Design of displacement detection system for differential inductance sensor

Abstract

Abstract To improve the resolution of displacement detection of the differential inductance sensor and meet the requirement of real-time, that is, high output bandwidth of displacement detection system, a displacement detection system of differential inductance sensor was designed based on the Zynq-7020 platform. The PL terminal (FPGA) of Zynq 7020 is used to generate the sensor excitation signal, collect the sensor probe displacement signal, digital phase-lock amplification and demodulation of the sensor, and transmit the original shift signal and the displacement signal after demodulation at the PS terminal (ARM). The measurement error can be reduced by using the band-pass filter to pretreat the signal before the digital phase-locked amplifier. According to the experimental results, the resolution of the demodulated displacement signal can reach more than 0.0028%FS, and the nonlinear error can reach 0.0278%FS after smooth approximation fitting.