Development of multi-degree-of-freedom bilateral forceps robot system using FPGA

Fast growing use of minimally invasive endoscopic surgeries called for development of robots assisting in such procedures. However, existing surgical robots cannot transmit tactile sensation to the operator. To overcome this shortcoming, a bilateral teleoperation method was developed making it possible to accurately convey tactile sensation in single-degree-of-freedom forceps robots. This paper deals with the development of a multi-degree-of-freedom bilateral forceps robot system for surgical procedures which can adapt to actual conditions of the surgery. Bilateral teleoperation of multi-degree-of-freedom robots requires exchange of environmental information between master and slave devices in common coordinates. In this study we adopted mode coordinates which are better related to the motion of the robot. We also proposed a method to decouple the mechanical interference in mode coordinates. An FPGA-based controller introduced in this study makes it possible to reduce data processing time and to use hardware-based real-time control. As a result, multi-degree-of-freedom force feedback is attained. The experimental results show the viability of the proposed method.