Control allocation for over-actuated satellite laser communication systems

Abstract

This work proposes a methodology to optimize actuator contribution to the overall system for constellations with optical links between satellites and Earth, where multiple laser communication terminals are deployed on a common host platform to maximize link duration and enable data exchange between multiple communication nodes. To satisfy specifications regarding field of regard, bandwidth, and accuracy, a combination of dedicated actuators is employed. The strategy, known as control allocation, is tailored to meet the requirements of optical communication. The procedure considers the dynamics and constraints of each actuator, providing a comprehensive approach. It enables a modular design, including the host satellite platform itself. As a result, the allocation algorithm enables optimizations concerning power consumption, adaptation to dynamic link switching conditions, and tracking robustness compared to a decentralized approach. This is achieved by assigning disturbances to the most suitable actuator while meeting secondary objectives. Bounded non-linear weighted least squares optimization is used to account for coordinate system transformation, and a graphical tool is demonstrated to tune the involved weighting matrices in the developed multi-link scenario.