Search results for "Bust"

Trajectory robust control of autonomous quadcopters based on model decoupling and disturbance estimation

2021

In this article, a systematic procedure is given for determining a robust motion control law for autonomous quadcopters, starting from an input–output linearizable model. In particular, the suggested technique can be considered as a robust feedback linearization (FL), where the nonlinear state-feedback terms, which contain the aerodynamic forces and moments and other unknown disturbances, are estimated online by means of extended state observers. Therefore, the control system is made robust against unmodelled dynamics and endogenous as well as exogenous disturbances. The desired closed-loop dynamics is obtained by means of pole assignment. To have a feasible control action, that is, the fo…

Wind gust estimation for precise quasi-hovering control of quadrotor aircraft

2021

Abstract This paper focuses on the control of quadrotor vehicles without wind sensors that are required to accurately track low-speed trajectories in the presence of moderate yet unknown wind gusts. By modeling the wind disturbance as exogenous inputs, and assuming that compensation of its effects can be achieved through quasi-static vehicle motions, this paper proposes an innovative estimation and control scheme comprising a linear dynamic filter for the estimation of such unknown inputs and requiring only position and attitude information. The filter is built upon results from Unknown Input Observer theory and allows estimation of wind and vehicle state without measurement of the wind its…

On using novel “Anti-Bayesian” techniques for the classification of dynamical data streams

2017

The classification of dynamical data streams is among the most complex problems encountered in classification. This is, firstly, because the distribution of the data streams is non-stationary, and it changes without any prior “warning”. Secondly, the manner in which it changes is also unknown. Thirdly, and more interestingly, the model operates with the assumption that the correct classes of previously-classified patterns become available at a juncture after their appearance. This paper pioneers the use of unreported novel schemes that can classify such dynamical data streams by invoking the recently-introduced “Anti-Bayesian” (AB) techniques. Contrary to the Bayesian paradigm, that compare…

Predictive modeling of aryl hydrocarbon receptor (AhR) agonism

2020

Abstract The aryl hydrocarbon receptor (AhR) plays a key role in the regulation of gene expression in metabolic machinery and detoxification systems. In the recent years, this receptor has attracted interest as a therapeutic target for immunological, oncogenic and inflammatory conditions. In the present report, in silico and in vitro approaches were combined to study the activation of the AhR. To this end, a large database of chemical compounds with known AhR agonistic activity was employed to build 5 classifiers based on the Adaboost (AdB), Gradient Boosting (GB), Random Forest (RF), Multilayer Perceptron (MLP) and Support Vector Machine (SVM) algorithms, respectively. The built classifier…

An LMI approach to quantized H<inf>∞</inf> control of uncertain linear systems with network-induced delays

2010

This paper deals with a convex optimization approach to the problem of robust network-based H ∞ control for linear systems connected over a common digital communication network with norm-bounded parameter uncertainties. Firstly, we investigate the effect of both the output quantization levels and the network conditions under static quantizers. Secondly, by introducing a descriptor technique, using Lyapunov-Krasovskii functional and a suitable change of variables, new required sufficient conditions are established in terms of delay-range-dependent linear matrix inequalities for the existence of the desired network-based quantized controllers with simultaneous consideration of network induced…

Structure evolution and reaction mechanism in the Ni/Al reactive multilayer nanofoils

2014

Abstract The extremely rapid gasless reactions in binary Ni/Al reactive multilayer nanofoils (RMNFs) are investigated both experimentally and theoretically. The quenching technique is used to study the dynamics of structural transformation on the micro- and nanoscales. The experimentally obtained patterns of structural evolution related to the heterogeneous reactions are compared with the results of molecular dynamics simulations carried out for the same reactive system. Based on the obtained data, the intrinsic mechanism of the reaction in Ni/Al RMNF is considered, which adequately explains the unusual parameters of a gasless combustion wave in such a system.

Experimental characterization of the RFID STENTag for passive vascular monitoring

2012

The possibility to monitor biological process in evolution and in particular the state of implanted devices such as vascular stent, has been recently proposed as one of the most challenging and fascinating application of the RFID passive technology. However, several issues are still in question and need to be analyzed in order to evaluate the real medical and sensing effectiveness of the proposed implantable radio sensor. The aim of this work is to experimentally evaluate the robustness of the RFID platform, its accuracy and its reproducibility as well as the effectiveness of the proposed sensing approach in term of human variability and pathology evolution.

SHEET STAMPING PROCESSES DESIGN: OPTIMIZATION METHODOLOGIES FOR ROBUST AND ENVIRONMENTAL CONSCIUS DECISION.

2012

Use of Reinforcement Learning in Two Real Applications

2008

In this paper, we present two sucessful applications of Reinforcement Learning (RL) in real life. First, the optimization of anemia management in patients undergoing Chronic Renal Failure is presented. The aim is to individualize the treatment (Erythropoietin dosages) in order to stabilize patients within a targeted range of Hemoglobin (Hb). Results show that the use of RL increases the ratio of patients within the desired range of Hb. Thus, patients' quality of life is increased, and additionally, Health Care System reduces its expenses in anemia management. Second, RL is applied to modify a marketing campaign in order to maximize long-term profits. RL obtains an individualized policy depe…

Shifting of wrapped phase maps in the frequency domain using a rational number

2016

The number of phase wraps in an image can be either reduced, or completely eliminated, by transforming the image into the frequency domain using a Fourier transform, and then shifting the spectrum towards the origin. After this, the spectrum is transformed back to the spatial domain using the inverse Fourier transform and finally the phase is extracted using the arctangent function. However, it is a common concern that the spectrum can be shifted only by an integer number, meaning that the phase wrap reduction is often not optimal. In this paper we propose an algorithm than enables the spectrum to be frequency shifted by a rational number. The principle of the proposed method is confirmed b…