• Title/Summary/Keyword: 전륜

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A Study on Active Suspension Control System in Vehicle Bouncing and Pitching Vibration for Improving Ride Comfort (승차감 향상을 위한 차체 상하.피칭 능동 현가제어에 관한 연구)

  • Park, Jung-Hyen
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.2 s.46
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    • pp.325-331
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    • 2007
  • This paper proposed modelling and design method in suspension system design to analyze active suspension equipment by adopting active robust control theory. Recent in the field of suspension system design it is general to adopt active control scheme for stiffness and damping, and connection with other vehicle stability control equipment is also intricate, it is required for control system scheme to design more robust, higher response and precision control equipment. It is known that active suspension system is better than passive spring-damper system in designing suspension equipment. We analyze suspension system with considering location of front-rear wheel and driving velocity, then design control system. Numerical example is shown for validity of robust control system design in active suspension system.

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A Study on Adopting Intelligent Control System in Active Suspension Equipment (능동 현가장치에의 지능형 제어시스템 적용에 관한 연구)

  • Park, Jung-Hyen
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.3
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    • pp.287-293
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    • 2007
  • This paper proposed modelling and design method in suspension system design to analyze active suspension equipment by adopting intelligent robust control theory. Recent in the field of suspension system design it is general to adopt active control scheme for stiffness and damping, and connection with other vehicle stability control equipment is also intricate, it is required for control system scheme to design more robust, higher response and precision control equipment. It is known that active suspension system is better than passive spring-damper system in designing suspension equipment. We analyze suspension system with considering location of front-rear wheel and driving velocity, then design robust control system. Numerical example is shown for validity of intelligent control system design in active suspension system.

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A VR-Based Integrated Simulation for the Remote Operation Technology Development of Unmanned-Vehicles in PRT System (자동 운전 PRT 차량의 무선 관제 기술 개발을 위한 가상 환경 기반 통합 시뮬레이터 개발)

  • Park, Pyung-Sun;Kim, Hyun-Myung;Ok, Min-Hwan;Jung, Jae-Il
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.1
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    • pp.43-56
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    • 2013
  • Personal Rapid Transit(PRT), which is one of the next generation convergence transport technology, PRT system requires operation technology for controlling diverse vehicles and dealing with a variety of abnormal driving situations on a large scale trackway structures in expected operational area more efficiently and reliably. Before developing PRT control technology, it is essential that multiple testing procedures stepwise with building small scale test-tracks and develop real unmanned-vehicles. However, it is expected that the experiments demand huge amount of time and physical cost. Thus, simulation in virtual environment is efficient to develop wireless based control technology for multiple PRT vehicles prior to building real-test environment. In this paper, we propose a VR-based integrated simulator which physics engine is applied so that it enables simulation of front-wheel-steering PRT system rather than simple rail track system. The proposed simulator is also developed that it can reflect geographical features, infrastructures and network topology of expected driving region.

Optimum Design of Front Toe Angle Using Design of Experiment and Dynamic Simulation for Evaluation of Handling Performances (실험계획법을 이용한 전륜 토우각의 최적설계 및 조종 안정성능 평가 시뮬레이션)

  • 서권희;민한기;천인범
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.2
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    • pp.120-128
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    • 2000
  • At the initial design stage of a new vehicle, the chassis layout has the most important influence on the overall vehicle performance. Most chassis designers have achieved the target performances by trial and error method as well as individual knowhow. Accordingly, a general procedure for determining the optimum location of suspension hard points with respect to the kinematic characteristics needs to be developed. In this paper, a method to optimize the toe angle in the double wishbone type front suspension of the four-wheel-drive vehicle is presented using the design of experiment, multibody dynamic simulation, and optimum design program. The handling performances of two full vehicle models having the initial and optimized toe angle are compared through the single lane change simulation. The sensitive design variables with respect to the kinematic characteristics are selected through the experimental design sensitivity analysis using the perturbation method. An object function is defined in terms of the toe angle among those kinematic characteristics. By the design of experiment and regression analysis, the regression model function of toe angle is obtained. The design variables which make the toe angle optimized ae extracted using the optimum design program DOT. The single lane change simulation and test of the full vehicle model are carried out to survey the handling performances of vehicle with toe angle optimized. The results of the single lane change simulation show that the optimized vehicle has the more improved understeer tendency than the initial vehicle.

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Simulation Analysis on Triple Collision between Wrecker, Towed Car and Driving Car (견인차-피견인차-주행차량의 3중 추돌에 관한 시뮬레이션 해석)

  • Cho, Jae-Ung;Kim, Eu-Gene;Kim, Key-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.11
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    • pp.4100-4107
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    • 2010
  • The wrecker truck of lift type is used to move damaged car in accident spot or to move illegal vehicle in towaway zone toward pound.. This special vehicle drives by lifting front or rear side of car with the driving type of towed car. Each car is modelled with CATIA and is simulated with FEM analysis program ANSYS. This study analyzes how dangerous is the triple collision among the wrecker-towed car-driving car as comparing with the usual collision accident with cars. It is studied how responsible is the towed car in case of crashing its back side by driving car. The influence on the driving angle of towed car by lifting wrecker is also considered.

The Road Speed Sign Board Recognition, Steering Angle and Speed Control Methodology based on Double Vision Sensors and Deep Learning (2개의 비전 센서 및 딥 러닝을 이용한 도로 속도 표지판 인식, 자동차 조향 및 속도제어 방법론)

  • Kim, In-Sung;Seo, Jin-Woo;Ha, Dae-Wan;Ko, Yun-Seok
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.4
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    • pp.699-708
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    • 2021
  • In this paper, a steering control and speed control algorithm was presented for autonomous driving based on two vision sensors and road speed sign board. A car speed control algorithm was developed to recognize the speed sign by using TensorFlow, a deep learning program provided by Google to the road speed sign image provided from vision sensor B, and then let the car follows the recognized speed. At the same time, a steering angle control algorithm that detects lanes by analyzing road images transmitted from vision sensor A in real time, calculates steering angles, controls the front axle through PWM control, and allows the vehicle to track the lane. To verify the effectiveness of the proposed algorithm's steering and speed control algorithms, a car's prototype based on the Python language, Raspberry Pi and OpenCV was made. In addition, accuracy could be confirmed by verifying various scenarios related to steering and speed control on the test produced track.

Components sizing of powertrain for a Parallel Hybridization of the Mid-size Low-Floor Buses (중형저상버스 병렬형 하이브리드화를 위한 동력전달계 용량매칭)

  • Kim, Gisu;Park, Yeong-il;Ro, Yun-sik;Jung, Jae-wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.8
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    • pp.582-594
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    • 2016
  • Most studies on hybrid buses are on large-sized buses and not mid-sized low-floor buses. This study uses MATLAB simulation to evaluate the fuel efficiency of such buses powered by diesel. Based on the results, a hybrid electric vehicle system is recommended for the best combination of power and gear ratio. A parallel hybrid system was selected for the hybridization, which transmits front and rear wheel power independently. The necessary power to satisfy the target performance was calculated, and the applicable capacity area was designed. Dynamic programing was used to create and optimize a component sizing algorithm, which was used to scale the capacity of each component of the power source to satisfy the design criteria. The fuel efficiency rate, optimum power source capacity, and gear ratio can be improved by converting a conventional bus into a parallel hybrid bus.

Evaluation of Static Behaviour of Orthotropic Steel Deck Considering the Loading Patterns (하중재하 패턴을 고려한 강바닥판의 정적거동 평가)

  • Kim, Seok Tae;Huh, Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.2
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    • pp.98-106
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    • 2011
  • The deck of steel box girder bridges is composed of deck plate, longitudinal rib, and transverse ribs. The orthotropic steel decks have high possibility to fatigue damage due to numbers of welded connection part, the heavy contact loadings, and the increase of repeated loadings. Generally, the local stress by the repeated loadings of heavy vehicles causes the orthotropic steel deck bridge to fatigue cracks. The increase of traffic volume and heavy vehicle loadings are promoted the possibility of fatigue cracks. Thus, it is important to exactly evaluate the structural behavior of bridge considering the contact loading area of heavy vehicles and real load patterns of heavy trucks which have effects on the bridge. This study estimated the effect of contact area of design loads and real traffic vehicles through the finite element analysis considering the real loading conditions. The finite element analysis carried out 4 cases of loading patterns in the orthotropic steel deck bridge. Also, analysis estimated the influence of contact area of real truck loadings by the existence of diaphragm plate. The result of finite element analysis indicated that single tire loadings of real trucks occurred higher local stress than one of design loadings, and especially the deck plate got the most influence by the single tire loading. It was found that the diaphragm attachment at joint part of longitudinal ribs and transverse ribs had no effects on the improvement of structural performance against fatigue resistance in elastic analysis.

Field Measurements and Review of the Curve Squeal Noise of Urban Railways (도시철도 차량 주행시 곡선스킬소음 실험 및 고찰)

  • Kim, Jae-chul;Kim, Kwanju;Lee, Junheon;Kim, Jiyong
    • Journal of the Korean Society for Railway
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    • v.20 no.2
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    • pp.165-172
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    • 2017
  • High frequency squeal noise can be generated when a railroad vehicle runs a sharp curved section; this noise causes environmental complaints and excessive wear on the wheel and the railroad track. In this paper, curved squeal noise experiments on a commercial railway were carried out to investigate this phenomenon. The relationship of the squeal noise pressure level, the frequency characteristics, the railway running speed, and the modal behavior of the wheel were investigated. At the same time, the lateral motion of the wheel relative to the rail was captured using a video camera; wheel movement was calculated when the noise was generated. queal noise occurred at the highest level at the inner front wheel; this phenomena is considered to be related to the lateral vibration response characteristics of the wheel. It can be seen that the magnitude of this squeal noise is not directly related to the increase in vehicle speed.

Running stability analysis of the Semi-Crawler Type Mini-Forwarder by Using a Dynamic Analysis Program (동역학분석 프로그램을 이용한 반궤도식 임내작업차의 주행안정성 분석)

  • Kim, Jae-Hwan;Park, Sang-Jun
    • Journal of Korean Society of Forest Science
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    • v.104 no.1
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    • pp.98-103
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    • 2015
  • This study was conducted to analyze the running stability of a semi-crawler type mini-forwarder. The running stability analysis was performed by using a dynamic analysis program, RecurDyn. Physical properties of the semi-crawler type mini-forwarder was performed by using 3D CAD modeler, AutoCAD 3D. As a result from the computer simulation of stationary sideways overturning, it was found that the semi-crawler type mini-forwarder runs safely on a road with a slope not bigger than $20^{\circ}$ regardless whether it is empty or loaded, but in case of a road with a slope bigger than $20^{\circ}$, it is assumed that it is difficult for the car to run safely due to some dangers. In addition, it was found that the critical slope of its sideways overturning gets much smaller when empty since the location of its gravity center is elevated and much higher when it is loaded. As a result from the computer simulation of its hill-climbing ability, since the running speed is unstable in case of a road with a vertical slope not smaller than $28^{\circ}$, it is assumed that it is safe to drive it on a road with a slope not bigger than $28^{\circ}$. Taking a look at the result from an analysis of the running safety when it passes an obstacle, it was observed that a front tire comes off the ground when the running speed of the car is 5 and 4 km per hour respectively when it is empty and loaded while the gravity center of the front tire is watched. When taking a look at the changes in the location of the gravity center of the rear wheel crawler shaft, it was not found that the shaft comes off the ground at the test speeds both when it is empty and loaded.