To address challenges in the detection of wind turbine blade damage images, characterized by complex backgrounds and multiscale feature distribution, we propose a method based on an enhanced YOLOV8 model. Our approach focuses three key aspects: First, enhance extraction small target features integrating CBAM attention mechanism into backbone network. Second, fusion process is refined using Weighted Bidirectional Feature Pyramid Network (BiFPN) to replace path aggregation network (PANet)....

This paper numerically studies the performance of a piezoelectrically actuated valveless micropump with consideration three-way electro–mechanical–fluid couplings. Simulation (PVAM) indicates that both pumping rate and membrane deflection amplitude increase actuating frequency in low range (<7.5 kHz). However, because electro-mechanical–fluid couplings, deflects an undesirable way at high frequencies. will lower frequencies (>7.5 At even higher (>50 kHz), decreases further decreases. agrees...

We simulate the gas-atomization process of a close-coupled annular nozzle for vacuum induction gas atomization at three-dimensional scale. Moreover, relationship between simulated droplet type and experimentally metallic powder is established by comparing morphology droplets with powders. Herein, primary described volume-of-fluid (VOF) approach, whereas prediction diameter after secondary realized VOF-Lagrangian method. In addition, to completely reflect breaking deformation flow, we employ...

Accurate and reliable fault diagnosis is one of the key difficult issues in mechanical condition monitoring. In recent years, Convolutional Neural Network (CNN) has been widely used monitoring, which also a great breakthrough field bearing diagnosis. However, CNN can only extract local features signals. The model accuracy generalization original vibration signals are very low process signal processing by CNN. Based on above problems, this paper improves traditional convolution layer CNN,...

Abstract Metal micropatterns play critical roles in flexible electronics. However, the lack of versatile strategies for micropatterning diverse metal materials on various thin, or stretchable substrates has limited rapid development Here, a method by triboelectric spark discharge under atmospheric environment is developed, where nanogenerator (TENG) employed to precisely and safely control voltage, current, frequency discharges. Micropatterns films like gold, silver, copper, aluminum...

The detection of wear debris in lubricating oil is effective for determining current equipment operating conditions fault diagnosis. In this paper, a permanent magnet ferromagnetic sensor proposed that composed compact structure and coil generates an induced voltage when passes through magnetic field. A three-dimensional model the established, internal axisymmetric high-gradient field analyzed, mathematical signal proposed. effects air gap relative permeability, velocity, volume on...

In order to monitor the diagnosis of mechanical equipment by monitoring metal wear particles carried in large aperture lubricating oil tubes, simulation optimization structure design was out based on traditional three-coil inductance particle sensor. The numerical model electromotive force induced sensor established, and coil distance turns were simulated finite element analysis software. When permalloy is covered surface excitation induction coil, background magnetic field at air gap...

Accurate estimation of the amplitude parameter sinusoidal signals from noisy observations is an important problem in many signal processing applications. In this paper, investigated under assumption non-Gaussian noise Alpha stable distribution. According to chaos theory and properties almost periodic functions, a new method for proposed. This paper introduces principle concrete implementation process. The simulation experiments show that can effectively estimate weak alpha accuracy higher than FFT.

Abstract The analysis of wear based on on-line visual ferrograph provides crucial insights for the faults in mechanical equipment.However, online has been greatly limited by low imaging quality and recognition accuracy particle chains high hubbles when analyzing lubricant oils practical applications. To address this issue,this paper proposes an enhanced OLVF image detection model YOLOv8 applies it to multi-class intelligent images .The cascade group attention module is introduced enhance...

In response to the safety and stability issues of current electric vehicle charging connection devices, this study proposes a system planning for vehicles with different capacity piles based on user behavior characteristics Monte Carlo methods. It is found that predicted results under set management strategy are most consistent trend actual load changes. Moreover, in prediction weekly load, research has better performance than traditional unmanaged strategies. Under scheme, average speed A B...

Multilevel diffractive lenses with a small F -number ( #≤10) and high diffraction efficiency can shorten optical system length improve detection accuracy. The of the multilevel lens fabricated by high-precision, low-cost nanofabrication method proposed in this paper reaches 90% maximum theoretical efficiency. Furthermore, spectral imaging characteristics are analysis experimental verification. results show that measured resolution is 1.5 nm spatial 116 lp/mm, respectively, which close to values.

In this paper, the welding techniques for brackets and rings of grading used on UHV transmission lines in high altitude areas are optimized, four new methods, including strengthening surface ring welding, single side drilling bending bracket combination were proposed. The conventional method was as control group to carry out tensile torsion tests. According test results, two essentially produce same results technique when specimens their state. punching one significantly outperforms a...

In order to obtain high precision Fresnel lens, the processing technology of single point diamond turning (SPDT) is investigated. Through cutting experiments, compared performance lens manufactured on different metal materials and by tools, respectively. The results show that material characteristics tool nose radius affect shape machining parameters surface roughness. Therefore, choosing appropriate extremely important for improving lens.

As the critical parts of wind turbines, rolling bearings are prone to faults due extreme operating conditions. To avoid influence on turbine performance and asset damages, many methods have been developed monitor health by accurately analyzing their vibration signals. Stochastic resonance (SR)-based signal enhancement is one effective extract characteristic frequencies weak fault This paper constructs a new SR model, which established based joint properties both Power Function Type...

This paper presents a new approach to numerical implementation of classical Preisach model hystersis modeling Shape Memory Alloys (SMA). Classical hysteresis is phenomenological and it offers various advantages over other models. After reviewing the basic properties model, this reveals one difficulty numerically implement model. Numerical simulations have be done in two different cases: 1) when input ascends 2) descends. Based on geometrical interpretation, proposed unified there no need...

A micromirror fabricated by surface micromachined process is developed. The developed contains four pre-stress comb-drive actuators, which support tip/tilt/piston degrees of freedom. Pre-stress actuators have the advantage large displacement and fast response. Prototype a commercially available MEMS process. Experimental results indicate that device can realize designed function potential in MOEMS applications.

In this overview of micropumps actuated by smart materials, we outline different materials actuating mechanisms and their fabrication, theoretical analyses simulations. Suggestions are made for designs future trends materials.

According to the Schupmann's achromatic theory, a calculation method of off-axis four-mirror diffractive imaging optical system is introduced. By using method, an which has aperture 1 m, F-number 8, full field view 0.12°, waveband 582.8 nm~682.8 nm designed. The results show that chromatic aberration corrected effectively. modulation transfer function (MTF) more than 0.53 in range 50 lp/mm, and RMS radius diffusion spot less airy radius. It demonstrates image quality this close diffraction...