文档介绍：ABSTRACT Multi-gas blending device plays allimportant roleinairquality monitoring Its degree uracy has adirectimpact on airqualitymonitoring on the research ofgas blending technique,the principle of andfuzzy control algorithms,this paper mainly introduces an automatic multi-gas blending device based Onmass flowImthod. Major issuesofthe paper are asfollows: Tl】eadvantages anddisadvamages of various gas blending programs were analysed selectofsuitable scheme forlowconcentration blending using thedynamic flowmatching a n' based on multi-gasblending device. ARM7 procesSor isemployed toachieve fastand accurate controlofgasflow,and itsbuilt-inhardware multipliers can achieve arapid dataoperation andimprove the operationalspeed andprecision of mass flowcon行olier bearslittlerelationtotemperature variationand presstn'e p letesystem’S hardware circuitdesignanddebug achieve agood include A/D、D/A conversion circuits,keybord circui_t,LCD citeuit,solenoid valve ekeuit,and SO on. Inthe control algorithm,according tOcharacteristics ofcontrol object,a roller isdesigned toimprove the reaction speed ofthe system byinputting thedevmtion and itsvariation ratebetween thedetected value of flowand setvalue ofthe ratetothe mass flow controller tocontrolthevolume of ℃fuzzy controller can improve thesystem’S reaction theMatlab environment,Fuzzy Toobox and Simulink toolbox areapplied for control system simulation,with the resultsshowing thatthesystem’srobustness,stability,and control effect are satisfactory. Inlight ofthedesigns ofallfunctional modules inthesystem,the system is optimized with multitask program by employing uC/OS一Ⅱas theoperating system, andthishelps thesystem realizefriendly interfaceandexcellent signalacquisitionand system boasts outstanding expansibility analyzing theuncertainty ofthesy