Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Vehicle subsystem or accessory control
Reexamination Certificate
1998-07-17
2001-01-09
Zanelli, Michael J. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Vehicle subsystem or accessory control
C280S735000
Reexamination Certificate
active
06173224
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to automotive vehicle occupant restraints in general, and more specifically to a method and apparatus for deploying an inflatable occupant restraint.
BACKGROUND OF THE INVENTION
It is common to use inflatable occupant restraints, sometimes referred to as airbags, in an automotive vehicle. The deployment of such devices is typically accomplished using a method that determines whether and when operation is appropriate. Currently, there are two prominent methods for deploying an airbag. One relies on jerk, the rate of change of acceleration of a vehicle colliding with another object. This method initiates deployment if and only if it determines that the magnitude of the observed jerk exceeds a prescribed magnitude. The other relies on a collision library, a collection of waveforms that represent simulated accelerations of a vehicle colliding with other objects under different configurations. This method initiates deployment if and only if it determines that the observed waveform correlates favorably with a library acceleration for which deployment is appropriate. As specified, however, both methods have shortcomings. The first relies exclusively on jerk, ignoring both absolute kinetic energy and absolute linear momentum with respect to the ground, or earth. For example, it can deploy inappropriately when jerk is large but changes in energy or momentum are small, conditions that hold for elastic, nearly elastic, and curb collisions at low speeds for which deployment is normally inappropriate. The second relies exclusively on acceleration, also ignoring both energy and linear momentum. For example, it cannot distinguish the difference between identically configured two-body collisions with the same relative velocity but with different energies and momenta. Although the relative velocity and vehicular damage are the same, the energies and momenta provide a way to distinguish the different configurations with respect to the ground. Because the two-body configurations have different ground speeds, they experience different air, road, and control conditions during collisions. Thus, they might require different strategies for deployment. Besides the defects already cited, both methods fail to account for statistical variations in observed data, especially variations inherent in all vehicular collisions.
SUMMARY OF THE INVENTION
The present invention overcomes the aforementioned disadvantages by providing a more general and effective method using energy, momentum, and statistical inference, to deploy an occupant restraint. An on-board implementation using microprocessors is also disclosed. The method for occupant-restraint deployment of the present invention rests on four basic notions: energy-momentum (e-m) waveforms, collision classes, signature waveforms, and semimetric distances between e-m waveforms. First, an e-m waveform is a two-dimensional, vector-valued function of which the first and second components represent an energy waveform and a momentum waveform, respectively. These components derive from both the acceleration and the initial velocity measured on the vehicle during a collision. Second, a collision class is the set of observable (statistically possible) e-m waveforms that could result from a specified type of collision, a class for which deployment is either appropriate or inappropriate, but not both. Third, a signature waveform is the mathematical expectation (average) of all the observable e-m waveforms of a collision class. It represents an e-m waveform best characterizing the class. And fourth, a semimetric distance between two e-m waveforms is an assigned nonnegative, nondimentional number quantifying the difference between these two objects.
The occupant-restraint deployment method of the present invention comprises the steps of measuring an initial vehicle velocity and a vehicle acceleration sample for a discreet time interval, calculating a vehicle velocity from the initial vehicle velocity and the vehicle acceleration, determining an e-m waveform for the time interval based upon the vehicle velocity and a vehicle mass, calculating a semimetric distance between the e-m waveform and each of a set of signature waveforms characterizing a collision class, identifying a collision class based upon the semimetric distances, and activating the deployment of an occupant restraint if the identified collision class indicates a collision for which deployment is appropriate.
The method is preferably implemented in computer code on a vehicle occupant-restraint controller having a microprocessor with parallel processing capabilities. The occupant-restraint system has an occupant restraint, such as an airbag, and a controller, as described above, connected to an occupant-restraint activation module.
An advantage of the present invention is an occupant-restraint deployment method and a system that accurately determines collisions for which deployment of an occupant restraint is appropriate.
A feature of the present invention is a method using energy, momentum, and statistical inference to deploy an occupant restraint.
REFERENCES:
patent: 4994972 (1991-02-01), Diller
patent: 5040118 (1991-08-01), Diller
patent: 5073860 (1991-12-01), Blackburn et al.
patent: 5216607 (1993-06-01), Diller et al.
patent: 5337238 (1994-08-01), Gioutsos et al.
patent: 5339242 (1994-08-01), Reid et al.
patent: 5345402 (1994-09-01), Gioutsos et al.
patent: 5394326 (1995-02-01), Liu
patent: 5436838 (1995-07-01), Miyamori
patent: 5483449 (1996-01-01), Caruso et al.
patent: 5490069 (1996-02-01), Gioutsos et al.
patent: 5508918 (1996-04-01), Gioutsos
patent: 5718451 (1998-02-01), White
Mahmud et al.; A new decision making algorithm for airbag control; IEEE-Vehicular Tech, vol. 44, iss. 3; Aug. 1995; pp. 690-697.
Alrabady et al.; Development of a decision making algorithm for airbag control; IEEE-Instrumentation and Measurement Tech, May 1993; pp. 81-84.
Gioutsos; Signal processing for automotive applications; IEEE-Accoustics, Speech, & Signal Processing, May 1995; vol. 5, pp. 2975-2978.*
Barnard Robert D.
Riesner Miloslav
Ford Global Technologies Inc.
Kelley David B.
Zanelli Michael J.
LandOfFree
Occupant-restraint deployment method and system for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Occupant-restraint deployment method and system for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Occupant-restraint deployment method and system for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2444766