Method for improving precision of encoder
By using components such as central processors and MR3 adjustment chips in the encoder, the flexible calibration and subdivision of sine signals and string signals can be achieved, and the problems of inconvenience and real -time effectiveness in traditional methods have been solved. Accuracy and resolution.
Patent Information
- Application Number
- CN202411557901.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-01-28
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Traditional methods to improve encoder accuracy have inconvenient manual adjustment and poor real-time effectiveness, especially in the phase calibration of sinusoidal and cosine signals.
Through the encoder composed of central processors, AD modulus converters, MR3 regulating chips, etc., use MR3 to adjust chip analysis to generate a correction amount, uniformly modify the signal to calibrate the orthogonal signal of 90 ° phase standard. Credit calibration of the DC level and amplitude value, generate compensation angle and make supplementary segmentation.
The flexible adjustment of the encoder signal is realized, the segmentation accuracy is improved, the operation is easy, and the real -time effectiveness is good, which can effectively improve the angle measurement accuracy and resolution of the encoder.
Smart Images
Figure CN119374640A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of angular displacement sensing, and in particular to a method for improving the accuracy of an encoder. Background Art
[0002] Photoelectric shaft angle encoder is a representative angular displacement sensor that is widely used at present. Many automatic control systems rely on photoelectric shaft angle encoders, and at the same time, higher requirements are placed on the angle measurement accuracy and resolution of photoelectric encoders. The encoder accuracy consists of large-angle angle measurement accuracy and single-cycle angle measurement accuracy. The large-angle angle measurement accuracy mainly depends on the eccentricity of the code disk relative to the bearing, commonly known as the code disk eccentricity; the single signal cycle angle measurement accuracy depends on the quality of the sinusoidal scanning signal and its subdivision circuit. Factors that affect the single-cycle measurement accuracy include the size of the signal period, the sinusoidality of the signal, the orthogonality of the signal, the symmetry of the signal, and the stability and dynamic performance of the subsequent circuit processing analog signals.
[0003] At present, the traditional method to improve the accuracy of encoders is mainly implemented through the combination of software and hardware in three stages. The first stage is the calibration of the original signal before data processing, the phase calibration of sine and cosine, the calibration of sine and cosine offset, and the calibration of sine and cosine gain. The second stage is the calibration of the algorithm in data processing, the calibration of the subdivision program algorithm and the mathematical model. The third stage is the accuracy compensation after data processing, the long-period error compensation or the short-period error compensation. Hardware methods are often used to manually adjust the DC level and signal amplitude. There is no effective method with simple operation, reliability and high real-time performance for the phase calibration of sine and cosine signals. Summary of the invention
[0004] In view of the shortcomings of the prior art, the present invention provides a method for improving the accuracy of the encoder, which has the advantages of flexible adjustment of high subdivision accuracy, simple operation and good real-time effectiveness, and solves the problem that the traditional method of improving the accuracy of the encoder is inconvenient manual adjustment and has poor real-time effectiveness.
[0005] To achieve the above object, the present invention provides the following technical solution: a method for improving the accuracy of an encoder, wherein the encoder is composed of a central processing unit, an AD analog-to-digital converter, an MR3 adjustment chip, a medium-fine code shaping amplifier circuit, a coarse-fine code shaping amplifier circuit, a secondary voltage stabilization circuit and a differential data interface circuit, and the method for improving the accuracy of the encoder comprises the following steps: Step 1: When the encoder receives a sine signal or a cosine signal, the MR3 adjustment chip analyzes and generates a correction degree The signals are uniformly corrected and calibrated to orthogonal signals with a 90° phase standard; Step 2: The CPU analyzes and generates the offset based on the corrected and calibrated signal and correction level , and according to the correction level Correcting the DC component of the calibration signal; Step 3: The CPU collects the amplitude of the signal through the AD converter and analyzes and generates the gain multiple. and correction amplitude , and according to the correction amplitude Correcting the amplitude of the calibration signal; Step 4: The central processor analyzes and generates the compensation angle based on the signals after phase correction calibration, DC level correction calibration and amplitude correction calibration. , and according to the compensation angle Perform interpolation subdivision.
[0006] Preferably, in step 1, the adjustment chip marks the received sinusoidal signal as , the cosine signal is marked as , Indicates the time point when the adjustment chip receives the signal. The measurement of the position of the sinusoidal signal waveform on the time axis, that is, the phase angle of the sinusoidal signal, The measure of the position of the cosine signal waveform on the time axis is the phase angle of the cosine signal.
[0007] Preferably, in step 1, the correction degree The calculation formula is as follows: ;In the formula, Indicates the correction degree, 90° represents the constant in the correction degree calculation formula, which is the standard phase angle of the orthogonal signal. It means that when the encoder receives a sinusoidal signal, the difference between the sinusoidal signal phase angle and the 90° phase standard is calculated, which is the correction degree. It means that when the encoder receives a cosine signal, the difference between the phase angle of the cosine signal and the 90° phase standard is calculated, which is the correction degree.
[0008] Preferably, in step 2, the central processing unit converts the sine signal and cosine signal after the phase correction calibration into a sine digital signal and a cosine digital signal through an AD analog-to-digital converter, and marks the sine digital signal as , the cosine digital signal is marked as .
[0009] Preferably, in step 2, the offset The calculation formula is as follows: ;In the formula, Indicates the offset, Represents the highest point in the sinusoidal digital signal waveform. Represents the lowest point in the sinusoidal digital signal waveform. It represents the average voltage level at the midpoint of the sinusoidal digital signal waveform, that is, the DC component value of the sinusoidal digital signal. Represents the highest point in the cosine digital signal waveform. Represents the lowest point in the cosine digital signal waveform. It represents the average voltage level of the midpoint of the cosine digital signal waveform, that is, the DC component value of the cosine digital signal. The offset includes the DC component value of the sine digital signal and the DC component value of the cosine digital signal.
[0010] Preferably, in step 2, the AD analog-to-digital converter is provided with a DC component reference value , the CPU uses the offset and DC component reference value , analyze and generate correction levels , and its calculation formula is as follows: In the formula, Indicates the correction level, The difference between the DC component value of the digital signal and the DC component reference value is the correction level.
[0011] Preferably, in step 2, the central processing unit marks the amplitude of the sinusoidal digital signal after the phase correction calibration and the DC level correction calibration as The amplitude of the cosine digital signal after the phase correction calibration and DC level correction calibration is marked as .
[0012] Preferably, in step three, the gain multiple The calculation formula is as follows: ;In the formula, Indicates the gain multiple, Represents the output voltage of the AD analog-to-digital converter, Represents the maximum amplitude of a sinusoidal digital signal, Represents the minimum amplitude in a sinusoidal digital signal, It means the output voltage is divided by the difference between the maximum and minimum input amplitudes to obtain the gain ratio of the sinusoidal digital signal. Represents the maximum amplitude in the cosine digital signal, Represents the minimum amplitude in the cosine digital signal, It means that the output voltage is divided by the difference between the maximum and minimum input amplitudes to obtain the gain ratio of the cosine digital signal. The gain multiple includes the gain ratio of the sine digital signal and the gain ratio of the cosine digital signal.
[0013] Preferably, in step 3, the correction amplitude The calculation formula is as follows: ;In the formula, represents the correction amplitude, Represents the DC component value of the sinusoidal digital signal, Represents the gain ratio of the sinusoidal digital signal, It means that the corrected amplitude of the sinusoidal digital signal is obtained by subtracting the offset from the sinusoidal digital signal and multiplying it by the gain multiple. Represents the DC component value of the cosine digital signal, Represents the gain ratio of the cosine digital signal, It means that the cosine digital signal is subtracted from the offset and then multiplied by the gain multiple to obtain the corrected amplitude of the cosine digital signal. The corrected amplitude includes the corrected amplitude of the sine digital signal and the corrected amplitude of the cosine digital signal.
[0014] Preferably, in step 4, the compensation angle The calculation process is as follows: Constructing a 2D coordinate system , and then substitute the digital signal into the two-dimensional coordinate system ; In the two-dimensional coordinate system In, extract sampling points, the coordinates of a single sampling point are , the coordinates of the other sampling point are , and calculate the slope of the straight line between every two sampling points , and its calculation formula is as follows: In the formula, represents the slope of the straight line, Represents two sampling points in a two-dimensional coordinate system The difference in the coordinate values along the axis direction, Represents two sampling points in a two-dimensional coordinate system The difference in coordinate values along the axis direction, Indicates simultaneous calculation The slope of the straight line between the sampling points; In the formula, Indicates the compensation angle, Represents the angle value of the digital signal, Indicates the output angle value after digital signal compensation.
[0015] Compared with the prior art, the present invention provides a method for improving the accuracy of an encoder, which has the following beneficial effects: The present invention comprises an encoder through a central processing unit, an AD analog-to-digital converter, an MR3 adjustment chip, a medium-precision code shaping amplifier circuit, a coarse-precision code shaping amplifier circuit, a secondary voltage stabilization circuit and a differential data interface circuit. When the encoder receives a sine signal or a cosine signal, the MR3 adjustment chip adjusts the signal according to the correction degree. The signals are uniformly corrected and calibrated to orthogonal signals with a 90° phase standard, so that the two sine and cosine signals entering the subdivision program have good orthogonality and symmetry, which can effectively improve the subsequent subdivision accuracy. The central processor converts the sine and cosine signals after phase correction and calibration into sine digital signals and cosine digital signals through the AD analog-to-digital converter, and analyzes and generates the offset and correction level , correct the DC component of the calibration signal, the central processor collects the amplitude of the signal through the AD analog-to-digital converter, analyzes and generates the gain multiple and correction amplitude , correct the amplitude of the calibration signal, amplify the sine digital signal and cosine digital signal to the ideal amplitude, the corrected sine digital signal and cosine digital signal can reach the standard waveform, and the subdivision accuracy is high.
[0016] The present invention uses a central processor to analyze and generate a compensation angle according to the signals after phase correction calibration, DC level correction calibration and amplitude correction calibration. , and interpolation and subdivision are performed to compensate for the error caused by the eccentricity of the code disk and the error caused by the quality of the precision code signal, thereby achieving a very high resolution, simple operation, and good real-time effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the steps of the method of the present invention; Figure 2 It is a schematic diagram of the structure of the encoder circuit board of the present invention. DETAILED DESCRIPTION
[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0019] Since the traditional method of improving encoder accuracy is mainly implemented through the combination of software and hardware in three stages, the first stage is the calibration of the original signal before data processing, the phase calibration of sine and cosine, the calibration of sine and cosine offset, and the calibration of sine and cosine gain; the second stage is the calibration of the algorithm in data processing, the calibration of the subdivision program algorithm and the mathematical model; the third stage is the accuracy compensation after data processing, the long-period error compensation or the short-period error compensation. Hardware methods are often used to manually adjust the DC level and signal amplitude. There is no simple, reliable and high-real-time effective method for the phase calibration of sine and cosine signals. Therefore, a method for improving encoder accuracy is provided. Please refer to Figure 1 , Figure 1 Schematic diagram of the process steps of the present invention. Figure 2 , Figure 2 Schematic diagram of the structure of the encoder circuit board of the present invention, as shown in Figure 2 As shown, the encoder is composed of a central processing unit, an AD analog-to-digital converter, an MR3 adjustment chip, a medium-precision code shaping amplifier circuit, a coarse-precision code shaping amplifier circuit, a secondary voltage stabilization circuit and a differential data interface circuit. The core of the MR3 technology is a new type of magnetoresistive random access memory technology, which improves the storage density, does not lose data after power failure, and has a very fast reading and writing speed, which can reach the nanosecond level. The method for improving the encoder accuracy includes the following steps: Step 1: When the encoder receives a sine signal or a cosine signal, the MR3 regulator chip marks the received sine signal as , the cosine signal is marked as , Indicates the time point when the adjustment chip receives the signal. The measurement of the position of the sinusoidal signal waveform on the time axis, that is, the phase angle of the sinusoidal signal, The measurement of the position of the cosine signal waveform on the time axis is the phase angle of the cosine signal, and the correction degree is generated by analysis , and its calculation formula is as follows: ;In the formula, Indicates the correction degree, 90° represents the constant in the correction degree calculation formula, which is the standard phase angle of the orthogonal signal. It means that when the encoder receives a sinusoidal signal, the difference between the sinusoidal signal phase angle and the 90° phase standard is calculated, which is the correction degree. It means that when the encoder receives a cosine signal, the difference between the phase angle of the cosine signal and the 90° phase standard is calculated, which is the correction degree; Step 2: The central processor converts the sine signal and cosine signal after phase correction calibration into sine digital signal and cosine digital signal through the AD analog-to-digital converter, and marks the sine digital signal as , the cosine digital signal is marked as , analyze the generated offset and correction level , and its calculation formula is as follows: ;In the formula, Indicates the offset, Represents the highest point in the sinusoidal digital signal waveform. Represents the lowest point in the sinusoidal digital signal waveform. It represents the average voltage level at the midpoint of the sinusoidal digital signal waveform, that is, the DC component value of the sinusoidal digital signal. Represents the highest point in the cosine digital signal waveform. Represents the lowest point in the cosine digital signal waveform. Indicates the average voltage level of the midpoint of the cosine digital signal waveform, that is, the DC component value of the cosine digital signal, and the offset includes the DC component value of the sine digital signal and the DC component value of the cosine digital signal; The AD converter is set with a DC component reference value , the CPU uses the offset and DC component reference value , analyze and generate correction levels , and its calculation formula is as follows: In the formula, Indicates the correction level, The difference between the DC component value of the digital signal and the DC component reference value is the correction level. The central processor adjusts the correction level according to the correction level. Correcting the DC component of the calibration signal; Step 3: The central processor collects the amplitude of the signal through the AD analog-to-digital converter, and marks the amplitude of the sinusoidal digital signal after the phase correction calibration and DC level correction calibration as The amplitude of the cosine digital signal after the phase correction calibration and DC level correction calibration is marked as , and analyze the generated gain multiples and correction amplitude , and its calculation formula is as follows: ;In the formula, Indicates the gain multiple, Represents the output voltage of the AD analog-to-digital converter, Represents the maximum amplitude of a sinusoidal digital signal, Represents the minimum amplitude in a sinusoidal digital signal, It means the output voltage is divided by the difference between the maximum and minimum input amplitudes to obtain the gain ratio of the sinusoidal digital signal. Represents the maximum amplitude in the cosine digital signal, Represents the minimum amplitude in the cosine digital signal, It means that the output voltage is divided by the difference between the maximum and minimum input amplitudes to obtain the gain ratio of the cosine digital signal. The gain multiple includes the gain ratio of the sine digital signal and the gain ratio of the cosine digital signal. ;In the formula, represents the correction amplitude, Represents the DC component value of the sinusoidal digital signal, Represents the gain ratio of the sinusoidal digital signal, It means that the corrected amplitude of the sinusoidal digital signal is obtained by subtracting the offset from the sinusoidal digital signal and multiplying it by the gain multiple. Represents the DC component value of the cosine digital signal, Represents the gain ratio of the cosine digital signal, It means that the cosine digital signal is subtracted from the offset and then multiplied by the gain multiple to obtain the corrected amplitude of the cosine digital signal. The corrected amplitude includes the corrected amplitude of the sine digital signal and the corrected amplitude of the cosine digital signal. The central processor calculates the corrected amplitude according to the corrected amplitude. Correct the amplitude of the calibration signal and amplify the sine digital signal and cosine digital signal to the ideal amplitude. The corrected sine digital signal and cosine digital signal can reach the standard waveform, and the subdivision accuracy is high with flexible adjustment. Step 4: In order to improve the angle measurement accuracy and resolution of the encoder, it is usually necessary to interpolate and subdivide the minimum periodic grating signal of the code disk. The central processor analyzes and generates the compensation angle according to the signal after phase correction calibration, DC level correction calibration and amplitude correction calibration. , both the sine digital signal and the cosine digital signal go through the same interpolation subdivision process, and the calculation process is as follows: Constructing a 2D coordinate system , and then substitute the digital signal into the two-dimensional coordinate system ; In the two-dimensional coordinate system In, extract sampling points, the coordinates of a single sampling point are , the coordinates of the other sampling point are , and calculate the slope of the straight line between every two sampling points , and its calculation formula is as follows: In the formula, represents the slope of the straight line, Represents two sampling points in a two-dimensional coordinate system The difference in coordinate values along the axis direction, Represents two sampling points in a two-dimensional coordinate system The difference in coordinate values along the axis direction, Indicates simultaneous calculation The slope of the straight line between the sampling points; In the formula, Indicates the compensation angle, Represents the angle value of the digital signal, Indicates the output angle value after digital signal compensation. The central processor Interpolation and subdivision are performed. Interpolation and subdivision are post-compensation methods. They mainly calibrate the long period and short period respectively, and use the central processing unit to perform software algorithm compensation on the error fitting curve. On the one hand, it is long-period error compensation to make up for the error caused by the eccentricity of the code disk. On the other hand, it is short-period error compensation to make up for the error caused by the quality of the precision code signal, thereby achieving a very high resolution with simple operation and good real-time effectiveness.
[0020] Example 1: In this experiment, the phase angle of the sine signal is set to 79.58°, the phase angle of the cosine signal is set to 110.42°, and the correction degree is The calculation formula is as follows: In the formula, Indicates the correction degree, 90° represents the constant in the correction degree calculation formula, which is the standard phase angle of the orthogonal signal. It means that when the encoder receives a sinusoidal signal, the difference between the sinusoidal signal phase angle and the 90° phase standard is calculated, which is the correction degree. It means that when the encoder receives a cosine signal, the difference between the phase angle of the cosine signal and the 90° phase standard is calculated, which is the correction degree. The adjustment chip corrects and calibrates the sine signal to an orthogonal signal with a 90° phase standard according to 10.42°, and corrects and calibrates the cosine signal to an orthogonal signal with a 90° phase standard according to -20.42°.
[0021] Example 2: In this experiment, the digital signal is set with 2 sampling points, the coordinates of a single sampling point are (2, 3), and the coordinates of the other sampling point are (4, 7). The angle value of the digital signal is set to 77°, and the slope of the straight line between the two sampling points is calculated. and compensation angle , and its calculation formula is as follows: ; ; In the formula, the straight line slope of the digital signal is 2, the output angle value after digital signal compensation is 153°, and the central processing unit interpolates and subdivides with the final angle value of 153°.
[0022] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for improving the accuracy of an encoder, characterized in that: The encoder is composed of a central processing unit, an AD analog-to-digital converter, an MR3 adjustment chip, a medium-precision code shaping amplifier circuit, a coarse-precision code shaping amplifier circuit, a secondary voltage stabilization circuit and a differential data interface circuit. The method for improving the accuracy of the encoder includes the following steps: Step 1: When the encoder receives a sine signal or a cosine signal, the MR3 adjustment chip analyzes and generates a correction degree , and according to the correction degree The signals are uniformly corrected and calibrated to orthogonal signals with a 90° phase standard; Step 2: The CPU analyzes and generates the offset based on the corrected and calibrated signal and correction level , and according to the correction level Correcting the DC component of the calibration signal; Step 3: The CPU collects the amplitude of the signal through the AD converter and analyzes and generates the gain multiple. and correction amplitude , and according to the correction amplitude Correcting the amplitude of the calibration signal; Step 4: The central processor analyzes and generates the compensation angle based on the signals after phase correction calibration, DC level correction calibration and amplitude correction calibration. , and according to the compensation angle Perform interpolation subdivision.
2. The method for improving encoder accuracy according to claim 1, characterized in that: In step 1, the adjustment chip marks the received sinusoidal signal as , the cosine signal is marked as , Indicates the time point when the adjustment chip receives the signal. The measurement of the position of the sinusoidal signal waveform on the time axis, that is, the phase angle of the sinusoidal signal, The measure of the position of the cosine signal waveform on the time axis is the phase angle of the cosine signal.
3. The method for improving encoder accuracy according to claim 2, characterized in that: In the step 1, the correction degree The calculation formula is as follows: ;In the formula, Indicates the correction degree, 90° represents the constant in the correction degree calculation formula, which is the standard phase angle of the orthogonal signal. It means that when the encoder receives a sinusoidal signal, the difference between the sinusoidal signal phase angle and the 90° phase standard is calculated, which is the correction degree. It means that when the encoder receives a cosine signal, the difference between the phase angle of the cosine signal and the 90° phase standard is calculated, which is the correction degree.
4. The method for improving encoder accuracy according to claim 3, characterized in that: In the step 2, the central processing unit converts the sine signal and cosine signal after the phase correction calibration into a sine digital signal and a cosine digital signal through an AD analog-to-digital converter, and marks the sine digital signal as , the cosine digital signal is marked as .
5. The method for improving encoder accuracy according to claim 4, characterized in that: In the step 2, the offset The calculation formula is as follows: ;In the formula, Indicates the offset, Represents the highest point in the sinusoidal digital signal waveform. Represents the lowest point in the sinusoidal digital signal waveform. It represents the average voltage level at the midpoint of the sinusoidal digital signal waveform, that is, the DC component value of the sinusoidal digital signal. Represents the highest point in the cosine digital signal waveform. Represents the lowest point in the cosine digital signal waveform. It represents the average voltage level of the midpoint of the cosine digital signal waveform, that is, the DC component value of the cosine digital signal. The offset includes the DC component value of the sine digital signal and the DC component value of the cosine digital signal.
6. The method for improving encoder accuracy according to claim 5, characterized in that: In step 2, the AD analog-to-digital converter is provided with a DC component reference value , the CPU uses the offset and DC component reference value , analyze and generate correction levels , and its calculation formula is as follows: In the formula, Indicates the correction level, The difference between the DC component value of the digital signal and the DC component reference value is the correction level.
7. The method for improving encoder accuracy according to claim 6, characterized in that: In the step 2, the central processing unit marks the amplitude of the sinusoidal digital signal after the phase correction calibration and the DC level correction calibration as The amplitude of the cosine digital signal after completing the phase correction calibration and DC level correction calibration is marked as .
8. The method for improving encoder accuracy according to claim 7, characterized in that: In step 3, the gain multiple The calculation formula is as follows: ;In the formula, Indicates the gain multiple, Represents the output voltage of the AD analog-to-digital converter, Represents the maximum amplitude of a sinusoidal digital signal, Represents the minimum amplitude in a sinusoidal digital signal, It means the output voltage is divided by the difference between the maximum and minimum input amplitudes to obtain the gain ratio of the sinusoidal digital signal. Represents the maximum amplitude in the cosine digital signal, Represents the minimum amplitude in the cosine digital signal, It means that the output voltage is divided by the difference between the maximum and minimum input amplitudes to obtain the gain ratio of the cosine digital signal. The gain multiple includes the gain ratio of the sine digital signal and the gain ratio of the cosine digital signal.
9. The method for improving encoder accuracy according to claim 8, characterized in that: In step 3, the correction amplitude The calculation formula is as follows: ;In the formula, represents the correction amplitude, Represents the DC component value of the sinusoidal digital signal, Represents the gain ratio of the sinusoidal digital signal, It means that the corrected amplitude of the sinusoidal digital signal is obtained by subtracting the offset from the sinusoidal digital signal and multiplying it by the gain multiple. Represents the DC component value of the cosine digital signal, Represents the gain ratio of the cosine digital signal, It means that the cosine digital signal is subtracted from the offset and then multiplied by the gain multiple to obtain the corrected amplitude of the cosine digital signal. The corrected amplitude includes the corrected amplitude of the sine digital signal and the corrected amplitude of the cosine digital signal.
10. The method for improving encoder accuracy according to claim 9, characterized in that: In step 4, the compensation angle The calculation process is as follows: Constructing a 2D coordinate system , and then substitute the digital signal into the two-dimensional coordinate system ; In the two-dimensional coordinate system In, extract sampling points, the coordinates of a single sampling point are , the coordinates of the other sampling point are , and calculate the slope of the straight line between every two sampling points , and its calculation formula is as follows: In the formula, represents the slope of the straight line, Represents two sampling points in a two-dimensional coordinate system The difference in the coordinate values along the axis direction, Represents two sampling points in a two-dimensional coordinate system The difference in the coordinate values along the axis direction, Indicates simultaneous calculation The slope of the straight line between the sampling points; In the formula, Indicates the compensation angle, Represents the angle value of the digital signal, Indicates the output angle value after digital signal compensation.