Instrumentation and control for precision grinding machines
This thesis examines the present methods of centre less bearing
grinding, with a view to applying IIDderncontrol nethods in order
to reduce the distribution of output size variations and improve
the quality of surface finish.
Established rrodels of the grinding process shew that various
inportant parameters describing the process can be derived,
providing that the grinding power can be accurately rronitored.
Several alternative control strategies based on paNer rronitoring
The drive systems of a typical grinding machine are rrodelled as
they react through the non-linear grinding wheel/work interface.
A simplified computer simulation of the process is demonstrated.
Suitable rrethods of instrumentation are evaluated including the
optical shaft encoder as a source of high resolution data for the
estimation of drive shaft dynamics. A method is devised for on
line pararreter estimation of the drive system transfer functions.
This enables the important grinding power to be estimated fran
shaft dynamics and also al loes the rronitoring of the drive system
parameters. The cpt.ica l shaft encoder is also assessed as the
source of data for vibration detection.
A development conputer with real tine multi-tasking operating
system software and specialised shaft encoder interfacing has
been established as a basis for an expandable control and
rronitoring system. A plan for feeackcontrol of the grinding,
involving several separate control algorithms cormunicating with
an expert system executive controller, is outlined.