Center of weight sensor

• US 6,223,606 B1
• Filed: 10/09/1998
• Issued: 05/01/2001
• Est. Priority Date: 01/08/1997
• Status: Expired due to Term

• Current Assignee: Trustees of Boston University
• Original Assignee: Trustees of Boston University
• Inventors: Burke, Shawn E., Hubbard, James E. Jr.
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US09/169,759
• Time in Patent Office: 935 Days
• Field of Search: 73/862, 73/862.041, 73/862.042, 73/862.043, 73/862.044, 73/862.045, 73/862.046
• US Class Current: 73/862.041
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/01526 using piezoelectric elements
• CPC Class Codes: G01G 19/4142 for controlling activation of safety devices, e.g. airbag systems electrical circuits for triggering safety arrangements in case of vehicle accidents B60R21/015
• CPC Class Codes: G06V 40/10 Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands

Abstract

A sensor system preferably for use in a vehicle airbag deployment system employs spatial shading techniques and centroiding analysis to calculate an equivalent point load in two dimensional space. The location of the equivalent point load, as well as the weight of the passenger as determined from the sensors, are used to construct a set of fuzzy set logic boundaries defining different modes of deploying the airbag. The filmy set logic boundaries may include a full deployment, soft deployment, no deployment and other intermediate deployment zones. In the event of a vehicle airbag incident, the airbag is deployed in accordance with the fuzzy set logic boundary in which the weight and equivalent point load of the vehicle occupant are located.

Claims

1. A method for detecting stress patterns over a surface of a body, comprising the steps of:

(a) providing at least three sensors disposed in an array over an area of said body, each sensor producing an output signal varying over a range that is a function of the magnitude of the stress applied over an area of the sensor in response to a distributed force between the body and the sensors;

(b) applying spatial weights to the values of the sensor output signals and summing the weighted values to determine the magnitude of the force and the position of an equivalent point load of the force in said array; and

(c) measuring the variation over time of the magnitude and position of the equivalent point load relative to the array.

2. The method according to claim 1 further comprising the step of providing said array over an insole area of an item of footwear applied to said body.

3. The method according to claim 2 further comprising the step of measuring said variation as said body moves.

4. The method according to claim 3 further comprising the step of measuring parameters representative of a gait of said body as said body moves.

5. The method of claim 4 wherein said parameters are selected from the group consisting of vertigo, strains, sprains and recovery, or combinations thereof.