A lead through approach for programming a welding arm robot using machine vision

Welding is a complex manufacturing process. Its quality depends on the welder skills, especially in welding complex paths. For consistency in modern industries, the arm robot is used to accomplish this task. However, its programming and reprogramming are time consuming and costly and need an expert programmer. These limit the use of robots in medium and small industries. This paper introduces a new supervised learning technique for programming a 4-degree of freedom (DOF) welding arm robot with an automatic feeding electrode. This technique is based on grasping the welding path control points and motion behavior of an expert welder. This is achieved by letting the welder move the robot end effector, which represents the welding torch, through the welding path. At the path control points, the position and speed are recorded using a vision system. Later, these data are retrieved by the robot to replicate the welding path. Several 2D paths are tested to assess the proposed approach accuracy and programming time and easiness in comparison with the common one. The results prove that the proposed approach includes fewer steps and consumes less programming time. Moreover, programming can be accomplished by the welder and no need for an expert programmer. These enhancements will improve the share of robots in welding and similar industries.

Expert Programmer versus Parallelizing Compiler: A Comparative Study of Two Approaches for Distributed Shared Memory

This article critically examines current parallel programming practice and optimizing compiler development. The general strategies employed by compiler and programmer to optimize a Fortran program are described, and then illustrated for a specific case by applying them to a well-known scientific program, TRED2, using the KSR-1 as the target architecture. Extensive measurement is applied to the resulting versions of the program, which are compared with a version produced by a commercial optimizing compiler, KAP. The compiler strategy significantly outperforms KAP and does not fall far short of the performance achieved by the programmer. Following the experimental section each approach is critiqued by the other. Perceived flaws, advantages, and common ground are outlined, with an eye to improving both schemes.