System and method for determining angle of articulated trailer

Abstract

The present system and method determine the angle of an articulated trailer relative to a tractor to which the trailer is attached. An optical encoder is positioned below the fifth wheel of the tractor and is coupled to the trailer kingpin when the trailer is attached to the tractor. The optical coupler has a rotating shaft that may include a pin that physically interacts with the kingpin and / or may include a magnet that is magnetically attached to the kingpin. A gap cleaning block may be positioned on a spring plate to interact with the bottom surface of the trailer kingpin during the attachment of the trailer to the tractor. A LiDAR attached to the tractor may detect the front end of the trailer to determine the angle of the trailer relative to the tractor.

Description

[0001] Priority Document

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 214,227, filed on June 23, 2021, and U.S. Provisional Patent Application No. 63 / 327,723, filed on April 5, 2025. The entire contents of each priority application are incorporated herein by reference. Background Art

[0003] Trucks are an essential part of modern commerce. Trucks move materials and finished goods from place to place within their spacious interiors. Such goods are loaded and unloaded at a variety of facilities, including manufacturers, ports, distributors, retailers, and end users. The origin and destination locations are called "yards" and include areas where trailers are parked (and / or prepared) and moved, and for tractors (trucks) to enter and exit, load goods into dock doors for loading / unloading to related facilities, and exit the yard to and enter the yard from the destination. Autonomous yard vehicle technology includes tractors (trucks) that can automatically (without human intervention or through remote operation) couple, uncouple, and maneuver trailers within the yard.

[0004] Safety is of utmost importance in such automated freight yards. The automated steering of the trailer can lead to situations where the tractor may not be aware of a person or other obstacle if that person or other obstacle is in the intended path of the trailer or tractor because no one is operating the tractor. Therefore, additional sensors are required for the controller of the automated tractor to safely steer the trailer.

[0005] Additional difficulties arise because various manufacturers and trucking companies have their own trailers. While automated yard vehicles may have associated sensors, it is difficult to utilize the sensors on the trailer itself because humans (or machines) need to intervene with the trailer before maneuvering it. This additional intervention step must be timely, which increases safety risks. Summary of the invention

[0006] Trucks are an essential part of modern commerce. Trucks move materials and finished goods from place to place within their spacious interiors. Such goods are loaded and unloaded at a variety of facilities, including manufacturers, ports, distributors, retailers and end users. Large Over-The-Road (OTR) trucks usually consist of a tractor or cab unit and a separate detachable trailer that is detachably interconnected to the cab via a hitch system (consisting of a so-called fifth wheel and a kingpin).

[0007] Other challenges in trucking involve docking and loading and unloading of cargo to trailers. Warehouses and cargo delivery facilities have yards with multiple docks, and the trailer is positioned at one of the docks for loading and unloading. In an automated yard, the OTR truck stops at a designated location in the yard staging area, and the OTR tractor detaches, leaving the trailer at the designated location. The autonomous tractor moves the trailer to the first dock for unloading and / or loading. When loading and / or unloading is complete, another or the same autonomous tractor moves the trailer off the dock and parks the trailer at the designated location in the staging area. The trailer can also be moved between docks as needed by another or the same autonomous tractor. Another or the same OTR tractor couples to the trailer, and the OTR truck leaves the yard for another destination.

[0008] On the one hand, the embodiments of this aspect recognize that in order for the autonomous tractor to accurately and safely reverse the articulated trailer to a specified location, such as a loading dock, the autonomous tractor needs to always accurately know the position and / or location and / or orientation of the rear end of the articulated trailer. However, the articulated trailer does not have a sensor for determining this information. In order to solve the above problem, the embodiments of this aspect determine the angle between the articulated trailer and the autonomous tractor, and then infer the position of the rear end of the articulated trailer based on the location of the autonomous tractor, the orientation of the autonomous tractor, the length of the articulated trailer, and the angle between the articulated trailer and the autonomous tractor.

[0009] In certain embodiments, a trailer angle encoder for determining an angle between a tractor and a trailer coupled thereto includes an arm coupled at a pivot to a flange below a fifth wheel of the tractor; an optical encoder positioned at a first end of the arm and having a rotational axis with a mechanical coupler, the arm positioned so that the mechanical coupler is mechanically coupled to a kingpin of the trailer.

[0010] In certain embodiments, a method for determining the angle between a tractor and a trailer coupled to each other includes: controlling the tractor by a controller of the tractor to pull the trailer a short distance; determining the angle change between the tractor and the trailer by an optical encoder assembled on the tractor and mechanically coupled to the trailer; and calculating the angle between the tractor and the trailer based on the angle change.

[0011] In certain embodiments, a trailer angle encoder for determining an angle between a tractor and a trailer coupled thereto includes: a spring plate for coupling to an underside of a fifth wheel of the tractor at a first end; an optical encoder attached to the spring plate; a magnet assembled to a rotating shaft of the optical encoder; and a gap cleaning block positioned on the spring plate to interact with a bottom surface of a trailer kingpin during coupling of the tractor to the trailer, wherein the magnet is magnetically coupled to the bottom surface of the kingpin when the tractor is coupled to the trailer.

[0012] In certain embodiments, a software product includes instructions stored on a non-transitory computer-readable medium, wherein when the instructions are executed by a processor, steps are implemented for determining an angle between a tractor and a trailer that are coupled to each other. The software product includes the following instructions: controlling the tractor by a controller of the tractor to pull the trailer a short distance; determining the angle change between the tractor and the trailer by an optical encoder assembled on the tractor and mechanically coupled to the trailer; and calculating the angle between the tractor and the trailer based on the angle change.

[0013] In certain embodiments, a method for determining the angle between a tractor and a trailer coupled to each other includes: within a controller of the tractor, capturing a point cloud using a rear-facing LiDAR positioned on the tractor; converting points in the point cloud corresponding to the front corners of the trailer into coordinate form; and calculating the angle between the tractor and the trailer based on the coordinates of the front corner of the trailer.

[0014] In certain embodiments, a software product includes instructions stored on a non-transitory computer-readable medium, wherein when the instructions are executed by a processor, steps are implemented for determining an angle between a tractor and a trailer coupled to each other, the software product including the following instructions: within a controller of the tractor, using a rear-facing LiDAR positioned on the tractor to capture a point cloud; converting points in the point cloud corresponding to the front corners of the trailer into coordinate form; and calculating the angle between the tractor and the trailer based on the coordinates of the front corner of the trailer. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a bird's eye view of an example autonomous freight yard in which autonomous tractors are used to move trailers between a staging area and a cargo dock in accordance with an embodiment of the present invention.

[0016] Figure 2 To illustrate the embodiment of the present invention Figure 1 Block diagram of the key functional components of the autonomous tractor shown.

[0017] Figure 3 To illustrate the embodiment of the present invention Figure 1 Side view of the tractor shown backed up below the underside of the trailer.

[0018] Figure 4 The embodiment of the present invention is shown Figure 2 An example hitch and unhitch state sequence for coupling and uncoupling a tractor vehicle to a trailer as implemented by a functional state machine is shown.

[0019] Figure 5 The embodiment of the present invention is shown Figure 2 More example details of the trailer angle module shown.

[0020] Figure 6 To illustrate the embodiment of the present invention Figures 1 to 3The tractor is shown backing the trailer to Figure 1 A schematic plan view of one of a plurality of adjacent loading docks of a warehouse is shown.

[0021] Figure 7 A schematic diagram illustrating an example assumption made when a motion planner running in a tractor maneuvering module determines a steering angle for controlling a tractor to reverse a trailer in an embodiment of the present invention.

[0022] Figure 8 To illustrate an example trailer angle encoder positioned at an embodiment of the present invention Figures 1 to 3 Schematic diagram showing below the tractor vehicle FW and in the decoupled position when the tractor vehicle is coupled to the trailer.

[0023] Fig. 9 To illustrate the embodiment of the present invention, when the tractor and the trailer are coupled to each other Figure 8 Schematic diagram showing a trailer angle encoder in the engaged position mechanically coupled to the trailer kingpin.

[0024] Figures 10 to 12 To illustrate another example of the trailer angle encoder in the embodiment of the present invention, Figures 1 to 3 Schematic diagram of the underside of the tractor vehicle FW is shown.

[0025] Fig.13 The embodiment of the present invention is shown Figure 2 The LiDAR is shown assembled on the tractor cab portion to face the trailer.

[0026] Fig.14 To illustrate the embodiment of the present invention, when the trailer and the tractor are in a straight line Fig.13 A schematic diagram of an example operation of a LiDAR to detect the front corner of a trailer is shown.

[0027] Fig.15 To illustrate the embodiment of the present invention, when the trailer and the tractor are at an angle of 20 degrees Fig.13 A schematic diagram of an example operation of a LiDAR to detect the front corner of a trailer is shown.

[0028] Fig.16 In the embodiment of the present invention, Figure 1 A perspective front view of a tractor coupled to a trailer is shown, showing the LiDAR assembled to the retractable mast.

[0029] Fig.17 The schematic diagram is to show an example of a magnetically coupled trailer angle encoder positioned below the tractor FW before the tractor is coupled (hooked) to the trailer in an embodiment of the present invention.

[0030] Fig.18 To illustrate the embodiment of the present invention Fig.17Schematic diagram of a magnetically coupled trailer angle encoder magnetically coupled to a kingpin of a trailer coupled to a tractor.

[0031] Figure 19, Figure 20 and Fig.21 The embodiments of the present invention are respectively shown Fig.17 and Fig.18 Side, top and front views of the spring plate shown.

[0032] Fig. 22 In the embodiment of the present invention Fig.17 and Fig.18 Top view of a magnetically coupled trailer angle encoder.

[0033] Fig.23 , Fig.24 and Fig.25 In the embodiment of the present invention respectively Fig.17 and Fig.18 Front, side and top views of the dual-axis positioning stage shown. DETAILED DESCRIPTION

[0034] In an automated freight yard, autonomous tractors move trailers between the staging area and the loading dock for unloading and / or loading. Autonomous tractors repeatedly couple (hook up) trailers, move trailers, and then uncouple (detach) from trailers.

[0035] Figure 1 A bird's eye view of an exemplary autonomous cargo yard 100 (e.g., cargo handling facility, transportation facility, etc.) is shown, in which autonomous tractors 104 are used to move trailers 106 between a staging area 130 and a loading dock of a cargo hold 110. For example, an over-the-road (OTR) tractor 108 delivers trailers 106 loaded with cargo from remote locations and retrieves trailers 106 for return to these locations (or elsewhere, such as a storage facility). In standard operating procedures, the OTR tractor 108 arrives at a facility entrance checkpoint 109 with trailers 106 and is registered there. The guard / service personnel enters information (e.g., trailer number already in the system or QR (ID) code scan embedded information, typically including trailer brand / model / year / service connection location, etc.) into a mission controller 102 (e.g., a computer software server, which can be located off-site, in the cloud, fully on-site, or partially within the facility building complex, shown as cargo hold 110). Warehouse 110 includes peripheral loading docks (located on one or more sides of the building), associated (usually elevated) cargo portals, and ground storage, all of which are arranged in a manner well known to those skilled in the art of transportation, logistics, and the like.

[0036] To take simplified operation as an example, after the OTR tractor 108 and trailer 106 arrive, the guard / service personnel at the checkpoint 109 instruct the driver to transport the trailer 106 to a specifically numbered parking space in the designated preparation area 130, which may include a large number of side-by-side trailer parking spaces arranged according to the overall layout of the facility.

[0037] Once the driver has parked the trailer in a designated parking spot in the staging area 130, he disconnects the service line and ensures that the connector is in an accessible position (i.e., if adjustable / sealable), and uncouples the OTR tractor 108 from the trailer 106. If the trailer 106 is equipped with double doors, the driver will also have the opportunity to unlock and clamp the trailer doors in the open position under the guidance of the yard personnel.

[0038] For example, at some later time (e.g., when the cargo hold is ready to handle the loaded trailer), the mission controller 102 instructs (e.g., commands or otherwise controls) the tractor 104 to automatically couple (e.g., hook up) the trailer 106 at the pick-up position of the staging area 130 and move the trailer 106 to a return position at a designated unloading dock in the unloading area 140. Accordingly, the tractor 104 couples to the trailer 106 at the pick-up position, moves the trailer 106 to the unloading area 140, and then backs the trailer 106 into the designated loading dock at the return position, so that the rear of the trailer 106 is positioned adjacent to the portal and cargo door of the cargo hold 110. The pick-up position and the return position may be any designated trailer parking location in the staging area 130, any loading dock in the unloading area 140, and any loading dock in the loading area 150.

[0039] The cargo is unloaded from the trailer 106 into the cargo hold 110 using manual and / or automated techniques. During unloading, the tractor 104 may remain attached to the trailer 106 or may be uncoupled (e.g., detached) to perform other tasks. After unloading, the mission controller 102 instructs the tractor 104 to move the trailer 106 from the pick-up position in the unloading area 140 to the return position, or to return the trailer 106 to the staging area 130 or to transport the trailer 106 to a designated loading dock in the loading area 150 of the cargo hold 110, and then load the trailer 106 there. Once loaded, the mission controller 102 instructs the tractor 104 to move the trailer 106 from the pick-up position in the loading area 150 to the return position in the staging area 130, where it may wait to be collected by another (or the same) OTR tractor 108. Given a pick-up position and a return position, the tractor 104 can move the trailer 106 autonomously.

[0040] Figure 21 is a block diagram illustrating key functional components of the tractor 104. The tractor 104 includes a battery 202 and a controller 206, the battery 202 providing power to the components of the tractor 104, and at least one digital processor 208 of the controller 206 being communicatively coupled to a memory 210, which may include one or both of a volatile memory (e.g., RAM, SRAM, etc.) and a non-volatile memory (e.g., PROM, flash memory, magnetic, optical, etc.). The memory 210 stores a plurality of software modules including machine-readable instructions that, when executed by the at least one processor 208, cause the at least one processor 208 to implement the functions of the tractor 104 as described herein to operate autonomously within the autonomous yard 100 under the direction of the mission controller 102.

[0041] When the tractor 104 is an electric tractor, the tractor 104 also includes at least one drive motor 212, and the drive circuit 214 controls the drive motor 212 to mechanically drive a plurality of wheels (not shown) to maneuver the tractor 104. The drive circuit 214 includes a safety feature 215, which deactivates the movement of the tractor 104 if it is detected that the rotation of the drive motor 212 is blocked (e.g., stalled) and the current of the drive motor 212 reaches or exceeds a stall threshold (e.g., higher than 400A, 500A, 600A, 700A, etc., depending on the configuration of the drive motor 212) for a predetermined period of time (e.g., 5 seconds). Thus, when the tractor 104 is obstructed by an object, the safety feature 215 can prevent damage to the tractor 104 and / or other objects around the tractor 104. The safety feature 215 is described above with respect to electric tractors. It should be understood that diesel-based tractors can include similar safety features, such as reducing engine power when the RPM threshold is higher than a preset threshold. When the safety feature 215 is triggered, the tractor 104 needs to be manually reactivated to resume movement. Accordingly, the trip safety feature 215 is not ideal.

[0042] The tractor 104 also includes a positioning unit 216 (e.g., a GPS receiver) for determining the absolute position and orientation of the tractor 104, a plurality of cameras 218 for capturing images of objects around the tractor 104, and at least one laser detection and ranging (LiDAR) device 220 (hereinafter referred to as LiDAR 220) for determining a point cloud around the tractor 104. The positioning unit 216, the plurality of cameras 218, and the at least one LiDAR 220 cooperate with the controller 206 to achieve autonomous maneuverability and safety of the tractor 104. The tractor 104 includes a fifth wheel (FW) 222 for coupling the trailer 106 and a FW actuator 224, and the controller 206 controls the FW actuator 224 to position the FW 222 at a desired height. In some embodiments, the FW actuator 224 includes an electric motor coupled to a hydraulic pump, which drives a hydraulic piston to move the FW 222. However, without departing from the scope of the present invention, the FW actuator 224 may include other means for positioning the FW 222. The tractor 104 may also include an air actuator 238 and a brake actuator 239, wherein the air actuator 238 controls the air supplied to the trailer 106 and the brake actuator 239 controls the braking of the tractor 104 and the trailer 106 connected thereto via the air actuator 238.

[0043] The controller 206 also includes a trailer angle module 232 that determines a trailer angle 233 between the tractor 104 and the trailer 106 based on one or both of a trailer angle measured by an optical encoder 204 positioned near the FW 222 and mechanically coupled to the trailer 106 and a point cloud 221 captured by at least one LiDAR 220.

[0044] The controller 206 may implement a functional state machine 226 that controls the operation of the tractors 104 based on commands (requests) received from the mission controller 102. For example, the mission controller 102 may receive a request (e.g., via an API and / or via a GUI used by a dispatch operator) to move a trailer 106 from a first location (e.g., a slot X in the staging area 130) to a second location (e.g., a dock Y in the unloading area 140). Once the request is validated, the mission controller 102 invokes a mission planner (e.g., a software package, not shown) to calculate a "mission plan" for each tractor 104. For example, a mission plan is an ordered sequence of high-level primitives that a tractor 104 follows to move a trailer 106 from location X to location Y. The mission plan may include primitives such as driving along a first route, coupling a trailer 106 parked at location X, driving along a second route, dumping a trailer 106 into a dock, and decoupling from a trailer 106.

[0045] Functional state machine 226 includes a plurality of states, each state being associated with at least one software routine (e.g., machine-readable instructions) executed by processor 208 to implement a particular function of tractor 104. Functional state machine 226 may transition through one or more states as it follows primitives from mission controller 102 to complete mission planning.

[0046] The controller 206 may also include an articulation steering module 240 implemented as machine-readable instructions that, when executed by the processor 208 , cause the processor 208 to control the drive circuit 214 and the steering actuator 225 to steer the tractor 104 based on instructions from the mission controller 102 .

[0047] The controller 206 may also include a navigation module 234 that uses the position unit 216 to determine the current position and orientation of the tractor 104. The navigation module 234 may also use other sensors (e.g., the camera 218 and / or the LiDAR 220) to determine the current position and orientation of the tractor 104 using dead reckoning techniques.

[0048] Figure 3 To show Figure 1 A side view of the tractor 104 is shown backing up below the lower surface 302 of the trailer 106 . Figure 4 Shows Figures 1 to 3 An example coupling sequence 400 of the tractor 104 and trailer 106 implemented by the functional state machine 226 of the tractor 104 and an example detaching sequence 450 of the tractor 104 and trailer 106 implemented by the functional state machine 226 are shown. Figure 4 Also shown are example transitions between sequences when an alignment failure is detected (eg, when an activity in the current state fails for some reason), which allows the functional state machine 226 to recover from the failure (eg, undo certain actions) and retry the command. Figure 3 and Figure 4 It is best to refer to the following.

[0049] like Figure 3As shown, the landing gear 306 of the trailer 106 is fully extended so that the ground clearance of the lower surface 302 (e.g., FW deck) at the front end of the trailer 106 is sufficient to allow the FW 222 to be pushed under it when fully retracted without stalling the drive motor 212 of the tractor 104. That is, the power provided by the drive motor 212 is sufficient to push the FW 222 under the lower surface 302. However, when the trailer 106 is left in the staging area 130 of the autonomous cargo yard 100, the driver of the OTR tractor 108 extends the landing gear 306, so that the height of the lower surface 302 is determined by the driver and may not be consistent between trailers 106. In addition, the force required to move the FW 222 under the lower surface 302 also depends on the weight at the front end of the trailer 106 (e.g., the weight of the cargo). When the force provided by the drive motor 212 is not sufficient to push the FW 222 under the lower surface 302, for example, when the landing gear 306 is not fully extended, the drive motor 212 stalls.

[0050] In response to receiving the hitch command from the mission controller 102, once the tractor 104 is aligned with the trailer 106, in state 402, the controller 206 retracts the FW 222 and controls the drive circuit 214 to slowly move the tractor 104 backward, as shown by arrow 304. When the controller 206 detects that the FW 222 is below the lower surface 302 of the trailer 106, the drive motor 212 stops and the functional state machine 226 transitions to state 404. If the controller 206 determines that the tractor 104 is not properly aligned with the trailer 106, the functional state machine 226 transitions to state 458 of the unhook sequence 450 to try again. In state 404, the controller 206 controls the FW actuator 224 to lift the trailer 106 and controls the drive circuit 214 to back the tractor 104 and thus the FW 222 to the kingpin 308 of the trailer 106. In state 406, the controller 206 controls the FW actuator 224 to raise the FW 222 and thereby lift the front end of the trailer 106 for trailer connection (TC), such as the process of connecting the air lines / electrical lines from the tractor 104 to the trailer 106 using the trailer connector ID and orientation. In state 408, the controller 206 controls the drive circuit 214 to perform a towing test. If the controller 206 determines that the tractor 104 is not properly coupled to the trailer 106 (e.g., the kingpin is not locked), the functional state machine 226 transitions to state 458 of the unhook sequence 450 for another attempt. In state 410, the controller 206 controls the trailer air actuator 238 to perform a TC connection. If the controller 206 determines that the TC is not successfully connected, the functional state machine 226 transitions to state 454 of the unhook sequence 450 for another attempt. In state 412, the controller 206 controls the trailer air actuator 238 to supply trailer air and controls the FW actuator 224 to raise the FW 222 higher to ensure that the trailer landing gear is off the ground and ready to drive.

[0051] In response to receiving the unhitch command from the mission controller 1102, once the trailer 106 is properly positioned, in state 452, the controller 206 controls the trailer air actuator 238 to release the trailer air and controls the FW actuator 224 to lower the FW 222 and the front end of the trailer 106. In state 454, the controller 206 controls the trailer air actuator 238 to disconnect the TC from the trailer 106. In state 456, the controller 206 controls the drive circuit 214 to move the tractor 104 forward to perform the towing test. In state 458, the controller 206 controls the FW actuator 224 to lower the front end of the trailer 106 to the ground. In state 460, the controller 206 controls the FW actuator 224 to unlock from the trailer kingpin. In state 462, the controller 206 controls the FW actuator 224 to stow the FW 222 and controls the drive circuit 214 to move the tractor 104 forward away from the trailer 106.

[0052] Trailer angle measurement

[0053] Figure 5 Shows Figure 2 206 . The trailer angle module 232 includes a LiDAR angle estimator 510 for determining a LiDAR angle 512, which estimates the angle of the trailer 106 relative to the tractor 104 based on the point cloud 221 captured by the LiDAR 220 (including a point corresponding to the front end of the trailer 106). The trailer angle module 232 also includes an initial angle estimator 520, whose algorithm determines an optical trailer angle 522 based on an angle change 502 output by the trailer angle encoder 204 during a short-range movement of the tractor 104 and the trailer 106 (e.g., shortly after the trailer 106 is coupled / hook up to the tractor 104). The trailer angle module 232 also includes an encoder estimator 530, which updates the current trailer angle 233 based on the angle change 502. The encoder estimator 530 may include a Kalman filter 532 that processes the LiDAR angle 512 and the angle change 502 to generate the current trailer angle 233. For example, the Kalman filter 532 de-noises the LiDAR angle 512. The Kalman filter 532 estimates an unknown initial bias of the optical trailer angle 522 (e.g., incremental encoder data from the angle encoder 204) based on the LiDAR angle 512 determined from the LiDAR 220 (described below). The estimated bias is refined and removed from the angle change 502, resulting in a low-noise optical trailer angle 522. Short-range motion calculations may be used to remove further bias caused by a bent tandem axle and / or trailer, as described below.

[0054] Figure 6A schematic plan view of a tractor 104 backing a trailer 106 onto one of a plurality of adjacent docks 602(1)-602(5) of a cargo hold 110 is shown. The tractor 104 coupled to the trailer 106 may be referred to as a vehicle 612. Each of the docks 602(1)-602(5) has a corresponding loading door 604(1)-604(5), and as shown, a trailer 106(2) is parked at a dock 602(3). The trailer door is located behind the trailer 106, so the trailer 106 is backed onto the dock 602 and properly aligned with the loading door 604 to provide sufficient safe passage for the trailer 106. A reference path 606 may be defined for the dock 602(2) to help align the trailer 106(1) with the dock 602(2). When determining the steering angle 250 of the steer wheels 610 of the tractor 104 , the steering module 240 can predict the path 608 of the trailer 106 ( 1 ).

[0055] Figure 7 A schematic diagram is provided to illustrate example assumptions made by the steering module 240 of the tractor 104 when determining the steering angle 250 used to control the tractor 104 to reverse the trailer 106. For simplicity purposes, the tractor 104 and the trailer 106 are approximated as bicycle motion models with non-holonomic constraints. The front axle 702 of the tractor 104 is approximated as a single steerable model wheel 704 at the center of the axle, the rear axle 706 of the tractor 104 is approximated as a single non-steer model wheel 708 at the center of the axle, and the tandem axle 710 of the trailer 106 is approximated as a single non-steer model wheel 712 centered between the two axles of the tandem axle 710. This simplified representation of the tractor 104 and trailer 106 allows any complex dynamic interactions between the actual wheels to be ignored, and the non-holonomic constraints mean that there is no actual wheel lateral movement. As Figure 7 As shown, the tractor 104 is assumed to move along a circle 714 perpendicular to the non-steering model wheel 708 around the tractor rotation center 716, and the trailer 106 is assumed to travel along a circle 718 perpendicular to the non-steering model wheel 712 around the trailer rotation center 720. This assumption is generally safe when the tractor 104 and trailer 106 are moving at low speeds (e.g., less than 15 miles per hour). Other assumptions include: the tires do not deform, the tires are properly aligned along the axles, and the steering wheel motion of the front axle 702 is approximately the average wheel angle.

[0056] However, in order to accurately back the trailer 106 into the loading dock 602 ( 2 ), the tractor 104 needs to accurately know the position of the rear end of the trailer 106 and the non-steering model wheels 712 relative to the tractor 104 .

[0057] Figure 8Schematic diagram showing an example trailer angle encoder 800 positioned below the FW 222 of the tractor 104 and in a disengaged position when the tractor 104 is coupled (hitched) to the trailer 106. The trailer angle encoder 800 may represent Figure 2 A trailer angle encoder 204 is shown. Fig. 9 To show Figure 8 The trailer angle encoder 800 is shown in a schematic diagram of an engagement position mechanically coupled to the kingpin 308 of the trailer 106 when the tractor 104 and the trailer 106 are coupled to each other. The trailer angle encoder 800 measures the trailer angle by mechanically coupling with the kingpin 308 of the trailer 106. The trailer angle encoder 800 includes an arm 802, which is attached to the existing flange 806 of the FW 222 via a pivot 804. The optical encoder 808 is positioned at a first end of the arm 802 away from the pivot 804, so that it is positioned below the locking claw 810 of the FW 222 and can be pivoted away from the locking claw 810 of the FW 222. The trailer angle encoder 800 includes a disc 812 that is mechanically coupled to the input shaft of the optical encoder 808 and has a plurality of (e.g., three) vertical pins 814 (e.g., nails, teeth, blades, etc. that are perpendicular to the lower surface of the main pin 308) positioned around the upper surface of the disc 812. Figure 8 In the example of FIG. 1 , the solenoid 816 operates to compress the spring 818 and pull the second end (opposite the first end) of the arm 802 to retract the disc 812 and the pin 814 away from the pawl 810 (as indicated by arrow 820) when the tractor 104 moves under the trailer 106. Accordingly, when the pawl 810 captures the kingpin 308, the solenoid 816 is activated to move the disc 812, the pin 814, and the optical encoder 808 away from the FW 222, thereby preventing damage to the trailer angle encoder 800 during coupling and decoupling of the trailer 106 from the tractor 104. In other embodiments, the operation of the solenoid 816 and the spring 818 can be reversed, whereby when the tractor 104 and the trailer 106 are coupled to each other, the solenoid 816 is activated to move the disc 812, the pin 814, and the optical encoder 808 toward the FW 222. Other actuators may be used in place of the solenoid 816 and the spring 818 to move the arm 802 without departing from the scope of the present invention.

[0058] Fig. 9 Shows Figure 8The trailer angle encoder 800 is shown mechanically coupled to the kingpin 308, which is captured by the pawl 810 of the FW 222. When the pawl 810 captures the kingpin 308, the solenoid 816 is deactivated, thereby allowing the spring 818 to push the second end of the arm 802 downward, and the arm 802 pivots about the pivot 804 so that the first end of the arm 802 presses the pin 814 into the bottom surface (e.g., the kingpin flange) of the kingpin 308. The pin 814 can be separately spring loaded to ensure good contact when the bottom surface of the kingpin 308 is uneven, and the pin 814 is durable (e.g., made of hardened steel or titanium) and mechanically coupled to the bottom surface of the kingpin 308 to cause the disc 812 and the input shaft of the optical encoder 808 to rotate when the kingpin 308 rotates relative to the tractor 104. For example, the input shaft of the optical encoder 808 has minimal resistance to rotation and thus moves with the kingpin 308 through contact with the pin 814. Advantageously, once the trailer 106 is coupled to the tractor 104 , the solenoid 816 is deactivated and the spring 818 maintains pressure on the arm 802 and the pin 814 remains in contact with the kingpin 308 .

[0059] Figures 10 to 12 To illustrate another example, a trailer angle encoder 1000 is located at Figure 1 A schematic diagram of the lower portion of the FW 222 of the tractor 104 is shown. The trailer angle encoder 1000 may represent Figure 2 A trailer angle encoder 204 is shown. Fig.10 The trailer angle encoder 1000 is shown in a disengaged position when the tractor 104 is coupled (hooked) to the trailer 106. Fig.11 Shows Fig.10 The trailer angle encoder 1000 is shown in an engaged position mechanically coupled to the kingpin 308 of the trailer 106 when the tractor 104 and the trailer 106 are coupled to each other. Fig.12 The details of the vertically and horizontally adjustable arm 1002 of the trailer angle encoder 1000 are shown. The trailer angle encoder 1000 is similar to Figure 8 and Fig. 9 The trailer angle encoder 800 shown is different from the trailer angle encoder 1000 except that the trailer angle encoder 1000 includes a tapered adapter 1012 instead of the disc 812 and the pin 814 mechanically coupled to the kingpin 308, and includes a longitudinally and transversely adjustable arm 1002 instead of the arm 802. Accordingly, only the differences between the trailer angle encoder 1000 and the trailer angle encoder 800 will be described.

[0060] The tapered adapter 1012 is coupled to the input shaft of the optical encoder 808, and the tapered adapter 1012 tapers inward from a first diameter (smaller than the flange diameter of the kingpin 308) closest to the optical encoder 808 to a second diameter (larger than the flange diameter of the kingpin 308). The tapered adapter 1012 is at least partially formed of a flexible material (e.g., rubber, polyurethane, oil-resistant room temperature vulcanized (RTV) silicone, etc.), and the tapered adapter 1012 mechanically clamps the flange of the kingpin 308 when pressed against the flange of the kingpin 308, so that when the kingpin 308 rotates relative to the tractor 104, the input shaft of the optical encoder 808 rotates accordingly. Fig.10 As shown, when the tractor 104 is coupled to the trailer 106, the solenoid 816 is activated to move the tapered adapter 1012 out of the path of the kingpin 308. Fig.11 As shown, once the tractor 104 is coupled to the trailer 106 , the solenoid 816 is deactivated and the tapered adapter 1012 is pressed against the flange of the kingpin 308 by the spring 818 .

[0061] like Fig.12 As shown, the longitudinally adjustable arm 1002 allows longitudinal and lateral movement to allow the tapered adapter 1012 to be centered on the kingpin 308. The arm 1002 is formed by a first plate 1202 forming an aperture 1204 for fixing the optical encoder 808 and a second plate 1206 pivotally coupled to the pivot 804. The plates 1202 and 1206 are connected by two longitudinal axes 1208(1), 1208(2) to allow longitudinal movement of the plate 1202 relative to the plate 1206 (as shown by arrows 1205). Two springs 1210(1), 1210(2) are positioned on the longitudinal axis 1208(1), one on each side of at least a portion of the plate 1202. Similarly, two additional springs 1210(3), 1210(4) are positioned on the longitudinal axis 1208(2), one on each side of at least a portion of the plate 1202. Accordingly, the springs 1210 return the plate 1202 to a nominal longitudinally centered position when the tapered adapter 1012 is decoupled from the kingpin 308. The pivot 804 allows the plate 1206 to rotate about the pivot 804 and the plate 1206 to translate laterally along the pivot 804. Two springs 1212(1), 1212(2) are positioned on the pivot 804, one on each side of at least a portion of the plate 1206, to return the second plate 1206 to a nominal laterally centered position when the tapered adapter 1012 is decoupled from the kingpin 308.

[0062] In one embodiment, the optical encoder 808 is an optical quadrature encoder that generates an angle change 205 (e.g., a count of pulses indicating angle change over time) when the kingpin 308 (e.g., trailer 106) rotates relative to the tractor 104. For example, if θ is the angle of the trailer 106 relative to the tractor 104, the quadrature encoder counter output of a 1024-line encoder is given by:

[0063]

[0064] where θ0 is estimated by the Kalman filter.

[0065] The standard deviation of the quadrature encoder quantization noise is:

[0066]

[0067] The signal-to-noise ratio quantization ratio is:

[0068] 20log 10 (2 14 )=84dB

[0069] Accordingly, optical encoder 808 provides a high resolution measurement of the angular change between trailer 106 and tractor 104. However, the angle between tractor 104 and trailer 106 is unknown when tractor 104 is coupled to trailer 106, and thus the relative change in angular position provided by optical encoder 808 in angular change 502 cannot indicate the absolute angle between tractor 104 and trailer 106.

[0070] Determining trailer angle using LiDAR

[0071] Fig.13 The LiDAR 220 is shown mounted on the cab portion 1300 of the tractor 104 facing the trailer 106. The kingpin 308 of the trailer 106 is captured by the FW 222 and thus serves as the rotation point of the trailer 106 relative to the tractor 104. Fig.14 13 is a schematic diagram showing an example operation of the LiDAR 220 detecting the front corners 1302 , 1304 of the trailer 106 when the trailer 106 is in line with the tractor 104 . Fig.15 1 is a schematic diagram showing an example operation of the LiDAR 220 detecting the front corners 1302, 1304 of the trailer 106 when the trailer 106 is at a 20 degree angle to the tractor 104. As shown, the front corners 1302, 1304 (e.g., the front of the trailer 106) rotate about the kingpin 308. Fig.13 , Fig.14 and Fig.15 It is best to refer to the following.

[0072] The LiDAR 220 generates a point cloud 221 by scanning at least one light beam 1402 and detecting reflected light from objects in the light path. The LiDAR 220 is positioned on the rearward-facing surface of the cab portion 1300 of the tractor 104 so that the light beam 1402 scans over at least the front end of the trailer 106. Each point in the point cloud 221 defines a distance r and an angle θ. The following uses n-row column vectors (n≥2) and scalars M and b. When the light beam 1402 misses the front end of the trailer 106, r has a high value and is ignored for trailer angle calculation purposes. Accordingly, the light beams 1402 corresponding to the front corners 1302, 1304 of the trailer 106 can be easily identified in the data from the LiDAR 220.

[0073] [r,θ] LiDAR data (e.g. point cloud 221) is converted into [x,Y] coordinate form, that is:

[0074] Y=M·x+b

[0075]

[0076]

[0077] gives:

[0078] Trailer angle = tan -1 (M)

[0079] The LiDAR angle estimator 510 includes at least one algorithm that implements at least some of the above equations to determine the LiDAR angle 512 based on the point cloud 221. Advantageously, the LiDAR angle estimator 510 generates the LiDAR angle 512 independently of the specific dynamics (e.g., length) of the trailer 106. In some embodiments, the LiDAR angle estimator 510 can be called at intervals and / or on demand to generate the LiDAR angle 512 to check the current trailer angle 233 generated by other mechanisms, and / or input can be provided to update the current trailer angle 233.

[0080] Determine trailer angle by short-distance movement

[0081] In an alternative embodiment, the initial angle of the trailer 106 is estimated using a motion equation model, short-range movement of the tractor 104 and trailer 106, and the change in trailer angle measured by the trailer angle encoder 204. The motion equation model is defined as follows. The circular motion is defined as:

[0082] v=r*ω

[0083] gives:

[0084]

[0085] Where r is the radius of the circle (radius of curvature, ). The equations of motion for the tractor 104 and trailer 106 are defined as:

[0086]

[0087]

[0088]

[0089]

[0090] Where x and y are positions, θ is the heading of the tractor 104 , and θ is the heading of the trailer 106 .

[0091] Solving for the steering angle:

[0092]

[0093] Solving for the trailer angle (e.g., the angle between the tractor 104 and the trailer 106):

[0094]

[0095] Where L is the length of the tractor 104 (eg, the distance between the single steerable model wheel 704 and the single non-steer model wheel 708), and L2 is the length of the trailer 106 (eg, the distance between the kingpin 308 and the single non-steer model wheel 712).

[0096] Accordingly, the radius of curvature of the trailer 106 is:

[0097]

[0098] Figure 5 The illustrated initial angle estimator 520 may implement at least one algorithm based on the above equation to determine the optical trailer angle 522 based on the angle change 502. Advantageously, the initial angle estimator 520 operates independently of trailer specific details such as the length of the trailer 106. In one example of operation, the initial angle estimator 520 reads the trailer angle encoder 204 (e.g., to reset the quadrature encoder counter), controls the tractor 104 to move a short distance, and then reads the angle change 502 from the optical encoder 808. To ensure that no angle change is lost in the quantization noise, the short distance movement should be at least one meter. For example, a two and a half degree angle change requires a one meter movement to make a twenty-five meter radius turn. The initial angle estimator 520 then calculates the current angle of the trailer 106 relative to the tractor 104 based on the movement distance ΔS, the angle change 502, and the following equation.

[0099]

[0100] gives:

[0101]

[0102] The initial angle estimator 520 may be called after the tractor 104 is coupled to the trailer 106 to determine an optical trailer angle 522, which is used to determine an initial value for the current trailer angle 233. Thereafter, the encoder estimator 530 updates the current trailer angle 233 based on the angle change 502 from the trailer angle encoder 204 (e.g., from the optical encoder 808). In some embodiments, the initial angle estimator 520 is called at intervals or on demand to verify and / or update the current trailer angle 233.

[0103] In some embodiments, the encoder estimator 530 can process the angle change 502 and the LiDAR angle 512 to update the current trailer angle 233. The encoder estimator 530 can also process input from other mechanisms that determine the current trailer angle 233, such as determining the trailer angle based on images captured by the camera 218.

[0104] Mast-mounted LiDAR

[0105] In some embodiments, the LiDAR 220 can be mounted to a retractable mast on the tractor 104 so that it can be raised high enough to capture the trailer 106 and allow determination of the current trailer angle 233. For example, after the tractor 104 is coupled to the trailer 106 and when the tractor 104 is stationary, the mast can be extended to reduce the load on the extended mast. After capturing the LiDAR data, the mast can be retracted before the tractor 104 moves (e.g., to stay below the vehicle maximum height limit).

[0106] Fig.16 A perspective front view of a tractor 104 coupled to a trailer 106 is shown with a LiDAR 220 (3) mounted to an extendable mast 1620. In certain embodiments, the mast 1620 incorporates an upward facing sensor, range finder, or similar sensor to warn and prevent the extended mast from colliding with overhead obstacles. In addition, the mast 1620 can be stabilized by a guy wire (not shown) that is deployed from a damping reel to reduce the sway of the LiDAR 220 (3) when the mast 1620 is extended. Similarly, a horizontal extension arm can be included to extend one or more sensors (e.g., camera 218 and / or LiDAR 220) horizontally. By raising the sensors above the height of the trailer 106 or away from the sides of the trailer 106, the sensors are not blocked by the trailer 106, thereby improving the viewing angle of the trailer 106 relative to the position of the tractor 104.

[0107] For example, the mast 1620 may be implemented as a Rolatube TM (although other telescoping members may be used) that extend from the tractor 104 vertically, horizontally, or at some other angle to provide one or more sensors with a better view (e.g., a bird's eye view) of the trailer 106. For example, a Rolatube may provide 10 to 20 feet of telescoping, allowing sensors (e.g., camera 218 and / or LiDAR 220) to view the sides of the trailer 106 at nearly any setback position and angle. In some embodiments, the telescoping mast is mounted on a turret that continuously rotates about a vertical axis, and further, a second actuator may transform the turret from horizontal to vertical. The turret may include slip ring connections for power and signals.

[0108] Additionally, a motorized element at the end of the Rolatube can be used in conjunction with a turret to position one or more sensors at the edge or behind the trailer so that they can look to the rear.

[0109] Magnetically coupled trailer angle encoder

[0110] Fig.17 Schematic diagram showing an example magnetically coupled trailer angle encoder 1700 positioned below the FW 222 of the tractor 104 before the tractor 104 is coupled (hitched) to the trailer 106. The trailer angle encoder 1700 includes a spring plate 1702, a dual-axis positioning stage 1704, a bearing 1706 and an optical encoder 1708, a magnet 1710, and a gap cleaning block 1712. Fig.18 To show Fig.17 Schematic diagram of a magnetically coupled trailer angle encoder 1700 magnetically coupled to the king pin 308 of a trailer 106 coupled to a tractor 104. Fig.21 They are shown respectively Fig.17 and Fig.18 The spring plate 1702 is shown in side, top and front views. Fig. 22 A top view of the magnetically coupled trailer angle encoder 1700 is shown. Fig.23 , Fig.24 and Fig.25 They are Fig.17 and Fig.18 The dual-axis positioning stage 1710 is shown in front, side, and top views. Figures 17 to 25 It is best to refer to the following.

[0111] Trailer angle encoder 1700 is Figure 2An exemplary embodiment of the trailer angle encoder 204 is shown. The trailer angle encoder 1700 uses an optical encoder that is magnetically coupled to the kingpin 308 to measure the trailer angle of the trailer 106, thereby capturing the rotational movement of the trailer 106 relative to the tractor 104. The spring plate 1702 is made of, for example, spring steel and is attached to the FW 222 at a first end 1703. In some embodiments, the first end 1703 of the spring plate 1702 includes structure and / or fasteners that attach to the FW 222 below a flange or other structure and toward the rear of the FW 222 (relative to the tractor 104) without interfering with the coupling of the FW 222 to the kingpin 308 of the trailer 106. Figures 19 to 19 Fig.21 In the illustrated embodiment, the spring plate 1702 may be shaped to attach to either side of the rear opening of the FW 222 that receives the kingpin 308 .

[0112] The dual-axis positioning stage 1704 is attached to a second end 1705 (opposite to the first end 1703) of the spring plate 1702, whereby the spring plate 1702 positions the dual-axis positioning stage 1704 below the locking claw 810 of the FW 222. The dual-axis positioning stage 1710 movably supports a bearing 1706, and a shaft of the optical encoder 1708 passes through the bearing 1706 and is rigidly attached to the magnet 1710. Accordingly, the magnet 1710 is positioned below the locking claw 810 so that the magnet 1710 is attached to the main pin 308 when the locking claw 810 captures the main pin 308.

[0113] The gap cleaning block 1712 is a beveled, ridged block positioned immediately behind the dual axis positioning stage 1704. In certain embodiments, the block 1712 is a solid block and is made of a durable plastic or rubber, and the height 1713 of the block 1712 relative to the spring plate 1702 is greater than the height 1711 of the top surface of the magnet 1710. The two functions of the block 1712 are: (a) to clean the bottom surface of the kingpin 308 when the tractor 104 moves under the trailer 106 during hitch; and (b) to depress the spring plate 1702 and force it downward when the kingpin 308 passes over the spring plate 1702, thereby preventing the kingpin 308 from hitting the side of the magnet 1710. As the tractor 104 moves under the trailer 106, the block 1712 wipes dirt from the underside of the kingpin 308, and when the kingpin 308 is seated in the FW 222 and locked in place by the locking pawl 810, the block 1712 moves away from the kingpin 308. When the kingpin 308 moves away from the block 1712, the spring plate 1702 returns to its nominal position and the upper surface of the magnet 1710 contacts the (cleaned) lower surface of the kingpin 308.

[0114] Since the kingpin 308 is made of steel, the magnet 1710 magnetically adheres to the kingpin 308. The dual-axis positioning stage 1710 allows for a slight offset in the alignment of the shaft of the optical encoder 1708 with the center of rotation of the kingpin 308, allowing the kingpin 308 to move relative to the tractor 104 during maneuvering of the trailer 106. For example, the tractor 104 applies force to move the trailer 106, which may cause the kingpin 308 to move slightly relative to the FW 222.

[0115] The magnetic force attracts the magnet 110 to the kingpin 308, causing friction between the bottom surface of the kingpin 308 and the top surface of the magnet 1710. The kingpin 308 rotates relative to the FW 222 (e.g., the tractor 104), causing the angular force applied to the magnet 1710 to be greater than any combined angular resistance of the bearing 1706 and the optical encoder 1708. Accordingly, the rotation of the kingpin 308 causes the optical encoder 1708 to rotate.

[0116] As shown in Figure 19 to Fig.21 As shown, the first end 1703 of the spring plate 1702 can form two folding ears 2002, 2004, which are attached to the lower structure and rear of the FW 222 at intervals without preventing the main pin 308 from entering the locking claw 810. The spring plate 1702 can also form a notch 2006 at the second end 1705, and the notch 2006 receives the optical encoder 1708, which extends below the dual-axis positioning stage 1710 and allows electrical connection thereto. The notch 2006 can have other shapes and sizes without departing from the scope of the present invention.

[0117] like Figure 22 to Figure 25 As shown, the dual-axis positioning stage 1710 has a top platform 2202 forming a first aperture 2502 and four mounting holes 2504(1)-2504(4) for coupling an optical encoder 1708. The top platform 2202 also has four mounting holes 2506(1)-2506(4) for attaching the bearing 1706 to the top platform 2202. The top platform 2202 is slidably attached to two parallel crossbars 2302, allowing the top platform 2202 to slide as shown by arrows 2402. The intermediate structure 2304 supports the crossbars 2302 and is attached to the two parallel crossbars 2306, which are perpendicular to the crossbars 2302 and allow the intermediate structure 2304 to move as shown by arrows 2310. The crossbars 2306 are supported by a bottom structure 2308 fixedly attached to the spring plate 1702. Accordingly, relative to the spring plate 1702, the top platform 2202 has lateral movement as indicated by arrows 2402, 2310, but cannot rotate.

[0118] In certain embodiments, such as Fig.23As shown, the dual-axis positioning stage 1710 includes two springs 2312, 2314, each having a first end attached near the center of one side of the intermediate structure 2304 and an opposite end attached to the opposite end of the same side of the bottom structure 2308. When no force is applied to the top platform 2202, the springs 2312, 2314 operate to center the intermediate structure 2304 on the bottom structure 2308. The force applied by the springs 2312, 2314 is less than the force required to move the magnet 1710 against the main pin 308. That is, the springs 2312, 2314 center the intermediate structure 2304 on the bottom structure 2308 until the magnet is coupled with the main pin 308.

[0119] The above method and system may be modified without departing from the scope of the present invention. It should be noted that the above description, including or shown in the accompanying drawings, should be interpreted as illustrative rather than restrictive. The appended claims are intended to cover all general and specific features described herein and all statements of the scope of the present method and system, which are between the two in terms of language.

[0120] Feature combination

[0121] The above features and the features claimed below may be combined in various ways without departing from the scope of the present invention. The following examples illustrate some possible non-limiting combinations:

[0122] (A1) A trailer angle encoder for determining the angle between a tractor and a trailer coupled thereto, comprising: an arm body coupled at a pivot to a flange located below the fifth wheel of the tractor; an optical encoder positioned at a first end of the arm body and having a rotating shaft with a mechanical coupler, wherein the arm body is positioned so that the mechanical coupler is mechanically coupled to the kingpin of the trailer.

[0123] (A2) According to embodiment (A1), it also includes a solenoid that is mechanically coupled to the flange and is operable to move the second end of the arm body against the spring.

[0124] (A3) According to any one of embodiments (A1) or (A2), the solenoid causes the arm to disengage the mechanical coupler from the kingpin, and when the solenoid is deactivated, the spring causes the arm to engage the mechanical coupler with the kingpin.

[0125] (A4) According to any of embodiments (A1) to (A3), the solenoid causes the arm to engage the mechanical coupler with the kingpin.

[0126] (A5) According to any one of embodiments (A1) to (A4), the mechanical coupler includes: a disk body mechanically coupled to the rotating shaft; and a plurality of pins distributed around a first side of the disk body, wherein the tip of each pin is mechanically engaged with the bottom surface of the main pin.

[0127] (A6) According to any one of embodiments (A1) to (A5), the mechanical coupler includes a tapered adapter, which is fixedly coupled to the rotating shaft and whose taper gradually tapers inward from a first diameter closest to the optical encoder to a second diameter, wherein the first diameter is smaller than the flange diameter of the kingpin and the second diameter is larger than the flange diameter.

[0128] (A7) According to any of embodiments (A1) to (A6), the tapered adapter is at least partially formed of a flexible material, and the tapered adapter mechanically clamps the flange when pressed against the flange.

[0129] (A8) According to any one of embodiments (A1) to (A7), the arm body includes: a first plate forming the first end; a second plate coupled to the pivot; and at least one longitudinal axis coupling the first plate to the second plate and allowing the first plate to move longitudinally relative to the second plate, wherein the longitudinal movement allows the conical adapter to be longitudinally centered on the flange.

[0130] (A9) According to any one of embodiments (A1) to (A8), it also includes: at least two springs positioned on the longitudinal axis to return the first plate to a nominal longitudinal center position when the tapered adapter is disengaged from the flange.

[0131] (A10) According to any of embodiments (A1) to (A9), the pivot includes a transverse axis, which further allows lateral movement of the second plate, wherein the lateral movement allows the tapered adapter to be laterally centered on the flange.

[0132] (A11) According to any of embodiments (A1) to (A10), it also includes: at least two springs positioned on the transverse axis to return the second plate to a nominal lateral center position when the tapered adapter is disengaged from the flange.

[0133] (A12) According to any one of embodiments (A1) to (A11), the first plate forms an aperture for stabilizing the optical encoder.

[0134] (B1) A method for determining the angle between a tractor and a trailer coupled to each other comprises: controlling the tractor by a controller to pull the trailer a short distance; determining the angle change between the tractor and the trailer by an optical encoder assembled on the tractor and mechanically coupled to the trailer; and calculating the angle between the tractor and the trailer based on the angle change.

[0135] (B2) According to embodiment (B1), the calculating step includes evaluating the formula:

[0136]

[0137] Wherein φ is the heading of the tractor, θ is the heading of the trailer, L2 is the length of the trailer, and ΔS is the moving distance.

[0138] (C1) A trailer angle encoder for determining the angle between a tractor and a trailer coupled thereto, comprising: a spring plate for coupling to the underside of a fifth wheel of the tractor at a first end; an optical encoder attached to the spring plate; a magnet assembled to a rotating shaft of the optical encoder; and a gap cleaning block positioned on the spring plate to interact with a bottom surface of a kingpin of the trailer during coupling of the tractor to the trailer, wherein the magnet is magnetically coupled to the bottom surface of the kingpin when the tractor is coupled to the trailer.

[0139] (C2) According to embodiment (C1), the spring plate positions the magnet below the king pin.

[0140] (C3) According to any one of embodiments (C1) or (C2), it also includes: a two-axis positioning stage, which is assembled to the spring plate and has a platform supporting the optical encoder.

[0141] (C4) According to any of embodiments (C1) to (C3), the platform provides limited biaxial movement of the optical encoder and the magnet relative to the fifth wheel.

[0142] (C5) According to any one of embodiments (C1) to (C4), it also includes a bearing supported by the platform and coupled to the rotating shaft of the optical encoder.

[0143] (C6) According to any of embodiments (C1) to (C5), it also includes at least two springs for urging the platform to return to the nominal lateral center position when the magnet is not magnetically coupled to the kingpin.

[0144] (C7) According to any one of embodiments (C1) to (C6), the height of the gap cleaning block is greater than the top surface height of the magnet, and the king pin is urged to press down the gap cleaning block during the connection of the tractor to the trailer, so that the spring plate bends downward to prevent the king pin from contacting the side of the magnet.

[0145] (C8) As in any of embodiments (C1) to (C7), the gap cleaning block is positioned to stop the interaction of the magnet with the kingpin before the fifth wheel captures the kingpin.

[0146] (C9) According to any one of embodiments (C1) to (C8), the interaction between the gap cleaning block and the bottom surface of the kingpin wipes off the bottom dirt of the kingpin.

[0147] (D1) A software product comprising instructions stored on a non-transitory computer-readable medium, wherein the instructions, when executed by a processor, implement steps for determining an angle between a tractor and a trailer coupled to each other, the software product comprising the following instructions: controlling the tractor by a controller of the tractor to pull the trailer a short distance; determining an angle change between the tractor and the trailer by an optical encoder assembled on the tractor and mechanically coupled to the trailer; and calculating the angle between the tractor and the trailer based on the angle change.

[0148] (E1) A method for determining the angle between a tractor and a trailer coupled to each other comprises: within a controller of the tractor, capturing a point cloud using a rear-facing LiDAR positioned on the tractor; converting points in the point cloud corresponding to the front corners of the trailer into coordinate form; and calculating the angle between the tractor and the trailer based on the coordinates of the front corners of the trailer.

[0149] (E2) According to embodiment (E1), the converting step includes converting the point into a coordinate form, namely:

[0150] Y=M·x+b

[0151]

[0152]

[0153] Where x and Y are coordinates, and M and b are scalars.

[0154] (F1) A software product comprising instructions stored on a non-transitory computer-readable medium, wherein the instructions, when executed by a processor, implement steps for determining an angle between a tractor and a trailer coupled to each other, the software product comprising the following instructions: within a controller of the tractor, using a rear-facing LiDAR positioned on the tractor to capture a point cloud; converting points in the point cloud corresponding to front corners of the trailer into coordinate form; and calculating the angle between the tractor and the trailer based on the coordinates of the front corner of the trailer.

Claims

1. A trailer angle encoder for determining an angle between a tractor and a trailer coupled thereto, comprising: a spring plate for coupling at a first end to an underside of a fifth wheel of the tractor; an optical encoder attached to the spring plate; a magnet assembled to the rotating shaft of the optical encoder; a gap cleaning block positioned on the spring plate to interact with an underside of a kingpin of the trailer during coupling of the tractor to the trailer; Wherein, when the tractor is coupled to the trailer, the magnet is magnetically coupled to the bottom surface of the kingpin.

2. The trailer angle encoder according to claim 1, wherein: The spring plate positions the magnet below the kingpin. 3 . The trailer angle encoder according to claim 1 , further comprising a dual-axis positioning stage assembled to the spring plate and having a platform supporting the optical encoder.

4. The trailer angle encoder of claim 3, wherein the platform provides limited biaxial movement of the optical encoder and the magnet relative to the fifth wheel.

5. The trailer angle encoder of claim 3, further comprising a bearing supported by the platform and coupled to a rotation axis of the optical encoder.

6. The trailer angle encoder of claim 3, said dual-axis positioning stage further comprising at least two springs for urging said platform back to a nominal lateral centered position when said magnet is not magnetically coupled to said kingpin.

7. The trailer angle encoder according to claim 1, wherein the height of the gap cleaning block is greater than the top surface height of the magnet, and the king pin is urged to press down the gap cleaning block during the coupling of the tractor to the trailer, so that the spring plate bends downward to prevent the king pin from contacting the side of the magnet.

8. The trailer angle encoder of claim 7, said gap cleaning block being positioned to stop interaction of said magnet with said kingpin prior to said fifth wheel capturing said kingpin.

9. The trailer angle encoder according to claim 1, wherein: The interaction of the gap cleaning block with the bottom surface of the kingpin wipes dirt off the bottom of the kingpin.

Images