Download or read book Helicopter Vibration and Its Reduction written by Royal Aeronautical Society and published by . This book was released on 1987 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Helicopter Vibration and Its Reduction written by and published by . This book was released on 1987 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Helicopter Vibration and Its Reduction written by The Royal Aeronautical Society Staff and published by . This book was released on 1987-11-01 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Helicopter Vibration and Its Reduction written by and published by . This book was released on 1987 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Smart Helicopter Rotors written by Ranjan Ganguli and published by Springer. This book was released on 2015-12-16 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploiting the properties of piezoelectric materials to minimize vibration in rotor-blade actuators, this book demonstrates the potential of smart helicopter rotors to achieve the smoothness of ride associated with jet-engined, fixed-wing aircraft. Vibration control is effected using the concepts of trailing-edge flaps and active-twist. The authors’ optimization-based approach shows the advantage of multiple trailing-edge flaps and algorithms for full-authority control of dual trailing-edge-flap actuators are presented. Hysteresis nonlinearity in piezoelectric stack actuators is highlighted and compensated by use of another algorithm. The idea of response surfaces provides for optimal placement of trailing-edge flaps. The concept of active twist involves the employment of piezoelectrically induced shear actuation in rotating beams. Shear is then demonstrated for a thin-walled aerofoil-section rotor blade under feedback-control vibration minimization. Active twist is shown to be significant in reducing vibration caused by dynamic stall. The exposition of ideas, materials and algorithms in this monograph is supported by extensive reporting of results from numerical simulations of smart helicopter rotors. This monograph will be a valuable source of reference for researchers and engineers with backgrounds in aerospace, mechanical and electrical engineering interested in smart materials and vibration control. Advances in Industrial Control aims to report and encourage the transfer of technology in control engineering. The rapid development of control technology has an impact on all areas of the control discipline. The series offers an opportunity for researchers to present an extended exposition of new work in all aspects of industrial control.
Download or read book Helicopter Vibration and Its Reduction written by and published by . This book was released on 1987 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Inverse Control for Helicopter Vibration Reduction written by and published by . This book was released on 1983 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Helicopter Vibration Reduction Using Robust Control written by Thomas Mannchen and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Helicopter Vibration and Its Reduction Monday 16th November 1987 written by and published by . This book was released on 1987 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Chaos Methods to Helicopter Vibration Reduction Using Higher Harmonic Control written by Martinus M. Sarigul-Klijn and published by . This book was released on 1990 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chaos is a discipline used in understanding complex nonlinear dynamics. The geometric and topological methods of Chaos theory are applied, for the first time, to the study of flight test data. Data analyzed is from the McDonnell Douglas OH-6A Higher Harmonic Control (HHC) test aircraft. HHC is an active control system used to suppress helicopter vibrations. Some of the first practical applications of Chaos methods are demonstrated with the HHC data. Although helicopter vibrations are mostly periodic, evidence of chaos was found. The presenc3e of a strange attractor was shown by computing a positive Lyapunov exponent and computing a non-integer fractal correlation dimension. Also, a broad band Fourier spectrum and a well defined attractor in pseudo phase space are observed. A limit exists to HHC vibration reduction due to the presence of chaos. A new technique based on a relationship between the Chaos methods (the Poincare section and Van der Pol plane) and the vibration amplitude and phase was discovered. This newly introduced technique results in the following: 1) it gives the limits of HHC vibration reduction, 2) it allows rapid determination of best phase for a HHC controller, 3) it determines the minimum HHC controller requirement for any helicopter from a few minutes duration of flight test data (for the OH-6A, a scheduled gain controller for HHC appears to be adequate for steady level flight), 4) it shows that the HHC controller transfer matrix is linear and repeatable when the vibrations are defined in the?Rotor Time Domain? and that the matrix is nonlinear and nonrepeatable when the vibrations are defined in the?Clock Time Domain.? This technique will reduce future HHC flight test requirements. Further, the technique does not require the helicopter to be equipped with HHC. These methods may be applicable to other vibration control and flight testing problems.
Download or read book Higher Harmonic Control Analysis for Vibration Reduction of Helicopter Rotor Systems written by and published by . This book was released on 1994 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Chaos Methods to Helicopter Vibration Reduction Using Higher Harmonic Control written by Martinus M. Sarigul-Klijn and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chaos is a discipline used in understanding complex nonlinear dynamics. The geometric and topological methods of Chaos theory are applied, for the first time, to the study of flight test data. Data analyzed is from the McDonnell Douglas OH-6A Higher Harmonic Control (HHC) test aircraft. HHC is an active control system used to suppress helicopter vibrations. Some of the first practical applications of Chaos methods are demonstrated with the HHC data. Although helicopter vibrations are mostly periodic, evidence of chaos was found. The presenc3e of a strange attractor was shown by computing a positive Lyapunov exponent and computing a non-integer fractal correlation dimension. Also, a broad band Fourier spectrum and a well defined attractor in pseudo phase space are observed. A limit exists to HHC vibration reduction due to the presence of chaos. A new technique based on a relationship between the Chaos methods (the Poincare section and Van der Pol plane) and the vibration amplitude and phase was discovered. This newly introduced technique results in the following: 1) it gives the limits of HHC vibration reduction, 2) it allows rapid determination of best phase for a HHC controller, 3) it determines the minimum HHC controller requirement for any helicopter from a few minutes duration of flight test data (for the OH-6A, a scheduled gain controller for HHC appears to be adequate for steady level flight), 4) it shows that the HHC controller transfer matrix is linear and repeatable when the vibrations are defined in the?Rotor Time Domain? and that the matrix is nonlinear and nonrepeatable when the vibrations are defined in the?Clock Time Domain.? This technique will reduce future HHC flight test requirements. Further, the technique does not require the helicopter to be equipped with HHC. These methods may be applicable to other vibration control and flight testing problems.
Download or read book Adaptive Inverse Control for Helicopter Vibration Reduction written by Stephen A. Jacklin and published by . This book was released on 1985 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimal Placement of Tuning Masses for Vibration Reduction in Helicopter Rotor Blades written by and published by . This book was released on 1988 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Servo Controlled Rotor Vibration Isolation System for the Reduction of Helicopter Vibration written by Leonard E. Smollen and published by . This book was released on 1962 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Higher Harmonic Blade Feathering for Helicopter Vibration Reduction written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-22 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Higher harmonic blade feathering for helicopter vibration reduction is considered. Recent wind tunnel tests confirmed the effectiveness of higher harmonic control in reducing articulated rotor vibratory hub loads. Several predictive analyses developed in support of the NASA program were shown to be capable of calculating single harmonic control inputs required to minimize a single 4P hub response. In addition, a multiple-input, multiple-output harmonic control predictive analysis was developed. All techniques developed thus far obtain a solution by extracting empirical transfer functions from sampled data. Algorithm data sampling and processing requirements are minimal to encourage adaptive control system application of such techniques in a flight environment. Powers, R. W. Unspecified Center NASA-CR-158985 NAS1-14552...
Download or read book Application of Higher Harmonic Blade Feathering on the OH 6A Helicopter for Vibration Reduction written by F. K. Straub and published by . This book was released on 1986 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
