关键词: 空间应用, 电涡流, 位移, 传感器, 非线性

Abstract: A high precision eddy current displacement sensor for space application is developed to meet the demand of precision noncontact displacement measurement for ultra quiet stable device. Based on the working principle of sensor, the impedance model of the sensor coil is established, and the natural nonlinear characteristic is analyzed. Based on the high precision balanced bridge circuit, a nonlinear calibration method is proposed. Without extra calibrating circuit, the nonlinearity of sensor is reduced from 12% to 0.98%, by the design of balanced bridge circuit impedance and demodulation phase. The measurement results show that the nonlinearity of high precision eddy current displacement sensor is 0.98% in the measurement range of ±3mm. And the sensor has already been used in space application.

Key words: space application, eddy current, displacement, sensor, nonlinearity