Computer-Aided Control System Design and Control Performance for Active Vibration Control Systems Based on μ Synthesis Theory

1994 ◽  
Vol 6 (4) ◽  
pp. 304-311
Author(s):  
Kenzo Nonami ◽  
◽  
Qi-fu Fan ◽  
Keyword(s):  
Control System ◽  
Vibration Control ◽  
System Design ◽  
Control Systems ◽  
Active Vibration Control ◽  
Singular Value ◽  
Control System Design ◽  
Robust Performance ◽  
Computer Aided ◽  
Active Vibration

The <I>H</I>∞ control theory is currently the most powerful method for robust control theory, and is useful as well as practical because a great amount of software related to computer-aided control system design is available. However, it has some disadvantages in that the <I>H</I>∞ control system is a conservative one and cannot deal with robust performance. This is due to maximum singular values. Doyle proposed a structured singular value instead of a maximum singular value. This is called ∞ synthesis theory and actively deals with robust performance using D-K iteration. This paper is concerned with computeraided design of active vibration control systems based on the μ synthesis theory. First, the paradigm of the μ synthesis theory is described concerning μ, robust performance, and D-K iteration. Next, the relationships between the μ controller, robust performance, nominal performance, and robust stability are discussed for vibration control systems.

Experiment Verification of Seismic Isolation Device Having Charging Function

2017 ◽  
Author(s):  
Takashi Yamaguchi ◽  
Hayato Nakakoji ◽  
Nanako Miura ◽  
Akira Sone
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Control Systems ◽  
Seismic Isolation ◽  
Active Vibration Control ◽  
Vibration Reduction ◽  
Large Earthquake ◽  
Energy Regeneration ◽  
Active Vibration ◽  
Isolation Device

In late years, many base isolated structures are planned as seismic design, because they suppress vibration response significantly against large earthquake. In addition, to achieve greater safety, semi-active or active vibration control system is installed in the structures as. Semi-active and active vibration control systems are more effective to large earthquake than passive one vibration control system in terms of vibration reduction. However semi-active and active vibration control systems cannot operate as required when external power supply is cut off. To solve the problem of energy consumption, we propose a self-powered active seismic isolation device which achieves active control system using regenerated vibration energy. This device doesn’t require external energy to produce control force. The purpose of this paper is to propose the seismic isolation device having charging function and verified its performance by experiment. In our previous research[1], we proposed the new model and optimized the control system and passive elements such as spring coefficients and damping coefficients using genetic algorithm. As a result, we proposed the model which is superior to the previous model in terms of vibration reduction and energy regeneration. In this study, we conducted an experiment and show its results. As a results, we confirmed the vibration reduction and energy regeneration of the seismic isolation device having charging function.

scholarly journals Seismic Risk Assessment of Actively Controlled Buildings under Probable Mainshock-Aftershock Scenarios during their Lifetime

2021 ◽  
Author(s):  
Ali Khansefid ◽  
Ali Bakhshi
Keyword(s):  
Risk Assessment ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Control System ◽  
Vibration Control ◽  
Control Systems ◽  
Seismic Risk ◽  
Active Vibration Control ◽  
Earthquake Scenarios ◽  
Active Vibration

Abstract This paper focuses on a new comprehensive probabilistic approach for lifetime risk assessment of buildings equipped with active vibration control systems under future probable mainshock-aftershock scenarios. This procedure starts from the seismic hazard simulation, continues with the building performance evaluation, and ends with the seismic risk assessment. The procedure attempts to reflect the effects of major uncertainty sources existing in both building properties and earthquake scenarios using the Monte-Carlo simulation technique. The method is applied to steel moment-resisting frame buildings armed with the optimally designed active vibration control system (using the linear quadratic regulator algorithm). In each realization of the Monte-Carlo simulation, first, a random earthquake scenario containing probable future mainshock-aftershock sequences and their corresponding synthetic stochastic accelerograms are procreated. Next, the buildings are designed in two separate cases, with and without the presence of active vibration control systems. The former is designed based on the international design codes, while the latter properties are obtained via an advanced optimization method. In the last step, considering all generated samples, the loss curve of buildings with the active control system is developed for two separate cases: with or without taking aftershocks’ effects into account. The application of this method indicates that the active control system works well in decreasing the loss value (on average 66%) of buildings during their 50-year lifetime, especially in the more intensive earthquake scenarios. Additionally, it is shown that by neglecting the aftershocks, the life-cycle cost of building will be estimated tangibly (on average 70%) less than what it would be. Finally, it is observed that the non-structural acceleration-sensitive damages have a higher contribution in total building losses in uncontrolled structures in comparison with the actively controlled building by considering aftershocks.

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