robot_localization incorrect map->utm transform

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Hello ,

I have some questions regarding robot_localization package using real map from Google or OSM.

Settings:

I have inputs from GPS sensor only - as a start for testing - generating 3 messages from it:

a- gpx/fix message (using lattitude , longitude from GPS)

b- sensor/imu message ( only orientation extracted from GPS )

c- nav_msg/odometry message ( using vx,vy from GPS )

I understand that the robot localization will be very inaccurate. However at this stage I am interested in getting the proper robot_localization settings and able to link the real map from google to the ROS localization (map_frame) and see it on RVIZ (note: google map is used as static obstacle map and I may use it later for goal settings as well. Main purpose of google map is static obstacles)

The issues / questions are:

1- How to tell robot localization that the origin of the map is at specific UTM co-ordinates? .................................................................................................................................................

2- I assumed that it can be done using datum parameter at navsat transform node as follows:

<param name="wait_for_datum"       value="true"/>
<rosparam param="datum">[30.070131 , 31.020022, 0.0]</rosparam>

I also set the following parameters for debugging.

<param name="broadcast_utm_transform" value="true"/>
<param name="publish filtered GPS" value="true"/>

When i run robot localization , These lines - from navsat transform.cpp - are printed:

Transform world frame pose is: Origin: (0 0 0) Rotation (RPY): (0, -0, 0) World frame->utm transform is Origin: (-3215764.3632935076021 911887.59913052641787 0) Rotation (RPY): (0, 0, -1.7544863270000004007)

and These UTM coordinates are not close to the map origin UTM coordinates: (latitude,longitude) = 30.070131 , 31.020022 should result ->(easting ,northing , zone) = 309151.07 , 3328209.18 , 36R

Accordingly on RVIZ the robot is not on the proper place on the map. So What is the problem? ...................................................................................................................................................................

3- In the datum param. I set the yaw to be 0 as the map is not tilted and the upper border is toward the north. I have no idea about the robot starting position nor orientation. So I set this value with respect to the map not to the robot.

<rosparam param="datum">[30.070131 , 31.020022, 0.0]</rosparam>

As mentioned earlier, navsat transform.cpp - is printed:

World frame->utm transform is Origin: (-3215764.3632935076021 911887.59913052641787 0) Rotation (RPY): (0, 0, -1.7544863270000004007)

Where did -1.7544863270000004007 came from?

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Robot: Rbcar robot (at this stage it's irrelevant which robot is used)

ROS distro: Indigo in Ubuntu 14.04

Launch files: navsat_transform ekf_nodes move_base-map_server-rviz

map : yaml file

Frame tree: frames

rqt_graph_output: graph

Example bag file:

This bag file was recorded while moving around a building one turn until we reached same start point with only GPS sensor (without the robot itself). The bag file was recorded in the same configuration .

bag file

RVIZ screenshot before moving , RVIZ screenshot at the end