Time to complete: 5 minutes
Using GPS navigation is as simple as specifying the GPS topic for displaying the robot's position, sending a waypoint to your robot, and watching it navigate to its destination.
To get started with GPS navigation, we'll walk through the following steps:
If you would like to enable low-latency control and video feeds, please enable WebRTC on your device. If you are doing passive monitoring and are not concerned about frame rate or command latencies, WebRTC is not required.
Navigate to SETTINGS → PILOT and select the ENVIRONMENT tab. In the GPS section, enter the name of the GPS topic used to specify the position of your robot. If you have a filtered version, you should use it.
GPS data should be formatted as the ROS type
sensor_msgs/NavSatFix. See here for more information.
You'll also need to specify a GPS waypoint topic. Freedom will publish a
sensor_msgs/NavSatFix message each time the operator clicks the waypoint button and drops a waypoint for the robot to travel to.
Now that everything is set up, click the PILOT tab. If you haven't yet selected the map view, click on the map in the top right corner of the screen. Press the map icon on the righthand side of your screen. You will now see a map with the GPS location of your robot.
You can now click TAKE OVER. You will see a button appear on the right side of the page that lets you drop a navigation waypoint. This will send in a waypoint on the GPS WAYPOINT TOPIC you specified.
Click on the icon and place a waypoint in a safe location where your you want your robot to drive to. When you click, you will see the message appear in your DATA STREAM if you are uploading that topic.
At some point, you need to cancel a navigation waypoint. When you are not actively driving the robot manually (e.g. because your robot is navigating autonomously to a waypoint), a red MANUAL CONTROL button will appear in the bottom right corner of the screen.
When your press the button, it will send in a zero-velocity
geometry_msgs/Twist command and also a custom "stop" message specified in the CONTROL tab of the SETTINGS → PILOT page. You can specify the topic, topic type, and message to send to notify the system that you are canceling navigation. The default behavior is sending an empty message to
Using the toolbar on the righthand side of the screen, you can switch between a satellite map and a simplified street map.
Updated over 1 year ago
With that set up, let's take a look at how you can control your robot with an external controller