• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.176.1-176
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• 2001

Conventional researches almost have been focused on the one dimensional inverted pendulum. Recently, Sprenger et al[2] have researched a two dimensional inverted pendulum Observing human's action to control an inverted pendulum, one can recognize that human uses a three dimensional metier including the up and down motion. In this paper, we propose a fuzzy logic controller(FLC) of a new three dimensional inverted pendulum system. We derive a dynamic equation of the mechanism including a 3-axis cartesian robot and a inverted pendulum. We propose a design method of a fuzzy controller of the yaw and pitch angles of a inverted pendulum. In the design, the redundant degree-of-freedom(DOF) of the robot ...

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.127-132
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• 1992

To relize the future intelligent robot the development of a special-purpose processor for a coordinate transformation is evidently challenging task. In this case the complexity of a hardware architecture strongly depends on the adopted algorithm. In this paper we have used an inverse kinemetics algorithm based on incremental unit computation method. This method considers the 3-axis articulated robot as the combination of two types of a 2-axis robot: polar robot and 2-axis planar articulated one. For each robot incremental units in the joint and Cartesian spaces are defined. With this approach the calculation of the inverse Jacobian matrix can be realized through a simple combinational logic gate. Futhermore, the incremental computation of the DDA integrator can be used to solve the direct kinematics. We have also designed a hardware architecture to implement the proposed algorithm. The architecture consists of serveral simple unitsl. The operative unit comprises several basic operators and simple data path with a small bit-length. The hardware architecture is realized byusing the EPLD. For the straight-line motion of the KAIST arm we have obtained maximum end effector's speed of 12.6 m/sec by adopting system clock of 8 MHz.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.3
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• pp.315-324
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• 2019

This paper present a novel 6-axis robotic base platform with force/moment sensing. The robotic base platform is made up of six loadcells connecting the moving plate to the fixed plate by spherical joints at the both ends of loadcells. The statics relation is derived, the robotic base platform prototype and the loadcell measurement system are developed. The force/moment calibrations in joint and Cartesian spaces are performed. The algorithm to detect external force applied at a working robot is derived, and using a 6-DOF robot mounted on the robotic base platform, force/moment measurement experiments have been performed.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.2
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• pp.137-147
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• 2003

The fuzzy control and implementation of a new three-dimensional(3-D) inverted pendulum system are addressed. In comparison with conventional 1-D and 2-D systems, the 3-D inverted pendulum system is a proper benchmark system to simulate human's control action which includes the up and down motion to stabilize an inverted pendulum. To investigate the characteristics of the 3-D inverted pendulum system and to design of a fuzzy controller, we derive dynamic equations of the mechanism including a 3-axis cartesian robot and an inverted pendulum. We propose a design method of a fuzzy controller of the yaw and pitch angles of an inverted pendulum. In the design, the redundant degree-of-freedom(DOF) of the robot and the constrained workspace are taken into account. The performance of the proposed system is proved by experimental results using a developed PC-based Multi-Motion Control(MMC) board.

• Journal of Biosystems Engineering
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• v.37 no.1
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• pp.65-74
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• 2012

Purpose: An autonomous robot was developed for harvesting strawberries cultivated in bench-type systems. Methods: The harvest robot consisted of four main components: an autonomous vehicle, a manipulator with four degrees of freedom (DOF), an end effector with two DOFs, and a color computer vision system. Strawberry detection was performed based on 3D image and distance information obtained from a stereo CCD color camera and a laser device, respectively. Results: In this work, a Cartesian type manipulator system was designed, including an intermediate revolute axis and a double driven arm-based joint axis, so that it could generate collision-free motions during harvesting. A DC servomotor-driven end-effector, consisting of a gripper and a cutter, was designed for gripping and cutting the strawberry stem without damaging the strawberry itself. Real-time position tracking algorithms were developed to detect, recognize, trace, and approach strawberries under natural light conditions. Conclusion: The developed robot system could harvest a strawberry within 7 seconds without damage.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.3
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• pp.139-149
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• 2015

In this paper, we describe a new approach to perform real-time implementation of an robust controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for robot manipulator consisting of dual arm with eight degrees of freedom at the joint space and cartesian space.

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.163-168
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• 2001

A manipulator for test-cup attachment modules, which was a part of a robot milking system, was developed to reduce cost and labor for cow milking processing. A Cartesian coordinate manipulator was designed for the milking process, because it was quite flexible and can be constructed more economically than any other configuration. The manipulator was made use of DC motors, screws for power transmission, a RS422 interface system for the transmission of coordinate values and a one-chip microprocessor, 89C52. Performance tests of the manipulator were conducted to measure experimentally the precision of all axes. Some of the results are as follows. 1. The Cartesian coordinate manipulator was designed and built. Dimension of the three perpendicular axes (X, Y, and Z) and one arm’s axis(W) to pick up and transfer the modules were 700㎜$\times$450㎜$\times$550㎜$\times$650㎜. The arm’s axis moved the teat-cup attachment module, which attached four teat-cup to four teats, detached four teat-cup from four teats, was designed and manufactured by using CAD, CAM and CNC. 3. After 10 replications of exercising the manipulator, mean precision values(positioning error) of X, Y, Z axes wee 0.48㎜, 0.20㎜, 0.19㎜, respectively. Therefore, we conclude the axes to have a precision better than 0.5㎜, had no problem to operate correctly the milking manipulator.

• The Journal of Korean Society for Radiation Therapy
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• v.23 no.1
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• pp.13-19
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• 2011

Purpose: It's essential to minimize the tumor motion and identify the exact location of the lesions to achieve the improvement in radiation therapy efficiency during SBRT. In this study, we made the established compression belt to reduce respiratory motion and evaluated the usefulness of clinical application in SBRT. Materials and Methods: We analyzed the merits and demerits of the established compression belt to reduce the respiratory motion and improved the reproducibility and precision in use. To evaluate the usefulness of improved compression belt for respiratory motion reduction in SBRT, firstly, we reviewed the spiral CT images acquired in inspiration and expiration states of 8 lung cancer cases, respectively, and analyzed the three dimensional tumor motion related to respiration. To evaluate isodose distribution, secondly, we also made the special phantom using EBT2 film (Gafchronic, ISP, USA) and we prepared the robot (Cartesian Robot-2 Axis, FARARCM4H, Samsung Mechatronics, Korea) to reproduce three dimensional tumor motion. And analysis was made for isodose curves and two dimensional isodose profiles with reproducibility of respiratory motion on the basis of CT images. Results: A respiratory motion reduction compression belt (Velcro type) that has convenient use and good reproducibility was developed. The moving differences of three dimensional tumor motion of lung cancer cases analyzed by CT images were mean 3.2 mm, 4.3 mm and 13 mm each in LR, AP and CC directions. The result of characteristic change in dose distribution using the phantom and rectangular coordinates robot showed that the distortion of isodose has great differences, mean length was 4.2 mm; the differences were 8.0% and 16.8% each for cranio-caudal and 8.1% and 10.9% each for left-right directions in underdose below the prescribed dose. Conclusion: In this study, we could develop the convenient and efficient compression belt that can make the organs' motion minimize. With this compression belt, we confirmed that underdose due to respiration can be coped with when CTV-PTV margins of mean 6 mm would be used. And we conclude that the respiratory motion reduction compression belt we developed can be used for clinical effective aids along with the gating system.