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 13 of 13 for “"Screw Theory"”.
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Augmenting Datum Flow Chain method to support the top-down design process for mechanical assemblies
… representation of mechanical assemblies and screw theory for representation of constraints between two parts. DFC captures the design intent by recording location scheme of assemblies. Screw theory can represent constraints in three dimensions. This thesis presents the design steps and …
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Applications of Geometric Algebra in Mathematical Engineering
… robotics algorithms. In Part II we explore how Screw Theory embeds into CGA, how to use this embedding for simulation of the dynamics of rigid bodies, and how practitioners can leverage the geometric primitives built into CGA to represent and solve constraints in multi-body robotic systems.
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A unified approach to modeling, verifying, and improving the manufacturability of mechanical assemblies
… model is developed using a combination of Screw Theory, Network Theory, Homogeneous Transformation Matrices, and Probability Theory. It is shown how this model can be used to verify the manufacturability of a mechanical assembly design. It is also shown how the model and the results …
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Design of flexure-based motion stages for mechatronic systems via Freedom, Actuation and Constraint Topologies (FACT)
… Each shape rapidly conveys the mathematics of screw theory, projective geometry, and constraint-based design by visually depicting regions where constraints and actuators may be placed for synthesizing optimal flexure concepts. In this way, designers may consider every flexure concept that …
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Trajectory Generation for a Multibody Robotic System: Modern Methods Based on Product of Exponentials
… of Exponentials (PoE) formulation, also known as screw theory. A PoE formulation is first developed to model the kinematics and dynamics of a multibody robotic manipulator (Sawyer Robot) with 7 revolute joints and an end-effector.</p> <p>In the first method, an Inverse Kinematics (IK) algorithm …
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Key characteristic coupling and resolving key characteristic conflict
… the scenarios of conflict in the assembly. Screw theory can be used to find the presence of coupling among requirements in the assembly. It can also be used to identify the nature of coupling. If coupling suggests that requirements are coupled, we analyze the intensity of the conflict. Not …
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Remote robotic manipulation task execution using affordance primitives
… in this dissertation. They are based on screw theory, and naturally capture simply articulated objects with one or more degrees of freedom. The implementation of affordance primitives is agnostic to the task, environment, and robot hardware, and allows flexibility in the control input …
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Microassembly technology for modular, polymer microfluidic devices
… passive alignment structures were analyzed using screw theory. A combination of three v-groove and hemisphere-tipped post joints constrained all degrees of freedom of the two mating modules without overconstraint. Simulations and experiments were performed to assess the predictability of …
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The Kinematics of Rigid Body Contact in the Design and Analysis of Machining Fixtures
… location of 3-2-1 locator schemes. Using screw theory, we derive new and simple geometric conditions for their deterministic location and good conditioning. Next, we develop combinatorial algorithms for the synthesis of near-optimal 3-2-1 locator schemes. We show that the search can be …
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Nonlinear Control for Dual Quaternion Systems
… (3). An eight dimensional representation of screw theory (combining dual numbers with traditional quaternions), dual quaternions allow for the development of control techniques for 6 DOF motion simultaneously. In this work variable structure nonlinear control methods are developed for dual …
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Task Modeling, Sequencing, and Allocation for In-Space Autonomous Assembly by Robotic Systems
… of four metrics and analyzed through the use of screw theory kinematics. The final contribution focuses on a set of metrics to guide the selection of a good scheduling method for different assembly situations. The experiments in this work demonstrate how the developed theory can be utilized and …
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Kinematics Analysis of Two Parallel Locomotion Mechanisms
… are developed respectively. Based on the screw theory, the Jacobian matrices are assembled. Using Grassmann Line Geometry, each row of the Jacobian matrices is interpreted as a line in 3D space and the analytical conditions of the linear dependency cases are identified, which corresponds …
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Design and analysis of a three degrees of freedom (DOF) parallel manipulator with decoupled motions
Parallel manipulators have been the subject of study of much robotic research during the past three decades. A parallel manipulator typically consists of a moving platform that is connected to a fixed base by at least two kinematic chains in parallel. Parallel manipulators can provide several …