Research On The Control System Of Yarn Guide Based On Linear Stepper Motor

In the current textile production machinery industry,the yarn guide structure of knitting machine is widely used servo motor to drive.This kind of mechanical transmission mode would have negative impact to the quality of the fabric when it use of this equipment for a long term because the wear and clearance of transmission mechanism would be appeared.Compared to rotary stepper motor,linear stepper motor,as the production of the innovative development of motor structure design,has improved in the traditional motor performance indicators such as positioning accuracy,speed of response.At present,there is no linear stepper motor be used in the yarn guide structure of knitting machine at home and abroad.The subject is try designing a linear stepper motor drive system,which is applied to the yarn guide mechanism of knitting machine and expect to achieve a new kind of transmission method of the yarn guide.Prior to the design of the project,the author has understand and analyzed the current situation of the controlling of yarn guide in China and abroad.On this basis,the paper has completed the following research work: analysising of the working principle of flat knitting machine and its yarn guide system;built the model of linear stepper motor and take its simulation;analysis the factors that causes the oscillation of stepping motor and their suppression method;enumerating the common methods of stepper motor driving,on the other hand,the SPWM subdivision driving method and hysteresis current control methods are simulated and compared,and the current hysteresis tracking control method was identified as the linear stepper motor in this paper;designed hardware and software of each module of the linear stepper motor drive system,completed the software and hardware debugging;finally,summarized the research work of this project and proposed an expectation to the further improving of the yarn guide controlling of linear step motor drive system.In the current market,the control method of the yarn guide used in the knitting machine can not make the yarn cross and exchange automatically,which leads to the low quality of the knitted fabric.In this paper,the linear stepper motor servo technology is applied to the knitting machine yarn nozzle,which can quickly improve the production efficiency of the three-dimensional fabric and complex weave pattern fabric,and reduce the production cost of knitted fabric.The control module selects STM32F103RBT6 MCU that based on ARM Cortex-M3 kernel as the main control chip of this drive system,through a combination debugging of hardware and software,the moving of linear stepper motor was achieved,and the running speed of the motor meets the requirements of yarn guide.This system has made a start to further study of the integration of linear stepper motor and the yarn guide control system in the future.