Integrated occupant protection system

An integrated occupant protection system (10) for a vehicle comprises a vehicle seat (12), which may be mounted in the vehicle. The seat (12) has a lower seat portion (14) and a seat back portion (16). An electrical communications bus (26) is mounted to the vehicle seat (12). A crash sensor (44) also is mounted to the vehicle seat (12) and electrically coupled to the communications bus (26). The crash sensor (44) senses a crash event and provides a signal indicative thereof to the communications bus (26). An actuatable occupant protection device (46, 48, 50 or 64) is mounted to the vehicle seat (12) and electrically coupled to the communications bus (26). When the protection device (46, 48, 50 or 64) is actuated, it helps to protect a vehicle occupant. The occupant protection device (46, 48, 50 or 64) is controlled over the communications bus (26) by a controller (47, 34).

TECHNICAL FIELD 
The present invention relates to a vehicle occupant protection system, and 
more particularly to an integrated occupant protection system which is 
part of a vehicle seat. 
BACKGROUND OF THE INVENTION 
Numerous vehicle occupant protection systems have been developed to help 
protect vehicle occupants during various types of crash events. Known 
actuatable occupant protection systems include, for example, front 
passenger and driver side air bags, seat belt pretensioner devices, side 
impact air bags, and air bags for the head. Crash sensors are used in such 
protection systems to sense various types of crash events. 
Known occupant safety equipment often requires substantial assembly and 
burdensome installation procedures by automobile manufacturers. The 
manufacturers also frequently purchase and install safety equipment as 
individual components. This generally results in undesirable expenses 
associated with inventory and with the installation and testing of such 
components. 
SUMMARY OF THE INVENTION 
The present invention is directed to an integrated occupant protection 
system for a vehicle. The system includes a vehicle seat mountable in the 
vehicle. The seat has a lower seat portion and a seat back portion. An 
electrical communications bus is mounted to the vehicle seat. A crash 
sensor is mounted to the vehicle seat and electrically coupled to the 
communications bus. The crash sensor senses a crash event and provides a 
signal indicative thereof to the communications bus. An actuatable 
occupant protection device is mounted to the vehicle seat and electrically 
coupled to the communications bus. When the protection device is actuated 
in response to a crash event, it helps to protect a vehicle occupant.

DESCRIPTION OF A PREFERRED EMBODIMENT 
A preferred embodiment of an integrated occupant protection system, 
generally indicated at 10, is illustrated in FIG. 1. The protection system 
10 is integrated as part of a modular vehicle seat 12. The seat 12 
includes a lower seat portion 14 and a seat back portion 16. The seat also 
includes an integral headrest portion 18 at the upper end of the seat back 
portion 14. Alternatively, the seat 12 might include an adjustable 
headrest. 
The seat 12 is mountable in a vehicle in a known manner. For example, the 
seat 12 includes a pair of spaced apart and parallel seat tracks 20 and 22 
affixed along the bottom portion of the lower seat portion 14. Another 
part of the seat tracks 20 and 22 is secured to a lower body portion of 
the vehicle 24. In general, the seat tracks 20 and 22 are formed of 
sliding members that permit front-to-aft adjustment of the seat 12 
relative to the lower body portion 24 of the vehicle. 
The system 10 also includes an electrical communication bus 26 mounted to 
the vehicle seat 12. Preferably, the bus 26 is mounted within an internal 
portion of the seat 12. The bus 26 is formed of a cable having two wires 
28 and 30. The first wire 28 provides power, control, diagnostic, and 
status information to and from various system components. The second wire 
30 provides an electrical power return from such components. It will be 
understood and appreciated by those skilled in the art that, 
alternatively, a single wire communications bus, over which both 
electrical power and control information are provided, may be used in 
combination with a chassis return. 
A connector, indicated at 32, provides an interface for electrically 
connecting appropriate external devices to the bus 26. Such external 
devices may include an electronic controller 34 which provides a suitable 
external source of power to the restraint system. Preferably, the 
connector 32 includes mating first and second connector parts 38 and 40. 
The first connector part 38 may be part of the vehicle seat 12, as shown, 
or it may be spaced from the seat 12 by an appropriate length of the 
cable. The second connector part 40 is attached to another cable which 
forms at least part of or is connected to an external communications bus 
42. The external bus 42 is electrically coupled to devices separate from 
the vehicle seat 12. The external bus 42 may be part of a vehicle 
communications system, with the bus 26 forming a subsystem thereof. The 
external bus 42 suitably includes two wires, both electrically connected 
with the controller 34. The connector 32 couples the external bus 42 to 
the communications bus 26 of the seat 12. 
The controller 34, for example, may be the central controller for a vehicle 
occupant protection system and preferably is a microcomputer. The 
controller 34 also may be an integrated circuit, a plurality of discrete 
components or a combination of discrete components and integrated circuits 
configured to provide desired control functions. 
The power source from controller 34 may be at vehicle battery level or a 
separate circuit electrically connected to the battery or alternator for 
providing a predetermined amount of power to the power line 28 of the bus 
26. 
The occupant protection system 10 further includes a plurality of 
components connected to or part of the vehicle seat 12, each of which is 
electrically coupled to the bus 26. Each component is addressable over the 
bus 26 using a known communication scheme, such as, for example, time 
division multiplexing or frequency division multiplexing. Accordingly, 
each component includes an appropriate demultiplexing circuit according to 
the particular scheme being used. Similarly, system components which 
provide signals to the bus 26 include appropriate multiplexing circuitry. 
Using an appropriate addressing scheme, information can be supplied to or 
retrieved from each component separately. 
A crash sensor 44 is mounted to the vehicle seat 12. Preferably, the crash 
sensor 44 is rigidly secured to the frame of the seat 12, although it may 
be mounted within the seat. The crash sensor 44 may take any of several 
forms, including an inertia switch or an acceleration sensing device. 
Preferably, the crash sensor 44 is an accelerometer of the type that 
outputs an electrical signal having a characteristic indicative of a 
vehicle crash event upon the occurrence of a crash event. The crash sensor 
44 is electrically coupled to the communication bus 26 and provides a 
signal indicative of the sensed crash event through the bus 26. By 
providing an acceleration sensing device as part of the vehicle seat, a 
more accurate indication of crash acceleration may be obtained for a 
vehicle occupant in the corresponding seat. The signal may be addressed to 
one or more components within seat 12, to an internal controller 47, or to 
an external device, such as the controller 34. Either the controller 47 or 
controller 34 will perform a crash algorithm on the crash signal and 
control actuatable restraint devices in the seat in response to the crash 
signal. 
The crash sensor 44 may be a side impact crash event sensor for sensing a 
side impact crash event. The crash event sensor 44 also may be a 
multi-directional sensor, or comprise a plurality of sensors for detecting 
a crash event originating from any of a plurality of directions. Such a 
multi-directional sensor provides a signal to the communication bus 26 
indicating the occurrence of a crash event and the direction or directions 
from which such crash event originated. The crash sensor 44 also may be 
configured to sense a vehicle rollover condition and provide a rollover 
signal in response to such event. 
The crash sensor 44 preferably is electrically connected to the external 
controller 34 over the bus 26 and the external bus 42. The controller 34 
analyzes the output signal from the crash sensor 44 and determines if a 
deployment crash condition is occurring. A deployment crash condition is 
one in which actuation of an actuatable occupant protection devices is 
desired. The controller 34 also determines which, if any, actuatable 
device should be activated in response to the crash sensor signal and when 
said actuation should occur. A suitable controller device 47 also may be 
part of the modular seat 12 and be electrically coupled directly to the 
seat communications bus 26. The control of certain restraint devices of 
seat 12 could be controlled by the internal controller 47. 
The system 10 includes at least one and preferably a plurality of 
actuatable occupant protection devices mounted to, and preferably within, 
the vehicle seat 12. One such device is an actuatable headrest device 46 
mounted to the vehicle seat 12 at the upper end of the seat back 16. This 
actuatable device 46 suitably is mounted within the headrest portion 18 of 
the seat 12. Preferably, the headrest occupant protection device 46 is an 
inflatable occupant protection device, such as an air bag, which may be 
actuated, for example, in response to the crash sensor 44 providing a 
signal indicating the occurrence of a rear impact crash event or a 
rollover condition. The actuatable headrest device 46 may be inflatable 
upward to help protect the occupant's head. 
Actuation of the actuatable headrest device 46 may be controlled by signals 
from the controller 34 in response to a sensed crash event. The control 
signals are addressed to the headrest device 46. Alternatively, the 
headrest device 46 may be actuated directly in response to the crash 
sensor signals on the bus 26 indicating a desirable deployment condition 
or under control of the internal controller 47. Such an on-board 
controller 47 preferably would be in communication with the vehicle 
central controller 34, such as for the relay of status and other 
information. 
The system 10 also preferably includes actuatable occupant protection 
devices for helping to protect a vehicle occupant during a side impact 
crash event. Such devices are schematically illustrated as right and left 
side restraints 48 and 50. The right and left side restraints 48 and 50 
are electrically coupled to the bus 26. The right and left side restraints 
48 and 50 preferably are inflatable occupant protection device, such as, 
for example, air bags, which cushion an occupant during a side impact 
crash event. Preferably, an occupant seat would include only one side 
restraint. A passenger's seat would have the right side restraint 48 and a 
driver's seat would have the left side restraint 50. For the purpose of 
discussion, the seat 12 includes both restrains 48, 50. 
The right side restraint 48 helps cushion a vehicle occupant of the seat 12 
(e.g., a passenger) when the crash sensor 44 detects a crash event 
originating from the right side of the vehicle. The right side restraint 
48 may be actuated upon detecting a crash sensor signal on the bus 26 
indicating a right side crash event. The crash signal may come directly 
from the sensor 44 or from the internal controller 47. Alternatively, the 
central controller 34 may receive the crash sensor signal and determine 
that a deployment crash event exists requiring actuation of the right side 
restraint device 48. The controller 34 then provides an appropriate 
control signal to the information line 28 of the bus 26 addressed to the 
right side restraint 48. The right side restraint 48 actuates in response 
to the control signal. 
Similarly, the left side restraint 50 helps cushion a vehicle occupant of 
the seat 12 (e.g., a driver) upon the crash sensor 44 detecting the 
occurrence of a crash event from the left side of the vehicle. The left 
side restraint 50 actuates upon detecting an appropriate signal from the 
bus 26. The signal may be the crash sensor signal provided directly by the 
crash sensor 44 or a control signal from the internal controller 47. 
Alternatively, the central controller 34 may receive the crash sensor 
signal. The controller 34, upon determining the occurrence of a deployment 
crash event on the left side of the vehicle, provides a control signal 
addressed to the left side restraint 50. The left side restraint 50 
receives the control signal from the information line 28 of the bus 26 and 
actuates in response thereto. 
Preferably, the system 10 also includes a seat belt assembly, indicated at 
52, which is part of the vehicle seat 12. The seat belt assembly 52 is 
illustrated in the buckled position, with the unbuckled position shown in 
phantom at 52'. The seat belt assembly 52 includes a webbing 53 and a 
buckle tongue 54. The buckle tongue 54 is slidable along the length of the 
seat belt webbing 53, and is releasably lockable in a buckle 56. The 
buckle tongue 54 divides the webbing 53 into a lap portion 58 and a chest 
portion 60, which may be positioned around a vehicle occupant. 
The seat belt assembly 52 also includes a seat belt retractor 62 mounted to 
and suitably forming part of the vehicle seat 12. The retractor 62 is 
mounted adjacent to a side of the lower seat portion 14 opposite from the 
buckle 56. The retractor 62 also could be mounted within a shoulder 
portion of the seat back 16 or to the buckle-side of the seat 12. The seat 
belt retractor 62 suitably includes a spool (not shown) upon which the 
webbing 53 is wound in a known manner. 
An actuatable pretensioner device 64 is operatively coupled to the 
retractor 62 for causing the retractor 62 to take up, or wind, the seat 
belt webbing 53 onto the spool under predetermined conditions to remove 
slack from the seat belt webbing. Alternatively, the pretensioner device 
64 may be connected to the buckle 56. When actuated, such a pretensioner 
device 64 would urge the seat belt 56 downward to pretension the seat belt 
webbing 53 around the occupant of the seat 12. The pretensioner device 64 
is electrically coupled to the bus 26, from which it receives control 
signals as well as electrical power. 
The system 10 also preferably includes a buckle switch element 66, which 
detects the presence or absence of the tongue 54 within the buckle 56. The 
buckle switch 66 is electrically coupled to the bus 26 and provides a 
signal, when addressed, indicative of the buckle condition, i.e., buckled 
or unbuckled, to the bus 26. The buckle switch signal may be received by 
the controller 34 or by other system components. For example, the 
pretensioner device 64 preferably actuates where the buckle switch 66 
detects a buckled seat belt condition and the crash sensor 44 detects a 
crash event. The pretensioner device 64 may be actuated upon receiving 
appropriate control signals over the bus 26 directly from the crash sensor 
44 and buckle switch 66 or from the internal controller 47. Alternatively, 
the central controller 34 may receive the crash sensor signal and the 
buckle switch signal on the bus 26 and determine that vehicle condition 
exists requiring actuation of the pretensioner device 64. The controller 
34 then provides an appropriate control signal to the communications bus 
26 of the seat 12, which signal is addressed to the pretensioner device 
64. When actuated, the pretensioner device 64 tightens the seat belt 
webbing 53 around a vehicle occupant. 
The system 10 further includes a weight sensor 68 mounted to the vehicle 
seat 12 for sensing a load applied to the vehicle seat 12. The weight 
sensor 68 also may be used to detect the presence or absence of a vehicle 
occupant in the seat 12. The weight sensor 68 is electrically connected to 
the bus 26. The weight sensor 68 can either be a weight sensing structure 
internal to the seat bottom 14 or can have one and preferably a plurality 
of weight sensor transducers 70 and 72 positioned between the lower 
portion 14 of the seat 12 and the lower body portion 24 of the vehicle. 
While two such transducers 70, 72 are shown in FIG. 1, it will be 
understood that typically a greater number of such transducers, such as 
one at each corner of the seat, can be used. For example, the weight 
sensor transducers 70 and 72 are mounted at the slidable members of the 
seat tracks 20 and 22. The weight sensor transducers 70 and 72 may be 
linear voltage displacement transducers (LVDT) or other known sensing 
devices such as a strain gauge. The weight sensor transducers 70 and 72 
provide signals to the weight sensor block 68 indicative of the weight on 
the lower portion 14 of the vehicle seat 12. In response to the signals 
from the transducers 70 and 72, the weight sensor 68 provides to the bus 
26 a signal indicative of the weight on the vehicle seat 12. As mentioned, 
the weight sensor 68 could be an array of weight sensors in the form of a 
flexible pad within the lower seat portion 14. Appropriate circuitry would 
monitor the array of sensors and provide, when addressed, a weight signal 
to the information line 28. The weight sensor signal may be used by any of 
the actuatable restraint devices 46, 48, 50, and 64 to adjust or control 
the actuation of such devices. In addition, the controller 34 and/or the 
controller 47 may use the weight sensor signal to adjust the control 
signals which it provides to such actuatable devices 46, 48, 50, and 64. 
Information regarding occupant weight from sensor 68 is communicated to the 
controller 34 for use in the control of other actuatable restraints in the 
vehicle such as front air bags. 
From the above description of the invention, those skilled in the art will 
perceive improvements, changes, and modifications. For example, additional 
sensors could be incorporated into the seat 12 such as occupant presence 
sensors, rearward facing infant seat detectors, etc. Additionally, the 
seat 12 may be configured to contain features for the comfort or 
convenience of the vehicle occupant, such as, for example, electrically 
adjustable seat controls, seat memory and other non-safety features. 
Further, the apparatus 10 might be configured such that the individual 
functions are isolated via multiple buses, all of which are accessed and 
controlled by the internal controller 47. Such improvements, changes, and 
modifications within the skill of the art are intended to be covered by 
the appended claims.