Low-cost rotating-engine speed control using event detection, in presence of uncertainties or disturbances

Considering the rotating engine speed control problem, speed sensors of measurement output are replaced by an event-detection scheme or simply an imprecise and low-resolution encoder. This results in considerable measurement simplification and cost reductions. Modeling the integrated plant-detector system will result in a nonlinear discrete-time model with a sample time dependent on state vector. For simplicity, plant is assumed to have a single pole transfer function. Two important practical problems of integrated model are uncertainties in event intervals and a periodic disturbance. These cases are considered in this article. A special observer is designed and a local stability near any working point is guaranteed by linearization.