The Research Of MEMS Accelerometer Sense Signal Readout Circuit And Performance Compensation System

MEMS accelerometers has been widely used in aerospace,industrial production and daily life as an important inertial device,so its performance is particularly important.The performance of accelerometer is mainly affected by manufacturing process,internal structure,materials,external environment.The accuracy of signal readout circuit and ambient temperature is the important inflprocessed and manufactured.Therefore,it's important to study how to improve the accuracy uence factor for the accelerometer that has been of sense signal readout circuit and overcome the influence of temperature error.This dissertation conducted a series of studies on processed pendulum silicon micro accelerometer's sense signal readout circuit and temperature error compensation to Improve accelerometer performance based on full study of pendulum silicon micro accelerometer's principle.Main work is included:(1)The working principle and temperature characteristics of pendulous silicon micro-accelerometer are analyzed theoretically,and the performance parameters and test method are introduced.(2)A single carrier double-ended pendulous silicon micro-accelerometer sense capacitive circuit with the core of charge amplifier is designed based on the comparative analysis of the typical sense capacitive readout circuit in this dissertation,and it's optimized from the detection circuit structure,component,parameter and PCB based on the analysis of the detection circuit noise.(3)Providing the guidance for the selection of final temperature compensation model based on the analysis of three compensation model's advantages and disadvantages established by polynomial fitting,BP neural network and improved PSO_BP neural network.A temperature compensation system has been designed from hardware systems and software systems.Testing the performance of pendulous silicon micro-accelerometer based on the related device test standards.Test results show that the output noise of the interface circuit is-110.9dBV/(?),equivalent capacitance resolution is 5.43×10-19F/(?),the results show that the detection circuit can meet the requirements of high-precision test for silicon micro capacitance accelerometer basically.The temperature coefficients of the scale factor,the nonlinear and the stability of zero bias are decreased from 4598ppm/?,41364ppm and 579.7mg to 290ppm/?,2445ppm and 20.2mg respectively after compensating with the temperature model,it proves the correctness and effectiveness of the improved PSO_BP_NN temperature compensation model.The compensation method is also applicable to other sensors to improve performance,and has broad engineering application prospects.