Experimental investigation of an active mass damper with acceleration feedback sliding mode control

Active control strategies are more powerful and attractive than passive and semi-active control strategies. An active control device, namely active mass damper (AMD), consists of mass, a guideway, and an AC-driven motor and can provide a widely applicable range of control forces with a very limited power requirement. This device can be more effective to suppress earthquake- or wind-induced vibrations to civil structures. Various innovative control algorithms have been developed to drive AMD against seismic loads, and these new or improved algorithms are also found as a key element in smart structure technology. Some research on active control strategies for the reduction of the seismic responses uses either full-state or, at least, velocity feedback; however, the accurate measurement of the displacement and velocity is typically unavailable from real-world structures. Instead, the control algorithms based on acceleration feedback are more feasible for the practical implementation of control system. In this study, an active control system is developed by integrating an AC-driven AMD and accelerometers. This system is comprised of a real-time embedded system with a control algorithm which executes the sliding mode control (SMC) with acceleration feedback. The acceleration feedback SMC controller is designed in accordance with an identified model of a model building. Subsequently, this control system is experimentally implemented and verified using shake table testing. Performance of the integrated system as well as the responses of the frame are evaluated and discussed to demonstrate the effectiveness of the acceleration feedback SMC algorithm in mitigating vibrations of seismically-excited structures.