Open Qsyn is a modern open source toolbox for QFT control synthesis.

Quantitative Feedback Theory (QFT) is a frequency domain robust control design technique, introduced by Isaac Horowitz.

This toolbox is the successor of the original Qsyn toolbox, developed in the 90s. It provides a modern and completely free open source toolbox to aid QFT control synthesis. The development is supported by the author of the original Qsyn toolbox, Prof. Per-Olof Gutman, and all reused code is done under his premission.

Typical QFT design is doen according to the following steps:

  1. Modeling of the uncertain plants
  2. Computating templates -- the set of all plant responses over the Nichols chart at specified frequencies
  3. Compute bounds over the Nichols chart that give constraint to the loop shaping of the open-loop \(L(s) = P(s) K(s)\)
  4. Design a feedback compensator \(K(s)\) which satisfy the bounds
  5. Design a pre-filter to shape the reference such that closed-loop sepcifications are satisfied