Aiming at continuous linear time-invariant system with network-induced delay,its network-based sliding-mode controller is designed and the corresponding closed loop form of the networked control system is established.
On consideration of noise, dynamic features of controller and output feedback, the uniformed modeling method for network control systems with multiple-packet transmission, single-packet transmission with data packet dropout and multiple-packet transmission with data packet dropout is developed. At the same time, we have given the theorem that network-induced delay can be lumped.
Considering the scheduling and stability problem of the networked control systems which share network resources the model of the networked control system is given with the effect of the network induced delay.
Considering a class of nonlinear networked control systems(NCS) to be Lurie systems,a hybrid system is used to describe such a class of nonlinear NCS with network induced delay,data packet dropout,etc.
The conceptof network control systems is presented in this paper. Some basic problems including time-varying transˉmission period,network scheduling,network induced delay,single-packet and multiple-transmission,wrong order of netˉwork packet,dropping network packets,driving mode of node and clock synchronization are discussed.
Supposed that the controller and actuator of the network control system(NCS) are event driven,the sensor node is time driven,the network induced delay is time-varying,uncertain and less than the sampling period, the generalized plant is modeled as an uncertain linear discrete system.
To describe the external characteristics of complicated communication subsystem in NCS, this thesis proposes a simplified dynamic model, consisting of a variable-period sampler and variable transport delay, to denote the packet dropping in data transmission and network-induced time delay.
However, since the communication network has been inserted in the networked control system, some new issues such as network-induced time delay, network scheduling, multiple-packet transmission and dropping network packets appear.
This thesis systematically analyze the characteristics of networked controlsystem, network-induced time delays and network data packet dropout etc, andthe effects made onto the control performances, then propose newly designedmethods which solve the stability and robustness problems of the controlsystem brought by the network-induced time delays and the data packetdropout.