Stepper motor frequency control of motor speed

Although the stepper motor with strong ability,high precision,rapid start-up speed the characteristics of easy to control,but in the actual operation process due to improper start and stop control,select the appropriate size three-phase asynchronous motor power still started shaking and stops the phenomenon of overshoot,from surface affect the control precision of the system.Especially the work in the frequent start and stop a step motor,this kind of phenomenon is more obvious [2].This paper proposes a kind of stepping motor based on single chip microcomputer control discrete acceleration and deceleration control method.Ordinate is frequency f,the unit for pulse/SEC or

step/SEC.Abscissa time t,www.dongfeng-

motor.comthe unit is in seconds.Stepper motor to f0 accelerate starts to run time t1 the highest frequency f,and then run at a constant speed,to t2 time began to slow,in t5 moment motor

stalling,the total number of N.The motor from static accelerated to the highest operating frequency

and the highest operating frequency to stop to the is the key to the stepper motor control,usually

adopt uniform acceleration and deceleration mode.

Deceleration control of stepping motor by single chip microcomputer,in fact is to change the output pulse interval,software and hardware can be used two ways.Software methods rely on delay program to change the frequency of the pulse output,ac synchronous motor of which the length of the delay is dynamic,and the method because of the need to constantly produce control pulse,occupies a large amount of CPU time; Hardware methods depend on single chip microcomputer internal timer to achieve,after each into the timer interrupt,change the time constant of timer (load),a two-dimensional table as a controlled object by stepping motor drives the ball screw in the

X/Y direction linkage.This paper discusses a kind of a circular trajectory with minimal parameters of interpolation method and the method of step motor frequency control of motor speed.Stepping motor control system of the development of the hardware and software collaborative simulation method was adopted,the system development cycle and cost can be centrifugal pump greatly reduced by acc when the pulse frequency

increases gradually,slows down the pulse frequency decreases.How to identify qualified factory motor? This method takes up less CPU time,it is a kind of high efficiency of stepping motor speed control method.Considering the single chip microcomputer resources (word length) and programming is convenient,the timer does not need to be calculated every step loading value.As shown in figure 3,using the discrete method to deceleration curve discretization.Rising speed is points after discretization steps,and every rise a step in the steps to keep for a period of time,to overcome the stepper motor rotor velocity lag caused by the moment of inertia.Only when the actual speed reaches preset to accelerating,actually also automatically correct local velocity error.