New measuring system for the distribution of a magnetic force by using an optical fiber

1993 ◽  
Vol 64 (1) ◽  
pp. 243-246 ◽  
Author(s):  
H. Ishigaki ◽  
T. Oya ◽  
M. Itoh ◽  
A. Hida ◽  
K. Iwata
Keyword(s):  
Optical Fiber ◽  
Magnetic Force ◽  
Measuring System

Effects of Rotational Inertia and Bearing Force on Stability of Permanent Maglev Rotator

2012 ◽  
Vol 150 ◽  
pp. 50-56
Author(s):  
Kun Xi Qian ◽  
Z.H. Xu ◽  
H. Wang
Keyword(s):  
Negative Correlation ◽  
High Speed ◽  
Magnetic Force ◽  
Measuring System ◽  
Rotational Inertia ◽  
Rotating Speed ◽  
Stable Suspension ◽  
Minimal Speed ◽  
Bearing Force ◽  
Magnetic Rings

The authors’ former works demonstrated that a passive magnetic (PM) rotator supported merely by PM bearings has a minimal speed, above which it can stabilize its equilibrium, under the function of a so-called Gyro-effect. It is unclear, however, by which factors is this minimal speed determined. This paper investigated the factors affecting the minimal stable speed of permanent maglev rotator, namely, the rotating inertia and PMB force. Two novel permanent maglev turbine models were designed: Model A---one stator and three rotors which have the same size but different rotational inertias; Model B---one rotor and one stator, but the stator has been devised with three different passive magnetic bearings: 1. a pair of small magnetic rings; 2. a pair of big magnetic rings; and 3. both of the two pairs of magnetic rings. Four Hall sensors distributed evenly at the turbine’s stator were used to detect the rotor’s eccentricity, and the speed sensor measured rotating speed. The calculated models of rotor’s eccentricity were established respectively for the two turbine models; the rotor’s eccentricity measuring system was built up and the rotor’s eccentricity of the two turbines was measured. The experimental data demonstrated that the rotational inertia of three rotors in the model A is 6.293×10-5 kg•m2, 1.074×10-4 kg•m2 and 2.081×10-4 kg•m2 respectively, and the corresponding minimal speed for suspension are 4597rpm, 3030rpm and 2222rpm respectively; in the model B, the magnetic force between the stator and rotor in the three cases is 92.12N, 123.48N, 212.66N respectively, corresponding to the minimal speed for suspension---3730rpm, 3120rpm and 2195rpm respectively. The results exhibited that same as the permanent maglev heart pump, permanent maglev turbines also have gyroscopic effect, which makes the rotors maintain stable suspension. And the minimal speed for suspension has a negative correlation with the rotor’s rotational inertia, namely, the bigger the inertia of the rotor, the smaller the required speed for suspension; the minimal speed for suspension also has a negative correlation with the magnetic force between the stator and rotor, that is, the larger the magnetic force, the smaller the rotating speed for suspension. Smaller minimal speed means better stability of the system, thereafter larger inertia or larger bearing force means better stability; besides, larger difference between minimal speed and performance speed of the rotator means better stability, it’s suggested permanent maglev be applied in high speed rotary machines.

scholarly journals Development of a Micro Hole Measuring System Using an Optical Fiber Probe (1st Report)

2009 ◽  
Vol 75 (12) ◽  
pp. 1476-1481 ◽  
Author(s):  
Hiroshi MURAKAMI ◽  
Akio KATSUKI ◽  
Hiromichi ONIKURA ◽  
Takao SAJIMA ◽  
Eiji KONDO
Keyword(s):  
Optical Fiber ◽  
Measuring System ◽  
Fiber Probe ◽  
Optical Fiber Probe ◽  
Micro Hole

A Vehicle Heading and Attitude Measurement System Based on Earth Magnetic Field Sensor

2012 ◽  
Vol 588-589 ◽  
pp. 1140-1143
Author(s):  
Hao Hu
Keyword(s):  
Magnetic Field ◽  
Magnetic Force ◽  
Magnetic Field Sensor ◽  
Measuring System ◽  
Attitude Measurement ◽  
Induced Voltage ◽  
The Earth ◽  
Earth Magnetic Field ◽  
Field Sensor ◽  
Magnetic Force Line

Measurement method is studied utilizing vertical gyroscopevertical gyroscopevertical gyroscope, static earth magnetic field sensor and CPU. According to electromagnetism induction law, when a wire loop incises the magnetic force line of the earth magnetic field, it will bring about the induction electromotive force, the earth magnetic field can be calculated by signal processing of induced voltage in measuring coil. A heading and attitude measuring system to vehicle are designed, the heading precision were raised. Experiment data states clearly the heading precision is not more than 0.5°. This system can be used to detect heading and attitude, and can be extended easily.

scholarly journals Measurement of Bangudae Rock Joint Using Non-adhesive, Non-contact Inclinometer Slope Laser Measuring System

2021 ◽  
Vol 37 (6) ◽  
pp. 617-625
Author(s):  
Jae Hyun Kim ◽  
Sang Ok Lee ◽  
Kwang Yong Chung ◽  
Min Su Han
Keyword(s):  
Optical Fiber ◽  
Rock Joint ◽  
Measuring System ◽  
Measuring Instrument ◽  
Contact Type ◽  
Short Period ◽  
Cultural Properties ◽  
The Future ◽  
Yangsan Fault ◽  
Provincial Park

Daegokcheon Stream in Daegok-ri, Ulju-gun, is an area with a developed valley and bedrock from Gajisan Provincial Park to the confluence of the Taehwa River across the Yangsan Fault. To measure the rock of Bangudae petroglyphs, the mineralogical weathering, joints, and scours or cavities at the bottom were confirmed. The measurement was carried out for a short period of time on the joint of the bedrock on which the Bangudae petroglyphs were engraved. Compared to the measured value obtained using existing optical fiber (Ch4 150 µm), a displacement value of 300 µm was obtained using the non-attached, non-contact type of measuring instrument. In the future, it is inferred that this instrument could be used for various cultural properties if the HSV-value suitable for illuminance and various measurement experiences are stored.

Fine-tuning filter for distributed optical fiber temperature measuring system

1998 ◽  
Author(s):  
Weimin Chen ◽  
Lingchuan Wu ◽  
Jian Zou ◽  
Shengjun Zhou ◽  
Shanglian Huang
Keyword(s):  
Optical Fiber ◽  
Fine Tuning ◽  
Measuring System ◽  
Temperature Measuring ◽  
Distributed Optical Fiber

Ground strain measuring system using optical fiber sensors

2000 ◽  
Author(s):  
Tadanobu Sato ◽  
Riki Honda ◽  
Shunjiro Shibata ◽  
Naoki Takegawa
Keyword(s):  
Optical Fiber ◽  
Optical Fiber Sensors ◽  
Measuring System ◽  
Fiber Sensors

Experimental research of optical fiber current sensors based on the Loren magnetic force

2014 ◽  
Author(s):  
Zhi Zhang ◽  
Haitao Yan ◽  
Xiaoyan Zhao ◽  
Jitao Xie ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Experimental Research ◽  
Magnetic Force ◽  
Current Sensors
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