Discrete large space structure control system design using positivity

Because of the cost and flexibility advantages offered by microprocessors, any control system to be considered for Large Space Structures (LSS) will likely be digital. This short paper proposes a combined positivity and W-plane, frequency domain design procedure for synthesizing the control of these structures. Positivity theory is used to ensure the stability and stability robustness of digital designs, inclusive of modal truncation and aliasing. Shaping the characteristic gains in an ??-shifted W-plane synthesizes the required performance. The combined approach has the advantage that it leads directly to robust and implementable low-order controllers. A design example using an LSS like structure concludes the paper.