METHOD AND APPARATUS FOR CONTROLLING AN AIRBAG

Abstract: An apparatus and method for controlling the deployment of airbags facing seats in a vehicle is provided. A seat is provided having a plurality of sensors and a computer output from said plurality of sensors, and an airbag is positioned opposite the seat. The airbag is deployed when the plurality of sensors exceed a threshold. The computer stores data concerning weight, center of gravity, and load distribution of an occupant, as determined from readings from the sensors, and the threshold is adjusted based upon that data. Where multiple airbags are provided, the computer controls the deployment only the airbags facing occupied seats when the threshold is exceeded.

Description: METHOD AND APPARATUS FOR CONTROLLING AN AIRBAG BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for controlling an airbag. More particularly, the present invention relates to an apparatus which controls the release of an airbag of an automobile in response to sensors in the automobile seat based upon the seated person's weight, height, center of gravity and load distribution. 2. Description of the Prior Art Maintaining a comfortable and useful seated posture for a long period of time can be difficult and may require special support. Disabled individuals who are confined or limited to a wheelchair are especially challenged to achieve a comfortable position. Appropriate posture is necessary to prevent pain, sores and injury such as deformity, retain good posture and improve the abilities of people restricted to wheelchairs. U.S. Patent No. 4,890,235, to Reger et al, pertains to a computer aided prescription of specialized seats for wheelchairs or other body supports. The system provides a surface which deforms to the shape of an object placed on it, and a sensor generates a force a distribution signal represent- ing the force distribution along the surface. A patient is placed upon the seat causing deformation of the surface. The seat surface is then selectively varied in accordance with the signal from the sensor by manipulating multiple pneumatic actuators. Data generated by the system is transmitted to a fabrication unit which produces a cushion with the desired characteristics . The Reger et al system however is only of limited use . The chair has sensors in only the seat and backrest with only one pneumatic actuator. The apparatus is designed to be controlled by others while the patient is seated, giving the patient no direct control of the process. The number of factors that need to be incorporated to obtain a comfortable seat for a patient are considerable, and the Reger et al system takes only a couple of factors into consideration. The human back is quite complex and a special support may be require for the head, pelvic region, thoracic region butt, thighs and arms. While the Reger et al system measures a persons contours, such measurements are performed in a static state. There is no provision for moving various components relative to one another prior to taking measurements. Movement of the components relative to one another will affect the readings used in developing the measurements, and therefor need to be considered to produce an optimum chair or support. SUMMARY OF THE INVENTION These and other deficiencies of the prior art are addressed by the present invention which is directed to a method and apparatus for producing a seat or patient support which takes measurements from a footrest, the seat, an anterior wedge, the armrests, a pelvic rest, a thoracic rest, a headrest and a backrest . It is an object of the present invention to over come the deficiencies of the existing system. Another object is to provide a method and apparatus which has separate components to support a patient, each of which can be independently actuated, and from which positional readings can be derived. Yet another object of the present invention is to provide a method and apparatus that can be controlled by the patient . Still another object of the present invention is to provide a device for triggering an airbag in an automobile depending upon measurements made by pressure sensors in the seat of the automobile. Yet another object of the present invention is to provide a device for triggering an airbag in an automobile depending upon measurements made by pressure sensors in the seat of the automobile depending upon predefined parameters, such as a person's weight, height, center of gravity and load distribution. The present invention provides support for a pa- tient's head, pelvic region, thoracic region butt, thighs and arms. Various components may be moved both angularly and linearly relative to one another prior to and subsequent to measurement and a chair or support is produced based upon the final measurement. The present invention includes pressure sensors which are placed at the same level as the actuators in order to inform the system of the position and movements of the occupant. The matrix of sensors are installed in the seat, backrest and other support regions in order to inform the system of the occupants posture, weight distribution, center of gravity and for auto-detection. For a car or truck seat, when the sensors register increases in reading of a sufficient level, an airbag will be deployed. The system can control multiple airbags so that they are only deployed for seats where there are occupants. BRIEF DESCRIPTION OF THE DRAWINGS These and other attributes of the present invention will be described with respect to the following drawings in which: FIG. 1 is a front view of a chair according to the present invention; FIG. 2 is a side view of the chair shown in FIG. 1; FIG. 3 is a front view of the chair shown in FIG. 1 showing the sensor components; FIG. 4 is a top plan view of the sensors for the seat, armrests and anterior wedge for the seat of FIG. 1; FIG. 5 is a front view of the chair shown in FIG. 1 showing the electro-mechanical components; FIG. 6 is a side view of the chair shown in FIG. 5; FIG. 7 is a flow chart for operation of the chair according to the present invention; FIG. 8 is a front view of the chair shown in FIG. 1 showing the operational components; and FIG. 9 is a perspective view of an embodiment of the present invention showing a vehicle seat, an airbag and opera- tional components thereof. DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2, the chair according to the resent invention has a backrest 14 and a seat 20, connected to one another and angularly adjustable relative to each other. A left and right armrest, 16 and 15, respectively, extends upwards from the sides of the seat 20. A head rest 11 is provided extending from the top of the backrest 14. Footrests 21 extend from the front of the seat 20, and are angularly adjustable relative to the seat 20. Right and left thoracic rests 12 and 13, respectively, extend forward from an upper portion of the backrest 14, as do right and left pelvic rests 17 and 18, respectively, from a lower portion of the backrest 14. Finally an anterior wedge 19 is provided on the front upper surface of the seat 20. The positioning of the backrest 14 relative to the seat 20, as well as the positioning of the remaining components: headrest 11, right and left thoracic rest 12 and 13, right and left arm rests 15 and 16, pelvic rests 17 and 18, anterior wedge 19, and footrests 21, can all be varied to achieve an optimum position for a patient, with regard to comfort, support and abilities. The chair has sensors in various components to develop data concerning the position of the patient and the orientation of the various components, as shown in FIGS 3 and 4. Sensors 31 are located in the backrest 14. Sensors 32 are positioned in the right thoracic rest 12 and sensors 33 are positioned in the left thoracic rest 13. Right and left arm rest 15 and 16 have sensors 34 and 35 provided in them, respectively. The seat 20 has sensors 36 and anterior wedge 19 has sensors 37. The third major system of the chair of the present invention, is shown in FIGS. 5 and 6, includes a series of actuators and transducer for controlling the movement and position of the various mechanical components of the chair. The actuators control the position of each of the components and the transducers aid in the calculation of the displacement of each component, both angularly and distance wise. An actuator 41 is provided in the backrest 14 to control the height of the head rest 11. An actuator 42 and transducer 51 control the position of the right thoracic rest 12 and an actuator 43 and transducer 52 control the position of the left thoracic rest 13. The position of the anterior wedge 19 is controlled by an actuator 44 and transducer 58 . The position of the seat 20 is controlled by three actuators and two transducers. The angle of the seat 20 relative to the ground is controlled by an actuator 45 and trans- ducer 57. The height of the seat from the ground is controlled by actuator 46 and transducer 56, and distance, or depth, the seat 20 extend from the backrest 14 is controlled by actuator 48 transducer 59. The angle of the backrest 14 relative to the seat 20 is controlled by actuator 47 and transducer 60. The position of the right and left pelvic rests 17 and 18, respectively, are controlled by transducers 52 and 53, respectively, and jointly by actuator 49. While many devices can be used as the sensors, the preferred sensors are force detector resistive components which are comparable to diaphragm-type commutators, or switches. However, unlike diaphragm-type commutators, the resistance decreases as the force applied to the force detector resistive components increases. For example, a human finger exerting a resistance of from IN to ION generates a continuous variance in resistance from 400 kilo ohms to 40 kilo ohms. The force detector resistive components are ideal for use in the chair of the present invention which utilizes touch sensitive sensors, as they are relatively inexpensive, are thin, less than 15mm thick, are durable, and can be used in a wide range of environments, as they are intrinsically insensitive to electromagnetic influences and they do not themselves generate interference. The force detector resistive components are available in matrix type arrays, or in individual elements having maximum dimensions of 55cm by 75cm, with force sensing capabilities of 20-30 grams to 20-30 kilograms. The operation of the chair of the present invention will now be described with reference to FIGS 7 and 8. After a patient sits in the chair, the various components are adjusted to achieve a comfortable position. The adjustment of the components can be performed by an operator, or alternatively, the patient can adjust the components using a remote control 78. The remote control is connected to a computer 90 through a remote control command module 80. If the patient is using the remote control 78, signals from the remote control are fed to the control module 80 and the computer 90 to instruct an actua- tor control 72 to activate one or more of the actuators and/or transducers via relays 70. If an operator is adjusting the position of the various components, the signals for controlling the actuators are generated directly at the computer 90. The remote control allows the user to affect the spatial positioning of the components the same way an operator would using the same program. The computer program allows for the input of information relating to which specific components are to be utilized in the chair conception. The various sensors, actuators and transducers send signals back to the computer 90 through input card 76 and 74. The optimum positioning of the various components is determined by trial and error and discussion with the patient. When the computer 90 is first activated, information concerning the patient is inputted. The patients postural disability is evaluated and the goals to be achieved are determined. The technique for achieve the goals for the patient are chosen and preset parameters are produced after which sequential settings are developed. The pressure distribution on the sensors of the chair are measured, and a prediagnostic is performed. The results of the prediagnostic are used in an empirical solution and the resulting parameters are authenticated. If the parame- ters are acceptable a simulation in produced and an assessment report generated. On the other hand, if the parameters are unacceptable, the faulty parameters are identified, a simulation is run, and corrective values are developed. The system then returns to the step of developing sequential settings are proceeds forward again. The system measures the angles and distances, and can provide pressure point graphics in two or three dimensions. Hard copy print outs can be produced, and/or the information can be sent to a CAD/CAM system 84. The CAD/CAM system may be at a remote location, such as a manufacturing site, and connected by modems 82. The CAD/CAM system can then produce a chair for each patient tailored to each one's individual needs and dimensions. Fig. 9 shows a vehicle seat 101 for a car, truck or other motor vehicle. The computer 105 can provide an automatic tally of the occupants using an autodetection feature of the present invention, which detects if an occupant is situated in the seat 101. Sensor pads 100, functioning in the same manner as the various sensors in the first embodiment, are disposed in various parts of the seat 101. The sensor pads 100 send data regarding activated pressure to input cards 103 and 104, which in turn is sent and analyzed by computer 105. The computer 105 can provide pressure mappings. More importantly, the computer 105 controls the release of the airbag 110. The computer 105 monitors the occupant's weight, center of gravity and other factors such as weight distribu- tion, using the sensor pads 100. In the event of a collision the sensor pads 100 which register significantly increased readings due to the force of the collision being transferred tot he occupant. If these readings exceed a predetermined threshold, the airbag 110 will be deployed. The threshold is selected depending upon predetermined factors and the individual factors of each occupant, such as height, weight, center of gravity, load distribution, etc. Thus the threshold may vary somewhat from one occupant to another. In a conventional automobile with an airbag, the force of a collision is detected and any and all airbags are deployed. In the present invention, sensor pads 100 in the seat 101 continuously monitor the pressure from an occupant . The threshold pressure reading for release of the airbag 110 changes somewhat from one occupant to another. Furthermore, instead of triggering all airbags in the event of a collision, as is the case in conventional airbags, the present invention deploys only the airbags facing occupied seats . Having described several embodiments of the in accordance with the present invention, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the description set forth above. For example, the present invention is equally applicable to wheelchairs, beds, ortheses, prostheses, corsets and feet. It is therefor to be understood that all such varia- tions, modifications and changes are believed to fall within the scope of the invention as defined in the appended claims.

Claims: WHAT IS CLAIMED IS: 1. An apparatus for controlling the release of an airbag in a vehicle, comprising: a seat ; a plurality of sensors disposed in said seat; a computer receiving output from said plurality of sensors ; and an airbag disposed facing said seat; wherein said airbag is deployed when said plurality of sensors exceed a threshold. 2. An apparatus for controlling the release of an airbag in a vehicle as recited in claim 1, wherein said computer stores data concerning weight, center of gravity, and load distribution of an occupant, as determined from readings from said plurality of sensors. 3. An apparatus for controlling the release of an airbag in a vehicle, as recited in claim 2, wherein said threshold is adjusted based upon said data concerning weight, center of gravity, and load distribution of an occupant. 4. An apparatus for controlling the release of airbags in a vehicle, comprising: a plurality of seats; a plurality of sensors disposed in each of said plurality of seats; a computer receiving output from said plurality of sensors ; and a plurality of airbags each disposed facing one of said plurality of seats; wherein said plurality of airbags are deployed when said plurality of sensors exceed a threshold. 5. An apparatus for controlling the release of an airbag in a vehicle, as recited in claim 4, wherein said computer monitors which of said plurality of seats is occupied, and only ones of said airbags facing occupied ones of said plurality of seats are deployed when said threshold is exceeded. 6. A method of controlling the release of an airbag in a vehicle, comprising the steps of: providing a seat with a plurality of sensors disposed in said seat; monitoring outputs of said plurality of sensors with a computer; providing an airbag facing said seat; and deploying said airbag when said plurality of sensors exceed a threshold. 7. A method of controlling the release of an airbag in a vehicle as recited in claim 6, further comprising the step of storing data concerning weight, center of gravity, and load distribution of an occupant, as determined from readings from said plurality of sensors, in said computer. 8. A method of controlling the release of an airbag in a vehicle, as recited in claim 7, further comprising the step of adjusting said threshold based upon said data concerning weight, center of gravity, and load distribution of an occupant . 9. A method of controlling the release of airbags in a vehicle, comprising the steps of: providing a plurality of seats; providing a plurality of sensors disposed in each of said plurality of seats; monitoring outputs of said plurality of sensors with a computer; providing a plurality of airbags each disposed facing one of said plurality of seats; and deploying said airbags when said plurality of sensors exceed a threshold. 10. A method of controlling the release of an airbag in a vehicle, as recited in claim 9, further comprising the steps of monitoring which of said plurality of seats is occupied, and deploying only ones of said airbags facing occupied ones of said plurality of seats when said threshold is exceeded.

Inventors: DUMONT DANIEL, GUERARD ERIC, LAFERRIERE ALAIN, DUMONT, DANIEL, GUERARD, ERIC, LAFERRIERE, ALAIN
Applicants: SEMAP S A R L, SEMAP S.A.R.L.
Application year: 1998
Main classification: B60R21
IPC codes: A61G5, B60N2, B60R21, G01G19