JP2012013044A - Battery control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery control system capable of quickly determining generation of multifunction so as to be able to carry out any countermeasure so as not to generate the problem caused by the multifunction when the booster circuit is out of order.SOLUTION: The battery control system 1 has a battery 2 and the booster circuits 41a, 41b of the same, boosting observing circuits 42a 42b for detecting the voltage of the battery when boosting, and a battery voltage control section 74 driving the booster circuits 41a, 41b and boosting the voltage of the battery 2 when starting an engine 8. The battery voltage control section 74 drives the booster circuits after boosting with the starting of the engine 8 and when the boosting is not needed and determines the multifunction of the booster circuits 41a, 41b based on the voltage of the battery detected by the boosting observing circuits 42a, 42b when boosted.

Description

  The present invention relates to a battery control system.

  Cars are equipped with various devices such as navigation systems, air conditioners, lights, starters, and electronic control units thereof. Electric power necessary for these devices is provided by batteries mounted on the vehicles. In addition, a booster circuit is connected to the battery in order to prevent a voltage drop at the time of starting the engine (when the starter is activated), and thus resetting the microcomputer included in the device.

  In recent years, hybrid vehicles having two or more power generation sources such as an engine and a motor, and idle stop vehicles having a function of stopping engine idling when the vehicle is stopped have been actively developed. In these hybrid vehicles and idle stop vehicles, since the engine is temporarily stopped and restarted frequently, the frequency of the booster circuit is increased. Therefore, particularly in recent vehicles, it is important that the booster circuit operates normally.

  Patent Document 1 discloses a procedure for determining a failure of such a booster circuit. In the technique disclosed in Patent Document 1, the voltage of the battery when the booster circuit is operated is monitored, and when the voltage does not reach a predetermined voltage, it is determined that the booster circuit has failed.

JP-A-2-308935

  When the booster circuit actually breaks down, it is preferable to repair or replace it, but there are cases where it cannot be repaired or replaced promptly for some reason. In such a case, it is necessary to take some measures temporarily so that the original purpose of providing the booster circuit, that is, preventing the resetting of the microcomputer can be achieved even in a state where the booster circuit has failed. . More specifically, for example, in an idle stop vehicle, a measure such as reducing the number of times the starter operates by prohibiting idling from being stopped can be considered.

  On the other hand, in the technique disclosed in Patent Document 1, the determination of the failure of the booster circuit is performed when the starter is activated. For this reason, in the technique of Patent Document 1, when the booster circuit actually fails, it is known that the booster circuit has failed only when the booster circuit is operated to achieve its original purpose. Therefore, if the booster circuit is out of order, the above-mentioned measures cannot be taken, and as a result, there is a possibility that the microcomputer cannot be boosted when necessary and the microcomputer is reset.

  The present invention is a battery control system provided with a booster circuit, and in the event that the booster circuit fails, the failure is determined so that some measure can be taken so as not to cause a malfunction caused by this failure. It aims at providing the battery control system which can determine rapidly.

  The present invention relates to a battery (for example, a battery 2 to be described later), a booster circuit (for example, to a later-described booster circuit 41a, 41b), and boost monitoring means for detecting the voltage of the battery at the time of boosting (for example, to a later-described boost monitoring). Circuit 42a, 42b) and an internal combustion engine (for example, an engine 8 to be described later) at the time of starting (for example, when the engine 8 is started by an after-mentioned starter 5) to drive the booster circuit to boost the voltage of the battery A battery control system (for example, a battery control system 1 to be described later) provided with a time boosting unit (for example, a battery voltage control unit 74 of the ECU 7 to be described later) is provided. The battery control system drives the booster circuit after boosting by the startup booster and when boosting is not necessary (for example, between time t2 and t4 in FIG. 3 described later), 2, a post-startup failure determination unit that determines a failure of the booster circuit based on the voltage of the battery detected by the booster monitoring unit (for example, a battery voltage control unit 74 described later and S5 and S6 in FIG. 2) Means).

  In the present invention, the start-up voltage boosting means drives the booster circuit to boost the battery voltage when the internal combustion engine is started. Thus, it is possible to prevent a problem that the voltage of the battery is greatly reduced when the internal combustion engine is started and the microcomputer is reset. On the other hand, the post-startup failure judging means drives the booster circuit after the boosting by the boosting means at the start and when boosting by the boosting circuit is not necessary, and based on the battery voltage detected at the boosting The failure of the booster circuit is determined. In this way, the determination of the failure of the booster circuit is performed when boosting is not necessary for its original purpose, so that the booster circuit actually fails compared with the case where the failure is determined when boosting is necessary. It is possible to reduce the influence of malfunctions that occur in the event of failure. In other words, by determining the failure when there is no need for boosting by the booster circuit, if the booster circuit has actually failed, some measure is taken between the determination of the failure and the need for boosting Therefore, it is possible to prevent the occurrence of a problem that the microcomputer included in the load is reset.

  In this case, the battery control system, after completion of the start of the internal combustion engine, generates electric power by the driving force generated in the internal combustion engine, and charges the generated electric power to the battery (for example, ACG 6 described later), Power generation prohibiting means for prohibiting power generation by the generator (for example, battery voltage control unit 74 described later and execution of S4 and S9 in FIG. Means).

  When the generator generates electricity, the battery voltage fluctuates. Therefore, in the present invention, while the booster circuit is driven by the failure determination means after starting and the voltage of the battery is boosted to determine the failure of the booster circuit, power generation by the generator is prohibited. Thereby, the determination accuracy of the failure of the booster circuit can be improved.

  In this case, the battery control system automatically stops the internal combustion engine in response to the establishment of a stop condition, and automatically stops and restarts the internal combustion engine that has been stopped in response to the establishment of a return condition. (For example, an automatic stop / start control unit 712, which will be described later) and an automatic prohibiting of stopping the internal combustion engine by the automatic stop start means when the post-startup failure determination means determines that the booster circuit has failed. It is preferable to further include a stop prohibiting unit (for example, a battery voltage control unit 74 described later and a unit related to the execution of S7 in FIG. 2).

  In a battery control system provided with an automatic stop starting means for temporarily stopping an internal combustion engine in response to establishment of a stop condition and restarting the internal combustion engine that has been temporarily stopped in response to establishment of a return condition Whenever the temporarily stopped internal combustion engine is started again, it is necessary to drive the starter and boost the voltage of the battery by the starting boosting means. Therefore, in the present invention, when it is determined by the failure determination means after start that the booster circuit has failed, the stop of the internal combustion engine by the automatic stop start means is prohibited. As a result, the number of times the booster circuit is driven can be reduced, so that it is possible to prevent the microcomputer from being reset even when the booster circuit fails.

  In this case, when the internal combustion engine is started by the automatic stop / starting means, the battery control system detects the voltage detected by the boost monitoring means at the time of boosting when the voltage of the battery is boosted by the starting boosting means. The apparatus further includes a start-up failure determination unit (for example, a battery voltage control unit 74) that determines a failure of the booster circuit based on a voltage of the battery, and the automatic stop prohibiting unit is configured to Even when it is determined that a failure has occurred, it is preferable to prohibit the internal combustion engine from being stopped by the automatic stop starting means.

  In the present invention, when the internal combustion engine is started by the automatic stop starting means, when the voltage of the battery is boosted by the starting boosting means, the failure determination at starting is performed to determine the failure of the boosting circuit based on the voltage of the battery at the time of boosting. Means were provided. In addition to the post-startup failure determination means for determining the failure of the booster circuit after the start of the internal combustion engine is completed, the failure determination frequency of the booster circuit can be increased by providing the startup failure determination means as described above. . Further, when it is determined by the start-up failure determination means that the booster circuit has failed, the automatic stop start means is prohibited from stopping the internal combustion engine, and the number of times the booster circuit is driven is reduced. Therefore, it is possible to prevent the microcomputer from being reset even when the booster circuit fails.

  In this case, further provided is a normal stop starting means (for example, a normal stop / start control unit 711 described later) for stopping or starting the internal combustion engine based on a signal transmitted from an ignition switch (for example, an ignition switch 9 described later). The automatic stop prohibiting means prohibits the internal stop of the internal combustion engine by the automatic stop start means, and after the next start of the internal combustion engine by the normal stop start means, the post-startup failure determination means makes the boost circuit normal. When it is determined that there is, it is preferable to release the prohibition.

  When the stop of the internal combustion engine by the automatic stop / starting means is prohibited as described above, the number of times of driving the booster circuit is reduced, and the frequency of determining a failure is also reduced. Therefore, for example, if it is determined that the booster circuit has failed due to erroneous determination, it will continue to be erroneously determined that the booster circuit has failed for a long period of time. Therefore, in the present invention, the automatic stop prohibiting means prohibits the stop of the internal combustion engine by the automatic stop start means, and after the next start of the internal combustion engine by the normal stop start means triggered by the ignition switch, the post-start failure determination means When it is determined that the booster circuit is normal, this prohibition is removed. Thereby, erroneous determination over a long period can be prevented.

  In this case, it is preferable that the post-startup failure determination means boosts the voltage of the battery to a voltage higher than the maximum voltage when determining the failure of the booster circuit.

  In the present invention, the booster circuit is driven so that the voltage of the battery becomes higher than the maximum voltage, and a failure of the booster circuit is determined based on the voltage of the battery at the time of boosting. Can be prevented.

  In this case, it is preferable that the failure determination means after start-up drives the booster circuit when the voltage of the battery at the time of non-boosting is equal to or lower than a reference voltage, and determines a failure of the booster circuit.

  The post-startup failure determination means drives the booster circuit, and determines the failure of the booster circuit based on the voltage of the battery at the time of boosting. Therefore, if a failure is determined by the failure determination means after start-up in a state where the voltage of the battery is originally high, it may be erroneously determined to be normal. Therefore, in the present invention, the post-startup failure determination means drives the booster circuit when the battery voltage at the time of non-boosting is equal to or lower than the reference voltage, and determines the failure of the booster circuit. Thereby, the determination accuracy of the failure of the booster circuit can be further improved.

It is a figure which shows the structure of the battery control system for vehicles which concerns on one Embodiment of this invention. It is a flowchart which shows the procedure of the failure determination process after a start based on the said embodiment. It is a figure which shows the voltage waveform of the battery at the time of starting normally the engine which concerns on the said embodiment. It is a figure which shows the voltage waveform of the battery at the time of idle stop return which concerns on the said embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration of a battery control system 1 for a vehicle according to the present embodiment. The battery control system 1 includes a battery 2, a DC-DC converter 4 connected between the battery 2 and loads 3a and 3b, a starter 5 and an ACG 6 of an engine 8, and an electronic control unit (hereinafter referred to as an electronic control unit). , Referred to as “ECU”) 7.

  The DC-DC converter 4 boosts the voltage of the battery 2 and supplies a plurality of booster circuits 41a and 41b to the loads 3a and 3b, and boost monitoring for detecting the voltage of the battery 2 at the time of boosting by the booster circuits 41a and 41b. Circuits 42a and 42b. Further, a plurality of fuses 43a and 43b are provided between the battery 2 and the DC-DC converter 4 in order to protect the booster circuits 41a and 41b, the booster monitoring circuits 42a and 42b, and the loads 3a and 3b from overcurrent. It has been.

  The battery 2 includes, in addition to the loads 3a and 3b connected via the DC-DC converter 4 as described above, a starter 5 that generates power for starting the engine 8, and after the start of the engine 8 is completed, 8 is connected to an ACG 6 serving as a generator that generates electric power using the driving force generated at 8 and charges the battery 2 with the generated electric power.

  The ECU 7 includes an engine control unit 71 that starts or stops the engine 8, an ACG control unit 72 that controls the ACG 6, and a battery voltage control unit 74 that controls the voltage of the battery 2.

  The engine control unit 71 includes a normal stop / start control unit 711 that starts or stops the engine 8 based on a signal transmitted from an ignition switch 9 provided in a driver seat of a vehicle (not shown), and various types of vehicle operating states. An automatic stop / start control unit 712 that starts or stops the engine 8 based on the input of the operation parameter.

  The normal stop / start control unit 711 starts the engine 8 by driving the starter 5 with the electric power of the battery 2 when receiving a normal start command signal for instructing the engine 8 to start from the ignition switch 9. Further, the normal stop / start control unit 711 stops the engine 8 when receiving a normal stop command signal for instructing the engine 8 to stop from the ignition switch 9.

The automatic stop / start control unit 712 starts the engine 8 based on input of various operation parameters indicating the driving state of the vehicle during the period from when the engine 8 is started by the normal stop / start control unit 711 until the engine 8 is stopped. Stop or start. These operating parameters include vehicle speed, accelerator pedal opening, and the like.
More specifically, the automatic stop / start control unit 712 determines whether or not a predetermined stop condition is satisfied based on the input operation parameter, and responds to this when the stop condition is satisfied. The engine 8 is temporarily stopped.
Further, after temporarily stopping the engine 8 as described above, the automatic stop / start control unit 712 determines whether or not a predetermined return condition is satisfied based on the input operation parameter, and this return condition If the above is established, the engine 8 is started again by driving the starter 5 with the electric power of the battery 2 accordingly.

  As described above, in the present embodiment, the engine 8 can be stopped or started by the normal stop / start control unit 711 and the automatic stop / start control unit 712. Hereinafter, starting the engine 8 by the normal stop / start control unit 711 is referred to as normal start, and then stopping the engine 8 by the normal stop / start control unit 711 is referred to as normal stop. Stopping the engine 8 temporarily by the automatic stop / start control unit 712 is referred to as idle stop, and then starting the engine 8 again by the automatic stop / start control unit 712 is referred to as idle stop return.

  The ACG control unit 72 controls the ACG 6 as necessary after the engine 8 is started by the engine control unit 71 and generates power using the power generated by the engine 8. The electric power generated by the ACG 6 is supplied to the battery 2, for example.

The battery voltage control unit 74 controls the voltage of the battery 2 by driving the booster circuits 41 a and 41 b of the DC-DC converter 4.
When the engine 8 is started by the normal stop / start control unit 711 and the automatic stop / start control unit 712, if the starter 5 is driven by the power of the battery 2, the voltage of the battery 2 is temporarily greatly reduced, and the minimum hold described later There is a risk that the voltage will fall below the voltage and the microcomputer included in the loads 3a and 3b will be reset. In order to prevent such a reset, the battery voltage control unit 74 drives the booster circuits 41a and 41b in accordance with the drive of the starter 5 when the engine 8 is started by the stop / start control units 711 and 712. The voltage of the battery 2 is boosted to a predetermined starting boost voltage so as not to fall below the minimum holding voltage (see times t0 to t1 in FIG. 3 described later).
Further, the battery voltage control unit 74 appropriately boosts the voltage of the battery 2 according to the demands of the loads 3a and 3b after the start of the engine 8 in addition to the start of the engine 8 as described above (described later). (Refer to time t4 and after in FIG. 3).
As described above, when the voltage of the battery 2 needs to be boosted by the booster circuits 41a and 41b, the voltage of the battery 2 is boosted when the engine 8 is started and according to the demands of the loads 3a and 3b. There is a time to do.

  The battery voltage control unit 74 drives the booster circuits 41a and 41b to boost the voltage of the battery 2, and the booster circuit 41a is based on the voltage of the battery 2 detected by the boost monitoring circuits 42a and 42b at the time of boosting. , 41b is determined. In the battery voltage control unit 74, with regard to such a failure determination process for determining a failure of the booster circuits 41 a and 41 b, a failure determination process after start for determining a failure after the engine 8 is started and a failure at the time of starting the engine 8 are determined. It is possible to execute two types of failure determination processing at start-up.

  In the failure determination process after start-up, the booster circuits 41a and 41b are driven when the booster circuits 41a and 41b need not be boosted after the voltage of the battery 2 is boosted as described above at the normal start of the engine 8. The failure of the booster circuits 41a and 41b is determined based on the voltage of the battery 2 at the time of boosting.

  In the start-up failure determination process, when the engine 8 is returned to idle, the voltage of the battery 2 is boosted in accordance with the drive of the starter 5 as described above, and the battery 2 detected by the boost monitoring circuits 42a and 42b at the time of this boosting. The failure of the booster circuits 41a and 41b is determined based on the voltage of.

  Hereinafter, the after-startup failure determination process and the start-up failure determination process by the battery voltage control unit 74 will be described.

With reference to FIG. 2 and FIG. 3, the procedure of the post-startup failure determination process will be described.
FIG. 2 is a flowchart showing the procedure of the failure determination process after starting. This post-startup failure determination process is executed by the battery voltage control unit in response to the normal start of the engine.

In S1, it is determined whether or not the normal start of the engine has been completed, that is, whether or not the boosting of the battery accompanying the normal start of the engine has been completed. Here, only when it is determined that the engine has been started, the process proceeds to the next step S2.
In S2, it is determined whether power generation by ACG is not performed. Here, the process proceeds to the next step S3 only when it is determined that power generation by ACG is not being performed, and therefore it can be determined that the battery voltage is in a stable state.
In S3, it is determined whether or not the current battery voltage that is not boosted by the booster circuit is equal to or lower than the reference voltage. Here, only when it is determined that the current battery voltage is equal to or lower than the reference voltage, the process proceeds to the next step S4.

  In S4, the power generation prohibition flag FACG_NG indicating that power generation is prohibited is set to “1” so that power generation by ACG is not performed while determining the failure of the booster circuit in the next steps S5 to S8. set. While the power generation prohibition flag FACG_NG is set to “1”, power generation using ACG by the ACG control unit described above is prohibited.

  In S5, in order to determine the failure of the booster circuit, the booster circuit is driven to boost the voltage of the battery to a predetermined determination voltage. This determination voltage is set to a voltage higher than the maximum voltage of the battery at the time of non-boosting. In S6, it is determined whether or not the booster circuit is normal based on the battery voltage detected by the booster monitoring circuit at the time of boosting. More specifically, when the booster circuit is driven so that the battery voltage reaches the determination voltage, the booster circuit is normal when it can be determined that the actual battery voltage has sufficiently reached the determination voltage. Judge that there is.

  If the determination in S6 is NO and it is determined that the booster circuit has failed, the process proceeds to S7. In S7, the idle stop prohibition flag FIDLE_NG indicating that the idle stop is prohibited is set to “1” in order to reduce the opportunity to drive the booster circuit in response to the determination that the booster circuit has failed. Set and go to S9. While the idle stop prohibition flag FIDLE_NG is set to “1”, engine idle stop by the automatic stop / start control unit described above is prohibited.

  On the other hand, if the determination in S6 is YES and it is determined that the booster circuit is normal, the process proceeds to S8. In S8, in response to the determination that the booster circuit is normal, the above-described idle stop prohibition flag FIDLE_NG is reset to “0”, and the process proceeds to S9.

  Note that the idle stop prohibition flag FIDLE_NG set to “1” in S7 is retained after the next normal start of the engine. Therefore, for example, even when the idle stop prohibition flag FIDLE_NG is set to “1” during the execution of the current post-startup failure determination process, it is determined that the booster circuit is normal when the next post-startup failure determination process is executed. Then, the idle stop prohibition flag FIDLE_NG is reset to “0”, and thus the prohibition of idle stop is released.

  In S9, the ACG power generation prohibition flag FACG_NG is reset to “0” in order to permit power generation in response to the completion of the boost circuit failure determination, and the post-startup failure determination processing ends.

FIG. 3 is a diagram showing a voltage waveform of the battery when the engine is normally started. In FIG. 3, a broken line shows a voltage waveform of the battery when the booster circuit is not driven.
First, the engine is started normally in response to the operation of the ignition switch at time t0. That is, from time t0 to t1, the starter is driven by the battery power, and the booster circuit is driven to boost the voltage of the battery to the startup boost voltage. Here, as shown by the broken line in FIG. 3, if the voltage of the battery is not boosted at the start of the engine, the voltage of the battery drops significantly by driving the starter, which falls below the minimum holding voltage and is included in the load. There is a risk of resetting various microcomputers. On the other hand, according to the battery control system of the present embodiment, it is possible to prevent the battery voltage from falling below the minimum holding voltage by increasing the voltage at the start of the engine.

  Thereafter, in response to the completion of the normal start of the engine at time t1 (see S1), whether or not power generation by ACG is performed from time t1 to t2 (see S2), and the battery voltage is the reference voltage It is determined whether it is lower (see S3) or the like, and power generation by ACG is prohibited (see S4).

At times t2 to t3, the booster circuit is driven to determine whether the booster circuit has failed, and the battery voltage is boosted (see S5). In the example shown in FIG. 3, since the voltage of the battery has sufficiently reached the determination voltage that is the target value, it is determined that the booster circuit is normal (see S6).
In addition, after the start-up failure determination process as described above is completed, after time t4, the booster circuit is driven according to the load request to boost the battery voltage.
As described above, in the post-startup failure determination process, the time t2 to t4 after the boosting time corresponding to the normal starting from the time t1 to the time t2 and excluding the boosting time corresponding to the load request after the time t4. When there is no need for boosting up to, a failure of the boosting circuit is determined.

Next, the procedure of the start-up failure determination process will be described with reference to FIG.
FIG. 4 is a diagram illustrating a voltage waveform of the battery at the time of idle stop return. In FIG. 4, a broken line shows a voltage waveform of the battery when the booster circuit is not driven.
First, at time t10, in response to the establishment of the return condition, the engine idle stop return is started. That is, from time t10 to t11, the starter is driven by the battery power, and the booster circuit is driven to boost the battery voltage to the startup boost voltage so that the battery voltage does not fall below the minimum holding voltage. In the start-up failure determination process, a failure of the booster circuits 41a and 41b is determined based on the voltage of the battery at the time of boosting. In the example shown in FIG. 4, since the voltage of the battery does not sufficiently reach the startup boost voltage that is the target value, it is determined that the booster circuit has failed. As in the above-described failure determination process after starting, the idle stop prohibition flag FIDLE_NG is also set to “1” and the idle stop is prohibited even when it is determined in this failure determination process at startup that the booster circuit has failed. To do.

According to this embodiment, the following effects can be obtained.
(1) In the failure determination process after starting, the determination of the failure of the booster circuit is performed when it is not necessary to increase the voltage for its original purpose, compared with the case where the failure is determined when the voltage needs to be increased, It is possible to reduce the influence of a problem that occurs when the booster circuit actually fails. In other words, by determining the failure when there is no need for boosting by the booster circuit, if the booster circuit is actually faulty, the idle time is determined between the determination of the failure and the need for boosting. Since it is possible to take some measures such as prohibiting the stop, it is possible to prevent problems such as resetting the microcomputer included in the load.

  (2) In the failure determination process after start-up, power generation by ACG is prohibited while determining the failure of the booster circuit by driving the booster circuit and boosting the voltage of the battery. Thereby, the determination accuracy of the failure of the booster circuit can be improved.

  (3) In the failure determination process after starting, when it is determined that the booster circuit has failed, idle stop is prohibited. As a result, the number of times the booster circuit is driven can be reduced, so that it is possible to prevent the microcomputer from being reset even when the booster circuit fails.

  (4) In this embodiment, in addition to the post-startup failure determination process for determining the failure of the booster circuit after the engine startup is completed, when the battery voltage is boosted at the time of idle recovery, the battery voltage at the time of boosting By executing the startup failure determination process for determining the failure of the booster circuit based on the above, the determination frequency of the booster circuit failure can be increased. Also in the start-up failure determination process, when it is determined that the booster circuit has failed, idle stop is prohibited and the number of times the booster circuit is driven is reduced. Therefore, it is possible to prevent the microcomputer from being reset even when the booster circuit fails.

  (5) If idle stop is prohibited as described above, the number of times the booster circuit is driven decreases, and the frequency of determining a failure also decreases. Therefore, for example, if it is determined that the booster circuit has failed due to erroneous determination, it will continue to be erroneously determined that the booster circuit has failed for a long period of time. In this embodiment, after prohibiting the idle stop, if the boost circuit is determined to be normal in the post-startup failure determination process after the start of the engine triggered by the next ignition switch, the prohibition is canceled. To do. Thereby, erroneous determination over a long period can be prevented.

  (6) In this embodiment, after driving the booster circuit so that the voltage of the battery becomes higher than the maximum voltage, the failure of the booster circuit is determined based on the voltage of the battery at the time of boosting. It is possible to prevent erroneous determination as being.

  (7) In the failure determination process after starting, the booster circuit is driven, and the failure of the booster circuit is determined based on the voltage of the battery at the time of boosting. Therefore, if a failure is determined as described above in a state where the voltage of the battery is originally high, there is a possibility that it is erroneously determined to be normal. Therefore, in this failure determination process after start-up, the booster circuit is driven when the battery voltage at the time of non-boosting is equal to or lower than the reference voltage, and the failure of the booster circuit is determined. Thereby, the determination accuracy of the failure of the booster circuit can be further improved.

The present invention is not limited to the embodiment described above, and various modifications can be made.
For example, in the above embodiment, as described with reference to FIG. 4, the start-up failure determination process is performed at the time of idle stop return, but the present invention is not limited to this. At the time of idle stop return, a post-startup failure determination process may be executed in the same way as during normal start-up.

DESCRIPTION OF SYMBOLS 1 ... Battery control system 2 ... Battery 3a, 3b ... Load 4 ... DC-DC converter 41a, 41b ... Boost circuit 42a, 42b ... Boost monitoring circuit (boost monitoring means)
5 ... Starter 6 ... ACG (generator)
7 ... ECU
71 ... Engine control unit 711 ... Normal stop / start control unit (normal stop start means)
712 ... Automatic stop / start control unit (automatic stop start means)
72 ... ACG control unit 74 ... Battery voltage control unit (start-up voltage boosting means, post-startup failure determination means, power generation prohibition means, automatic stop prohibition means, start-up failure determination means)
8. Engine (internal combustion engine)
9 ... Ignition switch

Claims (7)

A battery and its booster circuit;
Boost monitoring means for detecting the voltage of the battery during boosting;
A start-up booster that drives the booster circuit to boost the voltage of the battery at the start of the internal combustion engine;
The booster circuit is driven when boosting is not necessary after the start-up boosting means, and a failure of the booster circuit is detected based on the battery voltage detected by the boost monitoring means during the boosting. A battery control system comprising a post-startup failure determination means for determining. A generator for generating electric power by the driving force generated in the internal combustion engine after the start of the internal combustion engine and charging the battery with the generated electric power;
The battery control system according to claim 1, further comprising: a power generation prohibiting unit that prohibits power generation by the generator while the failure determination unit after starting determines the failure of the booster circuit. Automatic stop start means for temporarily stopping the internal combustion engine in response to a stop condition being satisfied, and restarting the stopped internal combustion engine in response to a return condition being satisfied;
The automatic stop prohibiting unit for prohibiting the stop of the internal combustion engine by the automatic stop start unit when the post-startup failure determination unit determines that the booster circuit has failed. The battery control system according to 1 or 2. When the internal combustion engine is started by the automatic stop starting means, when the voltage of the battery is boosted by the starting boosting means, the boosting circuit is based on the battery voltage detected by the boost monitoring means at the boosting time. Further comprising a start-up failure determination means for determining the failure of
The automatic stop prohibiting means prohibits the stop of the internal combustion engine by the automatic stop starting means even when it is determined by the startup failure determining means that the booster circuit has failed. The battery control system described. Normal stop starting means for stopping or starting the internal combustion engine based on a signal transmitted from the ignition switch,
The automatic stop prohibiting means prohibits the internal stop of the internal combustion engine by the automatic stop start means, and after the next start of the internal combustion engine by the normal stop start means, the post-startup failure determination means indicates that the boosting circuit is normal. The battery control system according to claim 4, wherein the prohibition is canceled when it is determined that   6. The battery control according to claim 1, wherein the failure determination unit after starting boosts the voltage of the battery to a voltage higher than the maximum voltage when determining a failure of the booster circuit. system.   7. The after-startup failure determination means drives the booster circuit when the voltage of the battery at the time of non-boosting is equal to or lower than a reference voltage, and determines a failure of the booster circuit. The battery control system according to any one of the above.

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