外文翻譯=汽車的轉(zhuǎn)向控制=4300字符

Spin control for cars Stability control systems are the latest in a string of technologies focusing on improved diriving safety. Such systems detect the initial phases of a skid and restore directional control in 40 milliseconds, seven times faster than the reaction time of the average human. They correct vehicle paths by adjusting engine torque or applying the left- or-right-side brakes, or both, as needed. The technology has already been applied to the Mercedes-Benz S600 coupe. Automatic stability systems can detect the onset of a skid and bring a fishtailing vehicle back on course even before its driver can react. Safety glass, seat belts, crumple zones, air bags, antilock brakes, traction control, and now stability control. The continuing progression of safety systems for cars has yielded yet another device designed to keep occupants from injury. Stability control systems help drivers recover from uncontrolled skids in curves, thus avoiding spinouts and accidents. Using computers and an array of sensors, a stability control system detects the onset of a skid and restores directional control more quickly than a human driver can. Every microsecond, the system takes a snapshot, calculating whether a car is going exactly in the direction it is being steered. If there is the slightest difference between where the driver is steering and where the vehicle is going, the system corrects its path in a split-second by adjusting engine torque and/or applying the cats left- or right-side brakes as needed. Typical reaction time is 40 milliseconds - seven times faster than that of the average human. A stability control system senses the drivers desired motion from the steering angle, the accelerator pedal position, and the brake pressure while determining the vehicles actual motion from the yaw rate (vehicle rotation about its vertical axis) and lateral acceleration, explained Anton van Zanten, project leader of the Robert Bosch engineering team. Van Zantens group and a team of engineers from Mercedes-Benz, led by project manager Armin Muller, developed the first fully effective stability control system, which regulates engine torque and wheel brake pressures using traction control components to minimize the difference between the desired and actual motion. Automotive safety experts believe that stability control systems will reduce the number of accidents, or at least the severity of damage. Safety statistics say that most of the deadly accidents in which a single car spins out (accounting for four percent of all deadly collisions) could be avoided using the new technology. The additional cost of the new systems are on the order of the increasingly popular antilock brake/traction control units now available for cars. The debut of stability control technology took place in Europe on the Mercedes-Benz S600 coupe this spring. Developed jointly during the past few years by Robert Bosch GmbH and Mercedes-Benz AG, both of Stuttgart, Germany, Vehicle Dynamics Control (VDC). in Bosch terminology, or the Electronic Stability Program (ESP), as Mercedes calls it, maintains vehicle stability in most driving situations. Bosch developed the system, and Mercedes-Benz integrated it into the vehicle. Mercedes engineers used the state-of-the-art Daimler-Benz virtual-reality driving simulator in Berlin to evaluate the system under extreme conditions, such as strong crosswinds. They then put the system through its paces on the slick ice of Lake Hornavan near Arjeplog, Sweden. Work is currently under way to adapt the technology to buses and large trucks, to avoid jack-knifing, for example. Bosch is not alone in developing such a safety system. ITT Automotive of Auburn Hills, Mich., introduced its Automotive Stability Management System (ASMS) in January at the 1995 North American International Auto Show in Detroit. ASMS is a quantum leap in the evolution of antilock brake systems, combining the best attributes of ABS and traction control into a total vehicle dynamics management system, said Timothy D. Leuliette, ITT Automotives president and chief executive officer. ASMS monitors what the vehicle controls indicate should be happening, compares that to what is actually happening, then works to compensate for the difference, said Johannes Graber, ASMS program manager at ITT Automotive Europe. ITTs system should begin appearing on vehicles worldwide near the end of the decade, according to Tom Mathues, director of engineering of Brake & Chassis Systems at ITT Automotive North America. Company engineers are now adapting the system to specific car models from six original equipment manufacturers. A less-sophisticated and less-effective Bosch stability control system already appears on the 1995 750iL and 850Ci V-12 models from Munich-based BMW AG. The BMW Dynamic Stability Control (DSC) system uses the same wheel-speed sensors as traction control and standard anti-lock brake (ABS) systems to recognize conditions that can destabilize a vehicle in curves and corners. To detect such potentially dangerous cornering situations, DSC measures differences in rotational speed between the two front wheels. The DSC system also adds a sensor for steering angle, Utilizes an existing one for vehicle velocity, and introduces its own software control elements in the over allantilock-brake/traction-control/stability-control system. The new Bosch and ITT Automotive stability control systems benefit from advanced technology developed for the aerospace industry. Just as in a supersonic fighter, the automotive stability control units use a sensor-based computer system to mediate between the human controller and the environment - in this case, the interface between tire and road. In addition, the system is built around a gyroscopelike sensor design used for missile guidance. BEYOND ABS AND TRACTION CONTROL Stability control is the logical extension of ABS and traction control, according to a Society of Automotive Engineers paper written by van Zanten and Bosch colleagues Rainer Erhardt and Georg Pfaff. Whereas ABS intervenes when wheel lock is imminent during braking, and traction control prevents wheel slippage when accelerating, stability control operates independently of the drivers actions even when the car is free-rolling. Depending on the particular driving situation, the system may activate an individual wheel brake or any combination of the four and adjust engine torque, stabilizing the car and severely reducing the danger of an uncontrolled skid. The new systems control the motion not only during full braking but also during partial braking, coasting, acceleration, and engine drag on the driven wheels, circumstances well beyond what ABS and traction control can handle. The idea behind the three active safety systems is the same: One wheel locking or slipping significantly decreases directional stability or makes steering a vehicle more difficult. If a car must brake on a low-friction surface, locking its wheels should be avoided to maintain stability and steerability. SPIN HANDLERS The new systems measure any tendency toward understeer (when a car responds slowly to steering changes), or over-steer (when the rear wheels try to swing around). If a car understeers and swerves off course when driven in a curve, the stability control system will correct the error by braking the inner (with respect to the curve) rear wheel. This enables the driver, as in the case of ABS, to approach the locking limit of the road-tire interface without losing control of the vehicle. The stability control system may reduce the vehicles drive momentum by throttling back the engine and/or by braking on individual wheels. Conversely, if the hteral stabilizing force on the rear axle is insufficient, the danger of oversteering may result in rear-end breakaway or spin-out. Here, the system acts as a stabilizer by applying the outer-front wheel brake. The influence of side slip angle on maneuverability, the Bosch researchers explained, shows that the sensitivity of the yaw moment on the vehicle, with respect to changes in the steering angle, decreases rapidly as the slip angle of the vehicle increases. Once the slip angle grows beyond a certain limit, the driver has a much harder time recovering by steering. On dry surfaces, maneuverability is lost at slip-angle values larger than approximately 10 degrees, and on packed snow at approximately 4 degrees. Most drivers have little experience recovering from skids. They arent aware of the coefficient of friction between the tires and the road and have no idea of their vehicles lateral stability margin. When the limit of adhesion is reached, the driver is usually caught by surprise and very often reacts in the wrong way, steering too much. Oversteering, ITTs Graber explained, causes the car to fishtail, throwing the vehicle even further out of control. ASMS sensors, he said, can quickly detect the beginning of a skid and momentarily activate the brakes at individual wheels to help return the vehicle to a stable line. It is important that stability control systems be user-friendly at the limit of adhesion - that is, to act predictably in a way similar to normal driving. The biggest advantage of stability control is its speed - it can respond immediately not only to skids but also to shifting vehicle conditions (such as changes in weight or tire wear) and road quality. Thus, the systems achieve optimum driving stability by changing the lateral stabilizing forces. For a stability control system to recognize the difference between what the driver wants (desired course) and the actual movement of the vehicle (actual course), current cars require an efficient set of sensors and a greater computer capacity for processing information. The Bosch VDC/ESP electronic control unit contains a conventional circuit board with two partly redundant microcontrollers using 48 kilobytes of ROM each. The 48-kB memory capacity is representative of the large amount of intelligence required to perform the design task, van Zanten said. ABS alone, he wrote in the SAE paper, would require one-quarter of this capacity, while ABS and traction control together require only one half of this software capacity. In addition to ABS and traction control systems and related sensors, VDC/ESP uses sensors for yaw rate, lateral acceleration, steering angle, and braking pressure as well as information on whether the car is accelerating, freely rolling, or braking. It obtains the necessary information on the current load condition of the engine from the engine controller. The steering-wheel angle sensor is based on a set of LED and photodiodes mounted in the steering wheel. A silicon-micromachine pressure sensor indicates the master cylinders braking pressure by measuring the brake fluid pressure in the brake circuit of the front wheels (and, therefore, the brake pressure induced by the driver). Determining the actual course of the vehicle is a more complicated task. Wheel speed signals, which are provided for antilock brakes/traction control by inductive wheel speed sensors, are required to derive longitudinal slip. For an exact analysis of possible movement, however, variables describing lateral motion are needed, so the system must be expanded with two additional sensors - yaw rate sensors and lateral acceleration sensors. A lateral accelerometer monitors the forces occurring in curves. This analog sensor operates according to a damped spring-mass mechanism, by which a linear Hall generator transforms the spring displacement into an electrical signal. The sensor must be very sensitive, with an operating range of plus or minus 1.4 g. YAW RATE GYRO At the heart of the latest stability control system type is the yaw rate sensor, which is similar in function to a gyroscope. The sensor measures the speed at which the car rotates about its vertical axis. This measuring principle originated in the aviation industry and was further developed by Bosch for large-scale vehicle production. The existing gyro market offers two widely different categories of devices: $6000 units for aerospace and navigation systems (supplied by firms such as GEC Marconi Avionics Ltd., of Rochester, Kent, U.K.) and $160 units for videocameras. Bosch chose a vibrating cylinder design that provides the highest performance at the lowest cost, according to the SAE paper. A large investment was necessary to develop this sensor so that it could withstand the extreme environmental conditions of automotive use. At the same time, the cost for the yaw rate sensor had to be reduced so that it would be sufficiently affordable for vehicle use. The yaw rate sensor has a complex internal structure centered around a small hollow steel cylinder that serves as the measuring element. The thin wall of the cylinder is excited with piezoelectric elements that vibrate at a frequency of 15 kilohertz. Four pairs of these piezo elements are arranged on the circumference of the cylinder, with paired elements positioned opposite each other. One of these pairs brings the open cylinder into resonance vibration by applying a sinusoidal voltage at its natural frequency to the transducers; another pair, which is displaced by 90 degrees, stabilizes the vibration. At both element pairs in between, so-called vibration nodes shift slightly depending on the rotation of the car about its vertical axis. If there is no yaw input, the vibration forms a standing wave. With a rate input, the positions of the nodes and antinodes move around the cylinder wall in the opposite direction to the direction of rotation (Coriolis acceleration). This slight shift serves as a measure for the yaw rate (angular velocity) of the car. Several drivers who have had hands-on experience with the new systems in slippery cornering conditions speak of their cars being suddenly nudged back onto the right track just before it seems that their back ends might break away. Some observers warn that stability controls might lure some drivers into overconfidence in low-friction driving situations, though they are in the minority. It may, however, be necessary to instruct drivers as to how to use the new capability properly. Recall that drivers had to learn not to pump antilock brake systems. Although little detail has been reported regarding next-generation active safety systems for future cars (beyond various types of costly radar proximity scanners and other similar systems), it is clear that accident-avoidance is the theme for automotive safety engineers. The most survivable accident is the one that never happens, said ITTs Graber. Stability control technology dovetails nicely with the tremendous strides that have been made to the physical structure and overall capabilities of the automobile. The next such safety system is expected to do the same. 汽車的轉(zhuǎn)向控制 控制系統(tǒng)穩(wěn)定性是針對(duì)提高駕駛安全性提出的一系列措施中最新的一個(gè)。這個(gè)系統(tǒng)能夠在 40 毫秒內(nèi)實(shí)現(xiàn)從制動(dòng)開(kāi)始到制動(dòng)恢復(fù)的過(guò)程，這個(gè)時(shí)間是人的反應(yīng)時(shí)間得七倍。他們通過(guò)調(diào)整汽車扭矩或者通過(guò)應(yīng)用汽車左側(cè)或右側(cè)制動(dòng)，如果需要甚至兩者兼用，來(lái)實(shí)現(xiàn)準(zhǔn)確的行車路線。這個(gè)系統(tǒng) 已被應(yīng)用于奔馳 S600 汽車了。 穩(wěn)定的機(jī)械自動(dòng)系統(tǒng)能夠在制動(dòng)時(shí)發(fā)現(xiàn)肇端，并且在駕駛?cè)藛T發(fā)現(xiàn)能夠反應(yīng)以前實(shí)現(xiàn)車輛的減速。 安全玻璃，安全帶，撞擊緩沖區(qū)，安全氣囊， ABS 系統(tǒng)，牽引力控制系統(tǒng)還有現(xiàn)在的穩(wěn)定調(diào)節(jié)系統(tǒng)。汽車安全系統(tǒng)的連續(xù)升級(jí)，已經(jīng)產(chǎn)生了一種為保護(hù)汽車所有者安全的設(shè)計(jì)模式。穩(wěn)定調(diào)節(jié)系統(tǒng)幫助駕駛員從不可控制的曲線制動(dòng)中解脫出來(lái)，從而避免了汽車的擺動(dòng)滑行和交通事故。 利用計(jì)算機(jī)和一系列傳感器，穩(wěn)定調(diào)節(jié)系統(tǒng)能夠檢測(cè)到制動(dòng)輪的打滑并且比人更快的恢復(fù)對(duì)汽車的方向控制。系統(tǒng)每百萬(wàn)分之一秒作出一次快速捕捉，以及斷斷汽車是否在按照駕駛員的路線行駛。如果檢測(cè)到汽車行駛路線和駕駛員駕駛路線存在一個(gè)微小的偏差 ，系統(tǒng)會(huì)在瞬間糾正發(fā)動(dòng)機(jī)扭矩或者應(yīng)用汽車左右制動(dòng)。過(guò)程的標(biāo)準(zhǔn)反應(yīng)時(shí)間是 40 毫秒 -人的平均反應(yīng)時(shí)間的七分之一。 羅伯特博世工程系統(tǒng)負(fù)責(zé)人安東范桑特解釋說(shuō)：“一個(gè)穩(wěn)定的控制系統(tǒng)能夠感覺(jué)到”駕駛員想要運(yùn)動(dòng)的方向，通過(guò)控制轉(zhuǎn)向角度，油門(mén)踏板的位置，制動(dòng)板的狀態(tài)來(lái)確定汽車實(shí)際運(yùn)動(dòng)路線的偏航比率（汽車偏離方向軸的角度）和橫向加速度”。項(xiàng)目負(fù)責(zé)人阿明馬勒領(lǐng)導(dǎo)著范桑特的工作小組和奔馳汽車公司的工程師發(fā)明了第一個(gè)完全有效的 穩(wěn)定調(diào)節(jié)系統(tǒng)，該系統(tǒng)由發(fā)動(dòng)機(jī)扭矩控制系統(tǒng)，制動(dòng)系統(tǒng)，牽引控制系統(tǒng)組成以實(shí)現(xiàn)理想與現(xiàn)實(shí)運(yùn)動(dòng)之間的最小差距。 汽車安全專家相信穩(wěn)定調(diào)節(jié)系統(tǒng)能夠減少交通事故的發(fā)生，至少是在傷亡嚴(yán)重的事故方面。安全統(tǒng)計(jì)表明，多數(shù)的單車撞擊事故傷亡（占傷亡事故發(fā)生的 4%），事故能夠通過(guò)應(yīng)用這項(xiàng)新技術(shù)避免。這項(xiàng)新系統(tǒng)的額外費(fèi)用主要用于一系列目前汽車日益普遍應(yīng)用的制動(dòng) /牽引控制鎖組件。 穩(wěn)定調(diào)節(jié)系統(tǒng)技術(shù)首次應(yīng)用于歐洲的奔馳 S600 汽車，是由德國(guó)斯圖加特市的羅伯特博世公司和奔馳公司在過(guò)去幾年共同研制的。該系統(tǒng)在博世公司被稱為汽車動(dòng)力控制（ VDC），而默西迪稱它為穩(wěn)定電控系統(tǒng)（ ESP），作用就是在任何狀況下維持車輛的穩(wěn)定性。博世公司開(kāi)發(fā)了這項(xiàng)系統(tǒng)，奔馳公司把它應(yīng)用于車輛。工程師默西迪絲在柏林應(yīng)用戴姆勒奔馳汽車虛擬駕駛模擬器在極限情況下對(duì)系統(tǒng)進(jìn)行評(píng)估，例如極強(qiáng)的側(cè)風(fēng)。然后他們?cè)谌鸬涞陌步芷談诟浇暮竽韧甙埠谋嫔线M(jìn)行性能測(cè)試。工作通常是在公路上進(jìn)行以適用于公共汽車和大卡車，例如避免的折合問(wèn)題。 穩(wěn)定調(diào)節(jié)系統(tǒng)將在 1995 年中應(yīng)用于歐洲 S 系列產(chǎn)品上，隨后會(huì)在 1996 年進(jìn)入美國(guó)市場(chǎng)（ 1995 年 11 月產(chǎn)品）。用戶可以選擇 750 美元的系統(tǒng)，就像應(yīng)用于梅 賽德斯的試驗(yàn)用的 V8 發(fā)動(dòng)機(jī)上的，也可以選擇價(jià)格為 2400 美元的應(yīng)用于六缸發(fā)動(dòng)機(jī)汽車的系統(tǒng)。后者的系統(tǒng)中差不多有 1650 美元是用于牽引控制系統(tǒng)，該系統(tǒng)是穩(wěn)定性系統(tǒng)的先決條件。 并不是只有博世公司一家在開(kāi)發(fā)這樣的安全系統(tǒng)，美國(guó)密歇根州的 ITT（美國(guó)國(guó)際電信公司）汽車公司的奧伯恩希爾，在 1995 年 1 月底特律北美國(guó)際汽車展覽會(huì)上展示了管理系統(tǒng)（ ASMS），“車輛控制器應(yīng)該像空對(duì)地導(dǎo)彈的控制器那樣，比較而言，事實(shí)上那已經(jīng)實(shí)現(xiàn)了，不同的是兩者的費(fèi)用不同”，美國(guó)國(guó)際電信公司駐歐洲空對(duì)地導(dǎo)彈控制工程負(fù)責(zé)人約翰尼斯格雷得 說(shuō)。北美 ITT 公司“汽車制動(dòng)和底盤(pán)工程”主管湯姆麥茲指出，在未來(lái)十年美國(guó)國(guó)際電信公司的系統(tǒng)要首先出現(xiàn)在車輛上。很多工程師正在六輛特殊制造的精密車輛模型上調(diào)試這種系統(tǒng)。 一個(gè)比較簡(jiǎn)單和較低效率的博世的穩(wěn)定調(diào)節(jié)系統(tǒng)也在 1995 年出現(xiàn)在慕尼黑寶馬公司的 AG 系列 750iL 和 850Ci V-12 兩款車上。寶馬公司的穩(wěn)定調(diào)節(jié)系統(tǒng)（ DSC）運(yùn)用的車輪速度傳感器同牽引控制系統(tǒng)和標(biāo)準(zhǔn) ABS 防抱死系統(tǒng)一樣能夠識(shí)別外部情況，使車輛更容易實(shí)現(xiàn)曲線行駛和轉(zhuǎn)彎。為了檢測(cè)出車輛轉(zhuǎn)彎時(shí)潛在的危險(xiǎn)， DSC系統(tǒng)檢測(cè)的是兩前輪在轉(zhuǎn)彎時(shí)的速度差 ， DSC 系統(tǒng)添加了一個(gè)更高級(jí)的角度傳感器利用現(xiàn)有的一個(gè)車輛速度，并且引入了它自身帶有的關(guān)于完全抱死系統(tǒng)，牽引控制系統(tǒng)，穩(wěn)定調(diào)節(jié)系統(tǒng)軟件控制原理。 新的博世和 ITT 自動(dòng)穩(wěn)定調(diào)節(jié)系統(tǒng)得益于航空工業(yè)高級(jí)技術(shù)的發(fā)展，就像超音速發(fā)動(dòng)機(jī)，汽車的穩(wěn)定調(diào)節(jié)單元運(yùn)用一個(gè)基于計(jì)算機(jī)系統(tǒng)的傳感器來(lái)調(diào)和人與系統(tǒng)之間的，還有輪胎與地面之間差異。另外，系統(tǒng)采用了用于導(dǎo)彈制導(dǎo)系統(tǒng)的回旋傳感器。 優(yōu)于 ABS 防抱死系統(tǒng)和牽引控制系統(tǒng)之處 根據(jù)范桑特和博世公司的瑞娜伊哈德，杰瑞帕夫在汽車工程師雜志所提到的，穩(wěn)定調(diào)節(jié)系統(tǒng)是 ABS 防抱死 系統(tǒng)和牽引控制系統(tǒng)的合理擴(kuò)展。但是 ABS系統(tǒng)的作用發(fā)生在制動(dòng)時(shí)車輪轉(zhuǎn)向?qū)⒈绘i死時(shí)，牽引控制是預(yù)防加速時(shí)的車輪滑動(dòng)，穩(wěn)定系統(tǒng)是當(dāng)汽車自由轉(zhuǎn)向時(shí)能獨(dú)立于駕駛員作出操作。依靠不同的駕駛狀況系統(tǒng)可以使每個(gè)車輪制動(dòng)或者迅速使四個(gè)輪轉(zhuǎn)速適合于發(fā)動(dòng)機(jī)的扭矩，從而使車輛穩(wěn)定和減少由于制動(dòng)失控帶來(lái)的危險(xiǎn)。新系統(tǒng)不僅僅控制完全制動(dòng)還可以作用與部分制動(dòng)，行車路線，加速度，車輪與發(fā)動(dòng)機(jī)動(dòng)作的滯后等，這些是 ABS 防抱死系統(tǒng)和牽引控制系統(tǒng)所遠(yuǎn)遠(yuǎn)不能達(dá)到的。 三種主動(dòng)的安全系統(tǒng)的作用時(shí)刻是一致的，那就是一個(gè)車輪被鎖死或者車輪漸漸失去方向 穩(wěn)定性或者車輪使得行駛更加困難。如果一輛車必須在較低摩擦系數(shù)的路面制動(dòng)，必須避免車輪抱死以保持行駛穩(wěn)定性和可駕駛性。 ABS 防抱死系統(tǒng)和牽引控制系統(tǒng)能夠預(yù)防側(cè)滑，而穩(wěn)定性系統(tǒng)采取減少側(cè)面受力的穩(wěn)定措施。如果行駛車輛的側(cè)力不再適當(dāng)?shù)姆峙湓谝粋€(gè)或者更多輪上，車輛就會(huì)失穩(wěn)，尤其是車輛沿曲線行駛時(shí)。駕駛員感覺(jué)到的“搖擺”起初是轉(zhuǎn)彎或者與車的軸線形成一個(gè)紡錘形時(shí)。一個(gè)獨(dú)立的傳感器必須能夠識(shí)別這個(gè)“紡錘”，而 ABS防抱死系統(tǒng)和牽引控制系統(tǒng)通過(guò)車輪的轉(zhuǎn)速不能檢測(cè)車輛的橫向運(yùn)動(dòng)。 轉(zhuǎn)向操作 新系統(tǒng)通過(guò)對(duì)微小的汽車不足轉(zhuǎn)向（當(dāng)車輛對(duì)于方向盤(pán)操作反應(yīng)遲緩）和方向盤(pán)的“過(guò)敏”反應(yīng)（后輪發(fā)生來(lái)回?cái)[動(dòng)）。當(dāng)車輛在轉(zhuǎn)向時(shí)如果發(fā)生不足轉(zhuǎn)向和過(guò)度轉(zhuǎn)向運(yùn)動(dòng)時(shí)，穩(wěn)定調(diào)節(jié)系統(tǒng)能夠通過(guò)后輪進(jìn)行內(nèi)部制動(dòng)（針對(duì)曲線）糾正錯(cuò)誤。這種情況是駕駛員不能感覺(jué)類似于 ABS 防抱死系統(tǒng)接近于抱死極限，