The Study On The Reconfigurable And Networked Control Of AC Servo Systems

Because the AC servo systems based on the conventional control method can only satisfy the single aspect of performance, its application adaptability and openess will be limited. Currently, the proprietary networked control AC servo systems cost is high, and its open ability is poor. Aiming at reducing the system's design cost, obtaining the wide application range and a good openess, this dissertation is focused on the study of the reconfigurable and networked control of AC servo systems, and the main contents are as follows.The study of the reconfigurable controller of AC servo systems is done. In this dissertation, the reconfigurable controller adopting some simple control strategies with different characteristics, were theoretically analyzed in detail. According to the performance requirements and the application environment of AC servo systems in application, the reconfigurable rules of control strategies are presented. The characteristics of control strategies are tested by the experiment and simulation results. The rationality of reconfiguration rules and validity of the reconfigurable control is provenThe analysis of communication protocol and the study on network-induced delay are done. In order to use some general communication networks in AC servo systems and eliminate the effect coming from the network-induced delay, some communication networks, such as Ethernet, ControlNet and CAN network, were analyzed in this dissertation. The relationship between the network-induced delay, the number of node, and the transmission period of messages is discovered. The configuration of the networked AC servo systems based on CAN has been setup, and it can reduce cost and enhance the open ability.A distributed dynamic message scheduling strategy based on the deadline of the message was proposed in CAN-based networked control systems. The realization principle of message scheduling strategy and the necessary condition of full schedulability of messages were investigated in detail. According to some experimental results, this strategy can satisfy some necessary performance requirements of the networked control systems, such as the deadline requirement, promoting system flexibility, the fairness of bandwidth allocation, supporting all kinds of messages and so on.A new method that can obtain the status feedback maximum allowable time interval(MATI) with less conservation was proposed. Based on this and the message scheduling strategy, we can control the networked AC servo systems deterministicly and obtain the expected system performance.Finally, the correctness of this method have been verified by simulation and experiment.On the basis of the analysis of the reconfigurable controller, the study of message scheduling strategy and the computation method of the MATI, the hardware platform on the reconfigurable and networked control of AC servo systems with two motors has been constructed and the control software has also been designed. According to the experimental results, they have almost the same performance as non-networked AC servo position control systems.