controller 61 selects an “emergency stop control mode” as the driving mode in Step S208, and temporarily ends this routine.
The “emergency stop control mode” is a mode in which the vehicle 10 is automatically brought to an emergency stop in order to avoid collision between the vehicle 10 and the control target. The emergency stop refers to braking of the vehicle 10 by, for example, emergency stop braking. In this case, in Step S208, the driving support controller 61 sets a deceleration of the vehicle 10 based on the distance between the vehicle 10 and the control target and the state of the driver. For example, when a control target has been detected to be in extremely close proximity to the vehicle 10, the deceleration may be set as high as possible, and when the distance between the vehicle 10 and the control target is relatively long, the deceleration may be set relatively gentle.
Meanwhile, when the presence of a control target has not been confirmed, the driving support controller 61 determines in Step S203 whether or not the driving mode can be shifted to the pull-over mode. The pull-over mode is a mode in which the vehicle 10 is pulled over to the roadside. In addition, a case in which the shift to the pull-over mode cannot be performed is, for example, a case in which the radar device 43 fails, a case in which an elapsed time after the driver falls into a situation in which the driver has difficulty in driving exceeds a specified time, and a case in which a distance traveled after the driver falls into a situation in which the driver has difficulty in driving exceeds a specified distance.
When the driving mode cannot be shifted to the pull-over mode, the driving support controller 61 selects a “vehicle stop control mode” as the driving mode in Step S207, and temporarily ends this routine. The “vehicle stop control mode” refers to a mode in which the vehicle 10 is quickly decelerated and stopped.
Meanwhile, when the driving mode can be shifted to the pull-over mode, the driving support controller 61 determines in Step S204 whether or not a pull-over area has been found and the vehicle 10 can enter the pull-over area. The pull-over area is an area having a size enough to stop the vehicle 10 therein. The pull-over area is searched for based on the information received from the object detection device 40 at a time point before the driver falls into a situation in which the driver has difficulty in driving. For example, the driving support controller 61 estimates a coordinate position of the vehicle 10 based on information received from the locator 45, and compares the estimated coordinate position and the map information to each other, to thereby search for the position of the pull-over area in the periphery of the vehicle 10.
Whether or not the vehicle 10 can enter the pull-over area is determined by determining based on the information received from the object detection device 40 whether or not an obstacle is present in the pull-over area. The driving support controller 61 determines that the vehicle 10 can enter the pull-over area when an obstacle is not present in the pull-over area, and determines that the vehicle 10 cannot enter the pull-over area when an obstacle is present in the pull-over area.
When a pull-over area is found and the vehicle 10 can enter the pull-over area, the driving support controller 61 selects a “second pull-over mode” as the driving mode in Step S206, and temporarily ends this routine. Meanwhile, when a pull-over area is not found or when the vehicle 10 cannot enter the pull-over area, the driving support controller 61 selects a “first pull-over mode” as the driving mode in Step S205, and temporarily ends this routine.
When the vehicle speed has already reduced to the first vehicle speed, in Step S303, the roadside pull-over controller 70 causes the vehicle 10 to maintain a lane in which the vehicle 10 is currently traveling. Meanwhile, when the vehicle speed has not been reduced to the first vehicle speed, in Step S302, the roadside pull-over controller 70 reduces the vehicle speed to the first vehicle speed. For example, the first vehicle speed is set to 50 km/h. A reason for reducing the vehicle speed to the first vehicle speed is to reduce collision damage caused to the periphery by the vehicle 10.
Subsequently, in Step S303, the roadside pull-over controller 70 causes the vehicle 10 to maintain the lane in which the vehicle 10 is currently traveling. As methods of causing the vehicle 10 to maintain a lane, there are a method of correcting a traveling position of the vehicle 10 based on the information received from the locator 45 and the map information and controlling the vehicle 10 in accordance with the correction and a method of controlling the vehicle 10 based on information regarding the white lines photographed by the camera 42.
Subsequently, in Step S304, the roadside pull-over controller 70 searches for a pull-over area, and temporarily ends this routine.
When the vehicle speed has not been reduced to the second vehicle speed, in Step S402, the roadside pull-over controller 70 reduces the vehicle speed to the second vehicle speed. Subsequently, in Step S403, the roadside pull-over controller 70 causes the vehicle 10 to maintain the lane in which the vehicle 10 is traveling.
Meanwhile, when the vehicle speed has been reduced to the second vehicle speed, the roadside pull-over controller 70 determines in Step S404 whether or not an operating mode of the radar device 43 is set to the automatic driving compatible mode.
When the operating mode of the radar device 43 is not the automatic driving compatible mode, in Step S405, the roadside pull-over controller 70 shifts the operating mode of the radar device 43 to the automatic driving compatible mode. Subsequently, in Step S403, the roadside pull-over controller 70 causes the vehicle 10 to maintain the lane in which the vehicle 10 is currently traveling.
Meanwhile, when the operating mode of the radar device 43 is the automatic driving compatible mode, in Step S406, the roadside pull-over controller 70 determines a pull-over path and a vehicle speed. Subsequently, in Step S407, the roadside pull-over controller 70 transmits, to the actuator controller 62, an instruction for controlling the vehicle 10 based on the determined pull-over path and the determined vehicle speed, and temporarily ends this routine.
When it is determined that the peripheral structure 81 is present, in Step S502, the vehicle motion limiter 72 calculates a limiting value of the pull-over path and a limiting value of a vehicle speed plan in consideration of performance of the radar device 43. Whether or not the peripheral structure 81 is present is determined based on, for example, the information received from the object detection device 40. In Step S501, for example, when the peripheral structure 81 has been detected to be present at a lateral position of 5 m from the vehicle 10 based on the information received from the object detection device 40, a distance from the peripheral structure 81 is assumed to be 5 m.
As a method of detecting the peripheral structure 81, there is, for example, a method of estimating a position of the peripheral structure 81 based on positional information on a stationary object detected by the radar device 43. There is also a method of estimating the traveling position of the vehicle 10 based on the information received from the locator 45 and estimating the position of the peripheral structure 81 with respect to the traveling position of the vehicle 10 by comparing the traveling position and the map information to each other. Subsequently, in Step S505, the pull-over path determiner 71 calculates the pull-over path and the vehicle speed plan within a range of the calculated limiting values, and temporarily ends this routine.
Meanwhile, when it is determined that the peripheral structure 81 is not present, the pull-over path determiner 71 determines in Step S503 whether or not to assume a virtual structure. For example, when a function of the radar device 43 is restricted so as not to detect a stationary object, the radar device 43 may not be able to detect the peripheral structure 81. In such a case, in Step S503, it is assumed that the peripheral structure 81 is present in a periphery of a planned travel path of the vehicle 10. The peripheral structure 81 assumed in this manner is referred to as “virtual structure.”
When a virtual structure is assumed, in Step S504, the pull-over path determiner 71 assumes coordinates of the virtual structure as coordinates of the peripheral structure 81.
For example, even when the peripheral structure 81 is not detected based on the information received from the object detection device 40, in a case in which detection accuracy of the peripheral structure 81 exhibited by the object detection device 40 is expected to be low, the vehicle 10 may be constantly controlled on the assumption that a virtual structure is present. In such a case, the determination of Step S503 always results in “Yes.”
In another example, when a determination result of presence/absence of the peripheral structure 81 based on information received from the camera 42 and a determination result of presence/absence of the peripheral structure 81 based on the information received from the radar device 43 are different from each other, the determination of the presence or absence of the peripheral structure 81 cannot be verified. In such a case, “Yes” may be determined as a result of Step S503.
Subsequently, in Step S502, the vehicle motion limiter 72 calculates the limiting value of the pull-over path and the limiting value of the vehicle speed plan in consideration of the performance of the radar device 43.
Subsequently, in Step S505, the pull-over path determiner 71 calculates the pull-over path and the vehicle speed plan within the range of the calculated limiting values, and temporarily ends this routine.
Meanwhile, when the virtual structure is not assumed, in Step S505, the pull-over path determiner 71 calculates the pull-over path and the vehicle speed plan, and temporarily ends this routine.
Now, the calculation of the limiting value of the pull-over path and the calculation of the limiting value of the vehicle speed plan, which are performed in Step S502, are described in more detail. The calculation of the limiting value of the pull-over path and the calculation of the limiting value of the vehicle speed plan are performed so as to allow the radar device 43 to separately detect an object assumed to be present within the control target monitoring area and the peripheral structure 81. Therefore, the calculation of the limiting value of the pull-over path and the calculation of the limiting value of the vehicle speed plan are performed based on the position of the vehicle 10 and the position of the peripheral structure 81.
The positional relationship between the vehicle 10 and the peripheral structure 81 changes depending on the position of the vehicle 10, the vehicle speed, and the azimuth angle of the vehicle 10. Therefore, a vehicle speed Vself, an azimuth angle θself of the vehicle 10, a lateral position Yself of the vehicle 10, and a longitudinal position Xself of the vehicle 10 are set as parameters for the limiting value of the pull-over path and the limiting value of the vehicle speed plan.
First, a case in which the peripheral structure 81 is arranged linearly along a road is described. The azimuth angle θself of the vehicle 10 is an angle formed between a direction conforming to the road and the traveling direction of the vehicle 10. Even when the peripheral structure 81 is not completely arranged linearly, the calculation may be performed by regarding the peripheral structure 81 as a straight line, or the calculation may be performed by approximating the peripheral structure 81 to a straight line.
Subsequently, in Step S602, the vehicle motion limiter 72 generates a separable lateral position table for the vehicle speed Vself and the azimuth angle θself of the vehicle 10, and temporarily ends this routine.
The free running distance is represented by a product of the vehicle speed immediately before start of braking due to emergency braking and a free running time. The free running time includes a processing time of the radar device 43 and a delay time after the driving support controller 61 outputs an emergency brake control command to the actuator controller 62 until a braking force is actually generated.
The braking distance due to emergency braking is a distance by which the vehicle 10 is moved after the braking force is actually generated until the vehicle 10 is stopped. The margin up to the control target is a distance margin between a position at which the vehicle 10 is stopped by emergency braking and a position of the control target.
Further, assuming that, for example, the width of the vehicle 10 is 1.8 m and the margins in the width direction are 0.1 m on both left and right sides, the length Ly of the control target monitoring area 83 in the width direction of the vehicle 10 is calculated as 2.0 m.
Subsequently, in Step S702, the vehicle motion limiter 72 calculates a second lateral position limiting value Ylimit_velocity[Vself] [θself]. The second lateral position limiting value Ylimit_velocity[Vself] [θself] is a lateral position limiting value that allows the peripheral structure 81 and the target object 82 to be separately detected in the relative velocity direction.
Subsequently, in Step S703, the vehicle motion limiter 72 selects, as the lateral position limiting value, the smaller one of the first lateral position limiting value Ylimit_range[Vself] [θself] or the second lateral position limiting value Ylimit_velocity[Vself] [θself]. The vehicle motion limiter 72 creates a separable lateral position table Ylimit[Vself] [θself] based on the selected lateral position limiting value. This means that the limiting value of the lateral position that allows the peripheral structure 81 and the target object 82 to be separately detected in one of the range direction or the relative velocity direction is selected.
Whether or not the peripheral structure 81 and the target object can be separately detected in the range direction can be determined by determining whether or not the object assumed to be present at a point A of
A condition for separately detecting the object assumed to be present at the point A and the peripheral structure 81 is that a difference between a distance Rb between a point B and the radar device 43 and a distance Ra between the point A and the radar device 43 is larger than a range difference Rseparate for enabling separate detection by the radar device 43. The point B is a point on the peripheral structure 81 which is closest to the radar device 43 within the FoV. That is, Expression (4) is satisfied.
R
a
+R
separate
<R
b (4)
The distance Rb between the point B and the radar device 43 is expressed by Expression (5). In Expression (5), θmax represents a maximum value of an angular direction of the FoV, Yb represents a relative lateral position of the radar device 43 with respect to the peripheral structure 81, and θself represents the azimuth angle of the vehicle 10.
R
b
=Y
b/sin(θmax+θself) (5)
That is, when Expression (6) or Expression (7) is satisfied, the object assumed to be present at the point A and the peripheral structure 81 are separately detected in the range direction by the radar device 43.
R
a
+R
separate
<Y
b/sin(θmax+θself) (6)
sin(θmax+θself)×(Ra+Rseparate)<Yb (7)
When the distance Ra between the point A and the radar device 43, the maximum value θmax of the FoV of the radar device 43 in the angular direction, the distance Rb between the point B and the radar device 43, and the azimuth angle θself of the vehicle 10 are fixed to some values, the lateral position Yb required for separately detecting two objects in the range direction is determined.
As a first example, assuming that Ra is 5 m, Rseparate is 0.2 m, θmax is 45 degrees, and θself is 0 degrees, Expression (8) is established.
Y
b>3.7m (8)
That is, when the radar device 43 is linearly moved along a position farther than 3.7 m from the linear peripheral structure 81 in parallel thereto, the radar device 43 can separately detect the object at the point A and the peripheral structure 81 in the range direction.
Further, when θself is set to 10 degrees in the first example, Expression (9) is established.
Y
b>4.3m (9)
This means that the radar device 43 cannot separately detect two objects in the range direction unless the vehicle 10 is moved farther away from the peripheral structure 81 as the azimuth angle θself of the vehicle 10 becomes larger, that is, as the traveling direction of the vehicle 10 becomes closer to a direction perpendicular to the peripheral structure 81.
Further, when Ra is set to 3 m in the first example, Expression (10) is established.
Y
b>2.3m (10)
As the vehicle speed Vself becomes lower, Ra becomes smaller, and the control target monitoring area 83 becomes smaller. Therefore, this means that the radar device 43 can further separately detect two objects in the range direction even when the vehicle 10 becomes closer to the peripheral structure 81 as the vehicle speed Vself becomes lower.
As described above, the first lateral position limiting value Ylimit_range[Vself] [θself] is defined as follows. The first lateral position limiting value Ylimit_range [Vself] [θself] is calculated for each vehicle speed Vself and each azimuth angle θself of the vehicle 10.
Y
limit_range
[V
self][θself]=sin(θmax+θself)×(Ra+Rseparate) (11)
Y
limit_range
[V
self][θself]=Yself−Ystat (12)
An antenna gain of the radar device 43 often tends to decrease as the FoV of the radar device 43 increases. Thus, it is more difficult for a wider-angle antenna to detect the target object. Therefore, the maximum value θmax of the FoV of the radar device 43 may be determined in consideration of the antenna gain. Further, in consideration that an intensity of the reflected waves decreases due to attenuation as the distance from the target object increases, the maximum value θmax of the FoV of the radar device 43 may be set to a value that differs for each distance.
Whether or not the peripheral structure 81 and the target object can be separately detected in the relative velocity direction can be determined by determining whether or not the object assumed to be present at a point C of
When a longitudinal position of the point C viewed from the radar device 43 is represented by xc and the lateral position of the point C viewed from the radar device 43 is represented by yc, the azimuth angle θc of the point C viewed from the radar device 43 is expressed by the following Expression (13).
θc=a tan(yc/xc) (13)
A magnitude of a relative velocity Vc of the object assumed to be present at the point C is detected by the radar device 43 and expressed by Expression (14).
V
c
=V
self×cos θc (14)
A condition for separately detecting the object assumed to be present at the point C and the peripheral structure 81 is that a difference between a relative velocity Vd of the peripheral structure 81 and the relative velocity Vc of the object assumed to be present at the point C is larger than a relative velocity difference Vseparate for enabling separate detection by the radar device 43. In the first embodiment, the peripheral structure 81 being a stationary object is present on a wide-angle side of the control target monitoring area 83, and hence the relative velocity Vc of the object assumed to be present at the point C is higher than the relative velocity Vd Of the peripheral structure 81. Therefore, the condition for separately detecting the object assumed to be present at the point C and the peripheral structure 81 is expressed by Expression (15).
V
c
−V
separate
>V
d (15)
The object assumed to be present at the point C and the peripheral structure 81 are positioned equidistant from the radar device 43. In
V
d
=V
self×cos θd (16)
Further, when a relative lateral position of the radar device 43 with respect to the peripheral structure 81 is represented by Yd, θd is expressed by Expression (17).
θd+θself=a sin(Yd/Rc) (17)
R
c=(xc2+yc2)1/2 (18)
That is, when Expression (19) or Expression (20) is satisfied, the object assumed to be present at the point C and the peripheral structure 81 are separately detected in the relative velocity direction by the radar device 43.
V
self×cos θc−Vseparate>Vself×cos θd (19)
cos θc−Vseparate/Vself>cos θd (20)
In this case, when 0<θd<90 degrees and 0<θc<90 degrees, cos θ decreases as θ increases, and hence Expression (20) can be replaced by Expression (21).
a cos(cos θc−(Vseparate/Vself))<θd (21)
When θd of Expression (17) is replaced by the inequality of Expression (21), Expression (22) or Expression (23) is obtained.
a cos(cos θc−(Vseparate/Vself))+θself<a sin(Yd/Rc) (22)
a cos(cos θc−(Vseparate/Vself))<a sin(Yd/Rc)−θself (23)
When 0<a sin(Yd/Rc)<90 degrees, sin θ increases as θ increases, and hence Expression (22) is expressed by Expression (24) or Expression (25).
sin{a cos(cos θc−(Vseparate/Vself))+θself}<Yd/Rc (24)
R
c×sin{a cos(cos θc−(Vseparate/Vself))+θself}<Yd (25)
When Rc, θc, Vseparate, Vself, and θself are fixed to some values, Yd required for separately detecting two objects in the relative velocity direction is determined.
As a first example, assuming that Vself is 10 km/h, xc is 5 m, yc is 0.9 m, Vseparate is 0.1 m/s, Rc is 5.08 m, θc is 10.2 degrees, and θself is 0 degrees, Expression (26) is established.
Y
d>1.61m (26)
That is, when the radar device 43 is linearly moved along a position farther than 1.61 m from the linear peripheral structure 81 in parallel thereto, the radar device 43 can separately detect the object at the point C and the peripheral structure 81 in the relative velocity direction.
Further, when θself is set to 10 degrees in the first example, Expression (27) is established.
Y
d>2.43m (27)
This means that the radar device 43 cannot separately detect two objects in the relative velocity direction unless the vehicle 10 is moved farther away from the peripheral structure 81 as the azimuth angle θself of the vehicle 10 becomes larger, that is, as the traveling direction of the vehicle 10 becomes closer to a direction perpendicular to the peripheral structure 81.
Further, when Vself is set to 5 km/h, xc is set to 3 m, yc is set to 0.9 m, Rc is set to 3.13 m, and θc is set to 16.7 degrees in the first example, Expression (28) is established.
Y
d>1.45m (28)
As the vehicle speed Vself becomes lower, xc becomes smaller, and the control target monitoring area 83 becomes smaller. Therefore, this means that the radar device 43 can further separately detect the peripheral structure 81 and the object at the point C in the relative velocity direction even when the vehicle 10 becomes closer to the peripheral structure 81 as the vehicle speed Vself becomes lower.
As described above, the second lateral position limiting value Ylimit_velocity[Vself] [θself] is defined as follows.
Y
limit_velocity
[V
self][θself]=Rc×sin{a cos(cos θc−(Vseparate/Vself))+θself} (29)
The second lateral position limiting value Ylimit_velocity[Vself] [θself] is calculated for each vehicle speed Vself and each azimuth angle θself of the vehicle 10. Then, in the same manner as in the case of the first lateral position limiting value Ylimit_range[Vself] [θself], such a table as shown in
The second lateral position limiting value Ylimit_velocity[Vself] [θself] represents relative coordinates with respect to the peripheral structure 81, and hence a relationship with the lateral position Yself of the vehicle 10 is expressed by the following expression. In this case, the lateral position Ystat represents a lateral position of the peripheral structure 81 with a freely-set coordinate position being used as the origin, and the lateral position Yself represents a lateral position of the vehicle 10 with a freely-set coordinate position being used as the origin.
Y
limit_velocity
[V
self][θself]=Yself−Ystat (30)
It has been assumed that Rc and Rd are equal to each other, but Rc and Rd may differ from each other. In addition, a range difference for enabling separate detection by the radar device 43 may be taken into consideration.
Next, a method of calculating the pull-over path and the vehicle speed plan to be performed by the pull-over path determiner 71 is described in more detail. After the separable lateral position table is created for each vehicle speed Vself and each azimuth angle θself of the vehicle 10 by the vehicle motion limiter 72, the pull-over path determiner 71 performs calculation of the pull-over path and calculation of the vehicle speed plan for causing the vehicle 10 to travel in such a travelable area as illustrated in each of
Not only the performance of the radar device 43 but also other restrictions are required to be taken into consideration for the pull-over path and the vehicle speed plan. Examples of the other restrictions include physical restrictions, restrictions imposed by road signs, restrictions relating to ride comfort, restrictions regarding a positional relationship with the peripheral structures 81, and restrictions regarding a positional relationship with another vehicle in the periphery. The physical restrictions include the vehicle speed Vself, the acceleration and deceleration, and the steering angle. The pull-over path determiner 71 determines the pull-over path and the vehicle speed plan in consideration of the performance of the radar device 43 within a range that does not depart from those other restrictions.
As methods of using the separable lateral position table, the following two examples are conceivable. In a first example, the pull-over path determiner 71 uses the separable lateral position table when determining the pull-over path and the vehicle speed, and calculates the path and the vehicle speed in consideration of the performance of the radar device 43. In a second example, the pull-over path determiner 71 determines the path and the vehicle speed without considering the performance of the radar device 43, and examines whether or not the determined path and vehicle speed fall within a range of values in the separable lateral position table. Then, the pull-over path determiner 71 reviews portions of the path and the vehicle speed that do not fall within the range of the separable lateral position table.
The second example is described below in detail with reference to the accompanying drawings.
In this case, an automatic driving vehicle is present in the travelable area at a location 01 and a location 03. Meanwhile, the automatic driving vehicle is supposed to travel in a non-travelable area at a location 02. The automatic driving vehicle is a vehicle 10 that automatically travels in accordance with the pull-over path and the vehicle speed plan that have been calculated.
At that time, the vehicle motion limiter 72 sets the vehicle speed lower than the vehicle speed determined by the pull-over path determiner 71 to cause the control target monitoring area 83 to become smaller without changing the pull-over path of the automatic driving vehicle at a location 12. This enables the automatic driving vehicle to travel in the travelable area.
In view of this, the vehicle motion limiter 72 sets the azimuth angle θself of the automatic driving vehicle smaller than the azimuth angle θself determined by the pull-over path determiner 71 under a state in which the vehicle speed Vself at the location 22 is fixed. Thus, the pull-over path subsequent to the location 22 is the pull-over path indicated by the solid line, and the automatic driving vehicle is supposed to head for a location 23. When the automatic driving vehicle travels along the pull-over path indicated by the solid line, the radar device 43 can separately detect the peripheral structure 81 and the object in the control target monitoring area 83.
In this manner, the vehicle motion limiter 72 limits at least one of the vehicle speed Vself or the travel path among the parameters regarding the motion of the vehicle 10.
The vehicle motion limiter 72 may keep the vehicle 10 away from the peripheral structure 81 under a state in which the vehicle speed Vself at the location 02 is fixed. The vehicle motion limiter 72 may also calculate the limiting value while changing the pull-over path and the vehicle speed Vself in association with each other.
The above description has been made on the assumption that the pull-over path determiner 71 creates the pull-over path and the vehicle speed plan before the vehicle 10 is pulled over, but the pull-over path and the vehicle speed plan may be reviewed as follows. For example, while the vehicle 10 is being pulled over, the pull-over path determiner 71 may acquire the position of the peripheral structure 81 from the object detection device 40 in real time and also acquire the vehicle speed and the steering angle from the vehicle state detector 50 to review the pull-over path and the vehicle speed plan based on those pieces of information.
When the routine of
Subsequently, in Step S802, the vehicle motion limiter 72 generates a separability table for the vehicle speed Vself, the azimuth angle θself of the vehicle 10, and the coordinates (Xself, Yself) of the vehicle 10.
Subsequently, in Step S902, the vehicle motion limiter 72 calculates whether or not the peripheral structure 81 and the object within the control target monitoring area 83 can be separately detected in the relative velocity direction for all the points within the control target monitoring area 83. In Step S902, whether or not the peripheral structure 81 and the object within the control target monitoring area 83 can be separately detected in the relative velocity direction is calculated for each vehicle speed Vself, each azimuth angle θself of the vehicle 10, and each set of the coordinates (Xself, Yself) of the vehicle 10.
Subsequently, in Step S903, the vehicle motion limiter 72 determines whether or not the peripheral structure 81 and the object within the control target monitoring area 83 can be separately detected in at least one of the range direction or the relative velocity direction.
When the peripheral structure 81 and the object within the control target monitoring area 83 can be separately detected in at least one of the range direction or the relative velocity direction, in Step S904, the vehicle motion limiter 72 inputs the fact of being “able to be separately detected” in a corresponding place of the separability table. The corresponding place refers to a place corresponding to each vehicle speed Vself, each azimuth angle θself of the vehicle 10, or each set of the coordinates (Xself, Yself) of the vehicle 10 that has been used for the calculation.
Meanwhile, when the peripheral structure 81 and the object within the control target monitoring area 83 cannot be separately detected in the range direction or the relative velocity direction, in Step S905, the vehicle motion limiter 72 inputs the fact of being “unable to be separately detected” in the separability table.
Now, the processing using the separability table is described more specifically with reference to the accompanying drawings.
When a distance between a point E being a part of the peripheral structure 81 and the radar device 43 is represented by Re, an object present at a point at which the distance from the radar device 43 is larger than Re-Rseparate and smaller than Re+Rseparate cannot be detected separately from an object present at the point E in the range direction. In the control target monitoring area 83, a range in which the distance from the radar device 43 is larger than Re-Rseparate and smaller than Re+Rseparate is indicated by a hatched area 86 of
In this example, the peripheral structure 81 is represented as a point, but when the peripheral structure 81 is present continuously like a wall, it is required to determine whether or not every point on the peripheral structure 81 within the FoV can be detected in the range direction separately from each point within the control target monitoring area 83. For example, when the number of points set on the peripheral structure 81 is represented by N and the number of points set within the control target monitoring area 83 is represented by M, it is determined whether or not the separate detection in the range direction is possible for N×M combinations. When the separate detection is possible for all the points within the control target monitoring area 83, the vehicle motion limiter 72 determines that the separate detection in the range direction is possible at the current vehicle speed Vself, azimuth angle θself of the vehicle 10, and coordinates (Xself, Yself) of the vehicle 10.
After the vehicle motion limiter 72 determines whether or not the separate detection in the range direction is possible for all the points within the control target monitoring area 83, the vehicle motion limiter 72 generates a separability table for the range direction which defines a relationship between the vehicle speed Vself, azimuth angle θself of the vehicle 10, and coordinates (Xself, Yself) of the vehicle 10 and travelability.
Next, a separability determination method for a relative velocity direction of Step S902 is described.
As illustrated in
Even when an object at the point H and an object at the point I can be separately detected, an object at the point F and an object at the point G may not be able to be separately detected. This is because the relative velocity difference Vseparate between the point F and the point G is smaller than the relative velocity difference Vseparate between the point H and the point I.
Therefore, similarly to the determination of Step S901, the vehicle motion limiter 72 computes whether or not every point on the peripheral structure 81 within the FoV can be detected in the relative velocity direction separately from each point within the control target monitoring area 83. When the separate detection is possible for all the points within the control target monitoring area 83, the vehicle motion limiter 72 determines that the separate detection in the relative velocity direction is possible at the current vehicle speed Vself, azimuth angle θself of the vehicle 10, and coordinates (Xself, Yself) of the vehicle 10.
After the vehicle motion limiter 72 determines whether or not the separate detection in the relative velocity direction is possible for all the points within the control target monitoring area 83, the vehicle motion limiter 72 generates a separability table for the relative velocity direction which defines the relationship between the vehicle speed Vself, azimuth angle θself of the vehicle 10, and coordinates (Xself, Yself) of the vehicle 10 and the travelability.
Next, the processing steps of from Step S903 to Step S905 of
In other words, the coordinates marked with “o” in the coordinate map of
A shape of the peripheral structure 81 illustrated in
In the first embodiment, detectability in each of the range direction and the relative velocity direction is determined for each predetermined vehicle speed Vself, each predetermined azimuth angle θself of the vehicle 10, and each predetermined set of the coordinates (Xself, Yself) of the vehicle 10. However, in order to shorten a computation time, the detectability in each of the range direction and the relative velocity direction may be determined by limiting a computation range to assumed vehicle speeds Vself, assumed azimuth angles θself of the vehicle 10, and assumed coordinates (Xself, Yself) of the vehicle 10.
As illustrated in
In the first embodiment, a table regarding the travelable area 85 of the vehicle 10 is generated for each vehicle speed Vself and each azimuth angle θself of the vehicle 10, but the table regarding the travelable area 85 of the vehicle 10 may be generated for each set of the coordinates (Xself, Yself) of the vehicle 10 and each vehicle speed Vself. Further, the table regarding the travelable area 85 of the vehicle 10 may be generated for each set of the coordinates (Xself, Yself) of the vehicle 10 and each azimuth angle θself of the vehicle 10.
That is, the vehicle motion limiter 72 may calculate at least one of a first limiting value, a second limiting value, or a third limiting value, and the vehicle controller 60 may control the motion of the vehicle 10 within a limit range which is based on at least one of the first limiting value, the second limiting value, or the third limiting value.
The first limiting value is a limiting value of the azimuth angle θself of the vehicle 10 to be used when the coordinates (Xself, Yself) of the vehicle 10 and the vehicle speed Vself are fixed. The second limiting value is a limiting value of the coordinates (Xself, Yself) of the vehicle 10 to be used when the vehicle speed Vself and the azimuth angle θself of the vehicle 10 are fixed. The third limiting value is a limiting value of the vehicle speed Vself to be used when the coordinates (Xself, Yself) of the vehicle 10 and the azimuth angle θself of the vehicle 10 are fixed.
In the first embodiment described above, the vehicle motion limiter 72 performs the calculation of the limiting value of the pull-over path and the calculation of the limiting value of the vehicle speed plan so as to allow the radar device 43 to separately detect the object assumed to be present within the control target monitoring area 83 and the peripheral structure 81. In contrast, in a second embodiment of this disclosure, the calculation of the limiting value of the pull-over path and the calculation of the limiting value of the vehicle speed plan are performed so as to allow the radar device 43 to separately detect a direct wave from the object assumed to be present within the control target monitoring area 83 and an indirect wave from the object via the peripheral structure 81. The indirect wave is a detected object that is different from the direct wave from an object assumed to be present in the control target monitoring area.
Processing steps to be executed by the roadside pull-over controller 70 are the same as the processing steps of the first embodiment up to the processing step of Step S801 in the pull-over-path-and-vehicle-speed-plan limiting value calculation routine in consideration of the radar performance which is illustrated in
In
When it is determined in Step S903 that the peripheral structure 81 and the object within the control target monitoring area 83 can be separately detected in at least one of the range direction or the relative velocity direction, the vehicle motion limiter 72 determines in Step S906 whether or not the direct wave from the object within the control target monitoring area 83 and the indirect wave from the object via the peripheral structure 81 can be separately detected for all the points within the control target monitoring area 83. The above-mentioned calculation is performed for each vehicle speed Vself, each azimuth angle θself of the vehicle 10, and each set of the coordinates (Xself, Yself) of the vehicle 10.
When the direct wave from the object within the control target monitoring area 83 and the indirect wave from the object via the peripheral structure 81 can be separately detected, in Step S907, the vehicle motion limiter 72 inputs the fact of being “able to be separately detected” in the corresponding place of the separability table. The corresponding place refers to a place corresponding to each vehicle speed Vself, each azimuth angle θself of the vehicle 10, or each set of the coordinates (Xself, Yself) of the vehicle 10 that has been used for the calculation.
When it is determined in Step S903 that the peripheral structure 81 and the object within the control target monitoring area 83 cannot be separately detected in the range direction or the relative velocity direction, in Step S908, the vehicle motion limiter 72 inputs the fact of being “unable to be separately detected” in the separability table. Further, when it is determined in Step S906 that the direct wave from the object within the control target monitoring area 83 and the indirect wave from the object via the peripheral structure 81 cannot be separately detected, in Step S908, the vehicle motion limiter 72 inputs the fact of being “unable to be separately detected” in the separability table.
Now, a method of determining in Step S906 whether or not the direct wave from the object within the control target monitoring area 83 and the indirect wave from the object via the peripheral structure 81 can be separately detected is described more specifically with reference to the accompanying drawings.
When a point within the control target monitoring area 83 is represented by J, a center point of the radar device 43 is represented by O, and a point being a part of the peripheral structure 81 is represented by K, a transmission wave transmitted from the radar device 43 is reflected at the point J and received by the radar device 43, that is, received as a direct wave. Meanwhile, the transmission wave transmitted from the radar device 43 is reflected at the point K, and a reflected wave thereof may be further reflected at the point J and received by the radar device 43, that is, received as an indirect wave.
In this case, a distance between the point O and the point J is represented by Roj, a distance between the point O and the point K is represented by Rok, and a distance between the point K and the point J is represented by Rkj. Further, a path of a radio wave obtained when the transmission wave transmitted from the radar device 43 is reflected at the point J and received by the radar device 43, that is, a path of the direct wave is set as a path 01, and a path of a radio wave obtained when the transmission wave transmitted from the radar device 43 reflected at the point K and the reflected wave thereof is further reflected at the point J and received by the radar device 43, that is, a path of the indirect wave is set as a path 02. At this time, the reflected wave on the path 01, that is, the direct wave is received by the radar device 43 at the distance Roj, and the reflected wave on the path 02, that is, the indirect wave is received by the radar device 43 at a distance (Rok+Rkj+Roj)/2.
Therefore, when a difference between the distance Roj of the reflected wave on the path 01, that is, of the direct wave and the distance (Rok+Rkj+Roj)/2 of the reflected wave on the path 02, that is, of the indirect wave is larger than the range difference Rseparate for enabling separate detection by the radar device 43, the direct wave and the indirect wave can be separately detected in the range direction.
As the vehicle 10 becomes farther from the peripheral structure 81, the difference between the distance Roj of the reflected wave on the path 01, that is, of the direct wave and the distance (Rok+Rkj+Roj)/2 of the reflected wave on the path 02, that is, of the indirect wave becomes larger, and hence the separate detection in the range direction becomes easier.
In this example, only one freely-selected point on the peripheral structure 81 is considered as the detected object, but when the peripheral structure 81 is present continuously like a wall illustrated in
Further, when the peripheral structure is linearly arranged, in the same manner as in the first embodiment, a lateral position at which the direct wave from the object within the control target monitoring area 83 and the indirect wave from the object via the peripheral structure 81 can be separately detected can be calculated for each vehicle speed Vself and each azimuth angle θself of the vehicle 10. At that time, instead of determining whether or not every point on the peripheral structure 81 within the FoV can be detected in the range direction separately from each point within the control target monitoring area 83, it is also conceivable to perform the calculation through selection of a point on the peripheral structure which is greatly influenced by the indirect wave.
After the vehicle motion limiter 72 determines whether or not the separate detection in the range direction is possible for all the points within the control target monitoring area 83, the vehicle motion limiter 72 generates a separability table for the direct wave and the indirect wave which defines the relationship between the vehicle speed Vself, azimuth angle θself of the vehicle 10, and coordinates (Xself, Yself) of the vehicle 10 and the travelability.
In this example, an exemplary case of determining whether or not the separate detection in the range direction is performed has been described, but it may be determined whether or not the separate detection in the relative velocity direction is performed, and when the separate detection in at least one of the directions has been performed, the fact of being “able to be separately detected” may be input in the separability table.
In this example, the path of the indirect wave is set as “radar device 43→point on the peripheral structure 81→point within the control target monitoring area 83→radar device 43,” but another path may be conceivable in the same manner.
In this example, an exemplary case in which, from Step S901 to Step S903, it is calculated whether or not the peripheral structure 81 and the object within the control target monitoring area 83 can be separately detected in the range direction and the relative velocity direction, and when it is determined that the separate detection in at least one of the range direction or the relative velocity direction is possible, it is calculated in Step S906 whether or not the direct wave from the object within the control target monitoring area 83 and the indirect wave from the object via the peripheral structure 81 can be separately detected has been described. However, the processing step of Step S906 may be performed without executing the processing steps of from Step S901 to Step S903.
The processing steps after Step S907 and Step S908, that is, the processing steps of Step S505 and the subsequent steps are the same as those of the first embodiment, and hence description thereof is omitted.
As described above, the automatic driving device 20 according to each of the first embodiment and the second embodiment includes the vehicle controller 60. The vehicle controller 60 controls the driving of the vehicle 10 based on the information received from the radar device 43. The radar device 43 is mounted to the vehicle 10.
The driving modes of the vehicle 10 to be used by the vehicle controller 60 include the separation mode. The control target monitoring area 83 is set for the vehicle controller 60. The control target monitoring area 83 is the area on the front side in the traveling direction of the vehicle 10.
In the separation mode, the vehicle controller 60 in the first embodiment controls the driving of the vehicle 10 so that the object assumed to be present in the control target monitoring area 83 and the peripheral structure 81 are separately detected by the radar device 43. The peripheral structure 81 is the structure outside the vehicle 10.
It becomes easier for the radar device 43 to separately detect the peripheral structure 81 and the object as the vehicle 10 becomes farther from the peripheral structure 81, the vehicle speed Vself becomes lower, and the azimuth angle θself of the vehicle 10 becomes smaller. Therefore, in the separation mode, the driving of the vehicle 10 is controlled so that it becomes easier for the radar device 43 to separately detect the peripheral structure 81 and the object. As a result, it is possible to suppress a decrease in accuracy of object detection by the radar device 43.
In the separation mode, the vehicle controller 60 in the second embodiment controls the driving of the vehicle 10 so that the direct wave from the object assumed to be present in the control target monitoring area 83 and the indirect wave from the object via the peripheral structure 81 are separately detected by the radar device 43. The peripheral structure 81 is the structure outside the vehicle 10.
It becomes easier for the radar device 43 to separately detect the direct wave and the indirect wave as the vehicle 10 becomes farther from the peripheral structure 81. Therefore, in the separation mode, the driving of the vehicle 10 is controlled so that it becomes easier for the radar device 43 to separately detect the direct wave and the indirect wave. As a result, it is possible to suppress a decrease in accuracy of object detection by the radar device 43.
The vehicle controller 60 in each of the first embodiment and the second embodiment includes the vehicle motion limiter 72. The vehicle motion limiter 72 limits the motion of the vehicle 10 based on the resolution of the radar device 43, the coordinates (Xself, Yself) of the vehicle 10, the vehicle speed Vself, and the azimuth angle θself of the vehicle 10.
With this configuration, the motion of the vehicle 10 is limited so that it becomes easier to separately detect the peripheral structure 81 and the object in the range direction or the relative velocity direction of the radar device 43. In addition, the motion of the vehicle 10 is limited so that it becomes easier to separately detect the direct wave from the object and the indirect wave from the object via the peripheral structure 81 in the range direction or the relative velocity direction of the radar device 43. This enables the radar device 43 to detect the object with higher reliability without increasing the resolution of the radar device 43.
In addition, the vehicle motion limiter 72 limits at least one of the vehicle speed Vself or the travel path of the vehicle 10 among the parameters regarding the motion of the vehicle 10.
For example, as the vehicle speed Vself is set lower, a distance to be traveled until the vehicle is stopped by braking becomes shorter, and hence the length Lx of the control target monitoring area 83 can be shortened. Further, as the vehicle speed Vself is set higher, it becomes easier to separately detect the peripheral structure 81 and the target object 82 in the relative velocity direction. Further, as the azimuth angle of the vehicle 10 with respect to the peripheral structure 81 becomes gentler, it becomes easier to separately detect the peripheral structure 81 and the target object 82 in the relative velocity direction. Further, as the distance between the peripheral structure 81 and the vehicle 10 becomes longer, it becomes easier to separately detect the peripheral structure 81 and the target object 82 in the range direction. As a result, limitation on the motion of the vehicle 10 can be mitigated. That is, when at least one of the vehicle speed Vself or the path is limited, it becomes easier to separately detect the peripheral structure 81 and the target object 82 in at least one direction of the range direction or the relative velocity direction. Further, as the vehicle 10 becomes farther from the peripheral structure 81, it becomes easier for the radar device 43 to separately detect the direct wave from the target object 82 and the indirect wave from the object via the peripheral structure 81. As a result, the limitation on the motion of the vehicle 10 can be mitigated.
Further, the radar device 43 has the plurality of control modes relating to the range resolution. The plurality of control modes include the manual driving compatible mode and the automatic driving compatible mode. The automatic driving compatible mode is the mode to be selected when the driving entity of the vehicle 10 is the vehicle controller 60. The first range resolution is higher than the second range resolution. The first range resolution is the range resolution in the automatic driving compatible mode. The second range resolution is the range resolution in the manual driving compatible mode.
In the automatic driving compatible mode, the vehicle controller 60 executes control for automatically stopping the vehicle 10 on the roadside.
Higher object detection reliability is required when the driving entity is a vehicle controller than when the driving entity is a driver. Therefore, when the driving entity is the vehicle controller 60, the control mode of the radar device 43 is switched to a higher-resolution mode. Thus, it is possible to expand an area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and an area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43. Under a state in which the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43 have been expanded, the vehicle 10 is automatically stopped on the roadside. As a result, it is possible to stop the vehicle 10 on the roadside more safely.
Further, the radar device 43 has the plurality of control modes relating to the relative velocity resolution. The plurality of control modes include the manual driving compatible mode and the automatic driving compatible mode. The automatic driving compatible mode is the mode to be selected when the driving entity of the vehicle 10 is the vehicle controller 60. The first relative velocity resolution is higher than the second relative velocity resolution. The first relative velocity resolution is the relative velocity resolution in the automatic driving compatible mode. The second relative velocity resolution is the relative velocity resolution in the manual driving compatible mode.
In the automatic driving compatible mode, the vehicle controller 60 executes control for automatically stopping the vehicle 10 on the roadside.
With this configuration, when the driving entity is the vehicle controller 60, the control mode of the radar device 43 is switched to the higher-resolution mode. Thus, it is possible to expand the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43. Under the state in which the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43 have been expanded, the vehicle 10 is automatically stopped on the roadside. As a result, it is possible to stop the vehicle 10 on the roadside more safely.
Further, the radar device 43 has the plurality of control modes relating to the range resolution and the relative velocity resolution. The vehicle controller 60 selects, from among the plurality of control modes, a control mode in which at least one of the range resolution or the relative velocity resolution is set higher as the vehicle speed Vself becomes lower.
With this configuration, by narrowing down the detection range and increasing at least one of the range resolution or the relative velocity resolution as the vehicle speed Vself becomes lower, it is possible to operate the radar device 43 in the higher-resolution mode within ranges of a limited memory capacity and a limited computation time. Therefore, it is possible to expand the area in which the separate detection can be performed by the radar device 43. As a result, the limitation on the motion of the vehicle 10 can be further mitigated.
Further, the radar device 43 has the plurality of control modes relating to the range resolution and the relative velocity resolution. The vehicle controller 60 selects, from among the plurality of control modes, a control mode in which at least one of the range resolution or the relative velocity resolution is set higher as the distance between the vehicle 10 and the peripheral structure 81 becomes shorter.
With this configuration, as the vehicle 10 approaches the peripheral structure 81, the control mode of the radar device 43 is switched to a control mode in which at least one of the range resolution or the relative velocity resolution is set higher. Thus, it is possible to expand the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43. As a result, the limitation on the motion of the vehicle 10 can be further mitigated.
Further, the vehicle motion limiter 72 determines whether or not the peripheral structure 81 and the object or the direct wave from the object and the indirect wave from the object via the peripheral structure 81 are separately detected by the radar device 43 in at least one direction of the range direction or the relative velocity direction at the coordinates (Xself, Yself) of the vehicle 10, the azimuth angle θself of the vehicle 10, and the vehicle speed Vself on a travelable path of the vehicle 10.
The vehicle motion limiter 72 calculates at least one of the limiting value of the azimuth angle θself of the vehicle 10 to be used when the coordinates (Xself, Yself) of the vehicle 10 and the vehicle speed Vself are fixed, the limiting value of the coordinates (Xself, Yself) of the vehicle 10 to be used when the vehicle speed Vself and the azimuth angle θself of the vehicle 10 are fixed, and the limiting value of the vehicle speed Vself to be used when the coordinates (Xself, Yself) of the vehicle and the azimuth angle θself of the vehicle 10 are fixed.
The vehicle controller 60 controls the motion of the vehicle 10 within a limit range which is based on the calculated at least one of the limiting value of the azimuth angle θself of the vehicle 10, the limiting value of the coordinates (Xself, Yself) of the vehicle 10, or the limiting value of the vehicle speed Vself.
With this configuration, it is possible to appropriately select a table regarding parameters for limiting the motion of the vehicle 10 depending on a situation of object detection by the radar device 43. Therefore, it is possible to more easily achieve an automatic driving device with which it is easy for the radar device 43 to separately detect the peripheral structure 81 and the target object 82 and it is easy for the radar device 43 to separately detect the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81.
Further, the radar device 43 in the present embodiments includes the radar main body 431 and the radar controller 432. The radar main body 431 is mounted to the vehicle 10. The radar controller 432 controls the radar main body 431 by the plurality of control modes relating to the range resolution.
The first range resolution is higher than the second range resolution. The first range resolution is the range resolution to be used in the automatic driving compatible mode. The second range resolution is the range resolution to be used in the manual driving compatible mode.
Higher object detection reliability is required when the driving entity is the vehicle controller 60 than when the driving entity is the driver. Therefore, when the driving entity is the vehicle controller 60, the control mode of the radar device 43 is switched to the higher-resolution mode. Thus, it is possible to expand the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43. As a result, it is possible to achieve the radar device 43 with which the limitation on the motion of the vehicle 10 can be further mitigated.
Further, the radar device 43 in the present embodiments includes the radar main body 431 and the radar controller 432. The radar main body 431 is mounted to the vehicle 10. The radar controller 432 controls the radar main body 431 by the plurality of control modes relating to the relative velocity resolution.
The first relative velocity resolution is higher than the second relative velocity resolution. The first relative velocity resolution is the relative velocity resolution in the automatic driving compatible mode. The second relative velocity resolution is the relative velocity resolution in the manual driving compatible mode.
Higher object detection reliability is required when the driving entity is the vehicle controller 60 than when the driving entity is the driver. Therefore, when the driving entity is the vehicle controller 60, the control mode of the radar device 43 is switched to the higher-resolution mode. Thus, it is possible to expand the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43. As a result, it is possible to achieve the radar device 43 with which the limitation on the motion of the vehicle 10 can be further mitigated.
Further, the radar device 43 in the present embodiments includes the radar main body 431 and the radar controller 432. The radar main body 431 is mounted to the vehicle 10. The radar controller 432 sets at least one of the range resolution or the relative velocity resolution higher as the vehicle speed Vself becomes lower.
With this configuration, by narrowing down the detection range and increasing at least one of the range resolution or the relative velocity resolution as the vehicle speed Vself becomes lower, it is possible to operate the radar device 43 in the higher-resolution mode within ranges of a limited memory capacity and a limited computation time. As a result, it is possible to achieve the radar device 43 with which the limitation on the motion of the vehicle 10 can be further mitigated.
Further, the radar device 43 in the present embodiments includes the radar main body 431 and the radar controller 432. The radar main body 431 is mounted to the vehicle 10. The radar controller 432 sets at least one of the range resolution or the relative velocity resolution higher as the distance between the vehicle 10 and the peripheral structure 81 becomes shorter.
With this configuration, as the vehicle 10 approaches the peripheral structure 81, the control mode of the radar device 43 is switched to a control mode in which at least one of the range resolution or the relative velocity resolution is set higher. Thus, it is possible to expand the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43. As a result, it is possible to achieve the radar device 43 with which the limitation on the motion of the vehicle 10 can be further mitigated.
Further, in the radar device 43 in each of the first embodiment and the second embodiment, the frequency modulation width B in the automatic driving compatible mode is wider than the frequency modulation width B in the manual driving compatible mode.
With this configuration, in the automatic driving compatible mode, it is possible to expand the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43. As a result, it is possible to achieve the radar device 43 with which the limitation on the motion of the vehicle 10 can be further mitigated.
Further, in the radar device 43 in each of the first embodiment and the second embodiment, the chirp sequence time Tcs in the automatic driving compatible mode is longer than the chirp sequence time Tcs in the manual driving compatible mode.
With this configuration, in the automatic driving compatible mode, it is possible to expand the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43. As a result, it is possible to achieve the radar device 43 with which the limitation on the motion of the vehicle 10 can be further mitigated.
Further, in the radar device 43 in each of the first embodiment and the second embodiment, a processing cycle period of modulation in the automatic driving compatible mode is longer than a processing cycle period of modulation in the manual driving compatible mode.
With this configuration, in the automatic driving compatible mode, it is possible to expand the area in which the peripheral structure 81 and the target object 82 can be separately detected by the radar device 43 and the area in which the direct wave from the target object 82 and the indirect wave from the target object 82 via the peripheral structure 81 can be separately detected by the radar device 43. As a result, it is possible to achieve the radar device 43 with which the limitation on the motion of the vehicle 10 can be further mitigated.
In the first embodiment and the second embodiment, as the FCM method, the frequency of the carrier wave is repeatedly caused to drop at a constant rate of change, but the frequency of the carrier wave may be repeatedly raised. The number Nchirp of chirps, the rate of change of the frequency, and the frequency modulation width B are not particularly limited by the above-mentioned examples. In addition, the modulation method of the radar device 43 may not be the FCM method. For example, a frequency modulated continuous wave (FM-CW) method or a pulse Doppler method may be employed.
Further, a part or all of the functions of the radar controller 432 may be incorporated in the vehicle controller 60.
Further, as the method of extracting the peak in Step S102, for example, a method of extracting such a frequency bin as to exceed a threshold set in advance and have a local maximum value from among frequency bins may be employed. In addition, data on reception channels may be added up at a previous stage of the peak detection. For example, the peak may be extracted after adding up and averaging amplitude values corresponding to four channels. Further, the peak may be extracted after directing the beam toward a direction set in advance by a publicly known digital beam forming (DBF) processing.
Further, the method of calculating the distance from the target object and the relative velocity with respect to the target object in Step S103 is not particularly limited to the FCM method.
Further, as the method of measuring the azimuth angle in Step S104, a super-resolution angle measurement method may be used, a maximum likelihood estimation method may be used, or another method may be used.
Further, in the first embodiment and the second embodiment, after it is determined that the pull-over area can be entered and the vehicle 10 is decelerated to the second vehicle speed, the control mode of the radar device 43 is changed from the manual driving compatible mode to the automatic driving compatible mode, but the method of shifting the mode is not limited thereto.
For example, the shift to the automatic driving compatible mode may be performed after the driver falls into a situation in which the driver has difficulty in driving. The shift to the automatic driving compatible mode may also be performed at any timing from start to end of a series of pull-over control. The series of pull-over control refers to such control as to cause the vehicle 10 to travel in the same lane at a constant speed for a while after the driver falls into a situation in which the driver has difficulty in driving, then decelerate the vehicle 10 at a time point at which an area that enables pull-over thereto is found, and stop the vehicle 10 on the roadside.
Further, the roadside pull-over controller 70 may change the range resolution of the radar device 43 stepwise in accordance with the vehicle speed, or may change the relative velocity resolution of the radar device 43 stepwise in accordance with the vehicle speed. The roadside pull-over controller 70 may also change the range resolution of the radar device 43 stepwise in accordance with the distance from the peripheral structure 81, or may change the relative velocity resolution of the radar device 43 stepwise in accordance with the distance from the peripheral structure 81.
Further, the roadside pull-over controller 70 may set the control target monitoring area in accordance with a behavior of an application to be controlled, and select the control mode of the radar device 43 so that the control target monitoring area is covered.
Further, the distance range and the relative velocity range to be observed are desired to be maintained with the range resolution and the relative velocity resolution having been set high, but to this end, it is required to increase the number Nsample of samples per chirp and the number Nchirp of chirps. This adversely increases a memory size of the radar controller 432. As a countermeasure against this, the distance range and the relative velocity range are desired to be limited in accordance with the vehicle speed.
Further, in the first embodiment and the second embodiment, the vehicle motion limiter 72 calculates the control target monitoring area 83, but the driving support controller 61 may calculate the control target monitoring area 83 and output a result of the calculation to the vehicle motion limiter 72.
Further, in the first embodiment and the second embodiment, the lateral position is calculated in real time for each vehicle speed Vself and each azimuth angle θself of the vehicle 10, but when several travel patterns for pulling over to the roadside are defined, the lateral position may be calculated in the following manner. For example, there may be provided such a table of the lateral position limiting values as to be used for limiting in advance the motion of the vehicle 10 by the travel pattern so that the object within the control target monitoring area 83 can be detected separately from the peripheral structure 81 in at least one direction of the range direction or the relative velocity direction. There may be also provided such a table of the lateral position limiting values as to be used for limiting in advance the motion of the vehicle 10 by the travel pattern so that the direct wave from the object within the control target monitoring area 83 can be detected separately from the indirect wave from the object via the peripheral structure 81 in at least one direction of the range direction or the relative velocity direction.
In such a case, even when the peripheral structure 81 is not actually present, the table may be created so that the object within the control target monitoring area 83 can be detected separately from the virtual structure being a virtual peripheral structure 81 in at least one direction of the range direction or the relative velocity direction. In addition, the table may be created so that the direct wave from the object within the control target monitoring area 83 can be detected separately from the indirect wave from the object via the virtual structure in at least one direction of the range direction or the relative velocity direction. When the virtual structure is assumed as the structure in this manner, it is possible to limit in advance the motion of the vehicle 10 by the travel pattern so as to enable the separate detection in at least one direction of the range direction or the relative velocity direction with a small amount of computation resources without calculating the lateral position in real time.
Further, in the examples illustrated in
Further, when the separate detection was performed by the radar device 43 in the past, through interpolation of data based on the past data, it is possible to complement a partial range in which the separate detection is impossible.
Further, in the present embodiments, when it is determined whether or not the separate detection in at least one direction of the range direction or the relative velocity direction is possible, the vehicle motion limiter 72 determines whether or not every point on the peripheral structure 81 within the FoV and each point within the control target monitoring area 83 can be separately detected. However, when the shape of the peripheral structure 81 is complicated, the vehicle motion limiter 72 may approximate the shape of the peripheral structure 81 to a simpler shape.
Further, when a travel pattern for pulling over to the roadside is defined in advance, instead of the real-time update of the separability table, there is provided such a table as to be used for limiting the motion of the vehicle 10 by the travel pattern so that the object within the control target monitoring area 83 can be detected separately from the peripheral structure 81 in at least one direction of the range direction or the relative velocity direction. There may be also provided such a table as to be used for limiting the motion of the vehicle 10 by the travel pattern so that the direct wave from the object within the control target monitoring area 83 can be detected separately from the indirect wave from the object via the peripheral structure 81 in at least one direction of the range direction or the relative velocity direction.
In this case, even when the peripheral structure 81 is not actually present, the table may be created so that the object in the control target monitoring area 83 can be detected separately from the virtual structure in at least one direction of the range direction or the relative velocity direction. In addition, the table may be created so that the direct wave from the object within the control target monitoring area 83 can be detected separately from the indirect wave from the object via the virtual structure in at least one direction of the range direction or the relative velocity direction. When the virtual structure is assumed as the structure in this manner, it is possible to limit in advance the motion of the vehicle 10 by the travel pattern so as to enable the separate detection in at least one direction of the range direction or the relative velocity direction with a small amount of computation resources without calculating the separability table in real time.
Further, in the first embodiment and the second embodiment, the pull-over area is searched for based on the information received from the locator 45, but may be searched for based on the information received from the camera 42, or may be searched for through estimation of the shape of the road based on the information received from the radar device 43. In any case, any method may be used as long as it can be determined whether or not the pull-over area is present.
Further, in the first embodiment and the second embodiment, the control routines illustrated in the flow charts are each executed every 50 ms, but a repetition interval for those routines is not limited thereto. For example, each control routine may be executed every 20 ms. In short, it suffices that each control routine is executed at a cycle period suitable for controlling the vehicle 10.
Further, in the first embodiment and the second embodiment, the object assumed to be present within the control target monitoring area 83 is assumed to be a stationary object, but even when the stationary object is replaced by a moving object, it is possible to determine whether or not the peripheral structure 81 and the moving object can be separately detected. In addition, even when the stationary object is replaced by the moving object, it is possible to determine whether or not a direct wave from the moving object and an indirect wave from the moving object via the peripheral structure 81 can be separately detected. It may also be assumed that the different detected object is not only the stationary object such as the peripheral structure but also a moving object such as a traveling vehicle or a pedestrian, and it is possible to determine whether or not the object within the control target monitoring area 83 and the moving object can be separately detected and to determine whether or not the direct wave from the object within the control target monitoring area 83 and the indirect wave from the object within the control target monitoring area 83 via the moving object can be separately detected.
Further, in the first embodiment and the second embodiment, it is determined whether or not the driver of the vehicle 10 is in a situation in which the driver has difficulty in driving in Step S201 of the driving mode selection routine illustrated in
Further, in the first embodiment, the example in which the object assumed to be present within the control target monitoring area 83 and the peripheral structure 81 are separately detected in the range direction or the relative velocity direction by the radar device 43 has been described. Further, in the second embodiment, the example in which the direct wave from the object assumed to be present within the control target monitoring area 83 and the indirect wave from the object via the peripheral structure 81 are separately detected in the range direction or the relative velocity direction by the radar device 43 has been described. However, a calculation flow for separate detection in the angular direction in addition to the range direction and the relative velocity direction may be added.
Further, the functions of the automatic driving device 20 according to each of the first embodiment and the second embodiment are implemented by a processing circuit.
Further, the processing circuit 100 corresponds to, for example, a single circuit, a complex circuit, a programmed processor, a processor for a parallel program, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a combination thereof.
Further,
In the processing circuit 200, the functions of the automatic driving device 20 are implemented by software, firmware, or a combination of software and firmware. The software and the firmware are described as programs to be stored in the memory 202. The processor 201 reads out and executes the programs stored in the memory 202, to thereby implement the respective functions.
The programs stored in the memory 202 can also be regarded as programs for causing a computer to execute the procedure or method of each of the above-mentioned components. In this case, the memory 202 corresponds to, for example, a nonvolatile or volatile semiconductor memory, such as a random access memory (RAM), a read only memory (ROM), a flash memory, an erasable programmable read only memory (EPROM), or an electronically erasable and programmable read only memory (EEPROM). Further, a magnetic disk, a flexible disk, an optical disc, a compact disc, a mini disc, or a DVD may also correspond to the memory 202.
The functions of the automatic driving device 20 described above may be implemented partially by dedicated hardware, and partially by software or firmware.
In this way, the processing circuit can implement the functions of the above-mentioned automatic driving device 20 by hardware, software, firmware, or a combination thereof.
Number | Date | Country | Kind |
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2022-082370 | May 2022 | JP | national |