Robustly Stabilizing Controllers with Internal Loop

Author(s):  
Ruth F. Curtain
2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Yufeng Lu ◽  
Chengkai Shi

We study the concept of stabilization with internal loop for infinite-dimensional discrete time-varying systems in the framework of nest algebra. We originally give a parametrization of all stabilizing controllers with internal loop, and it covers the parametrization of canonical or dual canonical controllers with internal loop obtained before. We show that, in practical application, the controller with internal loop overcomes the awkwardness brought by the extra invertibility condition in the parametrization of the conventional controllers. We also prove that the strong stabilization problem can be completely solved in the closed-loop system with internal loop. Thus the advantage of the controller with internal loop is addressed in the framework of nest algebra.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Nai-feng Gan ◽  
Yu-feng LU ◽  
Ting Gong

The concepts of stabilization with internal loop are analyzed for well-posed transfer functions. We obtain some sufficient and necessary conditions such that a stabilizing controller with internal loop stabilizes plant L. We also analyze two special subclasses of stabilizing controllers with internal loop, called canonical and dual canonical controllers, and show that all stabilizing controllers can be parameterized by a doubly coprime factorization of the original transfer function.


Author(s):  
Christian Richter ◽  
Katharina F. Hohmann ◽  
Sabrina Toews ◽  
Daniel Mathieu ◽  
Nadide Altincekic ◽  
...  

AbstractThe stem-loop (SL1) is the 5'-terminal structural element within the single-stranded SARS-CoV-2 RNA genome. It is formed by nucleotides 7–33 and consists of two short helical segments interrupted by an asymmetric internal loop. This architecture is conserved among Betacoronaviruses. SL1 is present in genomic SARS-CoV-2 RNA as well as in all subgenomic mRNA species produced by the virus during replication, thus representing a ubiquitous cis-regulatory RNA with potential functions at all stages of the viral life cycle. We present here the 1H, 13C and 15N chemical shift assignment of the 29 nucleotides-RNA construct 5_SL1, which denotes the native 27mer SL1 stabilized by an additional terminal G-C base-pair.


Author(s):  
Zhizheng Wu ◽  
Foued Ben Amara

Motivated by a class of surface tracking problems in mechanical systems subject to contact vibrations, this paper considers a regulation problem for discrete-time switched bimodal linear systems where it is desired to achieve output regulation against exogenous input signals featuring known deterministic and unknown random components. A first step in the regulator design involves constructing a set of observer-based parameterized stabilizing controllers that satisfy a sufficient regulation condition for the switched system against the known deterministic disturbance or reference signals. In the second step, an additional performance constraint is added to identify, from among the already constructed regulators, those that provide the best regulation performance against the unknown random disturbances. A corresponding regulator synthesis algorithm is developed based on iteratively solving properly formulated bilinear matrix inequalities. The proposed regulator is successfully evaluated on an experimental setup involving a switched bimodal mechanical system subject to contact vibrations, hence demonstrating the effectiveness of the proposed regulation approach.


2021 ◽  
Vol 54 (5) ◽  
pp. 19-24
Author(s):  
Tyler Westenbroek ◽  
Ayush Agrawal ◽  
Fernando Castañeda ◽  
S Shankar Sastry ◽  
Koushil Sreenath

Sign in / Sign up

Export Citation Format

Share Document