Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"Error Sensor"”.
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Error Sensor Placement for Active Control of an Axial Cooling Fan
… (ANC) for cooling fans have used near-field error sensors whose locations are determined according to a theoretical condition of minimized sound power. A theoretical point source model, based on the condition previously stated, reveals the location of near-field pressure nulls that may be …
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Optimization of Control Source and Error Sensor Locations in Free Field Active Noise Control
… fans. Optimization of the control source and error sensor placement is desired to maximize the attenuation using ANC. A genetic algorithm was developed to find the optimal placement of control sources for a given primary source. The optimal configuration of control sources around a single …
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Error Sensor Strategies for Active Noise Control and Active Acoustic Equalization in a Free Field
Several measurements may be used as error signals to determine how to appropriately control a sound field. These include pressure, particle velocity, energy density and intensity. In this thesis, numerical models are used to show which signals perform best in is free-field active noise control …
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Hybrid adaptive feedforward control of structures to seismic inputs
… system. 3. Peak. structural responses during sensor failures were observed to increase, in particular for the failure of the first error sensor. However, the peak. responses during these failures never reached the peak. values obtained by the system with passive control. This demonstrated the …
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Investigation of combined feedback and adaptive control of cylinder vibrations
… condition Polyvinylidene Fluoride Filnl (PVDF) sensor outputs as strain rate signals. The strain rate signals are used in the feedback loop to provide damping to the structure. In conjunction with the feedback loop a feedforward loop is also implemented. The feedforward loop utilizes the …
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Analytical investigation of active control of radiated inlet noise from turbofan engines
… configurations of secondary control sources and error sensors. Two error sensing strategies are considered in this work. The first approach uses microphones placed in the acoustic far field. The second sensing technique consists of placing distributed error sensors in the engine inlet. …
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Design of Active Structure Acoustic Control Systems Using Eigenassignment Approach
… system has equal number of control inputs and error sensor outputs, the feedforward controller can effectively modify the system dynamics (i.e., resonance frequencies and mode shapes). This provides the theoretical basis for the eigenassignment method. For the non-volumetric design, the …
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Active Minimization of Acoustic Energy Density in a Mock Tractor Cab
… sides and a Plexiglas® front. An energy density sensor, capable of measuring acoustic pressure as well as acoustic particle velocity, provided the error signal to the control system. The ANC system operated on a single reference signal, which, for experiments involving recorded tractor engine …
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Attenuation of Turbulent Boundary Layer Induced Interior Noise Using Integrated Smart Foam Elements
… Smart Foam actuators each having a reference and error sensor along with a feed forward, filtered-x controller. Studies were performed to determine if the use of multiple instances of single input, single output (SISO) control systems could be implemented with success given the difficulty of …
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Active control of automobile cabin noise with conventional and advanced speakers
… in order to optimize the positions of the error sensors and the control sources. Experimental work was performed with the optimized actuator and sensor locations in order to validate the model, and draw conclusions regarding the conditions to obtain global control of the sound field. …
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Active Minimization of Acoustic Energy Density to Attenuate Radiated Noise from a Diesel Generator
… control, but this was limited to regions at the error sensor. An overall SPL reduction of 1.9 dBA outside the enclosure was achieved near the power terminal side of the enclosure. This was accomplished using tonal and broadband feedforward control. Experimental results show that control source …
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Sensitivity Analyses of Optimized Attitude Estimators Using Sensor Fusion Solutions for Low-Cost MEMS Configurations
… analyses the performance and sensitivity of four sensor fusion solutions for attitude estimation under multiple simulated flight conditions. There are three different hardware configurations between the four estimators. For this reason, each estimator is tuned to be experimentally optimal, as to …
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Optimum design for feedforward structural-acoustic control of complex structural systems
… where the optimum modal control forces and modal error sensor components which minimize the total radiated power are obtained. These optimum modal parameters are then used in a set of lower level optimization problems to find the physical characteristics of the actuators and sensors to be …
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An Investigation of Active Tonal Spectrum Control as Applied to the Modern Trumpet
… of the acoustic control actuator and the error sensor to be used. With the chosen actuator and sensor, the two types of controllers are designed and realized. The farfield spectrum of the trumpet's response to a single note is analyzed for each controller and the resulting attenuations …
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The active minimisation of harmonic enclosed sound fields, with particular application to propeller induced cabin noise
… the squared pressures over a number of discrete sensors. Both theoretical and experimental results from using this cost function are presented. These show good agreement. The importance of both secondary source and error sensor locations is discussed. The reduction of low frequency propeller …
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A Study of Smart Foam for Noise Control Applications
… Filtered-x LMS control algorithm using one error sensor. Significant broadband sound attenuation is obtained. A more advanced noise control problem is investigated which minimizes plate radiation. The vibrating plate has a distributed modal response requiring a collective array of …
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Optimum Actuator Grouping in Feedforward Active Control Applications
… cost function to group actuators and control the error response with either initial condition. The heavy grouping cases achieved the same one channel control system from both initial conditions. The performance of the one channel solution was 1.5 dB lower than the performance of the ungrouped …
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A regression-based approach for simulating feedfoward active noise control, with application to fluid-structure interaction problems
… regression, can be used to model the effects of error sensor measurement noise to produce a more realistic simulation. Numerical results are presented for a finite-length, fluid-loaded cylindrical shell with clamped, rigid end closures. It is shown that when the controller reduces the radiated …
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Autonomous Vehicle Pose Estimation in GNSS-Denied Areas Using Cross-Track Error Measurements
… to vehicle pose estimation using cross-track error (CTE) measurements as supplemental inputs for GNSS denied environments. The proposed method leverages CTE, a measure of lateral deviation from a desired trajectory, to estimate the vehicle’s position and orientation in real-time using an …