SLAM

Some Study Codes and Projects about SLAM

Contents

1. Eg01_UseEigen
   Use Eigen library
2. Eg02_UseGeometry
   Some conversions between different geometry representation, like rotation matrix, angle axis, euler angles and quaterniond
3. Eg03_UseSophus
   use Sophus library to study Lie algebra and groups
4. Eg04_JoinMap
   Use PCL(Point Cloud Library) to join map from RGB-D images
5. Eg05_UseCeres
   Curve fit using Ceres
6. Eg06_UseG2O
   Curve fit using g2o
7. Eg07_FeatureDetectMatch
   Feature detect and match using OpenCV, and use features to estimate pose in 2D-2D
8. Eg08_PoseEstimation2D2D
   Estimate camera pos 2D-2D using epipolar geometry costraints, and triangulatio to obtain 3D point in world.
9. Eg09_PoseEstimation3D2D
   Get camera pose using PnP algorithm, and use bundle adjustment to optimize the pose.
10. Eg10_PoseEstimation3D3D
    Get camera pose using ICP algorithm(SVD and bundle adjustment) based on 3D-3D point pairs.
11. Eg11_Triangulation
    Triangulation to obtain position of map point
12. Eg15_BagOfWords
    Generate vocabulary from images and calculate the simularity among images, dataset comes from TUM RGBD dataset. Note the result using large vocabulary file don't seem good enough as books.

G2O Examples

1. g2o01_CurveFit
   Using g2o for curve fitting. Ref: https://github.com/RainerKuemmerle/g2o/blob/master/g2o/examples/data_fitting/curve_fit.cpp.
2. g2o02_CircleFit
   Using g2o for circle fitting, and compare with another solution, construct a linear least square problem solved by Eigen. Ref: circle_fit.cpp

Sphere Optimization

Read the data from file sphere2500.g20, and then optimize it with different method.

1. Sphere01_CeresQuaternion
   Optimize it using ceres and rotation is represented by quaternion, with AutoDiffCostFunction. Ref: https://github.com/ceres-solver/ceres-solver/tree/master/examples/slam/pose_graph_3d
2. Sphere02_CeresQuaternion
   Same as Sphere01_CeresQuaternion, but the parameter block are pose(quaternion and position), and use ProductParameterization for local parameterization.
3. Sphere03_CeresSO3
   Optimize the problem useing ceres, and rotation is represensted by SO3 with SO3Parameterization.
4. Sphere04_CeresSO3
   Same as Sphere03_CeresSO3, but the parameter block are pose(SO3 and position), and use ProductParameterization for local parameterization.
5. Sphere05_CeresSE3
   Optimize it using ceres, pose(rotation and translation) is represented by SE3 with SE3Parameterization.
6. Sphere06_CeresPoseParameterization
   Same as Sphere02_CeresQuaternion, but the parameter block are pose(quater and position), and use defined parameterization method, $q = q0 \times Exp(\delta phi), p = p0 + q0 \times \delta p \times \q0^*$. But the cost function are calculated by AutoDiff using Jet, and found that the jacobians calculation may be some error and the result will not convergency. If change the cost function to SizedFunction maybe solve this problem.

Problems

1. Some error occurs about LinearSolverCholmod/LinearSolverCSparse, and cannot find solution, try again later.

   Change FindCXSparse.cmake to shared library, Eg06 will be OK but others not.

Note

1. This repository will not be maintained right now, some of the example will be move to CPlusPlusStudy and VisionStudy with more better project stucture.