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 20 of 68 for “"Underactuated"”.
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Nonlinear Control of Underactuated and Constrained Systems
… to elaborate on the control of systems that are underactuated or otherwise constrained. To do so, local- and global-coordinate formulations are implemented to generate well-defined system dynamics for a multitude of scenarios. These dynamics are shown to lie on manifolds defined by mathematical …
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Morphological design methodology of rugged underactuated gripper
… is to extend the design tools for robust underactuated hand design. Disaster response robots operate in highly unstructured environments where they need to dynamically move and interface to successfully fulfill their task. Historically robotic hands have been optimized for grasp strength, …
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Autonomous thruster failure recovery for underactuated spacecraft
… failure may cause the spacecraft to become underactuated, requiring more advanced control techniques. Therefore, the objective of this thesis is to develop and analyze thruster failure recovery techniques for the attitude and translational control of underactuated spacecraft. To achieve this …
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Decentralized Declustering of Multiple Underactuated Autonomous Surface Vehicles
… deployed from a single location, and their underactuated nature, close proximity, and susceptibility to external disturbances make it difficult to achieve a mission-ready configuration without collisions. In this thesis, we address the problem of transitioning a set of underactuated …
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Underactuated Exoskeletons for Lifting, Carrying, and Walking Assistance
… force) with a single actuator on each leg. Its underactuated design directs force through the user's center of mass with a single sprocket-chain driven prismatic actuator on each leg, allowing for natural gait and mobility. The device is optimized for simplicity, ease of assembly, low cost, and …
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Swing-Up and Balancing Control of Underactuated Robotic Systems
… and implemented on the Pendubot, a two-link underactuated robot. The parameters of the Pendubot were varied by up to 50% in order to test robustness to parameter errors. The robust control scheme using sliding mode concepts successfully compensated for modeling imprecision and disturbances …
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Design and Evaluation of an Underactuated Lower Body Exoskeleton
An underactuated exoskeleton design for walking assistance is presented and evaluated. The exoskeleton uses one motor per leg and makes use of a pantograph to reduce the overall profile and allow the exoskeleton to closely follow the shape of the user's leg. Support is provided between the ball of …
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Exploration of Vibrational Control of Two Underactuated Mechanical Systems
Control of underactuated mechanical systems is of interest as it allows for control authority over all of a system's degrees of freedom without requiring actuation of the full system. In addition to this, open-loop control of a system provides the advantage of applying to systems with unmeasurable …
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Theoretical and Experimental Investigation of Attitude Control for Underactuated Spacecraft
… and attitude control capabilities of an underactuated 3U-CubeSat used for ESSENCE mission developed by York University. Three different types of actuatorsexternal thrusters, magnetorquers, and reaction wheelsare considered in the nonlinear rigid-body control problem. According to …
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Design of an Underactuated Lower Body Exoskeleton Using a Pantograph
This paper presents the design of an underactuated lower body exoskeleton to assist with walking. It reduces the amount of bodyweight going through the user's leg by providing a supporting force to the user that is engaged and disengaged depending on the stage of the gait cycle the user is in. It …
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Design, analysis and trajectory tracking control of underactuated mobile capsule robots.
… tracking control and implementation of underactuated mobile capsule robots. These capsule robots can be modified and used in in-vivo medical applications. Researches on the capsubottype underactuated system focus on the stabilization of the robot and tracking the actuated configuration. …
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Control of underactuated fluid-body systems with real-time particle image velocimetry
Controlling the interaction of a robot with a fluid, particularly when the desired behavior is intimately related to the dynamics of the fluid, is a difficult and important problem. High-performance aircraft cannot ignore nonlinear stall effects, and robots hoping to fly and swim with performance …
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A low-cost, high-strength, open-source, rapid prototypeable underactuated robot gripper
In this work, an underactuated robot gripper was designed to meet specifications for strength, cost, and ease of manufacturing with Open-Source distribution in mind. The specifications emerged from a need for inexpensive grippers that can be used on robots that help people brace and balance. The …
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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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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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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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Design and Integration of an Underactuated Robotic Finger with Vision-based Tactile Sensing
Underactuated fingers are adaptable to different shapes, robust, and cost-effective for executing sturdy and versatile grasps. However, they generally have limited control or require complex planning when performing tasks that require high precision or delicate handling. Vision-based tactile …
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Design and Evaluation of an Underactuated Robotic Gripper for Manipulation Associated with Disaster Response
… study focuses on the design and validation of an underactuated robotic gripper built for the Tactical Hazardous Operations Robot (THOR). THOR is a humanoid robot designed for use in the DARPA Robotics Challenge (DRC) and the Shipboard Autonomous Fire Fighting Robot (SAFFiR) project, both of which …
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Design and control of a gravity-assisted underactuated snake robot with application to aircraft wing assembly
… driving a multitude of passive joints. This underactuated arm design was motivated by the need for a compact snake-like robot for assembly operations inside an aircraft wing. The interior of the wing is accessible only through small access portholes distributed along the length. Currently, …
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Control of a nonlinear underactuated system with adaptation, numerical stability verification, and the use of the LQR Trees algorithm
Underactuated robotics, though surrounded by an established body of work, has certain limitations when nonlinear adaptive control principles are applied. This thesis applies a nonlinear adaptative controller that avoids many of these limitations using alterations inspired by the control of a …
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