Event-Based Estimation and Control

Researchers: Marcus Thelander Andrén, Johan RuuskanenAnton Cervin, Bo Bernhardsson, Kristian Soltesz

Funding: Swedish Research Council, WASP

The vast majority of all feedback controllers today are implemented using digital computers, relying on periodic sampling, computation, and actuation. For linear systems, sampled-data control theory provides powerful tools for direct digital design, while implementations of nonlinear control designs tend to rely on discretization combined with fast periodic sampling. In recent years, there has been a growing research interest in event-based control, in particular in connection to distributed and networked control systems. The basic idea is to communicate, compute, or control only when something significant has occurred in the system. The motivation for abandoning the time-triggered paradigm is to better cope with various constraints or bottlenecks in the system, such as sensors with limited resolution, limited communication or computation bandwidth, energy constraints, or constraints on the number of actuations.

During 2017 we have studied optimal event generation for reset control of linear stochastic systems. This is a fundamental event-based control problem whose solution can be applied in for instance H2-optimal networked control with communication costs. We have shown that optimization of the reset boundary is related to an elliptic convection-diffusion-type partial differential equation over a domain with free boundary, a so called Stefan problem.