Trailer backing with automated free space guidance

Abstract

A trailer traction assist system includes a camera that captures a rear-facing image of a trailer and its surroundings, a human-machine interface that displays the rear-facing image, an input device that receives user input, and an electronic processor. The electronic processor receives the backward image, identifies a target space within the ambient environment, determines a vehicle orientation relative to the target space, determines a trailer angle relative to the vehicle, determines a trailer trajectory within the ambient environment, and displays the trailer trajectory and the backward image on the human-machine interface. The electronic processor also controls the vehicle to follow the trailer trajectory along a centerline of the trailer trajectory in response to user input.

Description

Background Art

[0001] Additionally, embodiments, examples, and aspects are directed to a system and method for assisting rearward maneuvering of a trailer attached to a vehicle. Summary of the invention

[0002] Some existing vehicles (e.g., pickup trucks) include trailer towing assist systems. The inventors have learned that in some instances, it is difficult for an operator of the vehicle to discern whether a towed trailer is properly positioned when backing up the trailer. In some instances, the visual features provided by the towing assist system are not as helpful as desired. In other instances, it may be difficult for an operator of the vehicle to determine that the starting position of the trailer when backing up is a position from which the trailer can be maneuvered to a desired target position. Some trailer towing systems provide a visual track of the trailer that includes only a view of the current position of the trailer. However, providing only a view of the current trailer position is not always sufficient to ensure that the trailer will eventually reach the desired position.

[0003] Additionally, examples described herein provide a system and method for assisting rearward maneuvering of a trailer attached to a vehicle.

[0004] One example provides a trailer towing assist system for assisting rearward maneuvering of a trailer attached to a vehicle. The trailer towing assist system includes a camera that captures a rearward image of the trailer and its surroundings, a human-machine interface that displays the rearward image, an input device that receives user input, and an electronic processor. The electronic processor receives the rearward image, identifies a target space within the surroundings based on the rearward image, determines a vehicle orientation relative to the target space based on the rearward image, determines a trailer angle relative to the vehicle based on the rearward image, determines a trailer track within the surroundings based on the trailer angle, displays the trailer track and the rearward image on the human-machine interface, and in response to the user input, controls the vehicle to follow the trailer track along a centerline of the trailer track.

[0005] In some examples, the electronic processor determines objects to avoid within the target space.

[0006] In some examples, the electronic processor determines the boundaries based on the target space.

[0007] In some examples, the trailer tow assist system also includes a steering angle sensor and a steering control system, the steering angle sensor sensing a first angle of a steering wheel of the vehicle, the electronic processor determining a second angle based on the trailer trajectory and the first angle, and controlling the steering control system based on the second angle to follow the trailer trajectory.

[0008] In some examples, the electronic processor controls the steering control system in a first mode.

[0009] In some examples, during the first mode, the electronic processor controls the steering control system to maintain a first angle throughout the trailer trajectory.

[0010] In some examples, the electronic processor controls the steering control system in the second mode.

[0011] In some examples, during the second mode, the electronic processor controls the steering control system to maintain the second angle throughout the trailer trajectory.

[0012] In some examples, the trailer tow assist system also includes a brake control system and a master cylinder pressure sensor, the master cylinder pressure sensor sensing a first pressure difference of the brake control system. The electronic processor determines a second pressure difference based on the trailer trajectory and the first pressure difference, and controls the brake control system to apply the second pressure difference.

[0013] In some examples, the trailer tow assist system also includes an acceleration control system and a vehicle speed sensor, the vehicle speed sensor sensing a first speed of the vehicle. The electronic processor determines a second speed based on the trailer trajectory and the first speed, and controls the vehicle acceleration system based on the second speed.

[0014] Another example provides a method for assisting rearward maneuvering of a trailer attached to a vehicle using a trailer towing assist system including an electronic processor. The method implemented by an electronic controller includes receiving a rearward image of the trailer and its surroundings via a camera, identifying a target space within the surroundings based on the rearward image, determining a vehicle orientation relative to the target space based on the rearward image, determining an angle of the trailer relative to the vehicle based on the rearward image, determining a trailer track within the surroundings based on the trailer angle, and displaying the trailer track and the rearward image on a human-machine interface. The method also includes controlling the vehicle to follow the trailer track along a centerline of the trailer track in response to user input.

[0015] Other features, aspects, and benefits of the various examples will become apparent by consideration of the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a block diagram of a trailer tow assist system for assisting rearward maneuvering of a trailer attached to a vehicle according to one example.

[0017] Figure 2 Based on an example Figure 1 Block diagram of the electronic controller of the trailer tow assist system.

[0018] Figure 3 Based on an example Figure 1 Block diagram of the environmental detection system of the trailer towing assist system.

[0019] Figure 4Based on an example Figure 1 Block diagram of the human-machine interface of the trailer towing assist system.

[0020] Figure 5 is a block diagram of a trailer tow assist system for assisting rearward maneuvering of a trailer, illustrating components located in a vehicle, according to one example.

[0021] Figure 6 A vehicle and trailer are illustrated, wherein the vehicle backs the trailer into a free space area.

[0022] Figure 7 A flow chart of a method for assisting rearward maneuvering of a trailer attached to a vehicle is illustrated according to one example.

[0023] Figure 8 An image captured by a camera is illustrated, the image including the trailer, its surroundings, free space, and the image has been enhanced to depict the trailer trajectory.

[0024] Fig. 9 An image captured by a camera is illustrated, the image including the trailer, free space, the trailer track, and the image has been enhanced to depict maintaining the trailer track relative to the boundary.

[0025] Fig. 10A and Fig. 10B Picture shows Figure 1 Model of a trailer tow assist system for assisting rearward maneuvering of a trailer towards free space while maintaining the relative angle between the vehicle and the trailer.

[0026] Fig.11 A model of a vehicle and trailer and geometric relationships used to determine the angle of the trailer relative to the vehicle are illustrated according to one example. DETAILED DESCRIPTION

[0027] One or more examples are described and illustrated in the following description and accompanying drawings. These examples are not limited to the specific details provided herein and may be modified in various ways. Other examples not described herein may exist. For example, a device or structure that is "configured" in a particular manner is configured at least in that manner, but may also be configured in unlisted ways.

[0028] It should also be noted that in various embodiments, multiple hardware- and software-based devices and multiple different structural components can be utilized. Various aspects, features, and examples may include hardware, software, and electronic components or modules, which, for the purpose of discussion, may be illustrated and described as if most components are implemented only in hardware. However, those skilled in the art (and based on reading the detailed description) will recognize that, in at least one instance, various aspects may be implemented in software (e.g., stored on a non-transitory computer-readable medium), which may be executed by one or more processors. Therefore, various aspects and examples may be implemented using multiple hardware- and software-based devices and multiple different structural components. For example, the "control unit" and "controller" described in this specification may include one or more electronic processors, one or more memory modules including a non-transitory computer-readable medium, one or more input / output interfaces, and various connections (e.g., a system bus) connecting various components. It should be understood that, although some of the drawings illustrate hardware and software located within a particular device, these depictions are for illustrative purposes only. Unless the context clearly indicates otherwise, the illustrated components may be combined or divided into separate software, firmware, and / or hardware. For example, instead of being located within and executed by a single electronic processor, the logic and processing may be distributed among multiple electronic processors. Regardless of how they are combined or divided, the hardware and software components may be located on the same computing device or may be distributed among different computing devices connected by one or more networks or other suitable communication links.

[0029] The examples described herein may be implemented as a non-transitory computer-readable medium that stores instructions that can be executed by one or more electronic processors to perform the described functions. As used in this application, "non-transitory computer-readable medium" includes all computer-readable media, but does not include temporary propagation signals. Therefore, non-transitory computer-readable media may include, for example, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (read-only memory), a RAM (random access memory), a register memory, a processor cache, other memory and storage devices, or a combination of the above.

[0030] For ease of description, some or all of the example systems presented herein are illustrated using a single example of each of their constituent components. Some examples may not describe or illustrate all of the components of the system. Other examples may include more or fewer of each of the illustrated components, may combine some components, or may include additional or alternative components.

[0031] In addition, the wording and terminology used in this article are for descriptive purposes and should not be considered as limiting. For example, the use of "comprises", "contains", "includes", "has" and variations thereof herein is intended to include the items listed thereafter and their equivalents and additional items. The terms "connect" and "couple" are widely used and include direct and indirect connections and couplings. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings, and may include direct or indirect electrical connections or couplings. In addition, electronic communications and notifications may be performed using wired connections, wireless connections, or a combination of the above, and may be transmitted directly or through one or more intermediate devices through various types of networks, communication channels, and connections.

[0032] Unless the context in which they are used clearly indicates otherwise, the articles “a” and “an” should not be construed as meaning “one” or “only one.” Instead, these articles should be construed as meaning “at least one” or “one or more.”

[0033] Relational terms (eg, first and second, top and bottom, etc.) may be used herein solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0034] In some examples, method steps are performed in an order different from that described.

[0035] Figure 1 A system 100 for assisting rearward maneuvering of a trailer attached to a vehicle (e.g., backing up the trailer) is illustrated. The examples disclosed herein relate to a system commonly referred to as a trailer towing assist (TTA) system. In the illustrated example, the system 100 includes a vehicle 105, a trailer 205, and a surrounding environment S of the vehicle 105 and the trailer 205. The vehicle 105 has a rear R. For example, the surrounding environment S of the vehicle and the trailer includes an area near the vehicle 105 and the trailer 205. The vehicle 105 is illustrated as a four-wheel vehicle, but the various aspects, features, and embodiments described can be applied to wheeled vehicles of other types and designs. The trailer 205, although illustrated as a two-wheel trailer, can include trailers of various types and designs.

[0036] In the illustrated example, the vehicle 105 includes several hardware components, including a communication bus 110, an electronic controller 115, a human-machine interface 120, an environmental detection system 125, a steering control system 130, a brake control system 135, and an acceleration control system 140. These components are connected via the communication bus 110 (e.g., a FlexRay automotive communication bus, a controller area network (CAN) bus, or other types of buses). In the illustrated example, the trailer 205 includes at least one or more hardware components, including an environmental detection system 215. The environmental detection system 215 is connected to the communication bus 110 of the vehicle 105.

[0037] The vehicle 105 and the trailer 205 are mechanically connected via a trailer hitch 210 mounted to the rear R of the vehicle 105. In some examples, the environment detection system 125 is configured to detect the presence of the trailer 110 or the connection of the trailer 110 to the vehicle 105. In some examples, the presence of the trailer 110 can be determined without using the environment detection system 125. For example, a weight sensor in the vehicle 105 can be used to provide information to determine or estimate the mass of the vehicle 105 and the trailer 205. When the sensed weight or mass is greater than the known mass of the vehicle 105 (e.g., as provided by the vehicle manufacturer), the system can assume that the vehicle 105 is hitched to the trailer 205, and therefore the trailer 205 is present. In another example, multiple accelerometers in the vehicle 105 can be used to provide information to determine or estimate the acceleration measurements of the vehicle 105 and the trailer 205. The acceleration measurements can be used to estimate the applied forces (e.g., braking forces, acceleration forces, steering forces, etc.) acting on the vehicle 105 and the trailer 205. The estimate of the applied force and the acceleration measurements may be used to estimate the mass of the vehicle 105 and trailer 205. The presence of a trailer may be detected in other ways, for example, the presence of a trailer may be detected via the brake control system 135 by sensing a torque value that indicates that the trailer 205 is connected to the vehicle 105 (e.g., a braking torque greater than a known braking torque that would be used to brake the vehicle 105 without the weight of the trailer 205).

[0038] Figure 2 yes Figure 1100. The electronic controller 115 may include a plurality of electrical and electronic components that provide power, operational control, and protection for components and modules within the electronic controller 115. In addition, the electronic controller 115 includes an electronic processor 305 (such as a programmable electronic microprocessor, microcontroller, or similar device), a memory 310 (e.g., a non-transitory machine-readable medium), and an input / output interface 315. The electronic processor 305 is communicatively connected to the memory 310 and the input / output interface 315. In some instances, the environmental detection system 125, 215 is communicatively connected to the electronic processor 305 via the input / output interface 315. In some examples, in coordination with software stored in the memory 310 and information from the environmental detection system 125, 215, in addition, the electronic processor 305 is configured to implement the methods described herein.

[0039] Figure 3 is a block diagram illustrating possible configurations of the environment detection system 125 of the vehicle 105 and the environment detection system 215 of the trailer 205. Although illustrated as including the same components, the environment detection system 215 may include more or fewer components than the environment detection system 125. Figure 3 In the example shown in , the environment detection system 125 and the environment detection system 215 include image sensors, and three possible alternatives are shown: a lidar sensor 400, a camera 405, and a radio radar sensor 410. In some instances, in addition to one or more image sensors, the environment detection system 125 and the environment detection system 215 may also include an ultrasonic sensor 415. In one example, only the camera 405 is used to detect the surrounding environment S of the vehicle and trailer. In other examples, the environment detection system 125 and the environment detection system 215 use additional sensors (lidar sensor 400, radio radar sensor 410, or ultrasonic sensor 415) in combination with the camera 405 to detect the surrounding environment S of the vehicle and trailer. In some examples, there are more than one sensor of each of the sensors and they are located at different locations on the outside of the vehicle 105 or the trailer 205. For example, the camera 405 (or its components) is externally mounted to a part of the vehicle 105 (such as on a rearview mirror or trunk). In one example, the camera 405 is configured and / or positioned to capture images of the rear R of the vehicle 105 and the surroundings S of the vehicle and trailer. The images may include the trailer 205 being hitched to the vehicle 105 via the trailer hitch 210. The environment detection system 125 and the environment detection system 215 provide the images to the electronic controller 115 via the communication bus 110.

[0040] Figure 4 It is a graphic Figure 11 is a block diagram of a human-machine interface 120. The human-machine interface 120 may be one or more vehicle systems (e.g., an infotainment system) or may be a stand-alone system as shown. In an example, further provided is a human-machine interface 120 including an electronic processor 500, a memory 505, and a display 510. The electronic processor 500 is communicatively connected to the memory 505 and the display 510. The memory 505 includes several software components for creating a graphical user interface 515 and processing user input, including an operating system 520 and a graphical user interface generator 525. In coordination with the memory 505 and the display 510, the electronic processor 500 is configured to generate the graphical user interface 515 and receive user input from the display 510. Figure 4 In the example illustrated in , one or more images 530 captured by the environment detection system 125 and the environment detection system 215 are displayed in the graphical user interface 515. In some instances, the graphical user interface 515 is configured to display elements such as menus 535 and input devices 540. In some examples, the input device 540 is a knob configured to be rotated by a user. In other examples, the input device 540 is a virtual button configured to be actuated by a user. The user can input information to the display 510 in various ways (such as selecting via a mouse or touching the image 530, menu 535, or input device 540).

[0041] Figure 5 A system 600 is illustrated for assisting rearward maneuvering of a trailer attached to a vehicle 105. In the illustrated example, the system 600 includes the communication bus 110, the electronic controller 115, the environment detection system 125 and the environment detection system 215, the steering control system 130, and the display 510. The components of the system 600 may be similar to any other system described herein (e.g., the system 100) and be configured to operate similarly to any other system described herein (e.g., the system 100).

[0042] As described above, the environment detection system 125 and the environment detection system 215 are configured to capture images of the rear R of the vehicle 105 and the surrounding environment S of the vehicle and the trailer via the camera 405. The image may include the trailer 205 that is hooked to the vehicle 105 via the trailer hitch 210. The environment detection system 125 and the environment detection system 215 provide the image to the electronic processor 305 via the communication bus 110. In one example, the electronic processor 305 is configured to perform image analysis of the image by executing one or more applications to determine at least one or more characteristics of the surrounding environment S of the vehicle and the trailer. In some instances, the display 510 is configured to display the image and one or more characteristics of the surrounding environment S of the vehicle and the trailer based on the image analysis performed by the electronic processor 305.

[0043] In some examples, the system 600 includes a number of additional sensors. In one example, the system 600 includes a master cylinder pressure sensor 615. In one example, the master cylinder pressure sensor 615 is included in the brake control system 135. The master cylinder pressure sensor 615 senses a pressure difference in the vehicle brake system 135 and provides the sensed pressure difference to the electronic processor 305 via the communication bus 110. In some examples, the electronic processor 305 is configured to provide a braking command to the brake control system 135 based on the sensed pressure difference.

[0044] The system 600 also includes a steering angle sensor 620 that senses an input steering angle (e.g., the angle of the steering wheel) or an actual angle of the vehicle's steering wheel. The steering angle sensor 620 provides the sensed steering angle to the electronic processor 305 via the communication bus 110. In another example, the steering angle sensor 620 is configured to sense the rotation of a pinion gear fixed to a steering shaft of the steering control system 130. In another example, the steering angle sensor 620 senses the steering angle based on the motor rotation of the power steering control motor and the ratio relative to the rack and pinion gear. In some instances, the electronic processor 305 is configured to provide a steering command to the steering control system 130 based on the sensed angle.

[0045] In one example, the system 600 also includes a vehicle yaw rate sensor that senses an angular velocity (e.g., an angular velocity about a vertical axis) of the vehicle 105. In one example, the vehicle yaw rate sensor is included within the steering control system 130. The vehicle yaw rate sensor provides the sensed angular velocity to the electronic processor 305 via the communication bus 110. In some examples, the electronic processor 305 is configured to provide a steering command to the steering control system 130 based on the sensed angular velocity.

[0046] In one example, the system 600 also includes a vehicle speed sensor 625. The vehicle speed sensor 625 senses the vehicle speed and provides the sensed vehicle speed to the electronic processor 305 via the communication bus 110. In some examples, the vehicle speed sensor is included in the acceleration control system 140. In some examples, the electronic processor 305 is configured to provide an acceleration command to the acceleration control system 140 based on the sensed vehicle speed.

[0047] Figure 6A system 700 is illustrated that includes a vehicle 105 attached to a trailer 205. In the illustrated example, the vehicle 105 is backing up the trailer 205 in a direction 705 toward a free space 710 (e.g., a target space, a drivable area, etc.). The target space 710 is an area within the surroundings S of the trailer 205. For example, the target space 710 is a road, a lane, a driveway, a boat ramp, or any other area where the system 700 can back up the trailer 205 while maintaining the direction 705.

[0048] Figure 7 An example flow chart of a method 800 for assisting rearward maneuvering of a trailer 205 is illustrated. The method 800 begins at step 805 when the electronic processor 305 receives an image from the camera 405. For example, Figure 8 An image 900 including the trailer 205 and the surroundings S of the trailer is shown. In some examples, the image 900 is captured by the camera 405 of the environment detection system 125. In other examples, the image 900 is captured by the camera 405 of the environment detection system 215. In some examples, the electronic processor 305 determines whether the trailer 205 is attached to the vehicle 105 based on the image 900. At step 810, the electronic processor 305 identifies the target space 710 within the surroundings S of the trailer based on the received image 900. In some examples, the electronic processor 305 determines the direction (e.g., direction 705) of the target space 710 relative to the vehicle 105 within the surroundings S of the trailer. The direction 705 may include an orientation of the target space 710, such as one or more curves in the target space 710. The electronic processor 305 may identify the target space 710 and the direction 705 based on image analysis software stored in the memory 310. In some examples, the image analysis software is computer vision software or deep learning software, or software sometimes referred to as computer vision driver assistance (CVDA). In some examples, electronic processor 305 identifies target space 710 from the ground plane using semantic segmentation. In some examples, electronic processor 305 determines one or more landmarks, one or more boundaries, or one or more objects within target space 710 based on image 900.

[0049] At step 815, electronic processor 305 determines the vehicle orientation relative to target space 710. For example, electronic processor 305 determines the vehicle orientation based on image 900. The vehicle orientation may be the position of vehicle 105 or the direction of vehicle 105 relative to target space 710. At step 820, electronic processor 305 determines the trailer angle (e.g., Figure 8905). In some examples, method 800 may include an additional step of determining trailer angle 905, wherein a forward driving maneuver is performed. During the forward driving maneuver, electronic processor 305 receives an image captured by camera 405 and performs image analysis on the image to learn a trailer rotation point about trailer hitch 210. Based on the trailer rotation point, electronic processor 305 may calibrate the trailer rotation point to correspond to trailer angle 905. In some examples, electronic processor 305 determines trailer angle 905 based on image 900. Electronic processor 305 may use image analysis software to determine a coordinate plane near trailer hitch 210 that indicates the position of trailer hitch 210 relative to rear R. The coordinate plane may include a polar coordinate system or a radial coordinate system. Electronic processor 305 determines the change in position of trailer hitch 210 relative to rear R within the coordinate plane as trailer angle 905. For example, when the trailer hitch 210 is aligned with the rear portion R, the trailer angle 905 is approximately 0 degrees.

[0050] At step 825 , the electronic processor 305 determines the trailer trajectory (eg, Figure 8 8. The trailer track 910 is superimposed on the image 900 to illustrate the path from the trailer 205 to the target space 710. In some examples, the trailer track 910 includes a centerline. At step 830, the electronic processor 305 transmits the image 900 to the HMI 120, and the image 900 includes an overlay of the trailer track 910 in the direction of travel (e.g., direction 705) toward the target space 710. The HMI 120 displays the image 900 including the overlay of the trailer track 910 on the display 510, such as image 530.

[0051] At step 835, the electronic processor 305 determines whether to activate vehicle control (which may be implemented in whole or in part by the system 700 and other vehicle systems) to back the trailer 205 along the trailer trajectory 910 to the target space 710. In some examples, the electronic processor 305 activates the vehicle control in response to a user input via the input device 540. When the electronic processor 305 determines not to activate the vehicle control, the method 800 returns to step 805 to receive a subsequent image from the camera 405. When the electronic processor 305 activates the vehicle control, then the method 800 proceeds to step 840 and controls the vehicle 105 to follow the trailer trajectory 910 along the centerline of the trailer trajectory 910 until the trailer 205 reaches the target space 710. The electronic processor 305 may continuously identify the direction 705 and the target space 710 to update the trailer trajectory 910 (e.g., to follow one or more curves in the target space 710) during vehicle control. The electronic processor 305 can continuously determine the vehicle orientation and trailer angle 905 to follow the trailer track 910 during vehicle control. In some cases, the HMI 120 continuously displays the updated trailer track 910 and image 900 during vehicle control. In some examples, when the trailer track 910 cannot be achieved and the vehicle 105 and trailer 205 cannot reach the target space 710, the electronic processor 305 cancels vehicle control.

[0052] In some examples, the electronic processor 305 controls the steering control system 130 of the vehicle 105 to follow the trailer trajectory 910. The steering angle sensor 620 senses a first input steering angle (i.e., a first angle) of the steering wheel and transmits the first angle to the electronic processor 305. The electronic processor 305 determines a target vehicle yaw rate and a target trailer angle for achieving the trailer trajectory 910 based on the first angle. The electronic controller 305 transmits the target vehicle yaw rate and the target trailer angle 905 to the steering control system 130. The steering control system 130 applies the target vehicle yaw rate and the target trailer angle 905 to the vehicle control system 130 to follow the trailer trajectory 910, which can be done, for example, by changing the steering wheel angle of the vehicle 105. In some examples, the electronic processor 305 controls the steering control system 130 in a first mode to maintain the target vehicle yaw rate and the target trailer angle throughout the trailer trajectory 910. In other examples, the electronic processor 305 controls the steering control system 130 to maintain the first angle throughout the trailer trajectory 910.

[0053] In some examples, the electronic processor 305 controls the brake control system 135 of the vehicle 105 while controlling the vehicle 105 to follow the trailer trajectory 910. In some instances, when it is determined that the object is in the path of the trailer trajectory 910 or in the target space 710, braking is applied to the vehicle 105. The master cylinder pressure sensor 615 senses a first pressure differential of the brake control system 135 and transmits the first pressure differential to the electronic processor 305. The electronic processor 305 determines a second pressure differential based on the first pressure differential and the trailer trajectory 910. The electronic controller 305 transmits the second pressure differential to the brake control system 135. The brake control system 135 applies the second pressure differential to one or more wheels of the vehicle 105 via asymmetric or symmetric braking of the wheels of the vehicle 105.

[0054] In some examples, the electronic processor 305 controls the acceleration control system 140 to control or limit the speed of the vehicle 105 while controlling the vehicle 105 to follow the trailer trajectory 910. The vehicle speed sensor 625 senses a first speed of the vehicle 105 and transmits the first speed to the electronic processor 305. The electronic processor 305 determines a second speed (e.g., a target speed) based on the first speed and the trailer trajectory 910. The electronic processor 305 transmits the target speed to the acceleration control system 140 to control or limit the speed of the vehicle 105 while following the trailer trajectory 910.

[0055] When the system 100 backs the trailer 205 toward the target space 710, the system 100 may operate in a first mode or a second mode. In some cases, the system 100 operates in the first mode to maintain the trailer track 910 in a straight line while backing the trailer 205. The user may wish to maintain the current trailer track while maneuvering the vehicle 105 to back the trailer 205 into the target space 710. The first mode of the system 100 may be activated by a first user input via the input device 540. Fig. 9 The figure shows the trailer being backed into the target space 710 ( Figure 610 ). In one example, the electronic processor 305 determines the centerline 1005 and the trailer track 910. In some instances, it may be difficult for a user to determine when the trailer 205 is in the correct position for backing up in a straight direction (e.g., the trailer angle is 0 degrees). Vanishing points in the model 1000 may make it difficult for a user to determine whether the trailer track is parallel to the boundary 1010. In some examples, the electronic processor 305 determines the boundary 1010 based on the image 1000. Once the trailer 205 is positioned in the direction for backing up in the desired trailer track 910, a first mode of the system 100 is activated based on a first user input (e.g., a zeroing user input) via the input device 540. In the first mode of the system 100, the electronic processor 305 determines the centerline 1005 of the trailer track 910 as the desired trailer track for backing up the trailer 205 into the target space 710. In some cases, the centerline 1005 is parallel to the boundary 1010. The steering angle sensor 620 senses the input steering angle and transmits the input steering angle to the electronic processor 305. The electronic processor 305 determines the vehicle yaw rate based on the input steering angle. The electronic processor 305 transmits the vehicle yaw rate to the steering control system 130 to maintain the trailer angle 905 so as to back up the trailer 205 in a straight direction along the centerline 1005. In other words, once the first mode of the system 100 is activated, the electronic processor 305 adjusts the vehicle yaw rate based on the input steering angle to maintain the desired trailer track 910.

[0056] In some cases, the system 100 operates in the second mode to maintain the relative angle between the vehicle 105 and the trailer 205 while backing up the trailer 205. The user may wish to maintain the relative angle while backing up the trailer 205 into the target space 710, where the target space 710 is perpendicular to the vehicle 105. Fig. 10A and Fig. 10B Models 1100A and 1100B are illustrated, and the models 1100A and 1100B illustrate backing the trailer 205 along the centerline 1005 to the target space 710 ( FIG. 7 ) while maintaining the relative angle between the vehicle 105 and the trailer 205. Figure 6). In some instances, it may be difficult for a user to determine whether the trailer trajectory 910 will result in backing the trailer 205 into the target space 710 based on the geometry of the vehicle 105, the geometry of the trailer 205, and the objects within the trailer trajectory 910. A second mode of the system 100 may be activated based on a second user input via the input device 540. In the second mode of the system 100, the steering angle sensor 620 senses a first input steering angle (e.g., a first angle) of the steering wheel and transmits the first angle to the electronic processor 305. The first angle corresponds to a relative trailer angle between the vehicle 105 and the trailer 205. The electronic processor 305 determines a target vehicle yaw rate to maintain the relative trailer angle and follow the trailer trajectory 910. The electronic processor 305 transmits the target vehicle yaw rate to the steering control system 130. The steering control system 130 applies the target vehicle yaw rate to the vehicle control system 130 to maintain the relative trailer angle at a fixed arc length to follow the trailer trajectory 910. In addition, the electronic processor 305 transmits the image of the surrounding environment S including the vehicle and trailer received from the camera 405 to the HMI 120 for display via the display 510. The electronic processor 305 determines an overlay of the trailer trajectory 910 and transmits the overlay to the HMI 120 for display on the image. The overlay of the trailer trajectory 910 shows the future profile of the trailer 205 based on the relative trailer angle and the fixed arc length. Although illustrated from above in the models 1100A and 1100B, the future profile and the trailer trajectory 910 can be shown in the image on the display 510 at the ground level within the target space 710. The overlay includes a swing angle trajectory 1105 of the vehicle 105 and the trailer 205 based on the target vehicle yaw rate, which is used to maintain the relative trailer angle. Model 1100A shows a maximum fixed arc length based on the geometric parameters of the vehicle 105 and trailer 205 (at which the vehicle 105 and trailer 205 will fold). Model 1100B shows a fixed arc length less than the maximum fixed arc length (at which the vehicle 105 and trailer 205 will not fold). When the electronic processor 305 detects a folding condition between the vehicle 105 and trailer 205, the electronic processor 305 transmits a braking command to the brake control system 135. In response to the braking command, the brake control system 135 supplies additional pressure differentials to one or more wheels of the vehicle 105 via asymmetric or symmetric braking of the wheels of the vehicle 105 to alleviate the folding condition.

[0057] Fig.11 illustrates a model of the vehicle 105 and trailer 205 and a geometric relationship for determining a trailer angle 905 relative to the vehicle 105, Fig.11Also illustrated is an example of angles used to determine various values ​​of the algorithm executed in the first mode of the system 100 and the second mode of the system 100 relative to the XY axis. In one example, based on the vehicle speed v, the steering angle δ, the vehicle rear overhang length l 12 (the distance from the rear axle of the vehicle 105 to the tow ball of the trailer hitch 120), the vehicle wheelbase l 1 , and trailer length l 2 The trailer angle 905 (γ) can be determined based on the steering angle δ, the vehicle wheelbase l 1 The vehicle yaw rate is determined by the electronic processor 305 via image analysis software. 2 The electronic processor 305 estimates the trailer motion dynamics based on the images provided by the camera 405 .

[0058] Thus, among other things, examples provide a trailer tow assist system for assisting rearward maneuvering of a trailer. Various features, advantages and examples are set forth in the following claims.

Claims

1. A trailer towing assistance system for assisting in the backward maneuvering of a trailer attached to a vehicle, the trailer towing assistance system comprises: a camera configured to capture a backward image of the trailer and its surrounding environment; a human-machine interface configured to display the backward image, an input device configured to receive user input; and an electronic processor configured to: receive the backward image; identify a target space within the surrounding environment based on the backward image; determine the vehicle orientation relative to the target space based on the backward image; determine the trailer angle relative to the vehicle based on the backward image; determine a trailer trajectory within the surrounding environment based on the trailer angle; display the trailer trajectory and the backward image on the human-machine interface; and in response to the user input, control the vehicle to follow the trailer trajectory along the center line of the trailer trajectory.

2. The trailer towing assistance system according to claim 1, wherein the electronic processor is further configured to: determine an object within the target space to be avoided.

3. The trailer towing assistance system according to claim 1, wherein the electronic processor is further configured to: determine a boundary based on the target space.

4. The trailer towing assistance system according to claim 1, further comprises: a steering angle sensor configured to sense a first angle of the steering wheel of the vehicle; a steering control system; the electronic processor is further configured to: determine a second angle based on the trailer trajectory and the first angle; and control the steering control system based on the second angle to follow the trailer trajectory.

5. The trailer towing assistance system according to claim 4, wherein the electronic processor is further configured to: control the steering control system in a first mode.

6. The trailer towing assistance system according to claim 5, wherein during the first mode, the electronic processor is further configured to: control the steering control system to maintain the first angle throughout the trailer trajectory.

7. The trailer towing assistance system according to claim 4, wherein the electronic processor is further configured to: control the steering control system in a second mode.

8. The trailer towing assistance system according to claim 7, wherein during the second mode, the electronic processor is further configured to: control the steering control system to maintain the second angle throughout the trailer trajectory.

9. The trailer towing assistance system according to claim 1, further comprises: a brake control system; a master cylinder pressure sensor configured to sense a first pressure difference of the brake control system; the electronic processor is further configured to: determine a second pressure difference based on the trailer trajectory and the first pressure difference; and control the brake control system to apply the second pressure difference.

10. The trailer towing assistance system according to claim 1, further comprises: an acceleration control system; a vehicle speed sensor configured to sense a first speed of the vehicle; the electronic processor is further configured to: determine a second speed based on the trailer trajectory and the first speed; and control the vehicle acceleration system based on the second speed.

11. A method for assisting in the reverse maneuvering of a trailer attached to a vehicle using a trailer towing assistance system including an electronic processor, comprising: Receiving a rearward image of the trailer and its surrounding environment via a camera; Identifying a target space within the surrounding environment based on the rearward image; Determining a vehicle orientation relative to the target space based on the rearward image; Determining a trailer angle relative to the vehicle based on the rearward image; Determining a trailer trajectory within the surrounding environment based on the trailer angle; Displaying the trailer trajectory and the rearward image on a human-machine interface; and In response to a user input, controlling the vehicle to follow the trailer trajectory along the centerline of the trailer trajectory.

12. The method according to claim 11, wherein the method further comprises: Determining an object within the target space to be avoided.

13. The method according to claim 11, wherein the method further comprises: Determining a boundary based on the target space.

14. The method according to claim 11, wherein the method further comprises: Sensing a first angle of a steering wheel of the vehicle via a steering angle sensor; Determining a second angle via the electronic processor based on the trailer trajectory and the first angle; and Controlling a steering control system based on the second angle to follow the trailer trajectory.

15. The method according to claim 14, wherein the method further comprises: Controlling the steering control system in a first mode.

16. The method according to claim 15, wherein during the first mode, the method further comprises: Controlling the steering control system to maintain the first angle throughout the trailer trajectory.

17. The method according to claim 14, wherein the method further comprises: Controlling the steering control system in a second mode.

18. The method according to claim 17, wherein during the second mode, the method further comprises: Controlling the steering control system to maintain the second angle throughout the trailer trajectory.

19. The method according to claim 11, wherein the method further comprises: Sensing a first pressure difference of a brake control system via a master cylinder pressure sensor; Determining a second pressure difference via the electronic processor based on the trailer trajectory and the first pressure difference; and Controlling the brake control system to apply the second pressure difference.

20. The method according to claim 11, wherein the method further comprises: Sensing a first speed of the vehicle via a vehicle speed sensor; Determining a second speed via the electronic processor based on the trailer trajectory and the first speed; and Controlling a vehicle acceleration system based on the second speed.

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