{"title":"A Schur method for robust eigenvalue assignment of second-order singular systems","authors":"Kang Hu, Huiqing Xie","doi":"10.1016/j.apnum.2025.09.002","DOIUrl":null,"url":null,"abstract":"<div><div>A new method for eigenvalue assignment problem of a second-order singular system is proposed via displacement-velocity-acceleration feedback. The real Schur form of a regular quadratic pencil and a robustness measurement for the closed-loop second-order system are introduced. On these grounds, a Schur method for robust eigenvalue assignment of a second-order singular system is proposed. The presented method also can be seen as an extension of the Schur method for eigenvalue assignment of a first-order system to a second-order system. However, our method directly deals with a second-order system and avoids to transform a second-order system into a first-order system. There are two open problems in the Schur method for eigenvalue assignment problem. One is how to determine the first Schur vector and another is how to order the eigenvalues in the Schur form. We provide the strategies for these two open problems, which are our main contributions. The efficiency of the proposed method is illustrated by some numerical examples.</div></div>","PeriodicalId":8199,"journal":{"name":"Applied Numerical Mathematics","volume":"220 ","pages":"Pages 44-65"},"PeriodicalIF":2.3000,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Numerical Mathematics","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0168927425001771","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/9/17 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
引用次数: 0
Abstract
A new method for eigenvalue assignment problem of a second-order singular system is proposed via displacement-velocity-acceleration feedback. The real Schur form of a regular quadratic pencil and a robustness measurement for the closed-loop second-order system are introduced. On these grounds, a Schur method for robust eigenvalue assignment of a second-order singular system is proposed. The presented method also can be seen as an extension of the Schur method for eigenvalue assignment of a first-order system to a second-order system. However, our method directly deals with a second-order system and avoids to transform a second-order system into a first-order system. There are two open problems in the Schur method for eigenvalue assignment problem. One is how to determine the first Schur vector and another is how to order the eigenvalues in the Schur form. We provide the strategies for these two open problems, which are our main contributions. The efficiency of the proposed method is illustrated by some numerical examples.
期刊介绍:
The purpose of the journal is to provide a forum for the publication of high quality research and tutorial papers in computational mathematics. In addition to the traditional issues and problems in numerical analysis, the journal also publishes papers describing relevant applications in such fields as physics, fluid dynamics, engineering and other branches of applied science with a computational mathematics component. The journal strives to be flexible in the type of papers it publishes and their format. Equally desirable are:
(i) Full papers, which should be complete and relatively self-contained original contributions with an introduction that can be understood by the broad computational mathematics community. Both rigorous and heuristic styles are acceptable. Of particular interest are papers about new areas of research, in which other than strictly mathematical arguments may be important in establishing a basis for further developments.
(ii) Tutorial review papers, covering some of the important issues in Numerical Mathematics, Scientific Computing and their Applications. The journal will occasionally publish contributions which are larger than the usual format for regular papers.
(iii) Short notes, which present specific new results and techniques in a brief communication.