Turtlebot Wall Following Controller with PID Control

The given code is a Python script that implements a wall following controller for a Turtlebot. The controller uses a PID controller to maintain a certain distance from the right wall and avoid obstacles in the front. \n\nHere is a breakdown of the code:\n\n1. The script starts by importing the necessary libraries and packages, including rospy for ROS functionality and the required message types.\n\n2. The script defines global variables and parameters, such as the scan angles and ranges, PID parameters, and desired distance from the wall.\n\n3. The callback function is defined to receive laser scan data and store it in the 'x' variable. It also calculates the minimum distances from the left and right walls and the front wall.\n\n4. The main 'tmnt_controller' function is defined. It initializes the PID parameters and sets up the rospy node, publisher, and subscriber.\n\n5. Inside the main loop, the distance error is calculated as the difference between the desired distance from the wall and the actual distance from the right wall.\n\n6. The PD controller calculates the control output based on the distance error and the previous errors. The output is clipped to a certain range.\n\n7. The linear and angular velocities are calculated based on the distance error and the front wall distance. They are clipped to certain ranges.\n\n8. The current distance from the right wall and the front wall is printed for debugging purposes.\n\n9. The control velocities are published using the 'cmd_vel' topic.\n\n10. The main loop continues until the program is interrupted.\n\n11. Finally, the Turtlebot is stopped by publishing a zero velocity command.\n\nOverall, the script implements a wall following behavior using a PID controller to maintain a certain distance from the right wall and avoid obstacles in the front. The controller continuously adjusts the linear and angular velocities based on the distance error and the front wall distance.