Manipulation with Haptic Interface: An high performance 6-DoF system to verify assembly procedure on CAD models, , Genova 2007

The present work focuses on the design and development of a new system that allows the verification of assembly procedures directly from CAD models. A new haptic interface was realized to achieve high force resolution with good manipulation properties while moving the mechanical components to be assembled within a virtual scenario. The system integrates multimodal capabilities with simultaneous Audio, Vision and haptic feedback. The visual scenario makes use of the XVR technology to render feedback onto a stereographic screen. Collision detection has been implemented using a new high performance VPS algorithm that analyses inter-objects contacts in real time. VPS algorithm generates proper outputs hat have been used both for realtime rendering of the contact sounds as well as haptic rendering of interaction forces. The haptic interface was built as a parallel closed kinematic that integrates two existing 3DOF devices, the GRAB interface, using a specific motorized linkage between the two arms. The resulting device allows manipulation in a very large workspace, 400x400x600mm, with high continuous and peak torques, about 12-24N in all condition, while keeping very low the residual friction. The Haptic and Audio Virtual Environment (HAVE) allows the user to manipulate in a completely natural manner the mechanical components while allowing recognition of geometric features (corners, edges,..) through the force and torque feedback, as if he was grasping a real mock-up of the object. The realtime audio was generated using realtime convolution integral of the impulse response of the colliding pieces with the force profiles exerted by the user and measured trough the haptic device. Audio contacts were divided in short time windows whose convolution results was computed and sent to the audio databuffer each 25 mS. Volumetric haptic rendering for collision detection and force generation was performed by integrating an up to date state of art technique for 6dof haptic rendering provided by DLR within the new architecture.