Search results for "transducer"

Li-ion Battery Modeling and State of Charge Estimation Method Including the Hysteresis Effect

2019

In this paper, a new approach to modeling the hysteresis phenomenon of the open circuit voltage (OCV) of lithium-ion batteries and estimating the battery state of charge (SoC) is presented. A characterization procedure is proposed to identify the battery model parameters, in particular, those related to the hysteresis phenomenon and the transition between charging and discharging conditions. A linearization method is used to obtain a suitable trade-off between the model accuracy and a low computational cost, in order to allow the implementation of SoC estimation on common hardware platforms. The proposed characterization procedure and the model effectiveness for SoC estimation are experime…

An energy autonomous and battery-free measurement system for ambient light power with time domain readout

2021

Abstract Internet of Things (IoT) provides more and more adequate infrastructures for many applications and advanced services. This context promotes the ability to satisfy the growing demand for innovative measuring systems, increasingly popular with intelligent nodes, totally wireless, easy to install that require the least possible maintenance. This paper aims to contribute to the state-of-the-art with an energy-autonomous and battery-free measurement platform designed to measure the ambient light power when its level exceeds the Limit of Detection (LoD) threshold. The proposed system consists of a single photovoltaic transducer to harvest energy and simultaneously detect ambient light. T…

Extensive Assessment of Blood Glucose Monitoring During Postprandial Period and Its Impact on Closed-Loop Performance.

2017

[EN] Background: Closed-loop (CL) systems aims to outperform usual treatments in blood glucose control and continuous glucose monitors (CGM) are a key component in such systems. Meals represents one of the main disturbances in blood glucose control, and postprandial period (PP) is a challenging situation for both CL system and CGM accuracy. Methods: We performed an extensive analysis of sensor¿s performance by numerical accuracy and precision during PP, as well as its influence in blood glucose control under CL therapy. Results: During PP the mean absolute relative difference (MARD) for both sensors presented lower accuracy in the hypoglycemic range (19.4 ± 12.8%) than in other ranges (12.2…

Application of dual boundary element method in active sensing

2013

In this paper, a boundary element method (BEM) for the dynamic analysis of 3D solid structures with bonded piezoelectric transducers is presented. The host structure is modelled with BEM and the piezoelectric transducers are formulated using a 3D semi-analytical finite element approach. The elastodynamic analysis of the entire structure is carried out in Laplace domain and the response in time domain is obtained by inverse Laplace transform. The BEM is validated against established finite element method (FEM).

Back EMF Sensorless-Control Algorithm for High-Dynamic Performance PMSM

2010

In this paper, a low-time-consuming and low-cost sensorless-control algorithm for high-dynamic performance permanent-magnet synchronous motors, both surface and internal permanent-magnet mounted for position and speed estimation, is introduced, discussed, and experimentally validated. This control algorithm is based on the estimation of rotor speed and angular position starting from the back electromotive force space-vector determination without voltage sensors by using the reference voltages given by the current controllers instead of the actual ones. This choice obviously introduces some errors that must be vanished by means of a compensating function. The novelties of the proposed estima…

A low power interface circuit design for a CMOS based smart optical sensor

2012

In this paper, a CMOS interface circuit as part of an optical sensor-based microsystem for pH monitoring applications is presented. The proposed circuit is capable of processing a voltage signal produced by the light transducer and generating 8-bit digital outputs representing the color information (i.e. wavelength). A resolution of 8 different colors has been achieved as a proof of concept and can easily be extended to a higher number of colors without a major modification in the architecture. The proposed interface circuit is a mixed-signal solution that consists of analog as well as digital building blocks along with a light transducer. It can be used as a portable and non-intrusive opti…

Asymmetries in classically conditioned head movements and cingulate cortex slow potentials in cats.

1991

Presuming that conditioned head movements in the cat indicate a preference for a specific direction, asymmetries were also expected to be found in bilaterally recorded cingulate cortex slow potentials to a symmetrical tone stimulus during discriminative conditioning. Conditioned stimuli (CS, 1000 and 2500 Hz tones) were delivered through two miniature loudspeakers fitted to the head in front of both ears. The unconditioned stimulus (US) was an electrical stimulation of either the left or right lateral hypothalamus yielding, in addition to its rewarding effects, an unconditioned head turning response (UR) either to the left, right, forwards or upwards. Discrimination learning appeared as mor…

Tuning Of Organic Heterojunction Conductivity By The Substituents' Electronic Effects In Phthalocyanines For Ambipolar Gas Sensors

2021

Abstract Exploiting organic heterojunction effects in electrical devices are an important strategy to improve the electrical conductivity, which can be utilized into improving the conductometric gas sensors performances. In this endeavor, the present article reports fabrication of organic heterostructures in a bilayer device configuration incorporating octa-substituted nickel phthalocyanines (NiPc) and radical lutetium bis-phthalocyanine (LuPc2) and investigates their sensing properties towards NH3 vapor. NiPc having hexyl sulfanyl, hexyl sulfonyl and p-carboxyphenoxy moieties are synthesized, which electronic effects are electron donating, accepting and moderate accepting, respectively, al…

Hall Effect Clamp-on Current Transducer Characterization under Nonsinusoidal Conditions

2009

A Strain Sensing Structural Health Monitoring System for Delaminated Composite Structures

2012

Structural Health Monitoring (SHM) for composite materials is becoming a primary task due to their extended use in safety critical applications. Different methods, based on the use of piezoelectric transducers as well as of fiber optics, has been successfully proposed to detect and monitor damage in composite structural components with particular attention focused on delamination cracks.In the present paper a Structural Health Monitoring model, based on the use of piezoelectric sensors, already proposed by the authors for isotropic damaged components, is extended to delaminated composite structures. The dynamic behavior of the host damaged structure and the bonded piezoelectric sensors is m…