In control moment gyroscope (CMG) based on magnetically suspended rotor

owing to wide controller bandwidth required by nutation stability at high rotational speed

bending mode between disk and axis of rotor with I-shaped configuration becomes unstable and turns into self-exciting vibration within the range of rotor speed. This elastic vibration can be depressed through adopting notch filter (NF) in original controller of active magnetic bearing (AMB)

but NF design is still an issue since high-speed flat rotor features strong gyroscopic effect and coupling radial motions. An illustrative and robust method based on two-frequency Bode diagram to design NF parameters. By introducing two-frequency Bode diagram

stability of elastic modes are analyzed

correction angle requirements of bending mode at various rotor speeds are summarized

and NF parameters including grade

center frequency and pole damping are designed optimally to minimize influence to nutation stability. Employing the optimized notch filter

elastic vibration amplitude of statically suspended rotor of magnetically suspended CMG was attenuated significantly comparing to original and the rotor is robustly stabilized within entire speed range up to 20000r/min.