The Development Of Double Flat Knitting Machine Servo System Based On CANopen

With the development of the textile industry,the research of flat knitting machine with fully automatic function and high performance has become a hot spot at home and abroad,as the main executive body of the knitting machine servo system,its performance that was good or bad was directly related to the work efficiency of the flat knitting machine.This paper has designed a dual AC permanent magnet synchronous motor servo system with the function of CANopen for a special use of flat knitting machine,with STM32F407ZGT6 as the main controller,by using control method of vector control that was combined with space vector pulse width modulation,through the design of the system hardware circuit and software program,finally,two permanent magnet synchronous motors were used to realize the current,speed and position of the three closed-loop control respectively.First of all,Reading a lot of relevant data of AC servo system,by fully understand ing the AC permanent magnet synchronous model and control strategy,using Hall current sensor to detect the real-time current of stator,using incremental photoelectric encoder for detect rotor speed and position information,the strategy of vector control combined with the the space vetor pulse width modulation technique were used to generate PWM pulse for the drive of the motor inverter bridge power tube,so as to achieve the three closed-loop control of the motor.Secondly,the function of servo field bus CANopen in servo system is fully introduced and analyzed in this paper,and then the servo system hardware circuit and software program were designed according to the working performance and requirements of AC servo system.Hardware circuit mainly contained the minimum system circuit,CAN communication circuit,interface circuit of encoder,servo alarm circuit,servo control signal interface circuit,rectification circuit,three-phase inverter bridge circuit,stator current and DC bus voltage sampling circuit,switch power supply circuit.The design of software mainly includes C ANopen program,servo function program,system regulator,the current sampling,research on the key technology of the rotor speed and position calculation.Finally,three closed loop simulation of servo system was done to test and verify the rationality of the control system by using the MATLAB / Simulink.and the experiment platform of AC servo system was built,through the anaylsis of the experimental datum by using the CAN test software and an oscilloscope,the results showed that the design of the double knitting machine servo system can meet the design requirements of the servo system.