Active Grasping Control of Virtual-Dexterous-Robot Hand with Open Inventor

The grasping technology of the virtual-dexterous-robot (VDR) hand plays a key role in the teleoperation of the space robot. For a grasp task in the virtual environment, the collision detection and virtual force calculation need to be implemented. Firstly, a tree-structure virtual scene including a VDR hand and a target object is built up with open inventor (OIV). Secondly, the collision manager provided by OIV is used for collision detection and the oriented bounding box (OBB) is adopted to improve the real-time performance of collision detection. Thirdly, an algorithm is proposed for calculating the virtual force by using the contact deformation. And the contact deformation is calculated according to the transformation matrix between the coordinate systems of the two contact objects. Furthermore, the contact friction is also calculated by this matrix. Considering the virtual force, the modified stable grasping conditions are proposed which are suitable for the virtual grasping. Then a method is proposed for implementing the grasp or release operation by translating different nodes in the tree-structure scene, which can avoid destroying the tree structure. Finally, the viability and effectiveness of the proposed algorithms are proved by simulation experiments.