• Journal of Welding and Joining
• /
• 제11권3호
• /
• pp.22-33
• /
• 1993

Arc sensor is indispensable to arc welding robot systems for compensating the joint misalignment such as mismatch of the workpiece, ill-conditioned positioner and thermal deformation during welding. Furthermore, the amount of these mismatches cannot be preivously expected, and changes from time to time. There are many kinds of seam trackers for correcting the welding path of the robot, where non-contact type sensors arc prevalently used in arc welding robot systems. In this study, an arc sensor was developed for GMA and FCA welding robot system. Since the arc sensor uses the arc characteristics during welding, the operating principle of the arc sensor must be adjusted according to the welding condition. Especially in GMA welding with the $CO_{2}$ shielding gas, the welding arc is not stable because of the short circuit and non-axial globular transfer mode of the molten droplet. In this study, the 2nd order least square curve fitting algorithm was adopted and the applicability of this algorithm was investigated for robot welding systems. For easy usage of the arc sensor, the operating parameters for arc sensor were limited to eight which can be easily determined by the operator.

• 로봇학회논문지
• /
• 제19권1호
• /
• pp.53-57
• /
• 2024

A hopping robot can move through a confined environment while overcoming obstacles. To create a small hopping robot, it must be able to generate a large amount of energy and release it at the same time. However, due to the small size of the robot, there is a limit to the size of the actuator that can be used, so it is mainly used to collect energy in an elastic element and release it at once. In this paper, we propose a small hopping robot with a simplified design by removing ancillary parts and enabling continuous hopping using only a small actuator based on a direct-drive method. In addition, repeated actuation over the rated voltage can cause thermal breakdown of the actuator. To check the safety of the actuator at high voltage, we perform modeling to predict the temperature of the actuator and verify the accuracy of the modeling through experiments.

• 대한기계학회논문집A
• /
• 제37권8호
• /
• pp.1043-1050
• /
• 2013

병렬로봇은 구조적 특성 때문에 정밀성 및 고강성이 요구되는 분야와 고속성이 요구되는 분야에서 주로 적용되고 있다. 물류 분야에서 고속이송의 중요성은 날이 갈수록 증가하고 있으며, 본 연구에서도 동일한 목적으로 고속 이송에 적용될 병렬로봇이 개발되었다. 개발된 로봇은 최대 3kg의 부하를 이송할 수 있으며 0.1kg의 부하조건에서의 최대 운전 조건은 싸이클 타임 0.3sec로 최대 속도 약 4.5m/sec로 운전할 수 있으며(Pick & Place 작업, Adept cycle) 이때 최대 가속도는 약 13G에 달한다. 본 논문에서는 개발된 고속 병렬로봇의 설계 및 해석에 관한 연구결과와 개발된 로봇의 성능에 관해 소개하고자 한다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.957-962
• /
• 2005

Today, the elderly is increasing gradually in the Republic of Korea society and this problem will be more serious in the near future. Therefore, engineering support for aged people is required. We are establishing a new field of healthcare engineering for elderly people and aiming to support for aged people and disabled people using adaptive control and instrument technology. In this paper, the goal is to implement the shared control of a robot mobility aid for the elderly. As using this type of assistive technology to be useful by its intended user community, it supports elderly people and handicapped people to live independently in their private homes. The interface transforms the force applied by the user into the robot's motion. Devices like buttons, joysticks, and levers already exist for relaying user input; however, they require hand displacement that would loosen or otherwise release the user's hold. Such interfaces make operation very difficult and potentially unsafe. Therefore, we propose a shared control system. It's safe more than joysticks and buttons. The shared control is a means of registering the user's intention through physical interaction. It's an important component in the development of robotic elderly assistant. The concept of shared control describes a system which is two or more independent control systems. We are using that the three component blocks consist of pressure sensor (flexible force sensor), circuit of measurement and transfer function. Experimental trials of this paper have been tested at the indoor environment. The robot is able to know the user intended direction through haptic device were logged along with the robot's force sensor.

• 대한기계학회논문집A
• /
• 제36권7호
• /
• pp.813-822
• /
• 2012

LCD 생산라인의 공정 로봇에서 방사되는 비정상 작동 소음은 로봇의 결함 탐지에 사용된다. 이 신호의 장점은 상대적으로 낮은 민감도에 비해 단지 마이크로폰을 이용하여 다수의 결함을 확인할 수 있는 것이다. 결함요소 추출을 위한 웨이브렛 변환(WPT)과 불량의 분류를 위한 인공신경망 회로(ANN)이 본 논문에서 사용되었다. 결과적으로, 비정상 작동 소음이 기계요소의 결함 진단에 효율적으로 사용될 수 있다.

• 한국전자통신학회논문지
• /
• 제16권4호
• /
• pp.749-754
• /
• 2021

농업인구의 감소, 고령화 등의 문제를 해결하기 위해 다양한 농작업의 자동화를 목적으로 농업용 로봇의 연구가 활발히 진행 중이다. 농가 작업 중 가장 노동력이 많이 투입되는 과정은 수확 과정으로 타 과정 대비 약 2~3배 소모된다. 농가의 수확물 이송 작업은 인건비가 가장 많이 들고 작업 중 부상의 위험성도 있기 때문에 이송 작업을 농업용 로봇을 통해 자동화시키면 안전성 향상과 더불어 생산성을 대폭 향상할 수 있다. 따라서 본 논문은 농가 작업 현장에 최적화되고 자율주행이 가능한 농업용 로봇을 제안한다.

• 한국언어정보학회지:언어와정보
• /
• 제19권2호
• /
• pp.1-18
• /
• 2015

This paper retraces the development of Database Semantics (DBS) from its beginnings in Montague grammar. It describes the changes over the course of four decades and explains why they were seen to be necessary. DBS was designed to answer the central theoretical question for building a talking robot: How does the mechanism of natural language communication work? For doing what is requested and reporting what is going on, a talking robot requires not only language but also non-language cognition. The contents of non-language cognition are re-used as the meanings of the language surfaces. Robot-externally, DBS handles the language-based transfer of content by using nothing but modality-dependent unanalyzed external surfaces such as sound shapes or dots on paper, produced in the speak mode and recognized n the hear mode. Robot-internally, DBS reconstructs cognition by integrating linguistic notions like functor-argument and coordination, philosophical notions like concept-, pointer-, and baptism-based reference, and notions of computer science like input-output, interface, data structure, algorithm, database schema, and functional flow.

• 한국정밀공학회지
• /
• 제15권9호
• /
• pp.93-100
• /
• 1998

This study presents the new method which can transfer the expert's skill to deburring robot through neural network. The expert's skill is expressed as association mapping between the characteristics of the burr and human expert's action. Under the fundamental idea that the state of the deburring process can be extracted via the visual sense of the human, we employ vision system for the perception and identification of the changing burr. From the demonstration of human experts, force data are measured. Finally the characteristics of the burr and corresponding force are associated by the neural network which is trained through many demonstrations. The proposed method is verified in the deburring process of welding burr.

• 한국반도체및디스플레이장비학회:학술대회논문집
• /
• 한국반도체및디스플레이장비학회 2003년도 춘계학술대회 발표 논문집
• /
• pp.80-87
• /
• 2003

On this study, an End-Effector for the 300mm wafer transfer robot System is newly suggested. It is a mechanical type with $180^{\circ}$ rotating ranges and is composed of 3-point arms, two plate springs and single-axis DC motor. It is controlled by microchip for the DC motor control. To design, relationships on the gripping force and the wafer deformation is analyzed by FEM analysis. Criterion on gripping force of a suggested End-Effector is confirmed as $255 ~ 274g_f$ from experimental results. From experimented results on repeatable position accuracy, gripping force and gripping cycle times in a wafer cleaning system, we confirmed that the suggested End-Effector is well satisfied on the required performance for 300mm wafer transfer robot system.

• 로봇학회논문지
• /
• 제6권4호
• /
• pp.301-307
• /
• 2011

Based on the stability criteria of ZMP (Zero Moment Point), this paper proposes an adjusting algorithm that modifies walking trajectory of a bipedal robot for stable walking by analyzing ZMP trajectory of it. In order to maintain walking balance of the bipedal robot, ZMP should be located within a supporting polygon that is determined by the foot supporting area with stability margin. Initially tilting imposed to the trajectory of the upper body is proposed to transfer ZMP of the given walking trajectory into the stable region for the minimum stability. A neural network method is also proposed for the stable walking trajectory of the biped robot. It uses backpropagation learning with angles and angular velocities of all joints with tilting to get the improved walking trajectory. By applying the optimized walking trajectory that is obtained with the neural network model, the ZMP trajectory of the bipedal robot is certainly located within a stable area of the supporting polygon. Experimental results show that the optimally learned trajectory with neural network gives more stability even though the tilting of the pelvic joint has a great role for walking stability.