State observers and Kalman filtering for high performance vibration isolation systems.

Area of Science:

• Gravitational wave astronomy
• Experimental physics
• Advanced instrumentation

Background:

• Scientific interest in gravitational waves below current detection limits necessitates improved low-frequency sensitivity in ground-based detectors.
• Seismic motion is a primary obstacle to achieving high sensitivity at these lower frequencies.
• Effective vibration isolation systems are critical for future gravitational wave detector advancements.

Purpose of the Study:

• To introduce a compact vibration isolation system for Advanced Virgo's in-vacuum optical benches.
• To present the performance of this novel system.
• To demonstrate a new multi-channel feedback control scheme for enhanced vibration isolation.

Main Methods:

• Development and testing of a compact vibration isolation system for in-vacuum optical benches.
• Implementation of a novel multi-channel feedback control approach utilizing a linear quadratic regulator and a Kalman state observer.
• Performance evaluation through measurements on the Advanced Virgo optical bench suspension system.

Main Results:

• The compact vibration isolation system demonstrated effective performance for in-vacuum optical benches.
• The novel multi-channel feedback control scheme provided significant suppression of residual payload motion.
• Measurement results confirmed the efficacy of state observer-based feedback control for vibration isolation.

Conclusions:

• The developed vibration isolation system and novel control scheme are crucial for enhancing the low-frequency sensitivity of future gravitational wave detectors.
• Advanced Virgo's optical bench suspension system benefits from this state-of-the-art vibration isolation technology.
• The multi-channel feedback approach represents a significant advancement in controlling residual motion for sensitive scientific instruments.