Wireless event-driven networked predictive control over internet

In networked control systems, the network uncertainties can degrade the control performance and even result in instability, especially for the Internet-based control system with wireless communication in which the transmission delay could be many times of the sampling period of control systems. NPC (Networked Predictive Control) is an active method to compensate for the effects of network uncertainty. However, control systems need to make long time prediction due to the long transmission distance. Without an accurate mathematical model, the control performance can not be guaranteed. In order to address this problem, a new NPC scheme designed for wireless NPC with long time delay is introduced in this paper. It uses the information of the previous prediction errors to correct the future predictions. A correction algorithm is designed to reduce the predictive errors. To validate the new control schemes, both simulations and experiments have been conducted. The results show that even with “not so” accurate mathematical models, the new schemes can still maintain good control performance in Internet-based NPC with wireless communication.