Integrated Spectral and Geospatial Analysis of Mechanical Vibrations in a Light Urban Vehicle for Piezoelectric Energy Harvesting Optimization

This paper presents an integrated methodology for the spectral and geospatial analysis of mechanical vibrations in a light urban vehicle (Vespa Piaggio PX150) with the aim of optimizing piezoelectric energy harvesting (EH) systems. A triaxial accelerometer and GPS module were installed on the vehicle to acquire vibration and geolocation data along a real urban and suburban route. The signals were processed using Fast Fourier Transform (FFT) and Power Spectral Density (PSD) analysis, followed by a novel frequency approach based on Sturges’s rule, to identify dominant power bands. The results were georeferenced to produce a chromatically coded geographic map that highlighted optimal EH zones. The study confirms that lateral and vertical vibrations, particularly in the 45–65 Hz range, are most promising for EH applications. The proposed methodology is a first step in establishing a comprehensive framework for the design and development of vibration-based EH systems in urban mobility contexts.