Design of Closed-Loop Parameters With High Dynamic Performance for Micro-Grating Accelerometer

A novel closed-loop parameter design scheme with timing sequence control method is proposed to obtain fast tracking ability of micro-grating accelerometer. Firstly, we investigate a timing sequence control method to achieve the minimum time-delay of signal processing only dependent on the response capability of sensing element, which is the same as half modulation period in the designed closed-loop accelerometer system. Considering optical sensing principle and time-delay of signal processing, we establish a dynamic equation for closed-loop micro-grating accelerometer. Then, we analyze the design principle of closed-loop parameters on the condition of system stability, which describes the relationship between time-delay and control parameters to guarantee fast tracking performance of micro-grating accelerometer system. And, through proposed parameter design principle, the closed-loop parameters of micro-grating accelerometer can be obtained with the gains of forward channel and feedback channel in closed-loop detection system. The conducted experiment results show that micro-grating accelerometer can achieve the nonlinearity within 0.28%, the fast step response time of 0.8ms and −3dB bandwidth up to 525Hz, which validate the effectiveness of our parameter design scheme and timing sequence control method.