Research on Precise Tension Controller of Fiber Winding and Placement Machine
|School||Harbin Institute of Technology|
|Course||Mechanical Manufacturing and Automation|
|Keywords||tension control I-PD control PIC MCU digital AC servo motor LabVIEW|
Nowadays fiber composite materials are widely applied, because they can make up many defects of metal. Fiber winding and placement are two common methods in composite molding process, in which fiber tension is an important parameter, directly affects the performance of materials. Thus fiber tension control is a key technology during the winding or placement process. As the fiber winding or placement technology has its own characteristics, the requirements of tension control are also different, involving more factors than other kind of tension controller. The static and dynamic performance required of the system is also higher than others, which makes the research on this kind of tension controller complex and difficult.In this paper a closed-loop tension control system is built, with PIC16F877A MCU, digital AC servo motor as actuator and tension sensor for feedback. And the AC digital servo motors is not only the actuators but also the back yarn motor.According to the control system the mathematical model of main components are established and then transfer function of system is also obtained. Based on the analysis in the performance of system with PID correction simulation and analysis are complemented by SIMULINK toolbox of Matlab. Considering the characteristics of the tension control system finally I-PD control is adopted.The hardware and software of system are designed. Firstly, hardware system is designed according to the control performance requirement. Chip selection and periphery circuit development are accomplished, on the base of which the PCB design of main control circuit is also completed. Software includes design of program in MCU and PC. The program in MCU is mainly including integral PID algorithm, digital filter program, software interface of peripheral device, etc. Software in PC mainly realizes the real-time monitoring of tension, alarm for break yarn and data preservation, etc. Structure of the experimental table is introduced and standardization of the main components is accomplished. Analysis of dynamic and static performance of system is conducted by measuring the curve of real-time tension value when the setting value or speed change, steady state and yarn back. The results show that in constant speed and constant tension condition volatility and static slip of system meet the requirements for tension control. When the winding tension value or speed changes, tension controller acts rapidly and accurately.