In research on networked control systems (NCS), the performance of the control system is assumed to be affected by network-induced parameters such as delays, jitters, packet losses and link failures. In this paper, two delay compensation methods are studied, adaptive Smith Predictor and robust control, in the framework of Networked Control Systems while considering the protocol specifications. First, a clock synchronization protocol is implemented in each device of the network, thereby providing the possibility of end-to-end delay measurement, and a compensation strategy based on this measurement and the adaptive Smith Predictor is applied. Secondly, the end-to-end upper bound delay estimate is calculated on the basis of the network architecture and the traffic estimation, and then subsequently used in a robust control based compensation strategy. The switched Ethernet network is used as an example of the communication network of the NCS.
|Julkaisu||Control Engineering Practice|
|Tila||Julkaistu - 2009|
|OKM-julkaisutyyppi||A1 Julkaistu artikkeli, soviteltu|
- networked control systems, QoS estimation, delay compensation, real time systems, network calculus