Active Seismic Control Research Articles

Investigation of the Robust H-Infinity Filter's Effectiveness on the Model Predictive Control and Linear Quadratic Regulator for Active Seismic Control of High-Rise Buildings

Investigation of the Robust H-Infinity Filter's Effectiveness on the Model Predictive Control and Linear Quadratic Regulator for Active Seismic Control of High-Rise Buildings

Sensitivity and Reliability Analyses in to Actively Controlled Structures Under Earthquake

This study aims for a probabilistic assessment of active seismic control of structures in the presence of uncertainties of the structural model and the stochastic model of the ground acceleration. First, sensitivity analyses based on the Borgonovo sensitivity index are conducted to measure the effect of uncertainty sources on the maximum and root mean square (RMS) of the main structural responses in different seismic hazard regions. Then, the reliability analyses are conducted using Monte Carlo simulation (MCS) and importance sampling (IS) methods to the estimation of failure probabilities and reliability indices of the structures in different seismic hazard regions, force capacity of actuators, and seismic performance levels. Numerical studies carried out on a 10-story structure show that the uncertainties in peak ground acceleration (PGA) and story stiffness have the most effects on the seismic responses of the structure. The effect of the considered uncertainties is negligible on the maximum demand control force. The results also show that equipping the structure with an active control system results in a significant reduction in the failure probabilities of the structure. The target reliability index for the uncontrolled structure in life safety seismic performance level may not be satisfied in high and very high seismic hazard regions, it can however be easily dealt with, using the proposed technique, in the corresponding controlled structures. By increasing the control force capacity, an increment is observed in the reliability index. A high and suitable reliability index is given for both controlled and uncontrolled in the collapse prevention seismic performance level.

Active seismic control strategy for comparable simultaneous reductions of more than one response

Active seismic control strategy for comparable simultaneous reductions of more than one response

Relative Performance of Linear Quadratic Regulator and Pole Placement Technique for Active Seismic Control of Structures

This paper presents the study conducted on the comparison of the performance of the two popular active control algorithms viz. Linear Quadratic Regulator (LQR) and Pole Placement technique in terms of their capability to alleviate the response of a structure to an earthquake. To compare the performance of the two control algorithms, a ten story regular shear building frame with three active tendons located in 1st, 4th and 5th Storys and subjected to an El Centro earthquake has been considered. A comparison of the numerical results shows that the reductions of maximum top floor displacement, maximum story drift and base shear obtained using LQR control algorithm are 71.48%, 59.70% and 62.7% while the reductions obtained using Pole Placement technique are 73.77%, 73.14% and 77% respectively. The percentage reduction of the three performance parameters per unit control force obtained using the two methods have also been estimated and compared. Pole placement technique gives higher reduction while the LQR algorithm gives more reduction per unit control force.

Improving Active Preview Control System of Structures Using Online Prediction of Seismic Waves

AbstractThis paper presents a study on the applicability of the preview control method for improving the performance of active seismic control systems. The active preview control method is examined as described for its ability to improve vibration suppression as follows: (1) the relation between the number of preview steps and the degree of improvement in control performance is clarified by analysis using predicted earthquake waves, and (2) to evaluate the applicability to an actual structure, predicted surface seismic waves are calculated by an autoregressive model from observed KiK-net data on 100–200-m-deep underground seismic waves and the applicability of the method is confirmed.

Effect of feedback on PID controlled active structures under earthquake excitations

In this paper, different feedback control strategies are presented for active seismic control using proportional-integral-derivative (PID) type controllers. The parameters of PID controller are found by using an numerical algorithm considering time delay, maximum allowed control force and time domain analyses of shear buildings under different earthquake excitations. The numerical algorithm scans combinations of different controller parameters such as proportional gain (<TEX>$K_p$</TEX>), integral time (<TEX>$T_i$</TEX>) and derivative time (<TEX>$T_d$</TEX>) in order to minimize a defined response of the structure. The controllers for displacement, velocity and acceleration feedback control strategies are tuned for structures with active control at the first story and all stories. The performance and robustness of different feedback controls on time and frequency responses of structures are evaluated. All feedback controls are generally robust for the changing properties of the structure, but acceleration feedback control is the best one for efficiency and stability of control system.

The Research of Anti-Seismic Control Experiments of Spatial Reticulated Shell Structures

The large spatial reticulated structures belong to vibration and defects sensitive structures when vibrations will be easily produced under dynamic loading actions, and dynamic failure accidents will be caused. The application of the piezoelectric smart material in structural vibration control was researched with the shaking table test of active seismic control simulation of the spatial reticulated shell model structure.The results show that the piezoelectric actuators optimally arranged can effectively decrease earthquake responses of the structure, so it is a good active seismic control method.

Sliding mode and PID control of a structural system against earthquake

In this study, a non-chattering robust sliding mode controller (SMC) and a proportional integral derivative (PID) Controller are separately designed for an active seismic control device considering a multi-degree-of-freedom structural system against earthquakes. Since the PID control method can be applied easily and is widely known, it has an important place in control applications. But this method is insensitive to parameter changes. The advantage of an SMC is its robustness and ability to handle the non-linear behaviour of the system. The simulated system has four degrees of freedom. A structural system was simulated against the ground motion of the Marmara earthquake ( M w = 7.4 ) in Turkey on August 17th, 1999. The ground motion acts on the base. Both PID and sliding mode controllers are designed to suppress the building vibrations. Since the main effect of an earthquake occurs on the first floor, the controller is placed under it. At the end of the study, the time history of the first and top floor displacements, frequency responses of both the uncontrolled and controlled structures and control voltages are presented and the results are discussed.