Multi-channel verification redundant corner torque sensor and degradation measurement method thereof

Abstract

The sensor comprises two Hall type steering wheel angle sensors which are coaxially installed at a steering wheel transmission shaft, the models of the two Hall type steering wheel angle sensors are consistent, and the two Hall type steering wheel angle sensors are independently connected to a data processing module. When torque generated after the steering wheel is stressed acts on the steering wheel transmission shaft (1), a tubular column of the steering wheel transmission shaft deforms, rotation angles of deformation in different areas in the axial direction are different, and the two Hall type steering wheel angle sensors detect the tubular column rotation angles in the installation areas of the Hall type steering wheel angle sensors respectively and output the tubular column rotation angles to the data processing module. The data processing module calculates the torque borne by the steering wheel according to the angular deviation of the tubular column rotation angle measured by the two Hall type steering wheel angle sensors. Through cooperative work of the two sensors, the torque measuring function can be achieved, and the redundancy safety performance of the system can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobiles, in particular to a multi-path verified redundant rotation angle torque sensor and a degradation measurement method thereof. Background Art

[0002] The vehicle steering system is a key subsystem of the vehicle, and its safety performance is directly related to the safety of the entire vehicle. To ensure vehicle safety, information redundancy is essential. The steering wheel torque signal, a key signal from the vehicle's steering wheel, provides a basis for vehicle system intervention: the Electric Power Steering (EPS) system uses the steering wheel torque signal, combined with the vehicle's status, to adjust the output of the power-assisting motor. The Hands-Off Detection (HOD) function uses the steering wheel torque signal to determine whether the vehicle is in autonomous or driver-controlled mode, thereby switching the vehicle's driving mode. The vehicle's driving style system uses different torque signals to quantify differences in steering wheel rotation, providing personalized adaptation for vehicle control.

[0003] Existing technical solutions (CN 112407048 B, CN204788763 U) focus on obtaining accurate torque measurements and the data processing capabilities after obtaining the signal, but do not address the redundancy of the steering wheel torque signal. However, the ISO-26262 standard emphasizes that critical systems must achieve ASIL-D safety goals through redundant design. Therefore, in high-level autonomous driving, redundant backup of critical system information is required to meet safety requirements. Torque measurement signal redundancy is key to ensuring the redundancy of the steering system. Summary of the Invention

[0004] The present invention proposes a redundant angular torque sensor with multi-channel verification and a degradation measurement method thereof. By using dual sensors working in coordination, not only can the torque measurement function be realized, but also the redundant safety performance of the system can be improved.

[0005] The present invention adopts the following technical solutions.

[0006] A redundant angular torque sensor with multi-path verification, comprising two Hall-type steering wheel angle sensors coaxially mounted on a steering wheel transmission shaft, the two Hall-type steering wheel angle sensors being of the same model and independently connected to a data processing module, wherein when the torque after the steering wheel is stressed acts on the steering wheel transmission shaft (1), the column of the steering wheel transmission shaft is deformed and the rotation angles of the deformation in different axial regions are different, and the two Hall-type steering wheel angle sensors respectively detect the column rotation angles in their respective installation regions and output the results to the data processing module.

[0007] The data processing module calculates the torque applied to the steering wheel according to the angle deviation of the column rotation angle measured by the two Hall-type steering wheel angle sensors.

[0008] The two Hall-type steering wheel angle sensors are a first Hall-type steering wheel angle sensor located at the upper part of the column and a second Hall-type steering wheel angle sensor located at the lower part of the column;

[0009] The first Hall-type steering wheel angle sensor comprises a first Hall-type sensor (3) of the first steering wheel angle sensor, which is arranged at the center of a first driven gear (2) of the first steering wheel angle sensor, and a second Hall-type sensor (6) of the first steering wheel angle sensor, which is arranged at the center of a second driven gear (5) of the first steering wheel angle sensor. The first driven gear of the first steering wheel angle sensor and the second driven gear of the first steering wheel angle sensor are both meshed with a first steering wheel angle sensor driving gear (4) at the upper portion of the column.

[0010] The second Hall-type steering wheel angle sensor comprises a first Hall-type sensor (8) of the second steering wheel angle sensor arranged at the center of a first driven gear (7) of the second steering wheel angle sensor, and a second Hall-type sensor (11) of the second steering wheel angle sensor arranged at the center of a second driven gear (10) of the second steering wheel angle sensor. The first driven gear of the second steering wheel angle sensor and the second driven gear of the second steering wheel angle sensor are both engaged with a second steering wheel angle sensor driving gear (9) at the lower part of the column.

[0011] The first Hall-type steering wheel angle sensor and the second Hall-type steering wheel angle sensor each include a three-gear meshing structure consisting of a driving gear and two driven gears;

[0012] The driving gears are large gear rings fixed to the steering wheel transmission shaft column, namely the first steering wheel angle sensor driving gear (4) and the second steering wheel angle sensor driving gear (9);

[0013] The driven gear is a small gear, namely the first driven gear of the first steering wheel angle sensor, the second driven gear of the first steering wheel angle sensor, the first driven gear of the second steering wheel angle sensor, and the second driven gear of the second steering wheel angle sensor. The tooth shapes of the four small gears are the same, and the number of teeth of the first driven gear is N. 从1 Greater than the number of teeth N of the second driven gear 从2 ;

[0014] The two large gear rings have the same tooth shape and number of teeth, but their number of teeth is much greater than that of the four small gears.

[0015] The large gear ring is fixedly connected to the steering wheel drive shaft and transmits the rotation of the steering wheel drive shaft to the driven gear through gear meshing. The relationship between the rotation angles of the driving gear and the driven gear is the gear meshing relationship, which can be expressed as

[0016]

[0017] The number of driven gear teeth is N 从 , the number of teeth on the driving wheel is N 主 , the tooth profiles of the driving wheel and the driven wheel must be consistent, and the number of teeth of the two driven gears N 从1 、N 从2 Mutually prime.

[0018] The first Hall-effect steering wheel angle sensor and the second Hall-effect steering wheel angle sensor both detect the current angular position of the two driven wheels through their internal Hall sensors and output a single-turn angle signal ranging from 0° to 360°. The logic processing unit of the data processing module tracks and records the number of rotations n of the driven wheels in real time. The actual rotation angle of the driven wheels is calculated as follows:

[0019] φ 从 =θ 从 +360n

[0020] Based on the actual rotation angle of a single driven gear, the relative rotation angle of the driving gear can be calculated (assuming that the driving gear and the driven gear start rotating from the zero position). The specific calculation formula is:

[0021]

[0022] The data processing module calculates the absolute rotation angle of the driving gear through the actual rotation angle difference between the two driven gears of the same steering wheel sensor. This is the steering wheel drive shaft rotation angle measured by the steering wheel angle sensor at that position. The specific calculation formula is:

[0023]

[0024] In the absence of external force, the driving wheel rotation angles calculated by the data processing module from the first Hall-type steering wheel angle sensor and the second Hall-type steering wheel angle sensor are the same;

[0025] When the driver turns the steering wheel and applies torque to the steering shaft, the column undergoes elastic deformation, and different torque deformations occur on the upper and lower sides of the steering shaft. The steering shaft rotation angle calculated from the monitoring data of the two Hall-type steering wheel angle sensors is first output to the torque calculation module of the vehicle MCU through the CAN transmission protocol of the angle sensor, and the angle deviation Δφ of the two steering wheel angle sensors is calculated. 主绝对 ; Then, based on the mechanical relationship between torque and angle, the torque is calculated. The torque on the steering wheel drive shaft is a vector quantity, and its direction is defined by the right-hand rule: taking the axial direction of the steering wheel drive shaft as the reference direction, that is, from the steering wheel to the steering column, when the driver applies clockwise torque, the torque direction is the axial positive direction; counterclockwise torque is the axial negative direction.

[0026] The first steering wheel sensor is installed on the steering wheel side of the upper side of the column, and the second steering wheel sensor is installed on the steering column side of the lower side of the column; when the driver applies clockwise torque, the elastic deformation on the steering wheel side is greater than that on the steering column side, resulting in the rotation angle θ1 on the steering wheel side being greater than the rotation angle θ2 on the steering column side. At this time, T>0, indicating that the torque direction is the axial positive direction; otherwise it is the negative direction.

[0027] The specific calculation formula for torque is:

[0028] T=K*△φ 主绝对

[0029] △φ 主绝对 =(φ 主绝对1 -φ 主绝对2 )

[0030]

[0031] The formula for calculating the torsion angle based on material mechanics is:

[0032] Where T is the torque applied to the steering wheel drive shaft, K is the stiffness coefficient of the steering wheel drive shaft, the value of which is fixed when the steering wheel drive shaft leaves the factory. It can be calibrated through material mechanical properties and structural design experiments, and written into the torque calculation module of the data processing module as a known constant for calculation; G is the shear modulus of the material, in Pa; J is the polar moment of inertia of the section, in m 4 ; L is the length of the shaft, in meters.

[0033] A degradation measurement method for a redundant angular torque sensor with multi-channel verification uses the aforementioned redundant angular torque sensor with multi-channel verification. The Hall sensor of the Hall-effect steering wheel angle sensor is fixed to the PCB of the Hall-effect steering wheel angle sensor. The Hall sensor sends the acquired driven gear signal to the angle calculation module on the PCB, thereby obtaining the steering wheel drive shaft rotation angle.

[0034] The signals collected by each angle sensor are sent to the vehicle's internal MCU, which serves as a data processing module, through the PIN interface and CAN line on the angle sensor. The vehicle steering wheel torque is calculated by the torque calculation module of the vehicle's internal MCU.

[0035] The degradation measurement method is based on the measurement of the Hall-type steering wheel angle sensor and the redundant information of the Hall-type steering wheel angle sensor itself, and is used for the torque signal output in the event of a fault. That is: the angle measurement redundancy characteristics of the Hall-type steering wheel angle sensor are utilized, and the multi-gear meshing characteristics of the three-gear meshing structure are used to ensure the output of the relative angle of the steering wheel angle sensor, thereby ensuring the output of the torque signal and improving the redundant safety performance of the system.

[0036] The degraded measurement method is used for torque output in the following two fault scenarios: when a single driven gear of a single Hall-effect steering wheel angle sensor fails, or when a single driven gear of both the upper and lower Hall-effect steering wheel angle sensors fails.

[0037] The specific steps of the degradation measurement method are:

[0038] Assume that in the above fault scenario, when a driven gear of the Hall-type steering wheel angle sensor fails, it cannot output the absolute angle; but with the number of teeth N 主 The number of teeth of the driving gear in normal meshing is N 从正常 The driven gear can still detect its normal rotation angle θ through the Hall sensor 从正常 The number of revolutions of the driven gear n 从正常 , according to the absolute rotation angle φ at the previous moment 主上一时刻 and the rotation angle φ of the driven gear relative to the driving gear at the current moment 主相对 , calculate the relative rotation angle φ′ of the current driving gear 主相对 :

[0039] φ′ 主相对 =φ 主上一时刻 +φ 主相对

[0040]

[0041] Since the steering wheel angle sensor can still output its relative angle φ′ 主相对 , so the steering wheel torque can still be calculated based on the difference in the two steering wheel sensor angles:

[0042] T 相对 =K·△φ 主相对

[0043] △φ 主相对 =φ′ 主相对1 -φ′ 主相对2

[0044] Then use the specific calculation formula of torque to calculate the torque and output it.

[0045] Based on steering wheel angle sensor measurements and the sensor's inherent redundant information, this invention designs a torque signal output method suitable for fault conditions. This method ensures the output of a torque signal even in the event of a steering wheel angle sensor anomaly. Compared to traditional vehicle torque sensor measurements, this solution leverages the steering wheel angle sensor's angle measurement redundancy. While the steering wheel angle sensor may not output an absolute angle in the event of an internal fault, its multi-gear meshing mechanism ensures the steering wheel angle sensor outputs a relative angle, thereby ensuring the output of a torque signal and enhancing the system's redundant safety performance.

[0046] The present invention proposes a torque measurement method for installing two steering wheel angle sensors, which aims to achieve comprehensive measurement of steering wheel angle and torque by coaxially configuring two independent and identical Hall-type steering wheel angle sensors on the steering wheel drive shaft. The mechanical structure includes a steering wheel drive shaft, a first steering wheel sensor, and a second steering wheel sensor (the sensor integrates a driving gear, a first and a second driven gear, a Hall sensor corresponding to the driven wheel, and a magnet). Among them, the angle sensor adopts a Hall-type design, and internally contains a three-gear meshing structure consisting of a driving gear (large ring gear) and two driven gears (small gears). The Hall sensor is fixed on the PCB, and the Hall sensor sends the collected driven gear signal to the angle calculation module on the angle sensor PCB, thereby obtaining the steering wheel drive shaft rotation angle. The signals collected by each angle sensor are sent to the vehicle's internal MCU through the PIN interface and its CAN line on the angle sensor, and the vehicle steering wheel torque is calculated by the torque calculation module of the vehicle's internal MCU; the advantages of the present invention are:

[0047] (1) The present invention has a torque measurement method based on dual steering wheel angle sensors; by coaxially installing two independent and identical Hall-type steering wheel angle sensors on the steering wheel drive shaft, high-precision measurement of steering wheel torque is achieved. Compared with the traditional single sensor structure design, this method uses dual sensors to detect the steering wheel rotation angle separately, and reflects the torque applied to the steering wheel through the angle deviation between the two. The two sensors output consistent angle signals when there is no torque. When the torque is applied to cause elastic deformation of the column, the deviation of the measured angle signal can reflect the torque magnitude and direction. This method innovatively realizes the torque measurement function through the collaborative work of dual sensors.

[0048] (2) The present invention proposes a method for redundantly measuring torque under steering wheel angle sensor failure. Based on the steering wheel angle sensor measurement and the redundant information of the steering wheel angle sensor itself, the present invention designs a method for outputting torque signals in failure situations to ensure the output of torque signals in the event of an abnormal steering wheel angle sensor. Compared with traditional torque sensors, the present invention utilizes the angle measurement redundancy of the steering wheel angle sensor. When the steering wheel angle sensor has an internal failure, it cannot output the absolute angle. However, its multi-gear meshing feature can ensure the output of the relative angle of the steering wheel angle sensor, thereby ensuring the output of the torque signal and improving the redundant safety performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0050] Attachment Figure 1 2. It is a schematic structural diagram of the steering wheel angle sensor of the present invention for measuring torque;

[0051] Attachment Figure 2 This is a schematic diagram of the measurement signal transmission of the steering wheel angle sensor of the present invention;

[0052] Attachment Figure 3 This is a schematic diagram of the system principle block diagram of the steering wheel angle sensor used for torque measurement;

[0053] Attachment Figure 4 This is a schematic diagram of the torque measurement system principle of the steering wheel angle sensor in a fault scenario;

[0054] In the figure: 1. Steering wheel drive shaft; 2. First driven gear of first steering wheel angle sensor; 3. First Hall sensor of first steering wheel angle sensor; 4. Driving gear of first steering wheel angle sensor; 5. Second driven gear of first steering wheel angle sensor; 6. Second Hall sensor of first steering wheel angle sensor; 7. First driven gear of second steering wheel angle sensor; 8. First Hall sensor of second steering wheel angle sensor; 9. Driving gear of second steering wheel angle sensor; 10. Second driven gear of second steering wheel angle sensor; 11. Second Hall sensor of second steering wheel angle sensor; 13. PCB board of first steering wheel angle sensor; 14. PIN port of first steering wheel angle sensor; 15. Rotation angle calculation module of second steering wheel angle sensor; 16. PCB board of second steering wheel angle sensor; 17. PIN port of second steering wheel angle sensor; 18. CAN line of steering wheel sensor; 19. Torque calculation module of MCU inside vehicle; DETAILED DESCRIPTION

[0055] As shown in the figure, a redundant angular torque sensor with multi-channel verification includes two Hall-type steering wheel angle sensors coaxially installed on the steering wheel drive shaft. The two Hall-type steering wheel angle sensors are of the same model and are independently connected to the data processing module. When the torque after the steering wheel is subjected to force acts on the steering wheel drive shaft 1, the column of the steering wheel drive shaft is deformed and the rotation angles of the deformation in different axial areas are different. The two Hall-type steering wheel angle sensors respectively detect the column rotation angles in their installation areas and output them to the data processing module.

[0056] The data processing module calculates the torque applied to the steering wheel according to the angle deviation of the column rotation angle measured by the two Hall-type steering wheel angle sensors.

[0057] The two Hall-type steering wheel angle sensors are a first Hall-type steering wheel angle sensor located at the upper part of the column and a second Hall-type steering wheel angle sensor located at the lower part of the column;

[0058] The first Hall-type steering wheel angle sensor includes a first Hall-type sensor 3 of the first steering wheel angle sensor, which is arranged at the center of the first driven gear 2 of the first steering wheel angle sensor, and a second Hall-type sensor 6 of the first steering wheel angle sensor, which is arranged at the center of the second driven gear 5 of the first steering wheel angle sensor. The first driven gear of the first steering wheel angle sensor and the second driven gear of the first steering wheel angle sensor are both engaged with the first steering wheel angle sensor driving gear 4 at the upper part of the column.

[0059] The second Hall-type steering wheel angle sensor includes a first Hall-type sensor 8 of the second steering wheel angle sensor located at the center of the first driven gear 7 of the second steering wheel angle sensor, and a second Hall-type sensor 11 of the second steering wheel angle sensor located at the center of the second driven gear 10 of the second steering wheel angle sensor. The first driven gear of the second steering wheel angle sensor and the second driven gear of the second steering wheel angle sensor are both engaged with the second steering wheel angle sensor driving gear 9 at the lower part of the column.

[0060] The first Hall-type steering wheel angle sensor and the second Hall-type steering wheel angle sensor each include a three-gear meshing structure consisting of a driving gear and two driven gears;

[0061] The driving gear is a large gear ring fixed to the steering wheel drive shaft column, namely the first steering wheel angle sensor driving gear 4 and the second steering wheel angle sensor driving gear 9;

[0062] The driven gear is a small gear, namely the first driven gear of the first steering wheel angle sensor, the second driven gear of the first steering wheel angle sensor, the first driven gear of the second steering wheel angle sensor, and the second driven gear of the second steering wheel angle sensor. The tooth shapes of the four small gears are the same, and the number of teeth of the first driven gear is N. 从1 Greater than the number of teeth N of the second driven gear 从2 ;

[0063] The two large gear rings have the same tooth shape and number of teeth, but their number of teeth is much greater than that of the four small gears.

[0064] The large gear ring is fixedly connected to the steering wheel drive shaft and transmits the rotation of the steering wheel drive shaft to the driven gear through gear meshing. The relationship between the rotation angles of the driving gear and the driven gear is the gear meshing relationship, which can be expressed as

[0065]

[0066] The number of driven gear teeth is N 从 , the number of teeth on the driving wheel is N 主 , the tooth profiles of the driving wheel and the driven wheel must be consistent, and the number of teeth of the two driven gears N 从1 、N 从2 Mutually prime.

[0067] The first Hall-effect steering wheel angle sensor and the second Hall-effect steering wheel angle sensor both detect the current angular position of the two driven wheels through their internal Hall sensors and output a single-turn angle signal ranging from 0° to 360°. The logic processing unit of the data processing module tracks and records the number of rotations n of the driven wheels in real time. The actual rotation angle of the driven wheels is calculated as follows:

[0068] φ 从 =θ 从 +360n

[0069] Based on the actual rotation angle of a single driven gear, the relative rotation angle of the driving gear can be calculated. Assuming that the driving gear and the driven gear start to rotate from the zero position, the specific calculation formula is:

[0070]

[0071] The data processing module calculates the absolute rotation angle of the driving gear through the actual rotation angle difference between the two driven gears of the same steering wheel sensor. This is the steering wheel drive shaft rotation angle measured by the steering wheel angle sensor at that position. The specific calculation formula is:

[0072]

[0073] In the absence of external force, the driving wheel rotation angles calculated by the data processing module from the first Hall-type steering wheel angle sensor and the second Hall-type steering wheel angle sensor are the same;

[0074] When the driver turns the steering wheel and applies torque to the steering shaft, the column undergoes elastic deformation, and different torque deformations occur on the upper and lower sides of the steering shaft. The steering shaft rotation angle calculated from the monitoring data of the two Hall-type steering wheel angle sensors is first output to the torque calculation module of the vehicle MCU through the CAN transmission protocol of the angle sensor, and the angle deviation Δφ of the two steering wheel angle sensors is calculated. 主绝对 ; Then, based on the mechanical relationship between torque and angle, the torque is calculated. The torque on the steering wheel drive shaft is a vector quantity, and its direction is defined by the right-hand rule: taking the axial direction of the steering wheel drive shaft as the reference direction, that is, from the steering wheel to the steering column, when the driver applies clockwise torque, the torque direction is the axial positive direction; counterclockwise torque is the axial negative direction.

[0075] The first steering wheel sensor is installed on the steering wheel side of the upper side of the column, and the second steering wheel sensor is installed on the steering column side of the lower side of the column; when the driver applies clockwise torque, the elastic deformation on the steering wheel side is greater than that on the steering column side, resulting in the rotation angle θ1 on the steering wheel side being greater than the rotation angle θ2 on the steering column side. At this time, T>0, indicating that the torque direction is the axial positive direction; otherwise it is the negative direction.

[0076] In this example, the calculated torque signal is sent to the vehicle's MCU for use in the vehicle's corresponding systems. The steering wheel torque signal is used to determine whether the vehicle is in autonomous or driver-controlled mode, thereby switching the vehicle's driving mode. The vehicle's driving style system uses different torque signals to quantify differences in steering wheel rotation, providing personalized vehicle control.

[0077] In this example, the gear ratio is not limited. Since different steering wheel sensors may have different gear ratios, the gear ratio is not a necessary parameter.

[0078] The specific calculation formula for torque is:

[0079] T=K*△φ 主绝对

[0080] Δφ 主绝对 =(φ 主绝对1 -φ 主绝对2 )

[0081]

[0082] The formula for calculating the torsion angle based on material mechanics is: Where T is the torque applied to the steering wheel drive shaft, K is the stiffness coefficient of the steering wheel drive shaft, the value of which is fixed when the steering wheel drive shaft leaves the factory. It can be calibrated through material mechanical properties and structural design experiments, and written into the torque calculation module of the data processing module as a known constant for calculation; G is the shear modulus of the material, in Pa; J is the polar moment of inertia of the section, in m 4 ; L is the length of the shaft, in meters.

[0083] A degradation measurement method for a redundant angular torque sensor with multi-channel verification uses the aforementioned redundant angular torque sensor with multi-channel verification. The Hall sensor of the Hall-effect steering wheel angle sensor is fixed to the PCB of the Hall-effect steering wheel angle sensor. The Hall sensor sends the acquired driven gear signal to the angle calculation module on the PCB, thereby obtaining the steering wheel drive shaft rotation angle.

[0084] The signals collected by each angle sensor are sent to the vehicle's internal MCU, which serves as a data processing module, through the PIN interface and CAN line on the angle sensor. The vehicle steering wheel torque is calculated by the torque calculation module of the vehicle's internal MCU.

[0085] The degradation measurement method is based on the measurement of the Hall-type steering wheel angle sensor and the redundant information of the Hall-type steering wheel angle sensor itself, and is used for the torque signal output in the event of a fault. That is: the angle measurement redundancy characteristics of the Hall-type steering wheel angle sensor are utilized, and the multi-gear meshing characteristics of the three-gear meshing structure are used to ensure the output of the relative angle of the steering wheel angle sensor, thereby ensuring the output of the torque signal and improving the redundant safety performance of the system.

[0086] The degraded measurement method is used for torque output in the following two fault scenarios: when a single driven gear of a single Hall-effect steering wheel angle sensor fails, or when a single driven gear of both the upper and lower Hall-effect steering wheel angle sensors fails.

[0087] The specific steps of the degradation measurement method are:

[0088] Assume that in the above fault scenario, when a driven gear of the Hall-type steering wheel angle sensor fails, it cannot output the absolute angle; but with the number of teeth N 主 The number of teeth of the driving gear in normal meshing is N 从正常 The driven gear can still detect its normal rotation angle θ through the Hall sensor 从正常 The number of revolutions of the driven gear n 从正常 , according to the absolute rotation angle φ at the previous moment 主上一时刻 and the rotation angle φ of the driven gear relative to the driving gear at the current moment 主相对 , calculate the relative rotation angle φ′ of the current driving gear 主相对:

[0089] φ′ 主相对 =φ 主上一时刻 +φ 主相对

[0090]

[0091] Since the steering wheel angle sensor can still output its relative angle φ′ 主相对 , so the steering wheel torque can still be calculated based on the difference in the two steering wheel sensor angles:

[0092] T 相对 =K·△φ 主相对

[0093] △φ 主相对 =φ′ 主相对1 -φ′ 主相对2

[0094] Then use the specific calculation formula of torque to calculate the torque and output it.

Claims

1. Multi-channel redundant angular torque sensor, characterized by: The sensor comprises two Hall-type steering wheel angle sensors coaxially mounted on a steering wheel transmission shaft. The two Hall-type steering wheel angle sensors are of the same model and are independently connected to a data processing module. When the torque after the steering wheel is subjected to force acts on the steering wheel transmission shaft (1), the pipe column of the steering wheel transmission shaft is deformed and the rotation angles of the deformation in different axial regions are different. The two Hall-type steering wheel angle sensors respectively detect the rotation angles of the pipe column in their installation regions and output them to the data processing module.

2. The redundant angular torque sensor with multi-path verification according to claim 1, characterized in that: The data processing module calculates the torque applied to the steering wheel according to the angle deviation of the column rotation angle measured by the two Hall-type steering wheel angle sensors.

3. The redundant angular torque sensor with multi-path verification according to claim 1, characterized in that: The two Hall-type steering wheel angle sensors are a first Hall-type steering wheel angle sensor located at the upper part of the column and a second Hall-type steering wheel angle sensor located at the lower part of the column; The first Hall-type steering wheel angle sensor comprises a first Hall-type sensor (3) of the first steering wheel angle sensor, which is arranged at the center of a first driven gear (2) of the first steering wheel angle sensor, and a second Hall-type sensor (6) of the first steering wheel angle sensor, which is arranged at the center of a second driven gear (5) of the first steering wheel angle sensor. The first driven gear of the first steering wheel angle sensor and the second driven gear of the first steering wheel angle sensor are both meshed with a first steering wheel angle sensor driving gear (4) at the upper portion of the column. The second Hall-type steering wheel angle sensor comprises a first Hall-type sensor (8) of the second steering wheel angle sensor arranged at the center of a first driven gear (7) of the second steering wheel angle sensor, and a second Hall-type sensor (11) of the second steering wheel angle sensor arranged at the center of a second driven gear (10) of the second steering wheel angle sensor. The first driven gear of the second steering wheel angle sensor and the second driven gear of the second steering wheel angle sensor are both engaged with a second steering wheel angle sensor driving gear (9) at the lower part of the column.

4. The redundant angular torque sensor with multi-path verification according to claim 3, characterized in that: The first Hall-type steering wheel angle sensor and the second Hall-type steering wheel angle sensor each include a three-gear meshing structure consisting of a driving gear and two driven gears; The driving gears are large gear rings fixed to the steering wheel transmission shaft column, namely the first steering wheel angle sensor driving gear (4) and the second steering wheel angle sensor driving gear (9); The driven gear is a small gear, namely the first driven gear of the first steering wheel angle sensor, the second driven gear of the first steering wheel angle sensor, the first driven gear of the second steering wheel angle sensor, and the second driven gear of the second steering wheel angle sensor. The tooth shapes of the four small gears are the same, and the number of teeth of the first driven gear is N. 从1 Greater than the number of teeth N of the second driven gear 从2 ; The two large gear rings have the same tooth shape and number of teeth, but their number of teeth is much greater than that of the four small gears.

5. The redundant angular torque sensor with multi-path verification according to claim 4, characterized in that: The large ring gear is fixedly connected to the steering wheel drive shaft and transmits the rotation of the steering wheel drive shaft to the driven gear through gear meshing. The relationship between the rotation angles of the driving gear and the driven gear is the gear meshing relationship, which can be expressed as: The number of driven gear teeth is N 从 , the number of teeth on the driving wheel is N 主 , the tooth profiles of the driving wheel and the driven wheel must be consistent, and the number of teeth of the two driven gears N 从1 、N 从2 Mutually prime.

6. The redundant angular torque sensor with multi-path verification according to claim 5, characterized in that: The first Hall-effect steering wheel angle sensor and the second Hall-effect steering wheel angle sensor both detect the current angular position of the two driven wheels through their internal Hall sensors and output a single-turn angle signal ranging from 0° to 360°. The logic processing unit of the data processing module tracks and records the number of rotations n of the driven wheels in real time. The actual rotation angle of the driven wheels is calculated as follows: f 从 =θ 从 +360n Based on the actual rotation angle of a single driven gear, the relative rotation angle of the driving gear can be calculated (assuming that the driving gear and the driven gear start rotating from the zero position). The specific calculation formula is: The data processing module calculates the absolute rotation angle of the driving gear through the actual rotation angle difference between the two driven gears of the same steering wheel sensor. This is the steering wheel drive shaft rotation angle measured by the steering wheel angle sensor at that position. The specific calculation formula is:

7. The redundant angular torque sensor with multi-path verification according to claim 6, characterized in that: In the absence of external force, the driving wheel rotation angles calculated by the data processing module from the first Hall-type steering wheel angle sensor and the second Hall-type steering wheel angle sensor are the same; When the driver turns the steering wheel and applies torque to the steering shaft, the column undergoes elastic deformation, and different torque deformations occur on the upper and lower sides of the steering shaft. The steering shaft rotation angle calculated from the monitoring data of the two Hall-type steering wheel angle sensors is first output to the torque calculation module of the vehicle MCU through the CAN transmission protocol of the angle sensor, and the angle deviation Δφ of the two steering wheel angle sensors is calculated. 主绝对 ; Then, based on the mechanical relationship between torque and angle, the torque is calculated. The torque on the steering wheel drive shaft is a vector quantity, and its direction is defined by the right-hand rule: taking the axial direction of the steering wheel drive shaft as the reference direction, that is, from the steering wheel to the steering column, when the driver applies clockwise torque, the torque direction is the axial positive direction; counterclockwise torque is the axial negative direction. The first steering wheel sensor is installed on the steering wheel side of the upper side of the column, and the second steering wheel sensor is installed on the steering column side of the lower side of the column; when the driver applies clockwise torque, the elastic deformation on the steering wheel side is greater than that on the steering column side, resulting in the rotation angle θ1 on the steering wheel side being greater than the rotation angle θ2 on the steering column side. At this time, T>0, indicating that the torque direction is the axial positive direction; otherwise it is the negative direction.

8. The redundant angular torque sensor with multi-path verification according to claim 7, characterized in that: The specific calculation formula for torque is: T=K*△φ 主绝对 △φ 主绝对 =(φ 主绝对1 -f 主绝对2 ) The formula for calculating the torsion angle based on material mechanics is: Where T is the torque applied to the steering wheel drive shaft, K is the stiffness coefficient of the steering wheel drive shaft, the value of which is fixed when the steering wheel drive shaft leaves the factory. It can be calibrated through material mechanical properties and structural design experiments, and written into the torque calculation module of the data processing module as a known constant for calculation; G is the shear modulus of the material, in Pa; J is the polar moment of inertia of the section, in m 4 ; L is the length of the shaft, in meters.

9. A method for measuring degradation of a redundant angular torque sensor with multiple-channel verification, using the redundant angular torque sensor with multiple-channel verification according to claim 8, characterized in that: The Hall sensor of the Hall-type steering wheel angle sensor is fixed on the PCB of the Hall-type steering wheel angle sensor. The Hall sensor sends the collected driven gear signal to the angle calculation module on the PCB, and then obtains the rotation angle of the steering wheel drive shaft; The signals collected by each angle sensor are sent to the vehicle's internal MCU, which serves as a data processing module, through the PIN interface and CAN line on the angle sensor. The vehicle steering wheel torque is calculated by the torque calculation module of the vehicle's internal MCU. The degradation measurement method is based on the measurement of the Hall-type steering wheel angle sensor and the redundant information of the Hall-type steering wheel angle sensor itself, and is used for the torque signal output in the event of a fault. That is: the angle measurement redundancy characteristics of the Hall-type steering wheel angle sensor are utilized, and the multi-gear meshing characteristics of the three-gear meshing structure are used to ensure the output of the relative angle of the steering wheel angle sensor, thereby ensuring the output of the torque signal and improving the redundant safety performance of the system.

10. The degradation measurement method of a redundant angular torque sensor with multi-path verification according to claim 9, characterized in that: The degraded measurement method is used for torque output in the following two fault scenarios: when a single driven gear of a single Hall-effect steering wheel angle sensor fails, or when a single driven gear of both the upper and lower Hall-effect steering wheel angle sensors fails. The specific steps of the degradation measurement method are: Assume that in the above fault scenario, when a driven gear of the Hall-type steering wheel angle sensor fails, it cannot output the absolute angle; but with the number of teeth N 主 The number of teeth of the driving gear in normal meshing is N 从正常 The driven gear can still detect its normal rotation angle θ through the Hall sensor 从正常 The number of revolutions of the driven gear n 从正常 , according to the absolute rotation angle φ at the previous moment 主上一时刻 and the rotation angle φ of the driven gear relative to the driving gear at the current moment 主相对 , calculate the relative rotation angle φ′ of the current driving gear 主相对 : f′ 主相对 =φ 主上一时刻 +φ 主相对 Since the steering wheel angle sensor can still output its relative angle φ′ 主相对 , so the steering wheel torque can still be calculated based on the difference in the two steering wheel sensor angles: T 相对 =K·Δφ 主相对 △φ 主相对 =φ′ 主相对1 -f′ 主相对2 Then use the specific calculation formula of torque to calculate the torque and output it.

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