• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.66-71
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• 2006

Recently, there are lots of concerning on ubiquitous environment of robots and URC (Ubiquitous Robotic Companion). In this paper, a practical ubiquitous interface system far controlling mobile robots in indoor environments was proposed. The interface system was designed as a manager-agent model including a PC manager, a mobile manager, and robot agents for being able to be accessed by any network. In the system, the PC manager has a 3D virtual environment and shows real images for a human-friendly interface, and share the computation load of the robot such as path planning and managing geographical information. It also contains Hybrid Format Manager(HFM) working for transforming the image, position, and control data and interchanging them between the robots and the managers. Mobile manager working in the minimized computing condition of handsets has a mobile interface environment displaying the real images and the position of the robot and being able to control the robots by pressing keys. Experimental results showed the proposed system was able to control robots rising wired and wireless LAN and mobile Internet.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.743-746
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• 1996

A hybrid control scheme to regulate the force and position by dual arms is proposed, where two arms are treated as one arm in a kinematic viewpoint. Our approach is different from other hybrid control approaches which consider robot dynamics, in the sense that we employ a purely kinematic based approach for hybrid control, with regard to the nature of position-controlled industrial robots. The proposed scheme is applied to sawing task. In the sawing task, the trajectory of the saw grasped by dual arms is planned in an offline fashion. When the trajectory of the saw is planned to follow a line in a horizontal plane, 3 position parameters are to be controlled(i.e, two translational positions and one rotational position). And a certain level of contact force has to be controlled along the vertical direction(i.e., minus z-direction) not to loose the contact with the object to be sawn. Typical feature of sawing task is that the contact position where the force control is to be performed is continuously changing. Therefore, the kinematic mapping between the force controlled position and the joint actuators has to be updated continuously. The effectiveness of the proposed control scheme is experimentally demonstrated. The proposed hybrid control scheme can be applied to arbitrary dual arm systems, regardless of their kinematic structure and the number of actuated joints.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.5
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• pp.177-184
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• 1986

An effective cartesian coordinate model is presented to control a robot motion along a prescribed timebased hand trajectory in cartesian coordinates and to provide an adaptive feedback design approach utilizing self-tuning control methods without requiring a detailed mathematical description of the system dynamics. Assuming that each of the hybrid variable set of velocities and forces at the cartesian coordinate level is mutually independent, the dynamic model for the cartesian coordinate control is reduced to first-order SISO models for each degree of freedom of robot hand, including a term to represent all unmodeled effects, by which the number of parameters to be identified is minimized. The self-tuners are designde to minimize a chosen performance criterion, and the computed control forces are resolved into applied joint torques by the Jacobian matrix. The robustness of the model and controller is demonstrated by comparing with the other catesian coordinate controllers.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.530-532
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• 2006

In this paper, we propose stable walking algorithm using ZMP for the biped robot in the slope-way. At first, we define discrete state variables that classified stable area and unstable area by center of mass from ZMP during slope-way walking. For the stable walking gait, the discrete state controller for determining the high-level and low-level decision making are designed. The high-level decision making is composed of the discrete state variables; left foot support phase, right foot support phase, flat-way, and slope-way. Then the continuous state controller is implemented for the low-level decision making using ZMP.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.12
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• pp.1286-1293
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• 2008

This paper proposes a realization of robust trajectory tracking for an industrial robot by using PD-sliding mode hybrid control. The PD control has a good performance in the transient period while the sliding mode control has robustness against the system uncertainties. The proposed control method is proposed for the control of a multi-joint robot by taking advantages of both the PD and sliding mode controls. The embodiment of distributed controllers that drive 4-DOF axes has evaluated through experiments with the multi-joint robot AT1. The PD-sliding mode algorithm which is proposed in this paper shows a good performance in the transient period and robustness against disturbances and This paper shows accuracy of end-effector.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.575-578
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• 1995

In general, the control of robot manipulator is classified into position control and force control. Position controllers give adequate performance when a manipulator is following a trajectory through space and end-effector has no contact with environment. However for most tasks performed by robot manipulator in industry, contact is made between the end-effector and manipulator's environment, so position control may not suffice. The objective of this study is to control both position of a manipulator and the contact forces generated at the hand by using a conceptually simple control law. Position and force control problem is decoupled into subtasts via taskspace formulation and inverse dynamics. Then, the position controllers are designed for the task space variable which represent tangent motion and the forte controllers are designed for the lash space variables which represent normal force.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.9
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• pp.327-339
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• 1984

In this paper we present how to design the software-based speed and position controller of a DC servo drive system for an educational robot. The controller designed by fully digital scheme consists of a CPU, drive unit, encoder pulse coding unit, speed and position detector. The control algirithm of the controller is a hybrid one such that speed control and position control are switched at some instant to get more accuracy. The experimental resusts of the proposed DC servo-controller show good performances for the position and speed control of the proposed educational robot system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.4
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• pp.340-351
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• 1988

Up to now, hybrid torque/position control of robot manipulator have been researched under the assumption that link mass and/or load are known. This paper proposes a torque and position control method under unknown mass of links or load of a robot manipulator and the method extend control in joint space to control in operational space. In the method, known parameters are used to estimate unknown parameter. We illustrate the theory with some simulations and show that the result is effective.

• The Journal of Korea Robotics Society
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• v.14 no.3
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• pp.186-190
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• 2019

When problems occurred in the unstable and/or extreme terrain environment, formal field-driving robots were unable to provide any other options such as the transformation of the wheel and body structure, and so on. For such reason, this paper proposed a novel type of integrated wheel mechanism that can be operated as a conventional driving wheel mode and hybrid wheel-leg mode in order to be negotiated in an unstable terrain environment. The mechanical effect of the proposed variable wheel mechanism was analyzed considering the geometric constraint and power requirement of the actuator for the transformation. In addition, we designed and manufactured the prototype of field-driving robot, which reliably control the variable wheel shape. Finally, the effectiveness of the variable wheel mechanism was verified by preliminary experimental approach.

• Journal of KIISE
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• v.45 no.3
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• pp.211-223
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• 2018

In this paper, we propose a robot-centered direction relation representation and the relevant reasoning methods for indoor service robots. Many conventional works on qualitative spatial reasoning, when deciding the relative direction relation of the target object, are based on the use of position information only. These reasoning methods may infer an incorrect direction relation of the target object relative to the robot, since they do not take into consideration the heading direction of the robot itself as the base object. In this paper, we present a robot-centered direction relation representation and the reasoning methods. When deciding the relative directional relationship of target objects based on the robot in an indoor environment, the proposed methods make use of the orientation information as well as the position information of the robot. The robot-centered reasoning methods are implemented by extending the existing cone-based, matrix-based, and hybrid methods which utilized only the position information of two objects. In various experiments with both the physical Turtlebot and the simulated one, the proposed representation and reasoning methods displayed their high performance and applicability.