Multi-objective optimization of normally-open airbag of school buses under mixed conditions

doi:10.16265/j.cnki.issn1003-3033.2022.04.011

Abstract

Abstract:

In order to improve child occupants' safety on school buses under mixed conditions, protective performance of normally-open airbag was optimized. Firstly, injury thresholds of 6-year-old and 12-year-old children were determined. Secondly, a simulation model of school buses was established and verified by sled test data, and a coupling model of school buses and normally-open airbag was built. Finally, based on different combinations of collision conditions and child ages, six mixed conditions were established. Finally, a response surface proxy model was constructed with airbag's main design parameters as optimization factors and weighted injury criterion as optimization target. The results show that according to improved NSGA-Ⅱ algorithm, the optimal configuration is upper strap length at 0.258 8 m, height of installation position at 0.385 6 m, initial pressure of exhaust at 1.199 6×10⁵ Pa, and its opening degree at 0.98. And under mixed conditions, normally-open airbag with optimal configuration can minimize risk of injuries in child occupants.

Key words: mixed conditions, school buses, normally-open airbag, multi-objective optimization, children injury thresholds

HONG Liang, LIU Gang, GE Ruhai, LI Liang, LI Siyuan. Multi-objective optimization of normally-open airbag of school buses under mixed conditions[J]. China Safety Science Journal, 2022, 32(4): 72-79.

Figures/Tables 14

Tab.1

Injury thresholds of 6-year-old and 12-year-old children

损伤指标	阈值(第50百分位成年男性)	比例缩放系数	阈值(6岁儿童)	阈值(12岁儿童)
头部伤害指标H	700	$(λ E) 2 / (λ L H) 1.5$	365.4	700.0^*(779.2^#)
胸部3 ms合成加速度a/g	60	$λ E / λ L M$	60.0^*(61.6^#)	60.0^*(69.6^#)
胸部压缩量D/mm	63	$λ L D$	38.9	51.5
左大腿力F^L/N	10 000	$λ E (λ L F) 2$	—	6 805^*(6 820^#)
右大腿力F^R/N	10 000	$λ E (λ L F) 2$	—	6 805^*(6 820^#)

Tab.1

Fig.1

Fig.2

Fig.3

Fig.4

Fig.5

Tab.2

Fig.6

Tab.3

Fig.7

Fig.8

Tab.4

Tab.5

Tab.6

References 16

[1]	中华人民共和国国家统计局. 2014年《中国儿童发展纲要(2011—2020年)》实施情况统计报告[EB/OL]. [2015-11-27]. http://www.stats.gov.cn/tjsj/zxfb/201511/t20151127_1282230.html.
[2]	GUNTER L, DAVIS J, ABULHASSAN Y, et al. School bus rear emergency door design improvements to increase evacuation flow[J]. Safety Science, 2020, 121: 64-70. doi: 10.1016/j.ssci.2019.09.007
[3]	YANG Jingzhen, PEEK-ASA C, CHENG Gang, et al. Incidence and characteristics of school bus crashes and injuries[J]. Accident Analysis & Prevention, 2009, 41(2): 336-341. doi: 10.1016/j.aap.2008.12.012
[4]	贺新. 某新型校车车身结构碰撞安全性研究[D]. 北京: 清华大学, 2016.
	HE Xin. Research on crash safety of a new school bus body structure[D]. Beijing: Tsinghua University, 2016.
[5]	TANG Youming, LYU Na, YI Liao, et al. Optimization design for seat restraint system of school bus in front impact[J]. Journal of Applied Sciences, 2014, 14(20): 2608-2614. doi: 10.3923/jas.2014.2608.2614
[6]	王树凤, 李志豪, 刘宗锋. 不同约束下乘员在车辆正碰中损伤概率预测[J]. 中国安全科学学报, 2019, 29(2): 45-50.
	WANG Shufeng, LI Zhihao, LIU Zongfeng. Prediction of probability of damage to occupants under different constraints in vehicle collision[J]. China Safety Science Journal, 2019, 29(2): 45-50.
[7]	韩勇, 唐慧聪, 田丰翼, 等. 不同约束载荷下三岁儿童乘员胸部运动方程与损伤风险研究[J]. 振动与冲击, 2020, 39(1): 216-222.
	HAN Yong, TANG Huicong, TIAN Fengyi, et al. Chest motion equation and injury risk of a 3-year-old child under different constrained loads[J]. Journal of Vibration and Shock, 2020, 39(1): 216-222.
[8]	MIROLJUB T, BATRIC V, MILENKO C, et al. The assessment of airbag deployment and seatbelt use in preventing facial injuries[J]. Forensic Science Medicine & Pathology, 2018, 14(4): 503-508.
[9]	葛如海, 应龙, 陈珣. 校车用主动式儿童安全气囊装置及其控制方法:中国,CN103786681A[P]. 2014-05-14.
[10]	葛如海, 崔义忠, 洪亮, 等. 基于NSGA-II的主动式安全气囊参数优化[J]. 汽车工程, 2020, 42(9): 1216-1223.
	GE Ruhai, CUI Yizhong, HONG Liang, et al. Optimization on parameters of active safety airbag by using NSGA-II[J]. Automotive Engineering, 2020, 42(9): 1216-1223.
[11]	GB/T26158—2010,中国未成年人人体尺寸[S].
	GB/T26158-2010,Human dimensions of Chinese minors[S].
[12]	TANNOUS R, EPPINGER R, SUN E, et al. Development of improved injury criteria for the assessment of advanced automotive restraint systems-II[R]. National Highway Traffic Safety Administration, 1999.
[13]	司俊德, 李建平, 张博强, 等. 大客车正面碰撞乘客约束系统仿真分析[J]. 中国安全科学学报, 2021, 31(3): 135-141. doi: 10.16265/j.cnki.issn1003-3033.2021.03.019
	SI Junde, LI Jianping, ZHANG Boqiang, et al. Simulation analysis of passenger restraint system in coach frontal collision[J]. China Safety Science Journal, 2021, 31(3): 135-141. doi: 10.16265/j.cnki.issn1003-3033.2021.03.019
[14]	黄毅, 姬佩君, 马令晨, 等. 台车试验碰撞波形离散性及其对儿童约束系统响应影响的研究[J]. 汽车工程, 2016, 38(4): 440-445.
	HUANG Yi, JI Peijun, MA Lingchen, et al. A study on crash waveform dispersion and its effects on the responses of child restraint system[J]. Automotive Engineering, 2016, 38(4): 440-445.
[15]	蒋水华, 曾绍慧, 黄劲松, 等. 尾矿材料渗透系数序贯概率反演分析[J]. 中国安全科学学报, 2020, 30(6): 158-165. doi: 10.16265/j.cnki.issn1003-3033.2020.06.023
	JIANG Shuihua, ZENG Shaohui, HUANG Jinsong, et al. Sequential probabilistic back analysis on hydraulic conductivity of tailings materials[J]. China Safety Science Journal, 2020, 30(6): 158-165. doi: 10.16265/j.cnki.issn1003-3033.2020.06.023
[16]	郑彦辉, 朱昌锋, 王庆荣, 等. 考虑有限理性的应急物资博弈调配双目标优化[J]. 中国安全科学学报, 2020, 30(11): 168-174. doi: 10.16265/j.cnki.issn1003-3033.2020.11.025
	ZHENG Yanhui, ZHU Changfeng, WANG Qingrong, et al. Bi-objective optimization of emergency material game allocation considering limited rationality[J]. China Safety Science Journal, 2020, 30(11): 168-174. doi: 10.16265/j.cnki.issn1003-3033.2020.11.025

儿童年龄	损伤指标	原始波形	简化波形	误差/%
6岁	H	113.57	115.02	1.28
6岁	a/g	28.45	28.12	1.16
12岁	H	275.79	273.59	0.80
	N	1.114 1	1.071 2	3.85
	a/g	19.18	18.52	3.44
	F^L/N	940	954	1.49
	F^R/N	2 094	2 154	2.87

碰撞波形	6岁儿童	12岁儿童
波形1	工况1	工况4
波形2	工况2	工况5
波形3	工况3	工况6

优化因素	初始值	最优值
上部拉带长度x₁/m	0.235 0	0.258 8
安装点高度x₂/m	0.395 0	0.385 6
泄气阀开启压力x₃/Pa	1.250 0×10⁵	1.199 6×10⁵
泄气阀开度x₄	1.00	1.98

工况	H	a/g	W₆
工况1(优化前)	315.57	29.08	0.750 0
工况1(优化后)	164.04	26.87	0.448 6
优化前后伤害变化率/%	-48.02	-7.60	-40.19
工况2(优化前)	596.87	39.58	1.341 3
工况2(优化后)	355.62	38.49	0.873 7
优化前后伤害变化率/%	-40.42	-2.86	-34.86
工况3(优化前)	1 061.60	48.42	2.275 8
工况3(优化后)	696.32	48.61	1.577 0
优化前后伤害变化率/%	-34.41	+0.39	-30.71

工况	H	N	a/g	D/mm	W₁₂
工况4(优化前)	72.44	0.427 6	17.10	14.64	0.202 4
工况4(优化后)	40.96	0.302 6	16.47	12.13	0.154 3
优化前后伤害变化率/%	-43.46	-29.23	-3.68	-17.15	-23.77
工况5(优化前)	147.89	0.570 1	23.50	15.59	0.303 8
工况5(优化后)	99.17	0.443 7	20.94	13.05	0.237 7
优化前后伤害变化率/%	-32.94	-22.17	-10.89	-16.29	-21.76
工况6(优化前)	262.90	0.728 9	31.83	15.99	0.442 5
工况6(优化后)	186.71	0.596 5	28.41	14.20	0.355 1
优化前后伤害变化率/%	-28.98	-18.16	-10.75	-11.19	-19.75