Dose the Kd of the PID divide by dt or not?

Hi, I read some examples ,there are two types of kd :divide by dt and not.

I see they both have a certain time interval(sample time),but if the kd term should be divided by dt ,and the sample time I define is so small maybe 1ms, would the result become so big if the error-last_error is 1 or larger than 1, the result can be exceed over 1000?

check out PID at wikipedia - all the sums are there

I was taught when I did control theory that a Kd of about 0.7 is the best compromise between fast response and overshoot. It’s a good place to start



Kd is a constant that you have to discover. The best value will depend on dt, which should also be a constant for the best performance of the PID algorithm.

It doesn't usually matter whether the dt is treated separately, or is included in the Kd value.