Abstract: In view of the limited bandwidth issues prevalently existing in the network control system (NCS), a system control scheme based on model parameter identification was presented. The system consists of several subsystems,each subsystem including an identification module, an update module and a controller module. In the closed-loop system update cycle, NCS constructed a dynamic model of the controlled object and reconstructed its state through online identification by the identification module, the update module updated the model parameter of the controlled object by the identified parameters, and finally the controller module output control variables. By designing rational cycle time and adjusting the matching degree of the module with the controlled object, the systems requirement for network bandwidth was reduced, and network utilization was improved, and thus the model-based control scheme was achieved. Matlab simulation was conducted in combination with the networked system of DC motors and the result shows the effectiveness of the proposed method.

Key words: networked control system, limited bandwidth, model-based, parameter identification