Special Composite Strengthened Pipe Production Line Control System Design

Special composite strengthened pipe is a new kind of composite pipe, which makes up the deficiency of the ultra-high molecular weight polyethylene pipe. Its production line is made up of wire winding machine, extruder, main drawing machines, vice drawing machine and so on. To guarantee the quality and efficiency of the production, one centralized control system entails to be designed for the production line.The research uses B&R Power Panel as controller, RS485 bus as communication net, and Hitachi VVVFs and AC asynchronous motors as actuators, to design the centralized control system. There are two types of Hitachi VVVF in the production line,respectively SJ200 and SJ300, and these two types of Hitachi VVVF have different communication protocols, so the author designs the 485 double-loop communication, to use one single controller to control the two communication circuits.Working model of AC asynchronous motor is very complex and difficult to precisely control and simulate. The VVVFs in the production line take vector control mode, which makes VVVF and AC induction motor as an actuator equivalent to a DC motor, so the paper applies the working principle of DC motor to set up the dynamic devices working model. The author also uses Simulink works in matlab software to simulate the working process of the dynamic devices, and the optimized adjustable parameters of PID control are obtained via experience tuning.The author designs the internal circuit in the centralized control cabinet, software system of the control, and the installation drawings, also makes a reasonable selection of low-voltage electrical elements. The operating buttons of the devices are centralized to the control cabinet for the centralized control. To ease adjust of the devices alone, the paper also adopts MD204L type text display to achieve the remote control of the devices. The centralized control does not change the dynamic devices'independence, which means they can run normally after removing the control cabinet. In this paper, B&R software Automation Studio is used as development environment, the communication procedures and speed procedures for the control system are programmed, and also the human-machine interface for the control system is configured. In the configuration of human-machine interface, operation screen is designed simply to understand, and the self-locking procedures are set up to avoid misuse.