Engineering Commons^™

Design, Realization, And Verification Of A Planar, Tendon-Driven, Variable Stiffness Finger, Allison Goetz

Master's Theses (2009 -)

Traditional robotic manipulators are designed for accurate absolute positioning and require a highly structured environment to perform simple operations. They are unable to compensate for small discrepancies in the relative positioning of the robot end-effector with respect to its environment. A task-appropriate compliance allows a robotic manipulator to compensate for small discrepancies in the position or orientation of an object when the object is constrained. A better means of realizing task-appropriate structured compliant behavior is needed to allow a robot to perform dexterous manipulation.In this thesis, three agonist-antagonist variable stiffness actuators (VSAs) are used to independently control the joint stiffnesses …

Design, Assessment, And Comparison Of Antagonistic, Cable-Driven, Variable Stiffness Actuators, Ryan P. Moore

Master's Theses (2009 -)

This thesis presents the designs and test results for two antagonistic, cable-driven, variable stiffness actuator designs. Each of these variable stiffness actuators is compact, has a large range of controllable stiffness, and limits the inertia at the robotic link it is controlling. Each design consists of a cable running through a set of three pulleys. Tension on the cable displaces a linear spring, which moves along a path designed to achieve quadratic spring behavior. One design uses a variable radius path to achieve the nonlinear elastic behavior while the other uses a fixed radius (lever) path.A quasi-static model of …

Admittance Selection For Force Guided Assembly With Optimal Motion, Fernando Rodriguez Anton

Master's Theses (2009 -)

t

Current robots lack the precise relative positioning necessary to complete automatic assembly tasks. Several solutions have been proposed. Some approaches use complex vision and force sensing systems to generate corrective motion if misalignment is present in the assembly task. Other solutions rely on generating elastic behavior, known as compliance, between the end eector and the held movable part. This compliant mechanism helps guide the movable part of the assembly into its proper position. The project focuses on designing a process by which passive compliant systems can achieve successful assembly for a range of misalignment and generate error-reducing motion that …