13-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1. 重点：长句翻译方法； 相关术语的记忆2. 难点：长句翻译难点重点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. 较熟练翻译课文学习目标学习内容Automotive Design11.2 Braking system designmethodology;11.4 Developing and Testing the Engine Management SoftwareAutomotive Design11.2 Braking System Design MethodologyNew Words and Phrasesn.方法论，教学法，操作法，工艺n.满足，完成，实

3、现methodologymedldifullfulfi:lalbeit:lbi:itconj.尽管，虽然n.失败，失败者，疏忽，没做到+to-va.肌肉的，肌肉发达的，健壮的failurefeiljmuscularmskjulembraceimbreisv.包括，拥抱，围住，环绕Automotive Design11.2 Braking System Design MethodologyNew Wordsn. 调节，调整，调制modulationmdjulein huzfleksblhoseexiblen.软管n.可弯曲的，柔性的，可变通的n.分发，分配，分布，散布，销售 (量)v.捐赠，资助

4、，赋予(+with)n.轴距n.缘，边缘，轮辋，轮胎辋圈distributiondistribju:nendowwheelbase rimindauwi:lbeis rimAutomotive 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，反复，迭代，循环formalf:mla.正式的，有条理的，正规的a.比预期早的，过早的，不成熟的， 草率的premature p

5、ri:mtjuviolation vaileinn.违反，违背，妨害Automotive Design11.2 Braking System Design Methodologysecondary/emergency brake brake lineexible tube rigid tube brake hosebrake force distribution master cylinderwheel cylinder辅助/应急制动器制动管路柔性管刚性管制动蹄制动力分配主缸轮缸Automotive Design11.2 Braking System Design MethodologyThe

6、 primary functions 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/emerge

7、ncy brake 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

8、Design11.2 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 ener

9、gy source. 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 sys

10、tem which 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 th

11、rough which 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 oft

12、en makes use 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 Methodol

13、ogyThere are 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 t

14、he transmission 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 br

15、akes form 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 as

16、sembly and 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

17、 unladen; 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

18、nal design 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

19、 brakes having 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

20、the Engine Management SoftwareNew Words and Phrasesn.应用，应用程序，申请，申请书applicationplikeinone-off definable top-downfeasibility outcome complexityrepresenta.仅一次的，一次性的a.可限定的，可（下）定义的a. (规划或设计)从总体到细节的， 由上而下n.可行性，可能性n.结果，结局，后果，输出，产物n.复杂(性)，错综复杂的事物v.描绘，表现，象征，表示difainbl i:zbiliti autkm kmpleksiti reprizentdebu

21、gdi:bgv.排除错误，（程序）调试（整）Automotive Design11.4 Developing and Testing the Engine Management Softwaren.批准，确认，(有效性)验证validationvlideinvlidvalida.有根据的，合法的，正确的n.臭虫，故障，毛病，(程序中的)错误v.矫正，改正，整(流)，调整bugbgrectifyrektifain.踌躇，犹豫，迟缓，暂停hesitationheziteinaltitudelti tju:dn.高度，高地，海拔a.暗的，模糊的，含糊不清的，难解obscurebskju 的inten

22、tionintennn.意图,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 prog

23、rams used in the 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 proc

24、ess can be seen 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

25、of this stage 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 nu

26、mber of much smaller 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 a