Petri Nets Modeling for Fault Detection of Servo Electromechanical Actuator Used in Aircraft

This paper applies Petri Net modeling of servo electromechanical actuator used in aircrafts as a means of fault detection. In aircrafts, servo electromechanical actuator is used in order to control surfaces; i.e. roll, yaw and pitch angles. In any aircraft, reduction of the time for fault diagnosis is an important task. Petri Nets modeling can help us to diagnose faults easier. A fault is considered when the current of the actuator is exceeded from a threshold or when the actuator does not reach the desired angle in specified time or when the commanded angle exceeds the maximum revolving angle in each direction; the goal is to diagnose faults when they occur. This tool helps users recognize faults in the system visually. Petri Net-based controllers consist of three main steps; the first step is the modeling of the plants and the specifications, in the second step synchronized composition between the models gets the controlled model, and for resolve the problem of controllability sometimes the third step is required. As soon as the controller is designed, the system can accomplish the whole desired procedure, and then one can guarantee the performance and safety of the system after the occurrence of faults.