基于热释电红外传感器的静态人体存在感应器设计

Design of Static Human Presence Sensor Based on Pyroelectric Infrared Sensor

针对常规传感器的输出信号幅值小,获取传感数据异常,导致静态人体生理信号感应数据不精准的问题,设计了基于热释电红外传感器的静态人体存在感应器。构建静态人体存在感应器整体结构,通过感光元件将波长较小的红外信号转化为电子信号形式。利用基于菲涅尔透镜信号聚焦模块,聚焦热释光红外信号。采用热释电信号放大模块,便于热释电信号的放大。利用定时计数和测量脉宽方式甄别人体生理有效信号。构建整体旋转变换矩阵,校正传感位置数据。根据Lambert-Beer定律,分析血氧饱和度和吸光度变化量之间关系,感应血氧饱和度信号。利用热释电效应的形成机理,结合最小二乘拟合法感应脉搏信号。由实验结果可知,该感应器感应的血氧饱和度数值与实际数据分别存在最大为3%、脉搏频值最大数值偏差为1次,能够有效感应人体生理信号。

In the face of the problem that the output signal amplitude of conventional sensors is small and the sensing data obtained is abnormal,resulting in inaccurate sensing data of static human physiological signals,a static human presence sensor based on pyroelectric infrared sensor is designed.The overall structure of the static human presence sensor is constructed,and the infrared signal with small wavelength is converted into electronic signal form through the photosensitive element.The signal focusing module based on fresnel lens is used to focus the thermoluminescent infrared signal.The pyroelectric signal amplification module is used to facilitate the amplification of the thermal release signal.Use timing counting and pulse width measurement to discriminate physiological effective signals of human body.The whole rotation transformation matrix is constructed to correct the sensing position data.According to Lambert-Beer law,analyze the relationship between blood oxygen saturation and absorbance change,and sense the blood oxygen saturation signal.The formation mechanism of pyroelectric effect and the least square fitting method are used to induce pulse signal.According to the experimental results,the maximum difference between the oxygen saturation value induced by the sensor and the actual data is 3%,and the maximum value of pulse frequency value is 1,respectively,which can effectively sense human physiological signals.