步进电机驱动与变电流闭环控制

Stepping Motor Drive and Variable Current Closed Loop Control

现阶段步进电机大多采用开环控制,电流幅值恒定,导致电机发热严重,产生明显的振动问题。因此,设计了一种步进电机驱动的变电流闭环控制方式,给出了具体的控制方法和步骤。通过计算设定角度θref与其当前角度θr的差值来调节给定电流Ip,使得设定角度θref与其当前角度θr的差值始终维持在一定的范围内,从而达到电流闭环控制的效果。此外,根据实际操作情况引入一种滑模控制器,通过间接计算该步进电机的反电动势,优化消除步进电机电感计算与电流微分计算时可能产生的干扰因素,提高了闭环控制的可行性和精度。

At present,the stepper motor mostly adopts open-loop control,constant current amplitude,which makes the motor serious heating,obvious vibration and other problems and risks.In this paper,a variable current closed-loop control method driven by stepper motor is designed,and the specific control method and steps are given:by calculating the difference between the set angleθref and its current angleθr,the given current Ip is adjusted,so that the difference between the set angleθref and its current angleθr is always maintained within a certain range,so as to achieve the effect of current closed-loop control.According to the actual operation,a kind of sliding mode controller is introduced.By indirectly calculating the back EMF of the stepper motor,the possible interference factors in the calculation of inductance and current differential of the stepper motor are eliminated,and the feasibility and accuracy of the closed-loop control are improved.