I am using differential drive robot.

It has 2 servo motors to drive and encoder for odometry And also Lidar/laser sensor. I try to find out precision of navigation. Is there any information about accuracy of amcl or navigation ?

When i sent x=4.0 y=0.0 , my robot can not get exact position. it goes between 4.10-3.90 meters. I think Sensivity of navigation +-10 cm...

I echo /amclpose and also tf tfecho. They are not the same everytime. When actual position of robot is 4.10, tf tfecho shows me x=3.87. Which one is dependable ? Amclpose, tf tfecho /map /baselink or something else?

2) What is the reason of low accuracy. Amcl or navigation ? ( which params most effective in accuracy ? )

3) I want to reduce the weight of the odom and increase the weight of the laser in amcl calculation. Which params should be changed? second question , to improve localization and navigation...