Model Predictive Control with Compensation of Nonlinearities Applied to Position Control of an Electro-Hydraulic Actuator
Model Predictive Control, Nonlinearities Compensation, Electro-Hydraulic Systems, Position Control.
The search for the development of robots capable to perform highly dynamic tasks has led to a recent increase of interest in the use of electro-hydraulic actuators for robotic applications. The inherent nonlinear characteristics of electro-hydraulic systems make conventional controller design a challenge for high-performance applications. Model Predictive Control (MPC) uses the dynamic model of the system to predict it’s behavior, optimizing the control action chosen at each iteration. One of this method’s main characteristic, is the ability to deal with constraints very easily. Nevertheless, its nonlinear version (NMPC) requires a high computational cost, restricting its use only on slow dynamic systems. As an alternative, the MPC with nonlinearities compensation, compares the predictions of the linear and nonlinear models and calculates an additive term compensating their differences, keeping computional cost similar to the linear MPC. This work proposes using the MPC with nonlinearities compensation to design a position controller for an electro-hydraulic actuator and evaluete the results in comparison with other nonlinear control techniques already applied to this system.