Control of an electro-hydraulic system with intelligent PID controller

Hydraulic systems are frequently preferred in industrial applications due to their advantages such as high force, precise control and durability. The efficiency of these systems can be increased by improving the control effort. Controlling these systems becomes difficult due to their nonlinear system characteristics and the uncertainties they contain. The need for precise mathematical modeling in nonlinear control techniques and the complexity of the process of adjusting the controller gains, led to the search for a controller that is more applicable in the industry and can maintain its stability despite disturbing effects and uncertainties. In this study an i-PID (Intelligent PID) controller, which is predicted to meet these expectations with its many advantages, can be applied quickly and can maintain its stability in the permanent state, is presented. First, the nonlinear state space model of a hydraulic system and a Simscape model of the same system is obtained. For both simulation studies, the conventional PID controller designed with the classical Ziegler-Nichols method has been compared with the PID and i-PID controllers whose controller parameters are determined by particle swarm optimization, which is an heuristic optimization method. ISE, ITAE and RMS error criterias are applied seperately in the optimization method. Tracking performances examined by applying sinus, step and ramp inputs. The response performances of the i-PID and PID controllers designed for Simscape Fluids and nonlinear model simulations are examined. Both are investigated under the influence of friction force and different load perturbations, tracking performances are compared.