### Optimization and Systems Theory Seminar

Friday, November 16, 2001, 11.00-12.00, Room 3721, Lindstedtsv. 25

**Henrik Rehbinder**

Division of Optimization and Systems Theory

Department of Mathematics

KTH

E-mail: henrikr@math.kth.se

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State estimation for nonlinear robotic systems

In my thesis, two different control theoretic topics are studied,
nonlinear observer design for orientation estimation and control
design under limited communication. The specific problems originate
from control of mobile robots in difficult terrain, especially walking
robots. Different ensembles of rate gyros, accelerometers,
inclinometers and computer vision are investigated.
The seminar will focus on different aspects of nonlinear observer
design for the specific orientation estimation problems that the
thesis is concerned with. Particular attention will be paid to how the
observer design problem is tied to the rigid body kinematics
representation. It will be demonstrated how rate gyros and
accelerometers can be fused in a particularly simple way by using the
geometric structure of the underlying system. This is compared to a
more standard high-gain observer that does not use this structure. The
geometric way of viewing these problems is pushed further in a study
of computer vision where it is shown how observability of linear
systems is naturally generalized to an implicit output system evolving
on $SO(3)$. Finally, some implementational issues regarding the
computational constraints of computer vision is considered.

Calendar of seminars

*Last update: November 8, 2001 by
Anders Forsgren,
anders.forsgren@math.kth.se.
*