A Novel Controller Design for the Next Generation Space Electrostatic Accelerometer Based on Disturbance Observation...

Area of Science:

• Space instrumentation and control systems engineering.
• Precision measurement in geodesy and satellite technology.

Background:

• State-of-the-art accelerometers are crucial for space missions.
• Next-generation geodesic satellites demand accelerometers with performance near fundamental limits (8 × 10⁻¹³ m/s²/Hz¹/²).
• Strict control of the geodesic test mass (within 56 pm/Hz¹/²) is essential for instrument noise budgets.

Purpose of the Study:

• To present a novel digital controller design for next-generation electrostatic accelerometers.
• To address unprecedented control requirements and integrate calibration functions.
• To enhance flexibility and robustness in accelerometer control schemes.

Main Methods:

• Development of a novel digital controller based on disturbance observation and rejection using Embedded Model Control (EMC).
• Automatic parameter optimization using a non-smooth optimization toolbox with a weighted H-infinity norm.
• Generation of multiple controllers for various working modes through batch auto-tuning.

Main Results:

• The novel EMC controller meets precise frequency performance requirements.
• Demonstrated superior disturbance rejection compared to traditional Proportional Integral Derivative (PID) controllers.
• Achieved new instrument functions: easier tuning, separated measurement/control bandwidth, and smooth parameter switching.

Conclusions:

• The proposed EMC-based controller offers significant advantages for future electrostatic accelerometers.
• This approach enhances performance, robustness, and introduces valuable new functionalities for geodesic satellite applications.
• The automated tuning process simplifies controller generation for diverse operational needs.