Research On Temperature Control Of PCR Instrument Based On ARM

Polymerase Chain Reaction,which is called PCR for short,is a kind of nucleic acid amplification technology in vitro.Using this technique,reasearchers can produce millions of copies of specific sequences which are selected from complex DNA molecules.The PCR instrument is the instrument which can finish the polymerase chain reaction automatically.At present,PCR technology has been widely applied in life science research,biochemical analysis,clinical diagnosis,drug analysis,forensic identification and epidemic rapid test etc.This dissertation discusses about the temperature control of PCR instrument. Finish the hardware design of PCR instrument based on ARM9 embedded system. Research on temperature control algorithm and the temperature uniformity control for PCR instrument.The main contents are as follows:The first chapter summarizes the principle of PCR instrument,the genetal situation of PCR instrument and the research situation ahout the temperature controller and temperature control algorithm home and abroad.In this part,I finally put forward research contents,methods and difficulties.The second chapter introduces the hardware system design of PCR instrument.I introduce the constituents of hadware system first and then introduce the design of heating and cooling system based on TEC and temperature controller system based on embedded system in detail.Finally,I introduce some assistant departments like heat cover briefly.In chapter three,I study about temperature control algorithm.After introducing feed-forward control and fuzzy control which are not dependent on mathematic model, I put forward a mixture control algrithem which is constituded by feed-fordward control,fuzzy control and relay auto-turning PID control.The fourth chapter research on the PCR uniform temperature control,established the finite element simulation model of the sample block,got its temperature field, improved the sample block model.From the result of the simulation and experiments we can find out that this improved model can effectively improve PCR temperature uniformity.In the chapter five,I do some experiments on the PCR prototype with the relay auto-turnning PID algorithm,feed-forward PID algorithm and Fuzzy-feed-forward PID algorithm and get the temperature control result.The last chapter is a conclusion of the whole thesis and there are also some perspective opinions about the posterior tasks in it.