Seat load measuring system with zero point-adjusting capability

• US 6,759,604 B2
• Filed: 05/22/2002
• Issued: 07/06/2004
• Est. Priority Date: 06/28/2001
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ishida, Shoichi, Ozaki, Tadashi
• Primary Examiner(s): Gibson, Randy W.
• Application Number:
  US10/151,995
• Publication Number:
  US 20030000757A1
• Time in Patent Office: 776 Days
• Field of Search: 177/50, 177/144, 177/136, 177/210.R, 701/45, 702/101, 702/102, 180/273, 280/735, 73/11.3, 73/11.5
• US Class Current: 177/144
• 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
• 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: G01G 23/163 involving digital counting

Abstract

A seat load measuring system for use in a vehicle occupant protection device for a vehicle seat has a zero point adjusting capability. The seat load measuring system comprises four weight sensor assemblies; a hub assembly for collecting the weight sensor outputs and providing an output determined by the weight sensor outputs; and means for communicating a user'"'"'s desire for a zero point adjustment to each weight sensor assembly. Each weight sensor assembly includes a zero point adjusting section, which receives an output from the communication means for executing a zero point adjusting operation. If a zero point of a weight sensor assembly is not within a predetermined range, the zero point adjusting section may providing an alert. A zero point adjusting command may be entered by a command input device and passed to the zero point adjusting section. Alternatively, the zero point adjustment may be initiated through a momentary switch provided in the hub assembly.

Claims

1. An occupant protection system of a vehicle, including:

a seat load measuring subsystem for providing information depending on a weight of an occupant of a vehicle seat, said seat load measuring subsystem comprising;

a plurality of weight sensor assemblies each for providing a first output indicative of a weight component of said occupant which is applied to each of the weight sensor assemblies; and

hub means for collecting said first outputs and providing said information;

an air bag system comprising;

a crash sensor for detecting a crash of the vehicle; and

an air bag controller operatively connected to the hub means, the air bag, and the crash sensor for operating an air bag as well as a detection of an occurrence of the crash detected by the crash sensor; and

communication means operatively connected to the air bag controller for communicating a user'"'"'s command for re-adjustment of each weight sensor assembly to the air bag controller,

wherein said air ban controller controls a detection of the operated air bag on the basis of the information provided by the hub means and, when the user'"'"'s command is communicated from the communicating means, relays the user'"'"'s command to the hub means,

said hub means transfers the user'"'"'s command to each weight sensor assembly, and

wherein each of said weight sensor assemblies includes means responsive to a reception the user'"'"'s command transferred from the hub means for executing the re-adjustment operation.

2. An occupant protection system as defined in claim 1, wherein said means for executing the re-adjustment operation includes means for providing an alert if a zero point of said weight sensor assembly is not within a predetermined range.

3. The occupant protection system as defined in claim 1, wherein said communication means comprises:

an interface connectable to a maintenance service tool so that, after the vehicle is crashed, said maintenance service tool being configured to permit the user to enter the user'"'"'s command through the communication means to the air bag controller.

4. The occupant protection system as defined in claim 1, wherein said means for communicating the user'"'"'s command for the re-adjustment operation comprise

a momentary switch electrically connected to the hub means transferring an operation switch thereof as the user'"'"'s command to the hub means.

5. The occupant protection system as defined in claim 1, wherein each of said weight sensor assemblies comprises:

a weight sensor for generating an output voltage indicative of the weight component of said occupant;

a first operational amplifier for amplifying the output voltage from the weight sensor to an appropriate level;

a memory for storing an initial sign-inverted offset voltage for use in a correction of the output voltage from the first operational amplifier;

an adder for adding the stored offset voltage to the output voltage to output a zero-adjusted voltage;

a second operational amplifier for amplifying the outputted zero-adjusted signal to output the amplified zero-adjusted voltage; and

a controller operatively connected to the hub means,

said controller, when the user'"'"'s command is transferred from the hub means, measuring the zero-adjusted voltage without applying a load to the vehicle seat, and newly storing the measured zero-adjusted voltage as the initial offset voltage in the memory.