Sensorless metal object detection for wireless power transfer using machine learning

Purpose This study aims to realize a sensorless metal object detection (MOD) using machine learning, to prevent the wireless power transfer (WPT) system from the risks of electric discharge and fire accidents caused by foreign metal objects. Design/methodology/approach The data constructed by analyzing the input impedance using the finite element method are used in machine learning. From the loci of the input impedance of systems, the trained neural network (NN), support vector machine and naive Bayes classifier judge if a metal object exists. Then the proposed method is tested by experiments too. Findings In the test using simulated data, all of the three machine learning methods show high accuracy of over 80% for detecting an aluminum cylinder. And in the experimental verifications, the existence of an aluminum cylinder and empty can are successfully identified by a NN. Originality/value This work provides a new sensorless MOD method for WPT using three machine learning methods. And it shows that NNs obtain high accuracy than the others in both simulated and experimental verifications.

Microstructure and tribological properties of sprayed nanostructure Fe-based martensite coating on an aluminum cylinder liner

Purpose The purpose of this paper is to improve the tribological properties of aluminum cylinder liner. Higher martensite contents were closely related to the higher hardness and excellent wear resistance of Fe-based coatings. Furthermore, the grain size of the Fe-based coating was approximately 40 nm, which provides an excellent fine grain strengthening effect. Design/methodology/approach To improve the tribological properties of aluminum cylinder liners, a Fe-based martensite coating was prepared by internal plasma spraying technology, whose microstructure and tribological properties were then investigated. Findings Sprayed Fe-based coating possessed a low contact angle and strong adhesion with lubricating oil. In a simulated engine condition, Fe-based coating exhibited a decreased friction coefficient and increased wear resistance under oil lubrication, which was dominated by a stronger adhesive force with lubricating oil, higher martensite contents on the worn surface, higher hardness and higher H/E value than those of the reference HT 200 and Al-19Si cylinder material. Originality/value Nanostructure Fe-based martensite coating was sprayed on an aluminum cylinder liner, which demonstrated remarkable advantages over the reference cylinder material.

Investigation of adsorption and desorption behavior of small-volume cylinders and its relevance for atmospheric trace gas analysis

Atmospheric trace gas measurements of greenhouse gases are critical in their precision and accuracy. In the past 5 years, atmospheric measurement and gas metrology communities have turned their attention to possible surface effects due to pressure and temperature variations during a standard cylinder's lifetime. This study concentrates on this issue by introducing newly built small-volume aluminum and steel cylinders which enable the investigation of trace gases and their affinity for adsorption and desorption on various surfaces over a set of temperature and pressure ranges. The presented experiments are designed to test the filling pressure dependencies up to 30 bar and temperature dependencies from −10 ∘C up to 180 ∘C for these prototype cylinders. We present measurements of CO2, CH4, CO and H2O using a cavity ring-down spectroscopy analyzer under these conditions. Moreover, we investigated CO2 amount fractions using a novel quantum cascade laser spectrometer system enabling measurements at pressures as a low as 5 mbar. This extensive dataset revealed that for absolute pressures down to 150 mbar the enhancement in the amount fraction of CO2 relative to its initial value (at 1200 mbar absolute) is limited to 0.12 µmol mol−1 for the prototype aluminum cylinder. Up to 80 ∘C, the aluminum cylinder showed superior results and less response to varying temperature compared to the steel cylinder. For CO2, these changes were insignificant at 80 ∘C for the aluminum cylinder, whereas a 0.11 µmol mol−1 enhancement for the steel cylinder was observed. High-temperature experiments showed that for both cylinders irreversible temperature effects occur especially above 130 ∘C.

Investigation of adsorption/desorption behavior of small volume cylinders and its relevance for atmospheric trace gas analysis

Atmospheric trace gas measurements of greenhouse gases are critical in their precision and accuracy. In the past 5 years, atmospheric measurement and gas metrology communities have turned their attention to possible surface effects due to pressure and temperature variations during a standard cylinder’s lifetime. This study concentrates on this issue by introducing newly built small volume aluminum and steel cylinders which enable the investigation of trace gases and their affinity for adsorption/desorption on various surfaces over a set of temperature and pressure ranges. The presented experiments are designed to test the filling pressure dependencies up to 30 bar, and temperature dependencies from −10 °C up to 180 °C for these prototype cylinders. We present measurements of CO2, CH4, CO and H2O using a cavity ring down spectroscopy analyzer under these conditions. Moreover, we investigated CO2 amount fractions using a novel quantum cascade laser spectrometer system enabling measurements at pressures as a low as 5 mbar. This extensive dataset revealed that until pressures as low as 150 mbar the enhancement in the amount fraction of CO2 relative to its initial value (at 1200 mbar) is limited to 0.12 μmol mol−1 for the prototype aluminum cylinder. Up to 80 °C, the aluminum cylinder showed superior results and less response to varying temperature compared to the steel cylinder. For CO2, these changes were insignificant at 80 °C for the aluminum cylinder, whereas a 0.11 μmol mol−1 enhancement for the steel cylinder was observed. High temperature experiments showed that for both cylinders irreversible temperature effects occur especially above 130 °C.

Determination of The Rotational Friction Coefficients of Solid Cylinder with Various Inclined Plane Angle

The layer texture differences of an object have an influence on the friction force caused by both planes. This research aims to determine the static and kinetic friction coefficient on several solid cylinder materials. The benefits of this research can be used to develop experimental learning activities on friction coefficient. This research used experimental method. The research was carried out by rolling samples at various inclined plane angles and measuring the traveled distance traveled in one rotation (D). The results showed that the static and kinetic friction coefficients between aluminum cylinder and glass were 0.146 and 0.097, iron cylinder and glass were 0.136 and 0.096, glass cylinder and brass were 0.132 and 0.094, nylon cylinder and glass were 0.101 and 0.090, and stainsless cylinder and glass were 0.122 and 0.094, respectively.Perbedaan tekstur lapisan sebuah benda mempunyai pengaruh pada gaya gesek yang ditimbulkan oleh kedua bidang. Penelitian ini bertujuan untuk menentukan nilai koefisien gesek statis dan koefisien gesek kinetik pada beberapa bahan silinder pejal. Manfaat yang dapat diambil dari hasil penelitian ini adalah dapat digunakan sebagai mengembangkan kegiatan pembelajaran praktikum koefisien gesekan benda. Penelitian ini menggunakan metode eksperimen. Penelitian dilaksanakan dengan menggelindingkan sampel pada berbagai sudut kemiringan dan mengukur jarak tempuh untuk satu kali putaran (D). Hasil penelitian menunjukkan bahwa nilai koefisien gesek statis dan koefisien gesek kinetik secara berurutan untuk silinder aluminium dengan kaca sebesar 0,146 dan 0,097, untuk silinder besi dengan kaca sebesar 0,136 dan 0,096, untuk silinder kuningan dengan kaca 0,132 dan 0,094, untuk silinder nylon dengan kaca sebesar 0,101 dan 0,090, dan untuk stainsless dengan kaca sebesar 0,122 dan 0,094.