4-汽车专业英语课件-汽车设计制造部分修改后-section 413-braking system designengine management software ppt

1、复习o 提问Chapter 11 Automotive Designo Design of Dry Clutcheso Engine and Transmission Matchingo 11.1 Changing ratios-matching of the transmission to the vehicleo 11.2 Braking system design methodology;o 11.4 Developing and Testing the Engine Management Softwareo 11.3 Starting System Design本次课学习内容、目标和重

2、点难点学习内容Automotive Design11.2 Braking system designmethodology;11.4 Developing and Testing the Engine Management Software学习目标1. 掌握有关制动系统设计和发动机管理软件开发测试的专业术语2. 较熟练翻译课文难点重点1. 重点：长句翻译方法； 相关术语的记忆2. 难点：长句翻译Automotive Design11.2 Braking System Design MethodologyNew Words and Phrases艺fullfulfi:ln.满足，完成，实现alb

3、eit:lbi:itconj.尽管，虽然methodologymedldin.方法论，教学法，操作法，工+to-vmuscularmskjula.肌肉的，肌肉发达的，健壮的embraceimbreisv.包括，拥抱，围住，环绕failurefeiljn.失败，失败者，疏忽，没做到Automotive Design11.2 Braking System Design MethodologymodulationNew Wordsn. 调节，调整，调制mdjuleinhosehuzn.软管(量)endowindauv.捐赠，资助，赋予(+with)wheelbasewi:lbeisn.轴距rimri

4、mn.缘，边缘，轮辋，轮胎辋圈exiblefleksbln.可弯曲的，柔性的，可变通的distributiondistribju:nn.分发，分配，分布，散布，销售Automotive Design11.2 Braking System Design MethodologyNew WordsrecognizerekgnaizV.认出，识别，正式承认，认可precedingprisi:dia.在前的，在先的，前面的iteration itreinn.重复，重述， ，迭代，循环formalf:mla.正式的，有条理的，正规的premature pri:mtjua.比预期早的，过早的，不成熟的，草率

5、的violation vaileinn.违反，违背，妨害Automotive Design11.2 Braking System Design Methodologysecondary/emergency brake辅助/应急制动器brake line制动管路exible tube柔性管rigid tube刚性管brake hose制动蹄brake force distribution制动力分配master cylinder主缸wheel cylinder轮缸Automotive Design11.2 Braking System Design MethodologyThe primary f

6、unctions of a brake system must be fullled at all times. In the event of a system failure, the same functions must also be performed albeit(虽然） with a reducedefciency. Consequently the braking system of a typicalpassenger car comprises a service brake for normal braking, a secondary/emergency brake

7、used in the event of a service brake failure and a parking brake. Current practice permits service brake components to be used in the secondary/parking brake systems. Irrespective of the detail design considerations all brake systems can be divided into the following subsystems:Automotive Design11.2

8、 Braking System Design Methodology(1) Energy sourceThis includes all those components which generate, store or release energy required by the braking system. In standard passenger cars muscular pedal effort, applied by the driver, in combination with a vacuum boost system comprise the energy source.

9、 In the event of a boost failure, the driver can still apply the brakes by muscular effort alone. Alternative sources of energy include power braking systems, surge brakes, drop weight brakes, electric and spring brakes.(2) Modulation systemThis embraces（包括） those elements of the brake system which

10、are used to control the level of braking effort applied to each brake. Included in this system are the driver, pressurelimiting/modulating valves and, if tted, anti-lock braking systems ( ABSs ).Automotive Design11.2 Braking System Design Methodology(3) Transmission systemThe components through whic

11、h energy travels to the wheel brakes comprise the transmission system. Brake lines (rigid tubes) and brake hoses ( exible tubes ) areused in hydraulic and air brake systems. Mechanical brakes make use of rods, levers, cams and cables to transmit energy. The parking brake of a car quite often makes u

12、se of a mechanical transmission system.(4) wheel brakesThese assemblies generate the forces that oppose the motion of the vehicle and in doing so convert the kinetic energy associated with the longitudinal motion of the vehicle into heat.Automotive Design11.2 Braking System Design MethodologyThere a

13、re four main stages involved in the design of a brake system. The rst, and perhaps most fundamental stage, is the choice of brake force distribution between the axles of the vehicle. This is primarily a function of the vehicle dimensions and its weight distribution. Next is the design of the transmi

14、ssion system and this activity embraces the sizing of the master cylinder together with the front and rear wheel cylinders. Additional components, such as special valves that modulate the hydraulic pressure applied to each wheel are physically accounted for at this stage. The foundation brakes form

15、the focus of the third stage of the process. As well as being able to react the applied loads and torques, the foundation brakes must be endowed with（赋予） adequate thermal performance, wear and noise characteristics. The last phase in the process results in the incorporation of the pedal assembly and

16、 vacuum boost system into the brake system.Automotive Design11.2 Braking System Design MethodologyTo accomplish this design task, the engineer requires access to several fundamental vehicle parameters. These include: laden and unladen vehicle mass; static weight distribution when laden and unladen;

17、wheelbase; height of centre of gravity when laden and unladen; maximum vehicle speed; tyre and rim size; vehicle function; braking standards.Automotive Design11.2 Braking System Design MethodologyIt is essential to recognize that each of the preceding stages is closely linked and that the nal design

18、 will take many iterations（ 重 复 ）to realize. Thus any formal methodology must be designed so as not to compromise the overall system quality that could result from designchanges at the component level. By way of（作为） example, a reduction in package space could lead to smaller diameter wheel brakes ha

19、ving to be tted to the vehicle. This will change the brake force distribution unless checked, by say resizing the wheel cylinders, and in the worst case this could lead to premature（过早的）wheel lock and a violation（违反）of the governing legislation.Automotive Design11.4 Developing and Testing the Engine

20、 Management SoftwareNew Words and Phrasesapplicationn.应用，应用程序，申请，申请书plikeinone-offa.仅一次的，一次性的definabledifainbla.可限定的，可（下）定义的top-downa. (规划或设计)从总体到细节的， 由上而下feasibility i:zbilitin.可行性，可能性outcomeautkmn.结果，结局，后果，输出，产物complexitykmpleksitin.复杂(性)，错综复杂的事物represent reprizentv.描绘，表现，象征，表示debugdi:bgv.排除错误，（程序

21、）调试（整）Automotive Design11.4 Developing and Testing the Engine Management Softwarevalidation vlideinn.批准，确认，(有效性)验证validvlida.有根据的，合法的，正确的bugbgn.臭虫，故障，毛病，(程序中的)错误rectifyrektifaiv.矫正，改正，整(流)，调整hesitation heziteinn.踌躇，犹豫，迟缓，暂停altitudelti tju:dn.高度，高地，海拔obscurebskjua.暗的，模糊的，含糊不清的，难解 的intentionintennn.意图

22、,意向,目的Automotive Design11.4 Developing and Testing the Engine Management Softwarespecialist application专家系统，专门应用软件program code程序代码Automotive Design11.4 Developing and Testing the Engine Management SoftwareThere is, of course, more than one way of producing a computer program. Most programs used in t

23、he electronic control unit of a vehicle digital control system are specialist applications and, as such, are one-off creations. The method used to create the final program is known as the top down structured programming technique.Following on from a need for the final product, the process can be see

24、n to pass through six definable stages.1. Requirement analysis seeks to answer the question as to whether a computerized approach is the best solution. It is, in effect, a feasibility study.2. Task definition is a process of deciding exactly what the software will perform. The outcome of this stage

25、will be a set of functional specifications.Automotive Design11.4 Developing and Testing the Engine Management Software3. Program design becomes more important as the complexity of the task increases. This is because, where possible, it is recommended that the program be split into a number of much s

26、maller tasks, each with its own detailed specification.4. Coding is the stage at which the task begins to be represented by a computer language. This is when the task becomes more difficult to follow as the language now used is to be understood bythe computer.5. Debugging and validation is the process of correcting any errors or a bug in the program code and then finally ensuring that it is valid. This means checking that the desired outputs appearin response to appropriate inputs. In other words, does it work? (As a slight as