Automatic programming of arc welding robots

237 Pages·2017·3.29 MB·English

by  Srikanth Padmanabhan

Iowa State University Capstones, Theses and
Retrospective Theses and Dissertations
Dissertations
1991
Automatic programming of arc welding robots
Srikanth Padmanabhan
Iowa State University
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Recommended Citation
Padmanabhan, Srikanth, "Automatic programming of arc welding robots " (1991).Retrospective Theses and Dissertations. 9617.
https://lib.dr.iastate.edu/rtd/9617
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Automatic programming of arc welding robots
Padmanabhein, Srikanth, Ph.D.
Iowa State University, 1991
U M I
SOON.ZeebRd.
Ann Arbor, MI 48106

Automatic programming of arc welding robots
by
Srikanth Padmanabhan
A Dissertation Submitted to the
Graduate Faculty in Partial Fulfillment of the
Requirements for the Degree of
DOCTOR OF PHILOSOPHY
Major: Mechanical Engineering
Approved:
Signature was redacted for privacy.
Signature was redacted for privacy.
Signature was redacted for privacy.
For the Major Department
Signature was redacted for privacy.
Graduate College
Iowa State University
Ames, Iowa
1991
Copyright © Srikanth Padmanabhan, 1991. All rights reserved.
11
TABLE OF CONTENTS
ACKNOWLEDGEMENTS x
CHAPTER 1. INTRODUCTION 1
Research Goals 3
Dissertation Organization 4
CHAPTER 2. LITERATURE REVIEW 5
Geometric Modeling For Automated Manufacturing 5
Feature-based modeling systems 8
Secondary feature representation 10
Knowledge-Based Systems For Arc Welding 13
Integrated Robot And Positioner Systems 20
Off-line programming of industrial robots 20
Trajectory planning of integrated robots and positioners 21
Need For The Research 29
CHAPTER 3. REPRESENTATION OF WELD FEATURES AND
ATTRIBUTES IN SOLID MODELERS BASED ON CSG .... 30
Theory of representation of welds 31
Overall Methodology 36
Welding Attribute Graph (WAGRAPH) 41
iii
Hybrid Solid Modeler 50
Representational Issues 52
Incremental construction of the WAGRAPH 52
Validity and consistency checking 55
Summary 57
CHAPTER 4. KNOWLEDGE MAPPING SYSTEM FOR WEL­
DING PROCEDURE GENERATION 59
Background 60
Overall Methodology 62
Knowledge Acquisition 63
Structure of Questionnaire/Survey 64
GMAW knowledge for robotic welding 77
Overall Conclusions on Survey/Questionnaire on Robotic GMAW . . 82
Implementation Of The KBES Using A Shell 87
Consistency Checking In PCPLUS 93
Summary 97
CHAPTER 5. IMPLEMENTATION OF THE INTEGRATED WEL­
DING REPRESENTATION AND PROCESS MAPPING SYS­
TEM 98
Overall System Architecture 98
Object-Oriented Programming Paradigm 101
Welding Feature Representation Implementation 105
Generic object 105
Customizable objects 109
iv
Knowledge Mapping System Implementation 110
Framework 112
Geometry parameter extraction 116
Storage, retrieval, and traversal 122
Example rules 127
A Sample Session 129
Validation Of The System 134
Summary 135
CHAPTER 6. TRAJECTORY PLANNING OF THE INTEGRATED
ROBOT AND POSITIONER 137
Overall Methodology 138
Fixed Path Modified Continuation Method 141
Development Of Equations 143
The GEP50 robot 145
Two axis positioner 148
Trajectory Planning Of The Integrated Robot And Positioner 150
Examples 155
Example 1: A straight line weld 155
Example 2: A circular weld 158
Example 3: A quarter circle in the XZ plane 161
Summary 165
CHAPTER 7. CONCLUSIONS 170
Summary 170
Recommendations For Future Work 173