Estimating the Center of Mass of an Object with Non-uniform Density via High-speed Pushing

Abstract

An object's inertial parameters, such as the mass, the Center of Mass (CoM), and the moment of inertia, affect the response to the external forces exerted on it. It is important to estimate these parameters as accurately as possible in order to facilitate robot-led automation including grasping and manipulation. Traditionally, the estimation is conducted by employing special equipment in a controlled environment, which may not be always available for a small batch production system dealing with unknown objects. We propose an efficient exploratory type framework for estimating an object's CoM via force sensor-less high-speed robotic pushing, which only requires the use of a vision system for detecting the change in the object's pose. Accurately estimating an object's CoM aids robotic grasping and expands manipulation scenarios. We conducted intensive simulation and real robot experiments to show the accuracy of the estimation, robustness to friction variation, and generalization capability to novel objects, that the framework ensures only with a limited number of pushes.