# How compute odometry ?

I'm quite new to Ros. I'm using Navigation packages with a rover for doing mapping and localization. I have four encoders that measure the linear velocity of each wheel and four encoders for measuring the angles. How can I compute the odometry using four velocities and four angles? Is there a package that do this ? Can you suggest me which equations use for compute base's velocity and derive the odometry ? Thank you in advance

This tutorial should be a good place to start.

Thank you for your replay. I saw this tutorial and I think that it is useful for compute the variation of robot position using base's velocity. But I would like to know how compute vx, vy and vtheta using the eight encoders . Do you have any suggestion about it?

You can try starting with this question #q271254