JP5417931B2 - Vehicle control system - Google Patents

Description

  The present invention relates to a vehicle control system in which a plurality of ECUs are connected via communication lines, and more particularly to a vehicle control system that can reduce dark current in a state where an ignition switch is turned off.

  A vehicle such as an automobile includes an alternator (on-vehicle generator, AC generator), a battery, and the like. The electric power generated by the alternator in conjunction with the engine is used for charging the battery, and the electric power from the battery is supplied to an electrical component mounted on the vehicle and an ECU (electronic control unit) that controls the electrical component. Is done.

  The ECU includes a CPU, a RAM, an input / output interface, and the like, and exchanges information with each other through an in-vehicle LAN such as CAN or LIN. And many ECUs for controlling these various electrical components came to be mounted in the vehicle. For example, a vehicle includes a body ECU that performs door lock control, wiper control, and light control, an engine ECU that electronically controls the engine to operate the engine in an optimal state, and an instrument panel that controls display of various information in the driver's seat. An ECU and an air conditioner ECU for controlling the operation of the air conditioner are provided.

  On the other hand, a technique for reducing the power consumption of the battery and suppressing the consumption of the battery with the engine turned off has been developed. For example, when the ignition switch is turned off, the occupant's operation information and information necessary for control are stored in a nonvolatile memory (EPROM) built in each ECU or a hard disk drive (HDD) provided in the car navigation system, There has been disclosed a vehicle system that can reduce dark current when the engine is off by reducing the number of microcomputers that retain stored contents with a backup power supply (see, for example, Patent Document 1).

JP 2002-67834 A

  However, in the system of Patent Document 1, each ECU is provided with an EPROM that is a nonvolatile memory and a car navigation system. Although these conditions are met for relatively high-grade models, there are a number of models that are not equipped with EPROM or car navigation for relatively low-grade models. Can not reduce the power consumption when the engine is off.

  This invention is made | formed in view of such a situation, and it aims at providing the vehicle control system which can reduce the dark current of the state by which the ignition switch was turned off.

A vehicle control system according to a first aspect of the present invention includes a first ECU to which electric power is supplied regardless of whether an ignition switch is turned on or off, and a second ECU to which electric power is supplied or cut by turning on or off the ignition switch, in the connected vehicle control system in the communication line, before Symbol first 1ECU includes a memory for storing any information, and on-off judging portion judges on-off of the ignition switch, the ignition in said input switching determination unit If it is determined that the switch is turned off, and a writing section for writing the first 2ECU volatile information memory stored in the memory, the first 2ECU includes a volatile memory for storing any information When the on / off determination unit determines that the ignition switch has been turned off, the information stored in the volatile memory through the communication line. Is transmitted to the first ECU, and when the first ECU determines that the ignition switch is turned off by the receiving unit that receives the information and the on / off determination unit, the volatile memory of the second ECU An information determination unit that determines whether or not there is information stored in the information determination unit; and a transmission unit that transmits a request to transfer the information to the second ECU when the information determination unit determines that there is information. The unit is configured to write the information received by the receiving unit to the memory, the second ECU further includes a receiving unit that receives the transfer request, and the transmitting unit of the second ECU includes the receiving unit when receiving a transfer request in parts, the information stored in said volatile memory, wherein the configuration tare Rukoto to send to the first 1ECU.

The vehicle control system according to the second invention, Oite the first shot bright, wherein the 1ECU includes a volatile memory and a nonvolatile memory for storing any information, the writing unit, entering-switching When the determination unit determines that the ignition switch has been turned off, the information stored in the volatile memory of the second ECU is once written in the volatile memory, and when the information is written in the volatile memory, the information is Further, it is configured to write in the nonvolatile memory.

The vehicle control system according to the third invention, the first invention or the second shot Oite bright, the first 1ECU is characterized by a body system ECU.

The vehicle control system according to a fourth aspect of the present invention is the vehicle control system according to the first aspect, wherein when the second ECU determines that the ignition switch has been turned off by an on / off determination unit that determines whether the ignition switch is on or off, the information stored in said volatile memory through the communication line and a transmission unit for transmitting to the first 1ECU, wherein the 1ECU includes a receiver for receiving the information, the writing unit, by the receiving unit The received information is written in the memory.

  In the first invention, the first ECU includes a memory (may be a volatile memory or a nonvolatile memory) for storing arbitrary information, and the second ECU is a volatile memory for storing arbitrary information. Is provided. Here, the arbitrary information is, for example, occupant operation information or information necessary for control. When the first ECU determines that the ignition switch is turned off by the on / off determination unit, the first ECU writes the information stored in the volatile memory of the second ECU to the memory of the first ECU. Even when the ignition switch is turned off, power is supplied to the first ECU, so that the information written in the memory is not lost. As a result, even when each ECU is not equipped with an EPROM or when a hard disk or the like is not provided, a power supply for backup becomes unnecessary, and the dark current in a state where the ignition switch is turned off can be reduced. it can.

When the on / off determination unit of the first ECU determines that the ignition switch has been turned off, the second ECU transmits information stored in the volatile memory to the first ECU through the communication line by the transmission unit. In the first ECU, the reception unit receives the information, and the received information is written in the memory by the writing unit. By storing information necessary for the second ECU in the memory of the first ECU, it is not necessary to provide a non-volatile memory in the second ECU, and it is not necessary to provide a backup power source in the second ECU, thereby reducing power consumption. It is possible to store information of an ECU that does not include an EPROM.

In addition , when the first ECU determines that the ignition switch is turned off by the on / off determination unit, the information determination unit determines the presence or absence of information stored in the volatile memory of the second ECU. When the first ECU determines that there is information, the transmission unit transmits a transfer request for the information to the second ECU. When the second ECU receives the transfer request by the receiving unit, the second ECU transmits information stored in the volatile memory to the first ECU by the transmitting unit. Since the presence / absence of information to be backed up is determined when the ignition switch is turned off, for example, communication processing between ECUs is compared to a case where backup processing is periodically performed between ECUs. It is possible to reliably back up necessary information while reducing the labor required for this.

In the second invention, the first ECU includes a volatile memory (for example, RAM) and a nonvolatile memory (for example, EPROM) for storing arbitrary information, and the ignition switch is turned off by the on / off determination unit. If it is determined that the information is stored in the volatile memory of the first ECU, the writing unit temporarily writes the information stored in the volatile memory of the first ECU. Write to the non-volatile memory of the first ECU. By writing the information to be written once in RAM, which has a higher writing speed than EPROM, and then writing it in EPROM, even if there is a complicated operation immediately after the ignition switch is turned off, the information is surely stored. Can be backed up.

In the third invention, the first ECU is a body system ECU. Thereby, it is not necessary to provide a dedicated ECU for backing up information, and an increase in cost can be suppressed.

In the fourth invention, when the on / off determination unit of the second ECU determines that the ignition switch is turned off, the second ECU transmits the information stored in the volatile memory to the first ECU through the communication line by the transmission unit. . In the first ECU, the reception unit receives the information, and the received information is written in the memory by the writing unit. By storing information necessary for the second ECU in the memory of the first ECU, it is not necessary to provide a non-volatile memory in the second ECU, and it is not necessary to provide a backup power source in the second ECU, thereby reducing power consumption. It is possible to store information of an ECU that does not include an EPROM.

  According to the present invention, even when each ECU is not equipped with an EPROM or a hard disk or the like, a power supply for backup is not required, and dark current is reduced in a state where the ignition switch is turned off. can do.

It is a mimetic diagram showing an example of composition of a vehicle control system concerning the present invention. It is a block diagram which shows an example of a structure of body ECU. It is a block diagram which shows an example of a structure of engine ECU. It is a flowchart which shows the process sequence of body ECU. 6 is a block diagram illustrating an example of a configuration of a body ECU according to a second embodiment. FIG. FIG. 10 is a schematic diagram illustrating an example of a configuration of a vehicle control system according to a third embodiment.

Embodiment 1
Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a schematic diagram showing an example of the configuration of a vehicle control system according to the present invention. As shown in FIG. 1, the vehicle control system includes a body ECU 10 as a first ECU, an engine ECU 20 as a second ECU, an air conditioner ECU 30, an instrument panel ECU 40, and the like. Each ECU is connected to a CAN bus 3 as a communication line. The communication line is not limited to the CAN bus, but may be another in-vehicle LAN such as a LIN bus. Further, the number and types of ECUs are not limited to the example of FIG. 1, and a configuration including ECUs having other functions may be used.

  Regardless of whether an ignition switch (not shown) is turned on or off, electric power is supplied to the body ECU 10 via the + B electric wire 1. Further, power to the engine ECU 20, the air conditioner ECU 30 and the instrument panel ECU 40 is supplied or cut off via the IG electric wire 2 by turning on and off the ignition switch. That is, when the ignition switch is turned on, electric power is supplied to all ECUs of the body ECU 10, the engine ECU 20, the air conditioner ECU 30, and the instrument panel ECU 40. Further, when the ignition switch is turned off, electric power is supplied only to the body ECU 10. Note that the IG electric wire 2 may be connected to the body ECU 10.

  FIG. 2 is a block diagram illustrating an example of the configuration of the body ECU 10. The body ECU 10 includes a CPU 11 that controls the entire ECU, a RAM (Random Access Memory) 12 as a memory, and a transmission unit and reception of commands such as data (information) and transfer requests with other ECUs via the CAN bus 3. An interface unit 13 as a unit, an on / off determination unit that determines whether an ignition switch is on / off, and a determination unit 14 as an information determination unit that determines the presence or absence of information stored in a volatile memory of another ECU (second ECU), A writing unit 15 for writing information stored in a volatile memory of another ECU (second ECU) to the RAM 12 is provided. Note that the CPU 11 can also have the function of the determination unit 14. Further, the CPU 11 may have the function of the writing unit 15.

  The determination of whether the ignition switch is turned on or off by the determination unit 14 can be performed by, for example, transmitting a signal linked to the turning on / off of the ignition switch on the CAN bus 3. Alternatively, it is also possible to determine whether the ignition switch is turned on or off by detecting the voltage on the IG electric wire 2.

  The body ECU 10 is always supplied with electric power from a battery (not shown) via the + B electric wire 1 regardless of whether the ignition switch is turned on or off. The body ECU 10 performs functions such as door lock control, power window control, wiper control, steering control, and suspension control. For example, in the door lock control, all doors are locked and unlocked by a remote control for remote operation or a driver's seat switch, and the body ECU 10 is parked with the vehicle engine turned off. The power from the battery is always supplied so that it can be performed even in the state.

  Arbitrary information is stored in the RAM 12. Arbitrary information is information required for various control which occupant's operation information and body ECU10 perform, for example. Since the electric power is continuously supplied to the body ECU 10 even when the ignition switch is turned off, the information stored in the RAM 12 can be held.

  FIG. 3 is a block diagram showing an example of the configuration of the engine ECU 20. The engine ECU 20 is a CPU 21 that controls the entire ECU, a RAM (Random Access Memory) 22 as a volatile memory, and a data (information) and command transmission unit and a reception unit via the CAN bus 3 with other ECUs. Interface portion 23 and the like. Since the other air conditioner ECU 30 and instrument panel ECU 40 have the same configuration, description thereof will be omitted.

  The engine ECU 20 is supplied with electric power from a battery (not shown) via the IG electric wire 2 with the ignition switch turned on. In addition, when the ignition switch is off, power supply is cut off from a battery (not shown). The same applies to the other air conditioner ECU 30 and instrument panel ECU 40.

  Arbitrary information is stored in the RAM 22. The arbitrary information is, for example, information necessary for various controls performed by the occupant's operation information and the engine ECU 20. Since the power supply is cut off with the ignition switch turned off, the engine ECU 20 transfers the information stored in the RAM 22 to the body ECU 10 and stores the information transferred to the RAM 12 so that the information stored in the RAM 22 is not lost. Further, when the ignition switch is switched from OFF to ON, information for the engine ECU 20 stored in the RAM 12 of the body ECU 10 is transferred to the engine ECU 20, and the engine ECU 20 uses the transferred information to perform predetermined processing. Control. The same applies to the other air conditioner ECU 30 and instrument panel ECU 40.

  Next, the operation of the vehicle control system according to the present invention will be described. FIG. 4 is a flowchart showing a processing procedure of the body ECU 10. The CPU 11 instructs the determination unit 14 to determine whether the ignition switch is turned on or off (S11). When the ignition switch is turned on (turned on in S11), the processing in step S11 is continued.

  When the ignition switch is in the off state (the state switched from on to off) (in step S11), the CPU 11 instructs the determination unit 14 to determine whether there is backup data in another ECU. (S12). This can be determined, for example, by transmitting a command for confirming the presence or absence of backup data from the body ECU 10 to the other engine ECU 20, the air conditioner ECU 30 and the instrument panel ECU 40, and a response from the other ECU.

  When there is backup data in another ECU (YES in S12), the CPU 11 transmits a data transfer request to the other ECU (S13), and receives data transmitted from the other ECU (S14). The CPU 11 writes the received data to the RAM 12 by instructing the writing unit 15 (S15).

  The CPU 11 determines whether all data has been received (S16). Whether or not all data has been received can be determined by acquiring in advance the amount of data transferred by another ECU. If all the data has not been received (NO in S16), the CPU 11 continues the processing from step S14. Note that the received data may be written in the RAM 12 after all the data has been received.

  When all the data has been received (YES in S16), the CPU 11 determines whether or not the data match (S17). The data match determination is to determine whether or not the written data is correct data. For example, even if it is determined whether or not the written data is read again and matches the data before writing. Or, a function such as ECC (Error Check and Correct) may be used.

  If the data do not match (NO in S17), the CPU 11 performs the processing from step S13 onward. If the data matches (YES in S17), the data is correctly written in the RAM 12 and the transfer data is transferred. It is determined whether there is another ECU to have (S18). When there is another ECU (YES in S18), the CPU 11 continues the process from step S13, and when there is no other ECU (NO in S18), the process ends. If there is no backup data in another ECU (NO in S12), the CPU 11 ends the process.

  In the above-described processing, when there is data to be backed up, other ECUs (engine ECU 20, air conditioner ECU 30 and instrument panel ECU 40) respond to the confirmation of the presence or absence of backup data from the body ECU 10 in response. Further, when a data transfer request is received from the body ECU 10, another ECU transmits the amount of data to be transferred and the data to the body ECU 10.

  As described above, when the determination unit 14 determines that the ignition switch is turned off, the body ECU 10 writes the information stored in the RAM 22 of the engine ECU 20 in the RAM 12 of the body ECU 10 by the writing unit 15. Even when the ignition switch is turned off, power is supplied to the body ECU 10, so that data (information) written in the RAM 12 is not lost. As a result, even when each ECU is not equipped with an EPROM which is a non-volatile memory or a hard disk or the like is not provided, a power supply for backup becomes unnecessary, and dark current in a state where the ignition switch is turned off. Can be reduced.

  When the determination unit 14 of the body ECU 10 determines that the ignition switch has been turned off, the engine ECU 20 transmits (transfers) data stored in the RAM 22 to the body ECU 10 through the CAN bus 3. The body ECU 10 writes the received data in the RAM 12 by the writing unit 15. By storing the data required by the engine ECU 20 in the RAM 12 of the body ECU 10, it is not necessary to provide a non-volatile memory in the engine ECU 20 and it is not necessary to provide a backup power source in the engine ECU 20, thereby reducing power consumption. It is possible to store information of an ECU that does not include an EPROM.

  If the determination unit 14 determines that the ignition switch has been turned off, the body ECU 10 determines whether or not there is data stored in the RAM 22 of the engine ECU 20. That is, the body ECU 10 determines whether there is data of another ECU to be backed up. When the body ECU 10 determines that there is data to be backed up, the body ECU 10 transmits a transfer request for data to be backed up to the engine ECU 20. When the engine ECU 20 receives a transfer request from the body ECU 10, the engine ECU 20 transmits data stored in the RAM 22 to the body ECU 10. When the ignition switch is turned off (that is, when the power is cut off) without performing the backup process in a state where power is supplied, the presence / absence of information to be backed up is determined. For example, it is possible to reliably back up necessary information while reducing labor required for communication processing between ECUs necessary for backup processing, compared to a case where backup processing is periodically performed between ECUs.

  Further, since the body ECU 10 is configured as a backup ECU, there is no need to provide a dedicated ECU for backing up data, and an increase in cost can be suppressed.

Embodiment 2
FIG. 5 is a block diagram showing an example of the configuration of the body ECU 10 of the second embodiment. The difference from the first embodiment is that, in addition to the RAM 12 that is a volatile memory, an EPROM (Erasable Programmable ROM) 16 that is a nonvolatile memory is provided, and the writing unit 15 stores data (backup data) of other ECUs. It is a point which can be written in RAM12 and EPROM16 respectively. Since other configurations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

  In the second embodiment, when the determination unit 14 determines that the ignition switch is turned off, the writing unit 15 once writes the data stored in the RAM 22 of the engine ECU 20 to the RAM 12, and when the data is written to the RAM 12, The data is further written into the EPROM 16. Even if there is a complicated operation immediately after the ignition switch is turned off, the data to be written is once written in the RAM 12 whose writing speed is higher than that in the EPROM 16 and then written in the EPROM 16 which is a nonvolatile memory. Data can be backed up reliably. Instead of the EPROM 16, a nonvolatile memory such as an EEPROM (Electrically Erasable Programmable ROM) or a flash memory may be used.

Embodiment 3
FIG. 6 is a schematic diagram showing an example of the configuration of the vehicle control system of the third embodiment. The difference from the first embodiment is that a backup power source 5 is connected to the body ECU 10. Usually, the electric power from the battery is always supplied to the + B electric wire 1. However, when the vehicle is transported to a maintenance shop for vehicle repair or periodic inspection, the + B electric wire 1 is also disconnected from the battery during repair or inspection work, and the power to the body ECU 10 may be cut off. Assuming such a case, it is possible to prevent the data stored in the RAM 12 of the body ECU 10 from being lost by providing a backup power source that can supply only necessary power to the body ECU 10. Further, unlike the conventional backup power supply, the backup power supply 5 is used less frequently, so the life of the backup power supply 5 can be extended.

  Note that the mechanism for starting the backup power supply 5 when the power supply to the + B electric wire 1 is interrupted can be realized with a simple switch circuit, so that the cost is not increased.

  As described above, according to the present invention, even when each ECU is not equipped with an EPROM or when a hard disk or the like is not equipped, a power supply for backup becomes unnecessary, and the ignition switch is turned off. The dark current in the state can be reduced.

  In the above-described embodiment, the determination unit 14 is provided in the body ECU 10, but is not limited thereto, and may be provided in another ECU such as the engine ECU 20. In this case, for example, in the case of the engine ECU 20, when the engine ECU 20 determines that the ignition switch is turned off by the determination unit, the data stored in the RAM 22 is transmitted (transferred) to the body ECU 10 through the CAN bus 3. To do. The body ECU 10 writes the received data in the RAM 12 by the writing unit 15. By storing the data required by the engine ECU 20 in the RAM 12 of the body ECU 10, it is not necessary to provide a non-volatile memory in the engine ECU 20 and it is not necessary to provide a backup power source in the engine ECU 20, thereby reducing power consumption. It is possible to store information of an ECU that does not include an EPROM.

1 + B electric wire 2 IG electric wire 3 CAN bus 5 backup power source 10 body ECU (first ECU)
11 CPU
12 RAM (memory)
13 Interface unit (transmitter, receiver)
14 determination unit (on / off determination unit, information determination unit)
15 Writing unit 20 Engine ECU (second ECU)
21 CPU
22 RAM (volatile memory)
23 Interface part (transmitter, receiver)
30 Air conditioner ECU (second ECU)
40 Instrument panel ECU (second ECU)

Claims (4)

In a vehicle control system comprising a first ECU to which electric power is supplied regardless of whether an ignition switch is turned on or off, and a second ECU to which electric power is supplied or cut off by turning on or off the ignition switch, each ECU is connected by a communication line ,
Before Symbol first 1ECU is,
A memory for storing arbitrary information;
An on / off judging section for judging on / off of the ignition switch;
When the ignition switch is determined to have been cut by said input switching determination unit, and a writing section for writing the first 2ECU volatile information memory stored in the memory,
The second ECU
Volatile memory for storing arbitrary information;
A transmission unit that transmits information stored in the volatile memory to the first ECU through the communication line when the on / off determination unit determines that the ignition switch has been turned off;
With
The first ECU
A receiving unit for receiving the information;
When it is determined that the ignition switch is turned off by the on / off determination unit, an information determination unit that determines the presence or absence of information stored in the volatile memory of the second ECU;
A transmission unit that transmits a transfer request for the information to the second ECU when the information determination unit determines that there is information;
Further comprising
The writing unit
The information received by the receiving unit is configured to be written in the memory,
The second ECU
A receiver that receives the transfer request;
The transmitter of the second ECU is
When receiving a transfer request by the reception unit, a vehicle control system characterized tare Rukoto constitute the stored in the volatile memory information to send to the first 1ECU. The first ECU
Comprising a volatile memory and a non-volatile memory for storing arbitrary information;
The writing unit
When it is determined that the ignition switch is turned off by the on / off determination unit, the information stored in the volatile memory of the second ECU is once written in the volatile memory, and the information is written in the volatile memory. The vehicle control system according to claim 1, wherein the information is further written to the nonvolatile memory. Wherein the 1ECU the vehicle control system according to claim 1 or claim 2 characterized in that it is a body system ECU. The second ECU
An on / off judging section for judging on / off of the ignition switch;
If it is determined that the ignition switch is turned off by the determination unit, and a transmission unit for transmitting the information stored in said volatile memory via said communication line to said first 1ECU,
The first ECU
A receiving unit for receiving the information;
The writing unit
The vehicle control system according to claim 1, wherein information received by the receiving unit is configured to be written into the memory.

Images