lgmath

lgmath is a C++ library for handling geometry in state estimation problems in robotics. It is used to store, manipulate, and apply three-dimensional rotations and transformations and their associated uncertainties.

There are no minimal, constraint-free, singularity-free representations for these quantities, so lgmath exploits two different representations for the nominal and noisy parts of the uncertain random variable.

• Nominal rotations and transformations are represented using their composable, singularity-free matrix Lie groups, SO(3) and SE(3).
• Their uncertainties are represented as multiplicative perturbations on the minimal, constraint-free vectorspaces of their Lie algebras, so*(3)* and se*(3)*.

This library uses concepts and mathematics described in Timothy D. Barfoot's upcoming book State Estimation for Robotics. It is used for robotics research at the Autonomous Space Robotics Lab; most notably in the STEAM Engine, a library for Simultaneous Trajectory Estimation and Mapping.

Getting Started

You will need:

• A compiler with C++11 support
• Eigen, at least 3.2.5
• CMake (and optionally catkin) build systems

Dependencies

Eigen

In a folder for 3rd party dependencies,

wget http://bitbucket.org/eigen/eigen/get/3.2.5.tar.gz
tar zxvf 3.2.5.tar.gz
cd eigen-eigen-bdd17ee3b1b3/
mkdir build && cd build
cmake ..
sudo make install

Build

In your development folder

mkdir lgmath-ws && cd $_
git clone --recursive https://github.com/utiasASRL/lgmath.git

Using catkin and catkin tools (recommended)

cd deps/catkin && catkin build
cd ../.. && catkin build

Using CMake (manual)

cd .. && mkdir -p build/catkin_optional && cd $_
cmake ../../lgmath/deps/catkin/catkin_optional && make
cd ../.. && mkdir -p build/catch && cd $_
cmake ../../lgmath/deps/catkin/catch && make cd ../.. && mkdir -p build/lgmath && cd $_
cmake ../../lgmath && make -j4

Install (optional)

Since the catkin build produces a catkin workspace you can overlay, and the CMake build exports packageConfig.cmake files, it is unnecessary to install lgmath except in production environments. If you are really sure you need to install, you can use the following procedure.

Using catkin tools (recommended)

cd lgmath 
catkin profile add --copy-active install 
catkin profile set install 
catkin config --install 
catkin build

Using CMake (manual)

cd build/lgmath 
sudo make install

Uninstall (Optional)

If you have installed, and would like to uninstall,

Using catkin tools (recommended)

cd lgmath && catkin clean -i

Using CMake (manual)

cd build/lgmath && sudo make uninstall

Generating Documentation

Using catkin tool (recommended) In your catkin workspace

catkin build --make-arg doc

Using CMake (manual) In your build folder

make doc

The documentation will be found in the doc subdirectory of the build folder.