JP2018178838A - Vehicle control device - Google Patents

Abstract

A control device of a vehicle capable of permitting idling stop control even when the state of charge is unknown.
An ECU (5) is charged by an internal combustion engine (1) as a driving power source for traveling, an alternator (2) capable of generating electric power by rotation of the internal combustion engine (1), a starter (3) for starting the internal combustion engine (1) , And a battery 4 for supplying power to the starter 3. The ECU 5 is configured to be able to execute idling stop control to temporarily stop the internal combustion engine 1 and charge control to adjust the generated voltage of the alternator 2, and the initial SOC of the battery 4 could not be estimated when the ignition is off. In this case, the charging control is prohibited and the idling stop control is permitted.
[Selected figure] Figure 1

Description

  The present invention relates to a control device of a vehicle.

  Conventionally, an internal combustion engine, which is a driving power source for traveling, an alternator capable of generating electricity by rotation of the internal combustion engine, a starter for starting the internal combustion engine, and a battery charged by the alternator and supplying power to the starter A vehicle is known (see, for example, Patent Document 1).

  Such a control device for a vehicle is configured to be capable of performing idling stop control for temporarily stopping the internal combustion engine. In this idling stop control, the internal combustion engine is automatically stopped when the idling stop start condition is satisfied, and the internal combustion engine is automatically restarted when the idling stop end condition is satisfied. By this, it is possible to improve the fuel consumption.

JP, 2015-220863, A

  Here, the control device of the vehicle permits idling stop control when the SOC (State of Charge: state of charge) of the battery is a predetermined value or more, and prohibits idling stop control when the SOC of the battery is less than a predetermined value. Is configured as. In addition, for example, the control device of the vehicle estimates the initial SOC before the ignition is turned on (during the ignition off), adds the change amount of the SOC to the initial SOC, and calculates the current SOC. It is configured.

  However, even if the ignition is turned off and charging / discharging of the battery is stopped, it may take some time to eliminate the influence of polarization, which may make it impossible to estimate the initial SOC. As described above, when the initial SOC can not be estimated, it is conceivable that the idling stop control is prohibited because the SOC becomes unknown.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a control device of a vehicle capable of permitting idling stop control even when the state of charge is unknown. It is to provide.

  The control apparatus for a vehicle according to the present invention is charged by an internal combustion engine which is a driving power source for traveling, a generator capable of generating electric power by rotation of the internal combustion engine, a starter for starting the internal combustion engine, and the generator. And a battery for supplying power to the vehicle. The control device of the vehicle is configured to be able to execute idling stop control for temporarily stopping the internal combustion engine and charge control for adjusting the generated voltage of the generator, and the charge state of the battery can not be estimated when the ignition is off. In this case, the charging control is prohibited and the idling stop control is permitted.

  With this configuration, the battery can be charged by the generator, so even if the state of charge is unknown, idling stop control can be permitted.

  According to the control device for a vehicle of the present invention, idling stop control can be permitted even when the state of charge is unknown.

1 shows a schematic configuration of a vehicle equipped with an ECU according to an embodiment of the present invention. FIG. 2 is a block diagram showing the ECU of FIG. 1; It is a flowchart for demonstrating control by ECU of this embodiment.

  Hereinafter, an embodiment of the present invention will be described based on the drawings.

  First, a vehicle 100 provided with an ECU 5 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the vehicle 100 includes an internal combustion engine 1, an alternator 2, a starter 3, a battery 4, and an ECU 5. The vehicle 100 is configured to travel by the driving force from the internal combustion engine 1.

-Internal combustion engine-
The internal combustion engine 1 is a driving power source for traveling, and is, for example, a multi-cylinder gasoline engine. The internal combustion engine 1 is configured to be able to control the operating state by the throttle opening (amount of intake air), the fuel injection amount, the ignition timing, and the like. An alternator 2 and a starter 3 are mechanically connected to an output shaft of the internal combustion engine 1.

-Alternator-
The alternator 2 is configured to be able to generate power by the rotation of the internal combustion engine 1. In this alternator 2, it is possible to adjust the amount of generated power by adjusting the generated voltage. The electric power generated by the alternator 2 is used to charge the battery 4 and drive the electric components of the vehicle 100. The alternator 2 is an example of the “generator” in the present invention.

-Starter-
The starter 3 is provided to start the internal combustion engine 1. The starter 3 is configured to be driven by the power supplied from the battery 4. That is, the starter 3 is configured to crank the internal combustion engine 1 by the power from the battery 4.

-Battery-
The battery 4 is configured to store electric power generated by the alternator 2 and to supply the stored electric power to electric components of the vehicle 100 such as the starter 3. That is, the alternator 2 and the starter 3 are electrically connected to the battery 4. The battery 4 is, for example, a lead storage battery with a rated voltage of 12V.

-ECU-
The ECU 5 is configured to control the vehicle 100. As shown in FIG. 2, the ECU 5 includes a CPU 51, a ROM 52, a RAM 53, a backup RAM 54, an input interface 55, and an output interface 56. The ECU 5 is an example of the "vehicle control device" in the present invention.

  The CPU 51 executes arithmetic processing based on various control programs and maps stored in the ROM 52. The ROM 52 stores various control programs, maps referred to when the various control programs are executed, and the like. The RAM 53 is a memory for temporarily storing the calculation result by the CPU 51, the detection result of each sensor, and the like. The backup RAM 54 is a non-volatile memory for storing data to be stored when the ignition is turned off.

  Connected to the input interface 55 are a crank position sensor 61, an accelerator opening sensor 62, a throttle opening sensor 63, a vehicle speed sensor 64, a brake pedal sensor 65, a voltage sensor 66, a current sensor 67, a temperature sensor 68, an ignition switch 69, etc. It is done.

  The crank position sensor 61 is provided to calculate the rotational speed (angular velocity) of the internal combustion engine 1. The accelerator opening sensor 62 is provided to detect the depression amount of the accelerator pedal (accelerator opening). The throttle opening degree sensor 63 is provided to detect the throttle opening degree of the throttle valve. The vehicle speed sensor 64 is provided to calculate the vehicle speed of the vehicle 100. The brake pedal sensor 65 is provided to detect the presence or absence of depression of the brake pedal. The voltage sensor 66 is provided to detect the voltage of the battery 4. The current sensor 67 is provided to detect the charge / discharge current of the battery 4. The temperature sensor 68 is provided to detect the temperature of the battery 4. An ignition switch 69 is provided to switch on and off of the ignition.

  An injector 11, an igniter 12, a throttle motor 13, an alternator 2 and a starter 3 are connected to the output interface 56. The injector 11 is a fuel injection valve, and can adjust the fuel injection amount. The igniter 12 is provided to adjust the ignition timing by the spark plug. The throttle motor 13 is provided to adjust the throttle opening of the throttle valve.

  Then, the ECU 5 is configured to be able to control the operating state of the internal combustion engine 1 by controlling the throttle opening degree, the fuel injection amount, the ignition timing and the like based on the detection results of the respective sensors and the like.

  Here, the ECU 5 is configured to be capable of executing idling stop control for temporarily stopping the internal combustion engine 1. In this idling stop control, the internal combustion engine 1 is automatically stopped when the idling stop start condition is satisfied, and the internal combustion engine 1 is automatically restarted when the idling stop end condition is satisfied. By this, it is possible to improve the fuel consumption.

  In the ECU 5, for example, when the vehicle speed is equal to or less than the predetermined value and the brake pedal is depressed, it is determined that the idling stop start condition is satisfied. Further, for example, when the depression of the brake pedal is released after the idling stop start condition is satisfied, the ECU 5 determines that the idling stop end condition is satisfied.

  Further, the ECU 5 is configured to be able to execute charge control for adjusting the generated voltage of the alternator 2. In this charge control, the generated voltage is adjusted such that the SOC (State of Charge) of the battery 4 falls within a predetermined operation range. Further, in the charge control, the generated voltage of the alternator 2 is adjusted according to the traveling state of the vehicle 100. For example, at the time of constant speed or acceleration, electric power is mainly supplied from the battery 4 to the electric components of the vehicle 100 to suppress power generation by the alternator 2 to improve fuel efficiency, and at the time of deceleration braking. The battery 4 is charged by the regenerated electric power generated. That is, while reducing the power generation load when the internal combustion engine 1 is driven to improve the fuel efficiency, the battery 4 is charged by regenerative power generation when the internal combustion engine 1 is driven.

  Furthermore, the ECU 5 is configured to be capable of switching between permission and prohibition of idling stop control and charge control. The ECU 5 is configured, for example, to permit idling stop control and charge control when the SOC of the battery 4 is equal to or greater than a predetermined value, and to prohibit idling stop control and charge control when the SOC of the battery 4 is less than a predetermined value. It is done. In addition, when charge control is prohibited, the generated voltage of the alternator 2 is set to a predetermined value. This predetermined value is, for example, a constant value preset so that battery 4 is fully charged. Therefore, when the SOC of the battery 4 is less than the predetermined value, idling stop control and charge control for improving fuel consumption are prohibited, and charging of the battery 4 is performed with priority. That is, this predetermined value is, for example, a value set in advance, and is a threshold value for determining whether it is necessary to give priority to charging of battery 4 over fuel efficiency improvement.

  Further, the ECU 5 is configured to calculate the SOC of the battery 4. Specifically, the initial SOC is estimated before the ignition is turned on (during ignition off), and the amount of change in SOC is added to the initial SOC to calculate the current SOC. The initial SOC regards the OCV (Open Circuit Voltage) of the battery 4 as the OCV (Open Circuit Voltage) of the battery 4 when the voltage of the battery 4 at ignition off (battery voltage in the state where the influence of polarization is eliminated) is calculated. Calculated based on the OCV-SOC map showing the relationship with That is, the OCV-SOC map is stored in the ROM 52 of the ECU 5, and the initial SOC is derived from the voltage of the battery 4 (detection result of the voltage sensor 66) when the ignition is off using the OCV-SOC map. The change amount of the SOC is calculated based on the integrated value of the charge and discharge current of the battery 4.

  Here, even if the ignition is turned off and charging / discharging of the battery 4 is stopped, it takes time to eliminate the influence of polarization, which may make it impossible to estimate the initial SOC. For example, after the ignition is turned off, when a predetermined time has elapsed while the voltage of the battery 4 is stable, it can be determined that the influence of the polarization is eliminated, so the initial SOC using the voltage of the battery 4 at that time. However, if the ignition is turned on before the predetermined time has elapsed while the voltage of the battery 4 is stable, the initial SOC can not be estimated. Therefore, in the present embodiment, when the initial SOC can not be estimated, the ECU 5 is configured to prohibit the charging control and allow the idling stop control.

-Control by ECU-
Next, control by the ECU 5 of the present embodiment will be described with reference to FIG. The following flow is repeated at predetermined time intervals. Also, the following steps are executed by the ECU 5.

  First, in step S1 of FIG. 3, it is determined whether the ignition is turned on. For example, when the ignition switch 69 is turned on, it is determined that the ignition is turned on. When it is determined that the ignition is turned on, the process proceeds to step S2. On the other hand, if it is determined that the ignition is not turned on (if ignition off is continued), the process proceeds to step S6.

  Next, in step S2, it is determined whether the initial SOC can be estimated (in step S6 described later) while the ignition is off. Then, when it is determined that the initial SOC can be estimated, the process proceeds to step S3. On the other hand, if it is determined that the initial SOC can not be estimated, the SOC is unknown, and thus the process proceeds to step S7.

  Next, in step S3, the current SOC is estimated by adding the amount of change in SOC to the initial SOC. The amount of change in SOC is calculated based on the integrated value of the charge / discharge current of battery 4 detected by current sensor 67.

  Next, in step S4, permission and prohibition of idling stop control and charge control are determined based on the current SOC. For example, idling stop control and charge control are permitted when the current SOC is equal to or more than a predetermined value, and idling stop control and charge control are prohibited when the current SOC is less than the predetermined value.

  When the idling stop control is permitted, the internal combustion engine 1 is automatically stopped when the idling stop start condition is satisfied, and the internal combustion engine 1 is automatically restarted when the idling stop end condition is satisfied. Further, when the charge control is permitted, the generated voltage of the alternator 2 is adjusted according to the current SOC, the traveling state of the vehicle 100, and the like.

  When the idling stop control and the charge control are prohibited, the internal combustion engine 1 is not automatically stopped, and the generated voltage of the alternator 2 is set to a predetermined value. This predetermined value is, for example, a constant value preset so that battery 4 is fully charged. Therefore, the power generated by the alternator 2 charges the battery 4 and drives the electric components of the vehicle 100.

  Next, in step S5, it is determined whether the ignition is turned off. For example, when the ignition switch 69 is turned off, it is determined that the ignition is turned off. Then, when it is determined that the ignition is not turned off (when the ignition on is continued), the process returns to step S3. On the other hand, if it is determined that the ignition is turned off, the process proceeds to step S6.

  Next, in step S6, the initial SOC is estimated. For example, when a predetermined time has elapsed while the voltage of the battery 4 is stable after the ignition is turned off, the initial SOC is estimated based on the voltage of the battery 4 at that time, and the process proceeds to return. On the other hand, if the predetermined time has not elapsed while the voltage of the battery 4 is stable after the ignition is turned off, it is determined that estimation of the initial SOC can not be performed, and the process proceeds to return. The state in which the voltage of the battery 4 is stable is a state in which the voltage of the battery 4 is within the predetermined range. The predetermined time is, for example, a time set in advance to determine whether or not the influence of polarization is eliminated.

  When the initial SOC can not be estimated (step S2: No), charge control is prohibited in step S7. Therefore, the generated voltage of the alternator 2 is set to a predetermined value. Therefore, the power generated by the alternator 2 charges the battery 4 and drives the electric components of the vehicle 100. That is, if the internal combustion engine 1 is in operation, the battery 4 is not discharged.

  Next, in step S8, it is determined whether the voltage of the battery 4 is equal to or higher than a predetermined value. The predetermined value is, for example, a value set in advance, and is a threshold value for determining whether the idling stop control can be permitted. When it is determined that the voltage of battery 4 is equal to or higher than the predetermined value, battery capacity for driving starter 3 is secured in battery 4 when internal combustion engine 1 is restarted, so step S9. Move to On the other hand, when it is determined that the voltage of battery 4 is not equal to or higher than the predetermined value (when the voltage of battery 4 is less than the predetermined value), a battery for driving starter 3 when the internal combustion engine 1 is restarted. Since the capacity is not secured in the battery 4, the process moves to step S10.

  Then, in step S9, idling stop control is permitted. Therefore, the internal combustion engine 1 is automatically stopped when the idling stop start condition is satisfied, and the internal combustion engine 1 is automatically restarted when the idling stop end condition is satisfied. Note that when the internal combustion engine 1 is stopped, the alternator 2 does not generate power, and when the internal combustion engine 1 is restarted, power is supplied from the battery 4 to drive the starter 3. Thereafter, the process proceeds to step S11.

  Further, in step S10, idling stop control is prohibited. Therefore, the internal combustion engine 1 is not automatically stopped. Thereafter, the process proceeds to step S11.

  Next, in step S11, it is determined whether the ignition is turned off. Then, if it is determined that the ignition is not turned off (if the ignition on is continued), the process returns to step S7. On the other hand, if it is determined that the ignition is turned off, the process proceeds to step S6.

-Effect-
In the present embodiment, as described above, when the initial SOC can not be estimated when the ignition is off, the battery 4 can be charged by the alternator 2 by prohibiting the charge control and permitting the idling stop control. Therefore, the idling stop control can be permitted even when the SOC is unknown. Thereby, the deterioration of fuel consumption can be suppressed.

  Further, in the present embodiment, when the voltage of the battery 4 is equal to or higher than the predetermined value when the initial SOC can not be estimated when the ignition is off, idling stop control is permitted and the voltage of the battery 4 is less than the predetermined value. In this case, by prohibiting the idling stop control, the idling stop control can be permitted after securing the battery capacity for driving the starter 3 in the battery 4 when the internal combustion engine 1 is restarted.

-Other embodiment-
The embodiment disclosed this time is an example in all respects, and is not a basis for a limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-mentioned embodiment, and is defined based on the statement of a claim. Further, the technical scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

  For example, although the example in which the internal combustion engine 1 is a multi-cylinder gasoline engine is shown in the present embodiment, the present invention is not limited to this, and the internal combustion engine may be a diesel engine or the like.

  Moreover, although the example provided with the alternator 2 which functions as a generator was shown in this embodiment, it replaces with this and it may replace with an alternator and the motor generator which functions as a generator and an electric motor may be provided.

  Further, although the example in which the battery 4 is a lead storage battery is shown in the present embodiment, the present invention is not limited to this, and the battery may be a nickel hydrogen secondary battery or the like. Further, the lead storage battery and the nickel hydrogen secondary battery may be connected in parallel.

  Further, in the present embodiment, the ECU 5 may be configured by a plurality of ECUs.

  According to the present invention, an internal combustion engine as a driving power source for traveling, a generator capable of generating electricity by rotation of the internal combustion engine, a starter for starting the internal combustion engine, charging by the generator and supplying power to the starter The present invention is applicable to a control device of a vehicle that controls a vehicle including a battery.

1 Internal combustion engine 2 Alternator (generator)
3 Starter 4 Battery 5 ECU (Control Device of Vehicle)
100 vehicles

Claims (1)

An internal combustion engine as a driving power source for traveling, a generator capable of generating electricity by rotation of the internal combustion engine, a starter for starting the internal combustion engine, and charging by the generator while supplying power to the starter A control device of a vehicle applied to a vehicle including a battery, comprising:
It is configured to be able to execute idling stop control for temporarily stopping the internal combustion engine and charge control for adjusting the voltage generated by the generator.
A control apparatus for a vehicle, wherein the charging control is inhibited and the idling stop control is permitted when the charging state of the battery can not be estimated when an ignition is off.

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