Control algorithm for mobile robots platoon
Just imagine the future highway where each car joins a tight "platoon" of automated vehicles that follow each other closely and synchronize speeds via radar and radio communication. When a vehicle reaches its desired exit, it exits the platoon and the special lane, and the human driver takes over once again. Or similar scenario with a number of trucks each exactly following one after another where the first-leader truck is controlled by human and other following trucks just precisely follow the leader truck.
Here we show results of our experiments done on real mobile robots: small robot soccer robots and Pioneer 3AT mobile robot. First robot contains the trajectory tracking controller to precisely follow reference trajectory while other robots try to exactly follow the path done by the first robot and of course they keep the necessary safety distance between one another. Each robot can only measure the distance and the angle of the robot in front. So second robot will measure relative position data position data (in its local coordinate system) and then estimates the trajectory the first robot before him have traveled. Similarly is for the third robot which follows the second one in the platoon and so on. The control strategy only uses relative measured information and no other communication between robots is available. The positions of the following robots are obtained by odometry information only (integration of robots velocities over time). In the following a few experimental results are shown.
Simulated results of 2 and 3 mobile robots
Real experiments results of 2 and 3 mobile robots
Real experiments results 2 robots: robot soccer robot (leader) and Pioneer 3AT robot (follower)
Here the follower robot - Pioneer 3AT mobile robot (bigger one) must follow the
traveled path of the
head robot - robot soccer robot (smaller one). The follower measures the
distance and relative orientation
of the head robot using laser range scanner. The follower robot recognizes the leading robot by recognition
algorithm which identifies the leading robot from a laser range scan. Experiment details are seen on the following picture.
Results of the experiment: robots trajectory and distance between the robots.
Movie: RobotPlatoon