Steering wheel rotation absolute angle measuring device and method

Abstract

The invention provides a steering wheel rotation absolute angle measuring device and method. The steering wheel rotation absolute angle measuring device comprises an input shaft driving gear, an input rotation angle metering gear set, a driving turn number metering gear and an input turn number metering gear. The input shaft driving gear is meshed with the input rotation angle metering gear set; the input shaft driving gear and the steering wheel input shaft are fixedly connected and rotate synchronously. The driving turn number metering gear and the input shaft driving gear are fixedly connected and rotate synchronously; and the driving turn number metering gear is meshed with or separated from the input turn number metering gear in the process of synchronously rotating along with the input shaft driving gear. According to the invention, the accurate rotation angle calculation result of the driving gear of the input shaft is obtained through the meshing relation of the gears and the fault-tolerant mechanism of comprehensively outputting the rotation angle increment and the number of rotation turns when the gears rotate, so that the reliability of the absolute angle measurement result of steering wheel rotation is improved.

Description

Technical Field

[0001] The present invention relates to the field of automotive steering torque measurement, and particularly to a device and method for measuring the absolute angle of steering wheel rotation. Background Art

[0002] In an automotive electric power steering system (EPS), a follow-up servo control system needs to obtain the torque and rotation angle parameters of the steering wheel in real time to generate accurate and reliable auxiliary torque. Among them, the rotation angle parameters include: the absolute angle of steering wheel rotation, which refers to the angle turned by the steering wheel when it starts to rotate with a 0° angle as a reference.

[0003] Currently, the prior art often uses a sliding rheostat method to reflect the absolute angle of steering wheel rotation through resistance changes. Although this scheme is relatively intuitive, mechanical wear becomes an inevitable problem after long-term use; the optoelectronic coding measurement technology feeds back the absolute angle of steering wheel rotation by accurately counting pulses. Although this scheme is relatively accurate, its technical complexity and cumbersome process limit its wide application; at the hardware level, the prior art generally adopts a hardware architecture of "specific linear angle sensor + MCU", and measures the angle increment, angular velocity and angular acceleration through software algorithms. The output of this scheme is only the relative change of the steering wheel rotation. Since the MCU needs to continuously perform signal tracking and cumulative calculation, the processor load is too high. During long-term operation, sensor signal loss or noise interference will cause integration errors, and there is no effective anomaly detection mechanism. When abnormal conditions such as angle jumps or signal distortion occur in the sensor, the existing hardware architecture cannot correct the measured value independently, and it is easy to output an incorrect absolute angle of steering wheel rotation. In summary, the prior art has complex processes and large calculations, and can only provide the relative change of the steering wheel rotation. When there are abnormal changes in the sensor angle, it cannot correctly process the measured value and output it, resulting in the problem of unreliable measurement results of the absolute angle of steering wheel rotation. Summary of the Invention

[0004] In order to solve the problem of unreliable measurement results of the absolute angle of steering wheel rotation, the present invention proposes a device and method for measuring the absolute angle of steering wheel rotation, which realizes a fault tolerance mechanism for comprehensively outputting the rotation angle increment and the number of rotation turns when the gear rotates through the meshing relationship of the gears, and obtains an accurate calculation result of the rotation angle of the input shaft driving gear, thereby improving the reliability of the measurement result of the absolute angle of steering wheel rotation.

[0005] To achieve the above object, an embodiment of the present invention provides a device for measuring the absolute rotation angle of a steering wheel, which is arranged on the input shaft of the steering wheel and includes: an input shaft driving gear, an input rotation angle measuring gear set, a driving revolution measuring gear, and an input revolution measuring gear; the input shaft driving gear meshes with the input rotation angle measuring gear set; the input shaft driving gear is fixedly connected to the input shaft of the steering wheel and rotates synchronously therewith; the driving revolution measuring gear is fixedly connected to the input shaft driving gear and rotates synchronously therewith; the driving revolution measuring gear meshes with or disengages from the input revolution measuring gear during the process of rotating synchronously with the input shaft driving gear.

[0006] An embodiment of the present invention provides a device for measuring the absolute rotation angle of a steering wheel. The input shaft driving gear is fixedly connected to the input shaft of the steering wheel and rotates synchronously therewith. The input shaft driving gear meshes with the input rotation angle measuring gear set. Thus, the rotation angle increment of the input shaft driving gear that rotates with the input shaft driving gear can be obtained through each input rotation angle measuring gear in the input rotation angle measuring gear set. In addition, the driving revolution measuring gear is fixedly connected to the input shaft driving gear and rotates synchronously therewith. Thus, the number of revolutions of the input shaft driving gear can be obtained by the engagement or disengagement of the driving revolution measuring gear with the input revolution measuring gear during the process of rotating synchronously with the input shaft driving gear. Finally, the rotation angle increment and the number of revolutions of the input shaft driving gear are output. By considering the rotation angle increment and the number of revolutions of the input shaft driving gear, the rotation angle of the input shaft driving gear is obtained. Since the input shaft driving gear is fixedly connected to the input shaft of the steering wheel and rotates synchronously therewith, the rotation angle of the input shaft driving gear can reflect the absolute rotation angle of the steering wheel. Finally, the absolute rotation angle of the steering wheel is measured. Through the meshing relationship of the gears and the fault tolerance mechanism that comprehensively outputs the rotation angle increment and the number of revolutions during the rotation of the gears, the accuracy of the calculation result of the rotation angle of the input shaft driving gear is guaranteed, thereby improving the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0007] Further, the projection of the teeth of the driving revolution measuring gear on the input shaft driving gear completely coincides with some teeth of the input shaft driving gear.

[0008] Through the above solution, since the input shaft driving gear rotates synchronously with the input shaft, the number of revolutions of the input shaft driving gear can be measured subsequently through the change of the gear mechanism. By setting the projection of the teeth of the driving revolution measuring gear on the input shaft driving gear to completely coincide with some teeth of the input shaft driving gear, the process design of the gear structure is simplified, so that the input shaft driving gear rotates synchronously with the driving revolution measuring gear. Thus, the input revolution measuring gear can accurately obtain the number of revolutions of the input shaft driving gear, guarantee the accuracy of the calculation result of the rotation angle of the input shaft driving gear, and improve the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0009] Further, the input rotation angle measuring gear set includes at least two input rotation angle measuring gears, and the number of teeth of each input rotation angle measuring gear is not equal.

[0010] Through the above solution, by setting input rotation angle measuring gears with different numbers of teeth, during the rotation of the input shaft driving gear, the incremental rotation angle of the input shaft driving gear can be measured through the meshing relationship between the input rotation angle measuring gears with different numbers of teeth and the input shaft driving gear, so as to obtain the offset of the rotation of the input shaft driving gear, thereby more accurately obtaining the rotation angle of the input shaft driving gear, ensuring the accuracy of the calculation result of the rotation angle of the input shaft driving gear, and improving the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0011] Further, a device for measuring the absolute rotation angle of a steering wheel proposed in an embodiment of the present invention is also provided on the steering wheel output shaft. The steering wheel output shaft is connected to the steering wheel input shaft through a rotating shaft. The device for measuring the absolute rotation angle of the steering wheel further includes: an output shaft driving gear and an output rotation angle measuring gear set; the output shaft driving gear meshes with the output rotation angle measuring gear set, and the output shaft driving gear is fixedly connected to the steering wheel output shaft and rotates synchronously.

[0012] Through the above solution, the output shaft driving gear is also fixed on the steering wheel output shaft, ensuring that the input shaft driving gear and the output shaft driving gear rotate synchronously, guaranteeing the synchronization of data measurement, making the subsequent result of backing up the rotation angle of the input shaft driving gear more reliable. The rotation angle of the input shaft driving gear is backed up by each output rotation angle measuring gear in the output rotation angle measuring gear set for replacement when necessary, thereby ensuring the reliability of data processing and the accuracy of the calculation result of the rotation angle of the input shaft driving gear, and improving the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0013] Further, the output rotation angle measuring gear set includes at least two output rotation angle measuring gears. The number of gears in the output rotation angle measuring gear set is exactly the same as the number of gears in the input rotation angle measuring gear set, and the number of teeth of each output rotation angle measuring gear in the output rotation angle measuring gear set is set exactly the same as the number of teeth of each input rotation angle measuring gear in the input rotation angle measuring gear set.

[0014] Through the above solution, by setting the same gear configuration as the input rotation angle measuring gear set, during the rotation of the output shaft driving gear, a rotation angle backup value synchronized with the rotation angle of the input shaft driving gear can be obtained, thereby ensuring the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0015] Further, a PCB board is provided between the steering wheel input shaft and the steering wheel output shaft. Hall elements corresponding one by one to each input rotation angle measurement gear, the input rotation number measurement gear in the input rotation angle measurement gear set, and each output rotation angle measurement gear in the output rotation angle measurement gear set are provided on the PCB board; magnets are provided on each input rotation angle measurement gear, the input rotation number measurement gear in the input rotation angle measurement gear set, and each output rotation angle measurement gear in the output rotation angle measurement gear set.

[0016] With the above solution, the Hall elements are respectively arranged in one-to-one correspondence with each input rotation angle measurement gear, the input rotation number measurement gear in the input rotation angle measurement gear set, and each output rotation angle measurement gear in the output rotation angle measurement gear set, so that the magnetic induction signals generated during the rotation of the corresponding gears can be accurately converted into electrical signals, and finally the rotation angle of the input shaft driving gear is calculated in the form of electrical signals, and then the absolute rotation angle of the steering wheel is obtained, which can ensure the unity of data, reduce the data explosion caused by multi-source data, ensure the accuracy of the calculation result of the rotation angle of the input shaft driving gear, and improve the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0017] Further, the output rotation angle measurement gear set and the input rotation angle measurement gear set are arranged symmetrically about the center of the rotation axis.

[0018] With the above solution, at the same time, the output rotation angle measurement gear set and the input rotation angle measurement gear set are arranged symmetrically about the center of the rotation axis, preventing electromagnetic interference between each other caused by arranging Hall elements on the same side, further ensuring the accuracy of data acquisition, and then improving the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0019] The embodiment of the present invention also provides a method for measuring the absolute rotation angle of a steering wheel, including: obtaining a first rotation angle increment based on the input rotation angle measurement gear set; obtaining the number of rotations based on the input rotation number measurement gear; obtaining the rotation angle of the input shaft driving gear based on the first rotation angle increment and the number of rotations; obtaining the absolute rotation angle of the steering wheel based on the rotation angle of the input shaft driving gear. Further, obtaining a first rotation angle increment based on the input rotation angle measurement gear set includes: obtaining the first rotation angle increment by calculating the rotation angle difference of each input rotation angle measurement gear in the input rotation angle measurement gear set. Further, obtaining the number of rotations based on the input rotation number measurement gear includes: obtaining the number of rotations by obtaining the number of times the input rotation number measurement gear rotates through a preset angle. Further, obtaining the rotation angle of the input shaft driving gear based on the first rotation angle increment and the number of rotations includes: obtaining the rotation angle value by calculating the product of the number of rotations and the circumferential angle; obtaining the rotation angle of the input shaft driving gear by calculating the sum of the rotation angle value and the first rotation angle increment.

[0020] An embodiment of the present invention provides a method for measuring the absolute rotation angle of a steering wheel. By the rotation of each input rotation angle measuring gear in the input rotation angle measuring gear set along with the input shaft driving gear, the rotation angle of each input rotation angle measuring gear is obtained, the rotation angle difference of each input rotation angle measuring gear is calculated to obtain a first rotation angle increment, and by combining the number of times that the input rotation number measuring gear changes a preset angle when meshing and separating along with the driving rotation number measuring gear, the rotation number of the input shaft driving gear is obtained. Finally, the first rotation angle increment is obtained through the input rotation angle measuring gear set and combined with the current rotation number of the input shaft driving gear obtained through the input rotation number measuring gear to calculate the rotation angle of the input shaft driving gear. Since the input shaft driving gear is fixedly connected to the steering wheel input shaft and rotates synchronously, the rotation angle of the input shaft driving gear can reflect the absolute rotation angle of the steering wheel, and finally the absolute rotation angle of the steering wheel is measured. Through the meshing relationship of the gears and the fault tolerance mechanism that comprehensively outputs the rotation angle increment and the rotation number when the gears rotate, the accuracy of the calculation result of the rotation angle of the input shaft driving gear is ensured, thereby improving the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0021] Further, a method for measuring the absolute rotation angle of a steering wheel provided by an embodiment of the present invention further includes: calculating the rotation angle difference of each output rotation angle measuring gear in the output rotation angle measuring gear set to obtain a second rotation angle increment; and obtaining a backup value of the rotation angle of the input shaft driving gear based on the second rotation angle increment and the rotation number.

[0022] Through the above solution, the rotation angle difference generated by each output rotation angle measuring gear in the output rotation angle measuring gear set along with the rotation of the output shaft driving gear is calculated, and then the second rotation angle increment is calculated. Since the number of gears in the output rotation angle measuring gear set is equal to the number of gears in the input rotation angle measuring gear set, the backup information that also stores the rotation angle of the input shaft driving gear obtained by combining the input rotation number measuring gear can be used for replacement when necessary, and can also cope with abnormal signal changes, ensuring the accuracy of data measurement and ensuring that reliable data can still be provided when a fault occurs. By the way of mutual backup of multiple gears, the accuracy of the calculation result of the rotation angle of the input shaft driving gear is ensured to improve the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0023] Further, a method for measuring the absolute rotation angle of a steering wheel provided by an embodiment of the present invention, based on the input rotation angle measuring gear set, obtains a first rotation angle increment, including: during the rotation of the input rotation angle measuring gear set, obtaining a first magnetic induction signal and / or a first voltage signal corresponding to the input rotation angle measuring gear set, and obtaining a corresponding first rotation angle increment based on the first magnetic induction signal and / or the first voltage signal;

[0024] Based on the input rotation count measuring gear, obtain the number of rotations, including: during the rotation of the input rotation count measuring gear, obtain the second magnetic induction signal and / or the second voltage signal corresponding to the input rotation count measuring gear, and based on the second magnetic induction signal and / or the second voltage signal, obtain the corresponding number of rotations;

[0025] The obtaining of the second rotation angle increment by calculating the rotation angle differences of the output rotation angle measuring gears in the output rotation angle measuring gear set includes: during the rotation of the output rotation angle measuring gear set, obtain the third magnetic induction signal and / or the third voltage signal corresponding to the output rotation angle measuring gear set, and calculate the difference of the third magnetic induction signal corresponding to the output rotation angle measuring gear set and / or the difference of the third voltage signal corresponding to the output rotation angle measuring gear set to obtain the second rotation angle increment.

[0026] Through the above solution, the magnetic induction signal and / or voltage signal generated during the rotation of the corresponding gear will ultimately reflect the first rotation angle increment of the input shaft driving gear, the number of rotations of the input shaft driving gear, and the second rotation angle increment of the output rotation angle measuring gear set in the form of the magnetic induction signal and / or voltage signal, which is used for calculating the rotation angle of the input shaft driving gear and the backup value of the rotation angle of the input shaft driving gear, and further obtaining the absolute rotation angle of the steering wheel. This can ensure the unity of data, reduce data explosion caused by multi-source data, ensure the accuracy of the calculation result of the rotation angle of the input shaft driving gear, and improve the reliability of the measurement result of the absolute rotation angle of the steering wheel. Brief Description of the Drawings

[0027] Figure 1 Structural schematic of an absolute steering wheel rotation angle measuring device provided by an embodiment of the present invention Figure 1 ;

[0028] Figure 2 Structural schematic of an absolute steering wheel rotation angle measuring device provided by an embodiment of the present invention Figure 2 ;

[0029] Figure 3 Structural schematic of an absolute steering wheel rotation angle measuring device provided by an embodiment of the present invention Figure 3 ;

[0030] Figure 4 Structural schematic of an absolute steering wheel rotation angle measuring device provided by an embodiment of the present invention Figure 4 ;

[0031] Figure 5 Structural schematic of an absolute steering wheel rotation angle measuring device provided by an embodiment of the present invention Figure 5 ;

[0032] Figure 6 Schematic diagram of the PCB board circuit structure of an absolute steering wheel rotation angle measurement device provided by an embodiment of the present invention;

[0033] Figure 7 Schematic diagram of the comparison of the input signal and output signal waveforms of the PCB board circuit of an absolute steering wheel rotation angle measurement device provided by an embodiment of the present invention;

[0034] Figure 8 Schematic diagram of the step flow of a method for measuring the absolute steering wheel rotation angle provided by an embodiment of the present invention Figure 1 ;

[0035] Figure 9 Schematic diagram of the step flow of a method for measuring the absolute steering wheel rotation angle provided by an embodiment of the present invention Figure 2 ;

[0036] Reference numerals: 1, steering wheel input shaft; 2, rotating shaft; 3, steering wheel output shaft; 4, input shaft driving gear; 5, input rotation angle measuring gear set; 6, input revolution measuring gear; 7, driving revolution measuring gear; 8, processor; 9, Hall element; 10, output shaft driving gear; 11, output rotation angle measuring gear set. Detailed implementation manners

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying 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 of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] An embodiment of the present invention provides an absolute steering wheel rotation angle measurement device, which is applied to a steering wheel. Refer to Figure 1 , Figure 1 Schematic diagram of the structure of an absolute steering wheel rotation angle measurement device provided by an embodiment of the present invention Figure 1 . As Figure 1 shown, the steering wheel includes: a steering wheel input shaft 1, a rotating shaft 2, and a steering wheel output shaft 3. The steering wheel input shaft 1 is mechanically connected to the steering wheel output shaft 3 through the rotating shaft 2. Whenever the steering wheel rotates, the steering wheel input shaft 1 rotates synchronously, the rotating shaft 2 rotates with the steering wheel input shaft 1, and the steering wheel output shaft 3 rotates with the rotating shaft 2, thereby completing the rotation of the steering wheel. Among them, the rotating shaft 2 can be realized by means such as a torsion bar or a motor simulating a traditional torsion bar. Based on this principle, an absolute steering wheel rotation angle measurement device provided by an embodiment of the present invention is used to measure the absolute steering wheel rotation angle, and the specific description is as follows:

[0039] See Figure 1 , Figure 1 which is a schematic structural diagram of an absolute steering wheel rotation angle measurement device provided by an embodiment of the present invention Figure 1 ; as Figure 1 shown, an embodiment of the present invention provides an absolute steering wheel rotation angle measurement device disposed on the steering wheel input shaft 1, including: an input shaft drive gear 4, an input rotation angle measurement gear set 5, a drive revolution measurement gear 7, and an input revolution measurement gear 6; the input shaft drive gear 4 meshes with the input rotation angle measurement gear set 5; the input shaft drive gear 4 is fixedly connected to the steering wheel input shaft 1 and rotates synchronously therewith; the drive revolution measurement gear 7 is fixedly connected to the input shaft drive gear 4 and rotates synchronously therewith; during the synchronous rotation with the input shaft drive gear 4, the drive revolution measurement gear 7 meshes with or disengages from the input revolution measurement gear 6.

[0040] For a specific implementable manner, see Figure 2 , Figure 2 which is a schematic structural diagram of an absolute steering wheel rotation angle measurement device provided by an embodiment of the present invention Figure 2 ; as Figure 2 shown, fixedly connect the steering wheel input shaft 1 to the input shaft drive gear 4 to make the input shaft drive gear 4 rotate synchronously with the steering wheel input shaft 1, and then the input shaft drive gear 4 meshes with each input rotation angle measurement gear in the input rotation angle measurement gear set 5 respectively to obtain the rotation angle increment of the input shaft drive gear 4. Fix the drive revolution measurement gear 7 to the input shaft drive gear 4 to make the drive revolution measurement gear 7 rotate synchronously with the input shaft drive gear 4, and then the input revolution measurement gear 6 meshes with or disengages from the drive revolution measurement gear 7 to obtain the number of revolutions of the input shaft drive gear 4. Finally, calculate the rotation angle of the input shaft drive gear 4 according to the rotation angle increment of the input shaft drive gear 4 and the number of revolutions of the input shaft drive gear 4. Since the input shaft drive gear 4 is fixedly connected to the steering wheel input shaft 1 and rotates synchronously therewith, the rotation angle of the input shaft drive gear 4 can be reflected as the absolute steering wheel rotation angle, thereby realizing the measurement of the absolute steering wheel rotation angle. It is worth mentioning that the rotation angle increment represents the offset of the gear rotation angle; under the condition of no physical limit, the rotation angle of the steering wheel within 2160 degrees is defined as the absolute steering wheel rotation angle. After assembling the absolute steering wheel rotation angle measurement device proposed by the embodiment of the present invention to a vehicle, due to the influence of the vehicle physical limit, the absolute steering wheel rotation angle may be less than 2160 degrees. Among them, the physical limit may be generated by factors such as the vehicle structure. Therefore, in this embodiment, the absolute steering wheel rotation angle (within 2160 degrees) under the condition of no physical limit will be explained, and it will not be elaborated hereinafter;

[0041] An embodiment of the present invention provides a device for measuring the absolute rotation angle of a steering wheel. The input shaft driving gear 4 is fixedly connected to the steering wheel input shaft 1 and rotates synchronously. The input shaft driving gear 4 meshes with the input rotation angle measuring gear set 5. Thus, the rotation angle increment of the input shaft driving gear 4 obtained by the rotation of each input rotation angle measuring gear in the input rotation angle measuring gear set 5 as it rotates with the input shaft driving gear 4. In addition, the active rotation number measuring gear 7 is fixedly connected to the input shaft driving gear 4 and rotates synchronously. Thus, by the engagement or separation of the active rotation number measuring gear 7 with the input rotation number measuring gear 6 during the synchronous rotation with the input shaft driving gear 4, the rotation number of the input shaft driving gear 4 is obtained. Finally, the rotation angle increment of the input shaft driving gear 4 and the rotation number of the input shaft driving gear 4 are output. By considering the rotation angle increment of the input shaft driving gear 4 and the rotation number of the input shaft driving gear 4, the rotation angle of the input shaft driving gear 4 is obtained. Since the input shaft driving gear 4 is fixedly connected to the steering wheel input shaft 1 and rotates synchronously, the rotation angle of the input shaft driving gear 4 can reflect the absolute rotation angle of the steering wheel. Finally, the measurement of the absolute rotation angle of the steering wheel is realized. Through the meshing relationship of the gears and the fault tolerance mechanism that comprehensively outputs the rotation angle increment and the rotation number during gear rotation, the accuracy of the calculation result of the rotation angle of the input shaft driving gear 4 is guaranteed, thereby improving the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0042] As an example of an embodiment of the present invention, the projection of the teeth of the active rotation number measuring gear 7 on the input shaft driving gear 4 completely coincides with some of the teeth of the input shaft driving gear 4.

[0043] For a specific implementable manner, refer to Figure 3 and Figure 4 , Figure 3 is a structural schematic diagram of a device for measuring the absolute rotation angle of a steering wheel provided by an embodiment of the present invention Figure 3 ; Figure 4 is a structural schematic diagram of a device for measuring the absolute rotation angle of a steering wheel provided by an embodiment of the present invention Figure 4 ; As shown in Figure 3 and Figure 4As shown in the figure, the active revolution measuring gear 7 is fixedly connected to the input shaft driving gear 4, so that the active revolution measuring gear 7 rotates synchronously with the rotation of the input shaft driving gear 4. Then, the input revolution measuring gear 6 meshes with or disengages from the active revolution measuring gear 7 to obtain the number of revolutions of the input shaft driving gear 4. The projection of the teeth of the active revolution measuring gear 7 on the input shaft driving gear 4 completely coincides with some of the teeth of the input shaft driving gear 4. In this embodiment, the input shaft driving gear 4 is provided with 90 teeth, the length of the active revolution measuring gear 7 is set to 3 teeth, the input revolution measuring gear 6 and the active revolution measuring gear 7 are arranged in the same plane and are staggered from the input shaft driving gear 4 by two planes. Whenever the active revolution measuring gear 7 rotates one week, it drives the input revolution measuring gear 6 to rotate 3 teeth. Every time the input revolution measuring gear 6 rotates 3 teeth, it means that the input shaft driving gear 4 rotates one week. Finally, the number of revolutions of the input shaft driving gear 4 will be obtained through the rotation of the input revolution measuring gear 6.

[0044] Through the above scheme, since the input shaft driving gear 4 rotates synchronously with the input shaft, through the change of the gear mechanism, the number of revolutions of the input shaft driving gear 4 can be measured subsequently. And by setting the projection of the teeth of the active revolution measuring gear 7 on the input shaft driving gear 4 to completely coincide with some of the teeth of the input shaft driving gear 4, the process design of the gear structure is simplified, so that the rotation of the input shaft driving gear 4 is synchronized with the rotation of the active revolution measuring gear 7. In this way, the input revolution measuring gear 6 can accurately obtain the number of revolutions of the input shaft driving gear 4, ensuring the accuracy of the calculation result of the rotation angle of the input shaft driving gear 4 and improving the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0045] As an example of this embodiment, the input rotation angle measuring gear set 5 includes at least two input rotation angle measuring gears, and the number of teeth of each input rotation angle measuring gear is not equal.

[0046] For a specific implementable manner, refer to Figure 2 and Figure 3 , Figure 2 is a structural schematic diagram of an absolute steering wheel rotation angle measuring device provided by an embodiment of the present invention Figure 2 , Figure 3 is a structural schematic diagram of an absolute steering wheel rotation angle measuring device provided by an embodiment of the present invention Figure 3 ,such as Figure 2 and Figure 3As shown in the figure, the steering wheel input shaft 1 is fixedly connected to the input shaft driving gear 4, so that the input shaft driving gear 4 rotates synchronously with the steering wheel input shaft 1. Then, the input shaft driving gear 4 meshes with each input rotation angle measuring gear in the input rotation angle measuring gear set 5 respectively to obtain the rotation angle increment of the input shaft driving gear 4. The input rotation angle measuring gear set 5 includes at least two input rotation angle measuring gears, and the number of teeth of each input rotation angle measuring gear is not equal. In this embodiment, the input shaft driving gear 4 is set to have 90 teeth, the input rotation angle measuring gear set 5 is set to have two gears, one is set to have 24 teeth, and the other is set to have 18 teeth. The two input rotation angle measuring gears with different numbers of teeth can be used for subsequent calculation of the rotation angle of the input shaft driving gear 4. More specifically, by setting two input rotation angle measuring gears with different numbers of teeth, it is used to obtain the rotation angles of the two input rotation angle measuring gears with different numbers of teeth during the rotation of the input shaft driving gear 4, and then calculate the rotation angle increment of the input shaft driving gear 4. Among them, the rotation angle increment is obtained by calculating the rotation angle difference of each input rotation angle measuring gear in the input rotation angle measuring gear set 5.

[0047] Through the above solution, by setting input rotation angle measuring gears with different numbers of teeth, during the rotation of the input shaft driving gear 4, based on the meshing relationship between the input rotation angle measuring gears with different numbers of teeth and the input shaft driving gear 4, the rotation angle increment of the input shaft driving gear 4 can be measured to obtain the offset of the rotation of the input shaft driving gear, thereby more accurately obtaining the rotation angle of the input shaft driving gear 4 and ensuring the accuracy of the calculation result of the rotation angle of the input shaft driving gear 4, so as to improve the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0048] As an example of the embodiment of the present invention, a steering wheel rotation absolute angle measuring device proposed in the embodiment of the present invention is also provided on the steering wheel output shaft 3. The steering wheel output shaft 3 is connected to the steering wheel input shaft 1 through a rotating shaft 2. The steering wheel rotation absolute angle measuring device further includes: an output shaft driving gear 10 and an output rotation angle measuring gear set 11; the output shaft driving gear 10 meshes with the output rotation angle measuring gear set 11, and the output shaft driving gear 10 is fixedly connected to the steering wheel output shaft 3 and rotates synchronously.

[0049] For a specific implementable manner, refer to Figure 5 , Figure 5 which is a structural schematic diagram of a steering wheel rotation absolute angle measuring device provided in an embodiment of the present invention Figure 5 ; as shown in Figure 5As shown in the figure, an output shaft driving gear 10 and an output rotation angle measuring gear set 11 are arranged on the steering wheel output shaft 3; the output shaft driving gear 10 meshes with the output rotation angle measuring gear set 11. The output shaft driving gear 10 is fixedly connected to the steering wheel output shaft 3 and rotates synchronously therewith. By the output rotation angle measuring gear set 11 rotating synchronously with the output shaft driving gear 10, the rotation angle increment of the output shaft driving gear 10 is obtained. Since the steering wheel output shaft 3 is connected to the steering wheel input shaft 1 through a rotating shaft 2, and the output shaft driving gear 10 is fixedly connected to the steering wheel output shaft 3 and rotates synchronously therewith, the rotation of the output shaft driving gear 10 is synchronous with the rotation of the input shaft driving gear 4. Therefore, the rotation angle backup value of the input shaft driving gear 4 is calculated by combining the rotation angle increment of the output shaft driving gear 10 with the number of rotations of the input shaft driving gear 4; the rotation angle backup value of the input shaft driving gear 4 can be used to replace the abnormal rotation angle of the input shaft driving gear 4.

[0050] Through the above solution, the output shaft driving gear 10 is also fixed on the steering wheel output shaft 3, ensuring that the input shaft driving gear 4 and the output shaft driving gear 10 are synchronous in rotation, guaranteeing the synchronism of data measurement, making the subsequent result of the rotation angle backup of the input shaft driving gear 4 more reliable. The rotation angle of the input shaft driving gear 4 is backed up by each output rotation angle measuring gear in the output rotation angle measuring gear set 11 for replacement when necessary, thereby guaranteeing the reliability of data processing and also guaranteeing the accuracy of the calculation result of the rotation angle of the input shaft driving gear 4 to improve the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0051] As an example of the embodiment of the present invention, the output rotation angle measuring gear set 11 includes at least two output rotation angle measuring gears. The number of gears in the output rotation angle measuring gear set 11 is exactly the same as the number of gears in the input rotation angle measuring gear set 5, and the number of teeth of each output rotation angle measuring gear in the output rotation angle measuring gear set 11 is set exactly the same as the number of teeth of each input rotation angle measuring gear in the input rotation angle measuring gear set 5.

[0052] For a specific implementable manner, refer to Figure 5 , Figure 5 which is a structural schematic diagram of an absolute rotation angle measuring device for a steering wheel provided by an embodiment of the present invention Figure 5 ; as shown in Figure 5As shown, in this embodiment, the input shaft drive gear 4 and the output shaft drive gear 10 have the same number of teeth, i.e., 90 teeth. The output rotation angle measurement gear set 11 and the input rotation angle measurement gear set 5 are set with the same number and the same number of teeth, i.e., one is set to 24 teeth and the other is set to 18 teeth. Through the exactly same gear configuration, a rotational angle increment synchronous with the input rotation angle measurement gear set 5 can be obtained. Combining with the number of rotations obtained by the input rotation number measurement gear 6, the rotational angle backup value of the input shaft drive gear 4 can be finally calculated.

[0053] Through the above solution, by setting the same gear configuration as the input rotation angle measurement gear set 5, during the rotation of the output shaft drive gear 10, a rotational angle backup value synchronous with the rotational angle of the input shaft drive gear 4 can be obtained, thereby ensuring the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0054] As an example of an embodiment of the present invention, a PCB board is provided between the steering wheel input shaft 1 and the steering wheel output shaft 3. Hall elements 9 corresponding one-to-one to each input rotation angle measurement gear in the input rotation angle measurement gear set 5, the input rotation number measurement gear 6, and each output rotation angle measurement gear in the output rotation angle measurement gear set 11 are provided on the PCB board; magnets are provided on each input rotation angle measurement gear in the input rotation angle measurement gear set 5, the input rotation number measurement gear 6, and each output rotation angle measurement gear in the output rotation angle measurement gear set 11.

[0055] For a specific implementable manner, refer to Figure 1 , Figure 1 which is a structural schematic of an absolute rotation angle measurement device for a steering wheel provided in an embodiment of the present invention Figure 1 ; as Figure 1As shown, the Hall element 9 is aligned with each input rotation angle measuring gear in the input rotation angle measuring gear set 5, the input rotation number measuring gear 6, and each output rotation angle measuring gear in the output rotation angle measuring gear set 11 one by one. Specifically, the projections of each input rotation angle measuring gear in the input rotation angle measuring gear set 5, the input rotation number measuring gear 6, and each output rotation angle measuring gear in the output rotation angle measuring gear set 11 on the PCB are aligned with the position centers of the corresponding Hall elements 9 on the PCB. Moreover, magnets are provided on each input rotation angle measuring gear in the input rotation angle measuring gear set 5, the input rotation number measuring gear 6, and each output rotation angle measuring gear in the output rotation angle measuring gear set 11. Thus, the magnetic induction signals generated during the rotation of the corresponding gears can be accurately converted into electrical signals, and finally, the rotation angle of the input shaft driving gear 4 and the backup value of the rotation angle of the input shaft driving gear 4 are calculated in the form of electrical signals. In the embodiment of the present invention, by aligning the Hall elements 9 with each input rotation angle measuring gear in the input rotation angle measuring gear set 5, the input rotation number measuring gear 6, and each output rotation angle measuring gear in the output rotation angle measuring gear set 11, when the rotations of each input rotation angle measuring gear in the input rotation angle measuring gear set 5, the input rotation number measuring gear 6, and each output rotation angle measuring gear in the output rotation angle measuring gear set 11 change, the corresponding magnetic induction signals will also change correspondingly. The corresponding Hall elements 9 will capture the changes in the magnetic induction signals and convert the magnetic induction signals into electrical signals, representing the rotation angle increment of the corresponding input shaft driving gear 4 (equivalent to the first rotation angle increment), the rotation number of the input shaft driving gear 4 (equivalent to the rotation number), and the backup value of the rotation angle increment of the input shaft driving gear 4 (equivalent to the second rotation angle increment) through the electrical signals. Then, the processor 8 uses the rotation angle increment of the input shaft driving gear 4 (equivalent to the first rotation angle increment) and the rotation number of the input shaft driving gear 4 (equivalent to the rotation number) to calculate the rotation angle of the input shaft driving gear 4, and uses the backup value of the rotation angle increment of the input shaft driving gear 4 (equivalent to the second rotation angle increment) and the rotation number of the input shaft driving gear 4 (equivalent to the rotation number) to calculate the backup value of the rotation angle of the input shaft driving gear 4. Since the input shaft driving gear 4 is fixedly connected to the steering wheel input shaft 1 and rotates synchronously, the rotation angle of the input shaft driving gear 4 can be reflected as the absolute rotation angle of the steering wheel, thereby achieving the measurement of the absolute rotation angle of the steering wheel. In an example of this embodiment, several Hall elements 9 and the processor 8 are arranged on the PCB. The PCB is arranged parallel to the input shaft driving gear 4 and is disposed between the steering wheel input shaft 1 and the steering wheel output shaft 3. The distances from the PCB to the steering wheel input shaft 1 and the steering wheel output shaft 3 are set to be equal. In addition, in the embodiment of the present invention, all the obtained angle signals and phase signals are comprehensively processed by the processor 8 and then re-modulated and output. The output interface supports the SENT protocol, four-channel complementary PWM signals, or four-channel module sine voltage signals, which can be equipped as needed during engineering applications.It is worth mentioning that, in addition to obtaining the magnetoelectric signal through the Hall element 9 to calculate the rotation angle of the input shaft driving gear 4 and the backup value of the rotation angle of the input shaft driving gear 4, signal acquisition and signal conversion processes can also be implemented by means such as mature optoelectronic conversion in the prior art, which is not specially limited herein; in this embodiment, the alignment method of the Hall element with each gear is only used for explanation and can be adjusted according to the actual application situation, which is not specially limited herein.

[0056] For further explanation of the PCB board design proposed in the embodiments of the present invention, refer to Figure 6 and Figure 7 , Figure 6 is a schematic diagram of the PCB board circuit structure of a steering wheel rotation absolute angle measurement device provided in an embodiment of the present invention. Figure 7 is a schematic diagram of the comparison of the input signal and output signal waveforms of the PCB board of a steering wheel rotation absolute angle measurement device provided in an embodiment of the present invention. As shown in Figure 6 and Figure 7 In the processor 8 of the PCB board, in the embodiments of the present invention, an analog circuit hardware method is proposed to preprocess and output the change amount of the gear rotation angle, which includes several resistors (such as R1, R2, and R3) and a signal amplifier. The input terminals of the signal amplifier are d2 and d3, and the output terminal is d1. The implementation principle of the overall circuit is the same as that of the prior art. It can be seen from the signal waveform results in Figure 7 that the electrical signal (equivalent to Gin1) obtained from the magnetic induction signal change of the input rotation angle measurement gear set 5 and the electrical signal (equivalent to Gout1) obtained from the magnetic induction signal change of the output rotation angle measurement gear set 11 are basically the same under normal circumstances, indicating that the electrical signal obtained from the magnetic induction signal change of the output rotation angle measurement gear set 11 can be used as the backup value of the electrical signal obtained from the magnetic induction signal change of the input rotation angle measurement gear set 5. It is worth mentioning that Gin1 comes from the 24-tooth input rotation angle measurement gear, and Gout1 comes from the 24-tooth output rotation angle measurement gear; in addition to Gin1 and Gout1 being basically the same, the electrical signal Gin2 from the 18-tooth input rotation angle measurement gear and the electrical signal Gout2 from the 18-tooth output rotation angle measurement gear are also basically the same, which will not be elaborated herein. The results show that by setting the gear configuration of the output rotation angle measurement gear set 11 to be exactly the same as that of the input rotation angle measurement gear set 5, during the rotation of the output shaft driving gear 10, the output rotation angle measurement gear set 11 can obtain an absolute rotation angle backup value that is exactly the same as the absolute rotation angle of the input shaft driving gear 4 during normal rotation. It is worth mentioning that the conversion of the electromagnetic signal into an electrical signal and then the calculation of the absolute rotation angle of the steering wheel and the backup value of the absolute rotation angle of the steering wheel proposed in the embodiments of the present invention are only explained as one of the feasible implementation methods, and the signal acquisition method and the signal processing method are not limited.

[0057] Through the above solution, the Hall element 9 is respectively arranged in one-to-one correspondence with each input rotation angle measurement gear in the input rotation angle measurement gear set 5, the input rotation number measurement gear 6, and each output rotation angle measurement gear in the output rotation angle measurement gear set 11, so as to accurately convert the magnetic induction signal generated during the rotation of the corresponding gear into an electrical signal, and finally calculate the rotation angle of the input shaft driving gear 4 in the form of an electrical signal, thereby obtaining the absolute rotation angle of the steering wheel, which can ensure the unity of data, reduce the data explosion caused by multi-source data, ensure the accuracy of the calculation result of the rotation angle of the input shaft driving gear 4, and improve the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0058] As an example of an embodiment of the present invention, the output rotation angle measurement gear set 11 and the input rotation angle measurement gear set 5 are arranged symmetrically about the center of the rotation shaft 2.

[0059] In a specific implementable manner, the output rotation angle measurement gear set 11 and the input rotation angle measurement gear set 5 are arranged symmetrically about the center of the rotation shaft 2. Because the Hall element 9 needs to be aligned with the corresponding gear when it is set, if the output rotation angle measurement gear set 11 and the input rotation angle measurement gear set 5 are arranged at the same end, when the magnetic induction signal changes once, the Hall element 9 may receive the change of the magnetic induction signal twice. In addition to being arranged symmetrically about the center, the setting positions of the output rotation angle measurement gear set 11 and the input rotation angle measurement gear set 5 can also be correspondingly changed according to the actual application situation. In this embodiment, only the example of central symmetry is used for explanation, and no special limitation is made here.

[0060] Through the above solution, the output rotation angle measurement gear set 11 and the input rotation angle measurement gear set 5 are also arranged symmetrically about the center of the rotation shaft 2, preventing electromagnetic interference between them due to the Hall element 9 being arranged on the same side, further ensuring the accuracy of data acquisition, and thus improving the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0061] To further illustrate the principle of an absolute steering wheel rotation angle measurement device proposed in an embodiment of the present invention, refer to Figure 8 , Figure 8 which is a schematic step flow diagram of an absolute steering wheel rotation angle measurement method provided in an embodiment of the present invention Figure 1 ,as Figure 8 shown, the embodiment of the present invention also provides an absolute steering wheel rotation angle measurement method, including steps 101 to 104, and the specific steps are as follows:

[0062] Step 101, based on the input rotation angle measurement gear set 5, obtain the first rotation angle increment; further, by calculating the rotation angle difference of each input rotation angle measurement gear in the input rotation angle measurement gear set 5, the first rotation angle increment is obtained.

[0063] Step 102: Obtain the number of rotation turns based on the input rotation turn measuring gear 6. Further, obtain the number of rotation turns by acquiring the number of times the input rotation turn measuring gear 6 rotates through a preset angle change.

[0064] Step 103: Obtain the rotation angle of the input shaft driving gear 4 based on the first rotation angle increment and the number of rotation turns. Further, obtain the rotation angle value by calculating the product of the number of rotation turns and the circumferential angle, and obtain the rotation angle of the input shaft driving gear 4 by calculating the sum of the rotation angle value and the first rotation angle increment.

[0065] Step 104: Obtain the absolute steering wheel rotation angle based on the rotation angle of the input shaft driving gear 4.

[0066] In a specific implementable manner, in this embodiment, taking the 90-tooth input shaft driving gear 4, the 24-tooth input rotation angle measuring gear, the 18-tooth input rotation angle measuring gear, and the 3-tooth input rotation turn measuring gear 6 as examples, when measuring the absolute steering wheel rotation angle in the embodiment of the present invention, first, receive the corresponding measurement magnetic induction signals generated by the 24-tooth input rotation angle measuring gear and the 18-tooth input rotation angle measuring gear, convert them into corresponding electrical signals through the Hall element 9, and denote them as Gin1 and Gin2 respectively; and receive the corresponding measurement magnetic induction signal generated by the input rotation turn measuring gear 6, convert it into a corresponding electrical signal through the Hall element 9, and denote it as Gin3; when the input shaft driving gear 4 rotates, it drives the input rotation angle measuring gear set 5. During the rotation process, both the 24-tooth input rotation angle measuring gear and the 18-tooth input rotation angle measuring gear will generate corresponding magnetic induction signals. After being processed by the Hall element 9, obtain the angle difference between Gin1 and Gin2, and calculate the rotation angle increment. At this time, what is provided is a relative increment; and every 20 degrees (equivalent to the preset angle) change in the voltage signal of Gin3 indicates that the input shaft driving gear 4 rotates one circle. Calculate the corresponding number of rotation turns by calculating the number of changes in Gin3; finally, by setting the input rotation angle measuring gear set 5 and the input rotation turn measuring gear 6 in this way, the measurement of the absolute rotation angle of the steering wheel within 2160 degrees is realized; it is worth mentioning that since the input shaft driving gear 4 is fixedly connected to the steering wheel input shaft 1 and rotates synchronously, the rotation angle of the input shaft driving gear 4 can be reflected as the absolute steering wheel rotation angle. The calculation formula for the absolute steering wheel rotation angle θ is as follows:

[0067] θ = Gin3 * 360° + (|Gin1 - Gin2|);

[0068] By receiving the magnetic induction signals generated by the input rotation angle measuring gear set 5, obtaining the angle difference of the rotation of the input rotation angle measuring gear set 5 and calculating the angle increment of the input shaft driving gear 4, combining the magnetic induction signals generated by the input rotation number measuring gear 6, obtaining the voltage signals of the input rotation number measuring gear 6 for each change of the preset angle, obtaining the current rotation angle increment through the input rotation angle measuring gear set 5 and then combining the rotation number of turns of the input shaft driving gear 4 obtained through the input rotation number measuring gear 6, finally calculating the rotation angle of the input shaft driving gear 4, and reflecting it as the absolute steering wheel rotation angle θ.

[0069] An embodiment of the present invention provides a method for measuring the absolute steering wheel rotation angle. As the input rotation angle measuring gears in the input rotation angle measuring gear set 5 rotate with the input shaft driving gear 4, the rotation angles of the input rotation angle measuring gears are obtained, the rotation angle differences of the input rotation angle measuring gears are calculated to obtain the first rotation angle increment, and combined with the number of times the input rotation number measuring gear 6 changes the preset angle when meshing and separating as the driving rotation number measuring gear 7 rotates, the rotation number of turns of the input shaft driving gear 4 is obtained. Finally, the first rotation angle increment is obtained through the input rotation angle measuring gear set 5 and then combined with the current rotation number of turns of the input shaft driving gear 4 obtained through the input rotation number measuring gear 6 to calculate the rotation angle of the input shaft driving gear 4. Since the input shaft driving gear 4 is fixedly connected to the steering wheel input shaft 1 and rotates synchronously, the rotation angle of the input shaft driving gear 4 can reflect the absolute steering wheel rotation angle, and finally the measurement of the absolute steering wheel rotation angle is realized. Through the meshing relationship of the gears and the fault tolerance mechanism for comprehensively outputting the rotation angle increment and the rotation number of turns when the gears rotate, the accuracy of the calculation result of the rotation angle of the input shaft driving gear 4 is guaranteed, thereby improving the reliability of the absolute steering wheel rotation angle measurement result.

[0070] In order to further improve the reliability of the rotation angle measurement result, the embodiment of the present invention also proposes a backup mechanism. Specifically, refer to Figure 9 , Figure 9 which is a schematic flowchart of the steps of a method for measuring the absolute steering wheel rotation angle provided by an embodiment of the present invention Figure 2 ; as Figure 9 shown, it includes steps 201 to 202, and the specific steps are as follows:

[0071] Step 201, obtaining a second rotation angle increment by calculating the rotation angle differences of the output rotation angle measuring gears in the output rotation angle measuring gear set 11;

[0072] Step 202, obtaining a backup value of the rotation angle of the input shaft driving gear 4 based on the second rotation angle increment and the rotation number of turns.

[0073] In a specific implementable manner, since the gear configuration of the output rotation angle measurement gear set 11 is the same as that of the input rotation angle measurement gear set 5, the backup information of the absolute angle, which is also obtained by combining with the input rotation number measurement gear 6, can be used for replacement when necessary and to handle abnormal signal changes. Similarly, taking the 90-tooth output shaft drive gear 10, the 24-tooth output rotation angle measurement gear, the 18-tooth output rotation angle measurement gear, and the 3-tooth input rotation number measurement gear 6 as examples, when the output shaft drive gear 10 rotates with the rotation shaft 2, for every one full rotation of the steering wheel input shaft 1, the rotation shaft 2 rotates one full turn accordingly, and then the output shaft drive gear 10 rotates one full turn. At this time, the magnetic induction signals of both the 24-tooth output rotation angle measurement gear and the 18-tooth output rotation angle measurement gear change, that is, the corresponding measured magnetic induction signals are converted into corresponding electrical signals through the Hall element 9, denoted as Gout1 and Gout2 respectively. Then, by combining with the corresponding measured magnetic induction signal generated by the input rotation number measurement gear 6, it is converted into a corresponding electrical signal through the Hall element 9, denoted as Gin3, and the absolute backup value θ of the steering wheel rotation angle is calculated. ′ , the specific formula is as follows:

[0074] θ ′ = Gin3 * 360° + (|Gout1 - Gout2|);

[0075] From this, the absolute backup value θ of the steering wheel rotation angle is calculated. ′ ;

[0076] Under normal circumstances, it can be considered that the absolute steering wheel rotation angle θ is consistent with the absolute backup value θ of the steering wheel rotation angle. ′ However, in actual applications, the accuracy of reflecting the relative change in the steering wheel rotation through the absolute steering wheel rotation angle θ is higher than that of the absolute backup value θ of the steering wheel rotation angle. ′ Therefore, when applying, the absolute steering wheel rotation angle θ is preferably used as the standard. When a fault occurs, such as when the Gin1 or Gin2 signal is abnormal, at this time, the absolute steering wheel rotation angle θ cannot be calculated, and then the absolute backup value θ of the steering wheel rotation angle ′ is used as a substitute, thereby improving the reliability of the measurement result of the absolute steering wheel rotation angle.

[0077] Through the above solution, by outputting the rotation angle differences generated by each output rotation angle measurement gear in the output rotation angle measurement gear set 11 as it rotates with the output shaft drive gear 10, and then calculating the second rotation angle increment. Since the number of gears in the output rotation angle measurement gear set 11 is equal to the number of gears in the input rotation angle measurement gear set 5, therefore, combined with the backup information of the rotation angle of the input shaft drive gear 4 also obtained by the input rotation number measurement gear 6, it can be used for replacement when necessary to ensure reliable data can still be provided in case of a failure. By means of mutual backup of multiple gears, the accuracy of the calculation result of the rotation angle of the input shaft drive gear is guaranteed to improve the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0078] As an example of an embodiment of the present invention, a method for measuring the absolute rotation angle of a steering wheel proposed in an embodiment of the present invention, based on the input rotation angle measurement gear set 5, obtains a first rotation angle increment, including: during the rotation of the input rotation angle measurement gear set 5, obtaining a first magnetic induction signal and / or a first voltage signal corresponding to the input rotation angle measurement gear set 5, and based on the first magnetic induction signal and / or the first voltage signal, obtaining the corresponding first rotation angle increment; based on the input rotation number measurement gear 6, obtaining the number of rotation turns, including: during the rotation of the input rotation number measurement gear 6, obtaining a second magnetic induction signal and / or a second voltage signal corresponding to the input rotation number measurement gear 6, and based on the second magnetic induction signal and / or the second voltage signal, obtaining the corresponding number of rotation turns; the obtaining of the second rotation angle increment by calculating the rotation angle differences of the output rotation angle measurement gears in the output rotation angle measurement gear set 11 includes: during the rotation of the output rotation angle measurement gear set 11, obtaining a third magnetic induction signal and / or a third voltage signal corresponding to the output rotation angle measurement gear set 11, and calculating the difference of the third magnetic induction signal corresponding to the output rotation angle measurement gear set 11 and / or the difference of the third voltage signal corresponding to the output rotation angle measurement gear set 11 to obtain the second rotation angle increment.

[0079] In a specific implementable manner, by aligning the Hall element 9 with each input rotation angle measurement gear in the input rotation angle measurement gear set 5, the input rotation number measurement gear 6, and each output rotation angle measurement gear in the output rotation angle measurement gear set 11, when the rotation of each input rotation angle measurement gear in the input rotation angle measurement gear set 5, the input rotation number measurement gear 6, and each output rotation angle measurement gear in the output rotation angle measurement gear set 11 changes, the corresponding magnetic induction signal will also change accordingly. The corresponding Hall element 9 will capture the change in the magnetic induction signal and convert the magnetic induction signal into an electrical signal (equivalent to Gin1, Gin2, Gin3, Gout1, and Gout2). The electrical signal represents the rotation angle increment (equivalent to the first rotation angle increment), the number of rotations (equivalent to the rotation number) of the input shaft drive gear 4, and the backup value of the rotation angle increment (equivalent to the second rotation angle increment) of the input shaft drive gear 4. It is worth mentioning that in this embodiment, the signal processing method of converting the magnetic induction signal into an electrical signal is only one example of the embodiments of the present invention. There are no special limitations on the form of signal acquisition (such as: magnetic induction signal, voltage signal, and / or light sensing signal, etc.) and the signal processing method (such as: converting magnetic induction signal to voltage signal, converting light sensing signal to voltage signal, and / or converting voltage signal to voltage signal, etc.).

[0080] Through the above solution, the magnetic induction signal and / or voltage signal generated during the rotation of the corresponding gear will ultimately reflect the first rotation angle increment of the input shaft drive gear 4, the number of rotations of the input shaft drive gear 4, and the second rotation angle increment of the output rotation angle measurement gear set 11 in the form of a magnetic induction signal and / or voltage signal, which is used to calculate the rotation angle of the input shaft drive gear 4 and the backup value of the rotation angle of the input shaft drive gear 4, and then obtain the absolute rotation angle of the steering wheel. This can ensure the unity of data, reduce data explosion caused by multi-source data, ensure the accuracy of the calculation result of the rotation angle of the input shaft drive gear 4, and improve the reliability of the measurement result of the absolute rotation angle of the steering wheel.

[0081] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

[0082] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0083] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, "a plurality of" means two or more unless otherwise specifically defined.

Claims

1. An absolute angle measuring device for steering wheel rotation, characterized in that, A steering wheel rotation absolute angle measuring device is provided on the steering wheel input shaft, and includes: An input shaft driving gear, an input rotation angle measuring gear set, a driving rotation number measuring gear, and an input rotation number measuring gear; The input shaft driving gear meshes with the input rotation angle measuring gear set; the input shaft driving gear is fixedly connected to the steering wheel input shaft and rotates synchronously therewith; The driving rotation number measuring gear is fixedly connected to the input shaft driving gear and rotates synchronously therewith; During the synchronous rotation with the input shaft driving gear, the driving rotation number measuring gear meshes with or disengages from the input rotation number measuring gear.

2. The absolute angle measurement device for steering wheel rotation according to claim 1, characterized in that, The projection of the teeth of the driving rotation number measuring gear on the input shaft driving gear completely coincides with some teeth of the input shaft driving gear.

3. The absolute angle measurement device for steering wheel rotation according to claim 1, characterized in that The input rotation angle measuring gear set includes at least two input rotation angle measuring gears, and the number of teeth of each input rotation angle measuring gear is not equal.

4. A device for measuring the absolute angle of steering wheel rotation according to any one of claims 1 to 3, characterized in that, The steering wheel rotation absolute angle measuring device is further provided on the steering wheel output shaft. The steering wheel output shaft is connected to the steering wheel input shaft through a rotating shaft. The steering wheel rotation absolute angle measuring device further includes: an output shaft driving gear and an output rotation angle measuring gear set; The output shaft driving gear meshes with the output rotation angle measuring gear set, and the output shaft driving gear is fixedly connected to the steering wheel output shaft and rotates synchronously therewith.

5. The absolute angle measuring device for steering wheel rotation according to claim 4, characterized in that The output rotation angle measuring gear set includes at least two output rotation angle measuring gears. The number of gears of the output rotation angle measuring gear set is exactly the same as the number of gears of the input rotation angle measuring gear set. The number of teeth of each output rotation angle measuring gear in the output rotation angle measuring gear set is exactly the same as the number of teeth of each input rotation angle measuring gear in the input rotation angle measuring gear set.

6. The absolute angle measurement device for steering wheel rotation according to claim 4, characterized in that, A PCB board is provided between the steering wheel input shaft and the steering wheel output shaft. Hall elements corresponding one by one to each input rotation angle measuring gear in the input rotation angle measuring gear set, the input rotation number measuring gear, and each output rotation angle measuring gear in the output rotation angle measuring gear set are provided on the PCB board; Magnets are provided on each input rotation angle measuring gear in the input rotation angle measuring gear set, the input rotation number measuring gear, and each output rotation angle measuring gear in the output rotation angle measuring gear set.

7. The absolute angle measurement device for steering wheel rotation according to claim 6, characterized in that, The output rotation angle measuring gear set and the input rotation angle measuring gear set are symmetrically arranged about the center of the rotating shaft.

8. A method for measuring the absolute angle of steering wheel rotation, characterized in that, Applied to a steering wheel rotation absolute angle measuring device according to any one of claims 1 to 7, the steering wheel rotation absolute angle measuring method includes: Obtaining a first rotation angle increment based on the input rotation angle measuring gear set; Obtaining the number of rotation circles based on the input rotation number measuring gear; Obtaining the rotation angle of the input shaft driving gear based on the first rotation angle increment and the number of rotation circles; Obtaining the steering wheel rotation absolute angle based on the rotation angle of the input shaft driving gear.

9. The method for measuring the absolute rotation angle of a steering wheel according to claim 8, characterized in that, The obtaining a first rotation angle increment based on the input rotation angle measuring gear set includes: Obtaining a first rotation angle increment by calculating the rotation angle difference of each input rotation angle measuring gear in the input rotation angle measuring gear set.

10. A method for measuring the absolute angle of steering wheel rotation according to claim 8, characterized in that, The obtaining the number of rotation circles based on the input rotation number measuring gear includes: The number of rotations is obtained by acquiring the number of times the input rotation count gear rotates through a preset angle change.

11. A method for measuring the absolute angle of steering wheel rotation according to claim 8, characterized in that, Based on the first rotation angle increment and the number of rotations, obtaining the rotation angle of the input shaft driving gear includes: Obtaining a rotation angle value by calculating the product of the number of rotations and the circumferential angle; Obtaining the rotation angle of the input shaft driving gear by calculating the sum of the rotation angle value and the first rotation angle increment.

12. A method for measuring the absolute angle of steering wheel rotation according to claim 8, characterized in that, It further includes: Obtaining a second rotation angle increment by calculating the rotation angle differences of the output rotation angle measurement gears in the output rotation angle measurement gear set; Based on the second rotation angle increment and the number of rotations, obtaining a backup value of the rotation angle of the input shaft driving gear.

13. The method for measuring the absolute angle of steering wheel rotation according to claim 12, wherein, Based on the input rotation angle measurement gear set, acquiring the first rotation angle increment includes: during the rotation of the input rotation angle measurement gear set, acquiring the corresponding first magnetic induction signal and / or first voltage signal of the input rotation angle measurement gear set, and based on the first magnetic induction signal and / or the first voltage signal, acquiring the corresponding first rotation angle increment; Based on the input rotation count gear, acquiring the number of rotations includes: during the rotation of the input rotation count gear, acquiring the corresponding second magnetic induction signal and / or second voltage signal of the input rotation count gear, and based on the second magnetic induction signal and / or the second voltage signal, acquiring the corresponding number of rotations; The obtaining a second rotation angle increment by calculating the rotation angle differences of the output rotation angle measurement gears in the output rotation angle measurement gear set includes: during the rotation of the output rotation angle measurement gear set, acquiring the corresponding third magnetic induction signal and / or third voltage signal of the output rotation angle measurement gear set, and calculating the difference of the corresponding third magnetic induction signal of the output rotation angle measurement gear set and / or the difference of the corresponding third voltage signal of the output rotation angle measurement gear set, to obtain the second rotation angle increment.

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