| Author: | Chan, Foon-ming |
| Title: | An on-line two-dimensional error measurement system for forecasting and compensation control of turning operations |
| Degree: | M.Sc. |
| Year: | 2000 |
| Subject: | Machining Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Manufacturing Engineering |
| Pages: | xv, 216 leaves : ill. (some col.) ; 30 cm |
| Language: | English |
| Abstract: | The major aim of the machining process is to produce workpieces with the specified form and accuracy. Various techniques have been developed to increase the precision of a product. Apart from structural improvement of the machine tool accuracy itself through careful design and advanced manufacturing technology, the online compensatory control strategy is another approach to improve the machining accuracy of the workpieces. In this project, the 2-D motion errors measurement setup of the experimental turning lathe had been developed to detect the motion error signals in the sensitive directions. The methodology to determine the form errors of master taper and X-Y table had been developed and the data was used for estimating the 2-D motion errors of turning operation. With the approach of forecasting and compensation control (FCC) strategy combined with Autoregressive Moving Average (ARMA) algorithm, the 2-D ARMA models were fitted to the 2-D motion errors obtained. The online forecasting technique was used to predict the motion errors and moved the tool before it actually cut with the present errors. The 2-D compensation actions were obtained through the use of piezoelectric actuator. The adequate model order and parameters were found by performing the offline simulation. Through the application of the proposed system to simulated and actual cutting data, it had confirmed the effectiveness of the proposed strategy. The developed 2-D error measurement and FCC technique gives a promising result in roundness improvement. It was demonstrated that the maximum roundness improvement achieved could be 68.22%. The average roundness improvement was found to be 41%, which proved the effectiveness of the proposed method. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b15321332.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 12.91 MB | Adobe PDF | View/Open |
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