Positioning control of the leg of the humanoid robot by linear visual servoing

This paper presents a positioning control of the 4 d.o.f. leg of the humanoid robot by linear visual servoing. Linear visual servoing is based on the linear approximation between binocular visual space and joint space of the leg of the humanoid robot. It is very robust to calibration error, especially to camera angle errors and joint angle errors, because it uses neither camera angles nor joint angles to calculate feedback command. We obtain the linear approximation matrix of the inverse kinematics of the leg using the binocular visual space by the least squares approximation. Some experimental results are presented to demonstrate the effectiveness of the proposed method.