Control the Jackal™ Motors Using a Keyboard

This page describes how to run a quick test, which verifies that the Jackal™ robot has been set up appropriately. It verifies that the ROS 2 middleware is working and that the onboard computer of the Jackal™ robot can communicate with the Motor Control Unit (MCU).

Make sure that you have set up your Jackal™ robot as described on the Install the Robotics AI Dev Kit on the Jackal™ Onboard Computer page.

To execute the following steps, you must be logged in as the administrator user.

Run the following command to test whether the Clearpath Robotics services are running on your robot:

ros2 topic info -v /cmd_vel

Since you will need the /cmd_vel topic for controlling the motors, the output of this command should indicate that the /cmd_vel topic is subscribed by the twist_mux node, as shown here:

Type: geometry_msgs/msg/Twist

Publisher count: 0

Subscription count: 1

Node name: twist_mux
Node namespace: /
Topic type: geometry_msgs/msg/Twist
Endpoint type: SUBSCRIPTION
GID: 01.0f.7f.01.8f.08.4b.ac.01.00.00.00.00.00.12.04.00.00.00.00.00.00.00.00
QoS profile:
  Reliability: BEST_EFFORT
  History (Depth): UNKNOWN
  Durability: VOLATILE
  Lifespan: Infinite
  Deadline: Infinite
  Liveliness: AUTOMATIC
  Liveliness lease duration: Infinite

If you don’t see this output, there might be an issue with your installation of the Clearpath Robotics services. See the Jackal™ Troubleshooting section for debugging hints.

Now you can install the ros-humble-teleop-twist-keyboard ROS 2 package:

sudo apt-get update
sudo apt-get install ros-humble-teleop-twist-keyboard

Start the teleop_twist_keyboard command-line tool by means of:

ros2 run teleop_twist_keyboard teleop_twist_keyboard

Then you can control the robot using these keys:

u	i	o
j	k	l
m	,	.

You can also manually publish to the /cmd_vel topic to let the robot move. For example, to trigger a movement to the x direction, you can run:

ros2 topic pub /cmd_vel geometry_msgs/msg/Twist \
"linear:
  x: 1.0
  y: 0.0
  z: 0.0
angular:
  x: 0.0
  y: 0.0
  z: 0.0"