• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.234-239
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• 2003

A cylindrical shape object is widely used as a mechanical part and a water pipe or an oil pipeline which are of cylindrical shape are widely used in the infrastructure. In order to handling such objects automatically using a robot, the posture i.e. orientation in 3D space should be recognized. However, since there is no edge or vertex in the pipe, it is very difficult task for the robot. In this paper in order to guide the robot, two kind of algorithms which find the axis using the measured range data from the robot to the object surface are to be developed. The algorithms are verified using both the simulated range data and the measured one.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.3
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• pp.143-148
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• 2001

A lot of robot trajectory tracking methods are proposed to enhance the tracking error, but irregular tracking errors are always accompanied and very hard to reduce it. Up to now, these irregular tracking errors are reduced by introducing more complicated control algorithms. But, it is intuitively obvious to reduce only the big errors selectively in the irregular ones for the better performance instead of using more complicated control algorithms. By the characteristics of the robot, big tracking errors of the end-effector are generated mostly due to the fast moving of joint. So, in this paper, we introduce a new method which reduce the big tracking errors by clippings the joint velocity with the constraint of given path. Using this method, desired trajectory tracking is obtained within the far reduced error bound. Also, this method is successfully applied to generate the path-constrained error reducing trajectories for 2-axis SCARA type robot.

• International Journal of Control, Automation, and Systems
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• v.5 no.3
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• pp.343-348
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• 2007

This paper presents an adaptive controller for the compensation of state-dependent disturbance with unknown amplitude in a digital servo motor system. The state-dependent disturbance is caused by friction and eccentricity between the wheel axis and the motor driver of a mobile robot servo system. The proposed control scheme guarantees an asymptotical stability for both the velocity and position regulation. An experimental result shows the effectiveness of the adaptive disturbance compensator for wheeled-mobile robot in a low velocity diffusion tracking. A comparative experimental study with a simple PI controller is presented.

• The Journal of Korea Robotics Society
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• v.18 no.1
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• pp.37-47
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• 2023

This paper introduced how to construct Denavit-Hartenberg (DH) parameters from the Unified Robot Description Format (URDF). URDF is convenient for describing a robot even though the robot is very complex. On the other hand, DH convention is not an easy notation for many novices who want to describe a robot. Therefore, most vendors provide URDF and users prefer to use URDF to describe a robot. However, some controllers or algorithms are based on DH parameters to perform kinematics, dynamics, control, etc. To connect URDF and DH parameters, we present a three-step approach to construct DH parameters from URDF. The first step is to define the joint axis for constructing DH parameters. The second step is constructing DH parameters to define joint character. The final step is constructing DH parameters to define the coordinate frame of the child link. This approach is based on intuitive vector calculation and guarantees the uniqueness of DH parameters. To verify our approach, we applied our approach to a simple one-link robot, a manipulator with 6 DOF, and a quadruped robot with 3 DOF per leg. We verified that our approach worked well based on forward kinematic results.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.54-59
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• 2005

The cylindrical object are widely used as mechanical parts in the manufacturing process. In order to handling those objects using a robot or an automated machine automatically, the pose of the object must be known. The pose can be described by two rotation angles; one angle about the x axis and the other about the y axis. In the many previous researches these angles were obtained by the computationally intensive algorithm, that is, fitting the data as a polynomial and doing pseudo inverse. So that, this method required high performance microprocessor. In this paper in order to avoid complex computation, a new method based on a genetic algorithm is proposed and analyzed through a series of simulations. This algorithm utilized the geometry of the cylindrical shape. The simulation results show that this method find the pose angles very well In most cases, but the computation time is randomly changed because the genetic algorithm is basically one of the random search method.

• 전자공학회논문지 IE
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• v.45 no.4
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• pp.42-46
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• 2008

LED's production does Die bonding and Wire bonding on L/F board, and do epoxy dispensing to protect LED Chip and improve brightness. In this paper, we propose and realize a x-y-z axis robot mechanism detecting automatically eopxy's amount being filled, control data of pressure and time by the quantity automatic revision, and epoxy of the schedule amount dispensing.

• Journal of the Korea Society of Computer and Information
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• v.19 no.3
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• pp.11-16
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• 2014

In this paper, the two-wheels robot using a predictive controller to maintain the balance of the posture control in real time have been examined. A reaction wheel pendulum control method is adopted to maintain the balance while the bicycle robot is driving. The objective of this research was to design and implement a self-balancing algorithm using the dsPIC30F4013 embedded processor. To calculate the attitude in ARS using 2 axis gyro(roll, pitch) and 3 axis accelerometers (x, y, z). In this study, the disturbance of the posture for the asymmetrical propose to overcome the predictive controller which was a problem in the control of a remote system by introducing the two wheels of the robot controller and the linear prediction of the system controller combines the simulation was performed. Also, the robust characteristic for realizing the goal of designing a loop filter too robust controller is designed so that satisfactory stability of the control system to improve stability of the system to minimize degradation of performance was confirmed.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.137-141
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• 1988

A sampled data controller for the quadruped walking robot is presented. To provide systematic design procedure, the relation between PI gain of velocity controller and sampling rate is analyzed with the ISE performance index and the time responses. The position controller for one-leg, 3-axis, was developed under consideration of compactness and expendability. And several experiments were performed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.503-504
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.369-370
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• 2009