Assistance of virtual space manipulation by means of novel pseudo-force feedback devices

基于触觉信息在触觉识别中的作用大于本体感受信息的发现，提出了一种伪力反馈方法，该方法通过指尖的收紧来诱导指尖的触觉。该方法的概念是将显示感觉仅限于触觉，与传统的力反馈装置通过施加实际的反作用力来刺激触觉和本体感受器相反。采用开环控制器对样机进行控制，并引入高压初始加速脉冲，以减小器件延时。原型装置的紧固力达到2.3N。用户感知的反作用力感与所施加的接触力相关。两指抓取装置的原型表明，从10到70毫米的范围内的虚拟物体，成功地识别。在此基础上，构建了一个具有伪力反馈功能的虚拟物体操作系统原型，该系统由手指收紧伪力反馈装置、通用物理模拟器和虚拟耦合器组成。虚拟耦合分为两个部分，以实现模拟稳定性和清晰的接触感知。利用虚拟耦合产生的力矢量和虚拟手指的速度来检测操作对象与另一对象的碰撞。通过增加手指拧紧力近似地显示了碰撞力。实验结果表明，伪力反馈能提供更真实的抓取感觉，减少对虚拟物体的穿透，表明指尖收紧装置具有伪力显示的潜力，伪力显示可以有效地辅助虚拟空间操作。

Based on the finding that tactile information has larger role in haptic recognition than proprioceptive information, a pseudo-force-feedback method was proposed that induces tactile sense to each fingertip by its tightening. The concept of the method is limiting the display sense to tactile alone, in contrast to the conventional force-feedback devices stimulate both tactile and proprioceptive receptors by applying actual reaction force. The prototype device was controlled with open-loop controller with high-voltage initial acceleration pulse to reduce the device delay. The prototype device attained the tightening force up to 2.3N. The perceived reaction force sense by the users correlated with the applied contact force. The prototype two-fingered grasping device demonstrated that the wide range of virtual objects, from 10 to 70mm, were successfully recognized. The subjective sensation of grasping was more resemble to actual objects than the substitutive method using vibration.Further more, a virtual objects manipulation system with pseudo-force-feedback function was prototyped that consists of pseudo-force-feedback devices by finger-tightening, a general-purpose physical simulator and virtual couplings. The virtual coupling was divided into two components for simulation stability as well as clear contact perception. Collision of the manipulating object with another object was detected using the force vectors generated by the virtual couplings and velocity of the virtual fingers. The collision-force was approximately displayed by increasing finger-tightening force. Experimental trials demonstrated that pseudo-force-feedback provides more realistic grasping sensation and reduces penetration into virtual objects.These results suggested that fingertip tightening device has a potential of pseudo-force-display, and pseudo-force-display is effective for assisting virtual space manipulation.