An Intelligent Self-Powered Pipeline Inner Spherical Detector With Piezoelectric Energy Harvesting

To break the limits of traditional pipeline inner spherical detector (PISD) application distances, this paper proposes a design of a piezoelectric energy harvester to develop an intelligent self-powered PISD. The harvester converts rotating mechanical energy into electrical energy. Due to restrictions in internal space and prohibition of magnet application, the harvester consists of a piezoelectric cantilever beam without any auxiliary structures. The fixed end of the harvester is fixed to the PISD shell and the free end extends in the direction of the center. A dynamic model was derived through the Euler–Lagrange method and an experiment platform with macro fiber composite was built. The harvester was designed in three schemes, and the longest harvester of 100 mm achieved optimum performance. After load optimization, $15.27~\mu \text{W}$ was obtained at 2.6 Hz, which is the rotational frequency of the PISD. A PISD prototype with a harvester was built and a pipeline experiment was conducted to analyze the output characteristics of the smooth operation and the passing weld operation. The results demonstrate that the proposed piezoelectric energy harvester has the potential to establish an intelligent self-powered PISD.