Title
A mean-variance criterion for economic model predictive control of stochastic linear systems
Abstract
Stochastic linear systems arise in a large number of control applications. This paper presents a mean-variance criterion for economic model predictive control (EMPC) of such systems. The system operating cost and its variance is approximated based on a Monte-Carlo approach. Using convex relaxation, the tractability of the resulting optimal control problem is addressed. We use a power management case study to compare different variations of the mean-variance strategy with EMPC based on the certainty equivalence principle. The certainty equivalence strategy is much more computationally efficient than the mean-variance strategies, but it does not account for the variance of the uncertain parameters. Open-loop simulations suggest that a single-stage mean-variance approach yields a significantly lower operating cost than the certainty equivalence strategy. In closed-loop, the single-stage formulation is overly conservative, which results in a high operating cost. For this case, a two-stage extension of the mean-variance approach provides the best trade-off between the expected cost and its variance. It is demonstrated that by using a constraint back-off technique in the specific case study, certainty equivalence EMPC can be modified to perform almost as well as the two-stage mean-variance formulation. Nevertheless, we argue that the mean-variance approach can be used both as a strategy for evaluating less computational demanding methods such as the certainty equivalence method, and as an individual control strategy when heuristics such as constraint back-off do not perform well.
Year
DOI
Venue
2014
10.1109/CDC.2014.7040314
Decision and Control
Keywords
Field
DocType
Monte Carlo methods,convex programming,linear systems,open loop systems,optimal control,predictive control,stochastic systems,EMPC,Monte-Carlo approach,certainty equivalence strategy,convex relaxation,economic model predictive control,mean-variance criterion,open-loop simulations,optimal control problem,power management,stochastic linear systems
Variance Criterion,Power management,Mathematical optimization,Optimal control,Linear system,Control theory,Computer science,Heuristics,Economic model predictive control,Expected cost,Operating cost
Conference
ISSN
Citations 
PageRank 
0743-1546
1
0.35
References 
Authors
18
4
Name
Order
Citations
PageRank
Leo Emil Sokoler110.35
Bernd Dammann2402.46
H. Madsen340.99
John Bagterp Jørgensen4112.83