Aerospace Engineering Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2737
Browse
3 results
Search Results
Item MECHANICAL DESIGN OF DEXTEROUS MANIPULATOR LINKS(2018) Carlsen, Christopher James; Akin, David L; Aerospace Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This paper explores the challenges of dense structure-electronics packaging, specifically for a structural and electronics upgrade to the Ranger Tele-robotic Shuttle Experiment (RTSX) manipulators at the University of Maryland (UMD). Long serial-link manipulators are popular in the space industry, where the need for a long reach and high manipulability outweighs the need for high tip stiffness. For larger systems with co-located electronics, such as those used to berth vehicles on orbit, electronics packaging is not inhibited by the diameter of the link body. As link diameter decreases, co-locating electronics in the manipulator becomes diffcult without adding external extensions to house them. In such densely packed bodies, the control electronics are so integrated with structure that electronics maintenance requires disassembly of primary structure.Item HUMAN FACTORS EVALUATION OF OPERATOR INTERFACES FOR TELEOPERATION OF A DEXTEROUS MANIPULATOR(2014) Davis, Kevin Patrick; Akin, David L; Aerospace Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Ground teleoperation of a satellite servicing spacecraft is a challenging task for a human operator, especially when there is significant communications delay between the control station and spacecraft. On-orbit operations are further complicated by a communications time delay between the ground and spacecraft. Operator performance can be improved with the use of a graphical simulation of the robot. By displaying the robot's commanded position, graphical simulation can also mitigate some effects of time delay. This work implemented a visualization tool and commanded display to assist operation of a remote dexterous manipulator. A Fitts' Law experiment was designed to determine the effectiveness of the commanded display in reducing the impact of time delay. The experiment was conducted with a six degree of freedom manipulator over a range of time delays, from 0.0 to 6.0 seconds. The experimental results were analyzed to assess the reduction of task completion time and operator workload.Item DEVELOPMENT AND EVALUATION OF A FLEXIBLE DISTRIBUTED ROBOT CONTROL ARCHITECTURE(2010) Ellsberry, Andrew John; Akin, David; Aerospace Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The communications and electronic systems that comprise a distributed control architecture for a robotic manipulator tie the high level control and motion planning to the electromechanical components. Custom solutions to this problem can be expensive in terms of time, cost, and maintenance. The integration of commercial off the shelf (COTS) motion controllers, combined with a robust communication standard, offers the potential to reduce the costs and development times for new robots. This thesis demonstrates an implementation of this architecture using commercial controllers and the CANopen communications bus on two existing dexterous robots. Testing is conducted to quantify the single joint performance of these modules. Additionally, the implementation of the system on a second robot arm was conducted in order to test the flexibility of the system for use with different actuators and feedback.