Fibre Bragg grating temperature sensors for high-speed machining applications
In high-speed grinding research, it is required to measure temperature
within the workpiece. Present techniques are thermocouple based, and
often suffer from excessive electrical noise on the signal. This thesis
presents a number of novel and existing optical sensing devices that
overcome this limitation and also, in some cases, offer greater performance.
The optical sensors are fibre Bragg grating based and the optical
techniques used to interrogate that sensor include DWDM, WDM, athermic
grating, tuneable grating and coupler. Optical fibre devices are simpler to
place in situ prior to the machining tests and they offer faster response and
greater sensitivity than was previously possible. Results are presented from
machining tests and the new devices are compared with each other and
thermocouple based techniques. A method to relate internal measured
temperature to machined surface temperature is also demonstrated in the
context of high-speed machining.