JP6851743B2 - Jumping start judgment device - Google Patents

Description

The present invention relates to a jumping start determination device.

In recent years, IDS control has been adopted for vehicles using an engine as a drive source for the purpose of improving fuel efficiency and the like. In a vehicle adopting IDS control, for example, when the vehicle speed drops below a predetermined IDS start vehicle speed due to a driver's brake operation, the engine is automatically stopped (idling stop). After that, when the driver releases the brake operation, the engine is automatically restarted to return from the idling stop (IDS return).

Batteries deteriorate with their use. When the battery deteriorates, the terminal voltage (battery voltage) of the battery drops. If the IDS control is executed while the battery voltage is low, the voltage required for the starter that cranks the engine cannot be applied when the IDS is restored, and the engine may not be restarted. Therefore, in a vehicle in which IDS control is adopted, deterioration determination of the battery is performed when the engine is started, and if the battery is deteriorated, IDS control is prohibited.

For example, the so-called jump start (jump start), in which the engine is started by supplying power from an external power source (such as the battery of another vehicle) to the starter, is performed when the battery voltage is low due to deterioration of the battery. There are many. At a jump start, the engine hood is usually opened, an external power source is connected to the battery with a booster cable, and the start switch is turned on. Therefore, if the engine hood is opened even once while the ignition key switch is on, it can be estimated that a jumping start has occurred. Therefore, during the subsequent trip (until the ignition key switch is turned off), IDS control is performed. Is prohibited. The opening and closing of the engine hood can be detected by an engine hood switch that turns on / off according to the opening and closing of the engine hood.

Further, since the operating power of the starter is large, the battery voltage drops significantly during the operation of the starter. The greater the deterioration of the battery, the lower the minimum value of the battery voltage dropped during the operation of the starter. Therefore, when the battery voltage drops to a predetermined value or less, IDS control is prohibited during the subsequent trip.

Japanese Unexamined Patent Publication No. 2001-107768

However, if the battery is placed outside the space covered by the engine hood, for example, if the battery is placed directly under the front seats or under the luggage compartment at the rear of the vehicle, the engine hood has been opened. Therefore, it cannot be estimated that the jumping start has been performed, and the IDS control cannot be prohibited.

At the jump start, since the external power supply is connected to the battery, the battery voltage at the time of cranking does not drop below a predetermined value, so that IDS control is not prohibited based on the battery voltage at the time of cranking. ..

An object of the present invention is to provide a jumping start determination device capable of determining that a jumping start has been performed even if the battery is arranged in a space other than the space covered by the engine hood.

In order to achieve the above object, the jumping start determination device according to one aspect of the present invention is used in a vehicle equipped with an engine, a battery and a starter for cranking the engine, and is used by a power supplied from an external power source. It is a device that determines that a jumping start has been performed to start the engine by operating the engine, and is a change value acquisition means for acquiring a change value that changes according to the state of the battery due to the start of the engine when the engine is started. , The change value storage means for storing the change value acquired by the change value acquisition means, the change value stored in the change value storage means at the time of the previous engine start, and the change value acquired at the time of the current engine start. It includes a determination means for determining that the start of the engine this time is a jumping start when the difference from the change value is equal to or greater than a predetermined value.

When the engine is started, the power of the starter cranks the engine. For example, the terminal voltage of the battery (battery voltage) and the engine speed during cranking change according to the state of the battery. That is, the lower the battery voltage, the lower the minimum value of the battery voltage that has dropped with the start of the starter. Further, as the battery voltage is lower, the voltage applied from the battery to the starter (that is, the battery voltage) is lower, so that the rotation speed of the starter is lower and the rotation speed of the engine cranked by the power of the starter is lower.

When the engine is started, change values that change according to the state of the battery due to the start of the engine, such as the minimum value of the battery voltage at the start of the starter and the number of revolutions of the engine during cranking, are acquired. The change value is acquired every time the engine is started and stored in the change value storage means. At least the change value acquired at the time of the previous engine start is stored in the change value storage means. When a new change value is acquired, it is determined whether or not the difference between the change value acquired at the start of the current engine and the change value acquired at the start of the previous engine is equal to or greater than a predetermined value. .. Then, when the difference between the change values is equal to or greater than a predetermined value, it is determined that the engine start this time is a jumping start.

When the starter operates at the battery voltage and the engine is started both last time and this time, the difference between the change value acquired when the engine was started last time and the change value acquired when the engine was started this time (normal difference). ) Is small.

Last time, although the battery voltage was low, the starter operated at the battery voltage and the engine started, but this time the battery voltage is too low and the starter does not operate normally at the battery voltage and the engine starts. There are cases where a jumping start is performed because there was no such thing. At a jump start, an external power source is connected in parallel with the battery. Therefore, in the state of the battery at this time, the battery voltage becomes the same voltage as the output voltage of the external power supply, and the change value acquired at the time of starting the engine this time becomes a value corresponding to the output voltage of the external power supply. As a result, the change value acquired at the start of the engine this time greatly changes from the change value acquired at the start of the previous engine, and the difference between the change values becomes larger than the normal difference.

Therefore, when the difference between the change value acquired at the start of the engine this time and the change value acquired at the start of the previous engine is equal to or greater than a predetermined value, it can be determined that the jump start has been performed. As a result, even if the battery is arranged in a space other than the space covered by the engine hood, it is possible to accurately determine whether or not the jumping start has been performed.

The jumping start determination device according to another aspect of the present invention is used in an engine, a battery, a starter for cranking the engine, and a vehicle equipped with an electric load operated by electric current supplied from the battery, and is supplied from an external power source. It is a device that determines that a jumping start has been performed by operating the starter with the electric power to start the engine, and is a current value acquisition means for acquiring the current value flowing through the terminal of the battery and a predetermined time from the start of the engine. When the current value acquired by the current value acquisition means changes by a predetermined amount or more in a state where the vehicle continues to stop and the predetermined device included in the electric load is not operating before the lapse of time. , A determination means for determining that the engine start is a jumping start.

In a normal state where the battery is not deteriorated, if the vehicle continues to stop and certain equipment included in the electrical load (for example, equipment with relatively high power consumption) is not operating, it is specified from the start of the engine. Until the time elapses, the terminal voltage (battery voltage) of the battery does not drop significantly, and the alternator mounted on the vehicle does not charge the battery. Therefore, the value of the current flowing through the terminals of the battery does not change significantly from the start of the engine until a predetermined time elapses.

On the other hand, when a jump start is performed, the connection between the battery and the external power source is disconnected after the engine is started. When an external power source is connected to the battery, the battery is charged by the external power source, so that a relatively large charging current flows through the terminals of the battery. When the connection between the battery and the external power supply is disconnected, the charging current flowing through the battery terminal disappears, so that the current value flowing through the battery terminal decreases.

Therefore, before a predetermined time has elapsed from the start of the engine, the current value flowing through the terminal of the battery has decreased in a state where the vehicle continues to stop and the predetermined device included in the electric load is not operating. In this case, it can be determined that the jumping start has been performed. As a result, even if the battery is arranged in a space other than the space covered by the engine hood, it is possible to accurately determine whether or not the jumping start has been performed.

The jumping start determination device is an IDS control that stops the engine when a predetermined IDS start condition is satisfied and restarts the engine when a predetermined IDS return condition is satisfied during the stop. May be incorporated as a jumping start determination means in a vehicle control device including an IDS control means for executing the above.

In this case, the vehicle control device prohibits IDS control by the IDS control means when it is determined by the jumping start determination means that the jump start has been performed in addition to the IDS control means and the jumping start determination means. It is preferable to further provide means.

With this configuration, it is possible to prevent a problem that the engine cannot be restarted when the IDS is restored due to the deterioration of the battery.

Further, the jumping start determination device is used when the SOC (State Of Charge) of the battery is equal to or higher than the upper limit value of the charge control range and when the SOC is equal to or higher than the lower limit value and less than the upper limit value of the charge control range and the vehicle is not decelerating. In addition, when the power generation by the generator that generates power due to the rotation of the engine is stopped and the SOC is equal to or greater than the lower limit value and less than the upper limit value of the charge control range and the vehicle is decelerating, the charge control causes the generator to generate power. May be incorporated as a jumping start determination means in a vehicle control device including a charge control means for executing the above.

In this case, in addition to the charge control means and the jumping start determination means, the vehicle control device prohibits charge control by the charge control means when it is determined by the jump start determination means that the jump start has been performed. It is preferable to further provide means.

With this configuration, when the battery is deteriorated, it is possible to prevent the deterioration from further progressing due to the execution of the charge control. As a result, battery life can be extended.

According to the present invention, it is possible to accurately determine whether or not a jumping start has been performed even if the battery is arranged in a space other than the space covered by the engine hood.

It is a block diagram which shows the electrical structure of the main part of the vehicle which mounted the ECU which concerns on one Embodiment of this invention. It is a flowchart which shows the flow of a jumping start determination process.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Electrical configuration>
FIG. 1 is a block diagram showing an electrical configuration of a main part of a vehicle 1 on which an ECU 11 according to an embodiment of the present invention is mounted.

The vehicle 1 is an automobile whose drive source is the engine 2. Along with the engine 2, a starter 3 for cranking the engine 2 and an alternator 4 for generating electricity by the rotation of the engine 2 are provided. Further, the vehicle 1 is equipped with a battery 5. The battery 5 is, for example, a lead battery having a nominal voltage of 12 V.

When the engine 2 is started, a voltage is applied to the starter 3 from the battery 5 via the power supply line 6. A flywheel is held on the crankshaft of the engine 2. When a voltage is applied to the starter 3, the plunger of the starter 3 moves and the starter gear of the starter 3 meshes with the flywheel of the engine 2. Further, the relay built in the starter 3 is turned on, the current supplied from the battery 5 to the starter 3 increases, a large torque is input from the starter 3 to the engine 2, and the engine 2 is cranked by the torque. To torque. The engine 2 is started by sparking the spark plug of the engine 2 while the engine 2 is cranked.

Further, the voltage of the battery 5 is applied to the electric load 7 of the wiper motor, the headlight, the air conditioner, the audio device, and the like mounted on the vehicle 1.

The alternator (ALT) 4 includes a rotor, a stator, and an IC regulator. The rotor rotates with the rotation of the crankshaft of the engine 2. The rotor is provided with a field coil (rotor coil). By supplying a field current (exciting current) from the IC regulator to the field coil of the rotating rotor, a three-phase alternating current due to electromagnetic induction flows through the stator coil provided in the stator. The three-phase alternating current is rectified to a DC voltage by a rectifier. The alternator 4 outputs DC power as generated power, and the generated power is supplied to the battery 5 via the power supply line 6 to charge the battery 5.

Further, the vehicle 1 is provided with, for example, a plurality of ECUs (Electronic Control Units). The plurality of ECUs include the ECU 11 described below. Each ECU has a similar hardware configuration, and is connected so that bidirectional communication can be performed by a CAN (Controller Area Network) communication protocol.

The ECU 11 is provided with a CPU 12 and a memory 13 (ROM, RAM, etc.). A current sensor 14 provided in connection with the negative terminal of the battery 5 is connected to the ECU 11. As the current sensor 14, one that can distinguish and detect the charging current flowing through the negative terminal of the battery 5 and the discharging current flowing through the negative terminal of the battery 5 is adopted. Further, the terminal voltage (battery voltage) of the battery 5 is input to the ECU 11. Further, although not shown, the ECU 11 has an accelerator sensor that outputs a detection signal according to the operation amount of the accelerator pedal, and an engine rotation speed sensor that outputs a pulse signal synchronized with the rotation of the crank shaft of the engine 2 as a detection signal. , Various sensors such as a throttle opening sensor that outputs a detection signal according to the opening degree (throttle opening degree) of the electronic throttle valve of the engine 2 are connected.

The ECU 11 uses the electronic throttle valve of the engine 2 to start, stop, adjust the output, etc. of the engine 2 based on the information acquired from the detection signals of various sensors and / or various information input from other ECUs. It controls the injector, spark plug, starter 3, and so on. Further, the ECU 11 calculates the remaining battery level, which is the remaining charge of the battery 5, and controls the power generation by the alternator 4 based on the remaining battery level. Further, when the remaining battery level is calculated by the ECU 11, the calculated remaining battery level is updated and stored in the memory 13.

In the vehicle 1, IDS control (idling stop control) and charge control (charge / discharge control) can be executed by the ECU 11.

<IDS control>
IDS control is a technique for improving fuel efficiency by suppressing idling of the engine 2. In the IDS control, when the brake pedal is operated (depressed) while the vehicle 1 is traveling, it is determined whether or not a predetermined IDS start condition is satisfied. The IDS start condition is, for example, a condition that the vehicle speed is equal to or less than a predetermined idling stop implementation vehicle speed (for example, 10 km / h) and the brake pedal is operated for a certain period of time or longer. While the brake pedal is being operated, it is determined at regular intervals whether or not the IDS start condition is satisfied. Then, when the IDS start condition is satisfied, the engine 2 is stopped (idling stop). After the start of the idling stop, it is determined at a fixed cycle whether or not the predetermined IDS return condition is satisfied. The IDS return condition is, for example, a condition that the operation of the brake pedal is released during the idling stop (the driver's foot is released from the brake pedal). When the IDS return condition is satisfied, the starter 3 is operated and the engine 2 is restarted.

<Charge control>
Charge control is a technique for improving fuel efficiency by suppressing power generation by the alternator 4. In the charge control, the SOC (State Of Charge), which is the ratio of the remaining battery level stored in the memory 13 to the charge capacity (full charge amount) of the battery 5, is calculated. Then, when the SOC is equal to or higher than the upper limit value of the charge control range, the power generation by the alternator 4 is stopped. When the SOC is equal to or more than the lower limit value of the charge control range and less than the upper limit value, it is determined whether or not the vehicle 1 is decelerating, and the power generation of the alternator 4 is controlled according to the determination result. That is, when the vehicle 1 is not decelerating, the alternator 4 stops the power generation, and when the vehicle 1 is decelerating, the alternator 4 generates the power.

<Jumping start judgment processing>
FIG. 2 is a flowchart showing the flow of the jumping start determination process.

In the vehicle 1, every time the engine 2 is started (including restarting by IDS control), the ECU 11 executes a jumping start determination process.

In the jumping start determination process, first, it is determined whether or not the jumping start determination flag provided in the RAM of the memory 13 is reset to 0 (step S11). The jumping start determination flag is reset to 0 when the ignition is turned on (start switch is turned on), and when 1 is set, the jumping start determination flag is not reset to 0 during the ignition on (during trip).

When 1 is set in the jumping start determination flag (NO in step S11), steps S12 to S16 described below are not executed, and the jumping start determination process ends.

When the jumping start determination flag is reset to 0 (YES in step S11), the minimum value of the battery voltage acquired at the time of starting the engine 2 last time and the minimum value of the battery voltage acquired at the time of starting the engine 2 this time A difference (hereinafter, simply referred to as “difference of the lowest value of the battery voltage”) is obtained, and it is determined whether or not the difference is equal to or greater than a predetermined first determination value (step S12).

When the engine 2 is started, a voltage is applied from the battery 5 to the starter 3, the relay built in the starter 3 is turned on, and when the current supplied from the battery 5 to the starter 3 increases, the battery voltage is increased at that moment. It drops significantly. Every time the engine 2 is started, the ECU 11 acquires the minimum value of the battery voltage lowered at the time of the start. Then, the minimum value of the acquired battery voltage is stored in the RAM of the memory 13.

When the difference between the minimum values of the battery voltage is less than the first determination value (NO in step S12), whether or not the amount of change in the current value acquired from the detection signal of the current sensor 14 is equal to or more than the predetermined second determination value. Is determined (step S13).

Specifically, each time the engine 2 is started, the current value is repeatedly acquired from the detection signal of the current sensor 14 from the start of the engine 2 until a predetermined time elapses, and the current value within the predetermined time is obtained. The amount of change in is required. Then, within the predetermined time, the vehicle 1 continues to stop, and a predetermined device included in the electric load 7, for example, a device having a relatively large power consumption such as a headlight or an air conditioner is operating. If not, it is determined whether or not the amount of change in the current value is equal to or greater than a predetermined second determination value.

When the amount of change in the current value is less than the second determination value (NO in step S13), the difference between the cranking rotation speed acquired when the engine 2 was started last time and the number of cranking times acquired when the engine 2 was started this time. (Hereinafter, simply referred to as "difference in cranking rotation speed") is obtained, and it is determined whether or not the difference is equal to or greater than a predetermined third determination value (step S14).

Every time the engine 2 is started, the ECU 11 acquires the rotation speed (cranking rotation speed) of the engine 2 at the time of cranking. Then, the minimum value of the acquired battery voltage is stored in the RAM of the memory 13.

When the difference in the cranking rotation speed is less than the third determination value (NO in step S14), the jumping start determination process is terminated.

When the difference between the lowest values of the battery voltage is equal to or greater than the first determination value (YES in step S12), when the amount of change in the current value is equal to or greater than the second determination value (YES in step S13), or the cranking rotation speed. If the difference is equal to or greater than the third determination value (YES in step S14), the jumping start determination flag is set to 1 (step S15), and the jumping start determination process is completed.

When the engine 2 is started, the engine 2 is cranked by the power of the starter 3. The battery voltage and the cranking rotation speed change according to the state of the battery 5. That is, the lower the battery voltage, the lower the minimum value of the battery voltage that has decreased with the start of the starter 3. Further, as the battery voltage is lower, the voltage applied from the battery 5 to the starter 3 (that is, the battery voltage) is lower, so that the rotation speed of the starter 3 is lower and the rotation speed of the engine 2 cranked by the power of the starter 3 is higher. It gets lower.

When the starter 3 operates at the battery voltage and the engine 2 starts both in the previous time and this time, the difference (normal difference) of the minimum value of the battery voltage is small.

Last time, although the battery voltage was low, the starter 3 operated at the battery voltage and the engine 2 started, but this time, the battery voltage was too low and the starter 3 did not operate normally at the battery voltage, so the engine Since 2 did not start, a jumping start may be performed. At the jump start, an external power source is connected in parallel to the battery 5. Therefore, in the state of the battery 5 in which the external power supply is connected in parallel, the battery voltage becomes the same voltage as the output voltage of the external power supply, and the minimum value of the battery voltage acquired at the start of the engine 2 this time is that of the external power supply. The value corresponds to the output voltage. As a result, the minimum value of the battery voltage acquired at the start of the engine 2 this time greatly changes from the minimum value of the battery voltage acquired at the start of the engine 2 last time, and the difference between the minimum values of the battery voltage is usually Is larger than the difference of.

Therefore, when the difference between the minimum values of the battery voltage is equal to or greater than the first determination value (YES in step S12), it can be determined that the jumping start has been performed. In this case, 1 is set in the jumping start determination flag indicating that the jumping start has been performed (step S15).

Further, when the starter 3 is operated by the battery voltage and the engine 2 is started both in the previous time and this time, the difference in the cranking rotation speed (normal difference) is small.

Last time, although the battery voltage was low, the starter 3 operated at the battery voltage and the engine 2 started, but this time, the battery voltage was too low and the starter 3 did not operate normally at the battery voltage, so the engine Since 2 did not start, a jumping start may be performed. At the jump start, an external power source is connected in parallel to the battery 5. Therefore, in the state of the battery 5 in which the external power supply is connected in parallel, the battery voltage becomes the same voltage as the output voltage of the external power supply, and the cranking rotation speed acquired at the start of the engine 2 this time is the output of the external power supply. The value corresponds to the voltage (increased from the previous start of the engine 2). As a result, the cranking rotation speed acquired at the start of the engine 2 this time greatly changes from the cranking rotation speed acquired at the start of the previous engine 2, and the difference in the cranking rotation speed is larger than the normal difference. Will also grow.

Therefore, when the difference in the cranking rotation speed is equal to or greater than the third determination value (YES in step S14), it can be determined that the jumping start has been performed. In this case, 1 is set in the jumping start determination flag (step S15).

Further, in a normal state in which the battery 5 is not deteriorated, if the vehicle 1 continues to stop and the predetermined device included in the electric load 7 is not operating, until a predetermined time elapses from the start of the engine 2. During that time, the terminal voltage (battery voltage) of the battery 5 does not drop significantly, and the battery 5 is not charged by the alternator mounted on the vehicle. Therefore, the current value flowing through the terminals of the battery 5 does not change significantly from the start of the engine 2 until a predetermined time elapses.

On the other hand, when a jumping start is performed, the connection between the battery 5 and the external power source is released after the engine 2 is started. When an external power source is connected to the battery 5, the battery 5 is charged by the external power source, so that a relatively large charging current flows through the terminals of the battery 5. When the connection between the battery 5 and the external power source is disconnected, the charging current flowing through the terminal of the battery 5 disappears, so that the current value flowing through the terminal of the battery 5 decreases.

Therefore, the current value flowing through the terminal of the battery 5 is equal to or higher than the second determination value before the predetermined time elapses from the start of the engine 2 and the vehicle continues to stop and the electric load 7 is not operating. If it changes (YES in step S13), it can be determined that the jumping start has been performed. In this case, 1 is set in the jumping start determination flag (step S15).

When 1 is set in the jumping start determination flag, the above-mentioned IDS control and charge control are prohibited.

<Effect>
As described above, in the jumping start determination process, it is possible to accurately determine whether or not the jumping start has been performed even if the battery 5 is arranged in a space other than the space covered by the engine hood.

Then, when a jumping start is performed, 1 is set in the jumping start determination flag, and IDS control and charging control are prohibited. As a result, it is possible to prevent a problem that the engine 2 cannot be restarted when the IDS is restored because the battery 5 is deteriorated. Further, it is possible to suppress the progress of deterioration of the battery 5 by executing the charge control, and it is possible to extend the life of the battery 5.

<Modification example>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other embodiments.

For example, when push charging can be executed by the ECU 11, push charging may be prohibited in a state where 1 is set in the jumping start determination flag. Push charging is a technique for extending the life of the battery 5. Push charging is performed after the battery 5 has been fully charged. In order to determine whether or not the battery 5 has been fully charged, the current value of the charging current of the battery 5 is acquired based on the detection signal of the current sensor 14 during power generation by the alternator 4. Then, when the current value of the charging current drops to a predetermined full charge determination threshold value, it is determined that the battery 5 is in a fully charged state. Then, when the battery 5 is charged to a fully charged state, push-in charging is executed, and charging of the battery 5 with a constant charging current is continued until a predetermined push-in time elapses.

Further, in the IDS control, an ECU different from the ECU 11, for example, an IDS ECU for IDS control may determine whether or not the IDS start condition is satisfied. In this case, an engine stop request is transmitted from the IDSECU to the ECU 11 in response to the establishment of the IDS start condition, and the ECU 11 stops the engine 2 in response to the engine stop request. In addition, the IDSECU determines whether or not the IDS return condition is satisfied. Then, when the IDS return condition is satisfied, the IDSECU sends an engine restart request to the ECU 11, and the ECU 11 restarts the engine 2 in response to the engine restart request.

In addition, various design changes can be made to the above-mentioned configuration within the scope of the matters described in the claims.

1 Vehicle 2 Engine 3 Starter 5 Battery 7 Electric load 11 ECU (change value acquisition means, current value acquisition means, determination means)
13 Memory (change value storage means)

Claims (1)

The engine is used in a vehicle equipped with an engine, a battery, a starter for cranking the engine, and an electric load operated by the electric power supplied from the battery, and the starter is operated by the electric power supplied from an external power source to operate the engine. It is a device that determines that a jumping start has been performed.
A change value acquisition means for acquiring a change value that changes according to the state of the battery due to the start of the engine when the engine is started.
A change value storage means for storing the change value acquired by the change value acquisition means, and a change value storage means.
A current value acquisition means for acquiring the current value flowing through the terminal of the battery, and
Judgment as to whether or not the change value acquired at the start of the engine this time has increased by a predetermined value or more as compared with the change value acquired at the previous start of the engine stored in the change value storage means. And , before a predetermined time has elapsed from the start of the engine, the vehicle is continuously stopped and the predetermined device included in the electric load is not operating, and the current value acquisition means acquires the current value. When it is determined whether or not the current value to be generated has decreased by a predetermined amount or more and it is determined that the change value has increased by a predetermined value or more, or when it is determined that the current value has decreased by a predetermined amount or more , this time. A jumping start determination device including a determination unit for determining that the engine start is a jumping start.

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