Microstructure torque estimation using MEMS optical monitoring

Determination of microstructure torque is becoming of increasing importance for MEMS sensors and actuators. The micro-torque estimation for a rotary micro motor, assuming the availability of a MEMS optical monitoring data stream, is presented. The estimation technique is based on sliding mode. The dynamic model of the rotating MEMS system and the electrostatic torque is identified. The technique uses the estimated position signal to approach the actual measured position signal obtained from optical monitoring, meanwhile estimating the micro-torque and load torque. Both estimated micro-torque and load torque are low pass filtered to eliminate the switching behavior inherent in the sliding mode estimator. The simulation results of both electrostatic and load torques estimations are presented.