裝配圖大學(xué)生方程式賽車設(shè)計（總體設(shè)計）（有cad圖+三維圖）

裝配圖大學(xué)生方程式賽車設(shè)計（總體設(shè)計）（有cad圖+三維圖）,裝配,大學(xué)生,方程式賽車,設(shè)計,總體,整體,cad,三維 馬夫年會在福井。8月4日至6日,2003年 福井大學(xué)、日本 通過試驗臺實施跨車輛通信系統(tǒng)為車輛排實驗 跆拳道Min Kim Jae Weon崔 學(xué)校的機械工程和機械技術(shù)研究所 釜山國立大學(xué),609 - 735年,韓國釜山 文摘:本研究認(rèn)為通過試驗臺實現(xiàn)問題的跨車輛通信系統(tǒng)的車輛排實驗。這個試驗臺,包括三個車輛和一個RCS規(guī)模(遠(yuǎn)程控制sbation),在前面是作為一種工具來評價仿真功能和全尺寸的車輛之間的研究。合作通信的車輛,車輛或路車輛保持相對間距小的車輛排扮演一個關(guān)鍵角色。然后:交通容量會增大。靜態(tài)排控制,汽車的數(shù)量保持不變,他在適當(dāng)?shù)墓潭ㄩg隔傳播的信息就足夠了,而動態(tài)排控制如合并或者分立需要更靈活的網(wǎng)絡(luò)結(jié)構(gòu)的動態(tài)協(xié)調(diào)的通信序列。在這項研究中,無線通信設(shè)備和可靠的協(xié)議實現(xiàn)了靈活的網(wǎng)絡(luò)架構(gòu),6位單片機收發(fā)信機使用在近距離、低成本情況。 關(guān)鍵詞:車輛排、無線通信系統(tǒng)、試驗臺 1. 介紹 在大多數(shù)主要城市城市道路變得擁擠,因為越來越多的旅行需求超過公路通行能力。擁塞等問題導(dǎo)致許多其他問題:浪費時間和精力,交通事故,污染等等。作為一個SD智能Tkansportation系統(tǒng)積極開發(fā)成為這些問題的全局最優(yōu)解。特別是,臺灣(智能車輛和公路系統(tǒng))是主要的主題，它在臺灣的目的是通過自動化車輛和自動公路改善安全作為增加highvmy能力。在臺灣,一個模范高效的車輛控制的方法通過提出了oons在路徑程序在平臺分組。車輛排是一組車輛在一個高速度與相對較小的間距一起旅行。車輛為什么在近地層排反饋控制規(guī)律是動態(tài)耦合的。根據(jù)信息反饋和取決于這種a11信息是一個自動加工合成的嗎。車輛跟蹤控制律,在一個車輛字符串內(nèi)動態(tài)之間的相互作用會引起車輛不穩(wěn)定?？刂婆c信息鉛的車輛在一個排這是第一輛車,前面的車輛只能保證穩(wěn)定在一個汽車。 測距雷達可以得到相對靠前的車輛的信息。但這信息是不能作為所有在一排的車輛使用。無線通信只允許獲得所有車輛中最靠前車輛的信息。 對于靜態(tài)排控制的車輛來說這是足夠的，雷達獲取的信息保持不變,,因為信息到他傳播在適當(dāng)固定間隔內(nèi),每個車輛不需要頻繁的更新的控制輸入。這個方案可以保證每個汽車在一排有一個支持系統(tǒng)、統(tǒng)一發(fā)送每一個周期的信息。如果為動態(tài)排控制,如合并或分裂,更靈活網(wǎng)絡(luò)體系結(jié)構(gòu)是必需的。在這種情況下,因為機動車輛為合并或分割需要頻繁?？刂戚斎氲母聲剐畔⒈粋魉偷綑C動車輛應(yīng)該比其他人多。因此,來傳輸這個信息更多機會是給領(lǐng)導(dǎo)車輛和操縱車輛的。在這個方案中,cominunicat.ion應(yīng)該協(xié)調(diào)有效的序列，因為協(xié)調(diào)的通信序列可能會實現(xiàn)容易被RCS(遠(yuǎn)程控制站)控制。 在這項研究中,無線通信系統(tǒng),可以通過“RCS”協(xié)調(diào)通信序列實現(xiàn)車輛縱向排實驗。 2. 系統(tǒng)需求 能力是直接影響交通流的車輛排控制策略。需要在實時實現(xiàn)戰(zhàn)略時，控制策略可以衡量最大流量的流能力,衰減的間距錯誤，它可以保證一個排的有效性和信息的數(shù)量,。在臺灣:恒間距和持續(xù)的進展已被研究過是主要的控制手段。恒間距控制,在車輛跟蹤的基礎(chǔ)上而不斷進展的控制,所需的控制間距期望的進展是除了維護車輛本身增加車輛覆蓋之間的距離。恒間距使用的優(yōu)越性是在不斷進展增加控制高速公路車輛的吞吐量,雖然常數(shù)進展控制更優(yōu)惠但外部信息是必需的。在恒間距控制、外部信息是穩(wěn)定所需的字符串。無線通信系統(tǒng)可以利用這個外部信息傳遞。 在車輛排系統(tǒng)恒間距策略中,可以通過前面的車輛和車輛的信息獲得后面需要的車輛信息。這些信息包括位置、速度,加速度,和特定的命令的車輛，同時,由于指定的緊急事件可能需要命令RCS獲得每個車輛的信息。在前面的研究中測試床上的車輛縱向排實驗是發(fā)達的。試驗臺的圖1顯示的包含三個量表車和RCS。在圖2中顯示每個車輛傳感器的數(shù)據(jù)采集的可用的信息包括操作系統(tǒng)的計算的控制命令,執(zhí)行機構(gòu)的驅(qū)動和轉(zhuǎn)向為最有效的操縱,無線通信系統(tǒng)外部信息的交換,界面合成等基本功能。 圖1:測試平臺的配置 圖2:一個試驗臺的配置工具的規(guī)模 在前面的研究中,433 MHz射頻模塊,BIM-433,用于實現(xiàn)求解無線通信系統(tǒng)的構(gòu)架這個TDMA(時分多址)。數(shù)據(jù)傳輸速率為38 kbps，這模塊是載波監(jiān)聽算法不受支持的。因此,通信系統(tǒng)的性能對于調(diào)度序列控制同步和車輛是不足夠的。 對于每輛車穩(wěn)定運動測試,抽樣期的車輛應(yīng)低于40ms。傳感器用于試驗臺可以滿意抽樣段30 ms。 傳輸數(shù)據(jù)(12個字節(jié))和導(dǎo)言(上圖3 ms)在38 kbps這則需要高于5 ms。至于提高性能和穩(wěn)健性的通信系統(tǒng),因為開銷的增加更多的時間是必要的。此外,想要驗證各種網(wǎng)絡(luò)序列調(diào)度算法需要更靈活的網(wǎng)絡(luò)結(jié)構(gòu)。這個無線通信系統(tǒng)是由雙方的硬件和軟件組成的。硬件提供了連接各種電臺(車輛或RCS)網(wǎng)絡(luò)硬件組件。軟件不僅提供了智能控制組件，該軟件還將提供一個靈活和可靠的交換協(xié)議通信數(shù)據(jù)。 3. 硬件實現(xiàn) 硬件的無線通信系統(tǒng)由以下組件組成:射頻前端模塊,接口芯片留給射頻前端模塊和MCU(microcontrol1er單位)。 這個圖3演示了配置的無線通信系統(tǒng)。硬件的架構(gòu)分為四層,如下所示： ·PHY層(物理層) ·PHY-MAC層(物理到MAC層） ·MAC層(介質(zhì)訪問控制層） ·MAC應(yīng)用程序?qū)?MAC應(yīng)用程序?qū)? PHY層的實現(xiàn)是通過射頻前端模塊,RFW102收發(fā)器(發(fā)射機/接收機)芯片研制的RFWaves有限公司)。PHY-MAC層由接口芯片,I/O(輸入/輸出)口的MCU,I/O驅(qū)動在單片機里。獨家接口芯片,RFW-D100 RFWaves有限公司開發(fā)的用于接口的rfw - 102.8)MAC層,它的使用是維持秩序的一個共享的介質(zhì),是在AICU的軟件。Mac層是在以后的一章討論,因為它是軟件組件。在MAC應(yīng)用程序?qū)邮墙涌跓o線通信系統(tǒng)之間的部分,車輛RCS。 圖3:無線通信系統(tǒng)的配置 表1:RFW - 102的規(guī)格 物理媒介 DSSS,ISM波段(2.4 Ghz) 傳輸速率 高達1 mbps 帶寬 在-20分貝 30 Mhz 輸出功率峰值 2dBm 誤碼率 -80dBm 3.1 PHY層 PHY層實際處理的是一個無線通信系統(tǒng)之間的數(shù)據(jù)傳輸。在這一層,RFW -102收發(fā)器芯片用作射頻前端模塊。 RFW - 102的動機是其高數(shù)據(jù)傳輸速率,減輕在連接到外部設(shè)備,對載波監(jiān)聽算法的可用性。 表1顯示了規(guī)范的RFW - 102。 因為收發(fā)器芯片提供的最大輸出2dbm和靈敏度是-80 dbm.當(dāng)誤碼率(誤比特率)是在開放傳輸可用于的30米。這個范圍適用于測試平臺車輛的使用規(guī)模的大小約為0.3米。 3.2 PHY-MAC 層 PHY-MAC層之間的接口是射頻前端模塊和MAC協(xié)議。層構(gòu)造以下組件:接口對射頻前端模塊預(yù)留芯片組,I/O端口利用單片機的單位驅(qū)動I/O端口。 這個RFW-D100,RFIVaves有限公司開發(fā)的作為接口芯片的。RFW-D100中芯片到RFW- 102芯片組是免費的。它提供一個并行接口RFW - 102,使一個協(xié)議適合無線通信更容易實現(xiàn)。在這項研究中,MCU是負(fù)責(zé)MAC層協(xié)議和驅(qū)動I/O控制的。接口芯片降低MCU實時要求處理的MAC協(xié)議。這個接口芯片類似于內(nèi)存訪問,容易給MCU并行接口與射頻前端模塊。接口芯片轉(zhuǎn)換快串行輸入從射頻前端芯片到8打文字,然后適合一個8位MCU一起工作。此外,接口芯片要求一個更低的利率振蕩器的閑置模式.在空閑模式下,功耗RFW-102和RFW-D100大大減小了。這個接口芯片緩沖區(qū)數(shù)據(jù)通過第一字節(jié)FIFO(先入先出緩沖),這是可以給MCU訪問RFW - DlOO更有效率。而不是閱讀1字節(jié)/中斷,MCU可以讀到在每一個中斷16字節(jié)。每個傳入字節(jié)中斷的情況,這減少了單片機在閱讀傳入的話說的開銷，因為省去了堆棧填料和管道排空。當(dāng)使用先進先出,MCU支付所有的FIFO字節(jié)相同的開銷,而它不支付一個FIFO字節(jié)。 表2：Atmega 161L的規(guī)格 可操作的頻率 3.6864 MHz UART串行 2EA（最高1Mbps） 內(nèi)存 16K字節(jié)（閃） 1K字節(jié)（SRAM） 外部中斷 3EA 定時器/計數(shù)器 8-bit(2EA) 16-bit（1EA） 這個MCU實際由AIAC RFIV-D100處理協(xié)議和應(yīng)用D的。這個ATmega161L,由ATMEL Corp發(fā)展來用作MCU .表2顯示ATmega161L的規(guī)范。 在這項研究中,ATmega161L允許兩個外部中斷調(diào)用RFW-D100。 國家MAC層的變更中斷調(diào)用RFW-D100的事件。 根據(jù)變化的狀態(tài),執(zhí)行特定功能的MAC層,如接收、傳送、誤差檢驗,確認(rèn),和其他的數(shù)據(jù)處理。 3.3 MAC應(yīng)用程序?qū)? MAC應(yīng)用程序?qū)邮荕AC層和用程序(應(yīng)用程序)層之間接口。在這項研究中,應(yīng)用程序?qū)邮强刂泼枯v車的回路。這個應(yīng)用程序?qū)舆B接到可編程串行UART,這有一個中斷向量。因此,中斷調(diào)用的應(yīng)用程序?qū)幼鴺?biāo)是由國家的MAC層和特定的功能實現(xiàn)。此外,冗余的內(nèi)部SRAM是分配給接收和發(fā)送緩沖,它在FIFO中擴展了RFW-D100。 然后就可以在FIFO中不斷發(fā)送和接收比RFW - D1OO長尺寸的數(shù)據(jù) 。 4.軟件實現(xiàn) 圖4說明了在這項研究中框圖的軟件配置。軟件配置分為三個層次，分類如下: ·PHY-MAC層 ·MAC-APP層 ·MAC層 MAC層的MAC也分為MAC狀態(tài)和MAC數(shù)據(jù)。一般程序的MAC協(xié)議如下: 1.外部中斷調(diào)用的PHY層或者UART中斷調(diào)用的應(yīng)用程序?qū)蛹せ盍薓AC狀態(tài)管理。 2.MAC狀態(tài)管理檢查地位試用層,國家依照它的結(jié)果修改MAC。 3.根據(jù)最新對MAC狀態(tài)的修改,MAC數(shù)據(jù)管理控制數(shù)據(jù)流和RX / TX緩沖區(qū)。 4.然后,根據(jù)MAC的數(shù)據(jù)管理結(jié)果,MAC狀態(tài)管理設(shè)置新的MAC狀態(tài) 圖4 軟件配置的圖塊 兩個外部中斷的MCU是分配給分配層PHY的和UART中斷是分配給應(yīng)用程序?qū)?。MAC的過渡狀態(tài)是由這些中斷和8位定時器執(zhí)行控制時間的。因此,協(xié)議是保證配置邏輯是有效地改善和實時執(zhí)行的。此外,RX緩沖和TX緩沖區(qū)中MAC層有64字節(jié)的SRAM，RFW-D100的大小在主要約束在FIFO。 4.1可靠的協(xié)議 通常,通信是通過是一組很有效率、方便的數(shù)據(jù)包交流的。在這項研究中,數(shù)據(jù)包,見圖5,包括以下字段： ·前言:同步接收端 ·網(wǎng)絡(luò)ID:過濾數(shù)據(jù)包從其他網(wǎng)絡(luò) ·目的地：ID目的地 ·資料來源:ID資料來源 ·類型/ Seq:數(shù)據(jù)包類型/ Numher的序列 ·尺寸:整個數(shù)據(jù)包的大小 ·數(shù)據(jù):實際的數(shù)據(jù)傳輸 ·CRC:16位CRC檢查數(shù)據(jù)包的有效性 圖5:車輛與車輛間數(shù)據(jù)包的配置 數(shù)據(jù)域包含傳播的每一臺車輛的位置,速度,加速度數(shù)據(jù)。對于命令數(shù)據(jù)包的RCS;包括命令數(shù)據(jù)字段的RCS. 在這項研究中,射頻收發(fā)器是利用ISM波段。因為是一個波段之間的共享資源網(wǎng)會經(jīng)歷許多無線應(yīng)用程序(如IEEE 802.11和藍牙,一個重疊在時間、頻率和空間域可能會干擾其他網(wǎng)絡(luò)狀況的。每個標(biāo)準(zhǔn)IEEE等802.11和藍牙使用包只有片段時間有定向協(xié)議和利用共享通道。一個協(xié)議的應(yīng)用程序會有ISM的使用時間，在秩序轉(zhuǎn)移所需的數(shù)據(jù)間隔的通道是免費的或相對自由(干擾是弱)。當(dāng)一個節(jié)點想傳輸,節(jié)點聽通道和檢查 通道是免費的。機制RFW-DlOO支持CS(載波監(jiān)聽)這樣做。 為了確保一個數(shù)據(jù)包成功到達目的地(接收機),源(發(fā)射機)需要在某一固定時間從接收機的一面得到一些驗證。傳輸器將得到這個驗證,從接收端獲得一個承認(rèn)包。如果發(fā)射機不得到一個承認(rèn)包,發(fā)射機嘗試重新發(fā)送數(shù)據(jù)分組。 4.2協(xié)議的行為 對于靜態(tài)排控制,因為每一輛車不需要頻繁的更新控制輸入的劑量,傳輸數(shù)據(jù)包的機會均勻分配到每輛車。動態(tài)排控制,由于機動車輛為合并或分割要求頻繁更新的控制輸入,信息越多應(yīng)該傳給的數(shù)據(jù)包比其他機動車輛多。這也是為什么通信序列動態(tài)協(xié)調(diào)。該序列曾在崔和方舟子的工作算法中找到共通。這個協(xié)調(diào)通信序列通過RCS來實現(xiàn)。 圖6:協(xié)議行為的例子 圖6顯示了示例協(xié)議對一個周期無線通信系統(tǒng)之間的行為的研究。通信序列{ #1,# 2,# 3 }。RCS廣播主要的功能是,,每一個周期其他通信序列命令數(shù)據(jù)包和數(shù)據(jù)更新命令數(shù)據(jù)包。起初,RCS廣播命令通信序列 包。然后,每個車輛根據(jù)序列命令試圖傳播1.0通信數(shù)據(jù)包。對于同步的車輛控制,RCS廣播數(shù)據(jù)更新命令數(shù)據(jù)包，在最后的車輛(本研究在第三車)傳輸?shù)臄?shù)據(jù)包。通信系統(tǒng)的每輛車已收到數(shù)據(jù)更新命令發(fā)送接收到其他車輛的數(shù)據(jù)并從其車輛獲取新數(shù)據(jù)。此外,因為通信系統(tǒng),每輛車的嘗試將認(rèn)定為播放包同時承認(rèn)作為CSMA傳播。這個區(qū)間數(shù)據(jù)包的交流和確認(rèn)不到1毫秒。在這個階段的發(fā)展,因為UART的轉(zhuǎn)移率將是115.2 kbps,更多的時間是疲憊比之間的無線通信系統(tǒng)。自每輛車的取樣時間是40米的時間,期間的一個周期溝通是不到20 ms和兩個周期的溝通是疲憊比在每輛車的采樣時間。 4.3性能的協(xié)議 圖7顯示了在這項研究中實現(xiàn)無線通信系統(tǒng)。無線通信是安裝在每個規(guī)模車輛和試驗臺的RCS。 圖8展示了驗證無線通信系統(tǒng)的性能的裝置。作為d0或d1,32字節(jié)的數(shù)據(jù)包傳送在每個節(jié)點的固定順序。當(dāng)d0小于30米和dl是少于15米,在固定通信序列的案件包中沒有發(fā)現(xiàn)錯誤。車輛規(guī)模大小是0.3米,兩個規(guī)模汽車所需的距離不到l.O m,結(jié)果是合理的。否則,對于通信序列的命令就會改變。任意時間,它驗證的通信序列是到底是什么改變了。溝通序列修改的結(jié)果,見圖8,從源字段收到的數(shù)據(jù)包在RCS檢查。它表明,溝通序列在沒有錯誤情況下也改變了。 圖7:無線通信系統(tǒng)的實現(xiàn) 圖8:驗證過程的設(shè)置 5. 結(jié) 論 在這項研究中,無線通信系統(tǒng)車輛排實驗通過試驗臺實現(xiàn)。使用低投短程和大規(guī)?；旌霞蓭漕l收發(fā)器和一個%位單片機,無線通信系統(tǒng)它在適合條件的實驗中,現(xiàn)實和性能已被確認(rèn)的。使用可中斷單片機的定時器,保證了有效地實時操作。事實上,通信序列命令應(yīng)根據(jù)對車輛的傳輸狀態(tài)來變化。在未來的工作中RCS保持監(jiān)控車輛的狀態(tài)的功能。在這項研究中無線通信系統(tǒng)他會安裝在每個車輛和RCS的試驗臺實現(xiàn),并將有 效用于開發(fā)和驗證的一個品種車輛排控制策略和序列調(diào)度算法。 圖9:命令改變序列的結(jié)果 引 用 [1]P.Varaiya,“智能汽車智能道路:問題控制,”——IEEE自動控制,38卷1號,195 - 207頁 [2]S.E . Shladover,C . A . Desoer, J.k·亨德里克,人工智能。Tomizuka,J . Walrand,W·B·zhang,D.H.McMahonh·Peng,Sheikholeslam,N . McKeown,“自動車輛控制的發(fā)展路徑程序”,在交易車輛 IEEE技術(shù)卷。40歲,1號,114 - 130頁。 [3] D. Swaroop, J. K. Hedrick “恒間距、智能車隊”的策略在自動化高速公路系統(tǒng),動態(tài)系統(tǒng),測量和控制卷。121、462470頁。 [4] H. S. Song, T. hl. Kim, and J. W. Choi “通過遠(yuǎn)程控制站開發(fā)車輛縱向連排控制試驗臺,“2002年國際會議控制、自動化和系統(tǒng)學(xué)報,1039 - 1042頁 [5] Choi, J. W., Fang, T. H., Kwong, S., and Y. H. Kim“通過編碼器遙控排合并-通信網(wǎng)絡(luò)的估計量序列算法,“IEEE工業(yè)電子、50卷1號,,2003年。30-36頁。 161 J. W. Choi and T. H. Fang 最優(yōu)通信序列排用于遠(yuǎn)程控制的一個領(lǐng)頭車,”出現(xiàn)在2003在控制應(yīng)用IEEE會議,2003 [7] -, RFW-102 ISM llansceiuer Chipset, RFW有限公司., 2002 181 -, RFW-DlOO Standard Interface, RFW有限公司., 2002 [9] -, ATmegalGlL, Rev.l228c-AVR-O8/02, AtmelCo., 2002 10 Dynamic Characteristics on the Dual Power State of Flow in Hydro Mechanical Transmission Jibin Hu and Shihua Yuan Xiaolin Guo School of Mechanical and Vehicular Engineering Department of Automotive Engineering Beijing Institute of Technology Tsinghua University Beijing 100081 China Beijing 100084 China hujibin i jz is the mechanical path ratio i p is the transmission ratio from gear Z 22 to Z 3 i hz is the conflux ratio of mechanical path i hy is the conflux ratio of hydrostatic path i b is the transmission ratio from gear Z 5 to Z 7 MTF 1 is the variable displacement hydrostatic unit and can be describe as a variable gyrator The modulus of the gyrator is decided by parameter q p of the signal generator q m and q ml stand for conversion gain coefficient of the fixed displacement hydrostatic unit furthermore q m q ml 1 1 junction is a co flow node in which flow variables is equal 0 junction is a co effect node in which effect variables is equal 10 20 19 18 17 16 15 1413 12 11 29 28 27 26 25 24 2322 21 9 8 7 6 5 4 3 2 1 59 58 57 56 50 55 553 52 51 48 47 46 45 44 43 42 49 41 4039 38 37 36 35 34 33 32 31 30 1 I Io R g541o MTF MTF1 010 TF qm S f no Se Tb R Rp C Cp I Igl C Cm R Rm 1 R g541fm R g541b I Ib I Im 10 C Co 0 C Cb R Rgl 1 TF ihy 1 0 1TF qm1 R Rdl I Idl TF io R g541fp I Ip 1 Se pdl TF ip 1 TF ib 0 0 1 TF ihz R g541jz1 I Ijz1 C Cjz1 011TF ijz R g541jz3 C Cjz2 I Ijz3 I Ijz2 R g541jz2 qp Fig 2 Bond graph model of the HMT system g100 0 is coefficient of viscous friction on input shaft Ns m g100 fp is coefficient of viscous friction counteracting the rotation of the variable displacement hydrostatic unit g100 fm is coefficient of viscous friction counteracting the rotation of the fixed displacement hydrostatic unit g100 b is coefficient of viscous friction on output shaft R gl is leakage fluid resistance of oil in high pressure hydrostatic loop Ns m 5 R dl is leakage fluid resistance of oil in low pressure hydrostatic loop R p is leakage fluid resistance of oil in the variable displacement hydrostatic unit R m is leakage fluid resistance of oil in the fixed displacement hydrostatic unit g100 jz1 is coefficient of viscous friction in drive shafting of the mechanical path transmission g100 jz2 is coefficient of viscous friction in driven shafting of the mechanical path transmission g100 jz3 is coefficient of viscous friction in conflux shafting C o is coefficient of pliability of the input shaft m N C b is coefficient of pliability of the output shaft C p is the fluid capacitance of inner oil in the variable displacement hydrostatic unit m 5 N C m is the fluid capacitance of inner oil in the fixed displacement hydrostatic unit C jz1 is coefficient of pliability of the drive shafting of the mechanical path transmission C jz2 is coefficient of pliability of the driven shafting of the mechanical path transmission I o is the moment of inertia of the input shaft I p is the moment of inertia of the variable displacement hydrostatic unit I m is the moment of inertia of the fixed displacement hydrostatic unit I b is the moment of inertia of the output shaft I gl is the fluid inductance in high pressure oil loop Ns m 5 I dl is the fluid inductance in low pressure oil loop I jz1 is the moment of inertia of the drive shafting of the mechanical path transmission I jz2 is the moment of inertia of the driven shafting of the mechanical path transmission I jz3 is the moment of inertia of the conflux shafting C State equations of the HMT system Analyzing the dynamic characteristic of system using bond graph methods need to choose state variables of system reasonably and establish state equation of the system according to the known bond graph model of system In a general way the generalized momentum p of inertial unit and the generalized displacement of capacitive unit are introduced as state variables of system 5 10 If causalities of the bond graph are annotated according to principle of priority of the integral causality some energy storage elements in bond graph maybe have differential causality on occasion Under the circumstances the amount of state variables of the system is equal to the counterpart of energy storage elements which have the integral causality Energy variables of the energy storage elements which have the differential causality depend upon state variables of the system These variables are dependent variables Algebraic loop problem will occur while establishing state equation of 891 these kinds of bond graph The bond graph model of the HMT system established as above belongs to these kinds In Fig 2 energy variables in inertial elements I o I jz2 and I m have differential causalities The resolution is to express the generalized momentum and the generalized displacement of energy storage elements which have the differential causality with involved state variables and to work out the first derivative of these equations toward time The expressions of the inertial elements I o I jz2 and I m are derived as follows 274 p I Iii p p opo g6g6 g32 1 11 1 2 15 p Ii I p jzjz jz g6g6 g32 2 43 1 49 p I qI p dl mm g6g6 g32 3 Therefore the amount of state variables of the HMT system is just 12 2 tq 9 tq 11 tp 18 tq 20 tp 27 tp 31 tq 34 tp 37 tq 43 tp 55 tq 58 tp The input state vector U g62g64 T bdlo Tpng32 According to the structural characteristics of the system shown by bond graph the differentials of state variables can be describe as functions of state variables related to input variables 12 state equations can be formulated as follows 272 p I ii nq p po o g16g32g6 4 2711 1 9 1 p I i p I q p p jz g14g16g32g6 5 18 21 112 11 21 2 9 11 11 11 q CiC p iIC i q CC p jzjzjzjz jzjzjz jz g16 g14 g16g32 g80g80 g6 6 20 3 11 1 18 11 p I p Ii q jzjzjz g16g32g6 7 5520 3 3 18 2 20 11 q Cii p I q C p bbhzjz jz jz g16g16g32 g80 g6 8 27 2 22 9 12 2 2 27 p IC li q CC i q CC ii p p opofp jz p o po g80g80 g14 g16g16g32g6 dl p p p p C qt q CC qt 2 31 2 g72g72 g14g16 9 34312731 11 p I q CR p I qt q glppp p g16g16g32 g72 g6 10 37343134 11 q C p I R q C p mgl gl p g16g16g32g6 11 43373437 111 p I q CR p I q dlmmgl g16g16g32g6 12 432 3 2 37 3 43 1 p IqC Rq q CC p dlm dlmfm m g14 g16g32 g80 g6 dl bbhym p C q CiiqC 3 55 3 11 g16g16 13 584320 3 55 111 p I p Iqii p Iii q bdlmbhyjzbhz g16g14g32g6 14 b b b b Tp I q C p g14g16g32 585558 1 g80 g6 15 Where 1 2 1 2 1 1 jzjz jz Ii I C g14g32 p opo I Iii C 22 2 1g14g32 23 1 mdl m qI I C g14g32 III SIMULATION RESULTS In these equations above with the structural and calculative parameters of the known HMT system dynamic simulation can be done in computer In the process of simulation initial values are given primarily After the system stabilized input signal is stimulated Meanwhile the results of dynamic response of the system are recorded The response curves of the output speed of system and the oil pressure in main pipe of the bump motor system under varied input signals are shown from Fig 3 to Fig 8 Fig 3 shows the pulsed response curves of the output speed and the oil pressure of the system as the load change instantaneously The rising time of the oil pressure response is 22ms The control time is 445ms The overshoot is equal to 86 Times s Fig 3 Pulsed response of the system as load changing Pressure Output speed Speed response rpm Pressure response MPa 892 Fig 4 shows the pulsed response curves of the output speed and the oil pressure of the system as the speed changes instantaneously The rising time of the speed response is 17ms The control time is 479ms The overshoot is equal to 65 Times s Fig 4 Pulsed response of the system as speed changing Fig 5 shows a group of slope response curves as the angle of swing plate of the variable displacement bump is a ramp excitation In this figure the ascending gradients of the angle of swing plate whose range is from 0 to its maximum correspondingly relative rate of changing displacement is from 0 to 1 i e 1 0g32g72 are assigned some values respectively such as 50 20 8 4 corresponding rising time for ramp excitation are 0 04 0 10 0 25 0 50s The rising times of response of the output speed are 43 108 255 505 ms Overshoot are respectively 47 12 4 2 Times s Fig 5 Slope response of the system as angle of swing plate changing Fig 6 shows the pulsed response curves of the output speed and the main oil pressure of the system as the angle of swing plate changes instantaneously The rising time of the speed response is 22ms The control time is 420ms The overshoot is equal to 73 The bond graph model of the two range HMT system established by the author is a linear system The results of simulation demonstrate that the speed of response of the system is quite fast and the stability is satisfactory but the overshoot of step response is too large On condition that the input signal is ramp type and the gradients is greater than 8 the time interval in which the angle of swing plate changed from 0 to the maximum is not less than 0 25s the transition process of the system whose overshoot will not exceed 5 will approach steady state Times s Fig 6 Pulsed response of the system as angle of swing plate changing The results of simulation indicated by Fig 3 Fig 6 is acquired on condition that the fluid capacitances C m and C p in the model denoted in Fig 2 are set to 0 0085 As other conditions are invariable response curves indicated by Fig 7 and Fig 8 can be obtained for C m and C p are set to 0 0850 Fig 7 shows the slope response curves of the rotation speed and the pressure as the angle of swing plate changes on the principle of ramp excitation The rising times of response of the output speed are 87 121 204 519 ms Overshoot are respectively 52 38 11 5 Times s Fig 7 Slope response of the system when C m and C p are set to 0 0850 Pressure Output speed Speed response rpm Pressure response MPa Pressure Output speed Speed response rpm Pressure response MPa Pressure Output speed Speed response rpm Pressure response MPa Pressure Output speed Speed response rpm Pressure response MPa 893 Fig 8 shows the pulsed response curves of the rotation speed and the pressure The rising time of response of the output speed is 68ms Overshoot is 57 Compared with the results of simulation indicated in Fig 5 and Fig 6 the speed of response of the system is slowing down and the time interval needed to reach the steady state is delayed At the same time the number of oscillations of the response and fluctuating quantity of the pressure is decreasing The overshoot of the pulsed response increased a little but the overshoot of the slope response increased a bit as well Times s Fig 8 Pulsed response of the system when C m and C p are set to 0 0850 IV CONCLUSIONS A bond graph model of the dual power state of flow of the two ranges HMT system is established based on the bond graph theory The model can be applied to simulate and study the dynamic characteristics of a hydro mechanical transmission HMT system On conditions that the displacement of the hydrostatic bump is constant the system focused in this article can be simplified to a linear stationary system On conditions that the displacement of the hydrostatic bump changes along with time the system is a linear time varying system the transition of the system approaches to stable state while the ramp input signal draws 8s The value of the fluid capacitance in the hydrostatic system affects the dynamic response performance of the system A further study on the influence of the fluid capacitance and the fluid resistance will be done REFERENCES 1 X Liu Analysis of Vehicular Transmission System Beijing National Defense Industry Press 1998 pp 255 310 2 D Margolis T Shim A Bond Graph Model Incorporating Sensors Actuators and Vehicle Dynamics for Developing Controllers for Vehicle Safety Journal of the Franklin Institute Vol 338 pp 21 34 2001 3 M Cichy M Konczakowski Bond Graph Model of the IC Engine as an Element of Energetic Systems Mechanism and Machine Theory Vol 36 pp 683 687 2001 4 N Chenglie N Chen Y Na Dynamic Simulation Research of Power Matching on Axial Plunger Pump Journal of Gansu University of Technology Vol 26 24 pp 54 59 2000 5 Z Wang Bond Graph Theory and Its Application in System Dynamic Harbin Harbin Engineering University Press 2000 6 J Liu The Application of Bond Graph Theory for Dynamic Simulations on Driving Mechanism of Automobile Brake System Journal of Xi an Highway University Vol 19 pp 97 100 April 1999 7 J Zheng W Peng The Application of Bond Graph Theory for Dynamic Simulation on Hydraulic Control System Journal of Wuhan Automotive Polytechnic University Vol 20 pp 43 45 April 1998 8 R F Ngwompo P J Gawthrop Bond Graph based Simulation of Non linear Inverse Systems Using Physical Performance Specifications Journal of the Franklin Institute Vol 336 pp 1225 1247 1999 9 W Borutzky B Barnard J U Thoma Describing Bond Graph Models of Hydraulic Components in Modelica Mathematics and Computer in Simulation Vol 53 pp 381 387 2000 10 R Cacho J Felez C Vera Deriving Simulation Models from Bond Graphs with Algebraic Loops Journal of Franklin Institute Vol 337 pp 579 600 2000 Pressure Output speed Speed response rpm Pressure response MPa 894