Fuzzy logic and observer based fault detection for a mechatronic actuator

This paper deals with the fault detection occurred in the mechanical position sensor of a mechatronic actuator Pierburg which is used in the BMW M57 diesel engine. This actuator is in charge of the control of the input air in the vehicle engine. Concretely, it is located between the throttle valve and the combustion chamber. It is supposed to ensure the control of air flow entering to the cylinder. The mechanical position is controlled by a simple PID controller. This controller achieves correctly the position regulation of this actuator. We are not interested in developing a new position control but in detecting the presence of a fault in the mechanical position sensor. This fault detection is based on the use of a mechanical state observer (speed and position) and the use of a fuzzy logic theory. Simulations are presented exhibiting the good functioning of the proposed fault detector.