Publication

Economic model predictive control of nonlinear systems using a linear parameter varying approach

Journal Article (2021)

Journal

International Journal of Robust and Nonlinear Control

Doc link

http://dx.doi.org/10.1002/rnc.5477

File

Download the digital copy of the doc pdf document

Abstract

This paper proposes an Economic Model Predictive Control (EMPC) approach for Linear Parameter Varying (LPV) systems. An efficient implementation of the associated MPC optimization problem is introduced based on transforming the LPV model into a linear time-varying one by using an estimation of the scheduling variables along the prediction horizon. This estimation is based on the optimal states/inputs determined from the solution of the previous optimization problem while running the receding horizon strategy. Using this approach, the solution of the proposed LPVbased EMPC scheme would be possible by solving a series of quadratic programming problems at each time instant. This approach allows reducing the computational burden compared to the solution of a nonlinear optimization problem that would result naturally from the LPV-based formulation. The stability of the proposed approach is guaranteed by forcing the terminal state to converge towards the optimal equilibrium/working point of the system. Moreover, the terminal constraint is relaxed by using a constraint set around the terminal state instead of a constraint value and adding a penalty on the terminal state into the cost function. Besides, strict dissipativity is established as a sufficient condition to prove stability. Finally, the effectiveness of the LPV-based EMPC strategy is shown by controlling a small-scale pasteurization system in simulation. The comparison between the proposed control approach and standard MPC approaches is performed. Results showthe advantages of the proposed LPV-based EMPC controller in terms of economic cost minimization.

Categories

automation, control theory, optimisation.

Author keywords

model predictive control, linear parameter varying models, nonlinear systems, economic optimization, stability

Scientific reference

F. Karimi, V. Puig and C. Ocampo-Martínez. Economic model predictive control of nonlinear systems using a linear parameter varying approach. International Journal of Robust and Nonlinear Control, 2021, to appear.