基于边缘人体模型仿真的座椅设计方法研究

A Research on Seat Design Methodology Based on Boundary Manikin Simulation

为有效地指导座椅设计,提高坐姿舒适性,提出一种以边缘人体模型和体压分布仿真为依据的座椅正向设计方法。首先以某乘用车驾驶座椅设计为例,建立H点装置有限元模型,通过仿真H点装置在座椅上的落座来预测座椅H点,以此H点作为靠背设计的基准点;然后提炼出与数字人体建模和驾驶姿势预测相关的人体测量学尺度,通过Monte Carlo仿真建立目标人群的人体测量学尺度数据样本,并通过主成分分析,建立相应的边缘人模型;接着编写仿真程序,运用姿势预测模型来仿真边缘人背部特征点的分布,并将它们统一到以H点为原点的坐标系中;选取统一后的边缘人腰部特征点分布上下、前后方向的4个极限点来确定座椅腰部支撑面的位置和调节量;最后结合边缘人的人-椅压力分布仿真,反求椅背海绵的初始型面。该正向设计方法能保证人体背部与座椅之间合理的压力分布,使人体背部特征点与变形后靠背特征部位有效贴合,增加座椅的贴合感和支撑性,从而有效提高坐姿的舒适性。

For effectively guiding seat design and improving postural comfort, a forward design method for seat is proposed based on boundary manikin （ BM） and the simulation on body pressure distribution. Firstly with the design of a passenger car seat as an example,a finite element model for H-point machine is built and by simulating the subsiding of H-point machine to seat, the H-point position of seat is predicted and used as reference point for seatback design. Then anthropometry dimensions related to digital human modeling and driver posture prediction are extracted with the data samples of anthropometry dimensions of target population generated by Monte Carlo simulation, and the corresponding BMs are established through principal component analysis. And a computer program is developed to simulate the distribution of BMs’ back characteristic points with posture prediction model, and the characteristic points of BMs’ back are re-aligned into the Cartesian coordinate system with the H-point as its origin. Of realigned lumbar characteristic points of BMs, four extreme points in both up-down and foreaft directions are used to determine the position and adjustment range of seat lumbar support. Finally with a simulation on the distribution of pressure between seat and BMs’ body, the initial surface of seatback sponge is worked out inversely. The forward design method proposed can ensure the rational pressure distribution between human back and seat, and make the characteristic points of human back tightly fitted to the corresponding part of deformed seatback, enhancing the‘good fit’ feeling and support of seat, and hence effectively improving postural comfort.