- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Self-Mixing Interferometric Signal Enhancement Using Generative Adversarial Network for Laser Metric Sensing Applications
摘要： Measurement performance of self-mixing interferometric (SMI) laser sensor can be significantly affected due to the presence of noise. In this case, conventional signal enhancement techniques yield compromised performance due to several limitations which include processing signals in frequency domains only, relying mainly on first order statistics, loss of important information present in higher frequency band and handling limited number of noise types. To address these issues, we propose a solution based on using generative adversarial network, a popular deep learning scheme, to enhance SMI signal corrupted with different noise types. Thus, taking advantage of the deep networks that can learn arbitrary noise distribution from large example set, our proposed method trains the deep network model end-to-end, able to process raw waveforms directly, learn 51 different noise conditions including white noise and amplitude modulation noise for 1,140 different types of SMI waveforms made up of 285 different optical feedback coupling factor (C) values and 4 different line-width enhancement factor α values. The results show that the proposed method is able to significantly improve the SNR of noisy SM signals on average of 19.49, 16.29, 10.34 dB for weak-, moderate-, and strong-optical feedback regime signals, respectively. For amplitude modulated SMI signals, the proposed method has corrected the amplitude modulation with maximum error (using area-under-the-curve based quantitative analysis) of 0.73% for SMI signals belonging to all optical feedback regimes. Thus, our proposed method can effectively reduce the noise without distorting the original signal. We believe that such a unified and precise method leads to enhancement of performance of SMI laser sensors operating under real-world, noisy conditions.
关键词： signal noise removal,neural network for signal enhancement,Interferometry laser sensors,vibration measuring laser sensors,waveform enhancement,self-mixing signal enhancement,generative adversarial network (GAN)
更新于2025-09-16 10:30:52
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[IEEE 2019 24th Microoptics Conference (MOC) - Toyama, Japan (2019.11.17-2019.11.20)] 2019 24th Microoptics Conference (MOC) - High-Speed Electro-Optics Based on Lithium Niobate Nanophotonics
摘要： The strapdown inertial navigation system (SINS) can be installed on a shearer and used for monitoring its position. However, under the complex environment of the mechanized mining face, the strong vibration of the shearer may cause large calculation error. First, the dynamic model of a double-drum shearer is built with a force analysis, and the spectrum characteristics of linear vibration and angular vibration for the fuselage are then obtained. Second, the coning error and sculling error compensation models of SINS for the shearer are derived based on vibration characteristics. Meanwhile, according to the factor of the uncompensated model, multi-sample compensation model, and different coal and rock traits and different vibration frequencies of the fuselage, the shearer SINS error compensation property under multiple parameters is researched and analyzed in simulation. Finally, simulations indicate that the SINS error compensation model with the three-sample algorithm and four-sample algorithm can improve the calculating accuracy of the shearer SINS. The coning and sculling errors can be compensated effectively by the shearer error compensation model under many vibration conditions, such as different coal and rock traits and different frequencies of the fuselage.
关键词： error compensation,dynamic model of shearer,vibration characteristic,accuracy analysis,Strapdown inertial navigation system (SINS)
更新于2025-09-16 10:30:52
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Non-contact, bi-directional tool tip vibration measurement in CNC milling machines with a single optical sensor
摘要： Vibration measurements of tools are significant for machine modelling, error prone state identification and machine operation optimization. In the milling process, forced vibrations are the main factor resulting in shape deviations as well surface roughness of machined work pieces and depend on the spindle speed and tool properties. Numerical models for predicting the dynamic behavior of machine systems can help to reduce vibrations. For an optimization, the model parameters need to be evaluated by simultaneously measuring the vibration of the tool tip in force direction and its vertical direction under different rotational speeds with high spatio-temporal resolution. In this work, a non-contact, single-sensor system and a signal processing algorithm are presented for measuring the vibrational behavior inside of a CNC milling machine with a known force. It enables in situ, simultaneous bi-directional vibration measurements directly at the tool tip with measurement rates up to 50 kHz, a circumferential resolution below 230 lm and a displacement uncertainty down to 40 nm, at rotational speeds up to 300 Hz. The dynamic behavior parameters of the tool are evaluated depending on the measured vibration (cid:1)2, enabling model optimizations. The measurements show a decrease of the natural frequency with increasing spindle speed. While the laser-based measurement principle does not bias the vibrational behavior it inherently guarantees orthogonality of the sensing axes, as well.
关键词： Interferometry,Bi-directional measurement,Dynamic behavior,Tip vibration,High-speed,In-situ
更新于2025-09-16 10:30:52
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Residual Stresses in Ultrasonic-Assisted Laser Sintered Grinding Diamond Materials
摘要： Special processing, viz ultrasonic vibration-assisted laser sintering of diamonds was studied. This process would eliminate the drawbacks pertaining to existing super-hard grinding wheels. The composite process fully utilized the odds of laser sintering and ultrasonic vibration to homogenize the structure and reduce residual stresses. Diamond particles were added to a 45 steel matrix using a Ni–Cr alloy via ultrasonic vibration-assisted laser sintering in argon. Metallographic microscopy, and were used to examine the microstructure of a Ni–Cr alloy and abrasive diamond particle bonding interface microstructure, Raman spectrometry was applied to evaluate residual stresses. Acoustic flow and cavitation effects generated by ultrasonic vibration refine crystal grains in the cladding layer and the microstructure is more homogeneous than the microstructure without ultrasonic treatment. A Cr3C2 layer formed on the surface of abrasive diamond particles enhances the bonding ability of a Ni–Cr alloy to diamond, which ensures the diamond isolation and protection, ultrasonic vibration reduces residual stresses inside abrasive diamond particles.
关键词： diamond,laser sintering,ultrasonic vibration,interfacial microstructure,residual stress
更新于2025-09-12 10:27:22
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Study of Inconel 718 Welded by Bead-On-Plate Laser Welding under High-Frequency Micro-Vibration Condition
摘要： Inconel 718 alloy laser-welded joints have poor mechanical properties due to the presence of Laves phases and liquation cracks. This paper intends to solve the above problems by high-frequency micro-vibration-coupled bead-on-plate laser welding. According to the shape of the weld beam, the upper part of the weld is defined as the nail head, and the lower part is the nail body. The results showed that high-frequency micro-vibration can achieve grain refinement. The micro-vibration could break the primary dendrite arm to form secondary dendrite and reduce epitaxial growth of the cellular crystal region. Micro-vibration exacerbated the flow of Niobium (Nb) elements surrounded by dendrites and reduced dendritic segregation, which decreased the formation of Laves phases. The combination of interdendritic Nickel (Ni), Titanium (Ti), and Nb and the precipitation of strengthening phases γ′ and γ′′ were promoted. When the vibration acceleration was 50.10 m/s2, it could inhibit the formation of Laves phases among dendrites and the size of the bulk Laves phase was effectively reduced. The cracks generated in the Inconel 718 alloy were distributed at three locations including the nail-head, the nail-body, and the junction of nail-head and nail-body. When the vibration frequency was 919 Hz, the length of the liquation crack reduced from 180 to 110 μm. While under 1331 Hz, the expansion of the liquation crack was extended, with the length of 200 μm.
关键词： Inconel 718,liquation crack,Laves phase,bead-on-plate laser welding,high-frequency micro-vibration
更新于2025-09-12 10:27:22
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Vibration Sensor Based On Graphene-coated Excessively Tilted Fiber Grating
摘要： few-layers graphene assembled on excessively tilted fiber grating (ExTFG). tilted range of 0~0.5 m-1, bending We report the bending strain and low frequency vibration characteristics of few-layers graphene-coated excessively (ExTFG), which fiber grating enhanced the mechanical characteristics at the expense of sensitivity. The experimental results show that, in the curvature strain sensitivities of transverse electric (TE) and transverse magnetic (TM) modes based on wavelength variation are -2.78 nm/m-1 and -1.49 nm/m-1, respectively, and those based on intensity variation are -0.11 dB/m-1 and -0.24 dB/m-1, respectively. For the low frequency vibration, the maximum acceleration sensitivities of TE and TM modes at 3dB points are STE=46.64 mv/g and STM=73.84 mv/g, respectively, which also the larger than those of other wavelength positions. The proposed graphene-coated ExTFG may potential application prospects in optical fiber strain, torsion and vibration sensors.
关键词： Graphene,Vibration sensor,Bending strain,Excessively tilted fiber grating (ExTFG)
更新于2025-09-12 10:27:22
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Encyclopedia of Maritime and Offshore Engineering || Optical Fiber Sensors for Marine Structural Condition Monitoring
摘要： Effective structural condition monitoring, and the action from it, is likely to result in significant economic savings from a better determination of structural integrity and use of the structure itself. It is also essential for the enhanced prediction of structural service lifetimes based on real-time measurement data obtained. Fiber optic-based sensors have shown real promise for structural condition monitoring, due to the attractive features they possess, such as small size, geometric versatility, multiplexing capability, and resistance to corrosive and hazardous environments. As a result, these sensors have been explored widely for monitoring a wide range of structural materials, including composites, concrete, limestones, carbon/aluminum, and metals (Scott et al., 2013; Sun et al., 2012; Nguyen et al., 2014; Kerrouche et al., 2009a), and the key parameters that have been measured include temperature, strain, vibration, relative humidity, pH, and chlorides, and so on.
关键词： Moisture Ingress Sensor,pH Sensor,Fiber Bragg Grating,Optical Fiber Sensors,Vibration Sensors,Marine Structural Condition Monitoring
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Integrated Optical Fibre — Investigating the Vibrational Response using Optical Frequency Domain Reflectometry
摘要： Integrated Optical Fibre (IOF) is a new technology in integrated optics using flame hydrolysis deposition to permanently attach an optical fibre onto a silicon substrate. This approach combines the low losses of optical fibre with the mechanical integrity of an integrated planar platform. By attaching the fibre with high quality optical glass we create devices that transform the packaging of fibres for sensing applications removing any use of glues, epoxies, adhesives and making it suitable for harsh environments such as aerospace. The binding medium itself can also be used for its optical properties. Aerospace environments are demanding, both for temperature range (-50 to +120 °C), but also for vibration and shock. In this work we are investigating a technique for monitoring the vibration sensitivity and damage points of the IOF under typical structural vibration conditions. In particular, here we report the use of Optical Frequency Domain Reflectometry (OFDR), which can reveal spectral and spatial information of features within a fibre such as Fibre Bragg Gratings (FBGs). This is of particular interest when applied to structural health monitoring, distributed strain and temperature sensing.
关键词： Optical Frequency Domain Reflectometry,vibration sensitivity,structural health monitoring,Integrated Optical Fibre,Fibre Bragg Gratings
更新于2025-09-12 10:27:22
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High-nitrogen steel laser-arc hybrid welding in vibration condition
摘要： Welding porosity and nitrogen content are considered significant factors affecting the mechanical properties of fusion-welding joints of high-nitrogen steel. In this study, a method of applying mechanical vibration in the welding process to reduce weld porosity and increase weld nitrogen content was investigated. The effects of mechanical vibration on porosity, tensile, and impact properties were analysed. The results indicated that the bubble floating speed in the vibrating weld pool is faster than that in the general welding mode. With the increase of mechanical vibration frequency, the porosity of the weld decreased at first and then rose. The tensile strength and impact energy increased first and then decreased, and the fracture surface indicated a ductile fracture.
关键词： nitrogen content,vibration,porosity,austenitic stainless steel,high-nitrogen steel,Laser-arc hybrid welding,microstructure,mechanical properties
更新于2025-09-12 10:27:22
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Micro-Cantilever Displacement Detection Based in Optical Fiber Tip
摘要： This work demonstrates the potential of combining a microsphere with a tip for the functionality of the contact sensor. This sensor consists of a tip aligned with the fiber core and a microsphere, which appears during tip formation. This new structure was produced using the electric arc machine. The sensor operation consists of the variation of the tip curvature, which causes a variation of the optical paths and, consequently, a change in the output signal. The study of this micro-cantilever consisted of an exploration of the contact mode. In addition, the sensor was characterized by temperature, which shows very low sensitivity and vibration. This last characterization was performed with two configurations parallel and perpendicular to the oscillating surface. The perpendicular case showed higher sensitivity and has an operating band of 0 Hz to 20 kHz. In this configuration, for frequencies up to 2 Hz, the intensity varies linearly with the frequencies and with a sensitivity of 0.032 ± 0.001 (Hz?1). For the parallel case, the operating band was from 1.5 kHz to 7 kHz.
关键词： detection,physic,cantilever,microsphere,optical fiber structure,optic,sensor,vibration,tip
更新于2025-09-12 10:27:22