Decentralized receding horizon control of large scale dynamically decoupled systems

Decentralized control techniques today can be found in a broad spectrum of applications ranging from robotics and formation flight to civil engineering. Their importance for dynamically decoupled systems arises from the abundance of networks of independently actuated systems and the necessity of avoiding centralized design when this becomes computationally prohibitive or would require unrealistic expectations regarding information exchange.; A decentralized optimal control framework using distributed Receding Horizon Control (RHC) schemes is proposed to address this problem, which helps overcome drawbacks of currently available methods. Stability of the proposed scheme is analyzed in detail and a number of methodologies are enlisted to address the problem of feasibility. In particular, a feasible decentralized RHC scheme based on hierarchical decomposition and feasible set projection is developed. Another approach for guaranteed constraint fulfillment is described as well using invariant sets of emergency controllers and switching. A hybrid decentralized RHC framework is also introduced based on coordinating functions and logic rules.; The proposed framework makes use of algorithms that rely on results from computational geometry, mathematical programming solvers, constrained optimal control, invariant set computation and hybrid systems. These techniques allow the formulation of constrained optimal control problems and the computation of their equivalent look-up tables which are easily implementable in real-time. A summary of relevant background material related to these underlying techniques is provided in this thesis as well.; Applicability of the proposed framework is explored using the formation control problem of multiple Unmanned Air Vehicles (UAVs) as a motivating example. This particular application problem has a wide range of envisioned applications including distributed sensing and monitoring, which appear to be the most promising ones. The challenge in UAV formation flight is to formulate simple local problems and design decentralized controllers which would enable the UAVs to meet certain maneuvering challenges while maintaining relative positions and safe distances between each vehicle. This objective is achieved in this thesis by developing distributed control laws for cooperative multi-vehicle groups using constrained optimal control theory and their demonstration on high-fidelity models of an actual unmanned hovering vehicle platform.