Vehicle passenger detection device

• US 20040135406A1
• Filed: 10/10/2003
• Published: 07/15/2004
• Est. Priority Date: 10/16/2002
• Status: Active Grant

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Seto, Takayuki, Nishimoto, Yousuke
• Granted Patent: US 7,019,660 B2
• Time in Patent Office: Days
• US Class Current: 297/216.1
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/0152 using strain gauges
• CPC Class Codes: B60R 21/01546 using belt buckle sensors
• CPC Class Codes: B60R 21/01556 Child-seat detection systems
• 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

Abstract

The present invention has as its object to provide a vehicle passenger detection device that is able to prevent erroneous determinations arising from mechanical hysteresis. The present invention provides a vehicle passenger detection device comprising: weight measurement means, provided with a weight sensor disposed between a seat and floor of a vehicle, that measures the load applied to the seat; fluctuation amplitude detection means that detects the amplitude of fluctuation in values measured by the weight measurement means; correction means that applies a negative correction to the value measured by the weight measurement means when the fluctuation amplitude is smaller than a stipulated value; and passenger presence determination means that determines the presence of a passenger upon the seat by comparing the value measured by the weight measurement means against a stipulated threshold value.

Claims

1. A vehicle passenger detection device wherein the vehicle passenger detection device comprises:

weight measurement means, provided with a weight sensor disposed between a seat and floor of a vehicle, that measures the load applied to said seat;

fluctuation amplitude detection means that detects the amplitude of fluctuation in values measured by said weight measurement means;

correction means that applies a negative correction to the value measured by said weight measurement means when said fluctuation amplitude is smaller than a stipulated value; and

passenger presence determination means that determines the presence of a passenger upon said seat by comparing the value measured by said weight measurement means against a stipulated threshold value.

2. A vehicle passenger detection device according to claim 1,

wherein the weight measurement means comprises a plurality of weight sensors, and

the fluctuation amplitude detection means detects the amplitude of fluctuation in the values measured by the various weight sensors and

further comprises correction control means that controls the negative correction when the amplitude of fluctuation of the values measured by at least one of the weight sensors is greater than said stipulated value.

3. A vehicle passenger detection device according to claim 1, further comprising:

adult passenger determination means that compares said measured value against an adult passenger determination threshold value greater than said threshold value and thus determines if the passenger is an adult or child, and

display means that, when said passenger presence determination means determines that a passenger is present and said adult passenger determination means determines that the passenger is a child, disables airbag deployment and activates an indicator that indicates that airbag deployment is disabled.

4. A vehicle passenger detection device where the vehicle passenger detection device comprises:

weight measurement means, provided with a weight sensor disposed between a seat and floor of a vehicle, that measures the load applied to said seat;

fluctuation amplitude detection means that detects the amplitude of fluctuation in values measured by said weight measurement means; and

passenger presence determination means that determines the presence of a passenger by comparing the value measured by said weight measurement means against a stipulated threshold value,

wherein if said amplitude of fluctuation is greater than the stipulated value, said passenger presence determination means compares the value measured by the weight measurement means against a first threshold value to determine the presence of a passenger, and if the value measured by said weight measurement means is smaller than a stipulated value, the passenger presence determination means compares the value measured by said weight measurement means against a hysteresis threshold value greater than the first threshold value to determine the presence of a passenger.

5. A vehicle passenger detection device according to claim 4,

wherein the weight measurement means comprises a plurality of weight sensors, and

the fluctuation amplitude detection means detects the amplitude of fluctuation in the values measured by the various weight sensors, and

when the amplitude of fluctuation of the values measured by at least one of the weight sensors is greater than said stipulated value, said passenger presence determination means compares the values measured by said weight measurement means against said first threshold value and determines the presence of a passenger.

6. A vehicle passenger detection device according to claim 4, further comprising:

adult passenger determination means that compares said measured value against an adult passenger determination threshold value greater than said threshold value and thus determines if the passenger is an adult or child, and

display means that, when said passenger presence determination means determines that a passenger is present and said adult passenger determination means determines that the passenger is a child, disables airbag deployment and activates an indicator that indicates that airbag deployment is disabled.