control.ispassive

control.ispassive(sys, ofp_index=0, ifp_index=0)[source]

Indicate if a linear time invariant (LTI) system is passive.

Checks if system is passive with the given output feedback (OFP) and input feedforward (IFP) passivity indices.

Parameters
sysLTI

System to be checked.

ofp_indexfloat

Output feedback passivity index.

ifp_indexfloat

Input feedforward passivity index.

Returns
bool

The system is passive.

Notes

Querying if the system is passive in the sense of

V(x) >= 0 \land \dot{V}(x) <= y^T u

is equivalent to the default case of ofp_index = 0 and ifp_index = 0. Note that computing the ofp_index and ifp_index for a system, then using both values simultaneously as inputs to this function is not guaranteed to have an output of True (the system might not be passive with both indices at the same time).

For more details, see [1].

References

1

McCourt, Michael J., and Panos J. Antsaklis “Demonstrating passivity and dissipativity using computational methods.” Technical Report of the ISIS Group at the University of Notre Dame. ISIS-2013-008, Aug. 2013.