Sampled-Data Networked Control Systems with Random Time Delay –Stability Analysis and Experimental Results–

This paper is concerned with the stability analysis of networked control systems (NCSs) with random delays in the control loop. The time delay between sensor and controller is modeled as a Markov process, the time delay between controller and actuator is assumed constant. A sampled-data system approach is considered. We assume that the controller is able to monitor the transmission delay which is piecewise continuous and switches accordingly. The closed-loop system is a Markovian jump linear system with mode-dependent delay and controller. In this paper a delay-dependent condition for exponential mean square stability is derived. Experiments with the 3 degree-of-freedom (DoF) robotic manipulator ViSHaRD3 show the validity of the proposed approach. As alternative an approach with constant transmission delay is investigated which is achieved by buffering randomly delayed received data up to the maximal occuring time delay. The experimental comparison indicates performance benefits for the here proposed delaydependent controller switching approach.