Cascaded strapdown line-of-sight stabilization for Risley prisms on motion platforms

Area of Science:

• Optics and Photonics
• Control Systems Engineering
• Aerospace Engineering

Background:

• Maintaining stable line-of-sight (LOS) is critical for tracking in dynamic environments.
• Platform attitude disturbances pose a significant challenge to image stabilization systems.
• Existing methods struggle with complex disturbance coupling and residual errors.

Purpose of the Study:

• To propose a cascaded strapdown LOS stabilization and tracking method using Risley prisms.
• To address the challenge of maintaining image closed-loop stability under platform attitude disturbances.
• To develop a real-time compensation strategy for residual disturbances.

Main Methods:

• Introduced Risley prism and inertial space coordinate systems.
• Analyzed disturbance coupling between LOS and platform attitude.
• Utilized an inverse calculation model for disturbance suppression.
• Integrated a fast-steering mirror (FSM) for residual disturbance compensation.
• Established coupling relationship between FSM and Risley prism system residuals.

Main Results:

• The proposed cascaded method effectively suppresses platform disturbances.
• Real-time compensation of residual disturbances was achieved using FSM integration.
• Disturbance suppression ratio improved by approximately -12 dB at 1 Hz.
• Simulation and experimental platforms validated the method's effectiveness.

Conclusions:

• The cascaded strapdown LOS stabilization method for Risley prisms is effective.
• The integration of FSM significantly enhances disturbance suppression and tracking stability.
• This approach offers a robust solution for maintaining image stability in disturbed environments.