Device and method for detecting steering angle of hinge pin hinged vehicle

Abstract

The invention discloses a device and method for detecting the steering angle of a hinge pin hinged vehicle. The device comprises a front frame, a rear frame, a first steering oil cylinder, a second steering oil cylinder, a first displacement sensor, a second displacement sensor and a control module. The first displacement sensor is arranged in the first steering oil cylinder and used for detecting the telescopic stroke of the first steering oil cylinder in real time and forming first stroke data. The second displacement sensor is arranged in the second steering oil cylinder and used for detecting the telescopic stroke of the second steering oil cylinder in real time and forming second stroke data. The control module is used for calculating whether the steering angle is abnormal or not according to the first stroke data and the second stroke data. Structurally, the first displacement sensor and the second displacement sensor are arranged in the steering oil cylinder, the problem that an external angle encoder is exposed in a vehicle operation environment and is prone to damage is avoided, and whether the steering angle is abnormal or not is calculated in a geometric calculation mode of'reference distance + real-time stroke + cosine theorem '.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor vehicles, in particular to a pin shaft articulated vehicle steering angle detection device and method. BACKGROUND

[0002] In a pin shaft articulated vehicle (such as an engineering motor vehicle), the front and rear frames are relatively rotated through a middle hinge pin shaft, and accurate measurement of the steering angle is a core prerequisite for the vehicle to realize automatic steering, path planning and attitude stability control. At present, the commonly used steering angle measurement scheme in the industry is to install an angle encoder at the middle hinge position (i.e. the pin shaft articulation) of the front and rear frames, and to directly collect the relative rotation angle of the front and rear frames through the encoder.

[0003] However, the prior art has the following significant defects: Measurement error problem caused by pin shaft wear: the middle hinge pin shaft will be worn due to frequent rotation and load impact during long-term use of the vehicle, resulting in an increase in the fitting gap between the pin shaft and the hinge hole, and a shift in the relative position of the front and rear frames. In order to eliminate the influence of this shift on the measurement accuracy of the angle encoder, a complex mechanical compensation structure (such as an elastic compression mechanism, a gap adjustment assembly) needs to be designed, which not only increases the manufacturing cost and installation difficulty of the equipment, but also may further reduce the measurement stability due to the failure of the compensation structure.

[0004] Sensor damage problem: the angle encoder is installed externally (needs to be exposed near the middle hinge position), and the vehicle operating environment (such as dust, stone impact, vibration in the engineering site) is easy to cause damage to the encoder housing and failure of the internal components, thereby causing interruption of the steering angle detection and affecting the normal operation of the vehicle automatic steering function, and even causing safety hazards.

[0005] Therefore, there is an urgent need for a hinge vehicle steering angle detection scheme that can avoid sensor damage caused by external force impact and is not affected by pin shaft wear, and has fault diagnosis capability. SUMMARY

[0006] The main purpose of the present application is to provide a pin shaft articulated vehicle steering angle detection device and method, which aims to solve the technical problems of measurement error caused by pin shaft wear and sensor damage caused by external force impact in the prior art.

[0007] To achieve the above purpose, the pin shaft articulated vehicle steering angle detection device provided by the present application comprises a front frame, a rear frame, a first steering oil cylinder, a second steering oil cylinder, a first displacement sensor, a second displacement sensor and a control module. The front frame and the rear frame are rotationally hinged through a middle hinge pin shaft to form a hinge point O; one end of the first steering oil cylinder is hingedly connected with the front frame to form a hinge point A, and the other end is hingedly connected with the rear frame to form a hinge point B; one end of the second steering oil cylinder is hingedly connected with the front frame to form a hinge point A', and the other end is hingedly connected with the rear frame to form a hinge point B'; the first steering oil cylinder and the second steering oil cylinder are symmetrically distributed on both sides of the middle hinge pin shaft; The first displacement sensor is built in the first steering oil cylinder and is used for detecting the extension and contraction stroke of the first steering oil cylinder in real time and forming first stroke data; the second displacement sensor is built in the second steering oil cylinder and is used for detecting the extension and contraction stroke of the second steering oil cylinder in real time and forming second stroke data; The control module is used for calculating whether the steering angle is abnormal according to the first stroke data and the second stroke data.

[0008] Preferably, the control module comprises a data acquisition unit, and the data acquisition unit pre-stores reference distance data; The reference distance data comprises AO, BO, A'O, B'O, AB and A'B'; The AO is a reference distance from the A point to the O point; the BO is a reference distance from the B point to the O point; the A'O is a reference distance from the A' point to the O point; the B'O is a reference distance from the B' point to the O point, the AB is a reference distance from the A point to the B point; and the A'B' is a reference distance from the A' point to the B' point.

[0009] Preferably, the control module is electrically connected with the first displacement sensor and the second displacement sensor respectively; The control module further comprises a calculation unit, the calculation unit is used for acquiring the first stroke data and the reference distance data, and calculating the real-time distance between the hinge point A and the hinge point B to form real-time distance data AB; and is further used for acquiring the second stroke data and the reference distance data, and calculating the real-time distance between the hinge point A' and the hinge point B' to form real-time distance data A'B'; The calculation unit is further used for calculating the rotation angle value of ∠AOB according to the real-time distance data AB and the hinge point O, and calculating the rotation angle value of ∠A'OB' according to the real-time distance data A'B' and the hinge point O.

[0010] Preferably, the control module further comprises an alarm unit, and the alarm unit is electrically connected with the control module; The control module is further used for acquiring and comparing the two steering angles ∠AOB and ∠A'OB' to judge whether the rotation angle is accurate, whether the first displacement sensor and the second displacement sensor are faulty, and whether the middle hinge pin shaft is worn, and controls the alarm unit to send a warning signal.

[0011] Preferably, the AO=A'O, and the BO=B'O. A and A′ are symmetrically distributed with O as the center, and B and B′ are symmetrically distributed with O as the center; the center point between B and B′ forms the center point C, and the direction from C to O is perpendicular to the direction from A to A′.

[0012] Preferably, multiple tires are distributed on both sides of the bottom of the front frame and the rear frame, and the multiple tires roll in the same direction.

[0013] Multiple tires on both sides of the bottom of the front and rear frames roll in the same direction to ensure vehicle movement.

[0014] The present invention also proposes a method for detecting the steering angle of a pin-articulated vehicle, employing any one of the aforementioned pin-articulated vehicle steering angle detection devices. The method for detecting the steering angle of a pin-articulated vehicle includes the following steps: S1: Pre-measure and store reference distance data, which includes AO, BO, A′O, B′O, AB, and A′B′; AO is the reference distance from point A to point O; BO is the reference distance from point B to point O; A′O is the reference distance from point A′ to point O; B′O is the reference distance from point B′ to point O; AB is the reference distance from point A to point B; A′B′ is the reference distance from point A′ to point B′. S2: During vehicle operation, the first displacement sensor collects the extension and retraction stroke of the first steering cylinder in real time and outputs the first stroke data to the control module. The control module calculates the real-time distance data AB based on the first stroke data and the reference data AB. The second displacement sensor collects the extension and retraction stroke of the second steering cylinder in real time and outputs the second stroke data to the control module. The control module calculates the real-time distance data A′B′ based on the first stroke data and the reference data A′B′. S3: The control module calculates the steering angles according to the law of cosines: the first steering angle ∠AOB at the relative hinge point O between the front and rear frames is calculated using formula (1); the second steering angle ∠A′OB′ at the relative hinge point O between the front and rear frames is calculated using formula (2). ........(1) ...(2) In formula (1), AO and BO are the reference distance data AO and BO, and AB is the real-time distance data AB; in formula (2), A′O and B′O are the reference distance data A′O and B′O, and A′B′ is the real-time distance data A′B′. S4: Angle Verification and Fault Diagnosis: Calculate the difference Δθ between the first steering angle ∠AOB and the second steering angle ∠A′OB′; if Δθ ≤ a preset threshold, the current steering angle is deemed valid, and the average value of ∠AOB and ∠A′OB′ is taken as the final steering angle; if Δθ > a preset threshold, a fault is deemed to exist, including faults such as faults in the first displacement sensor, faults in the second displacement sensor, wear of the first steering cylinder, wear of the second steering cylinder, or wear of the center hinge pin, and a warning signal is issued.

[0015] Preferably, the preset threshold value in step S4 is in the range of 0.3° to 1°. When the vehicle is an engineering operation vehicle, the preset threshold value is 0.5° to 1°; when the vehicle is a precision transport vehicle, the preset threshold value is 0.3° to 0.5°.

[0016] Preferably, in step S2, the acquisition frequency of the first displacement sensor and the second displacement sensor is adjusted according to the vehicle's driving speed: the acquisition frequency is 10Hz-15Hz when driving at low speed (≤20km / h) and 20Hz-30Hz when driving at high speed (>20km / h) to ensure dynamic response.

[0017] Preferably, in step S4, if |∠AOB-∠A′OB′|>the preset threshold is detected N times consecutively and the difference shows an increasing trend, it is determined that the hinge pin is worn, and the control unit controls the alarm unit to issue a wear maintenance warning.

[0018] The technical solution of this invention systematically addresses the core pain points of existing pin-articulated vehicle steering angle detection from two aspects: structural design and detection method, as detailed below: Structurally, by embedding the first and second displacement sensors inside the steering cylinder, the problem of easy damage to external angle encoders exposed to the vehicle's operating environment (dust, gravel impact, vibration) is avoided, thus improving sensor durability. At the same time, the first and second steering cylinders are symmetrically distributed on both sides of the central hinge pin, laying a structural foundation for subsequent calculation of steering angle using the stroke data of the two cylinders, and realizing angle verification and fault diagnosis.

[0019] In terms of methodology, the steering angle is calculated using a geometric method of "baseline distance + real-time travel + cosine theorem" to determine whether the steering angle is abnormal. This improves the reliability of steering angle detection compared to single-sensor detection. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the pin-hinged vehicle steering angle detection device of the present invention.

[0022] Explanation of icon numbers: 1. Tire; 2. Front frame; 31. First displacement sensor; 32. Second displacement sensor; 41. First steering cylinder; 42. Second steering cylinder; 5. Rear frame; O. Hinge point between the front and rear frames; A. Hinge point between the first steering cylinder and the front frame; A′. Hinge point between the second steering cylinder and the front frame; B. Hinge point between the first steering cylinder and the rear frame; B′. Hinge point between the second steering cylinder and the rear frame; C. Center point between B and B′.

[0023] Purpose of the accompanying drawings: To illustrate the component composition of the vehicle, the location of the hinge points, and the installation location of the sensors, and to aid in understanding the technical solution of the present invention.

[0024] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0027] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0030] This invention proposes a device and method for detecting the steering angle of a pin-hinged vehicle.

[0031] Please refer to Figure 1 The pin-hinged vehicle steering angle detection device includes a front frame 2, a rear frame 5, a first steering cylinder 41, a second steering cylinder 42, a first displacement sensor 31, a second displacement sensor 32, and a control module. The front frame 2 and the rear frame 5 are rotatably hinged by a central hinge pin, forming hinge point O; one end of the first steering cylinder 41 is hinged to the front frame 2 to form hinge point A, and the other end is hinged to the rear frame 5 to form hinge point B; one end of the second steering cylinder 42 is hinged to the front frame 2 to form hinge point A′, and the other end is hinged to the rear frame 5 to form hinge point B′; the first steering cylinder 41 and the second steering cylinder 42 are symmetrically distributed on both sides of the central hinge pin. The first displacement sensor 31 is built into the first steering cylinder 41 and is used to detect the extension and retraction stroke of the first steering cylinder 41 in real time and generate first stroke data; the second displacement sensor 32 is built into the second steering cylinder 42 and is used to detect the extension and retraction stroke of the second steering cylinder 42 in real time and generate second stroke data. The control module is used to calculate whether the steering angle is abnormal based on the first stroke data and the second stroke data.

[0032] The technical solution of this invention systematically addresses the core pain points of existing pin-articulated vehicle steering angle detection from two aspects: structural design and detection method, as detailed below: Structurally, by embedding the first displacement sensor 31 and the second displacement sensor 32 inside the steering cylinder, the problem of easy damage to the external angle encoder exposed to the vehicle's operating environment (dust, gravel impact, vibration) is avoided, thus improving the durability of the sensors. At the same time, the first steering cylinder 41 and the second steering cylinder 42 are symmetrically distributed on both sides of the central hinge pin, laying a structural foundation for subsequent calculation of the steering angle through the stroke data of the two cylinders, and realizing angle verification and fault diagnosis.

[0033] In terms of methodology, the steering angle is calculated using a geometric method of "baseline distance + real-time travel + cosine theorem" to determine whether the steering angle is abnormal. This improves the reliability of steering angle detection compared to single-sensor detection.

[0034] Please refer to the appendix. Figure 1 The control module includes a data acquisition unit, which pre-stores reference distance data. The reference distance data includes AO, BO, A′O, B′O, AB, and A′B′; AO is the reference distance from point A to point O; BO is the reference distance from point B to point O; A′O is the reference distance from point A′ to point O; B′O is the reference distance from point B′ to point O; AB is the reference distance from point A to point B; and A′B′ is the reference distance from point A′ to point B′.

[0035] Provides a calculation benchmark to ensure accuracy: The data acquisition unit pre-stores benchmark distance data such as AO, BO, A′O, B′O, AB, and A′B′, eliminating the need to repeatedly measure the basic distance between fixed hinge points during vehicle operation. This reduces the computational load of real-time detection, improves efficiency, and provides a stable and accurate comparison benchmark for subsequent calculations of real-time distance data (such as real-time AB and A′B′) and steering angles, avoiding angle calculation errors caused by fluctuations in benchmark data.

[0036] Please refer to the appendix. Figure 1 The control module is electrically connected to the first displacement sensor 31 and the second displacement sensor 32 respectively; The control module further includes a calculation unit, which is used to acquire first travel data and reference distance data, calculate the real-time distance between hinge point A and hinge point B, and form real-time distance data AB; it is also used to acquire second travel data and reference distance data, calculate the real-time distance between hinge point A′ and hinge point B′, and form real-time distance data A′B′. The calculation unit is also used to calculate the turning angle value of ∠AOB based on the real-time distance data AB and the intersection point O; and to calculate the turning angle value of ∠A′OB′ based on the real-time distance data A′B′ and the intersection point O.

[0037] Eliminating pin wear error: The real-time AB and A′B′ distances are derived by combining “stroke data + reference distance data” through the calculation unit, and the rotation angles of ∠AOB and ∠A′OB′ are calculated based on the cosine theorem. This process does not directly depend on the mechanical fit accuracy of the central hinge pin, avoids the measurement error caused by the increased fit clearance after pin wear, eliminates the need to design complex mechanical compensation structures, and reduces equipment manufacturing costs and installation difficulty.

[0038] Dual-angle data support verification: Two symmetrical rotation angles (∠AOB, ∠A′OB′) are calculated simultaneously, providing "dual data comparison basis" for subsequent judgment of rotation accuracy and sensor failure. Compared with single-angle detection, this further improves the reliability of the detection results.

[0039] Please refer to the appendix. Figure 1 It also includes an alarm unit, which is electrically connected to the control module; The control module is also used to acquire and compare the two steering angles ∠AOB and ∠A′OB′ to determine whether the steering angle is accurate, whether the first displacement sensor 31 and the second displacement sensor 32 are faulty, and whether the central hinge pin is worn, and to control the alarm unit to issue a warning signal.

[0040] The alarm unit is linked with the control module. By comparing the difference between ∠AOB and ∠A′OB′, the control module can accurately identify three types of core problems (inaccurate steering angle, displacement sensor failure, and wear of the center hinge pin), avoiding safety hazards such as interruption of steering angle detection and loss of vehicle control caused by sensor failure or pin wear. At the same time, it issues warning signals in a timely manner, which makes it easier for operators to quickly troubleshoot faults and reduce vehicle maintenance costs and downtime losses.

[0041] Please refer to the appendix. Figure 1 , the AO=A′O, BO=B′O; A and A′ are symmetrically distributed with O as the center, and B and B′ are symmetrically distributed with O as the center; the center point between B and B′ forms the center point C, and the direction from C to O is perpendicular to the direction from A to A′.

[0042] By clearly defining AO=A′O and BO=B′O, and ensuring that A and A′, and B and B′ are symmetrical about O, reference distance data (such as AO and A′O, BO and B′O) can be accessed uniformly, reducing the storage of reference data and the parameter differences in the calculation process. At the same time, the direction from the center point C of B and B′ to O is perpendicular to the direction from A to A′, which can optimize the force balance during vehicle steering, avoid uneven cylinder wear caused by structural asymmetry, and indirectly extend the service life of the steering system.

[0043] Please refer to the appendix. Figure 1 The front frame 2 and the rear frame 5 are respectively provided with multiple tires 1 on both sides of the bottom, and the multiple tires 1 roll in the same direction.

[0044] Multiple tires 1 on both sides of the bottom of the front and rear frames 5 roll in the same direction to ensure vehicle movement.

[0045] The present invention also proposes a method for detecting the steering angle of a pin-articulated vehicle, employing any one of the aforementioned pin-articulated vehicle steering angle detection devices. The method for detecting the steering angle of a pin-articulated vehicle includes the following steps: S1: Pre-measure and store reference distance data, which includes AO, BO, A′O, B′O, AB, and A′B′; AO is the reference distance from point A to point O; BO is the reference distance from point B to point O; A′O is the reference distance from point A′ to point O; B′O is the reference distance from point B′ to point O; AB is the reference distance from point A to point B; A′B′ is the reference distance from point A′ to point B′. S2: During vehicle operation, the first displacement sensor 31 collects the extension and retraction stroke of the first steering cylinder 41 in real time and outputs the first stroke data to the control module. The control module calculates the real-time distance data AB based on the first stroke data and the reference data AB. The second displacement sensor 32 collects the extension and retraction stroke of the second steering cylinder 42 in real time and outputs the second stroke data to the control module. The control module calculates the real-time distance data A′B′ based on the first stroke data and the reference data A′B′. S3: The control module calculates the steering angles according to the law of cosines: the first steering angle ∠AOB between the front frame 2 and the rear frame 5 at the relative hinge point O is calculated using formula (1); the second steering angle ∠A′OB′ between the front frame 2 and the rear frame 5 at the relative hinge point O is calculated using formula (2). ........(1) ...(2) In formula (1), AO and BO are the reference distance data AO and BO, and AB is the real-time distance data AB; in formula (2), A′O and B′O are the reference distance data A′O and B′O, and A′B′ is the real-time distance data A′B′. S4: Angle Verification and Fault Diagnosis: Calculate the difference Δθ between the first steering angle ∠AOB and the second steering angle ∠A′OB′; if Δθ ≤ a preset threshold, the current steering angle is determined to be valid, and the average value of ∠AOB and ∠A′OB′ is taken as the final steering angle; if Δθ > a preset threshold, a fault is determined to exist, including faults in the first displacement sensor 31, the second displacement sensor 32, wear of the first steering cylinder 41, wear of the second steering cylinder 42, or wear of the central hinge pin, and a warning signal is issued.

[0046] The detection process is broken down into four steps: "pre-stored reference data → real-time acquisition of travel and calculation of real-time distance → cosine theorem calculation of angle → verification and fault diagnosis". The logic is clear and the operation is strong, ensuring that the detection can be performed stably under different working conditions. At the same time, the fault is judged by dual angle difference, which solves the problem of "unable to actively identify sensor or pin failure" in the existing technology, so that the steering angle detection has both "accuracy" and "fault tolerance".

[0047] Please refer to the appendix. Figure 1 The preset threshold value in step S4 is in the range of 0.3°~1°. When the vehicle is an engineering operation vehicle, the preset threshold value is 0.5°~1°; when the vehicle is a precision transport vehicle, the preset threshold value is 0.3°~0.5°.

[0048] Preset thresholds of 0.5°~1° and 0.3°~0.5° are set for engineering vehicles (which have relatively lenient requirements for steering accuracy) and precision transport vehicles (which have strict requirements for accuracy), respectively. This avoids the problem of insufficient adaptability of a "single threshold" to different types of vehicles (such as false alarms for engineering vehicles due to overly strict thresholds, and missed alarms for precision vehicles due to overly lenient thresholds), and improves the scenario applicability of the detection method.

[0049] Please refer to the appendix. Figure 1 In step S2, the sampling frequency of the first displacement sensor 31 and the second displacement sensor 32 is adjusted according to the vehicle speed: the sampling frequency is 10Hz-15Hz when driving at low speed (≤20km / h) and 20Hz-30Hz when driving at high speed (>20km / h) to ensure dynamic response.

[0050] The acquisition frequency is dynamically adjusted according to the vehicle's speed (10Hz~15Hz for low speeds and 20Hz~30Hz for high speeds). Reducing the frequency at low speeds can reduce the energy consumption of sensors and control modules and avoid resource waste. Increasing the frequency at high speeds can ensure the real-time acquisition of travel data and avoid deviations in steering angle calculation due to data lag, which is especially suitable for the dynamic steering control requirements of vehicles traveling at high speeds.

[0051] Please refer to the appendix. Figure 1 In step S4, if |∠AOB-∠A′OB′|>the preset threshold is detected N times consecutively and the difference shows an increasing trend, it is determined that the hinge pin is worn, and the control unit controls the alarm unit to issue a wear maintenance warning.

[0052] When the hinge pin wears and causes the clearance to increase, five consecutive measurements show that ∠AOB is 82.82°, 83.0°, 83.2°, 83.5°, and 83.8°, and ∠A′OB′ is 67.5°, 67.8°, 68.1°, 68.5°, and 68.9°, respectively. The difference increases from 15.32° to 14.9° (in reality, due to wear causing the hinge point to shift, the difference increases irregularly). The control unit determines that the pin is worn, triggering the instrument panel LED lights to flash and the buzzer to sound an alarm, prompting maintenance.

[0053] Example 1: Application of engineering work vehicles (wheel loaders) 1. Equipment Configuration Vehicle type: 5-ton wheel loader (for engineering operations, in environments with dust and gravel, with a travel speed of ≤30km / h). Pre-stored baseline data: Measure and store the baseline distances using a laser rangefinder: AO=A′O=800mm, BO=B′O=600mm, initial AB=A′B′=500mm; Threshold setting: The preset threshold for engineering operation vehicles is 0.8°; Acquisition frequency: 12Hz for low speed (≤20km / h, such as during loading operations) and 25Hz for high speed (>20km / h, such as during site transfer).

[0054] 2. Testing process S1: The control module data acquisition unit pre-stores the above-mentioned AO, BO, A′O, B′O, AB, and A′B′ reference data; S2: When the loader is loading gravel (vehicle speed 15km / h, low speed), the first displacement sensor 31 and the second displacement sensor 32 collect the extension and retraction strokes of the first steering cylinder 41 and the second steering cylinder 42 in real time (e.g., if the stroke of the first cylinder increases by 10mm, the stroke of the second cylinder decreases by 10mm). The control module combines the reference AB=500mm and A′B′=500mm to calculate the real-time AB=510mm and A′B′=490mm. S3: The control module calculates using the law of cosines: ; ; S4: Angle verification: Δθ=|38.2°-37.7°|=0.5°≤0.8° (preset threshold) determines that the steering angle is valid, and the final steering angle is the average value of 37.95°; if Δθ=1.2°>0.8° in a certain test, the control module determines the fault, triggers the alarm unit to issue an audible and visual warning, and prompts the operator to stop the machine for inspection.

[0055] Example 2: Application of Precision Transport Vehicles (Semiconductor Wafer Transport Vehicles) 1. Equipment Configuration Vehicle type: 2-ton semiconductor wafer transport vehicle (precision transport within the factory area, requiring high steering accuracy, driving speed ≤25km / h, and smooth road surface but avoiding vibration interference); Pre-stored benchmark data: Measure and store benchmark distances using a high-precision total station: AO=A′O=600mm, BO=B′O=450mm, initial AB=A′B′=350mm; Threshold setting: The preset threshold for precision transport vehicles is 0.4°; Data acquisition frequency: 10Hz for low speed (≤20km / h, such as shuttling within the factory area), and 20Hz for high speed (>20km / h, such as short-distance transfers between factories). 2. Testing process S1: The control module pre-stores the above-mentioned baseline data and loads the low-pass filter parameters at the same time; S2: When the transport vehicle is transporting wafers (vehicle speed 18km / h, low speed), the first displacement sensor 31 and the second displacement sensor 32 collect the stroke of the hydraulic cylinder (if the stroke of the first hydraulic cylinder decreases by 5mm, the stroke of the second hydraulic cylinder increases by 5mm). The control module filters the collected real-time AB and A′B′ data to eliminate the vibration interference from speed bumps, and calculates the real-time AB=345mm and A′B′=355mm. S3: The control module calculates using the law of cosines: ; ; S4: Angle verification: Δθ=|28.5°-29.0°|=0.5°>0.4° (preset threshold). The control module determines the fault (it was found that the first steering cylinder 41 had a slight wear of the seal, resulting in a deviation in the stroke data). The alarm unit is immediately triggered to issue a buzzer warning and simultaneously display "First cylinder wear, it is recommended to stop the machine for maintenance" on the cockpit display screen to avoid wafer transport deviation due to inaccurate steering angle.

[0056] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made under the concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A pin-hinged vehicle steering angle detection device, characterized in that, It includes a front frame, a rear frame, a first steering cylinder, a second steering cylinder, a first displacement sensor, a second displacement sensor, and a control module; The front frame and the rear frame are rotatably hinged by a central hinge pin, forming hinge point O; one end of the first steering cylinder is hinged to the front frame to form hinge point A, and the other end is hinged to the rear frame to form hinge point B; one end of the second steering cylinder is hinged to the front frame to form hinge point A′, and the other end is hinged to the rear frame to form hinge point B′; the first steering cylinder and the second steering cylinder are symmetrically distributed on both sides of the central hinge pin. The first displacement sensor is built into the first steering cylinder to detect the extension and retraction stroke of the first steering cylinder in real time and generate first stroke data; the second displacement sensor is built into the second steering cylinder to detect the extension and retraction stroke of the second steering cylinder in real time and generate second stroke data. The control module is used to calculate whether the steering angle is abnormal based on the first stroke data and the second stroke data.

2. The pin-hinged vehicle steering angle detection device according to claim 1, characterized in that, The control module includes a data acquisition unit, which pre-stores reference distance data. The reference distance data includes AO, BO, A′O, B′O, AB, and A′B′; AO is the reference distance from point A to point O; BO is the reference distance from point B to point O; A′O is the reference distance from point A′ to point O; B′O is the reference distance from point B′ to point O; AB is the reference distance from point A to point B; and A′B′ is the reference distance from point A′ to point B′.

3. The pin-hinged vehicle steering angle detection device according to claim 2, characterized in that, The control module is electrically connected to the first displacement sensor and the second displacement sensor respectively; The control module further includes a calculation unit, which is used to acquire first travel data and reference distance data, calculate the real-time distance between hinge point A and hinge point B, and form real-time distance data AB; it is also used to acquire second travel data and reference distance data, calculate the real-time distance between hinge point A′ and hinge point B′, and form real-time distance data A′B′. The calculation unit is also used to calculate the turning angle value of ∠AOB based on the real-time distance data AB and the intersection point O; and to calculate the turning angle value of ∠A′OB′ based on the real-time distance data A′B′ and the intersection point O.

4. The pin-hinged vehicle steering angle detection device according to claim 3, characterized in that, It also includes an alarm unit, which is electrically connected to the control module; The control module is also used to acquire and compare the two steering angles ∠AOB and ∠A′OB′ to determine whether the steering angle is accurate, whether the first displacement sensor and the second displacement sensor are faulty, and whether the central hinge pin is worn, and to control the alarm unit to issue a warning signal.

5. The pin-hinged vehicle steering angle detection device according to claim 2, characterized in that, The AO=A′O, BO=B′O; A and A′ are symmetrically distributed with O as the center, and B and B′ are symmetrically distributed with O as the center; the center point between B and B′ forms the center point C, and the direction from C to O is perpendicular to the direction from A to A′.

6. The pin-hinged vehicle steering angle detection device according to claim 1, characterized in that, Multiple tires are distributed on both sides of the bottom of the front frame and the rear frame, and the multiple tires roll in the same direction.

7. A method for detecting the steering angle of a pin-hinged vehicle, characterized in that, The method for detecting the steering angle of a pin-articulated vehicle using the pin-articulated vehicle steering angle detection device according to any one of claims 1-6 includes the following steps: S1: Pre-measure and store reference distance data, which includes AO, BO, A′O, B′O, AB, and A′B′; AO is the reference distance from point A to point O; BO is the reference distance from point B to point O; A′O is the reference distance from point A′ to point O; B′O is the reference distance from point B′ to point O; AB is the reference distance from point A to point B; A′B′ is the reference distance from point A′ to point B′. S2: During vehicle operation, the first displacement sensor collects the extension and retraction stroke of the first steering cylinder in real time and outputs the first stroke data to the control module. The control module calculates the real-time distance data AB based on the first stroke data and the reference data AB. The second displacement sensor collects the extension and retraction stroke of the second steering cylinder in real time and outputs the second stroke data to the control module. The control module calculates the real-time distance data A′B′ based on the first stroke data and the reference data A′B′. S3: The control module calculates the steering angles according to the law of cosines: the first steering angle ∠AOB at the relative hinge point O between the front and rear frames is calculated using formula (1); the second steering angle ∠A′OB′ at the relative hinge point O between the front and rear frames is calculated using formula (2). ........（1） .....（2） In formula (1), AO and BO are the reference distance data AO and BO, and AB is the real-time distance data AB; in formula (2), A′O and B′O are the reference distance data A′O and B′O, and A′B′ is the real-time distance data A′B′. S4: Angle Verification and Fault Diagnosis: Calculate the difference Δθ between the first steering angle ∠AOB and the second steering angle ∠A′OB′; if Δθ ≤ a preset threshold, the current steering angle is deemed valid, and the average value of ∠AOB and ∠A′OB′ is taken as the final steering angle; if Δθ > a preset threshold, a fault is deemed to exist, including faults such as faults in the first displacement sensor, faults in the second displacement sensor, wear of the first steering cylinder, wear of the second steering cylinder, or wear of the center hinge pin, and a warning signal is issued.

8. The method for detecting the steering angle of a pin-hinged vehicle according to claim 7, characterized in that, The preset threshold value in step S4 is in the range of 0.3°~1°. When the vehicle is an engineering operation vehicle, the preset threshold value is 0.5°~1°; when the vehicle is a precision transport vehicle, the preset threshold value is 0.3°~0.5°.

9. The method for detecting the steering angle of a pin-hinged vehicle according to claim 7, characterized in that, In step S2, the sampling frequency of the first displacement sensor and the second displacement sensor is adjusted according to the vehicle's driving speed: the sampling frequency is 10Hz-15Hz when driving at low speed (≤20km / h) and 20Hz-30Hz when driving at high speed (>20km / h) to ensure dynamic response.

10. The method for detecting the steering angle of a pin-hinged vehicle according to claim 7, characterized in that, In step S4, if |∠AOB-∠A′OB′|>the preset threshold is detected N times consecutively and the difference shows an increasing trend, it is determined that the hinge pin is worn, and the control unit controls the alarm unit to issue a wear maintenance warning.

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