• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.8 s.179
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• pp.1899-1909
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• 2000

This paper proposes a new $H_{\infty}$ yaw moment control scheme using brake torque switching for improving vehicle performance and stability especially in high speed driving. In the scheme, one wheel is selected, depending on the vehicle states, at which a brake torque for control is applied. Steering angles are modeled as a disturbance to the system and the $H_{\infty}$ controller is designed to minimize the difference between the performance of the vehicle and that of the desired model. Its performance robustness as well as stability robustness to system parameter variations is assured through ${\mu}$-analysis. Various simulations with a nonlinear 8-DOF vehicle model show that proposed controller enhances the vehicle performance and stability under disturbances and parameter variations as well as under the normal driving condition.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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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.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.4
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• pp.308-316
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• 2004

As we know that there are so many restrictions controlling the autonomous robot to turn and move in an indoor space. In this research, Ive adopted the concept ‘Omni-directional wheel’ as a driving equipment, which makes it possible for the robot to move in horizontal and diagonal directions. Most of all, we eliminated the slip error problem, which can occur when the system generates power by means of slip. In order to solve this problem, we developed a ‘slip error correction algorithm’. Following this program, whenever the robot moves in any directions, it defines its course by comparing pre-programmed direction and the current moving way, which can be decided by extracted image of floor line. Additionally, this robot also provides the limited security and service function. It detects the motion of vehicle, transmits pictures to multiple users and can be moved by simple order's. In this paper, we tried to propose a practical model which can be used in an office.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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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.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1125-1131
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• 2012

According to abrupt decrese in number of farmer and ageing society, there has been a need for development of low cost agricultural robot. In this paper, a H/W and S/W platform of caterpillar type agricultural chemical dusting robot based on XP embedded system were described. The developed agricultural robot has 2 d.o.f caterpillar type driving wheel and 2 d.o.f chemical dusting spray mechanical system. The H/W platform of the agricultural robot consists of robot controller, remote controller and sensor controller. In S/W platform, 5 processes work concurrently, which are task manager, TCP-IP communication process, localization process, wheel control, and sensor control process. This robot platform has been developed for chemical dusting robot. We proved this system's validity through field test.

• 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.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.110-119
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• 1997

Four wheel steering(4WS) systems which can control the lateral and yaw motions of vehicles by steering front and rear wheels simultaneously, have been regarded as effective for improving the stability and handing performance of vehicles. However, since the 4WS systems depend only on the lateral force of tire, they have some limitation due to the nonlinear characteristics of tire related with the saturation phenomenon of lateral force to the slip angle of tire in a near-limit-performance maneuvering range. In this study, in other to evaluate the effect of nonlinear characteristics of tire on the dynamic performance of vehicles, a new concept for driving the cornering stiffness of nonlinear tire by using the "Magic Formula" tire model is proposed. In addition, the nonlinear 4WS vehicle model is constructed based on the proposed cornering stiffness of nonlinear tire. It is noted from simulation that the nonlinear characteristics of tire affect greatly on the 4WS vehicle performance.rformance.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.397-402
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• 2005

In this paper, to improve the efficiency of welding and user convenience in the shipbuilding industry, a PC-based off-line programming (OLP) technique and the development of a robot transfer unit are presented. The developed OLP system is capable of not only robot motion simulations but also automatic generations of a series of robot programs. The strength of the developed OLP system lies in its flexibility in handling the changes of the welding robot's target objects. Moreover, for a precise transfer of the robot to a desired location, an auxiliary mobile platform named a robot-origin-transfer-unit (ROTU) was developed. To enhance the cornering capability of the platform in a narrow area, the developed ROTU is equipped with 2 steering wheels and 1 driving wheel. Both the OLP and the ROTU were field-tested and their performances were proven successful.

• International Journal of Control, Automation, and Systems
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• v.3 no.1
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• pp.32-42
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• 2005

In this paper, to improve the efficiency of welding and user convenience in the shipbuilding industry, a PC-based off-line programming (OLP) technique and the development of a robot transfer unit are presented. The developed OLP system is capable of not only robot motion simulations but also automatic generations of a series of robot programs. The strength of the developed OLP system lies in its flexibility in handling the changes of the welding robot's target objects. Moreover, for a precise transfer of the robot to a desired location, an auxiliary mobile platform named a robot-origin-transfer-unit (ROTU) was developed. To enhance the cornering capability of the platform in a narrow area, the developed ROTU is equipped with 2 steering wheels and 1 driving wheel. Both the OLP and the ROTU were field­tested and their performances were proven successful.

• Korean Journal of Artificial Intelligence
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• v.11 no.4
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• pp.21-27
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• 2023

This paper discusses a deep learning-based road surface analysis system that collects data by installing vibration sensors on the 4-axis wheel bearings of a vehicle, analyzes the data, and appropriately classifies the characteristics of the current driving road surface for use in the vehicle's control system. The data used for road surface analysis is real-time large-capacity data, with 48K samples per second, and the A2B protocol, which is used for large-capacity real-time data communication in modern vehicles, was used to collect the data. CAN and CAN-FD commonly used in vehicle communication, are unable to perform real-time road surface analysis due to bandwidth limitations. By using A2B communication, data was collected at a maximum bandwidth for real-time analysis, requiring a minimum of 24K samples/sec for evaluation. Based on the data collected for real-time analysis, performance was assessed using deep learning models such as LSTM, GRU, and RNN. The results showed similar road surface classification performance across all models. It was also observed that the quality of data used during the training process had an impact on the performance of each model.