pid

Constructs a continuous-time PID controller transfer function.

Syntax

C = pid(Kp')

C = pid(Kp, Ki')

C = pid(Kp, Ki, Kd')

C = pid(Kp, Ki, Kd, Tf')

Inputs

Kp
The proportional control gain constant (default: 1).
Ki
The integral control gain constant (default: 0).
Kd
The derivative control gain constant (default: 0).
Tf
The first order filter time constant (default: 0).

Output

C
Continuous-time PID controller transfer function.

Examples

C = pid(3,5,7)
Transfer function for input 1, output 1
 
          7 s^2 + 3 s + 5
          ---------------
                 s

Comments

The output transfer function is C(s) = Kp + (Ki/s) + (Kd s)/(Tf s + 1). The derivative term is a high pass filter, where Tf is related to the cutoff frequency.