JP2023103701A - electronic controller - Google Patents

Abstract

To properly reduce an occupation rate of vehicle information in storage capacity of a nonvolatile memory.SOLUTION: An electronic controller 1 includes: a volatile memory 7 for storing vehicle information; a nonvolatile memory 8 for storing the vehicle information; and a conversion operation unit 14 for converting the vehicle information read from the volatile memory, writing the converted vehicle information into the nonvolatile memory, inverse-converting the converted vehicle information read from the nonvolatile memory, and writing the vehicle information before the conversion into the volatile memory.SELECTED DRAWING: Figure 1

Description

The present invention relates to electronic control units.

For example, an in-vehicle electronic control unit (hereinafter referred to as an ECU (Electronic Control Unit)) is configured to store vehicle information related to vehicle control in a non-volatile memory. As a configuration for storing vehicle information in a non-volatile memory, for example, Patent Document 1 discloses reducing the data amount of vehicle information that has a large time deviation from the time of an accident occurrence, and occupies vehicle information that has a high degree of importance for analysis immediately before the accident occurrence. An arrangement is disclosed to increase the rate.

JP 2006-282032 A

In the configuration disclosed in Patent Document 1, the amount of vehicle information data is reduced depending on how much time the vehicle information acquisition timing deviates from the time of the accident, and the storage capacity of the nonvolatile memory is occupied by the vehicle information. reduce rate. However, when data accumulated over the life cycle of the vehicle is stored in the non-volatile memory as vehicle information, it is not possible to select a reference time for reducing the amount of vehicle information data. Therefore, there is a problem that the configuration disclosed in Patent Document 1 cannot be applied.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic control device capable of appropriately reducing the occupancy rate of vehicle information in the storage capacity of a nonvolatile memory.

According to the first aspect of the invention, a volatile memory (7) capable of storing vehicle information, a nonvolatile memory (8) capable of storing the vehicle information, and the vehicle information read from the volatile memory. and writes the converted vehicle information into the non-volatile memory, inversely converts the converted vehicle information read from the non-volatile memory, and writes the pre-converted vehicle information into the volatile memory. (14);

When writing the vehicle information to the non-volatile memory, convert the vehicle information read from the volatile memory and write the converted vehicle information to the non-volatile memory. The converted vehicle information read out from the memory is reverse-converted and the pre-converted vehicle information is written in the volatile memory. When the vehicle information is written in the nonvolatile memory, by converting the vehicle information to reduce the data amount of the vehicle information, the occupation rate of the vehicle information in the storage capacity of the nonvolatile memory can be appropriately reduced.

Functional block diagram showing one embodiment Diagram showing conversion map Data flow diagram when writing to non-volatile memory Data flow diagram when reading from non-volatile memory Flowchart showing processing when writing to non-volatile memory Flowchart showing processing when reading from non-volatile memory Diagram explaining LSB conversion Timing chart Diagram showing histogram

An embodiment applied to a motor control ECU mounted on a vehicle will be described below with reference to the drawings. The motor control ECU is an ECU that controls driving of a three-phase motor that outputs torque in an electric brake or the like. As shown in FIG. 1 , the motor control ECU 1 controls driving of the motor 3 by switching the inverter 2 by PWM control and supplying predetermined power from the inverter 2 to the motor 3 . A rotation angle sensor 4 for detecting an electrical angle θ of the motor 3 is arranged on the motor 3 . In the inverter 2, a plurality of switching elements forming a three-phase upper arm element and a lower arm element are bridge-connected, and the switching operation of the plurality of switching elements converts the DC power supplied from the high-voltage battery 5 into three-phase AC power. Then, a voltage is applied to the three-phase windings of the motor 3. The switching elements are, for example, IGBTs, MOSFETs, and the like.

The motor control ECU 1 includes a control section 6 , a volatile memory 7 , a nonvolatile memory 8 and a data communication section 9 . The control unit 6 is mainly composed of a microcomputer including CPU, ROM, RAM, I/O, and bus lines connecting these components. The control unit 6 executes software processing by executing a pre-stored program on the CPU, and control by hardware processing by a dedicated electronic circuit. The nonvolatile memory 8 may be arranged outside the motor control ECU 1 .

The data communication unit 9 can be connected to, for example, a data reading tool 10 operated by a dealer worker or the like via an in-vehicle network 11 . The data reading tool 10 is connected to an in-vehicle network 11 when analyzing vehicle information, which will be described later, and is connected to the motor control ECU 1 via the in-vehicle network 11 . The in-vehicle network 11 includes, for example, CAN (Controller Area Network) (registered trademark), LIN (Local Interconnect Network) (registered trademark), CXPI (Clock Extension Peripheral Interface) (registered trademark), FlexRay (registered trademark), MOST (Media Oriented Systems Transport (registered trademark), etc.

The control unit 6 includes an arithmetic control unit 12 , a sensor value acquisition unit 13 and a conversion operation unit 14 . The arithmetic control unit 12 has a function of time-differentiating the electrical angle θ detected by the rotation angle sensor 4 to calculate a speed, and calculates a speed deviation between a speed command input from a higher-level vehicle control circuit and the calculated speed. a function to calculate a torque command so that the calculated speed deviation approaches "0"; a function to calculate a dq-axis current command based on the calculated torque command; , a function to convert the three-phase currents Iu, Iv, and Iw into dq-axis currents using the electrical angle θ, a function to calculate the current deviation between the dq-axis current command and the dq-axis current, and the calculated A function to calculate the dq-axis voltage command so that the current deviation approaches "0", a function to dq-convert the calculated dq-axis voltage command using the electrical angle θ to a three-phase voltage command, a function to convert from the three-phase voltage command It also has a function of generating a PWM signal by PWM control that compares the duty ratio of each phase and the carrier.

The sensor value acquisition unit 13 periodically acquires various sensor values from the inverter 2 . The sensor values periodically acquired from the inverter 2 are, for example, switching element temperature and inverter voltage. The switching element temperature is a value calculated from the duty of the converted ON/OFF signal after converting the voltage of the temperature sensing diode into an ON/OFF signal. The inverter voltage is a value calculated by A/D converting the analog signal output from the sensor. In this embodiment, when the switching element temperature reaches a predetermined temperature (for example, 100 degrees), the number of times the switching element temperature reaches the predetermined temperature is written in the volatile memory 7 . Also, when the inverter voltage reaches a predetermined voltage (for example, 670 volts), the number of times the inverter voltage reaches the predetermined voltage is written in the volatile memory 7 . The number of times the switching element temperature reaches a predetermined temperature and the number of times the inverter voltage reaches a predetermined voltage are data accumulated over the life cycle of the vehicle.

When writing the vehicle information stored in the volatile memory 7 to the nonvolatile memory 8, the conversion calculation unit 14 converts the vehicle information read from the volatile memory 7 according to a predetermined conversion logic, The converted vehicle information is written in the nonvolatile memory 8 . When reading the vehicle information from the nonvolatile memory 8, the conversion calculation unit 14 inversely converts the vehicle information read from the nonvolatile memory 8 according to a predetermined inverse conversion logic, and volatilizes the vehicle information before conversion. write to the property memory 7.

Specifically, as shown in FIG. 2, the conversion calculation unit 14 holds a conversion map indicating the correspondence between the conversion index and the LSB conversion value. The conversion calculation unit 14 uses software to extract LSB conversion values from the conversion index, which are used when converting the vehicle information and when inversely converting the converted vehicle information. The conversion index ranges from '0' to '15', and the LSB conversion value is changed in 15 steps.

When writing the vehicle information stored in the volatile memory 7 to the nonvolatile memory 8, the conversion calculation unit 14 converts the vehicle information X stored in the volatile memory 7 into the nonvolatile memory 8 as shown in FIG. At the timing of writing into the memory 8, the vehicle information X and the conversion index Z are input, the vehicle information X is LSB-converted with the LSB conversion value corresponding to the conversion index Z, and the converted vehicle information Y is calculated. The conversion calculation unit 14 outputs the calculated converted vehicle information Y and conversion index Z, and writes the converted vehicle information Y and conversion index Z into the nonvolatile memory 8 .

When reading the vehicle information from the non-volatile memory 8, the conversion calculation unit 14 reads out the converted vehicle information Y from the non-volatile memory 8 as shown in FIG. and conversion index Z are input, the converted vehicle information Y is inversely LSB-converted with the LSB conversion value corresponding to the conversion index Z, and vehicle information X' is calculated. The conversion calculation unit 14 outputs the calculated vehicle information X′ and the conversion index Z, and writes the vehicle information X′ and the conversion index Z into the volatile memory 7 .

The conversion calculation unit 14 performs the process of writing the vehicle information into the nonvolatile memory 8 in the sequence at the end of the trip, and performs the process of reading the vehicle information from the nonvolatile memory 8 in the sequence at the start of the trip. Control can be added without affecting the processing load of cruise control. The time when the trip ends is when the ignition is turned off in the case of an engine vehicle, or when the drive motor is turned off in the case of an electric vehicle, and includes a time period within a predetermined time period from when the ignition is turned off or when the start is turned off, and when the trip ends. Also includes immediately after the end of the trip from the time until the predetermined time has passed. The trip start time is the time when the ignition is turned on for an engine vehicle, or the time when the drive motor is started for an electric vehicle, and includes the time period within a predetermined time after the ignition is turned on or when the start is turned on, and when the trip starts. Also includes immediately after the start of the trip until a predetermined time has passed since the start of the trip.

The data reading tool 10 transmits a data reading request to the data communication unit 9 when a data reading operation is performed by, for example, a dealer worker while being connected to the motor control ECU 1 via the in-vehicle network 11 . When the data communication unit 9 receives the data read request transmitted from the data reading tool 10, the control unit 6 reads the vehicle information stored in the nonvolatile memory 8, and transmits the read vehicle information to the data communication unit. 9 to the data reading tool 10 . By transferring the vehicle information from the motor control ECU 1 to the data reading tool 10, the vehicle information can be analyzed by the data reading tool 10 or the like.

Next, the operation of the above configuration will be described with reference to FIGS. 5 to 9. FIG. In this case, the processing for writing to the nonvolatile memory 8 and the processing for reading from the nonvolatile memory 8 will be described.

(1) Processing when writing to nonvolatile memory 8 (see FIG. 5)
When the control unit 6 detects the end of the trip and determines that the conditions for starting the writing process are satisfied, it starts the writing process. The control unit 6 reads and acquires the vehicle information X and the conversion index Z from the volatile memory 7 (S1), and acquires the LSB conversion value corresponding to the acquired conversion index Z (S2). The control unit 6 performs LSB conversion according to the following arithmetic expression to calculate post-conversion vehicle information Y (S3).
Converted vehicle information Y=Vehicle information X/LSB conversion value

The control unit 6 compares the calculated post-conversion vehicle information Y with a threshold, and determines whether or not the post-conversion vehicle information Y is equal to or greater than the threshold (S4). When the control unit 6 determines that the post-conversion vehicle information Y is not equal to or greater than the threshold (S4: NO), it writes the post-conversion vehicle information Y and the conversion index Z to the nonvolatile memory 8 (S8), and terminates the writing process.

On the other hand, when the control unit 6 determines that the converted vehicle information Y is equal to or greater than the threshold value (S4: YES), it adds "1" to the value of the conversion index Z (S5), and after adding "1" An LSB conversion value corresponding to the conversion index Z is obtained (S6). The control unit 6 performs LSB conversion according to the above-described arithmetic expression to calculate the converted vehicle information Y (S7), writes the converted vehicle information Y and the conversion index Z into the nonvolatile memory 8 (S8), End the write process.

(2) Processing when reading from the nonvolatile memory 8 (see FIG. 6)
When the control unit 6 detects the start of the trip and determines that the condition for starting the reading process is satisfied, it starts the reading process. The control unit 6 reads and acquires the post-conversion vehicle information Y and the conversion index Z from the nonvolatile memory 8 (S11), and acquires the LSB conversion value corresponding to the acquired conversion index Z (S12). The control unit 6 performs LSB inverse conversion according to the following arithmetic expression to calculate vehicle information X' (S13).
Vehicle information X′=Converted vehicle information Y×LSB conversion value The control unit 6 writes the calculated vehicle information X′ and the conversion index Z to the volatile memory 7 (S14), and ends the reading process.

LSB conversion will be described with reference to FIG. The vehicle information X with a unit data amount of 4 bytes, which was conventionally written in the nonvolatile memory 8, is written as the converted vehicle information Y with a unit data amount of 2 bytes and the conversion index Z with a unit data amount of 1 byte. Suppose.

In this case, a storage capacity of 3 bytes can be used instead of a 4-byte storage capacity, and the occupation rate of the vehicle information in the storage capacity of the nonvolatile memory 8 can be reduced by 25%. Until 65536 times, which is the upper limit of the storage capacity of 2 bytes, is first recorded, the vehicle information X is a value obtained by dividing the initial value ("0") of the conversion index Z by the LSB conversion value "1", that is, as it is. is written as vehicle information Y after conversion. When the vehicle information X reaches 65536 times or more, the value of the conversion index Z is incremented by "1" and the LSB conversion value becomes "2". At this time, a maximum of "1" data dropout occurs. Therefore, if the vehicle information X is data to which the vehicle information X is added only once per trip, the converted vehicle information Y may not be updated. However, in that situation, it takes about 44 years for the relevant vehicle information to reach the threshold of 65536 times where the LSB conversion value is "2" with 4 trips per day, so if the life cycle of the vehicle is assumed to be 20 years It is considered that there is no problem.

If the number of years of the life cycle of the vehicle is determined, the LSB conversion value can be determined by calculating back from there, so data omission can be designed. For example, if the life cycle of a vehicle is 20 years, and the next LSB conversion value is "5", the vehicle information X is added four times, which is the maximum number of data dropouts. Since it takes about 22 years to reach the threshold value of 131072 (65536×2) times, which is the conversion value of "5", it is thought that there is no problem because it is longer than the life cycle of the vehicle. Similarly, by providing LSB conversion values for 15 steps, 4294967295 times, which is the maximum value of 4-byte data, can be expressed by 65535 times, which is the maximum value of 2-byte data, and conversion index Z.

A specific description will be given with reference to the timing chart shown in FIG. When the control unit 6 detects the end of the trip at the timing of "t2" when the ignition is turned off, the control unit 6 performs the processing for writing to the nonvolatile memory 8. FIG. In this case, since the vehicle information X=3, the conversion index Z=0, and the LSB conversion value=0, the control unit 6 calculates post-conversion vehicle information Y=vehicle information X/LSB conversion value=3/1=3. do. Since the calculated value has not reached 65536 times exceeding the maximum value of the 2-byte data, the control unit 6 holds the value of the conversion index Z, converts the converted vehicle information Y=3 and the conversion index Z=0 into a non-volatile state. Write to memory 8.

When the control unit 6 detects the start of the trip at the timing of "t3" when the ignition is turned on, the control unit 6 performs the readout process from the nonvolatile memory 8. FIG. In this case, since the vehicle information after conversion Y=3, the conversion index Z=0, and the LSB conversion value=0, the control unit 6 determines that the vehicle information X′=the vehicle information after conversion Y×LSB conversion value=3×1= 3 is calculated, and the vehicle information X'=3 and the conversion index Z=0 are written in the volatile memory 7.

Similarly, when the control unit 6 detects the end of the trip at the timing of "t4" when the ignition is turned off, the control unit 6 performs the processing for writing to the nonvolatile memory 8. FIG. In this case, since the vehicle information X=5, the conversion index Z=0, and the LSB conversion value=0, the control unit 6 calculates post-conversion vehicle information Y=vehicle information X/LSB conversion value=5/1=5. do. Since the calculated value has not reached 65536 times exceeding the maximum value of 2-byte data, the control unit 6 holds the value of the conversion index Z, and sets the post-conversion vehicle information Y=5 and the conversion index Z=0 to non-volatile data. Write to memory 8.

Similarly, when the control unit 6 detects the start of a trip at the timing of "t5" when the ignition is turned on, the control unit 6 performs the readout process from the nonvolatile memory 8. FIG. In this case, since the vehicle information after conversion Y=5, the conversion index Z=0, and the LSB conversion value=0, the control unit 6 determines that the vehicle information X′=the vehicle information after conversion Y×LSB conversion value=5×1= 5 is calculated, and the vehicle information X'=5 and the conversion index Z=0 are written in the volatile memory 7.

When the control unit 6 detects the end of the trip at the timing of "tn (n is a natural number equal to or greater than 6)" when the ignition is turned off, the control unit 6 performs the process of writing to the nonvolatile memory 8. FIG. In this case, since the vehicle information X=65536, the conversion index Z=0, and the LSB conversion value=0, the control unit 6 calculates post-conversion vehicle information Y=vehicle information X/LSB conversion value=65536/1=65536. do. Since the calculated value exceeds the maximum value of 2-byte data and reaches 65536 times, the control unit 6 adds "1" to the value of the conversion index Z to change the conversion index Z to 1 and the LSB conversion value to 2. Then, post-conversion vehicle information Y=vehicle information X/LSB conversion value=65536/2=32768 is calculated, and post-conversion vehicle information Y=32768 and conversion index Z=1 are written in the nonvolatile memory 8 .

When the control unit 6 detects the start of the trip at the timing of "t(n+1)" when the ignition is turned on, the control unit 6 performs the readout process from the nonvolatile memory 8 . In this case, since the vehicle information after conversion Y=32768, the conversion index Z=1, and the LSB conversion value=2, the control unit 6 determines that the vehicle information X′=the vehicle information after conversion Y×LSB conversion value=32768×2= 65536 is calculated, and vehicle information X′=65536 and conversion index Z=1 are written in the volatile memory 7 .

When the control unit 6 detects the end of the trip at the timing of "t(n+2)" when the ignition is turned off, the control unit 6 performs the processing for writing to the nonvolatile memory 8. FIG. In this case, since the vehicle information X=65538, the conversion index Z=1, and the LSB conversion value=2, the control unit 6 calculates post-conversion vehicle information Y=vehicle information X/LSB conversion value=65538/2=32769. do. Since the calculated value has not reached 65536 times, which exceeds the maximum value of 2-byte data, the control unit 6 holds the value of the conversion index Z, converts the converted vehicle information Y=32769, and converts the conversion index Z=1 into non-volatile data. Write to memory 8.

After collecting the vehicle information stored in the nonvolatile memory 8, the data reading tool 10 creates a histogram for analyzing the collected vehicle information and uses it for reliability design, as shown in FIG. That is, by using the amount of data to be stored in the nonvolatile memory 8 as a reference for the amount of deletion, it becomes possible to select data based on uniform reliability, and it is possible to maintain necessary analyzability. Since vehicle information is not used for driving control and is data for creating histograms for analysis after collection, there is no problem even if the amount of data is reduced as long as it does not affect analysis using histograms. are using.

As described above, according to the embodiment, the following effects can be obtained.
In the motor control ECU 1, when writing vehicle information to the nonvolatile memory 8, the vehicle information read from the volatile memory 7 is converted and the converted vehicle information is written to the nonvolatile memory 8, and the vehicle information is written to the nonvolatile memory. 8, the converted vehicle information read out from the non-volatile memory 8 is reverse-converted, and the vehicle information before conversion is written in the volatile memory 7. FIG. The occupation rate of the vehicle information in the storage capacity of the nonvolatile memory 8 can be appropriately reduced.

The LSB conversion values used when converting vehicle information and when inversely converting vehicle information after conversion are referenced by software from the conversion index. By storing only the conversion index in the non-volatile memory 8 instead of storing both the conversion index and the LSB conversion value in the non-volatile memory 8, the occupation rate of the storage capacity of the non-volatile memory 8 can be further reduced. can be reduced appropriately. Also, by defining a transformation map, it is possible to design transformations with arbitrary precision.

The unit data amount of vehicle information after conversion is set to 2 bytes. By setting the unit data amount to 2 bytes, it is possible to store a maximum of 65536 times, and it is possible to construct a logic that changes in a larger unit every time the value obtained by converting the vehicle information reaches 65536 times. The fewer the number of events that occur in the vehicle life cycle, the smaller the numerical value used for conversion, so the data can be stored with high accuracy. be able to.

The conversion value is changed in 15 steps. For example, the conversion step can be arbitrarily designed based on the number of trips per day and the life cycle of the vehicle. The unit data amount of the conversion index representing the conversion value of 15 steps is assumed to be 1 byte. The 4-byte vehicle information stored in the volatile memory 7 can be stored in the non-volatile memory 8 as a total of 3 bytes including 2-byte converted vehicle information and 1-byte conversion index.

Vehicle information is data accumulated over the life cycle of the vehicle. It can be applied when data accumulated over the life cycle of the vehicle is stored in the non-volatile memory 8, and the occupancy rate of the vehicle information in the storage capacity of the non-volatile memory 8 can be appropriately reduced.

Vehicle information was used as data for creating a histogram. Since the reliability of the data, which is traded off with the reduction of the occupancy rate, is acceptable for the purpose of creating the histogram, it is possible to avoid affecting the analysis of the vehicle information.

A process of converting the vehicle information read from the volatile memory 7 and writing the converted vehicle information into the non-volatile memory 8 is executed in the sequence at the end of the trip, and the converted vehicle information read from the non-volatile memory 8 is reversed. The process of converting and writing the vehicle information before conversion into the volatile memory 7 is performed in a sequence at the start of a trip. By not performing conversion and inverse conversion while the vehicle is running, additional control can be added without affecting the processing load of the cruise control.

Although the present disclosure has been described with reference to examples, it is understood that it is not limited to such examples or structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and configurations, as well as other combinations and configurations including single elements, more, or less, are within the scope and spirit of this disclosure.

The controller and techniques described in this disclosure may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by the computer program. can be Alternatively, the controller and techniques described in this disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the controller and techniques described in this disclosure can be implemented by a combination of a processor and memory programmed to perform one or more functions and a processor configured with one or more hardware logic circuits. It may also be implemented by one or more dedicated computers configured. The computer program may also be stored as computer-executable instructions on a computer-readable non-transitional tangible storage medium.

The electronic control unit is not limited to the motor control ECU 1 that controls driving of a three-phase motor that outputs torque in an electric brake or the like of the vehicle, and may be an ECU that performs other vehicle control.

In the drawing, 1 is a motor control ECU (electronic control unit), 6 is a control section, 7 is a volatile memory, 8 is a nonvolatile memory, and 14 is a conversion calculation section.

Claims (9)

In the electronic control unit mounted on the vehicle,
a volatile memory (7) capable of storing vehicle information;
a non-volatile memory (8) capable of storing the vehicle information;
converting the vehicle information read from the volatile memory, writing the converted vehicle information into the nonvolatile memory, and inversely converting the converted vehicle information read from the nonvolatile memory to vehicle information before conversion. into the volatile memory. the non-volatile memory stores a translation index;
2. The electronic control device according to claim 1, wherein the conversion calculation unit uses software to obtain conversion values for converting the vehicle information and for inversely converting the converted vehicle information from the conversion index. 3. The electronic control unit according to claim 1, wherein the converted vehicle information has a unit data amount of 2 bytes. 4. The electronic control device according to claim 3, wherein the conversion calculation section changes the conversion value in 15 steps. 5. The electronic control device according to claim 4, wherein the unit data amount of the conversion index expressing the conversion values of the 15 steps is 1 byte. The electronic control unit according to any one of claims 1 to 5, wherein the vehicle information is data accumulated over the life cycle of the vehicle. The electronic control unit according to any one of claims 1 to 6, wherein the vehicle information is data for creating a histogram. The electronic control unit according to any one of claims 1 to 7, wherein the vehicle information is at least one of the number of times the switching element temperature reaches a predetermined temperature and the number of times the inverter voltage reaches a predetermined voltage. The conversion calculation unit converts the vehicle information read from the volatile memory and writes the converted vehicle information to the nonvolatile memory in a sequence at the end of the trip, and reads the vehicle information from the nonvolatile memory. The electronic control unit according to any one of claims 1 to 8, wherein the process of inversely converting the vehicle information after conversion and writing the vehicle information before conversion into the volatile memory is performed in a sequence at the start of a trip.

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