Broken Pid

[Barbyslayer]

I put a PID on a workshop jet but every time i turn it on it goes up forever. I have watched several tutorials but none of them show the 4th variable max value. everything is wired correctly, I've triple checked.

[Ra-Ra-Rasputin]

There's no 4th variable in a PID, but it sounds like you've not put your PID in correctly, as the integral is clearly too high and spooling out of control. Set Integral to 0 or to very low decimals (1:10000 or so)

[Barbyslayer]

1: the is a forth variable and 2: no matter what I do to the variables it just shoots up

[Ra-Ra-Rasputin]

PIDs have 3 variables:
Proportional
Integral
Derivative

That's also where the name comes from.
Zero out your Integral, then ensure that the data it receives is actually correct. You don't want to look at your speed readout when trying to make an altitude hold. It's an easy mistake to make.

[Barbyslayer]

I know that’s what everyone one is telling me is my game possessed or something?

[Alistair]

Are you sure you’re using a PID? What is the fourth values name?

[Barbyslayer]

The forth value is called Max Value. I have deleted and regrabed it from the inventory several times

[Alistair]

Is it definitely, definitely not an up/down counter? Please post a screenshot of all the values

[PenguinO]

The recently added option to PID brick not micro PID I think

[Ra-Ra-Rasputin]

Originally posted by PenguinO:

The recently added option to PID brick not micro PID I think

People use that thing? But it takes such gigantic space

[PenguinO]

Originally posted by Ra-Ra-Rasputin:

People use that thing? But it takes such gigantic space :lunar2019deadpanpig:

From what I heard, people were suffering integral limitless windup due to processing clock being as low as 60Hz.
And I believe the added limiter won't help much.

[Ra-Ra-Rasputin]

But the microprocessor logic works exactly as fast as the placeable chips do, they're tied to 62hz update rate too.
Why 62hz? Who knows.

[PenguinO]

Originally posted by Ra-Ra-Rasputin:

But the microprocessor logic works exactly as fast as the placeable chips do, they're tied to 62hz update rate too.
Why 62hz? Who knows.

Probably speed bonus when main process is with light load.
Logic clock rate is same as main fps (or very close).
Next moment, a new vehicle spawn, 62Hz may become 58Hz or less. :D

Instead of decreasing I value (which may be already as low as 0.00001), multiplying the process variable and setpoint up may help in certain cases.
This trades at least 1 tick lag for increased processing resolution.

[Ra-Ra-Rasputin]

A possibly major issue i've seen in a lot of cases is when people have functions inside the microcontroller for their pid. Since they cost ticks it'll nudge down the responsiveness of the PID significantly, which actually appears to be separate from how they act outside the microcontrollers. A string of 20 functions (just doing +1, then -1, repeat 5 times) seems to be as responsive as just 2 doing +1, then -1. But they're absolutely not if you have one microcontroller with 20 f(x) and one with 2 f(x).

I do wonder why there is a tick delay on operations, given that possibly massively complex LUA is ran every tick.

What i mean about the 62 hz thing is that it seems to be the cap... which makes little sense. It makes things like timers and such annoying to count for, when you have to specifically remember it's 62, not something sensible like 50 or even 60.