This proyect aims to implement new control straegies using a non-linear equipment as is the throttle valve of a gas based engine. In order to achive this, a model identification needs to be done; in this case a Piece Wise Affine (PWA) model has been calculated.
“In general terms, the throttle valve must regulate the air or mixture supply for the combustion engine. Depending on the engine concept, this serves different purposes. In the case of petrol engines, speed and power output are regulated by means of fresh air or mixture dosing. Diesel engines generally do not need a throttle valve. However, in modern diesel cars, throttling the amount of intake air facilitates precision control for exhaust gas recirculation and stops the engine from shaking when the ignition is switched off.
The throttle valve is installed in the intake air system of the combustion engine. The opening angle of the valve determines how much fresh air or air/fuel mixture flows into the cylinders (carburettor engines, for example). In older generation engines, the throttle valve is connected directly to the accelerator pedal and operated mechanically via a cable.”1)
The throttle valve which is used in Lab control is a German valve of reference 036 133 062 A. This is an electronic valve which has a strong spring to close the valve when te actuator isn't working, this is to prevent accidents when the actuator or the control system are damaged. The dynamical behavior of springs is nonlinear so, that makes this device completely nonlinear.
These valves have an opening range from aproximately 5° to 90° degrees; The initial angle is 5° because the motor for combustion needs air so this little amount of air keeps it on.