Title:
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The development of an automated system for on-line tool wear monitoring.
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An investigation has been completed to determine the
feasibility of using vibration measurement to develop an online
tool wear monitoring system.Conventionaltransducers and
FFT signal analysers have been used as the starting point
for data collection and analysis. Additional software has
been developed in order to obtain additional and enhanced
analysis using statistical data such as percentile analysis
and 4th statistical moments. The signal analysers have been
interfaced with an IBM compatible PC to allow efficient data
collection and analysis. •
The measurement of surface finish via the use of centre line
average has been selected as the primary indicator of tool
wear. An experimental programme has been completed which
examines the relationship between vibration measurement and
surface finish during turning operations. This has provided
sufficient general rules and guidelines to enable the method
to be extended to other processes. It also provides
information from which commonly occurring faults such as
looseness of the tool holder, changes in material properties
and swarf presence in the toolholder can be identified.
Tests have been completed using cast iron, ENS and EN3
steels.
An expert system has been developed. It has been
demonstrated that sufficient data can be collected during
the setting-up stage or commissioning part of a machining
process from which, using the expert system, reliable tool
wear monitoring can be achieved for all subsequent tests. In
addition to predicting'the surface for all stages of tool
life, the system can identify common faults such as
looseness of the toolholder, the presence of swarf in the
toolholder and changes in material properties. This system
has been evaluated in relation to the available data, the
present expectation of quality assesment required from the
machine operation and relative to available commercial
monitors. The system offers significant improvements.
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