TECHNICAL FIELD

The present disclosure relates to trailer reverse assist system that accommodates and corrects for deviations from an intended trailer path.

BACKGROUND

Backing a trailer with a vehicle is one of the more difficult tasks for a vehicle operator. Vehicles may now come equipped with trailer reverse assist systems that operate the vehicle based on a relative orientation between a tow vehicle and the trailer to direct the trailer along a desired path. A sensor is utilized to determine a relative angle between the trailer and the vehicle to proceed along the desired path. However, errors inherent in the sensor or disturbances to the trailer can result in an improper path that complicates operation and detracts from the usefulness of such systems.

The background description provided herein is for the purpose of generally presenting a context of this disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

SUMMARY

A trailer reverse assist system according to a disclosed example embodiment includes, among other possible things a controller configured to receive a first set of data from a first sensor indicative of an orientation between a vehicle and a trailer, a second set of data from a second sensor disposed on the vehicle that is indicative of a vehicle operating parameter and to verify that the trailer is on a selected trajectory based on the first set of data from the first sensor corresponding with the second set of data from the second sensor. In another embodiment of the foregoing trailer reverse assist system, the first set of data from the first sensor is indicative of an angle between the vehicle and the trailer.

In another embodiment of any of the foregoing trailer reverse assist systems, the first sensor comprises a camera mounted to the vehicle.

In another embodiment of any of the foregoing trailer reverse assist systems, the second sensor comprises a wheel speed sensor that generates information that is indicative of a direction of the vehicle.

In another embodiment of any of the foregoing trailer reverse assist systems, the second sensor comprises a steering angle sensor that generates information that is indicative of a direction of the vehicle.

In another embodiment of any of the foregoing trailer reverse assist systems, the second sensor comprises a sensor disposed on the vehicle that generates the second data set that is indicative of a direction of the vehicle.

In another embodiment of any of the foregoing trailer reverse assist systems, the controller is further configured to determine a deviation between an actual path of the trailer and an intended path of the trailer based on differences between a path indicated by the first set of data and the second set of data.

In another embodiment of any of the foregoing trailer reverse assist systems, the controller is further configured to correct the first set of data to correspond with the actual path of the trailer.

In another embodiment of any of the foregoing trailer reverse assist systems, the controller is further configured to generate an alternate path for the trailer to return the trailer to the intended path.

In another embodiment of any of the foregoing trailer reverse assist systems, the first sensor comprises a first camera mounted to the vehicle that detects an angle between the vehicle and the trailer.

A method of controlling a path of a trailer according to another disclosed embodiment includes, among other possible things, determining an orientation of a trailer relative to a vehicle with a first set of data from a first sensor, determining an orientation of the vehicle with a second set of data from a second sensor, wherein the second sensor is disposed on the vehicle and the second set of data is indicative of the orientation of the vehicle separate from the trailer and verifying that the trailer is on a selected trajectory based on a first trajectory determined with the first set of data corresponding with a second trajectory determined from the second set of data.

In another embodiment of the foregoing method, the first set of data from the first sensor is indicative of an angle between the vehicle and the trailer.

In another embodiment of any of the foregoing methods, the first sensor comprises a camera mounted to the vehicle.

In another embodiment of any of the foregoing methods, the second sensor comprises a sensor disposed on the vehicle that generates the second data set that is indicative of a direction of the vehicle.

Another embodiment of any of the foregoing methods further includes determining with a controller disposed within the vehicle a deviation between an actual path of the trailer and an intended path of the trailer based on differences between a path indicated by the first set of data and a path indicated by the second set of data.

Another embodiment of any of the foregoing methods further includes correcting the first set of data to correspond with the actual path of the trailer.

Another embodiment of any of the foregoing method further includes determining an alternate path for the trailer to return the trailer to the intended path and communicating the alternate path to a trailer reverse assist system of the vehicle.

A non-transitory computer readable medium including instructions executable by at least one processor according to another example embodiment includes, among other possible things, instructions executed by the at least one processor that prompt determining an orientation of a trailer relative to a vehicle with a first set of data from a first sensor, instructions executed by the at least one processor that prompt determining an orientation of the vehicle with a second set of data from a second sensor, wherein the second sensor is disposed on the vehicle and the second set of data is indicative of the orientation of the vehicle separate from the trailer and instructions executed by the at least one processor to prompt verifying that the trailer is on a selected trajectory based on a first trajectory determined with the first set of data corresponding with a second trajectory determined from the second set of data.

Another embodiment of the foregoing non-transitory computer readable medium further includes instructions executed by the processor for determining a deviation between an actual path of the trailer and an intended path of the trailer based on differences between a path indicated by the first set of data and a path indicated by the second set of data.

Another embodiment of any of the foregoing non-transitory computer readable mediums further includes instructions executed by the processor for determining an alternate path for the trailer to return the trailer to the intended path and for communicating the alternate path to a trailer reverse assist system of the vehicle. Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples.

These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic side view of a vehicle and trailer with an example embodiment of a trailer reverse assist system.

Figure 2 is a schematic top view of the vehicle and trailer with the example trailer reverse assist system.

Figure 3 is a schematic view of an example deviation from an intended trailer path and a corrected path.

Figure 4 is a schematic view of another example of a deviation from an intended trailer path and a corrected path.

Figure 5 is a flow diagram of example steps performed by the example trailer reverse assist system to correct for trailer drift. DETAILED DESCRIPTION

Referring to Figures 1 and 2, a vehicle 20 and trailer 22 are schematically shown with the vehicle including an example trailer reverse assist system 24. Backing a trailer is one of the most challenging maneuvers for a driver. A driver must steer the tow vehicle 20 in a manner that directs the trailer 22 along a desired intended path as schematically shown at 54. Steering of the tow vehicle 20 to direct the trailer 22 is not intuitive and therefore presents challenges for most drivers.

A trailer reverse assist system 24 is operated by a driver using controls other than the steering wheel and a display 25 located within the vehicle cabin. The system interprets the desired path set by the driver and automatically steers the tow vehicle 20 to direct the trailer 22. In one example, the angle of the trailer 22 relative to the tow vehicle 20 is utilized to provide information to the system 24 utilized to guide the tow vehicle 20. The angle is determined by information from a camera 34 mounted at the rear of the vehicle 20 or another suitable sensor, for example a radar sensor, lidar sensor, ultrasonic sensor or a mechanical sensor.

Information from the camera or sensor 34 may not be as accurate as needed to maintain the trailer 22 along the intended path 54. Even a small error between the indicated angle and the actual angle of the tow vehicle 20 and the trailer 22 can result in large deviations from the intended path.

The example system 24 provides for correction of any drift away from the intended path 54 by comparing information and data relating to operation of the tow vehicle 20 (such as wheel pulse senor data, wheel speed data, steering wheel angle data, radar data, vehicle speed, etc.) with information relating to the relative position of the trailer 22. The direction of the vehicle 20 is determined separate from the trailer 22. If the direction of the vehicle 20 does not correspond with the angular orientation of the trailer 22 or if the direction of the vehicle 20 does not correspond to the expected direction of the vehicle according to the angular orientation of the trailer 22, then some deviation has occurred and the trailer 22 is not on the intended path. However, if the information from the vehicle 20 corresponds with that of the trailer 22, then the trailer 22 is likely on the correct and intended path. The example system 24 uses a first set of data 48 from the camera 34 and a second set of data 50 from other sensors in the tow vehicle 20 to confirm that the trailer 22 is on the intended path.

The second set of data 50 is provided by systems on the tow vehicle 20, independent of a position of the trailer 22. The tow vehicle 20 includes wheel sensors 36 at each wheel 46, a steering sensor 40 and an accelerometer 42. The tow vehicle 20 may also include a radar or lidar/ultrasonic device(s) 38. Each of the tow vehicle sensors provide information that is indicative of the path of the vehicle 20.

If the vehicle path does not match the path of the trailer 22, then it is likely that something has disturbed the trailer 22 such that it is no longer moved along the path indicated by the camera 34. In other words, the sensor 34 provides information indicative of the angle of the trailer 22 relative to tow vehicle 20. If the data from the camera is not accurate, or the trailer 22 path has been disturbed, the actual path of the trailer 22 will be different than the intended path set by the operator.

The system 24 uses the trailer angle to set the trailer 22 on the intended path. The vehicle 20 is then operated to move the trailer 22 along the intended path. If the trailer 22 is disturbed and pushed off the path, the system would act to maintain the angle between the vehicle and trailer and thereby deviate from the intended path. The example system 24 uses vehicle sensors to check the information regarding the angle to determine if a deviation for the intended path has occurred and to correct for that deviation.

In one disclosed example, the wheel speed sensors 36 are utilized to provide data used to indicate a direction of the vehicle. Differences in wheel speed between the wheels 46 provides a very good indication of the direction of the vehicle. For example, outside wheels turn faster than inside wheels in a turn. The difference in wheel speed is therefore an indication of a turning radius and direction of the tow vehicle 20.

In another disclosed example, a steering wheel sensor 40 provides an indication of an angle of the front wheels. The angle of the front wheels provides the data needed to determine the direction of the vehicle 20. Other vehicle sensors may be also be utilized in combination or individually. For example, a radar device 38 and an accelerometer 42 could be utilized or combined with data from other sensors to determine the direction of the tow vehicle 20. Moreover, it should be understood that although several vehicle sensing devices are disclosed by way of example, any other sensing devices and systems that can provide information indicative of a vehicle direction could also be utilized and are within the scope and contemplation of this disclosure.

The vehicle 20 includes a controller 26 with a processor 28 and a memory device 30. The memory device 30 includes a set of instructions 32 executed by the processor 28 to use the first and second data sets 48, 50.

The example disclosed processor 28 may be a hardware device for executing software, particularly software stored in memory. The processor 28 can be a custom made or commercially available processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the computing device, a semiconductor based microprocessor (in the form of a microchip or chip set) or generally any device for executing software instructions.

The memory 30 can include any one or combination of volatile memory elements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM, VRAM, etc.)) and/or nonvolatile memory elements (e.g., ROM, hard drive, tape, CD- ROM, etc.). Moreover, the memory 30 may incorporate electronic, magnetic, optical, and/or other types of storage media. Note that the memory 30 can also have a distributed architecture, where various components are situated remotely from one another, but can be accessed by the processor.

The software instructions 32 in the memory 30 may include one or more separate programs, each of which includes an ordered listing of executable instructions for implementing logical functions. A system component embodied as software may also be construed as a source program, executable program (object code), script, or any other entity comprising a set of instructions to be performed. When constructed as a source program, the program is translated via a compiler, assembler, interpreter, or the like, which may or may not be included within the memory. The memory device 30 provides a non-transitory computer readable medium for storage of processor executable software instructions 32. The instructions 32 direct the processor 28 to determine an orientation of the trailer 22 relative to the tow vehicle 20 with the first set of data 48 from the camera 34. The instructions 32 further prompt the processor to determine an orientation of the vehicle 20 with the second set of data 50 from a second sensor. The second sensor is disposed on the vehicle 20 and include one or more wheel sensor 36, steering sensor 40, accelerometer 42 and/or radar device 38.

The instructions further prompt operation of the processor 28 to verify that the trailer 22 is on a selected trajectory based on a first trajectory determined with the first set of data 48 that corresponds with a second trajectory determined from the second set of data 50. The instructions 32 further prompt execution by the processor 28 for determining a deviation between an actual path of the trailer 22 and an intended path of the trailer 22 based on differences between a path indicated by the first set of data 48 and a path indicated by the second set of data 50. The processor 28 may then determine an alternate path for the trailer 22 that returns the trailer 22 to the intended path and communicates the alternate path to the trailer reverse assist system 24.

Referring to Figure 3 with continued reference to Figures 1 and 2, an example operation of the disclosed system 24 is schematically shown. In this example, a straight line intended path 54 is selected. The vehicle 20 moves along the intended path 54. If a disturbance such as a road bump, pothole or other discontinuity in the roadway disrupts the trailer 22, it may begin moving along another path as indicated at 60 that deviates from the intended path by a distance or angle 56. The vehicle 20 is however still moving along the path 58 to move the trailer 22 along the intended path 54. The system 24 uses information from the vehicle sensors to determine that the path 60 of the trailer 22 does not correspond with the path 58 of the vehicle, nor the intended path 54. The system 24 determines a correction path 62 to move the trailer back onto the intended path 54. The system 24 continually makes the comparison between the trailer path 60, vehicle path 58 and the intended path 54 to maintain and correct movement of the trailer 22. Referring to Figure 4, with continued reference to Figures 1 , 2 and 3, another example trailer path 54’ is shown and is curved. The system 24 determines the vehicle path 58 that provides the trailer path 60 needed to stay on the intended path 54’. A disturbance to the trailer 22 could result in the trailer 22 moving along a different path. In this example, the trailer 22 has deviated from the intended path 54’ as indicated at 56. The deviation may not be recognized by the vehicle camera 34 due to inherent functional limitations.

If only data from the camera 34 was relied upon, the trailer would continue along the incorrect path. However, the example system 24 uses data indicative of vehicle direction to verify that the trailer is on the correct path. In this example, the trailer 22 had moved from the intended path 54’. The system 24 determines the deviation from the path as indicated at 56 and determines a corrective path 62 to return the trailer 22 to the intended trajectory.

Referring to Figure 5 with continued reference to Figures 1 and 2, a flow diagram of example operation of a disclosed system embodiment is shown and generally indicated at 64.

Operation begins with a determination of an angle 52, or orientation of the trailer relative to the tow vehicle with the first set of data 48 from the camera 34 as indicated at 66. The orientation of the tow vehicle 20 with the second set of data 50 from a second sensor that is disposed on the vehicle as is indicated at 68. The second set of data 50 is indicative only of the direction and orientation of the vehicle without reference to the trailer 22.

The selected trajectory of the trailer 22 is then verified based on a first trajectory 60 determined with the first set of data 48 corresponding with a second trajectory 58 determined from the second set of data 50. If the first trajectory 60 and the second trajectory 58 do not correspond with the intended path 52, then the angle or distance of any deviation is determined as indicated at 70. The deviation 56 between the actual path or trajectory 60 of the trailer 22 and the intended path 54 is determined based on differences between the trajectory 60 indicated by the first set of data 48 and the trajectory indicated by the second set of data 50 as is indicated at 72. The system 24 will then make changes to account and correct for errors in the first set of data 48 such that the data 48 corresponds with the actual path of the trailer 22 as indicated at 74. Additionally, the system 24 will determine an alternate corrective path 62 for the trailer 22 to return the trailer 22 to the intended path 54 as indicated at 76.

Accordingly, the disclosed trailer reverse system 24 provides for the verification that a trailer is on an intended path by comparing information from additional sensors indicating the tow vehicle direction. If the sensors provide information indicating a deviation from the desired path, the system 24 will automatically initiate a correction by way of an alternate path to move the trailer 22 and vehicle 20 back to the desired intended path.

Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments.

It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure.

The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.