4-DOF biodynamic lumped-parameter models for a seated occupant

In order to study how vibrations from ground vehicles/aircraft will impact on the seated occupants, it is of significance to develop an effective biodynamic model for the seated occupants. In this paper, a wide variety of 4-degree-of-freedom (4-DOF) lumped-parameter models for a seated occupant is investigated. A linear 4-DOF model with 18 parameters is deduced and employed as an example. The parameters of the 4-DOF model are identified based on the Pareto optimization principle. The goodness of fit (epsilon) is established and employed to evaluate the effectiveness of the models. Then, all possible linear 4-DOF models are analyzed and discussed with the same parameters identification and effectiveness evaluation. The most-effective two models are obtained and compared with two other existing models. The research results show that: (i) The total types of linear 4-DOF models is limited and all the parameters of models are identifiable; (ii) The number of parameters of the 4-DOF models affects little on the goodness of fit (e); and (iii) The presented models are more effective than the two existing models.