Six Degree-of Freedom Haptic Rendering for Dental Implantology Simulation

International audienceDental implantology procedures are among the most com- plex surgical procedures executed by dentists. During the critical part of the procedure, the jawbone is drilled at the location of the missing tooth (or the missing group of teeth). This asks for specic skills from the dentists, who need to be well trained. In this paper we present a virtual reality based training system for im- plantology and we mainly focus on the simulation of drilling. We have two main contributions: The rst one is a method for precise haptic rendering of contacts between the drilling tool and the jawbone model issued from a CT-scan. The second one is the real-time simulation of the jawbone erosion during drilling which is compatible with the haptic rendering of contacts

A hybrid method for haptic feedback to support manual virtual product assembly

The purpose of this research is to develop methods to support manual virtual assembly using haptic (force) feedback in a virtual environment. The results of this research will be used in an engineering framework for assembly simulation, training, and maintenance. The key research challenge is to advance the ability of users to assemble complex, low clearance CAD parts as they exist digitally without the need to create expensive physical prototypes. The proposed method consists of a Virtual Reality (VR) system that combines voxel collision detection and boundary representation methods into a hybrid algorithm containing the necessary information for both force feedback and constraint recognition. The key to this approach will be successfully developing the data structure and logic needed to switch between collision detection and constraint recognition while maintaining a haptic refresh rate of 1000 Hz. VR is a set of unique technologies that support human-centered computer interaction. Experience with current VR systems that simulate low clearance assembly operations with haptic feedback indicate that such systems are highly desirable tools in the evaluation of preliminary designs, as well as virtual training and maintenance processes. This work will result in a novel interface for assembly methods prototyping, and an interface that will allow intuitive interaction with parts based on a powerful combination of analytical, visual and haptic tools

BREP Identification During Voxel-Based Collision Detection for Haptic Manual Assembly

This paper presents a novel method to tie geometric boundary representation (BREP) to voxel-based collision detection for use in haptic manual assembly simulation. Virtual Reality, in particular haptics, has been applied with promising results to improve preliminary product design, assembly prototyping and maintenance operations. However, current methodologies do not provide support for low clearance assembly tasks, reducing the applicability of haptics to a small subset of potential situations. This paper discusses a new approach, which combines highly accurate CAD geometry (boundary representation) with voxel models to support a hybrid method involving both geometric constraint enforcement and voxel-based collision detection to provide stable haptic force feedback. With the methods presented here, BREP data can be accessed during voxel-based collision detection. This information can be used for constraint recognition and lead to constraint-guidance during the assembly process

Standardized evaluation of haptic rendering systems

The development and evaluation of haptic rendering algorithms presents two unique challenges. Firstly, the haptic information channel is fundamentally bidirectional, so the output of a haptic environment is fundamentally dependent on user input, which is difficult to reliably reproduce. Additionally, it is difficult to compare haptic results to real-world, "gold standard" results, since such a comparison requires applying identical inputs to real and virtual objects and measuring the resulting forces, which requires hardware that is not widely available. We have addressed these challenges by building and releasing several sets of position and force information, collected by physically scanning a set of real-world objects, along with virtual models of those objects. We demonstrate novel applications of this data set for the development, debugging, optimization, evaluation, and comparison of haptic rendering algorithms

Design and development of a VR system for exploration of medical data using haptic rendering and high quality visualization

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SHARP: A System for Haptic Assembly and Realistic Prototyping

Virtual Reality (VR) technology holds promise as a virtual prototyping tool for mechanical assembly; however, several developmental challenges still need to be addressed before virtual prototyping applications can successfully be integrated into the product realization process. This paper describes the development of SHARP (System for Haptic Assembly & Realistic Prototyping), a portable VR interface for virtual assembly. SHARP uses physically-based modeling for simulating realistic part-to-part and hand-to-part interactions in virtual environments. A dual handed haptic interface for realistic part interaction using the PHANToM® haptic devices is presented. The capability of creating subassemblies enhances the application’s ability to handle a wide variety of assembly scenarios. Swept volumes are implemented for addressing maintainability issues and a network module is added for communicating with different VR systems at dispersed geographic locations. Support for various types of VR systems allows an easy integration of SHARP into the product realization process resulting in faster product development, faster identification of assembly and design issues and a more efficient and less costly product design process

The Use of the Voxmap Pointshell Method of Collision Detection in Virtual Assembly Methods Planning

Virtual reality (VR) provides the ability to work with digital models in an environment that provides 3 dimensional interaction. This technology can be used to evaluate how humans interact with products before costly physical prototypes are built. One of the advantages of using VR technology in design evaluation is the ability to easily explore many different what-if design scenarios. One of the areas of current research in the use of VR is in assembly methods planning. As a result of prior work performed at Iowa State University, it became clear that collision detection is an important component in the development of virtual assembly methods planning applications. This paper describes the use of the Voxmap Pointshell method of collision detection as it is applied to a general purpose virtual assembly planning application