Design Of A Redundant Endoscope ARM

Compared with the traditional open surgery, Minimally Invasive Surgery (MIS) has a lot of advantages, such as smaller patient-trauma, shorter rehabilitation, less pain, helping improving surgery quality and reducing medical cost.Using robot in MIS can obviously improve the surgery quality and reduce the surgeon's labor intensity. Therefore, robot-assisted minimally invasive surgery technologies have aroused widespread attention, and have become a popular research area in Robotics Field.Supported by the National 863 high-tech project"Research on minimally invasive Robot for laparoscopic surgery", this article discussed the detailed design and analysis of redundant endoscope arm in minimally invasive robot for laparoscopic surgery system.Firstly, the structure of redundant endoscope arm is designed. In the foundation of the analysis of operation request, as well as the advantages and drawbacks of existing structure, the robot's final configuration is established, and the detailed design of specific mechanism is carried out. a set of practical reliable transmission plan is put forward to compensate the low stiffness and precision of remote center motion mechanism, which puzzles the researchers a long time. By using computation and simulation, the request to robot's power and speed are calculated on the basis of the request to the robot movement's speed and acceleration in actual utilization. The type of the servo motor is selected according to the result. The error of the robot's key part, namely the remote center motion mechanism, is analyzed to prove the feasibility of the mechanism.Secondly,The arm length is optimized on the target of robot flexibility, and it obtains how the flexibility changes when robot moves. Its result will provide the basis for the arm configuration.Thirdly, the kinematics of the endoscope is discussed. The forward kinematics is solved by using D-H method to establish the rods coordinate system; the terminal actuator inverse kinematics is solved using method of variable separation.Forthly, the dynamics equation of endoscope arm is carried out. The general equation of the redundant endoscope arm actuator dynamics is put forward using Lagrange method. Put the parameter and information, namely the quality and inertia of robot rods and drive, which is got through 3d modeling software, to the dynamics equation to get the algebraic equations. By this means the correctness of the dynamic equation is verified.Finally, we observed the actual effect of movement using pro/E 5.0 to simulate preoperative ,arm configuratino and typical motion equation.