Hello,
I have been looking around and saw that PID control is the most popular one used to control line follower bots. Can anyone suggest even more advanced methods for controlling such bots with increased precision??
With something as simple as a line follower, a PID controller is already quite high tech. Most people get away with a lot less than that. I don't know of anything better. You might look for research papers and the like for something, but PID is about the most advanced mainstream control topology that is applicable here.
PID does need to be properly tuned to function well. This means that all of the coefficients must be set to their optimum values. This can be a bit of an art, and it takes a lot of time and trial and error. There are auto-tuners, but they work by repeated trials as well.