Move base sequence

Overview

This is a ROS package that uses a ROS Action server to manage sending multiple goals to the navigation stack (move base action server) on a robot in order to achieve them one after another. The package handles everything regarding the goals: receiving, storing, sending, error handling… etc.

ROS Wiki Page: http://wiki.ros.org/move-base-sequence

## Dependencies

• move_base: sudo apt-get install ros-$ROS_DISTRO-move-base
  • move_base_msgs
• actionlib: sudo apt-get install ros-$ROS_DISTRO-actionlib
  • actionlib_msgs
• gemoetry_msgs: sudo apt-get install ros-$ROS_DISTRO-geometry-msgs
• std_msgs: sudo apt-get install ros-$ROS_DISTRO-std-msgs

Note that if you’re using the binaries release as mentioned in the installing section, the missing dependencies will be installed automatically.

A guide on how to get the ROS distro that’s compatible with your system:
Ubuntu install of ROS Kinetic
Ubuntu install of ROS Melodic
Ubuntu install of ROS Noetic

Installing

ROS Distribution

ROS

The package is released as binaries for ROS Kinetic/Melodic/Noetic:
sudo apt-get install ros-$ROS_DISTRO-move-base-sequence

ROS2

For ROS2, There is a more suitable controller in Nav2 itself. Please refer to: Nav2 Waypoint Follower.

Build from source

To install the package,clone this repo git clone https://github.com/MarkNaeem/move_base_sequence.git in your catkin workspace, which is usually ~/catkin_ws, and build the package using catkin_make --pkg move_base_sequence, or by just using catkin_make to build the whole workspace. It is recommended to run rosdep rosdep install move_base_sequence before building the package to make sure all dependencies are properly installed

Nodes, topics, services, parameters

Nodes:

• move_base_sequence: the one that runs the actionlib server that handles everything about the goals sequence handling.

topics:

• wayposes: PoseArray, a visualization topic that shows the registered goals. It can also be sued to pass precalculated set of goals all at once by publishing on it.
• path: Path, visualization topic that draws the path that connects goals together.
• corner_pose: Pose, the topic that is used to append new goals to the goals sequence.

services:

_{note: A robot using move base sequence can have two states: paused: paused state stops the move base server and stops the sequence server so the robot stays at its place. operating: operating state means that the sequence server will be sending goals and waiting for move base response. In other words, the system will be fully functioning until something causes state to change to paused (e.g. a goal cancellation or abortion)}

• toggle_state: toggles the robot state from paused to operating.
• set_state: sets the state of the robot using True (opetating), False (paused).
• reset: deletes all registered goals and cancel any sent one. The node is then set to how it started.
• get_state: returns the current state of the server, either True (opetating), False (paused).

Parameters

• abortion_bahaviour: determines the behaviour of the robot should the move base server face any problems that cause goal abortion. Default is 'stop' but it can be set to 'continue' which will make the system ignore this goal and take the next one in the sequence. It takes 'continue' and 'stop' as strings.
• is_repeating: determines whether the robot should be looping on the goals in an infinite loop which is the default value and set to be True, or it should only achieve them once, delete them, and wait for new goals, which is set by False.

How to use it

What to do before using the package

To use the move base sequence package, all you need is to have your move base action server running (aka setup the navigation stack on your robot). Navigation stack has great tutorials and a detailed explanation about the whole stack and how it works.

Sequence server setup

The server runs through move_base_sequence node, which is initialized in server.py.

It can be called via:

• launch files:

<node name="move_base_sequence" pkg="move_base_sequence" type="server.py">
       <param name="/move_base_sequence/is_repeating" value="True"/>
       <param name="/move_base_sequence/abortion_behaviour" value="stop"/>
    </node>

• or rosrun command:

rosrun move_base_sequence server.py

Adding goals to the sequence server

To add goals to the sequence, there is three ways:

• Change the topic of 2D nav goal tool on rviz to /move_base_sequence/corner_pose as follows:
  1. Click on panels in the menus bar, a drop down menu will appear.
  2. From the menu, check Tools properties if not checked.
  3. A new window will show up, scroll down this menu unitl you get to 2D nav goal and change its topic to /move_base_sequence/corner_pose.
     With this, every time you use the 2D nav goal GUI tool on rviz, the topic published will be /move_base_sequence/corner_pose not the default /move_base_simple/goal. The following GIF shows how to do the mentioned steps.
• Publish the targeted pose directly without rviz on the topic /move_base_sequence/corner_pose.
• Publish the whole targeted set of poses on the topic /move_base_sequence/wayposes.

<img width="600" height="338" src=tool.gif>

Examples

Running move_base_sequence on turtlebot3

Since GithHb’s markdown does not support embedding of videos or the iframe tag in HTML, this video link was made by “video to markdown”