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arXiv · 1711.03896

A Geometric Characterization of Observability in Inertial Parameter Identification

Patrick M. Wensing·Günter Niemeyer·Jean-Jacques E. Slotine
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Abstract

This paper presents an algorithm to geometrically characterize inertial parameter identifiability for an articulated robot. The geometric approach tests identifiability across the infinite space of configurations using only a finite set of conditions and without approximation. It can be applied to general open-chain kinematic trees ranging from industrial manipulators to legged robots, and it is the first solution for this broad set of systems that is provably correct. The high-level operation of the algorithm is based on a key observation: Undetectable changes in inertial parameters can be represented as sequences of inertial transfers across the joints. Drawing on the exponential parameterization of rigid-body kinematics, undetectable inertial transfers are analyzed in terms of observability from linear systems theory. This analysis can be applied recursively, and lends an overall complexity of $O(N)$ to characterize parameter identifiability for a system of $N$ bodies. Matlab source code for the new algorithm is provided.

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Patrick M. Wensing, Günter Niemeyer, Jean-Jacques E. Slotine. 2017-11-10. A Geometric Characterization of Observability in Inertial Parameter Identification. https://arxiv.org/abs/1711.03896

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