• Title/Summary/Keyword: end-effector

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On the Development of Robot based Automation System for Loading Cargo in Small and Medium Sub Terminals

  • Park, Jae Min;Lee, Sang Min;Kim, Young Min
    • International Journal of Internet, Broadcasting and Communication
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    • v.13 no.4
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    • pp.90-96
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    • 2021
  • The logistics market is continuously growing due to the development of technology and the growth of the online market. In addition, the social atmosphere that emphasizes non-face-to-face due to the pandemic situation is accelerating the growth of logistics. Delivery of goods ordered online requires delivery process through courier worker. In order for the courier worker to ship the product, the work of loading the product on the truck must be preceded. The accident caused by such delivery and loading work is increasing and it is emerging as a social problem. This study proposes a robot-based automated loading system to efficiently handle the increasing volume of courier service and to construct a more efficient and safe working environment by replacing the physical labor that was overloaded to courier workers. The proposed system replaces the loading of the courier worker and proposes the optimal loading function through the automation system.

NMPC-based Obstacle Avoidance and Whole-body Motion Planning for Mobile Manipulator (모바일 매니퓰레이터의 NMPC 기반 장애물 회피 및 전신 모션 플래닝)

  • Kim, Sunhong;Sathya, Ajay;Swevers, Jan;Choi, Youngjin
    • The Journal of Korea Robotics Society
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    • v.17 no.3
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    • pp.359-364
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    • 2022
  • This study presents a nonlinear model predictive control (NMPC)-based obstacle avoidance and whole-body motion planning method for the mobile manipulators. For the whole-body motion control, the mobile manipulator with an omnidirectional mobile base was modeled as a nine degrees-of-freedom (DoFs) serial open chain with the PPR (base) plus 6R (arm) joints, and a swept sphere volume (SSV) was applied to define a convex hull for collision avoidance. The proposed receding horizon control scheme can generate a trajectory to track the end-effector pose while avoiding the self-collision and obstacle in the task space. The proposed method could be calculated using an interior-point (IP) method solver with 100[ms] sampling time and ten samples of horizon size, and the validation of the method was conducted in the environment of Pybullet simulation.

Learning Optimal Trajectory Generation for Low-Cost Redundant Manipulator using Deep Deterministic Policy Gradient(DDPG) (저가 Redundant Manipulator의 최적 경로 생성을 위한 Deep Deterministic Policy Gradient(DDPG) 학습)

  • Lee, Seunghyeon;Jin, Seongho;Hwang, Seonghyeon;Lee, Inho
    • The Journal of Korea Robotics Society
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    • v.17 no.1
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    • pp.58-67
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    • 2022
  • In this paper, we propose an approach resolving inaccuracy of the low-cost redundant manipulator workspace with low encoder and low stiffness. When the manipulators are manufactured with low-cost encoders and low-cost links, the robots can run into workspace inaccuracy issues. Furthermore, trajectory generation based on conventional forward/inverse kinematics without taking into account inaccuracy issues will introduce the risk of end-effector fluctuations. Hence, we propose an optimization for the trajectory generation method based on the DDPG (Deep Deterministic Policy Gradient) algorithm for the low-cost redundant manipulators reaching the target position in Euclidean space. We designed the DDPG algorithm minimizing the distance along with the jacobian condition number. The training environment is selected with an error rate of randomly generated joint spaces in a simulator that implemented real-world physics, the test environment is a real robotic experiment and demonstrated our approach.

Development of a 2-axis Delta Robot for Upper-limb Rehabilitation with Considering User Safety (사용자 안전요소를 고려한 상지 재활치료용 2축 델타로봇 개발)

  • Seung-Hwan Baek;Jun-Sik Lee
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.1
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    • pp.15-26
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    • 2023
  • In this study, an end-effector robot which is a two-axis delta robot type for upper-limb rehabilitation is designed. It is not only rehabilitation functions that has designed robot but also mechanical and electrical safety devices were constructed to ensure patient safety. By constructing the two-axis delta robot is combined with an LM guide, the operating range and rigidity required for rehabilitation were secured. The electrical safety system which is required for the medical robot was designed, and a safety strategy was established to ensure patient safety and it is applied in the integrated safety circuit. The safety is considered in whole design process from the robot's mechanical design to the electric control unit.

Obstacle-avoidance Algorithm using Reference Joint-Velocity for Redundant Robot Manipulator with Fruit-Harvesting Applications

  • Y.S. Ryuh;Ryu, K.H.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1996.06c
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    • pp.638-647
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    • 1996
  • Robot manipulators for harvesting fruits must be controlled to track the desired path of end-effector to avoid obstacles under the consideration of collision free area and safety path. This paper presents a robot path control algorithm to secure a collision free area with the recognition of work environments. The flexible space, which does not damage fruits or branches of tree due to their flexibility and physical properties , extends the workspace. Now the task is to control robot path in the extended workspace with the consideration of collision avoidance and velocity limitation at the time of collision concurrently. The feasibility and effectiveness of the new algorithm for redundant manipulators were tested through simulations of a redundant manipulator for different joint velocities.

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A study on the design and control of an articulated hand (다관절 손 기구의 설계 및 제어에 관한 연구)

  • Kim, Cheol-Woo;Gweon, Dae-Gab
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.4
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    • pp.200-205
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    • 1993
  • In many applications, the typical parallel-jaw end-effector of a robot arm has been remarkably satisfactory. But, it is not adequate for the applications such as complicated manipulation. In the study, a finger with 4 joints (so, having redundancy) was consturcted to investigate the characteristics of an articulated hand. Each joint was driven by one actuator, and the motor torque was transmited to each joint through a tendon-pulley system. In the context, major considerations for hardware design and the method to solve the inverse kinematics of a redundant manipulator were presented. Finally, the basic capabilities of an articulated hand were presented through experiments.

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Elastodynamic Control of Industrial Robotic Manipulators Using Piezoelectric Materials (압전재료를 이용한 산업용 로보트 매니퓰레이터의 동탄성 제어)

  • Choi, S.B.;Cheong, C.C.;Choi, I.S.;Lee, T.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.4
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    • pp.54-63
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    • 1993
  • This paper presents the dynamic modeling and control methodology to arrest structural deflections of industrial robotic manipulators featuring elastic members retrofitted with surface bonded pizoelectric actuators and sensors. The cynamic modeling is accomplished by employing a variational theorem, prior to developing a finite element formulation. This finite element formulation accounts for both original robot member elements and also bonded piezoelectric material elements. The governing equation of motion is then modified by condensing the electric potential vectors and subsequently two different negative velocity feedback controllers are established; a constant-gain feedback controller and a constant- amplitude feedback controller. By adopting a Model P50 articulating industrial robot manufactured by Gerneral Electric Company, conputer simulations are underlaken in order to demonstrate superior performance characteristics to be accrued from this proposed methodology such as smaller deflections at the end-effector.

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Design and Implementation of Low-Cost Articulate Manipulator for Academic Applications

  • Muhammad Asim Ali;Farhan Ali Shah
    • International Journal of Computer Science & Network Security
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    • v.24 no.1
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    • pp.17-22
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    • 2024
  • The objective of this work is to design a low cost yet fully functional 4-DOF articulate manipulator for educational applications. The design is based on general purpose, programmable smart servo motors namely the Dynamixel Ax-12. The mechanism for motion was developed by formulating the equations of kinematics and subsequent solutions for joint space variables. The trajectory of end-effector in joint variable space was determined by interpolation of a 3rd order polynomial. The solutions were verified through computer simulations and ultimately implemented on the hardware. Owing to the feedback from the built-in sensors, it is possible to correct the positioning error due to loading effects. The proposed solution offers an efficient and cost-effective platform to study the trajectory planning as well as dynamics of the manipulator.

Study on Dynamic Crawling of The Five-bar Planar Mechanism (5절 평면형 메커니즘의 동적 포복에 관한 연구)

  • Lee J.H.;Lim N.S.;Kim W.K.;Yi B.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1045-1049
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    • 2005
  • In this paper, the dynamic crawling of a five-bar planar mechanism is investigated. One complete cycle of the crawling selected in this study consists of four different steps, i) sliding at one contact point between the mechanism and the ground, ii) changing its configuration without sliding at two contact points, iii) sliding at the other contact point, and iv) again changing its configuration without sliding at two contact points. In this type of crawling, the crawling mechanism maintains the shape of the parallel structure throughout a complete crawling cycle. The modeling algorithm for serial manipulators proposed by M. Thomas and et al.[1] is employed by introducing imaginary joints and links which represent the contact interfaces between the one end of the mechanism and the ground, while the other end of the mechanism is regarded as an end-effector of the imaginary serial manipulator which treats the reaction force and torque at the contact point as external forces. Then, a complete cycle of dynamic crawling of the mechanism is investigated through various computer simulations. The simulation result show that the stable crawling characteristics of the mechanism could be secured when the proper configurations depending on specified frictional constraints are met.

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Development of a Robot for Automation of a Callus Inoculation (식물조직배양 자동화를 위한 로봇개발 - 엔드이펙터 및 시스템의 성능시험 -)

  • Chung, Suk-Hyun;No, Dae-Hyun
    • Journal of Bio-Environment Control
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    • v.18 no.2
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    • pp.87-94
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    • 2009
  • This study was conducted to develop an automation system of inoculation processing of a lily callus. The results are summarized as followings: The end-effector was manufactured as suction and machine type. And these end-effectors can separate the callus from the mediums and divide the separated callus and then inoculate the divided callus to new mediums. Using the machine type end-effect0r, the results of the experiment showed the success rate in the division process was 100% while the separation and inoculation process was 92%. To develop the automation controller of inoculation process, the system was developed to control an external device and the manipulator. The data communication program between a robot and a personal computer was also developed using CAsyncsocket and Ethernet Interface.