• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.04a
• /
• pp.376-380
• /
• 2004

This paper is to develop an optical ruer displacement sensor for monitoring high speed spindle. Proper magnitude of optical power as well as amplification of output signal are necessary to improve sensitivity of the sensor. In this paper, to meet the need of improvement of the sensor resolution, we choose proper optical power and amplification level through speculating on optical power of a laser diode.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.10a
• /
• pp.385-389
• /
• 2003

To make high speed spindle system work properly, sensors with outstanding resolution and dynamic characteristics are essential. An optical fiber displacement sensor is based on simple principles. Electrical signal responds to the optical flux change due to the displacement change between a target and a sensor probe. In this paper, the performance of optical fiber displacement sensor has been investigated according to properties of optical fiber Firstly, optical loss has been measured before and after polishing optical fiber endface. Secondly, allowance of optical fiber bending has been tested. thirdly sensitivity and linear range of the sensor has been found out according to the shape of cross section of optical fiber.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.10a
• /
• pp.131-136
• /
• 2003

Five expensive sensors are necessary to control a magnetic bearing system. The sensor price rate of magnetic bearing system is high. So it is necessary that cheap and good sensor is developed. The optical fiber displacement sensor is adaptive to satisfy this condition. We can design magnetically suspended spindle based on static characteristic of optical fiber displacement sensor developed. The controller can be designed by decoupled feedback PD. Therefore, it is simpler than any other controller comparatively.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.12
• /
• pp.27-32
• /
• 2002

The intensity modulated type (reflective method) optical fiber sensor is a well -known method and widely applied to the displacement measurements and other industrial purposes. This type sensor has the advantages of relatively cheap cost, small sensor size and easiness of operation. The sensitivity of the sensor is very dependent of several error terms; the variation in the intensity of the light source and the changes in the surface reflectivity of the object. An optical fiber coupled displacement probe with a new compensation method is presented in this paper. The proposed displacement sensor can measure the displacements of the target surface independent of surface reflectivity error that is caused by the materials and surface processing grade.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2003.10a
• /
• pp.556-565
• /
• 2003

Light losses in optical fibers are investigated by a fiber optic OTDR (Optical Time Domain Reflectometry) sensor system to develop fiber optic probes for structural displacement measurement. The displacement sensitivity was determined by the measurements of fiber-bending loss according to the gage length changes of the displacement sensor. The fiber optic displacement probe was manufactured to verify the feasibility of the structural displacement measurement.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.8 s.173
• /
• pp.50-56
• /
• 2005

This paper is described a development of an optical fiber displacement sensor. The optical fiber sensor using an intensity modulated measures the displacement between target and sensor. A prototype sensor is composed of a transmitting part, a receiving part and a signal processing circuit. The experiment was conducted not only the sensor performance but also factors that affect intensity. The main performance of this sensor is resolution of 0.37um and the non-linearity $0.7\%$ FS and the dynamic bandwidth of about 6.3kHz. As a result of rotation test, the prototype sensor showed an equivalent performance to a commercial eddy current sensor.

• Korean Journal of Optics and Photonics
• /
• v.17 no.6
• /
• pp.500-506
• /
• 2006

An optical fiber displacement sensor has the advantages of relatively simplicity, cheap, small probe size and immunity against environmental perturbation. The working principle of the sensor is based on the intensity modulation that is detection light intensity reflecting from the surface being measured. This paper presents the mathematical model of displacement measurement mechanism of this sensor type. The theoretical and experimental data are compared to verify the model in describing the realistic approach to sensor design. Finally, the analysis results show that displacement response characteristics such as sensitivity, measuring range are easily modified by principal design parameters such as magnitude of optical Power, diameter of optical fiber core and distance between transmitting fiber and receiving fiber.

• Proceedings of the KIEE Conference
• /
• 2003.11c
• /
• pp.823-825
• /
• 2003

A sensor system was designed to measure real time vibro displacement of civil structure. The He-Ne laser is used for the displacement measuring method, because it guarantees short time stabilization, long time output power stability. Also, it guarantees simple maintenances and repairs under actual using condition. The line CCD image sensor(Tcd-142d) is used to detect the displacement of Ne-Ne laser responding to the vibro of civil structure. For accurate measurement and comparison, CDP-50 is used. Usually CDF-50 (Strain type displacement device) is used for the standard correction device of optical measurement equipments. The data processing part is consists of Optical sensor part, Wireless data transmission device, DAQp-1200, and LapView program. The displacement data of vibro from optical sensor part inputted to wireless data transmission device and then transmitted to DAQp-1200 in main control room. DAQp-1200 performs A/D conversion for the receiving data. After that the converted data inputted to computer system using LapView program for user display. The significance of this paper is to develope a convenient, accurate and lost saving real time displacement measurement system for the civil structure.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.7
• /
• pp.87-94
• /
• 2008

The displacement sensor using optical pickup head is presented. The measuring principle of optical pickup head in focusing direction is adopted to measure displacement. The preliminary tests were carried out to verify the feasibility of the optical pickup head as a displacement sensor and optical pickup head showed about $8\;{\mu}m$ measuring range and 10nm resolution. The methodology to expand measuring range is proposed and proved its validity. The proposed displacement sensors are applied to AFM(Atomic Force Microscope) probe head to measure the deflection of micro-cantilever.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.10
• /
• pp.1959-1965
• /
• 2011

Measuring the movement of joint angle of human body is very important clinically. Human joint angle displacement can be used to evaluate the degree of disease and disability. Also, we can determine the rehabilitation process with angular information. Conventional methods for measuring angular displacement are many weakness. The purpose of this study is to overcome the limitations of existing equipments by using optical method. For this reason, optical sensor system was used to correlate detected light signal with joint angle. Experimental results of the applied joint model in this study showed that joint angular displacement can be measured by optical signals. The suggested method is simple, durable, small, lightweight, convenient, and cost effective.