• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1770-1771
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• 2011

In mission planning of UAV applications, especially for the missions requiring height transitions, it is required to generate reference flight trajectories considering the performances of the engine installed in the UAV. Even though the vertical line following guidance based height transition trajectory generation method has been developed to build reference height transition trajectories easily, it is not adequate for considering engine performances effectively since many engine characteristics and performances have conventionally been described in the V-H(speed-height) plane which is not the very space where the UAVs are actually flying. In this paper, we derive the trajectories in V-H plane for the vertical line following flights. And based on the results, a new algorithm to design the reference height transition trajectories for UAV applicaions. Simulation results demonstrate that the proposed algorithm is very effective and easily applicable.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.3
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• pp.125-131
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• 2018

In this paper, we propose a homogeneous multisensor-based navigation algorithm for a mobile robot, which is intelligently searching the goal location in unknown dynamic environments with moving obstacles using multi-ultrasonic sensor. Instead of using "sensor fusion" method which generates the trajectory of a robot based upon the environment model and sensory data, "command fusion" method by fuzzy inference is used to govern the robot motions. The major factors for robot navigation are represented as a cost function. Using the data of the robot states and the environment, the weight value of each factor using fuzzy inference is determined for an optimal trajectory in dynamic environments. For the evaluation of the proposed algorithm, we performed simulations in PC as well as real experiments with mobile robot, AmigoBot. The results show that the proposed algorithm is apt to identify obstacles in unknown environments to guide the robot to the goal location safely.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.45-48
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• 1988

This paper reveals the relation hereon the robot system dynamic constraints and the VSC parameters, and analyzes the effect on the trajectory of the joint angle and the hand when the result of the relation analysis is applied to the robot system control. The result of the analysis in this paper is applied effectively to the path tracking control and the trajectory planning using the VSC method.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.328-333
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• 1994

This paper presents a real-time calculation method to generate the trajectory of robot manipulator for the purpose of avoiding collision. In order to model 3-D workspace, we use octree which has been used for fast collision detection. The levels of octree are used as the cost function to represent the distance between the manipulator and the obstacles. This criterion is not exact, but, due to this, we can obtain the approximate feasible trajectory extremely quickly. We will show the effectiveness of our method with some simulation examples. For example, the proposed method can solve a problem within 1 second on Intel 80486 processor running at 33 MHz. It has taken more than half an hour with one of the previously proposed methods.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.503-506
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• 1996

An integrated Robot control system for SCARA robot is developed. The system consists of an off-line programming(OLP), software and a robot controller using four digital signal processor(TMS32OC50). The OLP has functions of teaching task, dynamic simulator, three dimensional animation, and trajectory planning. To develop robust dynamic control algorithm, a new sliding mode control algorithm for the robot is proposed. The trajectory tracking performance of these algorithm is evaluated by implementing to SCARA robot(SM5 type) using DSP controller which has conventional PI-FF control algorithm. To make SCARA robot operate according to off-line teaching, an interface between OLP and robot controller in the integrated system is designed. To demonstrate performance of the integrated system, the proposed control algorithm is applied to the system.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.105.1-105
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• 2002

$\textbullet$ This paper deals with obstacle avoidance of a quadruped robot with a vision system and a PSD sensor. $\textbullet$ The vision system needs for obstacle recognition toward robot. $\textbullet$ Ths PSD sensor is also important element for obstacle recognition. $\textbullet$ We propose algorithm that recognizes obstacles with one vision and PSD sensor. $\textbullet$ We also propose obstacle avoidance algorithm with map from obstacle recognition algorithm. $\textbullet$ Using these algorithm, Quadruped robot can generate gait trajectory. $\textbullet$ Therefore, robot can avoid obstacls, and can move to target point.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.635-642
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• 1989

We formulated the multi-robot trajectory problem into a series of NLP problem, each of which is that of finding the optimal tip positions of the robots for the next time step. The NLP problem is composed of an objective function and three constraints, namely: a) Joint position limits, b) Joint velocity limits, and c) Collision-avoidance constraints. By solving a series of NLP problem, optimally coordinated trajectories can be determined without requiring any prior path information. This is a novel departure from the previous approach in which either all paths or at least one path is assumed to be given. Practical application of the developed method is for optimal synthesis of multiple robot trajectories in off-line. To test the validity and effectiveness of the method, numerical examples are illustrated.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1046-1051
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• 1991

For the conveyor tracking application of a robot manipulator, a new control scheme is presented. The presented scheme is divided into two stages : the upper one is the motion planning stage and the lower one is the motion control stage. In the upper stage, the nominal trajectory which tracks the part moving in a constant velocity, is planned considering the robot arm dynamics. On the other hand, in the lower level, the perturbed trajectory is generated to track the variation in the velocity of conveyor belt via sensory feedback and the perturbed arm dynamics. In both stages, the conveyor tracking problem is formulated as an optimal tracking problem, and the torque constraints of a robot manipulator are taken into account. Simulation results are then presented and discussed.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.63-66
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• 1988

In the control of the robotic manipulators, the variable structure control method for the get Point Regualation has a advantage of the insensitivity about parameter variations and disturbances. When the robotic manipulators are controlled by a point-to-point scheme, no path constraint is considered. Thus, the variable structure control method will be effectively applied only if the trajectory of the robot hand is estimated precisely. In this paper, the joint trajectories in the joint space and the hand trajectory in the cartesian space are calculated by the variable structure control method, and an algorithm is suggested to elaborate the deviation error of the robot hand from a straight line path. The result of this study will become a base of the effective path planning about robotic manipulators with the variable structure control concept.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.4
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• pp.59-65
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• 1985

This paper presents a design of the PWM digital servo controller and a real-time trajectory planning algorithm and a trajectory tracking algorithm for industrial robot. To be specific, a decentralized control system with hierarchical structure for industrial robot, related hardware and software, and monitor program for convinence of user are implemented. Actually, it was recognized by experiments that continuous path control on the R4 plane was possible using the above servo controller and control algorithms.