Omni-directional crash sensor

• US 7,516,645 B2
• Filed: 06/08/2007
• Issued: 04/14/2009
• Est. Priority Date: 01/16/2003
• Status: Expired due to Fees

• Current Assignee: Methode Electronics Incorporated
• Original Assignee: Methode Electronics Incorporated
• Inventors: Kithil, Philip W., Du Rocher, Daniel J., Novak, James L.
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US11/808,382
• Publication Number:
  US 20070277622A1
• Time in Patent Office: 676 Days
• Field of Search: 73 1201- 1209, 737/77
• US Class Current: 73/12.09
• CPC Class Codes: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558
• CPC Class Codes: G01L 1/16 using properties of piezoelectric devices
• CPC Class Codes: G01L 5/0052 measuring forces due to impact G01L5/0061, G01L5/14 take precedence; impact testing of structures G01M7/08; impact testing of material G01N3/00

Abstract

A stress wave sensor comprising a piezoelectric film and means therein for connection to sensor electronics. The piezoelectric film preferably comprises polyvinylidene fluoride. Also a stress wave sensor system and methods employing one or more such stress wave sensors, preferably attached to a vehicle transparent component, most preferably to the vehicle windshield.

Claims

1. A method of characterizing a vehicle crash condition by reference to output from a plurality of sensors each comprising a piezoelectric film, the method comprising the steps of collecting output from the plurality of sensors;

and analyzing one or more of the group consisting of;

one or both of amplitude and rise time of each sensor'"'"'s output;

each sensor'"'"'s output in a plurality of frequency bands, preferably from at least bands at about 1 kHz-2.5 kHz and 5 kHz-20 kHz; and

time differentiated outputs of the sensors.

2. The method of claim 1, wherein the piezoelectric film comprises polyvinylidene fluoride.

3. The method of claim 1, wherein the analyzing step comprises estimating either or both of a vehicle crash origin point and a crash severity.

4. The method of claim 1, wherein the plurality of frequency bands include at least the ranges 1 kHz to 2.5 kHz and 5 kHz to 20 kHz;

and time differentiated outputs of the sensors.

5. The method of claim 2, wherein the plurality of sensors are attached to a vehicle transparent component.