Arm And Linux-based Knitting Machine Control System Design

The flat knitting machine researched in this paper is a kind of highly automated weft knitting machine controlled by an embedded control system, and it is used mainly in fabrication of clothes in textile industry. China is a big country of textile industry, and knitting machines have great demand. There is a broad cross-market prospect of independent research and development.Based on the analysis of the structure and theory of flat knitting machine, a doable hardware design which has three components is proposed: main controller design, coprocessor design and drive circuit design. Main controller (ARM) is designed for knit control and human interface; the coprocessor (FPGA) implements the commands from ARM and controls the drive circuit; the drive circuit which provides hardware interfaces for FPGA is faced with the components of flat knitting machine.Based on the solution of the hardware system, a new-style doable software design is proposed. The software design is based on embedded Linux, and it includes four components: control algorithm of taker-in roller system, driver design, knit control program design and graphical user interface design. The roller system which is implemented by fuzzy control algorithm controls the taker-in's speed; the driver implements the communication of the ARM and FPGA; the knit control program controls the machine to finish the knitting by analyzing the input file; the graphical user interface is provided for the operators.At last the debug flow which includes hardware debug, software debug and the total system debug is discussed.Compared with congener products, the machine based on this design is more advanced, easier to be transplanted, be able to be placed in a network and it has quite low cost.