• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1113-1114
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• 1996

We describe an algorithm to control an autonomous guided vehicle with 2-diagonal driving wheels, which navigates in the clean room.

• 제어로봇시스템학회지
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• 제2권2호
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• pp.57-65
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• 1996

본 고에서는 최근에 가장 대표적인 능동형 샤시시스템으로 부각되고 있는 각종 능동식 현가시스템 및 4륜 조향 시스템의 개발동향 및 기술적, 경제적인 측면에서의 종합적인 검토를 하고자 한다.

• 한국지능시스템학회논문지
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• 제22권5호
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• pp.570-576
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• 2012

본 논문에서는 역진자 기구와 기립 암을 이용하여 직립주행이 가능한 이동로봇용 구동 플랫폼을 개발한다. 기존에 주류를 이루고 있는 이동로봇은 4륜 혹은 3륜으로 구동되고 있으므로 그 몸체는 정역학적으로 용이하게 안정성이 확보되는 특징을 갖고 있다. 기존의 이동로봇의 형태는 평면적으로 넓적한 형태의 정사각형 혹은 직사각형 형태를 갖고 있으므로 몸체의 조향을 위해서 독립구동륜형 혹은 조향형 차륜을 장치하고 있다. 이동로봇은 협소한 지형에서 90도로 굽은 통로를 주행할 때, 전후진을 반복하는 등 특별한 조향기법을 필요로 하거나 몸체의 평면적 때문에 물리적으로 조향이 불가능한 경우에 처하게 된다. 이 때, 이동로봇은 평면적이 작은 방향 즉, 직립된 상태로 몸체의 형상을 변형시켜 해당 지형을 주행함으로써 주행곤란 문제를 회피할 수 있다. 본 연구에서는 이동로봇의 몸체를 직립시킬 수 있는 기립 암과 역진자 기구가 결합된 구동 플랫폼을 제안한다.

• 한국자동차공학회논문집
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• 제17권4호
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• pp.86-92
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• 2009

A driver-vehicle model means the integrated dynamic model that is able to estimate the steering wheel angle from the driver's desired path based on the dynamic characteristics of the driver and vehicle. Autonomous driving robot for factory automation has individual four-wheels which are driven by electronic motors. In this paper, the dynamic characteristics of several four-wheel steering systems with the simultaneously steerable front and rear wheels are investigated and compared by means of the driver-vehicle model. A diver-vehicle model is proposed by using the PID control to velocity and trajectory of control autonomous driving robot. To determine the optimum speed of a autonomous driving robot, steady-state circle simulation is carried out with the ADAMS program and MATLAB control model.

• 한국생산제조학회지
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• 제7권2호
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• pp.69-73
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• 1998

With increased loads in steered wheels and wider section tires the effort required at the steering wheel makes the driver's job very tiring and difficult. Improvements such as an increase in the mechanical efficiency of the steering system or lower steering box ratios help the reduce driver fatigue. Now using of power steering is increasing. It needs to be considering parts size of steering system as using power steering. This paper presents adjust part size of steering system form estimating reliability according to reducing torque under the dynamic load, In this paper, the spider of universial joint is selected to prove relation between steering and power steering reliability.

• 한국자동차공학회논문집
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• 제2권5호
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• pp.101-109
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• 1994

Recently, four-wheel steering systems have been developed and studied as one of the latest automotive technologies for improving the handling characteristics of a vehicle. In much of the proposed four-wheel steering systems, the side slip angle at the vehicle's center of gravity is maintained at zero. This approach allows the greater maneuverability at low speed by means of counter-phase rear steering and the improved stability at high speed through same-phase rear steering. In this paper, the effects of several four-wheel steering systems are studied and discussed on the responsiveness and stability of the vehicle by using the linear analysis. Especially, the effects of the cornering stiffnesses of both front and rear wheels are investigated on the yaw velocity gain and critical speed of the vehicle.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.209-220
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• 1996

In this paper, dynamic performance of 4WD/4WS Electric-driven vehicles is investigated. A coupled dynamic model is introduced for longitudinal, lateral and yawing motion of 4WD/4WS vehicles. Based on the coupled model, dynamic performance is analyzed for steady-state steering, acceleration steering and brake steering, respectively. These non steady-state cornering analysis is important for non-paved road maneuvering, trajectory projection for armored vehicle and future AVCS(Advanced Vehicle Control System) technology. Simulation results are obtained based on a simulink module for the introduced model.

• 한국자동차공학회논문집
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• 제6권2호
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• pp.1-11
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• 1998

The 4WS system is usually developed to improve the maneuverability at low speed and the straight line stability at high speed, but it is found to have the severe understeer characteristics at high speed. Therefore a 4WS vehicle requires to turn the steering wheel much more than a 2WS vehicle at high speeds even a driver goes through the same curved road. In this study, to enhance the cornering performance of the 4WS vehicle at high speed, a DYC 4WS system is proposed based on the nonlinear 4WS system and direct yaw moment control system. Especially the proposed DYC 4WS system is able to realize a zero side slip angle for vehicles and a cornering performance similar to the 2WS vehicle at high speed.

• 한국철도학회논문집
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• 제10권4호
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• pp.444-450
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• 2007

The bi-modal tram guided by the magnetic guidance system has two car-bodies and three axles. Each axle of the vehicle has an independent suspension to lower the floor of the car and improve ride quality. The turning radius of the vehicle may increase as a consequence of the long wheel base. Therefore, the vehicle is equipped with the All-Wheel-Steering(AWS) system for safe driving on a curved road. Front and rear axles should be steered in opposite directions, which means a negative mode, to minimize the turning radius. On the other hand, they also should be steered in the same direction, which means a positive mode, for the stopping mode. Moreover, only the front axle is steered for stability of the vehicle upon high-speed driving. In summary, steering angles and directions of the each axle should be changed according to the driving environment and steering mode. This paper proposes an appropriate AWS control algorithm for stable driving of the bi-modal tram. Furthermore, a multi-body model of the vehicle is simulated to verify the suitability of the algorithm. This model can also analyze the different dynamic characteristics between 2WS and AWS.

• 한국지능시스템학회논문지
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• 제25권6호
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• pp.578-584
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• 2015

본 연구에서 자동화된 기립 및 복귀 시스템이 적용된 직립주행이 가능한 이동로봇용 구동 플랫폼이 개발되었다. 종래 대부분의 이동로봇은 정역학적으로 안정된 평면형의 4륜 혹은 3륜 구동형으로 구성되어 있는데, 이러한 형태의 이동로봇은 방향 전환을 위해서 독립구동형 혹은 조향형 차륜을 갖추고 있다. 이동로봇이 매우 협소한 지형에서 직각으로 굽은 통로를 주행할 때, 이동로봇은 전후진을 반복하는 등 복잡한 조향동작을 필요로 하거나, 극단적인 경우, 물리적인 조향이 불가능한 경우에 처하게 된다. 직립주행이 가능한 이동로봇은 점유면적이 작은 직립된 상태로 몸체의 형상을 변형시켜 해당 지형을 원활하게 통과할 수 있다. 본 연구에서 기립(복귀)동작, 확인동작, 평형제어 순으로 각 단계가 수동으로 조작되었던 기립제어 단계가 몸체의 기울기 각도 검출로 자동화되어, 단일 자동제어로 조작되는 차륜형 역진자 시스템이 제안되었다.