Constrained model predictive force control of an electrohydraulic actuator

• Published in: Control engineering practice Vol. 19; no. 1; pp. 62 - 73
• Main Authors: Marusak, Piotr M., Kuntanapreeda, Suwat
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 2011; Elsevier
• Subjects: Actuators; Algorithms; Applied sciences; Computer science; control theory; systems; Constrained control; Control system synthesis; Control theory. Systems; Difference equations; Drives; Electrohydraulic; Electrohydraulic systems; Exact sciences and technology; Force control; Hydraulic actuators; Mathematical analysis; Mathematical models; Mechanical engineering. Machine design; Model predictive control; Optimal control; Polyimide resins; Sampling; Speed variators, torque converters. Hydraulic drives and controls, pneumatic drives and controls, fluids and components, hydraulic motors, pneumatic motors; Tracking; Model predictive control; Force control; Constrained control; Hydraulic actuators; Electrohydraulic systems; Integral proportional control; Tracking; Hydraulic control; Constraint satisfaction; Control synthesis; Electrohydraulics; Difference equation; Electrohydraulic control; Control constraint; Hydraulic motor; Sampling; Actuator; Capability index; Process control; Far field; Output signal; Experimental study; Constrained optimization; Engineering design; Design process; Tracking(movable target); Handling
• ISSN: 0967-0661; 1873-6939
• DOI: 10.1016/j.conengprac.2010.09.002

An analytical MPC controller was designed for force control of a single–rod electrohydraulic actuator. The controller based on a difference equation uses short control horizon. The constraints on both input and output variables are taken into consideration by the controller. The mechanism of output constraints satisfaction uses output prediction and makes possible to constrain the output values many sampling instants ahead. Thus, it extends capabilities of the analytical MPC controllers to the field reserved so far for much more computationally expensive numerical MPC algorithms. Results of real life experiments illustrate efficiency of the proposed controller. The results also show that the MPC controller has better tracking performance than conventional P and PI controllers. The MPC controller with the constraint handling mechanisms, though relatively simple, offers very good performance. As the design process is detailed, it is possible to relatively easy adapt the proposed approach to other control plants. ►An analytical MPC force controller with constraint handling mechanism is developed for a single-rod electrohydraulic actuator. ►The controller considers the constraints on both input and output variables. ►The controller is relative simple. ►Results of real life experiments illustrate efficiency of the developed controller. ►Results of real life experiments show that the controller has better tracking performance than conventional P and PI controllers.