Vibration isolation and low-frequency tracking based on magnetic levitation with composite control.

Area of Science:

• Aerospace Engineering
• Mechanical Engineering
• Control Systems

Background:

• Spacecraft precision equipment is vulnerable to vibrations from Control Moment Gyroscopes (CMGs).
• Traditional Active Vibration Isolation (AVI) methods face limitations due to actuator friction and control response delays.
• Existing feedback and feedforward control strategies exhibit performance bottlenecks, limiting low-frequency tracking and mid-frequency isolation.

Purpose of the Study:

• To propose a Magnetic Levitation Vibration Isolation System (MLVIS) for optimizing CMG AVI performance.
• To enhance both low-frequency tracking and mid-frequency vibration isolation capabilities in spacecraft.
• To address the limitations of traditional actuators and control methods in vibration isolation applications.

Main Methods:

• Implementation of a magnetic levitation actuator to eliminate friction and response delays.
• Adoption of a composite control strategy integrating integral force feedback and filtered-x recursive least squares.
• Utilizing mutual compensation between control methods to mitigate time delays and instability.

Main Results:

• Achieved low-frequency tracking errors of 2.71% (single-frequency) and 11.67% (dual-frequency excitation).
• Demonstrated 91.86% attenuation of natural-frequency vibration amplitude in the mid-frequency band.
• Experimental validation of the MLVIS's superior tracking and active vibration isolation performance.

Conclusions:

• The proposed MLVIS with composite control effectively overcomes limitations of traditional AVI systems.
• The system offers significant improvements in both low-frequency tracking and mid-frequency vibration isolation for spacecraft.
• This technology enhances the stability and precision of sensitive equipment in dynamic space environments.