Linear Model Predictive Control for a planar free-floating platform: A comparison of binary input constraint formulations
In 17th Symposium on Advanced Space Technologies in Robotics and Automation, (ASTRA-2023), 18.10.-20.10.2023, Leiden, ESA, 2023. ESA.
This work develops a first Model Predictive Controller for ESA's 3-dof free-floating platform. The challenges of the platform are the on/off thrusters, which cannot be actuated continuously and which are subject to certain timing constraints. This work compares penalty-term, Linear Complimentarity Constraints, and classical Mixed Integer formulations in order to develop a controller that natively handles binary inputs. Furthermore, linear constraints are proposed which enforce the timing constraints. Only the Mixed Integer formulation turns out to work sufficiently. Hence, this work develops a new Mixed Integer Model Predictive Controller on the decoupled model of the platform. Feasibility analysis and simulation results show that for a short enough prediction horizon, this controller can (sub)optimally stabilize and control the system under consideration of the constraints in real-time.