Precision of Orientation Data of Dual Forwards Photographing Cameras on MMS Determined by Visual Odometry Based on Disparity Changing

  • 傅 兆陽

Student thesis: Master's Thesis


This thesis uses Disparity Based Visual Odometry (DBVO) to estimate the pose of dual forwards photographing cameras on MMS in outdoor environment The input data of DBVO contain a sequence of forwards photographing stereo pairs Interior Orientation (IO) of dual cameras and their Relative Orientation (RO) The IO and RO are assumed to be invariant during taking images In the experiment the results of DBVO are transformed into mapping frame by means of the Exterior Orientation (EO) of first exposure station DBVO includes 4 steps: (1) Keypoint detection and matching (2) Calculating coordinates of object points by parallax equations (3) Determining ego-motion by 3D conformal transformation (4) Estimating pose of sequential images in mapping frame Test area is a block with an extra U turn MMS drives about 1 5 km and takes 447 stereo pairs In quality of ego-motion determination the RMSD of translations is 0 19 m and 0 05 m along and across depth direction respectively The RMSD of rotation angles ω φ and κ is 0 0416° 0 0837° and 0 0664° respectively Besides ego-motion determination has the same performance along straight and turning paths In quality of pose estimation in mapping frame The Absolute Difference (AD) of horizontal position depends on the scenes along the paths but the Relative Difference (RD) has elevated reduction when the moving distance increases The RD is lower than 1% when MMS drives more than 650 m The AD of elevation grows gradually as moving distance increases but the RD decreases slightly which is 0 20% when MMS drives 1 2 km In quality of object points determination The horizontal and vertical coordinate difference is 0 88 m and -0 04 m in the beginning As MMS drives about 550 m the horizontal and vertical coordinate difference is 138 73 m and 10 79 m respectively
Date of Award2017 Dec 20
Original languageEnglish
SupervisorJaan-Rong Tsay (Supervisor)

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