83 research outputs found
Road Slope Estimation in Bicycles without Torque Measurements
No full textElectrically Power Assisted Cycles (EPACs) have been gaining increasing attention worldwide during the past few years. The delivery of a good assistance during inclines makes or destroys an EPAC. This paper addresses the low-cost estimation of road slope on bicycle without pedaling torque measurement. Two estimation algorithms are discussed. A full 6 Degrees of Freedom kinematic Extended Kalman Filter and a simpler, more cost-effective 2 DoF Kalman filter based on the longitudinal kinematic model. The proposed reduced-sensor algorithm is shown to be very accurate during straight running; however it is affected by errors during cornering. This issue is addressed by augmenting the filter with a curve correction algorithm. The curve correction algorithm, based on a time-varying low pass filter is detailed and validated on experimental data, comparing the estimated road slope against cartographic data
Lithium-Ion batteries for Electric Vehicles:Characterization, Modeling, State-of-Charge estimation and Disequalization phenomena
No full textThe increased sensibility on environmental problems and the growing price of oil have focused research during the past few years on reducing energy consumption. As for the automotive field, research is devoted to increase vehicle efficiency and reduce pollutant emissions. In that context, the increasing interest on vehicle electrification (HEV, PHEV, EV) brought manufacturers and researchers to invest significant resources in the research and development of advanced energy storage systems, particularly in advanced battery systems. The Book focuses on lithium-ion technology because of its superior characteristics suitable for electric vehicles. Even if batteries are so common in day-by-day life, thanks to portable electronic systems, the need to use them in EVs and HEVs has underlined new issues with respect to the ones already solved for mobile electronic systems. Characterization, modeling, State-of-Charge etimations and disequalization phoenomena are the subjects of this Book
Kalman Filter SoC estimation for Li-Ion batteries
No full textState-of-Charge (SoC) estimation is a key factor
for correct and safe battery management, particularly for the
development of the Battery Management System (BMS).
The paper deals with this problem for the currently most
promising technology in the battery filed: Lithium-Ion
batteries. An electric model of the cell is identified and verified,
in order to apply Kalman Filter Theory and design an
algorithm for estimating SoC. Particularly the aim of the
algorithm is to reject measurement noise and parametric
uncertainties and be applicable to different cells of the same
manufacturer and technology. In this purpose, design criterions
that speed up the convergence time or make the estimation
robust to noise measurements are presented. Results on two
different cells of the same manufacturer and typology are
shown, focusing on the different behaviors of the estimation
due to different design choices
A new life estimation method for Lithium-ion batteries in Plug-in Hybrid Electric Vehicles applications
No full textThis paper presents a new approach to life estimation for lithium-ion batteries used in plug-in hybrid electric vehicles (PHEVs) applications. A new framework for battery life estimation is developed which investigates the effects of two primary factors of battery life reduction in PHEVs applications, namely, depth of discharge (DOD) and temperature (Tbatt), under typical driving conditions, driving habits, and average commute time of typical user over a year. This framework, whose development is built upon a weighted ampere-hour throughput model of the battery, is based on the novel concept of severity factor map which captures and quantifies the battery damage caused by different operating conditions. The proposed methodology can be a suitable tool to estimate battery life in terms of miles/year on-board of the vehicle
Pedaling Torque Reconstruction for Half Pedaling Sensor
No full textElectrically Power Assisted Cycles (EPACs) have
been gaining increasing attention worldwide during the past few
years. Market analysis show that cyclists prefer torque assisted
EPACs over velocity-based ones. A torque assisted cycle requires
an estimate or measurement of the cyclist torque, which
increases the cost and complexity of the set-up. Among the
viable solutions, sensors mounted on the pedal axis have several
advantages in terms of packaging and cost; unfortunately, they
are capable of measuring the torque exerted only on one pedal.
This paper deals with the development, implementation and
validation of two algorithms to estimate the entire revolution
torque using a half pedaling sensor. The algorithms are based
on the iso-power or iso-torque assumptions (checked on a highend
training bicycle). The algorithms are validated using road
measurements, showing that a sufficient level of accuracy for
EPAC is reached
Self-sustaining Strategy for a Hybrid Electric Bike
No full textElectrically Power Assisted Cycles (EPACs) have
been gaining attention as an efficient and clean means of
transportation. In this work, the concept of full hybrid bike
presented in previous research is further developed by
introducing a charge sustaining strategy. The main idea is to
consider the load-dependent efficiency of the cyclist and let the
electric motor assist the cyclist in low efficiency regions while
letting the cyclist recharge the battery in high efficiency
regions. To this end a State-of-Charge (SoC) controller is
designed. Its tuning is analyzed and compared in terms of
efficiency and feeling against the acausal strategy available in
the literature
Modeling and Online-Identification of Electrically Stimulated Antagonistic Muscles for Horizontal Shoulder Abduction and Adduction
No full textA comparison of two different models of a pair
of antagonistic muscles for horizontal shoulder abduction and
adduction is presented. The proposed models are based on
the so called Hill-model: a mechanical framework (inertia,
dampers and springs) is used for their development. The models
consider as inputs the estimates of the activation states of the
muscles based on digital filtering of the evoked electromyogram
(eEMG). Model outputs are angular velocity and position. Both
models show good results in terms of performance, but they
are different in terms of number of parameters that need
to be identified and in terms of physical interpretation. One
of the models, in fact, describes the muscle as a spring that
generates torque by changing its stiffness parameter depending
on its activation level. In order to enable adaptive modelbased
feed-forward and feedback control strategies for angular
position/velocity control, an online-identification method based
on an Extended Kalman Filter (EKF) is introduced for one of
the two models. Simulation and experimental results show the
good performance in terms of convergence time and accuracy
of the estimation
Oncological and Functional Outcomes of Radical Cystectomy and Orthotopic Bladder Replacement in Women. Editorial comment
No full textDuring the last decades, orthotopic bladder substitution (OBS) after radical cystectomy for bladder cancer in women has been increasingly proposed. Meanwhile, strict patient selection criteria, improved surgical techniques, long-term follow-up in large patient cohorts, and validated evaluation have defined the role of OBS in men. Several issues must be clarified in women: oncological outcome, complication rates, functional results, quality of life, and sexual function. As a matter of fact, the results of OBS in women are substantially unchanged in the last decade as stated in this paper.
From the oncological standpoint, the patient outcome seems objectively satisfactory but selection criteria are different in the published series. Fortunately, the problem of urethra recurrence seems less relevant in properly selected patients.
However several issues are still a matter of debate. Functional results in terms of continence and hypercontinence are still unsatisfactory because the optimal way to reconstruct the pelvic anatomy is still undefined. Early and late complication rates are poorly evaluated. Little data are also available about the quality of life and sexual function.
Validated evaluation criteria in a large patient cohort are needed to objectively evaluate the results and to improve the substantially unchanged results reported in last decade. It's time to move forward!!
Bicicletta a pedalata assistita elettricamente
No full textViene descritto un sistema elettronico (50) per
pilotare un dispositivo elettrico di una bicicletta
(1) assistita elettricamente per mezzo di una
batteria ricaricabile (6). Il dispositivo elettrico è
configurato per funzionare come un motore elettrico
alimentato dalla batteria o come un generatore
elettrico per caricare la batteria. Il sistema
comprende un modulo di misurazione (8) configurato
per misurare la velocità angolare (Sω_ped) dei pedali
della bicicletta e la coppia (Sτ_ped) dei pedali della
bicicletta, comprende un circuito (23) configurato
per rilevare uno stato di carica della batteria e
comprende un processore (20). Il processore è
configurato per calcolare una velocità della
bicicletta in funzione della velocità angolare del
motore elettrico, è configurato per calcolare (101)
una potenza dell’uomo (Pum) in funzione della coppia
misurata dei pedali della bicicletta e della velocità
angolare misurata dei pedali della bicicletta, è
configurato per stimare (101) una potenza d’attrito
(Pattr) della bicicletta in funzione della velocità
angolare del motore elettrico ed in funzione della
velocità della bicicletta, ed è configurato per
confrontare (101) la potenza dell’uomo calcolata
2
rispetto alla potenza d’attrito stimata della
bicicletta e controllare lo stato di carica della
batteria. Nel caso in cui viene rilevato che la
potenza dell’uomo calcolata è maggiore di o uguale
alla potenza d’attrito stimata della bicicletta e nel
caso in cui viene rilevato che lo stato di carica
della batteria è maggiore di o uguale ad una prima
soglia (Ssdc_min), il processore è tale da generare
(103) un valore di corrente di pilotaggio (ΔImot) per
pilotare il dispositivo elettrico funzionante come un
motore elettrico alimentato dalla batteria. Nel caso
in cui viene rilevato che la potenza dell’uomo
calcolata è minore della potenza d’attrito stimata
della bicicletta, il processore è tale da generare
(105) un altro valore di corrente di pilotaggio (Ichg)
per caricare la batteria dal dispositivo elettrico
funzionante come un generatore elettrico
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