Specific Subjects

ICP covariance

ICP error source:

  • wrong convergence (to local minimial), error of the initial pose estimation.
  • under-constrainted situation: the problem is indeterminted.
  • miss match.
  • sensor noise.

thumbs An accurate closed-form estimate of ICP’s covariance 2007. Use hessien matrix as the estimation of the covariance (but this method in some cases greatly over-estimates thte true covariance):

\[cov(\hat{x}) \approx 2\frac{residual}{K-3} [\frac{\partial^{2}}{\partial x^{2}}residual]^{-1}\]

This paper develop the following closed-form method :

\[cov(x) \approx [\frac{\partial^{2}}{\partial x^{2}}J]^{-1} [\frac{\partial^{2}}{\partial z\partial x}J]^{T} cov(z) [\frac{\partial^{2}}{\partial z\partial x}J] [\frac{\partial^{2}}{\partial x^{2}}J]^{-1}\]

thumbs A Closed-form Estimate of 3D ICP Covariance 2015. Based on the upper paper, and solve for point-to-point case.

thumbs On the Covariance of ICP-based Scan-matching Techniques 2016. Analysis the upper hessien based method. Find that the upper method fit for point-to-plane icp, but not for point-to-point icp.

thumbs A New Approach to 3D ICP Covariance Estimation 2019. Add an additional term for the covariance from the initial pose estimation.

Point cloud generation

  • (local method) 3d grid (TSDF, ESDF) + matching cube. (binary classification problem for octree vertices)
  • (global method) point cloud + possion reconstruction.
  • Delaunnay triangulation
  • Deep learning method

chrown0 (ONet) Occupancy networks: Learning 3d reconstruction in function space

thumbs SSRNet: Scalable 3D Surface Reconstruction Network

Line feature match

chrown0 structure-from-motion using lines representation triangulation and bundle adjustment 2005 Plucker representation of the line (by two points or two planes: the direction of the line, and the moment). The paper proposed a Orthonormal Representation of lines, takes only 4 dof (three SO(3) and one SO(2)).

chrown0 impact of landmark parameterization on monocular ekf-slam with points and lines 2010 Project lines into camera image space.

chrown0 PL-SLAM: a Stereo SLAM System through the Combination of Points and Line Segments 2017. Using the orthonormal representation of lines, and 3d point representation of points, to process visual slam (basicly ORBSLAM2 structure). And the first paper to derivative the line jacobians with detail.