• International Journal of Automotive Technology
• /
• 제7권2호
• /
• pp.155-160
• /
• 2006

This paper presents a vehicle model for analyzing the transient shifting characterisitics of a passenger car with automatic transmission. Then the presented vehicle model was linked with the dynamic model of an automatic transmission. In order to identify the parameters of the vehicle model, we installed a test equipment with an accelerometer in a conventional vehicle and performed road tests. With the proposed vehicle model, we simulated the dynamic characteristics during shifting, and benchmarked with experimental results. Moreover, a modal analysis was carried out to investigate the effect of the vehicle model in the frequency domain and to obtain the transfer function of the vehicle model. In addition, we showed the numerical results in the time domain for analyzing the effect of each stiffness element, such as engine mountings and suspensions.

• 한국소음진동공학회논문집
• /
• 제21권7호
• /
• pp.657-664
• /
• 2011

This paper shows a whole noise quality checking system for the new developed 6th speed automatic transmission manufactured in USA. Due to demand for manufacturing of the high NVH quality transmissions in the mass product line, some special checking system called EOL NVH is adapted. This EOL system is using vibration sensor and analysis technologies. Through adapting vibration analysis technologies and functions likewise RMS, crest factor, harmonics, peak, band and order tracking, various noise problems caused by wear, nick and deformations could be successfully detected and predicted. Therefore, automatic transmissions manufactured in the USA could get high NVH quality. The developing process described in this paper and results on EOL system will offer good guides to the engineers who built the next transmission factory.

• 드라이브 ㆍ 컨트롤
• /
• 제11권3호
• /
• pp.47-54
• /
• 2014

Clutches are an integral part of the automatic transmission for changing gears. Modern automatic transmissions make extensive use of wet multiple-disc clutches employing hydraulic actuation mechanism with electronic control. Although nowadays, highly advanced shifting algorithm implements the superior shift quality and transmission efficiency, its performance should be based on smooth, reliable engagement with a reasonably durable friction material as well as stable clutch piston dynamics. Particularly, clutch filling control is the crucial part of shifting process because only the open-loop control is available due to the lack of measurement. In this paper, the effect of clutch-fill control parameters on clutch piston dynamics is experimentally investigated by using clutch piston test equipment which enables the clutch piston to actuate similar to real shifting conditions. The experimental analysis results can be expected to be utilized for the calibration of proportional solenoid valve as reference current profile data in vehicle test.

• 유공압시스템학회논문집
• /
• 제6권3호
• /
• pp.23-31
• /
• 2009

Counter shaft transmission is a popular automatic transmission power train in construction vehicles such as wheel loader and forklift. The gear train layout of counter shaft transmission is a very basic and important development stage because it affects the most of components design including hydraulic system and shift control algorithm, etc. This paper presents a design methodology for the gear train layout from the analysis of power flow path and clutch hook-up of the existing counter shaft transmission that is adopted in commercialized construction vehicles. Also, independent constraints for the meshed gear ratios are derived in order to realize forward 4-speed and reverse 3-speed gear ratio. The layout design principle proposed here was applied to the new original counter shaft transmission that is underdevelopment.

• 제어로봇시스템학회논문지
• /
• 제14권3호
• /
• pp.301-306
• /
• 2008

Drivers are becoming more fatigued and uncomfortable with increase in traffic density, and this condition can lead to slower reaction time. Consequently, they may face the danger of traffic accidents due to their inability to cope with frequent gear shifting. To reduce this risk, some drivers prefer automatic transmission (AT) over manual transmission (MT). The AT offers more superior drivability and less shifting shock than the MT; therefore, the AT market share has been increasing. The AT is controlled by an electronic control unit (ECU), which provides better shifting performance. The transmission control unit (TCU) is a higher-value-added product, so the companies that have advanced technologies end to evade technology transfer. With more cars gradually using the ECU, the TCU is expected to be faster and more efficient for organic communication and arithmetic processing between the control systems than the l6-bit controller. In this paper, the model of an automatic transmission vehicle using MATLAB/Simulink is developed for the Hardware in-the-Loop (HIL) simulation with a 32-bit embedded system, and also the AT control logic for shifting is developed by using MATLAB/Simulink. The developed AT control logic, transformed automatically by real time workshop toolbox, is loaded to a 32-bit embedded system platform based on Freescale's MPC565. With both vehicle model and 32-bit embedded system platform, we make the HIL simulation system and HIL simulation of AT based on real time operating system (RTOS) is performed. According to the simulation results, the developed HIL simulator will be used for the performance test of embedded system for AT with low cost and effort.

• 산업경영시스템학회지
• /
• 제25권1호
• /
• pp.14-19
• /
• 2002

This paper describes an automatic parts design system for gears, brake, and clutch. These parts are important components of the power transmission assembly. In conventional design process, the design of power transmission requires a number of recurrent calculations and drawings. In this paper, we propose a three-dimensional automatic design system that reduces the number of recurrent calculations and drawings. The system consists of three modules for designing gear, brake, and clutch. The proposed system has been applied to develop a transmission of forklift truck and shown to be a useful system.

• 한국공작기계학회논문집
• /
• 제13권1호
• /
• pp.100-106
• /
• 2004

All vehicles need the good quality of riding. Especially shifting shock is very important in the evaluation of the riding. Shifting shock is caused by transmission operation that one part and other part of gem are contacting together. This shock affect the feeling of driving. It is clear from these results that the shifting shock is affected by clutch pressure, pressure mode, inertia etc.

• 전기학회논문지P
• /
• 제59권1호
• /
• pp.1-9
• /
• 2010

This paper summarizes an education and training system for the auto-reclosing of power transmission system using a real time digital simulator. The system is developed to understand the principle of reclosing and the sequence of automatic reclosing schemes, and practice the effects of reclosing actions to power system in real-time simulator. This study is concentrated into the following two parts. One is the development of real time education and training system of automatic reclosing schemes. For this, we use the RTDS(real time digital simulator) and the actual digital protective relay. The mathematical relay model of RTDS and the actual distance relay which is equipped automatic reclosing function are also used. The other is the user friendly interface between trainee and trainer. The various interface displays are used for user handing and result display. The conditions of automatic reclosing which is a number of reclosing, reclosing dead time, reset time, and so on, can be changed by the user interface panel. A number of scenario cases are reserved for the education and training. Through the test, we verified that the proposed system can be effectively used to accomplish the education and training of automatic reclosing.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 춘계학술대회논문집
• /
• pp.1790-1795
• /
• 2000

송전선로에 새로운 Spacer damper를 설계하는데 이 논문의 목적이며, 이 설계되는 새로운 Spacer damper는 매우 중요한 특징과 장점을 가지고 있다. 또한, 최근 Spacer damper의 문제가 프랑스, 일본 등 다른 나라에서도 자동화 시스템과 함께 많이 발전되어 왔다. 개발된 Spacer damper외 설치는 특별한 기기없이 설치가능하며, 최근 자동 클램핑 장치 이용한 Spacer damper가 도입되어 피로 파괴와 미풍진동에 매우 효과적임이 입증되었고 보수유지가 거의 필요없으므로 경제성도 높으나 고가의 수입가격으로 인해 국산화의 필요성이 절실하다.

• 동력기계공학회지
• /
• 제17권5호
• /
• pp.128-137
• /
• 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.