[雙語翻譯]外文翻譯--自動變速器換擋過程的仿真與分析（原文）

1、Abstract—The automatic transmission (AT) is one of the most important components of many automobile transmission systems. The shift quality has a significant influence on the ride comfort of the vehicle. During the AT

2、 shift process, the joint elements such as the clutch and bands engage or disengage, linking sets of gears to create a fixed gear ratio. Since these ratios differ between gears in a fixed gear ratio transmission, the

3、motion of the vehicle could change suddenly during the shift process if the joint elements are engaged or disengaged inappropriately, additionally impacting the entire transmission system and increasing the temperatur

4、e of connect elements.The objective was to establish a system model for an AT powertrain using Matlab/Simulink. This paper further analyses the effect of varying hydraulic pressure and the associated impact on shift q

5、uality during both engagment and disengagement of the joint elements, proving that shift quality improvements could be achieved with appropriate hydraulic pressure control. Keywords—Automatic transmission, Simulation

6、and analysis, Shift quality. I. INTRODUCTIONA. Motivation and Background ETHODS of AT control are continuously being improved in order to improve shift quality and provide better ride comfort for passengers. Shift qua

7、lity depends mostly on the smoothness during the shift process. In other words, a smooth shift means there is no exorbitant instantaneous acceleration or deceleration during shifting. Since automobile powertrains con

8、tain multi-rotation inertial systems, the shift process will always take a certain amount of time. With fixed gear ratio ATs vibration and shock can occur during shifting, which results in passenger discomfort. Theref

9、ore, in order to improve the shift quality, it is important to theoretically analyze the shift performance of an AT, choose an appropriate control method, and optimize the application of hydraulic pressure. B. Litera

10、ture Review Since the AT emerged within the automotive industry, shift quality has been the primary focus for the characterization and evaluation of different transmissions. In recent years, thanks to rapid developme

11、nts in electronic control technology, research in the field of ATs has been enhanced, with many major manufacturers around the world conducting intensive research. However, the traditional 4-speed AT cannot meet the d

12、emands of the modern customer, prompting automobile producers to develop more gear sets for ATs. For example, in 2001, Yamamoto el al developed a new Aisin 5-speed AT, which K. L. Kuo is with the Vehicle Engineering

13、Department, National Taipei University of Technology, Taiwan, ROC. (phone: 886-227712171#3623; e-mail: klkuo@ntut.edu.tw). used a new planetary gearbox resulting in a smaller size and better performance than the prev

14、ious 4-speed AT. [1] In 2003, Scherer presented that compared to the earlier 5-speed AT, the total amount of components of the new ZF 6-speed AT had been reduced by 29%, thelength had been shortened by 6% and the con

15、trol method had been quality and the response time. [2] In 2004, Greiner et al introduced the new Mercedes-Benz 7G-TRONIC 7-speed AT, with a shorter response time and better acceleration performance than any previous

16、AT. [3] In 2007, Kondo et al revealed the new Toyota AA80E 8-speed AT, with a 6.5% reduction in fuel consumption compared to the above 6-speed AT. [4] Using benefits derived from advanced control theory and improved

17、electronic control technology, the modern AT has seen significant improvements in shift quality as well as fuel consumption. II.AT SHIFT PROCESS ANALYSISShift process analysis is the key study for AT shift quality co

18、ntrol. The automatic shift process is usually achieved through the engagement or disengagement of a number of bands and clutches. The entire shift process can be divided into two phases. The torque phase, where the sp

19、eed ratio remains constant but output torque decreases, and the inertia phase, where the speed ratio changes. The shift process is complex and can be influenced by various factors. Therefore, it is necessary to deve

20、lop a general mathematical model for AT shift process analysis. It is also essential to simplify the motion equation in order to establish a dynamic model for the system, and use this dynamic model to analyze and inve

21、stigate the shift process [5] . A. Torque and inertia phases in the shift process Figure. 1 shows the curves of clutch pressure, output torque and engine speed during a gear change from 1st to 2nd Gear. [6] In this

22、figure, the solid line and dashed line represent well and poorly controlled clutch pressure respectively. Fig. 1 Shift process analysis Kei-Lin Kuo Simulation and Analysis of the Shift Process for an Automatic Transm

23、ission MWorld Academy of Science, Engineering and Technology 76 2011341Fig. 3 Mitsubishi F4A4 AT layout diagram[10] TABLE II CLUTCH ENGAGEMENT FOR DIFFERENT GEARSSimscape, which is embedded in the Matlab/Simulink envir

24、onment, has become an important toolrecently. It is a fundamental platform for modeling and simulating multi-domain physical systems. The greatest advantage of this software for users is the avoidance of complica

25、ted formula derivation Through the provision of fundamental building blocks for modeling system spanning mechanical, electrical, hydraulic, and other physical domains as physical networks. Using the built-in physica

26、l blocks for the engine, hydraulic torque converter, transmission, clutch, gearbox and other domains, the simulation structure for the vehicle was then established, as shown in Fig. 4. Table 4 shows the parameters fo

27、r the whole vehicle simulation. Fig. 4 Vehicle simulation structure Figure 5 portrays the hydraulic torque converter block diagram ,whose simulation parameters have been determined. The initial rotation rate of the pum

28、p impeller (engine) was 750 rpm, whilst the turbine initial rotation rate was 0 rpm. The assumptions for rotational inertia were 0.1 kg-m2 for the engine and pump impeller and 0.01 kg-m2 for the turbine and shaft. TAB

29、LE III VEHICLE PARAMETERS FOR SIMULATION Maximum engine power 86.64kW Maximum rotation rate 7000 rpm Overall weight 1165kg Tyre radius 0.289 m Assumed rolling resistance ratio ?r0.01 Assumed air resistance ratio Cd

30、 0.37 Windward area 1.96 m2Air density 1.204 kg/m3Fig. 5 Hydraulic torque converter block diagram Figure 6 shows the block model for the transmission, where the maximum application pressure for all clutches was 120

31、0 kPa, the effective motion radius was 0.0662 m, the fist gear deceleration ratio was 2.842, the second gear deceleration ratio was 1.529, and the assumed gear rotary inertia was 0.01 kg-m2.Fig. 6 Transmission block d

32、iagram Figure. 7 depicts the block diagram for the driving load, where the final deceleration ratio was 4.042, the assumed vehicle inertia was 125 kg-m2, the tier radius was 0.289 m, and the driving resistance was ass

33、umed as rolling resistance (Rr=?r×W) and air resistance ( 2 2 ? ? ? ? ? ? A C R d a ).IV. SIMULATION RESULTS AND ANALYSIS During the up-shift process for the Mitsubishi F4A4 AT, the off-going clutch alternates wit