阅读说明：本技术 具有转向获取和切换的自动挂接系统 (Automatic hitching system with steering acquisition and switching ) 是由 卢克·尼维亚多姆斯基 凯尔·西蒙斯 阿纳夫·夏尔马 于 2020-02-05 设计创作，主要内容包括：本公开提供了“具有转向获取和切换的自动挂接系统”。一种车辆挂接辅助系统包括转向系统,所述转向系统具有：转向车轮,所述转向车轮安装在所述车辆的外部；以及转向马达,所述转向马达与所述转向车轮机械地联接。所述系统还包括控制器,所述控制器通过与所述转向马达的连接来获取对所述转向车轮的控制,并且在获取对所述转向车轮的控制之后,接收执行自动挂接操纵的命令并使用所述转向马达来控制所述转向车轮。(The present disclosure provides an "automatic hitch system with steering acquisition and switching. A vehicle hitch assist system includes a steering system having: a steering wheel mounted on an exterior of the vehicle; and a steering motor mechanically coupled with the steered wheel. The system further includes a controller that acquires control of the steered wheel through connection with the steering motor, and after acquiring the control of the steered wheel, receives a command to perform an automatic hitch maneuver and controls the steered wheel using the steering motor.)

1. A vehicle hitch assist system comprising:

a steering system, the steering system comprising:

a steering wheel mounted on an exterior of the vehicle; and

a steering motor mechanically coupled with the steered wheel; and

a controller, the controller:

obtaining control of the steering wheel through a connection with the steering motor; and

after acquiring control of the steered wheels, receiving a command to perform an automatic hitch maneuver and controlling the steered wheels using the steering motor.

2. The system of claim 1, wherein the controller moves the steered wheels to a zero degree turn position upon either completion of the automatic hitch maneuver or no longer receiving the command to execute the automatic hitch maneuver.

3. The system of claim 2, wherein the controller relinquishes control of the steered wheel after moving the steered wheel to the zero degree turn position.

4. The system of claim 1, wherein the steering system further comprises a steering wheel mounted inside the vehicle and mechanically coupled with the steered wheels.

5. The system of claim 4, wherein the controller causes the steering motor to move the steering wheel to indicate control of the steered wheels.

6. The system of claim 5, wherein the controller causes the steering motor to move the steering wheel in low amplitude oscillations to indicate control of the steered wheels.

7. The system of claim 1, wherein the controller further receives a command to initiate the automatic hitch maneuver and then to gain control of the steered wheels.

8. The system of claim 1, wherein obtaining control of the steered wheel comprises determining an initial steered wheel angle.

9. The system of claim 8, wherein obtaining control of the steered wheel further comprises sending a command to the steering motor corresponding to the steered wheel moving to the initial steered wheel angle.

10. The system of claim 9, wherein the steering system further comprises a steering angle sensor, the controller in communication with the steering angle sensor.

11. The system of claim 10, wherein the controller determines the initial steering wheel angle from the steering angle sensor.

12. A vehicle comprising a vehicle hitch assist system as claimed in any one of the preceding claims.

13. The vehicle of claim 12, further comprising a steering wheel mounted inside the vehicle and mechanically coupled with the steerable wheels.

14. The vehicle of claim 13, wherein the controller causes the steering motor to move the steering wheel to indicate control of the steered wheels.

15. The vehicle of claim 13, wherein causing the steering wheel to move to the zero degree turn position causes the steering wheel to move to a centered position.

Technical Field

The present invention generally relates to a system for assisting a vehicle-trailer hitch operation. In particular, the present disclosure relates to a system having an improved process for system acquisition and switching of steering system control.

Background

Hitching a trailer to a vehicle can be a difficult and time consuming experience. In particular, depending on the initial position of the trailer relative to the vehicle, aligning the vehicle hitch ball with the desired trailer hitch may require repeated forward and reverse travel to properly position the vehicle in coordination with multiple steering maneuvers. Furthermore, during most of the travel required for proper hitch ball alignment, the trailer hitch cannot be seen, and in general, the driver cannot actually see the hitch ball. This lack of line of sight requires that the hitch ball and hitch positioning be inferred based on experience with the particular vehicle and trailer, and may still require multiple parking and exit vehicle scenarios to confirm alignment or record corrections applicable to a set of subsequent maneuvers. Further, the closeness of the hitch ball to the rear bumper of the vehicle means that any overshoot may cause the vehicle to collide with the trailer. Therefore, further improvements may be needed.

Disclosure of Invention

According to one aspect of the present invention, a vehicle hitch assist system includes a steering system having: a steering wheel mounted on an exterior of the vehicle; and a steering motor mechanically coupled with the steered wheel. The system further includes a controller that acquires control of the steered wheel through connection with the steering motor, and after acquiring the control of the steered wheel, receives a command to perform an automatic hitch maneuver and controls the steered wheel using the steering motor.

Embodiments of the first aspect of the invention may include any one or combination of the following features:

in either case of completing the automatic hitch maneuver or no longer receiving the command to execute the automatic hitch maneuver, the controller causes the steering wheels to move to a zero degree turn position;

after causing the steered wheel to move to the zero degree turn position, the controller relinquishes control of the steered wheel;

the steering system also comprises a steering wheel mounted inside the vehicle and mechanically coupled with the steered wheels;

the controller causes the steering motor to move the steering wheel to indicate control of the steered wheels;

the controller causes the steering motor to move the steering wheel in low amplitude oscillations to indicate control of the steered wheels;

the controller also receives a command to initiate the automatic hitch maneuver and then to regain control of the steered wheels;

obtaining control of the steered wheels comprises: determining an initial steering wheel angle; and sending a command to the steering motor corresponding to the steered wheel moving to the initial steered wheel angle; and is

The steering system further comprises a steering angle sensor, the controller is in communication with the steering angle sensor, and the controller determines the initial steering wheel angle from the steering angle sensor.

According to another aspect of the present invention, a vehicle hitch assist system includes a steering system having: a steering wheel mounted on an exterior of the vehicle; and a steering motor mechanically coupled with the steered wheel. The system further includes a controller that: receiving a command to perform an automatic hitch maneuver; performing the automatic hitch maneuver, including using the steering motor to control the steered wheels; and causing the steerable wheels to move to a zero degree turn position after the automatic hitch maneuver is ended.

According to another aspect of the present invention, a vehicle includes a steering system having: a steering wheel mounted on an exterior of the vehicle; and a steering motor mechanically coupled with the steered wheel. The vehicle further includes a controller that: obtaining control of the steering wheel through a connection with the steering motor; receiving a command to perform an automatic hitch maneuver and controlling the steered wheels using the steering motor after acquiring control of the steered wheels; and causing the steerable wheels to move to a zero degree turn position after the automatic hitch maneuver is ended.

These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.

Drawings

In the drawings:

FIG. 1 is a perspective view of a vehicle in an unhook position relative to a trailer;

FIG. 2 is a diagram of a system for assisting in aligning a vehicle with a trailer in a position for hitching the trailer to the vehicle, according to an aspect of the present disclosure;

FIG. 3 is a schematic top view of a vehicle during one step of an alignment sequence with a trailer;

FIG. 4 is a flow chart depicting steps in an alignment sequence, including a vehicle acquiring control of a vehicle steering system;

FIG. 5 is a perspective view of an exemplary vehicle steering system;

FIG. 6 is a schematic top view of the vehicle during a subsequent step of an alignment sequence with the trailer;

FIG. 7 is a depiction of images received from the vehicle camera during the alignment sequence step of FIG. 6;

FIG. 8 is a schematic top view of the vehicle during a subsequent step in an alignment sequence with the trailer;

FIG. 9 is a schematic top view of the vehicle during a later step of the alignment sequence with the trailer and showing the position of the hitch ball of the vehicle at the end of the derived alignment path;

FIG. 10 is a schematic top view of the vehicle during a subsequent step in an alignment sequence with the trailer in which the steerable wheels of the vehicle are returned to a centered position;

FIG. 11 is a flowchart depicting steps in an alignment sequence, including a vehicle relinquishing control of a vehicle steering system; and

12A-12C are front views of a vehicle human machine interface showing example messages that may be presented during a step in which the vehicle relinquishes control of the vehicle steering system to the driver.

Detailed Description

For purposes of description herein, the terms "upper," "lower," "right," "left," "rear," "front," "vertical," "horizontal," "inner," "outer," and derivatives thereof shall relate to the device as oriented in fig. 1. However, it is to be understood that the device may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. In addition, unless otherwise specified, it should be understood that discussion of a particular feature of a component extending in or along a given direction or the like does not imply that the feature or the component extends along a straight line or axis in that direction or only extends in that direction or plane without other directional components or deviations, unless otherwise specified.

Referring generally to fig. 1-12C, reference numeral 10 designates a vehicle hitch assist system. The system 10 may be included in the depicted vehicle 12, the vehicle 12 having a steering system 20, the steering system 20 having: a steering wheel 76, the steering wheel 76 being mounted on the exterior of the vehicle 12; and a steering motor 74, the steering motor 74 being mechanically coupled with a steering wheel 76. The vehicle 12 also includes a controller 26, which controller 26 derives control of the steerable wheels 76 through a connection with the steering motor 74. After acquiring control of the steered wheels 76, the controller 26 receives a command to perform an automatic hitch maneuver and controls the steered wheels 76 using the steering motor 74. In either case of completion of the automatic hitch maneuver or no longer receiving a command to execute the automatic hitch maneuver, the controller 26 causes the steerable wheels 76 to move to the zero degree turn position.

With respect to the general operation of the hitch assistance system 10 shown in the system diagram of fig. 2, the system 10 includes various sensors and devices that obtain or otherwise provide information regarding the state of the vehicle. This information includes positioning information from a positioning system 22, which positioning system 22 may include a dead reckoning device 24, or additionally or alternatively a Global Positioning System (GPS), to determine a coordinate position of the vehicle 12 based on one or more locations of devices within the positioning system 22. Specifically, the dead reckoning device 24 may establish and track the coordinate position of the vehicle 12 within the local coordinate system 82 based at least on the vehicle speed and the steering angle. Other vehicle information received by the hitch assistance system 10 may include the speed of the vehicle 12 from the speed sensor 56 and the yaw rate of the vehicle 12 from the yaw rate sensor 58. It is contemplated that in further embodiments, the proximity sensor 54 or array thereof and other vehicle sensors and devices may provide sensor signals or other information, such as a sequence of images of the trailer 16 including the detected coupler 14, which the controller 26 of the hitch assistance system 10 may process with various programs to determine the height H and position of the coupler 14 (e.g., based on the distance D)_hAnd corner α_h)。

As further shown in FIG. 2, one embodiment of the hitch assist system 10 is in communication with a steering system 20 of the vehicle 12, which steering system 20 may be a power assisted steering system 20 that includes an electric steering motor 74 for operating the steering wheels 76 (FIG. 1) of the vehicle 12 to move the vehicle 12 in such a manner that the vehicle yaw varies with vehicle speed and steering angle. In the illustrated embodiment, the power assisted steering system 20 is an electric power assisted steering ("EPAS") system including an electric steering motor 74 for turning a steering wheel 76 to a steering angle based on a steering command, whereby the steering angle may be sensed by a steering angle sensor 78 of the power assisted steering system 20. The steering command may be provided by the hitch assist system 10 for autonomously steering during a trailer hitch alignment maneuver, and may alternatively be provided manually via a rotational position (e.g., a turning angle) of the steering wheel 30 of the vehicle 12. However, in this example, the steering wheel 30 of the vehicle 12 is mechanically coupled with the steered wheels 76 of the vehicle 12 such that the steering wheel 30 moves in unison with the steered wheels 76, thereby preventing manual intervention by the steering wheel 30 during autonomous steering. More specifically, a torque sensor 80 is provided on the power assisted steering system 20, said torque sensor 80 sensing a torque on the steering wheel 30 which is not expected by the autonomous control of the steering wheel 30 and thus indicates a manual intervention, whereby the hitch assistance system 10 may warn the driver to stop the manual intervention on the steering wheel 30 and/or to stop the autonomous steering. In alternative embodiments, some vehicles have a power assisted steering system 20 that allows the steering wheel 30 to be partially decoupled from the movement of the steered wheels 76 of such vehicles.

With continued reference to fig. 2, the power assisted steering system 20 provides information relating to the rotational position of the steerable wheels 76 of the vehicle 12, including the steering angle, to the controller 26 of the hitch assistance system 10. The controller 26 in the illustrated embodiment, among other conditions of the vehicle 12, processes the current steering angle to guide the vehicle 12 along a desired path 32 (fig. 3). It is contemplated that in other embodiments, the hitch assistance system 10 may be an integrated component of the power assisted steering system 20. For example, power assisted steering system 20 may include a hitch assistance algorithm for generating vehicle steering information and commands from all or a portion of the information received from: the imaging system 18, the power assisted steering system 20, the vehicle brake control system 70, the powertrain control system 72, and other vehicle sensors and devices and human machine interface 40, as discussed further below.

As also shown in fig. 2, the vehicle brake control system 70 may also communicate with the controller 26 to provide braking information (such as vehicle wheel speed) to the hitch assist system 10 and receive braking commands from the controller 26. For example, the vehicle speed information may be determined based on the speed of each wheel monitored by the brake control system 70. Vehicle speed may also be determined based on powertrain control system 72, speed sensor 56, and positioning system 22, among other conceivable devices. In some embodiments, each wheel speed is used in place of or in addition to the vehicle yaw rate sensor 58Can also be used to determine the yaw rate of the vehicleThe determined vehicle yaw rate may be provided to the hitch assistance system 10. The hitch assistance system 10 may also provide vehicle braking information to the brake control system 70 for allowing the hitch assistance system 10 to control the braking of the vehicle 12 during the rollback of the trailer 16. For example, in some embodiments, the hitch assistance system 10 may adjust the speed of the vehicle 12 during alignment of the vehicle 12 with the coupler 14 of the trailer 16, which may reduce the likelihood of a collision with the trailer 16 and may bring the vehicle 12 to a complete stop at the determined end point 35 of the path 32. It is disclosed herein that the hitch assistance system 10 may additionally or alternatively issue an alarm signal corresponding to a notification of an actual, impending, and/or anticipated collision with a portion of the trailer 16. As shown in the embodiment illustrated in fig. 2, the powertrain control system 72 may also interact with the hitch assist system 10 for adjusting the speed and acceleration of the vehicle 12 during partial or autonomous alignment with the trailer 16. As mentioned above, adjusting the speed of the vehicle 12 may be beneficial in preventing a collision with the trailer 16.

Additionally, the hitch assistance system 10 may communicate with a human machine interface ("HMI") 40 of the vehicle 12. The HMI40 may include a vehicle display 44, such as a center console mounted navigation or entertainment display (FIG. 1). The HMI40 also includes an input device that may be implemented by configuring the display 44 as part of a touchscreen 42 having circuitry 46 to receive input corresponding to a location on the display 44. Other forms of input (including one or more joysticks, digital input pads, etc.) may be used instead of or in addition to the touch screen 42. Further, the hitch assistance system 10 may communicate with another embodiment of the HMI40 via wireless communication, such as with one or more handheld or portable devices 96 (fig. 1), including one or more smartphones. The portable device 96 may also include a display 44 for displaying one or more images and other information to the user. For example, the portable device 96 may display one or more images of the trailer 16 on the display 44, and may also be capable of receiving remote user input via the touch screen circuitry 46. In addition, the portable device 96 may provide feedback information, such as visual, audible, and tactile alerts.

Still referring to the embodiment shown in fig. 2, the controller 26 is configured with a microprocessor 60 for processing logic and programs stored in a memory 62 that receive information from the aforementioned sensors and vehicle systems, including the imaging system 18, the power assisted steering system 20, the vehicle brake control system 70, the powertrain control system 72, and other vehicle sensors and devices. The controller 26 may generate vehicle steering information and commands based on all or a portion of the received information. The vehicle steering information and commands may then be provided to the power assisted steering system 20 for affecting steering of the vehicle 12 to achieve a commanded path of travel 32 (fig. 3) for alignment with the coupling 14 of the trailer 16. Controller 26 may include a microprocessor 60 and/or other analog and/or digital circuitry for processing one or more programs. In addition, the controller 26 may include a memory 62 for storing one or more programs, including an image processing program 64 and/or an articulation detection program, a path derivation program 66, and an operation program 68. It should be appreciated that the controller 26 may be a stand-alone dedicated controller, or may be a shared controller integrated with other control functions, such as with the vehicle sensor system, the power assisted steering system 20, and other conceivable on-board or off-board vehicle control systems. It should also be understood that the image processing program 64 may be implemented by, for example, a dedicated processor (including the microprocessor 60) within the stand-alone imaging system of the vehicle 12 that can output the results of its image processing to other components and systems of the vehicle 12. Moreover, any system, computer, processor, etc., that performs image processing functions such as those described herein may be referred to herein as an "image processor," regardless of other functions that it may also perform (including functions performed concurrently with the execution of image processing program 64).

The system 10 may also incorporate an imaging system 18, the imaging system 18 including one or more external cameras, which in the illustrated example include a rear view camera 48, a Center High Mounted Stop Lamp (CHMSL) camera 50, and side view cameras 52a and 52b, although other devices including additional or alternative cameras are possible. In one example, the imaging system 18 may include only the rear-view camera 48, or may be configured such that the system 10 utilizes only the rear-view camera 48 in a vehicle having multiple exterior cameras. In another example, the various cameras 48, 50, 52a, 52b included in the imaging system 18 may be positioned to substantially overlap in their respective fields of view, which may correspond to the rear-view camera 48, the center high mounted stop-light (CHMSL) camera 50, and the side- view cameras 52a and 52b, respectively. In this manner, image data from two or more cameras may be combined into a single image in image processing program 64 or in another dedicated image processor within imaging system 18. In an extension of this example, the image data may be used to derive stereoscopic image data that may be used to reconstruct a three-dimensional scene of one or more regions within the overlapping regions of the various fields of view 49, 51, 53a, 53b, including any objects therein (e.g., obstructions or couplings 14). In one embodiment, in view of the known spatial relationship between image sources, the use of two images comprising the same object may be used to determine the position of the object relative to the two image sources. In this regard, the image processing program 64 may use known programming and/or functionality to identify objects within the image data from the various cameras 48, 50, 52a, and 52b within the imaging system 18. In either example, the image processing program 64 may include information related to the location of any of the cameras 48, 50, 52a, and 52b present on the vehicle 12 or utilized by the system 10 (e.g., including the location relative to the center 36 (fig. 1) of the vehicle 12) such that the location of the cameras 48, 50, 52a, and 52b relative to the center 36 and/or each other may be used for object location calculations, as well as for obtaining object location data, for example, relative to the center 36 of the vehicle 12 or other features of the vehicle 12, such as the hitch ball 34 (fig. 1), the location relative to the center 36 being known.

The image processing program 64 may be specifically programmed or otherwise configured to position the coupler 14 within the image data. In one example, the image processing program 64 may first attempt to identify any trailers 16 within the image data, which may be done based on stored or other known visual characteristics of trailers 16 of a variety of different trailer types, sizes, or configurations compatible with the system 10, as well as trailers in general. The controller 26 may seek to confirm to the user that the identification of the trailer 16 is accurate and the correct trailer for which an automatic hitch operation is to be completed as described further below. After identifying the trailer 16, the controller 26 may then similarly identify the coupler 14 of the trailer 16 in the image data based on stored or otherwise known visual characteristics of the coupler 14 or couplers in general. In another embodiment, a marking in the form of a sticker or the like may be applied to the trailer 16 in a designated position relative to the coupler 14 in a manner similar to that described in commonly assigned U.S. patent No. 9,102,271, the entire disclosure of which is incorporated herein by reference. In such embodiments, the image processing program 64 may be programmed to identify the nature of the markers for the locations in the image data and the positioning of the coupler 14 relative to such markers so that the location 28 of the coupler 14 may be determined based on the marker locations. Additionally or alternatively, the controller 26 may seek confirmation of the determined coupling 14 via a prompt on the touch screen 42. If the determination of the coupler 14 is not confirmed, further image processing may be provided, or a touch screen 42 or another input may be used to facilitate user adjustment of the position 28 of the coupler 14 to allow the user to move the depicted position 28 of the coupler 14 on the touch screen 42, which the controller 26 uses to adjust the determination of the position 28 of the coupler 14 relative to the vehicle 12 based on the use of the image data described above.

In various examples, the controller 26 may initially rely on identification of the trailer 16 for an initial phase of an automatic hitch operation in which the path 32 is derived to move the hitch ball 34 relative to the trailer 16 toward a centered position and the path 32 is refined once the coupler 14 is identified. Such an operating scheme may be implemented when it is determined that the trailer 16 is sufficiently far from the vehicle 12 to begin backing up without knowing the precise end point 35 of the road path 32, and may be useful when the trailer 16 is at a distance where the resolution of the image data is such that the trailer 16 can be accurately identified, but the coupling 14 cannot be accurately identified. In this manner, the initial rearward movement of the vehicle 12 may allow for calibration of various system 10 inputs or measurements, which may, for example, improve the accuracy of the distance measurements, which may help make the identification of the coupling 14 more accurate. Similarly, movement of the vehicle 12 results in changing the particular image within the data, which may increase resolution or move the coupler 14 relative to the rest of the trailer 16 so that the trailer may be more easily identified.

As shown in fig. 3, the image processing routine 64 and the operating routine 68 may be used in conjunction with each other to determine a path 32 along which path 32 the hitch assist system 10 may guide the vehicle 12 to align the hitch ball 34 with the coupler 14 of the trailer 16. Upon initiating the hitch assistance system 10, such as by user input on, for example, the touch screen 42, the image processing program 64 may identify the coupler 14 within the image data and at least attempt to determine the distance D to the coupler 14 according to one example discussed above using the image data_cAnd an offset angle α between the coupler 14 and the longitudinal axis of the vehicle 12_cTo estimate the position 28 of the coupler 14 relative to the hitch ball 34. The image processing program 64 may also be configured to identify the trailer 16 as a whole and may use the image data of the trailer 16 alone or in combination with the image data of the coupling 14 to determine the orientation or heading 33 of the trailer 16. In this way, the path 32 may be further derived to align the vehicle 12 relative to the trailer 16, with the longitudinal axis 13 of the vehicle 12 within a predetermined angular range of the heading 33 of the trailer 16. Notably, such alignment may not require the longitudinal axis 13 of the vehicle 12 to be parallel or collinear with the heading 33 of the trailer 16, but may merely require the longitudinal axis to be within a range that generally allows the hitch ball 34 to be connected with the hitch 14 without a collision between the vehicle 12 and the trailer 16, and may also allow the vehicle 12 to be used to immediately control the backing of the trailer 16. In this manner, the angular range may be such that the vehicle 12 is in communication with the end of the operating program 68The alignment of the trailer 16 is such that the angle between the longitudinal axis 13 and the heading 33 is less than the bend angle between the vehicle 12 and the trailer 16 at the time of coupling or a reasonable estimate thereof. In one example, the angular range may be such that the longitudinal axis 13 is within about 30 of collinear deviation from the heading 33 in either direction. In various examples, such as when the length L of the trailer 16 is known, the angular range may be greater (if allowed) or may be smaller, depending on the desired tolerances of the system 10.

With continued reference to FIG. 3 with additional reference to FIG. 2, in one example, the location D of the coupling 14 has been estimated as discussed above_c、α_cThe controller 26 may execute the path derivation program 66 to determine the vehicle path 32 to align the vehicle hitch ball 34 with the coupler 14. Specifically, the controller 26 may store various characteristics of the vehicle 12 in the memory 62, including the wheelbase W, the distance from the rear axle to the hitch ball 34 (which is referred to herein as the drawbar length L), and the maximum angle at which the steerable wheel 76 may turn_max. As shown, the wheelbase W and the current steering angle may be used to determine the corresponding turning radius ρ of the vehicle 12 according to the following equation:

wherein the wheelbase W is fixed and the steering angle may be controlled by the controller 26 communicating with the steering system 20, as discussed above. In this way, when the maximum steering angle is known_maxWhile, turning radius rho_minIs determined as:

the path derivation program 66 may be programmed to derive the vehicle path 32 to align the known position of the vehicle hitch ball 34 with the estimated position 28 of the coupler 14, which aligns the determined minimum turn radius ρ_minTaken into account to allow path 32 to use a minimum amount of space and steering. In this manner, the path derivation program 66 mayThe position of the vehicle 12 (which may be based on the center 36 of the vehicle 12, the position along the rear axle, the position of the dead reckoning device 24, or another known position on the coordinate system 82) is used to determine the lateral distance from the coupler 14 and the forward or rearward distance from the coupler 14, and to derive the path 32, which path 32 achieves the desired lateral and forward-rearward movement of the vehicle 12 within the limits of the steering system 20. The derivation of path 32 also takes into account the location of hitch ball 34 relative to vehicle 12 (which may correspond to the center of mass 36 of vehicle 12, the location of a GPS receiver, or another designated known area) based on length L to determine a desired location of vehicle 12 to align hitch ball 34 with coupler 14. It should be noted that the hitch assistance system 10 may compensate for the horizontal movement Δ x of the coupler 14 in the direction of travel toward the vehicle 12 by determining the movement Δ y of the coupler 14 in the vertical direction that would be required to receive the hitch ball 34 within the coupler 14. Such functionality is further discussed in co-pending, commonly assigned U.S. patent application nos. 14/736,391 and 16/038,462, the entire disclosures of which are incorporated herein by reference.

As discussed above, once the desired path 32, including the endpoint 35, has been determined using any of the offset determination schemes described above, the controller 26 is allowed to control the steering system 20 of the vehicle 12 with at least the powertrain control system 72 and the brake control system 70 controlling the speed (forward or backward) of the vehicle 12 (whether controlled by the driver or by the controller 26, as described below). In this manner, the controller 26 may receive data from the positioning system 22 regarding the position of the vehicle 12 during its movement while controlling the steering system 20 as needed to maintain the vehicle 12 along the path 32. Specifically, the path 32, which has been determined based on the geometry of the vehicle 12 and the steering system 20, may adjust the steering angle dictated by the path according to the position of the vehicle 12 along the path 32. Additionally, it should be noted that in one embodiment, path 32 may include the progress of steering angle adjustment depending on the tracked vehicle position.

As shown in FIG. 3, the vehicle path 32 may be determined to be within the smallest area possible and/orThe required lateral and rearward movement is achieved with a minimum number of maneuvers. In the illustrated example of fig. 3, the path 32 may include multiple portions defined by the steering of the wheels 76 in different directions to collectively traverse the desired lateral movement of the vehicle 12 while providing a final straight rearward path of retreat for the hitch ball 34 to be in the offset alignment relationship with the coupler 14 described above. It should be noted that variations in the depicted path 32 may be used. It should be further noted that an estimate D of the location of the coupling 14_c、α_cMay become more accurate as the vehicle 12 traverses the path 32, including positioning the vehicle 12 in front of the trailer 16, and as the vehicle 12 approaches the coupler 14. Accordingly, such estimates may be continuously derived and used to update the path derivation program 66 as needed in determining the adjusted end point 35 of the path 32, as discussed above. In a similar manner, once the image processing program 64 can identify the coupler 14 in the image data, the path 32 derived using the position and orientation data acquired from the portable device or smartphone 96 can be fine-tuned, with the similarly derived path 32 continually updated as the image data becomes clearer and clearer as the trailer 16 is approached. It should also be noted that before such a determination can be made, the dead reckoning device 24 may be used to track the position of the vehicle 12 as it moves along the path 32 toward the initially derived end point 35.

It will be appreciated that the entire process of using the system 10 to align the hitch ball 34 of the vehicle 12 with the hitch 14 of the trailer 16 includes normally driving the vehicle under the control of the driver in addition to the vehicle 12 backing out under the control of the system 10 as described above. Specifically, as discussed above, the driver most commonly initially maneuvers the vehicle 12 to a location where the trailer 16 is located so that the system 10 may identify the trailer 16 or the coupler 14. If the vehicle 12 is started at a position relative to the trailer 16 such that identification can be immediately made, the vehicle will still start while the user is driving. Thus, the system 10 would be required to take control of the vehicle 12, including steering of the vehicle 12 to automatically reverse the trailer 16. In this regard, the system 10 may be operable to indicate to a user that the vehicle 12 is ready to be controlled and/or that control of the steering system 20 has been acquired, among other things. Further, the system 10 is configured to overcome various other limitations of the system 10 to provide such an indication at a time consistent with user expectations, which may improve user experience and reduce user interference with system 10 operation.

Specifically, as shown in FIG. 4, the process by which the system 10 acquires and directs vehicle control is incorporated into the initial stages of overall operation of the system 10, as generally discussed above. As discussed, the system 10 may begin the attach operation 210 upon user direction, such as by: selecting an appropriate menu item via the HMI 40; or activating a soft button presented on the HMI (which may be done automatically when the vehicle 12 is reversing and/or when the imaging system 18 identifies the trailer 16) or a physical button on the vehicle 12 dashboard. The system 10 then executes the above-described image processing routine 64 in communication with the imaging system 18 to identify 212 the trailer 16 and/or the coupler 14 within the field of view of the one or more cameras 50 (or within a particular area within the field of view). When the trailer 16 or the coupler 14 is identified, the system 10 indicates the identification (e.g., via the HMI40) and the system 10 is ready to navigate the vehicle 12 toward the trailer 16. In this example, the system 10 may be configured to actually initiate a process of controlling the vehicle 12 to navigate toward the trailer 16 after the driver shifts 214 the transmission 92 of the vehicle 12 to neutral (which is interpreted by the system 10 as indicating that the driver is ready to begin the automatic hitch process). In this regard, the system 10 may run a path derivation program 66, which path derivation program 66 may, among other things, generate an initial steering angle that will be commanded by the system 10 at the start of the operational program 68. However, the system 10 will wait at this point to actually begin the operational procedure 68 until a command from the user, as discussed below. In accordance with the present disclosure, the system 10 may prepare for this command and the corresponding execution of the operational program 68 prior to this command by taking control of the steering system 20 upon receipt of the user readiness indication 212 and indicating to the user that such control has been taken.

As shown, control of steering system 20 by controller 26 may be facilitated by steering system 20 having an operating mode in which steering motor 74 operates in a steering angle control mode in which steering system 20 receives as input a particular steering angle rather than, for example, steering wheel 30 torque (discussed further below). In this regard, the controller 26 may gain control of the steering system 20 by requesting 216 that the steering system 20 operate in a steering angle control mode while running and receiving the steering angle input from the controller 26 as an output of the operating program 68. In this regard, one or more prerequisites may be required for system 10 to gain control of steering system 20 in this manner. The system 10 evaluates 218 these prerequisites and if they are not satisfied, the system 10 continues to request 216 control until the prerequisites are satisfied or the operation is cancelled. In various examples, for controller 26 to gain control of steering system 20, the vehicle speed must be below a threshold and the torque applied to steering wheel 30 must be below a threshold. Additionally, there may be a time-based prerequisite such that after control is requested 216, the current angle of the steering wheel 30 must be maintained for a certain time to ensure that the steering motor 74 is properly engaged.

When the required preconditions are met, the controller 26 is brought into control of the steering system by a connection (directly or indirectly) with the steering motor 74. As discussed, in this example, this is accomplished by allowing the controller to output the steering angle of the operating program 68 as an input to the steering system 20 in the steering angle control mode. Again, because the operating program 68 has not been run, the operating program does not output a steering angle, and therefore, in such circumstances, the system 10 will not respond in a perceptible manner to the permitted control. Thus, after granting such control, system 10 may send an indication to output command 220 that steering control has been acquired (and thus, system 10 is ready to automatically perform hitch operations), and then actually activate operating program 68. In one example, the system 10 may output a message or other visual indication of the retrieval via the HMI 40. In another example, the system 10 may utilize available controls of the steering system 20 in a preemptive manner to provide a tactile indication of the acquisition of driver-perceptible controls. In yet another example, such visual and tactile indications may be given simultaneously. After taking control of the steerable wheels 76 and providing an indication of its desire to output command 220, controller 26 waits to receive a command 222 to perform an automatic hitch maneuver. In one aspect, the command may be given by the user pressing an additional soft button on the HMI40 or by pressing an additional physical button on the dashboard or the same button originally used to initiate the hitch operation 210. In one aspect, the button can be a "keep alive" button such that the user must continue to press the button before the system 10 can initiate and maintain the operation program 68. If the user stops pressing this button, the operating program 68 may pause or terminate altogether. In either example, upon receiving the output command 220, the system 10 allows the controller 26 to control the steered wheels 76 using the steering motor 74 to perform an automatic hitch maneuver 224 (which may also include control of the vehicle brake control system 70 and/or the powertrain control system 72) until a desired alignment 226 with the coupling 14 is achieved.

To provide the above-mentioned tactile indication of control of steering system 20, controller 26 may cause a degree of movement of steering wheel 30. In one application, the structure of the steering system 20 and its integration into the vehicle 12 may effectively facilitate such movement. In one aspect, as described herein, the system 10 includes an embodiment of the steering system 20 in which the steerable wheels 76 are mounted externally to the vehicle 12, as shown in FIG. 1. As discussed above, the steering motor 74 of the steering system 20 is mechanically coupled to the steering wheel 76. As shown in fig. 5, the steering system 20 also includes a steering wheel 30, the steering wheel 30 being mounted inside the vehicle 12 and mechanically coupled with the steered wheels 76. Specifically, the steering wheel 30 may be indirectly coupled to the steering column 84 such that rotation of the steering wheel 30 causes rotation of the steering column 84 (and vice versa). Steering column 84 may be coupled to a recirculating ball nut mechanism 86 at an input end of the steering column opposite steering wheel 30.

The recirculating ball nut mechanism 86 may be of general or suitable construction and may include an output or connecting member 100, the output or connecting member 100 always turning left (i.e., at a maximum steering angle) at least at the steerable wheel 76_max) Is always turned to the right (again at the maximum steering angle) with the steerable wheel 76_max) To the second position. More specifically, the mechanismThe output member 100 of 86 may be coupled to a drag link 102. The straight pull rod 102 is relatively coupled to a steering knuckle of one of the steerable wheels 76 (e.g., the right hand steerable wheel 76) such that movement of the output member 100 moves the straight pull rod 102 causing the steering knuckle to rotate the wheel to change the steering angle of the steerable wheel 76. The knuckle of the right hand steerable wheel 76 may also be coupled to a tie rod 104. The tie rod 104 may be relatively coupled to the knuckle of the left-hand steered wheel 76 so that the motion of the knuckle of the right-hand steered wheel 76 is directly transmitted to the motion of the left-hand steered wheel 76 through the tie rod 104 to simultaneously change the steering angle of the steered wheel 76. While the illustrated example is disclosed as including a straight-pull rod steering geometry as part of the steering system 20, it should be understood that the illustrated example may also include a Haltenberger or parallel link steering system or any other steering system that may be available or suitable in a vehicle according to the depicted example.

The steering system 20 also includes the above-mentioned steering motor 74. The output of the steering motor 74 may be provided as an input to a tie-rod 102 at the same connection point as the output member 100 of the ball nut mechanism 86 for assisting in rotating the steering wheel 76. Steering motor 74 may be relatively coupled to and supported on a cross beam support or cross member 106, which cross beam support or cross member 106 may extend between the left-hand and right-hand beams of frame 108 to transfer forces generated by steering motor 74 to drag link 102 using frame 108 as a basis. The steering motor 74 may be supplied with electrical power from the electrical system of the vehicle. The steering motor 74 is configured with an internal electric motor that generates a rotational output to drive linear motion of its output (i.e., the portion coupled to the drag link 102). Additional aspects and additional examples of EPAS steering systems 20 that may be used in conjunction with the system 10 described herein are found in commonly assigned U.S. patent No. 8,893,846, the entire disclosure of which is hereby incorporated by reference.

The steering motor 74 of the illustrated example may be controlled as needed or necessary to provide steering assistance during operation of the vehicle. As discussed above, the controller may be connected with the steering motor 74 to provide a variable current or otherwise vary the output of the steering motor 74 to provide the system 20 with desired steering assist characteristics, including meeting desired assistance for a typical power assisted steering system during normal driving of the host vehicle 12. Also as discussed above, the present controller 26 for implementing the hitch-assist functionality described herein may be the controller 26 associated with the EPAS steering system 20 and used to control the EPAS steering system 20, including for example, situations where the operating program 68 is not used during driving. More specifically, the hitch assist functionality described herein may be incorporated within the functionality of the steering system 20 such that the controller 26 executing the operating program 68 or the like is a controller of the steering system 20. During normal driving, the controller 26 may use the input from the torque sensor 80 in a closed-loop manner, for example, to allow user input on the steering wheel 30 to control the output of the steering motor 74 to provide the desired power assist to the steering provided by the user (additional inputs from the steering angle sensor 78, the vehicle speed sensor 56, etc. are employed in various examples).

The system 10 may operate by having the controller 26 fully control the steering system 20 through communication established with the steering motor 74 in the steering angle control mode described above. Specifically, controller 26 may operate steering motor 74 through its connection to steering motor 74 to command a desired steering angle as required by operating program 68 (e.g., without seeking input from torque sensor 80) and measured by steering angle sensor 78. In another example, the controller 26 may actually use the input of the torque sensor 80 as a fault signal in the operation routine 68 that may, in some cases, cause the operation routine 68 to terminate to abort the hitch assistance maneuver.

In this example or other similar examples, by making a connection between the steering wheel 30 and the controller 26 through the steering wheel motor 74, the controller 26 may cause the steering wheel motor 74 to move the steering wheel 30 to indicate control of the steering wheel 76, as discussed above. Specifically, the controller may cause the steering motor 74 to move the steering wheel 30 in low amplitude oscillations, indicating that the controller 26 has acquired control of the steering wheels 76. In one example, this movement may be accomplished by the controller 26 determining 228 an initial steering angle (i.e., "initial steering wheel angle") of the steering wheel 76 from the steering angle sensor 78 and sending the steering angle as a control input to the steering motor 74 operating in the steering angle control mode. Since the controller 26 is commanding the same steering angle that is already in place, the position of the steerable wheels 76 does not effectively change, and the vehicle 12 does not change position. However, by sending an active steering angle command input, the system 10 will engage the steering motor 74, which will produce a small but noticeable tactile indication to the user by moving the steering wheel 30. This motion may be characterized by a trembling, vibrating, stiffness, shaking, or jolting of steering wheel 30, thereby informing driver system 10 that control of steering system 20 has been achieved.

As discussed above, the tactile indication by the steering system 20 control of the system 10 communicates to the user that the system 10 is ready to begin an automatic hitch maneuver. In this manner, when the user provides the command 222 to begin maneuvering, the system 10 may respond quickly to begin controlling the steering angle to follow the planned path 32, at least in part because the steering motor 74 is already engaged. This engagement results in the system 10 hardly delaying commanding the desired steering angle in accordance with the operating program 68 and the corresponding motion of the vehicle 12 when the user provides the command 222. In addition, certain control schemes and systems that may be used to control the general functions of the steering system 20, including the steering angle control modes described above, do not broadcast an error condition unless a request for steering control is actually received (i.e., an actual steering angle is commanded or input). In this scenario, the control request is sent earlier than in other system designs, and if steering control is not available due to a failure, system 10 will recognize this sooner. In this regard, the system 10 may terminate the attach process and notify the driver a short time after giving the user ready command 214 (e.g., the driver shifts to neutral). Otherwise, the driver is not informed of such a fault until after the steering command 222 is given.

Referring additionally to fig. 6-10, once the user gives a maneuver command 222, the operating program 68 may use the hitch maneuver 224 to guide the vehicle 12 until the hitch ball 34 is in opposition to the hitch ballThe coupler 14 is positioned such that when the coupler 14 is lowered into horizontal alignment with the hitch ball, the coupler 14 engages the hitch ball 34. In the example discussed above, the image processing program 64 monitors the position D of the coupling 14 continuously or once available during execution of the operation program 68_c、α_cIncluding when the coupler 14 enters the clearer view of the rear-view camera 48 as shown in fig. 7, the vehicle 12 continues to move along the path 32 as shown in fig. 8. As discussed above, the position of the vehicle 12 may also be monitored by the dead reckoning device 24, where the path 32 and or the endpoint 35 may be refined or should be updated (e.g., due to closer resolution or additional image data resulting in the height H_cDistance D_cOr offset angle α_cInformation improved) the position 28 of the coupler 14 is continuously updated and fed into the path derivation program 66, including when the vehicle is near the trailer 16, as shown in fig. 8. Still further, it may be assumed that the coupling 14 is static, such that the position of the vehicle 12 may be tracked by continuing to track the coupling 14, eliminating the need to use the dead reckoning device 24. In a similar manner, a modified version of the operating program 68 may be made by a predetermined maneuver sequence involving steering the vehicle 12 at a maximum steering angle_maxOr below the maximum steering angle while tracking the position D of the coupling 14_c、α_cTo converge the known position of the hitch ball 34 to a desired position 38d of the hitch ball relative to the tracked position 28 of the coupler 14, as discussed above and shown in fig. 9.

After the system 10 causes the vehicle to arrive and stop at the position shown in fig. 9, with the hitch ball 34 of the vehicle 12 aligned 226 with the coupler 14 of the trailer 16 (fig. 4), the system 10 may end the automatic hitch maneuver 224 and execute a process according to the present disclosure (as shown in fig. 11) to yield control of the vehicle 12, and in particular the steering system 20, to the driver. In some aspects, the system 10 may cause actuation of the parking brake 98 upon reaching a desired position such that the vehicle 12 does not move from the aligned position when the vehicle service brake 71 is released. This and other similar actions taken to maintain the position of the vehicle 12 are considered part of the steps to complete the automatic hitch maneuver 224 in accordance with the present disclosure. Once the automatic hitch maneuver is completed or if the maneuver is aborted (which may include, for various reasons, the driver interfering with the steering wheel 30 or brake 71, the imaging system 18 losing visibility of the coupling 14, the vehicle 12 moving unexpectedly, the driver releasing a "keep alive" button, etc.), the system may, on the one hand, move 230 the steering wheel 76 to a centered position (i.e., a zero degree turn position or a steering angle with a zero value) as necessary, as depicted in fig. 10.

The action of the system in moving the steerable wheels 230 may be beneficial to the driver in subsequent control of the driving of the vehicle 12. Specifically, when system 10 completes or suspends automatic hitch maneuver 224, steerable wheel 76 is moved away at the last commanded angle of system 10. The angle may approach the maximum steering angle to the left or right_maxThis may not be apparent to the driver because the steering wheel 30 is not directly aligned with the steerable wheels 76 in various ranges of motion while remaining coupled with the steerable wheels 76. Since the driver does not actually turn the wheels during the automatic hitch maneuver 224, the driver may not know the actual steering angle, which may be inconvenient when the driver begins driving. For example, if a trailer is hitched and the driver begins to drive the vehicle 12 in a reverse direction, a trailer buckle condition may result. If the vehicle 12 is traveling in a forward direction, the trailer 16 may collide with an adjacent object due to the geometry of the trailer 16 pulling out of its parked position while turning. Other examples of adverse vehicle 12 handling at unknown high steering angles may be apparent. Furthermore, switching by the system 10 of the vehicle 12 in this state may not meet the driver's expectations and may be frustrating. In this regard, it may be generally desirable for the system 10 to maintain the same state of the vehicle 12 at all times after completion of various executions of the automatic hitch maneuver 224. If the vehicle 12 is repeatedly in the same state when the system 10 releases control, the driver may easily understand and expect such behavior of the system 10, which may reduce driver confusion.

Movement 230 of steerable wheel 76 to the centered position is performed by system 10 in a similar manner to the movement of steerable wheel 76 during an automatic hitch maneuver. Specifically, the controller 26 sends a zero degree turn angle command to the steering system 20 to operate in the steering angle control mode described above, whereby the steering system 20 uses the steering motor 74 to move the steering wheel 76 to the desired position, as discussed above with respect to fig. 5. Since the steering wheel 30 remains coupled with the steering wheel 76, movement of the steering wheel 76 to the centered position also moves the steering wheel 30 to the centered position. In at least one aspect, this movement signals to the driver that the steerable wheel 76 is moving to a centered position.

After the steerable wheel 76 moves 230 to the centered zero degree turn position, the controller relinquishes control 238 of the steerable wheel 76 (e.g., by having the controller 26 end the operating sequence 68 and change operation of the steering system 20 to the torque-based normal operating mode). However, depending on the final steering angle commanded by the operating program 68, the step of moving the steerable wheel 76 to the centered position may take considerable time. The time required to complete this step may not meet the driver's expectations for the behavior of the system 10, so the driver may not immediately know whether the maneuver was successfully completed or aborted. To communicate the status of the system 10 to the driver at a favorable time, the system 10 may present 232 a message or animation on the display 44 via the HMI 40. Some examples are shown in fig. 12A, 12B, and 12C. Specifically, in FIG. 12A, a message 110 is shown on the display 44, the message 110 indicating to the user that the system is aborting the maneuver (i.e., the system 10 has determined that the operating program should end and is preparing to return control of the steering system 20 to the driver, including moving the steering wheel 76 to the centered position). Further, in fig. 12B, a similar message 112 is presented to the user to communicate that the maneuver has been successfully completed by the alignment of the hitch ball 34 with the coupler 14. An alternative communication for either case is shown in fig. 12C, where the system 10 presents an animation 114, the animation 114 indicating system activity that caused the delay.

Returning to FIG. 11, once a command is given to move 230 the steerable wheel 76 to the centered position, the system 10 continuously evaluates 234 the steering angle for indicating that the steerable wheel 76 has reached the desired centered position, including through further communication with the angle sensor 78. When an indication of the desired steering wheel 76 position is given, the system 10 notifies 236 that the maneuver has been completed or aborted and relinquishes control 238 of the maneuver system 20 to the user. Notably, the threshold steering angle value may be used to determine whether steering may be considered "centered". Although the system 10 commands the steering system 20 that the steering angle is zero, the actual steering angle may not actually reach zero in view of potential real-world actuation and measurement imperfections. Thus, a threshold of, for example, ± 10 ° may be considered a reasonable approximation of a straight ahead or centered turn, and may therefore be used as a criterion to consider return-to-positive motion 230 as complete.

As long as the steering angle is not within the acceptable threshold, the system 10 may perform an additional check to determine if the system 10 should abort 236 the control process, or if the system 10 may continue to attempt to change the steering angle toward 0. In one example, the system 10 may monitor 240a the torque sensor 80 to determine whether the driver is applying any steering torque to the steering wheel 30. The system 10 may interpret this action as a steering override, whether intended or unintended by the driver, and may abort 242 the centering process. The system 10 may also monitor 240b the time derivative of the steering angle to assess whether the steering system 20 is responding to a centering command, as indicated by the movement of the steerable wheels 76 and the decrease in steering angle. If the system 20 observes a zero value for the steering angle time derivative, it can be concluded that the steering system 20 or the steered wheel 76 is stuck and the centering process can be similarly aborted 242. The system 10 may also limit 242c the total amount of time allowed for the correction process. If the 240c threshold is exceeded (e.g., 30 seconds), the centering process may be aborted 242.

After the centering process is completed or aborted 244, the system 10 may provide appropriate instructions to the driver, including additional messages on the screen 44 through the HMI 40. In some cases, the system 10 may determine 244 that the centering process of the abort 242 has reached a final steering angle, which may be considered close enough that the process may have a steering angle despite not being within a threshold at which the system 10 stops completing the centering process, such that the abort warning 246 need not be given. The threshold of step 244 may be greater than the value in determining 232 whether centering is complete. For example, the threshold for centering completion may be ± 2 °, but the threshold for abort indication in step 244 may be ± 10 °. In the event that the steering angle is above the threshold, the system 10 may notify 246 that the driver is still giving control over the driver instead of the steered wheel 76 being not centered. If the steering angle is below the threshold, the system 10 may notify 236 that the process has been completed rather than indicating that the steerable wheel 76 is not centered. As discussed above, after giving the appropriate message, the controller 26 relinquishes control 238 of the steerable wheel 76 (e.g., by having the controller 26 end the operating sequence 68 and change operation of the steering system 20 to the torque-based normal operating mode). In this case, the process is considered complete and the system 10 remains idle until a further initiation indication 200 is given.

It is noted that the control acquisition process discussed with reference to fig. 4 and the control "handover" process discussed with reference to fig. 11 may be implemented together in an embodiment of system 10, as discussed herein. In other examples, variations of system 10 may be configured to implement the acquisition processes described herein, but the described handover processes may be omitted or altered. In further variations, the system 10 may be configured to implement the handover procedures discussed herein, but the described acquisition procedures may be omitted or altered.

It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.

According to the present invention, there is provided a vehicle hitch assist system including: a steering system, the steering system comprising: a steering wheel mounted on an exterior of the vehicle; and a steering motor mechanically coupled with the steered wheel; and a controller that: obtaining control of the steering wheel through a connection with the steering motor; and after acquiring control of the steered wheels, receiving a command to perform an automatic hitch maneuver and controlling the steered wheels using the steering motor.

According to one embodiment, the controller causes the steerable wheels to move to a zero degree turn position upon either completion of the automatic hitch maneuver or no longer receiving the command to execute the automatic hitch maneuver.

According to one embodiment, the controller relinquishes control of the steered wheel after causing the steered wheel to move to the zero degree turn position.

According to one embodiment, the steering system further comprises a steering wheel mounted inside the vehicle and mechanically coupled with the steered wheels.

According to one embodiment, the controller causes the steering motor to move the steering wheel to indicate control of the steered wheels.

According to one embodiment, the controller causes the steering motor to move the steering wheel in low amplitude oscillations to indicate control of the steered wheels.

According to one embodiment, the controller further receives a command to initiate the automatic hitch maneuver and then to regain control of the steered wheels.

According to one embodiment, obtaining control of the steered wheels comprises: determining an initial steering wheel angle; and sending a command to the steering motor corresponding to the steered wheel moving to the initial steered wheel angle.

According to one embodiment, the steering system further comprises a steering angle sensor, the controller is in communication with the steering angle sensor, and the controller determines the initial steering wheel angle from the steering angle sensor.

According to the present invention, there is provided a vehicle hitch assist system having a steering system including: a steering wheel mounted on an exterior of the vehicle; and a steering motor mechanically coupled with the steered wheel; and a controller that: receiving a command to perform an automatic hitch maneuver; performing the automatic hitch maneuver, including using the steering motor to control the steered wheels; and causing the steerable wheels to move to a zero degree turn position after the automatic hitch maneuver is ended.

According to one embodiment, the controller relinquishes control of the steered wheel after causing the steered wheel to move to the zero degree turn position.

According to one embodiment, the controller also acquires control of the steered wheels through a connection with the steering motor, and is then able to receive the command to perform the automatic hitch maneuver.

According to one embodiment, the steering system further comprises a steering wheel mounted inside the vehicle and mechanically coupled with the steered wheels.

According to one embodiment, causing the steering wheel to move to the zero degree turn position causes the steering wheel to move to a centered position.

According to the present invention, there is provided a vehicle having a steering system including: a steering wheel mounted on an exterior of the vehicle; and a steering motor mechanically coupled with the steered wheel; and a controller that: obtaining control of the steering wheel through a connection with the steering motor; receiving a command to perform an automatic hitch maneuver and controlling the steered wheels using the steering motor after acquiring control of the steered wheels; and causing the steerable wheels to move to a zero degree turn position after the automatic hitch maneuver is ended.

According to one embodiment, the invention also features a steering wheel mounted inside the vehicle and mechanically coupled with the steerable wheels.

According to one embodiment, the controller causes the steering motor to move the steering wheel to indicate control of the steered wheels.

According to one embodiment, causing the steering wheel to move to the zero degree turn position causes the steering wheel to move to a centered position.

According to one embodiment, obtaining control of the steered wheels comprises: determining an initial steering wheel angle; and sending a command to the steering motor corresponding to the steered wheel moving to the initial steered wheel angle.

According to one embodiment, the controller relinquishes control of the steered wheel after causing the steered wheel to move to the zero degree turn position; and the controller also acquires control of the steered wheels through connection with the steering motor and is then able to receive the command to perform the automatic hitch maneuver.