Abstract: A system and method for controlling the inflation of an air bag in a vehicle utilizes a seat weight sensor, a seat belt tension measurement sensor, and a capacitive position sensing sensor. The capacitive sensor is mounted at a point relative to an air bag inflator door and responsive to the proximity thereto of an object to be sensed. An air bag control processor operatively coupled to a plurality of air bag squibs is provided for controlling the inflation of the air bag responsive to the force exerted on the vehicle seat, the tension sensed in the seat belt, and the proximity of an object or occupant to the inflator door.

Abstract: A variable resistance weight sensor incorporates a plurality of force sensitive resistance elements disposed between a pair of force distributing plates. One of the force distributing plates incorporates an associated plurality of protrusions for transferring, in cooperation with the second force distributing plate, an associated component of the compressive load to the associated force sensitive resistive element, whereby the resulting resistance of the force sensitive resistive element is inversely related to the magnitude of the associated compressive load component. The force sensitive resistive elements are interconnected in series, whereby a signal processor measures the applied load from the associated series resistance. A diode connected in parallel with the series combination of force sensitive resistive elements provides a means for diagnosing the sensor.

Abstract: A gas generator utilizes two segregated propellant container/combustion chambers, each having a plurality of nonazide propellant grains therein, and each having an igniter for separately igniting the propellant grains located within the respective chambers. A perforated insulating tube disposed between the two chambers precludes flame front and thermal propagation from one chamber to another, thus preventing redeployment of an activated airbag. Alternatively, a gas generator may contain two separate inflator subassemblies insulated to prevent heat conduction from one subassembly to another.

Abstract: A relatively narrow beam of either RF or optical electromagnetic radiation is scanned over a relatively wide azimuthal range. The return signal is processed to detect the range and velocity of each point of reflection. Individual targets are identified by clustering analysis and are tracked in a Cartesian coordinate system using a Kalman filter. The threat to the vehicle for a given target is assessed from estimates of the relative distance, velocity, and size of each target, and one or more vehicular devices are controlled responsive to the assessment of threat so as to enhance the safety of the vehicle occupant. In a preferred embodiment, a quantized linear frequency modulated continuous wave RF signal is transmitted from and received by a multi-beam antenna having an aziumthal range of at least +/-100 degrees and an individual beam width of approximately 10 degrees.

Abstract: High nitrogen gas generant compositions, useful for inflating passenger restraint gas inflator bags, comprise a nitrogen rich coordination compound selected from coordination complexes comprised of anionic nitro and nitrito ligands coordinated with a transitional metal template, and nonmetallic or nonmetallic/metallic cations. The gas generant compositions generate relatively more gas and less solids, and are safer than known gas generant compositions. Certain gas generant compositions ignite at lower autoignition temperatures thereby facilitating the use of an aluminum or light weight metal pressure vessel. Other gas generants self-deflagrate eliminating the need for other constituents in the composition. Novel methods for the synthesis of nonmetal derivative coordination complexes, guanidine and hydrazine for example, are also presented.

Abstract: A plurality of pneumatic hydrostatic weight sensors, each incorporating a fluid and a pressure sensor for sensing the pressure thereof, are incorporated in series with the load path within a vehicle seat to sense occupant weight. A signal processor measures the pressure within each pneumatic hydrostatic weight sensor and the weight of the occupant from the signal generated by the associated pressure sensor, and compensates for the effects of ambient pressure or temperature on the weight measurement responsive to the difference in pressure between the associated pressures of two of the pneumatic hydrostatic weight sensors.

Abstract: Thermally stable gas generant compositions incorporate a combination of one or more primary nonazide high-nitrogen fuels selected from a group including tetrazoles, bitetrazoles, and triazoles, and salts thereof; and one or more secondary nonazide high nitrogen fuels selected from azodicarbonamide and hydrazodicarbonamide. The primary and secondary fuels are combined with phase-stabilized ammonium nitrate that when combusted, results in a greater yield of gaseous products per mass unit of gas generant, a reduced yield of solid combustion products, lower combustion temperatures, and acceptable burn rates, thermal stability, and ballistic properties. These compositions are especially suitable for inflating air bags in passenger-restraint devices.

Abstract: A vehicular crash discrimination system (10) incorporates first (12) and second (14) crash sensors operatively coupled to a logic AND gate (16), which activates a safety restraint system (2). The first crash sensor (12) is mounted in a location which for a preferred sensing characteristic causes susceptibility to activation by crashes which are so directed that the safety restraint system (2) should not otherwise be activated. The second crash sensor (14), having a lower detection threshold than the first crash sensor (12), is mounted at a distinct location and is responsive to crashes for which the safety restraint system (2) is preferably activated, but is not responsive to those crashes which cause false activation of the first crash sensor (12). The instant invention thus provides for a preferred sensing characteristic determined by a first crash sensor mounted in an inferior location without being subject to false activation of the safety restraint system (2).

Abstract: A diagnostic method (100) with pre-assembly fault recording lock-out inhibits fault recording during assembly of a main system until the system has been determined operation at least once (116). The method will still note the detection of system failures/errors (112) by activating a warning lamp (120), but will not record these faults into memory until the system has determined that the main system has been powered up without any errors at least once (118 and 122). Thus, since these faults are not stored in memory during manufacture/assembly, the method of the present invention obviates the need for any additional assembly step(s) of erasing and/or clearing the memory, or externally controlled recording inputs for the diagnostic system.

Abstract: A plurality of hydrostatic weight sensors, each incorporating a fluid and a pressure sensor for sensing the pressure thereof, are incorporated in a vehicle seat to sense occupant weight, position, and stature. In one aspect, a hydrostatic weight sensor is located in the seat back and a separate hydrostatic weight sensor is located in the seat bottom. In another aspect, a plurality of laterally or longitudinally proximate hydrostatic weight sensors, or a single bladder with a plurality of chambers, is incorporated in the seat bottom to sense occupant position. In another aspect, a hydrostatic seat weight sensor is provided by forming a fluid filled cavity within a seat cushion and sensing the pressure of the fluid therein. A signal processor calculates the occupant weight, position, and stature from the respective pressure sensor output signals and controls a safety restraint system responsive thereto.

Abstract: A hydrostatic weight sensor element incorporates a volume restorer for restoring the volume thereof when the applied load is removed therefrom, whereupon a check valve in fluid communication therewith admits sensing fluid thereinto if the pressure of the sensing fluid within the hydrostatic weight sensor element is less than local atmospheric pressure, so as to replenish lost sensing fluid. The volume restorer may comprise either the seat cushion, operatively coupled to the load bearing surfaces of the hydrostatic weight sensor element, or an elastic medium incorporated within the hydrostatic weight sensor element, whereby the volume restorer is adapted so that the restored volume of fluid is less than the volume capacity of the hydrostatic weight sensor element. A pressure relief valve is provided for releasing sensing fluid so as to prevent damage from overload conditions.

Abstract: In accordance with a preferred embodiment, a vehicle crash discrimination system (10) comprises a plurality of coil sensors (18) permanently mounted to a vehicle pillar, and a magnet 20 either mounted to a door (14) edge surface juxtaposed to the coils, or to the pillar if a suitable ferromagnetic flux collector is mounted on the door edge. The shape, size and spacing of the coils is predetermined to provide output signals in the coils responsive to the change in the magnetic field caused by movement of the door surface. The change in magnetic field is analyzed to indicate a vehicle crash.

Abstract: An automotive radar incorporates a repetitive randomized equivalent LFM sequence of frequencies for improved immunity to jamming from other automotive radars. Each frequency in the sequence is of sufficient duration to travel round trip over the detection range of the radar. The Doppler shift in the received signal is estimated by performing a spectral analysis on similar frequency components of the received signal, and is then removed from the entire received signal. The received signal is then reordered so as to form an equivalent LFM received signal, and is compared with a similarly reordered image of the transmitted signal so as to estimate the range to the target. The randomization sequence, initial start frequency, or initial start time of the repetitive sequence are varied to minimize the effects of jamming by other radars, and this variation can be directionally dependent.

Abstract: A hydrostatic weight sensor comprises a continuous flexible sensing tube incorporated within the seat. A fluid is contained therein and a pressure sensor is operatively coupled thereto. The continuous flexible sensing tube may be arranged in a spiral or serpentine pattern, or comprise a plurality of segments each in fluid communication with a central port. A load applied to the seat causes the continuous flexible sensing tube to deform, thereby increasing the pressure of the fluid contained therein. A signal processor calculates the weight of the occupant from the pressure signal, and controls a safety restraint system responsive to the weight measurement.

Abstract: A vehicle crash sensing system for making omnidirectional acceleration measurements comprises 1) an assembly (26) of at least three preferably self-testable accelerometers (10, 12, 14) mounted in an array on a substantially common plane (16) with axes (18, 20, 22) both skewed relative to one another and intersecting a region near a point, and 2) an electronic control module (30). The accelerometer signals (A, B, C) provide a redundant measure of the associated acceleration vector (R). The magnitudes of components for associated acceleration basis vectors are calculated from the accelerometer signals (A, B, C) and used in the detection of crashes for associated safety restraint systems (801, 802, 803, 804).

Abstract: The disclosure relates to a bridgewire initiator used to ignite a booster charge in an airbag inflator. A pair of connectors are electrically connected to a bridgewire disposed within a charge holder containing an ignition composition. The ignition composition is biased against the bridgewire by an output cup having a concave end telescoped over the charge holder. When firing current is applied to the connectors the bridgewire is electrically heated thereby igniting the booster charge.

Abstract: An autoignition composition for the gas generator of a vehicle occupant restraint system that is thermally stable at temperatures up to 110.degree. C., autoignites between 150.degree. C. and 175.degree. C., produces minimal toxic gases upon combustion, provides for a reduced gas inflator size, and can be safely produced using simple processing methods. By mixing an alkali metal nitrite with a nitrogen-based fuel, the resulting gas generants autoignite at or below 175.degree. C. The addition of an alkaline earth metal nitrite or nitrate provides the stability needed to additionally function as a booster and/or a gas generant.

Abstract: A plurality of ultrasonic transmitters, at distinct locations and with distinct transmitting frequencies, direct beams of ultrasonic sound waves at a one or more detection regions of space. The amplitude of the ultrasonic sound waves is sufficient to generate from each detection region a sound wave having a frequency corresponding to the difference of the frequencies of the respective ultrasonic sound waves. A receiver disposed proximate to the ultrasonic transmitters detects the generated sound wave. An object occupying the detection region blocks one or more of the beams, and is detected therein when the magnitude of the generated sound wave is below a threshold. In another aspect of the instant invention, the ultrasonic transmitters are adapted to transmit pulses forming relatively broad spherical wavefronts which intersect to form a circular detection region which propagate with time, thereby enabling the detection of a profile of an object.

Abstract: A method and system (10) for detecting vehicle occupant type and position utilizes a single camera unit (12) positioned, for example at the driver or passenger side A-pillar, to generate image data of the front seating area of the vehicle. The present invention distinguishes between objects, forwardly or rearwardly facing child seats, and occupants, by periodically mapping the image taken of the interior of the vehicle into an image profile (104), and utilizing image profile matching with stored profile data (110) to determine the occupant or object type. The system and method of the present invention track occupant type and position in both parallel and perpendicular directions relative to a fixed structure such as the vehicle instrument panel to optimize both the efficiency and safety in controlling deployment of a occupant safety device, such as an air bag (28).

Abstract: A gas generator of an airbag passenger restraint device wherein the gas generator comprises a propellant tube having first and second end closures. The second end closure contains an end cap dual spring subassembly that substantially reduces the vibrations within the generator assembly and propellant. The liberation of fluorocarbons and other undesirable byproducts caused by end cap reactivity is eliminated by employing an inert end cap. By reducing the vibratory effect, inflator performance variability and noise level are substantially reduced.