New belt geometries in rear seat from a comfort, handling and safety perspective

Purpose and goal

The overall aim of the project was to evaluate different seat belt concepts that can help maintain the rear seated occupant well restrained during a crash, including potential pre-crash maneuvers. Different aspects influencing the seat belt position/placement was to be evaluated; including attitude, handling and comfort as well as various pre-crash scenarios such as evasive maneuvers. Two complete concepts with new belt geometries was developed and evaluated in attitude, handling and comfort aspects. o The attitude study resulted in comprehensive understanding of how new belt concepts are received and what makes the user wanting and not wanting to use the belt system. o The handling study resulted in increased knowledge of how the first time user handle this type of belt systems. o The driving studies resulted in increased knowledge of how the user perceive the comfort of the systems during driving sessions. oThe handling problems among the first time users were further evaluated in an in-depth study. Pre-pretensioner retention of child and adult crash dummies was evaluated for various pre-crash scenarios in an extensive test program; The studies have resulted in comprehensive knowledge, including new methods to evaluate belt systems in terms of attitude, handling and comfort and crash safety. This input can be used by the industry to design future safety systems. The project has resulted in academia results, such as several student project works, Master thesis (60 hp). There is ongoing work to publish results in scientific publications.

Results and expected effects

Qualitative input to the design of future safety systems, which will improve the protection to the occupant and thereby contribute to fulfill Vison Zero as well as VINNOVA´S aim of reducing fatalities in motor vehicle crashes. The project has contributed to improve the co-operation between university and industry as well as between industry partners. The comprehensive work, including concept development and evaluation, contributes to the possibility of industrial development of new products. The project has also contributed with further developing the competence within child safety research, an area where Swedish car industry has a long heritage and leading position. The project contributes to maintain and further develop the competence in pre-crash safety, both within product and method development The project has written internal reports and work is ongoing to publish result in peer-reviewed journals.

Approach and implementation

The project was divided into three phases: 1)concept development, 2)attitude, handling and comfort study, 3)safety aspect study. Initially, the focus was on evaluation of concepts with extra belt. A redesign of the concepts was made after each evaluation in order to adapt the product to the user. This was a user focused iterative development and evaluation process, resulting in solutions showing both advantages and disadvantages of the concepts. The crash safety study focused on a third concept, pre-pretensioner. Various pre-crash scenarios were evaluated in a comprehensive test program. The testing included methods such as crash tests with pre-braking, vehicle equipped with a robot driving device tested in steering maneuvers and in rough road driving into ditch and new test method in lab environment simulating rough road driving into ditch.