Ranger Telerobotic Shuttle Experiment Status Report Gardell G
Ranger Telerobotic Shuttle Experiment: Status Report Gardell G. Gefke, Craig R. Carignan, Brian J. Roberts, and J. Corde Lane University of Maryland Space Systems Laboratory http: //www. ssl. umd. edu/ Intelligent Systems and Advanced Manufacturing Conference Telemanipulators and Telepresence Technologies VIII 28 October 2001 1
Space Systems Laboratory • 25 years of experience in space systems research • A part of the Aerospace Engineering Department at University of Maryland • 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 involve students in every aspect of research Ranger Robotics Program: Status Report 2 Space Systems Laboratory University of Maryland
What are the Unknowns in Space Robotics? Human Workload Issues? Flexible Connections to Work Site? Capabilities and Limitations? Multi-arm Control and Operations? Control Station Design? Manipulator Design? Interaction with Nonrobot Compatible Interfaces? Hazard Detection and Avoidance? Utility of Interchangeable End Effectors? Ground-based Simulation Technologies? Effects and Mitigation of Time Delays? Ground Control? Ranger Robotics Program: Status Report Development, Production, and Operating Costs? 3 Space Systems Laboratory University of Maryland
“Ranger” Class Satellite Servicers • Ranger Telerobotic Flight e. Xperiment (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 e. Xperiment in 1996 Ranger Robotics Program: Status Report 4 Space Systems Laboratory University of Maryland
Ranger Telerobotic Shuttle e. Xperiment (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 Robotics Program: Status Report 5 Space Systems Laboratory University of Maryland
Ranger’s Place in Space Robotics How the Robot Interacts with the Worksite How the Operator Interacts with the Robot Ranger Robotics Program: Status Report 6 Space Systems Laboratory University of Maryland
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-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) » Stereo video camera at distal end – Positioning leg (75 long) ~1500 lbs weight; 14 length from base on SLP to outstretched arm tip » 6 DOF (R-P-R-P) » 25 lb of force and 200 ft-lbf of torque; can withstand 250 lbf at full extension while braked Ranger Robotics Program: Status Report 7 Space Systems Laboratory University of Maryland
Robot Stowed Configuration Ranger Robotics Program: Status Report 8 Space Systems Laboratory University of Maryland
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 • EVA ORU task – Articulating Portable Foot Restraint setup/tear down Ranger Robotics Program: Status Report – HST Electronics Control Unit insertion/removal 9 Space Systems Laboratory University of Maryland
End Effectors Bare Bolt Drive Right Angle Drive Microconical End Effector Tether Loop Gripper EVA Handrail Gripper SPAR Gripper Ranger Robotics Program: Status Report 10 Space Systems Laboratory University of Maryland
Operating Modalities Video Displays (3) • Flight Control Station (FCS) Keyboard, Monitor, Graphics Display – Single console – Selectable time delay 2 x 3 DOF Hand Controllers » No time delay » Induced time delay CPU (Silicon Graphics O 2) • 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) Ranger Robotics Program: Status Report 11 Space Systems Laboratory University of Maryland
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: – Supporting development, verification, operational, and scientific objectives of the RTSX mission – Flight crew training – Developing advanced scripts – Refining hardware – Modifying control algorithms – Verifying boundary management and computer control of hazards – Correlating space and neutral buoyancy operations • An articulated non-powered mock-up is used for hardware refinement and contingency EVA training Ranger Robotics Program: Status Report 12 Space Systems Laboratory University of Maryland
Graphical Simulation Task Simulation GUI Development Worksite Analysis Ranger Robotics Program: Status Report 13 Space Systems Laboratory University of Maryland
Simulation Correlation Strategy EVA/EVR Correlation Simulation Correlation All On-Orbit Operations Performed Pre/Post Flight with RTSX Neutral Buoyancy Vehicle for Flight/NB Simulation Correlation EVA/EVR Correlation Ranger Robotics Program: Status Report 14 Space Systems Laboratory University of Maryland
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 Ranger Robotics Program: Status Report 15 Space Systems Laboratory University of Maryland
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: EVA mock-up began operation (62 hours of underwater test time on 45 separate dives to date) October 2001: Prototype positioning leg pitch joint and 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 Ranger Robotics Program: Status Report 16 Space Systems Laboratory University of Maryland
Results of a Successful Ranger TSX Mission Demonstration of Dexterous Robotic Capabilities Precursor for Low-Cost Free-Flying Servicing Vehicles Ranger Robotics Program: Status Report Understanding of Human Factors Pathfinder for Flight of Complex Telerobot Control Testing of Advanced Robotics Lead-in to Cooperative EVA/Robotic Work Sites 17 Dexterous Robotics for Advanced Space Science Space Systems Laboratory University of Maryland
- Slides: 17