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Set up and Validation of METERON end-to-end Network for Robotic Experiments
François Bosquillon de Frescheville ESA/ESOC HSO-OSA
Directorate of Human Spaceflight and Operations S. Martin, N. Policella, D. Patterson, M. Aiple, P. Steele
ASTRA conference 12-14 April 2011
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METERON Presentation Plan
1.Short introduction/reminder.2.METERON architecture.3.Current METERON phase activities4.Presentation of validation tool5.Communication aspects6.METERON test environment7.Validation activities8.Conclusion.
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METERONShort introduction
• This project is a response to a call made in IAC 2008 (Glasgow) to start using the ISS as a test bed for future human space exploration.
• METERON is proposed by D/HSO and D/TEC as a collaboration with NASA, DLR, ROSKOSMOS, RKK Energia and RTC St Petersburg.
• It intend to use the ISS to simulate a manned station in orbit around the Moon, Mars, an Asteroid under directives from MissionControl on Earth.
• Astronauts will project their initiative and dexterity in real time on the surface of Earth simulating the relevant analog, through robotic device(s) to perform science or engineering tasks.
• METERON will provide a test bed to the robotic community both inflight and on ground as well as for the communications (such as DTN) and the operations communities (Human exploration scenarios).
• Lessons learned will permit to optimise all these technical domains for future human exploration benefit.
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METERONArchitecture description
This infrastructure is developed in two phases:
Phase 1 is validating the concept with simple, low cost and non redundant equipment.
Phase 2 will concern the total deployment of the infrastructure.
Manned ORBITER in orbit around Moon/Mars/Asteroid simulated by ISS
Earth Ground Segment
Moon/Mars/AsteroidGround segmentSimulating a Surface Robot and its communication system
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METERON Phase 1 activities: set up of the architecture concept
• To marry the 2 operational concepts of METERON, three steps are foreseen in the so called Quick Start activity which will be concluded by an OPERATIONAL READINESS DEMONSTRATION:
1. Establish basic connectivity between ESOC and Columbus in collaboration with University of Colorado using Delay tolerant Networking protocols.
2. Establish basic real time Robotic compatible connectivity between Columbus and the “analogue” ground via the Svezda module through the KONTUR-2 direct link.
3. Demonstrate the full end-to-end connectivity between ESOC and the “analogue” ground using the two previously established connectivity using DTN protocols.
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METERONValidation tool: MOCUP and MOPS (1)
The METERON Operation and CommUnication Prototype (MOCUP) is required to test the end-to-end communication chain with non real-time and real-time channels and to test operating concepts in the METERON context.
– It was therefore designed for driving in an easy environment.– It can be operated in real time mode or sequential mode and captures its
environment with a camera.
MOCUP OPeration Software (MOPS) is a suite of SW tools comprising:– MOPS graphical User Interface (MOPSUI) on the operator machine.– Controller SW running on the Robot computer.
CONCEPT– This simple validation tool enables early testing of METERON infrastructure end-to-
end without involving costly full-scale Robotics.– It can support communication test and explore operation concepts at a level beyond a
software simulator. – Rapid prototyping approach was retained (simplicity and short development time
favored over robustness and performance)
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METERONValidation tool: MOCUP and MOPS (2)
MOCUP was build using LEGO ® MINDSTORM NXT kit combined with an off-the –shelf computer called Beagleboard.
MOCUP architecture
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METERONValidation tool: MOCUP and MOPS (3)
MOCUP characteristics: 3 electrical motors (2 for motorisation and 1 to control the camera inclination). 3 ultrasonic distance sensors to prevent self inflict damage in sequence mode.1 USB camera.Caterpillar propelled.Beagleboard computer runs the communication stack, the video feedback.Beagleboard is equipped with wireless LAN adapter to ensure external link.Real time communications using standard Linux UDP over IP stack.A DTN node running on Beagleboard covers non real time communications. Dimensions: 42 cm long, 29 cm wide, 24 cm high
Performance: 25-50 ms E2E
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METERONValidation tool: MOCUP and MOPS (4)
MOPSUI : – Displays position and track of MOCUP on the map of the environment.– Includes the position of detected obstacles.– Operator can steer MOCUP in speed and direction in real time mode.– Operator can also modify the camera inclination.– In NRT mode, a list of way points can be set and activated or this can be provided by a file.– For reporting, points can be annotated on the map– A separate window provides a 128Kbits video from the camera
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METERONEnd-to-end communication diagram
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METERONCommunication aspects (1)
Non Real time link using Delay Tolerant Networking (DTN): – Tolerant to very long signal propagation latency and/or prolonged intervals of
unavailability.– Store and forward message switching.– Functionality achieved with a new protocol layer called the bundle protocol layer.– A DTN node can send, receive and/or forward bundles. – Interplanetary Overlay Network (ION) software distribution as been retained for
METERON.– For MOCUP and MOPS communication, an iterative process was followed from
standard TCP/IP toward MOCUP and MOPS based DTN nodes.– Testing the whole network consists in adding further DTN nodes once the links are
established.– Security principles and firewall introduced successively.
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METERONCommunication aspects (2)
Real time link:– Restricted to 4 Mbits/sec down and 256 Kbit/sec up link– 100-200 ms round trip delay– Early test to be done with a portable using UBUNTU 10.04 OS on 2.6 Linux kernel
(should be responsive enough to establish link latency).– QoS link rented between GS and robotic facility– Max 2 ms jitter (latency margin to be used to smooth out variance at reception)– MOPS will be installed on Columbus portable for early tests.
Use of Custom protocols:– For better handling and compatibility with ESA infrastructure software (test
environments, simulators, control systems, standardisation for plug and play)– More PUS and database supported protocols will be used for MOPS and MOCUP in
the future
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METERONTest environment
GSTVi (ground Segment Test and Validation Infrastructure)
Simulatore.g. GSTVi
SIF
SIF
SIF
SIF
SIF
SIF
SIF
SIF
SIF
SIF
SIF
SIF
SIF
SIF
SIF
MPTC
Exoskeleton/Joystick
Astronaut Ops. System
Standard Interface
MOCROC
Rover 1
Monitoring and Control (Site and Sim)
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METERONValidation of Communication chain
TESTS – MOCUP was controlled over a standard LAN environment using MOPS (TC, TM and
Video were transmitted) in real time. – An unknown remote environment was explored in an intuitive way.– Test will be extended over longer distance using off the shelf technology.
– MOCUP was controlled in sequence mode (no video) from ESOC DTN node 1 to ESOC DTN node 2 via a DTN node in boulder Colorado.
– Test to be extended towards the ISS CGBA and later Portable in Columbus
– Bridge the connection over a real time space link (KONTUR-2) transmitting UDP packets in CCSDS TM/TC frames. To be exercised with GSTVi until agreement with Russian signed.
– Then perform real activity.
FUTURE STRATEGY– Simulate the whole network using GSTVi– Replace with real hardware/software when it becomes available.
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METERONConclusion
The Operation and communication element of METERON is getting demonstrated at technical level thanks to phase 1 activities:
– Design of MOCUP and MOPS– METERON communication network set up– Getting familiar with DTN– Real time operations execution– Sequence operations execution– Test environment definition– Test program engaged
As soon as the political agreements with NASA and Russia are signed, this will permit quick progress to finish phase 1 and start phase 2 .
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Questions?
ACKNOWLEDGEMENTS:To B. Chesson, To K. Nergaard, Ph. Schoonejans, A. Schiele, J. Grenouilleau, B. Carey, K. Landzettel, A. Hooke, E. J. Wyatt, K.F. Nichols, K. Gifford, K. Scott, M. Kearney, L. Pitts, S. Burleigh, S. Williams who are working with the authors.
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ROKVISSOBC
CGBA-4ER3
Source: Presentation to ESA on CR 011812: “Integration of ESA/Columbus Ethernet LAN/PWS system into Joint Station LAN”, Brett Willman, NASA ISS Avionics & Software Office
European DTN Node& Robotics WS
BRI VLAN
Payload VLAN
CGBA-5ER2
CGBA-6ER1
(Up/Downlink)
Robotics “Work-station” (incl. DTN node) integration in ColumbusNetwork integration (local ISS, end-to-end)
METERONCommunications on the ISS
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METERON – Full Ground Architecture
