Investigation and Application on the Vertical Vibration Models of the Seated Human Body

Abstract

Investigation of the vertical vibration characteristics of the seated human body is beneficial for the design and development of vehicle ride comfort. In this study, we first established models of the seated human body with two, three and four degrees of freedom (DOF). Then, the vibration characteristics of 30 volunteers were tested under standard conditions with a vibration test rig to obtain data for the apparent mass, driving point mechanical impedance, and seat-to-head transfer function. Based on the experimental data, the parameters of these models are identified and the results show that the four-DOF model can simulate the vertical vibration characteristics of the seated human body more comprehensively. Then, different seated human body models were applied to optimize the damping of shock absorber. The results show that the optimized damping with the four-DOF Chinese seated human body model is 27% more than that with rigid mass and 7% less than that with ISO 5982:2001 seated human body model. Keywords

Development of a 7-DOF Biodynamic Model for a Seated Human and a Hybrid Optimization Method for Estimating Human-Seat Interaction Parameters

“…measured at the head, trunk, thigh, and leg were used as feeding data in the objective function to estimate the unknown stiffness and damping parameters. The parameters were subject to upper and lower bounds obtained from reviewing the published range of values of stiffness and damping in the literature [15,16,[25][26][27]. The specified bounds limit the estimated stiffness and damping coefficients to only positive values and speed up the convergence of the optimization algorithms.…”

“…However, there is still an exhaustive search for the appropriate optimization method that produces reliable estimates of these human parameters. For instance, Bae and Kang, Shao et al, and Huang et al (2020) [10,15,16] optimized the parameters of 2-, 3-, 4-, and 5-DOF models using the gradient-based MATLAB function, called "fmincon". Zhang et al [17] introduced a reference vector-guided evolutionary algorithm to obtain the parameters of a 7-DOF human model, whereas Zhao et al [18] explored multi-objective and genetic algorithms (GAs) for parameter identification of a 5-DOF model.…”