# Linear error of odometry

**URL:** <https://forum.ubiquityrobotics.com/t/linear-error-of-odometry/293>\
**Category:** General Questions\
**Created:** [April 15, 2019, 1:52pm UTC](https://forum.ubiquityrobotics.com/t/linear-error-of-odometry/293 "2019-04-15T13:52:58Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![COSTA](https://forum.ubiquityrobotics.com/letter_avatar_proxy/v4/letter/c/85f322/32.png) [@COSTA](https://forum.ubiquityrobotics.com/u/COSTA)\
**Post date:** [April 15, 2019, 1:52pm UTC](https://forum.ubiquityrobotics.com/t/linear-error-of-odometry/293/1 "2019-04-15T13:52:58Z")

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Hello,

I did a linear motion test with the robot at a distance of 5m. The robot travels the right distance but the odometry has presented a 20cm error.

Can I compensate for this odometry error without changing wheel movement control by code?

Thank you!

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**Author:** ![mjstn2011](https://forum.ubiquityrobotics.com/user_avatar/forum.ubiquityrobotics.com/mjstn2011/32/30_2.png) [@mjstn2011](https://forum.ubiquityrobotics.com/u/mjstn2011)\
**Post date:** [May 11, 2019, 8:04am UTC](https://forum.ubiquityrobotics.com/t/linear-error-of-odometry/293/2 "2019-05-11T08:04:48Z")

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That sounds like something is slipping on the floor perhaps? That is far more error than I could explain.

BUT if you really wish to compensate in a linear way you can play with the wheel radius we default to for our wheels. We have a .yaml file that holds this radius but keep in mind if you do an apt upgrade this file is overwritten so take a note of what you did.

Look at /opt/ros/kinetic/share/magni\_bringup/param/base.yaml and look for wheel\_radius.

Again keep in mind that ANY slip will throw off the best of odometry.