Pedestrian detection method and system

Abstract

The invention relates to a pedestrian detection method and system. A vehicle system for a commercial vehicle comprises a first foresight shooting device and a service braking controller. And a driver assistance controller in communication with the first foresight photographing device and the service brake controller. The driver assistance controller identifies a pedestrian as a target within a field of view of the first forward-looking camera, determines that a distance to the pedestrian is less than or equal to a predetermined distance, and in response to the distance to the pedestrian being less than or equal to the predetermined distance, transmits a signal to the service brake controller to request deceleration of the vehicle. The driver assistance controller maintains a signal to the service brake controller until the pedestrian is no longer identified as the target.

Description

Technical Field

[0001] The present application relates to systems, controllers, and methods for providing accurate target information when a commercial vehicle equipped with automatic emergency braking (AEB) detects a forward target. Background Art

[0002] In commercial vehicle applications, different systems control service braking, lane departure warning, parking, and automatic emergency braking. Different sensors throughout the vehicle, such as cameras and radars, provide information used in these systems to determine target recognition before and during the implementation of automatic emergency braking.

[0003] Some commercial vehicles are also equipped with pedestrian automatic emergency braking. Pedestrian automatic emergency braking requires at least one forward-facing camera. Pedestrians have different heights and may fall into the forward blind spot of a commercial vehicle when the camera is mounted behind the windshield. As the commercial vehicle moves closer to the target, the pedestrian may become completely within the forward blind spot. Therefore, there is an interest in improving the functionality of pedestrian automatic emergency braking based on sensor input and knowledge of the target position. Summary of the Invention

[0004] According to one embodiment, a vehicle system for a commercial vehicle includes a first forward-looking camera, a service brake controller; and a driver assistance controller in communication with the first forward-looking camera and the service brake controller. The driver assistance controller identifies a pedestrian as a target within the field of view of the first forward-looking camera, determines that the distance to the pedestrian is less than or equal to a predetermined distance, and in response to the distance to the pedestrian being less than or equal to the predetermined distance, transmits a signal to the service brake controller to request deceleration of the vehicle. The driver assistance controller maintains the signal to the service brake controller until the pedestrian is no longer identified as a target.

[0005] According to another embodiment, a method for controlling a commercial vehicle includes detecting a pedestrian using at least one forward-looking camera, determining that the distance to the pedestrian is less than or equal to a predetermined distance, and transmitting a signal requesting deceleration of the vehicle as long as the pedestrian is detected at a distance less than the predetermined distance. Brief Description of the Drawings

[0006] Figure 1 is a schematic diagram of a system on a commercial vehicle according to an example of the present invention.

[0007] Figure 2 is a schematic diagram of a vehicle equipped with the system as in Figure 1 and a sample target.

[0008] Figure 3 is as inFigure 1 Flowchart of the operation of the system in Detailed implementation mode

[0009] Reference Figure 1 , showing a system 10 for a commercial vehicle according to an example of the present invention. The vehicle system 10 includes a brake controller 12 that controls the vehicle's service brakes 26 under certain conditions. The brake controller 12 can include functionality for controlling anti-lock braking and stability control. The brake controller 12 responds to signals from sensors directly connected to the brake controller 12 or to messages received from other controllers on the vehicle. The brake controller 12 transmits signals to activate the electro-pneumatic devices at each wheel end to help slow down and stop the vehicle before or in addition to driver intervention.

[0010] The system 10 includes a driver assistance controller, such as an automatic emergency braking (AEB) controller 14, which transmits messages about potential obstacles in front of the vehicle. The AEB controller 14 can receive information about obstacles from sensors attached to the vehicle and facing forward, such as a forward-looking camera 18, a radar 20, and other sensors 22. Specifically, the AEB controller 14 is looking for other vehicles traveling on the same road that may be slowing down or entering the travel lane of the main vehicle. Generally, the AEB controller 14 identifies targets based on the trajectory of the main vehicle and potential targets in the path of the main vehicle. When the main vehicle is within a pre-programmed distance from the target, a following distance alert is triggered. When a pre-selected distance between the main vehicle and the target is breached, the AEB controller 14 requests automatic emergency braking.

[0011] The first camera 18 has a defined field of view in front of the vehicle. The field of view depends on the height at which the camera 18 is mounted in the cab and the length of the vehicle's hood. For example, the camera 18 will use a processing algorithm to identify whether a forward obstacle is another vehicle, a pedestrian, or a traffic sign. Other cameras can be mounted at other locations on the vehicle, such as a camera facing the driver or a side object detection camera. The radar 20 is also positioned to scan the forward area of the vehicle for potential obstacles in the vehicle's travel path. The AEB controller 14 uses information from both the camera 18 and the radar 20 to determine the size, type, and speed of a target in the vehicle's travel path.

[0012] Pedestrian AEB is a subset of AEB that specifically uses a forward-facing camera to identify pedestrians near the vehicle. The algorithm within the camera determines the distance between the pedestrian and the vehicle and transmits the information to the AEB controller 14.

[0013] System 10 includes a parking brake controller 16 that controls a parking brake 28 of a vehicle such that the vehicle remains stationary. The parking brake controller 16 can receive signals regarding a driver's expectation to park the vehicle and signals from other controllers to keep the vehicle stationary.

[0014] The brake controller 12, the AEB controller 14, and the parking brake controller 16 communicate on a vehicle serial communication bus 20. Messages can be transmitted and received on the communication bus 30 using a known protocol such as SAE J1939.

[0015] System 10 includes a driver interface 24. The driver interface can include switches for turning certain features of system 10 on or off. The driver interface 24 can also include lights or displays for indicating the status of system 10.

[0016] When the controller 14 determines that service braking may be necessary to mitigate a collision with a detected object, the AEB controller 14 transmits a message on the communication bus 30. The requested braking level depends on the speed of the vehicle and the position of the target. The braking level may also depend on the available braking force within the vehicle's service braking system. For example, in a pneumatic braking system, the available braking level is limited by the amount of pressure stored in the service brake reservoir. The brake controller 12 responds to the message by automatically activating the service brakes to slow down or stop the vehicle. When the target is no longer being tracked, the AEB controller 14 can stop sending messages requesting service brake application. Depending on the message from the AEB controller 14, the parking brake controller 16 can be used to keep the vehicle stationary after service brake application.

[0017] In another example, the functions of each of the controllers 12, 14, 16 can be combined in a single controller.

[0018] Accordingly, a vehicle system for a commercial vehicle includes a first forward-looking imaging device, a service brake controller; and a driver assistance controller in communication with the first forward-looking imaging device and the service brake controller. The driver assistance controller identifies a pedestrian as a target within the field of view of the first forward-looking imaging device, determines that the distance to the pedestrian is less than or equal to a predetermined distance, and in response to the distance to the pedestrian being less than or equal to the predetermined distance, transmits a signal to the service brake controller to request deceleration of the vehicle. The driver assistance controller maintains the signal to the service brake controller until the pedestrian is no longer identified as a target.

[0019] Figure 2Depicts a vehicle 40 having a system 10. The vehicle 40 is designed with an engine in a forward position, which creates a blind spot directly in front of the vehicle. A camera device 18 shown as a forward-facing camera device mounted in the cab of the vehicle has a field of view 44 in front of the vehicle 40, and the field of view 44 is shown by a shaded area emitted from the forward-looking camera device 18 located in the cab of the vehicle 40. A portion of the field of view of the camera device 18 is blocked by the hood of the vehicle 40, creating a blind spot for the camera device as well as for the driver. The radar 20 also has a field of view 46, which is shown by a line emitted from the radar 20 located on the fender of the vehicle 40. However, radar is typically useful for identifying metallic objects such as vehicles and signs rather than pedestrians.

[0020] The AEB controller 14 uses the camera device 18 to identify a first target as a pedestrian 42. The pedestrian 42 can be a person of small stature, such as a child. For example, a child may be four feet tall, which is lower than the height of a typical hood of a commercial vehicle.

[0021] The camera device 18 calculates that the pedestrian 42 is at a distance d2 from the front of the vehicle 40. In one example, the distance d2 is approximately 9 feet from the front fender of the vehicle 40. The pedestrian 42 is within the field of view 44 of the camera device 18, so the entire body of the pedestrian is identified by the camera device 18. Depending on the speed of the vehicle 40, the AEB controller 14 can send a message to the vehicle brake controller 12 to slow down or stop the vehicle, thereby mitigating any collision with the pedestrian 42.

[0022] The pedestrian 42 can move to a new position d1. The pedestrian 42 may have moved, or the change in distance between the vehicle 40 and the pedestrian 42 may be due to the movement of the vehicle 40. Most of the pedestrian 42 is within the field of view 44 of the camera device 18, but the entire body of the pedestrian is not identified by the camera device 18. Depending on the speed of the vehicle 40, the AEB controller 14 will send a message to the vehicle brake controller 12 to slow down or stop the vehicle 40, thereby mitigating any collision with the pedestrian 42.

[0023] Pedestrian 42 can move to a new position d0. In the absence of the present invention, the AEB controller 14 can deactivate any service brakes because pedestrian 42 is no longer within the field of view of the imaging device 18 and is thus no longer recognized as a target. With the present invention, when pedestrian 42 moves into and out of the field of view 44 of the imaging device 18, the AEB controller 14 maintains the service brake request active. When pedestrian 42 is no longer within the field of view of the imaging device 18, the AEB controller 14 uses historical data of the position of pedestrian 42. If pedestrian 42 is not detected by the imaging device 18 as moving out of the blind spot, the AEB controller 14 will request the parking brake controller 16 to activate the parking brake to prevent the vehicle 40 from moving. The AEB controller 14 assumes that pedestrian 42 is in the same position because they are not detected as moving out of the blind spot.

[0024] When pedestrian 42 is being reliably detected by the imaging device 18, the AEB controller 14 includes logic for managing event dynamics (such as host vehicle speed, pedestrian speed, host vehicle acceleration, longitudinal distance) to determine the likelihood that pedestrian 42 will enter a forward blind spot under dynamic conditions. When such a determination is made, the AEB controller 14 can set an internal flag. As the event continues, and if pedestrian detection becomes unreliable because pedestrian 42 is moving into the forward blind spot, the AEB controller 14 will continue to transmit a braking request to the service brake controller 12.

[0025] In another embodiment, when the AEB controller 14 determines that pedestrian 42 remains within the blind spot, an alert can be given to the driver of the vehicle 40 via the driver interface 24.

[0026] In another embodiment, the additional sensors 22 can include a second forward-facing imaging device added to the fender of the vehicle 40 near the radar 20. The second imaging device will be used by the AEB controller 14 to confirm whether pedestrian 42 is still within the blind spot of the first imaging device 18.

[0027] Figure 3 A method 60 for implementing a pedestrian monitoring algorithm using the system 10 is shown.

[0028] In step 62, method 60 begins. In step 62, pedestrian automatic emergency braking can be effective. System 10 can be deactivated in special circumstances, such as when the driver manually disables the system, when the imaging device 18, radar 20, and other sensors 22 are in an error state due to a failed self-diagnosis or are uncalibrated or blocked or not visible. If the driver or other systems on the vehicle 40 have disabled system 10 via a manual switch or communication message, method 60 returns to step 62. In another embodiment, system 10 can be activated by geolocation (such as when vehicle 40 is entering a known school zone). If pedestrian AEB is activated, method 60 continues to step 66.

[0029] In step 66, the longitudinal distance from vehicle 40 to pedestrian 42 is measured via imaging device 18 and / or radar 20. If the distance is greater than or equal to a predetermined distance d2, method 60 returns to step 62. System 10 assumes that at a distance d2 or greater, pedestrian 42 is fully visible to the driver and imaging device 18, such that conventional obstacle detection will be effective. If the distance is less than d2, method 60 continues to step 68.

[0030] In step 68, the relative speed of vehicle 40 with respect to the detected pedestrian 42 is measured. If the relative speed is greater than or equal to a predetermined threshold, the method proceeds to step 70. The predetermined threshold speed can be -3.5 m / s. In step 70, extended pedestrian automatic emergency braking is set to false. In step 72, pedestrian AEB continues to operate without the extended mode, and the service brake can be released when no target is detected. Method 60 ends at step 74.

[0031] However, if in step 66 the relative speed is less than the predetermined threshold, method 60 continues to step 76. This means that pedestrian 42 may be moving in such a way as to be in the front blind spot of vehicle 40. In step 76, extended pedestrian AEB is set to true. If in step 76 pedestrian 42 is no longer reliably detected as a target, extended pedestrian AEB remains true, and in step 78 pedestrian AEB is allowed to continue to request the service brake.

[0032] If target detection is unreliable in step 78, method 60 proceeds directly to step 82, where the vehicle is parked via a request to the parking brake controller 16. In step 84, method 60 ends.

[0033] A vehicle having such a system is particularly useful when the vehicle is passing through a known area with frequent child pedestrians, such as near a school. The system may be activated only when in these locations, or the system may be effective during the entire operation of the vehicle.

[0034] Accordingly, a method for controlling a commercial vehicle includes detecting a pedestrian using at least one forward-facing imaging device, determining that a distance to the pedestrian is less than or equal to a predetermined distance, and transmitting a signal requesting deceleration of the vehicle as long as the detected pedestrian is less than the predetermined distance.

[0035] While the invention has been illustrated by description of exemplary processes and system components, and while the various processes and components have been described in detail, Applicant does not intend to limit or in any way restrict the scope of the appended claims to such details. Additional modifications will be readily apparent to those skilled in the art. Accordingly, the invention in its broadest aspects is not limited to the specific details, implementations, or illustrative examples shown and described. Thus, departures may be made from such details without departing from the spirit or scope of Applicant's general inventive concept.

Claims

1. A vehicle system for a commercial vehicle, comprising: A first forward-looking imaging device; A service brake controller; And A driver assistance controller in communication with the first forward-looking imaging device and the service brake controller; Wherein the driver assistance controller Identifies a pedestrian as a target within the field of view of the first forward-looking imaging device; Determines that the distance to the pedestrian is less than or equal to a predetermined distance; In response to the distance to the pedestrian being less than or equal to the predetermined distance, transmits a signal to the service brake controller to request deceleration of the vehicle; And Maintains the signal to the service brake controller until the pedestrian is no longer identified as a target.

2. The vehicle system according to claim 1, further comprising a parking brake controller in communication with the driver assistance controller, wherein the driver assistance controller transmits a signal to the parking brake controller to park the vehicle in response to the pedestrian remaining a target.

3. The vehicle system according to claim 2, wherein, The driver of the vehicle can override the signal to the parking brake controller.

4. The vehicle system according to claim 1, wherein, When the pedestrian is detected at a distance greater than the predetermined distance, the pedestrian is no longer identified as a target.

5. The vehicle system according to claim 1, wherein, The driver assistance controller determines that the pedestrian remains a target and thereby continues to transmit the signal requesting deceleration in response to no longer detecting the pedestrian in the field of view of the first forward-facing imaging device and not detecting the pedestrian at a distance greater than the predetermined distance.

6. The system according to claim 1, wherein, The driver assistance controller and the service brake controller are a single controller.

7. The system according to claim 1, further comprising a second forward-looking imaging device mounted on the vehicle at a location separate from the first forward-looking imaging device, wherein the pedestrian is no longer a target when the second forward-looking imaging device detects the pedestrian at a distance greater than the predetermined distance.

8. A method for controlling a commercial vehicle, comprising: Detecting a pedestrian using at least one forward-looking imaging device; Determining that the distance to the pedestrian is less than or equal to a predetermined distance; And Transmitting a signal requesting deceleration of the vehicle as long as the pedestrian is detected at a distance less than the predetermined distance.

9. The method according to claim 8, further comprising maintaining the signal requesting deceleration of the vehicle until the pedestrian is detected at a distance greater than the predetermined distance.

10. The method according to claim 8, further comprising determining that the pedestrian remains at a distance less than the predetermined distance and continuing to transmit the signal requesting deceleration in response to the pedestrian no longer being detected by the at least one forward-looking imaging device.

11. The method according to claim 8 further comprises: Transmitting a signal to engage the parking brake of the commercial vehicle until the pedestrian has been detected at a distance greater than the predetermined distance.

12. The method according to claim 10 further comprises: Overriding the signal to engage the parking brake by an action of the driver of the commercial vehicle.

13. The method according to claim 11, further comprising: Detecting that the pedestrian has moved to a distance greater than the predetermined distance; And Transmitting a signal to release the parking brake of the commercial vehicle.

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