Autonomous Distributed LQR/APF Control Algorithm for Multiple Small Spacecraft during Simultaneous Close Proximity Operations

Autonomous Distributed LQR/APF Control Algorithm for Multiple Small Spacecraft during Simultaneous Close Proximity Operations

An autonomous distributed LQR/APF control algorithm for multiple small spacecraft during simultaneous close proximity operations has been developed. This research contributes to the control of multiple small spacecraft for emerging operation, which may include inspection, assembly, or servicing. A control algorithm is proposed which combines the control effort efficiency of the Linear Quadratic Regulator (LQR) and the robust collision avoidance capability of the Artificial Potential Function (APF) methods. The LQR control effort serves as the attractive force toward goal positions, while APF-based repulsive functions provide collision avoidance for both fixed and moving obstacles. Refinement of both the APF and LQR control algorithms to small spacecraft applications offered insight and enhancement of the resulting control algorithm. Comprehensive performance evaluation of the multiple small spacecraft LQR/APF control algorithm is conducted for simultaneous close proximity maneuvers, such as convergence, rally, rendezvous, and docking maneuvers. These simulations show the developed LQR/APF control algorithm to be both robust and efficient based on the primary metrics of maneuver duration and required vΔ. Promising simulation results are presented for simultaneous multiple small spacecraft gathering, rendezvous, and docking maneuvers.