Doubt in HAL.py of follow line exercise

[evadrake89]

How shall we know that frequency of operation should be greater than a particular value, in this case 90?

[JitinSaxenaa]

Hi @evadrake89

That freq = 90.0 isn’t a strict requirement — it’s more of an empirical value to keep the control loop responsive.

Frequency.tick() just controls how often the loop runs, so lower values (like 30 Hz, which I used) still work, but the robot reacts more slowly and can be less stable.

So 90 Hz is just a safe value that gives smoother control, and you can tune it depending on your setup.

[evadrake89]

Hello @JitinSaxenaa ,

I mean from a control systems point of view, I understood that in 1 sec it has to iterate atleast 90 times in order to calculate things at the right time, but my question is, did we followed any theoretical approach to calculate this value or is this just a hit and trial thing? And also there might be a maximum value in this case depending upon the compute available .....

[evadrake89]

Also currently I am going through the codebase, would you like to share with me some of your insights regarding there code structure because you are studying things from a long time..... Also have you setup the development environment on your local machine?

Thanks

[javizqh]

That is an internal value for the Ros2 spin and does not matter for the user application