Balance control of humanoid robot in object lifting task with tactile sensing system

This paper discusses an effective framework of humanoid robot during an object lifting task. The key component is a control technique for balancing in the external forces. Our aim is to simplify the balance control during manipulation tasks by utilizing a real time tactile feedback instead of the complex ZMP calculations. We also present a tactile sensing system and an active tactile sensing technique to enable the humanoid robot to grasp an object and balance autonomously. In order to achieve a balancing task efficiently, the minimal sensing elements are employed with a specialized layout to the soles of each foot to detect the reaction force from the ground. The system effectiveness was confirmed by the experiments on humanoid platform to lift up the objects approximately in half and quarter of their body weight with single left arm. Throughout experiments, information about ground floor or robot orientation is not required in advance.