norlab_imu_tools

imu_attitude_to_tf node has to acknowledge Hector_slam: http://wiki.ros.org/hector_slam, BSD licence: // Copyright (c) 2012, Stefan Kohlbrecher, TU Darmstadt // All rights reserved.

Parameters of the imu (and gps) to tf tool

IMPORTANT Skidoo moved backwards, so the GPS heading correction acts backwards as well. If used for anything else, find and disable the 180 deg rotation in the code...!

<remap from="imu_topic" to="/mti/sensor/imu" />   # Raw imu input topic 
<remap from="gps_odom_topic" to="/odom_utm" />    # UTM GPS coordinates input topic
<param name="odom_frame" value="world" />         # Fixed odometry frame

# Base link frame == IMU frame, orientation specified by the imu_alignment_rpy rosparam.
<param name="base_frame" value="imu_link" />      

# If false, translation=0. If true, translation from GPS UTM, set to zero when launched
<param name="publish_gps_translation" value="False" /> 

# Correction of the drifting heading by the information from GPS. 
<param name="apply_gps_heading_correction" value="True" /> # Apply or not
<param name="gps_heading_correction_weight" value="0.1" /> # Filtering factor (1==full correction from GPS applied at each step. 0.1 recommended for smooth behavior)
<param name="gps_heading_min_dist" value="1.5" /> # How long a GPS path segment should be for computing its tangent

# Fixed rotation between the physical IMU and the base_link frame
# Note that we neglect centrifugal acceleration, in skidoo, translation between IMU and Base link == 0
<rosparam param="imu_alignment_rpy">[3.14159265359, 0.0, 3.14159265359]</rosparam>  <!--Pelicase box for skidoo, all angles in radians! -->

# Initial magnetic north correction angle. Note that this value is later precised by the GPS information
<param name="mag_north_correction_yaw" value="0.27331833" /> <!-- 15.66 deg == 15°40'  => 0.27331833               0.43534373-->

Interactive Static Transform tool

This tool helps finding a transformation between two TF frames by providing an RVIZ interactive marker. The usage is straightforward:

• Set your parent and child frame names in the launch file
• Run the lauch file and also open the RVIZ
• The initial transformation is identity, but you can modify it by displaying the interactive marker and moving it around
• The marker also offers a context menu, the only command which is there prints the current transform value in the form of the static_transform_publisher rosrun command