Can robot_localization package be used on a full NED system?

My understanding is that the robot_localization uses NEU (north east up) coordinate frame for everything. It specifically states that IMU should be set up in NEU coordinate system (here)[http://docs.ros.org/melodic/api/robot_localization/html/preparing_sensor_data.html?highlight=north#coordinate-frames-and-transforming-sensor-data].

I was wondering if my whole system (baselink + sensors) is set up so that they output in NED coordinate system, could I just use the robotlocalization package to output NED (north east down) odom frame?

My rationale here is that if everything is in the same right-handed coordinate frame does it matter how the frame itself is oriented.

Asked by rumman on 2019-06-20 13:25:16 UTC

Comments

Just an observation: I don't know about robot_localization, but please be aware that ROS uses a right handed coord system exclusively. Refer to REP 103.

Asked by gvdhoorn on 2019-06-20 14:06:16 UTC

Sorry that was a typo, I meant right-handed cood frame. Thanks for mentioning it

Asked by rumman on 2019-06-20 14:07:23 UTC

Answers

Actually, robot_localization expects all IMU data to be in the ENU format, as stated on this documentation page under the heading "Coordinate Frames and Transforming Sensor Data".

To answer your question: No, you could technically have every frame on your robot in NED orientation, but the orientation vector is not going to be reported in the same way as if your robot used the ENU convention.

Orientation, especially concerning IMUs, is something you can get wrong VERY easily. And it is a huge pain to sort out when it does go wrong. Trust me on that. So I highly recommend you stick to the ROS conventions as closely as possible. If your IMU reports orientation in the NED format, you will need to write a small rosnode to dynamically convert and republish the data in the ENU format. Plus, if something does happen and you need to ask the ROS community here for help, it will become much harder for people to help you if you are using a custom orientation system.

Asked by M@t on 2019-06-20 18:13:24 UTC