Optimal-tuning nonlinear PID control of hydraulic systems

An optimal-tuning nonlinear PID controller design strategy is proposed for hydraulic systems. After an analysis of these systems, an analytic physical dynamical model with dead-zone nonlinearity is derived. A nonlinear PID control scheme with the inverse of the dead zone is introduced to overcome the dead zone in the hydraulic systems. An optimal PTD controller is designed to satisfy some desired time-domain performance requirements. Using an estimated process model, the optimal-tuning PID control provides optimal PID parameters even when the process dynamics are time variant. This strategy is implemented in an environment composed of dSPACE, MATLAB, SIMULINK and Real-Time Workshop. The performance of the controller is demonstrated on a hydraulic position control test rig. (C) 2000 Elsevier Science Ltd. All rights reserved.