Introduction Fiberglass reinforced plastic (FRP) pipes possess numerous advantages, including corrosion resistance, smooth inner walls, low fluid resistance, no secondary pollution to the transported medium, good thermal insulation performance, and low engineering costs, making them the best alternative to traditional steel pipes. They are widely used in oil and water transportation, chemical engineering, and thermal power projects. Reports indicate that in 2001, the market demand for FRP pipes in Western Europe reached 67,000 tons, with an annual growth rate exceeding 10%. Major FRP pipe manufacturers worldwide have strengthened their R&D efforts, greatly promoting the development of the FRP pipe industry. Currently, the main method for producing FRP pipes worldwide is fiber winding. The winding machine is the key equipment in fiber winding. During operation, fiber yarn impregnated with adhesive is laid regularly on the surface of the mandrel according to the designed line pattern through the nozzles on the winding machine carriage to form a winding layer. After multiple layers of winding, a wound component with female threads at the ends is formed. The winding machine developed in this paper is a horizontal type, with the mandrel placed horizontally. During winding, the mandrel rotates uniformly around its main shaft, and the trolley motor drives the trolley to reciprocate along the mandrel's axis, driving the winding nozzle to complete the winding and laying of fibers on the mandrel at a certain winding angle, achieving the technical requirements of the product. Modular open CNC systems have become the development direction of CNC technology today. The winding control system in this paper uses an embedded multi-task motion controller to realize synchronous motion control of the main shaft and the trolley, as well as winding logic control. The development of an open winding machine CNC system based on a PC and a TRIO motion controller is discussed. The structure of the fiberglass tube winding machine control system consists of a main shaft that drives the fiberglass tube mandrel to rotate, a trolley for arranging glass fibers on the mandrel, and a resin and curing agent supply system. During the winding operation of the horizontal winding machine, the mandrel rotates uniformly around its main shaft, and the trolley motor drives the trolley to reciprocate longitudinally on the worktable, driving the winding nozzle to complete the winding and laying of the fiber layer on the mandrel at a certain winding angle. The trolley motor needs to continuously accelerate and decelerate according to process requirements during reciprocating operation. Furthermore, the load on the trolley and main shaft changes with the amount of winding adhesive, easily causing changes in the relative position of the guide head and mandrel, resulting in yarn distortion and poor yarn overlap. The winding machine system is a nonlinear, time-varying position synchronous follow-up control system with a large inertia variation. Therefore, an electronic gear-based position tracking control method is adopted to ensure good yarn overlap. The electronic gear mode is actually a multi-axis linkage mode, and its motion effect is similar to the meshing motion of two mechanical gears. When the current axis operates in electronic gear mode, the electronic gear transmission ratio needs to be set, and the current axis will follow the drive axis according to this speed ratio. The drive axis can have any motion mode. The displacement increment of the current axis is equal to the displacement increment of the associated drive axis multiplied by the electronic gear transmission ratio. The structure of this winding machine control system is shown in Figure I. The host computer uses a Taiwan Advantech 1PC610 chassis and a PCA-6179 motherboard. It communicates with a UK Wood Motion Technology MC206 motion controller via an RS-232 serial port, forming a powerful open motion control system. The industrial PC is responsible for human-machine interface management, motion status display, remote monitoring, and process document storage. The motion controller is responsible for real-time motion control and logic control. This structure supports software upgrades and function expansion, and has both upper and lower level openness. The winding machine spindle motor is a 7.5 kW three-phase AC asynchronous motor, driven by a Japanese Yaskawa ICI MR-G7A47p5 frequency converter. For the spindle motor speed, this system adopts a closed-loop control method with high load variation resistance. The analog output of the motion controller's axis 3 interface serves as the speed control input signal for the frequency converter. In the open-loop control state of the motion controller, the analog voltage output value is set to achieve frequency converter speed control. A CWZ 1X rotary encoder mounted on the gearbox input shaft detects the spindle angle and speed. The frequency converter uses a PG vector control method. The PG-X 2 speed card uses one signal sampled by the encoder as the frequency converter input to achieve speed closed-loop control, and another signal as the speed and position signal input to the encoder interface 4 of the controller. This enables a single encoder to complete both speed closed-loop control and spindle angle and position sampling. The trolley uses a Yaskawa SGMGH-44 ACA61 servo motor for precise positioning. It reciprocates along the fiberglass tube axis, tracking the spindle movement with a certain response speed and accuracy according to the winding pattern. The axis 0 interface operates in servo mode, completing the closed-loop control of the trolley servo motor. The spindle encoder feedback is connected to the MC206 axis 4 interface as the input shaft of the reference encoder, providing an encoder input for the synchronous movement of the trolley. Software Design of the Winding Machine Control System The host computer program for the winding machine control system is developed using Microsoft's VC++ 6.0 based on the Windows 2000 platform. It handles functions such as process file setting and management, remote monitoring, and machine tool operation status display. The industrial computer and MC206 communicate via serial port using the MODBUS protocol to download process parameters and upload and display machine tool status parameters. Communication employs a master-slave query mechanism. The system designates the industrial computer as the master station and the MC206 as the slave station. The slave station only responds to queries from the master station; it cannot actively send data. During operation, the worker selects the pipe fitting model to be wound and downloads the process file, entering the winding processing state. At this time, all motion and logic control is completed by the master station, and the slave station only responds to queries from the master station and uploads status data. Even if the industrial computer malfunctions or crashes for some reason, it will not affect the current pipe winding processing, thus improving system stability and real-time control. The motion control program is written in Trio BASIC multi-tasking language. The compiled motion control program can be downloaded to MC 206 using the Motion Perfect software running on a PC for offline execution. Trio BASIC language has three different types of storage variables: named variables, VR() variables, and TABLE area variables. Named variables are local variables, valid only within the task in which they are defined. Variables are global variables that can be shared by multiple tasks and can be used for inter-task communication. The TABLE area is typically used to store CAM/instruction curves; in this program, it stores the process file for the winding pipe model. Running user programs are called threads or tasks. For complex multitasking programs, threads should be prioritized. The controller's default servo cycle is 1ms, which is internally divided into three time slices, each 1/3 ms. These time slices are used internally for servo functions, communication, and the usual "housekee" tasks, respectively. The remaining time within each time slice is used to run the user program. MC 206 can run up to 7 user threads, each numbered from 1 to 7. The highest-numbered threads (threads 7 and 6) are assigned fixed time slices and are called "fast tasks," primarily used for tasks with the following requirements: tasks that need to be processed in every servo cycle; tasks with a large amount of computation and processing; and tasks whose execution speed cannot be changed after the task starts. Threads are called "slow tasks," and they share a common priority; their execution speed decreases as the number of tasks increases. Users can use commands to start tasks and make them run at a specified priority. A "Terminal" window can be opened in the host computer software MotionPerfect to set a "C" priority. The command line port always uses task "0" to input commands from the host computer and execute them immediately. The winding machine control software has four tasks: Task 7 is used for motor motion control and machine tool logic control; Task 6 manages the machine tool's winding-related I/O signals and spindle speed control; Task 2 handles serial communication; and Task 1 controls glue delivery. The task functions and execution time allocation of the control program are shown in Figure 2. Tasks 7 and 6 have the highest priority and are allocated a time slice in each servo cycle (1 ns). Tasks 1, 2, and 6 have the same priority and are allocated a time slice in each servo cycle. The winding program task functions and execution time allocation are shown in Figure 2. The winding machine processing control has three states: manual, semi-automatic, and automatic. The manual state is used to control the movement of the mandrel and carriage individually. In the semi-automatic state, the mandrel and carriage move in coordination for circumferential winding. The winding length is controlled by the worker. In automatic operation, parameters can be set according to the process document to achieve automatic circumferential and helical winding. Furthermore, the control program also has functions such as zero-point correction, automatic zero-point winding, breakpoint winding, and manual intervention during the winding process. Conclusion This winding machine's CNC system combines the advantages of an industrial PC and an embedded motion controller, fully utilizing the electronic gear function of the TRIO motion controller. The system can automatically wind according to process requirements and has functions such as system operation status display, remote communication, fault diagnosis and alarm, and backlash compensation. The yarn width of this winding machine can be adjusted arbitrarily between 80 and 220 mm to meet the winding requirements of pipes with different diameters. The maximum yarn output speed can reach Mm/min, and the mandrel rotation angle resolution is 0.018. The trolley trajectory control error is less than 0 mm. The machine has a fast response speed, stable performance, and simple operation. This system has been applied to Daqing Zhutian Composite Materials Co., Ltd., and practice has proven that this system plays a very important role in improving the technical level, automation level, and pipe quality of FRP pipe winding molding process, and shortens the pipe development cycle. This reduces the labor intensity of workers, improves production efficiency, and lowers production costs. [b]References:[/b] Yue Hongjun. Fiberglass reinforced plastic (FRP) pipes [M]. Beijing: Science Press, 1998. Yu Ningjian, Dai Yun. New developments in the research and application of fiber-wound FRP pipes [J]. Fiber Composites, 1999, 1256-58. Wang Yongzhang. Machine tool digital control technology [M]. Harbin: Harbin Institute of Technology Press, 1995. Im ∞0 ldillat 0 rtechnicalrd em anual —. Tri io Mo tio nTechnology, 2005. Click here to download materials: Control system of winding machine based on embedded motion controller. Editor: He Shiping