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AIAA Guidance, Navigation, and control Conference

作者： Stott, James E. Shtessel, Yuri B. NASA Marshall Space Flight Center AL 35812 United States Department of Electrical and Computer Engineering University of Alabama in Huntsville Huntsville AL 35899 United States Safety and Mission Assurance Directorate QD33 United States

ISBN: (纸本)9781600869624

In determining flight controls for launch vehicle systems, several uncertain factors must be taken into account, including a variety of payloads, a wide range of flight conditions and different mission profiles, wind disturbances and plant uncertainties. Crewed vehicles must adhere to human rating requirements which limit the angular rates. Sliding mode control algorithms that are inherently robust to external disturbances and plant uncertainties are very good candidates for improving the robustness and accuracy of the flight control systems. Recently emerging Higher Order Sliding Mode (HOSM) control is even more powerful than the classical Sliding Mode controls (SMC), including the capability to handle systems with arbitrary relative degree. With the Higher Order Sliding Mode controller, any degree of control smoothness can be achieved with full dynamical collapse. This paper proposes sliding mode launch vehicle flight controls using higher-order multiple and single loop designs. A case study on the SLV-X Launch Vehicle studied under a joint DARPA/Air Force program called the Force Application and Launch from CONtinental United States (FALCON) program is shown. The intensive simulations demonstrate efficacy of the proposed control higher-order SMC algorithms for launch vehicle attitude control. Copyright © 2010 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Attitude control

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The Minimum Principle for Hybrid Systems with Partitioned State Space and Unspecified Discrete State Sequence

The Minimum Principle for Hybrid Systems with Partitioned St...

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2010 49th IEEE Conference on Decision and control

作者： Benjamin Passenberg Peter E. Caines Marion Sobotka Olaf Stursberg Martin Buss Institute of Automatic Control Department of Electrical Engineering and Information Technology Technische Universitat Munchen Munchen Germany Department of Electrical and Computer Engineering and the Center for Intelligent Machines McGill University Montreal Canada Institute of Control and System Theory Department of Electrical Engineering and Computer Science University of Kassel Kassel Germany

ISBN: (纸本)9781424477456

The hybrid minimum principle (HMP) gives necessary conditions to be satisfied for optimal solutions of a hybrid dynamical system. In particular, the HMP accounts for autonomous switching between discrete states that occurs whenever the trajectory hits switching manifolds. In this paper, the existing HMP is extended for hybrid systems with partitioned state space to provide necessary conditions for optimal trajectories that pass through an intersection of switching manifolds. This extension is especially useful for the numerical solution of hybrid optimal control problems as it allows for algorithms with significant reduction of computational complexity. Algorithms based on previous versions of the HMP solve separate optimal control problems for each possible sequence of discrete states. The extension enables us to consider the optimal sequence as subject of optimal control that is varied and finally determined during a single optimization run. A first numerical result illustrates the effectiveness of an algorithm based on the extended HMP.

关键词： state space minimum principle hybrid systems Manifolds Optimal control DYNAMICAL SYSTEMS discrete element

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An Algorithm for Discrete State Sequence and Trajectory Optimization for Hybrid Systems with Partitioned State Space

An Algorithm for Discrete State Sequence and Trajectory Opti...

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2010 49th IEEE Conference on Decision and control

作者： Benjamin Passenberg Marion Sobotka Olaf Stursberg Martin Buss Peter E. Caines Institute of Automatic Control Department of Electrical Engineering and Information Technology Technische Universitat Munchen Munchen Germany Institute of Control and System Theory Department of Electrical Engineering and Computer Science University of Kassel Kassel Germany Department of Electrical and Computer Engineering and the Center for Intelligent Machines McGill University Montreal Canada

ISBN: (纸本)9781424477456

An algorithm for hybrid optimal control is proposed that varies the discrete state sequence based on gradient information during the search for an optimal trajectory. The algorithm is developed for hybrid systems with partitioned state space. It uses a version of the hybrid minimum principle that allows optimal trajectories to pass through intersections of switching manifolds, which enables the algorithm to vary the sequence. Consequently, the combinatorial complexity of former algorithms can be avoided, since not each possible sequence has to be investigated separately anymore. The convergence of the algorithm is proven and a numerical example demonstrates the efficiency of the algorithm.

关键词： Switches Manifolds Trajectory Complexity theory Partitioning algorithms Convergence Aerospace electronics

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Augmented adaptive control of a wind turbine in the presence of structural modes

Augmented adaptive control of a wind turbine in the presence...

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作者： Frost, Susan A. Balas, Mark J. Wright, Alan D. NASA Ames Research Center Moffett Field CA 94035 United States Department of Electrical and Computer Engineering University of Wyoming Laramie WY 82071 United States National Renewable Energy Laboratory DOE Golden CO 80401 United States

ISBN: (纸本)9781424474264

Wind turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, potentially causing component fatigue and failure. Two key technology drivers for turbine manufacturers are increasing turbine up time and reducing maintenance costs. Since the trend in wind turbine design is towards larger, more flexible turbines with lower frequency structural modes, manufacturers will want to develop methods to operate in the presence of these modes. Accurate models of the dynamic characteristics of new wind turbines are often not available due to the complexity and expense of the modeling task, making wind turbines ideally suited to adaptive control. In this paper, we develop theory for adaptive control with rejection of disturbances in the presence of modes that inhibit the controller. We use this method to design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the interference of certain structural modes in feedback. The control objective is accomplished by collectively pitching the turbine blades. The adaptive pitch controller for Region 3 is compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller. © 2010 AACC.

关键词： Turbomachine blades

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Decision making strategy in the designing of a fuzzy controller for inverted pendulum-cart system

Decision making strategy in the designing of a fuzzy control...

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IEEE International Conference on Fuzzy Systems (FUZZ-IEEE)

作者： S. Khailaie P. Bahmanyar Caro Lucas Control and Intelligent Processing Center of Excellence School of Electrical and Computer Engineering University of Tehran Tehran Iran Department of Electrical Engineering Faculty of Engineering Ferdowsi University of Mashhad Mashhad Iran

In this paper, a multi-objective heuristic-based method of design of a fuzzy controller for an inverted pendulum-cart system is investigated. A heuristic search optimization called “Imperialist Competitive Algorithm” is proposed to be used in generating and optimizing the fuzzy rules engine. The main purpose of this paper is to design a model-free nonlinear controller for inverted pendulum-cart system which can regulate a wide range of initial conditions and minimize a pre-defined quadratic performance index by taking into account the physical system constraints. Also the system constraints are proposed to be coded using Pontryagin method. All the objectives and system constraints are assumed to be fuzzy objectives and fuzzy constraints. The simulation results show the effectiveness of the proposed algorithm in problem objectives and constraints satisfaction compared to the optimal linear and nonlinear controller.

关键词： Performance analysis Mathematical model Optimization Decision making Indexes Equations Approximation methods

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Active disturbance rejection control for non-minimum phase systems

Active disturbance rejection control for non-minimum phase s...

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Chinese control Conference (CCC)

作者： Shen Zhao Zhiqiang Gao Center for Advanced Control Technologies Department of Electrical and Computer Engineering Cleveland State University OH 44115 USA

Active disturbance rejection control (ADRC) has been applied to solve various types of control problems across many engineering disciplines, but largely within the confine of minimum phase systems. This paper, however, explores systematically its applications to non-minimum phase (NMP) systems, particularly those with transfer functions that have right half plane zeros. It is first shown that, a regular ADRC controller, if not tuned carefully, could easily yield an undesirable solution for NMP systems. We then demonstrate the reasons behind the difficulty using transfer function analysis, leading to a solution in how we tune the ADRC for NMP systems. In particular, a systematic design and tuning procedure is obtained based on the relationship between the high frequency gain of the system and the controller bandwidth. Finally, the proposed method allows a user to easily make a tradeoff between the undershoot, which is unique in NMP systems, and the response time, using the frequency response method of gain and phase compensation.

关键词： Bandwidth Observers Transfer functions control systems Tuning Simulation Frequency domain analysis

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RETRACTED ARTICLE: Remote access of building management system on windows mobile devices

RETRACTED ARTICLE: Remote access of building management syst...

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2010 International Conference on Networking and Information Technology, ICNIT 2010

作者： Krejcar, Ondrej Horkem, Jindrich Department of Measurement and Control Center for Applied Cybernetics VSB Technical University of Ostrava 17. Listopadu 15 70833 Ostrava-Poruba Czech Republic Department of Measurement and Control Faculty of Electrical Engineering and Computer Science VSB Technical University of Ostrava 17. Listopadu 15 70833 Ostrava-Poruba Czech Republic

ISBN: (纸本)9781424475773

The purpose of this project is to allow a free movement of Building Management System (BMS) operator in all controlled building area. The current state of the problem consists in an impossibility of operator's movement from control centre. We found a solution in using of mobile devices like PDA with a client of BMS to allow a remote access to all alarms of system. Solution consist in use of web services and web methods interface on BMS server, where is possible to connect a remote PDA client to interchange a requested info about alarms and trends. A web services and mobile client application was created using a Microsoft Visual Studio 2008. Future trends are also discussed to provide a solution for small and mid size constructions in direction of use a Microsoft .NET Micro Framework. © 2010 IEEE.

关键词： Web services

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Evaluation and testing of RT-Java parameters on aJiJe aJ-80 real time embedded platform

Evaluation and testing of RT-Java parameters on aJiJe aJ-80 ...

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2010 International Conference on Networking and Information Technology, ICNIT 2010

作者： Krejcar, Ondrej Adamec, Ondrej Department of Measurement and Control Center for Applied Cybernetics VSB Technical University of Ostrava 17. Listopadu 15 70833 Ostrava-Poruba Czech Republic Department of Measurement and Control Faculty of Electrical Engineering and Computer Science VSB Technical University of Ostrava 17. Listopadu 15 70833 Ostrava-Poruba Czech Republic

ISBN: (纸本)9781424475773

The purpose of this work is the implementation of the program code that enables digital filtration on aJ-80 embedded JAVA processor. While working the implementation filter we need to provide the fastest calculation with the greatest accuracy. Next, it is almost always necessary for the results to be available after the same time from the sample upload. These matters determine the digital filtration as a problem called RT, which is the problem suitable for testing of the processor aJ-80 and its RT features. The work also describes the chosen task example, which examines RT features of this processor. We also mention the attained results and their evaluation. Based on the evaluation, the performance of the hardware program of the processor aJ-80 is very effective. In this respect, the product is recommended to use in many hard RT areas. © 2010 IEEE.

关键词： IIR filters

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Robust Global Asymptotic Attitude Synchronization by Hybrid control

Robust Global Asymptotic Attitude Synchronization by Hybrid ...

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American control Conference

作者： Christopher G. Mayhew Ricardo G. Sanfelice Murat Arcak Andrew R. Teel Center for Control Engineering and Computation Electrical and Computer Engineering Department University of California Santa Barbara CA 93106-9560 Department of Aerospace and Mechanical Engineering University of Arizona Tucson AZ 85721 Electrical Engineering and Computer Sciences University of California Berkeley CA 94720

ISBN: (纸本)9781424474264

We apply recent results on robust global asymptotic stabilization of the attitude of a single rigid body to the problem of synchronizing the attitude of a network of rigid bodies using graph-local information. The proposed synchronization scheme relies on a hysteretic hybrid feedback based on the unit quaternion representation of rigid body attitude to achieve a global synchronization result that is robust to measurement noise. While the hysteretic feedback manages a trade-off between robustness to measurement noise and unwinding, the scheme necessitates the communication of a single binary logic variable between neighboring rigid bodies.

关键词： hybrid control Rigid bodies Noise measurement Human Posture Attitude Robustness asymptotic Hysteresis

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Bounds on probability of transformations between multipartite pure states

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Physical Review A 2010年第1期81卷 012111-012111页

作者： Wei Cui Wolfram Helwig Hoi-Kwong Lo []Center for Quantum Information and Quantum Control Department of Physics and Department of Electrical and Computer Engineering University of Toronto Toronto Ontario M5S 3G4 Canada

For a tripartite pure state of three qubits, it is well known that there are two inequivalent classes of genuine tripartite entanglement, namely the Greenberger-Horne-Zeilinger (GHZ) class and the W class. Any two states within the same class can be transformed into each other with stochastic local operations and classical communication with a nonzero probability. The optimal conversion probability, however, is only known for special cases. Here, lower and upper bounds are derived for the optimal probability of transformation from a GHZ state to other states of the GHZ class. A key idea in the derivation of the upper bounds is to consider the action of the local operations and classical communications (LOCC) protocol on a different input state, namely 1/2[|000〉−|111〉], and to demand that the probability of an outcome remains bounded by 1. We also find an upper bound for more general cases by using the constraints of the so-called interference term and 3-tangle. Moreover, some of the results are generalized to the case in which each party holds a higher dimensional system. In particular, the GHZ state generalized to three qutrits; that is, |GHZ3〉=1/3[|000〉+|111〉+|222〉] shared among three parties can be transformed to any tripartite three-qubit pure state with probability 1 via LOCC. Some of our results can also be generalized to the case of a multipartite state shared by more than three parties.

关键词： Probability

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