Measurement Of Temperature Field For The Spindle Of Machine Tool Based On Optical Fiber Bragg Grating Sensors

The change of spindle temperature field is an important factor which influencesmachining precision. Therefore, the control of machine tool thermal error is veryimportant to improve the machining precision. At present, the major method ofreducing the thermal error is thermal error compensation, and the spindle temperaturefield measurement is needed for the thermal error compensation. Many methods ofspindle temperature field measurement have been proposed. However, most of themethods are based on the traditional electric temperature sensors, they exist somedefect (e. g. anti-interference, multiplexing and stability capacity are poor), on theother hand the temperature measurement of the spindle of the machine tool isdifferent from the environment temperature measurement, it is actually a kind ofsurface temperature measurement. The emergence of the optical fiber gratingtemperature sensor solves these problems. Fiber Bragg grating sensor has thecharacteristic of small volume, anti-electromagnetic, corrosion resistance and goodstability, it is suitable for the surface temperature measurement, so it is very suitablefor the measurement of temperature field for the spindle of machine tool. It issusceptible to the interference from outside environment and poor security Whiledirectly using the bare fiber Bragg grating for the temperature measurement ofmachine tool spindle, so it is very important for the package of bare fiber Bragggrating before the temperature measurement of the machine tool spindle, afterpackage, the fiber Bragg grating shows good ability of temperature measurement andsafety.This paper first introduces the current research situation of the spindletemperature field and the basic theory of fiber Bragg grating temperature sensor.Then this paper introduces the surface temperature measurement theory and thetraditional methods of surface temperature measurement because the temperaturemeasurement of the machine tool spindle belongs to the surface temperaturemeasurement, therefore an experimental system of the surface temperaturemeasurement is constructed to study the temperature measurement ability of the barefiber Bragg grating and then according to the characteristics of the surface temperature measurement a packaging structure of fiber Bragg grating is designed.The experiment study of the packaged fiber Bragg grating surface temperature sensoris carried on the surface temperature measurement system, at the same time thetemperature field of the packaged fiber Bragg grating surface temperature sensor isanalyzed by finite element, the experiment and the simulation analysis show that thepackaged fiber Bragg grating surface temperature sensor can measure the surfacetemperature accurately and stably; then two temperature measurement system areconstructed about the spindle of machine tool——the thermal resistance temperaturemeasurement system and the optical fiber grating temperature measurement system,the temperature measurement experiment of the machine tool spindle is done by usingthe thermal resistance, bare optical fiber Bragg grating and the packaged fiber Bragggrating surface temperature sensor respectively; the contrast experiment shows thatthe packaged fiber Bragg grating surface temperature sensor can measure thetemperature of the machine tool spindle accurately and stably; finally, the researchachievements and problems of this article are summarized and the future researchwork are prospected.