Trailer collision avoidance system with trailer backtrack

Abstract

An integrated trailer collision‑avoidance system for a tow vehicle coupled to a trailer operates in a Trailer Turn Assist mode and a Trailer Backtrack mode. In Trailer Turn Assist mode, the system estimates a trailer path, detects objects in the estimated path, provides collision warnings during forward travel, determines whether a collision‑free forward path remains available, automatically stops the tow vehicle and enters a trailer reverse mode when no collision‑free forward path exists, and exits the reverse mode when a viable forward path is restored. The reverse mode supports autonomous, semi‑autonomous, and driver‑controlled reverse maneuvering. In Trailer Backtrack mode, the system records trailer axle path positions and angles in a ring buffer, detects stuck conditions, and autonomously reverses the tow vehicle and trailer along the recorded path to escape the stuck condition.

Description

Attorney Docket: 2025P02307WO TRAILER COLLISION AVOIDANCE SYSTEM WITH TRAILER BACKTRACKTECHNICAL FIELD

[0001] This disclosure relates to a trailer collision avoidance system and method, and particularly to a system and method for assisting a tow vehicle driver by avoiding collisions involving a connected trailer during forward travel, governing entry into and exit from a trailer reverse mode of operation when continued forward travel without collision is no longer possible, and autonomously maneuveringthe tow vehicle and trailer in reverse along a previously recorded trailer path to escape a stuck situation.BACKGROUND

[0002] Trailers are usually unpowered vehicles that are pulled by a powered tow vehicle.A trailer may be a utility trailer, a popup camper, a travel trailer, a livestock trailer, a flatbed trailer, an enclosed car hauler, a boat trailer, among others. The tow vehicle may be a car, a crossover, a truck, a van, a sports-utility-vehicle (SUV), a recreational vehicle (RV), or any other vehicle configured to attach to and pull the trailer. Because the trailer wheels follow a different path than the tow vehicle wheels — a consequence of the pivoting point between the tow vehicle and the trailer — trailers are susceptible to colliding with other vehicles or static objects such as curbs, particularly when the tow vehicle executes a sharp turn.Attorney Docket: 2025P02307WO

[0003] Existing trailer turn collision warning systems can detect objects in a trailer’s estimated path and warn a driver of a potential collision, and can indicate suggested safe forward paths to help the driver proactively avoid a collision. However, if a driver does not respond sufficiently to such warnings, a point can be reached at which no collision-free forward path remains available regardless of steering input. At that point, the driver must reverse the tow vehicle and trailer to a position from which a collision-free forward path is restored. Existing systems do not provide an integrated, algorithmically governed transition from forward collision warning to a forced stop, followed by entry into a trailer reverse mode with multiple levels of driver assistance, followed by continuous monitoring of the reverse maneuver and automatic exit from the reverse mode upon restoration of a viable forward path.

[0004] More generally, a driver towing a trailer may encounter any of several “stuck” situations — including a trailer-collision-warning scenario, a situation in which the tow vehicle and trailer are boxed in on multiple sides, or a dead-end situation in which continued forward travel is blocked — in each of which reversing the tow vehicle and trailer back along the path they traveled to reach the stuck situation is the most effective means of escape. Existing systems do not record the path of travel of the trailer axle in a manner that enables autonomous reversal along that recorded path to escape such stuck situations. A need therefore exists for a system and method that addresses this gap.Attorney Docket: 2025P02307WO BRIEF SUMMARY

[0005] In one aspect, a method for assisting in executing a turn operation by a tow vehicle connected to a trailer includes: receiving, by data processing hardware, sensor data from one or more sensors mounted to a tow vehicle having a trailer connected thereto; estimating, by the data processing hardware, a path of the trailer based upon the sensor data; detecting, by the data processing hardware, an object based upon the sensor data; determining, by the data processing hardware, whether the detected object is in the estimated path of the trailer; upon an affirmative determination that the detected object is in the estimated path, transmitting, by the data processing hardware, a warning to a user display to warn a driver of the tow vehicle to avoid the detected object; determining, by the data processing hardware, whether continued forward travel of the tow vehicle and the trailer is no longer possible without colliding with the detected object; upon an affirmative determination that continued forward travel is no longer possible, transmitting, by the data processing hardware, an instruction to cause the tow vehicle to stop and to enter a trailer reverse mode of operation for maneuvering the tow vehicle and the trailer in reverse; and during the trailer reverse mode of operation, determining, by the data processing hardware, whether reverse maneuvering of the tow vehicle and the trailer allows for forward travel by the tow vehicle and trailer without colliding with the detected object, and exiting the trailer reverse mode of operation upon an affirmativeAttorney Docket: 2025P02307WO determination that forward travel without colliding with the detected object is possible.

[0006] In another aspect, a method for executing a trailer-backtrack operation by a tow vehicle connected to a trailer includes: receiving, by data processing hardware, sensor data from one or more sensors mounted to a tow vehicle having a trailer connected thereto; recording in a ring buffer a series of positions and angles of a path of travel of an axle of the trailer; detecting, by the data processing hardware, a stuck situation based upon the sensor data; and upon detecting the stuck situation, transmitting, by the data processing hardware, an instruction to cause the tow vehicle to stop and to enter a trailer-backtrack mode of operation for using the series of positions and angles of the path of travel of the axle of the trailer recorded in the ring buffer to maneuver the tow vehicle and the trailer in reverse back along the recorded series of positions and angles of the path of travel of the axle of the trailer.

[0007] In yet another aspect, an integrated trailer collision avoidance system includes one or more sensors mounted to a tow vehicle having a trailer connected thereto; a user interface including a display; and a vehicle controller in communication with the one or more sensors and the user interface, the vehicle controller including data processing hardware and non-transitory memory storing instructions that, when executed on the data processing hardware, cause the data processing hardware to perform the operations of either or both of the foregoing aspects.Attorney Docket: 2025P02307WO

[0008] Implementations may include one or more of the following features. The method of the first aspect may further include receiving, during forward maneuvering, user input requesting that one or more of the most recent forward maneuvers be performed in reverse. The trailer reverse mode of operation may provide fully autonomous or partially autonomous control of reverse maneuvering. In implementations providing partially autonomous control, the driver may be enabled to steer in reverse via manipulation of a rotary knob of the user interface. The trailer-backtrack mode of the second aspect may be activated by user input received while the tow vehicle and trailer are stopped. The trailer-backtrack mode may provide fully autonomous or partially autonomous control of reverse maneuvering. Stuck situations that trigger the trailer-backtrack mode may include a trailer-collision-warning scenario, a boxed-in situation in which the tow vehicle and trailer are surrounded by objects on multiple sides, and a dead-end situation in which continued forward travel without collision is not feasible regardless of steering input.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a schematic top view of an example tow vehicle according to an example embodiment hitched to a trailer, showing the sensor system, vehicle axes, and reference numerals for the drive system and structural components.Attorney Docket: 2025P02307WG

[0010] FIG.2 is a schematic view of the example tow vehicle and trailer of FIG. 1 at a non-zero trailer angle a, illustrating the articulation angle formed between the longitudinal axes of the tow vehicle and the trailer.

[0011] FIG.3 is a block diagram of an example tow vehicle having an integrated trailer collision avoidance system according to an example embodiment, showingthe sensor system, vehicle controller with constituent functional modules, drive system, and user interface.

[0012] FIG.4 is a flowchart illustrating a trailer turn assist method according to an example embodiment, including forward collision warning, determination that no collision-free forward path remains, forced stop, entry into trailer reverse mode, and exit from trailer reverse mode upon restoration of a viable forward path.

[0013] FIG.5 is a schematic top-view display illustrating a possible collision with an object during forward maneuvering, showingthe tow vehicle and trailer with estimated paths and a prominent REVERSE instruction to the driver.

[0014] FIGS.6-11 depict an example trailer-backtrack operation in response to a first type of stuck situation in which a trailer-collision warning has been triggered. FIG.6 depicts a top view and a driver’s forward view of the tow vehicle making a turn with dynamic guidelines indicatingthe predicted path. FIG.7 depicts a top view and a passenger-side rearview mirror view showing trailer dynamic guidelines triggering a REVERSE warning and presenting a Trailer Backtrack button. FIG. 8 depicts multiple camera views showingthe tow vehicle and trailerAttorney Docket: 2025P02307WG having backtracked in reverse foliowin the collision warning. FIGS. 9-11 depict successive views of the tow vehicle and trailer backtracking from the collisionwarning position and passing safely by the obstacle.

[0015] FIGS. 12-18 depict a trailer-backtrack operation in response to a second type of stuck situation in which the tow vehicle and trailer are boxed in. FIGS. 12-15 depict the tow vehicle and trailer moving into a boxed-in parking location. FIGS.16-18 depict the trailer-backtrack operation in which the tow vehicle and trailer are autonomously reversed out of the boxed-in location along the recorded trailer axle path.

[0016] FIGS. 19-23 depict an example trailer-backtrack operation in response to a deadend situation. FIG. 19 depicts the tow vehicle in a dead-end with a Trailer Backtrack label indicating mode activation. FIG. 20 depicts the Trailer Backtrack user-interface button presented to the driver. FIGS. 21-23 depict successive views of the tow vehicle and trailer backtracking from the dead-end position to a position from which forward travel is again feasible.

[0017] FIG.24 is a block diagram of the example tow vehicle of FIG. 1 configured for Trailer Backtrack mode operation, showingthe trailer backtrack system and its constituent functional modules.

[0018] FIG.25 is a flowchart illustrating a method for executing a trailer-backtrack operation according to an example embodiment, including receiving sensorAttorney Docket: 2025P02307WG data, recording the ring buffer, detecting a stuck situation, and entering the trailer-backtrack mode.

[0019] FIG.26 is a geometric diagram depicting the tow vehicle-trailer kinematic relationship and the variables used for controllingvehicle steeringto achieve a desired trailer curvature during a trailer-backtrack maneuver.

[0020] Like reference symbols in the various drawings indicate like elements.DETAILED DESCRIPTION

[0021] A tow vehicle, such as but not limited to a car, a crossover, a truck, a van, a sports-utility vehicle (SUV), or a recreational vehicle (RV), may be configured to tow a trailer. The tow vehicle connects to the trailer byway of a vehicle coupler attached to a trailer hitch, for example a vehicle tow ball attached to a trailer hitch coupler. The tow vehicle includes an integrated trailer collision avoidance system that estimates the paths of the trailer tires and wheels, detects objects in the estimated trailer paths, governs entry into and exit from a trailer reverse mode of operation upon determining that continued forward travel without collision is no longer possible, and autonomously maneuvers the tow vehicle and trailer in reverse along a previously recorded trailer axle path to escape a stuck situation.

[0022] Referringto FIGS. 1-3, in some implementations a vehicle-trailer system 100 includes a tow vehicle 102 hitched to a trailer 104. The tow vehicle 102 includes a vehicle tow ball attached to a trailer hitch coupler 106 supported by a trailerAttorney Docket: 2025P02307WO hitch bar 108 of the trailer 104. The tow vehicle 102 includes a drive system 110 that maneuvers the tow vehicle 102 and thus moves the vehicle-trailer system 100 across a road surface. The drive system 110 includes a front right wheel 112a, a front left wheel 112b, a rear right wheel 112c, and a rear left wheel 112d, together with a motor or engine, brake system, acceleration system, and steering system.

[0023] The tow vehicle 102 may move across the road surface relative to three mutually perpendicular axes: a transverse axis XV, a fore-aft axis YV, and a central vertical axis ZV. A forward drive direction along YV is designated FV and a rearward drive direction is designated RV. When the tow vehicle 102 makes a turn while moving in the forward direction FV, the tow vehicle 102 and trailer 104 form a trailer angle a.

[0024] The trailer 104 follows the tow vehicle 102 relative to a trailer transverse axis XT, trailer fore-aft axis YT, and trailer central vertical axis ZT. The trailer transverse axis XT extends along a trailer turning axle 105. The trailer angle a is the angle between the vehicle fore-aft axis YV and the trailer fore-aft axis YT.

[0025] In some implementations, the tow vehicle 102 includes a sensor system 130 configured to provide sensor system data 136. The sensor system 130 may include one or more cameras 132 and one or more additional sensors 134 such as radar, sonar, LIDAR, ultrasonic sensors, and thermal cameras. Vehicle dynamics sensors provide odometry data including wheel speed, steering angle,Attorney Docket: 2025P02307WO and vehicle heading. An articulation angle sensor at or nearthe hitch coupler 106 provides a measurement of the current trailer angle a.

[0026] The tow vehicle 102 may include a user interface 140 with a display 142. The user interface 140 is in communication with a vehicle controller 150 that includes data processing hardware 152 in communication with non-transitory memory 155 storing instructions that, when executed, cause the vehicle controller 150 to perform operations of an integrated trailer collision avoidance system 160.

[0027] Referringto FIG.3, the integrated trailer collision avoidance system 160 operates in two primary modes: a TrailerTurn Assist mode and a Trailer Backtrack mode. The system 160 includes a path estimator module 154, an object detector module 156, a path monitor module 157, and a collision estimator module 158.

[0028] The path estimator module 154 estimates the path of the trailer 104 using trailer length and width, the trailer angle a, and the steering angle of the front wheels. During a trailer-backtrack maneuver, the path estimator module 154 also provides safe reverse paths based on the recorded trailer axle path stored in a ring buffer.

[0029] The path monitor module 157 monitors the estimated trailer path duringforward driving and also monitors the position and path during reverse maneuvering. In addition, the path monitor module 157 continuously records, in a ring buffer stored in the non-transitory memory 155, a series of positions and angles of the path of travel of the axle of the trailer 104 up to a predetermined distance limit,Attorney Docket: 2025P02307WG such as 50 meters, including multi-stroke forward and rearward maneuvers. The ring buffer is a fixed-size data structure that behaves like a circular array in which read and write pointers wrap around to the start once they reach the end.

[0030] The collision estimator module 158 determines whether a detected object and the trailer 104 or tow vehicle 102 will collide, determines a time to collision (TTC) value, and determines whether continued forward travel is no longer possible without collision.

[0031] FIG.4 illustrates a method 900 for performing the Trailer Turn Assist function.Sensor data is received at blocks 902 and 904. The vehicle controller 150 estimates the trailer path at block 906 and detects objects at block 908. If no detected object is in the estimated path (block 910), control returns to block 902. If a detected object is in the path, the collision estimator 158 evaluates the TTC atblock912. If collision is notimminent, awarningand camera vieware provided and control returns to block 902. If the vehicle controller 150 determines at block 912 that a collision is imminent and no collision-free forward path remains regardless of steering input, it sends instructions at block 914 to cease forward travel and alert the driver. To determine that no collision-free forward path remains, in one or more implementations, the vehicle simply checks if there is still a projected collision in the opposite full lock steering direction. In one or more other implementations, the vehicle could also possibly check for shallower angles to open up as well, but that involves more distance in reverse. As illustrated in FIG. 5, the display prominently shows REVERSE to communicateAttorney Docket: 2025P02307WO that the tow vehicle 102 must be driven in reverse to avoid the collision. The tow vehicle 102 then enters a trailer reverse mode at block 916, which may provide fully autonomous, partially autonomous, ordriver-controlled reverse maneuvering. In one implementation providing partially autonomous control, referred to herein as a Trailer Reverse Assist mode, longitudinal control of the tow vehicle 102 is managed by the vehicle controller 150 while the driver steers the tow vehicle 102 and trailer 104 in reverse by manipulating a rotary knob of the user interface 140, with the vehicle controller 150 translating rotation of the rotary knob into a commanded trailer curvature and a corresponding tow vehicle steering angle. In one implementation providing no autonomous control of maneuvering of the tow vehicle 102, the driver manually maneuvers the tow vehicle 102 and trailer 104 in reverse using the steering wheel, accelerator, and brake of the tow vehicle 102, and the vehicle controller 150 continues to monitor whether a collision-free forward path has been restored. When the vehicle controller 150 determines at block 918 that a viable collision-free forward path has been restored, the trailer reverse mode is exited at block 920. During the trailer-reverse mode, the system determines that a viable forward path has been restored by checking, as the tow vehicle and trailer are reversing, whether a projected collision remains in the opposite full-lock steering direction. Again, the system could be made to wait until a less aggressive counter steering is desired, but, with less aggressive counter steering, compromises are made on reverse distance required.Attorney Docket: 2025P02307WG

[0032] In addition to, or in lieu of, the automatic entry into the trailer reverse mode triggered by the vehicle controller 150 at block 914, in one or more implementations the user interface 140 receives, duringforward maneuvering of the tow vehicle 102 and the trailer 104, user input from the driver requesting that one or more of the most recent forward maneuvers of the tow vehicle 102 and the trailer 104 be performed in reverse. In response to the received user input, the vehicle controller 150 automatically maneuvers the tow vehicle 102 and the trailer 104 in reverse along a path correspondingto the one or more most recent forward maneuvers, using trailer axle positions and angles recorded duringthose most recent forward maneuvers. This driver-initiated short-range step-back function may be invoked by the driver before a collision warning is triggered and before no collision-free forward path remains, to proactively back out of a developingtight situation.

[0033] Referringto FIGS. 6-23, the system 160 also operates in a Trailer Backtrack mode. As illustrated in FIGS. 6-11 , when a trailer-collision warning is triggered during a turning maneuver, the system presents a Trailer Backtrack button to the driver (FIG.7). Upon activation, the system autonomously reverses the tow vehicle and trailer along the recorded ring buffer path, as shown in FIGS.8-11 , until the obstacle is safely cleared. As illustrated in FIGS. 12-18, when the tow vehicle and trailer become boxed in, the system autonomously reverses along the recorded path to exitthe confined location. As illustrated in FIGS. 19-23, when a dead-end is detected (FIG. 19) and theTrailer Backtrack button isAttorney Docket: 2025P02307WG activated (FIG. 20), the system reverses the tow vehicle and trailer back alongthe recorded path untilforward travel is again feasible (FIGS. 21-23).

[0034] Referringto FIG. 24, when operating in Trailer Backtrack mode, the path estimator module 154 provides reverse paths based on the trailer axle positions and angles stored in the ring buffer. The object detector module 156 detects objects and determines whether they are in the estimated paths. The path monitor module 157 records the trailer axle path information in the ring buffer and monitors the position and path during backtrack reverse maneuvering.

[0035] Referringto FIG.25, a method for executing a trailer-backtrack operation comprises: receiving sensor data (block 2502); recording in the ring buffer a series of positions and angles of the path of travel of the trailer axle (block 2504); detecting a stuck situation (block 2506); and upon detectingthe stuck situation, entering a trailer-backtrack mode of operation that uses the recorded ring buffer data to maneuverthe towvehicle and trailer in reverse back alongthe recorded path (block 2508). Stuck situations include a trailer-collision-warning situation, a boxed-in situation, and a dead-end situation, as described above. More specifically, in one or more implementations the trailer-collision-warning situation is a situation in which a predicted collision of the trailer 104 with a detected object cannot be avoided by steering input alone; the boxed-in situation is a situation in which the tow vehicle 102 and the trailer 104 are surrounded by objects on multiple sides such that continued forward travel without collision is not feasible; and the dead-end situation is a situation in which continued forwardAttorney Docket: 2025P02307WO travel without collision is not feasible regardless of steering input. To log the center of the trailer axles forward path for potential reversing, an implementation records: vehicle odometry: x, y, theta; steering angle; hitch angle between vehicle and trailer; and trailer axle length (hitch-to-axle). In an implementation, 50 meters was chosen based on experience in the tow vehicle. Other suitable distances could also be used. However, longer distances introduce more potential for odometry drift, thereby causing potential ground truth accuracy issues.

[0036] In addition to manual driver activation, the trailer collision avoidance system 160 may automatically detect stuck situations and offer or initiate the trailer- backtrack operation accordingly.

[0037] Simultaneous Localization and Mapping (SLAM) or another mapping technique may additionally be used to increase the distance over which trailer-backtrack information may be stored before a stuck situation arises, thereby extending the effective operating range of theTrailer Backtrack mode.

[0038] When SLAM or another mapping technique is used, the path monitor module 157 constructs or updates a local map of the environment as the tow vehicle 102 and trailer 104 travel, using sensor data from the sensor system 130. Recorded positions and angles of the trailer axle path are expressed in map-frame coordinates derived from the SLAM output rather than in the ego-frame coordinates of the tow vehicle 102. Because map-frame coordinates are notAttorney Docket: 2025P02307WC subject to the accumulated odometry drift that limits ego-frame recording, the ring buffer can effectively store trailer axle path information over distances substantially greater than the predetermined distance limit, such as 50 meters, that applies to ego-frame recording alone. During a trailer-backtrack operation, the stored map-frame positions and angles are transformed back into tow vehicle ego-frame coordinates as needed for the path estimator module 154 to compute steering commands. The SLAM-extended Trailer Backtrack mode is otherwise governed by the same control law and stuck-situation detection logic described herein.

[0039] FIG.26 is a geometric diagram depicting the tow vehicle-trailer kinematic relationship and the variables used for controllingvehicle steeringto achieve a desired trailer curvature during a trailer-backtrack maneuver, including the tow vehicle wheelbase LWB, hitch-to-axle distance LH, trailer length LT, current hitch angle y, lateral error sx, heading error 80, and target radius of curvature RC, together with the RC and steering angle 5 control equations. The tow vehicle has wheelbase LWB and is connected to the trailer via the hitch point. The trailer has a hitch-to-axle distance LH and an overall trailer length LT. The diagram depicts the lateral error sx and heading error s9 of the trailer axle relative to a target trailer path, and the target radius of curvature RC.

[0040] For the lateral control during a trailer-backtrack maneuver, a control algorithm governs vehicle steering to achieve the desired trailer curvature. With reference to the target trailer path, the trailer’s lateral error ex, heading error e0, and theAttorney Docket: 2025P02307WC target trailer curvature are taken into account within the derived control equations. The radius of curvature RC is calculated using differential geometry for the radius of curvature with equations of motion based on a spring-mass- damper model. The target curvature is calculated as follows:RC = ( (1 + tan2e0))3 / (C • tans© - K • ex + tan(0k - 0k-1 ) / distk-1 -k)

[0041] where C = 2 K (critically damped condition), 0k and 0k-1 are successive recorded heading angles of the trailer axle, and distk-1 -k is the distance between successive recorded trailer axle positions.

[0042] In the following equation, y denotes the current trailer hitch angle, equivalent to the trailer angle a described elsewhere in this specification. The steering angle 6 of the tow vehicle required to achieve the target trailer curvature RC is then calculated from the Trailer Reverse Assist (TRA) / Active Front Steering (AFS) trailer curvature control relationship as follows:5 = tan“1((cos(y) + (sin(y) ■ RC / LT) • LWB) / (sin(y) - (cos(y) • RC / LT) ■ LH))

[0043] where y is the current trailer hitch angle, LWB is the tow vehicle wheelbase, LH is the hitch-to-trailer-axle distance, and LT is the trailer length. For the longitudinal controls during a trailer-backtrack maneuver, a maximum velocity and distance- to-stop are specified and the controller manages acceleration and braking accordingly.

[0044] In addition to the driver being able to manually activate a trailer-backtrack operation, in at least one embodiment stuck situations are automaticallyAttorney Docket: 2025P02307WO detected by the trailer collision avoidance system 160, as described above. The Trailer Backtrack mode may also include automated jackknife resolution. A jackknife condition is detected when the trailer hitch angle a between the tow vehicle 102 and the trailer 104 exceeds a warning threshold a_warn, which is defined at a value safely below the physical jackknife limit a_max beyond which steering control of the reversing trailer is lost. Upon detection of a jackknife condition, the system executes a multi-stroke recovery sequence: (1 ) the rearward backtrack maneuver is halted; (2) the vehicle controller 150 computes a short forward pull-up path configured to reduce a; (3) the tow vehicle 102 is maneuvered forward along that pull-up path until a returns below a_warn; and (4) the rearward backtrack maneuver resumes along the recorded trailer axle path. The multi-stroke recovery sequence preserves the recorded ring buffer path and does not require the driver to re-activate the trailer-backtrack operation after recovery.

Claims

Attorney Docket: 2025P02307WO CLAIMS1. A method for assisting in executing a turn operation by a tow vehicle connected to a trailer, the method comprising:receiving, by data processing hardware, sensor data from one or more sensors mounted to a tow vehicle having a trailer connected thereto;estimating, by the data processing hardware, a path of the trailer based upon the sensor data;detecting, by the data processing hardware, an object based upon the sensor data; determining, by the data processing hardware, whether the detected object is in the estimated path of the trailer;upon an affirmative determination that the detected object is in the estimated path, transmitting, by the data processing hardware, a warning to a user display to warn a driver of the tow vehicle to avoid the detected object;determining, by the data processing hardware, whether continued forward travel of the tow vehicle and the trailer is no longer possible without colliding with the detected object;upon an affirmative determination that continued forward travel is no longer possible, transmitting, by the data processing hardware, an instruction to cause the tow vehicle to stop and to enter a trailer reverse mode of operation for maneuvering the tow vehicle and the trailer in reverse; andduring the trailer reverse mode of operation, determining, by the data processing hardware, whether reverse maneuvering of the tow vehicle and the trailer allows forAttorney Docket: 2025P02307WO forward travel by the tow vehicle and trailer without colliding with the detected object, and exiting the trailer reverse mode of operation upon an affirmative determination that forward travel by the tow vehicle and the trailer is possible without colliding with the detected object.

2. The method of claim 1 , further comprising:receiving, by the data processing hardware during forward maneuvering of the tow vehicle and the trailer, user input from the driver requesting that one or more of the most recent forward maneuvers of thetowvehicle and trailer be performed in reverse; and in response to the received user input, automatically maneuveringthe tow vehicle and the trailer in reverse along a path corresponding to the one or more most recent forward maneuvers.

3. The method of claim 1 , wherein the trailer reverse mode of operation provides one of fully autonomous control or partially autonomous control of maneuvering of the tow vehicle and the trailer in reverse.

4. The method of claim 3, wherein the trailer reverse mode of operation comprises a Trailer Reverse Assist mode in which the driver is enabled to steer the tow vehicle and the trailer in reverse via manipulation of a rotary knob of a user interface.Attorney Docket: 2025P02307WO 5. The method of claim 1 , wherein the trailer reverse mode of operation provides no autonomous control of maneuvering of the tow vehicle, and the tow vehicle driver is enabled to manually maneuver the tow vehicle and the trailer in reverse.

6. A method for executing a trailer-backtrack operation by a tow vehicle connected to a trailer, the method comprising:receiving, by data processing hardware, sensor data from one or more sensors mounted to a tow vehicle having a trailer connected thereto;recording in a ring buffer a series of positions and angles of a path of travel of an axle of the trailer;detecting, by the data processing hardware, a stuck situation based upon the sensor data; andupon detecting the stuck situation, transmitting, by the data processing hardware, an instruction to cause the tow vehicle to stop and to enter a trailer-backtrack mode of operation for usingthe series of positions and angles of the path of travel of the axle of the trailer recorded in the ring buffer to maneuver the tow vehicle and the trailer in reverse back along the recorded series of positions and angles of the path of travel of the axle of the trailer.

7. The method of claim 6, further comprising:Attorney Docket: 2025P02307WO receiving, by the data processing hardware while the tow vehicle and the trailer are stopped, user input from the driver requesting that the trailer-backtrack mode of operation be activated.

8. The method of claim 6, wherein the trailer-backtrack mode of operation provides one of fully autonomous control or partially autonomous control of maneuvering of the tow vehicle and the trailer in reverse.

9. The method of claim 6, wherein the stuck situation comprises one or more of: a trailer-collision-warning situation in which a predicted collision of the trailer with a detected object cannot be avoided by steering input alone; a boxed-in situation in which the tow vehicle and the trailer are surrounded by objects on multiple sides such that continued forward travel without collision is not feasible; or a dead-end situation in which continued forward travel without collision is not feasible regardless of steering input.

10. An integrated trailer collision avoidance system comprising:one or more sensors mounted to a tow vehicle having a trailer connected thereto, the one or more sensors configured to provide sensor data associated with an environment of the tow vehicle;a user interface including a display; anda vehicle controller in communication with the one or more sensors and the user interface, the vehicle controller including data processing hardware and non-transitoryAttorney Docket: 2025P02307WO memory storing instructions that, when executed on the data processing hardware, cause the data processing hardware to:estimate a path of the trailer based upon the sensor data;detect an object based upon the sensor data;determine whether the detected object is in the estimated path of the trailer; upon an affirmative determination that the detected object is in the estimated path, transmit a warning to the display to warn a driver of the tow vehicle to avoid the detected object;determine whether continued forward travel of the tow vehicle and the trailer is no longer possible without colliding with the detected object;upon an affirmative determination that continued forward travel is no longer possible, transmit an instruction to cause the tow vehicle to stop and to enter a trailer reverse mode of operation for maneuvering the tow vehicle and the trailer in reverse;during the trailer reverse mode of operation, determine whether reverse maneuvering of the tow vehicle and the trailer allows for forward travel by the tow vehicle and the trailer without colliding with the detected object, and exit the trailer reverse mode of operation upon an affirmative determination that forward travel by the tow vehicle and the trailer is possible without colliding with the detected object;record in a ring buffer a series of positions and angles of a path of travel of an axle of the trailer;detect a stuck situation based upon the sensor data; andAttorney Docket: 2025P02307WO upon detecting the stuck situation, transmit an instruction to cause the tow vehicle to stop and to enter a trailer-backtrack mode of operation for using the series of positions and angles recorded in the ring buffer to maneuver the tow vehicle and the trailer in reverse back along the recorded series of positions and angles.

11. The integrated trailer collision avoidance system of claim 10, wherein the stuck situation comprises one or more of: a trailer-collision-warning situation in which a predicted collision of the trailer with a detected object cannot be avoided by steering input alone; a boxed-in situation in which the tow vehicle and the trailer are surrounded by objects on multiple sides such that continued forward travel without collision is not feasible; or a dead-end situation in which continued forward travel without collision is not feasible regardless of steering input.

12. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to:receive sensor data from one or more sensors mounted to a tow vehicle having a trailer connected thereto;estimate a path of the trailer based upon the sensor data;detect an object based upon the sensor data;determine whether the detected object is in the estimated path of the trailer;Attorney Docket: 2025P02307WO upon an affirmative determination that the detected object is in the estimated path, transmit a warning to a user display to warn a driver of the tow vehicle to avoid the detected object;determine whether continued forward travel of the tow vehicle and the trailer is no longer possible without colliding with the detected object;upon an affirmative determination that continued forward travel is no longer possible, transmit an instruction to cause the tow vehicle to stop and to enter a trailer reverse mode of operation for maneuvering the tow vehicle and the trailer in reverse; and during the trailer reverse mode of operation, determine whether reverse maneuvering of the tow vehicle and the trailer allows for forward travel by the tow vehicle and the trailer without colliding with the detected object, and exit the trailer reverse mode of operation upon an affirmative determination that forward travel by the tow vehicle and the trailer is possible without colliding with the detected object.

13. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to:receive sensor data from one or more sensors mounted to a tow vehicle having a trailer connected thereto;record in a ring buffer a series of positions and angles of a path of travel of an axle of the trailer;detect a stuck situation based upon the sensor data; andAttorney Docket: 2025P02307WO upon detecting the stuck situation, transmit an instruction to cause the tow vehicle to stop and to enter a trailer-backtrack mode of operation for using the series of positions and angles of the path of travel of the axle of the trailer recorded in the ring buffer to maneuver the tow vehicle and the trailer in reverse back along the recorded series of positions and angles of the path of travel of the axle of the trailer.

14. The method of claim 6, wherein the trailer-backtrack mode of operation comprises:computing a target radius of curvature RC from a lateral error ex of the trailer axle, a heading error £0 of the trailer axle, and successive recorded heading angles and distances between successive recorded trailer axle positions; andcomputing a required steering angle 6 of the tow vehicle from RC, a current hitch angle y between the tow vehicle and the trailer, a tow vehicle wheelbase LWB, a hitch-to-trailer-axle distance LH, and a trailer length LT.

15. The method of claim 6, further comprising applying a mapping algorithm to extend a range of positions and angles storable in the ring buffer beyond a predetermined distance limit.

16. The method of claim 6, further comprising:detecting a jackknife condition when a hitch angle between the tow vehicle and the trailer exceeds a warning threshold defined below a physical jackknife limit; andAttorney Docket: 2025P02307WO upon detecting the jackknife condition, maneuveringthetowvehicle in a forward direction to reduce the hitch angle to below the warning threshold before resuming rearward maneuvering along the recorded path of travel of the axle of the trailer, while preserving the recorded series of positions and angles in the ring buffer.

17. The integrated trailer collision avoidance system of claim 10, wherein the instructions further cause the data processing hardware to, during the trailer-backtrack mode of operation:compute a target radius of curvature RC from a lateral error ex of the trailer axle, a heading error £0 of the trailer axle, and successive recorded heading angles and distances between successive recorded trailer axle positions; andcompute a required steering angle 5 of the tow vehicle from RC, a current hitch angle y, a tow vehicle wheelbase LWB, a hitch-to-trailer-axle distance LH, and a trailer length LT.

18. The integrated trailer collision avoidance system of claim 10, wherein the instructions further cause the data processing hardware to apply a mapping algorithm to extend a range of positions and angles storable in the ring buffer beyond a predetermined distance limit.

19. The integrated trailer collision avoidance system of claim 10, wherein the instructions further cause the data processing hardware to:Attorney Docket: 2025P02307WO detect a jackknife condition when a hitch angle between the tow vehicle and the trailer exceeds a warning threshold defined below a physical jackknife limit; andupon detecting the jackknife condition, maneuver the tow vehicle in a forward direction to reduce the hitch angle to below the warning threshold before resuming rearward maneuvering along the recorded path, while preserving the recorded series of positions and angles in the ring buffer.

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