Although the micro displacement mechanism can achieve high resolution, but in order to obtain reliable application, still need to position detection sensors. Considering the characteristics of the micro displacement mechanism, the current measurement of micro displacement device in addition to the front of grating measuring system and laser interferometer measurement system is introduced in this paper, there is resistance strain displacement sensor and capacitance decay displacement sensor, etc.

Resistance strain resistance decay displacement sensor is to be measured displacement ZhuanHuanLi quantity change device, mainly composed of elastomers, the resistance strain sensor and conversion circuit, etc. Using resistance strain decay of displacement sensor position closed loop control system, sensor and the micro displacement actuator can be integrated into an organic whole, without the need for additional institutions, so high sensitivity, small volume, low cost, high displacement resolution, but nonlinear error is bigger, is easily influenced by temperature.

Capacitance decay displacement sensor is the displacement is converted to electric capacity change device under test. It's essentially a capacitor with variable parameters. Unlike other sensors, capacitive displacement sensor input energy is extremely low, only need very little input force. Due to the electrostatic attraction between the panel board is very small, only a few Newton, therefore capacitance sensor is especially suitable for solving the problem of measuring very low energy input, especially suitable for small displacement measurement. Second can obtain larger relative variation, high linear circuit, dynamic range can be up to 100% or more, it can greatly improve the capability of the output of the sensor. Fast dynamic response. Capacitance sensor of light quality, high natural frequency of the system, at the same time, the capacitor dielectric loss is very small, and sensors can work in a few MHZ of carrier frequency, therefore, particularly suitable for the occasion of dynamic measurement.