Research On Kinematics And Trafficability Of An Endoscopic Robot

Research on endoscopic robot is of vital importance for diagnosis and minimum invasive surgery of human intestinal tract. Relying on outside doctor's thrust, endoscopic own stiffness, and the contact forces between intestinal wall and endoscope itself, conventional endoscope is propelled to the desired part of treatment. The process is very painful and maybe causes intestinal being knotted. Previous research was focused on fully interventional endoscopic robots, however, problems related to energy supply, lesion pinpointing and curing operation limited the research on prototype stage without breakthrough. Developing a partly interventional endoscopic robot with a controllable endoscope body, analyzing its kinematics and the way how it comes through intestine becomes urgent.First, in this paper, the features of the existing endoscopic robot's mechanical structure and its moving mode are investigated. The relationship of robot joint variables and the length of driving cables is built and the same relationship of absolutely continuum robot is derived using limit method. Also, the forward and inverse kinematics of the robot is analyzed, and the error of robot joint variables is given after making this robot continuum.Second, based on Microsoft Visual C++ and OpenGL, the spatial model of human intestine is built with medical data and its centerline equations at the fixed coordinate system are established. With those giving centerline equations or derived centerline equations from curve fitting, based on a method that the end points of every joint lie on the intestine centerline, and using Dichotomy or Broyden method, the robot pose equations are solved, so the trafficability of the robot is researched. The deviation from the intestine centerline to the robot centerline is analyzed when the robot is going into the intestine, and also the necessary condition for robot going through the intestine is obtained.At last, the control system and an experiment table for the endoscopic robot are developed. The validity of robot kinematics and the way how robot going through intestine model is testified by those experiments on the movement of one joint or double joints, and on the real robot going through intestine model.