Blind switch damping (BSD): A self-adaptive semi-active damping technique

Much attention was given to the control of vibrations for smart structures equipped with piezoelectric elements in the nineties. Active control has shown its efficiency, however, necessitating important power requirements and complex signal processing. To bypass these drawbacks, semi-passive control schemes have been proposed. In the semi-passive approach, the piezoelectric element is intermittently switched from open circuit to a specific circuit synchronously with the structure motion. Such systems are simpler than active control methods and require low power supply (they can even be self-powered), but necessitate a deterministic approach. In this paper, a novel semi-passive method is proposed for a piezoceramic actuator coupled with a switching resistor/inductor shunt. This method, named BSD (for blind switch damping), has the advantage of being independent from the structure vibrations and does not need any model of the smart structure. This technique also exhibits low requirements in terms of power supply. In the BSD technique, the piezoelectric element can be either switched on a short circuit or the piezovoltage magnitude can artificially be increased by switching on piecewise constant or adaptive voltage sources, making the approach semi-active. Experimental measurements carried out on a simple structure (clamped-free smart beam) show good agreements with theoretical predictions, exhibiting damping performances similar to previously proposed semi-passive and semi-active methods.