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RMP220 feedback data for odometry - turn in place

Posted: Fri Oct 04, 2013 10:46 am
by ChrisC
We would like to make the RMP unit turn in place, which we did by setting the velocity to 0 m/s and the yaw rate to the desired rad/s. However, we were unable find a useful feedback information from the UDFB to tell us how much we have turned. The other option was to make a table to map the wheel position to degrees turned; however, we would like to avoid making this table and for dynamic turns as well.

Re: RMP220 feedback data for odometry - turn in place

Posted: Mon Oct 07, 2013 2:16 pm
by phussey
Unfortunately there is no differential velocity integrator in the feedback data in the current release. There is plenty of literature that derives dead reckoning from individual wheel velocities which are available. But in order to get reasonable results one would need to run the calculations real-time at a reasonably high sample rate. It will be available for all platforms, in the upcoming release to support the balancing system.

One issue to keep in mind is that in curvilinear motion there is error introduced due to tire dynamics and slip which requires corrections for the physical configuration of the machine and environmental factors. The value that will be provided by the interface will only be integrated differential velocity without corrections.