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Finding a small object (e.g., earbuds, keys or a wallet) in an indoor environment (e.g., in a house or an office) can be frustrating. In this paper, we propose an innovative system, called HyperEar, to localize such an object using only a single smartphone, based on enhanced time-difference-of-arrival (TDoA) measurements over acoustic signals issued from the object. One major challenge is the hardware limitations of a Commercial-Off-The-Shelf (COTS) phone with a short separation between the two microphones and the low sampling rate of such microphones. HyperEar enhances the accuracy of TDoA measurements by virtually increasing distances between microphones through sliding the phone in the air. HyperEar requires no communication for synchronization between the phone and the object and is a low-cost and easy-to-use system. We evaluate the performance of HyperEar via extensive experiments in various indoor conditions and the results demonstrate that, for an object of 7 m away, HyperEar can achieve a mean localization accuracy of about 15 cm when the object in normal indoor environments. [ABSTRACT FROM AUTHOR]

Electrified powertrains are gaining a larger market share thanks to stricter emission regulation requirements and customer preferences. Ranging from micro hybrid to all-electric powertrains, however, their success highly depends on satisfactory life-long performance of onboard energy storage systems. In order to guide the battery pack design and management, real-world representative cell aging tests are essential for a successful product development. Focusing on cycle aging, this study proposes a novel methodology based on Welch's power spectral density estimation to characterize real-world cell duty cycles and synthesize representative profiles for cell aging tests. A 48-V mild hybrid vehicle model is developed in MATLAB/Simulink to relate the real-world vehicle-level drive cycles to cell-level duty cycles. Compared to existing test profiles found in literature, the newly designed profiles take the impacts of road conditions and driver styles into consideration to account for real-world resemblance. Experimental aging test results with the proposed aging profiles on nickel manganese cobalt lithium-ion cells not only hint at the real-world aging scenarios, but also lay the foundation for future work such as aging modeling. Repeatability of testing results is also investigated in this study. [ABSTRACT FROM PUBLISHER]