Sensory reflex control of a humanoid robot using FSR sensor

This paper proposes a zero moment point (ZMP) based walking control of humanoid robot using three sagittal joints in the lower body. The ankle joint plays a major role in balancing the whole body and thus needs to limit its joint angle in case of weakened posture stability. The knee joint can make the upper body move backward when the robot begins to tilt forward, and the hip joint is to correct upper body angle on the verge of falling back. The proposed angular adjustment rule of the three leg joints is based on the desired stable region assigned inside support foot area. Specifically, the difference angles for the knee and hip joints are calculated based on the kinematic model of a humanoid robot according to distance of the current ZMP from a boundary of desired region. The proposed approach is validated through walking experiment with a commercial humanoid robot platform Robotis-OP.