Closed-loop Adaptive Control Algorithm Of Quartz Flexible Accelerometer

Quartz flexible accelerometer usually uses the PID control algorithm with constant control parameters.In the aerospace and other applications,the decrease of the outside air pressure of the head will cause the gas inside the head to leak slowly,resulting in the reduction of the squeeze-film damping of the reed,which changes the open-loop transfer function of the header and affects the stability of the accelerometer system.At present,there are few studies on the squeeze-film damping,and there is no solution to the problem that the stability of the system is reduced due to the reducing of the squeeze-film damping.In order to solve the problem that the original control algorithm cannot effectively control the closed-loop system of quartz flexible accelerometer witheduced damping,a fuzzy adaptive PID control algorithm is proposed.This topic is mainly completed the work:(1)The design and FPGA realization of the fuzzy adaptive PID controller are completed.The fuzzy adaptive PID control algorithm is used as the control algorithm of the digital closedloop system of the quartz flexible accelerometer.The simulation model of the fuzzy adaptive PID controller is set up and the output of the model is called indirectly by the look-up table method.The FPGA implementation of the fuzzy adaptive algorithm is carried out and the modules of the algorithm are simulated and verified.(2)The simulation model of the variable damping parameter is established.The physical testing platform of the digital closed-loop system of quartz flexible accelerometer is built,the upper computer program is designed,a parameterized table-head behavior model is established by using the upper computer to carry out the open-loop step test on the table head,and the simulation model of variable damping parameters is established by changing the damping parameters periodically.(3)The control effect of the fuzzy Adaptive PID controller and the ordinary PID controller is verified.Based on the simulation model of the head,the simulation model of the digital closed-loop system of the quartz flexible accelerometer with fuzzy adaptive PID controller and the ordinary PID controller is constructed.The dynamic performance and stability of the two systems under different damping conditions are tested.The simulation results show that when the header is in critical damping state or underdamping state,the output of the standard PID controller whose parameter is set at the standard atmospheric pressure will oscillate.The output of digital closed-loop system with fuzzy Adaptive PID controller has always been able to follow the changes of system input.