基于单片机控制的智能调速系统.doc

摘 要 随着现代科技的发展，基于单片机控制的智能调速系统已成为电机控制的主流。本设 计为一种永磁无刷直流电机(PMBLDC)的闭环调速系统。该系统采用美国ATMEL公司生产的 低功耗，高性能CMOS 8位单片机AT89S51单片机为控制核心，采用美国国家半导体公司(NS)推出的专用于直流 电动机驱动的H桥组件LMD18200。通过光电编码器来反馈BLDC的位置，在单片机中进行转 速运算，并通过PID计算子程序进行闭环计算，达到精确控制电机转速。通过键盘输入控 制BLDC的启停和正反转。单片机中的程序能产生PWM波形，通过光电耦合与LMD18200相连 。采用LMD18200的双极性驱动方式，通过单片机产生的PWM控制信号的占空比来决定BLD C的转速，利用光电编码器捕获到的电机转子位置采样信号进行转速计算，并设计一组4 位LED数码管显示瞬时转速。本设计的单片机智能控制器在BLDC的调速系统中有着广泛的 应用。 关键词：永磁无刷直流电机(PMBLDC)； 单片机； LMD18200； 脉宽调制(PWM)； 闭环PID控制。 Controller Design of Permanent Magnet Brushless DC Motor Abstract: With the development of the modern scienceand technology, the intelligent velocity modulation system, which is based on single-chip, has become the mainstream. The design was a closed-loop-speed-control system of a permanent magnet brushless DC motor, which core is a low power, high- performance CMOS 8-bit single-chip AT89S51 produced by the United States ATMEL company. H bridge LMD18200 which has been produced by the USA National Semiconductor Company(NS) and is good used to drive the DC motor was used. The DC motor's rotor location was feed back through a optical- elec encoder, and was conversed by the single-chip, and close-loop was calculated by the PID subroutine, so as to control the motor's speed exactly. The BLDC's starting and pause and positive-anti positive turning was controlled by inputting the keyboard. The programmer in the single-chip can produce the PWM wave, which through the optocoupler connected with LMD18200. The BLDC's speed was determined by the duty cycle of the PWM control signal, which was generated in the single-chip, and by using LMD18200's bipolar drive mode, and the speed signal can be calculated by using the sampling signal of the rotor location captured by the optical- elec encoder, and the instantaneous speed can be displayed by a group of four LED digital tube. This design intelligent speed control, which is based on the single-chip, has been widely used in the speed control system of the BLDC. Keywords: PM