• Journal of Institute of Control, Robotics and Systems
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• v.19 no.4
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• pp.357-363
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• 2013

Most serious patients who have the paralysis of their ankles can't use of their feet freely. But their ankles can be recovered by an ankle bending rehabilitation exercise and a ankle rotating rehabilitation exercise. Recently, the professional rehabilitation therapeutists are much less than stroke patients in number. Therefore, the ankle-rehabilitation robot should be developed. The developed robot can be dangerous because it can't measure the applied bending force and twisting moment of the patients' ankles. In this paper, the six-axis force/moment sensor for the ankle-rehabilitation robot was specially designed the weight of foot and the applied force to foot in rehabilitation exercise. As a test results, the interference error of the six-axis force/moment sensor was less than 2.51%. It is thought that the sensor can be used to measure the bending force and twisting moment of the patients' ankles in rehabilitation exercise.

• The Journal of Korea Robotics Society
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• v.16 no.1
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• pp.1-11
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• 2021

Soft robotics has attracted a huge amount of interest in the recent decade or so, be it either actuators or sensors. Recently, a soft optical waveguide sensor has proven its effectiveness for various sensing applications such as strain, force, and bending measurements. The operation principle of the waveguide is simple, but the present technology is far too much complex to manufacture the waveguide. The waveguide fails to attract various practical applications in comparison to other types of sensors despite its superior safety and ease working principle. This study pursues to develop the soft sensors based on the optical phenomena so that the waveguide can be easily manufactured and its design can be conducted. Several physical properties of the waveguide are confirmed through the repetitive experiments in the aspects of strain, force, and bending of the waveguide. Finally, the waveguide sensor is embedded inside the actuator to verify the effectiveness of the proposed waveguide as well as to extend the application fields of the waveguide sensor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10A
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• pp.1200-1204
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• 2004

Fiber-optic sensor (FOS) using bending-sensitive fiber (BSF which detects physical variables according to the variation of fiber-bending is proposed. BSF is already used in variable optical attenuator. Three-dimensional finite difference beam propagation method (3D FD-BPM) is used to investigate the bending loss of BSF. Then, the results of bending experiment with FOS consisting of BSF is compared to numerical results of 3D FD-BPM. In particular, the optical power of fabricated FOS with BSF varies from -ldB to -2OdB when pressure given to the upper side of FOS changes from 0 MPa to 0.005 MPa, while the FOS consists of SMF shows no change of optical power at the same condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.554-558
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• 2002

A magnetostrictive sensor is used to measure stress waves propagating in a ferromagnetic cylinder without physical contact. The performance of a magnetostrictive sensor is affected most significantly by the bias magnetic field applied around the measurement location. The goal of this paper is to carry out the topology optimization of the bias magnet and yoke assembly to maximize the sensor output for traveling bending waves. We will use the multi-resolution topology optimization strategy to find the assembly of the bias magnet and the yoke that is easy to realize. The effectiveness of the present design is confirmed by an actual measurement of the sensor signal with the proposed bias magnet and yoke configuration.

• Korean Journal of Optics and Photonics
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• v.21 no.1
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• pp.12-15
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• 2010

In this paper, we have proposed and demonstrated a simple fiber-optic temperature sensor based on the bending loss of a TEC(thermally expended core) fiber attached to a bi-metal. The deformation of the bi-metal caused by the change in its temperature induces the bending loss of the TEC fiber. The experimental result shows that the temperature sensitivity and operation temperature range of the device are controllable through the adjustment of the structure of the expanded core fiber. The fabrication procedure of the device is described in detail.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.11
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• pp.1011-1016
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• 2013

Patients have the paralysis of their wrists, and can't use of their wrists freely. But their wrists can be recovered by wrist-bending rehabilitation exercise. Professional rehabilitation therapeutists exercise the wrists of patients in hospital. But the wrists of patients have not exercised enough for the rehabilitation, because the therapeutists are much less than patients in number. Therefore, the wrist rehabilitation robot should be developed, and it have to measure the applied force to the patients' wrists for their safety. In this paper, the four-axis force/moment sensor was designed for the wrist rehabilitation robot. As a test results, the interference error of the four-axis force/moment sensor was less than 0.91%. It is thought that the sensor can be used to measure the applied force to the patients' wrists.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.2 s.95
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• pp.239-247
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• 2005

This paper deals with the development of a contact-type counting device using a piezoelectric polymer film as a sensor. The piezoelectric and vibration characteristics of the film under a bending vibration were investigated theoretically and experimentally. A counting device, which includes filters, an amplifier, an analog-digital converter, and a display, was designed and fabricated. The performance of the piezoelectric polymer sensor was evaluated in the sense of the responses to contact force, contact frequency, and contact speed. The life and the temperature effect were also investigated for the piezoelectric film sensor.

• Journal of Sensor Science and Technology
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• v.22 no.4
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• pp.297-301
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• 2013

We proposed and demonstrated a distributed fiber-optic overheating detection sensor using optical time domain refrectometry. With increased of temperature the optical fiber is bended by a bi-metal and it result in optical leaky loss of the fiber. The sensor structure is designed in such a way that the signal of overheating is happen when the temperature exceeding a threshold temperature and the optical fiber is protected from excess bending.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.1089-1092
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• 2004

This paper deals with the development of a contact-type counting device using a piezoelectric polymer film as a sensor. The piezoelectric and vibration characteristics of the film under a bending vibration were investigated theoretically and experimentally. A counting device, which includes filters, an amplifier, an analog-digital converter, and a display, was designed and fabricated. The performance of the piezoelectric polymer sensor was evaluated in the sense of the responses to contact force, contact frequency, and contact speed. The life and the temperature effect were also investigated for the piezoelectric film sensor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.649-650
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• 2012