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Interpretation and Optimization of an Adaptive Restraint System With Special Consideration for "Out-of-Position" Situations
Technical Paper
2000-31-0007
Sector:
Event:
Airbag 2000
Language:
English
Abstract
As early as the November '96 "Airbag 2000
Symposium" different speakers had already presented
information about the problems associated with restraint systems.
The injury risk factors from out-of-position children and adults
were clearly identified, and potential solutions were presented.
These solutions centered mainly on multi-level output inflators,
that could support "smart restraint solutions." In
addition the different control parameters and load cases were
defined. A crash specialist from the medical profession recommends
that safety system deployment characteristics should be based upon
crash severity and its direction. It was further stated that the
system should be "tunable" to account for occupant size
as well as position within the vehicle compartment. A list of
potential sensor systems and actuators
(seatbelts/airbags/pre-tensioner/load-limiter) were also presented
at this time.
It can be seen that an increase in system requirements will
force larger expenditures for system development. The question is
how to optimize the system development to minimize testing and
ultimately costs. Numerical simulation is one such possibility that
has the potential to reduce these development costs.
In looking at the hardware, the question is: "Which sensors
and safety components, when combined, make the best safety
system." In other words which system will reduce occupant
injuries and yield the most benefit. This decision must be computed
together with the overall system expenditures, as no one wants to
develop and install a system that does not yield additional
benefit. From a sensor point of view we must concern ourselves not
only with which information is relevant, but also how reliable are
the sensors themselves. Each sensor system has the potential for
failure, and we must be aware of the consequences associated with
this possibility.
The objective of this study was to develop potential solutions
for better defining and optimizing a restraint system. This was
based on an understanding of the interactions between the different
subsystems, and ultimately defining a system strategies. The job
was undertaken by a multi-firm workgroup where each partner
contributed their respective strength to the project. Breed
Technology was chosen to be responsible for the airbag technology
because of there strength in design, production and module
optimization. Siemens Restraint Systems was brought in for their
expertise in numerical simulation and development methods. Finally,
Opel was responsible for the overall system development and
integration, based on a current vehicle platform.