ResponseExpression

Assume that you are designing a PID controller and the physical limit of the system impose a constraint on the gain:(1)

$$k_p^2+k_d^2\text{ + }{k}_i^2\le \text{ 1}$$

Here is a code snippet that shows how this is done with ResponseExpression:

>>> # Define Dvs
>>> kp = Dv(b = 0.5, blimit = [0,1])
>>> ki = Dv(b = 0.5, blimit = [0,1])
>>> kd = Dv(b = 0.5, blimit = [0,1])
>>>
>>> # Define the function expression
>>> sum_square = "k1**2 + k2**2 + k3**2" 
>>>
>>> # Define the ResponseExpression
>>> response    = ResponseExpression (
      label     = "Sum of square", 
      function  = sum_square, 
      symbols   = ["k1", "k2", "k3"],
      variables = [kp, ki, kd],
    )