Search NASA⌕ Search

SEARCH · Search NASA

Results for “Robotic Assembly”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18

Control of free-flying space robot manipulator systems

New control techniques for self contained, autonomous free flying space robots were developed and tested experimentally. Free flying robots are envisioned as a key element of any successful long term presence in space. These robots must be capable of performing the assembly, maintenance, and inspection, and repair tasks that currently require human extravehicular activity (EVA). A set of research projects were developed and carried out using lab models of satellite robots and a flexible manipulator. The second generation space robot models use air cushion vehicle (ACV) technology to simulate in 2-D the drag free, zero g conditions of space. The current work is divided into 5 major projects: Global Navigation and Control of a Free Floating Robot, Cooperative Manipulation from a Free Flying Robot, Multiple Robot Cooperation, Thrusterless Robotic Locomotion, and Dynamic Payload Manipulation. These projects are examined in detail.

Cannon, Robert H., Jr.↗

Inertial-space disturbance rejection for space-based manipulators

The implementation of a disturbance rejection controller for a 6-DOF PUMA manipulator mounted on a 3-DOF platform was described. A control algorithm is designed to track the desired position and attitude of the end-effector in inertial space, subject to unknown disturbances in the platform axes. Experimental results are presented for step, sinusoidal, and random disturbances in the platform rotational axis and in the neighborhood of kinematic singularities. Robotic manipulators were proposed as a means of reducing the amount of extra vehicular activity time required for space station assembly and maintenance. The proposed scenario involves a robotic manipulator attached to some mobile platform, such as a spacecraft, satellite, or the space station itself. Disturbances in the platform position and attitude may prevent the manipulator from successfully completing the task. The possibility of using the manipulator to compensate for platform disturbances was explored. The problem of controlling a robotic manipulator on a mobile platform has received considerable attention in the past few years. Joshi and Desrochers designed a nonlinear feedback control law to carry out tasks (with respect to the robot base frame) in the presence of roll, pitch and yaw disturbances in the platform axes. Dubowsky, Vance, and Torres proposed a time-optimal planning algorithm for a robotic manipulator mounted on a spacecraft, subject to saturation limits in the attitude control reaction jets. Papadopoulos and Dubowsky developed a general framework for analyzing the control of free-floating space manipulator systems. Most recently, Torres and Dubowsky have presented a technique called the enhanced disturbance map to find manipulator trajectories that reduce the effect of disturbances in the spacecraft position and attitude. One common assumption in the literature is that the disturbance signal is exactly known. If this is the case, then the end-effector location can be calculated without relying on direct end-point sensing. However, this assumption is invalid if there is a significant delay in the platform position and attitude measurements, or if the kinematics of the platform are not well known, or if the platform is a non-rigid structure. In the more likely case that only the nominal platform location and upper bound on the disturbance signal are known, direct end-point sensing is needed to measure the end-effector location.

Holt, Kevin↗

Segmented Hexagonal Antenna Reflector Concentrically Stacked Using Shape Memory Composite Tubular Hinges

A new architecture for solid surface reflector antennas scalable to sizes greater than 10 m is presented. The design combines the compact, lightness and simplicity characteristics of advanced deployable structures to create sub-reflectors that can be assembled in space into larger units using a robotic arm and operations under development by a related parallel project. The seven-panel hexagonal sub-reflector is divided into hexagonal panels of that efficiently stack concentrically and vertically. The central panel is connected to each side panel on the back side by a pair of tubular shape memory composite hinges that enable the required deployment kinematics. A secondary mechanism ultimately closes the interpanel gap. The focus of the paper is on the development of the sub-reflector elements, namely the tubular hinges that use embedded heaters and sensors for actuation, the actuation mechanisms, and the lightweight sandwich construction panels. A finite element analysis parametric study assessed how design features of the hinge affect its stowage and deployment dynamics. The component fabrication and testing plans for the two-panel assembly breadboard model are outlined.

deployable reflectors↗

Segmented Hexagonal Antenna Reflector Concentrically Stacked Using Shape Memory Composite Tubular Hinges

A new architecture for solid surface reflector antennas scalable to sizes greater than 10 m is presented. The design combines the compact, lightness and simplicity characteristics of advanced deployable structures to create sub-reflectors that can be assembled in space into larger units using a robotic arm and operations under development by a related parallel project. The seven-panel hexagonal sub-reflector is divided into hexagonal panels of that efficiently stack concentrically and vertically. The central panel is connected to each side panel on the back side by a pair of tubular shape memory composite hinges that enable the required deployment kinematics. A secondary mechanism ultimately closes the interpanel gap. The focus of the paper is on the development of the sub-reflector elements, namely the tubular hinges that use embedded heaters and sensors for actuation, the actuation mechanisms, and the lightweight sandwich construction panels. A finite element analysis parametric study assessed how design features of the hinge affect its stowage and deployment dynamics. The component fabrication and testing plans for the two-panel assembly breadboard model are outlined.

deployable reflectors↗

Ultra-Light, Strong, and Self-Reprogrammable Mechanical Metamaterials

Versatile programmable materials have long been envisioned that can reconfigure themselves to adapt to changing use cases in adaptive infrastructure, space exploration, disaster response, and more. We introduce a robotic structural system as an implementation of programmable matter, with mechanical performance and scale on par with conventional high-performance materials and truss systems. Fiber reinforced composite truss-like building-blocks form strong, stiff, and lightweight lattice structures as mechanical metamaterials. Two types of mobile robots operate over the exterior surface and through the interior of the system, performing transport, placement, and reversible fastening using the intrinsic lattice periodicity for indexing and metrology. Leveraging programmable matter algorithms to achieve scalability in size and complexity, this system design enables robust collective automated assembly and reconfiguration of large structures with simple robots. We describe the system design and experimental results from a 256-unit cell assembly demonstration and lattice mechanical testing, as well as demonstration of disassembly and reconfiguration. The assembled structural lattice material exhibits ultra-light mass density (0.0103 g/cc) with high strength and stiffness for its weight (0.01117 MPa and 1.1129 MPa, respectively), a material performance realm appropriate for applications like space structures. With simple robots and structure, high mass-specific structural performance, and competitive throughput, this system demonstrates potential for self-reconfiguring autonomous metamaterials for diverse applications.

Robotics↗

Autonomous Mechanical Assembly on the Space Shuttle: An Overview

The space shuttle will be equipped with a pair of 50 ft. manipulators used to handle payloads and to perform mechanical assembly operations. Although current plans call for these manipulators to be operated by a human teleoperator. The possibility of using results from robotics and machine intelligence to automate this shuttle assembly system was investigated. The major components of an autonomous mechanical assembly system are examined, along with the technology base upon which they depend. The state of the art in advanced automation is also assessed.

Raibert, M. H.↗

Split-Rail, Rolling-Friction Robotic Gripper With Tool Drive

Robotic gripper includes split-rail drive assembly that moves two gripping fingers toward or away from each other. Gripping fingers equipped with rollers mating with recesses and seating ramps on specially designed object. Similar in design and operation, to those described in "Rolling-Friction Robotic Gripper" (GSC-13261). Present gripper includes rotary tool operating on mechanism in gripped object.

Voellmer, George M.↗

International Space Station Video Progress Report

A narrated overview of the construction and assembly of the International Space Station (ISS) is given through a collection of clips ranging from the launch of the Russian Proton rocket containing the Zvezda module to computerized animations showing the installation of the Zarya and Unity connecting modules. Footage from some of the space missions that assembled the ISS in space (i.e., STS-106 and STS-92) are seen. The Z1 truss (including the deployment of the solar arrays), Destiny Laboratory Module, Leonardo Module, the Japanese Kibo Experiment Module, Columbus Pressurized Module, and the ISS's robotic arm are seen. Animations show the assembly and evolution of the ISS as new components are added.

Source record↗

Task planning and control synthesis for robotic manipulation in space applications

Space-based robotic systems for diagnosis, repair and assembly of systems will require new techniques of planning and manipulation to accomplish these complex tasks. Results of work in assembly task representation, discrete task planning, and control synthesis which provide a design environment for flexible assembly systems in manufacturing applications, and which extend to planning of manipulatiuon operations in unstructured environments are summarized. Assembly planning is carried out using the AND/OR graph representation which encompasses all possible partial orders of operations and may be used to plan assembly sequences. Discrete task planning uses the configuration map which facilitates search over a space of discrete operations parameters in sequential operations in order to achieve required goals in the space of bounded configuration sets.

Sanderson, A. C.↗

Planning robot actions under position and shape uncertainty

Geometric uncertainty may cause various failures during the execution of a robot control program. Avoiding such failures makes it necessary to reason about the effects of uncertainty in order to implement robust strategies. Researchers first point out that a manipulation program has to be faced with two types of uncertainty: those that might be locally processed using appropriate sensor based motions, and those that require a more global processing leading to insert new sensing operations. Then, they briefly describe how they solved the two related problems in the SHARP system: how to automatically synthesize a fine motion strategy allowing the robot to progressively achieve a given assembly relation despite position uncertainty, and how to represent uncertainty and to determine the points where a given manipulation program might fail.

Laugier, Christian↗

Proposal for a remotely manned space station

The United States is in trouble in space. The costs of the proposed Space Station Freedom have grown beyond reach, and the present design is obsolete. The trouble has come from imagining that there are only two alternatives: manned vs. unmanned. Both choices have led us into designs that do not appear to be practical. On one side, the United States simply does not possess the robotic technology needed to operate or assemble a sophisticated unmanned space station. On the other side, the manned designs that are now under way seem far too costly and dangerous, with all of its thousands of extravehicular activity (EVA) hours. More would be accomplished at far less cost by proceeding in a different way. The design of a space station made of modular, Erector Set-like parts is proposed which is to be assembled using earth-based remotely-controlled binary-tree telerobots. Earth-based workers could be trained to build the station in space using simulators. A small preassembled spacecraft would be launched with a few telerobots, and then, telerobots could be ferried into orbit along with stocks of additional parts. Trained terrestrial workers would remotely assemble a larger station, and materials for additional power and life support systems could be launched. Finally, human scientists and explorers could be sent to the space station. Other aspects of such a space station program are discussed.

Minsky, Marvin↗

Real-time fuzzy inference based robot path planning

This project addresses the problem of adaptive trajectory generation for a robot arm. Conventional trajectory generation involves computing a path in real time to minimize a performance measure such as expended energy. This method can be computationally intensive, and it may yield poor results if the trajectory is weakly constrained. Typically some implicit constraints are known, but cannot be encoded analytically. The alternative approach used here is to formulate domain-specific knowledge, including implicit and ill-defined constraints, in terms of fuzzy rules. These rules utilize linguistic terms to relate input variables to output variables. Since the fuzzy rulebase is determined off-line, only high-level, computationally light processing is required in real time. Potential applications for adaptive trajectory generation include missile guidance and various sophisticated robot control tasks, such as automotive assembly, high speed electrical parts insertion, stepper alignment, and motion control for high speed parcel transfer systems.

Pacini, Peter J.↗

International Space Station Freedom Program (SSFP) flight test demonstrations - Results and future plans

SSFP flight test demonstrations conducted to verify and quantify the performance of selected technologies needed for the development of the Space Station are described. Attention is focused on the performance of thermal systems, the effects of atomic oxygen on materials, and the difficulties of on-orbit crew mobility for assembly and operations utilizing either extravehicular robots or methods. Consideration is given to challenges in system development, a technology assessment summary for the areas of thermal systems, materials, EVA activities, and the results of flight demonstrations.

Simon, William E.↗

Self-Aligning Truss-Joint Mechanism

Self-aligning truss-joint mechanism actuated by single motor or manual rotary drive. Each subassembly connected permanently to one of two structural components to be joined. Mechanism facilitates quick assembly and disassembly and suitable for robotic operation. Features include automatic latching and redundant manual drive.

Wesselski, Clarence↗

Undersea applications of dexterous robotics

The revolution and application of dexterous robotics in the undersea energy production industry and how this mature technology has affected planned SSF dexterous robotic tasks are examined. Undersea telerobotics, or Remotely Operated Vehicles (ROV's), have evolved in design and use since the mid-1970s. Originally developed to replace commercial divers for both planned and unplanned tasks, they are now most commonly used to perform planned robotic tasks in all phases of assembly, inspection, and maintenance of undersea structures and installations. To accomplish these tasks, the worksites, the tasks themselves, and the tools are now engineered with both the telerobot's and the diver's capabilities in mind. In many cases, this planning has permitted a reduction in telerobot system complexity and cost. The philosophies and design practices that have resulted in the successful incorporation of telerobotics into the highly competitive and cost conscious offshore production industry have been largely ignored in the space community. Cases where these philosophies have been adopted or may be successfully adopted in the near future are explored.

Gittleman, Mark M.↗

NASA Tech Briefs, October 2009

Topics covered include: Light-Driven Polymeric Bimorph Actuators; Guaranteeing Failsafe Operation of Extended-Scene Shack-Hartmann Wavefront Sensor Algorithm; Cloud Water Content Sensor for Sounding Balloons and Small UAVs; Pixelized Device Control Actuators for Large Adaptive Optics; T-Slide Linear Actuators; G4FET Implementations of Some Logic Circuits; Electrically Variable or Programmable Nonvolatile Capacitors; System for Automated Calibration of Vector Modulators; Complementary Paired G4FETs as Voltage-Controlled NDR Device; Three MMIC Amplifiers for the 120-to-200 GHz Frequency Band; Low-Noise MMIC Amplifiers for 120 to 180 GHz; Using Ozone To Clean and Passivate Oxygen-Handling Hardware; Metal Standards for Waveguide Characterization of Materials; Two-Piece Screens for Decontaminating Granular Material; Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer; Improved Method of Design for Folding Inflatable Shells; Ultra-Large Solar Sail; Cooperative Three-Robot System for Traversing Steep Slopes; Assemblies of Conformal Tanks; Microfluidic Pumps Containing Teflon[Trademark] AF Diaphragms; Transparent Conveyor of Dielectric Liquids or Particles; Multi-Cone Model for Estimating GPS Ionospheric Delays; High-Sensitivity GaN Microchemical Sensors; On the Divergence of the Velocity Vector in Real-Gas Flow; Progress Toward a Compact, Highly Stable Ion Clock; Instruments for Imaging from Far to Near; Reflectors Made from Membranes Stretched Between Beams; Integrated Risk and Knowledge Management Program -- IRKM-P; LDPC Codes with Minimum Distance Proportional to Block Size; Constructing LDPC Codes from Loop-Free Encoding Modules; MMICs with Radial Probe Transitions to Waveguides; Tests of Low-Noise MMIC Amplifier Module at 290 to 340 GHz; and Extending Newtonian Dynamics to Include Stochastic Processes.

Source record↗

A Basic Robotic Excavator (the Glenn Digger): Description, Design, and Initial Operation

This paper describes the design, commercial part selections, fabrication, assembly, installation, and initial operation of a two degree of freedom robotic excavator. Colloquially referred to as "the NASA Glenn Digger," it was designed specifically to be mounted onto, and to operate with, the then newly developed Centaur 2 robotic mobility base. The excavator, when mounted to Centaur 2, is designed to scoop loose regolith from the terrain, raise its loaded bucket up and dump the load into a hopper of at least a 1-m-height. The hopper represents the input to a machine that would process the raw material, such as to produce oxygen from lunar regolith as would be required for long-term lunar habitation. This equipment debuted at the annual Research and Technology Studies ("Desert RATS", Ref. 1) event held north of Flagstaff, Arizona, in September of 2010, when the Digger was successfully joined to Centaur 2 and the shoveling articulation was demonstrated. During 2011, the hardware was modified for added strength, strain gauges were added to measure loads, and the controls were improved in preparation for the 2011 Desert RATS event, where additional "field operations" experience was gained.

backhoe↗

Commercial Application of In-Space Assembly

In-Space assembly (ISA) expands the opportunities for cost effective emplacement of systems in space. Currently, spacecraft are launched into space and deploy into their operational configuration through a carefully choreographed sequence of operations. The deployment operation dictates the arrangement of the primary systems on the spacecraft, limiting the ability to take full advantage of launch vehicles volume and mass capability. ISA enables vastly different spacecraft architectures and emplacement scenarios to be achieved, including optimal launch configurations ranging from single launch and assembly to on-orbit aggregation of multiple launches at different orbital locations and times. The spacecraft can be visited at different orbital locations and times to effect expansion and maintenance of an operational capability. To date, the primary application of ISA has been in large programs funded by government organizations, such as the International Space Station. Recently, Space Systems Loral (SSL) led a study funded by the Defense Advanced Research Projects Agency (DARPA), called Dragonfly, to investigate the commercial applicability and economic advantages of ISA. In the study, it was shown that ISA enables SSL to double the capability of a commercial satellite system by taking advantage of alternate packaging approaches for the reflectors. The study included an ultra-light-weight robotic system, derived from Mars manipulator designs, to complete assembly of portions of the antenna system using a tool derived from DARPA orbital express and National Aeronautics and Space Administration (NASA) automated structural assembly experience. The mechanical connector that enables robotic ISA takes advantage of decades of development by NASA from the 1970's to 1980's during the Space Station Freedom program, the precursor to the ISS. The mechanical connector was originally designed for rapid astronaut assembly while also providing a high quality structural connection with linear load deflection response. The paper will discuss the business case for ISA, the general approach taken to exploit on-orbit assembly in the GEO communication satellite market, and the concept of operations associated with the ISA approach, thus laying the foundation for ISA to become an accepted operational approach for commercial in-space operations.

Lymer, John↗