Development of a control method for micro-gyroscopes using self-excitation and frequency measurement techniques

Area of Science:

• * Inertial Navigation Systems
• * Sensor Technology
• * Control Systems Engineering

Background:

• * Micro-Hemispherical Resonator Gyroscopes (MHRGs) are critical for accurate inertial navigation.
• * Traditional MHRG control systems face challenges in precision and stability.
• * Force-to-rebalance mode offers enhanced performance but requires sophisticated control.

Purpose of the Study:

• * To introduce a novel digital closed-loop control system for MHRGs in force-to-rebalance mode.
• * To enhance oscillation initiation using a self-excitation technique.
• * To improve control accuracy and convergence speed for MHRG operation.

Main Methods:

• * Implementation of a self-excitation technique for oscillation initiation.
• * Digital closed-loop control involving amplitude calculation, amplification, and signal multiplication.
• * Integration of Direct Digital Synthesis (DDS) and Proportional-Integral-Derivative (PID) controllers for precise frequency adjustment.

Main Results:

• * Amplitude control demonstrated a variation of ±1% relative to the reference value.
• * Phase error between drive and detection signals maintained within ±0.5° across different MHRG parameters.
• * The system effectively utilizes a high-frequency clock for reference frequency range establishment.

Conclusions:

• * The proposed digital closed-loop control system significantly enhances MHRG performance.
• * The self-excitation and PID-controlled DDS approach ensures high accuracy and stability.
• * This methodology provides a robust solution for advanced inertial navigation applications.