Matching Items (3)
Description
Human operators have difficulty driving cranes quickly, accurately, and safely because of the slow response of heavy crane structures, non-intuitive control interfaces, and payload oscillations. Recently, a novel hand-motion crane control system has been proposed to improve performance by coupling an intuitive control interface with an element that reduces the complex oscillatory behavior of the payload. Hand-motion control allows operators to drive a crane by simply moving a hand-held radio-frequency tag through the desired path. Real-time location sensors are used to track the movements of the tag and the tag position is used in a feedback control loop to drive the crane. An input shaper is added to eliminate dangerous payload oscillations. However, tag position measurements are corrupted by noise. It is important to understand the noise properties so that appropriate filters can be designed to mitigate the effects of noise and improve tracking accuracy. This work discusses implementing filtering techniques to address the issue of noise in the operating environment. Five different filters are used on experimentally-acquired tag trajectories to reduce noise. The filtered trajectories are then used to drive crane simulations. Filter performance is evaluated with respect to the energy usage of the crane trolley, the settling time of the crane payload oscillations, and the safety corridor of the crane trajectory. The effects of filter window lengths on these parameters are also investigated. An adaptive filtering technique, namely the Kalman filter, adapts to the noise characteristics of the workspace to minimize the tag tracking error and performs better than the other filtering techniques examined.
ContributorsRagunathan, Sudarshan (Author) / Frakes, David (Thesis advisor) / Singhose, William (Committee member) / Tillery, Stephen Helms (Committee member) / Arizona State University (Publisher)
Created2012
Description
In this paper we explore the design, implementation, and analysis of two different approaches for providing music recommendations to targeted users by implementing the Gram-ART unsupervised learning algorithm. We provide a content filtering approach using a dataset of one million songs which include various metadata tags and a collaborative filtering approach using the listening histories of over one million users. The two methods are evaluated by their results from Million Song Dataset Challenge. While both placed near the top third of the 150 challenge participants, the knowledge gained from the experiments will help further refine the process and likely produced much higher results in a system with the potential to scale several magnitudes.
ContributorsMeiss, Trevor (Author) / Meuth, Ryan (Thesis director) / Miller, Phill (Committee member) / Barrett, The Honors College (Contributor)
Created2015-05
Description
Foveal sensors employ a small region of high acuity (the foveal region) surrounded by a periphery of lesser acuity. Consequently, the output map that describes their sensory acuity is nonlinear, rendering the vast corpus of linear system theory inapplicable immediately to the state estimation of a target being tracked by such a sensor. This thesis treats the adaptation of the Kalman filter, an iterative optimal estimator for linear-Gaussian dynamical systems, to enable its application to the nonlinear problem of foveal sensing. Results of simulations conducted to evaluate the effectiveness of this algorithm in tracking a target are presented, culminating in successful tracking for motion in two dimensions.
ContributorsSpell, Gregory Paul (Co-author) / Cochran, Douglas (Thesis director) / Morrell, Darryl (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2015-05