This article proposes a piezoelectric energy harvester to supply power for low-consumption devices in intelligent vehicle wheels. The is embedded the spoke and possesses ability of self-tuning due centrifugal force rotational motion. A dynamic model suitable design derived through Euler-Lagrange method verified by experiments. In order facilitate harvester, concept factor proposed discussed. wheel's characteristics measured road test designed R16 wheel. An experimental platform with Macro...

Dispersive acoustic metamaterials (AMMs) with graded refractive index is promising in sensing enhancement by providing rainbow trapping (ART) effect. However, previous solutions to this type of AMMs are based on 2D unit cells that require infinite or very large size the third dimension; they cannot integrate conventional sensors without deteriorating ability wave manipulation. In order advance their practical applications, paper proposes an axisymmetric, microphone embedded AMM device...

The detection of continuous acoustic sources on composite structures is an important research direction in the field structural health monitoring. However, complexity signal and anisotropy materials lead to difficulty location. Therefore, a method source location for structure based dispersion wave velocity modified beamforming proposed. In this method, L-shaped sensor array used locate with algorithm, velocity-direction curve constructed by selecting filter frequency band optimal weight...

Abstract Aerospace propellant tanks are subject to factors such as pressure disturbances, leading uncertainty in the position of internal liquid and pressurized gas within tank. The gas-liquid distribution tank reflects working state tank, affecting timing relief, overall attitude control, measurement remaining under high-pressure conditions. is crucial for normal operation spacecraft. Existing methods difficult apply spacecraft scenarios due their requirements number or volume sensors. This...

This paper proposed a strategy of tracking pipe PIG utilizing Fiber Optic Distributed Vibration Sensor (FODVS) and YOLO object detection algorithm. Phase sensitive Optical Time Domain Reflectometer (φ-OTDR) is employed as the distributed sensor to collect real field vibration signal generated result collision between leather bowl weld joint. The space-time graphs φ-OTDR are prepared construct data sets train typical YOLOv3 net model. trained model proved be able accurately capture invert-V...

The capacitive micro-machined ultrasonic transducer (CMUT) has a good acoustic matching with air. In this paper, 16-element CMUT array for airborne application is designed and fabricated by SOI wafer bonding process. All the cells have same geometric parameters circular sealed membrane, which vibrate uniformly transmission efficiency. And thin membrane small mass proposed to broaden bandwidth of CMUT. sensor operates at 215.6 kHz resonance frequency large -3dB fractional 15.7% consistency....

Piezoelectric energy harvesting is a promising way to develop self-sufficient systems. Structural design and parameter optimization are key issues improve the performance in applications. This paper presents magnetic coupled piezoelectric harvester increase output bandwidth. A lumped model considering static position established various modes simulated. focuses on “Low frequency repulsion mode”, which more practical. The experiment platform built with Macro Fiber Composite (MFC) material,...

In order to supply power for the wireless sensors in wheels, a piezoelectric energy harvester installed spokes is proposed this paper. The cantilever beam fixed spoke, which has higher practicability than method mentioned related research. periodic excitation generated by gravity effect of free-end mass rotation, and safety limiting structure designed. A dynamic model was derived through Euler–Lagrange verified experiments. Based on numerical simulation model, parameter design carried out...

In order to ensure the safety of spacecrafts in orbit, impact location is an important part structural health monitoring systems. this paper, algorithm based on posterior probability correlation proposed solve problem, that is, point stiffened structure a spacecraft difficult locate. The combines Gaussian cross-correlation possibility weight method and Bayesian method. superposition grids was used reduce dependence accuracy time difference extraction. normalized fitting were compensate...

The analysis of acoustic signals to localize emission (AE) sources has emerged as a kind favored approach. Despite recent advances, the task localizing AE such impacts in discontinuous structure with hole still poses considerable challenge. A method based on gradient vector descent is presented this article, which applied hole. When an impact event observed, will first calculate time difference-of-arrival values different sensors and set most likely location origin coordinates. Then, tracks...

The increase in the number of space debris is a serious threat to safe operation in-orbit spacecraft. propagation law impact signal stiffened panel spacecraft’s sealed bulkhead very complicated, and there less research on source location high-stiffened panel. In this paper, an adaptive energy compensation threshold filtering (AECTF) method based acoustic emission proposed, which can realize large-scale, fast accurate locating with resource consumption. influence stiffeners lamb wave analyzed...

Abstract This paper proposes a hybrid energy harvester (HEH) based on dual-frequency-up-conversion mechanism, which is suitable for ultra-low frequency rotation. mechanism takes full advantage of the periodic excitation provided by gravity to achieve two harvesting responses in one cycle. HEH consists piezoelectric (PEH) and electromagnetic harvester. The magnet component achieves up-conversion PEH impact, also induces electrical from coil, thus coupling parts together form continuous...