Patent Publication Number: US-2023136812-A1

Title: Trailer assist system with jackknife escape

Description:
TECHNICAL FIELD 
     The present disclosure relates to a trailer assist system that assists a driver in escaping a jackknife situation. 
     BACKGROUND 
     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, livestock trailer, flatbed trailer, enclosed car hauler, or 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 the trailer and pull the trailer. The trailer may be attached to a powered vehicle using a trailer hitch. The trailer hitch allows the trailer to swivel around the hitch horizontally so that the vehicle and trailer can move around corners. However, this can pose difficulties when the vehicle is traveling in reverse. 
     When the vehicle backs up, it pushes the trailer. The backing of trailers attached to vehicles often requires multiple persons to effectively control the vehicle and direct the path of the vehicle and trailer. Those unaccustomed to operating a vehicle towing a trailer may have difficulty in accurately controlling the path of the trailer while backing the vehicle and trailer. 
     The background description provided herein is for the purpose of generally presenting a context of this disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
     SUMMARY 
     A trailer assist system according to a disclosed example embodiment includes, among other possible things a controller configured to determine whether a trailer is in a jackknife condition based on an angle of the trailer relative to a vehicle. Determination is made whether the jackknife condition can be corrected by utilizing vehicle brakes, trailer brakes, or vehicle steering. 
     In another embodiment of any of the foregoing trailer assist system, the controller is configured to correct the jackknife condition by utilizing the vehicle brakes, trailer brakes, or vehicle steering. 
     In another embodiment of any of the foregoing trailer assist system, the controller is configured to autonomously control the vehicle brakes, trailer brakes, and/or vehicle steering when the jackknife condition can be corrected. 
     In another embodiment of any of the foregoing trailer assist system, the controller is in communication with a left vehicle brake and a right vehicle brake that can be activated separately. 
     In another embodiment of any of the foregoing trailer assist system, the controller is configured to correct the jackknife condition by braking one of the left vehicle brake and the right vehicle brake. 
     In another embodiment of any of the foregoing trailer assist system, the controller is configured to correct the jackknife condition by controlling the vehicle brakes and the vehicle steering. 
     In another embodiment of any of the foregoing trailer assist system, the trailer is in the jackknife condition when an angle between the vehicle and the trailer is above a predetermined threshold. 
     In another embodiment of any of the foregoing trailer assist system, the determination whether the jackknife condition can be corrected is based on a vehicle steering angle and a speed of the vehicle. 
     In another embodiment of any of the foregoing trailer assist system, the controller is configured to instruct a driver of the vehicle to stop or drive forward when the jackknife condition cannot be corrected. 
     In another embodiment of any of the foregoing trailer assist system, the controller is in communication with a plurality of sensors on the vehicle. 
     A method of controlling a path of a trailer according to another disclosed embodiment includes, among other possible things, determining an orientation of a trailer relative to a vehicle. A determination is made whether the trailer is in a jackknife condition based on the orientation. A determination is made whether the jackknife condition can be corrected by utilizing vehicle brakes, trailer brakes, or vehicle steering. 
     In another embodiment of any of the foregoing methods, a driver of the vehicle is instructed to stop or drive forward when the jackknife condition cannot be corrected. 
     In another embodiment of any of the foregoing methods, the jackknife condition is corrected by utilizing the vehicle brakes, trailer brakes, or vehicle steering. 
     In another embodiment of any of the foregoing methods, both the vehicle brakes and the vehicle steering are controlled in the correcting step. 
     In another embodiment of any of the foregoing methods, the vehicle brakes comprises a left brake and a right brake that can be controlled separately. 
     In another embodiment of any of the foregoing methods, the method includes activating one of the left brake and the right brake. 
     In another embodiment of any of the foregoing methods, the vehicle brakes, trailer brakes, or vehicle steering are controlled autonomously by a controller when the jackknife condition can be corrected. 
     A non-transitory computer readable medium including instructions is executable by at least one processor according to another example embodiment includes, among other possible things, instructions executed by the at least one processor that prompt determining an orientation of a trailer relative to a vehicle. Instructions are executed by the at least one processor that prompt determining whether the trailer is in a jackknife condition based on the orientation. Instructions executed by the at least one processor to prompt determining whether the jackknife condition can be corrected by utilizing vehicle brakes, trailer brakes, or vehicle steering. 
     Another embodiment of the foregoing non-transitory computer readable medium further includes instructions executed by the processor for correcting the jackknife condition by activating the vehicle brakes, trailer brakes, or vehicle steering. 
     Another embodiment of the foregoing non-transitory computer readable medium further includes instructions executed by the processor for activating one of a left brake and a right brake on the vehicle. 
     Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. 
     These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic side view of a vehicle and trailer with an example embodiment of a trailer assist system. 
         FIG.  2    is a schematic top view of the vehicle and trailer with the example trailer assist system. 
         FIG.  3    is a flow diagram of example steps performed by the example trailer assist system. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    schematically illustrates a tow vehicle  20  attached to a trailer  22  at a hitch  23 . The tow vehicle  20  includes a system  24  for assisting a driver in backing the trailer  22 . Backing a trailer is one of the most challenging maneuvers for a driver. A driver must steer the tow vehicle  20  in a manner that directs the trailer  22  along a desired intended path. Steering of the tow vehicle  20  to direct the trailer  22  is not intuitive and therefore presents challenges for most drivers. 
     When operating in reverse, the vehicle  20  pushes the trailer  22 . The steering controls for pushing the trailer  22  in reverse are opposite, which can be tricky. When the trailer gets to a certain maximum angle relative to the vehicle  20 , there is no way to straighten the trailer  22  with steering alone. When the trailer  22  is at or above this maximum angle, it is known as a jackknife condition or jackknife situation. In these situations, a driver typically must stop and move the vehicle  20  forward. The disclosed vehicle  20  has a trailer assist system  24  to help the driver escape jackknife situations. The trailer assist system  24  described herein is used to escape the jackknife situation using vehicle steering, vehicle brakes, and trailer brakes. 
     With reference to  FIG.  2   , and continuing reference to  FIG.  1   , the vehicle  20  has a midline  44  that extends longitudinally through the vehicle  20 . The trailer  22  has a midline  46  that extends longitudinally through the trailer  22 . Sometimes, the trailer  22  may be at an angle  48  relative to the vehicle  20 . The angle  48  may be the angle between the vehicle midline  44  and the trailer midline  46 . When the angle  48  exceeds a predetermined jackknife threshold, the trailer  22  is in a jackknife situation. Typically, in a jackknife situation, the angle  48  will only increase as the vehicle  20  continues travelling in reverse. The predetermined jackknife threshold depends upon the length  43  of the vehicle  20  and the length  45  of the trailer  22 . 
     The position of the trailer  22 , the angle  48 , and other vehicle parameters such as speed and steering angle are detected with several vehicle sensors. A sensor  34  at the tow hitch  23  may detect information about the trailer  22 , such as the angle  48 . The sensor  34  may be a radar detector or camera, for example. A steering wheel sensor  40  may provide an indication of an angle of the front wheels. The angle of the front wheels provides the data needed to determine the direction of the vehicle  20 . A radar device and/or an accelerometer  42  could be utilized or combined with data from other sensors to determine the direction of the tow vehicle  20 . Moreover, it should be understood that although several vehicle sensing devices are disclosed by way of example, any other sensing devices and systems that can provide information indicative of a vehicle direction could also be utilized and are within the scope and contemplation of this disclosure. 
     Each of the sensors  34 ,  40 ,  42  are in communication with a controller  26 . The controller  26  includes the trailer assist system  24 . The trailer assist system  24  determines whether the vehicle  20  and trailer  22  are in a jackknife situation. If the vehicle  20  and trailer  22  are in a jackknife situation, the trailer assist system  24  helps a driver to escape the jackknife situation by controlling vehicle brakes, trailer brakes, and/or vehicle steering, as will be further described below. The controller also includes a processor  28  and a memory device  30 . The memory device  30  includes a set of instructions  32  executed by the processor  28 . 
     The example disclosed processor  28  may be a hardware device for executing software, particularly software stored in memory. The processor  28  can be a custom made or commercially available processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the computing device, a semiconductor based microprocessor (in the form of a microchip or chip set) or generally any device for executing software instructions. 
     The memory  30  can include any one or combination of volatile memory elements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM, VRAM, etc.)) and/or nonvolatile memory elements (e.g., ROM, hard drive, tape, CD-ROM, etc.). Moreover, the memory  30  may incorporate electronic, magnetic, optical, and/or other types of storage media. Note that the memory  30  can also have a distributed architecture, where various components are situated remotely from one another, but can be accessed by the processor  28 . 
     The software instructions  32  in the memory  30  may include one or more separate programs, each of which includes an ordered listing of executable instructions for implementing logical functions. A system component embodied as software may also be construed as a source program, executable program (object code), script, or any other entity comprising a set of instructions to be performed. When constructed as a source program, the program is translated via a compiler, assembler, interpreter, or the like, which may or may not be included within the memory  30 . 
     The memory device  30  provides a non-transitory computer readable medium for storage of processor executable software instructions  32 . The instructions  32  direct the processor  28  to determine an orientation of the trailer  22  relative to the tow vehicle  20 . The instructions  32  further prompt the processor to determine whether the vehicle  20  and trailer  22  are in a jackknife situation. If the vehicle  20  and trailer  22  are in a jackknife situation, the instructions  32  further prompt operation of the processor  28  to determine how to escape the jackknife situation and communicates to the trailer assist system  24 . 
     The trailer assist system  24  may help a driver to escape a jackknife situation by controlling the vehicle brakes, the trailer brakes, and/or the vehicle steering. The vehicle  20  has a braking device  36 ,  37 ,  38 ,  39  at each wheel. In this example, the braking devices  36 ,  37  are arranged on a right side of the vehicle and the braking devices  38 ,  39  are arranged on a left side of the vehicle  20 . The right side braking devices  36 ,  37  can be controlled independently of the left side braking devices  38 ,  39 . Although four braking devices  36 ,  37 ,  38 ,  39  are shown, two braking devices on opposite sides of the vehicle  20  could be used in some examples. By braking the left or right side of the vehicle  20 , the turn radius of the vehicle  20  is decreased. This may allow the vehicle  20  to escape a jackknife situation without needing to stop or drive forward. In some examples, the trailer  22  has brakes on the left and right sides that are individually controlled. The trailer assist system  24  may also help escape a jackknife situation by controlling brakes on the trailer  22 . 
     Referring to  FIG.  3    with continued reference to  FIGS.  1  and  2   , a flow diagram of example operation of a disclosed system embodiment is shown and generally indicated at  64 . 
     Operation begins with a determination of an angle  48 , or orientation of the trailer relative to the tow vehicle  20  at  52 . The angle  48  may be determined with data from a sensor at the tow hitch or a camera or radar device  34 , for example. The angle  48  is compared with a predetermined jackknife angle at  66 . The predetermined jackknife angle is the maximum angle before the trailer  22  is in a jackknife situation. The predetermined jackknife angle is determined for a particular vehicle  20  and trailer  22  based on the lengths  43 ,  45  of the vehicle  20  and trailer  22 , respectively. If the angle  48  is less than the predetermined jackknife angle, the trailer  22  is not in a jackknife situation. 
     In some examples, the vehicle  20  may be equipped with a jackknife protection module  67 . The jackknife protection module  67  helps to prevent the trailer from being in a jackknife situation. If the trailer  22  is determined to not be in a jackknife situation at  66 , the jackknife protection module  67  will be operating. 
     If the trailer  22  is determined to be in a jackknife situation at  66 , the system then determines possible counter measures at  68 . The countermeasures  68  are determined using the trailer angle  48  and other vehicle information  54 , such as steering angle and speed. The system then determines whether it is feasible to escape the jackknife situation via the countermeasures at  70 . If it is not possible to escape the jackknife situation via the countermeasures, the vehicle  20  must stop and/or drive forward at  72 . The step  72  may automatically stop the vehicle, or may instruct the driver to stop and drive forward. The driver may be instructed via an audible alert and/or visual indication on a screen in the cab of the vehicle  20 , for example. 
     If it is possible to escape the jackknife situation via the countermeasures, then the countermeasures are activated at  74 . The countermeasures may include braking the vehicle  76 , braking the trailer  78 , or controlling steering  80 . One or any combination of these countermeasures may be used to escape the jackknife situation. The countermeasures  76 ,  78 ,  80  may be activated autonomously or partially autonomously, in some examples. 
     In one example, the countermeasures of braking the vehicle  76  and braking the trailer  78  include activating braking devices separately. That is, for example, activating only the left brake devices  36 ,  37  or the right brake devices  38 ,  39 . This may decrease the turning radius of the vehicle  20  and allow it to escape some jackknife situations. 
     Some known jackknife systems assist a driver in avoiding a jackknife situation. However, the disclosed system helps a driver escape a jackknife situation once they are in such a situation. The disclosed system utilizes vehicle parameters, trailer parameters, or a combination of both to escape jackknife situations. 
     In this disclosure, the relative directions of forward and rear or reverse are used in reference to the direction which an operator of the vehicle  20  would typically be facing when driving the vehicle  20 . 
     Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
     It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
     The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.