A displacement measurement method based on time grating displacement sensing system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHONGQING UNIV OF TECH
- Filing Date
- 2023-06-20
- Publication Date
- 2026-07-21
Smart Images
Figure CN117029654B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of precision displacement measurement, specifically relating to a displacement measurement method based on a time-grating displacement sensing system. Background Technology
[0002] Precision CNC systems are increasingly trending towards high frequency response, high speed, and high precision, which places ever higher demands on high-precision displacement measurement. However, current processing methods cannot fully combine high-speed and high-precision measurement. This forces a trade-off between high speed and high precision in displacement measurement, meaning that in practice, one must choose either high-speed, low-resolution measurement or high-resolution, low-speed measurement. This severely hinders the application of high-precision displacement measurement in modern precision CNC systems.
[0003] CN106052562A discloses an adaptive dynamic phase comparison time grating displacement measurement method and signal processing system. It can achieve high-resolution measurement at high speed by using an adaptive dynamic phase comparison control module. However, its measurement method is relatively cumbersome and cannot shorten the total measurement time while maintaining high resolution. Summary of the Invention
[0004] The purpose of this invention is to provide a displacement measurement method based on a time-grating displacement sensing system, which can significantly shorten the total measurement time while maintaining high resolution.
[0005] The displacement measurement method based on a time-grating displacement sensing system described in this invention includes a time-grating displacement sensor and a signal processing module connected to the time-grating displacement sensor; the displacement measurement method includes:
[0006] A high-frequency excitation signal is input to the first excitation module of the time-grating displacement sensor, and a low-frequency excitation signal is input to the second excitation module. The first sensing module of the time-grating displacement sensor outputs a corresponding high-frequency sensing signal, and the second sensing module outputs a corresponding low-frequency sensing signal. Then, the high-frequency excitation signal, low-frequency excitation signal, high-frequency sensing signal, and low-frequency sensing signal are input to the signal processing module. The frequency of the high-frequency sensing signal is the same as the frequency of the high-frequency excitation signal, and both are f1; the frequency of the low-frequency sensing signal is the same as the frequency of the low-frequency excitation signal, and both are f2.
[0007] The signal processing module uses high-frequency clock pulse I to interpolate the phase difference between the high-frequency induction signal and the high-frequency excitation signal, and uses high-frequency clock pulse II to interpolate the phase difference between the low-frequency induction signal and the low-frequency excitation signal.
[0008] The signal processing module calculates the coarse displacement x1 and the dynamic fine measurement mark θ based on the high-frequency excitation signal, the high-frequency induction signal and the high-frequency clock pulse I.
[0009] The signal processing module calculates the precision displacement x2 based on the high-frequency excitation signal, the low-frequency induction signal, the high-frequency clock pulse II, and the dynamic precision measurement mark θ.
[0010] The signal processing module adds the coarse displacement x1 and the fine displacement x2 as the displacement value x measured by the time grating displacement sensing system, that is, x = x1 + x2. This step can also be called calculating the complete displacement.
[0011] Preferably, the frequencies f1 and f2 satisfy: f1 = n × f2, where n is an integer and n ≥ 3.
[0012] Preferably, a method for the signal processing module to calculate the coarse displacement x1 and the dynamic fine measurement mark θ based on the high-frequency excitation signal, the high-frequency induction signal, and the high-frequency clock pulse I includes:
[0013] Within one cycle of a low-frequency excitation signal, when the arrival of the 2m-1th 0° electrical phase of the high-frequency excitation signal is detected (coarse measurement begins), counting of the interpolated high-frequency clock pulse I begins. When the arrival of the 2m-1th 0° electrical phase of the high-frequency induction signal is detected (coarse measurement ends), counting of the interpolated high-frequency clock pulse I stops, and the count value M of the high-frequency clock pulse I is obtained. 11 (i.e., counting yields M) 11 (I) high-frequency clock pulses; where m is an integer; if n is even, then If n is odd, then
[0014] Using the formula: x1 = M 11 ×P1 is used to calculate the coarse displacement x1. Here, P1 is the pulse equivalent corresponding to the high-frequency induction signal, that is, the magnitude of the measured displacement mapped by one high-frequency clock pulse I, which typically characterizes the measurement resolution of the time-grid displacement sensor. F1 is the frequency of the high-frequency clock pulse I, and w is the electrode spacing of the time-grating displacement sensor. From the formula for calculating P1, it can be seen that when the electrode spacing w and the frequency F1 of the high-frequency clock pulse I remain constant, the larger the frequency f1 of the high-frequency induction signal, the larger the value of P1, and the lower the sensor's measurement resolution, but the shorter the measurement time. Coarse measurement based on the high-frequency induction signal can complete the measurement of the same displacement faster than high-resolution fine measurement. Therefore, after aligning the displacement measurement starting points, using a low-frequency induction signal with higher measurement resolution to complete the fine measurement can achieve the same high resolution as the fine measurement for the entire measured displacement.
[0015] Using the formula:
[0016]
[0017] Calculate electrical phase delay That is when At that time, when At that time, Thus The value remains within the range of 0 to 2π.
[0018] Using the formula: The dynamic precision measurement marker θ is calculated. Here, the dynamic precision measurement marker is based on a fixed electrical phase (0°), with the addition of an electrical phase delay that dynamically changes with the displacement of the measured object. A new dynamic measurement marker for the end of timing is formed.
[0019] The magnitude of the initial segment of the measured displacement (i.e., the preliminary displacement) depends on the pulse equivalent P1 of the high-frequency induced signal during the coarse measurement. When the initial segment of the measured displacement is quantized by this pulse equivalent P1, if the unquantized portion of the measured displacement is entirely the final segment (i.e., the fine displacement), and this final segment is smaller than the pulse equivalent P1, then the quantized initial segment of the measured displacement reaches its maximum. Numerically, when the electrical phases of the counting start position (corresponding to the start of the coarse measurement) and the counting end position (corresponding to the end of the coarse measurement) are the same during the coarse measurement, the result of the coarse measurement is exactly consistent with the measurement result where the initial segment of the measured displacement reaches its maximum. Maximizing the initial segment of the measured displacement and increasing the proportion of the initial segment's measurement time in the total measurement time can achieve the effect of maximizing the reduction of the total measurement time.
[0020] Preferably, one method for the signal processing module to calculate the precision displacement x2 based on the high-frequency clock pulse II, the high-frequency excitation signal, the low-frequency induction signal, and the dynamic precision measurement marker θ includes:
[0021] Within one cycle of a low-frequency excitation signal, when the arrival of the 2mth 0° electrical phase of the high-frequency excitation signal is detected (precision measurement begins), counting of the interpolated high-frequency clock pulse II begins. When the phase of the low-frequency induced signal is detected to be equal to the dynamic precision measurement mark θ (precision measurement ends), counting of the interpolated high-frequency clock pulse II stops, and the count value M of the high-frequency clock pulse II is obtained. 12 (that is, M is obtained by counting) 12 (High-frequency clock pulse II). The start time of the fine measurement is the arrival time of the 0° electrical phase of the next high-frequency excitation signal after the completion of the coarse measurement, which ensures that the first part of the measured displacement measured in the coarse measurement and the last part of the measured displacement measured in the fine measurement do not intersect.
[0022] Using the formula: x² = M 12 ×P2 is used to calculate the precise displacement x2; where P2 is the pulse equivalent corresponding to the low-frequency induction signal, that is, the magnitude of the measured displacement mapped by one high-frequency clock pulse II, which usually characterizes the measurement resolution of the time-grid displacement sensor. F2 is the frequency of the high-frequency clock pulse II. Precision measurement based on low-frequency induction signals enables the measurement of the same displacement with higher resolution than coarse measurement.
[0023] Preferably, another method for the signal processing module to calculate the coarse displacement x1 and the dynamic fine measurement mark θ based on the high-frequency excitation signal, the high-frequency induction signal, and the high-frequency clock pulse I includes:
[0024] Within one cycle of a low-frequency excitation signal, when the arrival of the 2m-1th 180° electrical phase of the high-frequency excitation signal is detected (precision measurement begins), counting of the interpolated high-frequency clock pulse I begins. When the arrival of the 2m-1th 180° electrical phase of the high-frequency induction signal is detected (precision measurement ends), counting of the interpolated high-frequency clock pulse I stops, and the count value M of the high-frequency clock pulse I is obtained. 11 (that is, M is obtained by counting) 11 (I) high-frequency clock pulses; where m is an integer; if n is even, then If n is odd, then
[0025] Using the formula: x1 = M 11 ×P1 is used to calculate the coarse displacement x1; where P1 is the pulse equivalent corresponding to the high-frequency induction signal, that is, the magnitude of the measured displacement mapped by one high-frequency clock pulse I, which usually characterizes the measurement resolution of the time-grid displacement sensor. F1 is the frequency of the high-frequency clock pulse I, and w is the pole distance of the time-grid displacement sensor.
[0026] Using the formula:
[0027]
[0028] Calculate electrical phase delay The value range of is 0 to 2π.
[0029] Using the formula: The dynamic precision measurement indicator θ is calculated.
[0030] Preferably, another method for the signal processing module to calculate the precise displacement x2 based on the high-frequency excitation signal, the low-frequency induction signal, the high-frequency clock pulse II, and the dynamic precision measurement marker θ includes:
[0031] Within one cycle of a low-frequency excitation signal, when the arrival of the 2mth 180° electrical phase of the high-frequency excitation signal is detected, counting of the interpolated high-frequency clock pulse II begins. When the phase of the low-frequency induction signal is detected to be equal to the dynamic precision measurement mark θ, counting of the interpolated high-frequency clock pulse II stops, and the count value M of the high-frequency clock pulse II is obtained. 12 (that is, M is obtained by counting) 12A high-frequency clock pulse II.
[0032] Using the formula: x² = M 12 *P2 is used to calculate the precise displacement x2. Here, P2 is the pulse equivalent corresponding to the low-frequency induction signal, that is, the magnitude of the measured displacement mapped by one high-frequency clock pulse II, which typically characterizes the measurement resolution of the time-grid displacement sensor. F2 is the frequency of high-frequency clock pulse II.
[0033] Preferably, the frequencies F1, F2 and frequency f1 satisfy: F1 = F2, This ensures that the precision measurement is completed within one cycle of the high-frequency excitation signal, thus reducing the overall measurement time.
[0034] The count value M of the above high-frequency clock pulse I 11 The count value M of the high-frequency clock pulse II is proportional to the coarse displacement x1. 12 It is proportional to the precisely measured displacement x2. M 11 Multiply Then it becomes a time quantity, M 12 Multiply Then it becomes a time quantity. and Therefore, this aligns with the shortest time required to complete both the coarse and fine measurements. Thus, the shortest total time for the complete displacement measurement described above is...
[0035] Once the next low-frequency excitation signal arrives, the above measurement steps are repeated, and the loop continues.
[0036] The measured displacement value x, if measured using only high-frequency sensing signals (i.e., high-frequency excitation signal and high-frequency induction signal), has a measurement resolution characterized by P1, and its measurement time is:
[0037]
[0038] Since F1 = F2, therefore Right now
[0039] Compared to the present invention, although the total measurement time is shorter, the measurement resolution is significantly worse.
[0040] The measured displacement value x, if measured using only low-frequency sensing signals (i.e., low-frequency excitation signal and low-frequency induction signal), has a measurement resolution characterized by P2, and its measurement time is:
[0041]
[0042] Since F1 = F2, therefore Right now
[0043] Compared to the present invention, although the measurement resolution is the same, the total measurement time is significantly longer.
[0044] This invention divides a measurement cycle into two measurement segments (i.e., the first measurement segment and the second measurement segment). Calculating the coarse displacement x1 and the dynamic fine measurement marker θ belongs to the first measurement segment, which is completed within one cycle of the high-frequency excitation signal. Calculating the fine displacement x2 and the complete displacement belongs to the second measurement segment, which is completed within another cycle of the high-frequency excitation signal. Using this invention, displacement measurement can be completed within two high-frequency excitation signal cycles (i.e., one measurement cycle equals two high-frequency excitation signal cycles). The first measurement segment is based on a high-frequency induction signal, reducing the time required for the time grating to complete high-resolution fine measurement; the second measurement segment is based on a low-frequency induction signal, ensuring high resolution of the displacement measurement. Therefore, by combining the two measurement segments, the overall measurement time is shortened while maintaining high resolution in a simpler way, enabling high-speed and high-resolution displacement measurement. Attached Figure Description
[0045] Figure 1 This is a flowchart of the displacement measurement method based on the time-grating displacement sensing system in Example 1.
[0046] Figure 2 This is a flowchart of the displacement value x measured by the grid displacement sensing system during calculation in Example 1.
[0047] Figure 3 This is a segmented timing diagram measured in Example 1.
[0048] Figure 4 This is a schematic diagram of the displacement measurement principle of the time-grating displacement sensing system in Example 1.
[0049] Figure 5 This is a flowchart of the displacement value x measured by the grid displacement sensing system during calculation in Example 2. Detailed Implementation
[0050] Example 1: The time-grating displacement sensing system involved in this example includes a time-grating displacement sensor and a signal processing module connected to the time-grating displacement sensor. The time-grating displacement sensor has a first excitation module, a second excitation module, a first sensing module, and a second sensing module. The first sensing module and the first excitation module are aligned to form a first sensing unit, and the second sensing module and the second excitation module are aligned to form a second sensing unit. The first sensing unit and the second sensing unit are independent of each other and do not affect each other.
[0051] like Figures 1 to 4As shown, the displacement measurement method based on the time-grating displacement sensing system in this embodiment includes:
[0052] Step 1: Input a high-frequency excitation signal to the first excitation module and a low-frequency excitation signal to the second excitation module. The first sensing module outputs the corresponding high-frequency sensing signal, and the second sensing module outputs the corresponding low-frequency sensing signal. Then, input the high-frequency excitation signal, low-frequency excitation signal, high-frequency sensing signal, and low-frequency sensing signal to the signal processing module. The frequency of the high-frequency sensing signal is the same as the frequency of the high-frequency excitation signal, both being f1; the frequency of the low-frequency sensing signal is the same as the frequency of the low-frequency excitation signal, both being f2, where f1 = n × f2, n is an integer, and n ≥ 3. In this embodiment, f1 = 2800 Hz, f2 = 400 Hz, then n = 7. The measurement resolution of the low-frequency sensing signal is 7 times that of the high-frequency sensing signal. However, the measurement speed of the high-frequency sensing signal for one cycle is 7 times that of the low-frequency sensing signal for one cycle.
[0053] Step 2: The signal processing module uses high-frequency clock pulse I to interpolate the phase difference between the high-frequency induction signal and the high-frequency excitation signal, and uses high-frequency clock pulse II to interpolate the phase difference between the low-frequency induction signal and the low-frequency excitation signal.
[0054] Step 3: The signal processing module calculates the displacement value x measured by the time grid displacement sensing system based on the high-frequency excitation signal, high-frequency induction signal, low-frequency excitation signal, low-frequency induction signal, high-frequency clock pulse I, and high-frequency clock pulse II.
[0055] like Figure 2 As shown, the specific steps for the signal processing module to calculate the displacement value x measured by the grid displacement sensing system include:
[0056] S11. Set the value of n (based on the frequency relationship between the high-frequency excitation signal and the low-frequency excitation signal, for example, n = 7 in this embodiment) to make the measurement sequence number i = 1, and then execute S12.
[0057] S12. Determine whether the 0° electrical phase of the low-frequency excitation signal and the 0° electrical phase of the high-frequency excitation signal have both arrived. If so, execute S13; otherwise, continue executing S12.
[0058] S13. Start counting the interpolated high-frequency clock pulse I, and then execute S14.
[0059] S14. Determine if the 0° electrical phase of the high-frequency induction signal has arrived. If yes, execute S15; otherwise, continue executing S14.
[0060] S15. Stop counting the interpolated high-frequency clock pulse I, and obtain the count value M of high-frequency clock pulse I. 11 (see Figure 3, Figure 4 Then execute S16.
[0061] S16. Using the formula: x1 = M 11 Calculate the coarse displacement x1 using P1, then execute S17. Here, P1 is the pulse equivalent corresponding to the high-frequency induction signal. F1 is the frequency of the high-frequency clock pulse I, and w is the pole distance of the time-grating displacement sensor. In this embodiment, F1 = 80MHz, then...
[0062] S17. Using the formula:
[0063]
[0064] Calculate electrical phase delay Then execute S18. That is, when At that time, when At that time, Thus The value remains within the range of 0 to 2π.
[0065] S18. Using the formula: Calculate the dynamic precision measurement marker θ, and then execute S19.
[0066] S19. Determine if the 0° electrical phase of the high-frequency induction signal has arrived. If yes, execute S110; otherwise, continue executing S19.
[0067] S110, increment the measurement sequence number i by 1 (i.e., i = i + 1), and then execute S111.
[0068] S111: Start counting the interpolated high-frequency clock pulses II, and then execute S112.
[0069] S112. Determine whether the phase of the low-frequency induction signal is equal to the dynamic precision measurement flag θ. If yes, execute S113; otherwise, continue executing S112.
[0070] S113. Stop counting the interpolated high-frequency clock pulse II, and obtain the count value M of the high-frequency clock pulse II. 12 (see Figure 3 , Figure 4 Then execute S114.
[0071] S114. Using the formula: x² = M 12 Calculate the precise displacement x2 using P2, then execute S115. Here, P2 is the pulse equivalent corresponding to the low-frequency induction signal. F2 is the frequency of high-frequency clock pulse II. In this embodiment, F2 = 80MHz.
[0072] S115. Using the formula: x=x1+x2, calculate the displacement value x measured by the time grating displacement sensing system (i.e., calculate the complete displacement), and then execute S116.
[0073] S116. Determine if n is odd. If yes, execute S117; otherwise (meaning n is even), execute S118.
[0074] S117. Determine if i = n-1. If yes, execute S119; otherwise, execute S120.
[0075] S118. Determine if i = n. If yes, execute S119; otherwise, execute S120.
[0076] S119. Set measurement sequence number i = 1, and then return to execute S12.
[0077] S120, increment the measurement sequence number i by 1 (i.e., i = i + 1), and then execute S121.
[0078] S121. Determine if the 0° electrical phase of the high-frequency excitation signal has arrived. If yes, return to execute S13; otherwise, continue executing S121.
[0079] like Figure 3 As shown, this embodiment divides a measurement cycle into two measurement segments (i.e., the first measurement segment and the second measurement segment). Calculating the coarse displacement x1 and the dynamic fine measurement marker θ belongs to the first measurement segment, which is completed within one cycle of the high-frequency excitation signal. Calculating the fine displacement x2 and calculating the complete displacement belong to the second measurement segment, which is completed within another cycle of the high-frequency excitation signal. Using the above method, displacement measurement can be completed within two high-frequency excitation signal cycles.
[0080] Suppose that during a certain measurement, the pole distance of the time-grating displacement sensor is... Measured displacement Then it can be known Due to the limitation of the pulse equivalent P1 corresponding to the high-frequency induction signal, M 11 When M = 285, it is necessary to use low-frequency induction signals for measurement; at this time, M 12 =5, then its shortest measurement time can be determined. The measurement resolution is characterized by P2.
[0081] When only high-frequency induction signals are used for measurement, the measurement time The measurement resolution is characterized by P1.
[0082]
[0083] When only low-frequency induction signals are used for measurement, the measurement time The measurement resolution is characterized by P2.
[0084]
[0085] As in the example above, when the frequency of the high-frequency induction signal is seven times that of the low-frequency induction signal, the measurement results obtained using this method, under ideal conditions, show a seven-fold increase in measurement resolution compared to measurements using only the high-frequency induction signal, and a significant increase in measurement speed compared to measurements using only the low-frequency induction signal. This method significantly improves measurement resolution while drastically reducing measurement time.
[0086] Example 2: Most of the steps of the displacement measurement method based on the time-grating displacement sensing system in this example are the same as in Example 1. The difference lies in the specific steps of the signal processing module in calculating the displacement value x measured by the time-grating displacement sensing system (see Example 1). Figure 5 ),include:
[0087] S21. Set the value of n (based on the frequency relationship between the high-frequency excitation signal and the low-frequency excitation signal) to make the measurement sequence number i = 1, and then execute S22.
[0088] S22. Determine whether the 180° electrical phase of the low-frequency excitation signal and the 180° electrical phase of the high-frequency excitation signal have arrived. If yes, execute S23; otherwise, continue executing S22.
[0089] S23. Start counting the interpolated high-frequency clock pulse I, and then execute S24.
[0090] S24. Determine if the 180° electrical phase of the high-frequency induction signal has arrived. If yes, execute S25; otherwise, continue executing S24.
[0091] S25. Stop counting the interpolated high-frequency clock pulse I, and obtain the count value M of high-frequency clock pulse I. 11 (see Figure 3 , Figure 4 Then execute S26.
[0092] S26. Using the formula: x1 = M 11 Calculate the coarse displacement x1 using P1, then execute S27. Here, P1 is the pulse equivalent corresponding to the high-frequency induction signal. F1 is the frequency of the high-frequency clock pulse I, and w is the pole distance of the time-grating displacement sensor. In this embodiment, F1 = 80MHz, then...
[0093] S27. Using the formula:
[0094]
[0095] Calculate electrical phase delay Then execute S28.
[0096] S28. Use formula: The dynamic precision measurement indicator θ is calculated, and then S29 is executed.
[0097] S29. Determine if the 180° electrical phase of the high-frequency induction signal has arrived. If yes, execute S210; otherwise, continue executing S29.
[0098] S210, increment the measurement sequence number i by 1 (i.e., i = i + 1), and then execute S211.
[0099] S211. Start counting the interpolated high-frequency clock pulses II, and then execute S212.
[0100] S212. Determine whether the phase of the low-frequency induction signal is equal to the dynamic precision measurement mark θ. If yes, execute S213; otherwise, continue executing S212.
[0101] S213. Stop counting the interpolated high-frequency clock pulse II, and obtain the count value M of the high-frequency clock pulse II. 12 (see Figure 3 , Figure 4 Then execute S214.
[0102] S214. Using the formula: x² = M 12 Calculate the precise displacement x2 using P2, then execute S215. Here, P2 is the pulse equivalent corresponding to the low-frequency induction signal. F2 is the frequency of high-frequency clock pulse II. In this embodiment, F2 = 80MHz, then...
[0103] S215. Using the formula: x=x1+x2, calculate the displacement value x measured by the time grating displacement sensing system (i.e., calculate the complete displacement), and then execute S216.
[0104] S216. Determine if n is odd. If yes, execute S217; otherwise (meaning n is even), execute S218.
[0105] S217. Determine if i = n-1. If yes, execute S219; otherwise, execute S220.
[0106] S218. Determine if i = n. If yes, execute S219; otherwise, execute S220.
[0107] S219. Set measurement sequence number i = 1, then return to execute S22.
[0108] S220, increment the measurement sequence number i by 1 (i.e., i = i + 1), and then execute S221.
[0109] S221. Determine if the 180° electrical phase of the high-frequency excitation signal has arrived. If yes, return to execute S23; otherwise, continue executing S221.
Claims
1. A displacement measurement method based on a time-grating displacement sensing system, wherein the time-grating displacement sensing system includes a time-grating displacement sensor and a signal processing module connected to the time-grating displacement sensor; characterized in that, The displacement measurement method includes: A high-frequency excitation signal is input to the first excitation module of the time-grating displacement sensor, and a low-frequency excitation signal is input to the second excitation module. The first sensing module of the time-grating displacement sensor outputs a corresponding high-frequency sensing signal, and the second sensing module outputs a corresponding low-frequency sensing signal. Then, the high-frequency excitation signal, the low-frequency excitation signal, the high-frequency sensing signal, and the low-frequency sensing signal are input to a signal processing module. The frequency of the high-frequency sensing signal is the same as the frequency of the high-frequency excitation signal, and both are [missing information]. The frequency of the low-frequency induction signal is the same as the frequency of the low-frequency excitation signal, and both are... ;in, , It is an integer, and ; The signal processing module uses high-frequency clock pulse I to interpolate the phase difference between the high-frequency induction signal and the high-frequency excitation signal, and uses high-frequency clock pulse II to interpolate the phase difference between the low-frequency induction signal and the low-frequency excitation signal. The signal processing module calculates the coarse displacement based on the high-frequency excitation signal, the high-frequency induction signal, and the high-frequency clock pulse I. and dynamic precision measurement mark ; The signal processing module uses high-frequency excitation signals, low-frequency induction signals, high-frequency clock pulse II, and dynamic precision measurement markers. Calculate the precise displacement ; The signal processing module will coarsely measure the displacement. With precise displacement measurement The sum is used as the displacement value measured by the time-grating displacement sensing system. ; The signal processing module calculates the coarse displacement based on the high-frequency excitation signal, the high-frequency induction signal, and the high-frequency clock pulse I. and dynamic precision measurement mark The methods include: Within a low-frequency excitation signal cycle, when the high-frequency excitation signal is detected for the first time... When the first 0° electrical phase arrives, counting the interpolated high-frequency clock pulse I begins. When the first high-frequency induced signal is detected... When the 0° electrical phase arrives, stop counting the interpolated high-frequency clock pulse I, and obtain the count value of high-frequency clock pulse I. ;in, It is an integer; if n is even, then If n is odd, then ; Using the formula: The coarse displacement was calculated. ;in, This is the pulse equivalent corresponding to the high-frequency induction signal. , The frequency of high-frequency clock pulse I. The pole distance of the time-grating displacement sensor; Using the formula: ， Calculate electrical phase delay ; Using the formula: The dynamic precision measurement mark is calculated. ; The signal processing module uses high-frequency excitation signals, low-frequency induction signals, high-frequency clock pulse II, and dynamic precision measurement markers. Calculate the precise displacement The methods include: Within a low-frequency excitation signal cycle, when the high-frequency excitation signal is detected for the first time... When the 0° electrical phase arrives, the counting of the interpolated high-frequency clock pulse II begins. When the phase of the low-frequency induced signal is detected to be equal to the dynamic precision measurement mark... At that time, stop counting the interpolated high-frequency clock pulse II, and obtain the count value of high-frequency clock pulse II. ; Using the formula: The precise displacement was calculated. ;in, This is the pulse equivalent corresponding to the low-frequency induced signal. , The frequency of high-frequency clock pulse II.
2. The displacement measurement method based on a time-grating displacement sensing system according to claim 1, characterized in that: The frequency , With frequency satisfy: , .
3. A displacement measurement method based on a time-grating displacement sensing system, wherein the time-grating displacement sensing system includes a time-grating displacement sensor and a signal processing module connected to the time-grating displacement sensor; characterized in that, The displacement measurement method includes: A high-frequency excitation signal is input to the first excitation module of the time-grating displacement sensor, and a low-frequency excitation signal is input to the second excitation module. The first sensing module of the time-grating displacement sensor outputs a corresponding high-frequency sensing signal, and the second sensing module outputs a corresponding low-frequency sensing signal. Then, the high-frequency excitation signal, the low-frequency excitation signal, the high-frequency sensing signal, and the low-frequency sensing signal are input to a signal processing module. The frequency of the high-frequency sensing signal is the same as the frequency of the high-frequency excitation signal, and both are [missing information]. The frequency of the low-frequency induction signal is the same as the frequency of the low-frequency excitation signal, and both are... ;in, , It is an integer, and ; The signal processing module uses high-frequency clock pulse I to interpolate the phase difference between the high-frequency induction signal and the high-frequency excitation signal, and uses high-frequency clock pulse II to interpolate the phase difference between the low-frequency induction signal and the low-frequency excitation signal. The signal processing module calculates the coarse displacement based on the high-frequency excitation signal, the high-frequency induction signal, and the high-frequency clock pulse I. and dynamic precision measurement mark ; The signal processing module uses high-frequency excitation signals, low-frequency induction signals, high-frequency clock pulse II, and dynamic precision measurement markers. Calculate the precise displacement ; The signal processing module will coarsely measure the displacement. With precise displacement measurement The sum is used as the displacement value measured by the time-grating displacement sensing system. ; The signal processing module calculates the coarse displacement based on the high-frequency excitation signal, the high-frequency induction signal, and the high-frequency clock pulse I. and dynamic precision measurement mark The methods include: Within a low-frequency excitation signal cycle, when the high-frequency excitation signal is detected for the first time... When the first 180° electrical phase arrives, counting the interpolated high-frequency clock pulse I begins. When the first high-frequency induced signal is detected... When a 180° electrical phase arrives, stop counting the interpolated high-frequency clock pulse I, and obtain the count value of high-frequency clock pulse I. ;in, It is an integer; if n is even, then If n is odd, then ; Using the formula: The coarse displacement was calculated. ;in, This is the pulse equivalent corresponding to the high-frequency induction signal. , The frequency of high-frequency clock pulse I. The pole distance of the time-grating displacement sensor; Using the formula: ， Calculate electrical phase delay ; Using the formula: The dynamic precision measurement mark is calculated. ; The signal processing module uses high-frequency excitation signals, low-frequency induction signals, high-frequency clock pulse II, and dynamic precision measurement markers. Calculate the precise displacement The methods include: Within a low-frequency excitation signal cycle, when the high-frequency excitation signal is detected for the first time... When the 180° electrical phase arrives, the counting of the interpolated high-frequency clock pulse II begins. When the phase of the low-frequency induced signal is detected to be equal to the dynamic precision measurement mark... At that time, stop counting the interpolated high-frequency clock pulse II, and obtain the count value of high-frequency clock pulse II. ; Using the formula: The precise displacement was calculated. ;in, This is the pulse equivalent corresponding to the low-frequency induced signal. , The frequency of high-frequency clock pulse II.
4. The displacement measurement method based on a time-grating displacement sensing system according to claim 3, characterized in that: The frequency , With frequency satisfy: , .