Assembly line type time grating displacement sensing signal processing system

Abstract

The pipelined time grating displacement sensing signal processing system comprises a high and low frequency excitation signal generation module, a rough measurement module, a dynamic accurate measurement end position calculation module, a dynamic comparison circuit module, an accurate measurement module, an accurate measurement value selection module and a displacement weighting calculation module. The high and low frequency excitation signal generation module generates measured high and low frequency excitation signals; the rough measurement module completes first-section displacement measurement through a high-frequency sensing signal; a dynamic accurate measurement end position calculation module calculates an accurate measurement end position; the dynamic comparison circuit module converts the accurate measurement end bit digital signal into an analog signal and compares the analog signal with a low-frequency induction signal; the accurate measurement module completes second-section displacement measurement; the accurate measurement value selection module selects an appropriate value from the accurate measurement values and outputs the appropriate value; and the displacement weighting calculation module is used for weighting the two sections of measurement results to obtain a final displacement measurement value. Through time delay-based module combination and assembly line level division, efficient cooperative work of each module is realized, and efficient processing and accurate output of a complex measurement task are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of displacement measurement, in particular to a pipelined time-grating displacement sensing signal processing system. Background Art

[0002] In fields such as industrial automation, precision manufacturing, and testing, the requirements for displacement sensors are increasing, demanding not only high precision and high speed, but also excellent stability and reliability. However, existing displacement sensing technologies often suffer from low measurement accuracy and slow response speeds in complex and changing working environments, making them difficult to meet the demands of high-end applications. Especially in dynamic measurement scenarios, achieving fast and accurate displacement measurement has become a pressing issue.

[0003] Time-grating sensors achieve high-frequency response and high-resolution precision displacement measurement, making them particularly suitable for applications requiring high precision, such as high-end CNC equipment and industrial robots. They also feature simple manufacturing processes and relatively low costs, along with excellent long-term stability and low maintenance costs, making them suitable for large-scale applications.

[0004] After years of development, time-grating displacement sensors have seen a proliferation of related products, finding applications across a wide range of industries. However, achieving both high-frequency response and high-resolution in time-grating displacement sensors is often challenging, often requiring high costs. This often requires a trade-off between high-frequency response and high-resolution, limiting their application.

[0005] Traditional displacement sensing technologies primarily rely on analog signal processing, such as using Hall-effect sensors or eddy-current sensors for displacement measurement. While these technologies can achieve basic displacement detection, they suffer from significant deficiencies in measurement accuracy, response time, and interference immunity. For example, analog signals are susceptible to noise, resulting in unstable measurement results. Furthermore, due to a lack of effective signal processing, detection sensitivity for small displacement changes is low. Furthermore, traditional methods are inefficient when processing large amounts of data, making them inadequate for applications requiring high real-time performance.

[0006] In recent years, with the advancement of digital signal processing technology, FPGA (field-programmable gate array)-based displacement sensing has become a research hotspot. This technology improves measurement accuracy and stability through digital signal processing algorithms, while also enhancing the system's adaptability and flexibility. However, existing digital displacement sensing technology still faces several challenges. For example, when processing high-frequency signals, latency differences between FPGA modules can easily lead to measurement errors. Furthermore, ensuring the system's real-time performance while achieving high-precision measurements is a major challenge.

[0007] The pipelined time-grating displacement sensing signal processing system proposed in the present invention optimizes the signal processing process and adopts a multi-stage pipeline structure to effectively reduce system delay and improve measurement speed and accuracy. Summary of the Invention

[0008] A pipelined time-grid displacement sensing signal processing system includes an FPGA and an external hardware circuit;

[0009] The FPGA includes a signal generation module, a rough measurement module, a dynamic fine measurement end position calculation module, a dynamic comparison circuit module, a fine measurement module, a fine measurement value selection module, and a displacement weighted calculation module.

[0010] The external hardware circuit is used to convert the digital signal output by the FPGA into an analog signal, and input the square wave signal after dynamic comparison of the sensing signal into the FPGA;

[0011] The signal generating module generates at least three excitation signals required for measurement;

[0012] The coarse measurement module is respectively connected to the signal generation module, the dynamic fine measurement end position solution module, and the displacement weighted calculation module;

[0013] The input end of the coarse measurement module is connected to the high-frequency excitation signal, the high-frequency induction signal, and the high-frequency clock interpolation pulse signal; the output end of the coarse measurement module is connected to the dynamic fine measurement end position solution module and the displacement weighted calculation module;

[0014] The dynamic precise measurement end position calculation module is connected to the dynamic comparison circuit module and the precise measurement value selection module respectively; the input end of the dynamic precise measurement end position calculation module inputs the rough measurement result, and the output end is connected to the dynamic comparison circuit module and the precise measurement value selection module;

[0015] The input end of the precision measurement module inputs the low-frequency sensing signal and is connected to the dynamic precision measurement end position solution module, and the output end is connected to the precision measurement value selection module;

[0016] The precise measurement value selection module is respectively connected to the dynamic precise measurement end position solution module, the precise measurement module and the displacement weighted calculation module. The input end of the precise measurement value selection module inputs the dynamic precise measurement end position solution value and the precise measurement values ​​measured by the two-way low-frequency sensor signal, and the output end outputs it to the displacement weighted calculation module.

[0017] The displacement weighted calculation module outputs the final weighted calculation result through the IO port.

[0018] Preferably, the signal generating module generates three excitation signals, including a high-frequency excitation signal, a low-frequency excitation signal 1, and a low-frequency excitation signal 2;

[0019] The frequency of the high-frequency excitation signal is N times that of the low-frequency excitation signal, the value range of N is 3 times or more, and N is a natural number;

[0020] The low-frequency excitation signal 1 and the low-frequency excitation signal 2 have the same low-frequency excitation signal frequency;

[0021] The three excitation signals generate corresponding induction signals through electromagnetic coupling; and the two low-frequency excitation signals in the three excitation signals always maintain a 90° phase difference.

[0022] Preferably, the coarse measurement module uses the high-frequency excitation signal and the high-frequency induction signal to complete the first-stage displacement measurement, and transmits the measurement result to the dynamic fine measurement end position solution module and the displacement weighted calculation module.

[0023] Preferably, the dynamic fine measurement end bit calculation module calculates two fine measurement end bit flags using the coarse measurement value, and outputs the values ​​to the dynamic comparison circuit module and the fine measurement value selection module.

[0024] Preferably, the dynamic comparison circuit module converts the precise measurement end bit solution value corresponding to each low-frequency sensing signal into a corresponding analog signal through DAC; the dynamic comparison circuit module amplifies the analog signal composed of each route solution value and dynamically compares it with the corresponding low-frequency sensing signal to generate a square wave signal L for the precise measurement module. S1 and L S2 ;

[0025] The two square wave signals of the precise measurement module obtain two precise measurement values, which are input to the precise measurement value selection module.

[0026] Preferably, the precise measurement value selection module uses the dynamic precise measurement end position solution value corresponding to one of the low-frequency sensing signals to determine whether it is within [-π / 4,π / 4]∪[3π / 4,5π / 4] of its low-frequency sensing signal. If it is within the above range, the current precise measurement value is used; otherwise, the precise measurement value measured by the other low-frequency sensing signal is used to finally determine the precise measurement value, and the precise measurement value is input into the displacement weighted calculation module.

[0027] Preferably, the displacement weighted calculation module calculates the final displacement value according to the formula, which is as follows:

[0028] X=c1*e1+c2*e2

[0029] Where c1 is the number of high-frequency interpolation clocks counted in the coarse measurement phase, c2 is the number of high-frequency interpolation clocks counted in the fine measurement phase, e1 is the pulse equivalent of the high-frequency excitation signal in the coarse measurement phase, and e2 is the pulse equivalent of the high-frequency excitation signal in the fine measurement phase;

[0030] described Where w is the pole distance, f1 is the frequency of the high-frequency excitation signal in the coarse measurement stage, f2 is the frequency of the high-frequency excitation signal in the fine measurement stage, and F cl is the frequency of the clock pulse.

[0031] Preferably, the level division uses the coarse-measurement module delay as a basis for dividing the pipeline depth and uses the coarse-measurement module as a first-level pipeline.

[0032] Preferably, the depth of the pipeline needs to determine the delay of each module; the method for measuring displacement includes a coarse measurement module, a dynamic fine measurement end position calculation module, a dynamic comparison circuit module, a fine measurement module, a fine measurement value selection module, and a displacement weighted calculation module;

[0033] The delays of the above modules are t1, t2, t3, t4, t5, and t6 respectively;

[0034] The delay of the coarse measurement module is

[0035] The delay of the dynamic precision measurement end position solution module is where N is1 is the total number of instructions in the dynamic precision end bit solution module, IPC is the number of instructions executed per cycle, t p The delay reduction rate brought by parallel processing is 0≤|Δt|≤0.5t1;

[0036] The delay of the dynamic comparison circuit module is t3=t comp +t RC +t trs +Δt, where t comp is the response delay of the comparator itself, t RC is the response time of the external hardware circuit, t trs The delay caused by the signal transmission path; the delay of the precision measurement module is

[0037] The delay of the precise value selection module is where N is2 The number of instructions that the precision value selection module needs to execute;

[0038] The delay of the displacement weighted calculation module is N is3 The number of instructions that need to be executed for the displacement weight calculation module.

[0039] Preferably, the rough measurement module, the dynamic fine measurement end position calculation module, the dynamic comparison circuit module, the fine measurement module, the fine measurement value selection module, and the displacement weighted calculation module are combined to realize a pipeline signal processing system of different depths;

[0040] The secondary pipeline is t1=(t2+t3+t4+t5+t6)+Δt, with the coarse measurement module as the first-stage pipeline; the second-stage pipeline is composed of a combination of five modules: a dynamic fine measurement end position resolution module, a dynamic comparison circuit module, a fine measurement module, a fine measurement value selection module, and a displacement weighted calculation module;

[0041] The three-stage pipeline is t1=t2+t3+Δt=t4+t5+t6+Δt, with the coarse measurement module as the first stage pipeline; the dynamic fine measurement end position resolution module and the dynamic comparison circuit module are combined to form the second stage pipeline; the fine measurement module, the fine measurement value selection module, and the displacement weighted calculation module are combined to form the third stage pipeline;

[0042] The four-stage pipeline is t1=t2+t3+Δt=t4+Δt=t5+t6+Δt, with the coarse measurement module as the first stage pipeline; the dynamic fine measurement end position resolution module and the dynamic comparison circuit module as the second stage pipeline; the fine measurement module as the third stage pipeline; and the fine measurement value selection module and the displacement weighted calculation module as the fourth stage pipeline.

[0043] The five-stage pipeline is t1=t2+Δt=t3+Δt=t4+Δt=t5+t6+Δt, with the coarse measurement module as the first stage of the pipeline; the dynamic fine measurement end position resolution module as the second stage of the pipeline; the dynamic comparison circuit module as the third stage of the pipeline; the fine measurement module as the fourth stage of the pipeline; and the fine measurement value selection module and the displacement weighted calculation module as the fifth stage of the pipeline.

[0044] The six-stage pipeline is t1=t2+Δt=t3+Δt=t4+Δt=t5+Δt=t6+Δt, with the coarse measurement module as the first stage of the pipeline; the dynamic fine measurement end position resolution module as the second stage of the pipeline; the dynamic comparison circuit module as the third stage of the pipeline; the fine measurement module as the fourth stage of the pipeline; the fine measurement value selection module as the fifth stage of the pipeline; and the displacement weighted calculation module as the sixth stage of the pipeline.

[0045] The pipelines of different levels of depth correspond to high-frequency measurement signals and low-frequency measurement signals of different frequencies.

[0046] Compared with the prior art, the technical solution of this application has the following technical effects:

[0047] This invention solves the problem of traditional displacement sensing technology, where a single excitation signal struggles to balance measurement accuracy and response speed, by employing a multi-channel excitation signal combined with electromagnetic coupling technology. The signal generation module in this invention generates a multi-channel excitation signal, including a high-frequency excitation signal and two low-frequency excitation signals. The high-frequency excitation signal is used to quickly determine the approximate position of the displacement, while the two low-frequency excitation signals are used to accurately measure small displacement changes. This solution not only improves measurement accuracy but also speeds up measurement, making it particularly suitable for displacement measurement in dynamic environments.

[0048] This invention addresses the existing difficulty of balancing accuracy and efficiency with a single measurement method by designing a dual-stage measurement mechanism combining a coarse and fine measurement module. The coarse measurement module uses a high-frequency excitation signal to quickly locate the approximate displacement, while the fine measurement module uses a low-frequency sensing signal to perform more precise measurements. This combination ensures high measurement accuracy while improving the system's response speed, enabling stable operation under a wide range of operating conditions. It is particularly suitable for applications requiring high precision and fast response.

[0049] This invention addresses the difficulty in accurately controlling the fine measurement process in traditional displacement sensing technology by introducing a dynamic fine measurement end position calculation module and a fine measurement value selection module. The dynamic fine measurement end position calculation module automatically adjusts the fine measurement end point based on the rough measurement results, ensuring the effectiveness and accuracy of the fine measurement process. The fine measurement value selection module selects the most appropriate measurement result from multiple fine measurement values, avoiding measurement errors caused by signal interference or other factors. The synergistic effect of these two modules significantly improves the system's measurement accuracy and reliability.

[0050] This invention addresses the inefficiency of traditional displacement sensing technology when processing large amounts of data by implementing a pipelined signal processing architecture. It divides the measurement process into multiple stages, each handled by a dedicated module, creating a pipelined data processing flow. This not only reduces latency between modules and improves the overall processing speed of the system, but also enhances its scalability and flexibility, making it easily adaptable to diverse application scenarios, particularly those requiring real-time performance and high throughput.

[0051] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application so that it can be implemented in accordance with the contents of the specification, and to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following is a detailed description of the preferred embodiment of the present application in conjunction with the accompanying drawings.

[0052] Based on the detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings below, those skilled in the art will become more aware of the above and other objects, advantages and features of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without inventive work. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0054] Figure 1 Schematic diagram of pipeline time-grid signal processing system;

[0055] Figure 2 Figure 1 is the sensor structure diagram;

[0056] Figure 3 This is a schematic diagram of the quantization error measured by the time-grating sensor;

[0057] Figure 4 Run the flow chart for the precise value selection module;

[0058] Figure 5 Schematic diagram of the two-stage pipeline signal processing system. Specific embodiments

[0059] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. In the following description, specific details such as specific configurations and components are provided only to help fully understand the embodiments of the present application. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, for clarity and brevity, the description of known functions and structures has been omitted in the embodiments.

[0060] It should be understood that references throughout this specification to "one embodiment" or "this embodiment" mean that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present application. Therefore, the appearance of "one embodiment" or "this embodiment" throughout this specification does not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0061] In addition, the present application may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0062] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist at the same time. The term " / and" in this article describes another type of association object relationship, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0063] The term "at least one" in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, at least one of A and B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0064] It should also be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include," "comprises," or any other variations thereof are intended to cover non-exclusive inclusion.

[0065] Example 1

[0066] This embodiment mainly describes a pipeline time-grid displacement sensor signal processing system. Figure 1 As shown;

[0067] A pipelined time-grating displacement sensor signal processing system is designed based on the measurement principle of the time-grating sensor, specifically a signal processing system designed using a two-stage relay measurement method. The system includes a signal generation module, a coarse measurement module, a dynamic fine measurement end position calculation module, a dynamic comparison circuit module, a fine measurement module, a fine measurement value selection module, and a displacement weighted calculation module.

[0068] According to the delay of each measurement module, the modules are reasonably combined to form new modules and divided into pipelines of different depth levels. The delays between the new modules are similar to reduce the idle waiting time of each module, further improve the measurement response frequency, and ultimately enable the time-grating sensor to achieve the response frequency when only high-frequency sensor signals are used for measurement, while also achieving the measurement resolution when only low-frequency sensor signals are used for measurement, so that the time-grating displacement sensor takes into account both high-frequency response and high-resolution characteristics during the measurement process.

[0069] Based on the time-grating measurement principle, the time-grating displacement sensor uses the sensing signal to continuously compare phases with a reference signal of the same frequency that only contains time information. Usually, the time difference between the two signals when a specified electrical phase appears is counted by high-frequency interpolation clock pulses. The displacement information can be obtained using the number c of high-frequency clock pulses, that is, X = c*e.

[0070] According to the two-stage relay measurement method, a complete displacement measurement is divided into two stages, and high and low frequency sensor signals are used for segmented relay measurement. In the first stage, high-frequency sensor signals are used to complete large-span displacement measurement to ensure the measurement frequency response. In the second stage, low-frequency sensor signals are used to complete micro-nano displacement measurement to ensure the measurement resolution. The final measured displacement can be expressed as: X = c1*e1+c2*e2.

[0071] The signal generation module generates three excitation signals (sinusoidal waveforms) required for measurement. Based on the traveling wave construction principle of the time-grating sensor, the traveling wave is generated by electromagnetic coupling of two excitation signals of the same frequency and amplitude with a phase difference of π / 4. The three excitation signals are a high-frequency excitation signal, a low-frequency excitation signal 1, and a low-frequency excitation signal 2.

[0072] The phase difference between the two low-frequency excitation signals is always 90°. The frequency of the high-frequency excitation signal is N (N≥3) times that of the low-frequency excitation signal. The low-frequency excitation signals have the same frequency and amplitude.

[0073] The two low-frequency excitation signals with a phase difference of 90° are used to solve the problem of insufficient sensitivity when the dynamic precision measurement end position solution value appears at the peak and trough positions of the low-frequency sensing signal, and when the dynamic precision measurement end position solution value is not between [-π / 4,π / 4]∪[3π / 4,5π / 4] of the corresponding low-frequency sensing signal, the precision measurement value measured by the other low-frequency sensing signal with a phase difference of 90° is used.

[0074] The high-frequency excitation signal frequency f1 and the two low-frequency excitation signals f2 satisfy the following relationship:

[0075] f1=N×f2, where N≥3. The second-stage displacement is to further perform fine measurement of the micro-nano displacement with higher resolution that is not quantifiable by the coarse resolution of the first-stage displacement measurement, thereby ensuring the high resolution of the complete displacement measurement. When N=2, c2=1 or c2=0, the two-stage relay measurement method loses its meaning.

[0076] The at least two sets of sensor devices currently require separate sensor devices to perform spatial position sensing when each time-grating sensor uses a different excitation signal to measure displacement (the same excitation signals are only considered the same if the frequency, amplitude, and phase of the signals are all the same). Therefore, at least three sets of sensor devices are required to perform corresponding spatial position sensing for the three different excitation signals in the two signals. The present invention uses frequency division multiplexing to combine the two excitation signals with different high and low frequencies into a frequency division multiplexed excitation signal B1, and uses a single sensor device to perform spatial position sensing. This allows only two sensor devices to perform spatial position sensing for the three different excitation signals.

[0077] The excitation signal B1 and another low-frequency excitation signal are converted, filtered, and amplified by DAC and then input into the corresponding sensor device to generate the corresponding sensing signal B. i2 , L i2 , in the two induction signals, for induction signal B i2 After demodulation, the high-frequency induction signal H required is separated i1 and low-frequency induction signal L i1 .

[0078] The coarse measurement module uses a high-frequency, high-precision clock signal as a high-frequency interpolation pulse signal based on the measurement principle of the time-grating sensor to reflect the phase difference between the high-frequency excitation signal and the high-frequency sensing signal. The phase difference corresponds to the displacement difference. The displacement is calculated according to the formula: X1 = c1 * e1. Among them, c1 is the number of high-frequency interpolation clock signals of the rough measurement value, e1 is the displacement corresponding to each high-frequency interpolation clock when the high-frequency sensing signal measures the displacement, w is the pole distance, f1 is the frequency of the high-frequency excitation signal, F cl The frequency of the high-frequency clock interpolation signal is input into the dynamic fine measurement end position calculation module and the displacement weighted calculation module.

[0079] The dynamic precise measurement end position calculation module has two submodules, and different submodules calculate the precise measurement end position of the corresponding low-frequency sensing signal; the rough measurement value c1 is used to calculate the precise measurement end position of the two low-frequency sensing signals in the current high-frequency excitation signal period. The precise measurement end position The formula is as follows:

[0080]

[0081] The values ​​of the precise measurement end position solutions of the two low-frequency sensing signals are input into the dynamic comparison circuit module and the precise measurement value selection module.

[0082] The two-way dynamic precise measurement end position solution signal of the dynamic comparison circuit module is explained by taking one of them as an example: after the coarse measurement value is input into the dynamic precise measurement end position solution submodule corresponding to the first low-frequency sensor signal, the precise measurement end position of the current measurement stage is solved. The solution value is currently a digital signal, which is then converted by DAC and amplified according to a preset value, and compared with the amplitude voltage signal of the low-frequency sensing signal that has been amplified in the same way. If the voltage value of the low-frequency sensing signal is less than the current dynamic precise measurement end position voltage value, a low level is generated, otherwise a high level is generated; the second low-frequency sensing signal is processed in the same way as above, and finally two square wave signals used in the precise measurement stage are generated.

[0083] The precise measurement module uses the low-frequency sensing signal to complete the second-stage micro-nano displacement measurement. Taking the measurement of one of the low-frequency sensing signals as an example, when the dynamic precise measurement end position solution module completes the solution of the current rough measurement value, it starts counting the high-frequency clock interpolation pulses. When the low-frequency sensing signal shows the same amplitude information as the current solution value, it stops counting the high-frequency clock interpolation pulses; the same is true for the other channel, and finally two precise measurement values ​​are obtained.

[0084] The precise measurement value selection module selects the appropriate precise measurement value output according to the judgment conditions. If the current precise measurement end position solution value is not within the range of [-π / 4,π / 4]∪[3π / 4,5π / 4] of the corresponding low-frequency sensing signal, the precise measurement value measured using the current solution value will cause a large error and should be discarded. At this time, the precise measurement value of another channel using the low-frequency sensing signal should be input into the displacement weighted calculation module.

[0085] The displacement weighted calculation module inputs the rough measurement value and the precise measurement value into the displacement weighted calculation module to obtain the final displacement measurement value according to the formula X=c1*e1+c2*e2.

[0086] According to the delay of each measurement module, the modules are reasonably combined to form new modules and divided into pipelines of different depth levels. The delays between the new modules are similar to reduce the idle waiting time of each module, further improve the measurement response frequency, and thus achieve high-frequency response and high-resolution measurement result output of the time-grating displacement sensor.

[0087] The pipeline is divided into levels based on the delay of modules that cannot be further divided. In the present invention, the coarse measurement module is a separate and complete module that cannot be further subdivided. Therefore, the present invention forms a first-level pipeline with the coarse measurement module, and reasonably combines other modules based on the delay of the coarse measurement module so that the delay of the newly combined module is similar to that of the coarse measurement module. Then, the other newly combined modules are sequentially divided into pipelines of different depths.

[0088] According to the time-grating measurement principle, in the present invention, the coarse measurement starts when the high-frequency excitation signal reaches zero-degree phase; the coarse measurement ends when the high-frequency sensing signal reaches zero-degree phase; a complete coarse measurement delay is one high-frequency excitation signal cycle time, and the coarse measurement module delay is

[0089] The start time of fine measurement is when the dynamic fine measurement end position is calculated and the low frequency sensing signal reaches the calculated dynamic fine measurement end position.

[0090] The pulse equivalent e of the corresponding measurement signal can be calculated based on the frequency of the excitation signal. The formula is: in is the frequency of the measurement signal;

[0091] according to The fine measurement value e2 represents the part that cannot be measured in the rough measurement phase due to the use of high-frequency signal measurement, which leads to a large quantization error when only high-frequency sensor signal measurement is used; similarly, there is also quantization error in the fine measurement phase, so e2 must be smaller than N; therefore, the fine measurement phase delay is 0 <t4≤N;

[0092] The delay t2 of the dynamic precision end bit solution module is determined by the architecture, clock frequency, parallel processing capability and instruction execution efficiency of different chips. The formula is: where N is1 is the total number of instructions in the dynamic precision end bit solution module, IPC is the number of instructions executed per cycle, t p The delay reduction rate brought by parallel processing is 0≤|Δt|≤0.5t1.

[0093] The delay t3 of the dynamic comparison circuit module is mainly determined by the external hardware circuit design, and the formula is t3 = t comp +t RC +t trs +Δt, where t comp =t int +t swt +t out , t RC =R·C, where t comp is the response delay of the comparator itself, t RC is the response time of the external hardware circuit, t trs The delay caused by the signal transmission path, t int is the signal delay at the input, t swt is the comparator internal circuit switching delay, t out is the output signal propagation delay, R is the equivalent resistance in the circuit, C is the equivalent capacitance, L is the length of the signal transmission path, and v is the signal propagation speed. is the dielectric constant and c is the speed of light.

[0094] The delay t5 of the precision value selection module and the delay t6 of the displacement weighted calculation module are determined by the architecture, clock frequency, parallel processing capability and instruction execution efficiency of different chips;

[0095] The formula for module delay t5 is: N is2 The number of instructions that the precision value selection module needs to execute;

[0096] The formula for the displacement weighted calculation module delay t6 is: N is3 The number of instructions that the displacement weight calculation module needs to execute.

[0097] The above modules are combined into pipelines of different depths. The combination between modules is not random. The following rules should be followed to more easily implement a pipelined signal processing system. Specifically, the combination should be based on the principle of similar delays: using the delay of the coarse-measurement module as a benchmark, the combination between modules is determined by deriving the delay of each module according to the formula; the combination between modules should be based on the combination between adjacent modules. If cross-module combination is used, the following problems may occur:

[0098] Data hazards: There are data dependencies between different modules. Some modules are both input and output. If they are not combined in sequence, forcibly combining modules across different modules will lead to data hazards. This will make system design more complex.

[0099] Logic complexity and pipeline pauses: If modules with dependencies are combined, the number of pipeline pauses will increase;

[0100] Processing logic confusion: Each module has its own independent function. Combining two modules with very different processing functions will cause system logic processing confusion.

[0101] The two-stage pipeline is composed of a coarse measurement module as the first stage pipeline and a dynamic fine measurement end bit resolution module, a dynamic comparison circuit module, a fine measurement module, a fine measurement value selection module, and a displacement weighted calculation module as the second stage pipeline. The basis for dividing the pipeline is: t1 = (t2 + t3 + t4 + t5 + t6) + Δt, T1 = t2 + t3 + t4 + t5 + t6, Δt = t1 - T1, where 0 ≤ | Δt | ≤ 0.5 t1; that is, the delay of the coarse measurement module is equivalent to the sum of the delays of all the remaining modules. When the technical means for realizing the pipeline signal processing system are determined and the dynamic comparison circuit is designed, the delays of the four modules, namely, the dynamic fine measurement end bit resolution module, the dynamic comparison circuit module, the fine measurement value selection module, and the displacement weighted calculation module, can be calculated and determined according to the formula T1 = t2 + t3 + t4 + t5 + t6.

[0102] The three-stage pipeline is composed of a coarse measurement module as the first stage pipeline; a dynamic fine measurement end bit resolution module and a dynamic comparison circuit module as the second stage pipeline; a fine measurement module, a fine measurement value selection module, and a displacement weighted calculation module as the third stage pipeline. The basis for dividing the pipeline is t1=t2+t3+Δt=t4+t5+t6+Δt; the second stage pipeline delay T2=t2+t3; the third stage pipeline delay T3=t4+t5+t6; wherein, 0≤|Δt|≤0.5t1. When the technical means for realizing the pipeline signal processing system and the designed dynamic comparison circuit are determined, the delays T2 and T3 are calculated and determined.

[0103] The four-stage pipeline is composed of a coarse measurement module as the first stage; a dynamic fine measurement end bit resolution module and a dynamic comparison circuit module as the second stage; a fine measurement module as the third stage; and a fine measurement value selection module and a displacement weighted calculation module as the fourth stage. The basis for dividing the pipeline is t1=t2+t3+Δt=t4+Δt=t5+t6+Δt; wherein, 0≤|Δt|≤0.5t1. The four-stage pipeline has high requirements for the design of the dynamic comparison circuit. When the technical means for realizing the pipeline signal processing system are determined, the delays t2, t5, and t6 can be determined. Generally, the combined delay of t5+t6 is shorter. Then the delay of the dynamic comparison circuit module needs to satisfy t3=t5+t6+Δt1, wherein, 0≤|Δt1|≤0.2t1.

[0104] The five-stage pipeline is composed of a coarse measurement module as the first stage, a dynamic fine measurement end position resolution module as the second stage, a dynamic comparison circuit module as the third stage, a fine measurement module as the fourth stage, and a combination of a fine measurement value selection module and a displacement weighted calculation module as the fifth stage. The basis for dividing the pipeline is t1=t2+Δt=t3+Δt=t4+Δt=t5+t6+Δt, where 0≤|Δt|≤0.2t1, and the delays t2, t5, and t6 can be determined.

[0105] The six-stage pipeline is composed of a coarse measurement module as the first stage, a dynamic fine measurement end position resolution module as the second stage, a dynamic comparison circuit module as the third stage, a fine measurement module as the fourth stage, a fine measurement value selection module as the fifth stage, and a displacement weighted calculation module combination as the sixth stage. The basis for dividing the pipeline is t1=t2+Δt=t3+Δt=t4+Δt=t5+Δt=t6+Δt; wherein, 0≤|Δt|≤0.2t1.

[0106] The fine measurement value selection module will use the dynamic fine measurement end bit solution value, while the displacement weighted calculation module will use the coarse measurement value. Since the used values ​​are called across modules, additional registers need to be introduced. Otherwise, the measured value will be overwritten by the next measurement result, resulting in a large error in the final measurement value. The coarse measurement value and the dynamic fine measurement end bit solution value are stored in different registers. The delay of these two branch registers will be different depending on the pipeline depth.

[0107] Different pipeline depths result in different delays for the coarse measurement module branch register ROM1 and the dynamic fine measurement end bit calculation module branch register ROM2. For the secondary pipeline, ROM1 requires a delay of t1; otherwise, the next coarse measurement value will overwrite the current coarse measurement value, and the coarse measurement value used by the displacement weighted calculation module will be incorrect. Similarly, the ROM2 delay can be within the range of [0, t1].

[0108] Three-stage pipeline: ROM1 requires a delay within the range of (t1+t4+t5, 2t1); ROM2 delay is within (t1+t4, 2t1);

[0109] Four-stage pipeline: ROM1 needs a delay of (2t1+t5,3t1); ROM2 delay is (t1+t3+t5,2t1);

[0110] Five-stage pipeline: ROM1 needs a delay of (3t1+t5,4t1); ROM2 delay is (2t1+t5,3t1);

[0111] Six-stage pipeline: ROM1 requires a delay of (4t1, 5t1); ROM2 delay is (2t1, 3t1).

[0112] The above-mentioned division of pipeline depth also needs to consider reducing the delay of single measurement. Adding a register after each module will inevitably increase the delay of single measurement. The time used by the dynamic precision measurement end bit solution module, the two-way low-frequency signal switching module, the dynamic comparison circuit module, the precision measurement module, and the displacement weighted calculation module are all short. The pipeline depth is divided according to the specific situation.

[0113] The system of this embodiment not only quickly acquires approximate displacement information through the coarse measurement module, but also enables precise displacement measurement with the help of the fine measurement module, thus ensuring the accuracy of the measurement results. Furthermore, a properly designed displacement weighted calculation module further enhances the system's anti-interference capability and measurement stability. While maintaining high accuracy, it achieves faster response speed and greater adaptability, making it particularly suitable for demanding industrial measurement scenarios.

[0114] Example 2

[0115] This embodiment describes in detail the pipelined time-grating displacement sensor signal processing system of embodiment 1 with the help of examples;

[0116] The pipeline time-grating displacement sensor signal processing system includes: signal generation module, rough measurement module, dynamic precision measurement end position resolution module, dynamic comparison circuit module, precision measurement module, precision measurement value selection module, displacement weighted calculation module. The connection between each module is as follows: Figure 1 shown.

[0117] This example is based on the Xilinx XC7A35TFGG484 FPGA development board and external hardware circuit; the source clock frequency F c l = 50MHz; the sensor uses a 360-pole parasitic magnetic field time grating; its structure is shown in the figure Figure 2 shown.

[0118] A static measurement method is adopted to calculate the delay of each module of the first measurement result in the first low-frequency excitation signal by fixing the measurement rotation angle at 1°. The traditional time-grating sensor signal processing system using a two-stage relay measurement method is compared with the pipeline time-grating signal processing system. The method of controlling variables is adopted. Except for the difference in the signal processing system, other variables are the same.

[0119] The specific implementation process is as follows:

[0120] The signal generation module generates three excitation signals: a high-frequency excitation signal (100 kHz), a low-frequency excitation signal (400 Hz), and a low-frequency excitation signal (400 Hz). According to the principle of the time-grating sensor, an induction traveling wave needs to be generated for measurement, so each excitation signal is composed of two signals with the same frequency and amplitude but a phase difference of 90°.

[0121] In this invention, the generation of high-frequency excitation signals is taken as an example. The generation process utilizes the direct digital synthesis technology (DDS) of the FPGA platform. The high-frequency excitation signal requires two DDS signal generators. By setting the frequency control word and phase control word of each DDS signal generator, two target sinusoidal waveforms are generated. The remaining two low-frequency excitation signals are generated in the same way.

[0122] The signal generation module outputs the generated digital signal, which is then passed through an external DAC chip and hardware circuit to generate a corresponding analog signal. The high-frequency analog signal and the low-frequency analog signal 1 are multiplied by the external mixer to obtain a modulated signal and sent to sensor device 1. The second low-frequency analog signal with a phase difference of 90° is sent to sensor device 2 through the external circuit.

[0123] like Figure 3As shown, after modulated signal a is input into sensor device 1, a sensing signal A reflecting displacement information is obtained; after low-frequency analog signal b is input into sensor 2, a low-frequency sensing signal B reflecting displacement information is obtained. Both sensing signals are input into their corresponding measurement modules. Before entering the measurement module, sensing signal A is demodulated and separated into high-frequency sensing signal A1 and low-frequency sensing signal A2. Sensing signal A is passed through a bandpass filter. The center frequency and bandwidth of the bandpass filter are set according to the frequencies of the high- and low-frequency excitation signals. The high-frequency sensing signal A1 is separated and applied to the coarse measurement module, while the separated low-frequency sensing signal A2 is applied to the fine measurement module.

[0124] The coarse measurement module, based on the time-grid sensor measurement principle, starts counting high-frequency clock pulses when the high-frequency excitation signal reaches a 0° phase, and stops counting high-frequency clock pulses when the high-frequency sensing signal reaches a 0° phase, obtaining a final coarse measurement value c1=49;

[0125] like Figure 4 As shown, after receiving the coarse measurement value c1, the dynamic fine measurement end position calculation module calculates the fine measurement end phase of the two low-frequency sensing signals according to the formula. The fine measurement end position derivation formula of the low-frequency sensing signal A2 and the low-frequency sensing signal B is:

[0126]

[0127] Where i is the number of cycles of the current high-frequency excitation signal, c1 is the rough measurement value, e1 is the pulse equivalent corresponding to the high-frequency excitation signal, and e2 is the pulse equivalent corresponding to the low-frequency excitation signal.

[0128] According to the chip, IPC=1,t p = about 0.2, N is1 =15; According to the calculation formula:

[0129]

[0130] That is 15 clock cycles.

[0131] The main source of delay in the dynamic comparison circuit module is the comparator. The comparator used in this example is LM211D. According to the formula:

[0132] t3=t comp +t RC +t trs

[0133] Among them, the typical response time of LM211D is t comp = 200ns, in the external RC network, R = 1KΩ, c = 100pF, then t RC =R×C=100ns, because on a PCB board, the transmission delay ttrs Ignore; t3 = t comp +t RC +t trs ≤340ns, approximately 17 clock cycles.

[0134] The above-mentioned precision measurement module, based on the time grid measurement principle, uses the trigger signal from the dynamic precision measurement end position resolution module as the start of counting the high-frequency interpolation clock. When the high level of the low-frequency sensing square wave signal comes, the high-frequency interpolation clock counting stops. The two low-frequency sensing signals obtain the precision measurement value c 21 =245,c 22 =223. Then according to the formula Then t 41 =4900ns, t 42 =4460ns.

[0135] The precise measurement value selection module uses the current coarse measurement value to determine whether the precise measurement end position of the low-frequency sensing signal A2 is within the range [-π / 4, π / 4]∪[3π / 4, 5π / 4] of the corresponding low-frequency sensing signal. If it is within this range, the precise measurement value c1 is input into the displacement weighted calculation module. Otherwise, the precise measurement value c2 is input into the displacement weighted calculation module according to the formula:

[0136]

[0137] Wherein, i=1; if it is within the range, the precise measurement value c1 is input to the displacement weighted calculation module.

[0138] The delay of the precision value selection module mainly depends on the instruction execution efficiency, which can be calculated by the following formula:

[0139]

[0140] Among them, N is2 =7, i.e. 7 clock cycles.

[0141] The above displacement weighted calculation module uses the rough measurement value c1 and the precise measurement value c2 to obtain the final displacement value through weighted calculation;

[0142] X=c1*e1+c2*e2=3435.264′′≈0.95°

[0143] described Among them, N is3 =3, i.e. 3 clock cycles.

[0144] like Figure 5 As shown, the two-stage relay measurement method is a traditional time-grating displacement sensor using a two-stage relay measurement method. The delay is: TA =t1+t2+t3+t4+t5+t6≤15680ns. Due to the principle of time grating measurement, since the coarse measurement starts counting the high-frequency interpolation clock at the moment when the high-frequency excitation signal reaches 0° phase, the delay of the traditional time grating signal processing system of the two-stage relay measurement method is two complete high-frequency excitation signal cycles, that is, T A =20000ns.

[0145] According to the delay of each module, through calculation and analysis, the above modules can be divided according to the two-level pipeline, that is, satisfying the formula: t1 = (t2 + t3 + t4 + t5 + t6) + Δt, T1 = t2 + t3 + t4 + t5 + t6, Δt = t1 - T1, 0 ≤ |Δt| ≤ 0.5t1, where t1 = 9940ns, T1 = 5740ns, |Δt| = 0.42t1.

[0146] The chip XC7A35TFGG484 has a bus width of 32 bits and a register access time of approximately t ace = 2ns; calculate the delay required to store 12 bits of c1 into the register t d1 =22ns, where t ace is the register access time, F cl is the clock frequency, N is the chip bus width, n is the coarse measurement data width, and · is rounded up; since it takes 22ns to store a 12-bit coarse measurement value in the register, the delay is 2 clock cycles.

[0147] In summary, the delay of the output result of the two-stage pipeline is: T A =t1+t2+t3+t4+t5+t6+t R ≤15760ns, where the two registers have a delay of t R =80ns, first-stage pipeline delay t p1 =9980ns, t p2 =5780ns; starting from the third high-frequency excitation signal, a measurement value will be output every subsequent high-frequency excitation signal cycle time.

[0148] The delay of the two-stage pipeline ROM1 is 10040ns. Since it is a two-stage pipeline, there is no need to add a branch register ROM2. If ROM2 is set, the delay can be set in [0, 10040]ns.

[0149] When the technical means to implement the pipeline signal processing system and the dynamic comparison circuit are designed, the delays t2, t3, t5, and t6 can be calculated according to the actual formula. At the same time, there are certain requirements for the frequencies of high and low frequency signals. If the frequency difference N between the high and low frequency signals is too small, then there is little significance in dividing the pipeline.

[0150] This example uses a two-stage pipeline time-gate sensor signal processing system with an output frequency of f P =100KHz and the traditional two-stage relay measurement method responds to the frequency Compared with the signal processing system without pipeline, the accuracy is improved by 2 times. At the same time, the resolution reaches 0.029".

[0151] The applicable conditions of the present invention include, but are not limited to, the parameter conditions and angle measurements listed in the specific implementation, and other similar conditions are also applicable.

[0152] Through the examples of this embodiment, it can be seen that the technical solution of this application not only reduces the delay between modules and improves the overall processing speed of the system, but also enhances the scalability and flexibility of the system, so that the system can easily meet the needs of different application scenarios, especially for those measurement tasks that require real-time and high throughput.

[0153] The above are only preferred embodiments of the present invention, which do not limit the scope of protection of the present invention. For those skilled in the art, the present invention can be modified and varied in various ways. Any changes, modifications, replacements, integrations and parameter changes to these embodiments through conventional substitutions or that can achieve the same functions without departing from the principles and spirit of the present invention fall within the scope of protection of the present invention.

Claims

1. A pipeline time-grid displacement sensor signal processing system, characterized in that: Including FPGA and external hardware circuit; The FPGA internally includes a signal generation module, a rough measurement module, a dynamic fine measurement end position resolution module, a dynamic comparison circuit module, a fine measurement module, a fine measurement value selection module, and a displacement weighted calculation module; The external hardware circuit is used to convert the digital signal output by the FPGA into an analog signal, and input the square wave signal after dynamic comparison of the sensing signal into the FPGA; The signal generating module generates at least three excitation signals required for measurement; The rough measurement module is respectively connected to the signal generation module, the dynamic precise measurement end position calculation module, and the displacement weighted calculation module; The input end of the rough measurement module is connected to a high-frequency excitation signal, a high-frequency induction signal, and a high-frequency clock interpolation pulse signal; the output end of the rough measurement module is connected to a dynamic precise measurement end position calculation module and a displacement weighted calculation module; The dynamic precision measurement end position calculation module is connected to the dynamic comparison circuit module and the precision measurement value selection module respectively; the input end of the dynamic precision measurement end position calculation module inputs the rough measurement result, and the output end is connected to the dynamic comparison circuit module and the precision measurement value selection module; The input end of the precision measurement module inputs the low-frequency sensing signal and is connected to the dynamic precision measurement end position solving module, and the output end is connected to the precision measurement value selecting module; The precise measurement value selection module is respectively connected to the dynamic precise measurement end position solution module, the precise measurement module and the displacement weighted calculation module. The input end of the precise measurement value selection module inputs the dynamic precise measurement end position solution value and the precise measurement values ​​measured by the two-way low-frequency sensor signal, and the output end outputs to the displacement weighted calculation module. The displacement weighted calculation module outputs the final weighted calculation result through the IO port.

2. The pipeline time-grid displacement sensor signal processing system according to claim 1, characterized in that: The signal generating module generates three excitation signals, including a high-frequency excitation signal, a low-frequency excitation signal 1, and a low-frequency excitation signal 2; The frequency of the high-frequency excitation signal is N times that of the low-frequency excitation signal, the value range of N is 3 times or more, and N is a natural number; The low-frequency excitation signal 1 and the low-frequency excitation signal 2 have the same low-frequency excitation signal frequency; The three excitation signals generate corresponding induction signals through electromagnetic coupling; and two low-frequency excitation signals among the three excitation signals always maintain a phase difference of 90°.

3. The pipeline time-grid displacement sensor signal processing system according to claim 1, characterized in that: The rough measurement module uses the high-frequency excitation signal and the high-frequency induction signal to complete the first-stage displacement measurement, and transmits the measurement result to the dynamic precise measurement end position solution module and the displacement weighted calculation module.

4. The pipeline time-grid displacement sensor signal processing system according to claim 1, characterized in that: The dynamic precise measurement end position calculation module calculates two precise measurement end position flags using the rough measurement value, and outputs the values ​​to the dynamic comparison circuit module and the precise measurement value selection module.

5. The pipeline time-grid displacement sensor signal processing system according to claim 1, characterized in that: The dynamic comparison circuit module converts the precise measurement end position solution value corresponding to each low-frequency sensing signal into a corresponding analog signal through DAC; the dynamic comparison circuit module amplifies the analog signal composed of each route solution value and dynamically compares it with the corresponding low-frequency sensing signal to generate a square wave signal L for the precise measurement module. s1 and L S2 ; The two square wave signals of the precise measurement module obtain two precise measurement values, which are input to the precise measurement value selection module.

6. The pipeline time-grid displacement sensor signal processing system according to claim 5, characterized in that: The precise measurement value selection module uses the dynamic precise measurement end position solution value corresponding to one of the low-frequency sensing signals to determine whether it is within the range of [-π / 4, π / 4]∪[3π / 4, 5π / 4] of its low-frequency sensing signal. If it is within the above range, the current precise measurement value is used; otherwise, the precise measurement value measured by the other low-frequency sensing signal is used to finally determine the precise measurement value, and the precise measurement value is input into the displacement weighted calculation module.

7. The pipeline time-grid displacement sensor signal processing system according to claim 1, characterized in that: The displacement weighted calculation module calculates the final displacement value according to the formula, which is as follows: X=c1*e1+c2*e2 Where c1 is the number of high-frequency interpolation clocks counted in the coarse measurement stage, c2 is the number of high-frequency interpolation clocks counted in the fine measurement stage, e1 is the pulse equivalent of the high-frequency excitation signal in the coarse measurement stage, and e2 is the pulse equivalent of the high-frequency excitation signal in the fine measurement stage; Said Where w is the pole distance, f1 is the frequency of the high-frequency excitation signal in the rough measurement stage, f2 is the frequency of the high-frequency excitation signal in the fine measurement stage, and F cl is the frequency of the clock pulse.

8. According to the pipeline time-grating displacement sensor signal processing system of claim 1, the level division uses the coarse measurement module delay as the basis for dividing the pipeline depth and uses the coarse measurement module as the first-level pipeline.

9. According to the pipeline time-grid displacement sensor signal processing system of claim 1, the division of pipeline depth requires determining the delay of each module; the displacement measurement method comprises a rough measurement module, a dynamic precision measurement end position calculation module, a dynamic comparison circuit module, a precision measurement module, a precision measurement value selection module, and a displacement weighted calculation module; The delays of the above modules are t1, t2, t3, t4, t5, and t6 respectively; The delay of the coarse measurement module is The delay of the dynamic precision measurement end position solution module is Where N is1 is the total number of instructions in the dynamic precision end bit solution module, IPC is the number of instructions executed per cycle, t p The delay reduction rate brought by parallel processing, 0≤|Δt|≤0.5t1; The delay of the dynamic comparison circuit module is t3=t comp +t RC +t trs +Δt, where t comp is the response delay of the comparator itself, t RC is the response time of the external hardware circuit, t trs is the delay caused by the signal transmission path; the delay of the precision measurement module is The delay of the precise measurement value selection module is Where N is2 The number of instructions that the precision value selection module needs to execute; The delay of the displacement weighted calculation module is N is3 The number of instructions that need to be executed for the displacement weight calculation module.

10. A pipelined time-grid displacement sensor signal processing system according to claim 9, wherein the rough measurement module, the dynamic precise measurement end position calculation module, the dynamic comparison circuit module, the precise measurement module, the precise measurement value selection module, and the displacement weighted calculation module are combined to realize pipelined signal processing systems of different depths; The secondary pipeline is t1=(t2+t3+t4+t5+t6)+Δt, with the rough measurement module as the first-level pipeline; the second-level pipeline is composed of a combination of five modules, namely, a dynamic fine measurement end position resolution module, a dynamic comparison circuit module, a fine measurement module, a fine measurement value selection module, and a displacement weighted calculation module; The three-stage pipeline is t1=t2+t3+Δt=t4+t5+t6+Δt, with the rough measurement module as the first stage pipeline; the dynamic precision measurement end position resolution module and the dynamic comparison circuit module are combined to form the second stage pipeline; the precision measurement module, the precision measurement value selection module and the displacement weighted calculation module are combined to form the third stage pipeline; The four-stage pipeline is t1=t2+t3+Δt=t4+Δt=t5+t6+Δt, with the rough measurement module as the first stage pipeline; the dynamic precision measurement end position resolution module and the dynamic comparison circuit module as the second stage pipeline; the precision measurement module as the third stage pipeline; the precision measurement value selection module and the displacement weighted calculation module as the fourth stage pipeline; The five-stage pipeline is t1=t2+Δt=t3+Δt=t4+Δt=t5+t6+Δt, with the rough measurement module as the first stage of the pipeline; the dynamic precision measurement end position resolution module as the second stage of the pipeline; the dynamic comparison circuit module as the third stage of the pipeline; the precision measurement module as the fourth stage of the pipeline; the precision measurement value selection module and the displacement weighted calculation module as the fifth stage of the pipeline; The six-stage pipeline is t1=t2+Δt=t3+Δt=t4+Δt=t5+Δt=t6+Δt, with the rough measurement module as the first stage of the pipeline; the dynamic precision measurement end position resolution module as the second stage of the pipeline; the dynamic comparison circuit module as the third stage of the pipeline; the precision measurement module as the fourth stage of the pipeline; the precision measurement value selection module as the fifth stage of the pipeline; and the displacement weighted calculation module as the sixth stage of the pipeline; The pipelines of different levels of depth correspond to high-frequency measurement signals and low-frequency measurement signals of different frequencies.

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