AMT车辆自动变速技术的发展及国内现状1前言车辆的自动变速技术是车辆改进和完善传动系统的一个重要方向，从1939年带有液力变矩器的全自动传动系统问世以来，自动变速技术得到了长足的进步和发展，特别是近代微电子技术在车辆上的应用，使得自动变速技术在车辆上的应用越来越广泛。
自动变速技术在车辆上的应用主要有三种：AT(Automatic Transmission)传动系统、CVT(Con-tinuously Variable Transmission)传动系统、AMT(Automated Mechanical Transmission)传动系统。
AT传动系统是指液力变矩器+行星齿轮变速器组成的自动变速系统，这种变速系统诞生于20世纪30年代，经过60年的发展，其技术已十分成熟，目前占据着自动变速系统的主导地位。
AT在美国和日本有着较高的市场占有率，目前国产的自动变速车采用的都是AT传动系统。
AT传动系统简化了操纵、提高了舒适性和车辆平均速度以及行驶安全性和通过性，但是，它还存在传动效率低、结构复杂、制造困难、成本高等缺点。
无级传动CVT是驾驶简便、提高车辆燃料经济性的理想装置，但传动带的强度和寿命问题，以及传动带与带轮之间的滑磨等问题限制了CVT的传动效率，目前采用CVT产品的车型主要有：Nissan M6Hyper-CVT、Audi Multitronic CVT 等。
AMT传动系统是在原有有级固定轴式机械变速传动系统基础上增加自动变速操纵系统ASCS组成的。
AMT具有传统齿轮变速器传动效率高、成本低、易于制造等优点，同时也具有操纵方便的自动变速功能。
2AMT的原理AMT是在传统的固定轴式变速器和干式离合器的基础上，应用微电子驾驶和控制理论，以电子控制器(ECU)为核心，通过电动、液压或气动执行机构对选换档机构、离合器、油门进行操纵，来实现起步和换档的自动操作。
AMT的基本控制原理是：ECU根据驾驶员的操纵(油门踏板、制动踏板、转向盘、选档器的操纵)和车辆的运行状态(车速、发动机转速、变速器输入轴转速)，综合判断，确定驾驶员的意图以及路面情况，采用相应的控制规律，发出控制指令，借助于相应的执行机构，对车辆的动力传动系统进行联合操纵。
3AMT的发展AMT的发展大致分为2个阶段：单独控制阶段、整体控制阶段。
单独控制指AMT的控制对象只包括选换档机构、离合器、油门机构，其控制的策略只是实现起步，换档时的人工操纵的自动化；整体控制不仅实现人工操纵的自动化，而是对整个传动系统进行控制，以提高传动系统的性能和智能。
AMT的单独控制经历了3个阶段。
第一阶段是半自动AMT 的发展与成熟阶段。
早在六七十年代欧洲一些手动变速器生产厂家就已开始离合器自动化的研究，通过全机械或液压控制实现离合器的自动化，但这种系统的控制效果不好，没有太多的应用。
20世纪70年代中期，AMT的研究方向是半自动辅助换档系统。
车辆的换档时刻由驾驶员决定，由电子控制系统完成换档操作的功能。
瑞典Scania的CAG系统、德国Damler Benz的EPS系统采用的都是半自动AMT，驾驶员踩离合器确定换档时刻(电子显示器可提示驾驶员何时为最佳换档时刻)电子控制系统接受到换档指令后，控制执行机构实现换档操作。
同一时期，白俄罗斯工学院采用2参数换档规律由控制系统完成选档和换档时机的确定及其执行，但在起步时，仍由驾驶员操纵离合器以实现车辆的起步。
第二阶段是全自动AMT的发展。
从1981年底，五十铃公司和富士公司开始开发AMT，于1984年秋在世界上最先研制成功电子控制机械式有级全自动变速器NA VI-5装于ASKA轿车投放市场，该车已经能够实现车辆的起步、换档自动控制。
同期，日本的Nissan、瑞典的SAAB、美国的Ford、意大利的FIAT、德国的ZF、法国的Ranault都对全自动AMT进行了研究开发，研究的重点是离合器的起步控制、换档操纵规律，各大公司对全自动AMT的研究使全自动AMT进入了实用阶段。
第三阶段是AMT智能化的研究。
由于离合器的起步控制和换档操纵规律与外界道路环境情况、人的主观驾驶意图、车辆的运行状态密切相关，一般的控制策略易造成离合器的过快磨损、弯道意外换档等不良现象。
故采用模糊控制策略、神经网络控制策略等智能控制方法，以提高AMT传动系统的智能。
AMT的整体控制是在微电子技术在车辆上广泛采用的基础上产生的。
目前，电子产品在车辆上的应用已超过30％，电控发动机、电控自动变速、防抱死制动系统(ABS)、防侧滑(ASR)等相继在车辆上使用。
因此，将AMT的控制同发动机、ABS、ASR、ACCS(Autonomous Cruise Control System)的控制相结合，实现动力传动系统一体化控制，可提高传动系统的性能，优化控制效果。
美国伊顿公司的最新产品Autoshiff涵盖了6、7、10、18档变速器，与Caterpillar电控发动机相匹配，换档操作过程无需分离离合器，通过控制发动机及变速器内的制动装置对发动机转速进行调节，使换档主从件实现同步，完成换档操作。
由于采用AMT的车辆存在换档期间中断动力的缺点，将AMT与轮边电动机／发电机相结合，形成混合动力传动，换档期间电动机驱动车辆，车辆制动时发电机将机械能转换成电能储存起来，这种混合驱动方式可能是AMT技术发展的趋势。
4国内AMT的现状国内对AMT技术的研究开展的比较晚，九五期间被列为“九五”科技攻关项目。
目前，开展这方面研究的有吉林工业大学、北京理工大学、上海交通大学、深圳市欣源晟实业有限公司、哈尔滨埃姆特汽车电子有限公司、重庆东方欧翔汽车电子有限公司等。
国内的研制水平基本上处于AMT单独控制的第二阶段，和国外相比还存在着相当大的差距，但在理论上的研究和国际水平相当。
吉林工业大学对AMT理论进行了广泛的研究，先后提出了2参数最佳换档规律、动态3参数换档规律、最佳同步换档规律、动态闭环换档控制、离合器模糊起步控制等理论，并在轻型车、重型车、轿车等不同的车型上进行了装车实验。
北京理工大学对AMT的研究主要在重型车辆上，该校所研制的某装甲车AMT 产品已经进行了3000km定型试验考核，通过了产品设计定型。
该产品采用电控液压执行机构，能够完全进行自动换档操作，也可操作换档手柄进行人工换档，该产品还具有保持档功能、自学习功能。
原车的操纵机构仍然保留，在电控系统出现故障时，可以进行手动操纵。
深圳市欣源晟实业有限公司在轿车上实现了AMT自动换档，其执行机构为普通电机，由3个电机分别实现油门、离合器、选档、换档的操作动作，通过对传动机构的设计，选档和换档的操作只需一个电机就可完成，离合器的驱动机构采用省力装置，减小了驱动电机的功率。
由于国内车辆普遍装备固定轴式机械变速器，故在国内开展AMT技术研究大有前途，对手动机械变速器进行改造，实现车辆的自动换档，能够提升车辆档次。
目前国内生产的大部分轿车是从国外引进的，国内对这些轿车都没有独立的知识产权，外国厂商有可能不愿意采用国内的AMT技术来改造其手动传动系统。
因此，在国内自主生产的大客车、载货车辆等大型车辆上采用AMT技术，实现车辆的自动换档，具有广阔的前景。
作者：江铃股份公司全顺厂殷红幸北京理工大学董玉梁来源：《世界汽车》2002年第7期Title : A global market review of automotive transmissions - forecasts to 2012, 3rd edition (download)Price & Format :GB £2085 Multi-user Licence (pdf) FormatGB £695 Single-user Licence (pdf) FormatPublished :Nov 2004Description :This 3rd edition is the latest version of our hugely popularglobal transmissions forecast report. It represents the latest reporting andanalysis of transmissions technology, suppliers, integrators and OEMtransmission activity globally. We have also updated all JV/alliances, plusforecasts and manufacturer profiles have been completely overhauledsince the launch of our 2nd edition. You can also expect the same detailand depth of analysis from our transmissions expert Jeff Daniels (author ofthe 2nd edition).This report is your definitive guide to the world of automotive transmissions. It willgive you an incredible insight into:•Who is exploring which technologies, with which VMs and technologypartners•Explanations of IVT, CVT, AMT, dual clutch and innovative futuretechnologiesWill give you the following data:•Total vehicle market by region (inc cars, light trucks & LCVs) - to 2012•Manual transmission market shares and volumes - to 2012•Total manual transmissions - forecasts to 2012•Market shares & volumes (CVT) - to 2012•Market shares & volumes (AMT - including twin clutch) - to 2012•Market shares & volumes ("Innovative automatics") - to 2012Will show you what all the major players are doing - by transmission type:Conventional Automatics: Antonov, Audi, BMW, DaimlerChrysler, Fiat Auto,Ford, General Motors (GM), Honda, Mitsubishi, Nissan-JATCO, PSA, Renault,Toyota-Aisin AW, Volkswagen Group & ZFNew Automatics (CVT / IVT): Audi, BMW, Borg-Warner, Robert Bosch,DaimlerChrysler, Fiat Auto, Ford, General Motors, Honda, Nissan-JATCO, PSA,Renault, Ricardo, Subaru (Fuji Heavy Industry), Torotrak, Toyota-Aisin AW, Valeo, Volkswagen, Volvo & ZFNew additions for the 3rd edition:•Manual transmissions: future market prospects•Conventional automatic transmissions - future market prospects•Innovative transmissions - future market prospects•Electric traction effect on the transmission marketEnsure you keep your transmissions knowledge current with this unparalleled report.About the authorMultiple award-winner Jeff Daniels has been highly praised by his peers and readers on countless occasions. Amongst his accolades is the Pierre Dreyfus Award as UK Motoring Journalist of the Year in 2002. Despite numerous demanding clients, including The Economist Intelligence Unit, the Financial Times, Automotive Engineer, , European Automotive Design, Motor Industry Management, he continues to work as a journalist, translator and TV broadcaster.Extract from the report - Chapter 1 Automotive transmissions -present and futureRequirement: the need for transmissionBy definition, the transmission in a self-propelled vehicle is the system that transfers drive from the power unit output to the driven wheels. The power unit may take several forms, which create different transmission requirements. An electric motor can be brought to rest, and designed to provide substantial torque output from zero speed, which greatly simplifies the transmission requirement. However, the vast majority of vehicles are powered by internal combustion engines, and in this case the transmission has to compensate for the inherent drawbacks of the engine - including its need to remain running when the vehicle is stationary, and its low torque output except within a given speed range, typically 1,200-5,000rpm for a spark-ignition engine and 800-3,500rpm for a diesel. Some kind of clutching arrangement is therefore needed to enable the engine to continue running with the vehicle at standstill, and some form of gearbox is needed with a sufficient spread of input-to-output ratios to enable the engine's speed to be maintained within the useable torque range whatever the vehicle's speed. The clutch and gearbox assembly has itself become widely thought of as the "transmission", neglecting the many complexities that existbetween the gearbox output and the driven wheels.The greater part of this report sets out to deal with the transmission in this more restricted sense. It must still be borne in mind that significant engineering problems need to be overcome in the design of the final drive and differential unit, which provides a further gearing stage while dividing the input torque between the driven wheels, and in the design of the jointed propeller and/or drive shafts, which carry the drive to the wheels themselves.Overall solutionsFor the first half-century of the practical internal combustion engined road vehicle, there was only one form of transmission. This consisted of a friction clutch, operated by the driver via a pedal, and a gearbox in which various ratios could be selected by the driver, using some form of lever acting on the actual selector mechanism. By 1940 this arrangement had been brought to a level of development, mainly through improved clutch design and the introduction of synchromesh, which enabled vehicles to be driven without requiring any great strength or skill on the part of the driver. That development has continued, to the point where both the main components of a modern "manual" transmission - the clutch and the gearbox - are light and virtually foolproof in operation, with high durability unless they are consistently (accidentally or deliberately) mistreated.At the same time, from the early days of motoring, there was a desire to free the driver altogether from the task of manipulating the clutch and gearbox. Up to the 1930s many systems were tried, with fairly consistent lack of success. However, in 1940 General Motors began production and installation of the first Hydra-Matic automatic transmission, setting the pattern for most of the automatics in use today, with a fluid flywheel or torque converter taking the place of the manually operated clutch, and a gearbox with epicyclic trains delivering a range of gear ratios through the braking or clutching together of various elements of the trains, selection being entrusted to an automatic system reacting to various input signals, primarily vehicle speed and accelerator pedal position. The computation of shift points, once entrusted to complex hydro-mechanical systems, is now almost invariably electronic. This trend has made possible far more sophisticated operation, eliminating many of the less desirable characteristics of earlier automatic transmissions.The overall marketNeglecting the relatively small demand for reconditioned units, the size of the new vehicle market determines the size of the transmissions market. Worldwide sales of light-duty vehicles - passenger cars, SUVs, MPVs, light trucks and commercial vehicles up to 3.5 tonnes MGVW - amounted to over 54m in 2003. All these vehicles had basically similar transmission requirements, markedlydifferent from those for the heavy commercial vehicles mainly used for freight haulage.It is accepted that the figure will grow, although in present circumstances (as at October 2004) forecasts of growth in the fully developed markets are understandably being revised down. In the rapidly developing markets of Asia, and above all in China, the picture is conversely one of extremely rapid growth. While it remains likely that the NAFTA and EU markets will grow overall by less than 5% in the years to 2012, the same period is likely to see the Asian market (even when Japan is excluded) growing to rival the EU market in size. Forecasts prepared for this report, and shown in Table 1, taking the current political and economic uncertainties into account, suggest a world market for private passenger and light commercial vehicles of 72.3m by 2012, compared with 52.9m in 2000.Table of contentsChapter 1 Automotive transmissions - present and futureRequirement: the need for transmissionOverall solutionsThe overall marketTechnical alternativesChapter 2 Manual transmissionsThe market for manual transmissionsClutchesManual gearboxesManual gearbox manufacture and supplyManual transmissions: future market prospectsChapter 3 Conventional automatic transmissionsThe market for conventional automaticsThe main trendsAutomatic transmission manufacture and supplyAntonovAudiBMWDaimlerChryslerFiat AutoFordGeneral Motors (GM)HondaMitsubishiNissan-JATCOPSARenaultToyota-Aisin AWVolkswagen GroupZFConventional automatic transmissions - future market prospectsChapter 4 New types of automatic transmissionThe market for new types of automatic transmissionThe main trendsCVTsIVTsAutomated manual transmission (AMT)New types of transmission: manufacture and supplyAudiBMWBorg-WarnerRobert BoschDaimlerChryslerFiat AutoFordGeneral MotorsHondaNissan-JATCOPSARenaultRicardoSubaru (Fuji Heavy Industry)TorotrakToyota-Aisin AWValeoVolkswagenVolvoZFInnovative transmissions - future market prospectsChapter 5 The long-term prospectA reducing need?Hybrid vehiclesElectric vehiclesElectric traction effect on the transmission marketChapter 6 Downstream of the gearboxOther transmission componentsControl of torque distributionList of tablesTable 1: Total Vehicle Production by Area (includes cars, light trucks and LCVs)in units ('000s)Table 2: Manual transmission market shares and volumes ('000s units)Table 3: Automatic transmission market shares and volumes ('000s units)Table 4: Market Shares and Volumes: CVTTable 5: Market Shares and Volumes: AMT (including twin-clutch)Table 6: Market Shares and Volumes: All Innovative AutomaticsTable OfContents :To Order this report:Please contact us below:Oliver Wilkinson, Research Store ManagerPhone:+44 (0)1527 573 609 Internationally1-866-545-5878 toll free from the USEmail:*******************Fax:+44 (0)1527 577 423Post:Aroq Ltd, Seneca House, Buntsford Park Road, Bromsgrove, Worcs, B60 3DX, United Kingdom.Or, if online, click the 'Order Now' button below:Or der NowOr go to the below link to print out a fax order form: /store/fax_form_order.asp?product_id=30181汽車電子技術優勢探討作者＼張孟俊、孫鴻航現今的電子技術已經廣泛應用於汽車的各個領域，改善了汽車的性能，使汽車在安全、節能、環保及舒適等各方面都有了長足的進步。