• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.234-242
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• 2002

In this research, a transmission control unit was developed for a wheel loader on the basis of 16-bit microcontroller system. The TCU has the basic functions which include shifting control algorithm, actuation of six proportional solenoid valves, signal conditioning for four speed sensors, remote data monitoring capability with RF-module and duty cycle identification system which could identify the duty cycles from PWM signals. In order to design the control system, the overall transmission structure of the wheel loader was investigated and its characteristics of shifting were analyzed in advance. For the purpose of identifying the existing control algorithm and acquire some information about the shifting performance, the shifting experiments were performed for various shifting conditions with the conventional TCU. From the previous work on the conventional TCU, the shifting scheme was designed with the open-loop control which is based on the experimental data only to verify the feasibility of the developing TCU's shilling capability. The experimental results show comparable shifting characteristics to that of conventional TCU though the tests were performed at restricted shilling conditions. Hence, we could have the confidence for the development of the wheel loader automatic transmission TCU and its shifting quality could be improved with the adoption of appropriate feedback control scheme.

• International Journal of Automotive Technology
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• v.7 no.2
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• pp.155-160
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• 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.

• 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.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.107-114
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• 2006

This paper investigates the radiating source of electro-magnetic waves in the cabin of automobile with spark ignition engine. Front seats are very close to the engine room where electro-magnetic waves are expected to be radiating. But front seat area is believed to be a blind zone, which is not affected by radiating electro-magnetic waves, because a bulk board and floor board shield the front seat area. The level and frequency spectrum of electro-magnetic waves are measured at the passenger seat and the engine room. The measured frequency range is $145{\sim}365MHz$. As a results, the level of the electro-magnetic waves of automatic transmission vehicle is greater than -82dBm. The shapes of frequency spectrum of both engine room and passenger seat are look alike. But the level of electro-magnetic waves of manual transmission vehicle is less than -82dBm and the shapes of frequency spectrum of engine room and passenger seat are different to each other. From these results, we can say that any mal-function caused by electro-magnetic waves in the automobile cabin are only possible for automatic transmission vehicle. Also, it is believed that the radiating source of electro-magnetic waves is inside the vehicle. Thus, based on the transmission line theory, this paper presumably concludes that the cables which connect all the components inside a automatic transmission vehicle must be a radiating source of electro-magnetic waves in the cabin.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.1
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• pp.95-101
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• 2022

This paper proposes a method to process the shape of an optical transmission road and attempts to determine the most suitable single processing method for an acrylic plate optical transmission road. In addition, by manufacturing an automatic pattern processing device to generate certain shapes on the acrylic plate at regular intervals, and measuring the illuminance of the patterned acrylic plate optical transmission road, the measured illuminance was confirmed to fall under the KS illuminance values presented in Table 1. In conclusion, when an incident light of approximately 20,000 lx is applied, the transmission illumination is approximately 200 lx, which represents a transmission rate of approximately 1% for incident light and corresponds to the KS illumination criterion F. Additionally, the right-angle triangular pyramid base size (A) processed at a temperature of 350 ℃ for one second was 2 mm, exhibiting the largest transmission illumination of 280 lx. When the transparent acrylic plate was set to a constant size of 1.6 mm at the bottom of the right-angle triangular pyramid, the fastest response occurred at a processing tip temperature of 350 ℃ (0.04 s). On the other hand, it took 10 s to process the size of the bottom of the right-angled triangular pyramid at a temperature of 200 ℃ to 1.6 mm, and it was confirmed that the optical transmission efficiency was significantly reduced because of the burr that occurred at this time.

• Journal of Biosystems Engineering
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• v.18 no.4
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• pp.305-316
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• 1993

Fuel efficiency in tractor operations dep6nds on the selection of transmission gears and upon the engine being operated at or near maximum torque much of time. The objective of this study was to develop automatic control systems for tractor transmission ratio and governor setting so that the engine is operated at or near maximum torque as much of time as possible. An indoor test unit, which can be used to simulate tractor operation, was built in order to investigate the system design parameters and test the performance of the control system designed. The test-unit consists of engine, gear-type transmission, dynamometer, and control systems for transmission ratio and engine speed. Governor setting lever was controlled by a step motor, and the clutch and transmission levers were controlled by hydraulic cylinders and solenoid valves. The control systems showed good time responses which are assumed to be suitable for optimal tractor operation. The time required for shifting gears from clutch disengagement to engagement was about 1 second, which is almost the same as that for manual shift. And the settling time for engine speed control system was about 5 to 6 seconds.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.133-136
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• 2001

This paper partially presents a Hierachical neural network architecture for providing the intelligent control of complex Automatic Transmission(AJT) system which is usually nonlinear and hard to model mathematically. It consists of the module to apply or release an engine brake at the slope and that to judge the intention of the driver. The HNN architecture simplifies the structure of the overall system and is efficient for the learning time. This paper describes how the sub-neural networks of each module have been constructed and will compare the result of the intelligent hJT control to that of the conventional shift pattern.

• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.23-27
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• 2006

With the development of the today's advanced industry civilization, We are always inhering a safety frigidity about disasters of various kinds when and where we may happen. The fires and disasters to be enlarged day by day are reported everyday through the mass communication. Therefore, a prevention countermeasure about the every kind fire and disaster is above all important along the social and the days requirement. As a kind of such countermeasure, this paper is proposed about automatic transmission system of disasters alarm by using wire and wireless communication network. The automatic transmission system prevents the unexpected fire or disaster from a sudden occurrence at the house, industrial field or at the place without the human. The proposed system has the characteristic of high precision and high response speed comparing with conventional system. Also, as the proposed system is small size and lightweight, the users have economic advantage and simply install the system.

• Transactions of The Korea Fluid Power Systems Society
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• v.6 no.1
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• pp.10-16
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• 2009

Automatic power transmission systems consisted of a torque converter and several planetary gear sets, clutches and brakes are controlled by a hydraulic shift control circuit and an electronic transmission control unit. The hydraulic circuit serves for the operation of the torque converter and lubrication oil supply of the transmission system as well as for the actuation of clutches for the automatic gear shift. The complicated hydraulic control circuit constructed by many spools, solenoids, orifices and flow passages are integrated into one small valve block and it is powered by one hydraulic pump. In this paper, a test equipment was developed to measure the oil consumption of each component at various wide operating conditions. Test data about 730 sets acquired from five test items are analyzed and discussed on the oil capacity of the circuit.

• 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.