外文翻譯--液壓助力轉(zhuǎn)向系統(tǒng)（節(jié)選）

1、<p>　　中文3000單詞,2000單詞，1萬英文字符</p><p>　　本文來自于http://autospeed.com/cms/title_Electric-Power-Steering/A_110661/article.html</p><p>　　The conventional hydraulically-assisted power steering used

2、in most cars is soon to be replaced with electric power steering. Already, many manufacturers are using electronically controlled hydraulic systems, while some car manufacturers have recently introduced purely electric s

3、ystems to their vehicles. In addition to reducing engine loads, full electric power steering allows steering responsiveness to be automatically varied depending on speed, road conditions - and even the driver's abili

4、ty!</p><p>　　Traditional Hydraulic Power-Assisted Steering</p><p>　　Hydraulic Power Assisted Steering has been used in automotive applications for about 50 years. The systems use an engine-drive

5、n hydraulic pump, a control valve, steering cylinder and connecting hydraulic hoses. The pump is usually of a vane design with an integrated internal bypass. It is sized so that - even at idle rpm - it delivers enough oi

6、l flow to provide a suitable degree of power assistance.</p><p>　　The control valve uses a flexible torque-measuring device (such as a torsion bar, spiral spring or leaf spring) to convert the steering torqu

7、e into a small control movement. This movement is transferred to a valve that regulates fluid flow to the power assistance mechanism. In rack and pinion steering, a double-ended hydraulic ram mounted parallel to the rack

8、 (within the rack assembly) is used, while recirculating ball systems incorporate the mechanism into the steering box. Note that in the Nis</p><p>　　A major problem with simple conventional hydraulic steerin

9、g systems is that the assistance level is not reduced at high speeds, giving a lack of steering feel. American cars of the Fifties and Sixties were particularly well known for their feather-light steering effort during p

10、arking, a characteristic which resulted in extreme vagueness at high speeds. To overcome this problem, most conventional hydraulic steering systems of the last few decades have incorporated mechanisms that reduce steerin

11、g </p><p>　　commonly used as is that such a system can remain purely hydraulic, whereas using road speed as the control variable requires the use of an electronic system.</p><p>　　Electronically

12、-Controlled Hydraulic Steering</p><p>　　The introduction of electronic speedometers - and subsequently, full engine management - meant that an electronic road speed signal became available, allowing the wide

13、spread use of electronically-controlled hydraulic steering systems. These vary steering effort depending on road speed and also, in some cases, other factors as well.</p><p>　　A number of different hydraulic

14、 approaches to regulating steering assistance are used. These are:</p><p>　　Flow Control</p><p>　　A solenoid valve is located on the discharge port of the hydraulic pump. Electronic control is u

15、sed to control the solenoid valve opening, so regulating the fluid flow. The flow is reduced at high road speeds, reducing the degree of assistance provided.</p><p>　　Cylinder Bypass</p><p>　　A

16、solenoid valve and associated bypass line is located between the two chambers of the hydraulic cylinder, allowing the reduction of the pressure difference between them. The solenoid valve opening is controlled electronic

17、ally, its opening being greater at high road speeds. This reduces the degree of assistance that is provided.</p><p>　　Hydraulic Reaction Force</p><p>　　A hydraulic force is enabled that works ag

18、ainst the power assistance. As speed increases, the reaction force is increased. Since fluid flow to the power cylinder is not affected, the steering response rate can remain high without reductions occurring in feel.<

19、;/p><p>　　In their electronically-controlled hydraulic steering system, Hyundai use an ECU equipped with an 8-bit microprocessor. Two major inputs - vehicle speed and the speed of steering wheel movement - are

20、used. From these inputs, the ECU determines the driving condition and via a 3-dimensional look-up map, provides the appropriate current flow to a hydraulic solenoid valve.</p><p>　　Three different driving co

21、nditions are recognised:</p><p>　　Parking - maximum current is supplied to the solenoid valve, resulting in maximum steering assistance.</p><p>　　High Speed - minimum current is supplied to the

22、solenoid valve, resulting in minimum steering assistance.</p><p>　　Evasive Steering - a large and sudden steering input causes the ECU to supply a current to the solenoid proportional to the speed of the ste

23、ering input.</p><p>　　There are plenty of speed-sensitive hydraulic steering systems around. This diagram shows the layout of a Mazda MX6 system where the degree of assistance is based on road speed and stee

24、ring angle. (1) steering wheel; (2) steering shaft; (3) intermediate shaft; (4) steering</p><p>　　gear assembly; (5) pressure hose; (6) return hose; (7) oil pump; (8) solenoid valve; (9) ECU;</p><

25、;p>　　reserve tank; (11) steering angle sensor; (12) check connector.</p><p>　　Hybrid Hydraulic/Electric Power Steering Systems</p><p>　　Hybrid hydraulic steering systems use an electric motor

26、 to drive the hydraulic pump, rather than having the pump driven directly by the engine. This approach allows the steering effort to be easily controlled by varying the pump speed. Because flow can be better matched to a

27、ctual requirements, the power drain is reduced - fuel economy savings of up to 0.2 litres/100 km are possible.</p><p>　　The control approach that is taken can be of three types -</p><p>　　Drivin

28、g Mode - where driving conditions (such as city, country, highway, etc) are automatically judged with appropriate levels of assistance then provided.</p><p>　　Steering Wheel Input Mode- where the speed of th

29、e steering wheel movement is used to determine the degree of assistance required.</p><p>　　Steering Load Mode - where demand for power assistance is indicated by the counter-pressure of the hydraulic fluid,

30、sensed through variations in the motor current load.</p><p>　　The General Motors hybrid hydraulic steering system shown here uses Steering Load Mode to determine the actual steering loads and so the degree o

31、f assistance that needs to be provided. The 3-phase brushless DC motor (12) is supplied power by the Motor Power Circuit. The EHPS control provides a control signal to the Motor Power Circuit in response to input signals

32、 from</p><p>　　the motor angle sensor, motor current sensor and battery current sensor as well as operating system voltage. The temperature of the hydraulic fluid is also monitored.</p><p>　　Ele

33、ctric Power-Assisted Steering</p><p>　　Electric Power-Assisted Steering completely replaces the hydraulic system that previously has always been associated with power steering. Electric power steering system

34、s assist driver effort by the use of an electric motor which acts through a reversible gearbox and in some cases, also an electromagnetic clutch. An electronic control unit determines the degree of assistance that is ren

35、dered.</p><p>　　Electric power steering has some significant advantages over any form of conventional hydraulic steering, both for the owner of the car and its manufacturer. The reduction in engine load of a

36、n electric power steering system (it can be as low as 4 watts when the car is being driven in a straight line) means that the fuel economy of a car equipped with electric power steering is very similar to that of a car w

37、ith no form of power steering. Analyses provided by manufacturers of electric power steer</p><p>　　From a manufacturer's perspective, using electric power steering reduces assembly line time, allows the

38、easy software tuning of the steering assistance characteristics to suit a variety of cars (eg a sports car or a limousine - more on this in a minute), and has the potential to improve reliability - 53 per cent of all pow

39、er steering warranty claims are from pump and hose problems. Environmental gains are also possible from the decreased production and disposal of hydraulic fluid (worldwide, an </p><p>　　Depending on the loca

40、tion of the electric assist unit, the electric drive assistance can be transmitted to the steering mechanism by a number of means. These are:</p><p>　　So, How Good is Your Driving?</p><p>　　One

41、of the most interesting aspects of electric power steering is the ability that the manufacturer has to tune the system's responsiveness. As indicated earlier, this allows the easy software matching of a single electr

42、ic power steering to applications as diverse as a two-seater sports car or luxury sedan, but it also means that system responsiveness can be made to vary in different driving situations in the one car. When this approach

43、 is taken, the input by the driver of a certain amount of st</p><p>　　appropriate for the conditions, the steering assistance may be reduced or the steering input even actively resisted!</p><p>

44、　　As an indication of the far-reaching implications of this, Honda has very recently developed an electric power steering system that estimates the skill of the driver and provides steering assistance to match. In the Ho

45、nda system, a 'driver skill estimation device' is used, having inputs from:</p><p>　　a GPS system(!);</p><p>　　a vehicle speed sensor;</p><p>　　a steering sensor that provid

46、es information on steering angular speed, angular acceleration and torque input;</p><p>　　a brake pedal sensor that detects braking stroke, speed and force;</p><p>　　a throttle pedal sensor that

47、 detects accelerator stroke and speed;</p><p>　　a yaw rate sensor;</p><p>　　a road friction estimate input.</p><p>　　The road friction estimate is determined by the undertaking of a

48、n audio frequency analysis of the sound of the tyres on the road! From this it is determined whether the road is dry, wet, snowy, powdery snow or icy. (Note that while the GPS and yaw rate inputs are included in the Hond

49、a patent of the system, Honda state that the system can still work effectively without them.)</p><p>　　The 'driver skill estimation device' analyses the actual path taken by the vehicle and compares

50、this with a computed target trajectory. Using this and data on the vehicle wheelbase, the distance that the front and rear wheels are from the vehicle centre of gravity (and other factors), the system awards the driver a

51、n ability that varies on five levels from "very poor" to "very good". A very good driver is rewarded with very little steering force resistance (the driver gets what he or she asks for</p><

52、p>　　According to Honda, this allows the skilled driver to "positively control the turning behaviour of the vehicle so as to briskly manoeuvre the vehicle. Conversely, if the vehicle operator is not skilled, the c

53、ontrol system produces a reaction which prevents the vehicle operator from over-reacting to the vehicle response, and (so) stabilises the vehicle."</p><p>　　But you have to wonder what happens when a &#

54、39;very poor' driver suddenly needs to swerve around a child that runs out onto the road.... However, the Honda system does provide a very strong indication of the direction that electric power steering systems can b

55、e expected to follow in the future.</p><p>　　在大量車上使用傳統(tǒng)的液壓助力轉(zhuǎn)向系統(tǒng)很快將被電子控制轉(zhuǎn)向系統(tǒng)代替。很多汽車制造商已經(jīng)開始使用電控液壓助力轉(zhuǎn)向系統(tǒng)，另一些汽車制造商則引進(jìn)了純電動轉(zhuǎn)向系統(tǒng)應(yīng)用到了汽車上。為了減輕發(fā)動機負(fù)荷，全電控轉(zhuǎn)向系統(tǒng)可以使汽車自動隨車速，路面狀況甚至駕駛者的水平而自動調(diào)節(jié)最佳轉(zhuǎn)向狀態(tài)。</p><p>　　傳統(tǒng)的

56、液壓助力轉(zhuǎn)向系統(tǒng)</p><p>　　液壓助力轉(zhuǎn)向系統(tǒng)已經(jīng)被用于汽車達(dá)50年之久。系統(tǒng)使用一個以發(fā)動機驅(qū)動的液壓泵、一個控制閥，轉(zhuǎn)向液壓缸而且連接液壓油的油管。它被按規(guī)定尺寸制作以便－甚至在空閑狀態(tài)的轉(zhuǎn)/每分－它遞送充足的油流程提供一個的適當(dāng)程度的助力效果。</p><p>　　控制閥使用一個可調(diào)測量轉(zhuǎn)力矩的裝置 （像是一根扭矩把手，螺旋彈簧或者彈簧板）把傳遞轉(zhuǎn)力矩轉(zhuǎn)換成一次小的可控的運動

57、。這一次運動被轉(zhuǎn)換成液壓油提供助力的機構(gòu)。在架和齒輪組中，支架兩端被展開平行的液壓油路控制，當(dāng)再循環(huán)系統(tǒng)將機構(gòu)納入轉(zhuǎn)向器的時候。注意，在被顯示在這里的日產(chǎn)系統(tǒng)中，流動的油路與泵固定在了一起。</p><p>　　主要的簡單傳統(tǒng)的液壓轉(zhuǎn)向系統(tǒng)的問題是高速行駛時助力不能夠有效減小，給缺乏操縱感覺。五六十年代的美國汽車由于要達(dá)到高速時轉(zhuǎn)向穩(wěn)定的效果，因此在低速時就必須同樣提供的助力很小。要克服這一個問題，最近幾十年的大

58、部分傳統(tǒng)液壓助力轉(zhuǎn)向系統(tǒng)增加了一個機構(gòu)用來減少當(dāng)發(fā)動機轉(zhuǎn)速過高時的轉(zhuǎn)向助力。發(fā)動機轉(zhuǎn)速被引用的原因是這樣可以使系統(tǒng)仍然是一個純液壓的系統(tǒng)，而不至于增加電子系統(tǒng)的使用。</p><p><b>　　電控液壓助力轉(zhuǎn)向</b></p><p>　　電子速度計的運用以及后來的全引擎管理機制－意味著電子道路速度信號變成可得，允許電控液壓助力轉(zhuǎn)向系統(tǒng)的廣大使用。這些改變轉(zhuǎn)向狀況的

59、情況取決于道路速度以及一些其他因素。</p><p>　　一些不同的液壓助力方式被使用。這些是：</p><p><b>　　液體流動</b></p><p>　　一個螺線形電導(dǎo)管活閥位于水力泵的排放口之上。電子的控制被用來控制螺線形電導(dǎo)管閥打開，如此管理液壓油流動。流速在高速度時被減少，減少被提供的助力的程度。</p><

60、p><b>　　液壓缸旁路</b></p><p>　　一條螺線形閥門和固定于一起的旁路在液壓缸的這兩個腔之間，允許他們之間的壓力不同的減少。螺線形閥門的開關(guān)被電子控制，高速行駛時它的開口最大。這減少被提供的助力的程度。</p><p><b>　　液壓的反作用力</b></p><p>　　液壓的力量被能夠用來抵消

61、助力效果。如速度增加，反作用力量被增加。流動的液壓油流到液壓缸沒被影響，轉(zhuǎn)向反應(yīng)可以在不降低手感的情況下保持在較高的水平。在他們的電控液壓轉(zhuǎn)向系統(tǒng)中， Hyundai 使用被裝備一個 8 比特的微處理器作為ECU 。兩主要的輸入－車輛的速度和方向盤運動的速度－被采用。從這些輸入， ECU 決定了駕駛的情況并經(jīng)由3維的圖，提供適當(dāng)液壓油給一個水力的螺線形閥門。</p><p><b>　　三不同的駕駛狀況

62、：</b></p><p>　　停車－最大螺線形閥門，提供最大助力效果。</p><p>　　高速－最小螺線形電導(dǎo)管閥門開度，造成最小的助力效果。</p><p>　　緊急的轉(zhuǎn)向－大、突然的轉(zhuǎn)向輸入導(dǎo)致 ECU 對掌舵輸入的速度提供合適的轉(zhuǎn)向輸入。</p><p>　　液壓轉(zhuǎn)向系統(tǒng)有許多對速度敏感的部件。這一個圖表表示馬自達(dá)MX6

63、以行駛速度和轉(zhuǎn)向角度為參數(shù)的助力系統(tǒng) 。（1) 方向盤；（2) 轉(zhuǎn)向軸；（3) 中間軸；（4) 轉(zhuǎn)向齒輪組；（5) 壓力油管；（6)回油管；（7) 油泵；（8) 螺線形閥門；（9) ECU；（10) 后備缸；（11) 轉(zhuǎn)向角度轉(zhuǎn)動感應(yīng)器；（12) 聯(lián)軸器。</p><p>　　混合的液壓│電控轉(zhuǎn)向系統(tǒng)</p><p>　　混合液壓轉(zhuǎn)向系統(tǒng)使用一個電機馬達(dá)驅(qū)動液壓泵，而不是使用發(fā)動機帶動。這

64、方法讓轉(zhuǎn)向效果容易因泵的不同速度而受到控制。因為液壓油能更好地被分配到實際的需求，動力損失便被減小了。能量能節(jié)省達(dá) 0.2 公升每100 公里。</p><p>　　控制方法可能是有三類型的：</p><p>　　駕駛模態(tài)－駕駛狀況 （像是城市、國家，公路，及其他）自動地判斷并提供適度助力。</p><p>　　方向盤輸入模態(tài)－方向盤運動被用來決定助力的程度。<

65、;/p><p>　　轉(zhuǎn)向負(fù)荷模態(tài)－轉(zhuǎn)向助力可由液壓油壓力表示，在馬達(dá)的現(xiàn)在負(fù)載過程中被監(jiān)測。</p><p>　　這里這個普通混合式液壓轉(zhuǎn)向系統(tǒng)采用轉(zhuǎn)向負(fù)載模式來決定實際的轉(zhuǎn)向載荷由此便可以提供合適的轉(zhuǎn)向程度。第3階段無刷電機通過電機動力線圈提供動力。EHPS控制提供控制信號給電機線圈作為對來自于電機角度的輸入信號，電機感應(yīng)器和電池感受器的回應(yīng)。液壓油的溫度同樣被控制著。</p>

66、<p><b>　　電動助力轉(zhuǎn)向</b></p><p>　　電力協(xié)助的掌舵完全地以力量掌舵替換先前一直被聯(lián)合的水力的系統(tǒng)。電動轉(zhuǎn)向系統(tǒng)利用一種電機帶動可逆齒輪組和一個離合器工作。一個電控單位決定著助力的程度。</p><p>　　電動轉(zhuǎn)向系統(tǒng)比任何形式的傳統(tǒng)的液壓轉(zhuǎn)向系統(tǒng)都占優(yōu)勢，不僅對汽車的擁有者還有它的制造業(yè)商。電動轉(zhuǎn)向系統(tǒng)發(fā)動機負(fù)荷的減輕意味著燃油

67、的節(jié)省幾乎與沒有轉(zhuǎn)向系統(tǒng)的情況相當(dāng)。由電動轉(zhuǎn)向系統(tǒng)的制造商提供的分析指出與傳統(tǒng)的液壓轉(zhuǎn)向系統(tǒng)相比，電動轉(zhuǎn)向系統(tǒng)可以節(jié)省燃油4%-8%。系統(tǒng)脫離發(fā)動機而獨立工作也意味著轉(zhuǎn)向系統(tǒng)獨立工作不受影響。</p><p>　　從制造商的觀點，使用電力轉(zhuǎn)向系統(tǒng)減少生產(chǎn)裝配時間，允許運用簡易的軟件在不同的車上進(jìn)行調(diào)整（例如一輛跑車或者大轎車－更多的適用性工作在一分鐘內(nèi)便可解決）, 而且可以改善穩(wěn)定性－ 53% 的所有轉(zhuǎn)向系統(tǒng)保單

68、來至于液壓泵和液壓油管路的問題。液壓油的減少使用同時會降低環(huán)境的保護(hù)成本 （在全世界，被估計的四千萬公升液壓油在 1995 年在使用中) 而且可以減少不可循環(huán)使用的化學(xué)聚合物的使用。</p><p>　　根據(jù)電動轉(zhuǎn)向單元的固定位置不同，電動助力的傳遞方式可以有不同的路徑：</p><p>　　你的轉(zhuǎn)向系統(tǒng)有多好？</p><p>　　電動轉(zhuǎn)向系統(tǒng)最有趣的方面之一是制

69、造商需要調(diào)整系統(tǒng)的反應(yīng)能力。如前面指出的那樣，其適用性可以是一輛兩座位的跑車也需要是一樣的或者不同的奢侈私家轎車，但是它也意謂系統(tǒng)能夠在不同的駕駛狀況下做出變化的良好反應(yīng)能力。當(dāng)這樣的情況發(fā)生時，需要提供不同的助力效果。轉(zhuǎn)向助力需要根據(jù)實際情況減輕或者增強這種效果。</p><p>　　本田已經(jīng)非常最近發(fā)展電控轉(zhuǎn)向系統(tǒng)，提供與駕駛員駕駛技能匹配的助力效果。在本田系統(tǒng)中， " 駕駛員技能評估裝置 &quo

70、t; 被采用，有輸入信息來自：</p><p>　　一個全球定位系統(tǒng); </p><p>　　一輛車輛加速感應(yīng)器；</p><p>　　一個提供關(guān)于被輸入的轉(zhuǎn)向速度，有角的加速和轉(zhuǎn)力矩的轉(zhuǎn)向感應(yīng)器；</p><p>　　剎車踏板感應(yīng)器發(fā)現(xiàn)剎車動力、速度和力；</p><p><b>　　偏航率感應(yīng)器；<

71、/b></p><p><b>　　路面摩擦狀況輸入</b></p><p>　　道路摩擦評估由輪胎聲音頻率分析得出。由此，它決定是否道路是干、濕、以及是否是雪、粉末狀的雪或冰。（注意當(dāng)全球定位系統(tǒng)以及各種輸入都直接進(jìn)入時本田專利系統(tǒng)中的。及時沒有GPS仍然能夠良好工作。)</p><p>　　"駕駛員技能評估裝置 "

72、 采集信號與系統(tǒng)中的數(shù)據(jù)對比。運用汽車的數(shù)據(jù)庫，前后輪距離以及質(zhì)心位置。系統(tǒng)將駕駛員的技能分成五檔。好的駕駛員只需要很小的轉(zhuǎn)向助力（因為他懂得如何操作獲得更好的效果），水平比較差的的駕駛員會相反。</p><p>　　根據(jù)本田，這允許熟練的駕駛員到“為了要靈活的控制車輛，肯定其操控行為。相反地，如果車輛操作員不是很熟練，控制系統(tǒng)會預(yù)防車輛操作員的操縱反應(yīng)以防過度轉(zhuǎn)向等情況的發(fā)生，如此來穩(wěn)定車輛。”</p&g