고속 무한궤도 차량용 변속기 시뮬레이터 개발

정규홍(Gyuhong Jung) 유공압건설기계학회 2017 드라이브·컨트롤 Vol.14 No.4

Electronic control technologies that have long been developed for passenger cars spread to construction equipment and agricultural vehicles because of its outstanding performance achieved by embedded software. Especially, system program of transmission control unit (TCU) plays a crucial role for the superb shift quality, driving performance and fuel efficiency, etc. Since the control algorithm is embedded in software that is rarely analyzed, development of such a TCU cannot be conducted by conventional reverse engineering. Transmission simulator is a kind of electronic device that simulates the electric signals including driver operation command and output of various sensors installed in transmission. Standalone TCU can be run in normal operation mode with the signals provided by transmission simulator. In this research, transmission simulator for the tracked vehicle TCU is developed for the analysis of shift control algorithm from the experiments with standalone TCU. It was confirmed that shift experimental data for the simulator setup conditions can be used for the analysis of control algorithms on proportional solenoid valves and shift map.

[동력전달계부문] 휠로더 자동변속기의 TCU 개발 연구

정규홍(GyuHong Jung),이교일(KyoIl Lee) 한국자동차공학회 2000 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In this research, The basic functions of wheel loader automatic transmission TCU including micro-controller system, proportional solenoid valve driver, duty cycle identification system, speed sensor signal conditioning system and data monitoring system, etc were implemented and open-loop shifting control scheme which is based on the experimental data of conventional TCU was designed in order to verify the feasibility of the developing TCU's shifting performance. The experimental result shows comparable shifting characteristics to that of conventional TCU though the test was performed at restricted shifting condition. Hence, we could have confidence for the development of wheel loader automatic transmission TCU. The following plan of this research is to design the control algorithm which improves the shifting quality and verify its performance from the shifting experiment

고속 무한궤도 차량용 변속제어기 진단 알고리즘 분석

정규홍(Gyuhong Jung) 유공압건설기계학회 2018 드라이브·컨트롤 Vol.15 No.4

Electronic control units (ECUs) are currently popular, and have evolved further towards the high-end application of autonomous vehicles in the automotive industry. Such digital technologies have also become widespread, in agriculture and construction equipment. Likewise, transmission control of high-speed tracked vehicles is based on the transmission control unit (TCU), performing complex gear change control functions, and diagnostic algorithms (a TCU"s self-diagnostic and reporting capability of malfunction data through CAN communication). Since all functions of TCU are implemented by embedded-software, it is hardly possible to analyze specifications by reverse engineering. In this paper a real-time transmission simulator adaptable to TCU is presented, for analysis of diagnosis algorithm and standards. Signal simulation circuits are deliberately designed considering electrical characteristics of TCU inputs and various analysis tools, such as analog input auto scan function, and global output enable switch, are implemented in software. Test results from hardware-in-the-loop simulator verify tolerance time for each error, as well as cause of fault, error reset conditions.

지게차 자동변속기 저속주행기능 설계

정규홍(Gyuhong Jung) 유공압건설기계학회 2021 드라이브·컨트롤 Vol.18 No.2

A forklift is a powered industrial vehicle used to lift and move materials over short distances. Nowadays, almost all forklifts are equipped with an automatic transmission due to its improved operator comfort and increased productivity. Thanks to marked improvement of transmission control unit equipped with highly-advanced microcontrollers, recently developed automatic transmission for forklift have various auxiliary functions such as creep, auto retardation, and automatic shift with excellent shift quality. This paper deals with the creep function which enables one to maneuver a forklift at the designated low speed by slip control of clutches. The design of creep function was based on four modes of creep operation depending on the status of the operator’s shift lever and accelerator pedal. Control algorithms and control parameters for each mode were designed to achieve the desired static and dynamic performance. Vehicle test for the designed creep function was carried out with an independently developed embedded controller. Test results confirmed good creep speed control without speed error at a steady state with a mild shift shock during mode changes by stepping or releasing the accelerator.

가스 스프링을 이용한 높이조절 벙커침대 설계

정규홍(Gyuhong Jung) 유공압건설기계학회 2021 드라이브·컨트롤 Vol.18 No.4

A bunker bed is a type of furniture that efficiently utilizes a narrow indoor space by having a high bed and using the empty space below as a living and storage space. The demand for multi-purpose furniture is increasing due to the recent increase in single-person households and wide-spread shared accommodation. According to the consumer research, one of the major drawbacks of a bunker bed was to get on and off the bed through a ladder or stairs. In order to overcome these problems, it was confirmed that the height adjustment function that can easily adjust the minimum and maximum heights of the bed was necessary. In this study, a height adjustable bunker bed was designed by using a gas spring that generates a repulsive force by the compressed gas inside. The design process consisted of the following three steps: Firstly, the hysteresis characteristics due to a friction and spring constant of a commercial gas spring were confirmed by measuring the repulsive force vs. compressed displacement. Secondly, requirements of the vertical lifting force exerted on the bed against gravity force were derived. Finally, the height-adjustable bed using the four-bar link mechanism was designed with 4 parameters so that the bed weight of 60-70 kgf could be adjusted to 800 mm in height by an affordable initial operation force. The performance was verified through prototype production and the results of vertical displacement and force to move were nearly the same as designed. In addition, an electrically operated height-adjustable bed was also designed with linear actuators and the performance was proved with the prototype.

자동변속기의 변속특성시뮬레이션을 위한 HILS시스템 개발

정규홍(GyuHong Jung),이교일(Kyoll Lee) 한국자동차공학회 2001 한국 자동차공학회논문집 Vol.9 No.6

During the past several years, the major interests of car manufactueturers in development of automatic transmission were in durability and shift quality. However, a large number of researches for improving shift quality that are based on dynamic characteristics of shifting mechanism have been rarely adopted in the developing process because it is quite diffieult to predict the shifting performance from the dynamics simulation. One of the important reasons for the difference between simulation results and experiments arises from the automatic transmission hydraulic system that consists of many valves with high order model and shows a lot different dynamics to temperature variation. In this work, hardware-in-the-loop simulation system for automatic transmission was developed for improving the accuracy of simulated result by combining the real-time simulation model with the real hydraulic system. The real-time simulation for automatic trans- mission model excluding hydraulic system is executed with TTs TMS320C31 DSP and the interlacing board which includes 12bit A/D, PWM signal generator and driver, serial driver ,etc is designed for acquiring the simulation data and signal interface with hydraulic system. We verified the proper operation and correctness of shifting result by comparing the off~line simulation result with that of HILS and experimental result which was performed on transmission dynamometer driven by electric motor.<br/>

건설차량용 자동변속기의 변속제어기 개발연구

정규홍(GyuHong Jung),이교일(KyoIl Lee) 한국자동차공학회 2002 한국 자동차공학회논문집 Vol.10 No.2

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 shifting capability. The experimental results show comparable shifting characteristics to that of conventional TCU though the tests were performed at restricted shifting 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.

변속기 시뮬레이터를 이용한 진단 및 안전작동 알고리즘 분석

정규홍(Gyuhong Jung) 한국자동차공학회 2014 한국 자동차공학회논문집 Vol.22 No.4

As the digital control technologies in automotive industry have advanced, electronic control units(ECUs) play a key-role to improve system performance. Transmission control unit(TCU) is a shifting controller for automatic transmission of which major functions are to determine the shift and manage the shifting process considering the various sensor signal on transmission and drivers commands. As with any ECU in vehicle, TCU performs complex algorithms such as shift control, diagnostic and failsafe functions. However, firmware design analysis is hardly possible by the reverse engineering due to code protection. Transmission simulator is a hardware-in-the-loop simulator which enables TCU to work in normal mode by simulating the electrical signal of TCU interface. In this research, diagnosis and failsafe algorithm implemented on commercialized TCU is analyzed by using the transmission simulator that is developed for wheel loader construction vehicle. This paper gives various experimental results on the proportional solenoid current trajectories for different operating modes, error detection criterion and limphome mode gears for all the possible cases of clutch malfunction. The derived results for conventional TCU can be applied to the development of inherent TCU algorithms and the transmission simulator can also be utilized for the test of TCU to be developed.

2-모드 기계유압식 무단변속기의 성능 및 전달효율해석

정규홍(Gyuhong Jung),김형의(Hyoungeui Kim),김종기(Jongki Kim) 한국자동차공학회 2005 한국 자동차공학회논문집 Vol.13 No.1

HMT is a type of continuously variable transmission which has split power flow path characteristics with gear tram and hydro static unit. The benefit of unproved fuel economy and high power capacity enables it to be a promising application for large vehicles. This paper presents the analysis results including velocity, static torque, transmission efficiency and dynamic model of the HMT that is developed for city buses. The speeds of gear shafts, the static clutch torque and split power ratio for each mode are detailed here. From the analysis of HMT transmission efficiency considering the power loss in meshed gear and hydraulic unit, we can conclude that minimization of hydraulic power is necessary for improved fuel economy design. Also, the dynamic simulation result for mode shift characteristics shows that little shift shock is observed because of the synchronized rotation speed in clutch.

건설 중장비용 TCU 변속데이터 매칭 프로그램 개발

정규홍(Gyuhong Jung),김경동(Kyungdong Kim) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

All the automatic transmissions that are recently developed for passenger cars adopt an electronic control unit to improve fuel economy as sell as shift quality. It also applies to construction vehicles such as forklift and wheel loader as the driver’s demands for convenient operation and performance improvement in relation to repetitive tasks are increasing. After TCU decides the shift in view of transmission status and/or driver’s command, it manages the shifting process with the current control of proportional solenoid valves. Since the current trajectories of apply and release clutch during shift entirely affect the quality of shift, those should be well matched with shifting conditions. This paper briefly describes the development of shift data matching program which enables the design of shift data graphically and the communication with TCU. It was utilized in the wheel loader transmission matching test and proved useful for the calibration of shift data to implement a smoothing shift.