Huba Németh

Sliding Mode Position Control of an Electro-Pneumatic Clutch System

Abstract This paper presents a nonlinear control synthesis to design a position controller for an electro-pneumatic Clutch By Wire (CBW) system. In order to achieve high reference tracking performance and meet stability specifications, the Sliding Mode Control (SMC) synthesis is applied for controller design. The dynamic model of the CBW system is shown and transformed into an appropriate coordinate system. In this way, the controller can be designed to provide the track of the reference signal with predefined dynamics and reduce the effects of the disturbances on the performance. Moreover a controller reduction possibility is proposed to decrease the code length, memory claim and computing costs for embedded applications. In the paper, the model representation, coordinate transformation, control design strategy and finally the experimental results on a complete clutch bench are demonstrated and evaluated.

H-infinity Backpressure Controller for High Response Engine Exhaust Throttles

Modern engine exhaust restriction valves can be applied not only as retarders. A suitable pressure generation can assist the aftertreatment system (exhaust gas temperature management) and raw emission control as well. To provide these functionalities the exhaust backpressure has to be controlled arbitrarily. In this paper a model-based controller design is demonstrated to minimize calibration effort. A first engineering principle based, mean-value, nonlinear model was described and converted into linear parameter-varying (LPV) form. To satisfy the demands of the above applications the controller needs to be a high dynamic, stabilizing, tracking controller which is robust in the whole relevant engine operation range. The exhaust processes of the individual cylinders generate comparable amplitude pressure oscillations to the expected control accuracy. To fulfill the above requirements and manage the challenge of the exhaust pressure waves an H-infinity controller design method was chosen. In order to handle the saturation of the control signal a high gain anti-windup was applied. Seeking for the lowest possible computational demand the controller order reduction was proposed based on Hankel singular values. Finally the controller performance was demonstrated and evaluated in software-in-the-loop simulations.

Robust servo control design for an electro-pneumatic clutch system using the H ∞ method

This paper presents a robust servo control synthesis to design a position controller for an electro-pneumatic Clutch By Wire (CBW) system. In order to achieve high reference tracking performance and meet stability specifications, the H∞ synthesis is applied for controller design. The nonlinear dynamic model of the CBW system is shown and transformed into an appropriate coordinate system. Then exact linearization is performed via state feedback. In this way, the controller can be designed to provide the track of the reference signal with predefined dynamics and reduce the effects of the disturbances on the performance using the H∞ method. Moreover a controller order reduction is proposed based on the Hankel singular value based model order reduction. In order to handle the saturation of the control signal a high gain anti-windup is applied. Finally the simulation results are demonstrated and evaluated.