Overview

This repo contains 3 packages for duckiebot localization.

encoder_localization package utilizes wheel encoders to estimate current pose of the duckiebot. The initial pose is assumed to be (0.15,0) with rotation angle pi in the map frame. It subscribes to both wheel encoders' tick and publish the estimated transformation between baselink frame and map frame to topic encoder_localization_node/transform. A service called encoder_localization_node/frame_calibration is provided that uses the given transform to calibrate the estimated encoder frame transform. This service is called by the fused_localization_node.

at_localization package utilizes Apriltag to estimate current pose of the duckiebot. The position of the Apriltag is assumed to be at the origin of map frame. It subscribes to camera images and publish the estimated transformation between baselink frame and map frame to topic at_localization_node/transform.

fused_localization package provides a fused estimation of duckiebot pose. It subscribes to both encoder_localization and at_localization transformations mentioned above and publish the estimated transformation between baselink frame and map frame to topic fused_localization_node/transform. The first time the Apriltag becomes visible, it calls service encoder_localization_node/frame_calibration to calledcalibrate the encoder_baselink frame to match exactly the at_localization transformation. When Apriltag estimation is available, fused_localization completely relays on at_localization and projects at_localization results on the ground plane. When Apriltag is not visible, encoder estimation is used, starting from the last Apriltag pose received.

Usage

encoder_localization package

Edit default.sh inside launchers folder. Commented every lines start with dt-exec except

dt-exec roslaunch encoder_localization encoder_localization_node.launch veh:="$VEHICLE_NAME"

Then run command

dts devel build -H <duckiebot_name>.local -f

Replace <duckiebot_name> with your duckiebot name.

To run the image, use command

dts devel run -H <duckiebot_name>.local

To visualize frame transformations, run command in a new terminal

dts start_gui_tools <duckiebot_name>

Replace <duckiebot_name> with your duckiebot name.

Then run command rviz and select TF and image in the opening window.

at_localization package

Edit default.sh inside launchers folder. Commented every lines start with dt-exec except

dt-exec roslaunch at_localization at_localization_node.launch veh:="$VEHICLE_NAME"

Then run command

dts devel build -H <duckiebot_name>.local -f

Replace <duckiebot_name> with your duckiebot name.

To run the image, use command

dts devel run -H <duckiebot_name>.local

To visualize frame transformations, run command in a new terminal

dts start_gui_tools <duckiebot_name>

Replace <duckiebot_name> with your duckiebot name.

Then run command rviz and select TF and image in the opening window.

fused_localization package

Edit default.sh inside launchers folder. Commented every lines start with dt-exec except

dt-exec roslaunch fused_localization fused_localization_node.launch veh:="$VEHICLE_NAME"

Then run command

dts devel build -H <duckiebot_name>.local -f

Replace <duckiebot_name> with your duckiebot name.

To run the image, use command

dts devel run -H <duckiebot_name>.local

To visualize frame transformations, run command in a new terminal

dts start_gui_tools <duckiebot_name>

Replace <duckiebot_name> with your duckiebot name.

Then run command rviz and select TF and image in the opening window.