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Fuzzy neural network vibration control on a piezoelectric flexible hinged plate using stereo vision detection
摘要： Vibration control on a two-connected piezoelectric flexible hinged plate is investigated, using a fuzzy neural network algorithm based on binocular vision measurement. As for vision sensing, a method to acquire vibration signals of the low frequency bending and torsional mode is investigated. To damp out the residual vibration quickly, the fuzzy neural network is applied to ensure the stability and control effect adaptively. To verify the stereo vision measurement method and the applied controller, an experimental setup of the piezoelectric flexible hinged plate with a binocular stereo vision is constructed. Experiments are conducted by using the binocular stereo vision measurement system and the adopted controller. The experimental results demonstrate the feasibility of the visual measurement method. Furthermore, the designed fuzzy neural network can attenuate the bending and torsional vibrations quickly, in comparison with proportional and derivative control, particularly for the small-level residual vibration.
关键词： Piezoelectric flexible hinged plate,binocular vision measurement,experiments,vibration control,fuzzy neural network algorithm
更新于2025-09-23 15:22:29
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Stereovision monitoring of deflection of concrete beam strengthened with ultraviolet-cured glass-fiber reinforced polymer in a destructive test
摘要： To monitor three-dimensional structural displacements in civil engineering, a stereovision displacement measurement method based on structure coordinate system is proposed in the present paper, and the absolute displacements of structure can be obtained through establishing the structure coordinate system and coordinate transformation. The center identification algorithm for circular target is studied to acquire the subpixel coordinates of center by combining Canny algorithm and Zernike algorithm. The epipolar constraint is introduced to conduct stereo matching of initial image pairs, and Kalman filtering and neighborhood searching algorithm are both employed to track circular targets on the left and right sequence images. To validate the effectiveness of the proposed method, a destructive test of concrete beams strengthened with ultraviolet-cured glass fiber reinforced polymer is performed in lab. Results show that the load–displacement curves obtained by the proposed stereovision method and linear variable differential transformer agree with each other; this verifies that the proposed stereovision method is feasible and effective for monitoring structural displacement in a destructive test.
关键词： Structural health monitoring,stereovision,computer vision,displacement measurement
更新于2025-09-23 15:22:29
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The Automatic Measuring System Suitable for the Simplified Very Small Phase Difference Measurement Circuit
摘要： In order to implement the measurement and evaluation of analog signals in high accuracy, to detect not only amplitude level but also phase information is necessary. Particularly, measurement of very small phase difference is desired in fields such as electric power and organism-related. Therefore, we have proposed the simplified very small phase difference measurement circuit with automatic measuring system using microcontroller (Arduino) and automatic amplitude adjustment program. In this paper, we examine a new automatic measuring system in order to improve the measurement accuracy.
关键词： very small phase difference measurement circuit,automatic measuring system,automatic amplitude adjustment program
更新于2025-09-23 15:22:29
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Phase aberration compensation for digital holographic microscopy based on double fitting and background segmentation
摘要： We propose a purely automatic and accurate phase aberration compensation method in digital holographic microscopy for phase-contrast imaging of living cells. At first, a least-squares fitting procedure is implemented to correct a large proportion of the phase aberrations. Subsequently, the flat phase background is retrieved based on phase gradient and image segmentation. Finally, the residual phase aberrations are eliminated in another least-squares fitting procedure performed within the background region. This method needs no manual intervention or prior knowledge of optical setup. Not only phase curvature but also high order aberrations could be corrected without extra components. It outperforms the phase-variation-minimization method in terms of noise robustness and calculation speed. The performance of the proposed method is demonstrated with simulated and experimental results.
关键词： Phase measurement,Digital holographic microscopy,Aberration compensation
更新于2025-09-23 15:22:29
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[IEEE 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Varna, Bulgaria (2018.9.20-2018.9.22)] 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Design and Implementation of a Low-Cost Phasor Measurement Unit: A Comprehensive Review
摘要： The complexity of the contemporary electrical power systems imposes challenges in the aspect of monitoring, protection and control. In order to obtain a high speed of response, wide area effect and prices synchronisation, the grid control functions can be benefited by the implementation of Phasor Measurement Units (PMU). The paper is aimed to make a review of the commercial implementation of Phasor Measurement Units source based implementations (open architecture hardware and software). implementations; as a This paper focuses on standard consequence, the concept of virtual PMU is not discussed here. open then and
关键词： low cost,comparison,review,options,standards,Phasor Measurement Units (PMU)
更新于2025-09-23 15:22:29
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Fiber Bragg Gratings Sensors for Aircraft Wing Shape Measurement: Recent Applications and Technical Analysis
摘要： The safety monitoring and tracking of aircraft is becoming more and more important. Under aerodynamic loading, the aircraft wing will produce large bending and torsional deformation, which seriously affects the safety of aircraft. The variation of load on the aircraft wing directly affects the ground observation performance of the aircraft baseline. To compensate for baseline deformations caused by wing deformations, it is necessary to accurately obtain the deformation of the wing shape. The traditional aircraft wing shape measurement methods cannot meet the requirements of small size, light weight, low cost, anti-electromagnetic interference, and adapting to complex environment at the same time, the fiber optic sensing technology for aircraft wing shape measurement has been gradually proved to be a real time and online dynamic measurement method with many excellent characteristics. The principle technical characteristics and bonding technology of fiber Bragg grating sensors (FBGs) are reviewed in this paper. The advantages and disadvantages of other measurement methods are compared and analyzed and the application status of FBG sensing technology for aircraft wing shape measurement is emphatically analyzed. Finally, comprehensive suggestions for improving the accuracy of aircraft wing shape measurement based on FBG sensing technology is put forward.
关键词： accuracy,aircraft,FBGs,wing shape measurement
更新于2025-09-23 15:22:29
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Optimized decoherence suppression of tripartite entanglement in finite temperature environments using weak measurement and quantum measurement reversal
摘要： In practical application, since quantum entanglement is inevitably destroyed by thermal noise resulted from environment, protecting entanglement from decoherence in thermal bath environment becomes a critically important issue in the field of quantum information. In this work, we propose a scheme to protect the tripartite Greenberger–Horne–Zeilinger (GHZ) entanglement state subjected to the generalized amplitude damping (GAD) channel based on the quantum technique of weak measurement (WM) and quantum measurement reversal (QMR). By optimizing the strengths of WM and QMR, the decoherence caused by the channel can be effectively suppressed. The results show that after performing the optimal pre- and post-channel weak measurement, the negativity of the GHZ state can be effectively improved with a certain probability, and the phenomenon of sudden death can be delayed to a certain degree. This scheme can be applied to the decoherence suppression of GAD channel at finite temperature.
关键词： generalized amplitude damping channel,weak measurement,Decoherence suppression,tripartite entanglement.
更新于2025-09-23 15:22:29
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Polarization-based plug-and-play measurement-device-independent quantum key distribution
摘要： Measurement-device-independent quantum key distribution (MDI-QKD) has received much attention, with the goal of overcoming all of the security loopholes caused by an imperfect detection system. We here propose a plug-and-play MDI-QKD (P&P MDI-QKD) scheme whereby an untrusted relay node, Charlie, owns a laser and sends photons to Alice and Bob. Alice (Bob) modulates the polarization of the incident photons and returns them to Charlie. Charlie uses a modified Bell state analyzer (BSA) to perform Bell state measurements (BSM). In comparison with the original version of MDI-QKD, our scheme exploits a single untrusted laser as the photon source. This makes the signal photons identical and enhances the Hong-Ou-Mandel effect. Second, because of the P&P structure, the setup can automatically eliminate the birefringence influence of the fibers, which makes the setup highly stable. Finally, our modified BSA can identify |Φ?+ and |Φ?? of four Bell states with polarization encoding but not |Ψ?+ and |Ψ??. Based on practical experimental parameters, a simulation showed that the maximum theoretical secure transmission distance could reach more 280 km.
关键词： Plug-and-play,Measurement-device-independent,Quantum cryptography,Quantum key distribution
更新于2025-09-23 15:22:29
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Optical analysis during reduction of nitric oxide in microwave-induced plasma promoted by activated cokes at atmospheric pressure
摘要： Emission from microwave (MW)-induced argon plasma promoted by a bed of activated coke granules was analyzed spectroscopically during non-catalytic reduction of nitric oxide (NO) at atmospheric pressure. The spectral analysis with a high resolution revealed that strong 5 peaks were recognized in a similar wavelength region to N2+ first negative band when NO molecules were included in argon plasma. The strongest peak is caused by the Ar(II) ions excited with energy corresponding to 388.033 nm in the progress of atomic transition 3s23p4(3P)4d 4D1/2 → 3s23p4(3P)4p 4D°1/2. This transition must be enhanced by an interaction with any intermediates or radical species yielded during NO reduction reactions. The plasma temperatures were determined by Boltzmann plots from intensities of any two peaks in the spectral band. The temperature was significantly different dependently on choice of two peaks, whose fact is implying non-equilibrium plasma. The maximum temperature was recognized at a high level of 40,000 K due to the activation during the reactions. The images of the plasma observed by high-speed camera showed dynamic features so that MW discharge like streamer was generated frequently in the reactor. The reaction rate could be correlated with the ratio of the area dominated by dynamic plasma to the cross section in the reactor.
关键词： High-speed camera images,Argon plasma,Microwave discharge,Spectroscopic measurement,de-NOx
更新于2025-09-23 15:22:29
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A fast reconstruction method for three-dimensional shape measurement using dual-frequency grating projection and phase-to-height lookup table
摘要： Phase-to-height mapping is indispensable part of three-dimensional (3D) shape measurement system based on phase analysis, which guarantees the accuracy of 3D reconstruction. In this paper, a fast 3D shape reconstruction method based on dual-frequency grating projection and phase-to-height lookup table is proposed. In this proposed method, the reference plane is moved with known interval along the measurement depth direction to establish the mapping lookup table between the phase of the high and low frequency projected grating and their corresponding spatial height pixel by pixel respectively. Then, two methods to establish the lookup table with the unwrapped and the wrapped phase have been respectively introduced according to the characteristics of dual-frequency grating. The actual experimental results show that the two methods can effectively extend the measurement range of the current wrapped phase-to-height lookup method, and the reconstruction accuracy is better than the traditional phase-to-height quadratic fitting method. At the same time, the consumed time for 3D shape reconstruction of the tested object by the two methods is compared and analyzed. Finally, combining the high performance parallel computation of GPU, the fast 3D shape reconstruction is realized with the speed of 60fps.
关键词： Dual-frequency grating,Parallel computing,3D shape measurement,Multi-reference plane,Phase-to-height mapping
更新于2025-09-23 15:22:29