Research On Key Security Technologies In Table-board Subsystem Of Stage Machinery Control System

With the development of science and technology, the modern stage machinery system is becoming more and more powerful. The control system also becomes more and more complex. Both required greater security to advance. Stage machinery movement is directly related to the safety of the personnel and equipment. Therefore, security issues will always be the core issue of stage technology. In addition to the conventional safety measures such as limit operation, interlock protection and scram protection, the precision and robustness of synchronous control are key factors which affect the stage system security. Moreover, how could we make the fault diagnosis and fault-tolerant control technology applied to the stage control system is undoubtedly a significant breakthrough to ensure boot rate and security of the system.On this recommendation, this article focuses on the table-board subsystem of stage machinery control system according to Chinese control pattern "PLC+vector+motor". The monitoring software and PLC control program are developed. The OPC communication between PLC and host computer is realized. A method of multi-motor synchronous control which combines the speed parallel synchcronous control and the compensation of coupled shift with disturbance observer is designed to achieve multi-motor synchronous control. The encoder fault is diagnosised by using data-driven techniques. The fault-tolerant control is achieved by soft closed-loop. The main work include:1) The design of stage machinery control system softwareAim at meeting the control demands, parts of monitoring software and the OPC communication between PLC and host computer are developed by Visual Basic6.0. The PLC control program is developed with ladder diagram programming method by Step7V5.4of Siemens. The sophisticated limit operation, interlock protection and scram protection are set up in monitoring software and PLC control program.2) Multi-motor synchronous control for lifting stage system based on disturbance observerAiming at solving the non-synchronous problem of multiple lifting stages caused by internal and external uncertainty, a method of multi-motor synchronous control which combines the speed parallel synchcronous control and the compensation of coupled shift with disturbance observer is designed to achieve multi-motor synchronous control. As disturbance observer estimate and compensate internal and external uncertainty immediately and accurately during operating, precise synchronization of velocity and position is achieved. Simulation results show that this method not only has higher synchronous precision, but also better robustness.3) Encoder fault diagnosis based on data-driven techniques and soft closed-loop fault-tolerant controlAiming at detecting encoder fault in stage machinery control system, a method based on data-driven techniques which combined LS-SVM and SPRT is proposed. The LS-SVM prediction model is establish based on historical data. Compared the model predicted value and the actual output of the encoder to generate the residual. SPRT algorithm is used for fault detection. When an encoder fault, using the model predicted value to replace the fault encoder output as feedback to controller, in order to realize the soft loop fault tolerant control. The simulation results show that this method can diagnose the encoder fault accurately. The fault-tolerant control is achieved by switching to soft closed-loop promptly. The security of the system is improved.