Patent Application
20080300755
1. Field of the Invention
The present invention generally relates to intelligent transportation systems. More specifically, the invention relates to collision avoidance systems for motor vehicles.
2. Description of Related Art
When a driver of a motor vehicle desires to change lanes, the driver ordinarily should first glance in an appropriate side view mirror to make sure the adjacent lane is clear. However, not all drivers take the time to look to see if the adjacent lane is clear. In addition, even if they do look, the view provided by a side view mirror is limited and may not show the entire lane adjacent to the motor vehicle. The portion of the adjacent lane not shown in the side view mirror is called a blind spot. To check the blind spot, the driver is required to turn their head and look over their shoulder, resulting in a potentially dangerous situation since it requires the driver to completely take their eyes off of the road ahead.
To minimize the need for the driver to monitor the adjacent lane, some vehicles have implemented warning systems. Such warning systems use an external detector and a processor and provide a warning signal to the driver to alert them to the presence of an object in the adjacent lane. However, existing systems rely on the driver taking corrective action after being warned to prevent possible collisions with the object in the adjacent lane. These systems do not account for those drivers who may not notice the warning signal or may attempt to change lanes despite the warning signal, possibly resulting in a side collision with the object.
In view of the above, it is apparent that there exists a need for an improved side collision avoidance system.
In satisfying the above need, as well as overcoming the enumerated drawbacks and other limitations of the related art, the present invention provides a side collision avoidance system. The system generally includes a direction sensor generating a direction signal corresponding to a change in direction of the vehicle, an external detector generating a detector signal corresponding to a location of objects outside of the vehicle, and a braking control system including at least two independently operable braking devices coupled to respective wheels of the motor vehicle. A processor disposed within the motor vehicle is coupled to the direction sensor, the external detector, and the braking control system. The processor receives the direction signal and the detector signal and, based thereon, is configured to send an avoidance signal to the stability control. Upon receipt of the avoidance signal, the braking control system activates appropriate braking devices to avoid objects.
In one embodiment, the braking control system is coupled to four independently operable braking devices. In another embodiment, the braking devices are attached to wheels on opposing sides of the vehicle. In a further embodiment, the braking control system directs the vehicle away from objects using “steering-by-braking”. Steering-by-braking involves the activation of braking devices on the side of the vehicle opposite of the location of the objects to be avoided.
In one aspect of the invention, the processor is configured to calculate blind spot boundaries for the motor vehicle, compare the blind spot boundaries to the location of objects around the vehicle, and send the avoidance signal to the braking control system if an object is located within the blind spot boundaries. A blind sport warning indicator may also be coupled to the processor and may provide an indication to a driver if an object is within the calculated blind spot boundaries. The warning indicator may be, for example, provided interiorly and/or exteriorly of the vehicle and may include a visual and/or an audible warning device.
In another aspect, the blind spot boundaries are calculated based upon fixed or variable parameters relating to motor vehicle geometry supplied to the processor. The variable parameters may, for example, be supplied to the processor by at least one movable side viewing device being attached to the vehicle and moveable between a first orientation and a second orientation. In this example, the side viewing device is coupled to at least one position sensor adapted to generate a position signal corresponding to the orientation of the side view device. The processor is coupled to the position sensor to receive the position signal. A modified position signal is generated by the position sensor upon movement of the side viewing device. The processor of this embodiment then calculates altered blind spot boundaries based upon the modified position signal and compares the altered blind spot boundaries to the detector signal. If an object is within the altered blind spot boundaries, the processor provides the indication to the driver and sends the avoidance signal to the braking control system if appropriate.
In an alternative embodiment, a seat sensor may be disposed within the vehicle and coupled to at least a driver's seat of the vehicle. The seat sensor generates a seat signal corresponding to the orientation of the driver's seat. In this embodiment, the processor is also coupled to the seat sensor and configured to read the seat signal. The processor calculates the blind spot boundaries based on both the position signal and the seat signal.
In yet another embodiment, the vehicle may include a driver height sensor that is configured to measure the height of the driver. The driver height sensor then generates a height signal corresponding to the height of the driver, and the processor reads the height signal. The processor then calculates the blind spot boundaries based on both the position signal and the height signal.
In still another embodiment, the invention includes both the driver height sensor and the seat sensor coupled to the processor, and the processor dynamically calculates the blind spot boundaries based on the position signal, the seat signal, and the height signal. As with the prior embodiment, the processor compares the blind spot boundaries to the detector signal and provides an indication, or warning signal, to a driver if an object is located within the calculated blind spot boundaries.
In the various embodiments of the present invention, the external detector may include at least one of a radar sensor, a ladar sensor, an ultrasonic sensor, and an optical sensor. The optical sensor may include a digital camera. The direction sensor may include, for example, one of an accelerometer, a steering sensor, and a navigation sensor. These sensors may be used singly or in various combinations depending on the application.
In a further aspect, the present invention encompasses a method for avoiding side collisions. The method includes monitoring from a direction sensor a direction signal corresponds to a direction of motion of the vehicle; monitoring from an external detector a detector signal corresponding to the a location of objects outside of the vehicle; comparing the direction signal to the detector signal; sending an avoidance signal to a braking control system if the direction signal indicates that the motor vehicle is heading toward the location at least one of the objects; and activating appropriate braking devices coupled to the braking control system to direct the vehicle away from the object.
In further embodiments, the system/method may include overriding the appropriate braking devices by additional steering or braking input from a driver of the vehicle. Also, the avoidance signal may optionally be sent to the braking control system only if the location of an object correspond to a blind spot of the vehicle.
Further objects, features and advantages of this invention will become readily apparent to persons skilled in the art after a review of the following description, with reference to the drawings and claims that are appended to and form a part of this specification.
Referring now to
The external detector 14 is configured to generate a detector signal corresponding to a location of one or more objects, for example, a second and third motor vehicle 20 and 22 relative to the motor vehicle 11 (see
The external detector 14 may be any non-contact device capable of remotely detecting objects including, but not limited to, radar sensors, ladar sensors, lidar sensors, ultrasonic sensors, and optical sensors. Radar sensors scan the angle of view 46 by transmitting radio waves throughout the angle of view 46. The radar sensor detects any radio waves reflected from the surfaces of the motor vehicles 20 and 22, or any other objects, and determines the position, velocity, and other characteristics of the detected objects by analyzing the reflected radio waves.
The ladar and lidar sensors are basically forms of laser radar. Ladar stands for “laser detection and ranging” and lidar stands for “light detection and ranging” and they may be used interchangeably with one another. These types of sensors use laser light to scan the angle of view 46 and analyze any reflected laser light to locate and characterize the objects. The lader or lidar sensor may use any appropriate form of light including, for example, ultraviolet, visible, or near infrared laser light.
The ultrasonic sensor operates similar to the radar and ladar sensors. However, rather than electromagnetic radiation, they use ultra high frequency sound waves to scan the angle of view 46. Any reflected sound waves are detected and analyzed to locate and characterize the objects.
An optical sensor operates differently from the other sensors discussed above since it is completely passive. The optical sensor may include at least one digital video camera that monitors the angle of view 46. When objects move into the angle of view 46, electronics included with the optical sensor analyze the images captured by the video camera and to identify the location and other characteristics of the objects. As above, this information is then converted by the electronics into a detector signal corresponding to the location of the objects.
The direction sensor 15 can be any device configured to generate a direction signal corresponding to a direction of motion of the vehicle 11. As best shown in
The direction sensor 15 may be any appropriate device for determining the direction of motion of the motor vehicle 11. Some appropriate devices include accelerometers, gyroscopes, steering sensors, navigation sensors and visual sensors. It should be noted that the above devices are examples and any other appropriate devices may be used without falling beyond the scope and spirit of the present invention.
Accelerometers include any devices capable of registering a change in the acceleration of the vehicle 11. As the vehicle 11 is turned by the driver, the accelerometer experiences an acceleration having a particular direction. As a result, the accelerometer generates a signal proportional to the change in acceleration, and hence direction, of the motor vehicle.
Gyroscopes include devices having a rotating mass for measuring or maintaining orientation. A rotational axis of the rotating mass tends to have a fixed orientation independent of the orientation of the motor vehicle 11. Differences between the orientation of the rotational axis and that of the motor vehicle 11 are used to determine changes in direction of the motor vehicle 11 and generate the direction signal.
Steering sensors include any devices capable of registering a change in the steering input of the vehicle 11. For example, the steering sensor may include a potentiometer of other sensor coupled to the steering wheel of the motor vehicle. When the driver turns the steering wheel, a signal from the potentiometer will indicate the amount and direction the steering wheel is turned, resulting in a signal proportional to the change in the direction of motion of the vehicle 11.
Navigation sensors may include any devices capable of determining the direction of motion of the vehicle 11 based on external references including, but not limited to, satellites and cellular phone towers. The navigation sensors calculate the vehicle's direction and location by monitoring signals from the external references.
Visual sensors include cameras that, for example, monitor the boundaries of a road upon which the motor vehicle 11 travels. When the driver of the vehicle initiates a turn or lane change, the view of the boundaries monitored by the cameras changes. The amount of the change is proportional to the change in direction of the vehicle and may be used to generate the direction signal.
The braking control system 64 is disposed within the vehicle 11 and includes independently operable braking devices coupled to respective wheels of the vehicle 11. In the non-limiting example shown in
The braking control system 64 is configured to operate each of the braking devices 66a-66d independently or in concert with one another. The braking devices 66a-66d may include, but are not limited to, disc brakes or drum brakes. In the example of
The braking control system 64 is further configured to influence the direction of travel of the vehicle 11 using steering-by-braking. Steering-by-braking involves applying one or more braking devices on a side of the vehicle 11 corresponding to a direction in which it is desired to turn the vehicle. In other words, to steer away from an object in the road requires operating braking devices on the side of the vehicle opposite from the object.
Steering-by-braking is best illustrated by way of the non-limiting example shown in
Returning to
The processor 16 is configured to analyze the direction signal for any changes in the direction of motion of the vehicle 11. The processor 16 is also configured to analyze the detector signal to determine the location of any objects with respect to the motor vehicle 11. The direction of motion is compared to the location of any objects with respect to the motor vehicle 11 and the processor may, for example, calculate a probability of a collision with any of the objects. If the probability exceeds a certain threshold, the processor is configured to send an avoidance signal to the braking control system. The avoidance signal is received by the braking control system 64, which is configured to initiate steering-by-braking to avoid the objects as described above.
It should be appreciated that the processor 16 is able to respond to any vehicle and traffic changes as they occur by continuously performing these calculations. Thus, the processor 16 dynamically adjusts to any changes in direction of the vehicle 11 or in traffic as they occur, allowing the avoidance system 10 to quickly respond to dynamically changing environments.
The present invention may be used as described above or in an alternate embodiment to supplement a blind spot warning system as shown in
When used to supplement a blind spot warning system, an indication that the objects are located within the blind spot boundaries may be optionally provided to the driver. The indication to the driver may be provided by, for example, means of a warning indicator 50 coupled to the processor 16. The warning indicator 50 may, for example, be incorporated into an instrument cluster 52 of a vehicle instrument panel inside of the motor vehicle 11. The warning indicator 50 includes, but is not limited to, a visual warning signal 54, an audible warning signal 56 or a haptic warning device. The visual warning signal 54 may be a light or series of lights that indicate the presence, and optionally the location, of an object within the vehicle blind spot. In addition to, or in place of, the visual warning signal 54, a tone or other audible warning may be provided either through, for example, a dedicated speaker 56 as shown in
Depending on the embodiment, the blind spot boundaries may be calculated based upon predetermined, fixed parameters relating to the geometry of the vehicle 11. In this case, the boundaries need only be calculated once before being stored by processor 16. Alternately, the blind spot boundaries may be dynamically calculated based upon one or more variable parameters. This latter situation allows the boundaries to reflect changes in the motor vehicle including, but not limited to, orientational changes to the side view device 12. As best shown in
To check for objects in the first blind spot 32, the driver may choose to look over his or her shoulder or may choose to adjust the movable side view device 12 outward (relative to the vehicle 11). If the moveable side view device 12 is moved outward, a second viewing area 26, and hence the third motor vehicle 22, becomes visible to the driver. However, as can be seen, as shown in
Returning back to
In this embodiment, the processor 16 is configured to also analyze the position signal to determine the orientation of the side view device 12. Once the orientation of the side view device 12 has been determined, that information is used by the processor 16, along with the viewing angle information and other stored characteristics, to continuously calculate the boundaries of the blind spot 32. The processor 16 then compares the locations of the objects with the calculated boundaries of the first blind spot 32 (see
Turning to
In some embodiments, the side view device 12 may include a conventional side view mirror assembly. The side view mirror assembly may include a reflecting member 38 movably disposed within a stationary housing 40. In another example, the entire housing 40 may be movable in addition to, or instead of, the reflecting member 38. The reflecting member 38 may include a flat mirror, a convex mirror or both types of mirrors in combination.
In other embodiments, the side view device 12 may include a digital imaging device (not shown). The digital imaging device may, for example, be a digital video camera coupled to an interior video display. In this embodiment, the digital video camera captures images of the view area beside and to the rear of the motor vehicle. Those images are shown to the driver on an interior video display (not shown). In one example, only the digital camera need be moved to alter the field of view of the camera.
In another example, the avoidance system 10 may include a seat sensor 58 coupled to a driver's seat 60. Similar to the position sensor 18, the seat sensor 58 generates a seat signal corresponding to an orientation or position of the driver's seat 60. In this embodiment, the processor 16 is also coupled to the seat sensor 58 and is configured to analyze the seat signal to determine the orientation of the driver seat 60 and, hence, the position of the driver within the motor vehicle 11. The processor 16 then calculates, for example, the approximate position of the driver's eyes within the motor vehicle 11 and uses that information, along with the orientation of the side view device 12, to improve the calculation of the boundaries of the driver's blind spot. This increases the accuracy of the comparison by the processor 16 of the object's locations to the calculated boundaries, reducing the possibility of false positive indications that objects are within the driver's blind spots.
Yet another embodiment of the avoidance system 10 may include a driver height sensor 62. Depending on the particular application, the driver height sensor 62 may be in addition to, or instead of, the seat sensor 58. The height sensor 62 may be placed anywhere within the motor vehicle 11 appropriate for a particular sensor to measure the seated height of the driver and generate a height signal corresponding to the height of the driver. The processor 16 is coupled to the height sensor 62 and is configured to analyze the height signal to, for example, calculate the height of the driver and the approximate position of the driver's eyes. Once the position of the driver's eyes have been calculated a sight line of the driver to the side view device 12 may be calculated allowing further refinement of the blind spot boundaries. This and other calculations mentioned herein are well within the constraints of conventional engineering and need not be detailed further since they will be readily appreciated and derivable by those skilled in the art.
The driver height sensor 62 may be any appropriate sensing device including, for example, an ultrasonic sensor. As noted above, the ultrasonic sensor uses high frequency sound waves reflected off an object to characterize the object. In one example, the ultrasonic sensor may be attached to an interior roof of the motor vehicle 11. The sound waves are thus directed to reflect off of the top of the driver's head. Electronics associated with the ultrasonic sensor measure the time it takes the reflected sound waves to return to the sensor, thereby determining the distance between the ultrasonic sensor and the top of the driver's head. The processor may then use that information, along with other stored information regarding human attributes and the geometry of the motor vehicle, to calculate the height of the driver and the approximate position of the driver's eyes.
In another embodiment, the height sensor 62 may include a visual system. The visual system makes use of, for example, a digital camera positioned to image the head of the driver. Electronics within the height sensor 62, or the processor 16, analyze the image. Based on the location of the height sensor 62 within the motor vehicle 11, the electronics can calculate the height of the driver and a position of the driver's eyes. Depending on the precise location of the height sensor 62, this embodiment may allow the position of the driver's eyes to be directly measured, further increasing the accuracy of the calculated blind spot boundaries.
Another embodiment may further refine the calculation of the blind spot boundaries. This embodiment includes both the seat sensor 58 and the height sensor 62. The processor calculates, for example, the position of the driver's eyes within the motor vehicle 11 using both the seat signal and the height signal to maximize the accuracy of the calculation and further reduce the possibility of false positive indications.
In a further aspect of the present invention, a side collision avoidance method 100, illustrated in the flow chart of
As a person skilled in the art will readily appreciate, the above description is meant as an illustration of implementation of the principles this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from spirit of this invention, as defined in the following claims.
