The design and implementation of driving mode control for vibrational gyroscopes

The paper presents a novel oscillation controller for controlling the driving mode (or drive axis) of a vibrational gyroscope to oscillate at a desired trajectory. The controller consists of a PD controller and an online Extended State Observer (ESO). The ESO is used to estimate the system states and the discrepancy between the real system and the mathematical model of the gyroscope. The PD controller drives the estimated discrepancy and the tracking error of the output of the driving mode to zero. Since the controller design does not require exact information of system parameters, it is very robust against structural uncertainties of the gyroscope. The convergence of the estimation error of the ESO and the stability of the control system are theoretically proven. The controller is validated by software and analog hardware implementations on a vibrational piezoelectric beam gyroscope.