The purpose of this project is create a package that calculates the kinematics of a holonomic robot. Also, using a PID controller the robot performs a eight shaped trajectory. Then CyberLab Rosbot XL, a real hardware holonomic or omni-directional robot is used. The primary objective is to program the Rosbot XL to navigate through the CyberLab maze successfully. To achieve this, waypoints to guide the robot towards the goal position were provided. Additionally, control algorithms (PID) were tuned to facilitate fast and precise movements, enabling the robot to traverse each waypoint with optimal speed and accuracy.
Key Topics Learnt
Kinematics.
PID.
Method
First a distance controller for the Rosbot XL was developed, enabling it to move forward and stop precisely at a desired distance. This involves overcoming the challenge of the robot's inertia, which can cause it to overshoot even when instructed to slow down. Then a PID controller for the Rosbot XL to accurately turn and face each waypoint was created. Finally, integrating previous functionalities into one program with two states: turning and moving forward the robot solved the maze. The turning state uses the PID controller for quick orientation towards the next waypoint, while the moving forward state allows maximum speed with necessary course corrections to maintain alignment.
Omnidirectional wheeled mobile robots typically employ either omniwheels or mecanum wheels, which are typical wheels augmented with rollers on their outer circumference. These rollers spin freely and they allow sideways sliding while the wheel drives forward or backward without slip in that direction. Unlike the front wheels in a car, those wheels are not steered, only driven forward or backward.
Results
The robot will follow a pattern of turning and moving forward, stopping at the last waypoint, to efficiently navigate a maze with speed and precision, the waypoints were collected from the real maze and the gains of the PID controller adjusted to not overshoot the desired positions. Finally, the robot was tested in the maze.
Maze test.