多传感模块融合的空气流量计的设计

Design of Air Flow Meter with Multi Sensor Modules

根据热式空气流量计的基本原理,空气的密度会对质量流量的测量造成一定误差。设计多传感模块融合的空气流量计,在Bosch HFM-7系列热膜式空气流量计流道结构的基础上,融合空气流量敏感元件和温湿度检测模块,分别将流量敏感元件输出的模拟信号和温湿度检测模块输出的数字信号在控制核心中分析整合,并最终采用单边半字节传输通信协议(SENT)发送给汽车电子控制单元。经实验验证,此多传感模块融合的空气流量计能够精准提供进入发动机的空气的温度、湿度以及质量流量信号,协助发动机控制空燃比,保证燃油充分燃烧,减少尾气排放,节约能耗,保护环境。

According to the principle of thermal air flow meter,the density of the air have an influence on the measurement of mass air flow.Based on the flow structure of Bosch HFM-7 series hot film air flow meter,a new air flow meter was designed,which includes air flow sensitive element as well as temperature and humidity measurement modules.The output analog signals of the air flow sensitive element and the digital signals produced by the temperature and humidity measurement module were analyzed and synthesized in the control core,and finally,was sent to the electronic control unit by single edge nibble transmission protocol.The experimental results show that air flow meter with multi sensor modules can accurately provide the temperature,humidity and mass flow signals of the air entering the engine,enabling the engine to control the air-fuel ratio ensuring full combustion of fuel,reducing exhaust emissions,saving energy consumption and protecting the enviro nment.