Active solid-state devices (e.g. – transistors – solid-state diode – Integrated circuit structure with electrically isolated... – Passive components in ics
Reexamination Certificate
2001-08-24
2004-09-21
Nguyen, Cuong (Department: 2811)
Active solid-state devices (e.g., transistors, solid-state diode
Integrated circuit structure with electrically isolated...
Passive components in ics
Reexamination Certificate
active
06794728
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention (Technical Field)
The present invention relates to capacitive sensors, particularly those employed in automotive vehicular environments.
2. Background Art
Sensor technologies are becoming increasingly important in the development of safety and convenience features of vehicles. Because of differing vehicle geometries and extreme environmental conditions to which they are subjected, the sensors presently available are deficient in many regards.
Automobile air bag systems are a well known means of attempting to reduce the likelihood of serious injury to passengers in collisions. These systems are designed to very quickly inflate an air bag in front of a passenger during a collision, so as to hopefully prevent the passenger from colliding with hard objects in the passenger compartment interior, particularly the steering column and/or the dashboard. Such systems typically sense that the vehicle is involved in a collision, by using an accelerometer to sense sudden deceleration of the vehicle. Rapid inflation of the air bag may be obtained by electrical ignition of a pyrotechnic substance which rapidly generates a volume of gas sufficient to inflate the air bag, or by electrical opening of a valve for release of compressed gas stored in a chamber which is part of the air bag system.
The performance of an air bag system, in terms of its success or failure in preventing serious passenger injury, may be critically dependent on facts concerning the initial position and subsequent motion of the passenger, which are not made known to the system by an accelerometer which senses deceleration of the vehicle as a whole. Passenger head motion is particularly important, due to the seriousness of head injuries. For example, if the passenger is seated too far forward, or has his/her head too far forward, occupying the space into which the air bag will deploy, the passenger may be seriously injured by the deployment of the air bag intended to prevent passenger injury. So there is dearly a need for passenger position sensing apparatus, which can prevent air bag deployment when the passenger is already too far forward when the collision begins.
But even if the passenger is not too far forward at the beginning of the collision, the passenger will tend to move rapidly forward, with the passenger's head leading that motion, relative to the vehicle, as the vehicle rapidly decelerates, and will tend to move into the air bag deployment space, at least in the case of forward collisions, and may be too far into the air bag deployment space, before the completion of air bag deployment, to escape injury from the air bag deployment. There are a number of factors which may strongly influence the forward motion of the passenger, in addition to initial position, in ways which may vary markedly from one passenger to another. The relative forward motion of the passenger will depend strongly on whether the passenger has secured a seat lap belt and/or shoulder harness prior to the collision. The passenger's motion may also be influenced somewhat by the strength of any tensing up reaction the passenger has to the collision, i.e., instinctively pushing forward with the feet against the floorboard to restrain forward motion of the body. Such a protective reaction may vary greatly from one passenger to another, and may be greatly reduced or wholly absent if the collision is too sudden, so that the passenger has no time to react, or if the passenger is intoxicated or otherwise impaired. Also variation of the crash intensity by itself will cause considerable variation in passenger acceleration. So there is a need for systems which account for various positional and motion data, and analyze that information in making the yes or no decision on air bag deployment. Overhead sensors offer an advantage over those previously known systems having beam-emitting sensors located in front of the passenger, as in air bag systems with acoustic sensors mounted on the steering column, for which the beam from the sensor will at times by blocked from operating by the hands and/or forearms of the driver.
The use of capacitive sensors offers advantages over beam—emitting sensors, since each capacitive coupling sensor functions by sensing the change in the capacitance of a capacitor, caused by the nearby presence of a person, an effect which is essentially instantaneous (since propagated at light speed), rather than requiring a finite, non-negligible beam travel time as in the case of an ultrasonic position sensor, and since the capacitive coupling sensor does not require transmission and detection of a beam which might be blocked. And the use of an overhead array of capacitive coupling proximity sensors, the signals from which are analyzed by a microprocessor, allows essentially instantaneous and continuous monitoring of passenger position and motion through triangulation based on the distances of the passenger to the various sensors of the array, so that the overhead sensor array can be used to accurately and continuously determine fore—aft, diagonal, and lateral passenger motion. Since the passenger's head will be closest to the overhead sensors, this method will be particularly sensitive to passenger head motion.
The current state of the art is reflected by the following patents: U.S. Pat. No. 5,702,123, to Takahashi et al., entitled “Air Bag Apparatus for Passenger Seat”; U.S. Pat. No. 5,653,462, to Breed et al., entitled “Vehicle Occupant Position and Velocity Sensor”; U.S. Pat. No. 5,602,734, to Kithil, entitled “Automobile Air Bag Systems”; U.S. Pat. No. 5,549,323, to Davis, entitled “Plastic Air Bag Cover Having an integrated Occupant-Sensing Sensor Module”; U.S. Pat. No. 5,512,836, to Chen et al., entitled “Solid-State Proximity Sensor”; U.S. Pat. No. 5,365,241, to Kithil, entitled “Automobile Air Bag System”; U.S. Pat. No. 5,802,479, to Kithil, entitled “Motor Vehicle Occupant Sensing Systems;” U.S. Pat. No. 6,014,602, to Kithil, entitled “Motor Vehicle Occupant Sensing Systems;” U.S. Pat. No. 5,363,051, to Jenstrom et al., entitled “Steering Capaciflector Sensor”; and U.S. Pat. No. 5,118,134, to Mattes et al., entitled “Method and Apparatus for Protecting Motor Vehicle Occupants”.
Capacitive sensor arrays are employed in the art for detection of persons, including for presence and position within automobiles. Further representative of the art are U.S. Pat. No. 3,864,668, entitled “Seat Belt Warning and Ignition Interlock System”, to Bickford; U.S. Pat. No. 3,898,472, entitled “Occupancy Detector Apparatus for Automotive Safety System”, to Long; U.S. Pat. No. 4,796,013, entitled “Capacitive Occupancy Detector Apparatus”, to Yasuda et al.; and U.S. Pat. No. 4,887,024, entitled “Person Detecting Device”, to Sugiyama et al. U.S. Pat. Nos. 4,972,154 and 5,394,097, entitled “Apparatus and Method for Measuring Wood Grain Angle”, and “Dielectric Sensor”, respectively, to Bechtel, et al., exemplify one and two-sided fabrication of electrodes on traditional printed circuit (PC) boards.
The present invention provides apparatuses and methods addressing deficiencies in the prior art, as described in the description of the preferred embodiments, below. The present invention concerns systems for sensing characteristics of motor vehicles and occupants for purposes such as deployment of air bags during vehicle crashes, to monitor drowsy drivers, and to determine crash characteristics. More particularly it concerns systems in which the system operation is affected not only by information about the motion of the vehicle caused by crash forces, but also measured data concerning the motion of the passenger, so that the system will operate in a manner to minimize the risk of serious injury to the passenger. The present invention also incorporates a microprocessor having memory to track data and compare it to reference data, as well as an algorithm to compensate for temperature effects upon the sensors.
SUMMARY OF THE INVENTION (DISCLOSURE OF THE INVENTION)
The present invention is of a
Advanced Safety Concepts, Inc.
Myers Jeffrey D.
Nguyen Cuong
Peacock Myers & Adams P.C.
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