QFT template generation for time-delay plants based on zero-inclusion test
✍ Scribed by Chyi Hwang; Shih-Feng Yang
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 184 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0167-6911
No coin nor oath required. For personal study only.
✦ Synopsis
Plant template generation is the key step in applying quantitative feedback theory (QFT) to design robust control for uncertain systems. In this paper we propose a technique for generating plant templates for a class of linear systems with an uncertain time delay and a ne parameter perturbations in coe cients. The main contribution lies in presenting a necessary and su cient condition for the zero inclusion of the value set f(T
}, where f( ; q) = g(q) + h(q)e -j ! * , g(q) and h(q) are both complex-valued a ne functions of the m-dimensional real vector q, and ! * is a ÿxed frequency. Based on this condition, an e cient algorithm which involves, in the worst case, evaluation of m algebraic inequalities and solution of m2 m-1 one-variable quadratic equations, is developed for testing the zero inclusion of the value set f(T; Q). This zero-inclusion test algorithm allows one to utilize a pivoting procedure to generate the outer boundary of a plant template with a prescribed accuracy or resolution. The proposed template generation technique has a linear computational complexity in resolution and is, therefore, more e cient than the parameter gridding and interval methods. A numerical example illustrating the proposed technique and its computational superiority over the interval method is included.