Implementation of Fast Predictive Controllers on FPGA Platforms based on Parallel Lipschitz Interpolation

Abstract

The implementation of nonlinear model predictive controllers for systems operating at high frequencies constitutes a significant challenge, mainly because of the complexity and time consumption of the optimization problem involved. An alternative that has been proposed is the employment of data-driven techniques to offline learn the control law, and then to implement it on a target embedded platform. Following this trend, in this paper we propose the implementation of predictive controllers on FPGA platforms making use of a parallel version of the machine learning technique known as Lipschitz interpolation. By doing this, computation time can be enormously accelerated. The results are compared to those obtained when the sequential algorithm runs on standard CPU platforms, and when the system is controlled by solving the optimization problem online, in terms of the error made and computing time. This method is validated in a case study where the nonlinear model predictive controller is employed to control a self-balancing two-wheel robot.