摘要
在不外加传感器的情况下,对普通永磁有刷直流电机进行精确位置控制。电机两极的反电势信号与转速成正比,通过A/D采集此信号,并在ARM微处理器中采用PID算法,输出PWM信号控制电机转速。由于转子的惯性,可以使PWM控制与反电势测量交替进行,利用电机两根供电线,不增加额外导线,即可实现闭环控制。通过积分,还可得到位置信号,实现机械臂的位置控制。由LMD18200组成H桥,ADS7805进行A/D转换。这种方法在不显著增加成本的前提下,大大扩展了直流电机的应用范围,并在精度要求不是非常严格的领域,可以取代光电码盘,降低系统的复杂度和成本。
Implemented precise closed loop control for permanent magnetic DC motor without any sensor. The back-EMF signals from the two terminals of a motor are directly proportional to the speed the motor was running. These signals were collected through A/D converter and processed in ARM microcontroller with PID algorithm. Then the motor speed was controlled by PWM signal given by ARM. Because of the inertia of the rotator, it keeps spinning while a measurement was taken. We can use the power supply wires, without extra cables, to complete closed loop control. When the voltage was integrated over time, the position can be inferred as well. The LMD18200 from National Semiconductor. and ADS7805 from Burr-brown Company, were selected to implement the PID control, measure the back-EMF. This method greatly extended the application of DC motor, while reducing the cost.
出处
《微电机》
北大核心
2008年第9期54-57,77,共5页
Micromotors
