I'm trying to tune the ros navigation parameters so that my 2WD robot behaves as expected. For now, it will reach the goal most of the time, but its behavior is somehow erratic. it obviously needs tuning.

following the ROS Navigation Tuning Guide, when it comes to planning i read

The most important thing for both planners is that the acceleration limit parameters are set correctly for a given robot)

However, I struggle to understand how to measure this in practice. the article suggest to write a script and observe odom data. But i am confused. What kind of script? what method? This is maybe the closest answer i found.

Besides, a few weeks ago, even before implementing any kind of PID for motor control, I noticed that the robot would go much slower depending on the physical load it has to carry around.Without payload, the robot weights about 5Kg. And if i tried to make it carry a significant load (say +30Kg), the motors did not seem to like it (different noise) and I would say it then went at about half the max speed without any load (i did not measure anything except the additional mass).

How should I measure the acceleration limits (both x and theta) in practice ? Should I do it with/without payload?

Besides, I manually tuned the motor PID controller with the wheels not even touching ground. I have no idea if i should change my Kp/Ki/Kd parameters to carry load. I dont even know how i would make it and I am not even sure of the tuning I made then. Just used observation and common sense.