This automatic_parking package can be divied into two parts, pattern recognition and moving to goal. In pattern recogintion, this package depends on laser_line extraction package to turn laser point clouds into line segments. Then, this package will go through these line segments to find the designed pattern and broadcast a frame, dock frame. After the frame being populated, the robot will move to the dock and the strategy is shown as the gif below. The ROS version is Melodic.

• Laser Line Extraction

Creat a new work space

mkdir -p docking_ws/src
cd docking_ws/src

Clone the automatic parking package.

git clone https://github.com/CuteJui/automatic_parking.git

Clone the Laser Line Extraction package.

git clone https://github.com/kam3k/laser_line_extraction
cd ..

Build the package.

catkin_make

Launch the package.

roslaunch auto_dock auto_dock.launch

• /line_segments (laser_line_extraction/LineSegmentList)

• /cmd_vel (geometry_msgs/Twist)

• pattern_angle1 (default: 4.21)
  • Theta 1 as shown in pattern angle definition. Note that the unit is radian.
• pattern_angle2 (default: 1.57)
  • Theta 2 as shown in pattern angle definition. Note that the unit is radian.
• pattern_angle3 (default: 4.21)
  • Theta 3 as shown in pattern angle definition. Note that the unit is radian.
• detect_angle_tolerance (default: 0.1)
  • The maximum difference between detected angle and pattern angle(pattern_angle1, pattern_angle2, pattern_angle3)
• group_dist_tolerance (default: 0.1)
  • The maximum distance between two line to be recognize as a part of pattern. Such as the distance between the end point of detected vector b and the start point of detected vector a should smaller than group_dist_tolerance to be consider as a part of pattern.
• laser_frame_id (default: "laser_frame")
  • The laser frame of the robot.
• base_frame_id (default: "base_link")
  • The base frame of the robot.
• min_v (default: 0.1)
  • Minimum linear velocity of the robot.
• min_w (default: 0.1)
  • Minimum angular velocity of the robot.
• max_v (default: 0.3)
  • Maximum linear velocity of the robot.
• max_w (default: 0.3)
  • Maximum angular velocity of the robot.
• threshold_v (default: 0.3)
  • The threshold of changing between minimum and maximum linear velocity.
• threshold_w (default: 0.4)
  • The threshold of changing between minimum and maximum angular velocity.
• dist_to_dock (default: 0.2)
  • Distance to the dock frame.
• dist_to_center (default: 0.03)
  • Distance to the center.

There are models of dock for Gazebo simulation in "Model" file.

The size of dock 1 is shown as the picture below.

The size of dock 2 is shown as the picture below.