Evaluate State Machine Libraries

[rohbotics]

We should evaluate all the available state machine libraries for ROS, C++ and Python.

Some ones off the top of my head

• ROS SMACC
• Boost::SML
• ROS BehaviorTrees

DOD: Some comparison document somewhere.

[rohbotics]

@kristjanreba please assign yourself to this issue when you accept the UbiquityRobotics org invite.

[kristjanreba]

Comparing different state machine libraries for ROS.

ROS SMACC https://discourse.ros.org/t/introducing-the-smacc-state-machine-library/14963
+ fast
+ relatively easy to use
- only C++
- new (no big community yet)

Boost::SML https://github.com/boost-ext/sml
+ large community
- only C++

ROS BehaviourTrees
+ light weight
+ C++ and Python
- not much community behind the project
- a bit too complicated

SMACH http://wiki.ros.org/smach
+ quick to implement in python
+ high level and easy to understand
+ larger community
- slow on low level systems
- only Python

Those are my impressions of the libraries.
I would use the SMACH for python code and ROS SMACC or Boost::SML for C++ (low level) code.

[rohbotics]

@kristjanreba Thanks for the comparison.