Abstract
The numerical approximation of the mu-value is key towards the measurement of instability, stability analysis, robustness, and the performance of linear feedback systems in system theory. The MATLAB function mussv available in MATLAB Control Toolbox efficiently computes both lower and upper bounds of the mu-value. This article deals with the numerical approximations of the lower bounds of mu-values by means of low-rank ordinary differential equation (ODE)-based techniques. The numerical simulation shows that approximated lower bounds of mu-values are much tighter when compared to those obtained by the MATLAB function mussv.