On Stability Analysis of Varying-speed Tilting Flywheel under Two Distinct Control Schemes

Varying-speed Tilting Flywheel(VSTF) is an innovative device that combines the actuating capabilities of the control moment gyro with the rate sensing capabilities of the tuned rotor gyro by using a spinning flex-gimbal system. Precession and nutation stability of high-speed rotor is the primary factor determining stability of the VSTF system. In this paper, a simplified mathematical model of VSTF is established, based on which the complex coefficient transfer function is derived and the classical Nyquist criterion using Bode diagram can be extended to the complex coefficient frequency domain. Then, the double-frequency Bode diagram and the Nyquist criterion are used for analyzing the stability of the VSTF system and designing the parameters of the PD controller and adaptive nutation damper. Simulation results are presented to verify the effectiveness of two distinct control schemes and the proposed stability analysis method.