Discrete-time sliding mode control of electronic throttle valve

Unlike a conventional throttle valve which is connected to the accelerator directly by a wire, an electronic throttle valve is driven by a DC motor and can move independently from the position of the accelerator. This feature provides flexibility in determining the amount of air flow into the engine. However, it is difficult to control the electronic throttle valve as the valve system involves nonsmooth nonlinearities such as stick-slip friction, gear backlash, and nonlinear spring. The electronic throttle valve system is modeled with the nonsmooth nonlinearities considered. A discrete-time sliding mode controller and observer are designed to realize robust tracking control of the valve system. Experimental results are presented.