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How can I visualize magnetometer data in Rviz?

asked 2018-08-21 06:04:35 -0500

hbaqueiro gravatar image

Hi, I am using a magnetometer plugin ( from UUV Simulator in Gazebo and it delivers sensor_msgs/MagneticField messages. In order to see if it is working (well, I've already echoed the topic and it is indeed working), but I would like to have a way to visualize it in Rviz so that the data is easily understandable.

A general view of what I wanted to do is to provide a way for the robot to know the North direction and I am assuming using the magnetometer is the best way to do that. Opinions are welcome.

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answered 2018-08-21 09:11:25 -0500

The magnetic field information is fundamentally a 3D vector, with the direction and strength of the field. You could use an Arrow Marker message to represent this information. If you set the start of the arrow to your robot body and scale the length suitably so it's visible this should work.

Unless you're near the equator this vector will be pointing up or down a fair bit since the Earth's magnetic field isn't parallel to the surface of the earth. So if you're just interested in the direction of magnetic north you could zero out the z element of the magnetic field vector and normalize the length of the vector to 1.

You'd need to make a small node to subscribe to sensor_msgs/MagneticField messages and publish an equivalent visualization_msgs/Marker to do this.

Hope this helps.

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Asked: 2018-08-21 06:04:35 -0500

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Last updated: Aug 21 '18