Software Design Of Constant Yarn Tension Control System

Textile industry takes an important part in the development of national economy in our country, which is related to the national economy and the people’s livelihood.Since the reform and opening policy in 1970 s, China has become the largest country in textile industry all over the world with the most plentiful of spinning product structure as the most complete industry chain. However, since the high-end textile equipment is relatively backward,quality of textile products still stays in less high quality and ordinary class, so it can not satisfy the market’s requirements for high technology,high quality and low price.Textile product’s quality depends on constant of yarn tension when textile process.Legitimately controlling high tension refrain from fabric overcrowded, less elastic even break. As low tension,textile products will be slack with poor performing. In view of the above problems, this paper studies a constant tension control system, which can display the yarn tension in real time. The software will precise adjustment of design, ensure that yarn tension will be constant by setting system.Firstly, analysis and conclude to the domestic and foreign research status, make a design scheme based on DSP yarn constant tension control system, which is divided into four modules: tension acquisition, regulate, control, display and setting.Acquisition module choose resistance strain type tension sensor real-time detection;regulating choose the Brushless DC motor, using PWM modulation mode to control motor rolling speed in order to adjust the tension; control module choose TMS320F2808 chip belonging to DSP series to complete the tension measurement value of the A / D converter and motor control; display and setting module select buttons and LCD screen.Secondly design the control strategy of the system, using fuzzy PID controller to achieve converting the tension value into motor speed value, using the the speed pi-pi current double closed loop control mode to realize the precise control of the Brushless DC Motor, and using Matlab/Simulink to establish fuzzy PID and motor simulation models for the simulation analysis, to verify the feasibility of the proposed control strategy.Finally, software design and programming, adopting the idea of modular structure to give the main program, sub-program of A / D interrupt service, capture interrupt sub-program and flow chart of PID fuzzy control sub-program. Using C language in CCS3.3 compiler environment to write the program and debug. The results show that the yarn constant tension control system can not only realize the accurately display and control of the yarn tension, but also has the advantages of high precision, over-current protection, good real-time performance and so on.