Optimization of a swinging energy harvesting from car suspending using bat algorithm: a study

ABSTRACT To enhance the electrical power supply for electric vehicles, this study proposes integrating a gear–rack mechanism within the suspension system to generate rotational electricity. The mechanism employs a generator coupled concentrically with the gear, enabling higher induced power output. When the rack undergoes vertical reciprocating motion due to suspension vibrations, the gear is engaged through the gear–rack mechanism, thereby driving the generator to produce electricity. The generator is driven by the oscillatory gear motion transformed by the gear–rack mechanism. To simplify the analysis of energy harvesting, a quarter-car model is adopted. This study investigates the influence of sinusoidal road excitations on power generation and evaluates the maximum power generation capacity under acceptable ride comfort conditions. To maximize electrical power extraction from the suspension system using oscillatory energy harvesters, the Bat Algorithm is employed. The root-mean-square (RMS) electrical power, denoted as PWT(RMS), is selected as the optimization objective. Considering ride comfort efficiency (RCE), a penalty factor is incorporated into the optimization process to eliminate inferior design solutions. Both constant-speed and variable-speed driving scenarios are examined. The results show that, under constant vehicle speed without RCE constraints, a quarter-car model equipped with two energy harvesters can achieve a maximum power output of 15.407 W. With the RCE constraint applied under constant vehicle speed, the maximum power output is 8.5 W. Under the RCE constraint with varying vehicle speeds from 60 to 90 km/h, the combined electrical power from the two energy harvesters reaches 10.3 W.