車(chē)輛工程外文翻譯-地面車(chē)輛自動(dòng)變速器的換擋節(jié)能研究【中文3880字】【PDF+中文WORD】
車(chē)輛工程外文翻譯-地面車(chē)輛自動(dòng)變速器的換擋節(jié)能研究【中文3880字】【PDF+中文WORD】,中文3880字,PDF+中文WORD,車(chē)輛,工程,外文,翻譯,地面,自動(dòng)變速器,換擋,節(jié)能,研究,中文,3880,PDF,WORD
地面車(chē)輛自動(dòng)變速器的換擋節(jié)能研究龔捷,趙丁選,陳鷹,陳寧摘要:為了改善地面車(chē)輛的效率,通過(guò)對(duì)車(chē)輛動(dòng)力傳動(dòng)系統(tǒng)的液力變矩器和傳輸功能的研究,提出了地面車(chē)輛自動(dòng)變速器的換擋規(guī)律。這種轉(zhuǎn)變計(jì)劃可以保持轉(zhuǎn)矩變換器在高效率范圍內(nèi)的所有工作條件下工作,除了當(dāng)傳輸工作在左側(cè)最低轉(zhuǎn)變時(shí)和在右側(cè)最高轉(zhuǎn)變時(shí)的低效率范圍內(nèi)。對(duì)換擋質(zhì)量的關(guān)鍵因素進(jìn)行了分析。自動(dòng)反式。對(duì)自動(dòng)變速器試驗(yàn)臺(tái)采用這種轉(zhuǎn)變的時(shí)間表進(jìn)行了臺(tái)架試驗(yàn)的任務(wù),試驗(yàn)結(jié)果表明,換擋規(guī)律是正確的,這種轉(zhuǎn)變質(zhì)量可控。關(guān)鍵詞:地面車(chē)輛,液力傳動(dòng),自動(dòng)變速器,換擋,節(jié)約能源,換擋品質(zhì) 文獻(xiàn)標(biāo)識(shí)碼:A 中圖分類(lèi)號(hào):u270.1 引言 汽車(chē)自動(dòng)變速技術(shù)廣泛應(yīng)用于地面車(chē)輛,來(lái)提高生產(chǎn)率和降低勞動(dòng)強(qiáng)度。然而,在低速、重負(fù)荷和負(fù)荷急劇變化等各種操作條件的地面車(chē)輛的性能,與正常操作的汽車(chē)非常不同。因此,不能采用地面車(chē)輛鎖定離合器的方法用于汽車(chē)液力變矩器解決在低效率的工作范圍(龔,2002)。為了使能源的合理利用。根據(jù)實(shí)際的負(fù)載和換擋規(guī)律的研究,以決定轉(zhuǎn)變可能在高效率范圍內(nèi)工作的扭矩轉(zhuǎn)換器。這是轉(zhuǎn)變的決策問(wèn)題。我們知道,車(chē)輛發(fā)動(dòng)機(jī)與液力變矩器是復(fù)雜的非線(xiàn)性系統(tǒng),很難控制。模糊控制結(jié)合人類(lèi)經(jīng)驗(yàn)算法能夠處理非線(xiàn)性系統(tǒng),不需要正式分析結(jié)構(gòu)的應(yīng)用能力。在過(guò)去的十年中,大量的工作人員對(duì)自動(dòng)化變速器的控制系統(tǒng)進(jìn)行了模糊控制的探索性工作(山口等人,1993;坂口,1993;沈,1997)。與傳統(tǒng)的控制相比,模糊控制是一種滿(mǎn)意而不是最優(yōu)的控制。本研究關(guān)注的是液力變矩器和變速器在車(chē)輛傳動(dòng)系的控制作用,確定變矩器保持在高效區(qū)工作的一個(gè)新的換擋變速。 換擋循環(huán) 轉(zhuǎn)變調(diào)節(jié)移矩(自動(dòng)變速器的各種變化)的控制參數(shù)。是自動(dòng)變速器開(kāi)發(fā)的關(guān)鍵技術(shù);并直接影響車(chē)輛的經(jīng)濟(jì)性能和動(dòng)力性能。這部分內(nèi)容如下:首先,給出高效率范圍和低效率范圍的定義。而后,對(duì)為什么變矩器在低效率范圍內(nèi)工作的原因進(jìn)行了討論。最后,提出了解決問(wèn)題的方法。 效率高范圍和低效率的范圍定義 為了評(píng)估液力變矩器的經(jīng)濟(jì)性能,變矩器的效率不應(yīng)小于理想值( = 75%使用在工程機(jī)械, = 80%的汽車(chē)通常)。YJ355的液力變矩器的主要特點(diǎn)是顯示在圖1(趙 et a1。,2001)。有兩點(diǎn)滿(mǎn)足= 。全工況變矩器的條件分為兩個(gè)點(diǎn),即三個(gè)地區(qū),效率低的范圍,低比轉(zhuǎn)速定位,高效率范圍和低效率范圍在高速率的定位。當(dāng)轉(zhuǎn)矩變換器工作在效率低的范圍內(nèi),工況點(diǎn)位于低或高速率,換擋規(guī)律必須控制變速器的換擋,使變矩器在高效區(qū)工作。 圖1. YJ355液力變矩器的主要特點(diǎn) 液力變矩器的低效率范圍內(nèi)工作的原因 根據(jù)不同的操作條件,液力變矩器可乘以轉(zhuǎn)矩。對(duì)于裝有液力變矩器的地面車(chē)輛,液力變矩器的工況點(diǎn)從高的效率范圍內(nèi)移到低效率范圍,定位在低速率作為車(chē)輛的持續(xù)性增加。反之,變矩器的工況點(diǎn)從高的效率范圍移到低效率范圍,定位在高速率作為車(chē)輛的持續(xù)性降低。它可以被稱(chēng)為自動(dòng)控制系統(tǒng)。因此,換擋規(guī)律的計(jì)算公式如下。 轉(zhuǎn)換理論 換擋規(guī)律是控制發(fā)動(dòng)機(jī)和液力變矩器的一套共同工作點(diǎn),使液力變矩器的效率不小于理想值;換句話(huà)說(shuō),滿(mǎn)足條件的點(diǎn) =作為換擋點(diǎn)。換擋決定自動(dòng)變速控制系統(tǒng)計(jì)算傳動(dòng)比,控制液力變矩器在的范圍內(nèi)工作。 地面車(chē)輛模型如圖2所示(龔和趙,2001a;2001b)。 圖.2 車(chē)輛的模型 首先,我們考慮的情況下,變矩器低速比的工作定位在低效率的范圍。據(jù)推測(cè),在圖1表示的兩個(gè)工況點(diǎn)滿(mǎn)足在低效率范圍內(nèi)定位在低速比和換擋點(diǎn)的條件 = r,、分別代表兩個(gè)點(diǎn)的轉(zhuǎn)矩。 假設(shè)它是傳動(dòng)齒輪比。動(dòng)工況點(diǎn)在效率低的范圍內(nèi)的效率高,傳動(dòng)是用來(lái)增加轉(zhuǎn)矩。然后是 (1)液力變矩器在低效率的范圍定位在高速率工作時(shí),方程(1)中得到的相同的方式。不同的是,是在高速率的換擋點(diǎn)對(duì)應(yīng)的輸出轉(zhuǎn)矩。 以上兩種情況綜合起來(lái)。由于在車(chē)輛驅(qū)動(dòng)系統(tǒng)的傳輸函數(shù)是通過(guò)變速調(diào)節(jié)驅(qū)動(dòng)系統(tǒng)的輸出轉(zhuǎn)矩,上面得到的是多個(gè)(或分?jǐn)?shù))的變速器輸出轉(zhuǎn)矩在接下來(lái)的時(shí)刻。然而,一個(gè)連續(xù)的換擋過(guò)程中,變速器已經(jīng)在一定的轉(zhuǎn)移,即,變速器輸出扭矩被放大到一小部分在目前的大小是傳動(dòng)裝置的傳動(dòng)比。因此,多(或分?jǐn)?shù))的變速器輸出轉(zhuǎn)矩在下一刻,必須增加(或減少)由一個(gè)因子一次。換句話(huà)說(shuō),在下一個(gè)時(shí)刻齒輪比必須增加(或減少)的一個(gè)因素,它在現(xiàn)有的齒輪比的基礎(chǔ)上,這是 (2)其中是在下一個(gè)時(shí)刻齒輪傳動(dòng)比,是目前齒輪傳動(dòng)比。 從方程:(1)和(2),該換擋規(guī)律的計(jì)算公式如下: (3)雖然傳輸?shù)睦硐雮鲃?dòng)比連續(xù)值。實(shí)際的齒輪比的傳輸提供的是離散的有限值。在實(shí)際應(yīng)用中,齒輪比的選擇根據(jù)是否變矩器的工況點(diǎn)位于低速率的地區(qū)或高一。的條件下,對(duì)液力變矩器工況點(diǎn)位于低速率最低的區(qū)域轉(zhuǎn)移時(shí)選用計(jì)算傳動(dòng)比大于傳輸?shù)淖畲髠鲃?dòng)比更大的齒輪比。否則會(huì)選擇當(dāng)計(jì)算傳動(dòng)比傳動(dòng)的傳動(dòng)比之間的兩個(gè)實(shí)際的情況。液力變矩器的工作工況點(diǎn)位于高速率下的地區(qū),最高的移位時(shí)選用計(jì)算傳動(dòng)比小于最小傳動(dòng)比的傳動(dòng)小齒輪比。 否則,小齒輪比將選擇當(dāng)計(jì)算傳動(dòng)比傳動(dòng)的傳動(dòng)比之間的兩個(gè)實(shí)際。 現(xiàn)在。舉例說(shuō)明如何使用它。假設(shè)4班制傳輸,i4i3 i2 i,其中是齒輪比,移位,和1,2,3, 4.轉(zhuǎn)變?yōu)楸?所示。 為了防止循環(huán)移位的方法 就像前面討論的,在上面的換擋加速點(diǎn)和降擋點(diǎn)是相同的。為了防止傳輸“狩獵”中使用,采用的方法是區(qū)分正常從頻繁的齒輪變化。首先,由于地面車(chē)輛的換擋頻率幾乎是每小時(shí)一千次(Wang et a1 . 2000)。從一個(gè)轉(zhuǎn)移到下一個(gè)的最小時(shí)間間隔為2秒。假設(shè)的數(shù)據(jù)采集時(shí)間T(MS),兩個(gè)位移的擋位決策的頻率2000.因此,當(dāng)頻率上移(或降擋)是轉(zhuǎn)移決策時(shí)間的一半,這是一種常見(jiàn)的齒輪的變化。當(dāng)上轉(zhuǎn)移的時(shí)代(或降擋)是為轉(zhuǎn)移的決策時(shí)間相同,這是一個(gè)正常的齒輪變化。 該方法不僅適用于上述換擋規(guī)律。同時(shí)也充當(dāng)所有班次,以避免循環(huán)移位的一般方法。 換擋品質(zhì) 換擋是通過(guò)控制離合器或制動(dòng)器接合或脫離完成。為轉(zhuǎn)移的質(zhì)量與換擋是否可以應(yīng)用于實(shí)際的車(chē)輛有密切的關(guān)系。討論了指數(shù)和影響換擋品質(zhì)的主要因素,為了改善換擋品質(zhì)提供理論依據(jù)。 目前,加加速度作為評(píng)定指標(biāo)的換擋品質(zhì)。加加速度被定義作為汽車(chē)縱向加速度的變化。它的表達(dá)式(Lei et a1 . 1999) (4)其中J,V分別加加速度,車(chē)輛的加速度,速度,t為時(shí)間,是車(chē)輪半徑,是變速器輸出軸和驅(qū)動(dòng)輪之間的傳動(dòng)比,是變速器輸出軸,角速度和扭矩分別,是的阻力力矩作用于車(chē)輪,而應(yīng)該在移位不變,是有關(guān)變速器輸出軸的轉(zhuǎn)動(dòng)慣量。 上述公式表明,降低痙攣的有效方法是控制在變速器輸出軸,即轉(zhuǎn)矩變化的影響,使轉(zhuǎn)矩變化最小。 發(fā)動(dòng)機(jī)臺(tái)架試驗(yàn)為了驗(yàn)證換擋,自動(dòng)變速器試驗(yàn)研究了自動(dòng)變速器試驗(yàn)臺(tái)。 自動(dòng)變速器試驗(yàn)臺(tái)的組成部分 部件和控制的自動(dòng)變速器實(shí)驗(yàn)臺(tái)的方法如圖3所示??梢钥闯觯囼?yàn)臺(tái)自動(dòng)變速器由發(fā)動(dòng)機(jī),變矩器,傳動(dòng),增速器,和電渦流測(cè)功機(jī)。該機(jī)電源。電渦流測(cè)功機(jī)是一種用于加載的驅(qū)動(dòng)繞組電流的變化通過(guò)調(diào)整制動(dòng)負(fù)載功率損耗的裝置。增速器用于電渦流測(cè)功機(jī)匹配的轉(zhuǎn)速。在測(cè)試過(guò)程中,速度和轉(zhuǎn)矩的發(fā)動(dòng)機(jī)和液力變矩器進(jìn)行采集和計(jì)算機(jī)處理的計(jì)算機(jī)控制的電磁致動(dòng)器。閥門(mén)的開(kāi)啟或關(guān)閉來(lái)實(shí)現(xiàn)移位根據(jù)換擋規(guī)律。 圖3 自動(dòng)換擋試驗(yàn)臺(tái)示意圖 換擋規(guī)律的實(shí)驗(yàn)結(jié)果 液力變矩器的效率控制在測(cè)試中的75%。數(shù)據(jù)采集的時(shí)間間隔設(shè)置為200毫秒。通過(guò)連接各點(diǎn)的數(shù)據(jù)采集所得到的實(shí)驗(yàn)結(jié)果示于圖4。降檔的過(guò)程中,對(duì)應(yīng)圖4b中的負(fù)荷增加。升檔的過(guò)程中,與降低的負(fù)載對(duì)應(yīng)。升檔的過(guò)程中與降低的負(fù)載相對(duì)應(yīng)的效率低于75,在圖4a中那些點(diǎn)是由換檔決定的。實(shí)驗(yàn)結(jié)果證明,變速節(jié)能可以根據(jù)作用在傳動(dòng)系統(tǒng)的實(shí)際負(fù)荷使換擋在變矩器的高效區(qū)工作。 時(shí)間t (s) (a) 時(shí)間t (s) (b) 時(shí)間t (s) (c) 圖4實(shí)驗(yàn)結(jié)果自動(dòng)換擋試驗(yàn)臺(tái)(一)效率的變化; (b)換擋改變;(c)渦輪轉(zhuǎn)矩的變化換擋質(zhì)量的實(shí)驗(yàn)結(jié)果 變矩器的輸出扭矩的測(cè)量結(jié)果顯示在圖.4c 。1) 在試驗(yàn)現(xiàn)場(chǎng),我們認(rèn)為,降擋的沖擊和振動(dòng)比升擋更強(qiáng)。這其中的原因,由式(4)和圖4c解釋了,是降擋的扭矩變化比升擋大。 2) 在圖4c中有4個(gè)槽,對(duì)應(yīng)于每個(gè)換擋點(diǎn)。這種現(xiàn)象表明了換擋過(guò)程中發(fā)生電力中斷。 3)研究了換擋質(zhì)量的可控性條件,在測(cè)試的十三個(gè)轉(zhuǎn)變點(diǎn)進(jìn)行了仔細(xì)的分析。闡述了換擋過(guò)程中,變速課程三實(shí)驗(yàn)數(shù)據(jù),從實(shí)驗(yàn)記錄中提取,并在表2中列出。為了方便地描述換擋過(guò)程的。測(cè)量點(diǎn)后移,發(fā)送指令掉叫轉(zhuǎn)向點(diǎn)和標(biāo)記為1點(diǎn)。在轉(zhuǎn)移點(diǎn)標(biāo)記為點(diǎn)0點(diǎn)。后移點(diǎn)標(biāo)記為點(diǎn)2點(diǎn),其余可以類(lèi)推。每一組的液力變矩器的輸出扭矩的變化規(guī)律:點(diǎn)L液力變矩器的輸出扭矩低于0點(diǎn),2點(diǎn)的變矩器的輸出扭矩降低超過(guò)1點(diǎn)。3點(diǎn),在液力變矩器的輸出扭矩。折痕高于2點(diǎn),4點(diǎn)的液力變矩器的輸出扭矩是那些2最大的點(diǎn),點(diǎn)3和5點(diǎn)。 在換擋過(guò)程表明,原來(lái)的換擋離合器開(kāi)始下滑1點(diǎn)。原來(lái)的移位脫離和新轉(zhuǎn)向離合器離合器沒(méi)有進(jìn)行2點(diǎn)。這時(shí),電力中斷發(fā)生的轉(zhuǎn)變。新的離合器開(kāi)始下滑3點(diǎn),4點(diǎn)嚙合。 結(jié)論 從以上實(shí)驗(yàn)結(jié)果,我們可以得出這樣的結(jié)論: 1) 排班節(jié)能可以維持轉(zhuǎn)矩變換器工作在理想值范圍內(nèi)的所有工作條件下,除了以下兩種情況。一個(gè)是在傳輸中的最低擋工作時(shí)左效率低的范圍內(nèi)。而另一個(gè)是右邊的低效率的傳輸范圍在最高擋工作時(shí)。 2)隨機(jī)載荷試驗(yàn)時(shí)施加在傳動(dòng)。雖然通過(guò)對(duì)液力變矩器的主要特征得到了上述換擋節(jié)能,試驗(yàn)結(jié)果表明,變速節(jié)能是正確的,液力變矩器的動(dòng)力學(xué)特性的條件下工作。 3)為了減少在測(cè)試換擋沖擊可能會(huì)知道新?lián)Q擋離合器應(yīng)接合200毫秒,比要脫離原有的轉(zhuǎn)移較早。因此,換擋質(zhì)量可以通過(guò)定時(shí)控制改進(jìn)。 總結(jié) 為了解決地面車(chē)輛自動(dòng)變速器在重負(fù)載下的低扭矩轉(zhuǎn)換器的效率問(wèn)題,提出了一個(gè)新的變速節(jié)能自動(dòng)變速器。在自動(dòng)變速器試驗(yàn)臺(tái)上對(duì)自動(dòng)變速器進(jìn)行了該換擋規(guī)律的試驗(yàn)。實(shí)驗(yàn)結(jié)果表明,該換擋規(guī)律是正確的,換擋質(zhì)量是可控的。上述研究結(jié)果為地面車(chē)輛提高換擋品質(zhì)的應(yīng)用提供了可靠的依據(jù)。 維普資訊 http:/www.cqv1p.com878Gong et al. I J Zhejiang Univ SCI 2004 5(:878-883Journal of Zhejiang University SCIENCE ISSN I 009-3095http:/www.習(xí)u.edu.c叫zus E-mail: jzus 習(xí)u.edu .cnStudy on shift schedule saving energy of automatic transmission of ground vehicles*。GONG Jie (龔 捷)t 氣 ZHAO Ding、-xuan (趙丁選)1, CHEN Ying (陳 鷹)2, CHEN Ning (陳 寧)( 1College of Mechanical Science and Engineering, Jilin Universi紗,Changchun / 30025, China)(1Stale Key Lab of Fluid Power Transm.ission and Control, Zh iang Universi秒,Hangzhou 3 /0027, China)飛 mail: gongjie勾uedu.cnReceived Oct. 8, 2003電revision accepted Jan. I 0, 2004Abstract: To improve ground vehicle efficiency, shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetrain. The shift schedule can keep the torque converter working in the high efficiency range under all the working conditions except in the low efficiency range on the left when the transmission worked at the lowest shift, and in the low efficiency range on the right when the transmission worked at the highest shift. The shift quality key factors were analysed. The automatic trans missions bench-test adopting this shift schedule was made on the automatic transmissions test-bed. The experimental results showed that the shift schedule was coect and that the shift quality was controllable.Key words: Ground vehicle, Hydrodynamic drive, Automatic transmission, Shift schedule, Saving energy, Shift quality Document code:ACLC number:U270. lINTRODUCTIONThe technology of automatic transmission in the automobile is widely applied in the ground vehicle to increase productivity and decrease in tensity of labor. However, the performance of the ground vehicle in various operating conditions, such as low speed, heavy load and sharply changing load, is very different from that of the automobile in normal operation. Therefore, the ground vehicle cannot adopt the method of the lock-up clutch used in the automobile to solve the problem of the torque conve口er working in its low efficiency range (Gong, 2002). In order to make reasonable use of energy sources, a shift schedule is studied in order to de cide which shift could ensure that the torque con-Project (No. 59705005) supported by the National Natural Science Foundation of Chinaverter works in its high efficiency range according to the actual load. This is the problem of shifs decision-making.As we know, the engine and torque converter in the vehicle drivetrain are complicated nonlinear systems ve difficult to control. The main advan tage of fuzzy control inco叩orating human experi ences in the algorithm is its ability to deal with nonlinear systems and not requiring a formal ana lytical structure in application. In the last decade, a number of researchers conducted exploratory work on fuzzy control for the control systems of the automatic transmission (Yamaguchi et al., 1993; Sakaguchi, 1993; Shen, 1997). Compared with the traditional control, fuzzy control is a satisfactory but not an optimal control. In this study, we are concerned with the control effect of the torque converter and transmission on the vehicular drivetrain and determining that the torque converter維普資訊 http:/www.cqv1p.comGong et al. I J Zhejiang Univ SCI 2004 5(7):878-883879is maintained working in its high efficiency range by gear shift with a new shift schedule.SHIFT SCHEDULEShift scheduling adjusts the shifting moment (of various shifts of the automatic transmission changes) with the control parameters. It is the key technology of the automatic transmission I 0.4The ground vehicle model is shown in Fig.2 (Gong and Zhao, 2001a; 2001b).First, we consider the case of the torque conv-100.2o l。V l o0.20.40.60.81.0Speed ratio iFig.I YJ355 Torque converter primary characteristicsFig.2 Model of vehicle維普資訊 http:/www.cqvip.com880Gong et al.I J Zhejiang Lniv SCI 2004 5(刀878氣883erter working in the low efficiency range locating in the low speed ratio. It is supposed that the two points in Fig. I represent the working conditionli_ ;Inexlt pres町11 咱句1c lim(3)point in the low efficiency range locating in the low speed ratio and the shift point meeting the condition of 1J1c = 1J1c min, respectively, and Tic, Tic lim represent the two points torque, respectively.Suppose that the transmission gear ratio is i1. To move the working condition point to the high efficiency range from the low efficiency range, the transmission is used to increase the torque. Then there is、,且,aE、i,兀 I T.c1 mWhen the torque converter works in the low effi ciency range locating in the high speed ratio, Eq.( 1) is obtained in the same way, where the difference is that Tic lim is the output torque coesponding to the shift point in the high speed ratio.The above two situations are considered to gether. Since the function of the transmission in the vehicular drive system is to adjust the output torque of the drive system by gear shift, the above obtained i1 is the multiple (or fraction) of the transmission output torque at the next moment. However, during a continuous shift, the transmission is already in a certain shift, that is, the transmission output torque has been magnified to a fraction at the present moment and the magnitude is the gear ratio of the transmission . Therefore, the multiple (or fraction) of the transmission output torque at the next mo ment must be increased (or decreased) by a factor i1 again. In other words, the gear ratio at the next moment must be increased (or decreased) by a factor i1 on the basis of the present gear ratio, that isAlthough the ideal gear ratios of the trans mission are continuous values, the actual gear ra tios of the transmission supplied are discrete finite values. In practical applications, the gear ratio is chosen according to whether the working condition point of the torque converter locates in the low speed ratio region or in the high one. Under the condition that the working condition point of the torque converter locates in the low speed ratio re gion, the lowest shift is chosen when the calculated gear ratio is larger than the maximum gear ratio of the transmission . Otherwise the bigger gear ratio will be chosen when the calculated gear ratio is between the two actual gear ratios of the transmis sion. Under the condition that the working condi tion point of the torque conve口er locates in the high-speed ratio region, the highest shift is chosen when the calculated gear ratio is smaller than the minimum gear ratio of the transmission. Otherwise the smaller gear ratio will be chosen when the calculated gear ratio is between the two actual gear ratios of the transmission .Now, an example is taken to show how it is used. Suppose that a transmission with 4 shifts, i4 i3 i2 i1, where i, is gear ratio, n is shift, and= 1,2,3,4. The shift is chosen as shown in Table 1.腳1ethod to prevent shift cyclingAs discussed before, the upshift point and the downshift point are the same in the above shiftschedule. In order to prevent the transmission hunting” in use, a method is adopted to distinguishTable 1 Shi“ choosing measurel Inexl = lIpresenl lt(2)where i1nex1 is the transmission gear ratio at the next moment, i1 present is the transmission gear ratio at present.From Eqs.( 1) and (2), the shift schedule for mula is as follows:i, nexr i4/4 i, nex 1 i313 11 ne I i2i2 iInexl i1Shift when theShift when the working point isworking point is in i n low speed ratiohigh speed ratio4A 句d3叮h2維普資訊 h憂(yōu)p:/www.cqvip.comGong et al. 1 J Zh吃;iang U11ii SCI 2004 5(刀878-883 881the normal from the frequent gear that changes shi白Firstly, since the shift frequency of the ground vehicle is nearly a thousand times per hour (Wang et al., 2000), the minimum time interval from one shift to the next is chosen to be 2 seconds. Supposethat the time of the data acquisition is t (m時(shí),thefrequency of the shift decision between two shifts is 2000/t . Therefore, when the frequency of the up shift (or downshift) is half of the shift decisiontimes, it is a frequent gear changes shift. When the times of the upshi白(or downshift) are the same asthe shift decision times, it is a normal gear changes shift.The method not only adapts to the above shift schedule, but also acts as a general method for all shift schedules to avoid shift cycling.SHIFT QUALITYThe gear shift is completed by controlling clutch or brake to engage or disengage. As shift quality is closely linked to whether a shift schedule can be applied to the actual vehicle, it is necessary to discuss the deliberated index and the main fac tors affecting shift quality, in order to provide a theoretical basis for improving shift quality.At present, jerk is used as the deliberated index of shift smoothness. Jerk is defined as the change of the longitudinal acceleration of the automobile. Its mathematical expression is (Lei et al., 1999)unchanged during a shi白,lw is the moment of in ertia relating to the part of the transmission output sha白The above formula shows that the effective method of decreasing jerk is to control the effect of torque change on the transmission output shaft, that is, to make the torque change minimum .BENCH-TESTIn order to verify the shift schedule, an automatic transmission test experiment was made on an automatic transmission s test-bed.Componen t of automatic transmission s test-bed The components and control method of the automatic transmission stest-bed is shown in Fig.3.It can be seen that the automatic transmission stest-bed consists of an engine, a torque converter, a transmission, a speed increaser, and an electric eddy current dynamometer. The engine is a power supply. The electric eddy cuent dynamometer is a power dissipation device used for loading for the drivetrain by adjusting winding cuent to change the brake load. The speed increaser is used for matching the rotational speed for the electric eddy current dynamometer. During the test, the speed and torque of the engine and the torque converter were acquired and processed by a computer. The computer control actuators electromagnetic valveElectric eddy current dyna mometer controller(4)iof wdti0lwdtwhere ),v are the jerk , acceleration and speed of the vehicle, respectively , t is time, rr is the wheel radius, i0 is the gear ratio between the transmission output shaft and the driving wheel, woT, ToT are the angular velocity and torque of the transmissionoutput shaft, respectively , Tw is the resistanceFig.3 Schematic diagram for the automatic gear sh惱s moment acting on the wheel, and supposed to betest-bed維普資訊 h憂(yōu)p:/www.cqv1p.com882Gong et al. I J Zh吃;iang l.ini SCI 2004 5(7):878-883opened or closed to implement shift according to the shift schedule.Experimental results of shift schedule氣dlF31u(法)PEzguE兇The torque converter efficiency was controlled to be over 75% in the test. The time interval of the data acquisition was set to be 200 ms. The ex perimental results obtained by connecting the points of the data acquisition are shown in Fig.4. Thecourse of downshift corresponded with that of in creasing load in Fig.4b. The course of upshi白cor responded with that of decreasing load. The points of efficiency less than 75% in Fig.4a were those determined by shift decision. The experimental results proved that the shift schedule saving energy could make torque converter work in the high ef ficiency range by gear shift according to the actual load acting on the drivetrain.句、“句,62出 口 。叫目的gESH4400i350邑 300氈,否。250C-; 200:-e I SO 100100200300400500氣d 5氣,1 o lrLTime t (s)(a)100200300Time t (s)(b)400500Experimental results of shift qualityThe measured results of the torque converter output torque are shown in Fig.4c.I) On the test site, we felt that the impact and vibration of the downshift were stronger than that of the upshift. The reason for this, as explained by Eq.(4) and Fig.4c, is that the torque change of the downshift is bigger than that of the upshift.2) There is a trough in Fig.4c, coesponding to each shift point. This phenomenon indicates oc cuence of power inteuptions during gear shi位,3) To study the controllability condition of shift quality, the thirteen shift points in the test were carefully analysed. To expound the course of gear shift, the experimental data of three gear shift courses were extracted from the experimental re cord, and listed in Table 2. In order to easily de scribe the course of the gear shift. The measured point, after shift instruction is sent out, is called a shift point and marked as point l . The point before the shift point is marked as point 0. The point after the shift point is marked as point 2, the rest can be deduced by analogy. The torque converter output torque of each group has the following changing rule:the torque converter output torque of point 1 is less than that of point 0, the torque converter output torque of point 2 reduces more than that of point 1, the torque converter output torque of point 3 in creases more than that of point 2, the torque con verter output torque of point 4 is the biggest amongthose of point 2, point 3 and point 5.nnvl200300400Time t (s)(c)500The course of the gear shift indicates that the clutch of the original shift began to slip at point l .The clutch of the original shift disengaged and theFig.4 Experimental results of the automatic gear shiftstest-bed (a) Efficiency change; (b) Transmission shift change; (c) Turbine torque changeclutch of the new shift did not engage at point 2. At this moment, power interruptions occurred. The維普資訊 http:/www.cqv1p.comGong et al.I J Zhejiang Univ SCI 2004 5(7):878-883883clutch of the new shift began to slip at point 3 and engaged at point 4.ConclusionFrom the above experimental results, we canconclude that:SUMMARYIn order to solve the problem of the low torque converter efficiency in the automatic transmission of the ground vehicle under heavy load, a new shift schedule saving energy is proposed for the auto1) The shift schedule saving energycanmatic transmission of the ground vehicle. Experimaintain the torque converter working in the range of an ideal value under all the working conditions except the following two cases, one is the low ef ficiency range on the left when the transmission works in the lowest shift, and the other is the low efficiency range on the right when the transmissi(?n works in the highest shift.2) Random load was imposed on the drivetrain during the test. Although the above shift schedulesaving energy was obtained by the studying torque converters primary characteristic, the experimen tal results showed that the shift schedule saving energy is coect while the torque converter isworking under conditions of the kinetic characteristic.3) In order to reduce the impact of the gear shift in the test, it could be known that the clutch of the new shift should be engaged 200 ms earlier than that of the original shift to be disengaged. Therefore, shift quality can be improved by timing control.Table 2 Experimental data of three shift coursesTorque converter outputment on the automatic transmission bench-test adopting this shift schedule was made on theautomatic transmission s test-bed. The experimental results showed that the shift schedule was coect and that shift quality was controllable. The above research results provide reliable basis for application to ground vehicle and improving shift quality.ReferencesGong, J., Zhao, D.X., 200 la. Study on shift schedule and simulation of automatic transmission . Chinese Journal of Mechanical Engineering , 14:250-253 .Gong,工,Zhao, D.X., 2001b. Study on shift schedule andauto-controlling simulation of automatic transmission . Journal of 刀an Jiaotong Universi紗,35:930-934 (in Chinese).Gong, J., 2002. Study on Shift Schedule of Automatic Transmission for High Efficiency. Ph.D thesis, Jilin University, China (in Chinese).Lei, Y.L., Ge, A.L., Qin, G.H., 1999. Testing study of improving shift quality of automated mechan
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