The Development Of Computer Flat Knitting Machine Control Software Based On Embedded Linux

With the continuous improvement of living standards, people's pursuit of knitwear is becoming hotter day by day; fashion, comfort and individuation of knitted garments has become a world trend, which requires a new demand of the flat knitting machine weaving. Computerized flat knitting machine is currently one of the most important models in sweater manufacturing industry. With machine controlled system as its core, the machine mainly functions in this way: by receiving a variety of control information from the analysis of pattern data file and synchronizing signals from the machine, it timely issues various control instructions so as to conduct all specific actions required in weaving to complete the weaving automatically.Based on the analysis of the structure and function of computerized flat knitting machine control system, this thesis proposed a solution to the system based on ARM9 processor and embedded Linux system. This program basically meets the requirements of controlling various functions of a computerized flat knitting machine.Computerized flat knitting machine hardware consists of three main components, the mainly control section, the knitting part based on the computerized flat knitting machine head and the CPLD control part. The mainly control section is controlled by the AT91SAM9261 processor, the main function is to send the control commands to the knitting part of the machine head through the CAN bus, on the other hand, it controls the CPLD part via bus. Controlled by the processor of STM32, the knitting part, executes the corresponding weaving actions by receiving instructions from the mainly control section; CPLD control part is responsible for the control of two servo motors and a stepper motor motion of flat knitting machine, meanwhile, it reads the main servo motor encoder feedback value, and detects various sensor input signals.The development of software controlled part in computerized flat knitting machine is conducted in the Linux environment; it mainly consists of four parts: CAN data transmission subroutine, subroutine of read CPLD, knitting control program and the SDL application. CAN is responsible for sending control commands to the machine head. Read and write subroutine of CPLD is responsible for coordinating the normal operation of across machine by reading the CPLD's registers; knitting control program is the main body of the software, it functions in the whole process from pattern data reading to flower pattern weaving; SDL application provides a humanized graphical user interface for knitting machine control software, which consists of the main interface, the interface of reading pattern data files and parameter setting interface and so on.