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Mavros local_position plugin

ROS / ros eco / packages / mavros

Topics

topic
pose publish position in enu coordinate system
pose_cov
velocity_local publish linear and angular velocity enu coordinate system angulate
velocity_body publish linera and angular velocity body coordinate system (angular velocity fill from other source TODO: check)
velocity_body_cov
accel only LOCAL_POSITION_NED_COV include acceleration data, publish in enu coordinate system
odom

mavlink site definition

The filtered local position (e.g. fused computer vision and accelerometers). Coordinate frame is right-handed, Z-axis down (aeronautical frame, NED / north-east-down convention)

todo: check ardupilot message sources

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# LOCAL_POSITION_NED
ros2 service call /mavros/set_message_interval mavros_msgs/srv/MessageInterval "{\"message_id\": 32, \"message_rate\": 2 }"

# LOCAL_POSITION_NED_COV
ros2 service call /mavros/set_message_interval mavros_msgs/srv/MessageInterval "{\"message_id\": 65, \"message_rate\": 2 }"
mavlink mavros topic(message)
LOCAL_POSITION_NED (32) odom
LOCAL_POSITION_NED (32) pose
LOCAL_POSITION_NED (32) velocity_local
LOCAL_POSITION_NED (32) velocity_body
LOCAL_POSITION_NED_COV (64) odom
LOCAL_POSITION_NED_COV (64) pose_cov
LOCAL_POSITION_NED_COV (64) velocity_body_cov
LOCAL_POSITION_NED_COV (64) accel

if we register to both message the odom message data publish from LOCAL_POSITION_NED_COV the tf if enable publish from LOCAL_POSITION_NED data

!!! LOCAL_POSITION_NED_COV include acceleration data

Parameters

Name Desc default
frame_id map
tf.send false
tf.frame_id map
tf_child_frame_id control to odom message chile_frame_id base_link

The odometry carries both pose and velocity

Frames

  • header.frame_id: The reference frame for pose (commonly odom or map)

  • child_frame_id: The moving frame being described (commonly base_link or base_footprint)

  • Pose: expressed in the header.frame_id (usually odom frame).

  • Velocity : expressed in the child_frame_id (usually base_link). - twist.twist.linear.x → forward speed along the robot’s x-axis - twist.twist.linear.y → sideways (lateral) speed along the robot’s y-axis - twist.twist.linear.z → vertical speed (up/down) - twist.twist.angular → angular velocity around each axis, also in the child frame
nav_msgs/Odometry
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std_msgs/Header header
string child_frame_id
geometry_msgs/PoseWithCovariance pose
geometry_msgs/TwistWithCovariance twist

Mavros methods

Method Description / usage
ftf::transform_frame_baselink_enu
ftf::transform_frame_enu_baselink