Fault Tolerance Micro-manipulation System and Its Application to Teleoperation Tasks

力反馈在微操作系统中的作用已得到广泛认可。然而，实际应用尚未看到的事实是由于以下两个主要原因：(1)缺乏提供稳定的力反馈信号的手段；(2)缺乏在存在通信延迟的情况下实现遥操作的手段。目前的研究旨在解决这些问题在微观操作的情况下。为了处理(1)，我们提出利用冗余感知手段应用“容错”的概念。通过这样做，故障传感器可以由辅助传感器备份，以便操作方可以不中断地继续接收力信号。（二）通过模拟微操作系统的操作探针的虚拟模型来处理。虚拟模型使操作员能够根据模型反射的反作用力而不是实际系统反射的反作用力来完成操作任务。采用这种虚拟模型的最大优点是没有时延。如果根据实际测力产生力反馈信号，通信时延大，操作者难以执行操作任务。我们进行了实际的远程操作实验，其中使用触觉设备（PHANToM）在互联网上操作微操作系统。为了比较，我们测试了TCP和UDP，发现UDP更适合我们的目的。我们还验证了虚拟模型非常有用，即使是新手也可以在远程操作下操作微操作系统。此外，还引入了一种新的机构来增强微操作系统的功能。采用偏置平面铰链连杆机构对探头进行姿态控制。

Efficacy of force feedback in a micro manipulation system has been widely recognized. However, the fact that a practical application is yet to be seen is due to the following two major reasons : (I) lack of means to provide a stable force feedback signals, (II) lack of means to realize a teleoperation even under the presence of communication delay. The current study is aimed at dealing with these problems under the scenario of micro manipulation. In order to deal with (I), we propose to apply the concept of "fault tolerance" by utilizing redundant sensing means. By doing so, a faulty sensor can be backed up by a secondary sensor so that the operation side can keep receiving force signals without interruptions. (II) is coped with by means of the virtual model which mimics an operational probe of the micro manipulation system. The virtual model enables the operator to accomplish manipulation tasks according to a reaction force reflected from the model rather than from the actual system. The biggest advantage of adopting such a virtual model is the absence of time-delay. If the force feedback signal is created based on the real force measurement, the communication time-delay becomes substantial so that the operator can hardly execute manipulation tasks.We have conducted actual teleoperation experiments in which a haptic device (PHANToM) was used to operate the micro manipulation system over the Internet. TCP and UDP were tested for comparison purposes and it was found that UDP serves better for our purpose. We also verified that the virtual model is extremely useful so that even novice user can handle the micro manipulation system under teleoperation. In addition, a new mechanism was introduced to enhance the functionality of the micro manipulation system. Offset planar hinge link mechanism was adopted to provide a posture control of the probe.