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Future trends in automobile designThe aim of this chapter is to: Demonstrate the mechanical and electrical possibilities for futurevehicle design; Indicate how current advances will create fundamental designchanges for future vehicles.1.1 IntroductionThe design of modern cars has already reached the stage where the Ford Fiesta has more computing power than Space Shuttle. There isdefinitely going to be a great expansion in electrical control and itsattendant systems. To make this distinction more obvious this chapterhas been split into electrical and mechanical future possibilities,but this does in no way mean that these two futures are separate, theyare inevitably intertwined. There are many future possibilities butnow more than ever before they are dependent on the development offuture technologies, such as electrical systems using light as acarrier medium. 1.2 Mechanical possibilitiesThis section is split into six areas where significant changes willoccur in the near future,however this does not preclude changes inother areas of vehicle design that may have a profound effect on thesedesigns. There is inevitably an inter-linking between mechanical andelectrical possibilities, so where this occurs the emphasis has beenplaced on the electrical side as this is the area that will show mostchange over the coming years.1.2.1 Design possibilities There are approximately 15 000 components that make up anautomobile. Each of these components needs to be designed for efficientuse of materials and costed down to a price. Each one must have asuitable reliability since any failure will inevitably result incustomer dissatisfaction.This results in the total component number continuously droppingto increase reliability and drive costs down. Systems such as FMEA(Failure Modes and Effects Analysis), ENTRA and weighted objectivesmethods (Cross, 1989) can be used effectively to optimize design andreduce component numbers. A recent example is a development of an engine design where the basic layout remained but a redesign reducedthe number of components by seventy. This was in spite of the fact thatthe redesign contained new features such as liquid cooling and fourvalves per cylinder.It should be noted that the quality of the final assembly is alwaysa function of the number of component parts.The use of these processeswill increase, especially with the aid of computerized integrateddesign packages. There are many possibilities here but several may wellbe: (a) design packages where the designer is continually updated on all the legal implications of each design change, thereby avoidinginternational vehicle acceptance problems.(b) at the concept design stage previous models and currentcompetitor vehicles could be analysed to create design envelopes fora new vehicle. These envelopes, which could be external shape, drivesystem design or interior layout, could then be explored to create newgenerations of vehicles.(c) in a similar vein, new component parts could be developed witha computer system such that an existing part can be manipulated (bystretching, compressing, etc.) to quickly create a suitable new component. Obviously a life and reliability analysis would have to be performed but it avoids the blank sheet of paper situation. It couldbe argued that these systems could remove innovative ideas; however,it usually takes less time to develop an existing idea than create theidea from scratch. However, there will always be a need to practicallytest designs to confirm the computed outcomes.This is of increasing importance as the times for vehicleprogrammes reduce. It currently takes approximately three years fora new vehicle to be produced from concept, but two years could wellbe on the horizon. This means the design and development programme hasto be thoroughly integrated so that resources and manpower are available exactly as required. An increasing use of project planningand constant appraisal is also indicated, as any delay could becatastrophic for the project. Again, computers will be essential herenot only to run the design and development programme but also to predictlikely problem areas.An increasing role is being played by parts suppliers as they take onthe design and development of their products. This leaves the vehiclemanufacturer to collect and collate the design data to ensure theproduct as a whole will have the required performance. Thus, a complexcomputer network is being developed to enhance the design lead-time. This bringsabout the essential requirement that the design is constantly updatedas changes are made, so that every group involved with the project isaware of the updates as they happen and can comment as necessary.It also provides a record so that back-tracking can occur whennecessary.The recycling of vehicle parts will always be an issue, which againneeds a continual interlinking of the groups concerned with designissues. The cost of strip-down and ease of recycling is reduced whenthere are compatible materials used in component assemblies; for example, the complete dash-panel should be made of compatible plastics so that no sorting or breaking down of the panel is required forrecycling.Prototype models of design variants can now and increasingly willbe made from computer models by the use of Rapid Prototyping processes(Jacobs, 1996; Venus, 1997; Kalpakjian,1997). The time for theseprocesses will reduce and will mean that tests such as coolant flowvisualization in engines can be performed before any metal has beencut. This will also aid the design of electrical systems againstelectromagnetic interference, which will become an increasinglyimportant issue as the whole vehicle becomes computer controlled. These on-board computers could also be used to relay vehicleperformance and reliability information back to the Future trends inautomobile designmanufacturers so that the vehicle could be updated before any potentialproblems (and expensive recalls) occur. This could be a two-way processas vehicle transmitter/receiver (not necessarily of a radio type)could also receive updates as well.Further methods for decreasing design and development time revolvearound modular design systems. This process has been used for a longtime, but the advent of cheap high-powered computers brings far more scope to this reality. Various manufacturers currently use this systemfor engine design, but this system could easily be brought into bodydesign. This could be achieved, for example, by the use of lightweightspace frame chassis structures (platforms) to which plastic clip-onbody panels are attached. These panels could readily be changed inshape using injection moulding techniques, which could providerelatively inexpensive model re?vamps. New technology will inevitablybring with it new design possibilities, which could well be almostendless. These developments will mainly come from manufacturingprocesses becoming available with faster and improved final product properties. There is a definite trend towards lightweight materials, such as aluminium, where improved processing techniques will eliminatemost of the machining processes. Styling will inevitably change to thelimits of these processes, so for example the replacement of carbonin rubber with silicon or the use of prisms for mirrors could bringabout a plethora of new design concepts. It is up to the design teamsto realize the potential of these new technologies when they occur andexploit them fully.1.2.2 Advances in manufacturing methodsMost automotive manufacturers currently have links of various forms with other automotive manufacturers. These ties will strengthenin the future mainly due to the economy of scale,especially with powersystems and transmissions. There has also been a tendency for bodystyling to be updated regularly but the basic platform to remainsimilar to previous models, e.g.Ford Ka and Toyota Classic. Thisintermixing will create many new versions of basic vehicles withoutthe costs of a completely new vehicle, so manufacturers will have atendency for linking to create the broadest coverage of specificationsfor their vehicle range. This has further repercussions where, at least,first tier suppliers would be involved at all stages of the vehicle design. They could then supply and be responsible for complete systems.The main problem with this scenario is confidentiality with suppliersto more than one manufacturer. This can be alleviated by having a solesupplier relationship, patenting or allowing other manufacturers theuse of designs for a fee.These arrangements could result in the vehicle manufacturer havingoverall control of the design and development of its vehicles, but justbeing an assembler of component parts. Some manufacturers are alreadywell down this path, and have a good showing within the market place.This is probably partly due to the extra control the vehicle assembler has on the quality of its bought-in parts. Some of these relationships are being formalized now in Target Agreements which create a legalas well as a working relationship. There is now necessarily a logicalend to this process as it depends on the strength of the linking, butwould unquestionably mean that the limit would be the stage where thevehicle manufacturer feels that their individuality is brought intodoubt, as this differentiates one company s products from those ofanother. Thiswill create, however far down this route this process goes, a mutualresponsibility which will have knock-on effects for all the workforcesinvolved and could lead to service support systems relating the vehicle manufacturer to its supply companies. The inter-linking ofautomotivemanufacturers may well lead to there being only three or four majorplayers in the world market.An extension to this, that some companies are already arranging,is to create a supplier park where first tier companies aregeographically located close to the assembly plant. This may be anobvious move for new companies, but for established ones it may notbe so simple, especially when Just in Time (JiT) systems arebecoming the industry norm. This will result in clusters of automotive industry within countries and indeed, the world. Labour costs will varyfrom country to country over a period of time which means that labourintensive activities will be based on a short term basis geographically.A knock-on effect of modularization is that robotization is moreeffective which may bring an end to these shortterm policies for most production plants. This would seem to be thecase especially when the spiralling of future transport costs ofcomponents are considered.Part of the emphasis in computer controlled manufacturing is thatfeedback loops could exist to continually reduce production times. This could be built into the manufacturing system so that the processes are continually monitored and optimized. Mathematical modelling ofproduction lines could also be used as part of this feedback loop.These processes could also be used to reduce the time taken toobtain a required production rate from a new line, or even for a newvehicle. Currently a new vehicle takes about thirty days from thestart-up of the line to the required rate for most manufacturers.However, a few companies manage this in one day with efficient planningand feedback systems incorporated into their computer managementsystems.Further use of computerized control systems could be used to improve various stages of production within the complete cycle. Anexample of this could be the elimination of hot engine testing fromthe production process. Once the characteristics of an engine have beenevaluated with bandwidths set for the control variables, engines couldbe cold tested at low crankingspeeds to check factors such as crankshaft torque to turn, compressionanalysis, cylinder block airflow and liquid cavity leaks. Even NVHtests could be performed at, say, 1500 r.p.m. Again, the use ofmodularization would make such systems more economically feasible.Another process that demonstrates the use of overall computer control by using experimental data as an initialization is paintingby electrostatic deposition. These systems totally avoid theuse of solvents by using water as a carrier. Flake orientation (formetallic paints) can be determined by the charge and the position ofthe spray gun, which could be computer variables. The carrier watercould then either be re-circulated after cleaning (which involveslarge costand potential contamination problems), or passed to filter beds andthen into the local river system. This whole process could be automatedonce the system characteristics have been determined, so that these systems require systematic development but once set up could be self correcting for all eventualities. Implementation of such processeswould greatly reduce costs and also minimize plant equipment costs.Such simplified control systems could be implemented throughoutautomotive production plants to improve final quality and reduce costsand provide innovative finishes.It is certain that there will be an ever increasing technologicaladvance that cannot be predicted, but these advances usually comethrough the application of older processes with new materials andcontrol systems. An example of this is the use of hydra-forming. Thisprocess has been used for many years in the brass musical instrument manufacturing industry for forming complex curved tubes at fairly lowfluid pressures. Advances in sealing technology mean that this processis currently used for the manufacture of camshafts and exhaustmanifolds, but there is no reason why sills, rails and posts could notbe manufactured by this process. This would avoid flanges and couldthus make optimum use of the space taken by the current designs. Thisprocess of up-dating old processes will continue on the back ofadvances in appropriate technology.1.2.3 Materials advances The use of lightweight materials within road vehicles has beenconsidered for at least twenty years (Automotive Engineering, 1991)but it is only recently that a few manufacturers have produced lowvolume mass production vehicles that use a substantial volume of thesematerials.As yet there are no truly mass produced lightweight (approx. 500 kg)road vehicles, this is bound to change. Current projected vehiclespropose 40% by weight of aluminium for a vehicle weighing 1 Mg. thatwould return 100 m.p.g. using a hybrid power system. Part of the reasonfor the concentration on a range of medium/large sized vehicles is that the return on development costs would be greater. Aspects of true mass production can also be explored with this type of vehicle before anymajor small car mass production takes place. However, aluminium is notthe only contender for lightweight structures. The magnesium industrypredicts (Automotive Engineering, 1993) a 15 20% annual growth withinthe automotive industry over the next ten years. Castings would be themost likely form of usage, and doors and dash-panels using this methodhave already been developed. Further uses could be for the nodes (lugs)of a space frame chassis and engine mountings. Other possible materialsare highly ductile stainless steels with a yield stress over 800 MPaand high tensile steels. However, body shells need to be designed specifically for these materials and a direct replacement of currentsteel systems would not be appropriate. Part of this re-design wouldhave to be a re-consideration of NVH properties. This could be aidedby suitable positioning of sandwich constructionpanels, which is currently used as sound deadened steels, but theprinciple could be applied to other metals than steel, once the bondingtechnology has been developed. A further development would be to useplastics for the complete body shell including the windows, howeverat the moment their inherent brittle transition phase is hindering thisadvance. A metal plastic composite could be the answer here. It is reckonedthat an aluminium body shell could weigh 60% of a steel equivalent anda plastic one could be even less than that. The assumption here is thatthere is sufficient package space to absorb this intrusion. Plasticscurrently have a very efficient application in the absorption of impactenergy in race cars in the form of honeycomb structures. Thistechnology is extremely expensive, but there are continuing pressuresto develop this technology to reduce costs. This would be a greatadvance in road vehicle design and should, if implemented, radicallyalter body shapes and lengths. Development prototype engines have been built where plastics have been the major material, up to about 80%, with the use of mainly ceramiccoatings by various companies for racing and motorcycle use. Both theseuses require lightweight and fast throttle response whereas the latterwas also considered as a throw-away engine. These engines have nevergot beyond the development stage to date, like many other prototypeengines before them. However, plastics are finding their way below thebonnet as heat exchangers, cam covers, inlet manifolds and electricmotor housings, so there could well be in the near future, a leap toplastic engines. Part of these advances is the development ofprocessing technologies. Currently work is being centred on metal matrices and long fibre injection processes. Metal matrices have theadvantage that their properties can be tuned to suit the particularapplication, where not only fibre or whisker density is altered butalso their orientation. This tuning of properties would be of greatuse for engine components such as pistons and connecting rods.Combinations of metals, plastics and ceramics will be combined tocreate specific use composites for vehicle building of the future andjust needs the technology to advance so that efficientmass-manufacturing processes can be developed. 外文資料譯文 1 未來的汽車設(shè)計趨勢本 章 的 目 的 是 ：為 今 后 的 車 輛 設(shè) 計 展 示 機 械 和 電 氣 方 面 的 可 能 性 ；說 明 目 前 的 進(jìn) 展 將 如 何 為 未 來 的 車 輛 帶 來 根 本 性 的 設(shè) 計 變 化 。1 .1 介 紹現(xiàn) 代 汽 車 的 設(shè) 計 已 經(jīng) 達(dá) 到 了 比 航 天 飛 機 更 有 計 算 能 力 的 階 段 。 電 氣 控 制肯 定 會 有 很 大 的 擴 展 ， 它 的 附 屬 系 統(tǒng) 。 為 了 使 這 一 區(qū) 別 更 加 明 顯 ， 這 一 章 被分 成 了 電 氣 和 機 械 兩 種 未 來 的 可 能 性 ， 但 這 并 不 意 味 著 這 兩 種 未 來 是 分 開 的 。 相 提 并 論 ， 它 們 不 可 避 免 地 交 織 在 一 起 。 有 許 多 未 來 的 可 能 性 ， 但 現(xiàn) 在 比 以往 任 何 時 候 都 更 依 賴 于 未 來 技 術(shù) 的 發(fā) 展 ， 例 如 電 氣 系 統(tǒng) 的 應(yīng) 用 。 光 作 為 載 體介 質(zhì) 。1 .2 機 械 可 能 性本 節(jié) 分 為 六 個 領(lǐng) 域 ， 在 不 久 的 將 來 將 發(fā) 生 重 大 變 化 ， 但 這 并 不 排 除 在 車輛 設(shè) 計 的 其 他 領(lǐng) 域 發(fā) 生 的 變 化 ， 這 些 變 化 可 能 會 對 車 輛 設(shè) 計 產(chǎn) 生 深 遠(yuǎn) 的 影 響 。這 些 設(shè) 計 。 機 械 和 電 氣 的 可 能 性 之 間 不 可 避 免 地 存 在 著 相 互 聯(lián) 系 ， 因 此 在 發(fā)生 這 種 情 況 時 ， 重 點 放 在 電 氣 方 面 ， 因 為 這 是 將 在 未 來 幾 年 中 表 現(xiàn) 出 最 多 的變 化 。 1 .2 .1 設(shè) 計 可 能 性大 約 有 1 5 0 0 0 個 組 成 汽 車 的 部 件 。 這 些 部 件 中 的 每 一 個 都 需 要 被 設(shè) 計 用于 有 效 地 使 用 材 料 并 將 成 本 降 低 到 一 個 價 格 。 每 個 人 都 必 須 有 一 個 表 可 靠 性由 于 任 何 故 障 將 不 可 避 免 地 導(dǎo) 致 客 戶 不 滿 。 這 導(dǎo) 致 總 部 件 數(shù) 不 斷 下 降 ， 以 增加 可 靠 性 和 降 低 驅(qū) 動 成 本 。 系 統(tǒng) ， 如 故 障 模 式 和 影 響 分 析 和 加 權(quán) 目 標(biāo) 方 法 可有 效 地 用 于 優(yōu) 化 設(shè) 計 和 減 少 部 件 號 。 最 近 的 一 個 例 子 是 發(fā) 動 機 設(shè) 計 的 發(fā) 展 ,其 中 基 本 布 局 仍 然 保 留 但 重 新 設(shè) 計 紅 色 把 組 件 的 數(shù) 量 減 少 了 7 0 。 這 是 盡 管 重新 設(shè) 計 包 含 了 新 的 特 點 ， 如 液 體 冷 卻 和 每 缸 四 個 閥 門 。應(yīng) 該 注 意 的 是 ， 最 終 裝 配 的 質(zhì) 量 總 是 取 決 于 零 件 的 數(shù) 量 ， 這 些 過 程 的 使 外文資料譯文 2 用 將 會 增 加 ， 特 別 是 借 助 計 算 機 化 的 額 定 設(shè) 計 包 。 這 里 有 許 多 可 能 性 ， 但 有幾 個 可 能 是 ：（ a） 設(shè) 計 包 裝 ， 設(shè) 計 人 員 不 斷 更 新 每 次 設(shè) 計 變 更 的 所 有 法 律 影 響 ， 從 而避 免 國 際 車 輛 驗 收 問 題 。（ b） 在 概 念 設(shè) 計 階 段 ， 可 以 分 析 以 前 的 車 型 和 當(dāng) 前 的 競 爭 對 手 車 輛 ，以 創(chuàng) 建 新 車 輛 的 設(shè) 計 包 絡(luò) 。 這 些 封 套 可 以 是 外 部 形 狀 ， 驅(qū) 動 器 設(shè) 計 或 內(nèi) 部 布局 ， 然 后 可 以 被 探 索 以 創(chuàng) 建 新 一 代 車 輛 。（ c） 在 類 似 的 靜 脈 中 ， 可 以 使 用 計 算 機 系 統(tǒng) 開 發(fā) 新 的 部 件 ， 以 便 能 夠 （ 通過 拉 伸 、 壓 縮 等 ） 操 作 現(xiàn) 有 零 件 快 速 創(chuàng) 建 合 適 的 新 功 能 。 組 件 。 顯 然 ， 必 須進(jìn) 行 壽 命 和 可 靠 性 分 析 ， 但 它 避 免 了 白 紙 的 情 況 。 可 以 說 ， 這 些 系 統(tǒng) 可 以 消 除 創(chuàng) 新 的 想 法 ； 當(dāng) 然 ， 開 發(fā) 一 個 現(xiàn) 有 的 想 法 通 常 比 從 頭 開 始 創(chuàng) 建 這 個 想 法 花費 的 時 間 更 少 。 然 而 ， 總 是 需 要 實 際 測 試 設(shè) 計 ， 以 確 定 計 算 結(jié) 果 。隨 著 車 輛 計 劃 時 間 的 減 少 ， 這 一 點 越 來 越 重 要 。 目 前 一 款 新 的 汽 車 從 概念 上 生 產(chǎn) 大 約 需 要 三 年 時 間 ， 但 很 可 能 需 要 兩 年 時 間 。 地 平 線 。 這 意 味 著 設(shè)計 和 發(fā) 展 方 案 必 須 徹 底 整 合 ， 以 便 完 全 按 照 需 要 提 供 資 源 和 人 力 。 越 來 越 多地 使 用 項 目 規(guī) 劃 還 指 出 經(jīng) 常 進(jìn) 行 評 估 ， 因 為 任 何 拖 延 都 可 能 對 項 目 造 成 災(zāi) 難性