The University of Southampton
University of Southampton Institutional Repository

Systematic modelling of a three-axes, non-contact coordinate measurement system

Systematic modelling of a three-axes, non-contact coordinate measurement system
Systematic modelling of a three-axes, non-contact coordinate measurement system
A coordinate measurement machine (CMM) is an advanced, multi-purpose quality control system used to help inspection keep pace with modern production requirements. These machines can provide repeatable dimensional and geometric accuracy (micro- or nano-metre accuracy) of everything from small engine blocks, to sheet metal parts, to circuit boards. However, their performance may degrade when subjected to different forms of external disturbances, including geometric, kinematic, thermal and dynamic forces. By studying the influences of these disturbances, the impact on the machine measuring accuracy can be understood.
The research work described in this thesis investigates two important aspects of machine accuracy of a newly developed coordinate measurement machine. The Small Coordinate Measuring Machine (SCMM) consists of a non-contact laser displacement probe supported on three mutually perpendicular (X, Y & Z) axes. The geometric and kinematic errors, which have been shown to account for more than two-thirds of the machine errors, of the SCMM were studied. A mathematical model has been proposed and incorporates geometric, kinematic and orientation errors of the probe that may have been introduced during the assembly process. Using the Renishaw performance measurement system, the error components of each individual carriage were diagnosed. The resulting study of these errors provided a better understanding of the performance of these positioning carriages. The mathematical model was also able to show the extent of the positioning errors of the carriages and the combined volumetric error of the SCMM.
The second part of this research investigated the influence of drift on the probe output. This study aimed to demonstrate the magnitude of these environmental changes and the impact it has on the stability of the output of the non-contact, laser displacement probe. System Identification has been used to identify the correlation of the drift in the output of the probe and the changes reflected in the environment. A linear, 3rd order AutoRegressive model with eXogeneous input (ARX) has been chosen based on its merits. The results obtained from both the mathematical and linear models were eventually applied to a practical measurement problem, leading to a significant improvement in the measurement accuracy.
Loh, Ming Hock (Jeremy)
525f9ca2-b7b4-4a60-9f5b-eebed4e38db2
Loh, Ming Hock (Jeremy)
525f9ca2-b7b4-4a60-9f5b-eebed4e38db2

Loh, Ming Hock (Jeremy) (2002) Systematic modelling of a three-axes, non-contact coordinate measurement system. University of Southampton, School of Engineering Sciences, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

A coordinate measurement machine (CMM) is an advanced, multi-purpose quality control system used to help inspection keep pace with modern production requirements. These machines can provide repeatable dimensional and geometric accuracy (micro- or nano-metre accuracy) of everything from small engine blocks, to sheet metal parts, to circuit boards. However, their performance may degrade when subjected to different forms of external disturbances, including geometric, kinematic, thermal and dynamic forces. By studying the influences of these disturbances, the impact on the machine measuring accuracy can be understood.
The research work described in this thesis investigates two important aspects of machine accuracy of a newly developed coordinate measurement machine. The Small Coordinate Measuring Machine (SCMM) consists of a non-contact laser displacement probe supported on three mutually perpendicular (X, Y & Z) axes. The geometric and kinematic errors, which have been shown to account for more than two-thirds of the machine errors, of the SCMM were studied. A mathematical model has been proposed and incorporates geometric, kinematic and orientation errors of the probe that may have been introduced during the assembly process. Using the Renishaw performance measurement system, the error components of each individual carriage were diagnosed. The resulting study of these errors provided a better understanding of the performance of these positioning carriages. The mathematical model was also able to show the extent of the positioning errors of the carriages and the combined volumetric error of the SCMM.
The second part of this research investigated the influence of drift on the probe output. This study aimed to demonstrate the magnitude of these environmental changes and the impact it has on the stability of the output of the non-contact, laser displacement probe. System Identification has been used to identify the correlation of the drift in the output of the probe and the changes reflected in the environment. A linear, 3rd order AutoRegressive model with eXogeneous input (ARX) has been chosen based on its merits. The results obtained from both the mathematical and linear models were eventually applied to a practical measurement problem, leading to a significant improvement in the measurement accuracy.

Full text not available from this repository.

More information

Published date: 2002
Organisations: University of Southampton

Identifiers

Local EPrints ID: 47553
URI: https://eprints.soton.ac.uk/id/eprint/47553
PURE UUID: e7cfa358-6a26-4c41-908e-775e779d586e

Catalogue record

Date deposited: 03 Aug 2007
Last modified: 13 Mar 2019 20:59

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×