Research Of Industrial Sewing Machine Servo Control System Based On Freescale DSC

With the development and application of new technologies, intelligent automatic industrial sewing machine is gradually replacing the traditional clutch-type sewing machine into the main sewing equipment. Based on the actual demand and Freescale Digital Signal Controller(DSC), a stable and reliable performance of industrial sewing machine servo control system has been designed.1. The PMSM is chosen as the drive motor of the system in the paper, it has the advantage of Simple structure, small size, light weight, low noise, low rotor inertia, /high efficiency and power factor, easy for heat dissipation and maintenance etc. it is increasingly widely used in industrial sewing machine servo system. The id=0 vector control strategy is adopted to decouple the stator current, SVPWM is adopted to reduce the energy loss during the switching and to improve the voltage utilization after the analysis of the structure and mathematical model of PMSM.2. Due to the frequent starting and stopping working characteristics of industrial sewing machine, in this paper three closed-loops control algorithm are designed which include position loop, speed loop, current loop to ensure the system obtain a performance of fast response and stability. The current loop based on PI control method, the speed control loop based on integral separation PID and precise control method of needle position are described in detail in this paper.3. The control system adopts the Freescale’s 16-bit high-performance chip MC56F8255 DSC as the main control chip, the third generation of Mitsubishi intelligent power module(IPM) PM30CSJ060 as the main power-driven devices, the main control circuit, power drive circuit, signal detection circuit, power supply circuit and the electromagnet drive circuit were designed, across to the reasonable design of protection circuit, isolation circuit and filter circuit design, the electromagnetic compatibility and anti-jamming capability of the hardware system are improved.4. The designed industrial sewing machine servo control system can realize stepless speed regulation and the automatic functions such as automatic needle positioning, automatic trimmer and wiper, backtracking, constant-stitch sewing, automatic presser lifting and so on. Hardware test, software test and speed response test are applied in the experimental platform, the results showed that stable output power supply, circuit board working properly, the output of the PWM waveform conform to the requirements of the need, the motor start-up time is less than 200 ms, braking time is less than 150 ms and motor run smoothly during operation, it can basicly meet the design needs.