Program to simulate autonomous path following robot using Coppelia Sim.
Part of a class project for Introduction to Autonomous Systems.
OBJECTIVE
To program the robot to detect and follow the provided track and complete a full lap even when encountering gaps. This requires writing a program that reads three vision sensors, and, depending on the state of the vision sensors, adjusts the motor velocities to either make the robot turn or align itself with the track.
Challenges
Because we are controlling a non-holonomic mobile robot, the left and right joints need to individually have their velocities set to 0 in order to brake. The order in which the wheel joint velocities are adjusted can affect the robot’s trajectory. Even though the instructions to stop both wheels occur one after the other, the small delay between the execution of the instructions can affect the robot’s trajectory. Similarly, the delay of function calls have a similar effect on the robot’s trajectory.
The starting position of the robot affected the sensors that would be detecting the track. At the beginning of the project, depending on the robot’s position and the speed in which it curved, the robot had the possibility of leaving the track or skipping part of it. Also, because the robot’s position was changed, the sensors obtaining any information about the track were also modified. The idea of moving its position was to analyze different situations that the robot may face in another moment, searching and storing the information given by the sensors, and how the robot interacted with the gaps.
RESULTS
We wrote a program that read three vision sensors, and, depending on the state of the vision sensors, adjusts the motor velocities to either make the robot turn or align itself with the track. As a result the robot was able to follow the path and turn around at the origin to follow the path in the opposite direction. Completion time was 1 min and 40 Seconds, 3 min was the maximum time so simulation was successful.