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 “"Underactuated Systems"”.
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Robust Control and Motion Planning for Nonlinear Underactuated Systems Using H -Infinity Techniques
… and robustly controlling the motion of nonlinear underactuated vehicles when disturbances are present and only imperfect state measurements are available for feedback. The basic motion planning algorithm uses cubic splines or Pythagorean hodograph curves to connect the initial and final …
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Nonlinear control of underactuated mechanical systems with application to robotics and aerospace vehicles
… control, reduction, and classification of underactuated mechanical systems. Underactuated systems are mechanical control systems with fewer controls than the number of configuration variables. Control of underactuated systems is currently an active field of research due to their broad …
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L1 adaptive control for nonlinear and non-square multivariable systems
… nonlinear, and non-square multivariable systems. The objective is to extend the L1 adaptive control framework to cover a wide class of underactuated systems with uniform performance and robustness guarantees. This dissertation starts by investigating some structural properties of …
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Design and process/measurement for immersed element control in a reconfigurable vertically falling soap film
… successful at harnessing the passive dynamics of underactuated systems to achieve least energy solutions. However, coupled fluid-structural models are too computationally intensive for in-the-loop control in viscous flow regimes. My vertically falling soap film will provide a reconfigurable …
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Design, construction, and experiments with a compass gait walking robot
… techniques for the control of nonlinear and underactuated systems have been developed and tested largely in theory and simulation. In order to better understand how these new tools are applied to real systems and to expose areas where the theory is lacking testing on a physical model system …
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Robust Control Methods for Nonlinear Systems with Uncertain Dynamics and Unknown Control Direction
… reliable and accurate tracking control for systems containing dynamic uncertainty, unmodeled disturbances, and actuator anomalies that result in an unknown and time-varying control direction. In order to ease readability of this dissertation, detailed explanations of the relevant …
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Toward optimal motion planning for dynamic robots : applications on-orbit
… practical for real-time deployment on current systems. However, robots that have dynamics, operate with uncertainty, or navigate difficult environments are at the edge of what is deployable today. While one may be able to develop a kinematic trajectory for a stationary fully-actuated robotic …
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Bio-inspired robotic control in underactuation: principles for energy efficacy, dynamic compliance interactions and adaptability.
Biological systems achieve energy efficient and adaptive behaviours through extensive autologous and exogenous compliant interactions. Active dynamic compliances are created and enhanced from musculoskeletal system (joint-space) to external environment (task-space) amongst the underactuated …
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Control of the motion of nonholonomic systems
… and stabilisation of nonlinear, non¬holonomic systems. It is shown that the kinematics of the system can be separated from the dynamics of the system by using successively two inverse dynamics type of transformations. This leads to a linear decoupled kinematical system, control strategies can …
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Discrete-time Stable Geometric Controller and Observer Designs for Unmanned Vehicles
… dissertation, we consider tracking control of underactuated systems on the tangent bundle of the six-dimensional Lie group of rigid body motions, SE(3). We formulate both asymptotically and finite-time stable tracking control schemes for underactuated rigid bodies that have one translational …
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Simulations of a three degree of freedom brachiating Y-bot robot
… was designed to solve optimization problems of underactuated systems. The main method used in the trajectory optimization was direct collocation. The task of the robot in the simulations was to swing from a one "branch" point to another. The trajectories of two Y-bot models swinging from rest …
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Design, Analysis, and Optimization of Vibrational Control Strategies
… control strategies for mechanical control-affine systems with high-frequency, high-amplitude inputs. Since these control systems use high-frequency, zero-mean, periodic inputs, averaging techniques are widely used in the analysis of their dynamics. By studying their time-averaged approximations, …
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Sample-based motion planning in high-dimensional and differentially-constrained systems
… have proven to be effective in path planning for systems subject to complex kinematic and geometric constraints. The performance of these algorithms, however, degrade as the dimension of the system increases. Furthermore, sample-based planners rely on distance metrics which do not work well when …
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Robust online motion planning with reachable sets
… work on feedback motion planning for nonlinear systems was limited to offline planning due to the computational cost of safety verification. Here we augment the traditional trajectory library approach by designing locally stabilizing controllers for each nominal trajectory in the library and …
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On data-driven modelling and terminal sliding mode control of dynamic systems with applications
… fast terminal sliding mode control alongside underactuated crane control, and robotic pointing system for thermoelastic stress analysis (TSA). The first part is devoted to system modelling. A dynamic model can be identified from data collected (input and output data from the plant). However, …
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Robust adaptive sampled-data control design for MIMO systems: Applications in cyber-physical security
… framework. Multi-input multi-output non-square (underactuated) systems are considered with different sampling rates for inputs and outputs. The sampled-data framework allows to address non-minimum phase systems, subject to less restrictive assumptions as compared to continuous time framework. It …
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Computational Methods to Improve Satellite Attitude Determination and Control with a Focus on Autonomy, Generalizability, and Underactuation
… stability and performance, particularly for underactuated systems–improving pointing accuracy by up to 20 degrees. The developed control laws are adaptable to various actuator configurations, disturbance environments, and pointing objectives. This flexibility extends to modifying pointing …
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Stability and robustness of adaptive controllers for underactuated Lagrangian systems and robotic networks
… robustness of an adaptive control framework for underactuated Lagrangian systems and robotic networks. In particular, an adaptive control framework is designed for a manipulator, which operates on an underactuated dynamic platform. The framework promotes the use of a filter in the control input …
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Practical Challenges in the Method of Controlled Lagrangians
… is an energy shaping control technique for underactuated Lagrangian systems. Energy shaping control design methods are appealing as they retain the underlying nonlinear dynamics and can provide stability results that hold over larger domain than can be obtained using linear design and …