I am planning to use Pure Pursuit system. It requires odometry system. So is there an odometry system requiring no additional hardware like extra wheels. Or odometry is completely obsolete.
It’s possible to use odometry with just an inertial sensor (at least on tank drive). You can use the sensors built into the motors although they won’t be as accurate as tracking wheels.
Uh, odometry will never be obsolete until we get like a real Lidar sensor, even then it would still be useful. You can definitely calculate position off of your existing drivetrain motor encoders/wheels. People use separate tracking wheels due to the powered wheels high likelihood of slipping which will make the robot think I moved an amount when it didn’t. You really should use an inertial sensor. I would highly recommend an tracking wheel based odometry system if you want your pure pursuit system to perform the best. You also can’t detect horizontal drift without a tracking wheel, so at the very least use that plus an inertial. Good luck!