• Journal of Biosystems Engineering
• /
• 제25권5호
• /
• pp.399-408
• /
• 2000

This study is final focused on developing fruit harvesting robot can distinguish fruit type and status accurately. Multi-joint robot is able to discriminate tree shape and select mature fruit by image processing. The multi-joint robot consists of (a) rotating base, (b)turning first joint-arm, (c)rotating and turning second joint-arm, (d)rotating and turning third joint-arm, (e)rotating and turning last joint and (f)picker hand. The operational ranges of the robot are: horizontal 860~2,220mm, vertical 1,440~2,260mm, 270 degrees’rotation angle, 90 or 270 degrees’turning angle. The robot weighs 330kg. The multi-joint robot was designed in high accuracy and efficiency by getting as close as the movements of human arms and waist.

• Industrial Engineering and Management Systems
• /
• 제3권1호
• /
• pp.78-84
• /
• 2004

To optimize movement of a multi-joint robot arm is known to be a difficult problem, because it is a kind of redundant system. Although the end-effector is set its position by each angle of the joints, the angle of each joint cannot be uniquely determined by the position of the end-effector. There exist the infinite number of different sets of joint angles which represent the same position of the end-effector. This paper describes how to manage the angle of each joint to move its end-effector preferably on an X-Y plane with obstacles in the end-effector’s reachable area, and how to optimize the movement of a multi-joint robot arm, evading obstacles. The definition of “preferable” movement depends upon a purpose of robot operation. First, we divide viewpoints of preference into two, 1) the standpoint of the end-effector, and 2) the standpoint of joints. Then, we define multiple objective functions, and formulate it into a multi-objective programming problem. Finally, we solve it using multi-purpose genetic algorithm, and obtain reasonable results. The method described here is possible to add appropriate objective function if necessary for the purpose.

• 로봇학회논문지
• /
• 제12권1호
• /
• pp.11-18
• /
• 2017

Static balance of an articulated robot arm at various configurations requires a torque compensating for the gravitational torque of each joint due to the robot mass. Such compensation torque can be provided by a spring-based counterbalance mechanism. However, simple installation of a counterbalance mechanism at each pitch joint does not work because the gravitational torque at each joint is dependent on other joints. In this paper, a 6 DOF industrial robot arm based on the parallelogram for multi-DOF counterbalancing is proposed to cope with this problem. Two passive counterbalance mechanisms are applied to pitch joints, which reduces the required torque at each joint by compensating the gravitational torque. The performance of this mechanism is evaluated experimentally.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.756-759
• /
• 1997

Multi-arm cooperation robot system is required for more specific and dextrous jobs such as transferring very large or heavy objects, or grasping work piece while processing on it. There is little research on 3-dimensional multi-arm robot. Here we propose two performance indices presenting isotropy of end-effector's acceleration and velocity capabilities with constraints of joint torques, that is Isotropic Acceleration Radius [IAR] and Isotropic Velocity Radius [IVRI. Also the procedure to find 3-dimensional IAR, IVR is proposed, where available acceleration set concept is used. The case of 3-dimensional two 3 joint robot system was simulated and the distributions of IAR, IVR was studied.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.92-95
• /
• 2004

This study proposes an industrial rehabilitation robot system which can exercise two joints in 3 dimensional spaces. The robot kinematics analysis and the results of studies on each joint for the rehabilitation robot could verify possibility of rehabilitation motion to exercise a joint. The force and torques sensor not only measures a rehabilitation performance of subjects between the abnormal limb and the manipulator, but also carries out an important function of safety device to prevent accidents. Also, limit sensors and emergency stop switch are used for high safety in this system. In this real test, the possibility of rehabilitation robot system is evaluated by C&R ARM I which is similar to upper-limb.

• International Journal of Ocean System Engineering
• /
• 제1권4호
• /
• pp.222-229
• /
• 2011

In this paper, we present the concept and main mission of the Crabster, an underwater walking robot. The main focus is on the modeling of drag and lift forces on the legs of the robot, which comprise the main difference in dynamic characteristics between on-land and underwater robots. Drag and lift forces acting on the underwater link are described as a function of the relative velocity of the link with respect to the fluid using the strip theory. Using the translational velocity of the link as the rotational velocity of the joint, we describe the drag force as a function of joint variables. Generalized drag torque is successfully derived from the drag force as a function of generalized variables and its first derivative, even though the arm has a roll joint and twist angles between the joints. To verify the proposed model, we conducted drag torque simulations using a simple Selective Compliant Articulated Robot Arm.

• 한국정밀공학회지
• /
• 제19권2호
• /
• pp.126-132
• /
• 2002

Robot manipulator has highly nonlinear dynamics. Therefore the control of multi-link robot arms is a challenging and difficult problem. In this paper an independent joint adaptive fuzzy sliding mode scheme is developed leer control of robot manipulators. The proposed scheme does not require an accurate manipulator dynamic model, yet it guarantees asymptotic trajectory tracking despite gross robot parameter variations. Numerical simulation for independent joint control of a 3-axis PUMA arm will also be included.

• 대한기계학회논문집B
• /
• 제41권8호
• /
• pp.505-510
• /
• 2017

본 논문에서는 다양한 견관절 장애 증상에 적용할 수 있는 보급형 상지 재활 로봇의 설계를 다룬다. 견관절의 회전에 수반되는 관절 중심의 위치변화를 추종하고, 사용자의 상지와 장치의 무게를 상쇄하는 3자유도 견관절 추종 및 중력보상 메커니즘을 구현하였다. 다양한 방향의 어깨 재활 동작을 구현할 수 있도록 구동축의 방향을 변환하는 메커니즘을 설계하여, 견관절에 대한 구동기의 상대적인 오리엔테이션을 변화시킴으로써 대표적인 5가지 견관절 동작을 수행할 수 있었다. 동시에 재활 운동 중의 견관절의 위치 변화를 추종하여 자연스러운 견관절 운동을 구현할 수 있었다. 최소의 구동기를 사용하는 보급형 로봇으로도 다양한 견관절 질환에 효과적으로 대응할 수 있음을 확인하였다.

• 한국정밀공학회지
• /
• 제5권3호
• /
• pp.20-30
• /
• 1988

Using the design parameters of multi-joint manipulator, worspace of the manipulator were evaluated analytically, and the relation between such design parameters and nonlinearity of the manipulator were presented dynamically. The ratio of the volumes of a manipulator's workspace to the cube of its total link length presents a kinematic performance index [NVI] for the manipullator. It is possible to geometrically represent the manipulator dynamics with the generalized inertia ellipsoid (GIE). The relation between the GIE configuration and the characteristics of manipulator dynamics was analysed in terms of inertia and nonlinear forces (Coliolis and centrifugal forces). The nonlinearity caused by the change of the GIE configuration were affected by the difference between the major and minor axes length of the GIE. The results of this investigationare applied to the optimal design of the manipulator.

• 한국항행학회논문지
• /
• 제27권1호
• /
• pp.139-145
• /
• 2023

의사가 병원에서 환자를 진찰할 때 의사는 환자의 상태를 직접 확인하고 환자와의 대화를 통해 대면 진단을 한다. 그러나 의사가 환자를 직접 진료하기 어려운 경우가 많다. 최근에는 여러 유형의 원격 의료 시스템이 개발되었다. 그러나 현존하는 많은 시스템이 심장질환, 목상태, 피부상태, 귀의 내부상태 등을 관찰할 수 있는 능력이 부족하다. 이러한 문제를 해결하기 위하여 본 논문에서는 환자의 육안 검사와 청진이 가능하도록 실내에서 자율주행이 가능한 대화형 원격진료 로봇 시스템을 개발한다. 개발된 로봇은 WebRTC 플랫폼을 통해 원격 제어가 가능하도록 다관절 로봇팔을 이용해 의사의 관찰 하에 환자에게 다가가 환자의 상태를 확인할 수 있다. 환자로부터 원격으로 얻은 영상 정보, 음성 정보, 환자의 심음 및 기타 데이터를 WebRTC 플랫폼을 통해 의사에게 전송할 수 있다. 개발된 시스템은 의사가 참석할 수 없는 다양한 장소에 적용이 가능하다.