This document discusses recent accomplishments and future plans in planetary robotics. It summarizes the MER, MSL/Curiosity, and Chinese lunar missions. Current research focuses on improved autonomy through techniques like visual odometry, machine learning from terrain sensors, and differential wheel control. Upcoming missions include the Mars 2020 rover and ExoMars 2020 rover with flexible wheels. Challenges include ensuring mobility in unknown environments through testing and predictive modeling of wheel-soil interactions.

1. Planetary robotics:
recent accomplishments
MER (2004)
MFEX/Sojourner (1997)
MSL/Curiosity (2012)
NASA / JPL family of rocker-
bogie suspension Mars
rovers

2. Planetary robotics: recent accomplishments
MER-B Opportunity still fully
operational after > 12 years

5. Sol 4315 – 32 deg slope high slip event

7. Planetary robotics: recent
accomplishments
MSL / Curiosity:
In operations since 2012
Sedimentary rock sampling and analysis for
organics

8. MSL / Curiosity:
wheel damage

10. NASA / JPL
Mars 2020
rover (derived
from MSL)

11. European Space Agency (ESA)
ExoMars 2020 rover mission

12. European Space Agency (ESA)
ExoMars 2020 rover mission

13. European Space Agency (ESA)
ExoMars 2020 rover mission
Flexible wheels for adequate traction

14. Planetary robotics: recent accomplishments
Chinese program:
Successful lunar lander & rover in 2013 / 2014
Plan for Mars orbiter, lander, rover mission in 2020

15. Design drivers
• Stowage ! -> collapsable
chassis often needed
• Mobility sizing for
partially unknown
environments
• Mobility verificiation on
the ground (difference in
gravity)
• S/C on wheels…

16. Off-the-road vehicles: what can go wrong (1)

17. Off-the-road vehicles: what can go wrong (2)
MER Spirit rover
on Mars

18. Off-the-road vehicles: what can go wrong (3)
• Embedding of vehicles
(terrestrial and planetary) in
soil-like materials due to:
– Surprising, unknown terrain
properties
– Deficiencies in operations
planning
– Inadequate predictive models
for design sizing
– Inadequate testing
Empirical model for motion resistance, using
Cone Index (CI) measured on terrain

19. Pruiksma et al., 2011
FEM
DEM
Examples of modeling & simulation for planetary rovers
Nakashima et al., 2010
Knuth et al., 2011
DEM (trenching
MER rover wheel)

20. Current research: improved autonomy for
planetary rovers 1 / 2
• In-line embedding detection, slip & traction control
– Visual odometry (in use on Mars rovers already, computationally
expensive)
– Gonzales et al., this conference: machine-learning
– Higa et al., this conference: real-time sinkage from TOF camera
– Dedicated terrain sensing instruments
– Upcoming MSL / Curiosity S/W patch: differential wheel drives control
(Moreland et al., this conference)

21. Wheeled Bevameter for
planetary rovers (Richter et
al., ISTVS 2014)

22. Current research: improved autonomy for
planetary rovers 2 / 2
• Faster real-time stereo vision for geometrical
obstacles detection & avoidance