Coupled Dynamic Analysis and Decoupling Optimization Method of the Laser Gyro Inertial Measurement Unit

Area of Science:

• Mechanical Engineering
• Optical Engineering
• Inertial Navigation

Background:

• Mechanical dithered ring laser gyros (RLGs) overcome lock-in effects for accurate low angular rate sensing.
• Dither excitation in inertial measurement unit (IMU) systems causes coupled vibrations, limiting RLG accuracy.

Purpose of the Study:

• To analyze the vibration frequency response characteristics of laser gyro IMUs.
• To develop a dynamic decoupling optimization method for IMUs to minimize coupled vibrations.

Main Methods:

• Established a dynamic model of the IMU using multi-rigid body dynamics for vibration frequency response analysis.
• Developed and compared a new IMU dynamic decoupling optimization method against previous approaches.

Main Results:

• Clearly described multi-degree-of-freedom coupling vibration in IMUs due to gyro dither excitation.
• The proposed method demonstrated more effective restraint of coupled IMU vibrations compared to previous methods.
• Prototype experimental tests validated the effectiveness of the new optimization method.

Conclusions:

• The new dynamic decoupling method significantly improves the measuring accuracy of RLGs within IMU systems.
• This research offers valuable improvements for practical engineering applications requiring high-precision inertial measurements.