Scheduling of event-triggered controllers on a shared network

• Published in: 2008 47th IEEE Conference on Decision and Control pp. 3601 - 3606
• Main Authors: Cervin, A., Henningsson, T.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.12.2008
• Subjects: Actuators; Communication system control; Communication system traffic control; Control systems; Frequency division multiaccess; Multiaccess communication; Sampling methods; Sensor systems; Stochastic systems; Time division multiple access
• ISBN: 9781424431236; 1424431239
• ISSN: 0191-2216
• DOI: 10.1109/CDC.2008.4738939

We consider a system where a number of independent, time-triggered or event-triggered control loops are closed over a shared communication network. Each plant is described by a first-order linear stochastic system. In the event-triggered case, a sensor at each plant frequently samples the output but attempts to communicate only when the magnitude of the output is above a threshold. Once access to the network has been gained, the network is busy for T seconds (corresponding to the communication delay from sensor to actuator), after which the control action is applied to the plant. Using numerical methods, we compute the minimum-variance control performance under various common MAC-protocols, including TDMA, FDMA, and CSMA (with random, dynamic-priority, or static-priority access). The results show that event-triggered control under CSMA gives the best performance throughout.