• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.66-71
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• 2011

This article proposes a novel shift automation mechanism for an automated manual transmission (AMT). The development of an automated manual transmission is currently being paid considerable attention by vehicle manufacturers, with the prospects of combining the comfort of an automatic transmission and the high efficiency of a manual transmission. In order to automate the shift mechanism of a manual transmission, the proposed shift automation mechanism consists of two electric motors, cross shaped pinion gears, rack type shift rails, and a ball splined hollow shaft. First we describe the shift mechanism and operating principles of a manual transmission to investigate important design criteria for the shift automation device. And a new shift automation mechanism is described with its structure, elements, and operating principles in detail. Using a conventional manual transmission, we develop a full three-dimensional CAD model of an AMT which includes main components of the manual transmission and the designed shift automation mechanism. Finally we investigate the operating performances and feasibility of the designed AMT by a dynamic analysis.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.128-137
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• 2013

Modern transmission technologies such as automated manual transmission(AMT) and dual clutch transmission(DCT) are interested to all manufactures due to their fuel efficiency and driver's convenience, especially in a hybrid system. AMT has advantages in that they have a high efficiency of manual transmissions(MT) and offer operation convenience similar to automatic transmissions(AT), but it has some disadvantages in that they have torque gap during gear shift and shift time. To reduce disadvantages, it is necessary to evaluate errors and characteristics as a developing simulation model before experimental verification. The purpose of this study is to develop virtual components and simulate the transient response of AMT. A dynamic AMT model and a control logic for an integrated vehicle model have been developed using Matlab/Simulink as a simulation platform. In this paper, the clutch model to describe the stick-slip transition mode and the transmission model to describe the neutral gear shifting is introduced and compared with each other.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.10
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• pp.75-82
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• 2007

The AMT(Automated Manual Transmission) has been developed by utilizing the auto clutch system and the automatic shift mechanism, to automate the clutch operation and shift operation of the existing MT(Manual Transmission). The use of hydraulic actuator for each actuator of the clutch and gear has realized a reduction of fuel consumption and exhaust emission. In this paper, we develop a simulator for the transmission control system of the AMT using AMESim. The developed simulator can be applied to design the hydraulic select actuator system of an AMT.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.86-93
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• 2006

This study is concerned with the investigation of characteristics of an AMT (Automated Manual Transmission) which are composed of clutch part and transmission part. When a shilling signal is received from the controller, the clutch is disengaged first, and shifting action including selecting action is followed, and then the clutch is engaged last. The characteristics of transmission shifting response are affected by various parameters of clutch and transmission control elements. Analytical results are in fair agreement with experimental results. It is found that the operating pressure level is the most important for the response of AMT characteristics, and that the other parameters such as natural frequency and damping ratio of the control valve are less important.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.3
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• pp.287-293
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• 2015

With the rise in oil prices and ongoing concerns about environment, there is an increased amount of interest in automated manual transmission (AMT) vehicles. Torque control in an AMT vehicle is attained by controlling the displacement of the dry-type clutch's actuator. To provide good ride comfort akin to that of an automatic transmission vehicle, the clutch control is vital to an AMT vehicle. In this study, a method of obtaining the clutch torque from a dynamometer test is devised. This method is able to identify the relationship between the displacement of the clutch actuator and the clutch torque. A simulator for estimating the performance of an AMT vehicle is developed using MATLAB Simulink. The results obtained from both the vehicle and simulation exhibit a similar trend.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.96-106
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• 1999

In this study, the advanced shift control algorithm for parallel type hybrid drivetrain system with automated manual transmission(AMT) is proposed. The AMT can be easily realized by mounting the pneumatic actuators and sensors on the clutch and shift levers of the conventional manual transmission. By using the electronic-controlled AMT, engine and induction machine, it is possible to achieve the integrated control of overall system for the efficiency and the performance of the vehicle. Performing the speed control of the induction machine and the engine, the synchronization at gear shifting and the smooth engagement of clutch can be guaranteed. And it enables to reduce the shift shock and shorten the shift time. Hence, it results in the improvement of shift quality and the driving comfort of the vehicle. Dynamometer-based experiments are carried out to prove the validity of the proposed shift control algorithm.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.136-148
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• 1999

Detailed mathematical models of hybrid drivertrain components are presented and numerical simulations are carried out to analyze the shift characteristics and to improve the driving comfortability when the hybrid drivetrain is applied at the vehicle . Theoretical results are compared with experimental ones from the dynamometer as same condition in order to prove the appropriateness of modeling . Adding the vehicle body modeling, included in the suspension and the engine mount, it is possible to predict the dynamic behavior and shift characteristics more actually when shifts are occurred by automated manual transmission(AMT). these additional results are also compared with the same simulation ones of internal combustion engined vehicle equipped conventional manual transmission. Hence, it can be expected that the hybrid vehicle with AMT has a good shift quality.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.3
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• pp.118-126
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• 2010

The automated mechanical transmission(AMT) is composed of electronic control management(ECM) and automatic shift gear(ASG). The AMT has advantages which are high efficiency of manual transmissions(MT) and offer operation convenience similar to automatic transmissions(AT). However, it has defects that are the torque gap during gear shift transients and shift time is long. To reduce such defects, it is necessary practically to evaluate error and characteristics as developing simulation model before the control algorithm is applied. In this paper, models are composed of vehicle model and AMT shift control model. Particularly AMT shift control model consists of main clutch management model (MCM) and shift control management model(SCM). The developed models were verified by comparing the simulated and experimental results under the same operational conditions. It can also be used to evaluate shift algorithm.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.372-378
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• 2016

Clutch torque control is the key to the ride comfort improvement of a vehicle equipped with AMT (automated manual transmission). For such control, the torque transfer starting point, known as the "kiss point," should be indicated or at least estimated to compensate for the clutch torque. The kiss point changes due to wear, high temperature, and fatigue; as such, it should be estimated while the vehicle is being driven. In this study, the method of kiss point active estimation for an AMT vehicle with a dry-type clutch was devised. The kiss point is learned while the engine is in an idle state and while the transmission is at a neutral gear position. It is determined when the input shaft of the transmission starts to rotate by slowly engaging the clutch. The noise of the shaft speed signal during the slow engagement process is filtered for accurate control. The kiss point estimation at various clutch engagement speeds was analyzed via a vehicle test.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.105-114
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• 2001

In this study, a shift control algorithm far improving the shift quality of a parallel hybrid drivetrain with an automated manual transmission (AM) is proposed. The general AMT requires the sophisticated control of clutch in the clutch engagement to improve its shift characteristics, and that is generally known to be difficult. But in this hybrid drivetrain, we can control the speeds of clutch plates by engine and motor control, and it provides the easier clutch control in shift process than general AMT. Additionally, it permits the much-reduced shift shock. The motor control during the shift period is also to achieve reduced velocity drop of the vehicle in comparison with that of a general AMT. Furthermore various dynamometer-based experiments are carried out to prove the validity of the proposed shift control algorithm.