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Tracking of the sun, which increases the efficiency of solar energy production systems, has shown considerable development in recent years. This development has been achieved by custom-positioned light sensors, image cameras, sensorless chronological systems and intelligent controller supported systems or by synergetic use of these systems. This study contributes to this research area with a novel spherical-based sensor which measures spherical light source emittance and localizes the light source. This sensor was built by using miniature light sensors placed on a spherical shaped three-dimensional printed body with data acquisition electronic circuitry. Besides the developed sensor data acquisition embedded software, preprocessing and filtering processes were conducted on these measured data. In the study, the outputs of Moving Average, Savitzky-Golay, and Median filters were used for the localization of the light source. The center of gravity for each filter used was determined as a point, and the location of the light source was determined. The spherical sensor system obtained by this study is applicable for various solar tracking methods. The approach of the study also shows that this measurement system is applicable for obtaining the position of local light sources such as the ones placed on mobile or cooperative robots. [ABSTRACT FROM AUTHOR]

Nowadays, piezoceramics are widely used in sensor technology. However, due to their brittle nature, they can be cracked either in severe environmental conditions or during careless installation. Besides, the abrasion of their surface is a challenging problem in some applications. Hereby, the usage of a protective layer can prolong their effective working life. In this study, we analyze the electro-elastic behavior of a spherical piezoceramic sensor coated by a homogeneous protective layer. Then, with the motivation of reducing possible interfacial problems across the sensor/coating interface, and also improving the sensing ability of the coated sensor, material gradation concept is utilized. For this intent, two sensor/coating systems are studied: a piezoelectric sensor coated with a functionally graded material, and a functionally graded piezoelectric sensor coated with a homogeneous material. The governing equations are derived within the context of electro-elasticity theory and closed-form solutions are presented for coated sensors. It is concluded that a piezoceramic sensor protected with a functionally graded coating can improve the interfacial condition of the coated sensor, as well as enhancing its sensing ability. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this study is to design a spherical sensor which can detect the surge from various directions to lay the foundation of the research of surge. Design/methodology/approach – This paper designed a spherical sensor to detect the impact force generated by the surge. To realize the depth and stability control of the shallow underwater vehicles, it is necessary to do research and analysis on the surge in shallow waters. The spherical sensor with novel structure was skillfully composed of 24 cantilever beam pressure-type strain sensors. It is powerful to detect the surge from various directions simultaneously. Findings – It is proved that the spherical sensor can accurately collect the surge data from multiple directions through experiments, which laid the foundation of the anti-surge study. Research limitations/implications – Surge is not a new topic. But there is no effective tool to detect surge. The research of this paper is an attempt to provide an available tool to analyze surge. The research limitation is that the pool where the spherical sensor is installed is a little small. In the future, a bigger pool can be used. Practical implications – A deep and comprehensive analysis of surge can be conducted according to the surge data detected by the spherical sensor to achieve the essential features of surge. This lays the foundation for the accurate control of Autonomous Underwater Vehicles (AUVs), especially fixed depth and stability control. Social implications – As the control accuracy of AUVs increases, the AUVs can perform much more difficult tasks such as port monitoring, underwater salvaging, underwater pipeline maintenance and so on. These can be applied in commercial applications or in the national defense of many countries. Originality/value – A novel spherical sensor using 24 cantilever beam pressure-type strain sensors to detect the surge was designed. The spherical sensor was installed in the physical surge simulator to collect surge data and conduct an analysis of the collected data. [ABSTRACT FROM AUTHOR]

In this work an analytical model for the energy harvesting of an acoustic spherical sensor has been developed in the context to make it autonomous. Our spherical sensor is composed of two half-spheres of Plexiglas and a piezoelectric ring of PZ26 that can be used as exciter or sensor. For the analytical model, the piezoelectric ring was modeled using two primary modes of vibration: thickness and radial. For each mode, the ring is described by an equivalent electromechanical model which connects the mechanical part (forces and velocities) to the electrical part (voltage and current). The proposed paper theoretical model enables building a global electromechanical circuit in order to simulate the total harvested voltage response.