Method and system for real-time subdivision and equalization of signals of a circular grating multi-read head

Abstract

This invention discloses a method and system for real-time subdivision and equal averaging of signals from multiple circular grating readout heads; it relates to the field of displacement sensing technology; by synchronously acquiring and processing each digital signal before outputting the result signal in the form of TTL pulses, it provides a technical approach for the online application of the multi-readout head equal averaging algorithm; it can achieve equal averaging of any number of readout heads, not limited to 2. N The system for real-time subdivision and averaging of multiple reading head signals is independent of the motor servo control system. The data collected by multiple reading heads is first processed by the system for real-time subdivision and averaging of multiple reading head signals before being input into the motor servo control system. The motor servo control system can directly apply the data after real-time subdivision and averaging offline, so that the data after subdivision and averaging can participate in the online control of the motor in real time.

Description

Technical Field

[0001] This invention relates to the field of displacement sensing technology, specifically to a method and system for real-time subdivision and equal averaging of circular grating multi-reader signals. Background Technology

[0002] A circular grating encoder is an angular displacement sensor. Its angle measurement accuracy is mainly affected by factors such as the geometric accuracy of the rotating shaft, installation errors, engraving errors, and signal processing errors. In applications such as precision turntables, astronomical telescopes, and laser trackers, high angular accuracy is required. However, the angular measurement accuracy of the circular grating itself is insufficient to meet these requirements. Therefore, it is necessary to compensate for the accuracy of the circular grating to minimize the impact of errors.

[0003] A common method for compensating the accuracy of circular gratings is the averaging method based on a multi-readhead layout. By arranging a certain number of readheads, most low-order errors can be eliminated, thereby significantly improving the angle measurement accuracy of the circular grating. However, this method has two significant problems in practical applications.

[0004] First, although the multi-reading head equal division averaging method improves measurement accuracy, the equal division average cannot be used for control.

[0005] In a motor servo system, the position feedback channel and the motor drive channel are in one-to-one correspondence, and the position feedback value cannot be edited by the user. This prevents multi-channel reading head signals from being used for motor closed-loop control. Consequently, the multi-reading head equal-division averaging method can only be applied offline, such as... Figure 2 As shown, users can only control the device by providing feedback data from a single reading head, while the average value of multiple reading heads can only be measured offline via a computer and cannot be used for online motor control. This significantly reduces the practicality of the multi-reading head averaging method.

[0006] A small number of commercially available motor servo systems can achieve 2 through their special functions. N The effect of equal division and averaging of (N = 1, 2, 3...) reading heads can be achieved. For example, a servo system in gantry drive mode can achieve the effect of equal division and averaging control of two reading heads; or, as with the PMAC motion control card, it can support control of two... N The encoder feedback values ​​of a number of channels (N = 1, 2, 3...) are accumulated, and an equal distribution is achieved through a shift operation. The drawback is that it can only achieve 2... N The encoder with a number of channels is divided equally, and this method is very expensive in terms of hardware.

[0007] Second, the problem of uniform output of the average value of multiple reading heads.

[0008] After averaging the data from multiple reading heads, the average value needs to be output to the motor servo control system. There are typically two output methods: protocol output and TTL pulse signal output. If TTL pulse signal output is used, the average value must be output to the servo control system evenly and continuously; otherwise, it will cause the controlled motor to jitter or even become unstable. Currently, according to publicly available information, there is no data on how to output the average value from multiple reading heads to the control system, and there is even less research on how to output the average value evenly in the form of TTL pulses. Summary of the Invention

[0009] The technical problem this invention aims to solve is that the common circular grating accuracy compensation method using multiple reading heads for equal division and averaging is difficult to apply online in real-time in motor servo control systems. This invention provides a method and system for real-time subdivision and equal division averaging of circular grating multi-reader signals. By first synchronously acquiring each digital signal, and then sequentially performing error compensation processing, grating subdivision processing, real-time equal division averaging processing, and equal division average output processing on the synchronously sampled signals, the resulting signal is output in TTL pulse form. This provides a technical approach for the online application of the multi-reader equal division averaging algorithm. Furthermore, this invention can achieve equal division averaging with any number of reading heads, not just 2. N The reading head signal is processed by equal division and averaging.

[0010] This invention is achieved through the following technical solution:

[0011] This solution provides a method for real-time subdivision and equal averaging of circular grating multi-readhead signals, including:

[0012] Acquire multiple raw angle signals from the circular grating multi-reading head, wherein the raw angle signals are analog signals;

[0013] Convert the original angle signal into a digital signal;

[0014] Each digital signal is first synchronously acquired, and then the synchronously sampled signal is sequentially processed by error compensation, grating subdivision, real-time equal division averaging, and equal division average output, and the result signal is output in the form of TTL pulse;

[0015] Convert the TTL pulse result signal from a single-ended signal to a differential signal.

[0016] The common circular grating accuracy compensation method involving multiple reading heads and equal division averaging is difficult to apply in real-time online in motor servo control systems. This invention aims to provide a method and system for real-time subdivision and equal division averaging of circular grating multi-reader signals. By first synchronously acquiring each digital signal, and then sequentially performing error compensation processing, grating subdivision processing, real-time equal division averaging processing, and equal division average output processing on the synchronously sampled signals, the resulting signal is output in TTL pulse form. This provides a technical approach for the online application of the multi-reader equal division averaging algorithm. Furthermore, this invention can achieve equal division averaging with any number of reading heads, not just two. N This invention involves the equal division and averaging of individual reading head signals. It has wide applications in precision and ultra-precision angle control, enabling angle accuracy control at the arcsecond and deep sub-arcsecond levels.

[0017] A further optimized scheme is that the error compensation calculation includes the following methods: performing DC error compensation processing, amplitude error compensation processing, and orthogonal error compensation processing on the synchronous sampling signal;

[0018] For synchronously sampled signals containing DC errors:

[0019]

[0020] In the formula, u s For a sinusoidal signal, u c Cosine signal, DC s and DC c θ represents the DC error compensation for the sine signal and the cosine signal; θ is the phase of the synchronous sampling signal.

[0021] The DC error compensation amount is calculated using the following formula:

[0022]

[0023]

[0024] In the formula, u smax u cmax These are the maximum values ​​of the sine and cosine signals, respectively, within one synchronous sampling signal period; u smin u cmin These are the minimum values ​​of the sine and cosine signals within one synchronous sampling signal period, respectively.

[0025] A further optimization scheme is proposed for synchronously sampled signals containing amplitude errors:

[0026]

[0027] In the formula, ξ s ξ cThese are the amplitude error of the sine signal and the amplitude error of the cosine signal, respectively.

[0028] The amplitude error compensation amount is calculated according to the following formula:

[0029]

[0030] In the formula, U0 is the standard signal amplitude, u smax u cmax These represent the maximum values ​​of the sine and cosine signals, respectively.

[0031] A further optimization scheme is proposed for synchronously sampled signals containing orthogonal errors:

[0032]

[0033] In the formula, δ is the orthogonality error between the sine and cosine signals;

[0034] The orthogonal error compensation process can be represented as:

[0035] First, perform cross-calculation:

[0036] u s2 =u s +u c =2cos(45°+δ / 2)sin(θ+δ / 2+45°)

[0037] u c2 =u c -u s =2cos(45°-δ / 2)cos(θ+δ / 2+45°)

[0038] In the formula u s2 The sum of a sine and a cosine signal; u c2 This is the difference between the cosine and sine signals;

[0039] Then perform amplitude compensation:

[0040] u s3 =sin(θ+δ / 2+45°)

[0041] u c3 =cos(θ+δ / 2+45°)

[0042] In the formula, u s3 This is the amplitude compensation amount for the sinusoidal signal; u c3 This is the amplitude compensation amount for the cosine signal.

[0043] A further optimization scheme is that the grating subdivision processing includes the following method:

[0044] A tangent function is constructed based on the synchronously sampled signal after error compensation processing. Then, an arctangent algorithm is implemented based on the CORDIC algorithm to solve for the subdivision value.

[0045] A further optimized solution is that the real-time equal division and averaging process includes the following methods:

[0046] Synchronously acquire the subdivision values ​​obtained from the grating subdivision processing to obtain N subdivision values ​​β1, β2, ..., β N Calculate the cumulative subdivision value β all =β1+β2+…+β N For the accumulated subdivision value β all Divide the sample into equal parts and average the results to obtain the average value β:

[0047] A further optimized solution is that the equal-division average output processing outputs the result signal in the form of a TTL pulse, including the following method:

[0048] Calculate the counter increment for each clock cycle:

[0049]

[0050] In the formula, D is the counter increment, β is the average of the subdivision values, N is a positive integer, and T is a variable value. s The sampling period for synchronous acquisition is T, where T is the clock period;

[0051] Counter increment value D add Starting from 0, the counter increments by D at the end of each clock cycle. add Add D;

[0052] Based on shift operations, the accumulated value D add Complete 2 N The comparison value is obtained by right shifting the bit.

[0053] At the arrival of each clock cycle, the comparison value of the current clock cycle is compared with the comparison value of the previous clock cycle. If the comparison value of the current clock cycle changes, a TTL pulse signal is output. The TTL pulse signal outputs two signals, signal A and signal B.

[0054] A further optimized solution is to convert the TTL pulse-form result signal from a single-ended signal to a differential signal, including the following method:

[0055] Convert signal A into signals A+ and A-, and convert signal B into signals B+ and B-.

[0056] This solution provides a system for real-time subdivision and equal-division averaging of circular grating multi-reader signals, used to implement the aforementioned method for real-time subdivision and equal-division averaging of circular grating multi-reader signals; including:

[0057] Multiple reading heads are used to acquire multiple raw angle signals of the circular grating, wherein the raw angle signals are analog signals;

[0058] The analog-to-digital converter module is used to convert the raw angle signal into a digital signal;

[0059] The data processing module is used to first synchronously acquire each digital signal, and then sequentially perform error compensation processing, grating subdivision processing, real-time equal division averaging processing, and equal division average value output processing on the synchronous sampled signal, and finally output the result signal in the form of TTL pulse.

[0060] The single-ended to differential module is used to convert TTL pulse-form result signals from single-ended signals to differential signals.

[0061] A further optimized solution is that the data processing module includes: a synchronous acquisition unit, an error compensation processing unit, a grating subdivision processing unit, a real-time equal division averaging processing unit, and an equal division average output processing unit;

[0062] The synchronous acquisition unit synchronously triggers the analog-to-digital conversion modules of multiple channels, and the period of synchronous triggering is the sampling period T of synchronous acquisition. s .

[0063] In traditional motor servo control systems, the position feedback channel and motor drive channel are in a one-to-one correspondence, and the position feedback value cannot be edited by the user. This prevents multi-channel readout signals from being used for closed-loop control of the motor servo system. Consequently, the multi-readout equal-division averaging method can only be applied offline, such as... Figure 2 As shown, users can only control the device by feeding back data from a single reading head, while the average value of multiple reading heads can only be measured offline via a computer and cannot be used for online motor control; this greatly reduces the practicality of the multi-reading head averaging method. The proposed solution designs a system for real-time subdivision and averaging of circular grating multi-reading head signals, positioned before the motor servo control system and independent of it. Data collected by multiple reading heads is first processed by this system before being input into the motor servo control system. The motor servo control system can then directly apply the processed data offline, enabling it to participate in real-time online motor control.

[0064] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0065] 1. The purpose of this invention is to provide a method and system for real-time subdivision and equal averaging of circular grating multi-readhead signals. This involves synchronously acquiring each digital signal, then sequentially performing error compensation processing, grating subdivision processing, real-time equal averaging processing, and equal averaging output processing on the synchronously sampled signals, finally outputting the result signal in TTL pulse form. This provides a technical approach for the online application of multi-readhead equal averaging algorithms. Furthermore, this invention can achieve equal averaging with any number of readheads, and is not limited to 2. N This invention involves the equal division and averaging of individual reading head signals. It can be widely applied in the fields of precision and ultra-precision angle control, and can achieve angle accuracy control at the arcsecond level and deep sub-arcsecond level.

[0066] 2. The system for real-time subdivision and equal averaging of circular grating multi-reader signals designed in this invention can be set before the motor servo control system and is independent of the motor servo control system. The data collected by multiple readers is first processed by the system for real-time subdivision and equal averaging of circular grating multi-reader signals before being input into the motor servo control system. The motor servo control system can directly apply the data after real-time subdivision and equal averaging offline, so that the data after subdivision and equal averaging can participate in the online control of the motor in real time. Attached Figure Description

[0067] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0068] Figure 1 A schematic diagram of the method for real-time subdivision and equal averaging of signals from multiple reading heads of circular gratings;

[0069] Figure 2 A schematic diagram illustrating the application effect of a traditional multi-reader equal division averaging system;

[0070] Figure 3 This is a schematic diagram illustrating the system application effect of real-time subdivision and equal averaging of circular grating multi-reader signals according to the present invention;

[0071] Figure 4 This is a schematic diagram of the system for real-time subdivision and equal averaging of circular grating multi-reader signals according to the present invention. Detailed Implementation

[0072] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are only for explaining this invention and are not intended to limit this invention.

[0073] Example 1

[0074] This embodiment provides a method for real-time subdivision and equal averaging of circular grating multi-readhead signals, such as... Figure 1 As shown, it includes:

[0075] Step 1: Acquire multiple raw angle signals from the circular grating multi-reading head, wherein the raw angle signals are analog signals;

[0076] Step 2: Convert the raw angle signal into a digital signal;

[0077] Step 3: First, synchronously acquire each digital signal, then sequentially perform error compensation processing, grating subdivision processing, real-time equal division averaging processing, and equal division average value output processing on the synchronous sampled signal, and finally output the result signal in the form of TTL pulse;

[0078] Error compensation calculation includes the following methods: DC error compensation processing, amplitude error compensation processing, and quadrature error compensation processing are performed on the synchronous sampling signal to obtain the compensated grating signal;

[0079] For synchronously sampled signals containing DC errors:

[0080]

[0081] In the formula, u s For a sinusoidal signal, u c Cosine signal, DC s and DC c θ represents the DC error compensation for the sine signal and the cosine signal; θ is the phase of the synchronous sampling signal.

[0082] The DC error compensation amount is calculated using the following formula:

[0083]

[0084]

[0085] In the formula, u smax u cmax These are the maximum values ​​of the sine and cosine signals, respectively, within one synchronous sampling signal period; u smin u cmin These are the minimum values ​​of the sine and cosine signals within one synchronous sampling signal period, respectively.

[0086] For synchronously sampled signals containing amplitude errors:

[0087]

[0088] In the formula, ξ s ξ c These are the amplitude error of the sine signal and the amplitude error of the cosine signal, respectively.

[0089] The amplitude error compensation amount is calculated according to the following formula:

[0090]

[0091] In the formula, U0 is the standard signal amplitude, u smax u cmax These represent the maximum values ​​of the sine and cosine signals, respectively.

[0092] For synchronously sampled signals containing orthogonal errors:

[0093]

[0094] In the formula, δ is the orthogonality error between the sine and cosine signals;

[0095] The orthogonal error compensation process can be represented as:

[0096] First, perform cross-calculation:

[0097] u s2 =u s +u c =2cos(45°+δ / 2)sin(θ+δ / 2+45°)

[0098] u c2 =u c -u s =2cos(45°-δ / 2)cos(θ+δ / 2+45°)

[0099] In the formula u s2 The sum of a sine and a cosine signal; u c2 This is the difference between the cosine and sine signals;

[0100] Then perform amplitude compensation:

[0101] u s3 =sin(θ+δ / 2+45°)

[0102] u c3 =cos(θ+δ / 2+45°)

[0103] In the formula, u s3 This is the amplitude compensation amount for the sinusoidal signal; u c3This is the amplitude compensation amount for the cosine signal.

[0104] This embodiment achieves orthogonal error compensation by leading the final result of the grating digital signal by a constant δ / 2+45°; thus, division operations can be avoided when performing orthogonal error compensation, greatly improving the computational efficiency of the algorithm.

[0105] Raster subdivision processing, including methods:

[0106] A tangent function is constructed based on the synchronously sampled signal after error compensation processing. Then, an arctangent algorithm is implemented based on the CORDIC algorithm to solve for the subdivision value.

[0107] Real-time equal division and averaging processing, including methods:

[0108] Synchronously acquire the subdivision values ​​obtained from the grating subdivision processing to obtain N subdivision values ​​β1, β2, ..., β N Calculate the cumulative subdivision value β all =β1+β2+…+β N For the accumulated subdivision value β all Divide the sample into equal parts and average the results to obtain the average value β:

[0109] The equal-value output processing, outputting the result signal in TTL pulse form, includes the following methods:

[0110] Calculate the counter increment for each clock cycle:

[0111]

[0112] In the formula, D is the counter increment, β is the average of the subdivision values, N is a positive integer, and T is a variable value. s The sampling period for synchronous acquisition is T, where T is the clock period;

[0113] Counter increment value D add Starting from 0, the counter increments by D at the end of each clock cycle. add Increase D; if m clock cycles arrive, then:

[0114] D add =m*D

[0115] Based on shift operations, the accumulated value D add Complete 2 N Right shift (i.e., divide the counter value by 2) N ) to obtain the comparison value

[0116] At the arrival of each clock cycle, the comparison value of the current clock cycle is compared with the comparison value of the previous clock cycle. If the comparison value of the current clock cycle changes, a TTL pulse signal is output. The TTL pulse signal outputs two signals, signal A and signal B.

[0117] The timing for outputting the average value is: during the previous sampling period T. s1 The average value θ of the equal division is calculated within the first sampling period, and then in the next sampling period T... s2 The average value of the equal division is output uniformly within a time limit;

[0118] Suppose at a certain moment, N = 8, θ = 15, T s / T=40, then:

[0119]

[0120] Step 4: Convert the TTL pulse result signal from a single-ended signal to a differential signal.

[0121] Converting TTL pulse-form result signals from single-ended signals to differential signals includes the following methods:

[0122] Convert signal A into signals A+ and A-, and convert signal B into signals B+ and B-.

[0123] Example 2

[0124] This embodiment provides a system for real-time subdivision and equal division averaging of circular grating multi-reader signals, used to implement the aforementioned method for real-time subdivision and equal division averaging of circular grating multi-reader signals; such as Figure 3 and Figure 4 As shown, it includes:

[0125] Multiple reading heads are used to acquire multiple raw angle signals of the circular grating. The raw angle signals are analog signals, which are sine and cosine analog signals in the form of 1Vpp.

[0126] The analog-to-digital converter module is used to convert the raw angle signal into a digital signal;

[0127] The data processing module is used to first synchronously acquire each digital signal, and then sequentially perform error compensation processing, grating subdivision processing, real-time equal division averaging processing, and equal division average value output processing on the synchronous sampled signal, and finally output the result signal in the form of TTL pulse.

[0128] The single-ended to differential module is used to convert TTL pulse-form result signals from single-ended signals to differential signals.

[0129] The data processing module includes: a synchronous acquisition unit, an error compensation processing unit, a grating subdivision processing unit, a real-time equal division averaging processing unit, and an equal division average output processing unit; each subunit of the above data processing module is executed in an FPGA, model EP4CE22E22C8N.

[0130] The synchronous acquisition module uses the FPGA to synchronously trigger the analog-to-digital converter modules of the four channels, ensuring that multiple ADC chips sample simultaneously; the period of synchronous triggering is the sampling period T. s The purpose of sampling is to ensure that the data processed by real-time equal division and averaging are all sampled data from the same moment.

[0131] The circular grating and reading head in this invention are separate structures, and multiple reading heads can be installed on a single circular grating according to usage requirements. The analog-to-digital conversion module uses an ADC chip with a resolution of 16 bits and a sampling rate of 3000ksps to convert the sine and cosine analog signals into digital signals; there are four such analog-to-digital conversion modules, each corresponding to a reading head.

[0132] Example 3

[0133] The output timing of the equivalent average value of the multi-read head signal is shown in the table below, where 0 represents no output and 1 represents output for TTL pulse output.

[0134]

[0135]

[0136]

[0137] Through the above embodiments, a uniform output of 15 equivalent average values ​​was achieved within 40 FPGA clock cycles.

[0138] The single-ended to differential module uses a dedicated single-ended to differential chip to convert signal A into signal A+ and signal A-, and signal B into signal B+ and signal B-.

[0139] This embodiment provides an application of a real-time equal-division averaging method for a circular grating four-readhead, and an implementation case where 15 equally divided average values ​​need to be output uniformly within 40 FPGA clock cycles at a certain moment. This invention is highly versatile, with a simple algorithm that is easy to implement in engineering.

[0140] The above embodiments achieve synchronous acquisition of multi-reader signals; error compensation of multi-reader signals; subdivision of multi-reader signals; real-time equal division and averaging of multi-reader signals; and uniform output of the real-time equal division average of multi-reader signals. Through this invention, the equal division average of multi-reader signals can be integrated into a servo control system, such as... Figure 2 As shown, this provides a technical approach for the online application of the multi-reading head equal division averaging algorithm. Furthermore, this invention can achieve equal division averaging with any number of reading heads, not just 2. N This method involves equal division and averaging of individual reading head signals. It has wide applications in precision and ultra-precision angle control, enabling angle accuracy control at the arcsecond and deep sub-arcsecond levels.

[0141] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for real-time subdivision and equalization of signals from a circular grating multi-read head, characterized in that, include: Acquire multiple raw angle signals from the circular grating multi-reading head, wherein the raw angle signals are analog signals; Convert the original angle signal into a digital signal; Each digital signal is first synchronously acquired, and then the synchronously sampled signal is sequentially processed by error compensation, grating subdivision, real-time equal division averaging, and equal division average output, and the result signal is output in the form of TTL pulse; Convert the TTL pulse result signal from a single-ended signal to a differential signal; For synchronously sampled signals containing orthogonal errors: ； In the formula, This represents the orthogonality error between the sine and cosine signals; The orthogonal error compensation process can be represented as: First, perform cross-compensation: ； ； wherein is the cross compensation for the sine signal; is the cross compensation for the cosine signal. Then perform amplitude compensation: ； ； wherein is the amplitude compensation for the sine signal; is the amplitude compensation for the cosine signal; The equal-value output processing outputs the result signal in TTL pulse form, including the following methods: Calculate the counter increment for each clock cycle: ； In the formula, D is a counter increment, is an equal average value of the sub-values, N is a positive integer, is a sampling period of synchronous acquisition, T is a clock period; Counter increment value Starting from 0, the counter increments by 0 at the end of each clock cycle. Add D; based on a shift operation, the accumulated value complete bit right shift to obtain a comparison value ; At the arrival of each clock cycle, the comparison value of the current clock cycle is compared with the comparison value of the previous clock cycle. If the comparison value of the current clock cycle changes, a TTL pulse signal is output. The TTL pulse signal outputs two signals, signal A and signal B.

2. The method for real-time subdivision and equalization of signals of a circular grating multi-reading head according to claim 1, characterized in that, The error compensation calculation includes the following methods: performing DC error compensation processing, amplitude error compensation processing, and quadrature error compensation processing on the synchronously sampled signal; For synchronous sampling signals containing DC errors: ; wherein is a sine signal, is a cosine signal, and is a direct current error compensation quantity of the sine signal and a direct current error compensation quantity of the cosine signal; is a phase of the synchronous sampling signal; The DC error compensation amount is calculated using the following formula: ； ； In the formula, These are the maximum values ​​of the sine and cosine signals within one synchronous sampling signal period, respectively. These are the minimum values ​​of the sine and cosine signals within one synchronous sampling signal period, respectively.

3. The method for real-time subdivision and equal averaging of circular grating multi-reader signals according to claim 2, characterized in that, For synchronously sampled signals containing amplitude errors: ； wherein , are the amplitude error of the sine signal and the amplitude error of the cosine signal, respectively. The amplitude error compensation amount is calculated according to the following formula: ； wherein is the standard signal amplitude, , is the maximum value of the sine signal and the maximum value of the cosine signal, respectively.

4. The method for real-time subdivision and equalization of signals from a circular grating multi-read head according to claim 1, wherein, The grating subdivision process includes the following methods: A tangent function is constructed based on the synchronously sampled signal after error compensation processing. Then, an arctangent algorithm is implemented based on the CORDIC algorithm to solve for the subdivision value.

5. The method for real-time subdivision and equalization of signals of a circular grating multi-reading head according to claim 4, characterized in that, The real-time equal division and averaging process includes the following methods: Synchronously collect the subdivision values obtained by the grating subdivision processing to obtain N subdivision values , calculate the accumulated subdivision values , divide and average the accumulated subdivision values to obtain the divided and averaged values : .

6. The method for real-time subdivision and equalization of signals from a circular grating multi-read head according to claim 1, wherein, The method for converting the TTL pulse result signal from a single-ended signal to a differential signal includes: Convert signal A into signals A+ and A-, and convert signal B into signals B+ and B-.

7. A system for real-time subdivision and equalization of signals from a circular grating multi-read head, characterized by, A method for real-time subdivision and equal division averaging of circular grating multi-readhead signals as described in any one of claims 1-6; comprising: Multiple reading heads are used to acquire multiple raw angle signals of the circular grating, wherein the raw angle signals are analog signals; The analog-to-digital converter module is used to convert the raw angle signal into a digital signal; The data processing module is used to first synchronously acquire each digital signal, and then sequentially perform error compensation processing, grating subdivision processing, real-time equal division averaging processing, and equal division average value output processing on the synchronous sampled signal, and output the result signal in the form of TTL pulse; The single-ended to differential module is used to convert TTL pulse-form result signals from single-ended signals to differential signals.

8. The circular grating multi-read head signal real-time subdivision and equalization averaging system according to claim 7, characterized in that, The data processing module includes: a synchronous acquisition unit, an error compensation processing unit, a grating subdivision processing unit, a real-time equal division averaging processing unit, and an equal division averaging output processing unit; The synchronization acquisition unit synchronously triggers the analog-digital conversion modules of the multiple channels, and the period of the synchronous triggering is the sampling period of the synchronization acquisition .

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