• International Journal of Control, Automation, and Systems
• /
• v.1 no.3
• /
• pp.376-384
• /
• 2003

In this paper, the simple geometric kinematics of a three-wheeled holonomic mobile robot is proposed. Wheel architecture is developed for the holonomic mobile platform in order to provide omni-directional motions by three individually driven and steered wheels. Three types of basic motions are proposed for the path generation of the developed mobile robot. All paths of the mobile robot can be achieved through a combination of the proposed basic motion trajectories. The proposed method is verified through computer simulations and the developed mobile robot.

• Journal of Institute of Control, Robotics and Systems
• /
• v.11 no.9
• /
• pp.761-767
• /
• 2005

There exists a structural limit of 2WS cars that drivers would not like simultaneously to follow the desired path and attenuate moments resulting from disturbances because lateral acceleration and yaw rate are coupled inherently. In order to overcome the limit, the 4WS cars that have rear wheel steering as an additional input have been introduced. But the 4WS cars have disadvantages that much cost is required due to structural alteration, it is difficult to be used to the driving circumstances and tire performances are not efficient in nonlinear or large lateral acceleration ranges. Therefore, it is proposed that, in this paper, a robust controller is easy to apply to 2WS cars by using direct yaw moment, decouples lateral acceleration from yaw motion and is robust against disturbances and uncertainties of system parameters, and thus the proposed control method has the advantages of 4WS cars which can be achieved in 2WS cars.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.11
• /
• pp.1082-1091
• /
• 2007

In this paper, we developed a new hybrid mobile robot which can climb stairs and go over thresholds by crawl gait with embedded real-time control software. This robot is also categorized into hybrid robot that has advantages of wheeled mobile robot and legged mobile robot, but adopts gait feature of crocodile named belly crawl. We imitated the belly crawl using four legs of 2 DOF, four omni-directional wheels, and embedded control software which controls legs and wheels. This software is developed using RTAI/Linux, real-time drivers. As a result, the new hybrid mobile robot has crawl gait. Using this feature, the new hybrid mobile robot can climb stairs and go over thresholds just by path planning of each leg with size of stairs and thresholds, and computing the movement distance of robot body center without considering stability. The performance of our new hybrid mobile robot is verified via experiments.

• Proceedings of the IEEK Conference
• /
• 2002.07a
• /
• pp.583-586
• /
• 2002

In this research, we propose a flexible conveying system (FCS) which consists of multiple arrays of cells. Each cell is a wheel driven by a two degree-of-freedom mechanism. The direction and velocity of cell are controlled based on the concept of hybrid control under a distributed network. Each cell has its own controller under a subsumption architecture for low-level control. A cell communicates with its four neighboring cells to manipulate n targeted object towards its desired position. The high-level control assigns a desired position and direction of the object to each cell. The path of each object is generated by many supporting cells. Moreover, the FCS can handle multiple objects simultaneously. To study the flexible conveying system, a GUI-based simulator of flexible conveying system is constructed. The simulated results show that the system can handle multiple objects independently and simultaneously under the proposed hybrid control architecture.

• Proceedings of the KIPE Conference
• /
• 2013.11a
• /
• pp.69-70
• /
• 2013

By using differential force between left and right wheel, lateral motion can be controlled known as Direct Yaw-moment Control (DYC). In previous researches, DYC control is proposed to increase the stability of the vehicle, but maneuverability has not been discussed sufficiently. The car handling condition which is called the index parameter of maneuverability is dependent on the vehicle velocity and steering angle. To achieve the desired vehicle's cornering path, the car handling condition must be considered sufficiently. In this paper, the novel DYC method is proposed which gives the car handling condition regardless of the longitudinal speed. The proposed controller is based on the PI controller to feedback the curvature parameter. The controlled system shows the advantages of DYC regarding to the reference trajectory by the dual motor system. With respect to the uncontrolled model, the effectiveness of the proposed method is validated by numerical examples.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.363-366
• /
• 1996

A Reclaimer is used to dig raw material from a pile and transfer it to the blast furnaces. In this paper, we propose the method for trajectory landing position of bucket of reclaimer to fully automate the reclaimer. We use 3-dimensional range finder to detect the shape of a pile. From the image which was detected by 3-dimensional range finder, we extract the outline paths which has same height, and then determine digging height. Finally, we compute the landing point from the outline path. We can prevent overload which can occur on the bucket wheel and guarantee maximum production rate by using the algorithm for determining the landing position on the piles.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.629-632
• /
• 1999

In this paper, color coordinate system transformation based visual servo controller has been considered. Mobile robot always has a position error and an orientation error resulted from wheel slipping etc.. Even more, the errors have accumulative properties. So feedback from environments is important. In this paper, by using color model faster land mark extraction can be achieved. And the global position and the orientation of mobile robot can be known by only two land marks positions in image coordinate system. Finally, the adoption of visual information in path tracking problem makes visual servo control.

• Journal of Biomedical Engineering Research
• /
• v.8 no.1
• /
• pp.49-56
• /
• 1987

This paper designed LOCOMOTION SYSTEM of a mobile robot for the blind guidance and LOCOMOTION COMMAND SYSTEM that gave the moving path to the locomotion system. This system analyzed COMMAND and calculated the speed and direction of the robot. And during locomotion it measured wheel's rotation number for the position and speed control. Also, this system was considered about the 110 interface with host computer and the locomotion method for the blind. In the locomotion experiment the standard speed of robot was 0.4m/sec and the locomotion error was below 5%

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.561-562
• /
• 2006

To enhance the precision and productivity of ultra precision aspheric surface micro lens, the development of ultra-precision grinding system and process for the aspheric surface micro lens are described. In the work reported in this paper, an ultra-precision grinding system for manufacturing the aspheric surface micro lens was developed by considering the factors affecting the grinding surface roughness and profile accuracy. This paper deals with mirror grinding of an aspheric surface micro lens by resin bonded diamond wheel and spherical lens of BK7. The optimization of grinding conditions on ground surface roughness and profiles accuracy is investigated using the design of experiments.

• The Journal of Korea Robotics Society
• /
• v.2 no.2
• /
• pp.161-167
• /
• 2007

It is dangerous that an inspector overhauls defects and condition of the inner parts of an oil tanker because of many harmful gases, complex structures, and etc. However, these inspections are necessary to many oil tankers over old years. In this study, we proposed the design of mobile robot for inspection of CAS in oil tanker. The developed CAS inspection mobile robot has four modules, a measurement module of oil tanker's thickness, a corrosion inspection module, a climbing module of the surface on a wall, and a monitoring module. In order to get over at a check position, the driving control algorithm was developed. Magnetic wheels are used to move on the surface of a wall. This study constructed a communication network and the monitoring program to operate the developed mobile robot from remote sites. In order to evaluate the inspection ability, the experiments about performance of CAS inspection using the developed mobile robot have been carried out.