Abstract: An improved positionbased visual servo (PBVS) grasping algorithm was proposed for the service robot in home environment. First, the rapid identification of object was achieved by using Naomark, and the position and pose information of the object was estimated through the world homography matrix decomposition. Secondly, the kinematic model of the NAO robot′s arm was established, and PBVS control law was designed for either unimanual or bimanual grasping. Finally, for purpose of improving the stability and robustness of the grasping operation, path planning of the endeffector was added to the original PBVS control law. Experimental results showed that the proposed method could grasp the objects rapidly and stably.

Key words: visual servo, NAO robot;homography decomposition, kinematic model;unimanual／bimanual grasp