A装配图
42BYG020步进电机的单片机细分驱动器设计
摘要
步进电机是一种通过电脉冲信号控制相绕组电流实现定角转动的机电元件，具有易于开环精确控制、无积累误差等优点，但由于受到自身制造工艺的限制，步距角一般较大且是固定的，步进分辨率低、缺乏灵活性、在低频运行时振动。
细分驱动技术是一种能有效改善步进电机低频特性和提高步进精度的驱动技术，在不改变电机内部参数的情况下，减小步距角、减小步进误差，即提高了分辨率和步距精度。细分后，驱动电流的变化幅度减小，故转子达到平衡位置时的过剩能量也减少；另一方面，控制信号的频率提高了N倍(细分数)，可远离转子的低频谐振频率。从而减弱了低频振荡问题。
细分控制的基本思想是在每次输入脉冲切换时，不像单拍或双拍那样将相绕组电流全部通入或切除，而只改变相应绕组中额定电流的一部分，这样步进电机的合成磁势也只旋转步距角的一部分，从而使转子每步运行角度也只是步距角的一部分。
本文主要通过对42BYG020步进电机进行性能指标、结构及其工作原理的分析，多种细分方式的比较，进而设计了基于AT89S51单片机控制的斩波恒流均匀细分驱动方案及实现技术，并对微步距角进行测量及修正，进而以实现消除步进电机的低频共振现象，减少振动，降低工作噪音等。
关键词：42BYG020；单片机；斩波恒流；细分驱动
Abstract
Stepper motor is an electrical component to achieve angle rotation through controllingwinding phase currentwith electrical pulse signal,which has the advantages of ease for precise control of open-loop and no accumulation of errors. However, due to the own limitations of manufacturing process of Stepper motor, step angle is generally larger and fixed, low in step resolution, lack of flexibility, andvibrating in the low-frequency operation.
Subdivision driving is a driving technologywhich can improve low-frequency characteristics and the stepper accuracy of stepper motors.It reduces the step angle and the stepping error in case of not changing the internal parameters of the motor,which means,it improves resolution and step precision.After subdivision, the range of driving currentwill reduce, so the excess energy is also reducedwhen the rotor reaches the balance position; On the other hand, the frequency of control signalwill increase N times(the number of subdivision),which can make the rotor far away from low-frequency resonant. Thus the problem of low frequency oscillation is reduced.
The basic idea of subdivision control is to change only a part of rated current inwinding phase currentwhen each input pulse switches, different from a single pulse or double pulse that makeswinding phase current go into or removewholly. As a result, synthesis magnetic potential of stepper motor only rotates a part of step angle, and so that each operation angle of the rotor is only a part of step angle.
By the analysis of performance indicators, the structure andworking principle of the stepper motor 42BYG020, aswell as comparison of avariety of sub-ways, this paper aims to put forward and introduce the program and technology realization of chopper constant-current uniform subdivision driving based on the control of single-chip microcomputer AT89S51, moreover, measure and the amend Micro-step angle, and then realize to eliminate the phenomenon of low-frequency resonance(concussion) of stepper motor, reduce thevibration and reducedworking noise, etc.
Keywords：42BYG020; Single-chip microcomputer; Chopper constant-current; Subdivision driven
目录
引言1
1绪论2
1.1 42BYG020步进电机的概述2
1.2 42BYG020步进电机的指标和参数2
1.2.1 42BYG020步进电机的指标2
1.2.2 42BYG020步进电机的参数3
1.3 42BYG020步进电机的工作原理4
2 42BYG020步进电机的细分驱动5
2.1步进电机的细分驱动技术5
2.2细分驱动的原理5
2.3 42BYG020步进电机细分电流6
2.3.1等电流细分驱动法7
2.3.2电流矢量恒幅均匀旋转法9
3驱动电路方案的比较和选择11
3.1单电压驱动方式11
3.2高低压驱动方式12
3.3脉宽调制法12
3.4斩波恒流电路13
4驱动电路的设计16
4.1基于单片机控制的电路框图的设计16
4.2控制电路中主要元器件的选择16
4.2.1单片机的选择16
4.2.2数模转换器（DAC）的选择19
4.2.3运算放大器、比较器的选择22
4.3驱动电路的设计23
5步进电机细分驱动的软件设计24
5.1系统软件总体结构24
5.2步进电机控制主程序设计24
5.3按键扫描程序的设计25
5.4步进电机细分驱动程序设计26
6细分步距角误差的拟合与修正29
6.1步距角测量装置的设计29
6.1.1圆光栅的选择29
6.1.2步进电机与圆光栅零点对位启动30
6.1.3步距角测量装置的设计30
6.2步进电机细分步距角的测量30
6.3步距角的拟合与修正31
6.4结果分析31
7结论33
谢辞34
参考文献35
附录36
齿轮零件图
方案示意图
减速器
流程图
支架
轴零件图
3设计所包含文件
4目录
1字数
2摘要
