Javier Hidalgo Carrió DFKI Bremen & Universität Bremen Robotics Innovation Center Navigation and Slip Kinematics for High Performance Motion Models

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

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

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

5 State of the Art

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

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 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 Kinematics Modeling ATTITUDE

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

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

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

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

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

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

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

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

Thank you very much for your attention!! DFKI Bremen & Universität Bremen Robotics Innovation Center Director: Prof. Dr. Frank Kirchner

20 Kinematics Modeling ATTITUDE

21 Kinematics Modeling ATTITUDE

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

23 Kinematics Modeling

24 Kinematics Modeling

25 Kinematics Modeling

26 Kinematics Modeling