来源：http://www.jnmcd.com 发布时间：2019-04-10 浏览：次
动门的重量普通在数公斤到数十公斤之间，要想带动它们在导轨上灵敏工作，需求一个较大功率的步进电机。本文选用三相三线式混合式步进电机（57HS350B），其工作电压为24 V，电流为5.8 A，而MSP430单片机的最大灌电流为30 mA。由于单片机没有方法直接控制电机工作，需求驱动电路，因而驱动电路的性能决议了自动门的工作性能。采用分立元件搭建驱动电路，带动自动门工作。用MSP430单片机作为主控制器，静态工作电流小，合适长时间工作，搭建驱动电流，驱动步进电机工作，带动自动门运动，这是目前自动门控制中较为抢先的尝试，是本文的创新点。
The weight of the moving door is usually between several kilograms and tens of kilograms. In order to drive them to work sensitively on the guide rail, a high-power stepping motor is needed. In this paper, three-phase three-wire hybrid stepping motor (57HS350B) is selected. Its working voltage is 24 V, current is 5.8 A, and the maximum filling current of MSP430 single chip computer is 30 mA. Because SCM has no way to control the motor directly, the driving circuit is needed, so the performance of the driving circuit determines the performance of the automatic door. The drive circuit is constructed with discrete components to drive the automatic door to work. Using MSP430 MCU as the main controller, the static working current is small, suitable for a long time to work, build driving current, drive stepper motor to work, and drive the automatic door movement. This is a more preemptive attempt in automatic door control, which is the innovation of this paper.
1 Working Principle of Automatic Door
The automatic door system based on stepper motor consists of nine parts and the connection between them.
Automatic door motor
MSP430 MCU is the controller of the system and the central module of the whole system. It accepts the signals transmitted by manual door button, speed adjustment button, infrared sensor HZKT002 and stroke switch. After pyrolysis disposal, the detailed action commands are converted into corresponding output signals, which are transmitted to pulse distributor and converted into pulse signals that can control the stepping motor. No. 1, the pulse signal is sent to the drive circuit of discrete components. After amplification, the 57HS350B stepper motor is driven to act accordingly, which drives the flat-open automatic door to move on the guide rail. The limit position of the open and close guide rails of the automatic door is equipped with a stroke switch. After the automatic door moves to the limit position and touches the stroke switch, the stroke switch transmits the corresponding signal to MSP430 single chip. Machine.
The automatic door is divided into two working states: the sensor is self-opening when it works normally; when the sensor fails, it can control the opening and closing of the automatic door with the manual switch button.
红外感应器HZKT002是一个全自动式感应器，感应范围为0.5 m~7 m，能够依据需求本人调理感应范围。当人体进入感应范围后，输出高电平；当人体分开感应范围后输出低电平。其工作电流为微安级别，所以能够直接与单片机相连。
Infrared sensor HZKT002 is a fully automatic sensor, the induction range is 0.5 m~7 m, can adjust the induction range according to the demand. When the human body enters the induction range, it outputs high level; when the human body separates the induction range, it outputs low level. Its working current is micro-ampere level, so it can be directly connected with the single chip computer.
In the system, the speed adjustment button is set, which can adjust the speed of the automatic door manually according to different needs.
2 Step Motor Control Pulse Distribution Circuit
Stepping motor is a kind of actuator which converts electric pulse signal into linear or angular displacement. It can not be directly connected to AC/DC power supply. It is necessary to use special devices to convert DC power supply signal into electric pulse signal. The typical stepping motor control system is shown in Fig. 2. The controller can emit pulses with frequencies ranging from several hertz to tens of kilohertz, and the pulse frequencies can vary continuously. It provides the pulse sequence for the ring distributor. The main function of the ring distributor is to distribute the pulse sequence from the control link according to certain rules, and then add the amplification of the power amplifier to the input terminals of the driving power supply of the stepper motor to drive the rotation of the stepper motor.
There are two main types of circular distributors: one is to complete the function of circular distributor requests by means of computer software design, which is usually called soft-circular distributor; the other is circular distributor composed of hardware, which is usually called hard-circular distributor. The power amplifier mainly stops amplifying the small output signal of the ring distributor to achieve the purpose of driving the stepper motor. This system adopts a three-phase three-wire hybrid stepping motor (57HS350B). Because the soft ring distributor is unstable and vulnerable to external interference, the hard ring distributor is adopted in this system.
Three-phase stepper motor controller is a control system for hybrid three-phase stepper motor. It is mainly composed of instruction control module, pulse distribution module and power drive module. The pulse allocation module adopts the integrated chip SI-7600 of Sanken Company of Japan, which can distribute the input clock signal into six power driving modules of the post-pulse control stage to generate the working sequence of three-phase stepping motor. It can not only control the speed of the motor by changing the clock frequency of the chip, but also control the positive and negative rotation and persistence of the motor by simple logic signal. The built-in dead-time generator of the chip can effectively ensure that the two power chips in the same group will not be short-circuited instantaneously.