JP5432315B2 - Electronic control device for vehicle - Google Patents

Description

  The present invention relates to a vehicular electronic control device that reads vehicle-specific data written in storage means and controls in-vehicle devices.

  The vehicle electronic control device includes external storage means (external EEPROM) capable of electrically writing vehicle-specific data and a computer system such as a microcomputer (hereinafter referred to as a microcomputer), and the microcomputer is written to the external storage means. The vehicle-specific device data is read out and the vehicle-mounted device is controlled based on a preset control program.

  An electronic control unit (microcomputer) is connected to external storage means (non-volatile memory) that stores data for controlling the electronic control unit and vehicle type data, and the electronic control unit is mounted on the vehicle based on the data in the external storage means. In order to check the consistency of the vehicle type data in the external storage means, an internal storage means for storing a vehicle type identification code in advance inside the electronic control unit is provided in the electronic control device for vehicles. After the control unit completes the initialization process after the power is turned on, the vehicle type identification code of the external storage means and the vehicle type identification code of the internal storage means are compared. It is known to have done so. (See Patent Document 1)

JP 2004-330958 A

The vehicle electronic control device has a function of controlling various input / output devices suitable for the vehicle type, and it is necessary to switch the input / output state of the port of the microcomputer in accordance with the mounted vehicle type.
Generally, the input / output state is switched at the time of initialization processing immediately after the microcomputer is turned on. After the initialization processing is completed as in the conventional technique described above, is the vehicle-specific data the data of the vehicle type? If it is checked, for example, if the microcomputer switches the port state to the input state and sets the output state for the device to be used due to incorrect writing of vehicle type data, the installed input / output device or vehicle There is a risk of detrimental effects such as destruction of the input / output interface inside the vehicle electronic control device, which may lead to a decrease in the reliability of the vehicle electronic control device.

As an example, an interface of an EGR (Exhaust Gas Recirculation) valve driving related part will be described with reference to FIG.
The microcomputer 1 performs initialization processing of the microcomputer port immediately after the power is turned on. At this time, the EGR valve driving stepping motor drive signal ports 35 to 38 are set to output, and the disconnection detection ports 31 to 34 of the EGR valve driving stepping motor are set to input. Next, in order to set the initial position of the EGR valve driving stepping motor, the FETs 47 and 49 in the EGR driving interface 51 are turned on by setting the outputs of the EGR valve driving stepping motor drive signal ports 35 and 37 to High. As a result, the stepping motor output terminals 39 and 41 are set to Low.

At the same time, by setting the outputs of the EGR valve driving stepping motor drive signal ports 36 and 38 to Low, the FETs 48 and 50 are turned OFF, and as a result, the stepping motor output terminals 40 and 42 are set to High. At this time, the transistors 46 and 44 in the EGR valve disconnection detection interface 52 are turned OFF, and no current flows between the emitters and collectors of the transistors 46 and 44. Therefore, the disconnection detection ports 32 and 34 of the stepping motor for driving the EGR valve The input value is High. At the same time, the transistors 45 and 43 are turned on, a current of about 1 mA flows between the emitters and collectors of the transistors 45 and 43, and the input values of the disconnection detection ports 31 and 33 of the stepping motor for driving the EGR valve become Low.

  When the EGR valve driving stepping motor is disconnected, even if the output of the EGR valve driving stepping motor drive signal port is set to Low, the stepping motor output terminal does not become High, and the EGR valve driving stepping motor disconnection detection port Since the input value remains high, the disconnection of the stepping motor for driving the EGR valve can be detected.

  However, when data of a different vehicle type is written by mistake, for example, the data of the vehicle type using the disconnection detection port 31 of the stepping motor for driving the EGR valve as an output port (for example, tachometer output) instead of an input port. If it is, the output port may be set at the time of initialization processing of the microcomputer port immediately after the microcomputer is turned on, and the output level may be set to High. In this case, as described above, since the EGR valve driving stepping motor drive signal port 38 is set to Low output, the transistor 43 is turned ON, and the output current 10 mA flows from the disconnection detection port 31 of the EGR valve driving stepping motor. The transistor's rated current will be exceeded and it will break.

Incidentally, the operation of the tachometer output port will be described with reference to FIG. The tachometer output switches the output value High / Low of the tachometer output terminal 53 at a predetermined timing of engine rotation. When the output of the tachometer output port 54 is set to Low, the transistor 55 is turned off, and the tachometer output terminal 53 Is set to High, and when the output of the tachometer output port 54 is set to High, the transistor 55 is turned ON and the tachometer output terminal 53 is set to Low.
In the initialization process of the microcomputer port, the tachometer output terminal 53 needs to be set to Low, and the tachometer output port 54 is set to High.
Therefore, if the port state (input or output) of the microcomputer 1 is set in an inconsistent state, there is a risk of causing destruction of the device.

  The present invention has been made to solve the above-described problems, and is intended for a vehicle in which the port state of the microcomputer in the vehicle electronic control device is prevented from becoming inconsistent with the vehicle. An object of the present invention is to provide an electronic control device.

An electronic control device for a vehicle according to the present invention includes a writable first storage means for storing unique identification data corresponding to a vehicle type and a microcomputer. The microcomputer is a control program for controlling on-vehicle equipment , A second storage means in which checksum data calculated in advance for the area in which the control program is written and hardware identification data corresponding to the control program are written; a CPU having an input / output port setting means; A serial communication port for communicating with an external device and an input / output port are provided. The CPU sets the identification data read from the first storage means and the second storage means in the initialization process immediately after the power is turned on. Identification data comparison means for comparing the hardware identification data and the checksum of the area where the control program is written A checksum data calculation means for calculating the over data, and a checksum data comparing means for comparing the checksum data checksum data calculation means is read from the result of calculation and the second storage unit, identification data comparing When both the comparison result by the means and the comparison result by the checksum data comparison means match, the input / output port setting means initializes the input / output port.

  According to the present invention, even when a control program for another vehicle is erroneously written in the storage means, both the comparison results by the identification data comparison means and the checksum data comparison means in the initialization process immediately after the power is turned on. If they match, the input / output port setting means initializes the input / output ports so that the microcomputer port state in the vehicle electronic control unit is prevented from becoming inconsistent with the vehicle. The input / output interface inside the output device and the vehicle electronic control device can be protected from destruction.

1 is a block configuration diagram of a vehicle electronic control device showing Embodiment 1 of the present invention. FIG. It is a figure which shows the operation | movement flowchart of the electronic controller for vehicles in Embodiment 1 of this invention. It is a figure which shows the interface of EGR which is an example of the input / output interface in the electronic controller for vehicles. It is a figure which shows the interface of a tachometer output which is an example of the input / output interface inside the electronic controller for vehicles.

Embodiment 1 FIG.
Hereinafter, a vehicle electronic control device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an electronic control device for a vehicle, and FIG. 2 is a flowchart showing its operation.

In FIG. 1, a vehicle electronic control unit 20 includes an input / output interface for inputting / outputting signals between a microcomputer 1, external storage means 2 of an electrically rewritable nonvolatile memory (hereinafter referred to as EEPROM), and an external device. 3 is provided.
The microcomputer 1 includes a ROM storage means 4, which is a nonvolatile memory, a RAM 5, a CPU 6, a serial communication port 7, and an input / output port 8.
Various input / output devices 21 of in-vehicle devices are connected to the input / output interface 3 of the vehicle electronic control device 20, and the serial communication port 7 of the microcomputer 1 is a program rewriting device that is an external device. 22 is connected.

  The storage means 2 of the EEPROM stores vehicle hardware identification data 9 which is data specific to the vehicle type on which the vehicle electronic control device 20 is mounted. The hardware identification data 9 is written when the control program is written in the ROM storage means 4 of the microcomputer 1 in the manufacturing process of the vehicle electronic control device 20, and cannot be rewritten after being written once.

The ROM storage means 4 includes a control program 11 for controlling the in-vehicle device, checksum data 12 calculated in advance for the area in which the control program 11 is written, and a vehicle on which the vehicle electronic control device 20 is mounted. The hardware identification data 13 is stored.
The control program 11 is written from the program rewriting device 22 via the serial communication port 7. The checksum data 12 is written at the timing when the control program 11 is written.
Note that the checksum data is one of error detection methods for transmitting and receiving data, and is generally known.

The CPU 6 of the microcomputer 1 stores the checksum data calculation means 14 for calculating the checksum data in the area where the control program 11 is written, the hardware identification data 9 read from the EEPROM storage means 2 and the ROM storage means 4. The checksum data for comparing the checksum data obtained by the storage means 4 with the checksum data obtained by the identification means comparing means 15 and the checksum data calculating means 14 for comparing the hardware identification data 13 that has been read. The comparator 16 and the input / output port setting means 17 for setting the input / output port 8 for controlling the input / output device 21 are provided.

The checksum data calculation means 14 divides the data of the area of the control program 11 written in the storage means 4 of the ROM into, for example, 4-byte units, and adds values every 4-byte units. The obtained value is the checksum data. This checksum data is calculated from the data in the area of the control program 11 by the checksum data calculation means 14 immediately after the power is turned on.
In the vehicle electronic control device 20, the CPU 6 controls the vehicle by reading the control program 11 and controlling the input / output device 21 via the input / output port 8 and the input / output interface 3.

  Here, the ROM storage means 4 is configured to be rewritable when there is a problem in the drivability improvement purpose or the control program 11. The ROM storage means 4 is rewritten by receiving a new control program from the dedicated program rewriting device 22 via the serial communication port 7.

  In the program rewriting device 22, vehicle information and a control program corresponding to the vehicle are managed in a database, and a control program for a vehicle type different from that of the vehicle on which the vehicle electronic control device 20 is mounted is normally rewritten. There is no. However, if there is an error in database management, there is a possibility that a control program for a vehicle type different from that of the vehicle on which the vehicle electronic control device 20 is mounted will be rewritten.

  If a control program for a vehicle type different from that of the vehicle on which the vehicle electronic control device 20 is mounted is rewritten, the setting of the input / output port 8 of the microcomputer 1 is actually mounted on the vehicle electronic control device 20. Since it is different from the input / output device 21 of the vehicle, the input / output interface 21 in the input / output device 21 or the vehicle electronic control device 20 may be broken conventionally. As a specific example, there is an EGR interface to be solved by the above-described invention.

  In order to cope with this, in the present invention, in the initialization process immediately after the power is turned on, the consistency between the vehicle on which the vehicle electronic control device 20 is mounted and the rewritten control program is confirmed. By performing the initial setting of the output port 8, the input / output device 21 connected to the vehicle electronic control device 20 and the input / output interface 3 inside the vehicle electronic control device 20 are prevented from being broken.

FIG. 2 is a flowchart showing the operation of the vehicle electronic control apparatus according to Embodiment 1 of the present invention.
First, the settings of the input / output port 8 are all defaulted by a hardware reset after a power-on reset immediately after the power is turned on, or after the control program 11 stored in the ROM storage means 4 is rewritten by the program rewriting device 22. It is set to the input that is the setting. Thereafter, in step S100, the program starts operating, and executes initialization processing other than the setting of the input / output port 8.

  Next, in step S101, the checksum data calculation means 14 calculates the checksum data of the area where the control program 11 is written. In step S102, the checksum data comparison unit 16 compares the checksum data calculated in step S101 with the checksum data 12 stored in the ROM storage unit 4. If the comparison result of the checksum data does not match in step S102, it is determined that the ROM storage means 4 is abnormal, and the initialization process is terminated without initial setting of the input / output port 8 thereafter.

  If the comparison result of the checksum data matches in step S102, the process proceeds to step S103 to set the serial communication port 7 connected from the microcomputer 1 to the storage means 2 of the EEPROM. In step S104, the hardware identification data 9 stored in the storage means 2 of the EEPROM is read out and input to the CPU. In step S105, the identification data comparison unit 15 compares the hardware identification data 9 read from the EEPROM storage unit 2 with the hardware identification data 13 stored in the ROM storage unit 4. If the comparison result of the hardware identification data does not match in step S105, it is determined that the vehicle in which the vehicle electronic control device 20 is mounted and the rewritten control program do not match, and the subsequent input / output port 8 The initialization process is terminated without initial setting.

  If the comparison result of the hardware identification data matches in step S105, the process proceeds to step S106, where it is determined that the vehicle in which the vehicle electronic control device 20 is mounted and the rewritten control program 11 match. Set the input / output port 8. Then, the initialization process is terminated, and the process proceeds to a process for controlling the vehicle.

  In the EGR interface of FIG. 3, if the comparison result of the hardware identification data does not match, the input / output port is not set, and the input / output port is set to the default input, and the transistors 43 to 46 are not connected. It will not break because no current exceeding the rating will flow.

  As a result, the input / output port is set only when the rewritten control program matches the vehicle on which the vehicle electronic control device 20 is mounted, thereby being connected to the vehicle electronic control device 20. It is possible to prevent the input / output device 21 and the input / output interface 3 inside the vehicle electronic control device 20 from being broken.

  Even when the rewritten control program for the vehicle on which the vehicle electronic control device 20 is mounted does not match, the input / output port 8 is set by rewriting the correct control program from the program rewriting device 22, and the control program 11 controls the vehicle.

As described above, the vehicle electronic control device 20 of the present invention includes the ROM storage means 4, the CPU 6, the microcomputer 1 including the input / output port 8, and the external EEPROM storage means 2 for storing the hardware identification data 9. The CPU 6 includes an identification data comparison unit 15, a checksum data comparison unit 16, and an input / output port setting unit 17. In the initialization process immediately after the power is turned on, the checksum data comparison unit 16 controls the storage unit 4. The result of computing the checksum data in the area where the program 11 is written is compared with the checksum data 12 stored on the storage means 4, and the identification data comparison means 15 is stored on the storage means 4. The hardware identification data 13 is compared with the hardware identification data 9 stored on the storage means 2 of the external EEPROM. That.
When both the comparison results of the checksum data comparison means 16 and the identification data comparison means 15 match, the input / output port 8 is initialized by the input / output port setting means 17. It is possible to prevent the port state of the microcomputer in the control device from becoming inconsistent with the vehicle, and to protect the input / output device and the input / output interface inside the vehicle electronic control device from being destroyed.

1: microcomputer, 2: first storage means (EEPROM),
3: input / output interface, 4: second storage means (ROM),
5: RAM, 6: CPU,
7: Serial communication port, 8: I / O port,
9: Hardware identification data, 11: Control program,
12: Checksum data, 13: Hardware identification data,
14: checksum data calculation means, 15: identification data comparison means,
16: Checksum data comparison means, 17: Input / output port setting means,
20: Electronic control device for vehicles, 21: Input / output device,
22: Program rewriting device.

Claims (1)

Consists of a writable first storage means for storing unique identification data corresponding to the vehicle type and a microcomputer, which is a control program for controlling in-vehicle devices, and an area in which this control program is written Serial communication for communicating with a second storage means in which checksum data calculated in advance and hardware identification data corresponding to the control program are written, a CPU having input / output port setting means, and an external device A port and an input / output port ,
The CPU, in the initializing process immediately after power-on, the identification data comparing means for comparing the hardware identification data set in the first and the identification data read out from the storage means a second storage means, Checksum data calculation means for calculating checksum data in the area in which the control program is written, and a check for comparing the result calculated by the checksum data calculation means with the checksum data read from the second storage means and a sum data comparing means, when the comparison result by the comparison result and the checksum data comparison unit according to the identification data comparing means are matched both, the initial setting of the input and output ports by said output port setting means An electronic control device for a vehicle.

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