基于虚拟手的交互技术在人机交互和人机工程学测试等应用中发挥着重要的作用。为了实现直观自然、实时准确、接近真实世界中的虚拟手与虚拟物体的交互，并计算出反馈作用力，首先提出了用非线性弹簧模型计算抓取作用力，使虚拟手和虚拟环境之间实现了基于物理的交互；然后将计算结果以视觉渲染的形式反馈给用户，并对仿真的速率做了定量分析，以便使仿真速率可以达到屏幕刷新频率和力反馈刷新频率的要求。实验结果表明，虚拟手不仅可以直观自然地抓取3维虚拟物体，而且和3维物体之间能够进行实时交互，同时可计算出反馈作用力。

Interaction techniques based on virtual hand play an important role in applications such as human computer interaction and ergonomics test, etc. For the purpose of a naturally real time interaction between virtual hand and virtual objects, also for the purpose of the feedback force calculation, a new non linear spring model is proposed. A hand model with facility movement control and visually realistic appearance is established, the established hand model is the same as real man hand in fingers degree of freedoms. We also presented the virtual hand movement control method which is based on vector rotation. The simple spring model is improved and the grasping force is calculated with a non linear spring model. The non linear spring model is expressed in a three piecewise function. The results feedback to the users are in the form of visual rendering a quantitative analysis is done on simulation rate which is fast enough for screen refresh rate and force rendering rate. Experimental results show that virtual grasping can be executed naturally in real time.