Familiarizing with Opensource Robotics Packages (Running Post)

There are two tracks of self-development I have in mind:

• Familiarizing with famous opensource robotic packages — This is to know what’s the best out there by running their example demonstrations, even if I don’t get the maths yet
• Making a library of my own implementations — This is to re-invent the wheels by consolidating the maths and my intuition, attempting to bridge the gap of what I know and what’s out there

This blog attempts to journal my odyssey through the first track.

# First time setup steps
# I will keep referring to ROOT_DIR in the rest of the post
ROOT_DIR=<ASSIGN PREFERRED ROOT DIRECTORY ADDRESS HERE>
cd $ROOT_DIR
mkdir -p opensource_ws/src
cd opensource_ws

# Install catkin-tools: https://catkin-tools.readthedocs.io/en/latest/installing.html
catkin init
catkin build

Table of Contents

1. Kindr
2. Grid Map
3. Elevation Mapping
4. Legged Control
5. Acknowledgements

Kindr

Summary: The kindr package provides interfaces to standard mathematical quantities encountered in kinematics and dynamics for robotics.

Latest as of: Mar 26, 2023

Compilation Steps

cd $ROOT_DIR
cd opensource_ws/src
git clone https://github.com/ANYbotics/kindr.git
catkin build kindr

Simpletest package

trunc8/kindr_simpletest

Grid Map

Summary: The grid_map is intended for 2.5-dimensional grid mapping, i.e., heightmaps. It is intended to be used as a local data map and it uses a circular buffer to shift the data as the robot moves.

Latest as of: Mar 26, 2023

Compilation Steps

cd $ROOT_DIR
cd opensource_ws/src
git clone https://github.com/ANYbotics/grid_map.git
catkin build grid_map

Interesting aside here: The grid_map package is a metapackage. The other packages like grid_map_core and grid_map_octomap are where the actual code is implemented. So what’s the difference between a package and a metapackage? I answer it in a short blog post.

Simpletest package

trunc8/grid_map_simpletest

Learned a new aspect of ROS CMakeLists.txt while writing the above simpletest. The grid_map library source code is not accessible even if you include the relevant package names. You have to link to the library using the following code –

target_link_libraries(${PROJECT_NAME}_node
  ${catkin_LIBRARIES}
)

I created this grid map after figuring out the APIs from grid_map source code —

Elevation Mapping

Summary: The elevation_mapping package creates a local heightmap around the robot. It needs to be provided with range sensor data and robot pose estimation.

Latest as of: Mar 28, 2023

Compilation Steps

• Environment: ROS Noetic
• Packages that I cloned and built in the same workspace:
  • kindr
  • kindr_ros
  • message_logger
  • grid_map
  • (optional) turtlebot3_simulations
  • (optional) turtlebot3
  • (optional) point_cloud_io

cd $ROOT_DIR
cd opensource_ws/src
git clone https://github.com/ANYbotics/grid_map.git
catkin build grid_map

Aside — I tried building it on ROS Melodic as well. Melodic fixes below:

• https://github.com/ANYbotics/grid_map/issues/292: Replace filter_base.hpp with filter_base.h, filter_chain.hpp with filter_chain.h
• https://github.com/ANYbotics/grid_map/issues/355 They have fixed things in Noetic, not in Melodic. Ended up commenting out the line:

    # find_package(TBB 2020.1 EXACT REQUIRED)
  

• https://github.com/ANYbotics/elevation_mapping/issues/151They seem to have fixed this in Noetic, not in Melodic. Changed PCL_MAKE_ALIGNED_OPERATOR_NEW to EIGEN_MAKE_ALIGNED_OPERATOR_NEW in elevation_mapping package PointXYZRGBConfidenceRatio.hpp.

Simpletest package

trunc8/elevation_mapping_simpletest

Legged Control

Summary: The legged_control package is a legged robot control stack based on NMPC (Nonlinear Model Predictive Control) and WBC (Whole Body Controller).

Latest as of: Apr 01, 2023

Compilation Steps

• Environment: ROS Noetic
• Packages that I cloned and built in the same workspace:
  • ocs2
  • pinocchio
  • hpp-fcl
  • ocs2_robotic_assets
• Apt installed
  • liburdfdom-dev liboctomap-dev libassimp-dev

cd $ROOT_DIR
cd opensource_ws/src
mkdir legged_control_pkgs && cd legged_control_pkgs

# Clone legged_control
git clone git@github.com:qiayuanliao/legged_control.git
# Clone OCS2
git clone git@github.com:leggedrobotics/ocs2.git
# Clone pinocchio
git clone --recurse-submodules https://github.com/leggedrobotics/pinocchio.git
# Clone hpp-fcl
git clone --recurse-submodules https://github.com/leggedrobotics/hpp-fcl.git
# Clone ocs2_robotic_assets
git clone https://github.com/leggedrobotics/ocs2_robotic_assets.git
# Install dependencies
sudo apt install liburdfdom-dev liboctomap-dev libassimp-dev

catkin config -DCMAKE_BUILD_TYPE=RelWithDebInfo
catkin build ocs2_legged_robot_ros ocs2_self_collision_visualization

Simpletest

source $ROOT_DIR/devel/setup.zsh
roslaunch ocs2_legged_robot_ros legged_robot_ddp.launch

Acknowledgements