亮度式测温仪自动瞄准系统设计

Design of Automatic Aiming System of the Luminance Thermometer

亮度式测温仪的校准大多采用人工方式，人为影响因素较大且校准重复性较低．为了使测温仪在校准时能够准确自动地瞄准温度灯的瞄准点，采用YG-QP36四象限探测器，设计出双自由度自动瞄准系统的机械运动结构，利用步进电机的自锁和双向精确定位特性，双自由度扫描温度灯的瞄准点。用光纤将电子元器件与高温环境隔离开，减少温度对电子元器件的影响．在800～l200℃温度范围内采集测温仪的温度一电压数据，并用最小二乘支持向量机进行拟合，测量数据的相对误差小于0．05％，重构均方差为0．0196．对光斑圆心到坐标原点的距离与电压进行最小二乘拟合，光斑直径测量数据表明，双自由度自动瞄准系统能够提高校准准确度，减小重复校准误差．

Manual calibration is often used in the luminance thermometer, which exists a high influential artificial factor and a low repeat ability of calibration. In order to make the thermometer accurately and automatically aim at the aiming point of the lamp, double degree of freedom automatic aiming system is designed. The YG-QP36 four quadrants detector was chosen as the photoelectric detector. The mechanical structure of automatic aiming system is designed, and the stepper motor has the characteristic of self-locking and two-way accurate location, which can scan the aiming point of the lamp in two degree of freedom. The optical fiber can isolate electronic components from high temperature environment, which reduces the temperature influence on electronic components. The temperature-voltage data was collected in 800--1 200℃, and the data was fitted with the least squares support vector machine. The relative error is less than 0.05%, the reconstruction of mean square error is 0. 019 6. The least squares fitting between the distance of the flare of the circle to the origin of coordinates and voltage was made. The spot diameter was measured, experiment results show that the double degree of freedom automatic aiming system can improve the accuracy of calibration, and reduce the repeated calibration error.