Modeling and control performance of a negative stiffness damper for suppressing stay cable vibrations

2015 ◽  
Vol 23 (4) ◽  
pp. 764-782 ◽  
Author(s):  
Peng Zhou ◽  
Hui Li
Keyword(s):  
Negative Stiffness ◽  
Control Performance ◽  
Stay Cable ◽  
Modeling And Control ◽  
Cable Vibrations ◽  
And Control

Multi-mode control performance of nonlinear dampers in stay cable vibrations

2009 ◽  
pp. n/a-n/a ◽  
Author(s):  
Nam Hoang ◽  
Yozo Fujino
Keyword(s):  
Control Performance ◽  
Stay Cable ◽  
Mode Control ◽  
Cable Vibrations ◽  
Multi Mode

Data analysis, modeling and control performance enhancement of an industrial fluid catalytic cracking unit

2007 ◽  
Vol 62 (7) ◽  
pp. 1958-1973 ◽  
Author(s):  
Rohit Ramachandran ◽  
G.P. Rangaiah ◽  
S. Lakshminarayanan
Keyword(s):  
Data Analysis ◽  
Catalytic Cracking ◽  
Performance Enhancement ◽  
Fluid Catalytic Cracking ◽  
Control Performance ◽  
Modeling And Control ◽  
And Control

Optimal Design of Dampers for Multi-Mode Cable Vibration Control Based on Genetic Algorithm

2021 ◽  
pp. 2150058
Author(s):  
Fangdian Di ◽  
Lin Chen ◽  
Limin Sun
Keyword(s):  
Genetic Algorithm ◽  
Vibration Control ◽  
Performance Optimization ◽  
Negative Stiffness ◽  
Stay Cable ◽  
Control Effect ◽  
Cable Vibration ◽  
Cable Vibrations ◽  
Damper Design ◽  
Multi Mode

Cables in cable-stayed bridges are subjected to the problem of multi-mode vibrations. Particularly, the first ten modes of long cables can have a frequency less than 3[Formula: see text]Hz and hence are vulnerable to wind-rain induced vibrations. In practice, mechanical dampers are widely used to mitigate such cable vibrations and thus they have to be designed to provide sufficient damping for all the concerned vibration modes. Meanwhile, the behaviors of practical dampers are complicated and better to be described by mechanical models with many parameters. Furthermore, additional mechanical components such as inerters and negative stiffness devices have been proposed to enhance the damper performance on cables. Therefore, it is increasingly difficult to optimize the damper parameters for suppressing multi-mode cable vibrations. To address this issue, this study proposes a novel damper design method based on the genetic algorithm (GA). The procedure of the method is first introduced where the damper performance optimization is formulated as a single-objective multi-parameter optimization problem. The effectiveness of the method is then verified by considering a viscous damper on a stay cable. Subsequently, the method is applied to optimize three typical dampers for cable vibration control, i.e. the positive stiffness damper, the negative stiffness damper, and the viscous inertial mass damper. The results show that the GA-based method is effective and efficient for cable damper design to achieve best multi-mode control effect and it is particularly useful for dampers with more parameters.

Mitigation of Wind-Rain-Induced Cable Vibration in Cable-Stayed Bridges: Energy Cost Assessment

2011 ◽  
Vol 105-107 ◽  
pp. 1165-1169
Author(s):  
Ling Yun Wang ◽  
Quan Feng Wang
Keyword(s):  
Energy Cost ◽  
Control Method ◽  
Control Technique ◽  
Stay Cable ◽  
External Energy ◽  
Design Guideline ◽  
Significant Control ◽  
Cable Vibrations ◽  
Control Forces ◽  
And Control

The cables in a cable-stayed bridge usually possess low inherent damping and are prone to vibrate by many factors. The wind-rain-induced vibration of the prototype stay cable is a special vibration problem associating with rain and wind. Many methods have been proposed to mitigate wind-rain-induced cable vibrations such as mechanical measures, aerodynamic modification, and control technology. Active control technique has significant control capability because of utilizing the external energy supply but it may not be realistic to large civil engineering structure due to enormous power demand. The two-stage control method has been proposed to control the wind-rain-induced cable vibrations of the prototype stay cable. The studies are carried out to investigate the energy cost features of the control forces as a design guideline.

Modeling and Control System Design of a Marine Condensing System

2011 ◽  
Author(s):  
Zhixin Sun ◽  
Jiangfeng Wang ◽  
Yiping Dai ◽  
Danmei Xie
Keyword(s):  
Control System ◽  
Cooling Water ◽  
Pi Controller ◽  
Control System Design ◽  
Control Performance ◽  
Water Pump ◽  
Feed Forward ◽  
Modeling And Control ◽  
Valve Opening ◽  
And Control

Rapid and frequent load changes bring a number of challenges to the control system of a marine condenser. However, few studies have been published in this area. In this paper, a whole condensing system, which includes condenser, ejector, cooling water pump and its driving turbine, was modeled based on three conservation laws. Propulsion steam turbine was also modeled to simulate the load changes. A proportional integral (PI) controller was developed to regulate the condenser pressure. Opening signal of the governing valve of the propulsion turbine was added to the controller as a feed forward signal, and to improve the performance further, fuzzy algorithm was adopted to tune the gains of PI controller. Numerical experiments were conducted to study the dynamic behavior and the control performance of the condensing system. The simulation results show that employing the valve opening signal of main turbine as feed forward signal and tuning the gains of conventional PI controller by fuzzy logic are both effectual approaches to enhance the control performance. The former is good at reducing maximum overshooting while the latter is good at decreasing settling time. The combination of these two methods can improve the performance of simple PI controller further.

Modeling and Control of a Food Extrusion Process

1997 ◽  
Vol 21 (1-2) ◽  
pp. S361-S366 ◽  
Author(s):  
J Elsey
Keyword(s):  
Extrusion Process ◽  
Modeling And Control ◽  
Food Extrusion ◽  
And Control
Sign in / Sign up

Export Citation Format

Share Document