371 research outputs found

    The Simulation Model of Vehicle's Control Systems

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    Tato bakalářská práce se zabývá modelováním systémů pro řízení vozidla s využitím prostředí Mathworks Matlab/Simulink. První kapitoly jsou věnovány teoretické rešerši z oblasti řídicích prvků automobilu. Jsou zde popsány systémy, kterými řidič ovlivňuje chod vozidla. Další část práce obsahuje modelování a simulace těchto systémů. Cílem této bakalářské práce je seznámení s jednotlivými řídicími systémy, jejich modelováním v softwarovém programu a porovnání výsledků získaných na modelu, s výsledky z reálných měření na vozidle.This bachelor thesis deals with modelling of vehicle’s control systems in software program Matlab-Simulink. First parts of the work are dedicated to a theoretical research of vehicle control systems. There are descripted systems that can be affected by a driver. Second part is aimed to modelling and simulating these systems. The main purpose of this work is to get informations about modelling vehicle control systems and comparing simulation results with measurements on the real vehicle.430 - Katedra elektronikyvelmi dobř

    Different view on PQ theory used in the control algorithm of active power filters

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    The improvement of power quality is a frequently discussed issue, which still requires a considerable research effort to be devoted to the study of the problem. The aim of this paper is to describe some problems related to the control of switching compensators, commonly known as active power filters. It also includes some shortcomings of pq theory regarded as three phase instantaneous power theory. The term “shortcomings” means that the pq theory does not provide a proper description of power properties. Moreover the control algorithm based on this theory only achieves satisfactory results for sinusoidal balanced voltage system. Nevertheless it can still be considered a helpful approach to the problem under study. The simulation results presented in this paper illustrate the weaknesses of the pq theory

    Genuine converging solution of self-consistent field equations for extended many-electron systems

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    Calculations of the ground state of inhomogeneous many-electron systems involve a solving of the Poisson equation for Coulomb potential and the Schroedinger equation for single-particle orbitals. Due to nonlinearity and complexity this set of equations, one believes in the iterative method for the solution that should consist in consecutive improvement of the potential and the electron density until the self-consistency is attained. Though this approach exists for a long time there are two grave problems accompanying its implementation to infinitely extended systems. The first of them is related with the Poisson equation and lies in possible incompatibility of the boundary conditions for the potential with the electron density distribution. The analysis of this difficulty and suggested resolution are presented for both infinite conducting systems in jellium approximation and periodic solids. It provides the existence of self-consistent solution for the potential at every iteration step due to realization of a screening effect. The second problem results from the existence of continuous spectrum of Hamiltonian eigenvalues for unbounded systems. It needs to have a definition of Hilbert space basis with eigenfunctions of continuous spectrum as elements, which would be convenient in numerical applications. The definition of scalar product specifying the Hilbert space is proposed that incorporates a limiting transition. It provides self-adjointness of Hamiltonian and, respectively, the orthogonality of eigenfunctions corresponding to the different eigenvalues. In addition, it allows to normalize them effectively to delta-function and to prove in the general case the orthogonality of the 'right' and 'left' eigenfunctions belonging to twofold degenerate eigenvalues.Comment: 12 pages. Reported on Interdisciplinary Workshop "Nonequilibrium Green's Functions III", August 22 - 26, 2005, University Kiel, Germany. To be published in Journal of Physics: Conference Series, 2006; Typos in Eqs. (37), (53) and (54) are corrected. The content of the footnote is changed. Published version available free online at http://www.iop.org/EJ/abstract/1742-6596/35/1/01

    A cryogenic rotation stage with a large clear aperture for the half-wave plates in the Spider instrument

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    We describe the cryogenic half-wave plate rotation mechanisms built for and used in Spider, a polarization-sensitive balloon-borne telescope array that observed the Cosmic Microwave Background at 95 GHz and 150 GHz during a stratospheric balloon flight from Antarctica in January 2015. The mechanisms operate at liquid helium temperature in flight. A three-point contact design keeps the mechanical bearings relatively small but allows for a large (305 mm) diameter clear aperture. A worm gear driven by a cryogenic stepper motor allows for precise positioning and prevents undesired rotation when the motors are depowered. A custom-built optical encoder system monitors the bearing angle to an absolute accuracy of +/- 0.1 degrees. The system performed well in Spider during its successful 16 day flight.Comment: 11 pages, 7 figures, Published in Review of Scientific Instruments. v2 includes reviewer changes and longer literature revie

    Design and Implementation of Programmable Control Unit for the Central Electronics System of the Electric Car Biro

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    ZIGMUND, K.: Návrh a realizace integrace programovatelné řídicí jednotky pro systém centrální elektroniky automobilu s elektrickým pohonem Biro. Ostrava, 2020. Diplomová práce. Vysoká škola báňská – Technická univerzita Ostrava. Vedoucí diplomové práce Ing. Petr Šimoník, Ph.D. Tato diplomová práce se zabývá analýzou systému centrální elektroniky elektrického vozidla Biro, návrhem a praktickou realizací integrace programovatelné řídicí jednotky na tomto vozidle. První část práce je věnována teoretické rešerši, která má za úkol poskytnout čtenáři základní přehled o použité elektronice ve vozidle a způsobu jejího zapojení. Popisuje analýzu, která je nutná pro postup návrhu a praktické realizace integrace. V další kapitole je popsán samotný návrh a integrace programovatelné řídicí jednotky. V této části práce jsou shrnuty vlastnosti vytipované programovatelné řídicí jednotky společnosti Pi Innovo. Třetí kapitola práce je věnována popisu následné tvorby softwaru jednotky v prostředí Matlab-Simulink. Závěrečná část se zabývá experimentálnímu ověření funkčnosti elektroniky vozidla.ZIGMUND, K.: Design and Implementation of Programmable Control Unit for the Central Electronics System of the Electric Car Biro. Ostrava, 2020. Diploma thesis. VŠB – Technical University of Ostrava. Thesis supervisor Ing. Petr Šimoník Ph.D. This diploma thesis deals with an analysis of central electronics of the electric vehicle Biro, design and practical realisation of integration of the programmable control unit on this vehicle. The first section is dedicated to the theoretical searches, which aims to provide basic overview about used electronics in the vehicle. Reader there can find how the system is connected, information about analysis of system behaviour. All these parts are necessary to be able do next steps of this thesis. The next chapter describes the design and integration of the programmable control unit. There are described programmable control unit properties too. Third chapter of the thesis tells reader how was model-based software made in Matlab-Simulink. Final chapter is devoted to experimental test of all functions.430 - Katedra elektronikyvelmi dobř

    Relating therapy for voices (the R2V study): study protocol for a pilot randomized controlled trial

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    Background Evidence exists for the effectiveness of cognitive behaviour therapy for psychosis with moderate effect sizes, but the evidence for cognitive behaviour therapy specifically for distressing voices is less convincing. An alternative symptom-based approach may be warranted and a body of literature has explored distressing voices from an interpersonal perspective. This literature has informed the development of relating therapy and findings from a case series suggested that this intervention was acceptable to hearers and therapists. Methods/Design An external pilot randomized controlled trial (RCT) comparing outcomes for 15 patients receiving 16 hours (weekly sessions of one hour) of relating therapy and their usual treatment with 15 patients receiving only their usual treatment. Participants will be assessed using questionnaires at baseline, 16 weeks (post-intervention), and 36 weeks (follow-up). Discussion Expected outcomes will include a refined study protocol and an estimate of the effect size to inform the sample size of a definitive RCT. If evidence from a fully powered RCT suggests that relating therapy is effective, the therapy will extend the range of evidence-based psychological therapies available to people who hear distressing voices

    Proposta de implantação de um programa da qualidade em uma indústria de embalagens plásticas

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    Orientador : João Carlos da CunhaProjeto técnico (especialização) - Universidade Federal do Paraná, Setor de Ciências Sociais Aplicadas. Curso de Especialização em Gestão da QualidadeInclui referência

    Pointing control for the SPIDER balloon-borne telescope

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    We present the technology and control methods developed for the pointing system of the SPIDER experiment. SPIDER is a balloon-borne polarimeter designed to detect the imprint of primordial gravitational waves in the polarization of the Cosmic Microwave Background radiation. We describe the two main components of the telescope's azimuth drive: the reaction wheel and the motorized pivot. A 13 kHz PI control loop runs on a digital signal processor, with feedback from fibre optic rate gyroscopes. This system can control azimuthal speed with < 0.02 deg/s RMS error. To control elevation, SPIDER uses stepper-motor-driven linear actuators to rotate the cryostat, which houses the optical instruments, relative to the outer frame. With the velocity in each axis controlled in this way, higher-level control loops on the onboard flight computers can implement the pointing and scanning observation modes required for the experiment. We have accomplished the non-trivial task of scanning a 5000 lb payload sinusoidally in azimuth at a peak acceleration of 0.8 deg/s2^2, and a peak speed of 6 deg/s. We can do so while reliably achieving sub-arcminute pointing control accuracy.Comment: 20 pages, 12 figures, Presented at SPIE Ground-based and Airborne Telescopes V, June 23, 2014. To be published in Proceedings of SPIE Volume 914

    Feasibility of trial procedures for a randomised controlled trial of a community based group exercise intervention for falls prevention for visually impaired older people: the VIOLET study

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    Background Visually impaired older people (VIOP) have a higher risk of falling than their sighted peers, and are likely to avoid physical activity. The aim was to adapt the existing Falls Management Exercise (FaME) programme for VIOP, delivered in the community, and to investigate the feasibility of conducting a definitive randomised controlled trial (RCT) of this adapted intervention. Methods Two-centre randomised mixed methods pilot trial and economic evaluation of the adapted group-based FaME programme for VIOP versus usual care. A one hour exercise programme ran weekly over 12 weeks at the study sites (Newcastle and Glasgow), delivered by third sector (voluntary and community) organisations. Participants were advised to exercise at home for an additional two hours over the week. Those randomised to the usual activities group received no intervention. Outcome measures were completed at baseline, 12 and 24 weeks. The potential primary outcome was the Short Form Falls Efficacy Scale – International (SFES-I). Participants’ adherence was assessed by reviewing attendance records and self-reported compliance to the home exercises. Adherence with the course content (fidelity) by instructors was assessed by a researcher. Adverse events were collected in a weekly phone call. Results Eighteen participants, drawn from community-living VIOP were screened; 68 met the inclusion criteria; 64 participants were randomised with 33 allocated to the intervention and 31 to the usual activities arm. 94% of participants provided data at the 12 week visit and 92% at 24 weeks. Adherence was high. The intervention was found to be safe with 76% attending nine or more classes. Median time for home exercise was 50 min per week. There was little or no evidence that fear of falling, balance and falls risk, physical activity, emotional, attitudinal or quality of life outcomes differed between trial arms at follow-up. Conclusions The intervention, FaME, was implemented successfully for VIOP and all progression criteria for a main trial were met. The lack of difference between groups on fear of falling was unsurprising given it was a pilot study but there may have been other contributory factors including suboptimal exercise dose and apparent low risk of falls in participants. These issues need addressing for a future trial

    Evaluating rehabilitation following lumbar fusion surgery (REFS): study protocol for a randomised controlled trial

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    BACKGROUND: The rate of lumbar fusion surgery (LFS) is increasing. Clinical recovery often lags technical outcome. Approximately 40% of patients undergoing LFS rate themselves as symptomatically unchanged or worse following surgery. There is little research describing rehabilitation following LFS with no clear consensus as to what constitutes the optimum strategy. It is important to develop appropriate rehabilitation strategies to help patients manage pain and recover lost function following LFS. METHODS/DESIGN: The study design is a randomised controlled feasibility trial exploring the feasibility of providing a complex multi-method rehabilitation intervention 3 months following LFS. The rehabilitation protocol that we have developed involves small participant groups of therapist led structured education utilising principles of cognitive behavioral therapy (CBT), progressive, individualised exercise and peer support. Participants will be randomly allocated to either usual care (UC) or the rehabilitation group (RG). We will recruit 50 subjects, planning to undergo LFS, over 30 months. Following LFS all participants will experience normal care for the first 3 months. Subsequent to a satisfactory 3 month surgical review they will commence their allocated post-operative treatment (RG or UC). Data collection will occur at baseline (pre-operatively), 3, 6 and 12 months post-operatively. Primary outcomes will include an assessment of feasibility factors (including recruitment and compliance). Secondary outcomes will evaluate the acceptability and characteristics of a limited cluster of quantitative measures including the Oswestry Disability Index (ODI) and an aggregated assessment of physical function (walking 50 yards, ascend/descend a flight of stairs). A nested qualitative study will evaluate participants' experiences. DISCUSSION: This study will evaluate the feasibility of providing complex, structured rehabilitation in small groups 3 months following technically successful LFS. We will identify strengths and weakness of the proposed protocol and the usefulness and characteristics of the planned outcome measures. This will help shape the development of rehabilitation strategies and inform future work aimed at evaluating clinical efficacy. TRIAL REGISTRATION: ISRCTN60891364, 10/07/2014
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