Airbag with bag mounted sensor
View Patent ↗A vehicle occupant position sensor is mounted on the front of an airbag which is deployed toward a vehicle occupant. The sensor comprises a capacitance sensor constructed by rendering portions of the airbag which face the vehicle occupant conductive. The airbag on which the sensor is placed is also constructed to allow venting of the airbag before it is fully deployed. The distance between the sensor and the vehicle occupant is continually determined with respect to the sensor. The output of the capacitive sensor is processed by a control system and is used to predict the interaction between the airbag and the vehicle passenger and to cause the airbag to be vented if that interaction is predicted to be more harmful than beneficial to the vehicle occupant. A system which prevents airbag venting once the airbag is inflated or nearly inflated can also be employed.
1. An airbag system comprising:
An airbag housing;
An airbag mounted to the airbag housing, and having an occupant facing portion which, when the airbag is inflated, faces an occupant position;
a source of gas mounted to the airbag housing in gas supplying connection to the airbag to cause the airbag to inflate when a flow of gas is initiated;
an electromagnetic wave transmitter fixedly mounted with respect to the airbag housing;
an electromagnetic wave receiver fixedly mounted with respect to the airbag housing;
a reflector mounted to the occupant facing portion of the airbag so that when electromagnetic waves are transmitted by the transmitter toward the reflector, the electromagnetic waves are reflected toward the receiver;
a controller operably connected to the transmitter and receiver to calculate at least one displacement derivative with respect to the reflector, wherein the controller is connected in controlling relation to a vent mounted to the airbag housing and operable, in response to a command from the controller, to allow an escape of gas from the airbag; and
a means for detecting at least one stage of airbag inflation, and operatively connected to the vent to inhibit opening of the vent when the at least one stage of airbag inflation is detected.
2. The airbag system of claim 1 wherein the reflector comprises a conductive area of the occupant facing portion of the airbag.
3. The airbag system of claim 1 wherein the reflector is a passive reflector.
4. The airbag system of claim 1 wherein the means for detecting at least one stage of the airbag inflation is a wire connected to the occupant facing portion of the airbag.