A novel servomechanism based proportional–integral controller with Kalman filter estimator for seismic response control of structures using magneto‐rheological dampers

Abstract

This study presents a novel digital control algorithm with state estimator technique for semi-active control of structures with magneto-rheological (MR) damper. The proposed control strategy is based on servomechanism (popularly known as command-following or tracking system), where the measured output of a system pursues the command of reference input. This is achieved through a hybrid proportional-integral (PI) controller, different from the conventional output or state-based feedback design, where the control force is proportional to the feedback of internal state (i.e., displacement and velocity) as well as the integral state (i.e., integral of output error signal) of the system. In this approach, optimal observer technique through Kalman filter is modified to estimate the full state and integral state vector of the system for feedback from the measured absolute acceleration output. Optimal gains of the proposed regulator (i.e., both proportional and integrator gains) and estimator are formulated by minimizing a desired performance index in discrete time. In addition, the present study proposes a direct algorithm, where the applied voltage to the MR damper varies continuously between the maximum and minimum range instead of being restricted to only maximum and minimum values. The adequacy of the proposed strategy is studied in terms of reduction in the following: (a) structural responses, (b) optimal control force, (c) sensor noise and process noise covariance of the filter output, and (d) applied voltage (as compared to clipped on-off case). Finally, it has been demonstrated that the proposed control algorithm provides superior performance and stability in comparison to the conventional proportional (state)based techniques.

Decentralized H2-Based Semi-Active Control To Suppress Transient Vibration Of Structures

“…For the time-history analysis, present study considered 4 ground motions (GMs) from SAC ground motion database having different hazard levels [10]. The detailed characteristics of the GMs are provided in Table 2.…”

“…Here, the notations 𝐹, 𝑔 𝑞 , and 𝐸 represent the system plant matrix and the input matrices for the external actuator force and seismic excitation, respectively [10]. Further, a controller is designed to stabilize the system in Eq.…”

“…In case study, the efficacy of the designed decentralized controller is examined by performing a numerical simulation with an 8-story shear building as shown in Fig. 2(a) [10]. The designed controller in H2 framework is implemented in the discrete time domain.…”

Development and performance evaluation of a robust suboptimal H ∞ ‐based proportional–integral controller–observer system with target tracking for better control of seismic responses

“…Recently, Chakraborty et al 18 and Sachdeva et al 19 have applied nonlinear conical spring as re‐centring mechanism for the flat sliding base‐isolation system, which shows that the nonlinear spring though effective in reducing base sliding, amplified the relative floor displacement during strong shaking. In order to reduce in inter‐storey drift during strong ground shaking while resisting the huge base sliding, a servo‐mechanism‐based proportional to state and integral of output error (proportional–integral [PI]) controller is proposed to mitigate the responses of a building during strong ground shaking 20 …”

“…In order to reduce in inter-storey drift during strong ground shaking while resisting the huge base sliding, a servo-mechanism-based proportional to state and integral of output error (proportional-integral [PI]) controller is proposed to mitigate the responses of a building during strong ground shaking. 20 In practice, robust control technique is preferred for mathematical models having unmodelled dynamics and uncertainty in the physical parameters and are exposed to external disturbances and measurement noises. As elaborated in Zand et al 21 and Zhang et al, 22 the representative models in such scenario is different from the actual ones, and the available conventional control theories 1 may not provide the desired performance and stability of the perturbed structure-controller system.…”