【作者】 王旭东；

【导师】 韩燮；

【作者基本信息】 中北大学 ， 计算机应用技术， 2009， 硕士

【摘要】 长期以来,人们对虚拟现实技术的研究和应用主要集中在视觉和听觉模拟上。近年来,随着计算机科学和机器人技术的不断发展与进步,虚拟现实技术中的力觉交互技术逐渐成为新的国内外研究热点,得到了前所未有的重视。许多发达国家在这方面开展了大量研究,目前国外已出现商品化的力觉交互设备。相比之下,目前国内对虚拟现实技术的研究与应用都尚处于起步阶段,尤其是在力觉交互技术方面与国外有着相当大的差距。本文首先介绍了虚拟现实技术中力觉交互技术的概念以及国内外研究现状,探讨了目前在领域内实现人机力觉交互的方法和原理。提出了本文的主要研究内容:建立一套具有力反馈交互的虚拟操作面板,利用该面板可以操纵航天器的点火,发射以及复位,该系统的关键问题是改进点到面的碰撞检测速度问题和解决力反馈数学建模问题。为了保持视景画面的逼真性和实时性,需要基于本系统对碰撞检测算法进行优化与改进。本文在分析AABB算法和OBB算法的基础上,对AABB算法进行了改进,测试结果证明改进的算法的速度得到了提高。在力反馈物理建模方面,首先运用冲量定理和弹性恢复系数,求得质点刚体在二维空间碰撞后的运动状态,然后结合库仑定理,生成质点刚体有摩擦的碰撞力,并拓展到三维空间的虚拟环境中,计算非质点的虚拟刚体碰撞的力矩,再通过虚拟手静力抓持力觉生成模型,将碰撞力和碰撞力矩作用到虚拟质点上,求得质点受到的冲击力.再加上场力、阻尼力和惯性力,通过力反馈器将冲击传给用户实现力反馈.使用该方法成功解决了本系统力反馈数学建模的问题,并通过与Popescu等人改进了的弹簧线性模型算法的比较,证明该方法的有效性。更多还原

【Abstract】 Traditionally, the research and applications of VR are limited in the field of graphical and audio displays. However, with the developments of computer science and robotic technology, the haptic interaction art comes into the focus of VR field across the world recently. Many institutions of developed countries have explored this area and even developed some commercial products. In contrast, the domestic state-of-art technology in VR, especially in haptic interaction, has a considerable gap compared to the developed states.In this thesis, above all, the concept and applications of haptic interaction in VR are introduced; the domestic and overseas state-of-art is described; the various methods and philosophies enabling the haptic display at present are discussed. The main research content of this thesis about the steerable virtual panel (SVP), the operator can ignite, launch and reset air vehicle with SVP. The key points of this thesis include: improving the velocity of collision detection from point to faceplate and considerable mathematic modeling for a particle in haptic interaction.Fast and exact collision detection is very important to improve reality and enhance immersion for virtual environment. In order to keep in step with visual scene and operation, the collision detection arithmetic needed to be improved and optimized. Based on the analysis the characteristics of AABB(Axis-Aligned Bounding Boxes) and OBB (Oriented Bounding Box)algorithm, AABB is optimized and the test proves that the velocity of optimized arithmetic has improved.A method of collision force generation and feedback with friction for virtual particle interaction in virtual environments is proposed. Based on impulse theorem and coefficient of elastic recovery, the motion rules for virtual objects after collision in 2-Division space are deduced. By Coulomb’s friction model, this paper describes the generation of collision force in planar space which is explored to 3D virtual space, and collision force and collision moment in virtual environment are achieved. The means of collision force acting on hand is discussed, and impulsive force with field force, damp force and inertia force for particle is calculated by virtual particle optimized models with minimum force spiral. Experimental results show that using the collision force generation and feedback method, the user can sense realistic impulsive forces via the SensAble Phantom Haptic Device caused by virtual collision. This method succeeds in solving the problem of haptic modeling in this system.更多还原