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 12 of 12 for “"multiple actuators"”.
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Robust and Adaptive Nonlinear Control of Limit Cycle Oscillations in UAVs Using Synthetic Jet Actuators
… UAV systems that do not require heavy mechanical actuators (e.g., ailerons). To address this, the use of synthetic jet actuators (SJAs) in UAV fight control systems is becoming popular as a practical alternative to mechanical deflection surfaces. SJAs are promising tools for LCO suppression …
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Limiting controls in vector state space systems
… method of actuation. The first NCS contains multiple actuators but only one is allowed to be utilized during any time step. An optimal control policy is found, and the trade-off between utilizing each actuator is analyzed. In the second NCS either all actuators are utilized or none are. A …
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Acquisition and control of a precision formation flying mission
… Missions such as Stellar Imager plan to use multiple spacecraft in a formation instead of a typical monolithic space telescope, achieving a resolution up to 0.1 milliarcseconds. In order to assemble into a formation, these satellites must first locate each other using limited field-of-view …
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Design and analysis of active fluid-and-cellular solid composites for controllable stiffness robotic elements
… often faced the challenges of developing actuators that were "soft" but still discrete, and were limited in performance. In contrast, the controllable-stiffness composites proposed in this thesis eliminate the need for multiple actuators; a single structure can transition between various …
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A novel Adaptive Filtering approach to Drive File Identification for Service Environment Replication
… of dynamic time series commands that drive the actuators in order to replicate the responses of the actual dynamic system measured separately in its service environment. A novel adaptive filtering approach, called the Pulse Train Filtered-x Least Mean Square algorithm for waveform generation and …
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Kinematic Design and Analysis of a Morphing Wing
… would enable a wing design to be optimized for multiple missions. Engineers at the National Aeronautics and Space Administration (NASA) Langley Research Center are investigating a new Hyper-Elliptic Cambered Span (HECS) wing configuration that may lead to increased stability and control, and to …
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A compositional approach to robotic impedance control
… or closed kinematic chain manipulation with multiple actuators. In this work, compositional impedance control, or linearly superimposing impedance controllers on a robot, is presented as a step towards closing this performance gap. First, an overview of compositional impedance control is …
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Robust Nonlinear Estimation and Control Applications using Synthetic Jet Actuators
… wing. To address this, the use of synthetic jet actuators (SJAs) in UAV flight control systems is becoming popular as a practical alternative and to mechanical deflection surfaces.</p> <p>Synthetic jet actuators are promising tools for LCO suppression systems in small UAVs due to their small …
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Feedback control of oscillations in combustion and cavity flows
… and azimuthally, and which require multiple sensors and multiple actuators for control. One of the requirements of Lyapunov-based adaptive control which is particularly troublesome for combustion systems is then addressed: that the sign of the high-frequency gain of the open-loop …
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Design and Integration of a Novel Robotic Leg Mechanism for Dynamic Locomotion at High-Speeds
… algorithms. Part of this is owed to the multiple degrees of freedom (DOFs) these intricate mechanisms possess and the other is a result of the complex nature of dynamic legged locomotion. The underlying dynamics of this class of non-linear systems must be addressed in order to develop …
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Development and implementation of a multi-axial real-time hybrid simulation framework
… multi-axial loading, a loading assembly with multiple parallel actuators connected to a rigid moving platform is required to impose realistic boundary conditions on physical components. This loading assembly is expected to exhibit significant dynamic actuator coupling and suffer from …
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Mechanism and applications of elastic actuators
… the mechanics and applications of elastic actuators, with a focus on twisted and coiled polymer actuators (TCPAs) and their integration into robotic systems. TCPAs are fabricated with varying geometric parameters from polymer yarns. The fabrication process includes twisting and coiling …