Battery-Less Soft Sensor of Spacecraft Vibration with Advanced Piezoelectric Energy Harvester

Suppression of structural vibration in a spacecraft is crucial because the vibration hinders the proper operation of the spacecraft and scientific investigations. An active vibration control method has a more effective damping performance than a passive control method. An active method requires an actuator, a power source, and a sensor to realize the vibration suppression. However, the active method has not been adapted for suppression of structural vibration on a spacecraft because the three components required for the active method lead to structural weight gain and a more complex spacecraft design. Recently, smart structurization has been received considerable attention as an effective method to realize a low-weight advanced control system. A piezoelectric transducer attached to a vibrating structure can function as an actuator, an energy source, and a sensor and thereby meets the three requirements for an active vibration control method. This paper reports on the integration of the three functions into a single piezoelectric transducer. The proposed system achieves vibration suppression with a minimal number of components and a simple design. Experimental validation of the estimation and vibration suppression performance are presented. The proposed system achieves the vibration suppression using a single transducer. Evaluation of the robustness of the vibration suppression performance against observation noise is also detailed. The proposed system can maintain effective performance while operating under noise-contaminated conditions.