Complete Compensation for Time Delay in Networked Control System Based on GPC and BP Neural Network

A new framework is proposed to cope with the uncertain time delay of networked control system. Event-clock-driven controller nodes, together with clock-driven sensor nodes and actuator nodes are required in this framework. Queuing Strategy is introduced both in controller nodes and actuator nodes while the time delay between controller node and actuator node is compensated by multi-step control increment given by the algorithm of General Predictive Control. An output error prediction model is built using BP neural network to deal with the time delay between sensor node and controller node. The principle of this model is to revise the predictive output of general predictive control model using predictive error signal; if the value of time delay exceeds the upper limit, controller nodes will immediately produce the control strategies adopting the revised predictive output, and thus the compensation for time delay between sensor nodes and controller nodes would be accomplished. Simulation experiments are practiced over Ethernet network which embraces both kinds of time delay. It is proved that the scheme of complete compensation remains a good control performance.