GUI controls as ROS 2 rqt plugin

[jkaniuka]

Motivation

Hi, I have been using PyBullet in my engineering thesis and recently noticed that you have made the ROS-PyBullet Interface code available. I was very comfortable using Pybullet, but at the time I was surprised why it was not available as a ROS package. I see that the ROS 2 branch is in early development, so I decided to add something from myself.

Description

I took care of the GUI implementation in the form of the rqt plugin. The reference point for me was the rpbi_controls_node.py file from main branch of ros_pybullet_interface repository.

• When the Start, Step, or Stop button is pressed, an attempt is made to connect to the corresponding service server. The GUI code using the tkinter library used the get_srv_handler() function from the custom_ros_tools package. I created an analogous function so as not to immediately rewrite the entire custom_ros_tools repository to ROS 2.
• Pressing the Send button does nothing. This is because the value of the robot_name parameter is used when handling the press event of this button. In ROS 2 the concept of parameters has been completely changed. There is no global parameter anymore. Each parameter is specific to a node. This issue requires careful consideration.

Screenshot

How to run

1. In the root of your workspace build ros_pybullet_rqt_plugin package and source setup file.

colcon build --packages-select ros_pybullet_rqt_plugin
. install/setup.bash

2. Refresh rqt cache memory to make the plugin visible (details can be found here)

rqt --force-discover

3. You can run the GUI in one of three ways:
   • Open rqt (use rqt command) and navigate to Plugins ➡️ Introspection ➡️ PyBullet Interface Controls
   • Start only this plugin using -s (standalone) flag

   rqt -s ros_pybullet_rqt_plugin
   

   • Open GUI as a ROS 2 node:

   ros2 run ros_pybullet_rqt_plugin ros_pybullet_rqt_plugin 
   

My setup

• Ubuntu 22.04
• ROS 2 Humble Hawksbill
• Python 3.10.6

Tools used in the development

• Qt 5 Designer - I used this tool to design the graphical interface of the plugin

How to test

You can test whether the status information is displayed correctly by publishing a message on the rpbi/status topic.

ros2 topic pub /rpbi/status -1 std_msgs/msg/Int64 "{data: 1}"

[cmower]

Thanks for the contribution @jkaniuka! I am a bit short on time, but will try to find some over the next few weeks to look into this PR.