Two-dimensional car suspension energy harvesting system with road harmonic base excitation

Abstract

Synthesis and analysis of suspension-embedded energy harvesters using quarter-car model is inefficient and skews the performance results of the harvesters. The preliminary analysis showed that only a small amount of vibration energy can be recovered. The quarter-car model does not allow inclusion of both the pitch and heave effects leading to underestimation of the harvesters' power generation. A 2-D suspension system is explored to capture the dynamics between the front and back wheels of the car as well as the variation in the road profile. A Go-Kart vehicle is used here to validate the model used to represent the harvesters’ dynamics and energy conversion capability. The vehicle was retrofitted with a front-mounted energy harvester built in our lab to assess the efficiency of the harvester to generate energy from speed bumps. The generated electrical power transmissibility index is used as the main objective function and constrained by a minimal ride comfort efficiency index. During the optimization process, a critical threshold ride comfort level is guaranteed through the use of a penalty factor in the objective function. The harvesters are able to recover significant amount of energy and maintain a reasonable comfort level.