用虚拟细分法控制步进电机

Controlling stepper motor by virtual subsection method

针对步进电机控制中容易出现的问题,提出一种虚拟细分的方法,该方法既能够适应复杂的控制环境,又大大提高了控制精度。首先将电机的步进角平均分为N(其值根据精度要求确定)个固定细分步,以该量作为基本计算单位,提出控制策略,即按照定周期变步长(转速慢时)和变周期定步长(转速快时)两种方式进行控制;其次,根据匀加速、匀速和匀减速三种运行状态,采用运动学公式建立了数学模型,计算当前载波周期的角位移和转速,并根据转速确定下一载波周期的大小,根据转子的当前位置确定是否换相,从而实现全过程的控制;最后,通过应用实例证明,该方法在工程实践中是可行的,完全能够获得满足精度的步进参数。

A virtual subsection method is put forward aiming at the common problems in controlling of stepper motor. The method can not only be adaptable to complicated controlling environment, but also increase the controlling precision. Firstly, the stepping angel is divided averagely to N （determined by the precision requirement） fixed micro -steps, which is used as the basic unit. Then the controlling strategy is put forward, i. e. , con variable period, fixed trolling the motor according to both fixed period,variable step -length（worming） and step -length （speediness）. Secondly, according to the moving state of uniform accel- eration, uniform speed and uniformly - retarded motion, the mathematic model is built with kinematics formula, the angle displacement and rotating speed in the present period are calculated out. The value of the next period is obtained according to the rotating speed, and changing phase or not is determined according to the present position. Consequently, the total process controlling is realized. Practical examples proved that the method is feasible in engineering and can obtain stepper parameters with satisfied precision.