Smart kingpin for omnidirectional towing force detection, and Anti-jackknifing control method

Abstract

A smart kingpin for omnidirectional towing force detection, and an anti-jackknifing control method. The axis of a kingpin (1) is provided with a through hole (14), and both ends of the through hole (14) are sealed. The smart kingpin comprises the kingpin (1) detachably mounted on a fifth wheel. The kingpin (1) comprises a connecting disc (11), a transition cylinder (12), and a pin body (13). The connecting disc (11), the transition cylinder (12), and the pin body (13) are of an integrated structure. The transition cylinder (12) is provided with an annular groove (121), and an elastomer (122) is arranged in the annular groove (121). The elastomer (122) and the transition cylinder (12) are of an integrated structure. Multiple strain gauges (123) are circumferentially arranged on the inner wall of the elastomer (122), and the strain gauges (123) are configured to detect towing force data and are connected to a processing system.

Description

Intelligent traction pin and anti-folding control method for omnidirectional traction force detection

[0001] This application claims priority to Chinese Patent Application No. 202520561007.4, filed with the Chinese Patent Office on March 28, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of tractor technology, for example to an intelligent traction pin for omnidirectional traction force detection and an anti-folding control method. Background Technology

[0003] In conventional semi-trailer traction systems, the drawbar, a key component connecting the tractor and trailer, typically employs a solid cylindrical structure. It achieves omnidirectional traction through a fixed fit with the tractor's saddle. However, this traditional drawbar serves only as a mechanical connection and cannot detect traction force data between the tractor and trailer in real time. Trailer handling systems rely on additional auxiliary equipment for traction force detection, leading to system complexity and increased costs. The dependence on auxiliary equipment for traction force detection introduces errors during signal transmission and processing, resulting in low detection accuracy and failing to meet the demands for high-precision traction force detection. The installation of auxiliary equipment also requires additional space, increasing system complexity and hindering maintenance and repair. In the context of rapid development in intelligent logistics and autonomous driving technologies, traditional drawbars cannot provide real-time data support, failing to meet the intelligent and data-driven needs of modern vehicles. Summary of the Invention

[0004] This application provides an intelligent traction pin for universal traction force detection. The intelligent traction pin for universal traction force detection includes a traction pin detachably mounted on a saddle. The traction pin has a through hole at its axis, and both ends of the through hole are sealed ends. The traction pin includes a connecting disc, a transition cylinder, and a pin body. The connecting disc, the transition cylinder, and the pin body are integrally formed. An annular groove is provided on the transition cylinder, and an elastic body is disposed within the annular groove. The elastic body and the transition cylinder are integrally formed. Multiple strain gauges are arranged circumferentially near the inner wall of the elastic body in the through hole. The strain gauges are configured to detect traction force data and are connected to a processing system.

[0005] In one embodiment, a plurality of temperature compensation plates are arranged circumferentially near the inner wall of the strain gauge in the through hole. The temperature compensation plates are configured to compensate the temperature of the strain gauge to improve the accuracy of traction force detection.

[0006] In one embodiment, the connecting plate is provided with a wire hole that communicates with the through hole, and the strain gauge and the temperature compensation plate are connected by a cable that passes through the wire hole and is connected to the processing system.

[0007] In one embodiment, the transition cylinder is provided with an auxiliary hole for accommodating a cable, and the auxiliary hole communicates with the through hole.

[0008] In one embodiment, the connecting plate is provided with a plurality of connecting holes along the circumference for fixed connection with the trailer.

[0009] In one embodiment, the elastomer is a cylindrical structure.

[0010] In one embodiment, the strain gauge is a double-bridge strain gauge, which is used to improve the accuracy and anti-interference capability of traction force detection.

[0011] This application provides an anti-folding control method applicable to intelligent traction pins for omnidirectional traction force detection as described in any of the above embodiments, the anti-folding control method comprising:

[0012] The strain signals of the longitudinal traction force and the lateral force on the traction pin are obtained, and the combined traction force vector is calculated.

[0013] Obtain the articulation angle of the main trailer and calculate the rate of change of the angle of the main trailer;

[0014] Based on the longitudinal traction force, the lateral force, and the rate of change of the included angle of the main trailer, it is determined whether the main trailer is at risk of folding. In response to the risk of folding, it is determined whether the main trailer is at tendency to fold based on the composite traction force vector. In response to the tendency of folding, the main trailer is controlled to execute an anti-folding control command to correct the driving posture of the main trailer.

[0015] In response to the completion of the driving posture correction of the main trailer, the main trailer is controlled to exit the anti-folding control command and adjust to the normal driving control mode.

[0016] In one embodiment, calculating the composite traction force vector includes:

[0017] The formula for calculating the magnitude of the composite traction force vector is: F = √(Fx² + Fy²).

[0018] The formula for calculating the direction of the combined traction force is: θF = arctan(Fy / Fx);

[0019] Wherein, F is the magnitude of the combined traction force vector, θF is the direction of the combined traction force, Fx is the longitudinal traction force, and Fy is the lateral force.

[0020] In one embodiment, calculating the rate of change of the included angle of the main trailer includes:

[0021] ;

[0022] in, The angle change rate of the main trailer; The angle between the main trailer and the trailer at the current moment; The angle between the main trailer and the trailer as described at the previous sampling time; The period is the signal sampling period.

[0023] In one embodiment, determining whether the main trailer is at risk of folding includes:

[0024] In response to the fact that the angle change rate of the main trailer exceeds a preset angle change rate threshold, posing a risk of folding; and / or,

[0025] In response to a risk of folding arising from a ratio exceeding a preset threshold value for the lateral force to the longitudinal traction force; and / or,

[0026] The risk of folding exists as the rate of change of the included angle of the main trailer and the rate of change of the lateral force continue to increase.

[0027] In one embodiment, the response to the continuously increasing rate of change of the included angle of the main trailer and the rate of change of the lateral force includes:

[0028] In response to and This is characterized by a continuous increase in the rate of change of the included angle of the main trailer and the rate of change of the lateral force.

[0029] in, The rate of change of the included angle of the main trailer is given. The rate of change of the lateral force is given.

[0030] In one embodiment, determining whether the main trailer has a folding tendency based on the composite traction force vector includes:

[0031] In response to the fact that the direction of the combined traction force is consistent with the deflection direction of the angle change rate of the main trailer, it is determined that there is a folding tendency, and the main trailer is controlled to execute an anti-folding control command.

[0032] The signal is determined to be an external interference signal because the direction of the combined traction force and the deflection direction of the rate of change of the angle between the main trailer and the main trailer are inconsistent.

[0033] In one embodiment, controlling the main trailer to execute the anti-folding control command includes:

[0034] The braking response speed of the main trailer is improved by means of the electric braking system (EBS) of the main trailer; and / or,

[0035] Reduce the braking force of the main trailer; and / or,

[0036] Limit the output torque of the main trailer; and / or,

[0037] A unilateral designation is performed on the main trailer to correct its driving posture. Attached Figure Description

[0038] Figure 1 is a schematic diagram from one perspective of the intelligent traction pin for universal traction force detection provided in an embodiment of this application;

[0039] Figure 2 is a schematic diagram from another perspective of the intelligent traction pin for universal traction force detection provided in an embodiment of this application;

[0040] Figure 3 is a cross-sectional view of an intelligent traction pin for universal traction force detection provided in an embodiment of this application;

[0041] Figure 4 is a flowchart of the anti-folding control method provided in the embodiment of this application.

[0042] In the picture:

[0043] 1. Traction pin; 11. Connecting disc; 12. Transition cylinder; 13. Pin body; 14. Through hole; 121. Annular groove; 122. Elastomer; 123. Strain gauge; 124. Temperature compensation gauge; 125. Auxiliary hole; 111. Wire hole; 112. Connecting hole. Detailed Implementation

[0044] This application provides an intelligent towing pin and anti-folding control method for universal traction force detection. It can not only detect the traction force data between the tractor and trailer in real time, but also simplify the system structure, improve the detection accuracy, provide data support for intelligent vehicle management, and thus improve driving safety and operational efficiency.

[0045] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0046] As shown in Figures 1-2, an embodiment of this application provides an intelligent traction pin for universal traction force detection, including a traction pin 1 detachably mounted on a saddle. The traction pin 1 has a through hole 14 at its axis, and both ends of the through hole 14 are sealed ends. The traction pin 1 includes a connecting plate 11, a transition cylinder 12, and a pin body 13. The connecting plate 11, the transition cylinder 12, and the pin body 13 are integrally formed. The transition cylinder 12 has an annular groove 121, and an elastic body 122 is disposed in the annular groove 121. The elastic body 122 and the transition cylinder 12 are integrally formed. Multiple strain gauges 123 are disposed circumferentially near the inner wall of the through hole 14 close to the elastic body 122. The strain gauges 123 are configured to detect traction force data and are connected to a processing system.

[0047] For example, the connecting disc 11 of the towing pin 1 is connected to the trailer. The saddle is first fixedly connected to the main vehicle. The locking mechanism on the saddle locks the pin 13 of the towing pin 1, so that the main vehicle and the trailer are connected. When the locking mechanism on the saddle releases the pin 13 of the towing pin 1, the main vehicle and the trailer are disengaged. An elastic body 122 is provided in the middle part of the transition cylinder 12. The elastic body 122 is a cylindrical tube. Its function is to generate a sufficiently large strain on the inner wall of the pin 13 under the external force, while meeting the connection strength required by the towing pin. The outer diameter of the elastic body is 68-72 mm, the inner diameter is 28-32 mm, and the height is 10-14 mm. Multiple strain gauges 123 are evenly attached to the inner wall of the through hole 14 near the elastic body 122.

[0048] Strain gauges 123 are located at the top of the inner wall of the elastic body 122 and are evenly distributed along the circumference of the through hole 14. Multiple temperature compensation plates 124 are arranged circumferentially near the strain gauges 123 in the through hole 14. The temperature compensation plates 124 are located at the bottom of the inner wall of the elastic body 122 and are evenly distributed along the circumference of the through hole 14. Through the strain gauges 123 evenly distributed circumferentially in the through hole 14, combined with the temperature compensation plates 124 that do not participate in force measurement, the common mode component caused by thermal expansion is eliminated in the bridge circuit. The direction and magnitude of the external force on the pin 13 are calculated and decomposed into front-back and left-right components according to the X and Y directions specified by the traction pin 1.

[0049] The strain gauge 123 and the temperature compensation gauge 124 are connected together by a cable and communicate with a processing system, which includes an operational amplifier circuit board and an electronic control system.

[0050] Strain gauge 123 is connected to an operational amplifier circuit board, which in turn is connected to the electronic control system. The circuit board acquires the resistance change of strain gauge 123, converts it into a traction force value, and outputs it to the controller area network (CAN) of the electronic control system, allowing the system to read and control the trailer.

[0051] When the tractor unit pulls the trailer, it applies traction force to the traction pin 1 through the saddle. The traction force is transmitted to the transition cylinder 12 and the elastic body 122 through the pin 13. The elastic body 122 undergoes slight deformation under the action of the traction force, and the deformation is proportional to the magnitude of the traction force. The strain gauge 123 senses the deformation of the elastic body 122 and generates a change in resistance, converting the mechanical signal into an electrical signal. The electrical signal of the strain gauge 123 is transmitted to the processing system through a cable. The processing system processes the signal and outputs traction force data. The processing system monitors the vehicle's operating status based on the traction force data and provides real-time feedback or control commands to ensure driving safety.

[0052] In the above structure, the elastic body 122 is a cylindrical tube. The largest strain portion of this structure is located at the top of the inner wall of the elastic body 122, where the strain gauge 123 is attached. This amplifies the strain generated by the external force on the traction pin. Through the cooperation of the elastic body 122 and the strain gauge 123, accurate traction force data can be detected under traction forces in different directions, achieving real-time detection and high-precision measurement of traction force. It also boasts advantages such as compact structure, convenient installation, and wide applicability. The placement of the elastic body 122 ensures uniform force distribution, avoids localized stress concentration, and provides a stable deformation signal for the strain gauge 123. The intelligent traction pin used for universal traction force detection not only improves the accuracy and reliability of traction force detection but also provides crucial support for intelligent vehicle management and driving safety, exhibiting broad application prospects and significant technological advantages.

[0053] As shown in Figures 1 and 3, in one embodiment, multiple temperature compensation plates 124 are circumferentially arranged on the inner wall of the through hole 14 of the intelligent traction pin for omnidirectional traction force detection, near the strain gauge 123. The temperature compensation plates 124 are configured to compensate for the temperature of the strain gauge 123, thereby improving the accuracy of traction force detection. Multiple temperature compensation plates 124 are attached to the inner wall of the through hole 14 below or above the strain gauge 123, and the strain gauge 123 and temperature compensation plates 124 are connected together by a cable and communicated with the processing system. The temperature compensation plates 124 are configured to eliminate the influence of temperature changes on the detection results of the strain gauge 123. The combined use of the temperature compensation plates 124 and the strain gauge 123 significantly improves the accuracy and reliability of traction force detection.

[0054] As shown in Figures 1 and 2, in one embodiment, the connecting disc 11 of the intelligent traction pin for universal traction force detection is provided with a wire hole 111. The wire hole 111 communicates with the through hole 14. The strain gauge 123 and the temperature compensation plate 124 are connected by cables, which pass through the wire hole 111 and connect to the processing system. The cables of the strain gauge 123 and the temperature compensation plate 124 can be centrally led out from the wire hole 111 and connected to the processing system. The wire hole 111 simplifies wiring, improves reliability, protects the cables, extends their service life, and improves installation convenience.

[0055] In one embodiment, the transition cylinder 12 of the intelligent traction pin for omnidirectional traction force detection is provided with an auxiliary hole 125 for accommodating cables, and the auxiliary hole 125 communicates with the through hole 14. The auxiliary hole 125 facilitates the accommodation of the cables of the strain gauge 123 and the temperature compensation plate 124, thereby improving the ease of installation of the strain gauge 123 and the temperature compensation plate 124.

[0056] As shown in Figures 1 and 2, in one embodiment, the connecting disc 11 of the intelligent tow pin for omnidirectional traction detection is provided with a plurality of connecting holes 112 along its circumference for fixed connection with the trailer. For example, eight connecting holes 112 are provided along the circumference of the connecting disc 11, and the tow pin 1 is fixed to the trailer by passing a self-locking bolt assembly through the connecting holes 112. This arrangement improves the ease of connecting the tow pin 1 to the trailer.

[0057] As shown in Figures 1 and 3, in one embodiment, the elastic body 122 of the smart traction pin for omnidirectional traction force detection is a cylindrical structure. The elastic body 122 is configured to match the annular groove 121, thereby ensuring uniform force distribution and accurate detection.

[0058] As shown in Figure 1, in one embodiment, the strain gauge 123 of the intelligent traction pin used for universal traction force detection is a double-bridge strain gauge 123. The double-bridge strain gauge 123 is configured to improve the accuracy and anti-interference capability of traction force detection. The application of the double-bridge strain gauge 123 can improve the accuracy and anti-interference capability of traction force detection.

[0059] It should be noted that this application uses multiple sets of double-bridge strain gauges 123 built into the traction pin 1 to form a Wheatstone full bridge, thereby achieving accurate calculation of the bridge output voltage signal to the six component forces (longitudinal traction force Fx, lateral force Fy, vertical force Fz, torque Mx around the X-axis, bending moment My around the Y-axis, and bending moment Mz around the Z-axis). The decoupled calculation method of voltage-strain-stress-six component forces is as follows:

[0060] Step 1: Convert the bridge output voltage into micro-strain of the elastic body

[0061] Six independent Wheatstone bridges are arranged circumferentially on the elastic body 122 inside the transition cylinder 12, corresponding to the six force measurement channels respectively. The output voltage of each bridge is Uo1, Uo2, Uo3, Uo4, Uo5, and Uo6. The strain gauge sensitivity coefficient is K, and the bridge circuit excitation power supply voltage is Uin. After the temperature drift interference is eliminated by the temperature compensation plate 124, the formula for calculating the micro-strain of the elastic body measured by each bridge is:

[0062] εi=4•Uoi / (K•Uin), (i=1,2,3,4,5,6);

[0063] In the formula: εi is the micro-strain of the elastic body corresponding to the i-th group of bridge circuits; Uoi is the output voltage of the i-th group of strain gauge bridge circuits; K is the strain gauge sensitivity coefficient; Uin is the bridge circuit excitation power supply voltage.

[0064] Step 2: Converting micro-strain into three-dimensional normal stress and shear stress

[0065] Based on the generalized Hooke's law, and combined with the elastic modulus E and Poisson's ratio ν of the elastomer material, the normal stresses in the X, Y, and Z directions, as well as the shear stress for torque calculation, are obtained through decoupling.

[0066] σx = E / (1-ν²)(εx + νεy);

[0067] σy=E / (1-ν²)(εy+νεx);

[0068] σz = E•εz;

[0069] τ=E / (2(1+ν))•(ε45°-ε135°);

[0070] In the formula: σx, σy, and σz are the normal stresses in the X, Y, and Z directions, respectively; τ is the shear stress of the elastic body; εx, εy, and εz are the corresponding axial strains; ε45° and ε135° are the output strains of the 45° and 135° oblique strain gauges, respectively; E is the elastic modulus of the elastic body material; and ν is the Poisson's ratio of the elastic body material.

[0071] Step 3: Converting stress into six components

[0072] Based on the effective cross-sectional area A of the elastic body ring under stress, the flexural section modulus W, and the torsional section modulus Wt, the stress is calculated as three-dimensional force and three-dimensional moment:

[0073] Fx = σx•A;

[0074] Fy = σy•A;

[0075] Fz = σz•A;

[0076] Mx = τ•Wt;

[0077] My = σy•W;

[0078] Mz = σx•W;

[0079] In the formula: Fx is the longitudinal traction force, Fy is the lateral force, Fz is the vertical force; Mx is the torque about the X-axis, My is the bending moment about the Y-axis, Mz is the bending moment about the Z-axis; A is the effective cross-sectional area of ​​the elastic body; Wt is the torsional section modulus of the elastic body; W is the bending section modulus of the elastic body.

[0080] Step 4: Precise compensation of the six-dimensional coupling decoupling matrix

[0081] Because the six components of the force under the traction pin exhibit mutual coupling interference, a 6×6 decoupling coefficient matrix C is obtained through actual vehicle calibration. The six components of the force are then directly calculated from the bridge output voltage to eliminate the coupling effects between different dimensions. The decoupling matrix formula is as follows:

[0082] [Fx; Fy; Fz; Mx; My; Mz]=[C11 C12 … C16; C21 C22 … C26; …; C61 C62 … C66]•[Uo1; Uo2; Uo3; Uo4; Uo5; Uo6];

[0083] In the formula: Cij is the six-dimensional decoupling coefficient obtained through calibration tests, which is used to compensate for the coupling interference between forces and moments in each direction.

[0084] Step 5: Simplified decoupling formula for anti-folding control

[0085] For the folding control of the main trailer (including the main vehicle and trailer, which are hinged together by intelligent towing pins) only requiring longitudinal traction force and lateral force, two sets of independent full-bridge measurements of the X-direction and Y-direction bridge voltages Uox and Uoy are used. The simplified decoupling formula is as follows:

[0086] Fx=EA / (1-ν²)(4Uox / (K Uin)+ν·4Uoy / (K Uin));

[0087] Fy=EA / (1-ν²)(4Uoy / (K Uin)+ν·4Uox / (K Uin));

[0088] The operational amplifier circuit board substitutes the collected bridge voltage into the above formula to calculate the longitudinal traction force Fx and the lateral force Fy in real time. Then, it synthesizes the traction force vector (which is a vector, including magnitude and direction) based on the longitudinal traction force Fx and the lateral force Fy, and transmits the traction force to the vehicle control unit (VCU) via the CAN bus. This provides core mechanical data support for subsequent assessment of the folding risk of the main trailer and attitude control.

[0089] This embodiment also provides an anti-folding control method applicable to the intelligent towing pin used for omnidirectional traction force detection in any of the above schemes. The anti-folding control method is shown in Figure 4, including: firstly, acquiring the longitudinal traction force and lateral force received by the towing pin 1, and synthesizing a traction force vector based on the longitudinal traction force and lateral force; acquiring the articulation angle of the main trailer and calculating the angle change rate of the main trailer; then, determining whether the main trailer has a folding risk based on the longitudinal traction force, lateral force, and angle change rate of the main trailer; in response to the folding risk of the main trailer, determining whether the main trailer has a folding tendency based on the synthesized traction force vector; in response to the folding tendency of the main trailer, controlling the main trailer to execute an anti-folding control command to correct the driving posture of the main trailer; in response to the completion of the driving posture correction of the main trailer, controlling the main trailer to exit the anti-folding control command and adjust to the normal driving control mode. The above control method can effectively correct the driving posture of the main trailer to prevent the main trailer from folding, providing important support for intelligent vehicle management and driving safety, and has broad application prospects and significant technical advantages.

[0090] In one embodiment, calculating the composite traction force vector includes:

[0091] The formula for calculating the magnitude of the composite traction force vector is: F = √(Fx² + Fy²).

[0092] The formula for calculating the direction of the composite traction force is: θF = arctan(Fy / Fx);

[0093] Where F is the magnitude of the resultant traction force vector, θF is the direction of the resultant traction force, Fx is the longitudinal traction force, and Fy is the lateral force.

[0094] It should be noted that a multi-dimensional force sensor is built into the traction pin 1. This sensor is integrated into the elastic body 122 within the annular groove 121 of the transition cylinder 12. It consists of circumferentially distributed double-bridge strain gauges 123 and temperature compensation gauges 124. The strain gauges 123 are arranged circumferentially along the top of the inner wall of the through hole 14 at 0°, 45°, 90°, and 135°, directly acquiring the strain signals generated by the longitudinal traction force and lateral force experienced by the traction pin 1. The temperature compensation gauges 124 are located at the bottom of the inner wall of the elastic body 122 and are only used to eliminate the interference of temperature changes on strain measurement; they do not participate in the acquisition of mechanical signals. The weak voltage signal acquired by the strain gauges 123 is amplified, filtered, and converted by an operational amplifier circuit board. Then, using the voltage-six-component force decoupling formula described above, the longitudinal traction force Fx and the lateral force Fy are obtained in real time through decoupling.

[0095] In one embodiment, calculating the rate of change of the included angle between the main trailer and the trailer includes:

[0096] ;

[0097] in, The angle change rate of the main trailer; The angle between the main trailer and the trailer at the current moment; The angle between the main trailer and the trailer as described at the previous sampling time; The signal sampling period is defined as follows. The VCU synchronously receives signals of the magnitude and direction of the synthetic traction force, the angle between the main trailer and the trailer, and the rate of change of the angle between the main trailer and the trailer. This completes signal synchronization, filtering, and time alignment, providing accurate data input for folding risk assessment.

[0098] In one embodiment, determining whether the main trailer is at risk of folding includes:

[0099] If the angle change rate of the main trailer exceeds a preset angle change rate threshold, there is a risk of folding; and / or,

[0100] If the ratio of lateral force to longitudinal traction exceeds a preset threshold, there is a risk of folding; and / or,

[0101] If the rate of change of the included angle between the main trailer and the trailer is determined and the rate of change of the lateral force continues to increase, then there is a risk of folding.

[0102] In one embodiment, determining that the rate of change of the included angle of the main trailer and the rate of change of the lateral force continue to increase includes:

[0103] like and This indicates that the rate of change of the included angle between the main trailer and the trailer, as well as the rate of change of the lateral force, continue to increase.

[0104] in, The rate of change of the included angle of the main trailer is given. This represents the rate of change of the lateral force.

[0105] In one embodiment, determining whether the main trailer exhibits a folding tendency based on the synthesized traction force vector includes:

[0106] First, the VCU controller cross-verifies the direction of the traction vector and the deflection direction of the angle change rate between the main trailer and the traction vector, distinguishing between the actual folding trend and external interference such as road bumps and crosswinds.

[0107] If the direction of the combined traction force is consistent with the deflection direction of the rate of change of the angle between the main trailer and the trailer, it is determined that there is a folding tendency, and the main trailer is controlled to execute the anti-folding control command.

[0108] If the direction of the combined traction force is inconsistent with the deflection direction of the rate of change of the angle between the main trailer and the trailer, it is determined to be an external interference signal.

[0109] In one embodiment, controlling the main trailer to execute anti-folding control commands includes:

[0110] The braking response speed of the main trailer is improved by the Electronic Braking System (EBS) of the main trailer; and / or, the braking force of the main trailer is reduced; and / or, the output torque of the main trailer is limited; and / or, unilateral designation is applied to the main trailer to correct its driving posture.

[0111] The VCU outputs graded control commands based on the fault classification logic (Level 1 general fault, Level 2 serious fault, Level 3 fatal fault), and the EBS and main vehicle braking system work together to execute control actions.

[0112] Prioritize EBS allocation, leveraging the millisecond-level rapid response of electric braking to enhance the braking response speed of the main and trailer vehicles; simultaneously reduce the braking force of the main and trailer vehicles to prevent lock-up deceleration from exacerbating trailer swaying; limit the output torque of the main and trailer vehicles, cutting off power input to prevent amplification of traction force and folding tendency; when a Level 3 fatal fault is determined and the risk of folding is extremely high, single-sided braking is applied to the main and trailer vehicles, using the difference in braking force between the left and right sides to assist in correcting the overall vehicle driving posture.

[0113] When the angle change rate of the main trailer falls back to the preset safe range, the lateral force satisfies |Fy|<0.1•|Fx|, and the traction vector direction returns to the longitudinal axis of the vehicle, the VCU gradually exits the anti-folding control strategy according to the sequence of first restoring the power of the main trailer and then restoring the braking system, and the main trailer returns to the normal driving control mode.

Claims

1. An intelligent traction pin for detecting omnidirectional traction force, comprising a traction pin (1) detachably mounted on a saddle, wherein the traction pin (1) has a through hole (14) at its axis, and both ends of the through hole (14) are sealed ends; the traction pin (1) comprises a connecting disc (11), a transition cylinder (12) and a pin body (13); the connecting disc (11), the transition cylinder (12) and the pin body (13) are integrally formed; the transition cylinder (12) is provided with an annular groove (121); an elastic body (122) is provided in the annular groove (121); the elastic body (122) and the transition cylinder (12) are integrally formed; a plurality of strain gauges (123) are provided circumferentially on the inner wall of the elastic body (122); the strain gauges (123) are configured to detect traction force data and be connected to a processing system.

2. The intelligent drag pin for universal drag force detection of claim 1, wherein, The through hole (14) is located near the inner wall of the strain gauge (123), and a plurality of temperature compensation plates (124) are arranged circumferentially thereon. The temperature compensation plates (124) are configured to compensate the temperature of the strain gauge (123) to improve the accuracy of traction force detection.

3. The intelligent drag pin for gimbal drag force detection of claim 2, wherein, The connecting plate (11) is provided with a wire hole (111), which is connected to the through hole (14). The strain gauge (123) and the temperature compensation plate (124) are connected by a cable, which passes through the wire hole (111) and is connected to the processing system.

4. The intelligent drag pin for universal drag force detection of claim 1, wherein, The transition cylinder (12) is provided with an auxiliary hole (125) for accommodating cables, and the auxiliary hole (125) is connected to the through hole (14).

5. The intelligent truing of universal traction force detection of claim 1, wherein, The connecting plate (11) is provided with a plurality of connecting holes (112) along the circumference for fixed connection with the trailer.

6. The intelligent truing of universal traction force detection of claim 1, wherein, The elastomer (122) has a cylindrical structure.

7. The intelligent truing of universal traction force detection of claim 1, wherein, The strain gauge (123) is a double-bridge strain gauge (123), which is configured to improve the accuracy and anti-interference capability of traction force detection.

8. A folding prevention control method, applicable to the intelligent traction pin for universal traction force detection as described in any one of claims 1-7, the folding prevention control method comprising: Obtain the longitudinal traction force and lateral force on the traction pin (1), and calculate the combined traction force vector based on the longitudinal traction force and lateral force; Obtain the articulation angle of the main trailer and calculate the rate of change of the angle of the main trailer; Based on the longitudinal traction force, the lateral force, and the rate of change of the included angle of the main trailer, it is determined whether the main trailer is at risk of folding. In response to the presence of a risk of folding in the main trailer, it is determined whether the main trailer has a tendency to fold based on the composite traction force vector. In response to the folding tendency of the main trailer, the main trailer is controlled to execute an anti-folding control command to correct the driving posture of the main trailer; In response to the completion of the driving posture correction of the main trailer, the main trailer is controlled to exit the anti-folding control command and adjust to the normal driving control mode.

9. The anti-fold control method of claim 8, wherein, The calculation of the combined traction force vector includes: The formula for calculating the magnitude of the composite traction force vector is: F = √(Fx² + Fy²). The formula for calculating the direction of the combined traction force is: θF = arctan(Fy / Fx); Wherein, F is the magnitude of the combined traction force vector, θF is the direction of the combined traction force, Fx is the longitudinal traction force, and Fy is the lateral force.

10. The anti-fold control method of claim 9, wherein, The calculation of the angle change rate of the main trailer includes: ； wherein a rate of change of the included angle for the host trailer; the main trailer angle for the current time instant; The angle between the main trailer and the trailer as described at the previous sampling time; The period is the signal sampling period.

11. The anti-folding control method according to claim 10, wherein, Determining whether the main trailer is at risk of folding includes: In response to the fact that the angle change rate of the main trailer exceeds a preset angle change rate threshold, posing a risk of folding; and / or, In response to a risk of folding arising from a ratio exceeding a preset threshold value for the lateral force to the longitudinal traction force; and / or, The risk of folding exists as the rate of change of the included angle of the main trailer and the rate of change of the lateral force continue to increase.

12. The anti-folding control method according to claim 11, wherein, In response to a continuous increase in the rate of change of the included angle of the main trailer and the rate of change of the lateral force, including: In response to and This is characterized by a continuous increase in the rate of change of the included angle of the main trailer and the rate of change of the lateral force. in, The rate of change of the included angle of the main trailer is given. The rate of change of the lateral force is given.

13. The anti-folding control method according to claim 9, wherein, Determining whether the main trailer exhibits a folding tendency based on the synthesized traction force vector includes: The direction of the combined traction force is consistent with the deflection direction of the rate of change of the angle between the main trailer and the tractor, and it is determined that there is a folding tendency. The signal is determined to be an external interference signal because the direction of the combined traction force and the deflection direction of the rate of change of the angle between the main trailer and the main trailer are inconsistent.

14. The anti-folding control method according to claim 8, wherein, Controlling the main trailer to execute the anti-folding control command includes: The braking response speed of the main trailer is improved by means of the electric braking system (EBS) of the main trailer; and / or, Reduce the braking force of the main trailer; and / or, Limit the output torque of the main trailer; and / or, A unilateral designation is performed on the main trailer to correct its driving posture.

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