Research On High Precision Position And Orientation Method Based On Digital Measurable Image And GPS/IMU Integration

The high-precision dynamic position and orientation technology, digital sensor technology,close-range photogrammetry technology, and autocontrol technology have had greatdevelopments and integration and fusion, which makes it possible for close rangephotogrammetry and terrestrial remote sensing, and as a result, a new subdiscipline namedvehicle borne mobile measurement come into being, which has opened up a new way for fasthigh-precision measurement and information updating in the three-dimensional space. Themobile road measurement technology charactered by high-speed in dynamic position and largeamount of information in terrestrial close range photogrammetry improves the efficiency offield space data acquisition. The stereo images obtained by mobile road measurementtechnology make it flexible in data processing and applications. With the organic combinationof the stereo image and the GPS/IMU data from the mobile road measurement system, a newapproach is provided for the high-precision and high reliability of the mobile measurementsystem.The mobile measurement system is a typical multi-sensor integrated systems. On one hand,the high-precision data provided by POS are used in the fusion of the remote sensing imagesand the georeferenced information, and then the uncontrolled and fast remote sensing arerealized. On the other hand, the DMI（Digital Measurable Image）with position capabilityobtained by uncontrolled system is a sequence of images with strict geometry pass parameters.When the DMI as a new data source is fused with the GPS/INS data, a more complex integratednavigation system with GPS/INS/DMI positioning and orientation technology is built, whichmake it possible to improve the position and orientation precision and reliability of the mobilemeasurement system in the future.In this thesis, the study object is the position and orientation measurement based ondirectly georeferenced of the uncontrolled mobile measurement system, and the reliable andprecise position and orientation technologies based on multi-sensor integration are researched,which include the high-precision methods based on GPS, INS and odometer, thetightly-coupled GPS/INS technologies, and the methods based on the sequence of measurementimages of mobile measurement system. On the basis of the above studies, the position andorientation models and algorithms based on the integration and fusion of GPS, INS, odometerand the sequence of measurable images are researched. And then the GPS/IMU/DMI integratedmethods for position and orientation based on the combination of the measurable images and the vector position recursive parameters are discussed. At last, the multi-sensor data fusionintegrated POS is designed and the process precision and reliability of GPS/IMU integratedposition and orientation system are developed, which provides theoretical and technicalsupports for uncontrolled mobile measurement technology.Surrounding the Position and orientation technologies based on land-based mobilemeasurement system, the following studies have been made in this thesis.1) Uncontrolled mobile measurement can be realized by integrating the position andorientation sensors of POS with the CCD cameras of remote sensing system. Firstly, thetheories and methods of multi-sensor integration and uncontrolled mobile road measurementare summarized and the uncontrolled mobile measurement model is analyzed, based on whichthe key technologies of uncontrolled mobile measurement are advanced. Secondly, the errormodel and the key technology of uncontrolled mobile measurement are detailed. Then, the datafrom land-based uncontrolled mobile measurement are analyzed. Finally, the basic model ofmulti-source data fusion for position and orientation is aerated, and its technical feasibility isdiscussed.2) The position and orientation methods of land-based mobile measurement system aresystemically summarized and analyzed, they consist of position and orientation methods usingGPS and the methods using inertial measurement. The position and orientation methods usinginertial measurement mainly include SINS, DR and3G1M. Next, on the basis of above studies,the GPS/IMU position and orientation model is discussed, the principles and algorithms ofGPS/IMU loosely-coupled integration are analyzed, and the GPS/IMU loosely-coupledintegration algorithms are tested in the land-based mobile measurement system. Then, thetightly-coupled GPS/IMU integration position and orientation model is presented, it consists ofthe fixed algorithm based on the IMU GPS ambiguity and the detection algorithm of IMUassisted GPS cycle slip. Immediately, the validity and reliability of the algorithms are verifiedby using the data obtained from land-based mobile measurement system. Finally, the tri-satellitepositioning method aided by INS in the case of tightly-coupled integration is put forward, and itis tested by the real data. The result shows that the method is applicative.3) Based on the analysis of image position and orientation technology and the presentresearch status at home and abroad, the following researches have been done. Firstly, thepositioning model based on the digital measurable image (DMI) of uncontrolled mobilemeasurement system is proposed, the error is analyzed, and the key factors in position andorientation are pointed out. Secondly, due to the fact that the measurable sequence imagespositioning is visual positioning essentially, the precision and reliability can be improved by theintegrated fusion of POS and visual positioning. Thirdly, the integrated navigation system with GPS/INS/DMI is built, and the precision and reliability are further improved by the way ofusing the integrated fusion of the DMI and GPS/INS data. At last, the sequence DMIautomatically matching method based on SIFT is proposed to improve the precision andreliability of DMI position and orientation.4)In the mobile measurement system, DMI,GPS and IMU have different advantages andcharacteristics in position and orientation. Whatever it is based on what kind of sensor, Kalmanfiltering is the most commonly used method to realize the data fusion of different sensors.Kalman filtering needs appropriate state model, state noise matrix and measurement noisematrix. If the given noise matrix is not appropriate to reflect the uncertainty of state parameters,the filtering solution will be affected, which leads to the suboptimal evaluation or filteringdispersion.In order to solve the above problems, in consideration of the characteristics of DMI data,the single-factor adaptive filtering and multi-factor adaptive filtering based on DMI areproposed. At first, the method of adaptive factor structure is studied, some adaptive factormodels are given, and the application in DMI position and orientation is analyzed. Then,adaptive Kalman filtering based on multi-sensor space constraints is put forward, and it isapplied in the GPS/IMU/DMI integrated position and orientation. Finally, the robust adaptiveGPS/IMU/DMI integrated position and orientation model and space constraints integratedposition and orientation model based on multi-sensor are presented.5)The land-based mobile measurement system and the experimental fields are introduced.Then, on the basis of a large amount of DMI, GPS and IMU data obtained from differentexperimental fields, the GPS/IMU loose combination experiments, the GPS/IMUtightly-coupled integration experiments and the DMI/GPS/IMU integrated position experimentsare conducted, and the experimental results are analyzed, which show that the proposed methodis effective and reasonable. At last, the mode of DMI/GPS/IMU integrated position andorientation is discussed.In conclution, with the combination of the firsthand data obtained from position andorientation GPS/IMU and the secondhand measurable images by using the theoretical methodsof mult-sensor integration and the Robust approach of multi-sensor multi-source data, tworesults can be obtained: one is that the position and orientation precision can be improved bythe way of tightly-coupled GPS/IMU integration, and the other one is that the reliability isenhanced and the utility range is broadened by using of DMI position and orientationdeductions from the measurable images obtained by land-based mobile measurement system.