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Seeking guidance on rtk gps topic names, message types

asked 2015-11-10 00:11:01 -0500

PaulBouchier gravatar image

updated 2015-11-10 03:26:48 -0500

I will shortly release a new package that supports the swiftnav piksi rtk-gps module ( http://www.swiftnav.com/piksi.html ) and would like to get the message types and topic names correct. rtk-gps enables 2cm accuracy in ideal conditions, and it provides the rover position relative to a base station, which may or may not be at a surveyed location.

The driver currently publishes: 1. the gps data (3m accuracy) in message type sensor_msgs::NavSatFix on topic gps/fix 2. the rtk fix (2cm accuracy best case) in message type nav_msgs::Odometry on topic gps/rtkfix. 3. the gps time in message type sensor_msgs::TimeReference on gps/time

My question is, is this correct?

It could also publish velocity based on the rtk fix, if you think that would be useful and can suggest a message type/topic name

Since it is a gps sensor, I imagine it will frequently be a data source for robot_pose_ekf (which subscribes to nav_msgs::Odometry on topic /vo) or for robot_localization (which subscribes to message nav_msgs::Odometry on topic /odometry/gps).

Can the experts out there please guide me as to message types and topic names. I know topic names are less critical because they can be remapped, but it would be nice to make them maximally compatible.

Thanks

Paul

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Would this be something to involve the ppl over at ros-sig-drivers in?

gvdhoorn gravatar imagegvdhoorn ( 2015-11-10 02:10:57 -0500 )edit

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answered 2015-11-10 11:21:45 -0500

Tom Moore gravatar image

For robot_localization, as long as the odometry message conforms to ROS standards, then it should work fine.

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Thanks Tom. I believe it will work fine - the question is really if there are any maturing thoughts on topic names. If not, I'll run with what I've got.

PaulBouchier gravatar imagePaulBouchier ( 2015-11-10 23:39:07 -0500 )edit

Ah, I see, sorry. For r_l, there are no fixed topic names for inputs. You specify the inputs in the config file (and not with remapping). Apologies if I'm missing your point.

Tom Moore gravatar imageTom Moore ( 2015-11-11 06:48:22 -0500 )edit

@PaulBouchier @TomMoore. Quick question: Am I correct in assuming the rtk-fixed GPS messages go as nav_msgs/odometry into a robot_localization_node after passing through a navsat_transform_node? Thanks!

Venkat Ganesh gravatar imageVenkat Ganesh ( 2016-05-24 07:47:28 -0500 )edit

That is correct, yes. Feed the output of navsat_transform_node back into the ekf_localization_node.

Tom Moore gravatar imageTom Moore ( 2016-05-30 05:08:33 -0500 )edit

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Asked: 2015-11-10 00:11:01 -0500

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Last updated: Nov 10 '15