Is there a distinction between the D term and the derivative component of the PID controller?

Is there a distinction between the D term and the derivative component of the PID controller?

<simulink block> <PID block>

<result>

Let's configure the PID block by setting P = 0, I = 0, and D = 1. When we compare the outputs of the derivative blocks, we observe that they yield varying values. The input signal applied to the system is a sine wave with an amplitude of 1 and a frequency of 100 (rad/s).

Answer 1

[Paul]

If P = I = 0, and D = 1, we're left with:

PID(s) = N/(1 + N/s) = N*s/(s + N)

With the block parameter value of N = 100

PID(s) = 100*s/(s + 100)

With N ~= 0, the "derivative" term in the PID controller isn't really a pure derivative.

[yooung Soo]

Thank you so much for your accurate answer.