やわはだおとめ:片段翻译

As a new research area with many open issues.network technology has been integrated into ontrol system for reducing cabling costs and increasing modularity. Control systems communicating with sensors and actuators over communicatio network is called networked control systems(NCS). In the specific network technologies appliedfor industrial processes, Fieldbus technologies take the dominant positions, such as CAN bust DeviceNet etc. To achieve a longer transmision distance, all fieldbus technologies are time multiplex networks, which inevitably induce time delays due to the limited bandwidth. The time delays deteriorate system performance and even lead to control systems instability. In addition, time delays introduced by networks vary randomly with the environment such that NCS has to be consid Bred as time-varying systems. Control desiogn for the compensation of time delays is an area of major interest with many challenges So me a ssumptionsw erem adeo n time delays in literatures. In Refs. [2]and[3] it was assumed that the sensor node and controller node are time
driven with a certain period. This assumption in fact introduces extra delays in the closed-loop system,because the data from the sensor has to wait for being processed until the beginning of next can trolp eriod. A more reasonable assumption was given in Ref. [4] by Nilsson, which is considered in this paper too. In this assumption, the sensor node takes samples with a constant sampling period h，and both the controller and the actuator node are event driven, i. e. when the controller (actuator)receives the data from the sensor (controller),an interrupt routine will be activated to process
these data. Figure 1 shows the block diagram of N(S with delays, where r" is the delays in the communication path from the sensor to the controller and r" is the delays in the communication path from the controller to the actuator.