OBLAM Assignment: Loop Closure and Pose-Graph Optimization

The course materials and instructions can be found at KTH Canvas .

Please download pointcloud data here, Then declare the path to the data in the launch file run_pgo.launch.

Installation

Dependencies

The software was developed on the following dependancies, Test System: Ubuntu 20.04, ROS Noetic full-desktop

Printer logger (glog, gflag are also dependencies on Ceres)

# maybe need sudo if you are running it in your desktop
curl -sL https://raw.githubusercontent.com/Kin-Zhang/Kin-Zhang/main/Dockerfiles/installGlog_ownenv.sh | bash

Solver: Ceres 2.1.0 (do checkout the branch 2.1.0 after git clone)

git clone https://ceres-solver.googlesource.com/ceres-solver
cd ceres-solver && git fetch --all --tags
git checkout tags/2.1.0
mkdir build && cd build
cmake .. && make -j$(nproc)
sudo make install

Build

Please install all dependencies first. Afterwards, create a ros workspace, clone the package to the workspace, and build by catkin build or catkin_make, for e.g.:

mkdir -p oblam/src
cd oblam/src
git clone https://github.com/brytsknguyen/oblam_pgo
cd ../..; catkin build

Run

After finished the assignment part, run the launch

source devel/setup.zsh
roslaunch oblam_pgo run_pgo.launch

Results

Demo

Go to the function OptimmizePoseGraph() and create a ceres problem and solve it. If it works you should see a loop closure event like this.

Demo effects here

Kin's results

Video Here:

export.mp4

The ATE for ablation study:

Config	ATE
No loop closure	1.8518
loop closure only on prior	1.8518
loop closure only on relative pose	1.8573
loop closure on both of them	0.7235