畢 業(yè) 設 計（論 文）外 文 參 考 資 料 及 譯 文譯文題目： Advances in Automobile Engineering: Brake Assisted Differential Locking System 汽車工程研究進展：制動輔助差速鎖系統(tǒng) 學生姓名：專 業(yè)：所在學院：指導教師：1說明：要求學生結合畢業(yè)設計（論文）課題參閱一篇以上的外文資料，并翻譯至少一萬印刷符（或譯出 3千漢字）以上的譯文。譯文原則上要求打?。ㄈ缡謱?，一律用 400字方格稿紙書寫） ，連同學校提供的統(tǒng)一封面及英文原文裝訂，于畢業(yè)設計（論文）工作開始后 2周內完成，作為成績考核的一部分。2Abstract : “It takes 8,460 bolts to assemble an automobile, and one nut to scatter it all over the road.”Some of the biggest advances in the field of automotive technology in the past 10 years have come in the area of safety. Spurred by the improvements in the microprocessor speed, miniaturization, and software development, the automobile continues to evolve.In this new approach proposed, I am going to have an electronic and a pneumatic circuit to automatically control the traction of the vehicle.During ordinary conditions, when the vehicle is driven down a straight road, or if the difference between speeds of the two (rear) wheels is below a specified limit, no signal will be generated by the electronic circuit. This helps the vehicle negotiate the turns with better traction control as differential action is unaltered. But if the difference between speeds is beyond a specified limit, the signal will be generated by the electronic circuit which will actuate the pneumatic circuit. This causes gradual braking on the faster wheel until it gains traction. Hence, the wheels will never lose traction.Keywords : Differential locking，traction control，Limited slip differential，pneumatic braking.A: INTRODUCTIONAre you REALLY comfortable manoeuvring your vehicle through a muddy patch?In dry conditions, when there is plenty of traction, the amount of torque applied to the wheels is limited by the engine and gearing; in a low traction situation, such as when driving on ice, the amount of torque is limited to the greatest amount that will not cause a wheel to slip under those conditions. So, even though a car may be able to produce more torque, there needs to be enough traction to transmit that torque to the ground .As long as the tyre grips the road, providing a resistance to turning, the drive train forces the vehicle forward.Limitations of the Limited Slip Differential1:Heat dissipation leads to lube film breakage, metal-to-metal contact occurs.2:If the friction lining of the energized clutch is damaged, the whole assembly has to be dissembled.3:High quality lubrication required.4:Due to presence of large number of mechanical components, reliability is less.35:As the speed increases, noise of vehicle also increases.6:Complicated and costly.B: PROPOSED INNOVATION-BRAKE ASSISTED DIFFERENTIAL LOCKING SYSTEM (BADLS)In this new approach, there is an electronic and a pneumatic circuit to automatically control the traction of the vehicle. During the ordinary conditions, when the vehicle is driven down the straight road, or if the difference between the speeds of the two (rear) wheels is below a specified limit, no signal will be generated by the electronic circuit. This helps the vehicle negotiate the turns with better traction control, as the differential action is unaltered. But if the difference between the speeds is beyond a specified limit, the signal will be generated by the electronic circuit, which will actuate the pneumatic circuit. This causes gradual braking on the faster wheel until it gains traction. Hence, the wheels will never lose traction. The BADLS control module senses that a wheel is about to slip based on the input sensor data and in turn pulses the normally open inlet solenoid valve closed for that circuit. This allows fluid to enter the circuit. At the same time, the control module opens the normally closed solenoid valve for that circuit. This leads to the application of pneumatic pressure on the brake pads, leading to the artificial braking. Once the affected wheel returns to the same speed as the other wheel the control module returns both the valves to their respective normal positions releasing any residual pressure in the pneumatic circuit of theaffected brake. engine to the driven wheels and permitting relative velocity between the driven wheels. The control system includes two wheel velocity sensor, a comparator circuit and a control circuit. The wheel velocity sensor is configured to detect the angular velocity of the two driven wheels and to generate a signal. The comparator circuit is coupled to the wheel velocity sensor and is configured to compare the signals of the sensors and to generate a slip signal representative of the degree of slip of the driven wheels. The control circuit is coupled to the comparator circuit and to the brake assisted differential locking mechanism and is configured to generate control signals when a predetermined degree of slip occurs and to apply the control signals to the differential locking mechanism to limit relative velocity between the driven wheels.4C: PROPOSED ARCHITECTURE FORBRAKE ASSISTED DIFFERENTIAL LOCKING SYSTEMThe control circuit shown below in Fig.3 is configured to receive signals representative of vehicle operating parameters (condition of slipping of wheels) and to generate control signals corresponding to the desired state of the brake assisted differential locking mechanism for limiting relative velocity between two driven wheels. Sensors are associated with the rear wheels. Control logic executed by the control circuit in a continuously cycled routine determines the desired state of thedifferential locking mechanism based upon the operating parameters. The control circuit applies an appropriate control signal to the differential locking mechanism causing engagement or disengagement in accordance with the desiredAIR BRAKING SYSTEMIn the air brake's simplest form, called the straight air system, compressed air pushes on a piston in a cylinder. The piston is connected to a brake shoe, which can rub on the wheel, using the resulting friction to slow the train. The pressurized air comes from an air compressor and is circulated by a pneumatic line made up of pipes and hoses. In order to apply the braking force to the brake shoes, compressed air is used. An air brake system in general includes a compressor unit, air-reservoir tank, brake chamber and wheel mechanism. For maintaining adequate braking force at all times even when the engine is not running and air-reservoir tank is also necessary. To maintain air pressure, which is small air pump, is used.The compressor takes air from the atmosphere through the filter and the compressor air is sent to the reservoir through the unloader valve, which gets lifted at a predetermined reservoir pressure and relieves the compressor load. From the reservoir the air goes to the various accessories and also to the brake chambers also called the diaphragm units at each wheel, through the brake valve. The control of brake valve is with the driver who can control the intensity of breaking according to the requirements. The unloader valve in the air breaking system serves to regulate the line pressure.D: TESTING AND EVALUATION PARAMETERSThe system has been tested on a SAE BAJA test vehicle at the Automotive Research 5Association of India (ARAI), pune. This was done keeping in mind that this application would be really helpful for SAE BAJA teams who encounter conditions like slipping of wheels very often. Since vehicle slip is usually about 12-15% while turning, this microcontroller of the system has been designed to active at about 20% slip conditions and deactivates at about 5% slip. The system was tested successfully and the next step would be practical implementation in automobiles after some minor modification. The vehicle was jacked up on one wheel with the other wheel resting on ground surface .This was done to simulate the condition of maximum slipping. This condition will be present in actual conditions when vehicle is negotiating rocky terrain. The engine was started and accelerated. Due to one wheel being in air, the vehicle did not move forward and the jacked wheel rotated excessively. Now the solenoid was activated for the slipping wheel and artificial braking was provided. As a result the torque transmitting capacity of the wheels increases and consequently, the vehicle pulls over the rocks and gravel on the basis of the torque from the individual wheel.E： COST COMPARISION TABLEAs can be seen from the above table that this system ensures a reduction of more than 50% in the capital investment as compared to the already existing systems.Driveline torque is evenly distributed between the two rear drive axle shafts by the differential. When one tyre encounters a slippery spot on the road, it looses traction, resistance to rotation drops, and the wheel begins to spin. Because the resistance has dropped, the torque delivered to both the wheels changes. The wheel with good traction is no longer driven. If the vehicle is stationary in this condition, only the wheel over the slippery spot rotates. Hence the vehicle does not move. This situation places stress on differential gears. As the traction fewer wheels rotates at a very high speed, amount of heat generated increases rapidly, lube film breaks down, metal to metal contact occurs, and the parts are damaged. Now if the spinning wheel suddenly has traction, then the shock of the sudden traction can cause severe damage to the drive axle assembly.So presently how do we overcome these difficulties?To overcome these problems, differential manufacturers have developed the –Limited Slip Differential. In automotive applications, a limited slip differential (LSD) is a modified or derived type of differential gear arrangement that allows for some difference in rotational velocity of the output shafts, but does not allow the difference in speed to increase beyond a preset amount. In 6an automobile, such limited slip differentials are sometimes used in place of a standard differential, where they convey certain dynamic advantages, at the expense of greater complexity. The main advantage of a limited slip differential is found by considering the case of a standard (or “open“) differential where one wheel has no contact with the ground at all. In such a case, the contacting wheel will remain stationary, and the non-contacting wheel will rotate at twice its intended velocity – the torque transmitted will be equal at both wheels, but will not exceed the threshold of torque needed to move the vehicle, thus the vehicle will remain stationary. In everyday use on typical roads, such a situation is very unlikely, and so a normal differential suffices. For more demanding use however, such as driving off-road, or for high performance vehicles, such a state of affairs is undesirable, and the LSD can be employed to deal with it. By limiting the velocity difference between a pair of driven wheels, useful torque can be transmitted as long as there is some friction available on at least one of the wheels. The clutch type LSD responds to drive shaft torque. The more drive shaft input torque present, the harder the clutches are pressed together and thus the more closely the drive wheels are coupled to each other.Flowchart to explain working of the circuit shown in Fig 1 is given above in Fig 2 First flowchart shows working of normal breaking circuit and the latter shows the working when the badls circuit is working. During normal breaking condition solenoid valve 1 is in closed condition so air from master cylinder flows in main braking circuit bypassing the auxiliary circuit through solenoid valve 1 and thus normal breaking action is achieved. .In slipping condition microcontroller actuates normally closed solenoid valve and normally open solenoid valve 2 and thus artificial braking is applied to the required wheel.The BADLS Control moduleThe system is provided a control system, at least two driven wheels, a differential for transmitting power from the state. Wheel velocity sensor are configured to detect the velocity of the two rear wheels and to generate a wheel velocity signal given as an input to the micro controller. A comparator circuit of the micro controller is coupled to the wheel velocity sensors generate a slip signal representative of the degree of slip of the driven wheel. A control circuit is coupled to the comparator circuit and to the differential locking mechanism and configured to generate control signals when a predetermined degree of slip occurs and to apply the control signals to the differential locking mechanism to limit relative velocity between the driven wheels 7by applying artificial braking by actuating the solenoid valves. The control circuit is further configured to disengage the differential locking mechanism when the degree of slip decreases to a level below a predetermined threshold. Wheel velocity sensor is provided for each of the driven wheels, each of the wheel velocity sensors being configured to generate wheel velocity signals and to apply the wheel velocity signals to the comparator circuit, and wherein the control circuit is configured to generate control signals for limiting relative velocity between the driven wheels when slip of any driven wheel exceeds a predetermined threshold value.F: SPECIFICATIONS FOR ELECTRONIC COMPONENTSMICRO CONTROLLERANALOG TO DIGITAL CONVERTERSIGNAL CONDITIONER1．Transistor2．DiodeA.MICROCONTROLLERUSE IN BADLS: The microcontroller input is the speed of the two wheel speed sensors. The microcontroller obtains the difference in between the two speed sensor outputs and compares it with the maximum allowable variation. If the variation is beyond the stipulated value, it activates the solenoid valves, thus enabling the auxiliary circuit, avoiding any slipping of the wheels.B.SOLENOID VALVEUSE IN BADLS: They act as ON/OFF switches and control flow of pressurized air into the Auxiliary Circuit. TYPE:Spool Type8C.ANALOG TO DIGITAL CONVERTERUSE IN BADLS: the analog speed signal from the wheel speed sensors is converted into the digital format by the ADC which is supplied as the input to the microcontrollerG: ADVANTAGES1 Can be easily implemented in vehicles having pneumatic braking systems with slight modification.2 As electronic circuitry is used, response time, control and reliability are better than the existing systems.3 Low grade lubricants can be used as heat loss is reduced.4 Last but not the least; the system is economical and simple.H: LIMITATIONSThe overall efficiency depends on the combined efficiency of both the electronic as well as the pneumatic system.I: APPLICATIONSThe system can be successfully incorporated in vehicles having pneumatic/hydraulic braking system, with a view to provide improves traction. It can be put to use in especially All Terrain Vehicles (ATV) and vehicles operating in high altitude areas (vehicles for military application) where snow causes excessive loss of traction. This system ensures a reduction of more than 50% in the capital investment as compared to the already existing systems which ensures the cost effectiveness of the endeavour.9汽車工程研究進展：制動輔助差速鎖系統(tǒng)摘要：“組裝汽車需要 8460個螺栓，和一個螺母把它撒在生產(chǎn)線上。 ”在過去 10年汽車技術領域的一些最大的進步已經(jīng)來到了安全領域。在微處理器速度、小型化和軟件開發(fā)方面的進步促使汽車繼續(xù)發(fā)展。在這種新的方法，我將有一個電子和一個氣動電路，自動控制車輛的牽引。在正常情況下，當車輛被驅動下一條直道，或如果兩者的速度（后輪）的差異是低于規(guī)定的限制，沒有信號會產(chǎn)生的電子電路。這有助于車輛的轉彎與更好的牽引力控制的微分動作是不變的。但如果速度之間的差異超過某一限度，信號將由電子電路將驅動氣動電路產(chǎn)生。這會導致在更快的車輪制動，直到它獲得牽引力。因此，車輪永遠不會失去牽引力。關鍵詞：差速鎖，牽引控制，限滑差速器，氣動制動A：簡介你真的是舒適的操縱你的車輛通過泥濘的道路嗎？在干燥的條件下，當有足夠的牽引力，施加到車輪的轉矩的量是有限的，由發(fā)動機和齒輪，在低牽引力的情況，如在冰上行駛時，扭矩的量是有限的，不會導致車輪在這些條件下的最大金額。所以，即使一輛車可能會產(chǎn)生更多的扭矩，也需要有足夠的牽引力將扭矩傳遞給地面，只要輪胎在路面上，提供一個阻力來轉動，傳動系統(tǒng)會迫使車輛向前行駛。限滑差速器的局限性1：散熱導致潤滑油膜破裂，金屬與金屬接觸發(fā)生。2：如果通電離合器摩擦襯片損壞，整個組件都將被拆。3：高質量潤滑要求。4：由于是大量的機械部件，可靠性低。105：隨著車速的增加，車輛噪聲也隨之增大。6：復雜且昂貴。B：提出 innovation-brake輔助差速器鎖止系統(tǒng)（BADLS）在這種新的方法中，用一個電子和一個氣動電路，自動控制車輛的牽引。在一般情況下，當車輛在被驅動下的直道行駛，或如果兩者的速度之間的差異（后輪）是低于規(guī)定的限制，電子電路將沒有信號。這有助于車輛進行判斷轉向時有更好的牽引力控制。微分動作是不變的。但如果之間的速度差超過某一限度，電子電路將產(chǎn)生信號，這將驅動氣動回路。這會導致在更快的車輪上制動，直到它獲得牽引力。因此，車輪永遠不會失去牽引力。界線控制模塊在檢測到車輪由滑基于輸入的傳感器數(shù)據(jù)和反過來脈沖常開進水電磁閥的信號，將關閉電路。這時允許流體進入電路。同時，控制模塊為該電路打開常閉電磁閥。這導致了氣壓在剎車片上的制動，導致了人工制動。一旦車輪返回相同的速度，另一輪的控制模塊返回閥門各自的正常位置影響制動氣動回路釋放任何剩余壓力。發(fā)動機的驅動輪和允許相對速度之間的驅動輪。控制系統(tǒng)包括雙輪速度傳感器、比較器電路和控制電路。車輪速度傳感器被配置來檢測 2個驅動輪的角速度，并產(chǎn)生一個信號。比較器電路耦接于車輪速度傳感器，并配置成比較傳感器的信號，并產(chǎn)生滑差信號代表，該驅動輪的滑動程度?？刂齐娐否罱佑诒容^器電路和制動輔助差分鎖定機構，并配置為產(chǎn)生控制信號，當預定度發(fā)生滑移時，將控制信號應用于差動鎖定機構，以限制從動輪之間的相對速度。C：提出建筑 forbrake輔助微分鎖定系統(tǒng)控制電路如下圖配置為接收代表車輛運行參數(shù)信號（滑動輪子的條件）并產(chǎn)生相應的制動所需的狀態(tài)輔助鑒別限制兩驅動輪之間的相對速度的鎖定機構的控制信號。傳感器與后輪相關聯(lián)?？刂七壿媹?zhí)行的控制電路在一個不斷循環(huán)的程序確定微分鎖機制基于操作參數(shù)的理想狀態(tài)?？刂齐娐穼⒁粋€適當?shù)目刂菩盘枒糜谝鸾雍匣蛎撾x接觸的差動鎖定機構空氣制動系統(tǒng)在空氣制動器的最簡單的形式，稱為直的空氣系統(tǒng)，壓縮空氣推動活塞在汽缸。活11塞被連接到一個制動蹄上，它可以在車輪上摩擦，使用由此產(chǎn)生的摩擦來減緩列車。加壓的空氣來自空氣壓縮機，并由一個由管道和軟管組成的氣動管路散發(fā)。為了將制動力應用于制動鞋，使用了壓縮空氣。一般的空氣制動系統(tǒng)包括一個壓縮機組、空氣儲罐、制動室和輪機構。為了保持足夠的制動力，在任何時候，即使當發(fā)動機沒有運行，空氣儲罐也是必要的。保持空氣壓力，這是小空氣泵，是使用的。壓縮機把空氣從空氣通過過濾器和壓縮空氣通過卸荷閥送到水庫，使在預定的儲層壓力解除，減輕壓縮機的負荷。從水庫的空氣到各種配件，也對制動室也被稱為在每個車輪的隔膜單位，通過制動閥。制動閥的控制是可以控制的，可以根據(jù)要求控制強度的。在空氣制動系統(tǒng)的卸荷閥用于調節(jié)管路壓力。D：測試和評估參數(shù)該系統(tǒng)已在 SAE下測試車在印度汽車研究協(xié)會（協(xié)會） ，浦那的測試。這樣做，記住，這個應用程序將是非常有益的 SAE下車隊遇到像打滑的車輪經(jīng)常條件。由于車輛滑移通常是大約 12-15%而轉動，單片機系統(tǒng)的設計上已活躍在 20%左右滑移條件和失效在 5%左右滑。該系統(tǒng)被測試成功，下一步將是實際的實施在汽車后，一些輕微的修改。車輛被頂起一輪與其他輪擱在地面上。這樣做的目的是模擬最大滑移條件。這種情況將在實際情況下，當車輛正在談判巖石地形。發(fā)動機開始加速。由于一個輪子在空氣中，車輛沒有前進和頂輪過度轉動。現(xiàn)在的電磁閥被激活的滑動輪和人工制動。由于車輪的扭矩傳遞能力的增加，因此，車輛的基礎上的扭矩使單個車輪從巖石中出來。E：電子：成本比較從上面的表中可以看出，該系統(tǒng)將確保在與現(xiàn)有系統(tǒng)相比，資本投資減少了 50%以上。傳動系統(tǒng)扭矩均勻分布在兩個后輪驅動軸之間的差。當一個輪胎在路上遇到一個滑點，失去牽引，旋轉阻力下降，與輪開始旋轉。因為電阻已下降，扭矩傳遞給車輪的變化。具有良好牽引力的車輪不再被驅動。如果車輛在這種情況下是靜止的，只有車輪上的車輪轉動。因此車輛不動。這種情況下的應力差齒輪。由于牽引較少的車輪在一個非常高的速度旋轉，產(chǎn)生的熱量迅速增加，潤滑油膜破裂，金屬與金屬接觸發(fā)生，并損壞零件。如果旋轉的車輪突然有牽引力，那么突然的沖擊力會引起驅動橋總成嚴重損壞。12那么現(xiàn)在我們如何克服這些困難呢？為了克服這些問題，差分生產(chǎn)商已經(jīng)開發(fā)出了有限差分。在汽車應用中，一個限滑差速器（LSD）是一種改性或派生型差動齒輪裝置，允許在輸出軸的轉速差一些，但不在增長速度超過預定量的允許差。在汽車上，這種有限的滑動差速器有時用于一個標準差分的地方，在那里，它們傳遞某些動態(tài)的優(yōu)點，在更大的復雜性的費用?？紤]的情況下，一個標準的（或“開” ）差，一個車輪有沒有接觸地面的情況下，發(fā)現(xiàn)一個有限的滑移微分的主要優(yōu)點是。在這種情況下，接觸輪將保持靜止，和非接觸輪將以兩倍的速度旋轉，所傳遞的扭矩將是平等的兩個車輪，但不會超過所需車輛移動的閾值，從而車輛將保持平穩(wěn)。在日常生活中使用的典型的道路，這樣的情況是不太可能的，所以一個正常的差就夠了。更多的要求，然而，如駕駛越野車，或高性能車，這種狀態(tài)是不可取的，而 LSD可以用來對付它。通過限制一對驅動輪之間的速度差，有用的扭矩可以被傳輸，只要有一些摩擦可在至少一個車輪。離合器式 LSD對傳動軸扭矩。越來越多的驅動軸輸入扭矩，更難的離合器被壓在一起，從而更緊密的驅動輪彼此耦合。流程說明圖 1所示的電路工作在圖 2上面給出的第一個流程圖顯示正常分斷電路工作，后者顯示工作當 BADLS電路工作。在正常工況條件下電磁閥 1處于關閉狀態(tài)，所以空氣從主制動回路中流過主制動回路，通過電磁閥旁路輔助電路，從而達到正常的破斷動作 1。單片機驅動滑動條件。在常閉電磁閥和常開電磁閥 2，因此人工制動所需的輪。界線控制模塊該系統(tǒng)提供了一個控制系統(tǒng)，至少 2個驅動輪，用于發(fā)射功率從該狀態(tài)的差。輪速傳感器被配置來檢測 2個后輪的速度，并產(chǎn)生一個車輪速度信號，作為輸入到微控制器。一個比較器電路的微控制器被耦合到車輪速度傳感器產(chǎn)生的滑動信號代表的程度的從動輪?？刂齐娐否罱佑诒容^器電路和差動鎖定機構，并配置以產(chǎn)生控制信號，當一個預定的滑移發(fā)生并將控制信號應用于差動鎖定機構，通過應用人工制動驅動電磁閥來限制驅動輪之間的相對速度。控制電路還被配置為將差速器鎖止機構當滑移程度降低到低于預定的閾值水平。車輪速度傳感器為每一個驅動輪，被配置為產(chǎn)生車輪速度信號的輪速傳感器，并將車輪速度信號應用于比較器電路，其中控制電路被配置為產(chǎn)生控制信號的驅動輪之間的限制相對速度超過預定閾值時的驅動輪。F：電子元器件規(guī)格1．微控制器132．模數(shù)轉換器3．信號調理器1) 晶體管2) 二極管A.單片機使用的界線：單片機輸入的兩個車輪速度傳感器的速度。微控制器獲得的差異，兩者之間的速度傳感器輸出，并比較它與最大允許變化。如果這些變化超出了規(guī)定的值，則它會激活電磁閥，從而使輔助電路能夠避免車輪的滑動B.電磁閥使用的界線：他們作為開關和加壓空氣進入輔助電路控制流。類型：閥芯類型C.模數(shù)轉換器使用的界線：從車輪速度傳感器的模擬速度信號通過 ADC是提供作為單片機輸入轉換為數(shù)字格式G：優(yōu)勢①可以有氣動制動系統(tǒng)稍加改動車輛容易實現(xiàn)。②電子電路、響應時間、控制和可靠性均優(yōu)于現(xiàn)有的系統(tǒng)。③低級潤滑油可以減少熱損失。④最后但并非最不重要的；系統(tǒng)是經(jīng)濟的和簡單的。H：局限性整體效率取決于電子以及氣動系統(tǒng)的綜合效率。I：應用該系統(tǒng)可以成功地納入車輛有氣動/液壓制動系統(tǒng)，以提供改善牽引力。它可以派上用場，特別是全地形車（ATV）和車輛在高海拔地區(qū)運行（軍用車輛）大雪導致牽引過度流失。該系統(tǒng)確保減少 50%以上的資本投資相比，已經(jīng)存在的系統(tǒng)，以確保成本效益的努14力。