Search results for "Inertia"

2020

Gait variability observed in step duration is predictive of impending adverse health outcomes among apparently healthy older adults and could potentially be evaluated using wearable sensors (inertial measurement units, IMU). The purpose of the present study was to establish the reliability and concurrent validity of gait variability and complexity evaluated with a waist and an ankle-worn IMU. Seventeen women (age 74.8 (SD 44) years) and 10 men (73.7 (4.1) years) attended two laboratory measurement sessions a week apart. Their stride duration variability was concurrently evaluated based on a continuous 3 min walk using a force plate and a waist- and an ankle-worn IMU. Their gait complexity (…

Constant Power Model in Arm Rotation—A New Approach to Hill’s Equation

2014

The purpose of this study was to further develop the constant power model of a previous study and to provide the final solution of Hill’s force-velocity equation. Forearm and whole arm rotations of three different subjects were performed downwards (elbow and shoulder extension) and upwards (elbow and shoulder flexion) with maximum velocity. These arm rotations were recorded with a special camera system and the theoretically derived model of constant maximum power was fitted to the experimentally measured data. The moment of inertia of the arm sectors was calculated using immersion technique for determining accurate values of friction coefficients of elbow and whole arm rotations. The experi…

Real Time Localization Systems for autonomous navigation: Modelling, Analysis and Control

2021

Questo lavoro di tesi riguarda la derivazione di osservatori ibridi dello stato, analisi e controllo, di sistemi di localizzazione e navigazione in tempo reale (RTLS). In particolare, il framework dei sistemi ibridi è stato utilizzato per tener conto delle dinamiche continue e discrete coinvolte nel processo di stima e della natura sporadica e tempo randomica delle misure provenienti da vari sensori di distanza e/o inerziali. Analisi di convergenza sono state effettuate per dimostrare la stabilità delle soluzioni proposte e la capacità di filtraggio dei rumori presenti nelle misure. Il presente lavoro è corredato dai risultati delle prove sperimentali di laboratorio a conferma della validit…

Previsione delle prestazioni del veicolo su strada: stato dell’arte

2016

Questo lavoro contiene una rassegna dei metodi che sono usati per la previsione delle prestazioni del veicolo su strada, in dipendenza del motore installato. La prima parte mostra il calcolo delle resistenze al moto, cioè le forze che il veicolo deve vincere per avanzare sulle strade piane e in salita. Particolarmente interessante appare la parte che riguarda la resistenza aerodinamica, della quale si tratta di metodi sperimentali (galleria del vento), metodi empirici e metodi CFD. Si propone inoltre l’applicazione della norma CUNA sulla velocità per la determinazione dei consumi anche al calcolo dei coefficienti aerodinamici. La rassegna esclude la resistenza accidentale in curva perché no…

Assessing the performance of different model-based techniques to estimate water content in the upper soil layer

2016

he knowledge of soil water content (SWC) of the upper soil layer is important for most hydrological processes occurring over vegetated areas and under dry climate. Because direct field measurements of SWC are difficult, the use of different type of sensors and model-based approaches have been proposed and extensively used during the last decade. The main objective of this work is to assess the performance of two models estimating SWC of the upper soil layer: the transient line heat source method and the physically based Hydrus-1D model. The models' performance is assessed using field measurements acquired through a Time Domain Reflectometer (TDR). The experiment was carried out on an olive …

miMic

2016

miMic, a sonic analogue of paper and pencil is proposed: An augmented microphone for vocal and gestural sonic sketching. Vocalizations are classified and interpreted as instances of sound models, which the user can play with by vocal and gestural control. The physical device is based on a modified microphone, with embedded inertial sensors and buttons. Sound models can be selected by vocal imitations that are automatically classified, and each model is mapped to vocal and gestural features for real-time control. With miMic, the sound designer can explore a vast sonic space and quickly produce expressive sonic sketches, which may be turned into sound prototypes by further adjustment of model…

Mapping soil water content under sparse vegetation and changeable sky conditions: comparison of two thermal inertia approaches

2013

A critical analysis of a thermal inertia approach to map surface soil water content on bare and sparsely vegetated soils by means of remotely sensed data is reported. The study area is an experimental field located in Barrax, Spain. In situ data were acquired within the Barrax 2011 research project. An advanced hyperspectral scanner airborne imager provides images in the visible/near-infrared and thermal infrared bands. Images were acquired both in day and night times by the Instituto Nacional de Técnica Aeroespacial between 12th and 13th of June 2011. The scene covers a corn irrigation pivot surrounded by bare soil, where a set of in situ data have been collected both previously and simult…

Engine/Transmission Matching

2014

This chapter deals with the forecasting of vehicle performance on the road, according to the installed engine. It begins with Section 1, which shows the calculation of the resistance to motion, that is, the forces that the vehicle must overcome to advance on flat roads and uphill. The calculation excludes accidental resistance in curves because it is not essential for predicting the behavior of the vehicle on the road. Section 2 begins with the power characteristic, the forecast by traction–speed and power–speed diagrams, calculation of gear ratios, and then passing to the limits to the estimated acceleration, feature consumption, and distance. This chapter concludes with a section on the d…

Vegetation Patterns in the Hyperbolic Klausmeier Model with Secondary Seed Dispersal

2023

This work focuses on the dynamics of vegetation stripes in sloped semi-arid environments in the presence of secondary seed dispersal and inertial effects. To this aim, a hyperbolic generalization of the Klausmeier model that encloses the advective downhill transport of plant biomass is taken into account. Analytical investigations were performed to deduce the wave and Turing instability loci at which oscillatory and stationary vegetation patterns arise, respectively. Additional information on the possibility of predicting a null-migrating behavior was extracted with suitable approximations of the dispersion relation. Numerical simulations were also carried out to corroborate theoretical pre…

Sensitivity Analysis and Frequency Dynamics of Grid-Connected Converters with Virtual Inertia

2021

For the participation in the frequency control of the system, power converters can be controlled with different strategies and methods, sharing the common concept of virtual inertia capability. In this work, a sensitivity analysis of two main categories of converter controls with virtual inertia is presented. The considered schemes are a grid-following current vector control with additional virtual inertia block and a grid-forming control scheme based on virtual synchronous machine concept. A proper basis for the comparison is first assessed providing an analytical correlation between the control parameters of the two schemes. For the two control strategies, the sensitivity analysis of the …