| Precision measurement technology is a very important indicator for measuring a country's industrial competitiveness and manufacturing level.It is widely used in major national projects such as aerospace,defense equipment manufacturing,and ultra-precision processing.In the field of precision displacement measurement,in response to the problem that traditional measurement technology relies on high-precision reticle,the author's team has developed a time grid displacement sensor based on clock pulses for displacement measurement.Its biggest feature is that it does not rely on spatial precision reticle to achieve high resolution.Force and high-precision displacement measurement.This subject takes the magnetic field time grid sensor as the research object,studies the time grid error function model and error compensation algorithm,studies the time grid adaptive signal processing method,and designs the system to improve the measurement accuracy and stability of the sensor.The main research contents include:(1)Based on the basic sensing theory of the time grid sensor,further study the principle of magnetic field time grid measurement,analyze the source of the error,determine the error component,analyze the influence of various parameters on the error,establish an error function model,and analyze and verify the simulation through simulation analysis and verification.The sensing mechanism of sensing signals in the measurement system.(2)Investigate the time-gap adaptive signal processing method.First,coarse processing is performed by passband gain and coefficient compensation,and then fine-processing by adaptive signal processing(voltage-controlled variable-capacity narrowband filtering,frequency measurement,and identification)to ensure the signal.The system error caused by the gain error and the unstable center frequency of the signal are controlled.(3)Based on the adaptive signal processing method,design an adaptive signal processing system,and analyze,design,and verify the parameters of the entire system.The FPGA is used to drive the high-accuracy DAC-AD5766 and the electronic control switch CD4066 to control the capacitance of the variable capacitor LXRW19V201-058,to fit the nonlinear voltage-capacitance(VC)curve piecewise function of the LXRW,and to use the variable capacitor-Approximation of the resonance center frequency(C-fo)by the binary tree algorithm,which makes the setting of the piecewise function more reasonable and the control accuracy higher.(4)Based on the mathematical model of the time grid sensor error,establish an error parameter identification model based on genetic algorithms,conduct simulation research and optimization design on the model,and analyze,discuss,and verify the identification results.The error compensation method is researched based on the error parameter identification results.The mathematical model of error compensation is established.The error compensation model is used to compensate the error results.The compensation results are analyzed and discussed.(5)Set up an experimental platform and experiments show that the traveling wave center frequency fo using the adaptive signal processing scheme is reduced from 9.98kHz to 10.02kHz to 9.96kHz to 10.04kHz,and the output voltage Uvot is reduced from 3.98V to 4.02V to 3.95V 4.08V.Using the genetic algorithm-based time grid error parameter identification and compensation method can effectively reduce the second and fourth time errors,the reductions are 66.67%and 54.05%,and using this method can effectively reduce the measurement error of the entire cycle of the sensor.Magnetic field time grid The peak-to-peak error of the original signal error of the sensor was reduced from 57.3" to 17.3".In summary,the designed adaptive signal processing method and the proposed error compensation algorithm improve the measurement accuracy of the magnetic field time grid,and have made a certain scientific accumulation in the signal processing and error compensation algorithm research of the time grid. |
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