Variable-Structure Control of Electronic Throttle Valve

In recent years, the use of electronic throttle valve systems has been very popular in the automotive industry. However, there exist difficulties in controlling the electronic throttle valve because of multiple nonsmooth nonlinearities including stick–slip friction, backlash, and a discontinuous nonlinear spring involved in the system. To alleviate the aforementioned difficulties in controlling the opening angle of a throttle plate and to realize a highly robust controller against uncertainties in the throttle body's mathematical model with limited cost, the variable structure concept is utilized after the employment of feedback backstepping techniques in the intermediate stages of design. Furthermore, the sliding mode observer design technique with equivalent control is exploited in order to estimate the values of necessary states that are not measured. The performance of the proposed controller is evaluated by performing some experiments on the throttle valve setup. First, small scale reference signals that pass through the nonsmooth nonlinearities are tracked even in different disturbed situations by the throttle valve plate, and then, the performance of the controller is tested for large-scale reference signals to observe the reaction time of the controller to sudden changes. For all the cases, the controller works rather well and meets the performance specifications.