Ranger Telerobotics Program
Download
1 / 25

Brian Roberts University of Maryland Space Systems Laboratory ssl.umd/ - PowerPoint PPT Presentation


  • 148 Views
  • Uploaded on

Ranger Telerobotics Program. Brian Roberts University of Maryland Space Systems Laboratory http://www.ssl.umd.edu/. On-Orbit Servicing Workshop 14 November 2001. Space Systems Laboratory. 25 years of experience in space systems research

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Brian Roberts University of Maryland Space Systems Laboratory ssl.umd/' - orrick


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Slide1 l.jpg

Ranger Telerobotics Program

Brian Roberts

University of Maryland

Space Systems Laboratory

http://www.ssl.umd.edu/

On-Orbit Servicing Workshop

14 November 2001


Space systems laboratory l.jpg
Space Systems Laboratory

  • 25 years of experience in space systems research

  • Focus is to develop and test complete systems capable of performing complex space tasks end-to-end

  • People

    • 4 full time faculty

    • 12 research and technical staff

    • 18 graduate students

    • 28 undergraduate students

  • Facilities

    • Neutral Buoyancy Research Facility (25 ft deep x 50 ft in diameter)

      • About 150 tests a year

      • Only neutral buoyancy facility dedicated to basic research and only one in world located on a university campus

      • Fabrication capabilities include rapid prototype machine, CNC mill and lathe for prototype and flight hardware

    • Class 100,000 controlled work area for flight integration

  • Basic tenet is to maximize involvement of students in every level of research activities


Ssl assets for on orbit servicing l.jpg
SSL Assets for On-Orbit Servicing

  • Development and testing of multiple complete robotic systems capable of performing complex space tasks end-to-end:

    • Docking

    • Assembly

    • Inspection

    • Maintenance

  • Facility for evaluating systems in a simulated 6 degree-of-freedom (DOF) microgravity environment

  • Expertise:

    • Autonomous control of multiple robotic systems

    • Design of dexterous robotic manipulators

    • Adaptive control techniques for vehicle dynamics

    • Use of interchangeable end effectors

    • Investigation of satellite missions benefiting most from robotic servicing


What are the unknowns in space robotics l.jpg
What are the Unknowns in Space Robotics?

Flexible Connections to Work Site?

Capabilities and Limitations?

Human Workload Issues?

Multi-arm Control and Operations?

Control Station Design?

Interaction with Non-robot Compatible Interfaces?

ManipulatorDesign?

Hazard Detection and Avoidance?

Utility of InterchangeableEnd Effectors?

Development, Production, and Operating Costs?

Ground-based Simulation Technologies?

Effects and Mitigation of Time Delays?

Ground Control?


Multimode proximity operations device mpod l.jpg
Multimode Proximity Operations Device (MPOD)

  • System to evaluate controls associated with robotic docking

  • Full 6 DOF mobility base

  • Full state feedback through an on-board sensor suite, including an acoustic-based sensor system

  • Probe-drogue docking system

  • Operational since 1986

  • Achievements:

    • Autonomous approach and docking

    • Maneuvering and berthing of large masses

    • Application of nonlinear adaptive neural network control system


Supplemental camera and maneuvering platform l.jpg
Supplemental Camera and Maneuvering Platform

  • Supplemental Camera and Maneuvering Platform (SCAMP) is a free-flying camera platform

    • 6 DOF mobility base

    • Stereo video and close-up color cameras

  • Originally used to observe neutral buoyancy operations

  • Evolved to evaluate robotic inspection

  • Operational since 1992

  • Achievements:

    • Used routinely to observe robotic and non-robotic neutral buoyancy operations

    • Demonstrated visual survey and inspection


Scamp space simulation vehicle ssv l.jpg
SCAMP Space Simulation Vehicle (SSV)

  • Continuation of SCAMP’s evolution into a high fidelity neutral buoyancy simulation of 6 DOF space flight dynamics

    • Uses onboard sensors (3-axis gyros, accelerometers, magnetometers, and a 3-D acoustic positioning system) to accurately calculate its position, attitude, and translational and rotational velocities

    • Robot is positioned to a specified location, determined by a mathematical computer simulation

  • Operational since 1997

  • Achievements:

    • Cancellation of water drag effects for flight dynamics

    • Model-referenced vehicle flight control

    • Adaptive control of unknown docked payloads

    • Autonomous docking

    • Different methods of trajectory planning are being investigated


Beam assembly teleoperator bat l.jpg
Beam Assembly Teleoperator (BAT)

  • Free-flying robotic system to demonstrate assembly of an existing space structure not robot friendly:

  • 6 DOF mobility base

  • 5 DOF dexterous assembly manipulator

  • Two pairs of stereo monochrome video cameras

  • Non-articulated grappling arm for grasping the structure under assembly

  • Specialized manipulator for performing the coarse alignment task for the long struts of the truss assembly

  • Operational since 1984

    • Achievements:

      • Combination of simple 1 DOF arm with dexterous 5 DOF manipulator proved to be a useful approach for assembly of a tetrahedral structure

      • Demonstrated utility of small dexterous manipulator to augment larger, less dexterous manipulator

      • Assisted in the change out of spacecraft batteries of Hubble Space Telescope


    Ranger class servicers l.jpg
    “Ranger” Class Servicers

    • Ranger Telerobotic Flight eXperiment (RTFX)

      • Free-flight satellite servicer designed in 1993; neutral buoyancy vehicle operational since 1995

      • Robotic prototype testbed for satellite inspection, maintenance, refueling, and orbit adjustment

    • Demonstrated robotic tasks in neutral buoyancy

      • Robotic compatible ORU replacement

      • Complete end-to-end connect and disconnect of electrical connector

      • Adaptive control for free-flight operation and station keeping

      • Two-arm coordinated motion

      • Coordinated multi-location control

      • Night operations

    • With potential Shuttle launch opportunity, RTFX evolved into Ranger Telerobotic Shuttle eXperiment in 1996


    Ranger telerobotic shuttle experiment rtsx l.jpg
    Ranger Telerobotic Shuttle eXperiment (RTSX)

    • Demonstration of dexterous robotic on-orbit satellite servicing

      • Robot attached to a Spacelab pallet within the cargo bay of the orbiter

      • Task ranging from simple calibration to complex dexterous operations not originally intended for robotic servicing

      • Uses interchangeable end effectors designed for different tasks

      • Controlled from orbiter and from the ground

    • A joint project between NASA’s Office of Space Science (Code S) and the University of Maryland Space Systems Laboratory

    • Key team members

      • UMD - project management, robot, task elements, ground control station

      • Payload Systems, Inc. - safety, payload integration, flight control station

      • Veridian - system engineering and integration, environmental testing

      • NASA/JSC - environmental testing


    Ranger s place in space robotics l.jpg
    Ranger’s Place in Space Robotics

    How the Operator Interacts with the Robot

    How the Robot Interacts with the Worksite


    Robot characteristics l.jpg
    Robot Characteristics

    • Body

      • Internal: main computers and power distribution

      • External: end effector storage and anchor for launch restraints

    • Head = 12 cube

    • Four manipulators

      • Two dexterous manipulators (5.5 in diameter; 48 long)

        • 8 DOF (R-P-R-P-R-P-Y-R)

        • 30 lb of force and 30 ft-lbf of torque at end point

      • Video manipulator (55 long)

        • 7 DOF (R-P-R-P-R-P-R)

        • Stereo video camera at distal end

      • Positioning leg (75 long)

        • 6 DOF (R-P-R-P-R-P)

        • 25 lb of force and 200 ft-lbf of torque; can withstand 250 lbf at full extension while braked

    ~1500 lbs weight; 14 length from base on SLP to outstretched arm tip


    Task suite l.jpg
    Task Suite

    • Fiduciary tasks

      • Static force compliance task (spring plate)

      • Dynamic force-compliant control over complex trajectory (contour task)

      • High-precision endpoint control (peg-in-hole task)

    • Robotic ORU task

      • Remote Power Controller Module insertion/removal

    • Robotic assistance of EVA

      • Articulating Portable Foot Restraint setup/tear down

    • Non-robotic ORU task

      • HST Electronics Control Unit insertion/removal


    End effectors l.jpg
    End Effectors

    Microconical End Effector

    Bare Bolt Drive

    Right Angle Drive

    Tether Loop Gripper

    EVA Handrail Gripper

    SPAR Gripper


    Operating modalities l.jpg
    Operating Modalities

    Video Displays (3)

    • Flight Control Station (FCS)

      • Single console

      • Selectable time delay

        • No time delay

        • Induced time delay

    • Ground Control Station

      • Multiple consoles

      • Communication time delay for all operations

      • Multiple user interfaces

        • FCS equivalent interface

        • Advanced control station interfaces (3-axis joysticks, 3-D position trackers, mechanical mini-masters, and force balls)

    Keyboard, Monitor, Graphics Display

    2x3 DOF Hand Controllers

    CPU (Silicon Graphics O2)


    Ranger neutral buoyancy vehicles l.jpg
    Ranger Neutral Buoyancy Vehicles

    • Neutral Buoyancy Vehicle I (RNBV I)

      • Free-flight prototype vehicle operational since 1995

      • Used to simulate RTSX tasks and provide preliminary data until RNBVII becomes operational

    • RNBV II is a fully-functional, powered engineering test unit for the RTSX flight robot. It is used for:

    • Refining hardware

    • Modifying control algorithms and developing advanced scripts

    • Verifying boundary management and computer control of hazards

    • Correlating space and neutral buoyancy operations

    • Supporting development, verification, operational, and scientific objectives of the RTSX mission

    • Flight crew training

    • An articulated non-powered mock-up is used for hardware refinement and contingency EVA training


    Graphical simulation l.jpg
    Graphical Simulation

    Task Simulation

    GUI Development

    Worksite Analysis


    Simulation correlation strategy l.jpg
    Simulation Correlation Strategy

    EVA/EVR

    Correlation

    All On-Orbit

    Operations Performed

    Pre/Post Flight with

    RTSX Neutral

    Buoyancy Vehicle for

    Flight/NB Simulation

    Correlation

    Simulation

    Correlation

    Simulation

    Correlation

    EVA/EVR

    Correlation


    Arm evolution l.jpg
    Arm Evolution

    Roboticus Dexterus

    Roboticus Videus

    Roboticus Grapplus

    BAT Dexterous Arm (5 DOF)

    BAT Tilt & Pan Unit (2 DOF)

    BAT Grapple Arm (0 DOF)

    ca. 1984

    ca. 1984

    ca. 1984

    Ranger Dexterous Arm Mark 1 (7 DOF)

    Ranger Grapple Arm (7 DOF)

    ca. 1994

    ca. 1996

    Ranger Dexterous Arm Mark 2 (8 DOF)

    Ranger Video Arm (7 DOF)

    Ranger Positioning Leg (6 DOF)

    ca. 1996

    ca. 1996

    ca. 1998


    Program status l.jpg
    Program Status

    • 1995: RNBV I operations began at the NBRF

    • 1996: Ranger TSX development began

    • June 1999: Ranger TSX critical design review

    • December 1999: Space Shuttle Program Phase 2 Payload Safety Review

    • April 2000: Mock-up began operation (62 hours of underwater test time on 45 separate dives to date)

    • October 2001: Prototype positioning leg pitch joint and Mark 2 dexterous arm wrist began testing

    • Today: RNBV II is being integrated; 75% of the flight robot is procured

    • January 2002: RNBV II operations planned to begin

    • Ranger TSX is #1 cargo bay payload for NASA’s Office of Space Science and #2 on Space Shuttle Program’s cargo bay priority list


    Ssl assets for on orbit servicing21 l.jpg
    SSL Assets for On-Orbit Servicing

    • Development and testing of multiple complete robotic systems capable of performing complex space tasks end-to-end:

      • Docking: MPOD and Ranger TFX

      • Assembly: BAT and Ranger

      • Inspection: SCAMP

      • Maintenance: Ranger

    • Facility for evaluating systems in a simulated 6 DOF microgravity environment

    • Expertise:

      • Autonomous control of multiple robotic systems

      • Design of dexterous robotic manipulators

      • Adaptive control techniques for vehicle dynamics

      • Use of interchangeable end effectors

      • Investigation of satellite missions benefiting most from robotic servicing




    Computer control of hazards l.jpg
    Computer Control of Hazards

    • Human response is inadequate to respond to the robot’s speed, complex motions, and multiple degrees of freedom

    • Onboard boundary management algorithms keep robot from exceeding safe operational envelope regardless of commanded input


    Results of a successful ranger tsx mission l.jpg
    Results of a Successful Ranger TSX Mission

    Demonstration of DexterousRobotic Capabilities

    Understanding of Human Factorsof Complex Telerobot Control

    Pathfinder for FlightTesting of Advanced Robotics

    Precursor for Low-CostFree-Flying Servicing Vehicles

    Lead-in to CooperativeEVA/Robotic Work Sites

    Dexterous Robotics forAdvanced Space Science


    ad