`USOOS413378A
`[11] Patent Number:
`
`5,413,378
`
`[45} Date of Patent:
`
`May 9, 1995
`
` ,
`
`Umted States Patent [191
`
`Steffens, Jr. et a1.
`
`[54] METHOD AND APPARATUS FOR
`
`{75}
`
`RESTRAINING DEVICE IN RESPONSE TO
`DISCRETE CONTROL ZONES
`Inventors: Charles E. Steffens, Jr” Washington;
`Thomas H. Vos, Rochester; Scott B.
`Gentry, Romeo; Joseph F. Mazur,
`Egggfngn of MghBlafibm,
`’
`'
`[73] Assignee: TRW Vehicle Safety Systems Inc.,
`Lyndhurst Ohio
`’
`
`[21] Appl. No.: 161"“
`{22] Filed:
`Dec. 2, 1993
`[51]
`Int. CL" ....................... 360R 21/25; 360R 21/28
`[52] US. Cl. .................................... 280/735; 280/736;
`[58] F‘ 111‘ f Sear
`280/739; 180/268
`1e
`0
`Ch """""""""" 280/735! 734' 730 R’
`280/732, 731, 728 R. 739. 736; 180/268. 273.
`282
`
`[56]
`
`References Cited
`
`U‘S' PATENT DOCUMENTS
`5,071,160 12/1991 White ct a1.
`......................2 280/735
`5,072,966 12/1991 Nishitake eta].
`.... 280/734
`
`5,074,533 12/1991 Fajita eta].
`280/735
`
`5,118,134 6/1992 Mam etal.
`280/735
`5,172,790 12/1992 Ishikawa ct al.
`
`ZSOH”
`5,174,500 12/1992 Jahn eta]. ..
`éggggg
`
`5,184,845 2/1993 Omura .....
`
`280/735
`5,205,582 4/1993 Shiga et a1.
`230/735
`5,232,243
`2/1993 Blackme et a1.
`
`5,330,225 7/1994 Gentry et al. ...................... 280/735
`
`2516185 10/1975 Germany .
`3802159 8/1989 Germany .
`3809074 10/1989 G
`........................ 280/728 R
`4023109
`1/1992 Grit-32$ ............................ 280/734
`4137719 9/1992 Germany .
`4214222 4/1993 Germany ........................ 280/728 R
`Primary Examiner—Margaret A. Focarino
`Assistant Examiner—Peter C. English
`Attorney, Agent. or Finn—Tarolli, Sundheim & Covell
`’
`[57]
`ABSTRACT
`‘
`An apparatus for controlling an occupant restraint sys-
`2:131,sséxclsissfan air hag (102), includes position sensgrs
`,
`,
`or sensmg 130510011 0 an occupant an a
`weight sensor (70) for sensing weight of the occupant.
`Both the position sensors (30’ 34, 86) and the weight
`sensor (70) are connected to a controller (24). A seat
`position sensor (30), a seat back incline sensor (36), and
`a belt payout sensor (64) are also used to determine
`occupant weight and position. A vent valve (120) is
`connected to the reaction can (103) of the air bag (102)
`and is controlled by the controller (24). The controller
`(24) establishes an occupant weight range from the
`weight sensors and an occupant position range from the
`position sensors. The controller (24) selects one of a
`plurality of discrete control zones dependant upon both
`the sensed occupant position range and the sensed occu-
`pant weight range. The controller (24) then provides a
`regulating signal to the vent valve (120) based on the
`.
`5315““ 03" °f the dlscre‘e ”mm 79"”
`
`37 Claims, 4 Drawing Sheets
`
`
`
`Page 1 of 13
`
`Hyundai Exhibit 1006
`
`Page 1 of 13
`
`Hyundai Exhibit 1006
`
`
`
`US. Patent
`
`May 9, 1995
`
`Sheet 1 of 4
`
`5,413,378
`
`
`
`Page 2 of 13
`
`Page 2 of 13
`
`
`
`US. Patent
`
`May 9, 1995
`
`Sheet 2 of 4
`
`5,413,378
`
`SEAT BACK
`
`ANGLE SENSOR
`
`36 I
`
`22
`
`r‘
`
`20
`
`I
`
`SEAT POSITION
`SENSOR
`
`102
`’
`10"
`SQUIB — AIR BAG
`I
`BELT PAYOUT 24-1
`SENSOR
`
`so
`
`54
`
`SEAT BUCKLE
`SENSOR
`
`so
`
`OCCUPéAgTSPOSITION
`N OR
`
`80.84.86
`
`OCCUPANT WEIGHT
`SENSORS
`
`I
`
`7O
`
`88
`
`TEMPERAHJRE
`SENSOR
`
`90
`
`CRASH SENSOR
`
`CONTROLLER
`
`
`
`r_______'
`WE'REYJ
`
`F'|g_2
`
`120
`
`SEAT BELT
`' CONTROLS
`
`124
`
` OCCUPANT
`
`146/
`
`WEIGHT
`
`O WEIGHT
`
`W N
`PosmON
`F193
`
`m
`
`‘
`
`E
`
`OCCUPANT PosmON
`
`I o PosmON
`\
`I44
`
`Page 3 of 13
`
`Page 3 of 13
`
`
`
`US. Patent
`
`May 9, 1995
`
`Sheet 3 of 4
`
`5,413,378
`
`204
`
`
`SAMPLE SEAT SCALE. SEAT
`INCUNE AND
`BELT PAYOUT SENSORS
`
`
`
`
`DETERMINE OCCUPATION WEIGHT
`
`
`
`
`
`SAMPLE BELT PAYOUT. SEAT
`POSlTION AND SEAT INCUNE
`SENSORS
`
`
`208
`220
`O COMPENSATE BELT PAYOUT AND
`SEAT SCALE READINGS
`
`\ 2
`
`1
`
`D
`
`226
`
`
`DO
`' Y
`WEIGHT
`
`SENSOR RANGES
`“5,5
`
`N
`
`
`
`DETERMINE AVERAGE
`0R PRIORITY WEIGHT
`
`
`OUTPUT TO RESTRAINT STAGE
`
`R
`W
`SEAT INCUNE SENSOR
`
`214-
`
`LOOK-UP COMPENSATION VALUES
`
`216
`
`READ SEAT SCALE AND BELT
`PAYOUT SENSORS
`
`Fig.5
`
`Page 4 of 13
`
`Page 4 of 13
`
`
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`US. Patent
`
`May 9, 1995
`
`Sheet 4 of 4
`
`5,413,378
`
`
`248\ o
`252
`
`500
`
`READ POSITION RANGE
`AND WEIGHT RANGE
`
`
`
`302
`
`
`
`
`READ ULTRASOUND SENSOR VALUES
`256
`DETERMINE OCCUPANT POSITION RANGE
`
`
`
`
`
`LOOK-UP POSITION
`RANGE IN MATRIX TABLE
`
`
`
`o4
`
`DO
` LOOK—UP WEIGHT
`VALUES AGREE
`
`
`RANGE IN MATRIX TABLE
`FOR POSITION
`
`
`
`306
`RANGES
` 270
`
`?
`
`
`
`308
`
` READ BELT PAYOUT, COMPENSATED
`
`
`VALUE AND USE FOR POSITION RANGE
`DETERMINE SHIFT IN MATRIX
`
`
`POSITION FROM ZONE MODIFIERS
`
`
`
`260
`
`READ IN VALUES 0F ZONE
`MODIFIER DATA
`
`
`
`
`
`
`
` DO
`VALUES AGREE
`FOR POSITION
`RANGES
`
`
`7
` 376
`
` DETERMINE AVERAGE
`OR PRIORITY WEIGHT
`
`374
`
`H98
`
`410
`
`H99
`
`Page 5 of 13
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`Page 5 of 13
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`
`
`1
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`5,413,378
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`2
`straint system comprises the steps of sensing the posi-
`tion of an occupant and sensing the weight of the occu-
`pant. One of a plurality of discrete control zones is
`selected in response to both the sensed position and
`sensed weight of the occupant. The method further
`comprises the step of regulating an occupant restraining
`function of the occupant restraint system based on the
`selected control zone.
`In accordance with a preferred embodiment of the
`present invention, an apparatus is provided for control-
`ling an air bag operatively coupled to a source of infla-
`tion fluid. The air bag is inflated to an operative re-
`straining position upon detection of a vehicle crash
`condition. The apparatus includes position sensing
`means for sensing position of an occupant relative to the
`air bag and weight sensing means for sensing weight of
`the occupant. The apparatus further includes regulating
`means operatively connected to the air bag for venting
`off an amount of inflation fluid so as to regulate the
`restraining function of the air bag during a vehicle crash
`condition in response to a regulating control signal.
`Control means is operatively connected to the position
`sensing means, the weight sensing means, and to the
`regulating means for selecting one of a plurality of dis-
`crete control zones dependant upon both the sensed
`position and the sensed weight of the occupant and for
`providing the control signal based on the selected one
`of the discrete control zones. The control means in-
`cludes a look-up memory table having a plurality of
`stored occupant characterization blocks wherein each
`block is functionally related to both an occupant weight
`range and an occupant position range. The plurality of
`stored blocks are grouped into at least two discrete
`control zones. Each of the control zones has an associ-
`ated regulating control signal. The control means out-
`puts an associated one of the regulating control signals
`based on the selected control zone which results in
`control of the amount of inflation fluid vented.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Other features and advantages of the present inven‘
`tion will become apparent to those skilled in the art to
`which the present invention relates from a reading of
`the following detailed description of a preferred em-
`bodiment with reference to the accompanying draw—
`ings, in which:
`FIG. 1 is a schematic diagram of an occupant re-
`straint system made in accordance with the present
`invention;
`FIG. 2 is a schematic block diagram of the electrical
`control portion of the system shown in FIG. 1;
`FIG. 3 is a schematic depiction of a look-up table
`portion of the controller of FIG. 1 showing control
`zone groups; and
`FIGS. 4—9 are flow charts showing a control process
`in accordance with the present invention.
`DESCRIPTION OF PREFERRED
`EMBODIMENTS
`
`Referring to FIGS. 1 and 2, an apparatus 20 for con-
`trolling an occupant restraint system includes a plurality
`of sensors 22 operatively connected to a controller 24.
`Specifically, a seat position sensor 30 is operatively
`connected between a vehicle seat 32 and the vehicle
`floor 34 and is electrically connected to the controller
`24. The sensor 30 provides an electrical signal indicative
`of the position of the seat 32 relative to a fixed reference
`
`METHOD AND APPARATUS FOR CONTROLLING
`AN ACTUATABLE RESTRAINING DEVICE IN
`RESPONSE TO DISCRETE CONTROL ZONES
`
`TECHNICAL FIELD
`
`The present invention is directed to a vehicle occu-
`pant restraint system and is particularly directed to a
`method and apparatus for controlling an actuatable
`restraining device.
`BACKGROUND OF THE INVENTION
`
`Occupant restraint systems for use in vehicles are
`well known in the art. One such restraint system in-
`cludes a crash sensor, an inflatable air bag, and an actua—
`tion circuit that controls deployment of the air bag in
`response to an output from the crash sensor. The crash
`sensor can be an accelerometer that provides an electri-
`cal signal having a value functionally related to the
`vehicle’s deceleration. A controller evaluates the accel-
`erometer signal and provides an actuation signal when it
`determines a vehicle crash condition is occurring of
`such nature that the air bag should be deployed. The
`actuation circuit includes a squib operatively connected
`to a source of inflation fluid.
`In response to an actuation signal from the controller,
`the actuation circuit applies a current through the squib
`which causes the squib to ignite. When the squib ignites,
`the source of inflation fluid discharges gas into the air
`bag, which results in inflation of the air bag.
`The art has recognized that it is not always desirable
`to inflate the air bag with 100% of the gas provided
`from the source of inflation fluid. One proposed system
`controls the amount of gas that inflates the air bag in
`response to the detected weight of the occupant. Such a
`system is disclosed in US. Pat. No. 5,232,243 to Black-
`burn et a1. and assigned to the assignee of the present
`invention. Another proposed system, disclosed in Gen-
`try et al., US. patent application Ser. No. 986,041, filed
`Dec. 4, 1992, now US. Pat. No. 5,330,226, and assigned
`to the assignee of the present invention, controls the
`amount of gas that inflates the air bag in response to
`detected occupant position.
`SUMMARY OF THE INVENTION
`
`The present invention provides a method and appara-
`tus for controlling an occupant restraining device in
`accordance with a selected control zone which is de-
`pendant upon a determined occupant weight range and
`a determined occupant position range.
`In accordance with one aspect of the present inveno
`tion, an apparatus for controlling an occupant restraint
`system includes position sensing means for sensing posi—
`tion of an occupant and weight sensing means for sens-
`ing weight of the occupant. The apparatus further in-
`cludes regulating means operatively connected to an
`occupant restraining device of the occupant restraint
`system for regulating an occupant restraining function
`of the occupant restraining device in response to a con~
`trol signal. Control means is operatively connected to
`the position sensing means, the weight sensing means,
`and the regulating means for selecting one of a plurality
`of discrete control zones dependant upon both the
`sensed position and the sensed weight of the occupant
`and for providing the control signal based on the se-
`lected one of the discrete control zones.
`In accordance with another aspect of the present
`invention, a method for controlling an occupant re-
`
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`point in the interior of the vehicle interior. A seat back
`angle sensor 36 is operatively connected between a seat
`bottom 38 and the seat back 40 of seat 32 and is electri-
`cally connected to the controller 24. The seat back
`angle sensor 36 provides an electrical signal indicative
`of the angle of inclination of the seat back 40 relative to
`the seat bottom 38.
`A seat belt 50 is operatively secured to the vehicle 34
`at a first location 52 in a known manner. It is also con-
`templated that the seat belt 50 may be secured to the
`vehicle seat 32. When strapped around the occupant,
`one end 54 of the seat belt is received in and secured to
`a seat belt buckle 56 assembly using a tongue and buckle
`arrangement well known in the art. The buckle portion
`of the seat belt buckle assembly is secured to the vehicle
`34 in a known manner. It is also contemplated that the
`seat belt buckle assembly can be secured to the vehicle
`seat 32. The seat belt buckle assembly 56 includes a seat
`belt buckle switch 60 electrically connected to the con-
`troller 24. The seat belt buckle switch 60 provides an
`electrical signal
`to the controller 24 indicative of
`whether the seat belt tongue and buckle are in a latched
`condition. A web or belt payout sensor 64 is operatively
`connected to a seat belt retractor 66 and is electrically
`connected to the controller 24. The payout sensor 64
`provides an electrical signal indicative of the amount of
`seat belt webbing 50 that has been pulled from the re-
`tractor 66.
`
`An occupant weight sensor or scale 70 is operatively
`mounted in the bottom cushion 38 of the seat 32 and is
`electrically connected to the controller 24. The weight
`sensor 70 provides an electrical signal indicative of a
`measured weight of an object located on the seat cush-
`ion 38. A first occupant position sensor 80, such as an
`ultrasonic sensor, is mounted in the dashboard or instru-
`ment panel 82 aimed toward the seat back 40 and is
`electrically connected to the controller 24. A second
`position sensor 84, also an ultrasonic sensor, is mounted
`in the back portion 40 of the seat 32 aimed toward the
`front of the vehicle and is electrically connected to the
`controller 24. A third position sensor 86, also an ultra-
`sonic sensor,
`is preferably mounted in the side door
`forward of a normal occupant sitting location and
`aimed sideways across the vehicle and is electrically
`connected to the controller 24. The sensors 80, 84, 86
`are used to determine the occupant position relative to
`the deployment door or cover 150 of an inflatable occu-
`pant restraint system 100. It is contemplated that other
`types of sensors can be used to monitor position and that
`other locations of the sensors could be used.
`When the controller actuates the ultrasonic sensors
`80, 84, 86, each one outputs an associated ultrasonic
`pulse. The sensors 80, 84, 86 may be transponders or can
`be made up of a transmitter/receiver pair. Each of the
`sensors provides an electrical signal indicative of an
`associated return echo pulse in a manner well known in
`the art. By monitoring the time duration between a
`transmitted pulse and a received echo pulse, the con-
`troller 7A- determines the position of an occupant rela-
`tive to each of the sensors. Since the controller
`“knows” the location of the sensors relative to the de-
`ployment door or cover 150 of the inflatable occupant
`restraint system 100, the controller can determine the
`position of the occupant relative to the deployment
`door 150 using simple mathematics. The controller 24
`compensates the values of the distances measured by the
`front sensor 80 and rear sensor 84 based on seat position
`
`Page 7 of 13
`
`4
`as sensed by sensor 30 and seat incline as sensed by
`sensor 36.
`The front sensor 80 directs an ultrasonic pulse toward
`the front of the occupant. Based on the time duration
`between the transmitted pulse and the received echo
`pulse, the controller 24 determines the distance from the
`front of the occupant to the dashboard 82. The seat
`ultrasonic sensor 84 directs a pulse toward the occu-
`pant’s back. Based on the time duration between the
`transmitted pulse and the received echo pulse, the con-
`troller 24 determines the distance from the occupant’s
`back to the seat back 40. The sensor 86 functions as an
`assurance sensor to determine if the occupant is within
`a predetermined distance of the deployment door 150 of
`the inflatable occupant restraint system 100. Using the
`computed distance from the occupant to the front sen-
`sor 80, the computed distance from the occupant’s back
`to the seat back 40 (to sensor 84), the seat position from
`sensor 30, the seat incline angle from sensor 36, the seat
`belt webbing payout from sensor 64, and the return
`from sensor 86, the controller 24 can compute the occu-
`pant’s position relative to the deployment door 150 of
`the inflatable occupant restraint system 100.
`A vehicle crash sensor 90 is mounted to the vehicle
`5 and is electrically connected to the controller 24. The
`crash sensor 90 may take any one of many several
`forms, including an inertia switch. Preferably, the crash
`sensor 90 is an accelerometer of the type that outputs an
`electrical signal having a characteristic indicative of a
`vehicle crash condition upon the occurrence of a crash
`condition. The controller 24 analyzes the output signal
`from the accelerometer and determines if a deployment
`crash condition is occurring. A deployment crash con-
`dition is one in which deployment of the air bag is de-
`sired to enhance the restraining function for the occu-
`pant. A non-deployment condition is one in which the
`seat belts alone are sufficient to provide an adequate
`restraining function for the occupant.
`The inflatable occupant restraint system or air bag
`assembly 100 includes an air bag 102 operatively
`mounted in a housing or reaction can 103 which is, in
`turn, mounted in the dashboard or instrument panel 82.
`The controller 24 is electrically connected to a squib
`104 which is, in turn, operatively connected to an infla—
`tor 110. The inflator 110 is operatively connected to the
`air bag 102 so that when the controller ignites the squib
`104, inflation fluid, preferably an inert gas, is released
`from the inflator 110. The air bag 102 is then inflated to
`its operative position 102’ shown in FIG. 1.
`A temperature sensor 88 is mounted to the inflator
`110 and is electrically connected to the controller 24.
`The temperature sensor 88 provides an electrical signal
`to the controller 24 indicative of the temperature of the
`inflator 110.
`An electrically controlled venting device 120, such as
`a valve, is operatively connected to the reaction can 103
`and is electrically connected to the controller 24. The
`controller 24 controls the venting device 120 to control
`the amount of gas that flows out through the vent,
`thereby controlling the pressure of the gas in the air bag
`102. The controller 24 controls the venting device 120
`in response to the sensors 22.
`The source of inflation fluid 110 provides a predeter-
`mined amount of gas, referred to herein as 100% of the
`possible gas. The controller 24 controls the venting
`device 120 to vent away a portion of the gas from the air
`bag. The amount of inflation fluid that is directed away
`from the air bag 102 by the venting device 120 is deter-
`
`Page 7 of 13
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`
`
`5
`mined by the extent to which the venting device 120 is
`opened in response to the control signal from the con-
`troller 24. Those skilled in the art will appreciate that
`control of the amount of gas in the air bag 102 can be
`accomplished in other ways, such as providing a plural-
`ity of sources of inflation fluid and controlling the num-
`ber of sources actuated.
`The controller 24 is also electrically connected to seat
`belt controls 124, such as a seat belt load limiter. The
`controller 24 controls the seat belt controls 124 in re-
`sponse to the outputs from the sensors 22.
`Referring now to FIGS. 2 and 3, the controller 24,
`which is preferably a microcomputer, includes a mem-
`ory location 140 for storing a look-up table 142. The
`look-up table is divided into a plurality of occupant
`position ranges 144 and a plurality of occupant weight
`ranges 146. With regard to the occupant position ranges
`144, for the purposes of discussion, the distance between
`the deployment door or cover 150 of the air bag assem-
`bly 100 and the seat 32 when it is in its rearwardmost
`upright location, i.e., the maximum anticipated distance,
`is divided into four ranges. If the occupant is in a first
`range between a zero distance, i.e., against the door 150
`of the air bag assembly 100, and about 10% of the maxi-
`mum distance, the occupant is said to be in a first posi-
`tion range designated I. When the occupant is in a posi-
`tion greater than about 10% and not more than about
`30% of the maximum anticipated distance from door
`150, the occupant is in position range II. When the
`occupant is in a position greater than about 30% and not
`more than about 60% of the maximum anticipated dis-
`tance from door 150, the occupant is in position range
`III. When the occupant is in a position greater than
`about 60% of the maximum anticipated distance from
`door 150, the occupant is in occupant position range IV.
`The occupant weight is divided, for the purposes of
`discussion,
`into four weight
`ranges between zero
`weight and a maximum predetermined weight. An oc—
`cupant weighing more than the maximum predeter-
`mined weight will be characterized as being in the maxi-
`mum weight range. When an occupant’s weight is be-
`tween 0 and about 25% of the maximum predetermined
`weight value, the occupant is said to be in occupant
`weight range I. When the occupant’s weight is greater
`than about 25% and not more than about 50% of the
`maximum predetermined weight, the occupant’s weight
`is said to be in occupant weight range II. When the
`occupant’s weight is greater than about 50% and not
`more than about 75% of the maximum predetermined
`weight, the occupant’s weight is said to be in occupant
`weight range one III. When the occupant’s weight is
`greater than about 75% of the maximum predetermined
`weight, the occupant’s weight is said to be in occupant
`weight range IV.
`The four occupant weight ranges and position ranges
`form a 4x4 matrix that provides 16 occupant character-
`ization blocks labelled A~P. These 16 occupant charac—
`terization blocks are grouped into three control zones.
`Blocks D, H, L, P, and O are designated as a low control
`zone 150. Blocks C, G, J, K, M, and N are designated as
`a medium control zone 154. Blocks A, B, E, F and I are
`designated as a high control zone 158. The control
`zones 150, 154, 158 are used by the controller 24 to
`control the venting device 120.
`These control zones are based upon the amount of
`pressure needed in the air bag 102 to restrain the occu-
`pant by dissipating the occupant’s kinetic energy during
`a crash event and upon the amount of distance available
`
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`6
`for the bag 102 to stop the occupant’s forward motion
`before the occupant strikes the dashboard 82. During a
`crash event, the occupant has a kinetic energy equal to
`é mvz. M is the mass of the occupant and v is the veloc-
`ity at which the occupant is moving relative to the
`vehicle’s interior. V is a function of the crash severity
`and requires a dynamic determination from the crash
`sensor output
`signal. The occupant’s position and
`weight can be continuously monitored to enable the
`venting device 120 to be adjusted prior to the occur-
`rence of a crash event.
`
`The work required to restrain an occupant during a
`crash event is equal to the occupant’s kinetic energy.
`Work is defined as force times distance. Force is the
`force imparted by the restraint system, and distance is
`the distance over which the force can be imparted. The
`matrix of FIG. 3 considers both weight and distance
`and establishes three separate air bag pressures. By
`selecting a desired air bag pressure based upon measure—
`ments and determinations made prior to the occurrence
`of a crash event, the venting device is set in advance of
`a vehicle crash. The matrix approach permits simplicity
`in data manipulation to establish a control value.
`When an occupant’s weight and position places the
`occupant in the low control zone 150, the venting de-
`vice is opened a first amount to vent a first amount of
`gas, such as approximately 50% of the possible gas.
`When an occupant’s weight and position places him in
`the medium control zone 154, the venting device is
`opened a second amount to vent a second amount of
`gas, such as approximately 25% of the possible gas. If an
`occupant’s weight and position places him in the high
`control zone 158, the controller closes the venting de—
`vice so as to not vent any of the gas.
`Referring to FIGS. 4 through 9, the control process
`in accordance with the present invention will be better
`appreciated. The control process begins with step 200
`which occurs at power-up of the vehicle. In step 200, all
`internal states of the controller 24 are set to predeter-
`mined initial values. The controller proceeds to step 202
`where a determination is made as to whether the occu-
`pant has his seat belt buckled. This is determined by the
`controller 24 monitoring the seat belt buckle sensor 60.
`If the determination in step 202 is affirmative, the pro-
`cess stores that information in memory for later use and
`then proceeds to step 204 where the controller 24 sam-
`ples the occupant weight sensor or scale 70, the seat
`back incline sensor 36, and the belt payout sensor 64.
`The sampled values are stored in an internal memory of
`the controller 24 for later use.
`In step 206, the controller 24 determines the weight
`range into which the occupant’s weight falls. To deter-
`mine the weight range of the occupant, the controller
`24 follows a process designated by step 208 of FIG. 4
`and shown in detail in FIG. 5. In step 210, the controller
`reads the seat incline angle value that was stored in
`memory back in step 204. The occupant’s measured
`weight upon the seat as “seen” by the weight sensor 70
`is functionally related to the incline angle of the back
`portion 40 of the seat 32. As the seat incline angle is
`increased toward a reclining position, more of the occu-
`pant’s weight is transferred to the seat back 40 of the
`seat 32. This weight transfer is reflected in a decreased
`reading from the weight sensor 70. By using empirically
`determined data based upon a sampling of many occu-
`pants of various weights and heights, and taking into
`account various angles of incline of the seat back 40,
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`weight compensation values for all seat incline angles
`are prestored in the controller 24.
`Occupant weight can also be determined using belt
`payout. As with the occupant weight sensor 70, the
`value of the belt payout sensor 64 will be functionally
`related to the incline angle of the seat back 40. Again,
`empirical testing provides weight compensation values
`for belt payout based upon the incline angle of the back .
`portion 40 of the seat 32.
`In step 214, the controller 24 reads the compensation
`values that are dependent upon the measured angle of
`incline of the seat back 40. In step 216, the value of the
`weight sensor 70 and the value of the belt payout sensor
`64 stored in step 204 are read by the controller 24. In
`step 220, the values of the seat scale or weight sensor 70
`and the value of the belt payout sensor 64 are adjusted
`using the compensation values read in step 214.
`In step 224, the occupant’s actual weight is calculated
`in two separate ways. First, the occupant’s weight is
`calculated based upon the compensated value of the
`weight sensor 70. Second, the occupant’s weight is
`calculated depending on the compensated seat belt pay-
`out value. Those skilled in the art will appreciate that
`the two weight values can either be calculated using a
`predetermined formula or can be determined using
`look-up tables. In accordance with a preferred embodi-
`ment, the weight values determined in step 224 are the
`weight ranges shown in FIG. 3. The two determina-
`tions made are determinations as to which of the four
`weight ranges includes the occupant’s weight.
`In step 226, a determination is made as to whether the
`two calculated weight values, i.e., weight ranges, are in
`agreement. If the determination is affirmative, the pro-
`cess proceeds to step 228 where the occupant’s weight
`range is output to and stored in memory of the control-
`ler 24 for later use in the look-up table of FIG. 3. If the
`determination in step 226 is negative, the process pro—
`ceeds to step 230 where an averaging of the two deter—
`mined weight ranges is established or a weight range
`based on priority of sensors is selected.
`If the weight determination based on weight sensor
`70 is that the occupant is in range IV and the weight
`determination based on the belt payout sensor 64 is that
`the occupant is in weight range II, an average of weight
`range III is established in step 230 and output in step
`228. If, however, the weight determination based on
`weight sensor 70 is that the occupant’s weight is in
`range IV and the weight determination based on the
`belt payout sensor 64 is that the occupant weight is in
`range III, the weight sensor 70 determination is given
`priority as being more likely to be correct. In such a
`situation, the weight range IV would be output in the
`step 228 to establish the occupant’s weight as being in
`range IV. Whenever the calculation step 224 deter-
`mines that the weight ranges are different but are adja-
`cent weight ranges, the weight sensor 70 is always
`given priority as being more likely to be correct.
`Referring back to FIG. 4, after the weight range is
`determined, the process proceeds to step 240 where the
`controller 24 samples the occupant position sensors 80,
`84, 86, and the sampled values are stored in an internal
`memory of the controller 24 for later use. The process
`proceeds to step 242 where the seat belt payout sensor
`64, the seat position sensor 30, and the seat incline sen-
`sors 36 are sampled, and the sampled values are stored
`in an internal memory of the controller 24 for later use.
`In step 246, the occupant’s position range is determined.
`To determine the position range in which the occupant
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`resides, the controller 24 follows several process steps
`designated by step 248 of FIG. 4 and shown in detail in
`FIG. 6.
`Referring to FIG. 6, the values of the ultrasound
`sensors 80, 84, 86 which were stored in step 240 are read
`out of memory in step 252 by the controller 24. The
`occupant’s position range relative to the deployment
`door 150 of the air bag system 100 is determined instep
`256 from each of the three sensors 80, 84, 86. A determi-
`nation is made in step 260 as to whether the position
`ranges determined from the three independent sensors
`are in agreement.
`-
`If the determination in step 260 is affirmative, a value
`of the occupant’s position range is output in step 266. If
`the determination in step 260 is negative, the process
`proceeds to step 270 where the controller 24 reads the
`belt payout sensor 64. Occupant position based on belt
`payout must be compensated for in reSponse to seat
`incline and seat position. To establish compensated
`values for storage in a look-up table, several samplings
`are taken of occupants sitting in different positions on a
`vehicle seat with the seat moved to different positions
`and positioned with different inclines. The controller
`determines the occupant position range from the com-
`pensated belt payout value preferably from a look-up
`table. The determined occupant position range from the
`compensated belt payout is output to and stored in
`memory of the controller 24 as the occupant position
`range value in step 266. Occupant position range based
`on either the ultrasonic sensors or the belt payout can be
`either calculated or obtained using a look-up table.
`After the occupant weight range is determined and
`the occupant position range is determined, the process
`proceeds to a control process (designated as “A”) to
`tailor or control the venting device 120 to,
`in turn,
`control the pressure in the air bag 102. Controlling the
`amount of inflation fluid controls pressure of the fluid in
`the air bag 102. The inflation pressure of the air bag 102
`affects the response of the air bag to the occupant dur-
`ing a vehicle crash condition.
`The process proceeds to step 300, as shown in FIG. 7,
`where the occupant’s position range and the occupant’s
`weight range are read. Using the occupant’s position
`range (step 302) and occupant’s weight range (step 304),
`an occupant characterization block is selected or deter-
`mined from the matrix (FIG. 3). Assume that an occu-
`pant is in a weight range III and a position range II. The
`occupant would then be in the G occupant character-
`ization block of the matrix shown in FIG. 3, which falls
`within the medium control zone 154. Other factors in
`the system may move an oceupant’s selected or deter- »
`mined control zone location on the matrix of FIG. 3
`from one location to another location.
`In step 306, the controller 24 reads the sensors that
`may modify a selected or determined control zone for
`the occupant. One such zone modifier sensor may be the
`temperature sensor 88. When the temperature sensor
`senses that the inflator 110 is colder than a predeter-
`mined value such as — 10" F., it is known that the output
`from the inflation fluid source would normally be
`lower. Therefore, in such a cold environment, it