Electronic control apparatus and passenger detecting apparatus for an automotive vehicle

• US 20040143382A1
• Filed: 12/18/2003
• Published: 07/22/2004
• Est. Priority Date: 01/21/2003
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ishida, Shoichi
• Granted Patent: US 7,155,323 B2
• Time in Patent Office: Days
• US Class Current: 701/36
• CPC Class Codes: B60R 2021/01184 Fault detection or diagnostic circuits
• CPC Class Codes: B60R 21/01512 Passenger detection systems
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/0152 using strain gauges

Abstract

An auxiliary circuit continuously executes a timer counting operation under a condition that electric power is directly supplied from a vehicle battery to the auxiliary circuit. A main circuit receives no electric power during a waiting condition and hence minimizes current consumption. Only when a predetermined timer activation time is counted by the auxiliary circuit or an ignition key switch is turned on, electric power is supplied to the main circuit for allowing the main circuit to execute a zero point correction for load sensors.

Claims

1. An electronic control apparatus for an automotive vehicle, comprising:

an auxiliary circuit which receives electric power directly supplied from a battery for continuously executing a timer counting operation; and

a main circuit which receives electric power for occasionally executing predetermined processing only when a predetermined timer activation time is counted by said auxiliary circuit or an ignition key switch is turned on.

2. The electronic control apparatus for an automotive vehicle in accordance with claim 1, wherein

said auxiliary circuit is arranged so as to output a timer count condition establishment signal when said timer activation time is counted and supply said timer count condition establishment signal to said main circuit,

said main circuit comprises a signal voltage comparator having an OR connection for inputting an ignition key switch ON signal and said timer count condition establishment signal, and

electric power is supplied to said main circuit when a signal exceeding a predetermined threshold voltage is entered into said signal voltage comparator.

3. The electronic control apparatus for an automotive vehicle in accordance with claim 2, wherein

said ignition key switch ON signal is divided with resistors and entered in said signal voltage comparator,

a dividing ratio of said resistors is changed when said auxiliary circuit outputs said timer count condition establishment signal,

said timer count condition establishment signal is forcibly generated by said auxiliary circuit when said ignition key switch is turned on, and

function diagnosis of said auxiliary circuit is carried out by monitoring an input voltage change in said signal voltage comparator.

4. The electronic control apparatus for an automotive vehicle in accordance with claim 1, wherein

said auxiliary circuit includes an auxiliary electric power circuit and an auxiliary microcomputer,

said auxiliary electric power circuit is connected to said vehicle battery via an electric power supply line and regulates a battery voltage into a voltage supplied to said auxiliary microcomputer, and

said auxiliary microcomputer is associated with a means for generating a clock used in said timer counting operation.

5. The electronic control apparatus for an automotive vehicle in accordance with claim 1, wherein

said main circuit includes a main electric power circuit and a main microcomputer,

said main electric power circuit includes a signal voltage comparator for comparing an input voltage and a reference voltage and generating an output signal based on the comparison result, and

said main microcomputer is activated in response to said output signal of said signal voltage comparator.

6. The electronic control apparatus for an automotive vehicle in accordance with claim 5, wherein said input voltage supplied to said signal voltage comparator is changed when said predetermined timer activation time is counted by said auxiliary circuit or when said ignition key switch is turned on.

7. The electronic control apparatus for an automotive vehicle in accordance with claim 5, wherein said vehicle battery is connected to said signal voltage comparator of said main circuit via a path including said ignition key switch and a voltage dividing point of resistors.

8. The electronic control apparatus for an automotive vehicle in accordance with claim 2, wherein said timer count condition establishment signal produced from said auxiliary circuit is supplied to a dividing ratio changing circuit which changes an input voltage entered into said signal voltage comparator of said main circuit.

9. The electronic control apparatus for an automotive vehicle in accordance with claim 1, wherein said main circuit is directly connected to external circuits or devices, thereby allowing said main control circuit to execute said predetermined processing.

10. A passenger detecting apparatus for an automotive vehicle, comprising:

a load sensor provided for detecting a load applied on a vehicle seat;

means for judging passenger conditions based on a load detection result detected by said load sensor;

means for performing a zero point correction for said load sensor, which is activated at a predetermined timing after a waiting condition;

an auxiliary circuit for receiving electric power directly supplied from a battery for continuously executing a timer counting operation; and

a main circuit for receiving electric power only when a predetermined timer activation time is counted by said auxiliary circuit or an ignition key switch is turned on for executing predetermined processing including said zero point correction for said load sensor.

11. The passenger detecting apparatus for an automotive vehicle in accordance with claim 10, wherein

said auxiliary circuit is arranged so as to output a timer count condition establishment signal when said timer activation time is counted and supply said timer count condition establishment signal to said main circuit,

said main circuit comprises a signal voltage comparator having an OR connection for inputting an ignition key switch ON signal and said timer count condition establishment signal, and

electric power is supplied to said main circuit when a signal exceeding a predetermined threshold voltage is entered into said signal voltage comparator.

12. The passenger detecting apparatus for an automotive vehicle in accordance with claim 11, wherein

said ignition key switch ON signal is divided with resistors and entered in said signal voltage comparator,

a dividing ratio of said resistors is changed when said auxiliary circuit outputs said timer count condition establishment signal,

said timer count condition establishment signal is forcibly generated by said auxiliary circuit when said ignition key switch is turned on, and

function diagnosis of said auxiliary circuit is carried out by monitoring an input voltage change in said signal voltage comparator.

13. The passenger detecting apparatus for an automotive vehicle in accordance with claim 10, wherein

said auxiliary circuit includes an auxiliary electric power circuit and an auxiliary microcomputer,

said auxiliary electric power circuit is connected to said vehicle battery via an electric power supply line and regulates a battery voltage into a voltage supplied to said auxiliary microcomputer, and

said auxiliary microcomputer is associated with a means for generating a clock used in said timer counting operation.

14. The passenger detecting apparatus for an automotive vehicle in accordance with claim 10, wherein

said main circuit includes a main electric power circuit and a main microcomputer,

said main electric power circuit includes a signal voltage comparator for comparing an input voltage and a reference voltage and generating an output signal based on the comparison result, and

said main microcomputer is activated in response to said output signal of said signal voltage comparator.

15. The passenger detecting apparatus for an automotive vehicle in accordance with claim 14, wherein said input voltage supplied to said signal voltage comparator is changed when said predetermined timer activation time is counted by said auxiliary circuit or when said ignition key switch is turned on.

16. The passenger detecting apparatus for an automotive vehicle in accordance with claim 14, wherein said vehicle battery is connected to said signal voltage comparator of said main circuit via a path including said ignition key switch and a voltage dividing point of resistors.

17. The passenger detecting apparatus for an automotive vehicle in accordance with claim 11, wherein said timer count condition establishment signal produced from said auxiliary circuit is supplied to a dividing ratio changing circuit which changes an input voltage entered into said signal voltage comparator of said main circuit.

18. The passenger detecting apparatus for an automotive vehicle in accordance with claim 10, wherein said main circuit is directly connected to external circuits or devices including said load sensor, thereby allowing said main control circuit to execute said predetermined processing.