1、毕业设计（论文） 附 录 附录 The researches of GPS/GSM supervise and control system of vehicle 1. Summarization The current supervise and control system of vehicle is a kind of high-technology. The GPS supervision and control system which using GPS reception, wireless communication, GIS to supervise, query and s
2、uperintend the information of the mobile users dynamic position (longitude, latitude), time, status, etc. Dividing according tothesubfunction, thesupervisionandcontrolsystem ofvehicle is composed of three parts: positioning part, communicationpart,anddisplay part.There into,the often-used communicat
3、ionmodes are VHF/UHF single channel call web, competitive groupscommunication, and GSM short information traffic. The supervisionand control system of vehicle bases on VAF/UHF single channelcal web, it s design, organizing web and using is relatively simple,but it s working range is relatively small
4、； that GSM short informationtraffic is used in positioning data transmit is popular, its coverage is wide, allowing roaming throughout the land, whereas,its time delay problem is the bottleneck that limits it， development,furthermore, its call function can not compare with the collectivegroupssystem
5、； Collective group systemis dedicated dispatcherandsuperintendencesystem, ithasunspeakableadvantagetosome particular enterprise. But gather a group of systems to buildthepricea timetoohighandcoverthescopeissmall； Longrangedata that GSM that short information business used for the fixedpositiondatato
6、deliveris now thanforpopular,thecoverscopeisbig, canthe wholenationtravelextensively, and can realizethesmall batch quantity, its confirmable time delay, from the safety,stability, receive and dispatch the information to measure, can expand， using the expenses, two times development etc. The aspect
7、isall and very ideal, and suffer the environment influence small, 毕业设计（论文） 附 录 cansufficiencydemandthatsatisfythecustomer. Butthe system thatits time delay problem is a bottlenecktoinviteitsdevelopment.This text design and letter way thatGSM short information businessmethod bottom coin mountain stri
8、p mine GPS the vehicle superviseand control the system to make use of to wait the aspect proceedingthe introduction. 2. GSM short Message business Themost basicbusinessofGSM isvoicetransmitting； GPSdata can be converted audio signal by modem； and then be put intomobile-station torealizedatatransmitt
9、ance. Butbecause GSM is a system ofdigitalmobilecommunication, itisunnecessary andinvalid,firstly, GSM has the ability to transmit data, and can providethedatabusiness by itself； secondly, theoutputofhighfrequencyfrom modem isgenerallyabove2 .0kHz, thesignalthatits frequencyabove 1300Hz will results
10、 intobig distortion and inability todemodulate properly data tamed by audio signal if such signal istransmitted to audio interface of GSM mobile terminal. It has provedby experiment, if the signal based on the ITU- V.23 is transmittedthrough GSM audio-belt. The second choice is data business； GSMpro
11、vides transmittance for the signal of 2400bps, 4800bps, and9600bps, and to transmit GPS data for orientation. But GSM is thepublicnetandgetconnectedonlybydialinga number, onceconnnected,it will charge. At present the least charging unit of GSM localcommunication isoneminute, thedataoforientationfrom
12、 GPSeach time is not above 20 bytes, and it is also not more than 40bytesmodulatedbythemodethatonlyhas50% efficiency. Itwillspendabout0.04sintransmittingGPSorientationdataonetime by 9600bps, so to transmit GPS orientation data by data business is noteconomicincludingdelayusingthechargeunitofoneminut
13、e. Thethird business is short message business of GSM and it also is dividedinto two sorts； peer to peer and little district broadcast. Peer topeer message business can make user through GSM send or receivedigitalorlettermessagethatitslengthislessthan140bytes (8bit coding) and the short messages doe
14、s not affect communicationof voice； The short messages business can make it clear thatif the receiver has received the message by network, if it fails to receivethemessage, theanotherpeercalleddoesntanswerrightmessage, the network will retain transmitted message, once the networkdefectsthecalledcanb
15、econnected, 毕业设计（论文） 附 录 themessagesretainedcan be sent again until the called receives the message Theshort messagesbusinessisunparalleledformobile communicationnetwork, because itsendsmessagethrough letterreamchannel, it need not dial numbers and transmit directly informationincludingaddressofdest
16、ination to short messages service center,and then the message sent will be send the destination by shortmessagesservicecenter. Theshortmessagebusinesss expenditure is lower and it is valid for terminal to send orientation messageto supervise and control the center. In a word, we make use of shortmes
17、sages business to realize the GPS vehicle supervising and controlling. 3. TheGPSsuperviseandcontrolsystemof vehicle based on GSM short Message mode 3.1 System composition TopologystructureoftheGPSsuperviseandcontrolsystem ofvehiclebasedonshort messagebusinessisshow infigone, thecompositions and func
18、tions of the entire mobile vehicle are same. The GPS reception on the mobile vehicle is used to get information about current position andtime of itself, then send informationabout status and position to the supervision and control center workstationthroughshortmessagebusiness；In thesupervision and
19、control center workstation, to pass the GSM correspondence the net andmovetheinsides vehicletocommunicate, short messagestodeliver.Receive the short messages can use the GSM mobile terminal(suchasthecellularphone,etc),andalsocanusetheISDNmethodto directly link the ambulation to correspond by letter
20、the bureaus short messagesservicecenter, and like thisreceive the short messages more fast, the system capacity can be larger. At the master superviseandcontrolstation, andtheeachpositioninformationthat reception takes over information shout position of all the subworkstations,andthensendsthem to th
21、e electronicmapthroughcommunicationcontroller, anddisplayrunningtrackoftheentiremobilevehicle. Throughtheunvigilant software, systemcompletesthesupervisiononthestatusoftheentire mobilevehicle, usingwirelesscommunication, system dispatchesanddirectstheentiremobile vehicle, in this way, and system accomplishes the supervision and control management to the entire mobile vehicle.
