Earthquake is a kind of natural disaster, which will have a great impact on the building structure. In the vibration control field of building structures, the timeliness of system stability is extremely important. In traditional control methods, the timeliness is not paid enough attention for systems with uncertain seismic waves. For setting this problem, fuzzy adaptive compensation control for uncertain building structural systems by sliding-mode technology is proposed. It is combined with fuzzy adaptive control and sliding-mode control to ensure that the system can be stable with satisfied timeliness. Also, saturation function is used to ensure the feasible physical implementation of the control system. Compared with the traditional LQR (linear quadratic regulator) control, the simulation results showed that the proposed method can make the system reach a stable state with rapid convergence performance and has a feasible physical implementation.
During the past decades, earthquake has caused serious damage to cities, especially buildings. Thus, it is urgently needed to propose an effective control scheme to protect buildings from earthquake. To deal with building structure vibration easier, normally traditional control methods were researched on a certain earthquake wave; see [
It is important to prevent the building structure from vibration in a short time, which means that the control system should have a rapid convergence performance. Thus, the sliding-mode control is applied. On the basis of the system’s current deviation and various derivative values, the control system can be switched by jumping means in the transient process; see [
On the other hand, the physical implementation of the sliding-mode control method is difficult. Hence, the rapid convergence performance of the control system will be weakened. To ensure that the sliding-mode control method could be physically realized, the saturation function is presented to deal with the problem. In the switching process, it is improving the feasibility of physical implementation by avoiding direct derivation; see [
Depending on the aforementioned, fuzzy adaptive compensation control for uncertain building structural systems by sliding-mode technology is proposed. Fuzzy adaptive control is applied to compensate for the uncertain parts. Simultaneously, the sliding-mode control method is combined with saturation function to ensure the system rapid convergence performance and the feasibility of physical implementation. The main compensatory mechanism and contributions of the proposed schemes are summarized as follows.
Considering the uncertain parts of the control system, which will affect the control effect, adaptive fuzzy control is presented to approximate them. Also, building structural vibration should be suppressed in limited time, or the control is of slight significance. Thus, the commixture of the sliding-mode control and saturation function is proposed to ensure the rapid convergence performance and physical implementation.
The remaining part of the paper is constituted as follows. Models and problem statements are presented. Then, from the simulation results, the proposed method can be proved that it can suppress the uncertain seismic wave effectively by comparing with the LQR control method. They are described in Section
The one-layer building structure of interlaminar shear is researched as modeling. When the modeling suffers earthquake, the system can be described as follows:
Defining a state-space vector,
According to the rank criterion, the controllability of the building structure with earthquake can be certified. Thus, the structural vibration can be restrained by designing a control variable.
Setting
Associating with (
The system is composed of
In this section, a fuzzy logic system (FLS) is used to approximate a continuous function
For systems seen in (
Thus, the modeling of the building structure with uncertain earthquakes can be described as
The error function is designed as
According to (
Defining a Lyapunov function,
The derivative of (
Deriving from (
The traditional sliding-mode control is based on the switching function, which is designed as follows:
In order to reduce chattering, the saturation function is applied to substitute the switch function. Thus, the above control law can be transferred as follows:
In the above equation,
The derivative of (
Set
In this section, the system of the building structure is simulated. Then, the LQR control method and fuzzy adaptive compensation control are used to suppress vibration of the building structure, which is subjected to El earthquake wave. The maximum of earthquake acceleration is
The contrast simulation curves of the displacement, velocity, acceleration response, and control force are shown in Figures
Displacement response example.
Velocity response example.
Acceleration response example.
Controlling force example.
According to Table
Maximum displacement, velocity, and acceleration of first floor for example.
Control strategy | Proposed control | LQR control | No control |
---|---|---|---|
Parameter | |||
Displacement (mm) | 12 | 66 | 277 |
Velocity (m/s) | 0.03 | 0.33 | 0.71 |
Acceleration (m/s2) | 1.22 | 3.3 | 3.88 |
Therefore, it is obviously shown that vibration of a building structure can be suppressed by LQR and the proposed control method. Also, the proposed control is more effective than the LQR control, and interstory displacement is controlled within a small range. Meanwhile, the issue of chattering from the sliding modeling control is decreased effectively.
In this paper, a fuzzy adaptive compensation control for uncertain building structural systems by sliding-mode technology is proposed. For most traditional structural vibration control methods, they are difficult to ensure the system to reach a steady state with rapid convergence performance under the influence of the unknown seismic wave. The proposed method adopts fuzzy adaptive control and sliding-mode control to solve the problem. It is ensuring that the system can reach a stable state with rapid convergence performance. At the same time, in order to make the system have a satisfied physical implementation, the saturation function is applied. Finally, the control effect of the proposed method has been compared with the control effect of the LQR control method. Simulation results showed that the proposed method could meet the control requirements. From the above discussion, the feasibility and effectiveness of the proposed method are verified. In this paper, the structural parameters of building structures under unknown seismic waves deserve further study. Research in this part helps us get more accurate results.
The data used to support the findings of this study are included within the article.
The authors declare that there is no conflict of interest regarding the publication of this paper.
Zicong Chen is a co-first author.
The authors would like to thank the Associate Editors and anonymous reviewers for numerous constructive comments that have improved the presentation of this paper. This work is supported by the National Natural Science Foundation (NNSF) of China under grant numbers 51775122 and 51505092, Guangzhou City College scientific research project under grant number 1201630173, Science and Technology Planning Project of Guangdong under grant number 2016B090912007, Natural Science Foundation of Guangdong Province, China, under grant number 2015A030308011, and Program of Foshan Innovation Team of Science and Technology under grant number 2015IT100072.