車輛工程外文翻譯-地面車輛自動變速器的換擋節(jié)能研究【中文3880字】【PDF+中文WORD】

車輛工程外文翻譯-地面車輛自動變速器的換擋節(jié)能研究【中文3880字】【PDF+中文WORD】,中文3880字,PDF+中文WORD,車輛,工程,外文,翻譯,地面,自動變速器,換擋,節(jié)能,研究,中文,3880,PDF,WORD 維普資訊 http://www.cqv1p.com 878 Gong et al. I J Zhejiang Univ SCI 2004 5（η：878-883 Journal of Zhejiang University SCIENCE ISSN I 009-3095 http://www.習(xí)u.edu.c叫zus E-mail: jzus ＠習(xí)u.edu .cn Study 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.cn Received Oct. 8, 2003電revision accepted Jan. I 0, 2004 Abstract: 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- mission’s bench-test adopting this shift schedule was made on the automatic transmission’s test-bed. The experimental results showed that the shift schedule was coπect and that the shift quality was controllable. Key words: Ground vehicle, Hydrodynamic drive, Automatic transmission, Shift schedule, Saving energy, Shift quality Document code: A CLC number: U270. l INTRODUCTION The 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 China verter works in its high efficiency range according to the actual load. This is the problem of shifγs decision-making. As we know, the engine and torque converter in the vehicle drivetrain are complicated nonlinear systems veη 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.com Gong et al. I J Zhejiang Univ SCI 2004 5(7):878-883 879 is maintained working in its high efficiency range by gear shift with a new shift schedule. SHIFT SCHEDULE Shift 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 0.4 The ground vehicle model is shown in Fig.2 (Gong and Zhao, 2001a; 2001b). First, we consider the case of the torque conv- [10 0.2 o l 。V l o 0.2 0.4 0.6 0.8 1.0 Speed ratio i Fig.I YJ355 Torque converter primary characteristics Fig.2 Model of vehicle 維普資訊 http://www.cqvip.com 880 Gong et al.I J Zhejiang L’niv SCI 2004 5（刀·878氣883 erter 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 condition  l i _ ; Inexl ’t 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 m When 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 coηesponding 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 is Although 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 cycling As discussed before, the upshift point and the downshift point are the same in the above shift schedule. In order to prevent the transmission "hunting” in use, a method is adopted to distinguish Table 1 Shi“ choosing measure l 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 < i3 13 < 11 ne< I < i2 i2 < iInexl < iI i, nex 1 > i1 Shift when the Shift when the working point is working point is in i n low speed ratio high speed ratio 4 A『 句‘d 3 ?！痟 2 維普資訊 h憂p://www.cqvip.com Gong et al. 1 J Zh吃;iang U11ii· SCI 2004 5（刀·878-883 881 the 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. Suppose that the time of the data acquisition is t (m時(shí)，the frequency 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 decision times, it is a frequent gear changes shift. When the times of the upshi白（or downshift) are the same as the 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 QUALITY The 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-TEST In order to verify the shift schedule, an auto- matic 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 ’s test-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 cuπent dynamometer is a power dissipation device used for loading for the drivetrain by adjusting winding cuπent 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 actuator’s electromagnetic valve Electric eddy current dyna- mometer controller (4) iof w dt i0lw dt where ），α，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 transmission output shaft, respectively , Tw is the resistance Fig.3 Schematic diagram for the automatic gear sh惱’s moment acting on the wheel, and supposed to be test-bed 維普資訊 h憂p://www.cqv1p.com 882 Gong et al. I J Zh吃;iang l.iniν SCI 2004 5(7):878-883 opened or closed to implement shift according to the shift schedule. Experimental results of shift schedule 氣d l F3 1 u （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. The course 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g－ ESH 4 400 i350 邑 300 氈， 否。250 C -;; 200 :-e I SO ← 100  100 200 300 400 500 氣d 5 氣， 1 o· l α rL Time t (s) (a) 100 200 300 Time t (s) (b)  400  500 Experimental results of shift quality The 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, coπesponding to each shift point. This phenomenon indicates oc- cuπence of power inteπuptions 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 among those of point 2, point 3 and point 5. nυ nv l 200 300 400 Time t (s) (c) 500 The 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 the Fig.4 Experimental results of the automatic gear shift’s test-bed (a) Efficiency change; (b) Transmission shift change; (c) Turbine torque change clutch of the new shift did not engage at point 2. At this moment, power interruptions occurred. The 維普資訊 http://www.cqv1p.com Gong et al.I J Zhejiang Univ SCI 2004 5(7):878-883 883 clutch of the new shift began to slip at point 3 and engaged at point 4. Conclusion From the above experimental results, we can conclude that:  SUMMARY In 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 auto- 1) The shift schedule saving energy can matic transmission of the ground vehicle. Experi- maintain 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 schedule saving energy was obtained by the studying torque converter’s primary characteristic, the experimen- tal results showed that the shift schedule saving energy is coηect while the torque converter is working 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 courses Torque converter output ment on the automatic transmission bench-test adopting this shift schedule was made on the automatic transmission ’s test-bed. The experi- mental results showed that the shift schedule was coηect and that shift quality was controllable. The above research results provide reliable basis for application to ground vehicle and improving shift quality. References Gong, 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 and auto-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