Tool force adaptation in soil-digging task for humanoid robot

Simultaneous control of position and force of robots is one of the difficult and important problems in the field of robotics. Even if we can get a desirable positional trajectory of robots' end effectors or tools that they use, it is not easy to know how much force we should apply in order to execute planned tasks. We propose a method that enables robots to exert the required force to successfully carry out tasks. In this paper, we introduce a method to realize online updating of the force applied to the environment through tools and modification of Center of Gravity (CoG) based on the reference force. The update direction of the force is set in advance considering the interaction between tools and environment. We take manipulation of a shovel as an example. To verify the effect of our method, a humanoid robot JAXON demonstrates the soil-digging task under various conditions.