Frequency-domain mapping approach of stability bounds for loop shaping of bilateral controllers

2013 ◽  
Author(s):  
G. Evers ◽  
G. J. L. Naus ◽  
M. J. G. van de Molengraft ◽  
M. Steinbuch
Keyword(s):  
Frequency Domain ◽  
Mapping Approach ◽  
Loop Shaping ◽  
Domain Mapping

Study on Dual-Loop Controller of Helicopter Based on the Robust H-Infinite Loop Shaping Method

2011 ◽  
Vol 130-134 ◽  
pp. 1182-1185 ◽  
Author(s):  
Zhe Yan Lang ◽  
Ai Guo Wu
Keyword(s):  
Frequency Domain ◽  
Simple Structure ◽  
Mimo System ◽  
Prototype Model ◽  
Design Requirement ◽  
Internal Loop ◽  
External Loop ◽  
Loop Shaping ◽  
Infinite Loop ◽  
Simulation Results

Helicopter is a typical MIMO system including the properties of non-stability, strong coupling, uncertainty. Firstly, a robust internal loop ACAH controller is designed and analyzed to ensure decoupling and robustness on each channel by the robust H-infinite loop shaping. Secondly, the external loop is designed using the classical PID method on the base of decoupling internal loop. Both loops contain the part of anti-windup. The simulation results of the prototype model demonstrate that in both time and frequency domain, the performance of the controller meets the design requirement with a comparative simple structure. The results can also prove that it has some effect against to the model perturbation and achieve LEVEL1 of ADS-33E-PRF.

Frequency Domain Design for Maximizing the Allowable Size of a Step Disturbance in Linear Uncertain Systems

1994 ◽  
Vol 116 (4) ◽  
pp. 635-642
Author(s):  
Suhada Jayasuriya ◽  
Massoud Sobhani
Keyword(s):  
Transfer Function ◽  
Frequency Domain ◽  
Time Domain ◽  
Design Procedure ◽  
Control Input ◽  
Low Frequencies ◽  
Loop Shaping ◽  
Loop Transfer Function ◽  
Step Disturbance ◽  
Domain Constraints

A design methodology is developed for a linear, uncertain, SISO system for maximizing the size of a step disturbance in the presence of hard time domain constraints on system states, control input, output and the bandwidth. It is assumed that the system dynamics can be represented by a combination of structured uncertainty in the low frequencies and unstructured uncertainty in the high frequencies. The design procedure is based on mapping the time domain constraints into an equivalent set of frequency domain constraints which are then used to determine an allowed design region for the nominal loop transfer function in the plane of amplitude-phase. Once such a region is found, classical loop shaping determines a suitable nominal loop transfer function. The pole-zero structure of the compensator is a natural consequence of loop shaping and is not preconceived. An illustrative example demonstrates the trade-off between controller bandwidth, or the cost of feedback, and the tolerable size of step disturbance.

scholarly journals A domain mapping approach for elliptic equations posed on random bulk and surface domains

2020 ◽  
Vol 146 (1) ◽  
pp. 1-49
Author(s):  
Lewis Church ◽  
Ana Djurdjevac ◽  
Charles M. Elliott
Keyword(s):  
Elliptic Equations ◽  
Mapping Approach ◽  
Domain Mapping ◽  
Surface Domains
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