Parallel-filter observer control with CCD measurements for space optical communication equipment on a moving platform

Area of Science:

• Aerospace Engineering
• Optical Communication Systems
• Control Systems Theory

Background:

• Space optical communication missions require precise line-of-sight (LOS) stabilization for effective trajectory tracking.
• Existing methods face bandwidth limitations with charge-coupled device (CCD) measurements on moving platforms.
• Degradation in stability can occur with single high-bandwidth filters in tracking systems.

Purpose of the Study:

• To develop a novel parallel-filter observer methodology for stabilizing LOS in space optical communication.
• To overcome the bandwidth limitations inherent in current trajectory tracking systems.
• To enhance the stability and tracking performance of gimbals in dynamic space environments.

Main Methods:

• Implementation of a parallel-filter observer to stabilize LOS.
• Introduction of an equivalent high-order parallel-filter compensator to reduce controller output.
• Utilization of tracking errors directly for LOS stabilization, avoiding complex target dynamics modeling.

Main Results:

• The parallel-filter observer effectively mitigates stability degradation compared to single high-bandwidth filters.
• A stabilized high-bandwidth observer is achieved, enhancing tracking accuracy.
• Simulation and experimental results confirm improved LOS stabilization under carrier disturbance and target motion.

Conclusions:

• The proposed parallel-filter observer methodology offers a simple and applicable solution for LOS stabilization in space optical communication.
• It provides excellent tracking performance for engineering applications with limited measurement bandwidth.
• The approach enhances gimbal stability in inertial space and is robust to disturbances.