The problem of vibration reduction of rotary wings in forward flight is studied using the concept of individual blade control. smartstructures are used as a means to construct geometric modal filters able to perform ...
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Military rotorcraft will need a high degree of maneuvering capability in future battlefield operations. Conventional design methods and blade control technology offer only limited means for improving current maneuver ...
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The feasibility of employing piezoceramic smartmaterials in active control of the higher harmonic vibration of hinged helicopter blades is investigated. The individual-blade-control concept is adopted to build feedba...
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The feasibility of employing piezoceramic smartmaterials in active control of the higher harmonic vibration of hinged helicopter blades is investigated. The individual-blade-control concept is adopted to build feedback controllers that employ collocated smart sensors and actuators and are optimized to achieve damping augmentation for blade modes that significantly contribute to the airframe dynamic response. The results indicate that there is a parameter that will help the development of efficient smart rotors.
The application of adaptive control algorithms for vibration suppression of smartstructures is investigated in this paper. An accurate mathematical representation is not required in this approach. The controller adap...
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This paper presents an adaptive control scheme based on a fuzzy-logic algorithm and its application in vibration suppression of smartstructures. Here, a fuzzy-based adaptive controller is considered due to its simpli...
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This paper presents an adaptive control scheme based on a fuzzy-logic algorithm and its application in vibration suppression of smartstructures. Here, a fuzzy-based adaptive controller is considered due to its simplicity and the fact that it does not require expression of the controller in terms of the system parameters, as is necessary in the case of self-tuning regulators. The objective is to attain an adaptive controller that retains the performance of the closed-loop system under large parameter perturbations. This controller is based on a functional fuzzy model where the consequents are crisp functions of the states and inputs and possibly their past values;these functions represent controllers designed for different operating regimes. The premise is constituted by the fuzzy subsets corresponding to the process parameters estimated in real time. The effectiveness of this new scheme is verified on a clamp-free beam instrumented with piezoceramic sensors and actuators.
smart structure has become an increasingly common term describing a structure embedded or bonded with a large number of lightweight active electromechanical sensors and actuators. In this paper, we consider the modeli...
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smart structure has become an increasingly common term describing a structure embedded or bonded with a large number of lightweight active electromechanical sensors and actuators. In this paper, we consider the modeling and control issues related to smartstructures bonded with piezoelectric sensors and actuators. We first apply Hamilton's principle to obtain a linearized equation of motion. The natural modes are then found by solving an eigenvalue problem. From the voltage input to current output, the transfer function is shown to be passive, which allows for any strictly passive feedback controller. Issues related to the design of the passive feedbackcontroller in the presence of model non-idealities and performance augmentation with a learning-based feedforward are then discussed.
This paper describes an integrated approach to design and implement robust controllers for smartstructures. To demonstrate this procedure, we have designed and fabricated a structural test article incorporating shape...
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The dynamic compliance coefficient S33 of hard ceramic structures can be changed by incorporating them as sensor-actuator combinations and applying electronic feedback in proper phase. These smart ceramic structures c...
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The dynamic compliance coefficient S33 of hard ceramic structures can be changed by incorporating them as sensor-actuator combinations and applying electronic feedback in proper phase. These smart ceramic structures can sense and react to pressure fluctuations by changing their compliance so that energy can be removed from the stimulus. Some basic geometries of smartstructures in which there is negligible field coupling between the sensor and the actuator and a basic smart structure with very high field coupling are developed and their applications in active vibration control investigated. Results for narrowband vibration control are presented which clearly show that ceramic structures can be made harder or softer depending on the phase of the feedback signal.
Microstructures can introduce significant dissipation to the signal propagation through the inhomogeneous media. We have demonstrated how to build up the proper microstructures to suppress vibration and noise in smart...
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ISBN:
(纸本)0819414840
Microstructures can introduce significant dissipation to the signal propagation through the inhomogeneous media. We have demonstrated how to build up the proper microstructures to suppress vibration and noise in smartstructures made of inhomogeneous media. We have shown that proper choice of the mismatch can become a very effective control of the structural damping.
A special design theory for distributed piezoelectric actuators is introduced, for reducing noise and vibration in structures. A uniform cylindrical shell is taken as an example of a host structure to illustrate the e...
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