• 센서학회지
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• 제32권5호
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• pp.267-274
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• 2023

LiDAR, one of the most important sensing methods used in mobile robots and cars with assistive/autonomous driving functions, is used to locate surrounding obstacles or to build maps. For real-time path generation, the detection of potholes or puddles on the driving surface is crucial. To achieve this, we used the coordinates of the reflection points provided by LiDAR as well as the intensity information to classify water areas, which was achieved by applying a linear regression method to the intensity distribution. The rationale for using the LiDAR index as an input variable for linear regression is presented, and we demonstrated that it is not affected by errors in the distance measurement value. Because of LiDAR vertical scanning, if the reflective surface is not uniform, it is divided into different groups according to the intensity distribution, and a mathematical basis for this is presented. Through experiments in an outdoor driving area, we could distinguish between flat ground, potholes, and puddles, and kinematic analysis was performed to calculate the maximum width that could be crossed for a given vehicle body size and wheel radius.

• 융합신호처리학회논문지
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• 제5권4호
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• pp.308-316
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• 2004

실내 환경에서 자율이동 로봇은 방향의 전환과 움직임에 있어서 많은 제약이 따른다. 본 연구는 이런 제약을 해결하기 위하여 수평, 대각이동이 가능한 Omni-Directional Wheel을 로봇 구동부에 적용하였다. 하지만 Slip에 의해서 동력을 얻는 Omni Directional Wheel 구동방식은 Slip에 의한 오차가 발생하는 문제점이 있었다. 이 문제점을 해결하기 위해 개발된 Slip 보정 알고리즘은 하나의 타일을 지날 때마다 외곽선을 추출하고, 추출된 외곽선과 로봇의 절대방위가 이루는 각도를 비교하여 오차가 발생할 경우 로봇의 절대방위를 수정하게 한다. 또한 로봇은 보안기능과 서비스 기능을 수행한다. 보안기능은 차 영상을 이용하여 움직임을 감지한다. 서비스 기능으로는 로봇에 입력되는 영상을 일반사용자에게 다중전송 하고, 간단한 이동명령이 있다. 본 연구에서 제안한 로봇 시스템은 실제 사무실에서 사용가능한 하나의 모델이 될 수 있다.

• International Journal of Automotive Technology
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• 제7권3호
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• pp.303-307
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• 2006

This paper presents the enhancement of vehicle stability by active geometry control suspension(AGCS) system as the world-first, unique and patented chassis technology, which has more advantages than the conventional active chassis control systems in terms of the basic concept. The control approach of the conventional systems such as active suspensions(slow active, full active) and four wheel steering(4WS) system is directly to control the same direction with acting load to stabilize vehicle behavior resulting from external inputs, but AGCS controls the cause of vehicle behaviors occurring from vehicle and thus makes the system stable because it works as mechanical system after control action. The effect of AGCS is the remarkable enhancement of avoidance performance in abrupt lane change driving by controlling the rear bump toe geometry.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.722-728
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• 2000

This study of field control machine in the recycled vinyl rail is gantry crane type and promoting agricultural automatization through self-controlled spraying, harvesting and conveyance. In addition to, that control machine could get a cost and labor reduction effect through automatization and make better environment by preventing farmers from agrichemical damage, accidents and recycling wasted vinyl. That machine is able to be divided as traveling, spraying, harvesting and conveyance sections. In driving section consists of girder frame, carrier, rail, control system, driving system, working machine, rail and loading device for working machine. This machine has following advantages to be able to bring a big innovation in the agricultural industry. I) Accurate performance is able to be done by proper positioning due to based on the rails. 2) The soil is not made hard like heavy tractor 3) The wheel is not sank into the soil and slipped well under rain like heavy tractor. Therefore, weather and soil situation could not affect working condition. 4) Complete unmanned control and 24hours-working are available due to traveling on the rails. 5) It could use various energy resources like not only liquid fuel but also solar, common electronic power due to traveling on the rails.

• 전기학회논문지
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• 제59권3호
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• pp.645-650
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• 2010

In this paper we present the Bimodal-tram simulator using the PXI embedded real-time controllers. The Bimodal-tram is developed in KRRI (Korea Railroad Research Institute). The vehicle can be automatically operated by navigation control system (NCS). For the automatic driving, the vehicle lanes will be marked with permanent magnets that are placed in the ground. The vehicle is controlled by NCS. NCS governs the manual mode and automatic mode driving. The simulator is designed by an identical conception with the real control condition. The dynamic motion of vehicle is simulated by the nonlinear dynamic model. The control computer calculates the control values. The signal interface is linked by CAN communication. The simulation is processed by real-time base. The test driver can see the graphic motion of vehicle and can operate the steering wheel, gas and brake pedal to control direction and velocity of vehicle during the simulation. At present, the simulator is only operated by manual mode. The automatic mode will be linked after the control algorithm is finished. We will use the simulator to develop the control algorithm in the automatic mode. This paper shows the simulator designed for Bimodal-tram using real-time based controller. The results of the test using the simulator are presented and discussed.

• 한국철도학회논문집
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• 제12권5호
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• pp.678-686
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• 2009

국내에서 개발된 한국형 틸팅열차는 현재 시제차량 제작을 마치고, 충북선을 시작으로 시운전 시험이 단계적으로 진행되고 있다. 시운전 시험에서는 한국형 틸팅열차의 시스템 안정화를 위해 차량 외에 궤도, 구조물, 전차선, 신호 등 각 시스템 상호간의 인터페이스 검증이 필요하며, 선로구축물 분야에서는 개발차량의 증속이 궤도구조에 미치는 영향을 비롯한 궤도부담력 검토를 통해 궤도구조의 안정성과 주행안정성 평가가 수행되어야 한다. 따라서 본 연구에 서는 완화곡선구간을 주행하는 틸팅차량(한빛200호), 고속차량(KTX) 및 일반차량(무궁화)에 의해 궤도에서 발생하는 동적 윤중 및 횡압을 측정하였다. 측정데이터를 통해 차종별 주행패턴을 비교하고 윤중과 횡압의 증감율을 확률적으로 분석하였다. 분석결과, 고정식 대치구조를 갖는 기존 차량의 캔트변화에 따른 발생 윤중 및 횡압의 분포범위는 일정 범위 내에서 작은 편차로 분포하였다. 반면 진자식 대차구조인 틸팅차량의 경우 캔트변화에 따른 차체의 틸팅작용에 의해 비교적 넓은 범위에 큰 편차로 궤도작용력이 분포하는 것으로 나타났다.

• 한국정밀공학회지
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• 제17권4호
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• pp.121-128
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• 2000

In this paper, the control algorithm fur an autonomous vehicle is studied and applied to an actual 2 wheel-driven vehicle system. In order to control a nonholonomic system, the kinematic model for an autonomous vehicle is constructed by relative velocity relationship about the virtual point at distance from the vehicle's frame. And the optimal controller that based on the kinematic model is operated on purpose to track a reference vehicle's path. The actual system is designed with named 'HYAVI' and the system controller is applied. Because all the results of simulation don't satisfy the driving conditions of HYAVI, a reformed control algorithm that satisfies an actual autonomous vehicle is applied at HYAVI. At the results of actual experiments, the path tracking works very well by the reformed control algorithm. An autonomous vehicle that applied this control algorithm can be easily used for a path generation algorithm.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.55-56
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• 2006

This paper describes a new concept of the robot that can climb on the vertical plane. The engineering design problem of the main structure is presented and the experimental results regarding a new mechanism of climbing on the vertical wall are discussed. The locomotive motion of the robot is realized by using a series chain of two caterpillar wheels on which 24-suction pads are installed. White each caterpillar wheel rotates on the vertical plane surface, the vacuum pads are activated in sequence based on the sequential opening by specially designed mechanical valves. The detail design feature of the valve is also described in this paper. The overall size of the robot is around 460 mm in width and length, respectively, and 200 mm in height. Its mass is slightly over 14 kg. The main mechanical structure of the robot consists of driving motors, vacuum caterpillar system, steering part, vacuum pump and battery. The performance of the robot is verified on the vertical wall.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.450-451
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• 2008

The Bimodal tram is developed in KRRI (Korea Railroad Research Institute). This vehicle will be used in the public transportation system. The Bimodal tram has the advantages of both bus and train. Bus system has the advantages of flexibility of the routes delivering passengers to the destination and easy accessibility. Train is to meet the scheduled arrival and massive public transportations. The vehicle is the rubber tired tram and is all wheel steered single articulation. The vehicle can be automatically operated by navigation control system (NCS). For the automatic driving, the vehicle lanes will be marked with permanent magnets that are buried in the road. The control algorithm developed for navigation control has to be verified before being applied in the vehicle. In this purpose, we design the simulator for controller test of the bimodal tram.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.160-163
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• 2005

The cute. race of CV(constant velocity) Joint is an important load-supporting automotive part, which transmits torque between the transmission gear box and driving wheel. The outer race is difficult to forge because its shape is very complicated and the required dimensional tolerances are very small. The forged CV Joint investigated in this study has six inner ball grooves requiring high operational accuracy. Therefore, the precise measurement of forged CV Joint is very important to guarantee the sound operation without noise and abnormal wear. In this study, unique in-situ measuring system designed specifically to measure the dimensional accuracy of six inner ball grooves of CV joint has been developed and implemented in shop environments. Newly developed system shows high measurement accuracy with simple operational sequence.