Control System Design For Internal-Heating-Cured High Pressure FRP Pipe Production Line

FRP pipe is a composite pipe with many advantages, such as corrosion-resistance, high strength, light weight, designable and easy to form, which make it has a wide application in the fields of oilfield, petrochemical industry, light industry, architecture, municipal administration, environmental protection and aerospace. FRP pipe winding machine is an important equipment of FRP pipe production. Our available FRP pipe production equipments are often mechanical winding machine and numerical control winding machine which are poor in flexibility and adaptability. So their complete opening is limited. Besides, the separate of winding, curing and taking off mandrel equipment increases the cost of equipment and production. Further, external curing has low efficiency and poor quality. Based on traditional production technology of FRP pipe, the technology of steam heating mandrel to design a manufacturing system is adopted in this paper. The system can finish three processes including winding, curing and demould of pipe production by only one machine.Combining with the status of existing FRP pipes winding machine at home and abroad and the modern numerical control technology, the scheme of opening winding machine control system is proposed in this paper according to the actual need of production. This scheme adopts the master-slave distribution, taking the industry PC as host and the embedded motion controller as slave. The host and the slave computers can communicate through RS232 serial port based on Modbus Protocol. This method improves the stability and the real-time performance of the control system.In this paper, winding rule and winding craft of FRP pipes are analysed theoretically and researched systematically. Process parameters and control parameters suitable for the winding machine are designed. Nonlinear time-variant position synchronous motion control adapted to big inertia change is researched. The fuzzy PID control algorithm is used in the winding synchronous motion control. The hardware and software of the FRP pipe internal curing production line control system are designed. The upper computer program is developed with VC++6.0, with the functions of human-computer interaction, process storage, motion state display, machine failure alarm, serial communication, etc. The lower computer has the functions of real-time motion control, logic control, machine protection, etc. The functions and technical index of the FRP pipe internal curing control system meet the qualification, and the stability, rapidity and accuracy meet the actual production requirements. The system runs well in long term, and is applied in many companies.