Title
Mixed Strategy for Constrained Stochastic Optimal Control.
Abstract
Choosing control inputs randomly can result in a reduced expected cost in optimal control problems with stochastic constraints, such as stochastic model predictive control (SMPC). We consider a controller with initial randomization, meaning that the controller randomly chooses from K+1 control sequences at the beginning (called K-randimization).It is known that, for a finite-state, finite-action Markov Decision Process (MDP) with K constraints, K-randimization is sufficient to achieve the minimum cost. We found that the same result holds for stochastic optimal control problems with continuous state and action spaces.Furthermore, we show the randomization of control input can result in reduced cost when the optimization problem is nonconvex, and the cost reduction is equal to the duality gap. We then provide the necessary and sufficient conditions for the optimality of a randomized solution, and develop an efficient solution method based on dual optimization. Furthermore, in a special case with K=1 such as a joint chance-constrained problem, the dual optimization can be solved even more efficiently by root finding. Finally, we test the theories and demonstrate the solution method on multiple practical problems ranging from path planning to the planning of entry, descent, and landing (EDL) for future Mars missions.
Year
Venue
Field
2016
arXiv: Robotics
Duality gap,Control theory,Stochastic optimization,Mathematical optimization,Reduced cost,Optimal control,Control theory,Markov decision process,Optimization problem,Mathematics,Stochastic control
DocType
Volume
Citations 
Journal
abs/1607.01478
0
PageRank 
References 
Authors
0.34
5
4
Name
Order
Citations
PageRank
Masahiro Ono113314.40
Mahmoud El Chamie2427.18
Marco Pavone358874.40
Behçet Açikmese44115.88