1. Javier Hidalgo Carrió DFKI Bremen & Universität Bremen Robotics Innovation Center www.dfki.de/robotics javier.hidalgo_carrio@dfki.de Navigation and Slip Kinematics for High Performance Motion Models

2. 2 Outline Motivation State of the Art Kinematics Modeling Approach Results Conclusion and Questions

3. 3 Motivation  The common 3D-planar assumption does not capture the complexity of the system

4. 4 Motivation  To find a common solution to easily extend to other systems. Transformation vs Geometric approach

5. 5 State of the Art

6. 6  P. Muir and C. Neuman (1986): Kinematics Modeling of Wheeled Mobile Robots

7. 7 State of the Art  M. Tarokh and G. J. McDermott (2005): Kinematics Modeling and Analysis of Articulated rovers  P. Muir and C. Neuman (1986): Kinematics Modeling of Wheeled Mobile Robots

8. 8 State of the Art  M.Görner and G. Hirzinger (2010): Analysis and Evaluation of [..] Eight-legged Walking robot  B. Gassmann (2005): Localization of Walking Robots  M. Tarokh and G. J. McDermott (2005): Kinematics Modeling and Analysis of Articulated rovers  P. Muir and C. Neuman (1986): Kinematics Modeling of Wheeled Mobile Robots

9. 9 Kinematics Modeling ATTITUDE

10. 10 Kinematics Modeling ATTITUDE  3D slip vector at the contact point with the ground

11. 11 Kinematics Modeling ATTITUDE  Ground contact angle which defines the direction of motion of the wheel.

12. 12 Kinematics Modeling ATTITUDE J 3j J 1j J 2j J 0j

13. 13 Kinematics Modeling  Least-Squares optimization to minimize the error of an overdetermined system.  It is important to define the single contribution of each wheels to the final movement (wheel-weighting matrix C).

14. 14 Results  Space Hall test at DFKI using Vicon System as ground truth ASGUARD

15. 15 Results  The localization results are much better than the conventional odometry

16. 16 Results  The wheel-weighting matrix defines the center of rotation

17. 17 Results  Slip vector analysis of each single wheel-contact point

18. 18 Conclusions 3. Definition of a wheel-weighting matrix to define each wheel contribution 1. Full Kinematics model of a leg-wheel hybrid system (including slip vector) 2. Improvements on motion models (dead-reckoning) 4. Better selection of the contact point 5. Field testing results are next to come

19. Thank you very much for your attention!! DFKI Bremen & Universität Bremen Robotics Innovation Center Director: Prof. Dr. Frank Kirchner www.dfki.de/robotics robotics@dfki.de

20. 20 Kinematics Modeling ATTITUDE

21. 21 Kinematics Modeling ATTITUDE

22. J 3j J 1j J 2j J 0j Kinematics Modeling

23. 23 Kinematics Modeling

24. 24 Kinematics Modeling

25. 25 Kinematics Modeling

26. 26 Kinematics Modeling