Control of LPV systems with partly measured parameters

The control of linear parameter-varying (LPV) systems with time-varying real uncertain parameters, where only some of the parameters are measured and available for feedback, is considered. The control objectives are internal stability and disturbance attenuation in the sense of a bounded induced L/sub 2/-norm from the disturbance to the controlled output. Using parametric Lyapunov functions, the solvability conditions for dynamic output feedback controllers that depend on the measured parameters are expressed in terms of a set of linear matrix inequalities (LMIs) and an additional coupling constraint which destroys the convexity of the overall problem. By transforming the coupling constraint into a rank condition, the problem is recast into a rank-minimization problem with LMI constraints. An example is included that demonstrates the application of the results.