Vehicle-mounted electronic control apparatus

• US 20060200276A1
• Filed: 08/12/2005
• Published: 09/07/2006
• Est. Priority Date: 03/01/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hashimoto, Kohji, Kanzaki, Shozo, Sayama, Masahiko
• Granted Patent: US 7,890,227 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 9/061 for DC powered loads

Abstract

A vehicle-mounted electronic control apparatus can perform a variety of abnormality detections while reducing the control load of a microprocessor in the abnormality detection of a volatile backup memory that is backed up by an on-board battery. The apparatus includes a control CPU which is fed with power from a main power supply circuit upon closure of a power switch, a nonvolatile control memory and a backup memory. Even if the power switch is opened, the backup memory, being a partial area of a RAM memory, is fed with power through an auxiliary power supply circuit connected directly to the battery. When the battery is replaced with a new one and connected again, a power supply interruption monitoring memory is reset. At the start of operation of the control CPU, the backup memory is initialized based on reset information, and the power supply interruption monitoring memory is rewritten into a set state.

Claims

1. A vehicle-mounted electronic control apparatus comprising:

a main power supply circuit that is connected to an on-board battery through a power switch in such a manner that it is fed with electric power from said on-board battery to generate a first stabilized control voltage when said power switch is closed;

an auxiliary power supply circuit that is directly fed with electric power from said on-board battery to generate a second stabilized control voltage;

a control CPU composed of a microprocessor including a nonvolatile control memory in which a control program and a reference control constant are written; and

a volatile backup memory that is always fed with electric power through said main power supply circuit or said auxiliary power supply circuit so as to store learning correction data for said reference control constant stored in said nonvolatile control memory;

wherein said control CPU is connected to a variety of kinds of input sensors and a variety of kinds of electric loads, and is fed with electric power through said main power supply circuit so as to control said electric loads in response to the contents of said nonvolatile control memory and the operating state of said input sensors;

said apparatus further comprising;

a power supply turn-on detection section that detects the turn-on state of said auxiliary power supply circuit;

a power supply interruption monitoring memory that responds to a detection operation of said power supply turn-on detection section;

an initialization section that initializes said backup memory;

an initialization completion storage section that stores an initialization completion state of said initialization section;

a hierarchization abnormality detection section that detects an abnormality in hierarchization of said backup memory; and

an abnormality detection selection section that selects the execution of abnormality detection by said hierarchization abnormality detection section;

wherein said power supply turn-on detection section stores the existence of a power supply interrupted state into said power supply interruption monitoring memory by putting the contents of said power supply interruption monitoring memory into a reset state in response to when said auxiliary power supply circuit is connected to said on-board battery;

said initialization section initializes the contents of said backup memory by means of said control CPU in response to when electric power is fed from said main power supply circuit to said control CPU and when the contents of said power supply interruption monitoring memory has not stored a set state;

said initialization completion storage section rewrites and changes the contents of said power supply interruption monitoring memory into a set state in response to when said control CPU has completed the initialization of said backup memory, and said initialization completion storage section includes an initialization storage verification section or a voltage monitoring section;

said initialization storage verification section verifies whether the rewriting and changing of said power supply interruption monitoring memory has been executed;

said voltage monitoring section monitors whether feeding power to said power supply interruption monitoring memory is executed;

said hierarchization abnormality detection section comprises a plurality of abnormality detection sections that are executed by said control CPU, and said hierarchization abnormality detection section determines whether there is an abnormality in the memory contents of said backup memory, and initializes said backup memory when an abnormality has been detected in the memory contents of said backup memory;

immediately after said power switch is turned on, even when no abnormality is detected in the execution result of a part of the abnormality detection sections in said hierarchization abnormality detection section, said abnormality detection selection section omits execution of the other abnormality detection sections in said hierarchization abnormality detection section; and

during operation of said control CPU, said abnormality detection selection section repeatedly executes at least one of the other abnormality detection sections in said hierarchization abnormality detection section in a sequential manner.

2. The vehicle-mounted electronic control apparatus as set forth in claim 1, wherein

said power supply turn-on detection section includes a threshold setting section that sets a first threshold and a second threshold that is higher than said first threshold, and puts the contents of said power supply interruption monitoring memory into a reset state when it is detected that an input voltage or an output voltage of said auxiliary power supply circuit has risen from said first threshold or below to said second threshold or above;

and

said backup memory continues its storage operation when the input voltage or the output voltage of said auxiliary power supply circuit is equal to or higher than a value corresponding to said first threshold.

3. The vehicle-mounted electronic control apparatus as set forth in claim 1, wherein

said hierarchization abnormality detection section includes at least one of first through third abnormality detection sections;

said first abnormality detection section constitutes a check section that makes, in response to when said power supply interruption monitoring memory has not stored a set state, a determination that stored information of said backup memory has been lost, too;

said second abnormality detection section checks whether a memory at a specific address in the backup memory correctly stores prescribed specific numerical data;

said third abnormality detection section checks the presence or absence of the missing or mixing of bit information in said backup memory; and

at least said first abnormality detection section is selectively executed immediately after said power switch has been turned on.

4. The vehicle-mounted electronic control apparatus as set forth in claim 3, wherein

said hierarchization abnormality detection section includes at least one of a fourth and a fifth abnormality detection section;

said initialization section includes a partial rewrite section;

said fourth abnormality detection section checks whether the values in the backup memory exceed a permitted correction variation range by making a comparison between the contents of the backup memory and data related to the permitted correction variation range stored in the nonvolatile control memory;

said fifth abnormality detection section stores positive logic data in said backup memory, additionally stores beforehand inverted logic data with respect to said positive logic data, and checks whether said inverted logic data and said positive logic data are mutually in an inverted logical relation with each other at the time of abnormality check; and

when it is determined by said fourth or fifth abnormality detection section that the content of a memory at a specific address in said backup memory is abnormal, said partial rewrite section initializes the content at said abnormal address in said backup memory.

5. The vehicle-mounted electronic control apparatus as set forth in claim 1, further comprising:

an engine state detection section that detects an operating/stopped state of an engine to be controlled;

an awake timer circuit part;

a multilevel selection section for at least one abnormality detection section in said hierarchization abnormality detection section; and

a stabilization power supply circuit that generates a predetermined stabilized voltage from said on-board battery;

wherein said awake timer circuit part is always fed with power through said stabilization power supply circuit, and measures the time during which said main power supply circuit has been interrupted, and when said time thus measured reaches a predetermined target awake time, said awake timer circuit part awakes and activates said control CPU in a stopped state of said engine by generating an awake output signal thereby to connect said main power supply circuit to said on-board battery; and

said multilevel selection section intensively executes a plurality of abnormality detection sections in said hierarchization abnormality detection section in response to when said control CPU executes an awake operation in the stopped state of said engine, and initializes said backup memory when an abnormality has been detected.

6. The vehicle-mounted electronic control apparatus as set forth in claim 5, wherein

said main power supply circuit is connected to said on-board battery through a power feed switching element that responds to an awake output signal from said awake timer circuit part, and awakes and activates said control CPU in response to when electric power is fed to said control CPU;

said power feed switching element comprises an output contact of a power supply relay to feed electric power to said electric loads or a power feed transistor connected singly to said main power supply circuit;

said awake output signal is stopped in response to activation of said control CPU; and

said power feed switching element is self-held by said control CPU, and is opened in response to the stop of an operating condition signal output or a self-hold drive command output of said control CPU.

7. The vehicle-mounted electronic control apparatus as set forth in claim 1, further comprising:

a power supply relay that is energized through said power switch;

a transfer and save section that is executed during the self-hold operation of said power supply relay; and

a nonvolatile data memory that is a save destination according to said transfer and save section;

wherein said main power supply circuit is fed with electric power from said on-board battery through an output contact of said power supply relay;

said power supply relay performs self-hold operation in response to the operation of said control CPU so that it continues self-hold feeding of electric power to said main power supply circuit even when said power switch is opened, and it is de-energized in response to the stop of an operating condition signal output or a self-hold drive command output of said control CPU;

said transfer and save section transfers and saves learning correction data, which is stored in a first area of said backup memory according to learning items, into a first area of said nonvolatile data memory, and also transfers and saves abnormality occurrence frequency data, which is stored in a second area of said backup memory according to abnormal code numbers, into a second area of said nonvolatile data memory; and

said initialization section reads out, transfers and writes the contents of said nonvolatile data memory into said first and second areas of said backup memory, writes said prescribed specific numerical data into the remaining specific addresses of said backup memory, and performs reset processing with respect to the other addresses of said backup memory.

8. The vehicle-mounted electronic control apparatus as set forth in claim 7, further comprising:

a multilevel selection section for said abnormality detection sections;

wherein said multilevel selection section intensively executes a plurality of abnormality detection sections in said hierarchization abnormality detection section in response to when self-hold power feed is executed due to the opening of said power switch, and initializes said backup memory when an abnormality is detected.

9. A vehicle-mounted electronic control apparatus comprising:

a main power supply circuit that is connected to an on-board battery through a power switch in such a manner that it is fed with electric power from said on-board battery to generate a first stabilized control voltage when said power switch is closed;

an auxiliary power supply circuit that is directly fed with electric power from said on-board battery to generate a second stabilized control voltage;

a control CPU composed of a microprocessor including a nonvolatile control memory in which a control program and a reference control constant are written; and

a volatile backup memory that is always fed with electric power through said main power supply circuit or said auxiliary power supply circuit so as to store learning correction data for said reference control constant stored in said nonvolatile control memory;

wherein said control CPU is connected to a variety of kinds of input sensors and a variety of kinds of electric loads, and is fed with electric power through said main power supply circuit so as to control said electric loads in response to the contents of said nonvolatile control memory and the operating state of said input sensors;

said apparatus further comprising;

an engine state detection section that detects an operating/stopped state of an engine to be controlled;

an awake timer circuit part composed of an awake CPU comprising a microprocessor including a nonvolatile awake memory and a RAM memory for arithmetic calculation;

an initialization reset section for said RAM memory;

an initialization section for said backup memory;

an initialization completion storage section that stores an initialization completion state of said initialization section;

a hierarchization abnormality detection section that detects an abnormality in hierarchization of said backup memory; and

an abnormality detection selection section that selects the execution of abnormality detection by said hierarchization abnormality detection section;

wherein said awake timer circuit part is always fed with electric power from said on-board battery through a stabilization power supply circuit generating a predetermined stabilized voltage, and measures the time during which said main power supply circuit has been interrupted, and when said time thus measured reaches a predetermined target awake time, said awake timer circuit part awakes and activates said control CPU in a stopped state of said engine by generating an awake output signal thereby to connect said main power supply circuit to said on-board battery;

said awake CPU is activated in response to when an output voltage of said stabilization power supply circuit becomes equal to or more than a predetermined value;

said initialization reset section resets the contents of said RAM memory at the time when the awake CPU is activated;

said initialization completion storage section writes and saves, in response to the completion of initialization of said backup memory by said control CPU, the fact that said awake CPU is in an initialization completion state with respect to a specific address of said RAM memory, based on an initialization completion signal from said control CPU, and said initialization completion storage section includes an initialization storage verification section or a voltage monitoring section;

said initialization storage verification section verifies whether the rewriting and changing of said RAM memory has been executed;

said voltage monitoring section monitors whether feeding power to said RAM memory is executed;

said initialization section initializes said backup memory by means of said control CPU in response to when electric power is fed from said main power supply circuit to said control CPU and when a specific address of said RAM memory has not stored an initialization completion state;

said hierarchization abnormality detection section comprises a plurality of abnormality detection sections that are executed by said control CPU, and said hierarchization abnormality detection section determines whether there is an abnormality in the memory contents of said backup memory, and initializes said backup memory when an abnormality has been detected in the memory contents of said backup memory;

immediately after said power switch is turned on, said abnormality detection selection section executes a part of the abnormality detection sections in said hierarchization abnormality detection section, and even when no abnormality is detected in the execution result, said abnormality detection selection section omits execution of the other abnormality detection sections in said hierarchization abnormality detection section; and

during operation of said control CPU, said abnormality detection selection section repeatedly executes at least one of the other abnormality detection sections in said hierarchization abnormality detection section in a sequential manner.

10. The vehicle-mounted electronic control apparatus as set forth in claim 9, wherein

said hierarchization abnormality detection section includes at least one of first through third abnormality detection sections;

said first abnormality detection section constitutes a check section that makes, in response to when said RAM memory has not stored an initialization completion state, a determination that stored information of said backup memory has been lost, too;

said second abnormality detection section checks whether a memory at a specific address in the backup memory correctly stores prescribed specific numerical data;

said third abnormality detection section checks the presence or absence of the missing or mixing of bit information in said backup memory; and

at least said first abnormality detection section is selectively executed immediately after said power switch has been turned on.

11. The vehicle-mounted electronic control apparatus as set forth in claim 10, wherein

said hierarchization abnormality detection section includes at least one of a fourth and a fifth abnormality detection section;

said initialization section includes a partial rewrite section;

said fourth abnormality detection section checks whether the values in the backup memory exceed a permitted correction variation range by making a comparison between the contents of the backup memory and data related to the permitted correction variation range stored in the nonvolatile control memory;

said fifth abnormality detection section stores positive logic data in said backup memory, additionally stores beforehand inverted logic data with respect to said positive logic data, and checks whether said inverted logic data and said positive logic data are mutually in an inverted logical relation with each other at the time of abnormality check; and

when it is determined by said fourth or fifth abnormality detection section that the content of a memory at a specific address in said backup memory is abnormal, said partial rewrite section initializes the content at said abnormal address in said backup memory.

12. The vehicle-mounted electronic control apparatus as set forth in claim 9, further comprising:

a multilevel selection section for said abnormality detection section;

wherein said multilevel selection section intensively executes a plurality of abnormality detection sections in said hierarchization abnormality detection section in response to when said control CPU executes an awake operation in a stopped state of said engine, and initializes said backup memory when an abnormality has been detected.

13. The vehicle-mounted electronic control apparatus as set forth in claim 12, wherein

an operating sign sensor comprising a door sensor or a key sensor is connected to said awake CPU that constitutes said awake timer circuit part;

and

said awake CPU monitors an operating state of said operating sign sensor and generates an awake output signal prior to starting of said engine.

14. The vehicle-mounted electronic control apparatus as set forth in claim 9, further comprising:

a power supply relay that is energized through said power switch;

a transfer and save section that is executed during the self-hold operation of said power supply relay; and

a nonvolatile data memory that is a save destination according to said transfer and save section;

wherein said main power supply circuit is fed with electric power from said on-board battery through an output contact of said power supply relay;

said power supply relay performs self-hold operation in response to the operation of said control CPU so that it continues self-hold feeding of electric power to said main power supply circuit even when said power switch is opened, and it is de-energized in response to the stop of an operating condition signal output or a self-hold drive command output of said control CPU;

said transfer and save section transfers and saves learning correction data, which is stored in a first area of said backup memory according to learning items, into a first area of said nonvolatile data memory, and also transfers and saves abnormality occurrence frequency data, which is stored in a second area of said backup memory according to abnormal code numbers, into a second area of said nonvolatile data memory; and

said initialization section reads out, transfers and writes the contents of said nonvolatile data memory into said first and second areas of said backup memory, writes said prescribed specific numerical data into the remaining specific addresses of said backup memory, and performs reset processing with respect to the other addresses of said backup memory.

15. The vehicle-mounted electronic control apparatus as set forth in claim 14, further comprising:

a multilevel selection section for said abnormality detection sections;

wherein said multilevel selection section intensively executes a plurality of abnormality detection sections in said hierarchization abnormality detection section in response to when self-hold power feed is executed due to the opening of said power switch, and initializes said backup memory when an abnormality is detected.

16. The vehicle-mounted electronic control apparatus as set forth in claim 9, wherein

said main power supply circuit is connected to said on-board battery through a power feed switching element that responds to an awake output signal from said awake timer circuit part, and awakes and activates said control CPU in response to when electric power is fed to said control CPU;

said power feed switching element comprises an output contact of a power supply relay to feed electric power to said electric loads or a power feed transistor connected singly to said main power supply circuit;

said awake output signal is stopped in response to activation of said control CPU; and

said power feed switching element is self-held by said control CPU, and is opened in response to the stop of an operating condition signal output or a self-hold drive command output of said control CPU.