Intellectual power generation by stand-alone active harvester with digital control unit

Abstract

Piezoelectric vibration energy harvester should harvest electricity from kinetic energy effectively. The passive harvester is limited in its harvesting performance by the scale of the disturbances. Intellectual harvesting has been proposed to obtain higher harvesting performance than the passive one from the same scale of disturbance. The intellectual harvesting is realized by a voltage inversion circuit, a specific control strategy, and a controller, which has enough computational capacity to achieve the adopted control strategy appropriately. The initial intellectual harvesting has been implemented by an analog controller, which has low energy consumption but low computational capacity, and a simple strategy. For higher performance and wider usage than the initial strategies, the computational capacity of the controller has required to increase in proportion to the complexity of the recent strategies. We proposed the stand-alone active harvester equipped with the digital controller to accomplish a novel control strategy for complex but high performance. The stand-alone harvester is driven in self-powered by the harvested electricity itself without an external energy source. The harvester has the noise reduction function with an observer based on Kalman filter theory owing to its high computational capacity and achieves appropriate controlling following the strategy even if noise is contaminated in an observation value. This study shows the whole evaluation of the proposed harvester.