Autonomous Drive Files

This folder contains the necessary files for the autonomous drive system of a 4-wheeled Rover

Folder Structure

├── Localization

└── Navigation Stack

Launchfiles and other params

to launch the stack run

roslaunch navstack_pub navigation_main.launch

launchfile params

Contents

• Global Parameters
• Stage Simulator
• Navigation Parameters
• Map Server
• AMCL
• Static Transforms
• Robot Pose EKF
• RTAB-Map
• Point Cloud to LaserScan Conversion
• Manual Pose Publisher
• RViz Visualisation

---

Global Parameters

• use_sim_time: Defines whether the ROS nodes should use simulated time. It’s currently set to false (real-time). This can be set to true when running the Stage simulation.

 <!-- ########## Global Parameters ########## -->
  <!-- <param name="/use_sim_time" value="true"/> -->
  <param name="/use_sim_time" value="false"/>

Stage Simulator

• stage_ros: Launches the Stage ROS simulator with a specified world file, iroc_arena.world. It publishes scan data remapped to the scan topic.

<!-- ########## Stage Simulator ########## -->
 <node pkg="stage_ros" type="stageros" name="stageros" args="$(find navstack_pub)/stage/iroc_arena.world">
<remap from="base_scan" to="scan"/>
</node> 

Navigation Parameters

• move_base: Core node for autonomous navigation, which integrates:
  • costmap_common_params.yaml: Configures global and local costmaps.
  • local_costmap_params.yaml and global_costmap_params.yaml: Parameters for local and global costmaps, respectively.
  • TEB Local Planner: Configured for car-like or differential drive by loading parameters from teb_local_planner_params.yaml (for car-like) or teb_local_planner_diff_drive.yaml (for differential drive).
  • Planner and Controller Settings: Defines frequency and patience of the planner and controller, as well as settings for clearing rotations which are disabled for a car-like robot.

<!-- Navigation Parameters -->
<node pkg="move_base" type="move_base" respawn="false" name="move_base" output="screen">
    <rosparam file="$(find navstack_pub)/param/costmap_common_params.yaml" command="load" ns="global_costmap" />
    <rosparam file="$(find navstack_pub)/param/costmap_common_params.yaml" command="load" ns="local_costmap" />
    <rosparam file="$(find navstack_pub)/param/local_costmap_params.yaml" command="load" ns="load"/>
    <rosparam file="$(find navstack_pub)/param/global_costmap_params.yaml" command="load" ns="load"/>
    <!-- <rosparam file="$(find navstack_pub)/param/teb_local_planner_params.yaml" command="load"/>  for a carlike system -->
    <rosparam file="$(find navstack_pub)/param/teb_local_planner_diff_drive.yaml" command="load"/> <!-- for a diff drive system -->
    <param name="base_global_planner" value="global_planner/GlobalPlanner" />
    <param name="planner_frequency" value="1.0" />
    <param name="planner_patience" value="5.0" />
    <param name="base_local_planner" value="teb_local_planner/TebLocalPlannerROS" />
    <param name="controller_frequency" value="5.0" />
    <param name="controller_patience" value="15.0" />
    <param name="clearing_rotation_allowed" value="false" /> <!-- Our carlike robot is not able to rotate in place -->
</node>

Map Server

• map_server: Loads the static map (iroc_arena.yaml) and publishes it to provide the robot’s environment.

<!-- ########## Map ########## -->
<!-- <arg name="map_file" default="$(find navstack_pub)/maps/final_map.yaml"/>
<node pkg="map_server" name="map_server" type="map_server" args="$(arg map_file)" >
<param name="frame_id" value="map"/>
</node> -->
<node name="map_server" pkg="map_server" type="map_server" args="$(find navstack_pub)/maps/iroc_arena.yaml" output="screen">
<param name="frame_id" value="map"/>
</node>

AMCL

• amcl: Adaptive Monte Carlo Localization node for localizing the robot within the static map. Loads parameters from amcl_params.yaml and sets initial positions (x, y, and orientation) for the robot.

<!-- ########## AMCL ########## -->
<node pkg="amcl" type="amcl" name="amcl" output="screen">
<rosparam file="$(find navstack_pub)/param/amcl_params.yaml" command="load" />
<param name="initial_pose_x" value="0.7"/> <!-- 0.5 -->
<param name="initial_pose_y" value="2.5"/> <!-- 2.5 -->
<param name="initial_pose_a" value="0"/>
</node>

Static Transforms

• tf2_ros: Static transformations to handle coordinate frames, e.g., base_footprint to base_link. Additional transformations can link sensor frames to the robot base.

<!-- ########## Static Transforms ########## -->
<!-- <node pkg="tf2_ros" type="static_transform_publisher" name="base_footprint_to_base_link" args="0 0 0.4 0 0 0  base_footprint base_link 10" /> -->
<!-- <node pkg="tf2_ros" type="static_transform_publisher" name="imu_broadcaster" args="0.2 -0.1 0.24 0 0 -1.5708 base_link zed2_imu_link 30" /> -->
<!-- <node pkg="tf2_ros" type="static_transform_publisher" name="map_to_base_footprint" args="0 0 0 0 0 0 map base_footprint 30" /> -->

Robot Pose EKF

• robot_pose_ekf: Combines data from multiple sensors, such as the IMU and odometry, to estimate the robot’s position more accurately.
  • output_frame: Defines the output frame (odom) for the combined position estimate.
  • base_footprint_frame: Frame of the robot’s base (base_link).
  • Sensor Configurations: IMU, odometry, and VO (Visual Odometry) inputs are enabled for enhanced accuracy, while GPS is disabled.

<!-- ########## Robot Pose EKF ########## -->
  <remap from="imu_data" to="/zed2i/zed_node/imu/data" />
  <remap from="odom" to="/zed2i/zed_node/odom" />
  <node pkg="robot_pose_ekf" type="robot_pose_ekf" name="robot_pose_ekf">
      <param name="output_frame" value="odom"/>
      <param name="base_footprint_frame" value="base_link"/>
      <param name="freq" value="30"/>
      <param name="sensor_timeout" value="3.0"/>
      <param name="odom_used" value="true"/>
      <param name="imu_used" value="true"/>
      <param name="vo_used" value="true"/>
      <param name="gps_used" value="false"/>
      <param name="debug" value="true"/>
      <param name="self_diagnose" value="true"/>
</node>

RTAB-Map

• rtabmap_odom: Optional RTAB-Map node for stereo odometry using ZED2 images, which remaps ZED2 stereo image and camera info topics for visual odometry.

<!-- ########## RtabMap ########## -->
 <node pkg="rtabmap_odom" type="stereo_odometry" name="rtabmap_stereo_odometry" output="screen">
    <remap from="/left/image_rect" to="/zed2i/zed_node/left/image_rect_color"/>
    <remap from="/right/image_rect" to="/zed2i/zed_node/right/image_rect_color"/>
    <remap from="/left/camera_info" to="/zed2i/zed_node/left/camera_info"/>
    <remap from="/right/camera_info" to="/zed2i/zed_node/right/camera_info"/>
    <param name="approx_sync" value="true"/>
    <param name="approx_sync_max_interval" value="0.017"/>
</node> 

Point Cloud to LaserScan Conversion

• pointcloud_to_laserscan: Converts ZED2 point cloud data to LaserScan format for use in 2D navigation. Launches a sample from the depthimage_to_laserscan package for this conversion.

  <!-- ########## Convert ZED2 Point CLoud / Depth Image to LaserScan ########## -->
  <!-- <include file="$(find depthimage_to_laserscan)/launch/launchfile_sample.launch"/> -->
  <include file="$(find navstack_pub)/launch/pointcloud_to_laserscan.launch"/>

Manual Pose Publisher

• localization_data_pub: Publishes robot’s pose manually by interacting with RViz, aiding manual localization setup if required.

  <!-- ########## Publishing Pose to Localize Manually ########## -->
  <node pkg="localization_data_pub" type="rviz_click_to_2d" name="rviz_click_to_2d"></node>

RViz Visualisation

• rviz: Launches RViz with a predefined configuration file, rviz_navigation.rviz, to visualize the robot’s environment, map, and navigation status.

<!-- ########## Rviz Visualisation ########## -->
<node name="rviz" pkg="rviz" type="rviz" args="-d $(find navstack_pub)/rviz/rviz_navigation.rviz"/>

---

Misc

├──Stage ROS

├──Mapserver

└──Rviz configs