Output feedback Parametric Controllers for an Active Valve Train Actuation System

The first commercial camless car engines featuring continuously variable valve timing are expected to be available by 2010 to meet the strict legislation on NO_x and CO_x emissions. A key factor for the development of this technology is the design of controllers that can maintain accurate signal tracking in the presence of variations in engine parameters and running conditions. Towards this direction, we present a control design methodology and a new control implementation of an advanced optimizing parametric controller (Parco) for a research active valve train system at Lotus Engineering. The controller is based on a mathematical model for the active valve train and is derived off-line using novel parametric programming techniques. The simple explicit form of the controller enables its implementation on the currently available commercial microprocessor with sampling times of 0.1 ms. Simulation and experimental results demonstrated the superiority of the parametric controller in comparison with a conventional proportional derivative (PD) control scheme