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차량 능동 현가시스템의 제어 알고리즘 구현 및 실차 성능시험
장효환(H.W.Chang),김주용(J.Y.Kim),정남훈(N.W.Chung),유병철(B.C.Yoo),송동우(D.W.Song) 한국자동차공학회 1995 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1995 No.6_2
In this study, PC Base electronic control unit was constructed for full car test of active suspension system. And sky-hook damping theory, roll and pitch control theory, and PID control theory were applied to a vehicle equipped with active suspension system in order to perform ride quality control, attitude control, and height control.<br/> The performance of ride quality was evaluated through high way ride quality test. The performance of attitude control was evaluated through steady state cornering, step steering, anti-dive, and anti- squat test. Finally height control test which is composed of constant height, height selection, and speed sensing height control was performed.<br/> As a result, through various test, active suspension system showed more excellent ride quality performance in frequency range adjacent to lHz, and more excellent attitude control effect than passive suspension system. Also excellent height control was performed through PCD control.<br/>
장효환(H.W.Chang),전윤식(Y.S.Jun) 한국자동차공학회 1995 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1995 No.6_2
Dynamic modeling of clutch-hydraulic control system in automatic transmission is performed systematically by using the bond-graph method. Transient characteristics of line pressure, PCSV control pressure and clutch/brake pressure are analyzed through experiments and simulation, and the validity of the proposed dynamic models is proved. Also, the dynamic model of overall power transmission is established by using the same bond-graph method and the driving characteristics of vehicle are analyzed through simulation. The simulation program with proposed dynamic model can be used to estimate dynamic responses for the change in design parameters in hydraulic circuit, and to design shift-transient controller which uses PCSV current as a control input.<br/>
장효환(H.W.Chang),송재복(J.B.Song),김병철(B.C.Kim),박병선(B.S.Park),김세윤(S.Y.Kim) 한국자동차공학회 1998 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1998 No.5_2
A traction control system(TCS) is the active safety system used to prevent the wheel slipping and thus improve acceleration performance, stability and steerability on slippery roads through the engine torque and/or brake torque control. While most vehicles are equipped with either the engine-based TCS or the brake-based TCS, the engine/brake integrated TCS logic is developed mainly on a simulation basis in this research. The simulation involves not only the actual experimental data on the engine, powertrain and brake systems but also 7-DOF vehicle dynamics along with the nonlinear tire model and driver model. In order to compare the performance of 3 approaches of the TCS, various simulations have been carried ort for the quick start-off 3 approaches of the TCS, various simulations have been carried out for the quick start-off conditions on the split roads. The simulation results show that the engine/brake integrated TCS has better acceleration performance than the engine-based TCS and better steerability that the brake-based TCS.<br/>
김세윤(S.Y.Kim),황선호(S.H.Hwang),장효환(H.W.Chang) 한국자동차공학회 1993 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Some control algorithms for TCS are proposed through computer simulation. They are<br/> algorithm based on the slip threshold, algorithm based on the acceleration threshold and algorithm based on the slip and acceleration thresholds, and the operating time difference between the TCS valve and the ABS valve is also considered as a system parameter in these algorithms. Algorithm based on the slip and acceleration<br/> thresholds shows better response characteristics than algorithm based on the slip threshold or algorithm based on the acceleration threshold, only. In case of considering the operating time difference between the two valves, it is showed that the wheel velocity error becomes smaller and the drivability becomes better than those of not considering them. Finally. it is verified that the proposed algorithms of this research have similar response characteristics compared with the road test results of the actual vehicle.<br/>
특이섭동법을 이용한 차량 능동 현가 시스템의 축차 귀환제어에 관한 연구
최용원(Y.W.Choi),김주용(J.Y.Kim),장효환(H.W.Chang) 한국자동차공학회 1993 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Reduced-order active suspension control strategies via the singular perturbation technique are applied to quarter car am half car models which have 2 and 4 DOFs, raspectively. The performance of the hydraulic active suspension system utilizing these control strategies are investigated and compared with that of the systems with the full-order<br/> state feedback and the sky-hook damping controls. Their performances are compared through computer simulation of the transient and frequency responses. It is shown that the reduced-order control strategies yield almost same<br/> performance as that of the full-order state feedback control. and gives better performance than that of the sky-hook damping control especially in nde quality.<br/>
차량 능동 현가시시스템의 최적 가변구조제어에 관한 연구
김주용(J.Y.Kim),장효환(H.W.Chang) 한국자동차공학회 1993 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The Performance of a Vehicle active suspension system ysing an optimal variabke structure control theory is investihated. The full car model has a 7 DOF which accounts for heave, pitch, roll motions of a sprung mass and vertical motions of 4 unsprung masses. The transient responses are analyzed when a vehicle passing through a bump with a constant speed and the frequency responses are analyzed for heave, pitch, roll, warp inputs at four wheels ln RMS domain. the two types of correlations are considered to compute the mean square responses of a vehicle to random road disturbance. l.e., the comelation between the left and right tracks. and the time delay between the front and rear wheels. A modified first-order shaping filter suggested by Rill ls used to account for the comelation between the left and right tracts. lt is shown that the optimal variable structure controller gives better performance of the vehicle active suspension system than an optimal controller.
Taguchi 방법을 이용한 순수 유압식 브레이커의 성능 최적화
곽광순(K. S. Kwak),장효환(H. W. Chang) 유공압건설기계학회 2008 드라이브·컨트롤 Vol.5 No.3
The optimal design of a large-size fully hydraulic breaker is studied in this paper. Mathematical modeling of the breaker is established and verified by experiments. Through sensitivity analysis, the key design parameters of the breaker are selected, which mostly affect the performance of the breaker. Taguchi method is used to optimize the key design parameters in order to maximize the output power through simulation using AMESim. As a result, the impact energy is increased by 18.9% and the output power is increased by 12.4% compared with the current design. The pressure pulsation in the supply line is also reduced by the optimization.