Semi-active control of flexible structures using closed-loop input shaping techniques

Abstract

In this research effort, a novel approach on the control of structures with magnetorheological (MR) dampers is presented, based on an appropriately adapted closed-loop version of the generic input shaping control theory. The MR damper is a very promising kind of semi-active control system (actuator), mixing the advantages of the active and passive structural control systems, hence their increasing use as attenuators that reject the effects of dynamic loads on civil engineering structures. The main contribution of this article is the application and performance evaluation of the novel 'Linear Matrix Inequality-based' feedback version of the input shaping control theory for the first time in the area of structural control. The need for the use of a feedback version of input shaping control stems from the design trade-off between robustness and speed of response requirements. A simulation of a benchmark three-story building with one MR damper is employed to verify the efficiency of the proposed control approach. The nonlinear behaviour of the MR damper, rigidly connected between the first floor of the structure and the ground, is captured by the well-known Bouc-Wen model. The superiority and effectiveness of the proposed scheme in reducing the responses of the structure were proved using seven quantifiable evaluation criteria and by comparing these results with those achieved by classical and well-established alternative control schemes.

Update of control parameters for semi‐actively controlled base‐isolated building to improve seismic performance

“…On the basis of control engineering, many researchers have investigated and proposed various kinds of control methods for base‐isolated buildings with semi‐active dampers: an optimal controller‐based approach, such as linear‐quadratic‐regulator and linear‐quadratic‐Gaussian (LQG) controllers and H ∞ control (Sadek and Mohraz; Wongprasert and Symans; Nagarajaiah and Narasimhan; Xu et al; Li and Ou; and Wang and Dyke); fuzzy logic (Choi et al; Lin et al; and Ali and Ramaswamy); neural network (Lee et al; Reigles and Symans; Bani‐Hani and Sheban; and Fukukita et al); a sliding mode control (Singh et al and Zhao et al); a pseudo‐negative‐stiffness control (Iemura et al; Wu et al; and Gong and Xiong), and others (Nitta et al; Pozo et al; Tu et al; Rodriguez et al; Alqado et al; Vu et al; Ho et al). Shook et al conducted a comparative study for multiple control methods.…”

Hysteretic active control of base-isolated buildings

“…Consider a hysteretic base‐isolated building structure as shown in Figure . The equation of motion of a seismically excited structure with multiple degrees of freedom that is controlled by a single active force acting on the base can be described as follows: where is the absolute ground acceleration; represents the horizontal displacement of the base and each floor of the structure with respect to the ground; n is the number of floors; and are the n + 1 dimensional vectors of the velocities and accelerations of the base and the floors of the structure; and M , C , and K are ( n + 1) × ( n + 1) mass, damping, and stiffness matrices, respectively, and have the following form: …”

“…Consider a hysteretic base-isolated building structure as shown in Figure 1. The equation of motion of a seismically excited structure with multiple degrees of freedom that is controlled by a single active force acting on the base can be described as follows [23][24][25] :…”

“…whereẍ g is the absolute ground acceleration; x = [x b , x 1 , x 2 , · · ·, x n ] T ∈ R n represents the horizontal displacement of the base and each floor of the structure with respect to the ground; n is the number of floors;ẋ andẍ are the n + 1 dimensional vectors of the velocities and accelerations of the base and the floors of the structure; and M, C, and K are (n + 1) × (n + 1) mass, damping, and stiffness matrices, respectively, and have the following form 24,25 :…”

Investigation of vibration induced by moving cranes in high-tech factories

“…A number of studies used isolators or dampers to reduce vibration for high-tech buildings. [16][17][18][19][20][21][22][23] Hwang et al 16 studied the seismic protective systems for high-tech structures, and found that the incorporation of viscous dampers not only enhance the seismic safety but also minimize the micro-vibration of the structure. Lin et al 17 proposed a micro vibration mitigation system using viscous dampers for high-tech buildings, and results presented that the vibration can be effectively captured by the viscous damper and converted to lower frequencycontent tremors.…”