Optimized path tracing analysis and application of four-bar linkage and CT guided robotic arm

Abstract

In this current research an optimized mechanism with four bar closed linkage with appreciable clearances over joints is designed. The characteristics have been evaluated and mathematical simulations have been done using differential evolution for solving nonlinear differential equation in order to stabilize and reduce vibrations of the robotic arm in industrial implementation and research. It can also be used for indicating the path to the end needle of the robotic arm which is designed to reach the target point by just taking coordinate points of the target as input. The target point coordinates can be determined from a computed tomography (CT) image for medical purpose. The main objective behind the modeling of this robotic arm is not only to assign a curvilinear path which splits the straight paths into smaller ones making it error free but also to enable it space efficient, suitable for medical environment and cost effective. This robotic arm is equipped with 6 links having 3 degrees of freedom with R-R-R joints. The utilization of CATIA software has been done to design the robotic arm. The equations have been formulated in evaluating and graphing of the workspace. MATLAB has been used to evaluate the joint angles of the arm. The principle of forward and inverse Kinematics is applied to formulate the equations formulated using Cartesian space method and Joint space method is used to analyze the Path to be traced by the end needle of the arm. Mathematical simulation using algorithms and Path tracing is done in MATLAB software. The final path which is traced is a straight line joining point to point. The simulated analysis/results of the robotic arm shows that there is almost null level of error in mm which is well acceptable in medical environmental conditions. The Errors have also been reduced significantly in the Four-bar linkage mechanism after optimization.