Design of multi-density foam-cell headrest using focus scattering whale optimisation

This study proposes a Focus Scattering Whale Optimisation Algorithm (FS-WOA), which is a modification of the Whale Optimisation Algorithm (WOA), a state-of-the-art meta-heuristic technique. This modification integrates two complementary strategies: a focusing process that facilitates efficient convergence towards the global optimum and a scattering process that promotes search across diverse regions of the global domain, thereby mitigating premature convergence for optimising high-dimensional problems as well as increasing computational efficiency with a minimum number of agents. The proposed algorithm was rigorously validated using 41 complex benchmark functions and subsequently employed to optimise the headrest position and spatially varying foam density distribution in a multi-density foam-cell (MF) headrest designed for wheelchair-accessible vehicles. The primary objective was to reduce passengers’ neck injury during rear-end collisions. It was found that the MF headrest was successfully optimised with the help of FS-WOA, which exhibited superior convergence characteristics and produced accurate solutions, highlighting its effectiveness in addressing complex, high-dimensional occupant safety optimisation problems.