Robust Risley prism control based on disturbance observer for system line-of-sight stabilization.

Area of Science:

• Control Systems Engineering
• Optical Systems
• Robotics

Background:

• Flexible thin-wall ring mechanisms in Risley prism systems (RPS) introduce tracking and pointing challenges.
• Disturbances like friction, shaft deformation, and model uncertainties degrade RPS accuracy.

Purpose of the Study:

• To propose robust control strategies for improving RPS tracking accuracy.
• To analyze and compare the disturbance observation and compensation (DOC) performance of different control methods.

Main Methods:

• Development of two distinct observer-based control methods for RPS.
• Implementation of disturbance observation and compensation (DOC) for error reduction.
• Comparative analysis of DOC performance through simulations and experiments.

Main Results:

• Both proposed control methods enhance tracking precision in RPS.
• The DOC-expanded state observer control mode demonstrated superior disturbance rejection capabilities.
• Simulation and experimental results validate the effectiveness of the proposed control strategies.

Conclusions:

• Observer-based robust control significantly improves RPS tracking accuracy.
• The DOC-expanded state observer offers the best performance for mitigating disturbances in RPS.
• The proposed methods provide a viable solution for precision pointing applications.