Friction fault diagnosis and fault tolerant control for electronic throttles with sliding mode and adaptive RBF estimator

The change of throttle viscous and coulomb frictions often cause inaccuracy or malfunction in electronic throttles, and lead to degradation of reliability of vehicles with internal combustion engines. A fault detection fault tolerant control scheme is proposed in this work to tackle the problem. A nonlinear dynamic model is derived for the throttle. A disturbance observer is designed based on the model to diagnose the fault, and a sliding mode control combined with an adaptive neural network estimator is developed for fault tolerant control. The system stability is ensured after the fault occurs and the throttle position tracking is maintained by the applied Lyapunov method. A Simulink model is developed for the throttle with real physical parameters to evaluate the performance. Abrupt and incipient changes are simulated in the throttle friction torque and the simulation results show that the developed method is effective in fault diagnosis and fault tolerant control.