CHAI 3D is an open source, freely available set of C++ libraries for computer haptics, visualization and interactive real-time simulation. CHAI 3D supports several commercially-available three- and six-degree-of-freedom haptic devices, and makes it simple to support new custom force feedback devices. CHAI 3D is especially suitable for education and research purposes, offering a light platform on which extensions can be developed. CHAI 3D’s support for multiple haptic devices also makes it easy to send your applications to remote sites that may use different hardware.
Characterization of 3D Deformable Models
In the field of real time 3D simulation, deformable models are now more and more often used, especially in the medical field. Based on the skeleton representation for deformable objects, the goal of this project is to define a correct set of stiffness parameters in order that the physical simulated model behaves like the real one under variable force constraints. The strategy for the characterization is to apply different known external forces on the real object and to measure the resulting displacement. Then, based on these measurements and the model’s skeleton, a custom Bayesian filter algorithm is used to estimate the springs’ parameters according to the evolution of the model.
Soft Tissue Modeling
Virtual reality based simulations of surgery have shown promise in assisting surgical training, surgical planning, pre-operative rehearsal, and intra-operative execution. Development of an effective virtual environment requires real-time interactivity and realistic visualization. Simulating deformable organs can be a heavy duty for a computer. This project presents an original method to allow real time deformation on complex virtual objects. The technique consists in creating much simpler models using filling spheres and three dimensional elastic links.
HapticDriver: Remote Driving with Force Feedback
The most difficult aspect of remote driving is that the operator is usually limited to visual information (e.g., camera video) for perception. Consequently, the operator often fails to understand the remote environment and makes judgement errors. This problem is most acute when precise motion is required, such as maneuvering in cluttered spaces or approaching a target. The HapticDriver addresses this problem by providing force feedback to the operator. Range sensor information is transformed to spatial forces using a linear model and then displayed to the operator using the Delta Haptic Device. Thus, the Haptic Driver enables the operator to feel the remote environment and to better performance precise driving tasks.
Nanomanipulation of Carbon Nanotubes
The aim of this project is to develop a force-feedback interface that enables a user to manipulate nanometer size objects with an Atomic Force Microscope (AFM). Our current interface integrates a high-performance force-feedback system (the Delta Haptic Device), real-time 3D graphics, and physics-based simulation of nanoscale AFM interaction. We have recently begun integrating our system with a commercial AFM and are now evaluating the suitability of different operation modes for nanomanipulation. By allowing bilateral scaling (geometric, kinematic and force), the DHD can make such operations easier and faster than traditional tools.
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