Development of a self reliant humanoid robot for sketch drawing

This paper demonstrates the capability of humanoid robot in the field of sketch drawing. Sketch drawing is a complex job which requires three basic problems to be solved. The first problem is to extract prominent features (the image point) of the object shown. Second is to define the image points lying on the Humanoid's camera plane with respect to its end effector position. The third problem is to provide the inverse kinematic solution and control strategy for smooth drawing. A H25 NAO humanoid robot is used as a test-bed in this paper to conduct this experiment and illustrate the whole process. A calibration matrix is defined which transforms image points in NAO body coordinate system while inverse kinematics has been solved using a gradient descent numerical method. The analytical solution of the inverse kinematics for NAO's hands are not suitable due to its mechanical design which is not following the piper's recommendation. The Denavit-Hartenberg (DH) parameters of the system has been defined in order to measure the working envelope of the right hand as well as to avoid singularities.