Hi @ShaiMahfud ,
You are right with your observation that the simulation robot properties does not exactly match with the real robot properties.
But this was done for a reason. The simulation does not have to be a 100% replica of the real robot. What does this mean? Simulation as such is only ~70% of the real robot conditions. But with this additional difference, we are enabling our students to adapt their program to suit different environments. So you as a student, should write robust and reliable programs that can adapt to these conditions. It will take a bit more time and add more lines to your code for sure, no arguments against that, but when you are programming robots, it is necessary that your code is versatile and flexible.
The only change between the simulation and the real robot is that the laser scanner is inverted by 180 degrees. So just adapt your program to this configuration and your program should be working well on both simulation and real environments.
This way you will learn that programs must not be hard coded and must be made as intelligent as possible so as to suit robotics applications!
I am sure you will find this additional exercise worthwhile in your ROS learning journey!
Regards,
Girish