摘 要

汽車電動(dòng)助力轉(zhuǎn)向系統(tǒng)(EPS)與傳統(tǒng)的機(jī)械、液壓助力轉(zhuǎn)向系統(tǒng)相比具有轉(zhuǎn)向靈敏、能耗低、與環(huán)境的兼容性好、成本低等優(yōu)點(diǎn)。目前，在很多高端車上都裝由EPS，因此，開發(fā)EPS具有很大的實(shí)際意義和商業(yè)價(jià)值。電動(dòng)助力轉(zhuǎn)向系統(tǒng)主要由控制部分、執(zhí)行部分和程序這三個(gè)部分組成，控制部分主要由信號(hào)采集電路、單片機(jī)和信號(hào)發(fā)送電路組成。其中單片機(jī)是控制部分的核心部件，信號(hào)采集電路采集到的轉(zhuǎn)矩和車速信號(hào)送單片機(jī)處理后，單片機(jī)再發(fā)出控制信號(hào)給信號(hào)發(fā)送電路，經(jīng)過驅(qū)動(dòng)電路驅(qū)動(dòng)電機(jī)轉(zhuǎn)動(dòng)。執(zhí)行部分主要由電機(jī)、減速機(jī)構(gòu)和電磁離合器的組成。它起著轉(zhuǎn)向輔助動(dòng)力的產(chǎn)生，傳遞和中斷的作用。而程序是助力控制方式的具體體現(xiàn)，它由控制方式和控制策略來決定。控制部分、程序、執(zhí)行部分相互組合就構(gòu)成了以一完整的汽車電動(dòng)助力轉(zhuǎn)向系統(tǒng)。經(jīng)過組建系統(tǒng)調(diào)試后，得出了我們所需要的助力特性曲線，經(jīng)過分析，采用的控制形式存在級(jí)變震動(dòng)，為了減小震動(dòng)的影響，必須增加助力曲線的數(shù)目以減小震動(dòng)幅度，但是幅度必須足夠的小，小到足以忽略頻率的影響。


關(guān)鍵詞：電動(dòng)助力轉(zhuǎn)向，單片機(jī)，助力曲線，直流電機(jī)，電機(jī)控制
















ABSTRACT

Electric power steering system (EPS) has the advantage of sensitive, low energy consumption and environmental compatibility, and low cost compared with the traditional mechanical and hydraulic power steering system. At present, in many high-end vehicles are installed by the EPS, therefore, the development of EPS has great practical significance and commercial value. EPS controlled by the controller, actuator and procedures. The controller controlled by the signal acquisition, SCM, and circuit sent signals. SCM is the core components of the system, signal acquisition circuit to the acquisition of torque and speed signals sent to deal with SCM. Then, SCM sent the control signals to the signal circuit, after, driving circuit driving motor rotation. Actuator controlled by motor, reducer, and electromagnetic clutch. It plays to the formation of auxiliary power, transmission and the role of interruption. The assistance program is a concrete manifestation of control. It is decided by the control strategies. Controller, procedures, operation each other are combination of a complete vehicle electric power steering system. After the system debugging, we need to come to the assistance of the curve. After analysis, there is a shocking when the speed changes from one state to another. In order to reduce the impact of shock, we need to increase the number of curve to reduce the rate shock, however, the rate must be small enough to neglect the impact of the frequency.


Key words： electric power steering, SCM, power curve , DC motor, motor control











目 錄

中文摘要 Ⅰ
ABSTRACT Ⅱ
緒論 1
1.1轉(zhuǎn)向系統(tǒng)的分類 1
1.2電動(dòng)助力轉(zhuǎn)向系統(tǒng)的發(fā)展現(xiàn)狀 2
1.3 EPS的分類 2
1.3.1轉(zhuǎn)向軸助力式 2
1.3.2轉(zhuǎn)向小齒輪助力式 2
1.3.3轉(zhuǎn)向齒條助力式 3
1.4 電動(dòng)助力轉(zhuǎn)向系統(tǒng)的優(yōu)點(diǎn) 3
1.5電動(dòng)助力轉(zhuǎn)向系統(tǒng)的工作原理 4
2.系統(tǒng)設(shè)計(jì) 5
2.1電動(dòng)助力轉(zhuǎn)向系統(tǒng)選型 5
2.2機(jī)械部分系統(tǒng)設(shè)計(jì) 5
2.2.1設(shè)計(jì)要求分析 5
2.2.2實(shí)現(xiàn)形式 5
2.3控制部分系統(tǒng)設(shè)計(jì) 7
2.4電動(dòng)轉(zhuǎn)向系統(tǒng)總體設(shè)計(jì) 7
3.主要零部件選型 9
3.1主要機(jī)械部件選型 9
3.1.1直流電機(jī)選型 9
3.1.2電磁離合器的選型 11
3.1.3 轉(zhuǎn)矩傳感器選型 12
3.2 主要控制芯片的選型 14
3.2.1 單片機(jī) 14
3.2.2數(shù)模D/A轉(zhuǎn)換器及模數(shù)A/D轉(zhuǎn)換器 15
3.2.3 鎖存器 17
3.2.4 STK6855電機(jī)控制芯片 18
3.2.5 TL494電機(jī)調(diào)速芯片 19
3.2.6LM224放大器 19
3.2.7場效應(yīng)管 20
3.2.8穩(wěn)壓芯片 20
3.2.9主要選購件列表 21
4．機(jī)械設(shè)計(jì)部分 22
4.1 減速機(jī)構(gòu)設(shè)計(jì) 22
4.1.1 減速器結(jié)構(gòu)設(shè)計(jì) 22
4.1.2 減速器齒輪齒圈設(shè)計(jì) 23
4.1.3 強(qiáng)度校核 26
4.2傳動(dòng)錐齒輪設(shè)計(jì) 31
4.2.1外形尺寸設(shè)計(jì) 31
4.2.2錐齒輪校核 33
5.電路設(shè)計(jì) 35
5.1信號(hào)采集及A/D電路設(shè)計(jì) 35
5.2信號(hào)發(fā)送及D/A電路設(shè)計(jì) 36
5.3電機(jī)正反轉(zhuǎn)電路設(shè)計(jì) 37
5.4 電磁離合器驅(qū)動(dòng)電路設(shè)計(jì) 39
5.5電源控制電路設(shè)計(jì) 40
5.6 總電路設(shè)計(jì) 40
6. 程序設(shè)計(jì) 42
6.1 電動(dòng)轉(zhuǎn)向系統(tǒng)的助力曲線 42
6.2程序的前期數(shù)學(xué)處理 43
6.3 程序框圖 46
6.4程序 48
6.5程序結(jié)果驗(yàn)證 54
6.6 助力曲線分析 58
參考文獻(xiàn) 59