Two-degree-of freedom H-infinity control of ship sterring

2005 ◽  
Author(s):  
Xingcheng Wang ◽  
Ran Wang
Keyword(s):  
Degree Of Freedom ◽  
H Infinity ◽  
H Infinity Control ◽  
Two Degree Of Freedom

The Two-Degree-of-Freedom Tuned-Mass Damper for Suppression of Single-Mode Vibration Under Random and Harmonic Excitation

2005 ◽  
Vol 128 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Lei Zuo ◽  
Samir A. Nayfeh
Keyword(s):  
Vibration Suppression ◽  
Single Mode ◽  
Tuned Mass Damper ◽  
Harmonic Excitation ◽  
Degree Of Freedom ◽  
Primary System ◽  
H Infinity ◽  
Mass Damper ◽  
Mode Vibration ◽  
Two Degree Of Freedom

Whenever a tuned-mass damper is attached to a primary system, motion of the absorber body in more than one degree of freedom (DOF) relative to the primary system can be used to attenuate vibration of the primary system. In this paper, we propose that more than one mode of vibration of an absorber body relative to a primary system be tuned to suppress single-mode vibration of a primary system. We cast the problem of optimization of the multi-degree-of-freedom connection between the absorber body and primary structure as a decentralized control problem and develop optimization algorithms based on the H2 and H-infinity norms to minimize the response to random and harmonic excitations, respectively. We find that a two-DOF absorber can attain better performance than the optimal SDOF absorber, even for the case where the rotary inertia of the absorber tends to zero. With properly chosen connection locations, the two-DOF absorber achieves better vibration suppression than two separate absorbers of optimized mass distribution. A two-DOF absorber with a negative damper in one of its two connections to the primary system yields significantly better performance than absorbers with only positive dampers.

Design of Robust Two-Degree-of-Freedom Controllers for Position Servos Using H-Infinity Theory

1992 ◽  
Vol 206 (2) ◽  
pp. 135-142 ◽  
Author(s):  
R Piché ◽  
S Pohjolainen ◽  
T Virvalo
Keyword(s):  
Closed Loop ◽  
Synthesis Method ◽  
Degree Of Freedom ◽  
Linear Feedback ◽  
Closed Loop System ◽  
Feedback Controllers ◽  
H Infinity ◽  
Structured Singular Value ◽  
Performance Specifications ◽  
Two Degree Of Freedom

Linear feedback controllers for position servos are designed using the structured singular value optimization (Doyle's μ-synthesis) method. The method produces a two-degree-of-freedom controller, including both the feedback and the prefilter, which is ‘performance robust’, in the sense that the closed-loop system is guaranteed to meet performance specifications in the presence of unmodelled dynamics. A detailed design of a low-order controller for a hydraulic position servo, including numerical non-linear simulation results, is presented.

Sign in / Sign up

Export Citation Format

Share Document