Pure Pursuit

To run this project, you need to complete the localization and record the waypoints.
Here are two corresponding projects: ROS_NDT_Localizer for the localization and ROS_Waypoints_Processor for waypoints recording & loading :)

Environment

• Ubuntu 18.04
• ROS Melodic

Data

• Waypoints record file (.txt format)
• RosBag for offline testing

IO

• input
  /waypoints (nav_msgs::Path)
  /odom (nav_msgs::Odometry)

• output
  /cmd_acker (ackermann_msgs::AckermannDriveStamped)
  /cmd_vel (geometry_msgs::Twist)
  /lookahead (visualization_msgs::Marker)

How to use

• Move the project into the ROS workspace (e.g. ~/ros_ws/src/)

• Build the project in the ROS workspace

  cd ros_ws/
  catkin_make

• Setup the configuration in pure_pursuit_node.launch

  <arg name="wheel_base" default="1.0" doc="wheelbase"/>
    <arg name="lookahead_distance" default="4.0" doc="lookahead distance"/>
    <arg name="w_max" default="1.0" doc="max rotational velocity"/>
    <arg name="position_tolerance" default="0.1" doc="position tolerance"/>
    <arg name="delta_vel" default="100.0" doc="steering angle velocity"/>
    <arg name="acc" default="100.0" doc="acceleration"/>
    <arg name="jerk" default="100.0" doc="jerk"/>
    <arg name="delta_max" default="1.57" doc="steering angle limit"/>
    <arg name="map_frame_id" default="map" doc="map frame id"/>
    <arg name="robot_frame_id" default="base_link" doc="robot frame id"/>
    <arg name="lookahead_frame_id" default="lookahead" doc="lookahead frame id"/>
    <arg name="acker_frame_id" default="rear_axle_midpoint" doc="ackermann frame id"/>

• Complete the localization and the waypoints loading steps, e.g. ROS_NDT_Localizer & ROS_Waypoints_Processor.

• Run the Pure-Pursuit

  • Source the setup.bash

    cd ros_ws
    source devel/setup.bash

  • Launch the Pure-Pursuit node

    roslaunch pure_pursuit pure_pursuit_node.launch

• Play the rosbag for offline testing

  rosbag play offline_testing.bag

• Subscribe the ackermann messages from the topic /cmd_acker.

  <!--  Demo  -->
  ---
  header: 
    seq: 224
    stamp: 
      secs: 1649337997
      nsecs:  48033928
    frame_id: ''
  drive: 
    steering_angle: 0.270921677351
    steering_angle_velocity: 100.0
    speed: 0.10000000149
    acceleration: 100.0
    jerk: 100.0
  ---

Acknowledgment

Part of the code refers to the open-sourced project Autoware

Related projects in pure ROS (Melodic)

• ROS_NDT_Mapping
• ROS_NDT_Localizer
• ROS_Waypoints_Processor
• ROS_Object_Cluster