OPS-G Forum
24 March 2006
AURORA - Operational Requirements
for Robotic Exploration
Reinhold Bertrand
OPS-GTM
RB / 2006-03-24 1
Op. Requirements for Robotic Exploration
Outline
1. Context and Motivation:
2. ExoMars: Typical Mission and System Requirements
3. Rover Navigation & Control
4. Operational Requirements
5. Conclusions
RB / 2006-03-24 ESOC OPS-G Forum 2

Aurora - ESA’s Space Exploration Programme
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OPS-G Forum, 2006-03-24
Op. Requirements for Robotic Exploration
Exploration Performance Drivers
Perception capabilities:
– Recognise / understand environment and targets
– “see”, process, analyse targets / samples
Mobility capabilities:
– Reach targets
– Access, touch, grasp, collect samples
(digging, drilling, etc.)
Operational capabilities:
– Autonomy (signal delays, hard real-time requirements,
mission duration constraints, ground interaction needs)
– Unstructured / unknown environment:
autonomous decision making,
unexpected situations, contingencies
– Adaptability / flexibility of operations
– Exploration System Approach (P/L↔Rover)
1. Robotic Systems
Context &
Motivation RB / 2006-03-24 ESOC OPS-G Forum 4

Op. Requirements for Robotic Exploration
Outline
1. Context and Motivation:
2. ExoMars: Typical Mission and System Requirements
3. Rover Navigation & Control
4. Operational Requirements
5. Conclusions
RB / 2006-03-24 ESOC OPS-G Forum 5
Op. Requirements for Robotic Exploration
What is ExoMars?
ExoMars?
Search for traces of
past and present life on Mars:
– Where does life come from
– How/where did it evolve
– Is Earth a normal case or
a singularity
Deploy on the Martian surface a Rover
carrying a suitable analytical P/L (Pasteur)
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 6

Op. Requirements for Robotic Exploration
ExoMars Objectives
Scientific Objectives:
– To search for traces of past and present life on Mars
– characterise, in the shallow subsurface, vertical
distribution profiles for water and
geochemical composition
– measure planetary geophysics parameters
– study the surface environment and identify hazards to
human missions
Technology Objectives
– Land large payloads on Mars
– Demonstrate high surface mobility
and subsurface access
– Prepare technologies for MSR
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 7
Op. Requirements for Robotic Exploration
Looking for signs of life:
Life is cells:
– Need water
– Requires sugars (energy source and
backbone for nucleic acids)
– Cell menbranes are built with phospholipids
Life has Homochirality
– 2 mirror forms of biomolecules (enantiomers)
– Life uses only one enantiomer, e.g.
Left handed (L) amino acids
Right handed (R) sugars
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 8

Op. Requirements for Robotic Exploration
What to search for?
Extant Life: Biomarkers, such as:
•••
Amino acids Nucleotides Sugars Phospholipids Pigments
Extinct Life:
– Organic residues of biological origin;
(chemical, chiral, spectroscopic, and isotopic information)
– Images of groups of fossil organisms and their structure;
(morphological evidence)
– Geochemical and mineralogical effects of biology on the environment.
(second order)
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 9
Op. Requirements for Robotic Exploration
Where to search?
Liquid water is presently unstable on the Martian surface
The solar UV dose is harmful to unprotected life and organic compounds.
the search for extant life will focus on the subsurface.
warm spots with evidence of water deposits at accessible depths, as
identified from remote sensing satellites, i.e. Mars Express & MRO.
For extinct life, the search strategy relies on looking for well-preserved
biosignatures, i.e. encased in the geological record as microfossils.
the search for extinct life will also focus on the subsurface.
On sites occupied by bodies of water over extended time periods:
– Sedimentary deposits in ancient lake beds,
– Remains of hydrothermal systems;
– Outflow regions of past water channel systems.
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 10

Op. Requirements for Robotic Exploration
ExoMars Landing Sites
+
45º
–
15º
2. ExoMars Latitude Landing Band
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 11
Op. Requirements for Robotic Exploration
How to look for signs of life: PASTEUR
Panoramic Stereo Camera
Infrared Spectrometer
Ground-Penetrating Radar
Close-up Imager
Moessbauer Spectrometer
Combined Laser Plasma / Raman Spectrometer
Microscope
XRD
Life Marker Chip
Mars Organic Detector (MOD/MOI)
Gas Chromatograph / Mass Spectrometer
Drilling system (2 m)
Sample preparation and handling subsystem
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 12

Op. Requirements for Robotic Exploration
ExoMars Payload:
CONTEXT
Pasteur PanCam
Remote
IR Spectr. SUPPORT
GPR
INSTRUMENTS
Neutron Scatt.
Close-up Imager
Contact
Mössbauer
Suite
APXS Drill System
Raman & LIBS (2-m depth & surface)
Microscope IR incl. Borehole IR
XRD
Analytical Lab.
ORGANICS/LIFE Manipulator Arm
MOD/MOI
GC-MS
Life Marker Chip Sample Preparation &
Distribution System
ENVIRONMENT
Dust & H2O
Ionising Rad. Accommodated
UV Rad. in GEP
2. P, T, Wind
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 13
Op. Requirements for Robotic Exploration
Pasteur: Drill System
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 14

Op. Requirements for Robotic Exploration
Pasteur: Analytical Laboratory
Non-destructive
analysis
Microscope
Raman / LIBS
Sample
Destructive
analysis
Rock Analyte Drill System
Crusher Extraction
Dust
MOD
MO
Extraction &
D GC-MS
Cruscible
Oxidants
Fluorescamine Nominal mission:
XRD Life
Marker 10 surface +
CE
2.
Chip 20 subsurface
samples
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 15
Op. Requirements for Robotic Exploration
ExoMars Top-Level Requirements
Top-
Transport, deploy and operate the Pasteur payload, in particular:
– Collect material samples at the surface and from the sub-surface (2 m)
– Store, process, and analyse samples „in-situ“
Implement at least 10 experiment cycles, composed of:
– Locomotion to next sampling site (500-2000 m)
– Sample collection (drilling) and processing
– Data processing and transmission
One command cycle per day (Sol) only
Compatible with Environmental Conditions/Requirements for
– Launch, interplanetary transfer, re-entry, landing
– Mars environment (10 ... 45° latitude North or South),
VL2 landing site conditions
– Planetary Protection
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 16

Op. Requirements for Robotic Exploration
ExoMars Rover Mission Parameters
Nominal mission: 180 sols;
Nominal science: 10 Experiment Cycles + 2 Vertical Surveys;
Extended mission: 10 additional Experiment Cycles;
Experiment Cycle length: 6 – 18 sols
Sandy slopes of up to: 25 deg;
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 17
Op. Requirements for Robotic Exploration
Typical Rover Design
Total mass (including 48 kg P/L) 253 kg
Body Dimensions (l x w x h) 1500 x 630 x 580 mm
Wheels Ø300 x 100 mm
Track distance (c-c) 1070 mm
Ground clearance 310 mm
Solar Array InGa/GaAs/Ge, 1.5 m2
Batteries Li-Ion, 1500 Wh
Thermal RHU, 2 x 15 W, loop heat pipes
Data: 680 Mbits per exp. cycle
Communications: X-band DTE, UHF to orbiter relay
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 18

Op. Requirements for Robotic Exploration
Typical Rover Design: Locomotion
Effective locomotion speed: 100 m/sol (72 m/h nominal)
Max. slope climbing: 25 Deg.
Tip-over limit 40 Deg.
Max. obstacle height: 300 mm
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 19
Op. Requirements for Robotic Exploration
ExoMars vs. MER
Mars Exploration Rovers (2004)
– Rover 185 kg
– P/L 14.8 kg
– Mobility: 10-40 m/d; < 1 km total
– Instruments: distributed, miniaturised
– Regional exploration
ExoMars (projected), 2011
– Rover 254 kg
– 48 kg complex P/L facility
– Mobility: ~100 m/d;
5 - 20 km total
– Regional exploration
– Multiple drilling/sampling,
sub-surface sampling
2.
ExoMars
RB / 2006-03-24 ESOC OPS-G Forum 20

Op. Requirements for Robotic Exploration
Outline
1. Context and Motivation:
2. ExoMars: Typical Mission and System Requirements
3. Rover Navigation & Control
4. Operational Requirements
5. Conclusions
RB / 2006-03-24 ESOC OPS-G Forum 21
Op. Requirements for Robotic Exploration
How to navigate through an unknown
environment ???
Action
locomotion monitoring & control
Perception
e.g. Stereo Vision
Decision Localisation Modelling
3. path, trajectories position, orientation Digital Terrain Model
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 22

Op. Requirements for Robotic Exploration
Basic Functions for Navigation & Control
Perception: Data Acquisition
(surrounding environment, stereo vision)
Environmental Modeling:
Digital Terrain Model (DTM)
Localisation: position and orientation in the DTM
Decision: path / trajectory planning, based on
DTM, obstacles, rover state, current objective,
resource/risk considerations
Action: locomotion monitoring and control
3.
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 23
Op. Requirements for Robotic Exploration
N&C Example 1: Sojourner
“classical” approach: Direct Control
(all planning on ground)
Earth Mars
Perception (stereo vision)
DTM on Ground
localisation
Decision
pre-planned sequence
Action
Minimised risk, max. control
Time consuming
Limited performance
in rough terrain
Not usable for “long” trajectories
3.
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 24

Op. Requirements for Robotic Exploration
N&C Example 2: MER
Largely Direct Control
Autonomous local navigation: AutoNav
“Obstacle Avoidance Scheme”
Earth Mars
Perception (stereo vision)
DTM
localisation
Decision:
elementary trajectory evaluation
Action: Trajectory execution (short distance)
3.
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 25
Op. Requirements for Robotic Exploration
MER Operations: Lessons learned
Localisation is critical in some situations (ground slippage)
Better locomotion abilities required (slip detection)
Higher autonomy required to traverse “cluttered” areas
(reach a given target through some sort of itinerary)
Several ground interactions required to place instruments
End of autonomous motions may leave rover in bad attitude
(w.r.t. antenna, solar panel)
3.
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 26

Op. Requirements for Robotic Exploration
ExoMars Navigation & Control Requirements
Enable autonomous operations for one sol (one comms session per sol)
Traverse > 100 m per sol
Reach a target location
– at a distance up to 100m with an accuracy of 10m
– distance up to 20m with an accuracy of 0.5m
– 2m with an accuracy of 0.05m
Path planning and execution functions:
– Autonomously advance along a sequence of way points
pre-planned on Ground
– Autonomous path planning (goal tracking, obstacle avoidance,
minimisation of risk and resource consumption)
Autonomously classify and negotiate obstacles:
– Ignore / overcome / avoid / stop
3.
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 27
Op. Requirements for Robotic Exploration
N&C Key Trade-Offs
Trade-
Degree of autonomy on the planetary surface
Distribution of functions, models, processing capabilities decision authority.
Efficiency / feasiblility versus safety, reliability, risk
Control Autonomy / role of human operator to be scaled according to the
control task:
– Type of environment
– Length of trajectories
– Motions w.r.t. a target
3.
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 28

Op. Requirements for Robotic Exploration
ExoMars Navigation & Control Approach
Four Control Modes:
Direct Control For short motions, easy traverses, difficult situations
No on-board decisions, trajectories planned on ground
Safeguarded Mode For easy traverses beyond the “3D view” of the operators
Local autonomous navigation (MER - AutoNav)
Target reaching Trajectory defined w.r.t. a locomotion target
mode
Long Range Mode Long traverses, difficult terrain
Define itinerary to follow, specification of goal and sub-goals
Operator selects and configures a suitable operational mode
3.
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 29
Op. Requirements for Robotic Exploration
ExoMars Navigation & Control Approach (2)
4 operational modes reflecting different levels of
autonomy / direct operator control
Perception through stereo vision
Localisation through multiple sensors:
– 3D Odometry (wheel encoders, steering angles, chassis angular config.)
– Inertial navigation (gyrometer, IMU)
– Visual odometry (motion tracking in images)
– Sun Sensor
Decision:
– Local DTM with traversability assessment per cell
– Merging into a global navigation map, maintained over long ranges
– Target tracking in visual model / DTM
– Definition of sub-goals (“path planner”) and associated perception tasks
– Definition of trajectories (“trajectory planner”)
3.
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 30

Op. Requirements for Robotic Exploration
ExoMars Navigation & Control Approach (3)
Action
– Several nested loops
individual wheel control
rover body speed control
navigation control
– Wheel walking control
– Locomotion monitoring
Position tracking
Attitude / chassis internal angles
Wheel slippage
Localisation algorithm monitoring
3.
Rover N&C
RB / 2006-03-24 ESOC OPS-G Forum 31
Op. Requirements for Robotic Exploration
Outline
1. Context and Motivation:
2. ExoMars: Typical Mission and System Requirements
3. Rover Navigation & Control
4. Operational Requirements
5. Conclusions
RB / 2006-03-24 ESOC OPS-G Forum 32

Op. Requirements for Robotic Exploration
Rover Operations Implications
Three players at least: Mission Control
– Overall mission control
– Rover navigation & control
– Payload control Rover Control Payload Control
Strong interrelationships
Overall exploration performance is
“end to end”: Mission – Rover – Pasteur
Strict separation MOC-SOC
not suitable
Scientific Users interface with rover and P/L control
Regional distribution of control centres is critical,
for rover and payload control a separation is unsuitable
4.
Ops. Requ.
RB / 2006-03-24 ESOC OPS-G Forum 33
Op. Requirements for Robotic Exploration
Operations Centres Requirements: Rover
Methods and tools to cover all operational modes
from direct control to long range mode
Specifics (besides “usual” M&C):
– DTM (local, regional, global),
to be updated constantly
– 3D Monitoring /
Visualisation techniques
– All related processing capabilities
(imaging, sensor filtering / fusion)
– Path and trajectory planners,
optimisation tools
– Simulators:
S/W
Rover test benches including H/W models
– Needs link to P/L control for both, planning and verification
– Public outreach issues
4.
Ops. Requ.
RB / 2006-03-24 ESOC OPS-G Forum 34

Op. Requirements for Robotic Exploration
Ground Support Tools
Global high level mission planning tools
(time / ressource constraints, overall rover activities)
Functional navigation tools
– 3D environment modeling
– Complex trajectory planner
– Rover simulator Situation analysis
Debriefing tools
– Localisation (w.r.t. skyline, orbiter map, panoramas)
Rough terrain traj. planner
4.
Ops. Requ.
RB / 2006-03-24 ESOC OPS-G Forum 35
Op. Requirements for Robotic Exploration
Operations Centres Requirements: P/L
earth earth earth
traverse wac gpr traverse wac gpr
environmental / hazard sensors
earth earth
AUTOMATIC ANALYSIS SEQUENCE
traverse wac gpr hrc drill lowmagmic raman libs mod gc-ms moi lmc
spds
environmental / hazard sensors
earth
DETAILED ANALYSIS SEQUENCE
himagmic raman libs mod gc-ms moi lmc
spds
environmental / hazard sensors
4.
Ops. Requ.
RB / 2006-03-24 ESOC OPS-G Forum 36

Op. Requirements for Robotic Exploration
Operations Centres Requirements: P/L
Pasteur contains classical science instruments
as well as robotic systems
(drill, robotic arm, PanCam, SPDS)
Strongly depends / interacts with
rover vehicle as carrying platform
Needs DTM in high resolution
(mm range)
Similar planning / verification tools
for robotic components
4.
Ops. Requ.
RB / 2006-03-24 ESOC OPS-G Forum 37
Op. Requirements for Robotic Exploration
Conclusions
Operation of a robotic exploration mission on planetary surfaces (ExoMars)
is characterised by
– Unknown and unstructured environment
– Control needs under hard real time conditions
– Complex rover and P/L operations
– Restricted communications access (frequency, delays, as usual)
“classical” direct control schemes and automation of operations
can not do the job
Change in culture: Operational Autonomy
“let the child walk on its own”
A third block of operational functions protrudes:
Mission – Rover Control – Payload Control
Operations concept must be truly interdisciplinary,
location/distribution of control centres is critical for performance
RB / 2006-03-24 ESOC OPS-G Forum 38

Op. Requirements for Robotic Exploration
Prepare the ground for new insights ...
The End
RB / 2006-03-24 ESOC OPS-G Forum 39
Op. Requirements for Robotic Exploration
Acknowledgments
Many Thanks for viewgraph and video contributions as well as for reviewing
support to
Michael McKay, OPS-OSC
Jorge Vago, HME-GAP
RB / 2006-03-24 ESOC OPS-G Forum 40

Op. Requirements for Robotic Exploration
Contributions to ExoMars (%)
40
France
Germany
Italy
14.51 7
Spain
Switzerland
5.47
United Kingdom
Canada
16.02 17.04 Others < 3%
8.74 1.01
Total Subscription 109.79% = 650.8 MEUROs
RB / 2006-03-24 ESOC OPS-G Forum 41