防抱死制動系統(tǒng)畢業(yè)論文外文翻譯
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1、附錄一 英文原文 Anti-lock braking system From Wikipedia, the free encyclopedia An anti-lock braking system (ABS) is a safety system that allows the wheels on a motor vehicle to continue interacting tractively with the road surface as directed by driver steering inputs while braking, preventing the wheel
2、s from locking up (that is, ceasing rotation) and therefore avoiding skidding. An ABS generally offers improved vehicle control and decreases stopping distances on dry and slippery surfaces for many drivers; however, on loose surfaces like gravel or snow-covered pavement, an ABS can significantly i
3、ncrease braking distance, although still improving vehicle control. Since initial widespread use in production cars, anti-lock braking systems have evolved considerably. Recent versions not only prevent wheel lock under braking, but also electronically control the front-to-rear brake bias. This fun
4、ction, depending on its specific capabilities and implementation, is known as electronic brakeforce distribution (EBD), traction control system, emergency brake assist, or electronic stability control (ESC). History Early systems The ABS was first developed for aircraft use in 1929 by the French
5、automobile and aircraft pioneer, Gabriel Voisin, as threshold braking on airplanes is nearly impossible. An early system was Dunlop's Maxaret system, which was introduced in the 1950s and is still in use on some aircraft models.These systems use a flywheel and valve attached to a hydraulic line that
6、 feeds the brake cylinders. The flywheel is attached to a drum that runs at the same speed as the wheel. In normal braking, the drum and flywheel should spin at the same speed. However, if a wheel were to slow down, then the drum would do the same, leaving the flywheel spinning at a faster rate. Thi
7、s causes the valve to open, allowing a small amount of brake fluid to bypass the master cylinder into a local reservoir, lowering the pressure on the cylinder and releasing the brakes. The use of the drum and flywheel meant the valve only opened when the wheel was turning. In testing, a 30% improvem
8、ent in braking performance was noted, because the pilots immediately applied full brakes instead of slowly increasing pressure in order to find the skid point. An additional benefit was the elimination of burned or burst tires. In 1958, a Royal Enfield Super Meteor motorcycle was used by the Road R
9、esearch Laboratory to test the Maxaret anti-lock brake. The experiments demonstrated that anti-lock brakes can be of great value to motorcycles, for which skidding is involved in a high proportion of accidents. Stopping distances were reduced in most of the tests compared with locked wheel braking,
10、particularly on slippery surfaces, in which the improvement could be as much as 30 percent. Enfield's technical director at the time, Tony Wilson-Jones, saw little future in the system, however, and it was not put into production by the company. A fully mechanical system saw limited automobile use
11、in the 1960s in the Ferguson P99 racing car, the Jensen FF, and the experimental all wheel drive Ford Zodiac, but saw no further use; the system proved expensive and unreliable in automobile use. Modern systems Chrysler, together with the Bendix Corporation, introduced a computerized, three-channe
12、l, four-sensor all-wheel ABS called "Sure Brake" for its 1971 Imperial.It was available for several years thereafter, functioned as intended, and proved reliable. In 1971, General Motors introduced the "Trackmaster" rear-wheel only ABS as an option on their Rear-wheel drive Cadillac models. In the s
13、ame year, Nissan offered an EAL (Electro Anti-lock System) as an option on the Nissan President, which became Japan's first electronic ABS. In 1988, BMW introduced the first motorcycle with an electronic-hydraulic ABS: the BMW K100. Honda followed suit in 1992 with the launch of its first motorcycl
14、e ABS on the ST1100 Pan European. In 2007, Suzuki launched its GSF1200SA (Bandit) with an ABS. In 2005, Harley-Davidson began offering ABS as an option for police bikes. In 2008, ABS became a factory-installed option on all Harley-Davidson Touring motorcycles and standard equipment on select models.
15、 Operation The anti-lock brake controller is also known as the CAB (Controller Anti-lock Brake). A typical ABS includes a central electronic control unit (ECU), four wheel speed sensors, and at least two hydraulic valves within the brake hydraulics. The ECU constantly monitors the rotational spe
16、ed of each wheel; if it detects a wheel rotating significantly slower than the others, a condition indicative of impending wheel lock, it actuates the valves to reduce hydraulic pressure to the brake at the affected wheel, thus reducing the braking force on that wheel; the wheel then turns faster. C
17、onversely, if the ECU detects a wheel turning significantly faster than the others, brake hydraulic pressure to the wheel is increased so the braking force is reapplied, slowing down the wheel. This process is repeated continuously and can be detected by the driver via brake pedal pulsation. Some an
18、ti-lock system can apply or release braking pressure 16 times per second. The ECU is programmed to disregard differences in wheel rotative speed below a critical threshold, because when the car is turning, the two wheels towards the center of the curve turn slower than the outer two. For this same
19、 reason, a differential is used in virtually all roadgoing vehicles. If a fault develops in any part of the ABS, a warning light will usually be illuminated on the vehicle instrument panel, and the ABS will be disabled until the fault is rectified. The modern ABS applies individual brake pressure
20、to all four wheels through a control system of hub-mounted sensors and a dedicated micro-controller. ABS is offered or comes standard on most road vehicles produced today and is the foundation for ESC systems, which are rapidly increasing in popularity due to the vast reduction in price of vehicle e
21、lectronics over the years. Modern electronic stability control (ESC or ESP) systems are an evolution of the ABS concept. Here, a minimum of two additional sensors are added to help the system work: these are a steering wheel angle sensor, and a gyroscopic sensor. The theory of operation is simple:
22、 when the gyroscopic sensor detects that the direction taken by the car does not coincide with what the steering wheel sensor reports, the ESC software will brake the necessary individual wheel(s) (up to three with the most sophisticated systems), so that the vehicle goes the way the driver intends.
23、 The steering wheel sensor also helps in the operation of Cornering Brake Control (CBC), since this will tell the ABS that wheels on the inside of the curve should brake more than wheels on the outside, and by how much. The ABS equipment may also be used to implement a traction control system(TCS)
24、on acceleration of the vehicle. If, when accelerating, the tire loses traction, the ABS controller can detect the situation and take suitable action so that traction is regained. More sophisticated versions of this can also control throttle levels and brakes simultaneously. Components There are fo
25、ur main components to an ABS: speed sensors, valves, a pump, and a controller. Speed sensors The anti-lock braking system needs some way of knowing when a wheel is about to lock up. The speed sensors, which are located at each wheel, or in some cases in the differential, provide this information
26、. Valves There is a valve in the brake line of each brake controlled by the ABS. On some systems, the valve has three positions: In position one, the valve is open; pressure from the master cylinder is passed right through to the brake. In position two, the valve blocks the line, isolating that
27、brake from the master cylinder. This prevents the pressure from rising further should the driver push the brake pedal harder. In position three, the valve releases some of the pressure from the brake. Pump Since the valve is able to release pressure from the brakes, there has to be some way to pu
28、t that pressure back. That is what the pump does; when a valve reduces the pressure in a line, the pump is there to get the pressure back up. Controller The controller is an ECU type unit in the car which receives information from each individual wheel speed sensor, in turn if a wheel loses tracti
29、on the signal is sent to the controller, the controller will then limit the brakeforce (EBD) and activate the ABS modulator which actuates the braking valves on and off. Use There are many different variations and control algorithms for use in an ABS. One of the simpler systems works as follows:
30、The controller monitors the speed sensors at all times. It is looking for decelerations in the wheel that are out of the ordinary. Right before a wheel locks up, it will experience a rapid deceleration. If left unchecked, the wheel would stop much more quickly than any car could. It might take a car
31、 five seconds to stop from 60?mph (96.6 km/h) under ideal conditions, but a wheel that locks up could stop spinning in less than a second. The ABS controller knows that such a rapid deceleration is impossible, so it reduces the pressure to that brake until it sees an acceleration, then it increases
32、 the pressure until it sees the deceleration again. It can do this very quickly, before the tire can actually significantly change speed. The result is that the tire slows down at the same rate as the car, with the brakes keeping the tires very near the point at which they will start to lock up. Thi
33、s gives the system maximum braking power. When the ABS system is in operation the driver will feel a pulsing in the brake pedal; this comes from the rapid opening and closing of the valves. This pulsing also tells the driver that the ABS has been triggered. Some ABS systems can cycle up to 16 times
34、 per second. Brake types Anti-lock braking systems use different schemes depending on the type of brakes in use. They can be differentiated by the number of channels: that is, how many valves that are individually controlled—and the number of speed sensors. Four-channel, four-sensor ABS This i
35、s the best scheme. There is a speed sensor on all four wheels and a separate valve for all four wheels. With this setup, the controller monitors each wheel individually to make sure it is achieving maximum braking force. Three-channel, three-sensor ABS This scheme, commonly found on pickup trucks
36、with four-wheel ABS, has a speed sensor and a valve for each of the front wheels, with one valve and one sensor for both rear wheels. The speed sensor for the rear wheels is located in the rear axle. This system provides individual control of the front wheels, so they can both achieve maximum braki
37、ng force. The rear wheels, however, are monitored together; they both have to start to lock up before the ABS will activate on the rear. With this system, it is possible that one of the rear wheels will lock during a stop, reducing brake effectiveness. One-channel, one-sensor ABS This system is co
38、mmonly found on pickup trucks with rear-wheel ABS. It has one valve, which controls both rear wheels, and one speed sensor, located in the rear axle. This system operates the same as the rear end of a three-channel system. The rear wheels are monitored together and they both have to start to lock up
39、 before the ABS kicks in. In this system it is also possible that one of the rear wheels will lock, reducing brake effectiveness. This system is easy to identify. Usually there will be one brake line going through a T-fitting to both rear wheels. Effectiveness A 2003 Australian study by Monash Uni
40、versity Accident Research Centre found that ABS: Reduced the risk of multiple vehicle crashes by 18 percent, Reduced the risk of run-off-road crashes by 35 percent. On high-traction surfaces such as bitumen, or concrete, many (though not all) ABS-equipped cars are able to attain braking distance
41、s better (i.e. shorter) than those that would be easily possible without the benefit of ABS. In real world conditions even an alert, skilled driver without ABS would find it difficult, even through the use of techniques like threshold braking, to match or improve on the performance of a typical driv
42、er with a modern ABS-equipped vehicle. ABS reduces chances of crashing, and/or the severity of impact. The recommended technique for non-expert drivers in an ABS-equipped car, in a typical full-braking emergency, is to press the brake pedal as firmly as possible and, where appropriate, to steer arou
43、nd obstructions. In such situations, ABS will significantly reduce the chances of a skid and subsequent loss of control. In gravel, sand and deep snow, ABS tends to increase braking distances. On these surfaces, locked wheels dig in and stop the vehicle more quickly. ABS prevents this from occurrin
44、g. Some ABS calibrations reduce this problem by slowing the cycling time, thus letting the wheels repeatedly briefly lock and unlock. Some vehicle manufacturers provide an "off-road" button to turn ABS function off. The primary benefit of ABS on such surfaces is to increase the ability of the driver
45、 to maintain control of the car rather than go into a skid, though loss of control remains more likely on soft surfaces like gravel or slippery surfaces like snow or ice. On a very slippery surface such as sheet ice or gravel, it is possible to lock multiple wheels at once, and this can defeat ABS (
46、which relies on comparing all four wheels, and detecting individual wheels skidding). Availability of ABS relieves most drivers from learning threshold braking. A June 1999 National Highway Traffic Safety Administration (NHTSA) study found that ABS increased stopping distances on loose gravel by an
47、 average of 22 percent. According to the NHTSA,"ABS works with your regular braking system by automatically pumping them. In vehicles not equipped with ABS, the driver has to manually pump the brakes to prevent wheel lockup. In vehicles equipped with ABS, your foot should remain firmly planted on t
48、he brake pedal, while ABS pumps the brakes for you so you can concentrate on steering to safety." When activated, some earlier ABS systems caused the brake pedal to pulse noticeably. As most drivers rarely or never brake hard enough to cause brake lock-up, and a significant number rarely bother to
49、read the car's manual, this may not be discovered until an emergency. When drivers do encounter an emergency that causes them to brake hard, and thus encounter this pulsing for the first time, many are believed to reduce pedal pressure, and thus lengthen braking distances, contributing to a higher l
50、evel of accidents than the superior emergency stopping capabilities of ABS would otherwise promise. Some manufacturers have therefore implemented a brake assist system that determines that the driver is attempting a "panic stop" (by detecting that the brake pedal was depressed very fast, unlike a no
51、rmal stop where the pedal pressure would usually be gradually increased, Some systems additionally monitor the rate at the accelerator was released) and the system automatically increases braking force where not enough pressure is applied. Hard or panic braking on bumpy surfaces, because of the bump
52、s causing the speed of the wheel(s) to become erratic may also trigger the ABS. Nevertheless, ABS significantly improves safety and control for drivers in most on-road situations. Anti-lock brakes are the subject of some experiments centred around risk compensation theory, which asserts that driver
53、s adapt to the safety benefit of ABS by driving more aggressively. In a Munich study, half a fleet of taxicabs was equipped with anti-lock brakes, while the other half had conventional brake systems. The crash rate was substantially the same for both types of cab, and Wilde concludes this was due to
54、 drivers of ABS-equipped cabs taking more risks, assuming that ABS would take care of them, while the non-ABS drivers drove more carefully since ABS would not be there to help in case of a dangerous situation.A similar study was carried out in Oslo, with similar results. References 1."Effectivenes
55、s of ABS and Vehicle Stability Control Systems" (PDF). Royal Automobile Club of Victoria. April 2004. Retrieved 2010-12-07.? 2."Classic Aviation Ads: Wheels Dunlop Maxaret 1957". A. 2010-07-20. Retrieved 2010-12-07.? 3."Non-Skid Braking". FLIGHT International. 30 October 1953. pp. 587–588. 4.Rey
56、nolds, Jim (1990). Best of British Bikes. Patrick Stephens Ltd. ISBN?1-85260-033-0.? 5."Chrysler Imperial Sure Brake system description". ImperialClub.org. 6."History". We Love Cadillacs. 7."1972 Cadillac Fleetwood History". MotorE. 8."Electro antilock system (installed in Nissan President)".
57、 240 Landmarks of Japanese Automotive Technology. Society of Automotive Engineers in Japan, Inc..? 9.KI4CY (2003-02-13). "Ram Glossary of abbreviations and terms". Dodgeram.org. Retrieved 2010-12-07.? 10. Nice, Karim. How "Anti-Lock Brakes Work". howstuffworks. Retrieved October 2, 2010. 11."ABS
58、Frequently Asked Questions". ABS Education Alliance. 2004-05-03. Retrieved 2009-10-22.? 12.NHTSA Light Vehicle Antilock Brake System Research Program Task 4: A Test Track Study of Light Vehicle ABS Performance Over a Broad Range of Surfaces and Maneuvers, Jan 1999 PDF 13.Gerald J. S. Wilde (1994).
59、 "7. Remedy by engineering?". Psyc.queensu.ca. Retrieved 2010-12-07. 注:本文出自“維基解密·自由百科全書” ,網(wǎng)址:http://en.wikipedia.org/wiki/Anti-lock_braking_system 附錄二 中文譯文 防抱死制動系統(tǒng) 防抱死制動系統(tǒng)(ABS)是一種在駕駛員采取緊急制動時使機(jī)動車車輪相對路面處于邊滾邊滑的狀態(tài),從而防止車輪抱死(即停止轉(zhuǎn)動)打滑的安全系統(tǒng)。 防抱死制動系統(tǒng)能夠幫助駕駛員提高在干燥和濕滑的路面上對車輪的控制和縮短制動距離。但是在松散碎石路面或者被雪
60、覆蓋的路面上,防抱死制動系統(tǒng)能使制動距離顯著增長,不過仍能提高對車輪的控制。 自從被廣泛使用在汽車生產(chǎn)上,防抱死制動系統(tǒng)有了很大的變化。最新型的防抱死制動系統(tǒng)不僅能夠在制動時防止車輪抱死,而且還能電子控制前、后輪的制動偏差。根據(jù)其特殊的功能和實施方式,這些功能被稱為電子制動力分配(EBD),牽引力控制系統(tǒng),緊急制動輔助或電子穩(wěn)定控制(ESC)。 一、防抱死制動系統(tǒng)(ABS)的發(fā)展歷程 1.早期的防抱死制動系統(tǒng) 防抱死制動系統(tǒng)(ABS)最早是由法國汽車和飛機(jī)的先驅(qū)加布里埃爾·佛伊辛(Gabriel Voisin)在1929年研制來供飛機(jī)使用的,但是用極限制動的法式來對一架飛機(jī)進(jìn)行制動幾
61、乎是不可能的。一個早期的防抱死制動系統(tǒng)是鄧祿普(Dunlop)的馬克塞里特(Maxaret)制動系統(tǒng),它是20世紀(jì)50年代發(fā)明的,至今還應(yīng)用在某些型號的飛機(jī)上。這種系統(tǒng)使用附有液壓連接線的飛輪和閥門與制動缸連接。飛輪與一個和車輪保持相同轉(zhuǎn)速的制動鼓連接。在正常制動時,制動鼓和飛輪以相同的速度轉(zhuǎn)動。但是,如果一個車輪轉(zhuǎn)速慢了下來,制動鼓的轉(zhuǎn)速也會慢下來,而飛輪則還在以原來的轉(zhuǎn)速快速轉(zhuǎn)動,這將導(dǎo)致閥門打開,允許少量的制動液由旁路繞過制動主缸流入儲液器,從而降低制動缸壓力,釋放制動器。制動鼓和飛輪的使用使得車輪只有在閥門打開時才會轉(zhuǎn)動。在測試中,為了便于找到滑行點,飛行員采取完全立即制動而不是緩慢增
62、加壓力來制動,這使得制動性能提高了30%。另外一個好處可以消除輪胎燒毀或爆炸的危險。 1958年,一輛皇家恩菲爾德超級摩托車被道路研究實驗室用來測試馬克塞里特(Maxaret)制動系統(tǒng)。實驗表明,防抱死制動系統(tǒng)應(yīng)用于摩托車上可以有很大價值,因為有很大部分的事故都與打滑有關(guān)。與車輪抱死的情況相比,在大多數(shù)實驗中,使用了這一系統(tǒng)的制動距離都減少了,特別是在濕滑路面上,其改善可高達(dá)百分之三十。恩菲爾德那時的技術(shù)總監(jiān)托尼·威爾遜-瓊斯(Tony Wilson-Jones)看到了這個系統(tǒng)沒什么前途,因此,它沒有被公司投入生產(chǎn)。 20世紀(jì)60年代,機(jī)械式防抱死制動系統(tǒng)在汽車上的使用還很有限,僅在弗格森
63、(Ferguson) P999賽車、杰森(Jensen) FF和測試版四輪驅(qū)動的福特十二生肖(Ford Zodiac)上使用,但以后卻沒有看到繼續(xù)使用。這一系統(tǒng)被證明不僅價格昂貴,而且使用在汽車上可靠性差。 2.現(xiàn)代防抱死制動系統(tǒng) 克萊斯勒(CHRYSLER)公司與本迪克斯(BENDIX)公司合作,共同開發(fā)了被稱為“萬無一失制動器(SURE-TRACK)”的具有電腦化控制、三通道、四傳感器的全輪防抱死制動系統(tǒng),并裝備于1971年的帝國(IMPERIAL)轎車。在這之后的許多年,它都按照期望的狀態(tài)運(yùn)作,并證明了其可靠性。1971年,通用汽車公司推出了賽道大師(Trackmaster)后輪
64、防抱死制動系統(tǒng)并將其作為其后輪驅(qū)動的凱迪拉克(Cadillac)車型的一個選配項目。同年,日產(chǎn)(Nissan)為日產(chǎn)總統(tǒng)(President)車型提供了一個選配項目——電控防抱死系統(tǒng)(EAL),這一系統(tǒng)是日本第一個電控防抱死制動系統(tǒng)。 1988年,寶馬(BMW)推出了第一款摩托車用電子液壓防抱死制動系統(tǒng):寶馬K100 。 本田(Honda)引入寶馬的技術(shù)于1992年推出了其第一款摩托車用防抱死制動系統(tǒng)并應(yīng)用于ST1100泛歐(Pan European)車型上。2007年,鈴木(Suzuki)推出了具有防抱死制動系統(tǒng)的GSF1200SA強(qiáng)盜(Bandit)車型。2005年,哈雷·戴維森(Ha
65、rley-Davidson)開始將防抱死制動系統(tǒng)作為警用摩托車的一個配置。2008年,防抱死制動系統(tǒng)的成為所有哈雷·戴維森旅行車型的工廠安裝選配項和一些選擇車型的標(biāo)準(zhǔn)配置。 二、防抱死制動系統(tǒng)工作原理 防抱死制動控制器被稱作CAB 。 一個典型的防抱死制動系統(tǒng)包括一個中央電子控制單元 (ECU),四個輪速傳感器和裝在制動回路上的至少兩個液壓閥構(gòu)成。電子控制單元不斷監(jiān)控每一個車輪的轉(zhuǎn)速,如果它檢測到某個車輪轉(zhuǎn)動的速度明顯比其它車輪低得多時(這個情況表示車輪即將緊急抱死),這時它將開啟液壓閥,以減少制動回路上的壓力,從而有效的減小作用在這個車輪上的制動力,使這個車輪轉(zhuǎn)速加快;相反地,如果電
66、子控制單元(ECU)檢測到某個車輪轉(zhuǎn)速比其它的速度明顯加快,作用在這個車輪上的液壓制動力將增加,增加的制動力使車輪轉(zhuǎn)速減慢。這個過程不斷重復(fù),由此產(chǎn)生了通過制動踏板可以感受到的極具特色的脈動。有些防抱死系統(tǒng),可每秒獲得或釋放制動壓力16次。 當(dāng)車輪轉(zhuǎn)速的差異值低于一個臨界值時,將會忽略這個差異,因為當(dāng)汽車轉(zhuǎn)彎時,相對轉(zhuǎn)彎曲線的中心,內(nèi)側(cè)兩個車輪轉(zhuǎn)速比外側(cè)兩個車輪轉(zhuǎn)速慢。出于這個原因,差速器被實際運(yùn)用于幾乎所有在路上行駛的車輛上。 如果故障發(fā)生在防抱死制動系統(tǒng)的某個部位上,在汽車儀表板上的警示燈通常會一直亮起,防抱死制動系統(tǒng)將被停用,直到故障被矯正。 現(xiàn)代的防抱死制動系統(tǒng)可以通過一個傳感器和專用微控制器系統(tǒng)單獨(dú)為每一個車輪提供制動壓力。目前,防抱死制動系統(tǒng)是大部分生產(chǎn)的車輛的標(biāo)準(zhǔn)配置,也是汽車電子穩(wěn)定控制系統(tǒng)(ESC)的基礎(chǔ),為了降低汽車電子產(chǎn)品的價格,這幾年汽車電子穩(wěn)定控制系統(tǒng)(ECS)正在迅速普及。 現(xiàn)代電子穩(wěn)定控制(ESC或ESP)系統(tǒng)是防抱死制動系統(tǒng)概念的一個演變。在這個系統(tǒng)中,至少增加兩個附加的傳感器來幫助系統(tǒng)工作:
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