Implementation of model predictive control for tracking in embedded systems using a sparse extended ADMM algorithm

Abstract

This article presents an implementation of a sparse, low-memory footprint optimization algorithm for the implementation of the model predictive control for tracking formulation in embedded systems. The algorithm is based on an extension of the alternating direction method of multipliers to problems with three separable functions in the objective function. One of the main advantages of the proposed algorithm is that its memory requirements grow linearly with the prediction horizon of the controller. Its sparse implementation is attained by identification of the particular structure of the optimization problem, and not by employing the common sparse algebra techniques, leading to a very computationally efficient implementation. We describe the controller formulation and provide a detailed description of the proposed algorithm, including its pseudocode. We also provide a simple (and sparse) warmstarting procedure that can significantly reduce the number of iterations. Finally, we show some preliminary numerical results of the performance of the algorithm.