A multi-sensor tool breakage detection system is introduced that chara
cterizes the state of measurements during normal (no-fault) condition
and at tool breakage by the two columns of a multi-valued influence ma
trix (MVIM). In this system the measurements are monitored on-line and
flagged upon the detection of abnormalities. Tool breakage detection
is performed by matching this vector of flagged measurements against t
he two columns of MVIM, which are estimated during a training session
so as to minimize the error in detection. The detection system is impl
emented in turning. Experimental results indicate that this system pro
vides excellent detection when the full range of tool breakage effect
on the measurements is included in training, and that its performance
is less dependent upon the training set than a multilayer neural net.