車電動助力轉(zhuǎn)向器電控單元(ECU)的研究__畢業(yè)設計論文

摘要
電動助力系統(tǒng)采用電動機提供助力，具有轉(zhuǎn)向力可變、路感良好、環(huán)保、耗能低和維修方便等優(yōu)點，充分體現(xiàn)出汽車向智能化發(fā)展、滿足未來安全性要求和環(huán)保要求的發(fā)展趨勢。
本文在深入學習電動助力系統(tǒng)工作原理的基礎上，設計了電動助力系統(tǒng)控制單元的硬件電路，研究了控制策略和算法，開發(fā)了相應的軟件程序，印制了電路板，在自行搭建的試驗平臺上進行了實驗驗證。具體工作內(nèi)容如下：
1. 研究了電動助力轉(zhuǎn)向系統(tǒng)的發(fā)展和系統(tǒng)的基本原理；
2. 在充分考慮滿足電動助力控制單元功能需求的基礎上，開發(fā)了一套基于單片機80C552的電機控制方案：利用電子執(zhí)行單元（ECU）實時采集信號，運用PWM技術實現(xiàn)對H橋和電動機進行電流閉環(huán)控制，并完成了硬件電路設計；
3. 在保證汽車的穩(wěn)定性和安全性條件下，通過深入研究助力控制、回正控制和阻尼控制策略，提出了基于PID的控制算法，開發(fā)了核心控制程序；
上述研究工作實現(xiàn)了電動助力系統(tǒng)低速輕便、高速穩(wěn)定的使用要求，為下一步的工程實用化奠定了先期技術基礎。

關鍵詞：電動機，PID，控制策略，PWM
 

Abstract
EPS is a kind of power steering system following the system of hydraulic, motor was adopted to offer power directly. EPS has many advantages such as adjusted power which is controlled by the automatically controlling unit，good way sense，environmental protection，low energy consumption, convenient maintenance. The development trend of intelligent vehicles, future security requirements and environmental requirements was fully represented by EPS.
In this thesis the Electronic Control Unit (ECU) and the software program of the ECU was designed, control strategies and algorithm were also studied based on the study of the operation principles of EPS. Following is the detailed process:
1. Basic components, working principle and mathematical model of Brushless DC Motor (BLDCM) were described in detail.
2. While the functions of ECU were considered, a scheme of motor control based on the high-performance microcontroller 80C552 was put forward and the ECU was designed. PWM technique was used to control H and closed loop motor current.
3. Three control strategies which are assisting mode return ability and damp mode to get a stable steering under various conditions was presented and discussed in this paper. And a control algorithm based on PID was proposed under the strategies.
The research above make the A/D acquisition program, speed signal acquisition program of the Electric power steering system come true, and t it laid a practical basis for the next preliminary technology.

Keywords: MOTOR; PID; Control Strategy; PWM
 

目錄
摘要 Ⅰ
Abstract Ⅱ
目錄 Ⅲ
第一章緒論 1
1.1電動助力轉(zhuǎn)向系統(tǒng) 1
1.1.1電動助力轉(zhuǎn)向系統(tǒng)的原理及發(fā)展 1
1.1.2 電動助力轉(zhuǎn)向系統(tǒng)控制單元 3
1.2國內(nèi)外研究現(xiàn)狀 4
1.3課題研究的目的和意義 6
1.4本文研究內(nèi)容 6
第二章助力特性和控制策略研究 8
2.1助力特性分析 8
2.1.1助力特性的概念 8
2.1.2助力特性曲線分類 9
2.2控制模式 10
2.2.1助力控制 11
2.2.2回正控制 12
2.3控制策略研究 13
2.3.1電機目標轉(zhuǎn)矩的控制策略 13
2.3.2助力電機的電流控制策略 14
2.3.3控制算法 14
2.4本章小結(jié) 16
第三章硬件控制系統(tǒng)設計 17
3.1 EPS控制系統(tǒng)的總體結(jié)構(gòu) 17
3.2 ECU的控制芯片 18
3.3電源電路和信號處理電路 19
3.3.1電源電路 19
3.3.2扭矩信號 20
3.3.3車速信號 21
3.4電機的控制電路和保護電路 21
3.4.1電動機的PWM調(diào)壓調(diào)速原理 22
3.4.2功率開關部件的選擇及其驅(qū)動電路 24
3.4.3電動機的保護電路 25
3.5故障診斷電路 26
3.6系統(tǒng)硬件的抗干擾性設計 27
3.7本章小結(jié) 27
第四章EPS控制軟件設計 28
4.1系統(tǒng)控制軟件概述 28
4.2 轉(zhuǎn)向盤轉(zhuǎn)矩信號采集子程序 29
4.3 車速信號的采集子程序 29
4.4 目標電流的確定 30
4.4.1 助力曲線與目標電流 30
4.4.2 助力特性曲線的確定 30
4.5 PWM 脈寬調(diào)制及電機控制 31
4.6 判斷轉(zhuǎn)向子程序 31
4.7 軟件濾波設計 31
4.8 本章小結(jié) 32
結(jié)論及展望 33
致謝 35
參考文獻 36
附錄 38