Hitch assist system with hitch connector recognition feature and hitch connector height estimation

Abstract

A hitch assist system and method are provided herein. An imager captures one or more images of a trailer having a hitch connector. A user input device is provided for specifying a location of the hitch connector in the one or more captured images. A controller generates an image patch around the user-specified location, segments the image patch to identify the hitch connector, and estimates a trailer height based on a height of the imager and projective geometry.

Description

Technical Field

[0001] The present invention relates generally to vehicle backup assist systems and, more particularly, to a vehicle backup assist system that facilitates hooking a vehicle to a trailer. Background Art

[0002] Backing up a vehicle toward a trailer in order to attach a trailer hitch to a hitch connector can be challenging for many drivers, especially for drivers who are generally unfamiliar with trailers and the hitching process. Therefore, there is a need for a system that assists the driver in navigating the vehicle toward the trailer so that a hitch connection can be made therebetween. The present disclosure is intended to meet this need. Summary of the invention

[0003] According to a first aspect of the present invention, a hitch assist system is provided. An imager captures one or more images of a trailer having a hitch connector. A user input device is provided for specifying a location of the hitch connector in the one or more captured images. A controller generates an image patch around the user-specified location, segments the image patch to identify the hitch connector, and estimates a trailer height based on the imager height and projective geometry.

[0004] Embodiments of the first aspect may include any one or combination of the following features:

[0005] The user input device includes a touch screen display of the vehicle;

[0006] The touch screen display registers thereon one or more touch events for specifying the position of the hitch connector;

[0007] An imager is located at the rear of the vehicle and is configured to capture one or more images of a rear vehicle scene;

[0008] Segment the image blocks to locate the boundaries of the hook connector;

[0009] Trailer height includes the height of the hitch connector relative to the ground;

[0010] The hitch connector includes a connector ball seat;

[0011] The projective geometry includes angles between a first plurality of field of view components of the imager and the ground and angles between a second plurality of field of view components of the imager and the longitudinal axis of the trailer;

[0012] The controller further determines a horizontal distance between the imager and the hitch connector based on an estimated trailer height, a height of the imager, a focal length of the imager, a pitch angle of the imager, and a distance between the imager and the vehicle's trailer hitch; and

[0013] The controller estimates the trailer height by solving two equations for a system simultaneously.

[0014] According to a second aspect of the present invention, a hitch assistance method is provided, and the hitch assistance method includes the following steps: capturing one or more images of a trailer having a hitch connector; specifying a location of the hitch connector in the one or more captured images; generating an image block around the user-specified location; segmenting the image block to identify the hitch connector; and estimating the trailer height based on the imager height and projective geometry.

[0015] Embodiments of the second aspect may include any one or combination of the following features:

[0016] ·Specified steps are performed using the vehicle’s touchscreen display;

[0017] The touch screen display registers thereon one or more touch events for specifying the position of the hitch connector;

[0018] One or more images include a rear vehicle scene;

[0019] The step of segmenting the image block includes locating the boundary of the hook connector;

[0020] Trailer height includes the height of the hitch connector relative to the ground;

[0021] The hitch connector includes a connector ball seat;

[0022] The projective geometry includes angles between a first plurality of field of view components of the imager and the ground and angles between a second plurality of field of view components of the imager and the longitudinal axis of the trailer;

[0023] The step of determining a horizontal distance between the imager and the hitch connector based on an estimated trailer height, a height of the imager, a focal length of the imager, a pitch angle of the imager, and a distance between the imager and the vehicle's trailer hitch; and

[0024] The procedure for estimating the trailer height involves solving a system of two equations simultaneously.

[0025] According to a third aspect of the present invention, a hitch assist system is provided. An imager captures one or more images of a trailer having a hitch connector. A user input device is provided for specifying a location of the hitch connector in the one or more captured images. A controller generates an image block around the user-specified location, segments the image block to identify the hitch connector, and estimates a height difference between the imager and the hitch connector based on the projective geometry of the imager.

[0026] These and other aspects, objects and features of the present invention will be understood and appreciated by those skilled in the art after studying the following specification, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In the attached picture:

[0028] Figure 1 is a top perspective view of a vehicle and a trailer, the vehicle being equipped with a hitch assist system according to one embodiment;

[0029] Figure 2 is a block diagram showing certain components of a hitch assist system;

[0030] Figure 3 is a flow chart of a method for identifying a hitch connector according to one embodiment;

[0031] Figure 4 Representing an image captured for display on a display of a vehicle and including a hitch connector embodied as a connector ball socket;

[0032] Figure 5 showing a cover generated on the display and embodied as a box centered on the display and corresponding to the minimum width of the trailer;

[0033] Figure 6 The width of the trailer filled with mulch is shown;

[0034] Figure 7 showing a top view generated on a display and including a connector ball socket;

[0035] Figure 8 An image block having increased resolution and containing a connector ball socket is shown;

[0036] Fig. 9 showing a touch event performed on a display to designate a location of a connector socket, and an icon being generated at the designated location;

[0037] Fig.10 An icon is shown mating to a connector socket;

[0038] Fig.11 is a flow chart of a method for identifying a hitch connector according to another embodiment;

[0039] Fig.12 showing an icon generated at a predetermined or arbitrary position on a display before a touch event is performed;

[0040] Fig.13 Shows that the Figure 3 and Fig.11 The subsequent steps to be performed during the process outlined in the methodology;

[0041] Fig.14 A pinhole camera model associated with an imager of a hitch assist system is shown; and

[0042] Fig.15 The variables used to estimate trailer height and its relationship to the geometry of the vehicle and trailer are shown. DETAILED DESCRIPTION

[0043] Upon request, detailed embodiments of the present invention are disclosed herein. However, it should be understood that the disclosed embodiments are merely exemplary of the present invention, and the present invention may be embodied in different and alternative forms. The accompanying drawings are not necessarily detailed designs and some illustrations may be enlarged or minimized to show a functional overview. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but only as a representative basis for teaching those skilled in the art to adopt the present invention in various ways.

[0044] As used herein, the term "and / or" when used to list two or more items means that any one of the listed items can be employed per se, or any combination of two or more of the listed items can be employed. For example, if a composition is described as comprising components A, B, and / or C, the composition can comprise A alone; B alone; C alone; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C.

[0045] refer to Figure 1 and Figure 2 , reference numeral 10 generally designates a hitch assist system for hooking a vehicle 12 to a trailer 14. Figure 1 As shown, the vehicle 12 is exemplarily embodied as a pickup truck having a bed 16 accessible via a fold-down tailgate 18. The vehicle 12 also includes a tow hitch in the form of a hitch ball 22 extending from a drawbar 24 connected to the rear of the vehicle 12. The hitch ball 22 is configured to be received by a hitch connector in the form of a connector ball socket 26 provided at a terminal end of a trailer tongue 28. The trailer 14 is exemplarily embodied as a single-axle trailer having a box frame 30 with an enclosed cargo area 32, from which the tongue 28 extends longitudinally.

[0046] The system 10 includes a controller 38 that communicates with an imager 40 located at the rear of the vehicle 12. The imager 40 may be located centrally at an upper region of the tailgate 18 such that the imager 40 is elevated relative to the tow bar 24 and the hitch ball 22. The imager 40 has a field of view 42 that is positioned and oriented to capture one or more images of a rear vehicle scene that generally includes, among other things, the hitch ball 22. The images captured by the imager 40 may be processed by the controller 38 to identify a hitch connector, such as the connector ball mount 26.

[0047] In addition to communicating with the imager 40, the controller 38 may also communicate with a plurality of proximity sensors 44, which are illustratively shown as ultrasonic or radar sensors spaced above a lower region of the vehicle tailgate 18 and configured to detect the proximity or distance of objects located behind the vehicle 12. Figure 2 In the illustrated embodiment of the system 10, additional vehicle-related information may be provided to the controller 38 by a positioning device 46, such as a global positioning system (GPS) located on the vehicle 12 and / or trailer 14. In addition, the controller 38 may communicate with an inertial system 47 including one or more gyroscopes 48 and accelerometers 49 to measure the position, orientation, direction, and / or velocity of the vehicle 12.

[0048] To achieve autonomous or semi-autonomous control of the vehicle 12, the controller 38 of the system 10 may be further configured to communicate with various vehicle devices. According to one embodiment, the controller 38 of the system 10 may control the power steering system 52 of the vehicle 12 to operate the steered wheels 53 of the vehicle 12 while reversing the vehicle 12 along the vehicle reverse path toward the trailer 14. The power steering system 52 may be an electric power steering (EPAS) system that includes an electric steering motor 54 for turning the steered wheels 53 to a steering angle based on a steering command generated by the controller 38, whereby the steering angle may be sensed by a steering angle sensor 56 of the power steering system 52 and provided to the controller 38. As described herein, the steering command may be provided for autonomously steering the vehicle 12 during a reverse maneuver, and may optionally be provided manually via the rotational position of the steering wheel 58 (e.g., steering wheel angle) or a steering input device 60, which may be provided to enable the driver to control or otherwise modify the desired curvature of the reverse path of the vehicle 12. The steering input device 60 may be communicatively connected to the controller 38 by wire or wirelessly, and provides information to the controller 38 that defines the desired curvature of the reverse path of the vehicle 12. In response, the controller 38 processes the information and generates corresponding steering commands that are supplied to the power steering system 52 of the vehicle 12. In one embodiment, the steering input device 60 includes a rotatable knob 62 that is operable between a plurality of rotational positions, each rotational position providing an incremental change to the desired curvature of the reverse path of the vehicle 12.

[0049] In some embodiments, the steering wheel 58 of the vehicle 12 can be mechanically connected to the steered wheels 53 of the vehicle 12 so that the steering wheel 58 moves in unison with the steered wheels 53 via an internal torque, thereby preventing manual intervention of the steering wheel 58 during autonomous steering of the vehicle 12. In such cases, the power steering system 52 can include a torque sensor 64 that senses torque (e.g., grip and / or rotation) on the steering wheel 58 that is not desirable for autonomous control of the steering wheel 58 and therefore indicates manual intervention by the driver. In some embodiments, the external torque applied to the steering wheel 58 can be used as a signal to the controller 38 that the driver has taken manual control and wants the system 10 to stop the autonomous steering function.

[0050] The controller 38 of the system 10 may also communicate with the vehicle brake control system 66 of the vehicle 12 to receive vehicle speed information, such as individual wheel speeds of the vehicle 12. Additionally or alternatively, the vehicle speed information may be provided to the controller 38 by the powertrain control system 68 and / or the vehicle speed sensor 70, among other conceivable means. In some embodiments, the controller 38 may provide a braking command to the vehicle brake control system 66, thereby allowing the system 10 to adjust the speed of the vehicle 12 during a reverse maneuver of the vehicle 12. It should be appreciated that the controller 38 may additionally or alternatively adjust the speed of the vehicle 12 via interaction with the powertrain control system 68.

[0051] By interacting with the power steering system 52, the vehicle brake control system 66, and / or the powertrain control system 68 of the vehicle 12, the likelihood of an unacceptable back-up condition occurring when the vehicle 12 is backing up toward the trailer 14 can be reduced. Examples of unacceptable back-up conditions include, but are not limited to, vehicle overspeed conditions, sensor failures, and the like. In such cases, the driver may not be aware of the failure until the unacceptable back-up condition is about to occur or has occurred. Therefore, it is disclosed herein that the controller 38 of the system 10 can generate an alarm signal corresponding to a notification of an actual, imminent, and / or expected unacceptable back-up condition, and generate countermeasures to prevent such an unacceptable back-up condition before the driver intervenes.

[0052] According to one embodiment, the controller 38 can communicate with one or more devices including a vehicle alarm system 72, which can prompt visual, audible, and tactile warnings. For example, the vehicle brake lights 74 and the vehicle emergency flashers can provide a visual alert, and the vehicle horn 76 and / or the speaker 78 can provide an audible alert. In addition, the controller 38 and / or the vehicle alarm system 72 can communicate with a human-machine interface (HMI) 80 of the vehicle 12. The HMI 80 can include a touch screen display 84 capable of displaying an image indicating the alert, such as a navigation or entertainment display mounted on a center console. Such an embodiment may wish to notify the driver of the vehicle 12 that an unacceptable back-up condition exists. In an alternative embodiment, the HMI 80 may include a portable device (e.g., a smartphone) capable of communicating with the controller 38 via a wireless interface.

[0053] The controller 38 is configured with a microprocessor 85 and / or other analog and / or digital circuitry for processing one or more logic routines stored in a memory 86. The logic routines may include one or more operating routines 88. Information from the imager 40 or other components of the system 10 may be supplied to the controller 38 via the communication network of the vehicle 12, which may include a controller area network (CAN), a local interconnect network (LIN), or other protocols used in the automotive industry. It should be appreciated that the controller 38 may be a stand-alone dedicated controller, or may be a shared controller integrated with the imager 40 or other components of the system 10 in addition to any other conceivable on-board or off-board vehicle control systems.

[0054] refer to Figure 3 , a method of identifying a hitch connector such as a hitch ball seat 26 is shown, and the method is exemplarily embodied as one of the operating routines 88 of the controller 38. In step S1, the controller 38 instructs the driver of the vehicle 12 to position the vehicle 12 so that the front of the trailer 14 is within the field of view of the imager 40. The image captured by the imager 40 can be displayed on the display 84 to assist the driver in positioning the vehicle 12 relative to the trailer 14. For example, Figure 4 An image 90 is shown captured by the imager 40. The image 90 is displayed on the display 84 and includes the front of the trailer 14, including the hitch connector, which is shown as the connector ball seat 26.

[0055] In step S2, the controller 38 may further instruct the user (typically the driver) to position the vehicle 12 so that the size of the trailer 14 fills the predetermined size of the display 84. Figure 5 As shown, the predetermined size is represented by an overlay 92 generated by the controller 38 on the display 84. The overlay 92 may be embodied as a box centered on the display 84 and corresponding to the minimum width of the trailer 14. The size of the overlay 92 may be determined to facilitate identification of the connector ball socket 26. Figure 5 As shown, the width of the trailer 14, shown as width W, is too small, or in other words, cannot fill the cover 92. In this situation, the controller 38 instructs the driver to further position the vehicle 12 so that the width W of the trailer 14 is as shown. Figure 6 The fill cover 92 is shown. For clarity, Figure 4 and Figure 5 The environment around the trailer 14 has been omitted.

[0056] Once the width W of the trailer 14 is filled with the cover 92, the controller 38 generates a display on the display 84 at step S3 as shown in FIG. Figure 7The top view 94 is shown. The top view 94 generally includes the trailer 14 or a portion thereof, namely the connector ball socket 26. In step S4, the controller 38 processes the captured image to detect the location of the connector ball socket 26 and / or other trailer structures such as, but not limited to, the tongue 28. To detect the connector ball socket 26 or other trailer structure, the controller 38 may employ any conventional technique, such as pattern recognition or pattern matching. Once the connector ball socket 26 or other trailer structure is identified, the controller 38 instructs the driver to stop the vehicle 12 in step S5, and increases the resolution of the image block containing the detected connector ball socket 26 or other trailer structure in step S6. For example, Figure 8 An image block 96 is shown having increased resolution and including connector socket 26. Image block 96 may be obtained from multiple image frames and displayed on display 84.

[0057] Next, at step S7, the user is instructed to perform one or more touch events on the image block 96 to specify the position of the connector ball seat 26. Fig. 9 As shown in the exemplary embodiment, the one or more touch events include physically touching the display 84 with a finger 97. In the example shown, the finger 97 touches the display 84 at a point P that is slightly offset from the center C of the connector ball socket 26. The display 84 is configured to register the one or more touch events, and the controller 38 is configured to generate an icon 98 at a specified location of the connector ball socket 26 at step S8.

[0058] like Fig.10 As shown, the controller 38 can mate the icon 98 to the detected connector ball socket 26 so that the icon 98 and the detected connector ball socket 26 coincide with each other and have matching shapes. Fig. 9 and Fig.10 In the illustrated embodiment of FIG. 1 , the icon 98 is represented as a circle, and the controller 38 mates the icon 98 to the connector ball seat 26 by aligning the circle concentrically to the connector ball seat 26 and adjusting the radius of the circle to match the radius of the connector ball seat 26. For clarity, a single radius 100 is shown in FIG. Fig.10 , and is common to both the icon 98 and the detected connector ball seat 26. It is contemplated that the icon 98 may be displayed in a variety of colors, such as, but not limited to, green.

[0059] refer to Fig.11, another method of identifying a hitch connector, such as a connector ball seat 26, is shown and is exemplarily embodied as one of the operating routines 88 of the controller 38. At step S1, the controller 38 instructs the driver of the vehicle 12 to position the vehicle 12 so that the front of the trailer 14 is within the field of view of the imager 40. At step S2, the controller 38 generates an overlay on the display 84, and at step S3, instructs the user to position the vehicle 12 so that the trailer 14 or a portion thereof fills the overlay. The overlay may correspond to the overlay 92 previously disclosed herein. Alternatively, the overlay may correspond to another minimum dimension of the trailer 14, such as, but not limited to, the tongue 28 of the trailer or other portion thereof.

[0060] In step S4, the controller 38 generates a display on the display 84 as shown in FIG. Fig.12 The top view 102 is shown. In the top view, the controller 38 generates an icon 104 on the display 84 in step S5. For example, the icon 104 is represented as a circle having a first color such as red. The icon 104 can be generated at a predetermined or arbitrary position on the display 84. For illustration purposes, the icon 104 is Fig.12 14. When the vehicle 12 stops or moves toward the trailer 14, the controller 38 instructs the user to move the icon 104 to the location of the designated connector ball seat 26 in step S6. The user can move the icon 104 by performing one or more touch events on the display 84. For example, the user can simply touch the display 84 at the designated location, and in response, the controller 38 moves the icon 104 to the designated location. Alternatively, the user can move the icon 104 by dragging the icon 104 to the designated location with his or her finger. Subsequently, once the icon is moved to the designated location of the connector ball seat 26, the icon 104 is displayed in a second color different from the first color. For example, the icon 104 can be represented as a green circle.

[0061] At step S7, controller 38 mates icon 104 to connector ball socket 26 as previously described herein by concentrically aligning the circle to connector ball socket 26 and adjusting the radius of the circle to match the radius of connector ball socket 26. In some embodiments, one or more touch events and / or subsequent mates of the circle may be performed on an image block having an increased resolution and containing connector ball socket 26.

[0062] Continuing with any of the methods provided above for identifying a hitch connector and referring to Fig.13 It is further contemplated that the controller 38 may track an image patch (eg, image patch 96; FIG. 9B ) surrounding the user-specified location of the connector ball seat 26 or other hitch connector at step S1′. Figure 8). In step S2', the controller 38 segments the connector ball socket 26 in the image block. By performing image segmentation on the image block, it is possible to identify the boundary of the connector ball socket 26 relative to the ground. As such and as described in more detail below, the controller 38 can estimate the trailer height corresponding to the height of the connector ball socket 26 relative to the ground and the horizontal distance between the imager 40 and the connector ball socket 26 in step S3'. At the end of steps S1' to S3', the vehicle 12 can be reversed toward the detected hitch connector of the trailer 14. As contemplated herein, the reverse of the vehicle 12 toward the detected hitch connector can be performed autonomously or semi-autonomously.

[0063] refer to Fig.14 , shows a pinhole camera model 106, which generally represents the imager 40 relative to the trailer 14. As shown, α represents the pitch angle of the imager 40, f represents the focal length of the imager 40, H represents the height of the imager 40 relative to the ground, and H hitch denotes the trailer height shown corresponding to the height of the hitch connector (eg, connector ball 26 ), and h is the distance between the imager 40 (eg, the center of the image) and the trailer hitch of the vehicle 12 .

[0064] According to the camera model 106, the horizontal distance D between the imager 40 and the connector ball socket 26 is provided by the following equation:

[0065]

[0066] In Equation 1, H is assumed to be known and β corresponds to the angle between the optical axis 108 of the imager 40 and the longitudinal axis 110 of the trailer 14. As shown, the optical axis 108 of the imager intersects the focal point 112 of the imager and the angle β is given by

[0067] The following equation provides:

[0068]

[0069] In Equation 2, α, h, and f are assumed to be known. Before the horizontal distance D can be solved using Equation 1, the trailer height H hitch Determined by solving two equations for a system simultaneously:

[0070]

[0071]

[0072] In equations 3 and 4, is an unknown scalar, T is a scaled translation estimated, for example, from visual odometry or wheel counts, and the angles γ1, γ2, θ1, and θ2 are obtained based on Fig.14 The projection geometry of the imager 40 for the pinhole camera model 106 is shown. Therefore, and H hitch can be determined by solving equations 3 and 4. Once H is known hitch , Equation 1 can be solved to determine the horizontal distance D. For illustration purposes, Fig.15 The variables associated with equations 3 and 4 are depicted in FIG. As shown, angles γ1 and γ2 correspond to the angles between the field of view components 114 and 116 and the longitudinal axis 110 of the trailer 14, while angles θ1 and θ2 correspond to the angles between the field of view components 118 and 120 and the ground. It will be understood that the field of view components 114 to 120 originate from the imager 40 and are selected based on the projection geometry of the imager 40. Assuming the trailer height H hitch Above the height of the trailer hitch (eg, hitch ball 22 ), the vehicle 12 may be successfully backed toward the trailer 14 such that the hitch ball 22 is vertically aligned with the coupler ball seat 26 of the trailer 14 .

[0073] It should be understood that changes and modifications may be made to the foregoing constructions without departing from the concepts of the present invention, and it should be further understood that such concepts are intended to be covered by the following claims unless the claims expressly state otherwise by their language.

[0074] According to the present invention, a hitch assist system is provided, the hitch assist system having an imager for capturing one or more images of a trailer having a hitch connector; a user input device for specifying a location of the hitch connector in the one or more captured images; and a controller for: generating an image block around the user-specified location; segmenting the image block to identify the hitch connector; and estimating a trailer height based on the imager height and projective geometry.

[0075] According to an embodiment, the above claims are further characterized by the user input device comprising a touch screen display of the vehicle.

[0076] According to an embodiment, the above claims are further characterized in that the touch screen display registers thereon one or more touch events for specifying the position of the hitch connector.

[0077] According to an embodiment, the above claims are further characterized by the imager being located at the rear of the vehicle and being arranged to capture one or more images of the rear vehicle scene.

[0078] According to an embodiment, the above claims are further characterized in that segmenting the image blocks locates the boundaries of the hitch connector.

[0079] According to an embodiment, the above claims are further characterized in that the trailer height comprises the height of the hitch connector relative to the ground.

[0080] According to an embodiment, the above claims are further characterized in that the hitch connector comprises a connector ball seat.

[0081] According to an embodiment, the above claims are further characterized in that the projective geometry includes angles between the first plurality of field of view components of the imager and the ground and angles between the second plurality of field of view components of the imager and the longitudinal axis of the trailer.

[0082] According to an embodiment, the above claims are further characterized in that the controller determines the horizontal distance between the imager and the hitch connector further based on the following: the estimated trailer height, the height of the imager, the focal length of the imager, the pitch angle of the imager, and the distance between the imager and the vehicle's trailer hitch.

[0083] According to an embodiment, the above claims are further characterized in that the controller estimates the trailer height by solving two equations of a system simultaneously.

[0084] According to the present invention, a hitch assistance method is provided, the hitch assistance method having the following steps: capturing one or more images of a trailer having a hitch connector; specifying a location of the hitch connector in the one or more captured images; generating an image patch around the user-specified location; segmenting the image patch to identify the hitch connector; and estimating a trailer height based on an imager height and projective geometry.

[0085] According to an embodiment, the above claims are further characterized in that the specified steps are performed using a touch screen display of the vehicle.

[0086] According to an embodiment, the above claims are further characterized in that the touch screen display registers thereon one or more touch events for specifying the position of the hitch connector.

[0087] According to an embodiment, the above claims are further characterized in that one or more images include a rear vehicle scene.

[0088] According to an embodiment, the above claim is further characterized in that the step of segmenting the image block comprises locating the boundaries of the hitch connector.

[0089] According to an embodiment, the above claims are further characterized in that the trailer height includes a height of the hitch connector relative to the ground, and wherein the hitch connector includes a connector ball seat.

[0090] According to an embodiment, the above claims are further characterized in that the projective geometry includes angles between the first plurality of field of view components of the imager and the ground and angles between the second plurality of field of view components of the imager and the longitudinal axis of the trailer.

[0091] According to an embodiment, the invention is further characterized by the following step: determining the horizontal distance between the imager and the hitch connector based on the estimated trailer height, the height of the imager, the focal length of the imager, the pitch angle of the imager, and the distance between the imager and the vehicle's trailer hitch.

[0092] According to an embodiment, the above claims are further characterized in that the step of estimating the trailer height comprises solving two equations of a system simultaneously.

[0093] According to the present invention, a hitch assist system is provided, the hitch assist system having: an imager for capturing one or more images of a trailer having a hitch connector; a user input device for specifying a location of the hitch connector in the one or more captured images; and a controller for: generating an image block around the user-specified location; segmenting the image block to identify the hitch connector; and estimating a height difference between the imager and the hitch connector based on the projective geometry of the imager.

Claims

1. A hitch assist system, the hitch assist system comprising: an imager for capturing one or more images of a trailer having a hitch connector; a user input device for specifying a location of the hitch connector in the one or more captured images; as well as A controller, the controller being used to: Generates image patches around user-specified locations; segmenting the image block to identify the hitch connector; and estimating a trailer height based on the imager height and projective geometry, The projective geometry includes angles between a first plurality of field of view components of the imager and the ground and angles between a second plurality of field of view components of the imager and a longitudinal axis of the trailer.

2. The hitch assist system of claim 1, wherein the user input device comprises a touch screen display of the vehicle.

3. The hitch assist system of claim 2, wherein the touch screen display records thereon one or more touch events for specifying the position of the hitch connector.

4. The hitch assist system of any one of claims 1-3, wherein the imager is located at the rear of the vehicle and is configured to capture one or more images of the rear vehicle scene.

5. The hitch assist system of any one of claims 1-3, wherein segmenting the image block locates a boundary of the hitch connector.

6. The hitch assist system of any one of claims 1-3, wherein the trailer height comprises a height of the hitch connector relative to the ground.

7. The hitch assist system of any one of claims 1-3, wherein the hitch connector comprises a connector ball socket.

8. The hitch assist system of any one of claims 1-3, wherein the controller further determines a horizontal distance between the imager and the hitch connector based on: the estimated trailer height, the height of the imager, a focal length of the imager, a pitch angle of the imager, and a distance between the imager and a trailer hitch of a vehicle.

9. The hitch assist system of any one of claims 1-3, wherein the controller estimates the trailer height by simultaneously solving two equations of a system.

10. A hitch assist method, the hitch assist method comprising the following steps: capturing, via an imager, one or more images of a trailer having a hitch connector; specifying a location of the hitch connector in the one or more captured images; Generates image patches around user-specified locations; segmenting the image block to identify the hitch connector; as well as estimating a trailer height based on the imager height and projective geometry, The projective geometry includes angles between a first plurality of field of view components of the imager and the ground and angles between a second plurality of field of view components of the imager and a longitudinal axis of the trailer.

Images