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.
Results
Showing 1 to 20 of 30 for “"filtered-x"”.
-
Application of the Filtered-X LMS Algorithm for Disturbance Rejection in Time-Periodic Systems
… systems in particular until recently. The filtered-X LMS algorithm is regarded as the best disturbance rejection technique for aperiodic systems by many, as has been proven in the acoustics industry for rejecting unwanted noise. Since this is essentially a feedforward approach, we might …
-
Improving Performance of the Filtered-X Least Mean Square Algorithm for Active Control of Noise Contatining Multiple Quasi-Stationary Tones
<p>The Filtered-X Least-Mean-Square (FXLMS) algorithm is widely used in active noise control due to its robustness, simplicity, and ability to be implemented in real time. In a feedforward implementation of the FXLMS algorithm, a reference signal that is highly correlated with the noise to be …
-
A Principal Component Algorithm for Feedforward Active Noise and Vibration Control
… a transform domain version of the multichannel filtered-x LMS algorithm. The transformation corresponds to the principal components of the transfer function matrix between the sensors and actuators in a control system at a single frequency. The method is similar to other transform domain LMS …
-
Optimum Actuator Grouping in Feedforward Active Control Applications
… based upon weights determined by converging the filtered-x LMS algorithm and simultaneously grouping and controlling with the compensator weights initialized to small arbitrary numbers. Test cases of heavy and light grouping parameters were evaluated from both initial conditions. The computer …
-
Investigation of combined feedback and adaptive control of cylinder vibrations
… implemented. The feedforward loop utilizes the filtered-x LMS algorithm. The result of combining the two control laws was unknown prior to implementation.The resulting control scheme shows that the feedback control law is effective in attenuating undesirable frequency components in the …
-
Ingeniería avanzada para sistemas de control de ruido acústico mediante técnicas adaptativas
… utilizados: algoritmos de entrada filtrada filtered-X/U LMS y algoritmos genéticos. La estimación de la función de transferencia de cancelación es muy importante en los algoritmos de entrada filtrada ya que los errores de esta estima determinan la estabilidad global del sistema de control. …
-
A Study of Smart Foam for Noise Control Applications
… is minimized according to the feedforward, 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 …
-
Active control of flexural power flow in elastic thin beams
… in good agreement. Control was achieved by a LMS Filtered-x algorithm implemented in assembler language on a TMS32020 digital signal processing chip. In general it is demonstrated that the flexural power flow in the beam types considered can be attenuated with a low number of active actuators.
-
Time average feedforward control techniques for time varying systems
… and vibrations~ Current approaches, such as the Filtered-X Least Mean Square algorithm, are limited in adaptability and applicability by the computationally intensive system identification process. The Time Average approach is a technique that promises to be a major advance in the active control …
-
Application of Active Noise Control to Reduce Cabin Noise in Single Engine General Aviation Aircraft
… aircraft is investigated through the use of the 'filtered x' least mean square algorithm and a simple acoustic feedforward method to generate a reference signal is tested. The system is designed to utilize one reference signal and up to two feedback signals and two audio speakers. The feedforward …
-
Advanced sensing techniques for active structural acoustic control
… algorithm in this study was the feed forward filtered-x version of the adaptive LMS algorithm. A much lower level of system modelling is required with this method of control in comparison to state feedback control methods. As a result, much of the structural acoustic coupling (i.e. system …
-
Demonstration of active structural acoustic control of cylinders
… signal processing hardware programmed with the filtered-x Least-Mean-Square adaptive control algorithm is used to control the vibration of the cylinder. The excitation is single-tone on-resonance. Acoustic - testing demonstrates that ASAC reduces the sound pressure level generated by the …
-
A novel Adaptive Filtering approach to Drive File Identification for Service Environment Replication
… filtering approach, called the Pulse Train Filtered-x Least Mean Square algorithm for waveform generation and drive file identification is proposed in this thesis based on methods developed for Active Noise and Vibration Control. Simulation studies are considered using various test benches …
-
Active Minimization of Acoustic Energy Density to Attenuate Radiated Noise from a Diesel Generator
… algorithms used in this research were based on a filtered-x LMS adaptive algorithm, which minimizes energy density (ED). Both feedforward and feedback control approaches were investigated. The noise spectrum produced by the diesel generator enclosure includes tonal and broadband components. The …
-
Low Frequency Noise Reduction Using Novel Poro-Elastic Acoustic Metamaterials
… noise control is achieved using a feedforward, filtered-x LMS control algorithm to minimize the downstream sound pressure level. Low-frequency absorption and transmission loss is successfully increased in the critical frequency range below 500 Hz. Acoustic metamaterials are compact compared to …
-
Addressing Stability Robustness, Period Uncertainties, and Startup of Multiple-Period Repetitive Control for Spacecraft Jitter Mitigation
… existing adaptive control algorithms, such as Filtered-X LMS, Adaptive Model Predictive Control, and Adaptive Basis Method, for mitigating jitter within the transmitting beam of Laser Communication (LaserCom) satellites.
-
Multiple Reference Active Noise Control
… handle this particular problem, the decorrelated Filtered-X LMS (DFXLMS) algorithm is developed and studied in this thesis. Both simulations and experiments have been conducted to verify the DFXLMS algorithm and other issues associated with multiple reference ANC. The results presented herein are …
-
The Control of Interior Cabin Noise Due to a Turbulent Boundary Layer Noise Excitation Using Smart Foam Elements
… in the anechoic box. An adaptive feedforward filtered-x Least-Mean-Squared (LMS) control algorithm was used to drive the smart foam actuators to reduce the sound pressure levels at an array of microphones. Accelerometers measured the response of the test panel and were used as the reference …
-
Adaptive feedforward control of broadband structural vibration
… systems. The algorithms are based on the filtered-X Least Mean Square (LMS) adaptive algorithm. A system identification of the plant control loop is required to implement this algorithm. An autoregressive moving-average (ARMA) model was used for the system identification since it provides …
-
Active control of acoustic radiation due to discontinuities on thin beams
… The digital controller employed was the filtered-x version of the adaptive LMS algorithm programmed on a dedicated signal processing board in a personal computer. An array of accelerometers was attached to the beam which were used to decompose the complex amplitudes of an assumed …
Page 1 of 2