Simulation model for micromechanical angular rate sensor

A simulation model for an angular rate sensor, a gyroscope, is presented. The device is based on a micromechanical dual torsional mass system which is actuated electrostatically and sensed capacitively. Model equations describing a dynamic, non-linear system are first presented and then realized as an electrical equivalent circuit. The vibrational modes of the system ate modelled with coupled resonator circuits. The electrostatic and Coriolis forces as well as variable capacitances in the small air gaps are modelled with non-linear controlled current sources. External forces, torques and electrical actuation can act as inputs to the device. The model presented allows numerical sensor simulations concurrently with the interfacing electronics in the time and frequency domains. The model is verified by comparing its simulation results to measured frequency responses and capacitance-voltage characteristics.