Event-triggered Networked Predictive Controller Design And Implementation

With the development of network and computer technology, networked controlsystems (NCSs) have attracted more attention. In NCSs, sensors, controllers and actuatorsare located in different areas and communicated by network. With the advantages in systemmaintenances and extensions, NCSs are widely used in control systems such asindustrial process control, space technology, and military field. At the same time, there aresome problems like packet dropout and transmission dealy in NCSs. These problems willaffect the dynamic performance and stability of the system.Scholars in the field of control have done much study on how to reduce the influenceon systems caused by transmission delay and packet dropout. The networked predictivecontrol method proposed by Guo-Ping Liu is one of the most effective ways. Although thismethod can compensate for the impact of network transmission delay in systems, but theinformation of u k is required, and much bandwidth will be consumed in datatransmission. These disadvantages limit applications of the networked predictive control.To solve above problems, a new event-triggered networked predictive controller isproposed. The main content of this thesis are as follows:First of all, a new kind of event-triggered predictive control strategy is proposed.Sufficient condition of the stability of closed-loop system is given, then is expressed as theform of Linear Matrix Inequalities (LMI). The state variable u k is not essential, whichsignificantly increases the practicality of the new strategy. The event-triggered adjustmentstrategy of sampling period decreases the amount of network data traffic, and can savebandwidth resources.Secondly, a networked experimental platform based on a brush direct current motoris established. The platform uses an IEEE802.11WIFI network for data transmission. ASTM32F2812DSP is used to measure motor speed and export PWM control signal. ARS9110-N-11-02model is used for the communication between the DSP and the controller.The controller is realized by a VC-developed windows program on a PC, and the programalso has the function of speed curve plotting and data storage. The system model isobtained by time-domain identification method.Then, a group of control experiments are accomplished which prove the effectivenessof the event-triggered predictive networked control method. Finally, a summary of this paper is made and new research directions in future areproposed.