The particle swarm modified quasi bang-bang controller for seismic vibration control

The frequent occurrence of seismic events results in the damage to the structures. Structural control is one of the popular methods to prevent these damages. In structural control, the main objective is to impart an adequate counterforce. This required counter force is determined by a suitable control algorithm. In this work, an optimized and adaptive control algorithm is proposed based on modified quasi bang-bang control algorithm to generate the adequate counterforce. The constant output weights used in the modified quasi bang-bang controller are optimized for best performance in dynamic loading such as earthquake using the particle swarm optimization (PSO). The proposed optimized controller is then applied to a three storey prototype structure fixed with an MR damper. This structure has been subjected to various seismic events for performance evaluation. The results thus obtained are compared with best performing clipped optimal linear quadratic Gaussian (LQG) controller, quasi bang-bang and modified quasi bang-bang controller. The results establish that the PSO modified quasi bang-bang controller is superior to the other controller in reducing the structural responses i.e. relative displacement, interstorey drift and the absolute accelerations. Further, the voltage comparison shows that the power consumption is less for the proposed controller in attaining better performance.