• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.108.6-108
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• 2002

It is greatly important to understand the mechanics of AFM-based nanorobotic manipulation for efficient and reliable handling of nanoparticles. Robust motion control of an AFM-based nanorobotic manipulation is much challenging due to uncertain mechanics in tip-sample interaction dominated by surface and intermolecular force and limitations in force and visual sensing capability to observe environment. This paper investigates a nanomechanic modeling which enables simulation for AFM-based nanorobotic manipulation , and its application to motion planning of an AFM-based nanorobot. Based on the modeling of intermolecular and adhesion force in AFM-based nanomanipulation, the behaviors of an AFM ca...

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.117-120
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• 2002

This paper is to develop the sensing system for opening-force measurement such as O-Ring muscular meridian. We designed to overcome the functional limit that the conventional force-sensor can measure just the closing-force. Therefore, the new sensor can meet a variety of application as well as O-Ring test. The structure of the new sensor is an actuator-type system using an electromagnet. That is made up of mechanical system, electromagnet, current transformer and computer interface circuit. Driving software and user interface program of the new sensor system also is explained in this paper.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1179-1182
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• 2005

To facilitate the cell based robot research, we presented a micro-mechanical force measurement system for the biological muscle actuators, which utilize glucose as a power source for potential application in a human body or blood vessels. The system is composed of a micro-manipulator, a force transducer with a glass probe, a signal processor, an inverted microscope and video recoding system. Using this measurement system, the contractile force and frequency of the cardiac myocytes were measured in real time and the magnitude of the contractile force of each cardiac myocyte on a different condition was compared. From the quantitative experimental results, we estimated that the force of cardiac myocytes is about $20{\sim}40\;{\mu}$N, and showed that there is difference between the control cells and the micro-patterned cells.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1524-1525
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• 2007

A flexible tactile sensor module based on polyimide matrix integrated with sensing elements and pluggable terminals connector was fabricated by polymer micromachining technology for robotic applications. The tactile sensor arrays are composed of $4{\times}4$, $8{\times}8$ and $16{\times}16$ sensing elements connected with pluggable terminals connector, respectively. Especially, both the tactile sensor array and the pluggable terminals are formed in the sensor module during the fabrication process. The fabricated tactile sensor module is measured continuously in the normal force range of $0{\sim}1N$ with tactile sensor auto-evaluation system. The value of resistance is relatively increased linearly with normal force in the overall range. The variation rate of resistance is about 2.0%/N in the range of $0{\sim}0.6N$ and 1.5%/N in the range of $0.6{\sim}1N$. Also, the flexibility of the sensing module is adequate to be placed on any curved surface as cylinder because the matrix consists of polymer and metal thin film.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.4
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• pp.309-316
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• 2016

In this study, we described the design of a three-axis force/torque sensor for measuring the force and torque in a lower-limb rehabilitation robot. The three-axis force/torque sensor is composed of Fx force sensor, Fz force sensor and Tz torque sensor. The sensing element for Fx force sensor and Tz torque sensor is used in a two-step parallel plate beam, and that of Fz force sensor is used in a parallel plate beam. The rated loads of Fx force sensor, Tz torque sensor and Fz force sensor are 300 N, 15 N m and 100 N, respectively. The three-axis force/torque sensor was designed using the finite element method, and manufactured using strain-gauges. The three-axis force sensor was further characterized. As a result, the interference error of the three-axis force/torque sensor was < 1.24%, the repeatability error of each sensor was < 0.03%, and the non-linearity was < 0.02%.

• Physical Therapy Korea
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• v.14 no.3
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• pp.16-22
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• 2007

The purpose of this study was to determine the influence of muscle fatigue in elbow flexors on the sense of force reproduction. Fifteen healthy subjects were recruited for this study. Maximum voluntary force (MVF) of elbow flexor muscles was measured by a digital tensiometer. Force errors were measured to test accuracy of the sense of force reproduction in elbow flexors. The subject was required to flex the elbow joint, to maintain and concentrate on about 20% of the MVF target force under visual feedback for 3 seconds. After a 5 second period rest, the subject was asked to duplicate the target force actively. Muscle fatigue was evoked with isometric contraction of the elbow flexors. Isometric contraction was continued until a 50% drop in MVF. The difference, in kilogram between the target force and the reproduced force was calculated for measuring force error. Force errors were compared between the non-fatigued condition and the fatigued condition by the paired t-test. Force errors were significantly increased in the fatigued condition compare to non-fatigued condition. This result suggests that the sense of force reproduction can be disturbed by localized muscle fatigue.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.7 s.196
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• pp.90-97
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• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.72-80
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• 2019

In this task, the tool dynamometer design and manufacture, and the Ansys S/W structural analysis program for tool attachment that satisfies the cutting force measurement requirements of the tool dynamometer system are used to determine the cutting force generated by metal cutting using 3-axis static structural analysis and the LabVIEW system. The cutting power in a cutting process using a milling tool for processing metals provides useful information for understanding the processing, optimization, tool status monitoring, and tool design. Thus, various methods of measuring cutting power have been proposed. The device consists of a strain-gauge-based sensor fitted to a new design force sensing element, which is then placed in a force reduction. The force-sensing element is designed as a symmetrical cross beam with four arms of a rectangular parallel line. Furthermore, data duplication is eliminated by the appropriate setting the strain gauge attachment position and the construction of a suitable Wheatstone full-bridge circuit. This device is intended for use with rotating spindles such as milling tools. Verification and machining tests were performed to determine the static and dynamic characteristics of the tool dynamometer. The verification tests were performed by analyzing the difference between strain data measured by weight and that derived by theoretical calculations. Processing test was performed by attaching a tool dynamometer to the MCT to analyze data generated by the measuring equipment during machining. To maintain high productivity and precision, the system monitors and suppresses process disturbances such as chatter vibration, imbalances, overload, collision, forced vibration due to tool failure, and excessive tool wear; additionally, a tool dynamometer with a high signal-to-noise ratio is provided.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.01a
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• pp.281-282
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• 2013

맥박을 측정하는 방법 중 하나인 PPG(photoplethysmography) 센서는 설계가 비교적 간편하며 사용이 편한 장점이 있지만, 움직임으로 인한 동잡음에 취약하다는 단점이 있다. 본 논문에서는 동잡음으로 인한 센서와 손가락 사이의 밀착되는 압력의 변화를 측정하여 왜곡된 신호를 보상하였다. PPG센서와 손가락 사이의 압력을 측정하기 위하여 FSR(force sensing resistor)센서를 이용하여 측정하였으며, 측정된 압력과 왜곡된 PPG 신호 비교를 통해 왜곡된 PPG신호와 FSR센서에서 얻은 압력 사이의 연관성을 확인하였고, 신호처리를 통하여 왜곡된 신호를 보상 시켰다. 이와 같은 방법으로 PPG신호를 보상하게 된다면 웨어러블한 환경에서의 적용뿐만 아니라 헬스케어로 응용이 가능할 것으로 보인다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.3
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• pp.13-19
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• 2003

The high speed machining technology has been improved remarkably in die/mold industry with the growth of parts and materials industries. Though the spindle speed of machine tool increases, the condition monitoring techniques of the machine tool, tool and workpiece in high speed machining ate incomplete. In tins study, efficient sensing technology in high speed machining is suggested by observing the characteristics of cutting force, gap sensor and accelerometer signal also, machinability of high-speed machining is experimentally evaluated sensing technique to monitor the machine tool and machining conditions was performed.