On-vehicle computer having function of protecting vehicular battery

• US 6,442,702 B1
• Filed: 08/10/1999
• Issued: 08/27/2002
• Est. Priority Date: 02/05/1999
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ishikawa, Wataru, Hamba, Nobuhiro, Iyama, Masaru, Shishikura, Kenichi, Nakamura, Atushi
• Primary Examiner(s): Ray, Gopal C.
• Application Number:
  US09/370,898
• Time in Patent Office: 1,113 Days
• Field of Search: 713/300, 713/323, 713/340, 320/104, 701/1, 340/635, 340/636, 702/63, 307/66, 307/130, 307/140, 700/293
• US Class Current: 713/340
• CPC Class Codes: G06F 11/004 Error avoidance G06F11/07 and subgroups take precedence
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/0796 Safety measures, i.e. ensuring safe condition in the event of error, e.g. for controlling element
• CPC Class Codes: G06F 11/1402 Saving, restoring, recovering or retrying
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

An on-vehicle computer includes a hardware timer. The hardware timer is started when a vehicle accessory switch changes to its OFF position. A suspending request is transmitted from a BIOS to an application program and a BIOS timer is started when the vehicle accessory switch changes to its OFF position. A suspending permission answer is returned from the application program to the BIOS and an application program timer is started in response to the suspending request. A first turn-OFF command is generated when an elapsed time measured by the application program timer reaches a first predetermined time interval (T2). The BIOS is enabled to generate a suspending command in response to the suspending permission answer. A second turn-OFF command is generated in cases where the suspending permission answer continuously fails to be returned to the BIOS until an elapsed time measured by the BIOS timer reaches a second predetermined time interval (T1). Power supply to the main computer portion is turned off in response to at least one of the first turn-OFF command and the second turn-OFF command. Power supply to the main computer portion is turned off in cases where the BIOS continuously fails to generate the suspending command and the first turn-OFF command and the second turn-OFF command continuously fail to be generated until an elapsed time measured by the hardware timer reaches a third predetermined time interval (T3).

Claims

1. An on-vehicle computer comprising:

first means for detecting whether or not a vehicle accessory switch changes to its OFF position;

a hardware timer;

second means for starting the hardware timer when the first means detects that the vehicle accessory switch changes to its OFF position;

third means for providing a BIOS timer;

fourth means for transmitting a suspending request from a BIOS to an application program and starting the BIOS timer when the first means detects that the vehicle accessory switch changes to its OFF position;

fifth means for providing an application program timer;

sixth means for returning a suspending permission answer from the application program to the BIOS and starting the application program timer in response to the suspending request;

seventh means for generating a first turn-OFF command when an elapsed time measured by the application program timer reaches a first predetermined time interval (T2);

eighth means for enabling the BIOS to generate a suspending command in response to the suspending permission answer;

ninth means for generating a second turn-OFF command in cases where the sixth means continues to fail to return the suspending permission answer to the BIOS until an elapsed time measured by the BIOS timer reaches a second predetermined time interval (T1);

a main computer portion;

tenth means for turning off power supply to the main computer portion in response to at least one of the first turn-OFF command and the second turn-OFF command; and

eleventh means for turning off power supply to the main computer portion in cases where the BIOS continues to fail to generate the suspending command and the seventh means and the ninth means continue to fail to generate the first turn-OFF command and the second turn-OFF command until an elapsed time measured by the hardware timer reaches a third predetermined time interval (T3);

wherein the first predetermined time interval (T2) is longer than the second predetermined time interval (T1), and is shorter than the third predetermined time interval (T3).

2. An on-vehicle computer comprising:

first means for detecting whether or not at least one of a vehicular-battery voltage and an internal-battery voltage continues to be lower than a predetermined reference voltage for a first predetermined time interval;

a hardware timer;

second means for starting the hardware timer when the first means detects that at least one of the vehicular-battery voltage and the internal-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval;

third means for providing a BIOS timer;

fourth means for transmitting a shutting-down request from a BIOS to an application program and starting the BIOS timer when the first means detects that at least one of the vehicular-battery voltage and the internal-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval;

fifth means for returning a shutting-down permission answer from the application program to the BIOS;

sixth means for enabling the BIOS to generate a shutting-down command in response to the shutting-down permission answer;

seventh means for generating a turn-OFF command in cases where the fifth means continues to fail to return the shutting-down permission answer to the BIOS until an elapsed time measured by the BIOS timer reaches a second predetermined time interval (T1);

a main computer portion;

eighth means for turning off power supply to the main computer portion in response to the turn-OFF command; and

ninth means for turning off power supply to the main computer portion in cases where the BIOS continues to fail to generate the shutting-down command and the seventh means continues to fail to generate the turn-OFF command until an elapsed time measured by the hardware timer reaches a third predetermined time interval (T3);

wherein the second predetermined time interval (T1) is shorter than the third predetermined time interval (T3).

3. An on-vehicle computer comprising:

first means for detecting whether or not the computer is in its suspended state;

second means means for, in cases where the first means detects that the computer is in its suspended state, detecting whether or not at least one of a vehicular-battery voltage and an internal-battery voltage continues to be lower than a predetermined reference voltage for a first predetermined time interval;

a hardware timer;

third means for starting the hardware timer when the second means detects that at least one of the vehicular-battery voltage and the internal-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval;

fourth means for providing a BIOS timer;

fifth means for transmitting a shutting-down request from a BIOS to an application program and starting the BIOS timer when the second means detects that at least one of the vehicular-battery voltage and the internal-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval;

sixth means for returning a shutting-down permission answer from the application program to the BIOS;

seventh means for enabling the BIOS to generate a shutting-down command in response to the shutting-down permission answer;

eighth means for generating a turn-OFF command in cases where the sixth means continues to fail to return the shutting-down permission answer to the BIOS until an elapsed time measured by the BIOS timer reaches a second predetermined time interval (T1);

a main computer portion;

ninth means for turning off power supply to the main computer portion in response to the turn-OFF command; and

tenth means for turning off power supply to the main computer portion in cases where the BIOS continues to fail to generate the shutting-down command and the eighth means continues to fail to generate the turn-OFF command until an elapsed time measured by the hardware timer reaches a third predetermined time interval (T3);

wherein the second predetermined time interval (T1) is shorter than the third predetermined time interval (T3).

4. An on-vehicle computer comprising:

first means for detecting whether or not a vehicle accessory switch changes to its OFF position;

a main computer portion including a CPU;

second means for enabling the CPU to output a suspending command when the first means detects that the vehicle accessory switch changes to its OFF position; and

third means for cutting off power supply to the main computer portion in cases where the CPU continuously fails to output the suspending command during a predetermined time interval after the first means detects that the vehicle accessory switch changes to its OFF position.

5. An on-vehicle computer comprising:

a power-supply management portion operating in accordance with a first program;

first means provided in the power-supply management portion for detecting whether or not a vehicle accessory switch changes to its OFF position;

a main computer portion including a CPU which operates in accordance with a second program different and separate from the first program;

second means provided in the power-supply management portion for feeding the CPU with information representing that the vehicle accessory switch changes to its OFF position;

third means for enabling the CPU to return a suspending command to the power-supply management portion in response to the information from the second means;

a power-supply controller for controlling power supply to the main computer portion; and

fourth means provided in the power-supply management portion for controlling the power-supply controller to cut off power supply to the main computer portion in cases where the CPU continuously fails to return the suspending command during a predetermined time interval after the first means detects that the vehicle accessory switch changes to its OFF position.

6. An on-vehicle computer comprising:

first means for detecting whether or not a vehicular-battery voltage continues to be lower than a predetermined reference voltage for a first predetermined time interval;

a main computer portion including a CPU;

second means for enabling the CPU to output a shutting-down command when the first means detects that the vehicular-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval; and

third means for cutting off power supply to the main computer portion in cases where the CPU continuously fails to output the shutting-down command during a second predetermined time interval after the first means detects that the vehicular-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval.

7. An on-vehicle computer comprising:

a power-supply management portion operating in accordance with a first program;

first means provided in the power-supply management portion for detecting whether or not a vehicular-battery voltage continues to be lower than a predetermined reference voltage for a first predetermined time interval;

a main computer portion including a CPU which operates in accordance with a second program different and separate from the first program;

second means provided in the power-supply management portion for feeding the CPU with information representing that the vehicular-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval;

third means for enabling the CPU to return a shutting-down command to the power-supply management portion in response to the information from the second means;

a power-supply controller for controlling power supply to the main computer portion; and

fourth means provided in the power-supply management portion for controlling the power-supply controller to cut off power supply to the main computer portion in cases where the CPU continuously fails to return the shutting-down command during a second predetermined time interval after the first means detects that the vehicular-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval.

8. An on-vehicle computer comprising:

first means for detecting whether or not the computer is in its suspended state;

second means means for, in cases where the first means detects that the computer is in its suspended state, detecting whether or not a vehicular-battery voltage continues to be lower than a predetermined reference voltage for a first predetermined time interval;

a main computer portion including a CPU;

third means for enabling the CPU to output a shutting-down command when the second means detects that the vehicular-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval; and

fourth means for cutting off power supply to the main computer portion in cases where the CPU continuously fails to output the shutting-down command during a second predetermined time interval after the second means detects that the vehicular-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval.

9. An on-vehicle computer comprising:

a power-supply management portion operating in accordance with a first program;

first means provided in the power-supply management portion for detecting whether or not the computer is in its suspended state;

second means means provided in the power-supply management portion for, in cases where the first means detects that the computer is in its suspended state, detecting whether or not a vehicular-battery voltage continues to be lower than a predetermined reference voltage for a first predetermined time interval;

a main computer portion including a CPU which operates in accordance with a second program different and separate from the first program;

third means provided in the power-supply management portion for feeding the CPU with information representing that the vehicular-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval;

fourth means for enabling the CPU to return a shutting-down command to the power-supply management portion in response to the information from the third means;

a power-supply controller for controlling power supply to the main computer portion; and

fifth means provided in the power-supply management portion for controlling the power-supply controller to cut off power supply to the main computer portion in cases where the CPU continuously fails to return the shutting-down command during a second predetermined time interval after the second means detects that the vehicular-battery voltage continues to be lower than the predetermined reference voltage for the first predetermined time interval.