Clarification of Force Feeling Mechanism based on both Telecommunication and Haptic Illusion

本研究的目的是利用基于触觉界面的虚拟现实技术来阐明人的力感机制，这是一种力显示装置。首先，利用机器人手指系统开发了触觉界面系统。它的优点是既易于在虚拟现实环境中通过改变数学模型来改变实验条件，又易于在实验过程中获取受试者的运动数据。为了充分利用这些优势，我们选择了Haptic Illusion领域来阐明力感机制。该领域的实验条件在实际物理场中很难改变。首先，为了验证该系统对触觉错觉的有效性，选择了水平-垂直错觉实验，实验结果表明了该系统的有效性。研究结果表明，当一个物体的重量突然加到操作者的手指上时，受试者手指的运动主要与被动动作的尺寸-重量错觉有关。该系统的另一个优点是实现了在自然环境中从未经历过的实验条件。针对这一优势，选取物体突然发生的微小重量变化现象来阐明力感机理。实验结果如下：增加和减少负荷过程的感知阈值是不同的。人类可以感知到重量随其变化速率的大小而变化。当被试无法感知其在阈值下的变化时，他可能会不自觉地调整他的肌肉指令以适应体重的变化。作为力感机构的一种应用，对力传进行了研究。采用机器人主从系统的概念构建了力通信系统，其基础研究表明，在操作空间中存在镜像，实现力感知不仅需要力信息，还需要位置信息。

The purpose of this research is to clarify force-feeling mechanism of a human being by using a Virtual Reality technology based on Haptic Interface, which is a force display device. At first, Haptic Interface system was developed using a robot finger system. Its advantages are easiness both to change experimental conditions by changing mathematical models in the virtual reality environment and to obtain subject's motion data during the experiment.By making the most use of these advantages, Haptic Illusion field was selected to clarify the force-feeling mechanism. Experimental conditions of this field are very difficult to change in actual physical field. At first, to confirm effectiveness of the system for the Haptic illusion, a Horizontal-Vertical illusion experiment was selected, whose results show its effectiveness. Next, Size-Weight illusion was studied, whose results show that subject finger motion is mainly related to the Size-Weight illusion for passive action when a weight of a object is suddenly added to the operator finger. Another advantage of this system is to realize experimental condition that is never experienced in natural environment. As to this advantage, sudden small weight change phenomenon of an object was selected to clarify the force-feeling mechanism. Theses experiments show the following results. Perceptive thresholds are different for adding and reducing load process. Human beings can perceive a weight change with the magnitude of its rate. When a subject cannot perceive its change under the threshold, he may unconsciously adjust his muscle command to the weight change.Force telecommunication was studied as an application of the force-feeling mechanism. The force telecommunication system was constructed by using a concept of robotic master-slave system, whose fundamental studies show that mirror image occurs in operational spaces and not only force information but also position information are necessary to realize the force-feeling.