Calibration rack with shaft for vehicle steering sensor

Abstract

The invention discloses a calibration rack with a shaft for a vehicle steering sensor, and relates to the technical field of sensor test equipment, the calibration rack comprises a rack and a steering measurement system, the steering measurement system comprises a data acquisition unit, a data analysis unit, a calibration control unit and a calibration burn-in unit; the sensor assembly is driven by the transmission mechanism to rotate, measurement is carried out while rotation is carried out, a measured value and an output value of the steering sensor are recorded and input into software of an upper computer at the same time, a PCB compensation parameter with the minimum mean square error is calculated, and then the PCB compensation parameter is burnt into a sensor chip through a programmer to be stored permanently. According to the invention, the dynamic optimization is completed under the condition of low investment, so that the torque signal output of any point in the full scale in a zero torque state is within 50% + / -0.5%, the calibration precision is ensured, an integrated equipment structure can be provided, and the operation is convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor testing equipment, and particularly to a shaft calibration bench for a vehicle steering sensor. Background Art

[0002] The use of a steering sensor requires the assembly of an input shaft, a torsion bar, and an output shaft. In the zero-torque state, the torque signal output should be 50%, and the current absolute angle should be readied for use by the steering controller. Therefore, a calibration process is required. Currently, there are two common practices in the industry. One is manual centering, rotating the relative positions of the input shaft and the output shaft so that the output of the torque signal is 50%, and fixing this relative position. The other method is to arbitrarily install the input shaft, the torsion bar, and the output shaft and fix them. The programmer calculates the current state to obtain a fixed offset value and writes it into the sensor chip for compensation calibration so that the output of the torque signal is 50%.

[0003] However, after the first manual mechanical centering, during the fixing process, it is easy to cause a deviation in position, resulting in the output of the torque signal exceeding the tolerance range of 50% ± 1%. The second single-point calibration method can only ensure that the output at the current position is 50% ± 0.5%. However, due to the machining tolerance chain of the input shaft, the torsion bar, and the output shaft, it cannot ensure that any point within the full range is within the tolerance range of 50% ± 1%.

[0004] In view of the above technical deficiencies, a solution is now proposed. Summary of the Invention

[0005] The object of the present invention is to achieve dynamic optimization with low investment, so that the torque signal output in the zero-torque state at any point within the full range is within 50% ± 0.5%, which not only ensures the calibration accuracy but also provides an integrated equipment structure for convenient operation.

[0006] To achieve the above object, the present invention adopts the following technical solution: A shaft calibration bench for a vehicle steering sensor, including a bench and a steering measurement system. A calibration bench is fixedly arranged inside the bench. A fixing groove is formed on the top surface of the calibration bench. A sensor assembly is arranged on the inner wall of the fixing groove. A hydraulic system is fixedly arranged on the top surface of the calibration bench. The bottom surface of the output end of the hydraulic system is connected to a transmission mechanism. A top chuck is fixedly arranged on the bottom surface of the transmission mechanism. A lifting mechanism is fixedly arranged on the bottom surface of the bench. The output ends of the lifting mechanism are respectively connected to a bottom chuck.

[0007] The steering measurement system includes a data acquisition unit, a data analysis unit, a calibration control unit, and a calibration programming unit.

[0008] The data acquisition unit is used to acquire the output parameters of the steering sensor during the calibration process. The output parameters include the absolute position of rotation and the corresponding torque signal, and send the output parameters to the data analysis unit;

[0009] The data analysis unit includes a parameter verification module and a parameter analysis module. The parameter verification module is used to acquire and process the output parameters. The self-calibration control unit acquires the stored standard parameters, verifies the output parameters one by one, eliminates invalid parameters to obtain the standard experimental data axis, and sends it to the parameter analysis module;

[0010] The parameter analysis module is used to acquire and process the standard experimental data axis, obtain the target parameters from the standard experimental data axis, calculate the PCB compensation parameters according to the optimization compensation algorithm, and send the PCB compensation parameters to the calibration and programming unit;

[0011] The calibration control unit is used to store the standard parameters and calibration operation steps during the calibration process, generate calibration control instructions according to the preset calibration period, and control the hydraulic system, lifting system and transmission system according to the calibration control instructions to achieve an automated control process;

[0012] The calibration and programming unit is used to acquire and process the PCB compensation parameters, verify the PCB compensation parameters, so that the mean square error value between the output values of the torque signals after compensation at all acquisition points and the preset standard torque signal output value reaches the preset minimum value, and program it into the sensor chip.

[0013] Furthermore, the sensor assembly includes an outer rotor and an input shaft. The outer rotor is sleeved on the outer surface of the input shaft. The outer rotor is fixed on the inner wall of the fixed groove. A sensor card slot is provided on the outer surface of the outer rotor. The bottom surface of the outer rotor is movably connected to an output shaft.

[0014] Furthermore, the transmission mechanism includes a rotating motor and a connecting shaft. The rotating motor is connected to the outer surface of the output end of the hydraulic system. The connecting shaft is fixed on the outer surface of the output end of the rotating motor. The upper chuck is fixed on the bottom surface of the connecting shaft.

[0015] Furthermore, the lifting mechanism includes a guide shaft and an electric telescopic rod. A plurality of the guide shafts are fixed between the calibration table and the bench. A lifting bottom plate is sleeved on the outer surface of the guide shaft. A lifting push plate is movably sleeved on the outer surface of the guide shaft. The electric telescopic rod is fixed between the lifting bottom plate and the lifting push plate. The upper chuck and the lower chuck are respectively fixed on the outer surface of the lifting push plate.

[0016] Furthermore, the upper chuck and the lower chuck are arranged oppositely. The upper chuck is in movable contact with the top surface of the sensor assembly, and the lower chuck is in movable contact with the bottom surface of the sensor assembly.

[0017] Further, the specific process of obtaining the standard experimental data axis is as follows:

[0018] S101. Obtain output parameters, where the output parameters include the absolute position of rotation and the corresponding torque signal. Taking the center position of the output shaft as the origin, and using the transverse and longitudinal directions of the calibration table as the X-axis and Y-axis respectively, establish a plane coordinate system;

[0019] S102. Mark the steering sensor fixed outside the output shaft as M, and then obtain the absolute position of the steering sensor, that is, the initial coordinate information M(xm, ym). At the same time, obtain the torque output signal K in the zero-torque state;

[0020] S103. Establish a time axis according to the preset calibration period during the calibration operation. Obtain several output parameters during the calibration operation, and mark the moment when the output parameters are obtained as detection nodes, and mark the output parameters on the time axis in sequence;

[0021] S104. The calibration control unit obtains the stored standard parameters, that is, the standard position information Mi(xi, yi) and the corresponding torque signal Ki during the calibration process, and calculates the calibration deviation coefficient Yi according to the following formula: where e1 and e2 are preset proportionality coefficients. The calibration deviation coefficient is used to represent the deviation degree between the standard parameters and the output parameters during the actual calibration process. The larger the calibration deviation coefficient, the greater the deviation degree, and vice versa, the smaller the calibration deviation coefficient, the smaller the deviation degree;

[0022] S105. Obtain the preset deviation judgment threshold. If the calibration deviation coefficient is greater than the deviation judgment threshold, mark the corresponding output parameter as an invalid parameter and remove it from the time axis to obtain the final standard experimental data axis.

[0023] Further, the specific process of calculating the PCB compensation parameter is as follows:

[0024] S201. Construct a PCB compensation circuit model and analyze the compensation factors during PCB transmission, specifically as follows:

[0025] The compensation factors include signal propagation delay compensation, impedance matching compensation, and temperature compensation;

[0026] Calculate the signal propagation delay compensation parameter te according to the following formula: where εr is the relative dielectric constant of the PCB material, C is the speed of light, S0 is the length of the signal line, t0 is the standard signal propagation duration, and α is a preset proportionality coefficient;

[0027] Calculate the impedance matching compensation parameter Z0 according to the following formula: where h is the distance from the torque signal layer to the formation, and ω is the width of the signal line;

[0028] Calculate the temperature compensation parameter Tr according to the following formula: where T0 is the standard temperature data of the signal line during the transmission of the torque signal, Ti is the actual temperature data of the signal line during the transmission of the torque signal, and β is a preset proportionality coefficient;

[0029] Obtain the expressions of the PCB standard parameters and the parameter influence coefficients as follows:

[0030] where Hk is the width of the signal line, Sk is the curvature of the routing path of the PCB, and mi is the number of resistors with temperature compensation characteristics, S0 is the length of the signal line, d is a preset constant, and di is the original number of resistors;

[0031] S202. Determine the optimized target parameters and the objective function for parameter optimization according to the expressions of the PCB standard parameters and the parameter influence coefficients, and determine the constraint conditions according to the requirements of the PCB standard parameters and the parameter influence coefficients;

[0032] S203. Use the particle swarm optimization algorithm to optimize the parameters and obtain the optimal parameters of the PCB compensation circuit model.

[0033] Furthermore, the specific process of burning into the sensor chip is as follows:

[0034] S301. Integrate the verified PCB compensation parameters into a parameter file, load the parameter file to be burned into the software of the burning tool, and connect the burning tool to the sensor chip;

[0035] S302. Write the parameter file into the memory of the sensor chip through the burning software, compare the MD5 value of the file in the burning software with the MD5 value of the original file stored in the memory of the sensor chip, and verify the correctness of the file in the burning software;

[0036] S303. After the burning is completed, perform a running test on the sensor chip to ensure that the hardware device can operate as expected.

[0037] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

[0038] The shafted calibration bench of the vehicle steering sensor drives the rotation of the sensor assembly through a transmission mechanism, measures while rotating, records the measured value and the output value of the steering sensor simultaneously and inputs them into the software of the host computer, calculates the PCB compensation parameter with the smallest mean square error, and then burns it into the sensor chip through a programmer for permanent storage. Then, repeat the rotation and measurement of the full range to determine whether the output of the torque signal meets the requirement that the torque signal output under the zero torque state at any point within the full range is within 50% ± 0.5%. It realizes dynamic optimization with low investment, makes the torque signal output under the zero torque state at any point within the full range within 50% ± 0.5%, not only ensures the calibration accuracy, but also can provide an integrated equipment structure and is convenient to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Shows the overall external structure schematic diagram of the present invention;

[0040] Figure 2 Shows the overall external structure schematic diagram of another angle of the present invention;

[0041] Figure 3 Shows the structure schematic diagram of the steering measurement system of the present invention;

[0042] Legend: 1. Bench; 2. Calibration bench; 3. Upper chuck; 4. Lower chuck; 5. Outer rotor; 6. Input shaft; 7. Sensor slot; 8. Output shaft; 9. Rotating motor; 10. Connecting shaft; 11. Guide shaft; 12. Lifting bottom plate; 13. Lifting push plate; 14. Electric telescopic rod. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0044] Embodiment 1:

[0045] As Figure 1-2 shown, a shafted calibration bench of a vehicle steering sensor includes a bench 1 and a steering measurement system. A calibration bench 2 is fixedly arranged inside the bench 1. A fixing groove is formed on the top surface of the calibration bench 2, and a sensor assembly is arranged on the inner wall of the fixing groove. A hydraulic system is fixedly arranged on the top surface of the calibration bench 2. The output end of the hydraulic system is connected to a transmission mechanism at the bottom surface, and an upper chuck 3 is fixedly arranged at the bottom surface of the transmission mechanism. A lifting mechanism is fixedly arranged at the bottom surface of the bench 1, and the output ends of the lifting mechanism are respectively connected to a lower chuck 4;

[0046] The sensor assembly includes an outer rotor 5 and an input shaft 6. The outer rotor 5 is sleeved on the outer surface of the input shaft 6. The outer rotor 5 is fixed to the inner wall of the fixed groove. A sensor card slot 7 is formed on the outer surface of the outer rotor 5. The bottom surface of the outer rotor 5 is movably connected to an output shaft 8.

[0047] The transmission mechanism includes a rotating motor 9 and a connecting shaft 10. The rotating motor 9 is connected to the outer surface of the output end of the hydraulic system. The connecting shaft 10 is fixed to the outer surface of the output end of the rotating motor 9. The upper chuck 3 is fixed to the bottom surface of the connecting shaft 10.

[0048] The lifting mechanism includes a guide shaft 11 and an electric telescopic rod 14. A plurality of guide shafts 11 are fixed between the calibration table 2 and the bench 1. A lifting bottom plate 12 is sleeved on the outer surface of the guide shaft 11. A lifting push plate 13 is movably sleeved on the outer surface of the guide shaft 11. The electric telescopic rod 14 is fixed between the lifting bottom plate 12 and the lifting push plate 13. The upper chuck 3 and the lower chuck 4 are respectively fixed to the outer surface of the lifting push plate 13.

[0049] The upper chuck 3 and the lower chuck 4 are arranged oppositely. The upper chuck 3 is in movable contact with the top surface of the sensor assembly, and the lower chuck 4 is in movable contact with the bottom surface of the sensor assembly.

[0050] The working process is as follows:

[0051] After starting the bench 1, static calibration is first performed, that is, single-point calibration. The torque signal at the current position is written into the offset value so that the torque output signal in the zero-torque state is 50%;

[0052] Control the hydraulic system to drive the upper chuck 3 to drop and clamp the input shaft 6, and then control the lower chuck 4 to relax, so that the sensor maintains a zero-torque state during rotation. Rotate the upper chuck 3 clockwise by 360° for forward optimization compensation, and then rotate it counterclockwise by 360° for reverse optimization compensation, and return to the starting point;

[0053] During the rotation process, the absolute position of the rotation and the output of the corresponding torque signal are recorded in real time. The PCB compensation parameters are calculated through the optimization compensation algorithm, so that the mean square error value between the torque signal output values after compensation of all acquisition points and 50% is minimized, and burned into the sensor chip;

[0054] Control the steering sensor to power off and reset, start the final inspection, control the upper chuck 3 to rotate clockwise by 360°, and then rotate it counterclockwise by 360° to measure and record the output of the torque signal in real time and make a judgment with 50% ± 0.5%. Then control the lifting mechanism to drive the lower chuck 4 to move upward, and then clamp the output shaft 8. Rotate the upper chuck 3 to measure other test items with torque;

[0055] After the final inspection is completed, first control the lifting mechanism to release the lower chuck 4, then release the upper chuck 3, and finally take out the workpiece and place it properly.

[0056] Embodiment 2:

[0057] As Figure 3 shown, a shaft calibration bench for a vehicle steering sensor includes a bench 1 and a steering measurement system. The steering measurement system includes a data acquisition unit, a data analysis unit, a calibration control unit, and a calibration programming unit;

[0058] The data acquisition unit is used to acquire the output parameters during the calibration process of the steering sensor. The output parameters include the absolute position of rotation and the corresponding torque signal, and send the output parameters to the data analysis unit;

[0059] The data analysis unit includes a parameter verification module and a parameter analysis module. The parameter verification module is used to acquire and process the output parameters. The calibration control unit acquires the stored standard parameters, verifies the output parameters one by one, eliminates the invalid parameters to obtain the standard experimental data axis, and sends it to the parameter analysis module;

[0060] The specific process of obtaining the standard experimental data axis is as follows:

[0061] S101. Acquire the output parameters. The output parameters include the absolute position of rotation and the corresponding torque signal. Take the center position of the output shaft 8 as the origin, and take the horizontal and vertical directions of the calibration bench 2 as the X-axis and Y-axis respectively to establish a plane coordinate system;

[0062] S102. Mark the steering sensor fixed outside the output shaft 8 as M, and then acquire the absolute position of the steering sensor, that is, the initial coordinate information M(xm, ym), and at the same time obtain the torque output signal K in the zero torque state;

[0063] S103. Establish a time axis according to the preset calibration period during the calibration operation. Obtain several output parameters during the calibration operation, mark the moment when the output parameters are obtained as the detection nodes, and mark the output parameters on the time axis in turn;

[0064] S104. The calibration control unit acquires the stored standard parameters, that is, the standard position information Mi(xi, yi) and the corresponding torque signal Ki during the calibration process, and calculates the calibration deviation coefficient Yi according to the following formula: where e1 and e2 are preset proportionality coefficients. The calibration deviation coefficient is used to represent the deviation degree between the standard parameters and the output parameters in the actual calibration process. The larger the calibration deviation coefficient, the greater the deviation degree. On the contrary, the smaller the calibration deviation coefficient, the smaller the deviation degree;

[0065] S105. Obtain the preset deviation judgment threshold. If the calibrated deviation coefficient is greater than the deviation judgment threshold, mark the corresponding output parameter as an invalid parameter and remove it from the time axis to obtain the final standard experimental data axis.

[0066] The parameter analysis module is used to obtain and process the standard experimental data axis, obtain the target parameter from the standard experimental data axis, calculate the PCB compensation parameter according to the optimization compensation algorithm, and send the PCB compensation parameter to the calibration and programming unit.

[0067] The specific process of calculating the PCB compensation parameter is as follows:

[0068] S201. Construct a PCB compensation circuit model and analyze the compensation factors during the PCB transmission process as follows:

[0069] The compensation factors include signal propagation delay compensation, impedance matching compensation, and temperature compensation.

[0070] Calculate the signal propagation delay compensation parameter te according to the following formula: Where εr is the relative dielectric constant of the PCB material, C is the speed of light, S0 is the length of the signal line, t0 is the standard signal propagation duration, and α is a preset proportionality coefficient.

[0071] Calculate the impedance matching compensation parameter Z0 according to the following formula: Where h is the distance from the torque signal layer to the ground layer, and ω is the width of the signal line.

[0072] Calculate the temperature compensation parameter Tr according to the following formula: Where T0 is the standard temperature data of the signal line during the torque signal transmission, Ti is the actual temperature data of the signal line during the torque signal transmission, and β is a preset proportionality coefficient.

[0073] The expressions for obtaining the PCB standard parameters and parameter influence coefficients are as follows:

[0074] Where Hk is the width of the signal line, Sk is the curvature of the PCB routing path, and mi is the number of resistors with temperature compensation characteristics, S0 is the length of the signal line, d is a preset constant, and di is the original number of resistors.

[0075] S202. According to the expressions of the PCB standard parameters and parameter influence coefficients, determine the optimized target parameters and the objective function for parameter optimization, and determine the constraint conditions according to the requirements of the PCB standard parameters and parameter influence coefficients.

[0076] S203. Use the particle swarm algorithm to optimize the parameters and obtain the optimal parameters of the PCB compensation circuit model.

[0077] The specific process of burning into the sensor chip is as follows:

[0078] S301. Integrate the verified PCB compensation parameters into a parameter file, load the parameter file to be burned into the software of the burning tool, and connect the burning tool to the sensor chip;

[0079] S302. Write the parameter file into the memory of the sensor chip through the burning software, compare the MD5 value of the file in the burning software with the MD5 value of the original file stored in the memory of the sensor chip, and verify the correctness of the file in the burning software;

[0080] S303. After the burning is completed, conduct a running test on the sensor chip to ensure that the hardware device can operate as expected.

[0081] The calibration control unit is used to store the standard parameters and calibration operation steps during the calibration process, generate calibration control instructions according to the preset calibration period and in accordance with the calibration operation steps, and control the hydraulic system, lifting system, and transmission system according to the calibration control instructions to achieve an automated control process;

[0082] The calibration burning unit is used to obtain and process the PCB compensation parameters, verify the PCB compensation parameters, so that the mean square error value between the torque signal output values after compensation at all acquisition points and the preset standard torque signal output value reaches the preset minimum value, and burn it into the sensor chip.

[0083] The setting of the size of the threshold is for the convenience of comparison. Regarding the size of the threshold, it depends on the amount of sample data and the number of base numbers set by those skilled in the art for each group of sample data; as long as it does not affect the proportional relationship between the parameters and the quantized values.

[0084] The above formulas are all dimensionless and take their numerical calculations. The formula is obtained by software simulation of a large amount of collected data to get a formula closest to the actual situation. The preset parameters in the formula are set by those skilled in the art according to the actual situation;

[0085] In the two embodiments provided in the present application, it should be understood that the disclosed devices and systems can be implemented in other ways; for example, the device embodiments described above are only illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there can be other division methods. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed; another point, the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the devices or modules can be in an electrical, mechanical or other forms;

[0086] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A shaft calibration stand for a vehicle steering sensor, characterized in that: The invention comprises a stand (1) and a steering measurement system, wherein a calibration stand (2) is fixedly arranged inside the stand (1), a fixing groove is provided on the top surface of the calibration stand (2), a sensor assembly is arranged on the inner wall of the fixing groove, a hydraulic system is fixedly arranged on the top surface of the calibration stand (2), a transmission mechanism is connected to the bottom surface of the output end of the hydraulic system, an upper chuck (3) is fixedly arranged on the bottom surface of the transmission mechanism, a lifting mechanism is fixedly arranged on the bottom surface of the stand (1), and the output ends of the lifting mechanism are respectively connected to lower chucks (4); The steering measurement system includes a data acquisition unit, a data analysis unit, a calibration control unit and a calibration burn-in unit; The data acquisition unit is used to acquire output parameters of the steering sensor during the calibration process, wherein the output parameters include the absolute position of rotation and the corresponding torque signal, and send the output parameters to the data analysis unit; The data analysis unit includes a parameter verification module and a parameter analysis module. The parameter verification module is used to obtain and process output parameters, obtain the stored standard parameters from the calibration control unit, verify the output parameters one by one, eliminate invalid parameters to obtain a standard experimental data axis, and send it to the parameter analysis module; The parameter analysis module is used to obtain and process the standard experimental data axis, obtain the target parameter from the standard experimental data axis, calculate the PCB compensation parameter according to the optimization compensation algorithm, and send the PCB compensation parameter to the calibration burning unit; The calibration control unit is used to store standard parameters and calibration operation steps in the calibration process, generate calibration control instructions according to the preset calibration cycle and calibration operation steps, and control the hydraulic system, lifting system and transmission system according to the calibration control instructions to realize the automatic control process; The calibration and burning unit is used to obtain and process the PCB compensation parameters, verify the PCB compensation parameters, so that the mean square error between the compensated torque signal output values ​​of all acquisition points and the preset standard torque signal output values ​​reaches a preset minimum value, and is burned into the sensor chip.

2. The shaft calibration stand for a vehicle steering sensor according to claim 1, characterized in that: The sensor assembly comprises an outer rotor (5) and an input shaft (6). The outer rotor (5) is sleeved on the outer surface of the input shaft (6). The outer rotor (5) is fixed to the inner wall of the fixing groove. The outer surface of the outer rotor (5) is provided with a sensor slot (7). The bottom end surface of the outer rotor (5) is movably connected with an output shaft (8).

3. The shaft calibration stand for a vehicle steering sensor according to claim 1, characterized in that: The transmission mechanism comprises a rotating motor (9) and a connecting shaft (10), wherein the rotating motor (9) is connected to the outer surface of the output end of the hydraulic system, the connecting shaft (10) is fixedly arranged on the outer surface of the output end of the rotating motor (9), and the upper chuck (3) is fixedly arranged on the bottom end surface of the connecting shaft (10).

4. The shaft calibration stand for a vehicle steering sensor according to claim 1, characterized in that: The lifting mechanism comprises a guide shaft (11) and an electric telescopic rod (14); a plurality of the guide shafts (11) are fixedly arranged between the calibration platform (2) and the platform (1); a lifting base plate (12) is sleeved on the outer surface of the guide shaft (11); a lifting push plate (13) is movably sleeved on the outer surface of the guide shaft (11); the electric telescopic rod (14) is fixedly arranged between the lifting base plate (12) and the lifting push plate (13); and the upper chuck (3) and the lower chuck (4) are respectively fixedly arranged on the outer surface of the lifting push plate (13).

5. The shaft calibration stand for a vehicle steering sensor according to claim 1, characterized in that: The upper chuck (3) and the lower chuck (4) are arranged opposite to each other, the upper chuck (3) is in active contact with the top surface of the sensor assembly, and the lower chuck (4) is in active contact with the bottom surface of the sensor assembly.

6. The shaft calibration stand for a vehicle steering sensor according to claim 1, characterized in that: The specific process of obtaining the standard experimental data axis is as follows: S101, obtaining output parameters, wherein the output parameters include an absolute position of rotation and a corresponding torque signal, and establishing a plane coordinate system with the center position of the output shaft (8) as the origin and the transverse and longitudinal directions of the calibration platform (2) as the X-axis and the Y-axis respectively; S102, marking the steering sensor fixed on the outside of the output shaft (8) as M, and then obtaining the absolute position of the steering sensor, that is, initial coordinate information M (xm, ym), and obtaining the torque output signal K in the zero torque state; S103, establishing a time axis according to a preset calibration cycle during the calibration operation, obtaining a number of output parameters during the calibration operation, marking the moment when the output parameters are obtained as a detection node, and marking the output parameters on the time axis in sequence; S104, the calibration control unit obtains the stored standard parameters, which are the standard position information Mi (xi, yi) and the corresponding torque signal Ki during the calibration process, and calculates the calibration deviation coefficient Yi according to the following formula: Where e1 and e2 are preset proportional coefficients, and the calibration deviation coefficient is used to indicate the degree of deviation between the standard parameters and the output parameters in the actual calibration process; S105, obtaining a preset deviation judgment threshold. If the calibration deviation coefficient is greater than the deviation judgment threshold, the corresponding output parameter is marked as an invalid parameter and removed from the time axis to obtain the final standard experimental data axis.

7. The shaft calibration stand for a vehicle steering sensor according to claim 1, characterized in that: The specific process of calculating the PCB compensation parameters is as follows: S201, constructing a PCB compensation circuit model, and analyzing the compensation factors during PCB transmission, as follows: The compensation factors include signal propagation delay compensation, impedance matching compensation and temperature compensation; The signal propagation delay compensation parameter te is calculated according to the following formula: Where εr is the relative dielectric constant of the PCB material, C is the speed of light, S0 is the length of the signal line, t0 is the standard time for signal propagation, and α is the preset proportional coefficient; The impedance matching compensation parameter Z0 is calculated according to the following formula: Where h is the distance from the torque signal layer to the ground layer, and ω is the width of the signal line; Calculate the temperature compensation parameter Tr according to the following formula: Wherein T0 is the standard temperature data of the signal line during the torque signal transmission process, Ti is the actual temperature data of the signal line during the torque signal transmission process, and β is the preset proportional coefficient; The expressions for obtaining PCB standard parameters and parameter influence coefficients are as follows: Where Hk is the width of the signal line, Sk is the curvature of the PCB routing path, mi is the number of resistors with temperature compensation characteristics, S0 is the length of the signal line, d is a preset constant, and di is the number of original resistors; S202, determining the target parameters for optimization and the target function for parameter optimization according to the expressions of the PCB standard parameters and the parameter influence coefficients, and determining the constraint conditions according to the requirements of the PCB standard parameters and the parameter influence coefficients; S203, using a particle swarm algorithm to optimize parameters and obtain optimal parameters of the PCB compensation circuit model.

8. The shaft calibration stand for a vehicle steering sensor according to claim 1, characterized in that: The specific process of burning into the sensor chip is as follows: S301, integrating the verified PCB compensation parameters into a parameter file, loading the parameter file to be burned into the software of the burning tool, and connecting the burning tool to the sensor chip; S302, writing the parameter file into the memory of the sensor chip through the burning software, comparing the MD5 value of the file in the burning software with the MD5 value of the original file stored in the memory of the sensor chip, and verifying the correctness of the file in the burning software; S303: After the burning is completed, the sensor chip is tested to ensure that the hardware device can operate as expected.

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