單片機控制直流電動機調速系統

電子機電論文編號:JD409字數:24813.頁數:58  

目  錄
摘  要 .....................................................................i
Abstract ...................................................................ii
目  錄 .....................................................................iii
1  緒論 .....................................................................1
1.1 序言 ....................................................................1
1.2 直流調速系統發展概況.....................................................1
1.3 單片機主流產品介紹.......................................................2
2  直流脈寬調速系統的理論研究................................................3
2.1 直流電動機的調速方案.....................................................3
2.2 直流電機PWM調速原理 .....................................................3
2.3 雙閉環可逆直流PWM調速系統原理............................................6
2.3.1 轉速、電流雙閉環調速系統的組成 ........................................6
2.3.2 穩態結構圖和靜特性.....................................................6
2.3.3 雙閉環脈寬調速系統的動態性能 ..........................................7
3 雙閉環可逆直流PWM調速系統的硬件設計 .......................................12
3.1 單片機的選擇.............................................................13
3.2 電流檢測電路 ............................................................15
3.2.1 AD574芯片及引腳功能簡介 ...............................................16
3.2.2 AD574的工作原理........................................................17
3.2.3 AD574與89C51單片機的接口電路 ..........................................17
3.3轉速測量電路 .............................................................18
3.3.1 M/T法測速原理 .........................................................18
3.3.2 8253可編程定時器/計數器芯片 ...........................................19
3.3.3 轉速測量硬件電路 ......................................................20
3.4 轉速設定/顯示電路 .......................................................21
3.4.1 8279可編程鍵盤、顯示接口芯片 ..........................................21
3.4.2 鍵盤/顯示接口電路 .....................................................23
3.5 PWM調制信號產生電路 .....................................................24
3.5.1 DAC1208內部結構與引腳功能 .............................................24
3.5.2 DAC1208與89C51單片機的接口 ............................................25
3.5.3 專用PWM集成電路芯片TL494 ..............................................26
3.5.4 TL494電路實現..........................................................27
3.6 直流電機PWM驅動電路 .....................................................28
3.6.1 LMD18200驅動電路原理...................................................28
3.6.2 專用直流電動機驅動芯片LMD18200 ........................................31
4 雙閉環可逆直流PWM調速系統的軟件設計 .......................................34
4.1 軟件的結構設計...........................................................34
4.2 主程序設計...............................................................36
4.3 電流調節器和轉速調節器的算法及軟件實現...................................37
全文總結.....................................................................41
致  謝 ......................................................................42
參考文獻 ....................................................................43
附  錄 ......................................................................44

摘      要 

本文介紹了一種基于單片機控制的PWM直流電機調速系統，系統以89C51單片機為核心,以小型直流電機為控制對象,實現雙閉環PI控制。系統包括轉速給定、轉速顯示、轉速檢測、電流檢測、PWM脈寬信號產生電路以及直流電機驅動電路。從直流調速系統原理出發，逐步建立了雙閉環直流PWM調速系統的數學模型，給出了該系統的詳細設計思路、軟硬件設計、電路結構和采用PI控制算法的控制程序流程。在芯片選擇方面，以89C51為控制核心，分別采用了AD574電流模/數轉換、8253轉速M/T法測量、8279轉速設定/顯示、DAC1208/TL494PWM波形產生、LDM18200電機驅動等芯片與一些外圍電路。該系統具有較好的控制精度,可以在中小功率直流電動機上廣泛應用。

關鍵詞: 單片機,直流電機,調速系統,PWM,雙閉環控制

Abstract

A kind of PWM direct current motor speeding control system by this paper is introduced based on Single-Chip Computer control.In this system, taking the single- chip computer89C51 as the core part and the small-type of DC motor as the control object.a double closed-loop PI control is implemented.This system consists of rotation setting,display and detection, current sensing, PWM pulse signals generator circuit and the DC drive circuit.Beginning with the theory of the DC timing system,this article has built up the maths model of the reversible DC-PWM timing system with a dual-converter and dual-closed-loop,Given the details of the system design, software and hardware design, circuit structure and control algorithms using the PI process control proce- dures. In the chip selection, to 89C51 for the control of the core,By using the AD574 current A/D converter, 8253 Speed M/T measurement, 8279 speed settings/Show, DAC1208/TL494PWM waveform generator, LDM18200 motor drive, such as chips and some external circuit.The system has better control accuracy, in small and medium-sized power on the wider use of DC motor.

Key  words: single-chip computer,DC motor, adjustment speed system, PWM,double closed-loop control