Fiber optic flowmeter for ship information and measuring system

The main requirements for flow meters are high accuracy, reliability, durability, resistance to aggressive media, cost-effectiveness, and the ability to output a signal in digital form. Most flowmeters that allow measuring mass flow are characterized by a very complex mechanical design and create a large hydrodynamic resistance to the flow. Fiber-optic flow meters undoubtedly have indisputable advantages and benefits: the absence of electric currents and voltages in the sensitive area of the device, immunity to external electromagnetic influences, absolute environmental and fire and explosion safety. At the same time, until recently, no successful circuitry solutions in the field of fiber-optic flowmeters for monitoring flammable liquids were known. Thus, the development and research of a new vortex fiber-optic flowmeter is an urgent scientific and technical problem. Analysis of the designs of known flow meters made it possible to specify the requirements for a new circuit design of the measuring device. The proposed design of the flow meter differs in that the main and control are essentially the same fiber made of sapphire glass, coaxially to which the sensitive fiber is located. And also a thermocompensating bimetallic plate is introduced into the meter circuit. The developed measuring device will provide: compensation of the influence of uncontrolled operational and climatological factors on the measuring and additional channel; lack of additional mechanical fiber tensioners; protection of sensitive elements of the device; constancy of the geometry of the optical channel under the influence of uncontrolled operational factors; identity of the location of the main and additional channels with respect to the flow of the controlled liquid; increased sensitivity and accuracy of the device.

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High-voltage monitoring by the fiber-optic recirculating measuring system

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2020-2-38-44 ◽

2020 ◽

pp. 38-44

Author(s):

A. V. Polyakov ◽

M. A. Ksenofontov

Keyword(s):

Optical Fibers ◽

High Voltage ◽

Optical Sensors ◽

Electromagnetic Interference ◽

Fiber Optic ◽

Electric Power Industry ◽

Measuring System ◽

Voltage Range ◽

External Electromagnetic Fields ◽

Optic Communication

Optical technologies for measuring electrical quantities attract great attention due to their unique properties and significant advantages over other technologies used in high-voltage electric power industry: the use of optical fibers ensures high stability of measuring equipment to electromagnetic interference and galvanic isolation of high-voltage sensors; external electromagnetic fields do not influence the data transmitted from optical sensors via fiber-optic communication lines; problems associated with ground loops are eliminated, there are no side electromagnetic radiation and crosstalk between the channels. The structure and operation principle of a quasi-distributed fiber-optic high-voltage monitoring system is presented. The sensitive element is a combination of a piezo-ceramic tube with an optical fiber wound around it. The device uses reverse transverse piezoelectric effect. The measurement principle is based on recording the change in the recirculation frequency under the applied voltage influence. When the measuring sections are arranged in ascending order of the measured effective voltages relative to the receiving-transmitting unit, a relative resolution of 0,3–0,45 % is achieved for the PZT-5H and 0,8–1,2 % for the PZT-4 in the voltage range 20–150 kV.

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COMPARATIVE ASSESSMENT OF INFORMATION PROTECTION AGAINST LEAK VIA AN OPTICAL CHANNEL IN DIGITAL FIBER-OPTIC TRANSMISSION SYSTEMS WITH AMPLITUDE AND PHASE MODULATION OF OPTICAL SIGNALS

Telecommunications and Radio Engineering ◽

10.1615/telecomradeng.v72.i13.30 ◽

2013 ◽

Vol 72 (13) ◽

pp. 1167-1179

Author(s):

G. N. Tolstikhin ◽

A. V. Popova

Keyword(s):

Phase Modulation ◽

Fiber Optic ◽

Comparative Assessment ◽

Optical Channel ◽

Information Protection ◽

Transmission Systems ◽

Optical Signals

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Robot Control Using Alternative Trajectories Based on Inverse Errors in the Workspace

Journal of Robotics ◽

10.1155/2021/9995787 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Quoc Khanh Duong ◽

Thanh Trung Trang ◽

Thanh Long Pham

Keyword(s):

Control System ◽

High Resolution ◽

Robot Control ◽

Low Cost ◽

Transmission System ◽

Measuring System ◽

Robot Calibration ◽

Measuring Device ◽

Calibration Solution ◽

System Errors

It is easy to realize that most robots do not move to the desired endpoint (Tool Center Point (TCP)) using high-resolution noncontact instrumentation because of manufacturing and assembly errors, transmission system errors, and mechanical wear. This paper presents a robot calibration solution by changing the endpoint trajectories while maintaining the robot’s control system and device usages. Two independent systems to measure the endpoint positions, the robot encoder and a noncontact measuring system with a high-resolution camera, are used to determine the endpoint errors. A new trajectory based on the measured errors will be built to replace the original trajectory. The results show that the proposed method can significantly reduce errors; moreover, this is a low-cost solution and easy to apply in practice and calibration can be done cyclically. The only requirement for this method is a noncontact measuring device with high-resolution and located independently with the robot in calibration.

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Continuous Evaluation of P a, Oa, O2 in Fish: Recording and Data Processing

Journal of Experimental Biology ◽

10.1242/jeb.82.1.321 ◽

1979 ◽

Vol 82 (1) ◽

pp. 321-330

Author(s):

ALAIN BELAUD ◽

YVES TROTTER ◽

CLAUDE PEYRAUD

Keyword(s):

Data Processing ◽

Breathing Pattern ◽

Measuring System ◽

Technical Improvement ◽

Measuring Device ◽

Continuous Evaluation ◽

System A ◽

Data Processing Method ◽

Rapid Changes ◽

Physiological Variations

1. In the eel (Anguilla anguxlla L.), the dorsal and ventral aortas and the subhepatic vein were catheterized to provide an external circulatory shunt. POO2 in the shunted blood was continuously recorded using a polarographic measuring device. 2. Spontaneous interruptions in the eel's ventilatory activity result in rapid changes in Pα, Oα, O2. The period of these Pα, Oα, O2 oscillations is sometimes less than 1 min. However, the response time of the measuring system is so great under the conditions of these experiments that only slow variations of Pα, Oα, O2 of a period greater than 5 min, are faithfully recorded. 3. In view of the impractibility of technical improvement in the recording system, a data processing method was developed to reconstitute the real physiological variations from the distorted experimental recordings. 4. Through this method of data correction, it is demonstrated that apnoeic or active ventilatory phases in the eel's breathing pattern are not triggered by constant low values of Pα, Oα, O2. Other physiological applications are suggested. Note: Equipe de Recherche Aasociee du Centre National de la Recherche Scientifique n 070623

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Discrete Portable Measuring Device for Monitoring Noninvasive Intraocular Pressure with a Nano-Structured Sensing Contact Lens Prototype

Digital Advances in Medicine, E-Health, and Communication Technologies ◽

10.4018/978-1-4666-2794-9.ch012 ◽

2012 ◽

pp. 214-229

Author(s):

Ana Moya ◽

Anton Guimerà ◽

Irene Sánchez ◽

Vladimir Laukin ◽

Raúl Martín ◽

...

Keyword(s):

Intraocular Pressure ◽

Contact Lens ◽

Data Transfer ◽

Measurement Instrument ◽

Measuring System ◽

Wireless Data ◽

Film Sensor ◽

Measuring Device ◽

Electronic Measurement ◽

Contact Lens Sensor

A new portable measuring device for monitoring intraocular pressure with a non invasive system using a prototype of contact lens has been developed. The contact lens is based on a new organic flexible highly piezo-resisitive film sensor that is glued to the central hole of a lens. The measuring system is wire connected to the contact lens and incorporates user interface methods and a Bluetooth link for bi-directional wireless data transfer. The key design aspects of such architecture are discussed in this paper. The system is designed with an architecture that can be integrated in the future in order to be placed in the contact lens. The discrete system is used to validate the electronic measurement operation and the contact lens sensor (CLS). The measurement instrument can calibrate the differences of the nominal value of the sensor and measure resistances variations that are related to pressure variations. The measuring system and the contact lens sensor were tested with an eye phantom and with enucleated pig eyes by applying pressure changes between 7 to 32 mmHg recording the electrical changes with the portable device.

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Comparison of test methods for measuring the net buoyant force of buoyant materials

Research Journal of Textile and Apparel ◽

10.1108/rjta-08-2019-0036 ◽

2020 ◽

Vol 24 (2) ◽

pp. 147-161 ◽

Cited By ~ 1

Author(s):

Nga-wun Li ◽

Chu-po Ho ◽

Kit-lun Yick ◽

Jin-yun Zhou

Keyword(s):

Traditional Method ◽

Functional Performance ◽

Test Methods ◽

Measuring System ◽

Small Scale ◽

Water Safety ◽

Buoyant Force ◽

Measuring Device ◽

Content Type ◽

Alternative Method

Purpose Net buoyant force is a crucial factor affecting the functional performance of clothing for water safety. This study aims to develop an alternative method for measuring the net buoyant force of various buoyant materials such as buoyant fabrics, on a small scale in a more accurate and efficient way than the existing method. Design/methodology/approach The net buoyant forces of buoyant materials with different thicknesses and forms were determined and compared using three methods. In Method 1, the traditional method involving mathematical calculations was used; Method 2 involved using the buoyancy-measuring device from the study of Jin et al. (2018) and Method 3 involved using an alternative buoyancy-measuring system that simulates the actual situation of using buoyant swimwear by measuring the force needed to submerge the buoyant material in water at a standard depth. The net buoyant forces of 22 buoyant materials were measured and compared to test these three methods. The accuracy, reproducibility, sensitivity and validity of these methods were then statistically compared. Findings The results obtained with the alternative buoyancy-measuring system had higher accuracy, reproducibility and validity than the results obtained through mathematical calculations. The sensitivity of the buoyancy-measuring system (Methods 2 and 3) was higher than that of the traditional method involving calculations (Method 1). Originality/value An alternative method is proposed to measure the net buoyant force of buoyant materials on a small scale with higher accuracy, reproducibility and sensitivity.

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Fiber Optic Strain Sensor Vibration Separation for Detection of Seeded Faults in Rotorcraft Transmissions

Smart Materials, Adaptive Structures and Intelligent Systems, Volume 2 ◽

10.1115/smasis2008-432 ◽

2008 ◽

Author(s):

Joseph D. Coker ◽

Darryll J. Pines ◽

Paul D. Samuel ◽

Jason Kiddy

Keyword(s):

Fiber Optic ◽

Local Strain ◽

Diagnostic Methods ◽

Fiber Optic Sensor ◽

University Of Maryland ◽

Planetary Gearbox ◽

Additional Processing ◽

Increased Sensitivity ◽

Fiber Optic Strain Sensors ◽

Helicopter Transmission

This paper presents a refined methodology for performing helicopter transmission anomaly detection through the use of vibration separation techniques applied to the output of a fiber optic sensor array. Fiber Bragg grating (FBG) sensors—distributed about the exterior of a planetary gearbox annulus—record the local strain response of the annulus surface due to tooth-mesh interactions. These strain profiles are collected for a number of loading conditions both with and without seeded faults. The profiles are separated and synchronously averaged to illustrate the effect of damage to planetary gears on local strain variation. Results of experiments conducted on the University of Maryland Transmission Test Rig (UMTTR) are included. Additional processing and comparison to traditional vibration-based diagnostic methods indicate the potential for increased sensitivity to damage of such a system and the feasibility of fiber optic strain sensors for in situ health and usage monitoring.

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