The transformation of modified 4-channel architecture

Bilateral control, the technology of teleoperation with force feedback, is progressing rapidly and has a field with an important application in space, oceanic engineering, medicine, and so on. Many researchers have employed velocity, force or impedance information to propose a variety of bilateral control. As a conventional bilateral control, position-position, force-position architecture are known. But, these architecture was only intuitive and did not have a clear performance index. Hannafod, Lawrence and so on had established a clear design method based on transparency by using the H matrix and a four-channel architecture, and among the control architectures that incorporate velocity and force feedforward, the 4-channel architecture has shown perfect transparency in ideal condition. Furthermore, by using a local force feedback, one can counteract an impact force imposed by the operator or the environment force reflection. But, it seems that this modified 4-channel architecture does not show the effect of local force feedback well from the point of view of visual. In addition, like a parallel control and a compliance control, control architecture which have a part where force information is converted into position information through filter cannot be expressed clearly in this architecture. So, the authors transformed the 4-channel architecture to make these control laws easy to evaluate. The authors introduce the transformation of the modified 4-channel architecture to clarify the meaning of local force feedback, and to express the above-mentioned controller clearly.