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ACTIVE control OF FAR-FIELD NOISE FROM A DUCTED PROPELLER

AIAA JOURNAL 1995年第2期33卷 231-236页

作者： SUTLIFF, DL NAGEL, RT North Carolina State University Raleigh North Carolina 27695

A feed forward control algorithm using a rpm reference signal and a rotor position signal was used to apply active noise control to reduce the far-field noise generated by a ducted propeller. This technique reduced the noise radiated from the plane wave and first circumferential (1, 0) spinning duct mode. Simultaneous cancellation of the blade passing frequency and the first harmonic was achieved. These reductions were obtained over a wide range of far-field angles with no increase in noise at other frequencies.

关键词： Ducted Propellers Active control Blade Passing Frequency control algorithm Sound Pressure Level Propeller Noise Blade Loading Anechoic Chambers Angle of Attack Data Analysis

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Navigation of autonomous tractor for orchards and plantations using a laser range finder: Automatic control of trailer position with tractor

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BIOSYSTEMS ENGINEERING 2016年 147卷 90-103页

作者： Thanpattranon, Pawin Ahamed, Tofael Takigawa, Tomohiro Univ Tsukuba Grad Sch Life & Environm Sci Tsukuba Ibaraki 305 Japan Univ Tsukuba Fac Life & Environm Sci Tsukuba Ibaraki 305 Japan

The autonomous control of a tractor-trailer system in orchards and plantations has frequently been observed for the transportation, loading and unloading of products between plants and trees. The objective of this research was to develop a control algorithm for a single-sensor tractor-trailer navigation system for navigating within a row plantation and travelling between plots. A control scheme for stopping the tractor-trailer for various in-field tasks, such as product loading/unloading using a laser range finder (LRF), is presented. The LRF was used to navigate a full-size autonomous agricultural tractor equipped with a two-wheeled trailer. For ease of operation in narrow rows, a sliding hitch bar (SHB) was developed to control the trailer by adjusting the position of the hitch-point between the tractor and trailer. Compared to the tractor-trailer system driven by human, the control system could navigate the tractor-trailer with the RMS differences of 0.275 m (SD: 0.009 m), 0.373 m (SD: 0.030 m) and 0.518 m (SD: 0.022 m) for wide curve, tight curve and U-turn experimental paths, respectively. The SHB unit also supported the navigation system with wider turn for the trailer than conventional single hitch point about 0.383 m (7.66% of the 5 m path width, SD: 0.028 m), 0.762 m (15.23% of 5 m path width, SD: 0.010 m) and 1.094m (21.88% of 5 m path width, SD: 0.037 m) for wide curve, tight curve and U-turn experimental paths, respectively. The control system also stopped the tractor trailer at the specified landmarks. The results show that the navigation of the tractor-trailer was demonstrated with satisfactory accuracy and that the trailer position was controlled by the SHB with a wider turn in the experimental paths. Therefore, this laser-based landmark navigation system, and the SHB unit, can be adopted for different applications of autonomous tractor-trailer systems with controlled trailer positioning. (C) 2016 Published by Elsevier Ltd on behalf of IAgrE.

关键词： control algorithm Landmarks Positioning Tractor-trailer system Hitch-point position control Navigation paths

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A precise control of AC servo motor using neural network PID controller

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CURRENT SCIENCE 2005年第1期89卷 23-29页

作者： Cho, GB Kim, PH Chosun Univ Coll Engn Dept Elect Engn Kwangju South Korea Seokang Coll Dept Informat & Commun Kwangju South Korea

A new control technique based on a neural network, is proposed here for control of AC servo motors. The PID control is widely used in servo systems as it has simple structure, safety and reliability. However, it has certain problems in a complex system, resulting in imperfect action in the presence of uncertain parameters. To solve these problems, a new hybrid control algorithm of the PID controller is proposed, which could prove the adequacy of the proposed control algorithm through simulation and experiments after driving the AC servo motor system using neural network PID controller.

关键词： .control of AC control algorithm servo system

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A new filter-based pseudo-negative-stiffness control for base-isolated buildings

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STRUCTURAL control & HEALTH MONITORING 2017年第5期24卷 pn/a-N.PAG页

作者： Gong, Wei Xiong, Shishu Huazhong Univ Sci & Technol Sch Civil Engn & Mech Wuhan 430074 Hubei Peoples R China

A filter-based pseudo-negative-stiffness (FPNS) control is proposed for seismic control of base-isolated structures. The control algorithm is designed to produce a negative stiffness friction damping force with a gradual change at velocity switches, so that it is potential to prevent structures from experiencing significant jerks especially under earthquakes rich of high-frequency components. The control algorithm requires information only on device's displacement. The effect of the control parameters on structural performance is studied and the optimal combination of control parameters is obtained with the consideration of control efficiency and the economy of control force. The superior performance of an active control system employing the FPNS control algorithm over that employing the conventional PNS control algorithm is verified. A semi-active control design, MC-FPNS, is developed to produce the control force of the FPNS control algorithm by MR dampers. The effectiveness and robustness of the MC-FPNS control system are investigated through numerical analysis of the base-isolated benchmark problem under earthquakes scaled to different intensity levels. The proposed MC-FPNS control system is shown to be effective to not only prevent the isolator from failure but also improve the isolation functionality for a variety of earthquakes with different frequency contents and intensity levels. Moreover, the MC-FPNS control system is capable of suppressing transference of high-frequency components of ground motions to the superstructure. Copyright (c) 2016 John Wiley & Sons, Ltd.

关键词： pseudo-negative stiffness control control algorithm semi-active control benchmark base-isolated building MR damper

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DISTRIBUTED PIEZOELECTRIC POLYMER ACTIVE VIBRATION control OF A CANTILEVER BEAM

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JOURNAL OF GUIDANCE control AND DYNAMICS 1985年第5期8卷 605-611页

作者： BAILEY, T HUBBARD, JE Massachusetts Institute of Technology Cambridge Massachusetts

An active vibration damper for a cantilever beam was designed using a distributed-parameter actuator and distributed-parameter control theory. The distributed-parameter actuator was a piezoelectric polymer, poly(vinylidene fluoride). Lyapuov's second method for distributed-parameter systems was used to design a control algorithm for the damper. If the angular velocity of the tip of the beam is known, all modes of the beam can be controlled simultaneously. Preliminary testing of the damper was performed on the first mode of the cantilever beam. A linear constant-gain controller and a nonlinear constant-amplitude controller were compared. The constant-gain controller provided more than a factor of two increase in the modal damping with a feedback voltage limit of 200 V rms. With the same voltage limit, the constant-amplitude controller achieved the same damping, but increased the modal loss factor by more than an order of magnitude to at least 0.040 for small vibration levels.

关键词： Cantilever Beam Piezoelectric Polymer Active Vibration control Distributed Parameter System Actuators control algorithm Accelerometer Bernoulli Euler Beams Transverse Vibrations Angular Motion Oscilloscope

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Quaternion Solution of the Problem on Optimum control of the Orientation of a Solid (Spacecraft) with a Combined Quality Criteria

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MECHANICS OF SOLIDS 2024年第1期59卷 167-182页

作者： Levskii, M. V. Khrunichev State Res & Prod Space Ctr Maksimov Space Syst Res & Dev Inst Korolev 141091 Moscow Oblast Russia

The problem on optimal rotation of a solid (spacecraft) from an arbitrary initial to a prescribed final angular position in the presence of restrictions on the control variables is studied. The turnaround time is set. To optimize the rotation control program, a combined quality criterion that reflects energy costs is used. The minimized functional combines in a given proportion the integral of the rotational energy and the contribution of control forces to the maneuver. Based on the Pontryagin's maximum principle and quaternion models of controlled motion of a solid, an analytical solution of the problem has been obtained. The properties of optimal movement are revealed in analytical form. To construct an optimal rotation program, formalized equations and calculation formulas are written. Analytical equations and relations for finding optimal control are given. The key relations that determine the optimal values of the parameters of the rotation control algorithm are given. In addition, a constructive scheme for solving the boundary value problem of the maximum principle for arbitrary turning conditions (initial and final positions and moments of inertia of a solid) is described. For a dynamically symmetric solid, a closed-form solution for the reorientation problem is obtained. A numerical example and mathematical modeling results that confirm the practical feasibility of the developed method for controlling the orientation of a spacecraft are presented.

关键词： quaternions orientation control maximum principle combined quality criterion control functions control algorithm boundary value problem

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Pole placement method to control the rocking motion of rigid blocks

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ENGINEERING STRUCTURES 2018年第Jul.15期167卷 39-47页

作者： Simoneschi, Giorgia Olivieri, Carlo de Leo, Andrea M. Di Egidio, Angelo Univ Aquila Dipartimento Ingn Civile Edile Architettura & Amb Laquila Italy Univ Aquila Dipartimento Ingn Ind & Informaz & Econ Laquila Italy

In recent years only a very small number of studies analysed the use of active or semi-active control methods in order to avoid the overturning of rigid block-like structures under base excitation. In this paper, an active control algorithm, based on the pole placement method, is developed for rigid blocks starting from a description of the rocking motion through linearised equations. Such an approach is an excellent approximation for slender rigid blocks for which linearised equations can fully describe the rocking motion due to the smallness of the inclination angle. The control method has two objective: the first one is related to the possibility of vanishing the extemal excitation at each instant, the second one is to make the rest position of the block a stable point. The first analyses revealed the good robustness of the control algorithm to a variation of the sampling time and of the time-delay of the real control devices. Furthermore, the further parametric analyses pointed out the good effectiveness of the proposed control algorithm both in the reduction of the rocking angle and in the protection from the overturning, also in the case of blocks with low slenderness. Overturning spectra are obtained in the case of rigid block with and without active control.

关键词： Pole placement method control algorithm Robustness Overturning spectrum

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HYPERVELOCITY ORBITAL INTERCEPT GUIDANCE USING CERTAINTY control

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JOURNAL OF GUIDANCE control AND DYNAMICS 1991年第3期14卷 574-580页

作者： ALFANO, S FOSHA, CE UNIV COLORADO DEPT ELECT ENGNCOLORADO SPRINGSCO 80918 UNIV COLORADO SPACE STUDIES PROGRAMCOLORADO SPRINGSCO 80918 UNIV COLORADO SPACE & FLIGHT SYST LABCOLORADO SPRINGSCO 80918

Terminal guidance of a hypervelocity exoatmospheric orbital interceptor with free end time is examined. A new approach called certainty control is developed where control energy expenditure is reduced by constraining the expected final state to a function of projected estimate error. Conceptually, the constraint produces a shrinking sphere about the predicted impact point with the radius being a function of estimated error. If the predicted miss is inside or touching the sphere, thrusting is not necessary. The interceptor is modeled as a satellite with lateral thrusting capability using two-body orbital dynamics. The target is modeled as an intercontinental ballistic missile (IBM) in its final boost phase prior to burnout. Filtering is accomplished using an eight-state extended Kalman filter with line-of-sight and range updates. The estimated relative trajectory and variances are propagated numerically to predicted impact time and then approximated by splines, eliminating the need to propagate new data repeatedly when present conditions are varied. A search is then made for a new impact time and point that will minimize present interceptor velocity changes and final miss distance. This control strategy, which is applied to two intercept problems, substantially reduces fuel consumption.

关键词： Extended Kalman Filter Predicted Impact Point Intercontinental Ballistic Missile Fuel Consumption Satellites Proportional Navigation Trajectory Optimization Earth control algorithm Nonlinear Systems

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The comparison of some advanced control methods for energy optimization and comfort management in buildings

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SUSTAINABLE CITIES AND SOCIETY 2018年 43卷 601-623页

作者： Esmaeilzadeh, Ahmad Zakerzadeh, Mohammad Reza Koma, Aghil Yousefi Univ Tehran Coll Engn Sch Mech Engn CAST Tehran Iran Univ Tehran Coll Engn Sch Mech Engn Tehran Iran

The purpose of this paper is to provide a control method to optimize energy consumption in buildings. A building in Tehran has been modeled considering one day and one month, as an example. The Proportional-Integral-Derivative (PID) control algorithms tuned by the fuzzy rule set, On-Off, and fuzzy logic control system are implemented on the hybrid solar-gas-electric thermal system in order to control the indoor temperature as well as the economic optimization of energy consumption. Also, the two methods of water reservoir and Phase Change Material (PCM) reservoir are used to store the excess solar energy received. The results show that the fuzzy logic control system, in addition to setting the ambient temperature with an error of less than 1%, reduces the cost of energy supply. It also uses the power supply properly so that the cost of energy consumed is reduced to 35% of the initial value compared to a system without an energy storage source. Furthermore, this algorithm has the ability to control the ambient temperature in unstable atmospheric conditions with the temperature error rate of less than 4%. Moreover, implementation of fuzzy controller decreases supply energy cost 12% monthly.

关键词： Building management system Optimization control algorithm Fuzzy logic system

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Closed-Loop control of Earth Observation Satellites

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JOURNAL OF SPACECRAFT AND ROCKETS 2019年第1期56卷 82-90页

作者： Guelman, Mauricio M. Shiryaev, Alexander Technion Israel Inst Technol Fac Aerosp Engn Asher Space Res Inst IL-32000 Haifa Israel Technion Israel Inst Technol Asher Space Res Inst IL-32000 Haifa Israel

Low-altitude satellite orbits, while enabling high-resolution imagery of the Earth surface, have limited coverage properties. This disadvantage of the remote sensing satellites can be offset by the low-thrust electric propulsion capability, which permits to combine high-resolution with short revisit times. The purpose of this work is to present a simple closed-loop control function that allows the direct control of the orbit, making the spacecraft to pass over prescribed sites on the terrestrial surface without the need of precomputed reference trajectories. The simplicity of application contributes to the autonomy of the remote sensing satellites. The performance of the new control algorithm is illustrated by representative numerical simulation results.

关键词： Modern control Theory Geosynchronous Satellite Earth Remote Sensing Earth Observation Satellite Electric Propulsion control algorithm Numerical Simulation Earth Centered Inertial Sunsynchronous Orbit

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