Function Reference: @lti/lft

Function File: sys = lft (sys1, sys2)

Function File: sys = lft (sys1, sys2, nu, ny)

Linear fractional tranformation, also known as Redheffer star product.

Inputs

sys1: Upper LTI model.
sys2: Lower LTI model.
nu: The last nu inputs of sys1 are connected with the first nu outputs of sys2. If not specified, min (m1, p2) is taken.
ny: The last ny outputs of sys1 are connected with the first ny inputs of sys2. If not specified, min (p1, m2) is taken.

Outputs

sys: Resulting LTI model.

Block Diagram

      .............sys..............
      :         +--------+         :
w1 ------------>|       |------------> z1
      :         | sys1  |        :
      : u +---->|       |-----+ y :
      :   |    +--------+     |  :          Lower LFT
      :   |                   |  :
      :   |    +--------+     |  :          lft (sys1, sys2)
      :   +-----| sys2  |<----+   :
      :         +--------+         :
      :............................:

      .............sys..............
      :         +--------+         :
      : u +---->| sys1  |-----+ y :
      :   |    +--------+     |  :          Upper LFT
      :   |                   |  :
      :   |    +--------+     |  :          lft (sys1, sys2)
      :   +-----|       |<----+   :
      :         | sys2  |        :
z2 <------------|       |<------------ w2
      :         +--------+         :
      :............................:

      .............sys..............
      :         +--------+         :
w1 ------------>|       |------------> z1
      :         | sys1  |        :
      : u +---->|       |-----+ y :
      :   |    +--------+     |  :
      :   |                   |  :          lft (sys1, sys2, nu, ny)
      :   |    +--------+     |  :
      :   +-----|       |<----+   :
      :         | sys2  |        :
z2 <------------|       |<------------ w2
      :         +--------+         :
      :............................:

Package: control

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