TECHNICAL FIELD

[0001] This disclosure relates to a trailer body length detection system for determining a trailer body length of a trailer attached to a tow vehicle. The tow vehicle includes rear facing sensors positioned on each side of the vehicle to determine one or more trailer parameters.

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, livestock trailer, flatbed trailer, enclosed car hauler, and 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. A receiver hitch mounts on the tow vehicle and connects to the trailer hitch to form a connection. The trailer hitch may be a ball and socket, a fifth wheel and gooseneck, or a trailer jack. Other attachment mechanisms may also be used. In addition to the mechanical connection between the trailer and the powered vehicle, in some examples, the trailer is electrically connected to the tow vehicle. As such, the electrical connection allows the trailer to take the feed from the powered vehicle’s rear light circuit, allowing the trailer to have taillights, turn signals, and brake lights that are in sync with the powered vehicle’s lights.

[0003] Some of the challenges that face tow vehicle drivers is performing tow vehicle maneuvers while the trailer is attached to the tow vehicle. In some examples, more than one person may be needed to maneuver the tow vehicle towards the specific location. Since the vehicle-trailer unit swivels around the hitch horizontally allowing the vehicle- trailer unit to move around corners, when the vehicle moves, it pushed/pulls the trailer. Drivers are often confused as to which way to turn the vehicle steering wheel to get the desired change of direction of the trailer when backing up, for example. Applying an incorrect steering angle in the vehicle may also cause the trailer to jack-knife and lose its course. Therefore, it is desirable to have a system that calculates a length of the trailer body and a distance to a virtual turning axle of the trailer based on data received from one or more sensors supported by the tow vehicle.

SUMMARY

[0004] One aspect of the disclosure provides a method for calculating one or more trailer parameters of a trailer attached to a tow vehicle while maneuvering the tow vehicle about a curve. The method includes receiving, at a data processing hardware, sensor system data from a sensor system supported by the tow vehicle. The sensor system data includes sensor data of at least one sensor positioned on a side of the tow vehicle and configured to capture sensor data of a side rearview of the tow vehicle. The method also includes determining, at the data processing hardware, a trailer edge of the trailer based on the sensor system data. The method includes determining, at the data processing hardware, a start-point of the trailer edge and an end-point of the trailer edge.

Additionally, the method includes determining, at the data processing hardware, the one or more trailer parameters based on the trailer edge, the start-point, and the end-point.

The method also includes transmitting, from the data processing hardware to one or more vehicle systems in communication with the data processing hardware, the one or more trailer parameters.

[0005] Implementations of disclosure may include one or more of the following optional features. In some implementations, the sensor system data includes sensor data i.e., images, from a camera and sensor data from a RADAR. In some examples, the method includes detecting the trailer edge, the start-point, and the end-point, for each sensor data. In this case, determining the trailer edge includes fusing the detected trailer edge of each sensor data; determining the start-point includes fusing the detected start- point of each sensor data; and determining the end-point includes fusing the detected end point of each sensor data.

[0006] In some implementations, the one or more trailer parameters include a trailer body length of a body of the trailer and an axle distance from the start-point of the trailer to an axle of the trailer along the trailer edge. In some examples, when the trailer includes two axles, the axle distance is determined from the start-point of the trailer to a virtual axle being a mean of distances to each one of the two axles along the trailer edge.

[0007] The sensor system data may include sensor data of at least one sensor positioned on a rear side of the tow vehicle and configured to capture sensor data of a rearview of the tow vehicle. In some examples, the method also includes determining a hitch length from a trailer hitch coupler to a face of the trailer based on the sensor data from the at least one sensor positioned on the rear side of the tow vehicle; and determining a hitch angle between a vehicle fore-aft axis and a trailer fore-aft axis based on the sensor data from the at least one sensor positioned on the rear side of the tow vehicle.

[0008] Another aspect of the disclosure provides a system that includes data processing hardware and memory hardware in communication with the data processing hardware. The memory hardware stores instructions that when executed on the data processing hardware cause the data processing hardware to perform operations. These operations may the method described above.

[0009] The details of one or more implementations of the disclosure are set forth in the accompanying drawings and the description below. Other aspects, features, and advantages will be apparent from the description and drawings, and from the claims. DESCRIPTION OF DRAWINGS

[0010] FIG. l is a schematic view of an exemplary tow vehicle hitched to a trailer.

[0011] FIG. 2 is a schematic view of the exemplary tow vehicle hitched to the trailer at a trailer angle.

[0012] FIG. 3 is perspective views of an exemplary image of trailer hitched to a tow [0013] vehicle captured by a camera.

[0014] FIG. 4 is a schematic view of the exemplary tow vehicle of FIG. 1 A.

[0015] FIG. 5 is a schematic view of an exemplary arrangement of operations for a method that provides vehicle assistance when parking in a parking lot.

[0016] Like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION

[0017] A tow vehicle, such as, but not limited to a car, a crossover, a truck, a van, a sports-utility -vehicle (SUV), and a recreational vehicle (RV) may be configured to tow a trailer. The tow vehicle connects to the trailer by way of a vehicle coupler attached to a trailer hitch, e.g., a vehicle tow ball attached to a trailer hitch coupler. It is desirable to for a tow vehicle to include a trailer length detection system configured to calculate trailer parameters based on sensor data from a sensor system. The sensor system may include one or more side sensors positioned on each side of the vehicle and configured to capture sensor data of the trailer during a vehicle-trailer system turn maneuver.

[0018] Referring to FIGS. 1-4, in some implementations, a vehicle-trailer system 100 includes a tow vehicle 102 hitched to a trailer 104. The tow vehicle includes a vehicle tow ball attached to a trailer hitch coupler 106 supported by a trailer hitch bar 108 of the trailer 104. The tow vehicle 102 includes a drive system 110 associated with the tow vehicle 102 that maneuvers the tow vehicle 102 and thus the vehicle-trailer system 100 across a road surface based on drive maneuvers or commands having x, y, and z components, for example. The drive system 110 includes a front right wheel 112, 112a, a front left wheel 112, 112b, a rear right wheel 112, 112c, and a rear left wheel 112, 112d. In addition, the drive system 110 may include wheels (not shown) associated with the trailer 104. The drive system 110 may include other wheel configurations as well. The drive system 110 may include a motor or an engine that converts one form of energy into mechanical energy allowing the vehicle 102 to move. The drive system 110 includes other components (not shown) that are in communication with and connected to the wheels 112 and engine and that allow the vehicle 102 to move, thus moving the trailer 104 as well. The drive system 110 may also include a brake system (not shown) that includes brakes associated with each wheel 112, 112a-d, where each brake is associated with a wheel 112a-d and is configured to slow down or stop the wheel 112a-n from rotating. In some examples, the brake system is connected to one or more brakes supported by the trailer 104. The drive system 110 may also include an acceleration system (not shown) that is configured to adjust a speed of the tow vehicle 102 and thus the vehicle-trailer system 100, and a steering system (not shown) that is configured to adjust a direction of the tow vehicle 102 and thus the vehicle-trailer system 100. The vehicle-trailer system 100 may include other systems as well.

[0019] The tow vehicle 102 may move across the road surface by various

combinations of movements relative to three mutually perpendicular axes defined by the tow vehicle 102: a transverse axis Xv, a fore-aft axis Yv, and a central vertical axis Zv. The transverse axis Xv extends between a right side R and a left side of the tow vehicle 102. A forward drive direction along the fore-aft axis Yv is designated as Fv, also referred to as a forward motion. In addition, an aft or rearward drive direction along the fore-aft direction Yv is designated as Rv, also referred to as rearward motion. In some examples, the tow vehicle 102 includes a suspension system (not shown), which when adjusted causes the tow vehicle 102 to tilt about the Xv axis and or the Yv axis, or move along the central vertical axis Zv. As the tow vehicle 102 moves, the trailer 104 follows along a path of the tow vehicle 102. Therefore, when the tow vehicle 102 makes a turn as it moves in the forward direction Fv, then the trailer 104 follows along. While turning, the tow vehicle 102 and the trailer 104 form a trailer angle a.

[0020] Moreover, the trailer 104 follows the tow vehicle 102 across the road surface by various combinations of movements relative to three mutually perpendicular axes defined by the trailer 104: a trailer transverse axis XT, a trailer fore-aft axis YT, and a trailer central vertical axis ZT. The trailer transverse axis XT extends between a right side and a left side of the trailer 104 along a trailer turning axle 105. In some examples, the trailer 104 includes a front axle (not shown) and rear axle 105. In this case, the trailer transverse axis XT extends between a right side and a left side of the trailer 104 along a midpoint of the front and rear axle (i.e., a virtual turning axle). A forward drive direction along the trailer fore-aft axis YT is designated as FT, also referred to as a forward motion. In addition, a trailer aft or rearward drive direction along the fore-aft direction YT is designated as RT, also referred to as rearward motion. Therefore, movement of the vehicle-trailer system 100 includes movement of the tow vehicle 102 along its transverse axis Xv, fore-aft axis Yv, and central vertical axis Zv, and movement of the trailer 104 along its trailer transverse axis XT, trailer fore-aft axis YT, and trailer central vertical axis ZT. Therefore, when the tow vehicle 102 makes a turn as it moves in the forward direction Fv, then the trailer 104 follows along. While turning, the tow vehicle 102 and the trailer 104 form the trailer angle a being an angle between the vehicle fore-aft axis Yv and the trailer fore-aft axis YT.

[0021] In some implementations, the vehicle 102 includes a sensor system 130 to provide sensor system data 136 that may be used to determine one or more

measurements, such as, a trailer body length LB and a total trailer length LT. In some examples, the vehicle 102 may be autonomous or semi-autonomous, therefore, the sensor system 130 provides reliable and robust autonomous driving. The sensor system 130 provides sensor system data 136 and may include different types of sensors 132 that may be used separately or with one another to create a perception of the tow vehicle’s environment or a portion thereof that is used by the vehicle-trailer system 100 to identify object(s) in its environment and/or in some examples autonomously drive and make intelligent decisions based on objects and obstacles detected by the sensor system 130. In some examples, the sensor system 130 includes one or more sensors 132 supported by a side portion of the tow vehicle 102 which provide sensor system data 136 associated with object(s) positioned on either side of the tow vehicle 102 and behind the tow vehicle 102. For examples, the sensor system 130 may be positioned on either side-view mirrors 170, 1701, 170r. Therefore, during a turning maneuver of the tow vehicle 102 while attached to the trailer 104, the sensor system 130 is configured to capture sensor system data 136 within a field of view (FoV) associated with the trailer 104, more specifically a side of the trailer 104, when the tow vehicle 102 and the trailer 104 are not aligned, i.e., the trailer angle a is greater or less than 0. Additionally, the sensor system 130 may include one or more sensors 132 supported by a rear portion of the tow vehicle 102 and provides sensor system data 136 associated with object(s) and the trailer 104 positioned behind the tow vehicle 102. The tow vehicle 102 may support the sensor system 130; while in other examples, the sensor system 130 is supported by the vehicle 102 and the trailer 104. The sensor system 130 may include, but is not limited to, one or more imaging devices 132, 132a (such as camera(s)), and sensors 132, 132b such as, but not limited to, radar, sonar, LIDAR (Light Detection and Ranging, which can entail optical remote sensing that measures properties of scattered light to find range and/or other information of a distant target), LADAR (Laser Detection and Ranging), ultrasonic, etc. The sensor system 130 provides sensor system data 136 that includes one or both of images 133 from the one or more cameras 132, 132a and sensor information 135 from the one or more other sensors 132, 132b. Therefore, the sensor system 130 is especially useful for receiving information of the environment or portion of the environment of the vehicle and for increasing safety in the vehicle-trailer system 100 which may operate by the driver or under semi-autonomous or autonomous conditions. In some implementations, a first camera 132aa and a second camera 132ab are positioned on each side of the vehicle 102. Additionally, a rear facing third camera 132ac may be mounted at the rear of the vehicle 102.

[0022] The tow vehicle 102 may include a user interface 140, such as a display. The user interface 140 is configured to display information to the driver. In some examples, the user interface 140 is configured to receive one or more user commands from the driver via one or more input mechanisms or a touch screen display and/or displays one or more notifications to the driver. In some examples, the user interface 140 is a touch screen display. In other examples, the user interface 140 is not a touchscreen and the driver may use an input device, such as, but not limited to, a rotary knob or a mouse to make a selection. In some examples, a trailer parameter detection system 160 instructs the user interface 140 to display one or more trailer parameters 162.

[0023] The user interface 140 is in communication with a vehicle controller 150 that includes a computing device (or data processing hardware) 152 (e.g., central processing unit having one or more computing processors) in communication with non-transitory memory or memory hardware 154 (e.g., a hard disk, flash memory, random-access memory) capable of storing instructions executable on the computing processor(s)). In some example, the non-transitory memory 154 stores instructions that when executed on the data processing hardware 152 cause the vehicle controller 150 to send a signal to one or more other vehicle systems. As shown, the vehicle controller 150 is supported by the tow vehicle 102; however, the vehicle controller 150 may be separate from the tow vehicle 102 and in communication with the tow vehicle 102 via a network (not shown).

In addition, the vehicle controller 150 is in communication with the sensor system 130 and receives sensor system data 136 from the sensor system 130. In some examples, the vehicle controller 150 is configured to process sensor system data 136 received from the sensor system 130. [0024] In some implementations, the vehicle controller 150 executes a trailer parameter detection system 160 that determines one or more trailer parameters 162 based on sensor system data 136 received from the sensor system 130 when the trailer 104 is attached to the tow vehicle 102 and the tow vehicle is executing a turn within a predefined trailer angle a. In some examples, the trailer parameter detection system 160 analyzes received sensor system data 136 from a sensor 132 supported by a left side-view mirror 1701 of the tow vehicle 102 while the vehicle-trailer system 100 is turning towards the left. The sensor 132 supported by the left side-view mirror 1701 captures sensor system data 136 within its Field of view (FoV) of a rearward direction including a partial front surface of the trailer 104 and the side of the trailer 104. Based on the analyzed sensor system data 136, the trailer parameter detection system 160 detects a lower trailer edge L of the trailer body 104a. The trailer parameter detection system 160 assumes that the trailer body 104a has a flat front surface and identifies a start-point F and an end-point R of the edge L of the trailer body 104a. Following, the trailer parameter detection system 160 converts the identified points, i.e., the start-point F and the end-point R of the edge L into real-world coordinates and the trailer body length LB of trailer edge L is determined. To improve the accuracy of the determined trailer body length LB, the trailer parameter detection system 160 determines multiple trailer body lengths LB at different times while the tow vehicle 102 is turning towards the left, for example. In other words, while the tow vehicle 102 is turning to the left, for examples, the trailer parameter detection system 160 detects a lower trailer edge L of the trailer body 104a and identifies a start-point F and an end-point R of the trailer edge L at a specific time based on the received sensor system data 136 at that time, and determines the trailer body length LB associated with each detected trailer edge L at each detected time during the movement of the vehicle-trailer system 100 where the trailer angle a changes. In some examples, the sensor system data 136 includes images 133 from a camera 132a. In this case, the trailer parameter detection system 160 identifies the lower trailer edge L of the trailer body 104a and a start-point F and an end-point R of the trailer edge L within each image captured during the movement towards the left of the vehicle-trailer system 100. In some examples, the trailer parameter detection system 160 fuses two or more determined trailer body lengths LB determined based on one or more sensors, for example, a trailer body length LB determined based on an image 133 and a trailer body length LB determined based on a RADAR sensor 135, or any other combination of sensors. Therefore, to improve the accuracy of the trailer body length LB, the trailer parameter detection system 160 fuses the determined trailer body lengths LB determined based on one or more sensors 132 and/or based on different trailer angles a. Additionally, the determined trailer body lengths LB based on a right sensor and left sensor are also combined to determine a more accurate trailer body lengths LB. In some implementations, the trailer parameter detection system 160, determines a distance to a rear vertical edge V based on the sensor system data 136, e.g., an image 133. By determining the distance between a front face of the trailer to a rear vertical edge V within the image 133, the trailer parameter detection system 160 can better identify the end-point R from the sensor system data 136.

[0025] In some implementations, the tow vehicle 102 supports a sensor 132 positioned on a rear portion of the tow vehicle 102 that is configured to capture sensor system data 136 associated with the rear environment of the tow vehicle 102. In this case, the rear sensor 132 may be used to improve the distance calculation to the start- point F of edge L and improve the detection of the trailer edge L, the lower trailer edge L, the start-point F, the end-point R, the rear vertical edge V, and an axle point W.

[0026] Moreover, the sensor 132 positioned on the rear portion of the tow vehicle 102 may be used to determine the trailer angle a and a hitch length LH since the sensor 132 can capture data of the trailer hitch coupler 106, the trailer hitch bar 108, and the face of the trailer as shown in FIG. 3. The hitch length LH being a distance between the trailer hitch coupler 106 and the face of the trailer 104.

[0027] Using a similar approach, the trailer parameter detection system 160 detects the trailer wheels 112 along the detected trailer edge L and determines an axle point W along the edge L, then determines a real world coordinate of the axle point W and based on that and the determined real-word coordinate of the start-point F, the trailer parameter detection system 160 determines an axle distance DT from the front of the trailer body 104a to the axle point W. In some examples, where the trailer 104 includes two axles 105, the trailer parameter detection system 160 determines the axle distance DT to the virtual axle being the mean of the distances to each axle 105 along the trailer edge L.

The virtual axle or the axle 105 is also referred to as the ideal turning axle.

[0028] In examples where the tow vehicle 102 includes a rear sensor 132, the trailer parameter detection system 160 additionally determines the hitch length LH. Following, the trailer parameter detection system 160 can determine the total trailer length LT being the summation of the hitch length LH and the trailer body length LB.

[0029] The trailer parameter detection system 160 is configured to determine the trailer body length LB and the axle distance DT based on one or more side sensors 132. In addition, the trailer parameter detection system 160 determines the hitch length LH, the trailer angle a, and the total trailer length LT when the parameter detection system 160 received sensor system data 136 from a sensor 132 positioned on the back of the tow vehicle 102, such as a rear camera 132aa. These parameters including the trailer body length LB, the axle distance DT, the hitch length LH, the trailer angle a, and the total trailer length LT may be provided to the driver by way of the user interface 140, i.e., the display and/or may be relied on by one or more other vehicle system to improve vehicle- trailer system 100 functionality and maneuvering. Some of the functionality that may be improved are trailer merge warning systems (blind spot warning including trailers) as well as trailer maneuvering and parking systems. In addition, Visualization functions may also be improved.

[0030] FIG. 5 provides an example arrangement of operations for a method 500 of calculating one or more trailer parameters 162 of a trailer 104 attached to a tow vehicle 102 while maneuvering the tow vehicle about a curve, for example towards the right or towards the left using the system of FIGS. 1-4. At block 502, the method includes receiving, at a data processing hardware 150, 152, sensor system data 136 from a sensor system 130 supported by the tow vehicle 102. The sensor system data 136 includes sensor data 133, 136 of at least one sensor 132 positioned on a side of the tow vehicle 102 and configured to capture sensor data 133, 136 of a side rearview (e.g., within the Field-of-view (FoV) shown in FIG. 2) of the tow vehicle 102. At block 504, the method 500 includes determining a trailer edge L of the trailer 104 based on the sensor system data 136. At block 506, the method 500 includes determining a start-point F of the trailer edge L. Additionally, at block 508, the method 500 includes determining an end-point R of the trailer edge L. At block 510, the method 500 includes determining the one or more trailer parameters 162 based on the trailer edge L, the start-point F, and the end-point R. At block 512, the method includes transmitting the one or more trailer parameters 162 from the data processing hardware 150, 152 to one or more vehicle systems in

communication with the data processing hardware 150, 152.

[0031] In some examples, the sensor system data 136 includes sensor data or images 133 from a camera 132a and sensor data 135 from a RADAR 132b. The method also includes converting the trailer edge L, the start-point F, and the end-point R into real- world coordinates, where the trailer parameters 162 are based on the real -word- coordinates of the trailer edge L, the start-point F, and the end-point R.

[0032] The method 500 may also include detecting the trailer edge L, the start-point F, and the end-point R for each sensor data 133, 135. In this case, determining the trailer edge L includes fusing the detected trailer edge L of each sensor data 133, 135;

determining the start-point F includes fusing the detected start-point F of each sensor data 133, 135; and determining the end-point R includes fusing the detected end-point R of each sensor data 133, 135.

[0033] The one or more trailer parameters 162 may include a trailer body length LB of a body 104a of the trailer 104 and an axle distance DT from the start-point F of the trailer 104 to an axle 105 of the trailer along the trailer edge L. In some examples, the trailer 104 includes two axles 105. As such, the axle distance DT is determined from the start-point F of the trailer 104 to a virtual axle being a mean of distances to each one of the two axles 105 along the trailer edge L.

[0034] In some implementations, the sensor system data 136 includes sensor data 133, 135 of at least one sensor 132, 132aa positioned on a rear side of the tow vehicle 102 and configured to capture sensor data 133, 135 of a rearview of the tow vehicle 102. Additionally, the method 500 may also include determining a hitch length LH from a trailer hitch coupler 106 to a face of the trailer 104 based on the sensor data 133, 135 from the at least one sensor 132, 132aa positioned on the rear side of the tow vehicle 102. THe method 500 also includes determining a hitch angle a between a vehicle fore-aft axis Yvand a trailer fore-aft axis YT based on the sensor data 133, 135 from the at least one sensor 132, 132aa positioned on the rear side of the tow vehicle 102. [0035] Various implementations of the systems and techniques described here can be realized in digital electronic circuitry, integrated circuitry, specially designed ASICs (application specific integrated circuits), computer hardware, firmware, software, and/or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0036] These computer programs (also known as programs, software, software applications or code) include machine instructions for a programmable processor, and can be implemented in a high-level procedural and/or object-oriented programming language, model-based design with auto-code generation, and/or in assembly/machine language. As used herein, the terms“machine-readable medium” and“computer-readable medium” refer to any computer program product, apparatus and/or device (e.g., magnetic discs, optical disks, memory, Programmable Logic Devices (PLDs)) used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term “machine-readable signal” refers to any signal used to provide machine instructions and/or data to a programmable processor.

[0037] Implementations of the subject matter and the functional operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Moreover, subject matter described in this specification can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more of them. The terms“data processing apparatus”,“computing device” and“computing processor” encompass all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal that is generated to encode information for transmission to suitable receiver apparatus.

[0038] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multi-tasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0039] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.