Python 3 for robotics simulation time and real world time mismatch

Course Support Python Basics For Robotics
#1
Hello I am currently on the unit 4 of the python 3 for robotics course. I find that there is a mismatch between the real world time and simulation run time. For example if I were to run robotcontrol.move_straight_time("forward", 0.3, 6) I would expect the robot to move forward for 6 seconds but it is not moving for 6 seconds it just moves for 1 or 2 seconds and stops. The code was working properly a week ago only now is it not working properly.
#2

One solution I found out was to change the rate variable in the class defenition found at

‘home/simulations/public_sim_ws/src/all/ros_basics_examples/python_course_class/robot_control_class.py’

there is a line :

i += 1 in the function move_straight_time

I changed it to

i += 0.1 just like in the function turn

which made the simulation time equal to the real world 6 seconds time.
If someone from robot ignite academy can see if this is the solution to the problem and modify the values in everybody class definition it would be great.

#3

Hi @pranav0506,

welcome to our community.

Thanks for pointing this out. We really updated the ros_basics_examples/python_course_class/robot_control_class.py on 2020-05-27, changing the rate from 1 to 10. This explains why the loop finishes faster now.

The ideal solution would be just to change the rate from 10 hz to 1 again.

I’ll talk to @albertoezquerro and we will wither update the rate back to 10 or update the notebook instructions.

Once again, thanks for point this out.
Cheers,