The Development Of The High Performance Computerized Falt Knitting Machine Control System Based On Arm

Computerized flat knitting machine is a mechatronic knitting machinery which combines the computer technology, automation technology and knitting technology suitable to weave cotton, linen, wool, cashmere and a variety of knitting yarns, has advantages like high-speed, high efficiency and high performance.Compared with foreign knitting machine products, the domestic knitting machine has issues such as low weaving efficiency, poor performance and poor stability. Especially in the circumstances of high speeds and small size fabric, the high-precision positioning of the handpiece has become a great problem which impedes company to produce at high-speed and high efficiency. Therefore, the study of high-precision positioning control method and development of high-performance computer knitting machine control system has practical significance for the promotion of enterprise development and improvement of the yield and quality.In this paper, the work done as follows:1. Summarizes the development status and trends of computerized flat knitting machine at home and abroad, introduces the mechanical structure of computerized flat knitting machines, weaving theory and production process, analyzes the function and performance requirements of the system, proposed a control scheme of computerized flat knitting machine which based on the architecture of ARM and three distributed control.2. For the issue of fast positioning of the handpiece, analyzes the features of dynamics of the handpiece movement, builds a mathematical model to find out the key factors of operating speed, handpiece weight, drive friction and so forth, based on the internal model principle, research the repetitive compensation control method, proposes a high-precision positioning algorithm of handpiece which based on repetitive compensation PID; for the high-precision positioning requirements, analyses the nonlinear, time-varying characteristics of the hanpiece, proposes a high-precision positioning control algorithms based on fuzzy CMAC. Simulation results verify the feasibility of the control algorithm.3. Completes a handpiece positioning control system, a DSP bottom-driven control system and a human-computer interaction real-time control system, including a ARM main control system circuit, a DSP bottom-driven control circuit, a servo system drive circuit and a head control system circuit etc; applies the state machine on the software programming of ARM and DSP, programs the human-computer interaction real-time control module of ARM, DSP bottom-driven servo system module, and handpiece control system layer module, enhances the reliability of the computerized flat knitting machine control system.4. Developes a prototype of computerized flat knitting machine control system, tests and analyses the system. The results show that the ARM-based computerized flat knitting machine control system achieves the automatic control function of selection of yarn and needle, density control and other movements, has the features of low cost, high reliability and accurate positioning, and can be applied in the small and medium-sized enterprises.