2.2.3 Attached Servicers

This segment of the program is focussed on the development of space robotics for on-orbit servicing by systems attached to supporting structures such as the Space Shuttle or Space Station. The purpose of this segment of the program is to focus the development of component technologies into applications and environments which will demonstrate their utility and additional capability when incorporated into operational systems. These technologies include virtual reality telepresence, advanced display technologies, proximity sensing for perception technologies, and robotic flaw detection. The target applications include such tasks as repair of small satellites, ground-based control of robotic servicers, and servicing of external space platform payloads. Each of these areas have been identified by the potential space robotics user community as applications where space robotics will be necessary to satisfy their planned requirements. This user community includes Space Station Alpha, Mission to Planet Earth, and the Space Transportation System.

Computer Vision Assisted Calibrated Synthetic Viewing

Remote Surface Inspection Technology Transfer

ISSA Telerobotic Maintenance Technology Transfer

Technology Transfer Roadmap Details

Computer Vision Assisted Calibrated Synthetic Viewing

The camera viewing problem is a major concern in ISSA (International Space Station Alpha) telerobotic operations, and payload alignment/mating techniques are critically needed to cope with this inadequate video coverage problem. The objectives of this task is to 1) develop and evaluate a computer vision assisted calibrated synthetic viewing (CSV) software environment to resolve the visual occlusion and limited camera viewing problems during the performance of telerobotic operations, 2) demonstrate reliable module/payload alignment and berthing operations under limited camera viewing conditions for ISSA telerobotic onboard and ground control, and 3) install the calibrated synthetic viewing (CSV) system at JSC ARMSS (Automated Robotic Maintenance for Space Station) testbed for technology assessment and demonstration to the Space Station Program.

The current baseline use of the onboard AVF (Artificial Vision System) has limitations in terms of both availability and viewing constraints of AVF vision targets, in particular, for small payloads. By contrast, the calibrated synthetic viewing (CSV) will enable reliable, high-precision alignment under limited/occluded camera viewing conditions through enhancements of existing edge-based semi-automatic VR (virtual reality) calibration and developments of a new local fine alignment algorithm. A quantitative analysis/experiments of alignment accuracy will be performed in comparison with vision-target based technique.

Focus and Directions:

FY 1996: develop and install a Computer Vision Assisted Calibrated Synthetic Viewing (CSV) system at the JSC ARMSS testbed by June 1996 and demonstrate the RPCM-like ORU insertion (with a 1/4 inch clearance) to the Space Station Program by September 1996.

FY 1997: develop and demonstrate an enhanced Computer Vision Assisted Calibrated Synthetic Viewing (CSV) system based on the Space Station Program feedback/ needs. New development will include network-transparent synthetic viewing with calibrated texture mapping.

Point of Contact:
Won S. Kim
(818)354-5047
wonsoo@telerobotics.jpl.nasa.gov

Remote Surface Inspection

JPL has developed a multi-sensor-based RSI (remote surface inspection) system for the past five years for potential use in Space Station maintenance. The objective of this task is to make the JPL-developed RSI system available at JSC ARMSS (Automated Robotic Maintenance of Space Station) testbed for technology demonstration to the Space Station Program. JPL already delivered the local-site operator interface software to JSC in FY'95, and through this task, will deliver the remote-site MCS (Manipulator Control System)and TIPSS (Teleoperated Inspection Subsystem) subsystems to JSC for on-site test and demonstration of remote surface inspection capabilities to the Space Station Program. The MCS and TIPSS subsystems consist of two chassis, various associated boards, and VxWorks-based real-time software.

Complex space missions require routine and unscheduled inspection for safe operation. The Jet Propulsion Laboratory has conducted a research and development program to develop supervised inspection techniques for tedious tasks as an aid to the operator. The telerobotic system would perform inspection relative to a given reference (e. g., the status of the facility at the time of the last inspection) and alert the operator to potential anomalies for verification and action. One example might be for the inspection of truss struts for micrometeoroid damage and visible cracks on thermal radiator surfaces. Simulation of realistic dynamic lighting conditions is included. In addition, configuration control of manipulators with redundant degrees of freedom pioneered by JPL has been implemented to assure dexterous manipulation near complete structures.

The baseline inspection task is to teleoperate a robotic arm which carries a pair of mini-wrist cameras. The operator uses a pair of 3-DOF joysticks and can control the lighting to better view the scene. Additional cameras with pan/tilt zoom/focus control are controlled by the operator to observe the arm's motion and to inspect objects which are far away from the arms. A local remote architecture is employed so that space and time distances can be effectively treated. Multi-sensor based inspection of gas leak, temperature, and damage is conducted. Subsequently, inspection tasks requiring contact such as Eddy current based crack detection is performed.

Focus and Directions:

FY 1994: Develop capability to perform inspection tasks requiring contact with environment. Detect cracks remotely via a telerobot. Crack length 0.08 inches, depth 0.01 inches, and width 0.007 inches. Develop whole arm proximity detection system and show safe operation within 1 foot of any unknown object.

FY 1995: Perform inspection tasks in hard-to-reach areas. Show capability to enter openings as small as 6 inches and inspect objects two feet deep inside the opening. Using whole arm proximity sensing, show capability to safely navigate in cluttered environment where the CAD data is missing objects. Document timeline and capabilities comparison versus conventional teleoperation for inspection.

FY 1996: JPL makes, tests, and delivers a copy of the existing Remote Surface Inspection MCS and TIPSS subsystems to JSC by the end of January 1996; JSC tests and demonstrates remote surface inspection capabilities by the end of May; JPL will lend the JPL sensor head and associated sensor electronics to JSC during this test/demo period.

Point of Contact:
Won S. Kim
(818)354-5047
wonsoo@telerobotics.jpl.nasa.gov

ISSA Telerobotic Maintenance Technology Transfer

The objectives of this activity are to identify, develop, evaluate, and validate telerobotic technologies for integration into the International Space Station (ISS) Program. Requirements are being developed by the TRIWG Extra Vehicular Robotics Analysis and Integration Team (EVR AIT) and the ISS that identify specific robotic technology application opportunities. Coordination of candidate robotic technologies through the TRIWG EVR AIT to insure conformance to these requirements is a significant portion of this task element. For promising technologies that are identified this task also includes laboratory testing of the technology against the ISS baseline. The Automated Robotic Maintenance of Space Station (ARMSS) facility has been constructed at NASA/JSC to emulate SPDM operational and control characteristics. The facility incorporates two 7-DOF Robotics Research manipulators, to perform candidate ISS/ORU servicing tasks on a full scale Pre-Integrated Truss (Space Station) mock-up. Extra-Vehicular Robotic (EVR) technologies under development at JSC and other NASA and university research centers are transferred to the ARMSS facility where the performance of the system can be assessed relative to the Space Station baseline.

Focus and Directions:

Remote Surface Inspection

The RSI system is a multi sensor based Remote Surface Inspection (RSI) system that JPL has developed. JPL has indicated the system is at the appropriate maturity level to transfer onto ARMSS for evaluation purposes. A JPL to JSC technology transfer plan has been agreed to which requires the activities, specified below, be performed by JSC to support the testing. FY96 Plans include addressing enhancements that may be required for integration onto the ISS as well as timeline issues for the RSI system with the TRIWG EVR AIT. All testing and evaluation will be done in FY97 in close coordination with the newly formed TRIWG EVR AIT. The final evaluation report will be published after the testing is completed in FY97. Copies of the report will be distributed to the ISS Advanced Engineering and Technology Development office and to the ISS Robotics IPT Lead. The capability to conduct remote surface inspection is one that has been identified by as a requirement by the ISS in a preliminary discussion of their technology needs.

Calibrated Synthetic Viewing

Lack of adequate camera views has been identified (by the ISS Program Office) as a significant concern on the ISS (International Space Station). This has been specifically in relation to telerobotic operations, and payload alignment/mating tasks. Technologies are being sought that can help alleviate these serious concerns. The Calibrated Synthetic Viewing (CSV) program is two year program designed to eliminate the visual occlusion problem through the use of artificially generated calibrated synthetic views. The objectives of this task is to use the ARMSS facility to assist in the development as well as in the evaluation of the computer vision assisted CSV system.

Image Registration Technology

The development of technologies to assist in the alignment, orientation, and berthing of ORU's have been identified as a major requirement by the ISS program. Image registration is a simply implemented technology that may assist in the performance of these functions. This is a JSC image recording and cancellation system that is a by product of our ongoing targeting system (Autotrac) development effort. Last fiscal year the system was briefly ported on to ARMSS for a "quick look" assessment and a judgment was made that the system should be more formally evaluated on ARMSS. This evaluation can be done at minimal expense due to the simplicity of the system. The product of this activity will be an assessment (short report) of the systems capabilities, potential and ISS integration issues to be released to the ISS, ER4, and NASA Headquarters.

3-T Intelligent Architecture

The development of autonomous control algorithms (i.e. autonomous inspection, manipulation, long term planning, with reactive real-time responses and decision making capabilities) are critical if significant reductions in crew workloads are to be achieved. Robotic systems must be developed which have the robust capabilities to handle planned tasks and yet posses operational flexibility to address unexpected situations. The 3-T Intelligent Architecture is a JSC developed autonomous system that is mature enough to be demonstrated and assessed on the ARMSS facility. The system is fully compatible with the existing infrastructure and should be one to the easier technologies to integrate on to the system for evaluation purposes. The system will be tested against the ISS baseline performing ORU servicing and maintenance activities.

Task Milestones:

The following technologies are currently planned for assessment on ARMSS in FY 96:
Remote Surface Inspection System
Calibrated Synthetic Viewing System
Image Registration Technology
3-T Intelligent Architecture

Point of Contact:
Naveed Quraishi
(713)483-9146