• 제어로봇시스템학회논문지
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• 제22권3호
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• pp.226-232
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• 2016

This paper describes the design of a smart three-axis force sensor for measuring forces Fx, Fy and Fz. The smart three-axis force sensor is composed of a three-axis force sensor, a force-measuring device, housing and a cover, where the three-axis force sensor and the force-measuring device are inside the housing and the cover. The measuring device measures forces Fx, Fy and Fz from the three-axis force sensor, and calculates the resultant force using the measured forces, and then sends the resultant force and forces to a PC or other controller using RS-485 communication. The repeatability error and the non-linearity error of the smart three-axis force sensor are less than 0.03%, and the interference error of the sensor is less than 0.87%. It is thought that the sensor can be used for measuring forces in a robot, automatic systems and so on.

• 제어로봇시스템학회논문지
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• 제22권7호
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• pp.524-529
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• 2016

We describe the design and fabrication of a two-axis force/torque sensor with parallel-plate beams (PPBs) and single beams for measuring force and torque in hip-joint rehabilitation exercise using a lower rehabilitation robot. The two-axis force/torque sensor is composed of an Fz force sensor and a Tz torque sensor, which detect z direction force and z direction torque, respectively. The two-axis force/torque sensor was designed using the FEM (Finite Element Method) and manufactured using strain gages. The characteristics experiment of the two-axis force/torque sensor was carried out. The test results show that the interference error of the two-axis force/torque sensor was less than 0.64% and the repeatability error and the non-linearity of the two-axis force/torque sensor were less than 0.03%. It is thought that the developed two-axis force/torque sensor could be used for a lower rehabilitation robot.

• 한국정밀공학회지
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• 제32권7호
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• pp.653-660
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• 2015

This paper describes the design of the force measuring system for an industrial robot's deburring work. The force measuring system is composed of a three-axis force sensor, a measuring device, a housing and a cover. The three-axis force sensor can detect x-direction force, y-direction force and z-direction force at the same time. The measuring device is designed using DSP(Digital Signal Processor), and have a RS-232 and a RS-485 communication port for sending force data to PC or other controller. As a result of test, the repeatability error and the non-lineality error of the three-axis force sensor are less than 0.03%, and the interference error of the sensor is less than 0.95%. It is thought that the force measuring system can be used for an industrial robot's deburring work.

• 한국정밀공학회지
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• 제20권7호
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• pp.105-113
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• 2003

This paper describes the development of a 6-axis robot's finger force/moment sensor, which measures forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously, for stably grasping an unknown object. In order to safely grasp an unknown object using the robot's gripper, it should measure the force in the gripping direction and the force in the gravity direction, and perform the force control using the measured forces. Thus, the robot's gripper should be composed of 6-axis robot's finger force/moment sensor that can measure forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously. In this paper, the 6-axis robot's finger force/moment sensor for measuring forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously was newly modeled using several parallel-plate beams, designed, and fabricated. The characteristic test of made sensor was performed. and the result shows that interference errors of the developed sensor are less than 3%. Also, Robot's gripper with the 6-axis robot's finger force/moment sensor for the characteristic test of force control was manufactured, and the characteristic test for grasping an unknown object was performed using it. The fabricated gripper could grasp an unknown object stably. Thus, the developed 6-axis robot's finger force/moment sensor may be used for robot's gripper.

• 한국정밀공학회지
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• 제23권1호
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• pp.145-151
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• 2006

Wheel bearing unit has been exclusively applied to car wheel supporting device. The seal for wheel bearing is required to have both high sealing effects and low reaction forces because wheel bearing are operated on adverse environmental conditions such as mud and splash water. High sealing effects are for the protection of bearing ball wear from dust influx. In order to ensure high sealing effects, it is a easiest way to increase contact force which are affected by geometric characteristics, material properties and interferences between seal and inner bearing but induces higher wear phenomena. Interferences in all variables are most important factor to determine the performance of wheel bearing. In this study, optimization of interference amount was performed with finite element analysis with commercial code ABAQUS. For the sake of finite element analysis, tensile tests of rubber material were conducted and governing equation of nonlinear behavior was achieved. Hock-up bearing was manufactured with optimized interference amount. Results of torque and mud spray tests using this bearing unit are performed. Less torque and moisture influx of bearing with optimized interference amount is evidence to validity of this study.

• 대한기계학회논문집
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• 제16권12호
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• pp.2261-2267
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• 1992

본 연구에서는 시일 립의 간섭량과 접촉력에 관련된 이론적 연구를 수행한다. 시일의 접촉면에서 축방향 접촉력이 크게 설계되면 시일 립 선단에서는 마찰과 마멸이 심하게 진행되어 시일수명을 크게 단출시킬 우려가 있고, 접촉력이 작으면 밀봉된 유 체의 누설유려가 증가되면서 볼과 레이스사이의 윤활상태를 나쁘게 하여 베어링 수명 을 크게 단축하는 결과를 초래하게 되므로 시일 립의 접촉력에 관련된 연구는 대단히 중요하다.

• Wind and Structures
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• 제11권1호
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• pp.1-18
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• 2008

Interference effects in five square tall buildings arranged in an L- or T-shaped pattern are investigated in the wind tunnel. Mean and fluctuating shear forces, overturning moments and torsional moment are measured on each building with a force balance mounted at its base. Results are obtained at two values of clear separation between adjacent buildings, at half and a quarter building breadth. It is found that strong interference effect exists on all member buildings, resulting in significant modifications of wind loads as compared with the isolated single building case. Sheltering effect is observed on wind loads acting along the direction of an arm of the "L" or "T" on the inner buildings. However, increase in these wind loads from the isolated single building case is found on the most upwind edge building in the arm when wind blows at a slight oblique angle to the arm. The corner formed by two arms of buildings results in some wind catchment effect leading to increased wind pressure on windward building faces. Interesting interference phenomena such as negative drag force are reported. Interference effects on wind load fluctuations, load spectra and dynamic building responses are also studied and discussed.

• 한국산학기술학회논문지
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• 제18권8호
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• pp.378-385
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• 2017

본 연구는 플라스틱 부품의 체결에 널리 활용되고 있는 스냅핏의 설계에 관하여 연구하였다. 이탈방지 기능이 우수한 이탈방지 스냅핏은 형상과 체결 메카니즘이 복잡하여 기존의 이론식에 기반한 체결력과 이탈력을 해석적으로 구할 수가 없다. 따라서 본 연구에서는 이탈방지 스냅핏에 대하여 체결 메커니즘을 분석하고, 실험계획법에 기반하여 체결력 및 이탈력을 측정하고, 분산분석을 통하여 회귀식을 도출하였다. 실험계획은 중심합성계획을 사용하였다. Polybutylene terephthalate를 이용하여 시편을 제작하여 미소인장시험기를 이용하여 체결력과 이탈력을 측정하였다. 설계인자는 Length, Width, Thickness, Interference 등 4개를 선정하였으며, 2차 회귀모형을 이용하여 체결력과 이탈력에 대한 회귀식을 도출하였다. Length와 Width가 증가할수록 체결력은 낮아졌으며, Thickness와 Interference는 증가할수록 체결력이 증가하였다. 이탈력은 체결력과 반대의 결과를 나타내었다. 유한요소법을 이용하여 체결 역학에 대하여 분석하였다. Width는 체결단계에서 단면관성모멘트의 증가를 통한 보의 강성 증가 효과 보다는, 오히려 길이 증가에 따른 연성증대로 인하여 체결력을 감소시키는 것으로 나타났다. 낮은 체결력과 높은 이탈력을 위한 인자들의 영향도는 서로 상반되는 것으로 나타났다. 적정 수준의 이탈력을 유지하면서 체결력을 최소화하는 설계가 필요한 것으로 나타났다.

• International Journal of Control, Automation, and Systems
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• 제5권4호
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• pp.419-428
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• 2007

This paper describes the development of a six-axis force/moment sensor with rectangular taper beams for an intelligent robot's wrist and ankle. In order to accurately push and pull an object with an intelligent robot's hand, and in order to safely walk with an intelligent robot's foot, the robot's wrist and ankle should measure three forces Fx, Fy, and Fz, and three moments Mx, My, and Mz simultaneously from the mounted six-axis force/moment sensor to the intelligent robot's wrist and ankle. Unfortunately, the developed six-axis force/moment sensor utilized in other industrial fields is not proper for an intelligent robot's wrist and ankle in the size and the rated output of the six-axis force/moment sensor. In this paper, the structure of a six-axis force/moment sensor with rectangular taper beams was newly modeled for an intelligent robot's wrist and ankle, and the sensing elements were designed by using the derived equations, following which the six-axis force/moment sensor was fabricated by attaching strain-gages on the sensing elements. Moreover, the characteristic test of the developed sensor was carried out by using the six-component force/moment sensor testing machine. The rated outputs from the derived equations agree well with those from the experiments. The interference error of the sensor is less than 2.87%.

• 한국정밀공학회지
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• 제27권10호
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• pp.61-68
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• 2010

In order to let the humanoid robot walk on the uneven terrains, the robot's foot should have the similar structure and function as human's. The intelligent foot should be made up of toes and heel. When it walks on the uneven terrains, the foot's sole senses the force and adjusts foot's position before robot losing his balance. In this paper, the force sensors of robot's intelligent foot for having the similar structure and function like human are developed. The heel 3-axis force/moment sensor and toe force sensors for humanoid robot's intelligent foot is developed, and the characteristic tests of them are carried out. As a result of characteristic test, the interference error of the heel 3-axis force/moment sensor is less than 2.2%. It is thought that the developed force sensors could be used to measure the reaction forces which is applied the toes and the heel of a humanoid robot.