Laser feedback control for robotics in aircraft assembly

This thesis presents a method for increasing the accuracy of an industrial robot by integrating a high accuracy measurement system in a feedback control loop. The performance of the system is evaluated on reconfiguring of ART modules and robotic drilling. Today robots are used for automation of high volume production, e.g. car industry. To achieve high enough accuracy for most manufacturing processes the robot process must be calibrated by hand. This takes long time and is not suitable for short series production. This thesis will treat the issue of increasing the accuracy of the robot so the calibration is not needed…

Contents

1 Introduction
1.1 Background
1.1.1 The use of robots
1.1.2 The ADFAST project
1.2 Objectives
1.3 Previous work
1.4 Thesis Outline
2 System description
2.1 Leica LTD800 laser tracker
2.1.1 Ball prism
2.1.2 6DOF Reflector
2.1.3 emScon
2.2 ABB IRB4400 Robot
2.2.1 S4Cplus controller
2.2.2 WebWare SDK
2.3 ART modules
2.4 Drilling
3 Mathematics
3.1 Translation
3.2 Rotation
3.2.1 Rotation matrices, R
3.2.2 Quaternions
3.2.3 Euler Z’Y’X’ angles and fixed XYZ axes angles
3.2.4 Transformations
3.2.5 Mean values of rotations
3.3 Homogeneous transformations
4 Error compensation
4.1 Background and assumptions
4.2 Translation
4.3 Orientation
4.4 Homogeneous transformation
4.5 Controller
4.5.1 Stability
4.6 Termination criteria
5 System analysis
5.1 The ABB IRB4400 Robot
5.1.1 Mechanical manipulator
5.1.2 Computer network
5.1.3 S4Cplus controller
5.1.4 WebWare SDK
5.1.5 Alternatives
5.2 The Leica LTD800 laser tracker
5.2.1 Alternatives
5.3 Master controller
6 System calibration
6.1 Tracker to Robot base and TCP0 to reflector
6.1.1 Method for cooptimization of T Tr Rob and TTCP0 Refl
6.1.2 Other methods
6.2 Tip of drilling machine
6.2.1 Measurement of T Tr Bushing
6.3 Location of drill frame
6.4 Location of robot chuck
7 System integration
7.1 Connection to robot controller
7.1.1 Ordinary program flow
7.1.2 Extraordinary program flow
7.1.3 Emulating a discrete controller
7.2 Connection to laser tracker controller
7.3 CAD-system integration
8 Results
8.1 System calibration
8.2 Module positioning
8.3 Drilling
8.4 Process automation and CAD integration
9 Conclusion
9.1 Further work
9.2 Industrial implementation
A Controlling RAPID program
B Robot model in Matlab Robotics Toolbox

Author: Sunnanbo, Albin

Source: Linköping University

Download URL 2: Visit Now

Leave a Comment