LMIs in Control/pages/H stabilization


There are a wide variety of control design problems that are addressed in a wide variety of different ways. One of the most important control design problem is that of state feedback stabilization. One such state feedback problem, which will be the main focus of this article, is that of -Stabilization, a form of -Stabilization where the real components are located on the left-half of the complex plane.

The SystemEdit

For this particular problem, suppose that we were given a linear system in the form of:


where   and  . Then the LMI for determining the  -stabilization case would be obtained as described below.

The DataEdit

In order to obtain the LMI, we need the following 2 matrices:  .

The Optimization ProblemEdit

Suppose - for the linear system given above - we were asked to design a state-feedback control law where   such that the closed-loop system:


is   stable, then the system would be stabilized as follows.

The LMI: -StabilizationEdit

From the given pieces of information, it is clear that the optimization problem only has a solution if there exists a matrix   and a symmetric matrix   that satisfy the following:



Given the resulting controller matrix  , it can be observed that the matrix is  -stable.


  • Example Code - A GitHub link that contains code (titled "HStability.m") that demonstrates how this LMI can be implemented using MATLAB-YALMIP.

Related LMIsEdit

  • D stabilization - Equivalent LMI for  -stabilization.

External LinksEdit

A list of references documenting and validating the LMI.

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