Research On Ease Of Use Rating System For Vehicle Child Restraint System

Misuse of child restraint system (CRS) is a common issue, although CRS canprovide protection only under correct use cases. While CRS popularity is a future trendfor children safety protection in car, high attention should be pay to the CRS usability.Based on the study on CRS usability and CRS misuse, this paper established the Ease ofUse Rating System through analytic hierarchy process (AHP) method. This ratingsystem can provide reasonable and impartial product information for CRS conmsumersfor proteceting their rights, and can also promote the CRS manufactures for highstandards in CRS designing and manufacturing.This paper carried out systemic study on CRS usability. All the design charactristicand information from labels and instructions of11child seats were collected forusability analysis, and usability specifications for labels and instructions were putforward.78usability tests were carried out to analyze the misue modes and theincidence relation between CRS usability and misuse.6child seats were classified bythe usability tests at the same time.To improve children on-board safety and reduce CRS misuse rate, a survey for240parents was conducted in Beijing. Survey results show that the CRS misuse rate is morethan70%in China, CRS users have little knowledge and awareness about CRS misuse.Based on this survey data and foreign CRS misuse data, this paper time carried out CRSmisuse sled tests containing8modes at the first. Sled tests results illuminate that CRSmisuse has significant impact on child safety, and among these different misuse modes,should-belt-under-armpit mode has the most significant impact on children safety whicheven increase500%on HIC15.Baed on the study on CRS usability, this paper established the CRS ease of userating index system, including4parts which are evaluation of labels, evaluation ofinstructions, evaluation of child securing and evaluation of seat installing.4rating tableswere formulated which defined each rating basis for every rating index. Based on risk ofmisus from the misuse sled tests and related foreign research results, each rating indexwas gave a weight value according to the indicence relation between indexs and misusemodes through the AHP method. With the index weight given and the fainal scoringmethod, the preliminary program of CRS Ease of Use Rating System was established.