Search results for "Server"

Robust Discrete-Time Lateral Control of Racecars by Unknown Input Observers

2023

This brief addresses the robust lateral control problem for self-driving racecars. It proposes a discrete-time estimation and control solution consisting of a delayed unknown input-state observer (UIO) and a robust tracking controller. Based on a nominal vehicle model, describing its motion with respect to a generic desired trajectory and requiring no information about the surrounding environment, the observer reconstructs the total force disturbance signal, resulting from imperfect knowledge of the time-varying tire-road interface characteristics, presence of other vehicles nearby, wind gusts, and other model uncertainty. Then, the controller actively compensates the estimated force and as…

A hybrid observer for localization from noisy inertial data and sporadic position measurements

2023

We propose an asymptotic position and speed observer for inertial navigation in the case where the position measurements are sporadic and affected by noise. We cast the problem in a hybrid dynamics framework where the continuous motion is affected by unknown continuous-time disturbances and the sporadic position measurements are affected by discrete-time noise. We show that the peculiar hybrid cascaded structure describing the estimation error dynamics is globally finite-gain exponentially ISS with gains depending intuitively on our tuning parameters. Experimental results, as well as the comparison with an Extended Kalman Filter (EKF), confirm the effectiveness of the proposed solution with…

Innovative Observers for Induction Motor Control

In this thesis the problem of designing observers and controllers for induction motors has been studied and thoroughly discussed using tools from the nonlinear system theory, both for analysis and control purposes. Useful techniques have been used to identify the machine parameters off-line. In the Introduction was dealt the design a control system for a drive of asynchronous machines that uses a voltage source inverter to generate the currents and voltages which carry the drive by making use of an observer of the state rotor variables. The used control algorithms is the \textit{field oriented control} (FOC). The model of the asynchronous induction motor is described starting from the mecha…

Mobile Interface for Content-Based Image Management

2010

People make more and more use of digital image acquisition devices to capture screenshots of their everyday life. The growing number of personal pictures raise the problem of their classification. Some of the authors proposed an automatic technique for personal photo album management dealing with multiple aspects (i. e., people, time and background) in a homogenous way. In this paper we discuss a solution that allows mobile users to remotely access such technique by means of their mobile phones, almost from everywhere, in a pervasive fashion. This allows users to classify pictures they store on their devices. The whole solution is presented, with particular regard to the user interface impl…

Why you trust in visual saliency

2015

Image understanding is a simple task for a human observer. Visual attention is automatically pointed to interesting regions by a natural objective stimulus in a first step and by prior knowledge in a second step. Saliency maps try to simulate human response and use actual eye-movements measurements as ground truth. An interesting question is: how much corruption in a digital image can affect saliency detection respect to the original image? One of the contributions of this work is to compare the performances of standard approaches with respect to different type of image corruptions and different threshold values on saliency maps. If the corruption can be estimated and/or the threshold is fi…

Bayesian Network Based Classification of Mammography Structured Reports

2013

In modern medical domain, documents are created directly in electronic form and stored on huge databases containing documents, text in integral form and images. Retrieving right informations from these servers is challenging and, sometimes, this is very time consuming. Current medical technology do not provide a smart methodology classification of such documents based on their content. In this work the radiological structured reports are analysed classified and assigning an appropriate label. The text classifier is used to label a mammographic structured report. The experimental data are real clinical report coming from a hospital server. Analysing the structured report content, the classif…

PDA -- Remote Display Interaction Framework

2008

This paper discusses the design of a PDA-driven remote display control system which was designed for a pervasive computing scenario. Our solution enables a PDA to perform as an interaction device (such as keyboard or mouse) to operate applications which are using remote displays. Our system consists of two components: one devoted to pair users and remote display according to their relative position, and one to provide the PDA with appropriate graphical interfaces and ad-hoc communication protocols. Besides a case study on the use of remote displays during a course with in our department, this paper discusses system highlights, components, and experiments as for standard multimedia and offic…

A Multichannel Information System to Build and Deliver Rich User-Experiences in Exhibits and Museums

2011

In this article a multichannel information system to build and deliver rich user experiences in exhibits and museums is presented. The system was designed to use information about a particular exhibit or museum while delivering a wide user experience based on different distribution channels. The overall information is used to build different solutions that can be delivered simultaneously on different media from touch-screen installations to portable devices like smart phones. Moreover, all the devices signed in the environment are able to communicate to each others to increase the level of the usability of the system. A case study and analysis of experimental results are also provided.

An Evolution of the Non-Parameter Harris Affine Corner Detector: A Distributed Approach

2009

A parallel version of a new automatic Harris-based corner detector is presented. A scheduler to dynamically and homogeneously distribute high computational workload on heterogeneous parallel architectures such as Grid systems has been implemented to speedup the whole procedure. Experimental results show the robustness of the underlying scheduler, which can be easily exploited in various automatic image analysis systems.

Observer-based finite-time fuzzy H∞ control for discrete-time systems with stochastic jumps and time-delays

2014

This paper is concerned with the problem of observer-based finite-time H ∞ control for a family of discrete-time Markovian jump nonlinear systems with time-delays represented by Takagi-Sugeno (T-S) model. The main contribution of this paper is to design an observer-based finite-time H ∞ controller such that the resulting closed-loop system is stochastic finite-time bounded and satisfies a prescribed H ∞ disturbance attenuation level over the given finite-time interval. Sufficient criteria on stochastic finite-time H ∞ stabilization via observer-based fuzzy state feedback are presented for the solvability of the problem, which can be tackled by a feasibility problem in terms of linear matrix…