Combining real and virtual sensors for measuring interaction forces and moments acting on a robot

• Published in: Proceedings of the ... IEEE/RSJ International Conference on Intelligent Robots and Systems pp. 794 - 800
• Main Authors: Buondonno, Gabriele, De Luca, Alessandro
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.10.2016
• Subjects: Collision avoidance; Force; Robot kinematics; Robot sensing systems; Torque
• ISSN: 2153-0866
• DOI: 10.1109/IROS.2016.7759142

We address the problem of estimating an external wrench acting along the structure of a robot manipulator, together with the contact position where the external force is being applied. For this, we consider the combined use of a force/torque sensor mounted at the robot base and of a model-based virtual sensor. The virtual sensor is provided by the residual vector commonly used for collision detection and isolation in human-robot interaction. Integrating the two types of measurement tools provides an efficient way to estimate all unknown quantities, using also the recursive Newton-Euler algorithm for dynamic computations. Different operative conditions are considered, including the special cases of pointwise interaction (pure contact force), known contact location, and of a base sensor measuring only forces. We highlight also the conditions for a correct estimation to be fully virtual, i.e., without resorting to a force/torque sensor. Realistic simulations assess the estimation performance for a 7R robot in motion, subject to an unknown external force applied to an unknown location.