control.feedback

control.feedback(sys1, sys2=1, sign=-1)

Feedback interconnection between two I/O systems.

Parameters:
  • sys1 (scalar, StateSpace, TransferFunction, FRD) – The primary plant.
  • sys2 (scalar, StateSpace, TransferFunction, FRD) – The feedback plant (often a feedback controller).
  • sign (scalar) – The sign of feedback. sign = -1 indicates negative feedback, and sign = 1 indicates positive feedback. sign is an optional argument; it assumes a value of -1 if not specified.
Returns:

out

Return type:

StateSpace or TransferFunction

Raises:
  • ValueError – if sys1 does not have as many inputs as sys2 has outputs, or if sys2 does not have as many inputs as sys1 has outputs
  • NotImplementedError – if an attempt is made to perform a feedback on a MIMO TransferFunction object

See also

series(), parallel()

Notes

This function is a wrapper for the feedback function in the StateSpace and TransferFunction classes. It calls TransferFunction.feedback if sys1 is a TransferFunction object, and StateSpace.feedback if sys1 is a StateSpace object. If sys1 is a scalar, then it is converted to sys2’s type, and the corresponding feedback function is used. If sys1 and sys2 are both scalars, then TransferFunction.feedback is used.