The nonlinear simulation results closely match the linear responses obtained in MATLAB.
Constraints on PID Gains
It is often useful to constrain the range of tuned parameters to weed out undesirable
solutions. For example, you may require that the proportional and derivative gains of the
PID controller be nonnegative. To do this, access the tuned block parameterization.
C = getBlockParam(ST0,'PID Controller')
C =
Parametric continuous-time PID controller "PID_Controller" with formula:
1 s
Kp + Ki --- + Kd --------
s Tf*s+1
and tunable parameters Kp, Ki, Kd, Tf.
Type "pid(C)" to see the current value and "get(C)" to see all properties.
Tune Control Systems in Simulink