A nonnegative matrix A is called primitive if A(k) is positive for some integer k > 0. A generalization by Protasov and Voynov (2012) of this concept to finite sets of matrices is as follows;a set of matrices, M = ...
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A nonnegative matrix A is called primitive if A(k) is positive for some integer k > 0. A generalization by Protasov and Voynov (2012) of this concept to finite sets of matrices is as follows;a set of matrices, M = {A(1), A(2), ..., A(m)} is primitive if A(i1)A(i2) ... A(ik) is positive for some indices i(1), i(2), ..., i(k). The concept of primitive sets of matrices comes up in a number of problems within the study of discrete-time switched systems. In this paper, we analyze the computational complexity of deciding if a given set of matrices is primitive and we derive bounds on the length of the shortest positive product. We show that while primitivity is algorithmically decidable, unless P = NP it is not possible to decide primitivity of a matrix set in polynomial time. Moreover, we show that the length of the shortest positive sequence can be superpolynomial in the dimension of the matrices. On the other hand, defining P to be the set of matrices with no zero rows or columns, we give a combinatorial proof of the Protasov-Voynov characterization (2012) of primitivity for matrices in P which can be tested in polynomial time. This latter observation is related to the well-known 1964 conjecture of Cerny on synchronizing automata;in fact, any bound on the minimal length of a synchronizing word for synchronizing automata immediately translates into a bound on the length of the shortest positive product of a primitive set of matrices in P. In particular, any primitive set of n x n matrices in P has a positive product of length O(n(3)). (C) 2015 Elsevier Ltd. All rights reserved.
The ever growing demand and socio-economic development, the conventional energy sources have almost become obsolete for nurturing this demand. Thus opening new avenues to search for the non-conventional sources. Photo...
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ISBN:
(纸本)9781467365406
The ever growing demand and socio-economic development, the conventional energy sources have almost become obsolete for nurturing this demand. Thus opening new avenues to search for the non-conventional sources. Photovoltaic is inexhaustible, renewable and non-polluting, so it is worth saying that it is one of the prospective solution for this crisis. But, having these benefits does not solve the problem as the efficiency is dependent on various factors such as irradiance, cell temperature, dust, sunlight's spectral density. Photovoltaic is a non-conventional and environment friendly technique which still has various challenges to overcome. This paper proposes an impressive Maximum Power Point Tracking (MPPT) algorithm using Fuzzy Logic in MATLAB-Simulink module alongside an analytical study with the traditional approach. This improvised MPPT technique reduces the tracking time and also solves the various issues associated with traditional MPPT algorithms such as Perturb and Observe, Incremental Conductance. The method involves as Fuzzy Logic controller which controls the switching of the DC-DC Boost Converter. In this paper the fuzzy logic MPPT controller is tested against variable irradiance, and temperature. Various performance indicators have been listed for the proposed MPPT. Fuzzy logic provide user with complete flexibility to choose the inputs and their relationship (rule base). The simulated results show that the fuzzy logic technique controls the integrated PV module output directly and rapidly. Thus showing the effectiveness and feasibility of the proposed controller.
The topic of this paper is the analysis of a control system for a semi active rear suspension in an off-road 2-wheel vehicle. Several control methods are studied, as well as the recently proposed Frequency Estimation ...
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ISBN:
(纸本)9781628415346
The topic of this paper is the analysis of a control system for a semi active rear suspension in an off-road 2-wheel vehicle. Several control methods are studied, as well as the recently proposed Frequency Estimation Based (FEB) algorithm. The test motorcycle dynamics, as well as the passive, semi active, and the algorithm controlled shock absorber models are loaded into BikeSim, a professional two-wheeled vehicle simulation software, and tested in several road conditions. The results show a detailed comparison of the theoretical performance of the different control approaches in a novel environment for semi active dampers.
This paper describes the switching algorithms for single phase matrix converter (switching logic for matrix converter). There is shown two basic methods of the control of the switches in the matrix converter and these...
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ISBN:
(纸本)9788026103868
This paper describes the switching algorithms for single phase matrix converter (switching logic for matrix converter). There is shown two basic methods of the control of the switches in the matrix converter and these modifications (and combining algorithm). First method needs the knowledge of the polarity of the output current of the converter and the second method needs the knowledge of the polarity of the input voltage.
We investigate the control of stochastic evolutionary games on networks, in which each edge represents a two-player repeating game between neighboring agents. The games occur simultaneously at each time step, after wh...
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We investigate the control of stochastic evolutionary games on networks, in which each edge represents a two-player repeating game between neighboring agents. The games occur simultaneously at each time step, after which the agents can update their strategies based on local payoff and strategy information, while a subset of agents can be assigned strategies and thus serve as control inputs. We seek here the smallest set of control agents that will guarantee convergence of the network to a desired strategy state. After deriving an exact solution that is too computationally complex to be practical on large networks, we present a hierarchical approximation algorithm, which we show computes the optimal results for special cases of complete and ring networks, while simulations show that it yields near-optimal results on trees and arbitrary networks in a wide-range of cases, performing best on coordination games.
The thesis has two primary objectives. First, it develops a high-fidelity 6DOF flight dynamics model of a multi-copter UAV, and uses it for the design and implementation of the linear attitude controller onboard of an...
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The thesis has two primary objectives. First, it develops a high-fidelity 6DOF flight dynamics model of a multi-copter UAV, and uses it for the design and implementation of the linear attitude controller onboard of an industrial quadcopter; both steps are implemented in Simulink. Second, it leverages the weakly joint efforts of MathWorks and the open-source community to build a software setup that enables rapid control software prototyping. This software architecture enables control system design and integration without the need for proficiency in embedded coding that typically utilizes high-level programming languages like C/C++. The higher impact of the dual objective is in advancing methods and tools of verifiable control system design and the embedded code generation that simplifies the V&V process. The 3DR Iris+ quadrotor, equipped with PX4 "Pixhawk" autopilot, is selected as the primary prototyping platform. The autopilot allows for the real-time execution of an application (attitude controller) that is auto- generated from MatLab/Simulink. This makes the Iris+ quadrotor an ideal platform for rapid flight control prototyping by using MathWork's auto code generation capability. Ultimately, the developed setup represents a convenient research and development tool that natively bridges the gap between the safety-critical flight control science and flight experimentation technology by "eliminating" the error-prone manual coding of embedded microcontrollers.
This paper presents the development and preliminary results of a rapidly reconfigurable autopilot for small Unmanned Aerial Vehicles. The autopilot presented differs from current commercial and open source autopilots ...
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ISBN:
(纸本)9780791849002
This paper presents the development and preliminary results of a rapidly reconfigurable autopilot for small Unmanned Aerial Vehicles. The autopilot presented differs from current commercial and open source autopilots mainly as it has been designed to: (i) be easily reprogrammable via Simulink (models are directly transferred to the autopilot through the Real-Time Workshop's code-generation capability);(ii) decouple the traditional tasks of attitude estimation/navigation and flight control by using two Digital Signal controllers (one for each task) interconnected via a Serial Peripheral Interface;and, (iii) being able to interact directly with Simulink as a Hardware-in-the-Loop simulator. This work details each of the main components of the autopilot and its ground control station software. Preliminary results for sensor calibration, Hardware-in-the-loop, ground and flight tests are presented.
Self reconfiguring robots are complex robotic systems composed of a finite number of modules, where each module of the system is considered to be a simple agent. Based on this context, the reconfiguration represents t...
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ISBN:
(纸本)3908451884
Self reconfiguring robots are complex robotic systems composed of a finite number of modules, where each module of the system is considered to be a simple agent. Based on this context, the reconfiguration represents the process of re-arranging each agent of the robotic system in order to have a working system. One versatile method to determine the most adequate movement and reconfiguration algorithms can be done using modeling methods and tools. Using this approach, the control algorithms necessary to drive such a system can be modeled, tested and implemented in an embedded system much easier than in a classical approach. This paper presents the case of a self reconfiguring robot for which, a reconfiguration algorithm and a movement algorithm were determined, analyzed, tested and validated.
In this work the control of an electro-hydraulic brake by wire system is presented. The actuator is composed of an electric motor, a mechanical transmission, a hydraulic pump and a pipeline connected to the brake cali...
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In this work the control of an electro-hydraulic brake by wire system is presented. The actuator is composed of an electric motor, a mechanical transmission, a hydraulic pump and a pipeline connected to the brake caliper. The highly nonlinear, time-varying relationship between pump piston position and plant pressure ismodelled, showing how the closed loop performances degrade without considering it. A hybrid position-pressure switching controller that aims at coping with the mentioned non-linearity is proposed. A position-pressure map estimation algorithm is introduced;this allows one to make the closed loop system robust with respect to temperature variation and brake pad wear. (C) 2013 European control Association. Published by Elsevier Ltd. All rights reserved.
New coating-design algorithms automatically produce designs suitable for real-life monitoring techniques and deposition processes, while retaining the coating's excellent spectral properties.
New coating-design algorithms automatically produce designs suitable for real-life monitoring techniques and deposition processes, while retaining the coating's excellent spectral properties.
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