가상토크를 통한 이족보행로봇의 안정적인 주행 속도 변화

Abstract

This paper proposes a method to generate a stable running trajectory for a biped robot based on virtual torque at the stepping foot for velocity changes. For a velocity change, an external force is necessary, which can be expressed by virtual torque. The virtual torque moves ZMP (Zero Moment Point). Therefore, applying the moving ZMP has the same effect as applying a virtual torque at the foot on the ground. By applying a moving ZMP to the running trjecoty of a biped robot, the velocity of the biped robot can be changed. When a running trajectory for a biped robot is generated based on its model modeled with a single particle, the dynamics of the real robot which has relatively large mass of the swing legs could make the biped robot motion unstable. Based on the gravity-compensated inverted pendulum model with the virtual torque at the stepping foot, a trajectory resulting in stable velocity changes is generated. The effectiveness and the improvements in the performance of the proposed method were shown in computer simulations with a 3D biped robot.