Performance Evaluation of Autonomous Contour Following Algorithms for Industrial Robot

Abstract

In this study, the performance evaluations of autonomous contour following task with three different algorithms have been performed for Adept SCARA robot. A prototype of smart tool integrated with sensor has been designed. It can be attached and reattached into robot gripper and interfaced through I/O pins of Adept robot controller for automated robot teaching operation. The algorithms developed were tested on a semicircle object of 40 millimeter radius. The semicircle object was selected because it exhibits the stringent test bed which provides the changing gradient gradually from steepest positive slope into zero slope of flat curve in the middle and finally to steepest negative slope. The adapting gradient method consumes medium teaching time at reasonable accuracy of standard deviation value of 2.3085 millimeter, while the staircase method consumes the longest teaching time at standard deviation value of 1.8412 millimeter. The sweeping radius method is very efficient in term of shortest teaching path but its standard deviation value of 3.2663 is a bit high. It can be concluded that the staircase method is the most accurate method, while the sweeping radius method has the shortest teaching path. These tests exhibit the performance of algorithms used which prove its possibility to be applied in the real world application. For the future, automatic curve radius determination between straight line segments can be improved by integrating vision system for the automation of top view (X-Y coordinate) edge finding and path planning. The integration of vision system with the present study will improve the automation level of the project from two to three dimensional capabilities.