Observer-based discrete-time sliding mode throttle control for drive-by-wire operation of a racing motorcycle engine

In this brief, the problem of designing a drive-by-wire throttle control system for a high-performance motorcycle engine is considered. Given the characteristics of the electromechanical system to be controlled, an observer-based, discrete-time sliding mode (DTSM) servo controller with integral action is adopted. The controller is designed on the basis of an identified model of the system, whose states are estimated by means of a state observer. Different state observer structures are analyzed, and it is shown that the main characteristics of standard state-feedback-based sliding mode control systems are preserved. A theoretical analysis is also presented showing that a separation principle holds, so that the state observer and the DTSM controller can be designed independently. The performances of the designed controller are illustrated by reporting the results of tests performed on track with a racing motorcycle.