Towards Autonomous Estimation of Lightweight Object's Mass by a Humanoid Robot during a Precision Grip with Soft Tactile Sensors

The estimation of the intrinsic properties of an unknown ob- ject is a very challenging problem, mainly due the limitations on the tactile technology. In this article we present a method to estimate an ob- ject's weight during a precision grip made by a humanoid robot. Tactile sensors on the ngertips provide information on the 3D force vector dur- ing a movement of grasping and lifting a cup lled with dierent masses (30-100g). Using the force measurements across time, we were able to successfully calculate the object weight for 8 dierent masses in two sce- narios: (i) Manually segmented force measurments and (ii) automatically segmented force measurments. Regarding the manually segmented data, we are able to have repeatable measurement and low deviations from the real value, especially for higher object masses. Regarding the automat- ically segmented data, we are able to identify the various phases of the grasping experiment and use the segmented phases to compute the mass automatically.