4、stlyintroducedthepracticalsituationandthedevelopingbackgroundofthesystem.Andthenhasdescribedthedesigninggoal、systemneedandthewholedesigningplan,hasdescribedthedetaileddesignandrealityofthesystemindetail.Finally,conclusionhasbeendrawnaboutthesystemandproblemhasalsobeenraised. The