cngsg gFlRENCE TO RELATED APP[._.ICA'l'[O1!§
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`l N . 09/128,490 filed A gust 4,
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`This application isa oontirtualion-in-pan of U.S. patent opplicati
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`l998Awltit:l| is both a contimralion-in-part of U.S. patent application Serial No. 08/474,783 filed June 7, 1995, now
`U.S. Patent No. 5,822,707, and a oonlinuati.on—in-part of U.S. patent application Serial No. 08/970,822 filed
`November 14, 1997]‘M " ‘'‘+'''‘i # 6 "'75?
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`The present invention relates to rnetllods and apparatus for measuring the weight of an occupying item of
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`a seat. in particular. a seat in an automotive vehicle
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`The present invention also relates to apparatus and methods for adjusting a vehicle component, system or
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`is evaluated using at least
`subsystem in which the oowparwy ofa seat. also referred to as the “seated state”
`a weight measuring apparatus and the component. system or subsystem may then be adjusted based on the
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`evaluated occupancy thereof. The vehicle component. system or nibsystem, hereinafter referred to simply as a
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`component. may be any adjustable eomponenrolillie vehiele including, but not limited to, the bottom portion and
`backrest ofthe seat, the rear view and side minors, the brake, clutch and melerator pedals, the steering wheel, the
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`steering column, a seat armrest. a cup holder.
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`the mounting unit
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`for a cellular telephone or another
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`communications or computing device and the visors. Further. the component may be _a system mch on as airbag
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`system. the deployment ofwhieh isoontrolledbased on the seated-state of the seat. The component may alsobe an
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`adjustable portion ofa system the operation of which might be advantageously adjusted based on the scated—state of
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`theseat,s:ehasade.t‘rioeforregulatingthe inflation ordeflatiouofanairbagthatisassocialedwithanairbag
`system
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`invention also relates to apparatus and method for automatically adjusting a vehicle
`The present
`component
`to a selested or optimum position for an occupant of a seat based on at least we measured
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`Page 1 of 89
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`Hyundai Exhibit 1013
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`Page 1 of 89
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`Hyundai Exhibit 1013
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`morphological characteristics of the occupant, one of which is the weight of tlte occupant. Other morphological
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`characteristics include the height of the occupant, the length of the occupant‘s arms, the length of the occt_.tpant’s
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`legs, the occupant‘s head diameter and the inclin_a_tion of the occupant’s hack relative to the seat bottom. Other,
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`unlisted morphological characteristics are also enyisioned for use in the invention.
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`BAQKGROUND OF THE INVENTIQN
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`Automobiles equipped with airbags are well known in the prior art. In such airbag systems, the car crash
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`is sensed and the airbags rapidly inflated thereby insuring the safety of an occupation in a car crash. Many lives
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`have now been saved by such airbag systems.
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`However, depending on the seated state of an occupant, there
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`are cases where his or her life cannot be saved even by present airbag systems. For example, when a passenger is
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`seated on the front passenger seat in a position other than a forward facing, normal state, eg., when the passenger
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`is out of position and near the deployment door of the airbag, there will be cases when the occupant will be
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`seriously injured or even killed by the deployment of the airbag.
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`Also, sometimes a child seat is placed on the passenger seat in a rear facing position and there are cases
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`where a child sitting in such a seat has been seriously injured or killed by the deployment of the airbag.
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`Furthermore,
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`in the case of a vacant seat, there is no need to deploy an airbag, and in such .1 case,
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`deploying the airbag is undesirable due to a high replacement cost and possible release of toxic gases into the
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`passenger compartment. Nevertheless, most airbag systems will deploy the airbag in a vehicle crash even if the
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`seat is unoccupied.
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`For these reasons, there has been prop-dsedia seated-state detecting unit such as disclosed in the following
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`U.S. Patents and Patent applications, which are included herein by reference, assigned to the current assignee of
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`the present application: Breed et al (U.S. Pat. No. 5.563.462); Breed et at (U.S. Patent application Serial No.
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`08/640,068 filed April 30, I996); Breed et al (US. Patent No. 5,822,707: Breed et al (U.S. Pat. No. 5,694,320);
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`Breed et al (U.S. Pat. No. 5,748,473); and Varga et al (U.S. Patent application Serial No. 08/798,029 filed
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`February 6, 1997). Typically, in some of these designs four sets of sensors are installed at four points in ‘a vehicle
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`‘passenger compartment for transmitting ultrasonic or electromagnetic waves toward the passenger or driver's seat
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`and receiving the reflected waves. Using appropriate hardware and sottware, the approximate configuration of the
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`occupancy of either the passenger or driver seat can be determined thereby identifying and categorizing the
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`occupancy of the relevant seat.
`However, in the aforementioned literature using ultrasonics, the pattern of reflected ultrasonic waves from
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`an adult occupant who may be out of position is sometimes similar to the pattern of reflectecl waves from at rear
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`facing child seat. Also, it is sometimes di.fl'tcult to discriminate the wave pattern of a normally seated child with
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`the seat in a rear facing position front an empty seat with the seat in a more forward position.
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`In other cases, the
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`reflected wave pattern from a thin slouching adult with raised knees can be similar to that front a rear facing child
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`seat. In still other cases, the reflected pattern from a passenger seat which is in a forward position can be similar to
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`the reflected wave pattern from a seat containing a forward facing child seat or a child sitting on me passenger
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`seat.
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`In each of these cases, the prior art ultrasonic systems can suppress the deployment of an airbag when
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`deployment is desired or, alternately, can enable deployment when deployment is not desired.
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`lftlre discrimination between these cases can be improved, then the reliability of the seated-state detecting
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`unit can be improved and more people saved from death or serious injury.
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`in addition, the unnecessary deployment
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`of an airbag can be prevented.
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`With respect to the adjustment of a vehicular seat, the adjustment of an automobile seat occupied by a
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`driver of the vehicle is now accomplished by the use of either electrical switches and motors or by mechanical
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`levers. As a result, the driver’s seat is rarely placed at the proper driving position which is defined as the seat
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`location which places the eyes of the driver in the so-called “eye ellipse" and permits him or her to contfottably
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`reach the pedals and steering wheel. The “eye ellipse" is the optimum eye position relative to the windshield and
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`rear view mirror of the vehicle.
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`The eye ellipse, which is actually an ellipsoid, is rarely achieved by the actions of the driver for a variety
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`of reasons. One specific reason is the poor design of most seat adjustment systems particularly the so-called “4-
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`way-seat". It is known that there are three degrees of frwclom of a seat bottom, namely vertical, longitudinal, and
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`itram "-
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`rotation about the lateral or pitch axis. The 4-way~seat ‘provides four motions to control the seat: (1) raising or
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`lowering the front of the seat, (2) raising or lowering the back of the seat, (3) raising or lowering the entire seat,
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`(4) moving the seat fore and afi. Such a seat adjustment system causes confusion since there are four control
`motions for three degrees of freedom. As a result, vehicle occupants are easily frustrated by such events as when
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`the controllto raise the seat is exercised. the seat not only is raised but is also rotated. Occupants thus find it
`difiicult to place the seat in the optimum location using this system and frequently give up trying leaving the seat
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`in an improper driving position
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`Many vehicles today are equipped with a lumbar support system that is never used by most occupants.
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`One reason is that the lumbar support cannot be preset since the shape of the lumbar for different occupants differs
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`significantly, i.e., a tall person has significantly different lumbar support requirements than a short person.
`Without knowledge ofthe size of the occupant, the-lumbar support cannot be automatically adjusted.
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`As discussed in the above referenced ‘32_0 patent, in approximately 95% of the cases where an occupant
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`suffers a whiplash injury, the headrest is not properly located to protect hint or her in a rear impact collision. Also,
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`the stiifness and damping characteristics of a seat are fixed and no attempt is made in any production vehicle to
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`adjust the stifiness and damping of the seat in relation to either the size or weight of an occupant, or to the
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`environmental conditions such as road roughness. All of these adjustments, if they are to be done automatically,
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`require knowledge of the morphology of the seat occupant.
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`Systems are now being used to attemptltc identify the vehicle occupant based on a coded key or other
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`object carried by the occupant. This requires special sensors within the vehicle to recognize the coded object.
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`Also, the system only works if the coded object is used by the particular person for whom the vehicle was
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`programmed It‘ the vehicle is used by a son or daughter, for example, who use their mother's key then the wrong
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`sent adjustments are made. Also, these systems preserve the choice of seat position without any regard for the
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`correctness of the seat position. With the problems associated with the 4-way seats, it is unliloely that the occupant
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`ever properly adjusts the seat. Therefore, the error will be repeated every time the occupant uses the vehicle.
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`Moreover, these coded systems are a crude attempt to identify the occupant. An improvement can he
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`made if the morphological characteristics of the occupant can be measured as described below.
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`Such
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`measurements can be made of the height andbweight, for example, and used not only to adjust a vehicular-
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`component to a_ proper position but also to remember that position, as fine tuned by the occupant, for re-positioning
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`the component the next time the occupant occupies the seat.
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`For the purposes herein, a morphological
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`characteristic will mean any measurable propertyhof a human such as height, weight, leg or arm length, head
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`diameter etc.
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`As dlSCllSS6d more fully below, in a preferred implementation, once at least one and preferably two of the
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`morphological characteristics of a driver are determined, e.g., by measuring his or her height and weight, the
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`component such as the seat can be adjusted and other features or components can be incorporated into the system
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`including, for example, the automatic adjustment of the rear view and/or side mirrors based on seat position and
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`occupant height.
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`In addition, a detennination of an out-of-position occupant can be made and based thereon,
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`airbag deployment suppressed if the occupant is more likely to be injured by the airbag than by the accident
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`without the protection of the airbag. Furthermore, the characteristics of the airbag including the amount of gas
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`produced by the inflator and the size of the airbag exit orifices can be adjusted to provide better protection for small
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`lightweight occupants as well as large, heavy people. Even the direction of the airbag deployment can, in some
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`cases, be controlled.
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`Still other features or components can now be adjusted based on the measured occupant morphology as
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`well as the fact that the occupant can now be identified. Some of these features or components include the
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`adjustment of seat armrest, cup holder, steering wheel (angle and telescoping), pedals, phone location and for that
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`matter the adjustment of all things in the vehicle which a person must reach or interact with. Some items that
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`depend on personal preferences can also be automatically adjusted including the radio station, temperature, ride
`and others.
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`l-leretofore, various methods have been proposed for measuring the weight of an occupying item of a
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`vehicular seat. The methods include pads, sheets or films that have placed in the seat cushion which attempt to
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`measure the pressure distribution of the occupying item. Prior to its first disclosure in U.S. Patent No.5,822,707
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`cross-referenced above; systems for measuring occupant weight based on the strain in the seat structure had not
`been considered. Prior art weight measurement systems have been notoriously inaccurate Thus, a more accurate
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`weight measuring system is desirable. The strain measurement systems described herein, substantially eliminate
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`the inaccuracy problems of prior art systems and permit an accurate determination of the weight of the occupying
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`item of the vehicle seat. Additionally, as disclosed herein, in many cases, sufiicient information can be obtained
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`for the control of a vehicle component without the necessity of determining the entire weight of the occupant. For
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`example, the force that the occupant exerts on one of the three support members may be sufficient.
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`Most, if not all, of the problems discussed above are diflicult to solve or unsolvable using conventional
`technology.
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`OBJECTS OF THE INVENTION
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`Accordingly, it is a principal object of the present invention to provide new and improved apparatus and
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`methods for measuring the weight of an occupying item on a vehicle seat which apparatus and methods may be
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`integrated into vehicular component adjustment apparatus and methods which evaluate the occupancy of the seat
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`and adjust the location and/or orientation relative to the occupant and/or operation of a part of the component or
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`the component in its entirety based on the evaluated occupancy of the seat.
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`It
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`is another object of the present invention to provide new and improved adjustment apparatus and
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`methods that evaluate the occupancy of the seat and adjust the location and/or orientation relative to the occupant
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`and/or operation of a part of the component or the component in its entirety based on the evaluated occupancy of
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`the seat and on a measurement of the occupant‘s weight or a measurement of a force exerted by the occupant on
`the seat.
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`It is another object of the present invention to provide new and improved adjustment apparatus and
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`methods that evaluate the occupancy of the seat by a combination of ultrasonic sensors and additional sensors and
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`adjust the location and/or orientation relative toithe occupant and/or operation of a part of the component or the
`component in its entirety based on the evaluated occupancy of the seat.
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`It is another object of the present invention to provide new and improved adjustment apparatus and
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`methods that reliably discriminate between a
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`seated passenger and a forward facing child seat, between
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`location and/or orientation relative to the
`in its entirely based thereon.
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`seat, and whether or not the seat is empty and adjust the
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`and/or operation of a part of the component or the component
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`It is another object of the present invention to provide an improved weight measurement system and
`thereby improve the accuracy of another apparatus or system which utilizes measured weight as input, e.g., a
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`component adjustment apparatus,
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`It is another object of the present invention to provide new and improved adjustment apparatus and
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`methods that evaluate the occupancy of the seat without the problems mentioned above.
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`Additional objects and advantages of this invention include:
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`1.
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`To provide a system for passively and automatically adjusting the position of a vehicle
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`component to a near optimum location based on the size of an occupant.
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`2.
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`To provide a system for recognizing a particular occupant of a vehicle and thereafler adjusting
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`various oomponents ofthe vehicle in accordance with the preferences of the recognized occupant.
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`3.
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`To provide systems for approximately locating the eyes of a vehicle driver to thereby permit the
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`placement of the driver’: eyes at a particular location in the vehicle.
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`To provide a pattern recog1il'lfidit"s'ystein to permit more accurate location of an oooupant’s head
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`and the parts thereof and to use this infonnatiotfioiadjust a vehicle component.
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`5.
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`To provide a method of determining whether a seat is occupied and, if not, leaving the seat at a
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`neutral position.
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`6.
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`To provide a system for automatically adjusting the position ofvarious components of the vehicle
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`to permit safer and more effective operation of the vehicle including the location of the pedals and steering wheel.
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`7.
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`To determine whether an occupant is out-of-position relative to the airbag and if so, to suppress
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`deployment of the airbag in a situation in which the airbag would otherwise be deployed.
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`8.
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`To adjust the now of gas into and/or out of the airbag based on the morphology and position of
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`the occupant to improve the performance oftho airbag in reducing occupant injury.
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`To provide a system where
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`sensors located within the seat.
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`gnioiphological characteristics of an occupant are measured by
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`To provide a system and nrethod wherein the weight of an occupant is detemtined utilizing
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`sensors located on the seat stmcture.
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`Further objects of the present invention will become apparent from the following discussion of the
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`preferred embodiments of the invention.
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`SUMMARY OF THE INVENTION
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`In one embodiment of an apparatus for measuring the weight of an occupying item of a seat,
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`the
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`apparatus includes at least one strain gage transducer, each mounted at a respective location on a suppon structure
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`of the seat and arranged to provide a measurement of the strain of the support structure thereat. A control system
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`is coupled to the strain gage transducer(s) for detennining the weight ofthe occupying item ofthe seat based on the
`strain of the support structure measured by the strain gage transducer(s). The support structure of the seat is
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`mounted to a substrate such as a floor pan of a motor vehicle. Electrical connection means such as wires connect
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`the strain gage transducer(s) to the control system.
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`Each strain gage transducer may incorporate signal
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`conditioning circuitry and an analog to digital converter such that the measured strain is output as a digital signal.
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`The positioning of the strain gage t.ransducer(s) depends in large part on the actual construction of the
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`nrpport stnrcture of the seat. Thus, when the support structure comprises two elongate slide mechanisms adapted
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`to be mounted on the substrate and support members for coupling the seat to the slide mechanisms, several strain
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`gage transducers may be used, each arranged on a respective support member.
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`If the support structure further
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`includes a slide member, another strain gage tiansducer may be mounted thereon. Means for increasing the
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`accuracy of the strain gage transducers are advantageous and include, for example, forming a support member
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`from first and second tubes having longitudinally opposed ends and a third tube overlying the opposed ends of the
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`first and second tubes and connected to the first and second tubes whereby a strain gage transducer is arranged on
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`the third tube. Naturally, other structural shapes may be used in place of one or more ofthe tubes.
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`In another embodiment of an apparatus for measuring the weight of an occupying item of a seat which
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`includes slide mechanisms for mounting the seat to a substrate and bolts for mounting the seat to the slide
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`mechanisms, the apparatus comprises at least one pressure sensor arranged between one of the slide mechanisms
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`and the seat for measuring pressure exerted on the seat. Each pressure sensor may comprise first and second layers
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`of shock absorbing material spaced from one another and a pressure sensitive material interposed between the first
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`and second layers of shock absorbing material. A control system is coupled to the pressure sensitive material for
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`determining the weight of the occupying itemtof the seat based on the pressure measured by the at least one
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`pressure sensor. The pressure sensitive material“may include an electrode on upper and lower faces thereof.
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`Another embodiment of an apparatus for mmsuring the weigltt of an occupying item of a seat includes a
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`load cell adapted to be mounted to the seat and to a substrate on which the seat is supported. The load cell includes
`a member and a strain gage arranged thereon"-to measure tensile strain in the member caused by weight of an
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`occupying item of the seat. A control system'is coupled to the strain gage for determining the weight of an
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`occupying item of the seat based on the strain in the member measured by the strain gage. Ifthe member is a beam
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`and the strain gage includes two strain sensing elements, then one strain sensing element is arranged in a
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`longitudinal direction of the beam and the other is arranged in a transverse direction of the beam.
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`If four strain
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`sensing elements are present, a first pair is arranged in a longitudinal direction of the beam and a second pair is
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`ananged in a transverse direction of the beam. The member may be a tube in which case, a strain sensing element
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`is arranged on the tube to measure compressive strain in the tube and another strain sensing element is arranged on
`the tube to measure tensile strain in the tube. The member may also be an elongate torsion bar mounted at its ends
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`to the substrate.
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`In this case, the load cell includes a lever arranged between the ends of the torsion bar and
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`connected to the seat such that a torque is imparted to the torsion bar upon weight being exerted on the seat. The
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`strain gage thus includes a torsional strain sensing element.
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`The weight measuring apparatus desclribecliabove may be used in apparatus and methods for adjusting a
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`vehicle component, although other weight measuring apparatus may also be used in the vehicle component
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`adjusting systems and methods described immediately below.
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`One
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`embodiment of such an apparatus in accordance with invention includes a first measuring system for
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`measuring a first morphological characteusdd iifiihekoocupying item of the seat and a second measuring system for
`measuring a second morphological characteristic joftlie occupying item. Morphological characteristics include the
`weight of the occupying item, the height of the occupying item from the bottom portion of the seat and if the
`occupying item is a human, the arm length, head diameter and leg length. The apparatus also includes processor
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`means for receiving the output of the first and second measuring systems and for processing the outputs to evaluate
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`a seated—state based on the outputs. The measuring systems described herein, as well as any other conventional
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`measuring systems, may be used in the invention to measure the morphological characteristics of the occupying
`item.
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`One preferred embodiment of an adjustment system in accordance with the invention includes a plurality
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`of wave-receiving sensors for receiving waves from the seat and its contents, if any, and one or more weight
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`sensors for detecting weight of an occupant in the seat or an absence of weight applied onto the seat indicative of a
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`vacant seat. The weight sensing apparatus may include strain sensors mounted on or associated with the seat
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`stnicrure such that the strain measuring elements respond to the magnitude of the weight of the occupying item.
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`The apparatus also includes processor means for receiving the output of the wave-receiving sensors and the weight
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`sensor(s) and for processing the outputs to evaluate a seated-state based on the outputs. The processor means then
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`adjusts a part of the component or the component in its entirety based at least on the evaluation of the seated-state
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`of the seat. The wave-receiving sensors maybe ultrasonic sensors, optical sensors or electromagnetic sensors. If
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`the wave-receiving sensors are ultrasonic or optical sensors, then they may also include transmitter means for
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`transmitting ultrasonic or optical waves toward the seat.
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`If the component is a seat, the system includes power means for moving at least one portion of the seat
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`relative to the passenger compartment and control means connected to the power means for controlling the power
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`means to move the portion(s) of the seat.
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`in this case, the processor means may direct the control means to affect
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`the power means based at least in part on the evaluation of the seated-state of the seat. With respect to the
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`direction or regulation of the control means by the processor means, this may take the form of a regulation signal
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`to the control means that no seat adjustment is needed, e.g., if the seat is occupied by a bag of groceries or a child
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`seat in a rear or fomard-facing position as detennined by the evaluation of the output from the ultrasonic or optical
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`and weight sensors. On the other hand, if the
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`means determines that the seat is occupied by an adult or
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`child for which adjuspnent of the seat is beneficial or desired, then the processor means may direct the control
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`means to afiect the power means accordingly. For example, if a child is detected on the seat, the processor means
`may be designed to lower the hcadrest.
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`In certain embodiments, the apparatus may include one or more sensors each of which measures a
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`morphological characteristic of the occupying item of the seat, e_g., the height or weight of the occupying item, and
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`the processor means are arranged to obtain the input from these sensors and adjust the component accordingly.
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`Thus, once the processor means evaluates the occupancy of the seat and detemtines that the occupancy is by an
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`adult or child, then the processor means may additionally use either the obtained weight measurement or conduct
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`additional measurements of morphological characteristics of the adult or child occupant and adjust the component
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`accordingly. The processor mears may be a single microprocessor for performing all of the ftmctions described
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`above. In the alternative, one microprocessor may be used for evaluating the occupancy of the seat and another for
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`adjusting the component.
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`The processor means may comprise an evaluation circuit implemented in hardware as an electronic circuit
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`or in software as a computer program.
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`In certain embodiments, a correlation fimction or state between the output of the various sensors and the
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`desired result (i.e., seat occupancy identification and categorization) is determined, e.g., by a neural network that
`may be implemented in hardware as a neural computer or in sofiware as a computer‘ program. The correlation
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`function or state that is determined by employing this neural network may also be contained in a microcomputer.
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`In this case, the microcomputer can be employed as an evaluation circuit. The word circuit herein will be used to
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`mean both an electronic circuit and the functional equivalent implemented on a microcomputer using software.
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`In enhanced embodiments, a heart beat sensor may be provided for detecting the heart beat of the
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`occupant and generating an output representative dtereof. The processor means additionally receive this output
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`and evaluate the seated—state of the seat based in part thereon.
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`In addition to or instead of such a heart beat sensor,
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`a capacitive sensor and/or a motion sensor may be provided. The capacitive sensor detects the presence of the
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`occupant and generates an output representative of the presence of the occupant. The motion sensor detects
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`movement of the occupant and generates an output representative thereof. These outputs are provided to the
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`processor means for possible use in the evaluation of the seated-state’ of the seat.
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`The portion of the apparatus which includes the ultrasonic, optical or electromagnetic sensors, weight
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`measuring means and processor means which evaluate the occupancy of the seat based on the measured weight of
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`the seat and its contents and the returned waves from the ultrasonic, optical or electromagnetic sensors may be
`considered to constitute a seated—state detecting unit.
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`The smtedstate detecting unit may further comprise a seat track position-detecting sensor. This sensor
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`determines the position of the seat on the seat track in the forward and an direction.
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`In this case, the evaluation
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`circuit evaluates the seated-state, based on a correlation function obtain from outputs of the ultrasonic sensors, an
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`output of the one or more weight sensors, and an output of the seat track position detecting sensor. With this
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`structure, there is the advantage that the identification between the flat configuration of a detected surface in a state
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`where a passenger is not sitting in the seal and the fiat configuration of a detected surface which is detected when a
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`seat is slid backwards by the amount of the thickness of a passenger, that is, of identification of whether a
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`passenger seat is vacant or occupied by a passenger, can be reliably performed.
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`Furthermore, the seated-state detecting unit may also comprise a reclining angle detecting sensor, and the
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`evaluation circuit may also evaluate the seated-state based on a correlation function obtained from outputs of the
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`ultrasonic, optical or electromagnetic sensors, an output of the weight sensor(s), and an output of the reclining
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`angle detecting sensor. In this case, if the tilted angle information of the back portion of the seat is added as
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`evaluation infonnation for the seated-state, identification can be clearly performed between the flat configuration of
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`a surface detected when a passenger is in a slightly slouching state and the configuration of a surface detected
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`when the back portion of a seat
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`is slightly
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`forward and similar dilficult-to-discriminate cases. This
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`embodiment may even be combined with the output from a seat track position-detecting sensor to further enhaiice
`the evaluation circuit.
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`Moreover, the seated-state detecting unit may further comprise a comparison circuit for comparing the
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`output of the weight sensor(s) with a referenceivalue. In this case, the evaluation circuit identifies an adult and a
`:79‘-,
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`child based on the reference value.
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`Preferably, the seated-state detecting unit comprises: a plurality of ultrasonic, optical or electromagnetic
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`sensors for transmitting ultrasonic or electromagnetic waves toward a seat and receiving reflected waves from the
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`seat; one or more weight sensors for detecting weight of a passenger in the seat; a seat track position detecting
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`sensor; a reclining angle detecting sensor; and a neural network circuit to which outputs of the ultrasonic or
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`12
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`

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`electromagnetic sensors and the weight sensor(s), an output of the seat track position detecting sensor, and an
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`output of the reclining angle detecting sensor are inputted and which evaluates several kinds of seated-states, based
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`on a correlation function obtained from the outputs.
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`The kinds of seated-states that can be evaluated and categorized by the neural network include the
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`following categories, among others, (i) a normally seated passenger and a forward facing child seat. (ii) an
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`abnormally seated passenger and a rear—facing child seat, and (iii) a vacant seat.
`The seated-state detecting unit may further comprise a comparison circuit for comparing the output of the
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`weight sensor(s) with a reference value and a gate circuit to which the evaluation signal and a comparison signal
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`from the comparison circuit are input. This gate circuit, which my be implemented in sofiware
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`hardware,
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`outputs signals which evaluates several kinds of seated-states. These kinds of seated-states can include a (i)
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`normally seated passenger, (ii) a forward facing seat, (iii) an abnormally seated passenger, (iv) a rear facing
`child seat, and (v) a vacant seat. With this arrangement, the identification between a nomtally seated passenger
`and a forward facing child seat, the identification between an abnormally seated passenger and a rear facing child
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`seat, and the identification of a vacant seat can be more reliably performed.
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`The outputs of the plurality of ultrasonic or electromagnetic sensors, the output of the weight sensor(s),
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`the outputs of the seat track position detecting sensor, and the outputs of the reclining angle detecting sensor are
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`inputted to the neural network or other pattern recognition circuit, and the neural network circuit determines the
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`correlation function, based on training thereof during a training phase. The correlation function is then typically
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`imp