JP7823637B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device.

There is technology that performs predetermined control based on the internal temperature of a control device in a vehicle with an engine (see, for example, Patent Document 1).

International Publication No. 2011/117969

It is conceivable that a diagnostic process for an abnormality in the control device is performed based on the internal temperature of the control device and the engine intake temperature. The control device may also control the charging of a battery installed in a vehicle. While the battery is charging, the internal temperature of the control device rises. If a diagnostic process is performed when the internal temperature of the control device is high, the accuracy of the abnormality diagnosis may decrease.

The present invention therefore aims to provide a vehicle control device that can charge the battery while minimizing a decrease in the accuracy of the control device's abnormality diagnosis.

The above objective can be achieved by a vehicle control device that is mounted on a vehicle having an engine and a battery and controls charging of the battery, the vehicle control device comprising: an internal temperature acquisition unit that acquires the internal temperature of the control device; an intake temperature acquisition unit that acquires the intake temperature of the engine; a diagnostic unit that switches the control device from OFF to ON when the ignition is off and performs a diagnostic process for an abnormality in the control device based on the internal temperature and the intake temperature; and a charging unit that switches the control device from OFF to ON when the ignition is off and performs a charging process for the battery, wherein if the internal temperature becomes equal to or higher than a threshold during the charging process but before the diagnostic process is performed, the charging unit turns off the control device and interrupts the charging process, the diagnostic unit performs the diagnostic process after the charging process is interrupted, and if the charging process is interrupted, the charging unit resumes the charging process after the diagnostic process is performed.

After the diagnostic process is completed, the charging unit may resume the charging process regardless of the diagnosis result of the diagnostic process.

The charging unit may resume the charging process if the diagnostic result of the diagnostic process is normal, and may not resume the charging process if the diagnostic result of the diagnostic process is abnormal.

The vehicle may have a motor as a driving power source, a motor control device that controls the motor, and a battery control device that controls the battery, and the control device may control the engine and the motor control device, and may perform the charging process by controlling the battery control device.

The present invention provides a vehicle control device that can charge a battery while minimizing a decrease in the accuracy of the control device's abnormality diagnosis.

FIG. 1 is a schematic diagram of a hybrid vehicle. 10 is a flowchart illustrating charging control. 10 is a flowchart illustrating diagnostic charging resumption control. 10 is a timing chart illustrating charging control and diagnostic charging resumption control. 10 is a flowchart of a modified example of diagnostic charging resumption control. 10 is a timing chart of a modified example of charging control and diagnostic charging resumption control.

[General configuration of hybrid vehicle]
FIG. 1 is a schematic diagram of a hybrid vehicle 1. The hybrid vehicle 1 is a plug-in hybrid vehicle that can charge a battery 40 using an external power source (hereinafter referred to as external charging). The hybrid vehicle 1 includes an engine 10, a motor 20, drive wheels 30, a battery 40, a DC-DC converter 45, an auxiliary battery 50, accessories 55, a charger 60, and a plug 65. The engine 10 and the motor 20 function as a driving power source. Driving power generated by the engine 10 and the motor 20 is transmitted to the drive wheels 30 to propel the hybrid vehicle 1. The engine 10 is a gasoline engine, but may also be a diesel engine.

The motor 20 is powered by electricity supplied from the battery 40. The motor 20 generates driving force for the vehicle in response to the power supplied from the battery 40. The motor 20 generates electricity using power from the engine 10 and drive wheels 30. The electricity generated by the motor 20 is charged into the battery 40. As mentioned above, the battery 40 can be externally charged via the charger 60 and plug 65.

The auxiliary battery 50 has a lower voltage than the battery 40. The auxiliary battery 50 supplies power to the auxiliary device 55. The auxiliary battery 50 is connected to the battery 40 via a DC-DC converter 45. By controlling the DC-DC converter 45, the auxiliary battery 50 can be charged using power from the battery 40 (hereinafter referred to as pumping charging). The auxiliary device 55 is, for example, an air conditioning device or a power steering device installed in the hybrid vehicle 1.

The hybrid vehicle 1 is equipped with an integrated ECU (Electronic Control Unit) 70, a motor ECU 72, a battery ECU 74, and a power supply ECU 76. The motor ECU 72 controls the operation of the motor 20. The battery ECU 74 controls the charging and discharging of the battery 40 and the DCDC converter 45. The power supply ECU 76 controls the charger 60. The integrated ECU 70 controls the operation of the engine 10 and also controls the motor ECU 72, battery ECU 74, and power supply ECU 76. These ECUs are electronic control units equipped with arithmetic processing circuits that perform various types of arithmetic processing and memory that stores control programs and data. The integrated ECU 70 is an example of a control device for the hybrid vehicle 1. The integrated ECU 70 functionally implements the internal temperature acquisition unit, intake air temperature acquisition unit, diagnosis unit, and charging unit, which will be described below.

Sensor group S3 is connected to the integrated ECU 70. Sensor group S3 includes, for example, a vehicle speed sensor, an accelerator opening sensor, a brake opening sensor, a motor rotation speed sensor, a crank angle sensor, a shift position sensor, a coolant temperature sensor, and an SOC (State Of Charge) sensor.

The integrated ECU 70 controls the operation of the engine 10 based on the detection values of the above sensors. In other words, the integrated ECU 70 has the functions of an engine ECU. The integrated ECU 70 also outputs operation commands for the motor 20 to the motor ECU 72 based on the detection values of these sensors. The motor ECU 72 controls the operation of the motor 20 in accordance with the operation commands from the integrated ECU 70. The motor ECU 72 is an example of a motor control device. The integrated ECU 70 also outputs operation commands for the battery 40 and auxiliary battery 50 to the battery ECU 74 based on the detection values of these sensors. The battery ECU 74 controls the battery 40 and auxiliary battery 50 in accordance with the operation commands from the integrated ECU 70.

As described above, the integrated ECU 70 has the functions of an engine ECU and the functions of controlling the motor ECU 72 and battery ECU 74. For example, compared to a case where an engine ECU, motor ECU 72, battery ECU 74, and an ECU that controls these are provided separately, the integrated ECU 70, as in this embodiment, has the functions of an engine ECU, thereby reducing the number of ECUs. This reduces costs.

The ignition switch S1 is connected to the power supply ECU 76. When the ignition switch S1 is switched from off to on, the power supply ECU 76 outputs an ignition signal to the integrated ECU 70, which turns on the integrated ECU 70. The integrated ECU 70 then turns on the motor ECU 72 and battery ECU 74. With the ignition on, the integrated ECU 70 controls the operation of the engine 10 and also controls the motor ECU 72 and battery ECU 74. When the ignition switch S1 is switched from on to off, the power supply ECU 76 issues a command to the integrated ECU 70, which then turns off the motor ECU 72 and battery ECU 74 and the integrated ECU 70 itself.

The intake air temperature sensor S2 detects the temperature of the intake air introduced into the engine 10. The intake air temperature sensor S2 is connected to the integrated ECU 70. The integrated ECU 70 obtains the intake air temperature based on the detection value of the intake air temperature sensor S2.

The internal temperature sensor S7 detects the internal temperature of the integrated ECU 70. The internal temperature sensor S7 is connected to the integrated ECU 70. The integrated ECU 70 acquires the internal temperature of the integrated ECU 70 based on the detection value of the internal temperature sensor S7. The integrated ECU 70 comprises a housing and a circuit board housed within the housing. The internal temperature sensor S7 is disposed within this housing and electrically connected to the circuit board.

The integrated ECU 70 is equipped with a soak timer T7. The soak timer T7 has a counter for measuring the elapsed time after the ignition is turned off. The soak timer T7 is powered by a backup power supply provided within the integrated ECU 70. Therefore, the soak timer T7 continues to measure the elapsed time even when the integrated ECU 70 is turned off.

When the plug 65 is connected to an external power source with the ignition off, the power supply ECU 76 turns on the integrated ECU 70, which turns on the battery ECU 74. The integrated ECU 70 issues a command to the battery ECU 74 to perform a charging process for externally charging the battery 40. Furthermore, after a predetermined time has elapsed with the ignition off, the power supply ECU 76 turns on the integrated ECU 70, which turns on the battery ECU 74. In this case, the integrated ECU 70 issues a command to the battery ECU 74 to control the DCDC converter 45, which performs a charging process for pumping and charging the auxiliary battery 50. In this way, the integrated ECU 70 controls the charging of the battery 40 and the auxiliary battery 50.

After a predetermined time has elapsed with the ignition off, the integrated ECU 70 is switched from off to on, and a diagnostic process for an abnormality in the integrated ECU 70 is performed. The diagnostic process is performed with the integrated ECU 70 on with the ignition off and based on the detection value of the internal temperature sensor S7. Specifically, if the difference between the intake air temperature and the internal temperature of the integrated ECU 70 based on the detection values of the intake air temperature sensor S2 and the internal temperature sensor S7 is less than a predetermined temperature, a provisional diagnosis of normality is made. If the difference is equal to or greater than the predetermined temperature, a provisional diagnosis of abnormality is made. The diagnostic process is performed three times with the ignition off, with a predetermined time interval between each provisional diagnosis. During each provisional diagnosis, the integrated ECU 70 is switched from off to on. Therefore, the integrated ECU 70 is switched from off to on three times with the ignition off. For example, if a provisional diagnosis of normality is made three times, the integrated ECU 70 is officially diagnosed as normal. If a provisional diagnosis of abnormality is made three times in a row, the integrated ECU 70 is officially diagnosed as abnormal. If at least one of the three tests results in a provisional diagnosis of an abnormality, a full diagnosis will not be performed. The execution times (hereinafter referred to as "diagnosis times") of each of the three provisional diagnoses performed after the ignition is turned off are preset. The diagnostic process is an example of processing performed by the diagnostic unit.

[Charging control, diagnostic charging restart control]
Fig. 2 is a flowchart illustrating charging control. Fig. 3 is a flowchart illustrating diagnostic charging restart control. Fig. 4 is a timing chart illustrating charging control and diagnostic charging restart control. Fig. 4 shows the presence or absence of a charging request, the on/off state of the integrated ECU 70, the coolant temperature, the internal temperature of the integrated ECU 70, and the changes in intake air temperature. The coolant temperature is the temperature of the coolant for the engine 10.

First, charging control will be explained with reference to Figures 2 and 4. The power supply ECU 76 determines whether the ignition is off (step S1). If the answer is No in step S1, charging control ends.

If step S1 returns Yes (time t1), the coolant temperature begins to drop. The intake air temperature rises once the engine 10 is stopped, and then begins to drop. The integrated ECU 70 is de-energized when the ignition is turned off. Therefore, the internal temperature of the integrated ECU 70 also begins to drop. Also, if step S1 returns Yes, the integrated ECU 70 determines whether there is a charging request (step S2). If step S2 returns No, charging control ends.

If the answer is Yes in step S2 (time t2), the integrated ECU 70 switches from OFF to ON (step S3), and the integrated ECU 70 executes a charging process (step S4). The execution of the charging process increases the internal temperature of the integrated ECU 70. Note that the coolant temperature and intake air temperature decrease even while the charging process is being executed.

The integrated ECU 70 determines whether the internal temperature of the integrated ECU 70 is equal to or higher than a threshold value based on the detection value of the internal temperature sensor S7 (step S5). The threshold value is set to a normal value for the internal temperature of the integrated ECU 70 that increases during the charging process. Step S5 is an example of processing performed by the internal temperature acquisition unit and charging unit. If the answer is No in step S5, the integrated ECU 70 determines whether the charging process is complete (step S6). If the answer is No in step S6, step S4 is executed again. If the answer is Yes in step S6, the integrated ECU 70 is turned off (step S9).

If step S5 returns Yes (time t3), the integrated ECU 70 suspends the charging process (step S7), schedules a time for resuming the charging process (step S8), and turns off (step S9). The resumption time is set to a time a predetermined time has elapsed since the diagnostic process ends. In other words, the charging process resumes after the diagnostic process is completed. When the charging process is suspended, the integrated ECU 70 stores the suspension history in memory. When the integrated ECU 70 is turned off, the internal temperature of the integrated ECU 70 drops. Steps S7 and S8 are an example of processing performed by the charging unit.

Next, the diagnostic charging restart control will be described with reference to Figures 3 and 4. The power supply ECU 76 determines whether the ignition is off (step S11). If the answer is No in step S11, the diagnostic control ends. If the answer is Yes in step S11, the soak timer T7 determines whether the measured time is the diagnostic time (step S12). If the answer is Yes in step S12 (time t4), the integrated ECU 70 turns on (step S13) and executes diagnostic processing based on the detected values of the intake air temperature sensor S2 and the internal temperature sensor S7 (step S14). As described above, because the charging process is interrupted before the diagnostic processing is executed (time t3), the internal temperature of the integrated ECU 70 has decreased by the time the diagnostic processing is executed (time t4). This prevents a decrease in the accuracy of the abnormality diagnosis by the integrated ECU 70. Step S14 is an example of processing executed by the intake air temperature acquisition unit and the diagnostic unit.

Then, the integrated ECU 70 is switched off (step S15). After step S15, or if step S12 returns No, the soak timer T7 determines whether the measured time is the time to resume the charging process (step S16). If step S16 returns No, this diagnostic control ends. If this diagnostic control is started again and step S11 returns Yes, indicating that it is time to perform the diagnosis again (time t5, step S12 returns Yes), the integrated ECU 70 is turned on again, the diagnostic process is performed, and then the integrated ECU 70 is turned off (steps S13, S14, S15). The same applies at time t6.

When the restart time arrives (time t7, Yes in step S16), the integrated ECU 70 turns on (step S17) and determines whether there is a history of the charging process being interrupted (step S18). If Yes in step S18, the integrated ECU 70 restarts the charging process (step S19) and determines whether the charging process has been completed (step S20). If No in step S20, the process of step S19 is executed again. If No in step S18 or Yes in step S20, the integrated ECU 70 turns off (step S21). Step S19 is an example of processing executed by the charging unit. If Yes in step S20, the integrated ECU 70 deletes the interruption history from memory.

As described above, the charging process is interrupted before the diagnostic process is executed, and then the diagnostic process is executed. This reduces the impact of the internal temperature of the integrated ECU 70 during the charging process, allowing for accurate abnormality diagnosis of the integrated ECU 70. Furthermore, the charging process is resumed after the diagnostic process is completed, regardless of the diagnostic results. This ensures the effectiveness of charging.

[Modification]
Next, a modified example of the above-described control will be described. FIG. 5 is a flowchart of a modified example of the diagnostic charging restart control. FIG. 6 is a timing chart of a modified example of the charging control and the diagnostic charging restart control. FIG. 6 corresponds to FIG. 4. Note that in the charging control of this modified example, the reservation of the restart time of the charging process shown in FIG. 2 (step S8) is not executed. Other than this, the charging control of this modified example is the same as the charging control shown in FIG. 2. Therefore, in this modified example, the charging process is also interrupted before the diagnostic process is executed, and then the diagnostic process is executed. Below, the diagnostic charging restart control of this modified example will be described in detail.

If the answer is No in step S11 or S12, this control ends. If the answer is Yes in steps S11 and S12 and steps S13 and S14 are executed (time t4), the integrated ECU 70 determines whether the results of the provisional diagnosis are normal (step S15a). If the answer is Yes in step S15a, the integrated ECU 70 determines whether there is an interruption history (step S16a). If the answer is No in step S15a or S16a, the integrated ECU 70 is turned off (step S23a).

If the answers to steps S15a and S16a are Yes, the charging process is resumed (step S17a). That is, if the result of the provisional diagnosis is normal, the charging process is resumed without the integrated ECU 70 being switched off. Step S17a is an example of processing executed by the charging unit.

Next, the integrated ECU 70 determines whether the diagnosis time has arrived while the charging process is being performed (step S18a). If the answer is Yes in step S18a (time t5), the integrated ECU 70 executes the diagnosis process (step S19a). Next, the integrated ECU 70 determines whether the result of the provisional diagnosis is abnormal (step S20a). If the answer is No in step S18a or S20a, the integrated ECU 70 determines whether the charging process has been completed (step S21a). If the answer is No in step S21a, step S17a is executed again. That is, as long as the result of the provisional diagnosis is normal, the charging process continues (time t6). If the answer is Yes in step S21a, the integrated ECU 70 turns off (step S23a).

If the answer is Yes in step S20a, the integrated ECU 70 suspends the charging process (step S22a) and turns off (step S23a). In other words, if the provisional diagnosis result indicates an abnormality, the charging process is suspended. Step S22a is an example of processing executed by the charging unit.

As described above, the charging process is resumed when the diagnostic process is executed, allowing the charging process to be completed quickly. Furthermore, if the results of the provisional diagnosis indicate an abnormality, the charging process is not resumed or is interrupted, and the integrated ECU 70 is turned off. This prevents the integrated ECU 70 from overheating.

In the above diagnostic process, an example was described in which three provisional diagnoses were performed, but the number of diagnoses is not limited to this, and a diagnosis may be performed only once.

Although the present invention has been described in detail above with reference to specific embodiments, the present invention is not limited to these specific embodiments, and various modifications and variations are possible within the scope of the invention as set forth in the claims.

10 Engine 20 Motor 40 Battery 50 Auxiliary battery 70 Integrated ECU (control device, internal temperature acquisition unit, intake temperature acquisition unit, charging unit, diagnostic unit)
72 Motor ECU (Motor Control Unit)
74 Battery ECU (battery control device)
S2 Intake air temperature sensor S7 Internal temperature sensor

Claims (4)

A vehicle control device mounted on a vehicle having an engine and a battery, the vehicle control device controlling charging of the battery,
an internal temperature acquisition unit that acquires an internal temperature of the control device;
an intake temperature acquisition unit that acquires an intake temperature of the engine;
a diagnosis unit that switches the control device from off to on while the ignition is off and executes a diagnosis process for an abnormality of the control device based on the internal temperature and the intake air temperature;
a charging unit that switches the control device from off to on when the ignition is off to execute a charging process for the battery,
the charging unit turns off the control device and interrupts the charging process when the internal temperature becomes equal to or higher than a threshold value during the charging process and before the diagnostic process is executed;
the diagnostic unit executes the diagnostic process after the charging process is interrupted,
The vehicle control device, wherein, when the charging process is interrupted, the charging unit resumes the charging process after the diagnostic process is performed. The vehicle control device of claim 1, wherein the charging unit resumes the charging process after the diagnostic process is completed, regardless of the diagnosis result of the diagnostic process. The vehicle control device of claim 1, wherein the charging unit resumes the charging process if the diagnostic result of the diagnostic process is normal, and does not resume the charging process if the diagnostic result of the diagnostic process is abnormal. The vehicle includes a motor that is a driving power source, a motor control device that controls the motor, and a battery control device that controls the battery,
4. The vehicle control device according to claim 1, wherein the control device controls the engine and the motor control device, and controls the battery control device to execute the charging process.