Electronic seat belt tensioning system
First Claim
1. A method of controlling the tension of a vehicle seat belt comprising the steps of:
- detecting deployment of said seat belt from a wound condition to an unwound condition;
determining the amount of seat belt which is unwound;
activating a winding means to incrementally rewind the seat belt until a first predetermined tensive force is exhibited by the seat belt on a vehicle occupant;
deactivating the winding means to substantially release the first predetermined tensive force exhibited by the seat belt on the occupant to place the seat belt in a substantially tensionless state;
continuously monitoring the amount of seat belt unwound while in the tensionless state;
comparing the monitored amount of seat belt unwound to a predetermined pay out value;
generating an out-of-position alarm if the monitored amount exceeds the predetermined pay out value;
continuously monitoring vehicle acceleration;
determining whether the vehicle acceleration has exceeded a first threshold value;
if the first threshold value is exceeded, activating the winding means to rewind the seat belt until a second predetermined tensive force is exhibited on the occupant;
deactivating the winding means to release the second predetermined tensive force exhibited by the seat belt if the vehicle acceleration falls back below the first threshold value;
determining whether the vehicle acceleration has exceeded a second threshold value greater than the first threshold value;
triggering a pretensioner means if the second threshold value has been exceeded, said pretensioner means rewinding said seat belt with a third predetermined tensive force greater than the second predetermined force generated by the winding means.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and system (10) for controlling the tensioning of a vehicle seat belt utilizes a control processor (20) and a motor (12) to provide initial tensioning of the seat belt. After initial tensioning, the control processor (20) removes substantially all tension on the seat belt while continuously monitoring seat belt pay out via an encoder (18). The system provides out-of-position warnings, and is responsive to vehicle acceleration information from a crash discrimination system (22) and/or an object detecting radar system (26) to control tensioning of the seat belt. The system further provides for earlier seat belt tensioning activation by utilizing a pyrotechnic pretensioner (32) having a replaceable pyrotechnic cartridge (38).
176 Citations
9 Claims
-
1. A method of controlling the tension of a vehicle seat belt comprising the steps of:
-
detecting deployment of said seat belt from a wound condition to an unwound condition; determining the amount of seat belt which is unwound; activating a winding means to incrementally rewind the seat belt until a first predetermined tensive force is exhibited by the seat belt on a vehicle occupant; deactivating the winding means to substantially release the first predetermined tensive force exhibited by the seat belt on the occupant to place the seat belt in a substantially tensionless state; continuously monitoring the amount of seat belt unwound while in the tensionless state; comparing the monitored amount of seat belt unwound to a predetermined pay out value; generating an out-of-position alarm if the monitored amount exceeds the predetermined pay out value; continuously monitoring vehicle acceleration; determining whether the vehicle acceleration has exceeded a first threshold value; if the first threshold value is exceeded, activating the winding means to rewind the seat belt until a second predetermined tensive force is exhibited on the occupant; deactivating the winding means to release the second predetermined tensive force exhibited by the seat belt if the vehicle acceleration falls back below the first threshold value; determining whether the vehicle acceleration has exceeded a second threshold value greater than the first threshold value; triggering a pretensioner means if the second threshold value has been exceeded, said pretensioner means rewinding said seat belt with a third predetermined tensive force greater than the second predetermined force generated by the winding means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A vehicle seat belt tension control system comprising:
-
a control means coupled to a seat belt tensioning mechanism, said control means comprising; a processor means for monitoring a predetermined condition of the vehicle; an electric motor coupled to said seat belt tensioning mechanism for adjusting the tension of said seat belt based on the monitored vehicle condition; means for detecting seat belt payout; means responsive to said pay out detecting means for detecting an unsafe occupant seating condition; and a tactile warning means coupled to said seating condition detection means and said control means for alerting the occupant to a detected unsafe seating condition by causing said electric motor to momentarily increase the seat belt tension to tug on the occupant; and a pretensioner means connected to the seat belt tensioning mechanism for tensioning the seat belt in response to a detected emergency vehicle condition, said pretensioner means comprising a replaceable pyrotechnic cartridge.
-
Specification