Research On Sewing Machine System Based On AC Permanent Magnet Servo Motor

The rapid development of clothing industry has promoted the upgrades of the sewingequipments. Along with the development and application of power electronics technology,computer technology and control technology, the intelligent industrial sewing machine servosystem is increasingly favored by the market for its advantages of small size, high efficiency,accurate positioning and intelligent operation. On this basis, the research and development ofindustrial sewing machines AC servo system with independent intellectual property rights is ofgreat significance to Chinese sewing equipment industry.Based on the analysis of the system movement characteristics and the principle of vectorcontrol on AC permanent magnet synchronous motor (PMSM), the industrial sewing machine ACservo system based on PMSM is researched and designed in this thesis. The paper presents asystem designed with the MCU SH7125of Renesas SuperH series as its control core, and detailsthe function and implementation of the key parts.Referring to the hardware design, the MCU SH7125is selected as the main controllerand the intelligent power module IKCS12F602C for power drive. The control board circuit,power inverter circuit and auxiliary power supply is designed then. Besides, the reasonabledesign of filter circuit, isolating circuit and protective circuits has improved the reliability andstability of the system. Furthermore, the system also provides the control panel circuit forhuman-computer interaction and downloading of parameter.As for software, three-closed-loop, including position loop, speed loop and current loop, isdesigned to ensure the stability and accuracy of the system, based on Rotor Field Oriented Controlwith Id=0of PMSM. The current loop based on integral partition PI controller and the speed loopbased on intelligent PI controller are designed to improve the speed of the system's dynamicresponse. Besides, the system uses the accurate positioning method to achieve its preciselypositioning. C language is used in the software design based on modularized design method inorder to facilitate the debugging, maintenance and extension of the software system, whichrealizes the key algorithms and a variety of sewing patterns of the system.Finally, the thesis fulfills the design and assembly of the industrial sewing machine ACservo system. Automatic functions such as needle positioning, automatic trimmer, backtracking, and constant-stitch sewing are realized. Dozens of tunable parameters areprovided to improve performance and flexibility. The test results show that the system fullymeet the design requirements and has good performance.