Implementation and Analysis of a Repetitive Controller for an Electro-Hydraulic Engine Valve System

• Published in: IEEE transactions on control systems technology Vol. 19; no. 5; pp. 1102 - 1113
• Main Authors: Liao, H., Roelle, M. J., Jyh-Shin Chen, Sungbae Park, Gerdes, J. C.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.09.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuators; Adaptive control; Applied sciences; Computer science; control theory; systems; Control system analysis; Control systems; Control theory. Systems; Controllers; Drives; Dynamical systems; Electro-hydraulic system; Electrohydraulics; Engines and turbines; Exact sciences and technology; Feedback; Internal combustion engines; Internal combustion engines: gazoline engine, diesel engines, etc; linear quadratic tracking controller; Mathematical models; Mechanical engineering. Machine design; Modelling and identification; Nonlinear dynamics; repetitive control; Speed variators, torque converters. Hydraulic drives and controls, pneumatic drives and controls, fluids and components, hydraulic motors, pneumatic motors; Studies; System identification; time-delayed system; Tracking errors; Valves; variable valve actuation (VVA) system; Error analysis; Tracking; Error estimation; Hydraulic control; Position control; Steady state stability; Feedback regulation; Dynamical system; Linear control; Electrohydraulic control; Modeling; Mean square error; Control valve; Accurate position; LQ control; time-delayed system; Tracking error; Delay time; System identification; Feedforward; Root mean square value; Mechanical control; linear quadratic tracking controller; Variance analysis; Time response; Engine valve; Delayed response; Response time; Tracking(movable target); variable valve actuation (VVA) system; Non linear effect; Hydraulic drive; Electro-hydraulic system; Repetitive control
• ISSN: 1063-6536; 1558-0865
• DOI: 10.1109/TCST.2010.2076387

Variable valve actuation plays an important role in modern engine design. Fuel economy, emissions, and power output can be improved through appropriately varying valve lift and timing. One means of independently and continuously adjusting these valve profile parameters is with an electro-hydraulic valve system (EHVS). However, with an EHVS, it is very difficult to achieve the same level of accurate position control that a mechanical cam provides. In particular, the response time delay and the nonlinear dynamics of the hydraulic system can lead to error in valve position control. The paper first describes the identification method used to obtain a mathematical model of the EHVS. Based on the model, two linear feedback controllers are developed and compared. To further improve the tracking performance, a repetitive feed-forward controller is added to augment the feedback controller and the root mean square tracking error is improved to under 40 μ m. Stability and steady-state tracking error variance analyses complete the mathematical framework of this work.