Hitch assist system featuring trailer position recognition

Abstract

A hitch assist system is provided herein. The system includes an imager for capturing an image of a rear vehicle scene including a trailer; and a controller for processing the captured image. A device is positioned at a trailer location and has a display configured to flash a shape at a predetermined frequency and alternating in color. The controller identifies the shape in the captured image to determine the trailer location.

Description

Technical Field

[0001] The present invention relates generally to systems for hooking a vehicle to a trailer, and more particularly to a hitch assist system capable of identifying a trailer position through image processing. 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. Some hitch assist systems employ conventional image processing methods to determine the trailer position prior to backing up the vehicle toward the trailer. However, these conventional image processing methods tend to be complex in nature and require significant computing resources. Therefore, there is a need for a system that can identify the trailer position in a simple manner that is less computationally demanding. The present disclosure is intended to meet this need. Summary of the invention

[0003] According to a first aspect of the present invention, there is provided a hitch assist system. The system includes an imager for capturing an image of a rear vehicle scene including a trailer; and a controller for processing the captured image. The device is positioned at the trailer location and has a display configured to flash shapes at a predetermined frequency and alternating in color. The controller identifies the shapes in the captured image to determine the trailer location.

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

[0005] Trailer position including trailer tongue;

[0006] The shape comprises a circular shape;

[0007] The shape alternates between a first color and a second color;

[0008] The first color comprises green and the second color comprises red;

[0009] The controller applies a Hough circle transform to detect one or more circular shape candidates in the captured image;

[0010] The controller selects only one or more circular shape candidates having one of the first color and the second color;

[0011] The controller applies a temporal Fourier transform to determine the frequency of one or more circular shape candidates having one of the first color and the second color;

[0012] The controller identifies any one of the one or more circular shape candidates whose frequency best matches a predetermined frequency as the shape;

[0013] If the controller cannot recognize the shape, the controller generates at least one of an alarm and troubleshooting instructions; and

[0014] • a vehicle display for displaying the shape identified in the captured image; and a user input device enabling a user to confirm the identification of the shape.

[0015] According to a second aspect of the present invention, a hitch assist system is provided. The system includes an imager for capturing an image of a rear vehicle scene including a trailer; and a controller for processing the captured image. The device is positioned at a trailer location proximate to a hitch connector and has a display configured to flash a circular shape at a predetermined frequency and alternately between a first color and a second color. The controller identifies the circular shape in the captured image to determine the trailer location.

[0016] Embodiments of the second aspect may include any one or combination of the following features:

[0017] The trailer position includes a trailer tongue, and the first color and the second color include red and green, respectively;

[0018] The controller applies a Hough circle transform to detect one or more circular shape candidates in the captured image;

[0019] The controller selects only one or more circular shape candidates having one of the first color and the second color;

[0020] The controller applies a temporal Fourier transform to determine the frequency of one or more circular shape candidates having one of the first color and the second color;

[0021] The controller identifies any one of the one or more circular shape candidates whose frequency best matches a predetermined frequency as a circular shape;

[0022] If the controller cannot recognize the shape, the controller generates at least one of an alarm and troubleshooting instructions; and

[0023] • a vehicle display for displaying the shape identified in the captured image; and a user input device enabling a user to confirm the identification of the shape.

[0024] According to a third aspect of the invention, a method is provided and includes the following steps: capturing an image of a rear vehicle scene including a trailer; processing the captured image; positioning a device at a trailer location proximate to a hitch connector and having a display configured to flash a circular shape at a predetermined frequency and alternately between a first color and a second color; and identifying the circular shape in the captured image to determine the trailer location.

[0025] 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

[0026] In the attached picture:

[0027] 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;

[0028] Figure 2 is a block diagram showing certain components of a hitch assist system;

[0029] Figure 3 The device is shown at a trailer location and having a display configured to flash a pattern;

[0030] Figure 4 Shows Figure 3 a sequence of flashes displayed on the device shown; and

[0031] Figure 5 is a flow chart of a method for determining a position of a trailer. DETAILED DESCRIPTION

[0032] 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 do not need to be 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.

[0033] 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.

[0034] 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 distal end of a trailer tongue 28. The trailer 14 is exemplarily embodied as a single-axle trailer having a box-shaped frame 30 with an enclosed cargo area 32 from which the tongue 28 extends longitudinally.

[0035] 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 centrally located 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.

[0036] 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 sensors spaced apart on 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. Additionally, 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.

[0037] 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 steer 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 reverse operation, 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.

[0038] In some embodiments, the steering wheel 58 of the vehicle 12 can be mechanically connected to the steering wheel 53 of the vehicle 12 so that the steering wheel 58 moves in unison with the steering wheel 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.

[0039] 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 reverse operation 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.

[0040] 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.

[0041] According to one embodiment, the controller 38 may communicate with one or more devices including a vehicle alarm system 72, which may prompt visual, audible, and tactile warnings. For example, the vehicle brake lights 74 and the vehicle emergency flashers may provide a visual warning, and the vehicle horn 76 and / or speaker 78 may provide an audible warning. In addition, the controller 38 and / or the vehicle alarm system 72 may communicate with a human machine interface (HMI) 80 of the vehicle 12. The HMI 80 may include a touch screen display 84, such as a center console mounted navigation or entertainment display, capable of displaying an image indicative of the warning. Such an embodiment may wish to notify the driver of the vehicle 12 that an unacceptable back-up condition exists.

[0042] 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 conventional 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.

[0043] refer to Figure 3 , the system 10 includes a device 90 that is positioned at a trailer location 92 and has a display 94 that is configured to flash a shape 96 at a predetermined frequency and in alternating colors. In the illustrated embodiment, the device 90 is a portable electronic device, such as a smart phone, a tablet computer, or the like. The trailer location 92 includes the tongue 28 and a portion thereof proximate to the hitch connector (e.g., the connector ball seat 26). The device 90 can be fastened to the tongue 28, for example, via a device holder, resting on the tongue 28 using a device stand, or held by hand near the trailer location 92. The shape 96 is exemplarily shown as a circular shape centrally located on the display 94 of the device 90. The size of the shape 96 is generally predetermined, and the flashing of the shape can be performed by a software application stored on the device 90.

[0044] refer to Figure 4 , an exemplary flashing pattern is shown. As shown, the device 90 flashes a shape 96 at a predetermined frequency so that the shape 96 alternates between a first color and a second color. For example, the predetermined frequency may correspond to 10 Hz, and the first color and the second color may be green and red, respectively. In the illustrated embodiment, a time period corresponds to a shape 96 that alternates once between the first color and the second color. Although the shape 96 is typically displayed in the same position for each color, it is contemplated that the shape 96 may be moved so that the shape is displayed in a different position for each corresponding color if desired. Therefore, although the shape 96 is essentially two-dimensional, the use of color alternation together with flashing the shape 96 in a temporal manner imparts a four-dimensional pattern to the shape 96 and enables the shape to be easily identified using image processing means.

[0045] In operation, the controller 38 identifies the shape 96 in the image captured by the imager 40 to determine the trailer position 92. For example, the controller 38 can be programmed to detect the reference Figure 4The flash pattern may be stored in the memory 86 of the controller 38 and the detection means may be provided in one or more operating routines 88 of the controller 38 .

[0046] For illustration purposes, Figure 5 A method of determining the position of a trailer is shown in FIG. 1 and is exemplarily embodied as one or more operating routines 88 of the controller 38 . Figure 4 The flash mode of the detection method is illustratively described. In step A, the device 90 is placed at a trailer location 92. As described herein, the trailer location 92 may include the tongue 28 and a portion thereof proximate the hitch connector. In step B, an image of a rear vehicle scene is captured, the rear vehicle scene including the trailer 14 and the device 90 at the trailer location 92. To do this, the user may need to position the vehicle 12 so that the trailer 14 and the device 90 are within the field of view 42 of the imager 40. In step C, the device 90 is operated to perform a flash mode, that is, to flash a shape 96 at a predetermined frequency so that the shape 96 alternates between a first color and a second color as described herein. The captured image including the device 90 is provided to the controller 38 for image processing.

[0047] In step D, the controller 38 applies the Hough circle transform to detect one or more circular shape candidates in the captured image. For example, the Hough circle transform can be applied to each video frame, and the circular shape candidates include shape 96 and may also include other objects with circular shapes in the captured image. In step E, the controller 38 selects only one or more circular shape candidates having one of the first color and the second color. For example, the controller 38 can filter the video frames from step D to separate only one or more circular shape candidates having green or red colors. In step F, a plurality of video frames containing only one or more circular candidates having the first color or the second color are stored (e.g., to the memory 86). For example, the plurality of video frames can have a duration of 3-5 seconds to ensure that the video frames contain one or more time periods of the flash pattern.

[0048] At step G, the controller 38 applies a temporal Fourier transform to the stored video frames to determine the frequency of one or more circular shape candidates having one of the first color and the second color. At step H, the controller 38 identifies any of the one or more circular shape candidates whose frequency approximately matches a predetermined frequency (e.g., 10 Hz) as shape 96. If the controller 38 identifies shape 96 at step H, the user may be prompted to confirm the identification of shape 96 at step I. For example, the identified shape may be displayed on a touch screen display 84 of the vehicle 12, and the user may confirm its identity by touching a designated area of ​​the display 84 or via other user input means. Conversely, if the controller 38 fails to identify shape 96 at step H, the controller 38 may generate at least one of an alarm and troubleshooting instructions at step J. For example, the controller 38 may enlist the vehicle alarm system 72 to instruct the user to position the vehicle 12 closer to the trailer 14 and repeat steps CH so that shape 96 can be identified. After successfully identifying shape 96, the system 10 may then reverse the vehicle 12 toward the trailer location 92. As described herein, backing up of the vehicle 12 may be performed autonomously or semi-autonomously.

[0049] Thus, a hitch assist system is provided herein. The system advantageously determines the trailer location by identifying shapes in a captured image. The shapes appear in a flashing pattern on a display on a device located at the trailer location. This form of identification is easy to implement and is generally less demanding than other forms of trailer identification that employ the use of imagers.

[0050] 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.

[0051] According to the present invention, there is provided a hitch assist system having an imager for capturing an image of a rear vehicle scene including a trailer; a controller for processing the captured image; and a device positioned at the trailer location and having a display configured to flash shapes at a predetermined frequency and alternating in color, wherein the controller recognizes the shapes in the captured image to determine the trailer location.

[0052] According to an embodiment, the above invention is further characterized in that the trailer location includes a trailer tongue.

[0053] According to an embodiment, the above invention is further characterized in that the shape includes a circular shape.

[0054] According to an embodiment, the above invention is further characterized in that the shape alternates between the first color and the second color.

[0055] According to an embodiment, the above invention is further characterized in that the first color includes green and the second color includes red.

[0056] According to an embodiment, the above invention is further characterized in that the controller applies Hough circle transform to detect one or more circular shape candidates in the captured image.

[0057] According to an embodiment, the above invention is further characterized in that the controller selects only one or more circular shape candidates having one of the first color and the second color.

[0058] According to an embodiment, the above invention is further characterized in that the controller applies a temporal Fourier transform to determine a frequency of one or more circular shape candidates having one of the first color and the second color.

[0059] According to an embodiment, the above invention is further characterized in that the controller identifies any one of the one or more circular shape candidates whose frequency best matches a predetermined frequency as the shape.

[0060] According to an embodiment, if the controller cannot recognize the shape, the controller generates at least one of an alarm and troubleshooting instructions.

[0061] According to an embodiment, the above invention is further characterized by a vehicle display for displaying the shape identified in the captured image; and a user input device that enables a user to confirm the identification of the shape.

[0062] According to the present invention, a hitch assist system is provided, the hitch assist system having an imager for capturing an image of a rear vehicle scene including a trailer; a controller for processing the captured image; and an apparatus disposed at a trailer location proximate to a hitch connector and having a display configured to flash a circular shape at a predetermined frequency and alternately between a first color and a second color, wherein the controller recognizes the circular shape in the captured image to determine the trailer location.

[0063] According to an embodiment, the above invention is further characterized in that the trailer location includes a trailer tongue, and the first color and the second color include red and green, respectively.

[0064] According to an embodiment, the above invention is further characterized in that the controller applies Hough circle transform to detect one or more circular shape candidates in the captured image.

[0065] According to an embodiment, the above invention is further characterized in that the controller selects only one or more circular shape candidates having one of the first color and the second color.

[0066] According to an embodiment, the above invention is further characterized in that the controller applies a temporal Fourier transform to determine a frequency of one or more circular shape candidates having one of the first color and the second color.

[0067] According to an embodiment, the above invention is further characterized in that the controller identifies any one of the one or more circular shape candidates whose frequency best matches a predetermined frequency as a circular shape.

[0068] According to an embodiment, if the controller cannot recognize the shape, the controller generates at least one of an alarm and troubleshooting instructions.

[0069] According to an embodiment, the above invention is further characterized by a device display for displaying the shape identified in the captured image; and a user input device that enables a user to confirm the identification of the shape.

[0070] According to the present invention, a method is provided, the method having the following steps: capturing an image of a rear vehicle scene including a trailer; processing the captured image; positioning a device at a trailer location proximate to a hitch connector and having a display configured to flash a circular shape at a predetermined frequency and alternating between a first color and a second color; and identifying the circular shape in the captured image to determine the trailer location.

Claims

1. A hitch assist system, the hitch assist system comprising: an imager for capturing an image of a rear vehicle scene including the trailer; a controller configured to process the captured image; A device is positioned at a trailer location and has a display configured to flash shapes at a predetermined frequency and alternating in color, wherein the controller identifies the shapes flashed on the display in the captured image to determine the trailer location.

2. The hitch assist system of claim 1, wherein the trailer location includes a trailer tongue.

3. The hitch assist system of claim 1, wherein the shape comprises a circular shape.

4. The hitch assist system of claim 3, wherein the shape alternates between a first color and a second color.

5. The hitch assist system of claim 4, wherein the first color comprises green and the second color comprises red.

6. The hitch assist system of claim 4, wherein the controller applies a Hough circle transform to detect one or more circular shape candidates in the captured image. 7 . The hitch assist system of claim 6 , wherein the controller selects only the one or more circular shape candidates having one of the first color and the second color.

8. The hitch assist system of claim 7, wherein the controller applies a temporal Fourier transform to determine the frequency of the one or more circular shape candidates having one of the first color and the second color.

9. The hitch assist system of claim 8, wherein the controller identifies as the shape any one of the one or more circular shape candidates whose frequency best matches the predetermined frequency.

10. The hitch assist system of any one of claims 1-9, wherein if the controller cannot recognize the shape, the controller generates at least one of an alarm and troubleshooting instructions.

11. The hitch assist system of any one of claims 1-9, further comprising a vehicle display for displaying the shape identified in the captured image; and a user input device for enabling a user to confirm the identification of the shape.

Images