Design Of Driver For Two-phase Hybrid Stepping Motor Based On DSP

This paper takes a two-phase hybrid stepping motor as the research object,due to its advantages of open-loop control,without feedback,simple structure,high positioning accuracy,the error does not accumulate and reliable work,it is more and more widely used in the field of industrial control,but the stepper motor with low frequency oscillation and high frequency torque decrease disadvantage restrict the scope of use of the stepper motor.Only taken the stepper motor,special drive and DC power supply as a system,the stepper motor can run normally,so the stepper motor drive system has a direct impact on the performance of the stepper motor.In this paper,the working principle and operating characteristics of the stepping motor are analyzed,and the mathematical model of the hybrid stepping motor is established.Aiming at the shortage of the stepper motor,based on various driving modes,this paper adopts a subdivision drive technology,designed a new form of stepper motor drive system,it is a kind of multi drive system can meet our 4 kinds of synchronization angle demand.According to the thought of modularization,this drive system has completed the design of hardware circuit and software system.The drive system's control chip is TMS320F2812 DSP produced by TI Company,through its EVA module to produce PWM wave to control the two-phase hybrid stepping motor.Meanwhile using DA analog-to-digital conversion module to complete the subdivision step angle.The power driving module designed in this paper using L6506 D and L298 P to drive stepper motor,the hardware includes power module,DSP minimum system,PWM module,current detection module,over-current protection and external input module.The software includes the main program,the capture interrupt service subroutine,the sine table generation program,the subdivision subroutine,the PWM generator and so on.Finally,the experimental platform was built,the function modules of the drive system were debugged and tested,and the running characteristic of the stepper motor under different fine fraction was analyzed.The experimental results verify the rationality of the design of the drive system,and show that the performance of the system is stable and can meet the requirements of the function.