毕业论文英文翻译GPS实时监测

1、GPS Real-Time Supervisory System and Application in the Construction of Face Rockfill DamHUANG Sheng xiang LIU Jingnan ZENG HuaienABSTRACT According to the quality control needs of filling construction of the face rockfilldam, by means o fthe global satellite positioning technology , the wireless da

2、ta communication technology, the computer technology and the data processing and analysis technology, and integrating with the roller compaction machine, theGPS real-time supervisory system is developed in this paper. It can be used to real-timely supervise the construction quality of the roller com

3、paction for filling engineering. The composition and applied characteristics ofGPS system, and the key technique problem and solution of the designare discussed. The height accuracy ofGPS system is analyzed and the preliminary application is introduced.KEY WORDS ：GPS; filling construction; quality c

4、ontrol; integrated system; face rockfill damIntroductionAt present , in the quality management of filling construction of the face rockfill dam，the quality control method of “dualcontrols”is mainly adopted, of which one is manually controling theparameters of roller compaction including thickness an

5、d roughness of filling layer and rolledtimes and rolled speed o f compaction machines,the other is inspecting the test hole samplingmanually in the area. The method play a positiverole in promoting domestic development of concrete faced rockfill dam. How ever, the traditional manual management mecha

6、nismcantmeet the demands of mo- dern mechanized construction and schedule anymore, with increasingof scale of con-crete face rockfill dam. Concretefaced rockfill dam of Shuibuya project inQing jiang River of Hubei Province, China,ranking first in dam height of the same type inthe world, is as high a

7、s 233 m. The project has atotal filling volume of 1. 6 ×107 m3and more than6×105 m3 for peak filling volume of asinglemonth, so demands much more to control the quality of filling construction of the dam. For the sake of supervising the filling construction quality quickly intime, it is ve

8、ry important to develop a supervisorysystem of the construction quality of the roller compaction for filling engineering, which has characteristics of real-time, continuity , automation andhigh precision. T he supervisorysystem has agreat meaning for improving the const- ructionquality of Shuibuya p

9、roject .As a brand-new technology of modern spatialsatellites navigation and position-ing system,GPS has g radually replaced the normal opticaland electrical surveying equipment in more andmore fields. Since 1980s, especially after 1990s,GPS techno- logy has lead the spatial positioningtechnology ,

10、combining with modern communi- cation technology，to a revolutionary change. Themethod for simultaneouslydeterm- ineing three dimensional coordinates by GPS has changed thetraditional positioning technology from land withinshore to entire ocean and outer space, fromstatics to kinematics, from point p

11、ositioning tonetwork difference, from afterwards processingto real-time positioning and navigation, and absolute and relative positioningprécisi- on comingto meterlevel, centimeterlevel, even submillimeterlevel, therefore, expands the fields of application and effect in every walk of life. Thef

12、ast development and improvement of moderndata communication technology, computer technology, electrical technology and the spatial positioning technology on behalf of GPS makesupervision ofhigh precision real-time continuityand automation feasible.According to the requirements o f constructionqualit

13、y management for roller compaction in filling engineering, by means of the global satellitepositioning technology, the wireless data communication technology, the computer technologyand the data processing and analysis technology,and integrating with the roller comp- action machine, in 2004 Wuhan Un

14、iversity and Qing jiangHydroelectric Develop- ment Corp. Ltd. Jointlydeveloped a real-time supervisory system suitable for the quality management needs of rollercompaction in filling engineering, i. e. real-timesupervisorysystem of filling construction quality( GPS system for short afterwards) . The

15、 systemhas comprehensive functions of real-time, highprecision, continuity, automation etc. , so canbe applied to real-time supervising constructionquality of filling compaction for dam, road, protection dike, airport etc. and becomes an effective assistant of ensuring the construction qualityfor pr

16、oject . Combining with engineering needsand system characteristics, the composition, keytechniques and schemes of the system are discussed in this paper. The height accuracy of thesystem is analyzed and the preliminary application is introduced.1 Composition and characteristics of GPSReal-time super

17、visory system1. 1 Composition of the systemHardware unit of the system mainly includes 3parts as follows:1) Receiving system of GPS satellite signals;2) Wireless network data communication system;3) Computer system.Fig. 1Illustration of the system network structureAccording to the requirements of co

18、mpactionfor filling and rammingenginee- ring and construction quality management to system, thesystem is composed of supervisory center, network relaystation, locale sub-control station,GPS reference station and mobile terminals ( including roller compaction machines and qualitysupervisor working ve

19、hicle) , regarding the effectof wireless communication from topographic environment. Fig . 1 is the illustration of construction quality supervisory system for filling compaction project . If the topographic environmentis good and the distance between the filling construction on-the-spot and the sys

20、tem supervisorycenter is not long, the network relay station can be removed.1. 1. 1 Supervisory centerSupervisory center is the heart of the system,where the differential data of GPS reference station are emitted to the GPS mobile stations, andat the same time, receiv- es the position information fe

21、d back by the mobile stations continuouslyand real- timely through wireless data communication. Combining the needs of construction,electronic display screen equipped in the supervisory center can real-timely display the accuratemoving location and status information of theroller compaction machin-

22、es as well as the qualitysupervisor working vehicle for compaction planesof the dam, remotely monitor the state of compaction quality of filling engineering, and offerleaders the basis of decision. T he processing ,analysis, storage of the system data and soonare carried out in the supervisory cente

23、r.1. 1. 2 Locale sub-supervisory stationLocale sub-supervisory station is the extensionof the system controlcenter, and provides convenience for locale supervisor. By accessing information of the system supervisory center, thesupervisor can master the status of engineeringconstruction and the constr

24、uction quality in timejust in the construction locale supervisorroom.Once quality deviation appears, the supervisorcan tackle with the construction side on the construction locale, reminding the constructors andasking them for rectifying.1. 1. 3 GPS reference stationGPS reference station is set for

25、increasing thesupervisory precision of the system by means ofDGPS technology. We set a GPS receiver on aknown site as a reference station and carry outGPS observation, then emit the GPS observationdata and known location information of the reference station real-timely to the GPS mobile stations, an

26、d process the data along with mobilestations' GPS observation data by means of diferential processing of carrier phases, consequently calculate the spatiallocation informationof the mobile stations, whose positioning precision can increase. T he method above is namedDGPS technology. In general,

27、GPS referencestation should be set up in the supervisory centerfor the sake of convenient supporting pow- er,management and maintenance. Toensure the supervisory precision, it is stressed that the distance between the GPS reference station and theconstruction area must be less than 5-6 km, andthe di

28、stance controlling requirement can be satisfied in practice.1. 1. 4 Mobile terminalMobile terminal includes system-requiringequipments installed in the project supervisorycar and roller compaction machines.1) Mobile terminal installed in the roller compaction machineA mobile terminal installed in a

29、roller compaction machine is mainly composed of an integratedsystem unit, a GPS receiver antenna and a wireless communication antenna. The system unit integrates main equipments of industrial platformcomputer, GPS receiver, wireless communication and soon. Mobile terminal is mobile super- visory equ

30、ipment like GPS moving station, andcarries out GPS mobile observation. Its controlitems mainly include the rolled track, rolledspeed, and rolled times of the roller compactionmachines. Mobile terminals feed back the effective observation result to the supervisory centercontinuously and real-timely.

31、Meanwhile, theplatform computer reflects the work status ofthe roller compaction machine real-timely, bymeans of figures and tables in the system unit ofdrivers cab of the roller compaction machine.The operator of the roller compaction machinecan check out whether his or her work meets thequality re

32、quirement on the display screen.2) Mobile terminal installed in the project supervisory carProject supervisory car is the working vehiclefor construction quality super- vising that isequipped exclusively for the project supervisors.Its main tasks are carr- ying out GPS mobile observation and supervi

33、sing locale quality . Its mainitems of observation are the thickness variations of paving layer before and after the compact- ion, supporting data for controlling the paving thickness and roughness of filling layer and calculating the compacted rate. T he supervisory car also feeds the observation r

34、esults back to supervisorycenter. Besides, according to the system supervisory data, it conducts the locale constructionfrom the point of riew of quality management .Mobile terminal installed in the project supervisory car and mobile terminal installed in the roller compaction machine resemble each

35、other.1. 2 Main characteristics of the systemMain characteristics of GPS real-time supervisory system are as follows.1 ) Continuous real-time supervision. Datacommunication achieves bi-direct- ional transmission in a real sense. The movement tracks andvelocities of the roller compaction machines can

36、be displayed real-timely , and three dimensionallocation information at the sampling rate of onesecond can be displayed real-timely on the display screen, no matter whether it is in the supervisory center, on localesubsuper- visory stationor in mobile terminals. The observation data ofthe system are

37、 cont- inuous, and the processed results at interval of onesecond meet enough theneed of continuity of supervisory data from thesystem.2) High degree of automation. In the wholesystem, it is fully automatic that emitting thedifferential data of reference station to mobileterminals, feeding back the

38、position informationof terminals to supervisory center, displayingthe movement track and velocities of all rollercompaction machines both in the supervisorycenter and in the mobile terminals, storing andproceeding data and feedback analyzing , etc.3) Easy and convenient operation. The supervisory ce

39、nter and network relay station of thesystem are designed fully according to the needof full automation, and the parts operated manually mainly concentrate on mobile terminals. T heoperation of the mobile terminalsis very easyand convenient, which contains only several simple necessary steps such as

40、turning on and offthe unit etc. Besides, the equipment s of mobileterminal are compact , of small weight and sizeand its loading and unloading is also very easy.4) High precision. Thank to GPS RTK technology adopted for data processing of the systemand the distance between the mobile terminals ofShu

41、ibuy a project and GPS reference station doesnot exceed 3 km, it s horizontal precisionachieves ±( 1- 2) cm, which fully meets supervisory quality needs of horizontal position of thecompaction construction, and can efficiently supervise the movement track, velocity and rolledtimes of the roller

42、 compaction machines. In regard to elevation, as long as the mobile terminalsoperate in a given way and rational elevation fitting model is adopted, the precision of the system also achieves ±( 1-2) cm( read the analysisafterwards) , which can meet the control needsof thickness and roughness of

43、 filling layers of thecompaction construction.5) Allweathered 24-hours work of many mobile terminals. In the case of using 10 mobileterminals simultaneously, the system has a communication rate no less than 100 Kbps, and cansupport the application of point-to-point, point-to-multipoint and network r

44、elay station. Thesystem does not suffer from the effect of weather , and meets the need of all-weathered 24-hourswork of dam project .2 Key problem and solution of the systemdesign1) Real-Time supervision of rolled parameters.Parameters of the roller compaction mainly refers to movement track, veloc

45、ity, rolled times ofthe roller compaction machines for mobile terminals, which need real- time supervision, and canbe used to control construction quality. Therefore, in order to ensure the real-time feedback ofpositioning data, the wireless communication data links need to achieve the function of p

46、oint-to-multipoint and bi-directional high communicationrate. The optimal design for solving the problemis to choose the mode of radio or GSM mobilephone. Taking account of the economy and practice- ability, the system adopts wireless frequencyaugmented communication technology , achieves transmitti

47、ng GPS differential data of the reference station real-timely to each mobile terminal, feeding back the three dimensional spatial location information of each mobile terminal real-timely to supervisory center and supporting position results at interval of one second. T his way,not only the system of

48、 each rollercompactionmachine can reflect its own status o f compaction.Real-timely on the display screen, but also thesupervisory center and locale sub-supervisorystation can supervise the working status of eachmobile terminal real-timely.2) Precision of observation data. The precision ofGPS RTK is

49、 cm-level in general, considering thatthe distance between the mobile terminals ofShuibuya project and GPS reference station does notexceed 3 km, its horizontal positioning precisionfully meets calculation precision needs of the movement track, velocity and rolled times of the rollercompaction machi

50、nes. In order to ensure the elevation precision of thickness and roughness of fillinglayer, besides choosing highperform- ance and anti-noise dual-frequency GPS receivers, adopting propermethod for acqui- ring three elevations data of beforefilling, after filling and after compaction and elev- ation

51、 fitted model, can make the elevation accuracy increase. By analysis, the elevate- ion precisioncan achieve± ( 1-2) cm, which fully meets thecontrol needs of thick- ness and roughness of filling layers.3) Stability of the system. Because the fillingconstruction of modern face rock- fill dam las

52、tsall-weathered 24-hours without break, and manyroller compaction machines work simultaneously, it is required that the supervisory center,network relay station and each mobile terminalof the system work stably for a long time. Because of the fixed set of supervisory center andnetwork relay station,

53、 if there is surely provisionof work power, and without manual destructionand incorrect manipulation, there is no problemfor running on normal condition. But the mobileterminal set in the roller compaction machine notonly suffers from the vibration effect of roller,but also is incorrectly manipulate

54、d easily whenthe driver suffers from work tiredness, therefore, the stability design of integrated system unit of mobile terminal becomes a key problem.4) Power-supply way. Because the referencestation is set in the supervisory center, power-supply of its GPS host, radio of emission and reception, a

55、nd superviso- ry computer has no problem. As involving each mobile terminal, it refersto the power-supply problems of GPS host , radio of emission and reception, plat form computerand fan for heat emission etc. Experiment worktakes out-set accumulator jars to provide power,which can ensure work in a

56、 short time, but cannot be used in a long time work of project , sothere is need to use the roller compaction machine to supply power in the formal operation ofsystem. The problem key of power-supply ispracticality and to ensure that it doesn't make destruction to the system equipment , in this

57、way,exclusive power component and relevant cableconductor and adapter connector are designedand produced.3 Elevation accuracy analysis of the systemIn order to evaluate the elevation accuracy ofthe system, on a filling surface of the experimental field, using a light car and taking themovement track

58、 covering the whole surface almost even, three groups of data of the same elevation surface are obtained. One group of movement track is illustrated as Fig . 2 ( the unit is meter) . As far as three groups of data collected inthe experiment are concerned, because thevelocity of the car are different

59、 and interval distanceof two neighbored track line are unequal, the amounts of dots of the groups are different , theyare 906, 922 and 639 respectively.It is necessary to adopt grid method to makefitting, regarding the data dots collected in factlike in Fig. 2 is irregular. Grid method is arraying matrixlike grid of small squares, and calculating elevation of each grid point by distanceweig- hted average method or least square curvedsurface fitting. In this paper, distance Weightedaverage method is adopted to calculate t