Research and Implementation of a Demodulation Switch Signal Phase Alignment System in Dynamic Environments

Area of Science:

• Space physics
• Gravitational wave detection
• Sensor technology

Background:

• Capacitance sensors are critical inertial sensors for space-based gravitational wave missions, providing an inertial reference.
• These sensors measure test mass (TM) position using AC induction and synchronous demodulation, but dynamic TM movement complicates phase alignment.

Purpose of the Study:

• To develop and implement a method for achieving precise phase alignment of demodulation switch signals in dynamic environments for capacitance sensors.
• To address the challenges posed by the suspended state of the test mass in gravitational wave detection missions.

Main Methods:

• A novel method involving adjusting the demodulation switch signal phase and computing the phase difference with the AC induction signal was proposed.
• A measurement and evaluation method for phase deviation was developed.
• An automatic phase alignment system was implemented on an FPGA platform and tested on a hexapod PI console platform.

Main Results:

• The system achieved accurate phase alignment in static environments with a phase deviation of 0.1394 radians.
• In simulated dynamic environments, the system maintained accurate phase alignment with a phase deviation of 0.1395 radians.

Conclusions:

• The developed automatic phase alignment system effectively addresses the challenges of dynamic environments in capacitance sensors for gravitational wave detection.
• The system demonstrates high accuracy and robustness, ensuring reliable performance for inertial sensing in space missions.