Odometry in the base_link frame

[precyon]

A question and not an issue.

I use the /zed/odom message from the ZED Mini as one of the odometry inputs for a mobile robot. When using this odometry input for sensor fusion or SLAM etc, I need an estimate of the base_link->odom transform. Clearly this is not as simple as transforming /zed/odom by the zed_center -> base_link transform. Because the /zed/odom does not publish twist, I do the following and it seems to work okay,

1. Compute velocity of the ZED from successive /zed/odom messages
2. Compute the speed of the robot center from ZED's speed using the static transform zed_center -> base_link
3. Integrate this speed to build my own estimate of the odometry of the robot center
4. Use this odometry for all the fusion etc

So my questions,

1. Is that how I should be doing this?
2. Does the ZED SDK maintain a speed estimate internally that can be published as twist in /zed/odom?

I use the ZED Mini on Ubuntu 16.04, ROS Kinetic and latest commit of this wrapper 8443d26

[Myzhar]

Hi @pvishal-carnd,
you are doing it right. The current stable version in the master branch requires exactly the process you described.

We are working on enhancements of the odom and pose messages and starting from the next v2.8 of the ZED SDK you will find the base_link as root of the ZED TF tree and odom and pose messages will be referred to the base_link frame.
Moreover the odometry will be integrated with the twist components and relative covariance.

Stay tuned

[precyon]

Thanks @Myzhar for that sneak peek in to the SDK v2.8! I'll wait.