SIAM Journal on Control and Optimization, Vol.47, No.6, 3185-3202, 2009
DELAY-INTEGRAL-QUADRATIC CONSTRAINTS AND ABSOLUTE STABILITY OF TIME-PERIODIC FEEDBACK SYSTEMS
The paper considers the problem of absolute stability of systems with time-periodic nonlinear blocks. The approach presented in this paper is based on the so-called quadratic criterion and relies on integral-quadratic inequalities (constraints), which also involve time delays. The results are given in the frequency domain. The paper also includes geometric interpretation and numerical treatment of the new stability criteria.