• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1792-1797
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• 2007

This paper try to find root-cause of failure in a connector used in transmitting signals for throttle body control in automotives by analyzing possible failure causes and performing experiments to simulate the cable failure in field. The connector comprises fins, wires, and case moldings. The failure is due to degradation of initial clamping force required fixing fins and wires in the connector. Expansion and compression of the case molding material surrounding fins would cause the degradation. Investigations of strict initial claming force and control of thermal expansion property of the molding are required to prevent the failure.

• 전자공학회논문지
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• 제54권6호
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• pp.134-139
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• 2017

본 논문에서는 전기자전거의 정밀 토크제어를 위하여 새로운 토크제어 방식을 제안하고 구현한다. 트로틀 노이즈를 제거하기 위한 이동 평균 필터를 채택함으로써 256 단계의 세분화된 트로틀 단계로 전기자전거의 제어가 가능하다. 설계된 컨트롤러는 전기자전거에 장착 실험되어 기존의 Cadence 감지 컨트롤러 대비 개선된 선형 제어특성을 확인하였다.

• 한국자동차공학회논문집
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• 제14권2호
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• pp.151-157
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• 2006

The passenger car drivers want in general to feel good driveability, but they sometimes feel uncomfortable by shock and jerk phenomena when they push or release acceleration pedal with clutch on state. In this paper, the shock and jerk characteristics are studied on the vehicles controlled by the throttle-by-wire system. Experiments and simulations were carried out on two vehicles which show different control characteristics. The engine torque control characteristics was analyzed by measuring cylinder pressure. Various specification factors of the vehicles and the torque control logic of the engines were simulated through experimental data basis. The result shows the spring effect of the trans-axle in the drive-train is one of the most important factors of the shock-jerk phenomena and the engine torque control method is also responsible for the reducing the shock-jerk amplitude. In this paper a new control logic of the engine torque is suggested for the better driveablility on the tip-in/out event.

• 한국기계가공학회지
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• 제19권11호
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• pp.58-63
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• 2020

The fuel injection amount and timing along with the ignition timing for the gasoline engine of a racing car were adjusted using an electronic control unit (ECU), and the engine performance was evaluated through an acceleration test. The fuel map for the fuel injection amount and ignition map for the ignition timing were derived. Using the transient throttle control, the air-fuel ratio could be maintained at a constant value even in the case of a sudden throttle operation. In the flat shift, ignition blocking was more effective than fuel blocking. In a 75 m acceleration test, the required duration without and with ECU control was 4.47 s and 3.99 s, respectively. Notably, the acceleration could be improved by approximately 10.7% when the ECU control was implemented.

• International journal of advanced smart convergence
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• 제6권4호
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• pp.1-8
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• 2017

In this work, the effects of fairly influential factors on performance of vacuum system, such as constant pressure and outgassing effect were simulated to propose the optimum design factors. Outgassing effects of selected vacuum materials on the vacuum characteristics were simulated by the $VacSim^{Multi}$ simulation tool. This investigation examined the feasibility of reliably simulating the outgassing characteristics of common vacuum chamber materials (aluminum, copper, stainless steel, nickel plated steel, Viton A). The optimum design factors for vacuum systems were suggested based on the simulation results. And, the effects of throttle valve applications on vacuum characteristics were also simulated to obtain the optimum design model of variable conductance on high vacuum system. Simulated vacuum characteristics of the proposed modelling were agreed with the observed experimental behaviour of real systems. Pressure limit valve and normally on-off control valve were schematized as the modelling of throttle valve for the constant process-pressure. Simulation results were plotted as pump-down curve of chamber and variable conductance of throttle valve. Simulated behaviors showed the applications of throttle valve sustained the process-pressure constantly, stably, and reliably.

• 로봇학회논문지
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• 제2권1호
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• pp.1-8
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• 2007

This paper presents a PID automatic gain-tuning algorithm for the electronic throttle valve which is driven by wire. Since the system characteristics of position control for electronic throttle valve are so complicated that both the real time robustness and the manufacturing cost must be considered for mass production. To resolve this paradox, a kind of algorithm called RLS (Recursive Least Square) is adopted for the control of the ETB (Electronic Throttle Body). Using this algorithm, the PID gains can be adjusted automatically with the estimated system parameters. Furthermore, a pre-filter is supplemented for the sake of the robustness against the friction and loads. From the industrial requests for the system, the design specifications are decided as follows: the settling time should be less than 1sec and the overshoot should be kept below 3%. The results of the experiments based on this approach show that the high robustness can be achieved while the system stability is satisfied steadily. A parameter estimation scheme and a gain-tuning algorithm have been properly combined and utilized in this research and the effectiveness is verified through the real experiments.

• 자동차안전학회지
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• 제14권1호
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• pp.39-44
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• 2022

This paper presents a development of throttle and brake controller for autonomous vehicle simulation environment. Most of 3D simulator control autonomous vehicle by throttle and brake command. Therefore additional longitudinal controller is required to calculate pedal input from desired acceleration. The controller consists of two parts, feedback controller and feedforward controller. The feedback controller is designed to compensate error between the actual acceleration and desired acceleration calculated from autonomous driving algorithm. The feedforward controller is designed for fast response and the output is determined by the actual vehicle speed and desired acceleration. To verify the performance of the controller, simulations were conducted for various scenarios, and it was confirmed that the controller can successfully follow the target acceleration.

• 한국자동차공학회논문집
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• 제10권2호
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• pp.1-8
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• 2002

The flow and combustion patterns have been investigated inside the gasoline engine cylinder with the swirl or tumble flow, whereas the air flow characteristics, which are generated in the part of intake system before entering into the intake manifold, have not been known completely. It is necessary to analyze the flow field in the intake system consisting of air rater, throttle valve and intake manifold. The throttle valve, used to control the intake air flow rate, is important because it makes various mass flow rate and flow patterns. Three-dimen-sional How characteristics such as velocities, turbulent intensities and Reynolds shear stresses are measured by the hot wire anemometer at the exit of the throttle valve with the variation in the valve opening angle($15^{\circ}$, $45^{\circ}$, $75^{\circ}$ and $90^{\circ}$) and the Reynolds numbers (45000, 70000 and 140000). There are a lot of changes in flow characteristics at $75^{\circ}$ due to the large recirculation flow comparing with those of the other cases, and the streamwise velocity is especially enforced strongly below the valve shaft. The other component velocities are relatively large near the centerline parallel to the valve shaft. The effects of the Reynolds number on the flow field are not severe.

• Journal of Mechanical Science and Technology
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• 제15권9호
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• pp.1248-1256
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• 2001

In this study, a test bed for vehicle longitudinal control is developed using a chassis dynamometer and real time 3-D graphics. The proposed test bed system consists of a chassis dynamometer on which test vehicle can run longitudinally, a video system that shows virtual driver view, and computers that control the test vehicle and realize the real time 3-D graphics. The purpose of the proposed system is to test vehicle longitudinal control and warning algorithms such as Adaptive Cruise Control(ACC), stop and go systems, and collision warning systems. For acceleration and deceleration situations which only need throttle movements, a vehicle longitudinal spacing control algorithm has been tested on the test bed. The spacing control algorithm has been designed based on sliding mode control and road grade estimation scheme which utilizes the vehicle engine torque map and gear shift information.

• 제어로봇시스템학회논문지
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• 제5권2호
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• pp.151-157
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• 1999

In this paper, an integrated nonlinear sliding mode observer and controller has been designed in order to control of an automotive engine idle speed. The primary objective of the engine idle speed control is to maintain the desired engine idle speed despite of various torque disturbances via estimating air mass flow at the location of the injector in intake manifold by using a sliding mode observer. Simulation results show that the case where both throttle angle and ignition time are used as control inputs outperforms the case where just only throttle angle is used as a control input.