Add 2D slam Cartographer for turtlebot navigation

[tongtybj]

Better 2D slam than gmapping or karto_slam:

1. add cartographer_ros as default run_depned
2. add repository cartographer_turtlebot in .rosinstall
3. modify the README.md for 2

[k-okada]

if you use .rosinstall file, you will not need 'set robot-programming'

[tongtybj]

Thank you for review. Modification: ee7f13e

[k-okada]

forget to add launch file using cartographer?
when you add launch file, please try to add roslaunch-check, understanding test mechanism will be a part of NEDO project
https://github.com/jsk-enshu/robot-programming/blob/master/dxl_armed_turtlebot/CMakeLists.txt#L9-L14

[tongtybj]

@k-okada

I thought to use the original launch file in cartographer_turtlebot.
e.g: roslaunch cartographer_turtlebot turtlebot_depth_camera_2d.launch

Should I create the similar launch file under this repository?

[k-okada]

I'm expected to update https://github.com/jsk-enshu/robot-programming/blob/master/dxl_armed_turtlebot/launch/dxl_armed_turtlebot_navigation.launch to add 'arg' to switch localization/mapping method.

[tongtybj]

Modified dxl_armed_turtlebot_navigation.launch with following points.

1. introduce 'arg' do_slam to separate mapping task and only localization task. Because I observed the localization(i.e. tf) is quite stable, if both node (slam and acml) runs at same time.
2. introduce 'arg' slam_mode to choose slam methods between karto_slam and cartographer.
3. the preparation of cartographer. I found the cartographer (version 0.2.0) is quite old, and no any version of cartographer_turtlebot is compatible with it. So I create another config file cartographer.lua
   , based on backpack_2d.lua. But the performance of this old cartographer is very bad (check the GIF), compared with the latest version. I think I lost some critical parameters.

[k-okada]

https://github.com/tork-a/roomblock/tree/master/roomblock_mapping/config or @7675t might help you.

[7675t]

@tongtybj
Hi, it looks just your IMU is oscillative. Why don't you try TRAJECTORY_BUILDER_2D.use_imu_data = false?

But it may be possible ver.0.2 is worse than 0.3. I haven't compared those intently.

[tongtybj]

@7675t Than you for your advice, tajima san!

I tried with TRAJECTORY_BUILDER_2D.use_imu_data = false, and the localization becomes much better as shown in the following GIF.

But, what makes me confused is this flag is set to true in the laster version of cartographer for turtlebot: https://github.com/googlecartographer/cartographer_turtlebot/blob/master/cartographer_turtlebot/configuration_files/turtlebot_depth_camera_2d.lua#L50.

The possible reason is that the latest cartographer might omit the horizontal angular velocity if MAP_BUILDER.use_trajectory_builder_2d (I have to check the code).

Then I tried to set the horizontal angular velocity to zero since I think the yaw velocity from imu should not be omitted, and get same good result as shown in the following GIF.

The send RP about this commit: https://github.com/googlecartographer/cartographer_turtlebot/pull/94/files. Hope they can merge this PR.

[7675t]

Yes, difference between 0.2 and the latest is annoying, not back-compatible. In kinetic we cant release the latest, but can use it by building by ourselves.

We may be safe to supply both version config files for a while, like turtlebot_v020.lua or something,expecting eventually migrated to newer release.