Fuzzy speed control and stability analysis of a networked induction motor system with time delays and packet dropouts

Connecting a spatially distributed system with sensors, actuators, and controllers as a networked control system by a shared data network can reduce the wiring and cost remarkably. Networked control strategy has been utilized in remote operation of linear systems. Nonlinearity is the major barrier in implementing a networked control scheme on an induction motor, which is the most widely used motor in industrial applications. In this case, we designed a sliding mode flux observer to linearize the induction motor model, such that the application of the networked control scheme is feasible. Due to the variable QoS, a fuzzy logic speed controller is proposed to adapt various network conditions. As part of the networked controller, a state predictor is designed to compensate the time delay in the feedback channel. In stability analysis, the upper bounds of time delays and packet dropouts are both given in terms of the Lyapunov theorem. Finally, simulations are conducted employing TrueTime toolbox to demonstrate the effectiveness of the control strategy.