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Showing 1 to 6 of 6 for “"Positive Position Feedback (PPF)"”.
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An experimental investigation into active damage control systems using positive position feedback for AVC
This work discusses the use of Positive Position Feedback (PPF) for Active Vibration Control as part of an Active Damage Control System (ADCS). Vibration control increases the fatigue life of a structure and decreases the in-plane stresses that can cause delamination in a composite. PPF is a …
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Adaptive Collocated Feedback for Noise Absorption in Acoustic Enclosures
This thesis focuses on adaptive feedback control for low frequency acoustic energy absorption in acoustic enclosures. The specific application chosen for this work is the reduction of high interior sound pressure levels (SPL) experienced during launch within launch vehicle payload fairings. Two …
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Vibration Suppression Using Smart Materials in the Presence of Temperature Changes
… controller. The active controller utilizes three positive position feedback (PPF) filters implemented through a digital signal processor board. This research develops two different adaptation methods to perform vibration suppression in the presence of thermally induced frequency changes of the …
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A Comprehensive Experimental Evaluation of Actively Controlled Piezoceramics with Positive Posistion Feedback for Structural Damping
… of actively controlled piezoceramics with positive position feedback (PPF) for reducing structural vibrations. A comparison is made between active control with PPF and a parallel resistor-inductor (RLC) shunt technique. The primary objectives of this study are to: 1. Explore the feasibility …
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Optimal Vibration Suppression Using On-line Pole/Zero Identification
… transfer function to design the optimum Positive Position Feedback (PPF) control law. The PPF control law uses second-order filters to add closed-loop damping to resonant structural modes. An on-line PPF design algorithm was developed based on the theoretical model of the collocated …
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Macro-Fiber Composites for Sensing, Actuation and Power Generation
… satellite component. The control system used a positive position feedback (PPF) controller and two pairs of sensors and actuators in order to provide global vibration suppression of an inflated torus. The experiments found that the MFC and control system was very effective at attenuating the …