Search NASA⌕ Search

SEARCH · Search NASA

Results for “Space Manipulator”

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 55 records · Page 3

Characteristics and requirements of robotic manipulators for space operations

A robotic manipulator, DTF-1, developed as part of the Flight Telerobotic Servicer (FTS) project at Goddard Space Flight Center is discussed focusing on the technical, operational, and safety requirements. The DTF-1 system design, which is based on the manipulator, gripper, cameras, computer, and an operator control station incorporates the fundamental building blocks of the original FTS, the end product of which was to have been a light-weight, dexterous telerobotic device. For the first time in the history of NASA, space technology and robotics were combined to find new and unique solutions to the demanding requirements of flying a sophisticated robotic manipulator in space. DTF-1 is considered to be the prototype for all future development in space robotics.

Andary, James F.↗

TV requirements for manipulation in space

Four tasks (docking, coupling, manipulation, and transportation), stressing work volume and element relationships, are outlined to test a video system for remote manipulation in space. A 4 degree of freedom motion frame was used to evaluate operating parameters, which grouped the visual dimensions into major areas of influence, e.g., depth precision, object differentiation, reference, dynamics, and resolution. Four video systems were included in the simulation testing: a black and white and a color monoscopic system, a stereoscopic system, and a black and white two-view system. The two-view system was found best suited for the operations described.

Freedman, L. A.↗

TV requirements for manipulation in space

A video system for remote manipulation in space was studied. Analysis of basic manipulation tasks and visual requirements; simulation testing to determine the effects of task, scene parameter, and type of video system on manipulation performance; and video system selection and specification are described.

Freedman, L. A.↗

Evolution of the Space Station Robotic Manipulator

The Space Station Remote Manipulator System (SSRMS), Canadarm2, was launched in 2001 and deployed on the International Space Station (ISS). The Canadarm2 has been instrumental in ISS assembly and maintenance. Canadarm2 shares its heritage with the Space Shuttle Arm (Canadarm). This article explores the evolution from the Shuttle Canadarm to the Space Station Canadarm2 design, which incorporates a 7 degree of freedom design, larger joints, and changeable operating base. This article also addresses phased design, redundancy, life and maintainability requirements. The design of Canadarm2 meets unique ISS requirements, including expanded handling capability and the ability to be maintained on orbit. The size of ISS necessitated a mobile manipulator, resulting in the unique capability of Canadarm2 to relocate by performing a walk off to base points located along the Station, and interchanging the tip and base of the manipulator. This provides the manipulator with reach and access to a large part of the Station, enabling on-orbit assembly of the Station and providing support to Extra-Vehicular Activity (EVA). Canadarm2 is evolving based on on-orbit operational experience and new functionality requirements. SSRMS functionality is being developed in phases to support evolving ISS assembly and operation as modules are added and the Station becomes more complex. Changes to sustaining software, hardware architecture, and operations have significantly enhanced SSRMS capability to support ISS mission requirements. As a result of operational experience, SSRMS changes have been implemented for Degraded Joint Operations, Force Moment Sensor Thermal Protection, Enabling Ground Controlled Operations, and Software Commutation. Planned Canadarm2 design modifications include: Force Moment Accommodation, Smart Safing, Separate Safing, and Hot Backup. In summary, Canadarm2 continues to evolve in support of new ISS requirements and improved operations. It is a tribute to the design that this evolution can be accomplished while conducting critical on-orbit operations with minimal hardware changes.

Razvi, Shakeel↗

Illumination requirements for operating a space remote manipulator

Critical issues and requirements involved in illuminating remote manipulator operations in space help establish engineering designs for these manipulators. A remote manipulator is defined as any mechanical device that is controlled indirectly or from a distance by a human operator for the purpose of performing potentially dangerous or hazardous tasks to increase safety, reliability, and efficiency. Future space flights will rely on remote manipulators for a variety of tasks including satellite repair and servicing, structural assembly, data collection and analysis, and performance of contingency tasks. Carefully designed illumination of these manipulators will assure that these tasks will be completed efficiently and successfully. Studies concerning the influence of illumination on operation of a remote manipulator are few. Available results show that illumination can influence how successfully a human operates a remote manipulator. The intent of this study was to more fully examine this topic.

Chandlee, George O.↗

Determination of the mass properties of a manipulator

Space applications for telerobotics requires a manipulator that is robust to the large payload variations that occur in a zero-g environment. One approach to provide the required performance for this large payload variation is to provide inertial decoupling to the controller. The equations to generate the required joint torques can be obtained in several manners but the independent parameters required to perform the calculations are difficult to obtain. This presentation consists of an overview of the inertial decoupling control system and discusses how to reduce the inertial parameter set to a minimum and obtain the required parameter set to a minimum and obtain the required parameter vector using sensed joint positions and torques. In addition, as telerobotic technology becomes more prevalent in the space environments the ability to emulate the effect of zero-g in a one-g environment is critical in learning how to perform tasks in space. To emulate the zero-g environment it is necessary to remove the effect of gravity on the manipulator by determining the feedforward joint torques. A subset of the algorithm developed to obtain the decoupling parameters is used to obtain the gravity offload parameters. These parameters are used to eliminate the effect of gravity. The algorithm is validated on Martin Marietta/NASA Langley's, 7 Degrees-Of-Freedom (DOF) Flight Telerobotic Servicer Hydraulic Manipulator Test Bed. A video portraying actual results of the algorithm is provided.

Goldenberg, Stewart↗

Adaptive control of space based robot manipulators

For space based robots in which the base is free to move, motion planning and control is complicated by uncertainties in the inertial properties of the manipulator and its load. A new adaptive control method is presented for space based robots which achieves globally stable trajectory tracking in the presence of uncertainties in the inertial parameters of the system. A partition is made of the fifteen degree of freedom system dynamics into two parts: a nine degree of freedom invertible portion and a six degree of freedom noninvertible portion. The controller is then designed to achieve trajectory tracking of the invertible portion of the system. This portion consist of the manipulator joint positions and the orientation of the base. The motion of the noninvertible portion is bounded, but unpredictable. This portion consist of the position of the robot's base and the position of the reaction wheel.

Walker, Michael W.↗

Graphical programming and the use of simulation for space-based manipulators

Robotic manipulators are difficult to program even without the special requirements of a zero-gravity environment. While attention should be paid to investigating the usefulness of industrial application programming methods to space manipulators, new methods with potential application to both environments need to be invented. These methods should allow various levels of autonomy and human-in-the-loop interaction and simple, rapid switching among them. For all methods simulation must be integrated to provide reliability and safety. Graphical programming of manipulators is a candidate for an effective robot programming method despite current limitations in input devices and displays. A research project in task-level robot programming has built an innovative interface to a state-of-the-art commercial simulation and robot programming platform. The prototype demonstrates simple augmented methods for graphical programming and simulation which may be of particular interest to those concerned with Space Station applications; its development has also raised important issues for the development of more sophisticated robot programming tools. Both aspects of the project are discussed.

Mcgrath, Debra S.↗

On the simulation of space based manipulators with contact

An efficient method of simulating the motion of space based manipulators is presented. Since the manipulators will come into contact with different objects in their environment while carrying out different tasks, an important part of the simulation is the modeling of those contacts. An inverse dynamics controller is used to control a two armed manipulator whose task is to grasp an object floating in space. Simulation results are presented and an evaluation is made of the performance of the controller.

Walker, Michael W.↗

Base reaction optimization of redundant manipulators for space applications

One of the problems associated with redundant manipulators which were proposed for space applications is that the reactions transmitted to the base of the manipulator as a result of the motion of the manipulator will cause undesirable effects on the dynamic behavior of the supporting space structure. It is therefore necessary to minimize the magnitudes of the forces and moments transmitted to the base. It is shown that kinematic redundancy can be used to solve the dynamic problem of minimizing the magnitude of the base reactions. The methodology described is applied to a four degree-of-freedom spatial manipulator with one redundant degree-of-freedom.

Chung, C. L.↗

Models of remote manipulation in space

Robots involved in high value manipulation must be effectively coupled to a human operator either at the work-site or remotely connected via communication links. In order to make use of experimental performance evaluation data, models must be developed. Powerful models of remote manipulation by humans can be used to predict manipulation performance in future systems based on today's laboratory systems. In this paradigm, the models are developed from experimental data, and then used to predict performance in slightly different situations. Second, accurate telemanipulation will allow design of manipulation systems which extend manipulation capability beyond its current bounds.

Hannaford, Blake↗

Automatic calibration of space based manipulators and mechanisms

Four tasks in manipulator kinematic calibration are summarized. Calibration of a seven degree of freedom manipulator was simulated. A calibration model is presented that can be applied on a closed-loop robot. It is an expansion of open-loop kinematic calibration algorithms subject to constraints. A closed-loop robot with a five-bar linkage transmission was tested. Results show that the algorithm converges within a few iterations. The concept of model differences is formalized. Differences are categorized as structural and numerical, with emphasis on the structural. The work demonstrates that geometric manipulators can be visualized as points in a vector space with the dimension of the space depending solely on the number and type of manipulator joint. Visualizing parameters in a kinematic model as the coordinates locating the manipulator in vector space enables a standard evaluation of the models. Key results include a derivation of the maximum number of parameters necessary for models, a formal discussion on the inclusion of extra parameters, and a method to predetermine a minimum model structure for a kinematic manipulator. A technique is presented that enables single point sensors to gather sufficient information to complete a calibration.

Everett, Louis J.↗

Operations with the special purpose dextrous manipulator on Space Station Freedom

SPAR Canada is actively participating in the Space Station Freedom Program by contributing the Mobile Servicing System (MSS) which will be involved in assembly, maintenance and servicing of both the Space Station and the MSS itself. Part of the MSS is the Special Purpose Dextrous Manipulator (SPDM), a two armed dextrous robot with advanced vision and manipulative capabilities. In addition to Space Station and payload servicing activities the SPDM will be designed to perform self maintenance on the MSS itself. The majority of Space Station equipment will be on orbit for the anticipated 30 year lifespan and the maintenance philosophy will be to repair by the exchange of Orbit Replacement Units or ORUs. The present concept, configuration, and operation of the SPDM and the detailed simulations associated with the maintenance of part of the MSS are described. The Design Reference Mission is the replacement of a Joint Drive Module on the Canadian large payload manipulator, the Space Station Remote Manipulator System. Other Design Reference Missions that were investigated are briefly described, and future operations activity to support the definition of SPDM requirements are discussed.

Cox, B.↗

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.↗

Control of robot manipulators for handling and assembly in space

Long-range NASA planning includes construction and erection of large systems in space requiring automatic handling equipment, teleoperators, or robots under supervisory control. This paper investigates and explores some of the requirements for the control of teleoperated and autonomous space manipulators. The critical technology development areas are identified and discussed in the context of the developments at the Jet Propulsion Laboratory (JPL), and other places.

Heer, E.↗

A shuttle and space station manipulator system for assembly, docking, maintenance cargo handling and spacecraft retrieval (preliminary design). Volume 1: Management summary

A preliminary design is established for a general purpose manipulator system which can be used interchangeably on the shuttle and station and can be transferred back and forth between them. Control of the manipulator is accomplished by hard wiring from internal control stations in the shuttle or station. A variety of shuttle and station manipulator operations are considered including servicing the Large Space Telescope; however, emphasis is placed on unloading modules from the shuttle and assembling the space station. Simulation studies on foveal stereoscopic viewing and manipulator supervisory computer control have been accomplished to investigate the feasibility of their use in the manipulator system. The basic manipulator system consists of a single 18.3 m long, 7 degree of freedom (DOF), electrically acutated main boom with an auxiliary 3 DOF electrically actuated, extendible 18.3 m maximum length, lighting, and viewing boom. A 3 DOF orientor assembly is located at the tip of the viewing boom to provide camera pan, tilt, and roll.

Source record↗

Control of free-flying space robot manipulator systems

Control techniques for self-contained, autonomous free-flying space robots are being tested and developed. Free-flying space 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 astronaut extra-vehicular activity (EVA). Use of robots will provide economic savings as well as improved astronaut safety by reducing and in many cases, eliminating the need for human EVA. The focus of the work is to develop and carry out a set of research projects using laboratory models of satellite robots. These devices use air-cushion-vehicle (ACV) technology to simulate in two dimensions the drag-free, zero-g conditions of space. Current work is divided into six major projects or research areas. Fixed-base cooperative manipulation work represents our initial entry into multiple arm cooperation and high-level control with a sophisticated user interface. The floating-base cooperative manipulation project strives to transfer some of the technologies developed in the fixed-base work onto a floating base. The global control and navigation experiment seeks to demonstrate simultaneous control of the robot manipulators and the robot base position so that tasks can be accomplished while the base is undergoing a controlled motion. The multiple-vehicle cooperation project's goal is to demonstrate multiple free-floating robots working in teams to carry out tasks too difficult or complex for a single robot to perform. The Location Enhancement Arm Push-off (LEAP) activity's goal is to provide a viable alternative to expendable gas thrusters for vehicle propulsion wherein the robot uses its manipulators to throw itself from place to place. Because the successful execution of the LEAP technique requires an accurate model of the robot and payload mass properties, it was deemed an attractive testbed for adaptive control technology.

Cannon, Robert H., Jr.↗

Dynamics and control of multibody/robotic systems with space applications; Proceedings of the ASME Winter Annual Meeting, San Francisco, CA, Dec. 10-15, 1989

The present conference on the dynamics and control methods of multibody robotic systems applicable to outer space applications first gives attention to such topics in multibody dynamics and control as the substructure synthesis approach to flexible multibody system control, an elastic finite-element kinematic analysis of a multirigid body, computational methods for high speed vehicles on flexible guideways, and multiarm coordination and control. Attention is then given to such issues in space manipulator dynamics and control methods as the global navigation of a free-flying space robot, dynamic singularities in the control of free-floating space manipulators, experimental results for compact space robot actuator control, and a 17-degree-of-freedom dexterous manipulator.

Joshi, Suresh M.↗