Robustness evaluation of the damped outrigger structure

Abstract

Robustness is defined as the insensitivity of the structure to uncertainties like earthquakes, fire, cyclones, explosions, tsunamis, etc. Robustness analysis of Kalman observer with robust controller for damped outrigger structure is studied to analyze its design performance in the presence of various effects like an earthquake. This is a novel innovative study undertaken in evaluating the robustness of the proposed controller to signify its performance in the field of structural control. The damped outrigger structure is modeled using the finite element approach by finding mode shapes, fundamental natural frequency, and period. The Kalman observer is modeled according to the requirement of the structure with the Riccati equation. The robust proportional–integral–derivative controller is designed according to the input disturbance with Ziegler–Nichols ultimate gain approach. The issue of deterioration in the system performance due to saturation was observed during the analytical investigation of the robust proportional–integral–derivative controller with Kalman observer, which has been addressed by the anti-windup approach. The robustness index of the structure is calculated using sensitivity and complementary sensitivity. The maximum amplitude ratio of the sensitivity for viscous damper-controlled structure is 1.4723 and the value decreases for the other controllers, with a minimum value of 1.0 for the proposed anti-windup robust proportional–integral–derivative controller with Kalman observer. Respectively, the percentage overshoot for the uncontrolled case is 23.4% that values decreasing for other controlled cases, with a minimum of 7.8% for proposed anti-windup robust proportional–integral–derivative controller with Kalman observer. This robustness index and performance indices discriminate the significant robust performance of the proposed robust proportional–integral–derivative controller with Kalman observer-based damped outrigger structure in comparison with other controlled and uncontrolled cases.