Passenger detection system

• US 20020171540A1
• Filed: 04/12/2002
• Published: 11/21/2002
• Est. Priority Date: 05/16/2001
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Ando, Junichi, Yamamoto, Yukiteru
• Granted Patent: US 6,727,823 B2
• Time in Patent Office: Days
• US Class Current: 340/457
• 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 21/0152 using strain gauges

Abstract

A passenger detection system is provided to determine if a passenger is present or not because the weight value corresponding to when the seat is empty has shifted. The passenger detection system detects when the door has changed from the closed state to the open state based on a signal from a door switch. The passenger detection system then senses the decrease in weight that occurs thereafter and stores the weight value obtained after the decrease as the empty seat value.

Claims

1. A passenger detection system comprising:

a weight detecting device arranged and configured to detect weight on a seat;

a door status detecting device arranged and configured to detect open/closed door status of a vehicle door;

a storage device arranged and configured to store a reference weight, said reference weight being set to a subsequent detected weight if said subsequent detected weight is lighter than a prior detected weight by an amount greater than or equal to a prescribed value after a first condition has been established indicating that the door status detected by said door status detecting device has changed from a door closed state to a door open state, and a second condition has been established indicating that the weight detected by said weight detecting device has changed from said prior detected weight to said subsequent detected weight; and

a determining device arranged and configured to determine if an object is present on the seat based on a difference between current detected weight by said weight detecting device and said reference weight stored in said storage device.

2. The passenger detection system as recited in claim 1, further comprising

an ignition detecting device arranged and configured to detect an ON/OFF status of an ignition switch of the vehicle, and

said storage device stores said subsequent detected weight as said reference weight when said ignition detecting device detects the ignition switch is in an ON state, said first condition has been established and afterwards said second condition has been established.

3. The passenger detection system as recited in claim 1, further comprising

an ignition detecting device arranged and configured to detect an ON/OFF status of an ignition switch of the vehicle, and

said storage device stores said subsequent detected weight as said reference weight when a third condition is established indicating that the ignition switch detected by said ignition detecting device changed from an ON state to an OFF state, said first condition has been established and afterwards said second condition has been established.

4. The passenger detection system as recited in claim 3, wherein

said storage device stores said subsequent detected weight as said reference weight when said first condition has been established within a first prescribed time period after said third condition has been established and after said second condition has been established.

5. The passenger detection system as recited in claim 4, wherein

said storage device stores said subsequent detected weight as said reference weight only when said second condition has been established within a second prescribed time period after said first condition has been established.

6. The passenger detection system as recited in claim 1, wherein

said storage device stores said subsequent detected weight as said reference weight only when said second condition has been established within a prescribed time period after said first condition has been established.

7. The passenger detection system as recited in claim 1, wherein

said storage device includes a history storage section to store a prescribed number of said subsequent detected weights, a computing section to execute statistical processing with respect to a plurality of said subsequent detected weights stored in said history storage section, and said storage device stores said reference weight based on the statistical processing executed by said computing section.

10. The passenger detection system as recited in claim 7, wherein

said storage device includes a history storage section to store a prescribed number of said detected weights, a computing section to execute statistical processing with respect to a plurality of said detected weights stored in said history storage section, and said storage device stores said reference weight based on the statistical processing executed by said computing section.

9. A passenger detection system comprising:

a weight detecting device arranged and configured to detect weight on a seat;

an ignition detecting device arranged and configured to detect an ON/OFF status of an ignition switch of the vehicle;

a storage device arranged and configured to store a reference weight, said reference weight being set to a detected weight detected by said weight detecting device when the ignition switch detected by said ignition detecting device changes from an OFF state to an ON state and said detected weight is negative relative to a prior value of said reference weight; and

a determining device arranged and configured to determine if an object is present on the seat based on a difference between a current weight detected by said weight detecting device and said reference weight stored in said storage device.

11. A passenger detection system comprising:

weight detecting means for detecting weight on a seat;

door status detecting means for detecting open/closed door status of a vehicle door;

memory means for storing a reference weight, said reference weight being set to a subsequent detected weight if said subsequent detected weight is lighter than a prior detected weight by an amount greater than or equal to a prescribed value after a first condition has been established indicating that the door status detected by said door status detecting means has changed from a door closed state to a door open state, and a second condition has been established indicating that the weight detected by said weight detecting means has changed from said prior detected weight to said subsequent detected weight; and

determining means for determining if an object is present on the seat based on a difference between current detected by said weight detecting means and said reference weight stored in said memory means.