Feedback vibration control of a base-isolated building with delayed measurements using h∞ techniques

n this paper we address the problem of vibration reduction of buildings with delayed measurements, where the delays are time-varying and bounded. We focus on a convex optimization approach to the problem of state-feedback H ∞ control design. An appropriate Lyapunov-Krasovskii functional and some free weighting matrices are used to establish some delay-range-dependent sufficient conditions for the design of desired controllers in terms of linear matrix inequalities (LMIs). The controller, which guarantees asymptotic stability and an H ∞ performance, simultaneously, for the closed-loop system of the structure, is then developed. The performance of the controller is evaluated through the simulation of an n-story base-isolated building

Static Output-Feedback Control for Vehicle Suspensions: A Single-Step Linear Matrix Inequality Approach

In this paper, a new strategy to design static output-feedback controllers for a class of vehicle suspension systems is presented. A theoretical background on recent advances in output-feedback control is first provided, which makes possible an effective synthesis of static output-feedback controllers by solving a single linear matrix inequality optimization problem. Next, a simplified model of a quarter-car suspension system is proposed, taking the ride comfort, suspension stroke, road holding ability, and control effort as the main performance criteria in the vehicle suspension design. The new approach is then used to design a static output-feedback H∞ controller that only uses the suspension deflection and the sprung mass velocity as feedback information. Numerical simulations indicate that, despite the restricted feedback information, this static output-feedback H∞ controller exhibits an excellent behavior in terms of both frequency and time responses, when compared with the corresponding state-feedback H∞ controller

Optimal design of complex passive-damping systems for vibration control of large structures: An energy-to-peak approach

Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2014/510236 Open AccessWe present a new design strategy that makes it possible to synthesize decentralized output-feedback controllers by solving two successive optimization problems with linear matrix inequality (LMI) constraints. In the initial LMI optimization problem, two auxiliary elements are computed: a standard state-feedback controller, which can be taken as a reference in the performance assessment, and a matrix that facilitates a proper definition of the main LMI optimization problem. Next, by solving the second optimization problem, the output-feedback controller is obtained. The proposed strategy extends recent results in static output-feedback control and can be applied to design complex passive-damping systems for vibrational control of large structures. More precisely, by taking advantages of the existing link between fully decentralized velocity-feedback controllers and passive linear dampers, advanced active feedback control strategies can be used to design complex passive-damping systems, which combine the simplicity and robustness of passive control systems with the efficiency of active feedback control. To demonstrate the effectiveness of the proposed approach, a passive-damping system for the seismic protection of a five-story building is designed with excellent results

Safety culture maturity assessment for mining activities in South America

BACKGROUND:Health and safety is a crucial issue in the mining industry due to the implication of accidents in the sector. OBJECTIVE:This study determines the safety culture characteristics in several mining activities from South America. METHODS:A survey of the safety culture maturity has been done by means of 24 questions regarding the type of activity, number of employees and safety culture characteristics of the activity: information of accidents and incidents, organizational structure to deal with information, involvement of the company in health and safety issues, the way it communicates accidents and incidents and commitment of the company towards health and safety. RESULTS:The questionnaire was completed by 62 managers from Bolivia, Peru and Colombia. Results show different behaviors depending on the type of company, Artisanal or Large-Scale Mines, ASM and LSM respectively. LSM show a level of maturity according to the size of the company, while ASM does not have a clear trend in terms of size, even though there is a relationship between employees and safety culture maturity. In addition, a remarkable difference can be seen between activities with and without continuous improvement systems implemented. CONCLUSIONS:Large scale mining improves their level of safety culture as the size of the company increases, because procedures and control systems are implemented. Cooperatives or small companies also achieve substantial gains when they introduce similar systems

Feedback vibration control of a base-isolated building with delayed measurements using h∞ techniques

Published version of a paper presented at the American Control Conference (ACC), 2010. (c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other worksn this paper we address the problem of vibration reduction of buildings with delayed measurements, where the delays are time-varying and bounded. We focus on a convex optimization approach to the problem of state-feedback H ∞ control design. An appropriate Lyapunov-Krasovskii functional and some free weighting matrices are used to establish some delay-range-dependent sufficient conditions for the design of desired controllers in terms of linear matrix inequalities (LMIs). The controller, which guarantees asymptotic stability and an H ∞ performance, simultaneously, for the closed-loop system of the structure, is then developed. The performance of the controller is evaluated through the simulation of an n-story base-isolated building

Child–robot interactions using educational robots: an ethical and inclusive perspective

This research was funded by the Spanish Ministerio de Ciencia e Innovación under Grant FECYT FCT-20-15626, Line of action 2. Education and scientific vocations (2nd place out of 120 awarded).Peer ReviewedObjectius de Desenvolupament Sostenible::5 - Igualtat de GènereObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraObjectius de Desenvolupament Sostenible::4 - Educació de QualitatObjectius de Desenvolupament Sostenible::10 - Reducció de les DesigualtatsPostprint (published version

Child-Robot Interactions Using Educational Robots : An Ethical and Inclusive Perspective

The Qui-Bot H2O project involves developing four educational sustainable robots and their associated software. Robots are equipped with HRI features such as voice recognition and color sensing, and they possess a humanoid appearance. The project highlights the social and ethical aspects of robotics applied to chemistry and industry 4.0 at an early age. Here, we report the results of an interactive study that involved 212 students aged within the range of 3-18. Our educational robots were used to measure the backgrounds, impact, and interest of students, as well as their satisfaction after interacting with them. Additionally, we provide an ethical study of the use of these robots in the classroom and a comparison of the interactions of humanoid versus non-humanoid educational robots observed in early childhood learning. Our findings demonstrate that these robots are useful in teaching technical and scientific concepts in a playful and intuitive manner, as well as in increasing the number of girls who are interested in science and engineering careers. In addition, major impact measures generated by the project within a year of its implementation were analyzed. Several public administrations in the area of gender equality endorsed and participated in the Qui-Bot H2O project in addition to educational and business entities