Electronic seat occupant classification system

• US 20040174004A1
• Filed: 03/07/2003
• Published: 09/09/2004
• Est. Priority Date: 03/07/2003
• Status: Active Grant

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Forwerck, Joshua, Smith, Francis N., Gauker, Bradford
• Granted Patent: US 6,918,612 B2
• Time in Patent Office: Days
• US Class Current: 280/735
• CPC Class Codes: B60R 21/01532 using electric or capacitive field sensors

Abstract

An occupant classification system for recognizing the type of occupant of a motor vehicle seat especially for use in controlling an inflatable restraint system. The classification system utilizes a number of on-off electrical switches arranged in a pattern on a seat cushion mat. Signals from the switches may be processed in a variety of manners to characterize the occupant.

Claims

1. An occupant classification system for a motor vehicle of the type having one or more occupant seats, an inflatable restraint system for providing impact protection for an occupant of the seat, and a belt restraint system associated with the seat, the occupant classification system for classifying an occupant of the seat for purposes of providing a control signal for the inflatable restraint system as a function of certain types of occupants occupying the seat, the occupant classification system comprising:

an array of on-off switches carried by a seat cushion of the seat;

a seat belt tension sensor providing an output related to the belt tension acting on the belt restraint system; and

a controller for receiving signals from the on-off switches and the seat belt tension sensor for providing the control signal for the inflatable restraint system, wherein a belt tension signal related to a belt tension above a predetermined level associated with the presence of a child restraint seat in the seat will produce a control signal for disabling the inflatable restraint system and the outputs from the on-off switches are interpreted to provide the control signal distinguishing between occupants for controlling the inflatable restraint system.

2. The classification system of claim 1 wherein the control signal selectively enables or disables the inflatable restraint system.

3. The classification system of claim 1 wherein the on-off switches are single-pole, single-throw, types.

4. The classification system of claim 3 wherein the on-off switches are normally open types.

5. The classification system of claim 1 wherein the controller provides the control signals based upon the total number of the on-off switches activated by an occupant.

6. The classification system of claim 1 wherein the seat cushion is divided into zones with at least one of the on-off switches in each of the zones.

7. The classification system of claim 6 wherein the control signal is based upon the number of the on-off switches activated in each of the zones, and the control signal being influenced to a greater degree by the on-off switches in a particular of the zones as compared with the on-off switches.

8. The classification system of claim 6 wherein the control signal is based upon the number of the zones having the on-off switches which are activated.

9. The classification system of claim 6 wherein the control signal is based upon the number of the zones having the on-off switches which are activated and the total number of the on-off switches which are activated.

10. The classification system of claim 6 wherein the control signal is based upon the product of the total number of the on-off switches which are activated and the number of zones having the on-off switches which are activated, divided by the number of zones associated with an adult occupant occupying the seat.

11. The classification system of claim 6 wherein the zones include at least a pair of lateral edge zones, a front edge zone, a center zone, and a rear zone.

12. The classification system of claim 1 wherein the on-off switches comprise a first electrical contact carried by a base sheet, an elastomeric dome carrying a second electrical contact, wherein compression of the elastomeric dome causes the first and second electrical contacts to electrically contact one another.

13. The classification system of claim 1 wherein the on-off switches are carried by an array mat.

14. The classification system of claim 1 wherein on-off switches are positioned between a foam seat cushion and a seat suspension.