Structural modal parameter identification incorporating with semi-active piezoelectric control

In this paper, we present a novel structural identification method using semi-active inputs generated by piezoelectric transducers. Structural identification using input and output information provides an accurate structural model. Conventional identification uses a maximum-length sequence, whose signal shape is similar to a square wave, as input. To generate inputs suitable for identification, several devices are required. These devices consume a lot of energy. If inputs are generated by a small number and simple design devices with low consumption, structural identification will be more practical. Piezoelectric semi-active control has been used in the research field of vibration control. This control generates a semi-active input whose signal shape is similar to a square wave. The semi-active input is generated by a simple circuit. The generation of the semi-active input consumes little energy. Therefore, the semi-active input has the potential to be used as an identification input instead of the maximum-length sequence. The property of the semi-active input is related to the generation strategy. This paper proposes a novel strategy to generate a semi-active input suitable for identification. Due to the unique mechanism of semi-active input generation, the novel strategy sometimes has the problem of generating semi-active inputs that are not suitable for identification. This paper discusses the reason and the solution to this problem. The feasibility of semi-active identification is presented through the numerical simulation and validation experiment. The identification result of the proposed method was close to the exact model. The proposed method achieved a 99% reduction in energy consumption.