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A fuzzy irrigation controller system

ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE 2000年第2期13卷 137-145页

作者： Bahat, M Inbar, G Yaniv, O Schneider, M Tel Aviv Univ Dept Elect Engn Syst IL-69978 Tel Aviv Israel

The paper presents a solution for an irrigation controller based on the fuzzy-logic methodology. First, it describes the general problem of irrigation. Then, it discusses the physical control model. Following the discussion and the formal presentation of the fuzzy controller, the paper provide examples that will show the simplicity in designing and constructing such a system and other advantages of using fuzzy logic in the feedback control problem. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词： fuzzy logic controller irrigation system fuzzy system open loop controller closed loop controller

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Control Allocation Framework with SVD-based Protection for a Tilt-rotor VTOL Transition Air Vehicle

Control Allocation Framework with SVD-based Protection for a...

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AIAA Aviation Forum and Exposition

作者： Zhang, Jiannan Bhardwaj, Pranav Raab, Stefan A. Holzapfel, Florian Tech Univ Munich Inst Flight Syst Dynam D-85748 Garching Germany

ISBN: (数字)9781624105890

ISBN: (纸本)9781624105890

Control allocation aims to solve for an inversion problem given the effectiveness matrix and commanded forces/moments while accounting for input saturations. In case of an ill conditioned effectiveness matrix, the solution of control allocation is subject to chattering, noise amplification, higher degree of saturation and internal conflict between effectors, thus degrading performance or even endangering safety. When the effectiveness is ill conditioned, it physically means the aircraft lacks capability in achieving forces/moments in certain directions, and such directions should be avoided from the commanded forces/moments. In this paper, a control allocation framework is implemented, highlighting an SVD-based protection in the main allocation algorithm. The proposed approach is compared with a baseline algorithm in an open-loop controller based on flight test data and shows improved numerical robustness and flight performance.

关键词： Singular Value Decomposition Tilt Rotor Air Vehicle Flight Testing open loop controller Flight Performance Pitching Moment Yaw Control Nonlinear Dynamic Inversion Heading Angle

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Tetrabot: Resonance Based Locomotion for Harsh Enviroments

Tetrabot: Resonance Based Locomotion for Harsh Enviroments

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IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： Neubert, Jonas Stockton, Jon Blechman, Ben Lipson, Hod Cornell Univ Computat Synth Lab Ithaca NY 14853 USA Cornell Univ Dept Engn Mech Ithaca NY 14853 USA

ISBN: (纸本)9781424466757

We describe a robotic architecture that combines the benefits of existing enclosed robots with passive dynamics. This combination results in a mobile robot with no moving parts exposed to the environment, making it ideal for tasks where wheeled or legged robots fail. Instead of suppressing resonance, the new robot morphology relies on the dynamics of resonance for locomotion. Actuators mounted on a central sphere excite a natural mode of vibration by pulling on strings through which the sphere is mounted to a tetrahedral frame. A simple open loop controller is sufficient to cause directed motion by hopping and sliding in a prototype. Rolling as a further gait is investigated theoretically. Fully enclosed resonant dynamic robots could lead to a new type of robot locomotion powered from a vibration source only. This is useful in the microscale where traditional actuators are not available, and at the macroscale where the robot's high ruggedness is favorable.

关键词： Tetrabot directed motion harsh environment legged locomotion legged robots mobile robot motion control open loop controller passive dynamics resonance based locomotion resonance suppression resonant dynamic robot locomotion robot dynamics robot morphology robotic architecture tetrahedral frame vibration source vibrations

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Impulse Based Dynamic Rolling in the Rolling Disk Biped

Impulse Based Dynamic Rolling in the Rolling Disk Biped

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3rd IEEE RAS and EMBS International Conference on Biomedical Robotics and Biomechatronics

作者： Floyd, Marshall Minor, Mark A. Univ Utah Salt Lake City UT 84112 USA

ISBN: (纸本)9781424477098

This paper explores the use of pushing off the ground to produce dynamic rolling for the Rolling Disk Biped (RDB). An open loop controller is used that periodically opens joints to kick off the ground to begin and continue rolling motions. This impulse based method of propulsion is suited to robots that have limited control of the center of gravity, or to robots that do not always form a continuous rolling surface. Hybrid mobility robots can use this method of rolling in order to utilize multiple modes of locomotion such as rolling and walking. Both simulations and experiments show that the use of impulse based rolling in the RDB can initiate rolling from a variety of initial conditions and can produce continuous rolling three times faster than center of gravity based rolling. The general impulse method presented can be used for some existing robots and will help in creating new hybrid mobility robots.

关键词： discs (structures) dynamic rolling general impulse method hybrid mobility robots mobile robots open loop controller propulsion robot kinematics rolling disk biped

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Pressure Feedback Active Flow Control of Unsteady Roll Moment on a UCAS Delta Wing

Pressure Feedback Active Flow Control of Unsteady Roll Momen...

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AIAA Science and Technology (SciTech) Forum and Exposition

作者： He, Xiaowei An, Xuanhong Williams, David R. Le Provost, Mathieu IIT MMAE Dept 10 W 32nd StREC Bldg Chicago IL 60616 USA Univ Calif Los Angeles MAE Dept BOX 95159748-121 E4 Los Angeles CA 90095 USA

ISBN: (数字)9781624105784

ISBN: (纸本)9781624105784

Based on a feedforward controller for attenuating the unsteady aerodynamic roll moment disturbances on a UCAS delta wing platform,(1) a feedback loop is added to the control system to correct the error in the controller. A black-box model for the plant is identified and used in the design of the feedforward loop. The disturbance model is identified through the same linear model identification approach. The open-loop feedforward controller is evaluated in real-time wind tunnel experiments under unsteady flow conditions in which the flow speed surges longitudinally. The wing is fixed at 15-degree angle of attack with a constant roll angle of -30 degrees. The changing roll moment due to the unsteadiness of the flow and the sideslip on the wing is predicted by surface pressure measurements from fourteen pressure sensors distributed on the upper surface of the wing. The measurements are used as a surrogate signal for the roll moment, which measure both the active flow control effect and the disturbance from the surging flow. The complete closed-loop controller is examined in real-time control cases, including sinusoidal and pseudo-random surging flows.

关键词： Aerodynamic Coefficients Mean Aerodynamic Chord Lift Coefficient open loop controller Pressure Sensors Flow Conditions Feedback Control Wind Tunnels Sideslip Angle Control Systems

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Fuzzy C-Means Clustering Technique applied for Modeling Parameters of an Intelligent Greenhouse open Control System

Fuzzy C-Means Clustering Technique applied for Modeling Para...

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IEEE Electronics, Robotics and Automotive Mechanics Conference (CERMA)

作者： Cepeda, Paul Romero, David Ponce, Pedro Molina, Arturo Tecnol Monterrey Campus Ciudad Monterrey Mexico

ISBN: (纸本)9780769545639

This paper presents the analysis, design and development of three intelligent open control systems: (1) temperature, (2) relative humidity, and (3) nutrients electrical conductivity - implemented in a sustainable greenhouse located at Tecnologico de Monterrey, Campus Ciudad de Mexico. The intelligent controllers are based on a "Fuzzy C-Means Takagi-Sugeno" control type in order to deal with the nonlinear environmental conditions and variables inside the greenhouse. The proposed open control system was developed using an Intelligent Control Toolkit for LabVIEW T. The intelligent controls are based on an open loop control system that could be used under the boundaries of different crops. Finally, experimental results are shown in order to validate the correct performance of the controllers.

关键词： Intelligent Greenhouse open loop controller Artificial Intelligence Takagi-Sugeno Type Fuzzy Logic Fuzzy C-Means

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Tailoring Wind Tunnel Gust Spectra with Feedback Control

Tailoring Wind Tunnel Gust Spectra with Feedback Control

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AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： He, Xiaowei Asztalos, Katherine J. Williams, David R. Buchert, Kevin Henry, James IIT MMAE Dept 10 W 32nd St REC Bldg Chicago IL 60616 USA Tech Inst Berlin MMAE Dept 10 W 32nd St REC Bldg Berlin Germany

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

The Andrew Fejer Unsteady Flow Wind Tunnel at Illinois Institute of Technology uses a controlled set of louvers at the downstream end of the test section to create random disturbances in the longitudinal flow velocity. The test-section velocity is determined by the louver angles and fan speeds, which provide the steady states for an open-loop controller of the velocity. A transfer function model is identified for the wind tunnel dynamics to control the fluctuation in the velocity, which is the feedforward loop of the control system. The control system is designed based on an assumption that the mean velocity and the fluctuation can be linearly superposed. The short time history of flow speed measured by a hot wire anemometer allows for the real-time calculation and update of the spectrum of the test-section velocity. The error spectrum is taken by comparing the instantaneous measurement of the test-section velocity spectrum with the spectrum of the reference velocity profile, which completes the feedback loop of the control system. The spectrum feedback approach is more feasible than using the direct velocity measurement for a controller that is designed to handle various velocity fluctuations and random gusts. The real-time tests prove that this feedback control system is capable of controlling both the mean flow velocity and the amplitude of the single or multi-frequency fluctuations.

关键词： Feedback Control System Wind Tunnel Tests open loop controller Cross Flow Velocity Turbulent Flow Control Systems Velocity Profiles Hot Wire Anemometers Dynamic Response Commercial Aircraft

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Resonant Control of Satellite Orbits

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2021年第12期44卷 2126-2142页

作者： Nie, Tao Gurfil, Pini Technion Israel Inst Technol Fac Aerosp Engn IL-32000 Haifa Israel

Low-thrust orbit control has been widely studied, mostly by using direct or indirect optimization to detect time-optimal and fuel-optimal orbit transfers. This paper proposes an alternative approach for designing efficient low-thrust orbit transfers. The main idea is to create an artificial resonance between the period of the control accelerations and a characteristic period of the orbital dynamics. To that end, Gauss's variational equations are written using a Fourier series expansion in the mean anomaly. The secular changes of the orbital elements are determined based on averaging theory. It is shown that an artificially created low-thrust resonance can save fuel compared with piecewise-constant thrust. A general resonant-control candidate for changing all mean orbital elements efficiently is proposed. Four simple decoupling control laws are designed for changing the semimajor axis, eccentricity, inclination, and right ascension of the ascending node separately. In addition, periodic corrections transforming between mean elements and osculating elements are derived. The proposed decoupling control laws are applied to a formation-keeping problem, illustrating the potential merit of the new control law compared with a fixed-thrust-magnitude feedback control.

关键词： Earth Satellites Highly Eccentric Orbit Feedback Control Right Ascension Orbital Eccentricity Fuel Consumption Numerical Simulation open loop controller Electric Propulsion Perturbation Theory

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Quaternion-Based Bang-Bang Attitude Stabilizer for Rotating Rigid Bodies

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2017年第6期40卷 1523-+页

作者： Serpelloni, Edoardo Maggiore, Manfredi Damaren, Christopher J. Univ Toronto Elect & Comp Engn Dept Toronto ON M5S 2J7 Canada Univ Toronto Inst Aerosp Studies Toronto ON M5S 2J7 Canada

The hybrid feedback is modified so as to take full advantage of the quaternion parametrization of the spacecraft attitude. The controller achieves practical stabilization of the spacecraft attitude assuming the full nonlinear dynamics of the spacecraft, while avoiding chattering and high-frequency switching of the actuators. An extensive Monte Carlo numerical analysis indicates that the result might be global. the attitude controller is the first bang-bang feedback controller with guaranteed stability properties and guaranteed bounded switching frequency, even in the presence of measurement noise.

关键词： Quaternions Attitude Stabilization open loop controller Hysteresis Spacecraft Attitude Rigid Spacecraft Pulse Width Modulation Bang Bang Control Spacecraft Configurations State Space Systems

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Closed-loop Control of the Orbit Evolution of "Smart Dust" Swarms

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2017年第7期40卷 1806-1814页

作者： Xu, Ming McInnes, Colin R. Beihang Univ Sch Astronaut Beijing 100191 Peoples R China Univ Glasgow Sch Engn Engn Sci Glasgow G12 8QQ Lanark Scotland Univ Glasgow Sch Engn Glasgow G12 8QQ Lanark Scotland

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