According to the delay property, linear time-delay (LTD) systems can be classified as LTD systems with depen- dent delays (LTD_DD) and LTD systems with independent delays (LTD_ID). This paper reveals that the st...According to the delay property, linear time-delay (LTD) systems can be classified as LTD systems with depen- dent delays (LTD_DD) and LTD systems with independent delays (LTD_ID). This paper reveals that the stability condition for LTD_ID systems can be applied to LTD_DD systems, a sufficient stability condition for LTD_DD systems is derived from it, while only fewer of the LTD_DD systems can satisfy the stability condition due to the very strict limitation for the delays of the LTD_DD systems. To solve the problem, based on two-dimensional (2-D) hybrid polynomials, some sufficient conditions for stability of LTD_DD systems are pro- posed. Examples show that the proposed stability test algorithms are simple and valid.展开更多
It is difficult to determine the stability of linear systems with interval delays (LID systems) because the roots of the characteristic polynomials of the systems are continuous and vary in a complex plane with the ...It is difficult to determine the stability of linear systems with interval delays (LID systems) because the roots of the characteristic polynomials of the systems are continuous and vary in a complex plane with the delay. To solve the problem, this paper develops a stability test of LID systems by resorting to 2-D hybrid polynomials and 2-D Hurwitz-Schur stability. Comparing with the existing test approaches for LID systems, the proposed 2-D Hurwitz-Schur stability test is easy to apply, and can obtain closed form constraint conditions for system parameters. This paper proposes some theorems as sufficient conditions for the stability of LID systems, and also reveals that recent results about the stability test of linear systems with any delays (LAD systems) are not suitable for LID systems because they are very conservative for the stability of LID systems.展开更多
基金supported by the National Natural Science Foundation of China(60572093)the Natural Science Foundation of Beijing(4102050)
文摘According to the delay property, linear time-delay (LTD) systems can be classified as LTD systems with depen- dent delays (LTD_DD) and LTD systems with independent delays (LTD_ID). This paper reveals that the stability condition for LTD_ID systems can be applied to LTD_DD systems, a sufficient stability condition for LTD_DD systems is derived from it, while only fewer of the LTD_DD systems can satisfy the stability condition due to the very strict limitation for the delays of the LTD_DD systems. To solve the problem, based on two-dimensional (2-D) hybrid polynomials, some sufficient conditions for stability of LTD_DD systems are pro- posed. Examples show that the proposed stability test algorithms are simple and valid.
基金supported by the National Natural Science Foundation of China (60572093)the Natural Science Foundation of Beijing(4102050)
文摘It is difficult to determine the stability of linear systems with interval delays (LID systems) because the roots of the characteristic polynomials of the systems are continuous and vary in a complex plane with the delay. To solve the problem, this paper develops a stability test of LID systems by resorting to 2-D hybrid polynomials and 2-D Hurwitz-Schur stability. Comparing with the existing test approaches for LID systems, the proposed 2-D Hurwitz-Schur stability test is easy to apply, and can obtain closed form constraint conditions for system parameters. This paper proposes some theorems as sufficient conditions for the stability of LID systems, and also reveals that recent results about the stability test of linear systems with any delays (LAD systems) are not suitable for LID systems because they are very conservative for the stability of LID systems.