Inertia Tensor Properties in Robot Dynamics Identification: A Linear Matrix Inequality Approach

Physical feasibility of robot dynamics identification is currently receiving renovated attention from the research community. Inertia tensor inequalities (namely the positive definite property) have been extensively used among other physical constraints to check physical consistency of identification methods. Recently, an extra inequality associated to inertia tensor eigenvalues has been included to check physical consistency, showing that the previous methods were incomplete. In this paper we show that this extra inequality incorporates the positive definite property, being more restrictive. We also include it in the linear matrix inequality framework for robot dynamics identification to obtain fully physical estimates. The relevance of the extra inequality is verified through real 7-DOF robot manipulator experiments.