The present application is based on and claims the benefit of priority from earlier Japanese Patent Application No. 2019-012645 filed on Jan. 29, 2019, the description of which is incorporated herein by reference.
The present disclosure relates to a road recognition device.
Road recognition devices that determine a reference line of a lane by using lane markings of a road recognized by a camera are known.
As an aspect of the present disclosure, a road recognition device for a vehicle having a surroundings sensor is provided. The road recognition device includes a surroundings recognition section that recognizes, as surroundings information, at least one of a shape of a roadside object detected by the surroundings sensor and a travel history of another vehicle; a reliability setting section that sets reliability of the surroundings information; a reference line setting section that preferentially uses the surroundings information having higher reliability to determine a reference line of an own lane in which the vehicle is traveling; and an output section that outputs the reference line. When a direction indicator of the vehicle is in operation, the reliability setting section sets reliability of the surroundings information for a direction opposite to a direction indicated by the direction indicator so as to be lower. When the direction indicator is in operation, and the vehicle is traveling in a lane change prohibition section, the reliability setting section sets reliability of the surroundings information including at least one of the shape of the roadside object and the travel history of the other vehicle so as to be lower.
In the accompanying drawings:
Road recognition devices that determine a reference line of a lane by using lane markings of a road recognized by a camera are known. For example, autonomous vehicles can automatically travel along a reference line. Japanese Patent No. 3871772 discloses a technique in which, at a merging point, a course along a traveling lane is determined by using a lane marking present in the direction opposite to the direction that a direction indicator indicates.
However, for example, in a merging lane merging into a main lane, if a reference line is determined by using a lane marking present in the direction opposite to the direction that a direction indicator indicates, the reference line may curve along the lane marking to enter the main lane. In this case, if the vehicle travels along the reference line, the vehicle may unintentionally enter the main lane without being controlled for the merging. Hence, a technique for appropriately determining a reference line is desired.
As shown in
The road recognition device 110 includes a surroundings recognition section 111, a reliability setting section 112, a reference line setting section 113, and an output section 114. The road recognition device 110 is configured by a microcomputer including a central processing unit (CPU), a RAM, and a ROM, and the like. The microcomputer executes a previously installed program to implement functions of these sections. Some or all of the functions of these sections may be implemented by hardware circuits.
The surroundings recognition section 111 recognizes surroundings information by using detection signals from the surroundings sensor 120. More specifically, the surroundings recognition section 111 recognizes, as the surroundings information, a shape of a lane marking of a road detected by the surroundings sensor 120, a shape of a roadside object, and a travel history of another vehicle. The reliability setting section 112 sets reliability of the surroundings information. The reference line setting section 113 preferentially uses the surroundings information having higher reliability to determine a reference line of a lane in which the vehicle 10 is traveling. The reference line is, for example, a center line of a lane. The vehicle 10 can automatically travel along the reference line. The reference line setting section 113 determines a reference line by displacing a line, which is obtained from a shape of a lane marking or a roadside object or a sequence of points representing a travel history of another vehicle, to the center of the lane. For example, when a shape of a lane marking is used, the reference line setting section 113 determines a reference line by displacing the line determined from the shape of the lane marking by half of the width of the lane. The output section 114 outputs the reference line determined by the reference line setting section 113 to the drive control unit 210 and the like through the in-vehicle network 260.
The surroundings sensor 120 includes a camera 122 and an object sensor 124. The camera 122 images the surroundings of the own vehicle to obtain images. The object sensor 124 detects a state of the surroundings of the own vehicle. As the object sensor 124, for example, a sensor utilizing reflected waves such as a laser radar, a millimeter-wave radar, and an ultrasonic sensor may be used. In the present embodiment, the surroundings recognition section 111 detects lane markings on the right and left sides of the road on which the vehicle is traveling and the locations of the lane markings, a roadside object and the location thereof, another vehicle and the location, size, distance, traveling direction, speed, and yaw angular velocity thereof, and the like. The surroundings recognition section 111 may detect part or all of the information through inter-vehicle communication with another vehicle.
The own vehicle state sensor 126 includes a vehicle sensor and a yaw rate sensor. The own vehicle state sensor 126 detects, as a state of the vehicle 10, a velocity of the vehicle 10, whether the direction indicator 250 is in operation, and a yaw rate.
The drive control unit 210 is configured by a microcomputer including a central processing unit (CPU), a RAM, and a ROM, or the like. The microcomputer executes a previously installed program to implement an autonomous driving function. The drive control unit 210 controls the driving force control ECU 220, the braking force control ECU 230, and the steering control ECU 240 so that, for example, the vehicle 10 travels along the reference line determined by the reference line setting section 113. For example, when the vehicle 10 makes a lane change to an adjacent lane, the drive control unit 210 may perform merging support so that the vehicle 10 travels from the reference line of the lane, in which the vehicle 10 is traveling, to the reference line of the adjacent lane. In addition, the drive control unit 210 controls operation of the direction indicator 250.
The driving force control ECU 220 is an electronic control unit that controls an actuator such as an engine generating driving force of the vehicle. When a driver manually drives the vehicle, the driving force control ECU 220 controls a power source, which is an engine or an electrical motor, depending on the amount of operation of an accelerator pedal. In contrast, when autonomous driving is performed, the driving force control ECU 220 controls the power source depending on required driving force calculated by the drive control unit 210.
The braking force control ECU 230 is an electronic control unit that controls a brake actuator generating braking force of the vehicle. When the driver manually drives the vehicle, the braking force control ECU 230 controls the brake actuator depending on the amount of operation of a brake pedal. In contrast, when autonomous driving is performed, the braking force control ECU 230 controls the brake actuator depending on required braking force calculated by the drive control unit 210.
The steering control ECU 240 is an electronic control unit that controls a motor generating steering torque of the vehicle. When the driver manually drives the vehicle, the steering control ECU 240 controls the motor depending on the operation of a steering wheel to generate assist torque for the operation of the steering wheel. Hence, the driver can operate the steering wheel with small force, which implements steering of the vehicle. In contrast, when autonomous driving is performed, the steering control ECU 240 controls the motor depending on a required steering angle calculated by the drive control unit 210 to perform steering.
The road recognition process shown in
First, in step S100, the surroundings recognition section 111 acquires surroundings information. More specifically, the surroundings recognition section 111 acquires surroundings information from images of the surroundings of the vehicle 10 captured by the camera 122 or a state of the surroundings of the vehicle 10 detected by the object sensor 124.
Next, in step S110, the reliability setting section 112 sets reliability of the surroundings information acquired in step S100. In the present embodiment, the reliability setting section 112 sets reliability of, as the surroundings information, (1) a shape of a lane marking of a road, (2) a shape of a roadside object, and (3) a travel history of another vehicle. The setting of the reliability will be described later in detail.
Next, in step S120, the reference line setting section 113 preferentially uses the surroundings information having higher reliability set in step S110 to determine a reference line of an own lane in which the vehicle 10 is traveling and a reference line of an adjacent lane. The determination of the reference lines will be described later in detail.
Finally, in step S130, the output section 114 outputs the reference lines determined in step S120 to the drive control unit 210.
The reliability setting process shown in
As shown in
The reference line setting process shown in
Next, in step S310, the reference line setting section 113 determines whether the adjacent lane Ln2 has been detected. Detecting the adjacent lane Ln2 uses surroundings information. For example, if the other vehicle 20 traveling in the same direction as the traveling direction of the vehicle 10 is recognized next to the vehicle 10 in the image picked up by the camera 122, the adjacent lane Ln2 is detected. If the adjacent lane Ln2 has not been detected, the reference line setting section 113 ends the reference line setting process. In contrast, if the adjacent lane Ln2 has been detected, the reference line setting section 113 proceeds to step S320, in which the reference line setting section 113 uses the reference line B1 of the own lane Ln1 to determine a reference line B2 of the adjacent lane Ln2. The reference line B2 of the adjacent lane Ln2 is determined by, for example, displacing the reference line B1 of the own lane Ln1 to the adjacent lane by the width of the lane Ln1.
As shown in
According to the road recognition device 110 of the present embodiment described above, when the direction indicator 250 is in operation, the reliability setting section 112 lowers the reliability of the surroundings information 12 and 13 for the direction opposite to the direction indicated by the direction indicator 250. The reference line setting section 113 preferentially uses the surroundings information I1 having higher reliability to determine the reference line B1. Hence, for example, the reference line can be prevented from curving along the lane marking in a merging lane, which merges into a main lane, and entering the main lane, whereby the reference line B1 can be appropriately determined.
The reference line setting section 113 determines the reference line B1 by using, in addition to a shape of a lane marking of a road, a shape of the roadside object 30 such as a wall or a guardrail and the travel history 21 of the other vehicle 20. Hence, even when the shape of the lane marking cannot be recognized, the reference line B1 can be determined. In addition, since the shape of the roadside object 30 or the travel history 21 of the other vehicle 20 can be used to recognize a longer distance than the lane marking of the road that is used, using the combination of the shape of the roadside object 30 or the travel history 21 of the other vehicle 20 and the lane marking of the road can determine a longer reference line B1 with high accuracy.
The reference line setting section 113 determines, in addition to the reference line B1 of the own lane Ln1, the reference line B2 of the adjacent lane Ln2. Hence, when a lane change is made, merging support for traveling along a route connecting the reference line B1 of the own lane Ln1 and the reference line B2 of the adjacent lane Ln2 can be performed.
A reliability setting process according to the second embodiment shown in
As shown in
In the second embodiment, if it is determined that the direction indicator 250 is in operation in step S200 (
A reference line setting process according to the second embodiment shown in
In the second embodiment, after step S300, in step S303, the reference line setting section 113 determines whether the road on which the vehicle 10 is traveling is a lane change prohibition section. The reference line setting section 113 may obtain the result of the determination whether the road on which the vehicle 10 is traveling is a lane change prohibition section in step S203 from the reliability setting section 112. If it is determined that the road on which the vehicle 10 is traveling is not a lane change prohibition section, the reference line setting section 113 proceeds to step S310, in which if an adjacent lane is detected, in step S320, the reference line setting section 113 determines a reference line of the adjacent lane Ln4. In contrast, if it is determined that the road on which the vehicle 10 is traveling is a lane change prohibition section, the reference line setting section 113 ends the reference line setting process, that is, the reference line setting section 113 does not determine a reference line of the adjacent lane Ln4.
According to the road recognition device 110 of the present embodiment described above, when the direction indicator 250 is in operation, and the vehicle 10 is traveling in a lane change prohibition section, the reliability setting section 112 sets, in addition to the reliability of the surroundings information for the direction opposite to the direction indicated by the direction indicator 250, the reliability of the surroundings information including at least one of a shape of a roadside object and a travel history of another vehicle so as to be lower. The reason is that, for example, in a lane change prohibition section, since the own lane Ln3 and the adjacent lane Ln4 may not be parallel, if a reference line of the own lane Ln3 is determined by using a travel history of another vehicle that is traveling in the adjacent lane Ln4 or a shape of a roadside object indicating a lane change prohibition section, the reference line may be different from the actual shape of the lane. Hence, according to the present embodiment, the reference line can be determined more appropriately.
In the present embodiment, when the vehicle 10 is traveling in the lane change prohibition section, the reference line setting section 113 does not determine a reference line of an adjacent lane. The reason is that, for example, in the lane change prohibition section, since the own lane Ln3 and the adjacent lane Ln4 may not be parallel, a reference line of the adjacent lane Ln4 having a shape different from the actual shape of the lane may be determined. Hence, according to the present embodiment, a reference line of the adjacent lane Ln4 having a shape different from the actual shape of the lane can be prevented from being determined. Since merging support associated with a lane change is not performed in the lane change prohibition section, the travel is not affected even when a reference line of the adjacent lane Ln4 is not determined.
A road recognition process according to the third embodiment shown in
As shown in
In the third embodiment, if it is determined that the direction indicator 250 is in operation in step S200 (
According to the road recognition device 110 of the present embodiment described above, when the direction indicator 250 is in operation and a merging point has been detected, the reliability setting section 112 sets reliability of the surroundings information for the direction opposite to the direction indicated by the direction indicator 250 so as to be lower. That is, even when the direction indicator 250 is in operation, if no merging point is detected, reliability of the surroundings information for the direction opposite to the direction indicated by the direction indicator 250 is not lowered. Hence, in the lane Ln5 in which no merging point is detected, the surroundings information for the direction opposite to the direction indicated by the direction indicator 250 can be prevented from being not used in excess (can be used as much as possible).
(D1) In the above embodiment, the reference line setting section 113 determines a reference line by using a shape of a lane marking or a roadside object or a travel history of another vehicle as surroundings information. Alternatively, the reference line setting section 113 may obtain a reference line by using not only the surroundings information but also a reference line, which is calculated by another vehicle, obtained through inter-vehicle communication with the other vehicle. For example, the reference line setting section 113 displaces a reference line calculated by another vehicle that is traveling in an adjacent lane by the width of the lane, displaces a line obtained from a shape of a lane marking to the center of an own lane, and average the lines, to obtain a reference line.
(D2) In the above embodiment, the output section 114 outputs a reference line obtained by the reference line setting section 113 to the drive control unit 210. Alternatively, the output section 114 may output the reference line to a road model calculation section that calculates a road model representing a road shape by lines more preciously than a reference line. The road model calculation section can calculate a road model by using, for example, a Kalman filter or a least square method based on the surroundings information or the reference line. In this case, the drive control unit 210 controls the ECUs so that the vehicle travels along the road model calculated by the road model calculation section.
(D3) In the above first embodiment, when the adjacent lane Ln2 is present, the reference line setting section 113 detects a reference line of the adjacent lane Ln2 by the reference line setting process shown in
The present disclosure is not limited to the above embodiments and can be implemented by various configurations within a scope not deviating from the gist of the present disclosure.
The control section and the method thereof of the present disclosure may be implemented by a dedicated computer provided by configuring a processor programmed to execute one or more functions embodied by computer programs and a memory. Alternatively, the control section and the method thereof described in the present disclosure may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control section and the method thereof described in the present disclosure may be implemented by one or more dedicated computers configured by combining a processor programmed to execute one or more functions and a memory, with a processor configured by one or more hardware logic circuits. The computer programs may be stored in a computer-readable non-transitional tangible storage medium as instructions executed by the computer.
According to the present disclosure, a road recognition device (110) for a vehicle (10) having a surroundings sensor (120) is provided. The road recognition device includes a surroundings recognition section (111) that recognizes, as surroundings information, at least one of a shape of a roadside object detected by the surroundings sensor and a travel history of another vehicle; a reliability setting section (112) that sets reliability of the surroundings information; a reference line setting section (113) that preferentially uses the surroundings information having higher reliability to determine a reference line of an own lane in which the vehicle is traveling; and an output section (114) that outputs the reference line. When a direction indicator (250) of the vehicle is in operation, the reliability setting section sets reliability of the surroundings information for a direction opposite to a direction indicated by the direction indicator so as to be lower. When the direction indicator is in operation, and the vehicle is traveling in a lane change prohibition section, the reliability setting section sets reliability of the surroundings information including at least one of the shape of the roadside object and the travel history of the other vehicle so as to be lower.
According to the above road recognition device, when the direction indicator is in operation, since reliability of the surroundings information for a direction opposite to a direction indicated by the direction indicator is lowered, a reference line can be determined appropriately.
Number | Date | Country | Kind |
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2019-012645 | Jan 2019 | JP | national |
Number | Date | Country | |
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Parent | PCT/JP2020/002485 | Jan 2020 | US |
Child | 17387489 | US |