Event-based control method for variable feedback rate nonlinear systems

This paper presents an event-driven approach for handling variable rate sensor feedback. Such systems are challenging as most discrete-time modeling techniques are based on constant sampling rate. Existing methods include oversampling, which is rather resource-intensive and linearization or linearizing feedback, which requires calculations for each operating point of the system. As an alternative to these methods, an event-driven algorithm is investigated, which provides appropriate results with moderate computational cost. The test system depicts a common problem in control engineering, namely angular speed control of a rotating shaft. Angular velocity is measured by an encoder, a variable rate sensor, which deteriorates significantly the performance of controllers designed for constant sampling rates. Performance of the event-driven control algorithm is first designed and evaluated by simulation and finally tested as the motion controller of a mobile platform.