Online Temperature Detecting System In Hot Machining Process

At present, the plasma heating cutting technology has been widely used in structural materials processing, because the surface temperature of the mechanical parts in cutting part is difficult to accurately measure, thus this will affect the cutting quality. Traditionally, the surface temperature is measured by thermocouple, but because the products are always in the rotation state, so it could not lead the beautiful measured effect.This paper describes the basic principle of radiation temperature measurement and colorimetric temperature measurement, this paper presents a kind of fiber optic colorimetric temperature measurement that is applicable to plasma cutting process of heating temperature measurement, the system has the features of high precision, strong anti-interference characteristics. Optic fiber temperature measurement technology has solved many problems that conventional infrared measuring and thermocouple thermometer could not solved, especially in strong electromagnetic interference, optical fiber temperature measurement technology shows the unique superiority in the surface temperature measurement of moving object.In the paper, it designs the particular signal acquisition and processing system. In the design of the light circuit, it researches the band scope of temperature measuring system; the band avoids the influence of environment on the measurement results, and improves the system temperature measurement precision. This paper analyzes the choice of the optical fiber transmission, the use of optic fiber is enhanced the anti-electromagnetism interference ability, and this realizes the light signal transmission over long distances. Two kinds of wavelength is selected for 830 nm and 960 nm, this brings down the measurement error in large part eliminated the firing rate of the object. It uses the suction or disconnection of the relay to keep out the light circuit, eliminates the influence of the temperature measurement results on the dark value, and improves the accuracy of the temperature; In the circuit of the design, it mainly bases on TMS320C5402 chips for peripheral circuit, with the aid of CCS2.0 software accomplish the software of the temperature measurement system. At the same time, the design of software and hardware consider the anti-disturbance, some practical measurements of the hardware and software anti-interference and filtering algorithm is designed, so it could ensure the reliable operation of the system.Finally, according to the regulation of JJG 415-2001 work thermometer verification, this paper does the experiment of whole system; the results indicate that the precision of the system can achieve±0.5%, the system has good repeatability, and it is up to the expectations.