Development of a Truss Joint for Robotic Assembly of Space Structures


Book Description

This report presents the results of a detailed study of mechanical fasteners which were designed to facilitate robotic assembly of structures. Design requirements for robotic structural assembly were developed, taking into account structural properties and overall system design, and four candidate fasteners were designed to meet them. These fasteners were built and evaluated in the laboratory, and the Hammer-Head joint was chosen as superior overall. It had a high reliability of fastening under misalignments of 2.54 mm (0.1 in) and 3 deg, the highest end fixity (2.18), the simplest end effector, an integral capture guide, good visual verification, and the lightest weight (782 g, 1.72 lb). The study found that a good design should incorporate chamfers sliding on chamfers, cylinders sliding on chamfers, and hard surface finishes on sliding surfaces. The study also comments on robot flexibility, sag, hysteresis, thermal expansion, and friction which were observed during the testing. Parma, George F. Johnson Space Center RTOP 472-46-07-17...




Intelligent Robotic Systems for Space Exploration


Book Description

Over the last twenty years, automation and robotics have played an increasingly important role in a variety of application domains including manufacturing, hazardous environments, defense, and service industries. Space is a unique environment where power, communications, atmospheric, gravitational, and sensing conditions impose harsh constraints on the ability of both man and machines to function productively. In this environment, intelligent automation and robotics are essential complements to the capabilities of humans. In the development of the United States Space Program, robotic manipulation systems have increased in importance as the complexity of space missions has grown. Future missions will require the construction, maintenance, and repair of large structures, such as the space station. This volume presents the effords of several groups that are working on robotic solutions to this problem. Much of the work in this book is related to assembly in space, and especially in-orbit assembly of large truss structures. Many of these so-called truss structures will be assembled in orbit. It is expected that robot manipulators will be used exclusively, or at least provide partial assistance to humans. Intelligent Robotic Systems for Space Exploration provides detailed algorithms and analysis for assembly of truss structure in space. It reports on actual implementations to date done at NASA's Langley Research Center. The Johnson Space Center, and the Jet Propulsion Laboratory. Other implementations and research done at Rensselaer are also reported. Analysis of robot control problems that are unique to a zero-gravity environment are presented.




NASA Technical Paper


Book Description