Research And Development Of Control System Of The Circular Knitting Machine

With the continuous improvement of our living standard, there are more and more requirements and options for the various costume fabrics. The circular knitting machine which refers to the industry of computer, mechanical, electronic, control engineering and so on is one kind of the typical complex mechatronic product. The control methods of the traditional machine which based on SCM and the IPC are gradually unable to meet the market.Along with the rapid development of the technology in microelectronic and the frequency conversion field, this article has put forward a computer controlling system which takes PLC and ARM controller as the core for the upscale knitting equipment based on the analysis of the functions and controlling requirements of the whole machine.Also, some utility research has been done aiming at the rotation rate of the circular knitting machine, and the needle selector controlling system after studying the mechanical principle of the needle selector as well as the characteristic of the primary periphery device.The main research content is as follows:1. Has analyzed the mechanical system of the circular knitting machine, selected S7-200 PLC as the controller. Using the STEP7-Micro/WIN programming software to design the program of each kind of movement pattern for the machine while taking the advantage of the characteristic of the hardware.2. Building the mathematical model for the drive system of the circular knitting machine and modeling the rotation rate driving control system. Using the fuzzy PID to control the rotation rate control system. Researching the application of the encoder which is the main component of the machine.3. Have made the detailed analysis to the component of the computer jacquard circular knitting machine, elaborated the principle of needle selection and knitting, and researched the structure of the piezoelectric ceramic slice and the selecting mechanism. Designing the drive circuit to the needle selector with the STM32F103 RB master control chip and using the C language to write the drive program. Finally, some theoretical analysis and research has been done aiming at the synchronization of the needle selection movement of the circular knitting machine.4. Finally, the communication methods have been illustrated among the S7-200 PLC, MM440 converter and the ARM controller. The main researching content include the chosen of the communication protocol and method, the setup of the parameter and the design of the program.Comparing with the tradition control system which based on the SCM, the control system following this design scheme has the characteristics of high performance, high integration level and high stability. This product has the wide application scope and market.