This paper describes the design and realization of a magnetic indoor positioning system. The system is entirely realized using off-the-shelf components and is based on inductive coupling between resonating coils. Both system-level architecture and realization details are described along with experimental results. The realized system exhibits a maximum positioning error of <;10 cm in an indoor environment over a 3 × 3 m ² area. Extensive experiments in larger areas, in nonline-of-sight conditions, and in unfavorable geometric configurations, show submeter accuracy, thus validating the robustness of the system with respect to other existing solutions.

In this paper, an ultrasonic positioning system is presented and characterized, based on the usage of a portable grid of beacons and of a few fixed anchors. Since the beacon grid can be moved to guarantee line-of-sight transmissions, the proposed strategy is potentially suitable for accurate positioning of a mobile object in an environment with a complex geometry. The system was tested experimentally, exhibiting a subcentimeter positioning accuracy in a range up to 4 m.

This article presents a compact measurement system for electrochemical impedance spectroscopy (EIS) on lithium-ion battery (LIB). The system is composed of a vector impedance analyzer (VIA) and state parameter estimation. The VIA architecture is based on delta-sigma digital-to-analog and analog-to-digital conversions to achieve the compactness, low-power consumption, and high resolution required to be potentially integrated within a battery cell. The estimation of state parameters is based on equivalent circuit models and the solution of nonlinear optimization problems. The proposed measurement system aims at the integration of complex measurement features directly into the battery cell to allow online and real-time diagnostic of the battery cell. A prototype of the compact measurement system was realized to assess the proposed approach. Experimental results are provided and validated by comparison with a reference laboratory instrument, showing good agreement. The VIA prototype is experimentally tested in both the online monitoring and aging monitoring of a commercial LIR2032 LIB cell. The modeling approach is applied to the experimental data provided by the VIA prototype, showing a good fit of the data. Moreover, parameters of the equivalent circuit models are extracted from the experimental data provided by the VIA prototype and identify trends related to the state of charge of the battery.

Electrochemical impedance spectroscopy (EIS) is of fundamental importance for characterization and monitoring of rechargeable batteries in automotive, energy storage, and electronics sectors. In this article, a low-complexity practical system for EIS of batteries is presented, and the uncertainty associated with its measurement results is analyzed. The system is based on a voltage-controlled current generator and the acquisition of current and voltage signals from the battery under test. Arbitrary current waveforms can be generated, and thus the system is flexible and reconfigurable. In particular, a broadband multisine excitation signal is used, enabling faster measurements with respect to the conventional stepped sine approach. The proposed system is characterized by repeated measurements on a 18 650 lithium-ion battery. Moreover, it is validated by comparison with a commercial benchtop instrument, and with the ground truth provided by a discrete component Randles circuit. Results show that the system is able to accurately and repeatably measure the impedance of a battery in a wide frequency range from 0.05 Hz to 1 kHz. Furthermore, it provides results that are consistent with the commercial instrument and with the ground truth of the $R$ – $C$ Randles circuit. Therefore, the proposed system using the broadband multisine method is suitable for implementing fast and inexpensive monitoring capabilities in smart battery management systems.

This paper presents research to develop an ultrawideband ranging sensor for personnel indoor localization based on the measurement of the pulse round-trip time. An approach combining flexibility, a high measurement update rate, and asynchronous operation with digital processing capability has been employed in the design of the sensor. The principle of operation, the architecture of the realized sensor, and the experimental setup are described. Finally, the results of a ranging calibration and validation test are presented and discussed. In the validation procedure, a root-mean-square error of 29 cm and a maximum absolute error of 81 cm with an operational range of approximately 10 m were observed.