• Journal of Biosystems Engineering
• /
• 제30권5호
• /
• pp.293-298
• /
• 2005

The purpose of this study was the development of a multi-joint robot manipulator for milking robot system. The multi-joint robot manipulator was controlled by 5 drivers with driver controller through the position information obtained from the image processing system. The robot manipulator to automatically attach each teat cup to the teats of a milking cow was developed and it's motion was accurately measured with error rate. Results were as follows. 1. Maximum errors in position accuracy were 4mm along X-axis, 4.5mm along Y-axis and 0.9mm along Z-axis. Absolute distance errors were maximum 4.8mm, minimum 2.7mm, and average 3.6mm. 2. Errors of repeatability were maximum 3.0mm along X-axis, 3.0mm along Y-axis, and 0.5mm along Z-axis. Distance error values were maximum 3.2mm, minimum 2.2mm, and average 2.5mm. It is envisaged that multi-joint robot manipulator can be applicate to milking robot system being developed in consideration of the experiment results.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1992년도 춘계학술대회 논문집
• /
• pp.127-132
• /
• 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.

• 한국공작기계학회논문집
• /
• 제17권4호
• /
• pp.8-14
• /
• 2008

This paper aims at finding out dominant robot configurations with maximal position errors, which can be attributed to the parameter errors, by using Monte-Carlo simulation for error analysis of a 3-axis SCARA(Selective Compliance Assembly Robot Arm) type robot. In particular, the Monte-Carlo simulation is used for virtually measuring on the position errors, instead of physical measurement. In order to measure the observability of the model parameters with respect to a set of robot configurations, we propose the observability index which is defined as the product of singular values for error propagation matrices. Thus the index can be used for discriminating dominant robot configurations from a set of simulated ones in conjunction with standard deviation of positional errors, This paper analyzed error by robot positional error.

• 한국안전학회지
• /
• 제8권1호
• /
• pp.64-70
• /
• 1993

Serious injuries and deaths due to multi-jointed robot occur when a man mispercepts. especially during robot teaching and maintenance work. Since industrial robots often operate with unpredictable motion patterns, establishment of safe speed limit of robot arm is indispensable. An experimental emergency conditions were simulated with a multi-jointed robot. and response characteristics of human operators were measured. The result showed that failure type, robot arm axis. and robot arm speed had significant effects on human reaction time. The reaction time was slightly increased with robot arm speed. though it showed somewhat different pattern owing to failure type. Furthermore the reaction time to the axis which could flex or extend. acting on a workpiece directly. was fastest and its standard deviation was small. The robot arm speed limit securing a‘possible contact zone’based on overrun distance was about 25cm/sec. and in this sense the validity of safe speed limits suggested by many precedent researchers were discussed.

• 한국공작기계학회논문집
• /
• 제12권1호
• /
• pp.8-15
• /
• 2003

The cylindrical object such as a water pipe or an oil pipeline are widely used in the infrastructure. Those pipes should be inspected periodically by human or a robot. However, since there is no edge or vertex in the pipe, it is very difficult for the robot to navigate along the pipe. In this paper in order to guide the robot along the axis of the pipe, an algorithm which find the axis using the measured range data from the robot to the pipe wall is developed The algorithm is verified using both the simulated range data and the measured one.

• 한국정밀공학회지
• /
• 제24권7호
• /
• pp.90-97
• /
• 2007

This paper describes the development of 6-axis force/moment sensor considered adult weight far an intelligent foot of humanoid robot. In order to walk on uneven terrain safely, the foot should perceive the applied forces Fx, Fy, Fz and moments Mx, My, Mz to itself and control the foot using the forces and moments. The applied forces and moments should be measured from a 6-axis force/moment sensor attached to the foot, which is composed of Fx sensor, Fy sensor, Fz sensor, Mx sensor, My sensor and Mz sensor in a body. Each sensor should get the deferent rated load, because the applied forces and moments to foot in walking are deferent. Therefore, one of the important things in the sensor is to design each sensor with the deferent rated load and the same rated output. In this paper, a 6-axis force/moment sensor (rated load of Fx and Fy are 500Nm and Fz sensor is 1000N, and those of Mx and My are 18Nm, Mz sensor is 8Nm) for perceiving forces and moments in a humanoid robot's foot was developed using many PPBs (parallel plate-beams). The structure of the sensor was newly modeled, and the sensing elements (plate-beams) of the sensor were designed using by ANSYS software (FEM (Finite Element Method) program). Then, a 6-axis force/moment sensor was fabricated by attaching strain-gages on the sensing elements, and the characteristic test of the developed sensor was carried out. The rated outputs from FEM analysis agree well with that from the characteristic test.

• 제어로봇시스템학회논문지
• /
• 제14권8호
• /
• pp.800-808
• /
• 2008

This paper presents a localization algorithm of the outdoor wheeled mobile robot using the sensor fusion method based on indirect Kalman filter(IKF). The wheeled mobile robot considered with in this paper is approximated to the two wheeled mobile robot. The mobile robot has the IMU and encoder sensor for inertia positioning system and GPS. Because the IMU and encoder sensor have bias errors, divergence of the estimated position from the measured data can occur when the mobile robot moves for a long time. Because of many natural and artificial conditions (i.e. atmosphere or GPS body itself), GPS has the maximum error about $10{\sim}20m$ when the mobile robot moves for a short time. Thus, the fusion algorithm of IMU, encoder sensor and GPS is needed. For the sensor fusion algorithm, we use IKF that estimates the errors of the position of the mobile robot. IKF proposed in this paper can be used other autonomous agents (i.e. UAV, UGV) because IKF in this paper use the position errors of the mobile robot. We can show the stability of the proposed sensor fusion method, using the fact that the covariance of error state of the IKF is bounded. To evaluate the performance of proposed algorithm, simulation and experimental results of IKF for the position(x-axis position, y-axis position, and yaw angle) of the outdoor wheeled mobile robot are presented.

• 전기전자학회논문지
• /
• 제23권4호
• /
• pp.1236-1242
• /
• 2019

최근 로봇 기술의 발전에 따라 모바일 로봇에 대한 연구가 주목을 받고 있다. 현재 모바일 로봇의 대부분은 2륜 및 4륜 기반으로 개발되어 직선 주행에는 강하지만 방향전환 및 제자리 회전에 제한이 있으며, 이러한 문제점을 극복하고자 구 형태의 바퀴를 사용하는 볼 로봇에 대한 연구가 진행되고 있다. 볼 로봇은 협소한 공간에서 큰 제약 없이 이동이 가능하다는 장점을 가지고 있지만, 구조적으로 불안정하여 안정적인 자세 및 주행 제어가 요구된다. 본 연구에서는 무선통신으로 자세 및 주행 제어가 가능한 스마트폰 어플리케이션을 제안하고, 이를 적용하여 제작된 볼 로봇을 이용하여 자세 및 주행 제어 실험을 수행하였다. 실험을 통해 Roll 각도 오차 ±0.8도, Pitch 각도 오차 ±0.7도 이내에서 제어됨을 확인하였으며, 1m 주행제어에 대해 x축 방향 위치오차 ±0.1m, y축 방향 위치오차 ±0.08m 이내에서 제어됨을 확인하였다.

• 한국생산제조학회지
• /
• 제8권5호
• /
• pp.76-82
• /
• 1999

During operating given working a robot manipulator makes some problems such as the accumulation of the error or the deviation from the command trajectory. These problems are mainly due to the disturbance noise or unmodeled system parameters. To solve these problems most of robot manipulators equip the controller. But if exact controller gains are not seleced we can't decrease the working efficiency(such as compensation about error or deviation) of the robot manipulator. So in this paper we present the controller gain tuning law by which we can find the controller gain which satisfies the per-formance specification of the robot manipulator during working of the robot. The proposed algorithm is derived from the Laypunov direct method. And by the simulation on the 4-axis SCARA type robot(SAMSUNG SM5 Robot) we guarantee the performance of this algorithm.

• 한국산학기술학회논문지
• /
• 제9권1호
• /
• pp.1-8
• /
• 2008

신발 버핑공정에서 로봇 메카니즘과 같은 5축 마이크로스크라이브에 의하여 신발창 형상을 따라서 버핑 로봇 경로를 오프라인으로 프로그래밍하는 방법을 제안한다. 개발한 마이크로스크라이브 시스템은 턴테이블이 부착된 5축 로봇링크, 신호처리장치, PC 및 응용 소프트웨어 프로그램으로 구성되어 있다. 많은 조인트를 가진 마이크로스크 라이브를 신발창 표면을 따라 이동시킴으로써 로봇 경로가 만들어진다. 개발시스템은 마이크로스크라이브 암의 회전에 해당되는 엔코더 펄스 값을 환산하며, 이 각도 값을 신호처리장치를 통하여 PC로 전송한다. Denavit-Hartenberg's(D-H) 직접 키네메틱스가 마이크로스크라이브 조인트 각도 값으로서 글로벌 좌표값을 만드는데 사용된다. 마이크로스크라이브의 키네메틱스 문제는 D-H 표현에 의하여 효과적이고 시스템적으로 해결된다. 개발시스템은 D-H식에 의하여 계산된 좌표 값으로서 신발 갑피 위에 버핑 게이지 라인을 그릴 수 있으며, 또한 신발 갑피 위에 각 점들과 그 점에 수직인 벡터와 결합된 2개의 외곽 라인으로서 로봇 경로를 얻는다. 개발시스템을 FMS의 버핑 로봇에 적용함으로써 실제적인 버핑 로봇의 경로를 프로그래밍하는데 효과적으로 사용될 수 있다.