Controlling and maximizing humanoid robot pushing force through posture

Pushing is one of many object manipulation strategies that requires interaction with the environment. Many force control approaches have been proposed for such manipulation. In a force controller implementation for a humanoid robot, however, there is no fixed base. If the required reaction force is greater than the humanoid robot can support, the robot will lose its balance. This paper presents a method to expand these force limits by changing a humanoid robot´s posture. Based on Double Inverted Pendulum (DIP) model, the force limitation that the humanoid robot can support is calculated. With a feet-apart strategy and whole-body posture, a method is proposed to maximize the force limitation under the condition that the height of the target object is constant. Finally, comparison of simulation and experimental data validates the approach.