JP2007083965A - Battery state detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery state detection device capable of performing accurate state determination not depending on the deterioration circumstance or the like of a battery. <P>SOLUTION: In the battery state detection device, an output voltage of the battery 1 is detected by a voltage sensor 23, the cranking number of revolutions of an engine is detected based on a waveform of the detection voltage and the state of the battery 1 is detected taking into consideration to the cranking number of revolutions. More specifically, when cranking of the engine is performed, the cranking number of revolutions of the engine is detected based on the waveform within a period of one waveform period or less including at least one peak included in the waveform of the detection voltage detected by the voltage sensor 23. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a battery state detection device that manages the state of a battery.

  In the battery state determination in the conventional battery state detection device, the internal resistance of the battery is measured from the amount of decrease in the output voltage of the battery at the start of the engine and the current value flowing at that time, and based on the measured internal resistance value The degree of deterioration of the battery is determined.

  However, there are various types of battery deterioration conditions, such as when lattice corrosion and sulfation overlap, and depending on the deterioration conditions, the correlation between the actual internal resistance and the open circuit voltage of the battery deteriorates. The correlation between the resistance and the amount of decrease in the battery output voltage at the time of starting the engine may also deteriorate. In this case, accurate state determination becomes difficult with the above-described prior art in which the state determination is performed by directly using the output voltage drop amount.

  Therefore, an object to be solved by the present invention is to provide a battery state detection device capable of accurately determining a state regardless of a deterioration state of the battery or the like.

  In order to solve the above problems, in the invention of claim 1, a battery state detection device for managing a state of a battery mounted on an automobile, the voltage sensor detecting the output voltage of the battery, and the voltage sensor A processing unit that detects the state of the battery in consideration of a detection voltage, and the processing unit is included in the waveform of the detection voltage detected by the voltage sensor when engine cranking is performed. Based on the waveform within a period of one waveform including one peak or less, the cranking rotational speed of the engine is detected, and the state of the battery is detected in consideration of the cranking rotational speed.

  According to a second aspect of the present invention, in the battery state detection device according to the first aspect of the invention, the processing unit considers whether or not the cranking rotational speed is equal to or higher than a preset reference rotational speed. The state of the battery is detected.

  According to the first aspect of the present invention, the battery output voltage is detected by the voltage sensor, the engine cranking speed is detected based on the waveform of the detected voltage, and the battery is considered in consideration of the cranking speed. Therefore, it is possible to accurately detect the state of the battery in response to the actual situation without taking into consideration various conditions such as the battery mounting environment such as the deterioration state and temperature and the vehicle type of the automobile.

  Further, when engine cranking is performed, the engine cranking rotation speed is determined based on a waveform within a period of one waveform period or less including any one peak included in the waveform of the detection voltage detected by the voltage sensor. Therefore, even if the waveform pattern of the detection voltage of the voltage sensor within the cranking period is a pattern that includes only one peak, the cranking rotation speed is detected based on the waveform of the detection voltage. be able to.

  According to the second aspect of the invention, the battery state is detected in consideration of whether or not the cranking rotational speed is equal to or higher than a preset reference rotational speed. Can be determined.

  The battery state detection device of the present embodiment determines whether or not the state of a battery mounted on an automobile is normal. Here, the normal battery is considered to be a state in which the engine can be appropriately started by power supply from the battery. First, what are the conditions? <1. Principle>. And the following <2. Configuration> and <3. Operation>, <1. An example of a battery state detection device configured based on the principle> principle will be introduced.

<1. Principle>
Inventors of the present application, as batteries mounted on automobiles, for each of a new battery and a battery in various deteriorated states, the remaining charge amount is variously changed, and the remaining charge amount is different. In the state, the battery was discharged at engine start, and the output voltage before and during the battery discharge was measured. Then, the relationship between the open-circuit voltage value before each engine start discharge in each remaining charge state of each battery with different deterioration conditions and the lower limit voltage value (discharge voltage value) immediately after the engine start discharge is examined. It was.

  Here, the engine start discharge is a discharge that is performed when the engine is started by operating the engine control ECU and the starter of the automobile. Further, the lower limit voltage value is the lowest value when the output voltage of the battery decreases due to the direct discharge at the engine start.

  FIG. 1 is a graph of the test results. The horizontal axis corresponds to the open-circuit voltage value of the battery before the start of engine start discharge in each discharge test, and the vertical axis represents the start of engine start discharge in each discharge test. It corresponds to the lower limit voltage value of the battery immediately after. Further, the curve G1 in FIG. 1 is drawn based on the measurement result for a new battery, and the curves G2 to G5 are drawn based on the measurement result for a battery that has been used and deteriorated to some extent. Curves G1 to G5 are obtained as a result of tests on batteries having different deterioration conditions. Among these, the curves G2 to G4 correspond to the batteries that are repeatedly charged and discharged in a manner close to a normal use state, and the use period of the batteries becomes longer and the deterioration progresses in the order of the curves G2, G3, and G4. Curve G5 corresponds to a battery that is frequently overcharged. The curves G4 and G5 have different deterioration conditions (deterioration factors), but the degree of deterioration (deterioration degree) is almost the same.

  Specifically, when focusing on the curve G1 corresponding to the new battery, the lower limit voltage value immediately after the engine start-up discharge is about 9.7 V when the open-circuit voltage value is about 12.9 V (almost fully charged). In other words, when the open-circuit voltage value is about 12.1V, the lower limit voltage value immediately after the engine start discharge is about 8.1V. Further, when attention is paid to the curve G4 corresponding to the battery having deteriorated, the lower limit voltage value immediately after the engine starting discharge is about 8.1V when the open circuit voltage value is about 12.5V.

  From the graph of FIG. 1, it can be seen that the corresponding curves G1 to G5 are shifted substantially in the right direction (or lower right direction) of the graph as the deterioration of the battery proceeds. In particular, in a region where the lower limit voltage value is a predetermined reference level (for example, 9 V) or less, the shift amount in the right direction of the curves G2 to G5 with respect to the curve G1 increases as the deterioration of the corresponding battery progresses. It turns out that there is a tendency.

  Considering this, for example, the point P1 (VO, VL) on the graph of FIG. 1 determined by the open circuit voltage and the lower limit voltage of the battery when the engine is discharged at the start of the engine is on the curve G1 corresponding to the new battery. With reference to the corresponding point P2 (VN, VL), it is possible to determine the degree of deterioration of the battery using the shift amount D shifted in the right direction of the horizontal axis. If the degree of deterioration of the battery is determined in this way, the relationship (for example, curves G1 to G5) between the open-circuit voltage value and the lower limit voltage value of the battery can be specified according to the degree of deterioration. For example, it is possible to predict the lower limit voltage value when the engine is started by operating the engine control ECU and the starter of the automobile only by detecting the open voltage.

  On the other hand, if the voltage required for starting the engine is found, the voltage is set to the starting limit level (for example, the starting limit line L01 in FIG. 1), and the lower limit voltage value is equal to or higher than the starting limit level (starting limit line L01). It is possible to determine whether or not the engine can be started based on the lower limit voltage value, that is, whether or not the battery is normal.

  However, the inventors of the present application have found that the start limit line L01 has a large variation due to various factors such as the resistance value in the power supply circuit in the automobile, such as the vehicle type and individual differences of the automobile. . On the other hand, since the battery is often mounted in common for a plurality of vehicle types, it is not desirable to uniformly determine the start limit line L01 in the combination of the vehicle and the battery mounted on the vehicle. Therefore, the following first to third conditions are focused so that it can be determined whether or not the battery is normal without using the start limit line L01.

  That is, as a condition necessary for starting the engine by the battery, first, as the first condition, it is necessary to ensure the operating voltage of the engine control ECU at the time of starting the engine. Further, as a second condition, it is necessary to ensure the operating voltage of the fuel injection / ignition system when starting the engine. Further, as a third condition, it is necessary that the cranking rotational speed at the time of engine ignition is an ignitable rotational speed.

  In this embodiment, whether or not the battery is normal is determined by paying attention to the first to third conditions. Hereinafter, these conditions will be described in detail.

(1-1. First condition)
As described above, first, as the first condition, it is necessary to ensure the operating voltage of the engine control ECU when starting the engine. Normally, when starting the engine, it is first necessary to drive the starter plunger to crank the engine and to operate the engine control ECU to control the fuel injection / ignition system. Therefore, it is necessary to secure the operating voltage of the engine control ECU and the driving voltage of the plunger. Generally, however, the operating voltage of the engine control ECU is secured because the operating voltage of the engine control ECU is higher than the driving voltage of the plunger. Then, the driving voltage of the plunger is also ensured. Therefore, first, it is necessary to ensure the operating voltage of the engine control ECU when starting the engine.

  Actually, in this embodiment, in FIG. 2, the lower limit voltage (lower limit voltage immediately after the start of battery discharge) VL of the battery that appears at the time T01 when the rush current flows after the ignition switch is turned on is It is determined whether or not the first condition is satisfied by determining whether or not the voltage is equal to or higher than a predetermined operable voltage value Vc.

  The predetermined operable voltage value Vc is a voltage value that ensures the operation of the engine control ECU, and is the same value as the minimum voltage value (for example, 4 V) necessary for the operation of the engine control ECU or a value thereof. High value. That is, the higher the predetermined operable voltage value Vc is set, the more sufficient the operating voltage of the engine control ECU can be secured when starting the engine.

  Thus, when the first condition is satisfied (that is, when the lower limit voltage VL immediately after the start of battery discharge is equal to or higher than the predetermined operable voltage value Vc for the engine control ECU), the ignition switch is turned on. When the engine is cranked, the engine control ECU operates appropriately to control the fuel injection / ignition system.

(1-2. Second condition)
However, even if the engine control ECU is activated, the engine will not start unless the fuel injection / ignition system is operated to perform fuel injection / ignition of the engine. Therefore, as described above, as the second condition, it is necessary to ensure the operating voltage of the fuel injection / ignition system when starting the engine. Actually, in this embodiment, in FIG. 2, whether or not the battery output voltage (ignition voltage) Va at the time of engine ignition T02 is equal to or higher than a predetermined operable voltage value Vt for the fuel injection / ignition system. To determine whether or not the second condition is satisfied.

  The predetermined operable voltage value Vt is a voltage value that ensures the operation of the fuel injection / ignition system, and is the same value as the minimum voltage (for example, 5 V) required for the operation of the fuel injection / ignition system, or The value is higher than the value. That is, the higher the predetermined operable voltage value Vt is set, the more sufficient the operating voltage of the fuel injection / ignition system can be secured when starting the engine.

  As a method for detecting the ignition time voltage Va, for example, referring to FIG. 2, the rising width ΔV1 from the nearest minimum point Pb in the output voltage waveform of the output voltage waveform of the battery is the nearest minimum. When a voltage ratio ΔV2 between the voltage value at the point Pb and the battery open voltage value V0 before discharging at the start of the engine reaches a predetermined ratio (for example, 50%) or more, the voltage value at the nearest minimum point Pb is The voltage is Va.

  As described above, when the second condition is satisfied (that is, when the drive voltage of the fuel injection / ignition system is ensured at the time of starting the engine), the fuel is appropriately injected at the time of engine fuel injection. At the same time, the engine is appropriately ignited at the time of engine ignition.

(1-3. Third condition)
However, even if the engine is properly ignited at the time of engine ignition T02, the engine is ignited if the cranking speed at T02 at the time of engine ignition is less than the minimum engine speed. Absent. That is, if the output voltage of the battery at the time of engine ignition T02 is low, the cranking rotation speed at the time of engine ignition T02 may decrease, and the engine may not be ignited. Therefore, as described above, as the third condition, it is necessary that the cranking rotational speed at the time of engine ignition T02 is an ignitable rotational speed. Actually, in this embodiment, it is determined whether or not the cranking rotation speed at T02 at the time of engine ignition is equal to or higher than a predetermined ignition-ready rotation speed (reference rotation speed) n01. It is determined whether the condition 3 is satisfied.

  The predetermined ignition possible rotation speed n01 is a cranking rotation speed that ensures ignition of the engine, and is a value equal to or higher than the minimum rotation speed required for engine ignition. That is, as the predetermined ignition speed n01 is set higher, the ignition of the engine can be secured more sufficiently. Hereinafter, a method for detecting the cranking rotation speed at the time of engine ignition T02 will be described in detail.

  As shown in FIG. 2, when the ignition switch is turned on at time T01 (inrush current flows from the battery to the starter at this time), the behavior of the output voltage of the battery at the start of the engine is accompanied by the cranking operation of the engine. The battery output voltage will oscillate. The vibration of the output voltage is caused by the engine and starter's rotational speed oscillating because the load when the starter cranks the engine fluctuates depending on the engine cycle state (intake, compression, expansion, exhaust). It will occur. For this reason, the cranking rotation speed of the engine can be detected by detecting the period of oscillation of the output voltage.

  Therefore, in the present embodiment, cranking at the time of engine ignition T02 is based on a voltage waveform within a period of one waveform period (a period corresponding to one period of the output voltage waveform) including the peak Pt immediately before the engine ignition point T02. The number of rotations is detected. More preferably, the cranking rotation speed is detected based on a voltage waveform within a period of three quarters of a waveform period including the peak Pt, half of a waveform period or less, or a quarter waveform period or less. ing.

  More specifically, for example, the following detection method can be employed.

  (a) The period length from when the output voltage of the battery reaches the peak Pt to when the output voltage reaches the same value as the peak Pt again through the valley (that is, the period length corresponding to a half cycle of the waveform) A method of measuring D1 and calculating the cranking rotation speed based on the period length D1.

  (b) The period length from the local minimum point Pb that is the engine ignition point T02 to the same value as the local minimum point Pb from the local minimum point Pb through the peak Pt (that is, the half cycle of the waveform) It is possible to adopt a method of measuring the cranking rotation speed based on the period length D2 by measuring the period length D2).

  (c) A method of calculating the cranking rotation speed based on the average value of the above-described period lengths D1 and D2.

  (d) A period length D3 (that is, a period length corresponding to a quarter period of the waveform) D3 until the output voltage reaches the minimum point Pb that is the engine ignition point T02 from the peak Pt is measured, and the period length D3 To calculate the cranking speed based on the above.

  Note that the waveform of the output voltage in FIG. 2 shows an example in which there is only one peak during the cranking period. Such a waveform pattern is seen in the case of a car whose engine starts immediately after the start of cranking, and the technology according to this embodiment is created mainly for such a car. It is. Therefore, when it is known in advance that the battery output voltage waveform has only one peak during the cranking period, the battery output voltage is first reduced to the lower limit Lm due to the inrush current to the starter motor. The period lengths D1 to D3 may be measured based on the peak Pt of the waveform appearing at. In this case, the minimum point Pb of the waveform that appears next to the lower limit point Lm is determined to be the engine ignition point T02.

  As described above, when the third condition is satisfied (that is, when the cranking rotation speed at T02 at the time of engine ignition is equal to or higher than the predetermined ignition speed n01), the engine is ignited by the ignition of the engine. Is started.

  Thus, in this embodiment, the first condition (that is, whether or not the lower limit voltage VL immediately after the start of battery discharge is equal to or higher than the predetermined operable voltage value Vc for the engine control ECU), and the second condition (that is, Whether or not the ignition time voltage Va is equal to or higher than a predetermined operable voltage value Vt for the fuel injection / ignition system and the third condition (that is, the cranking rotation speed at the engine ignition time T02 is a predetermined ignition speed n01) It is easy to determine whether or not the engine can be properly started by supplying power from the battery (that is, whether or not the state of the battery is normal) simply by determining whether or not the above is satisfied. Can be determined.

<2. Configuration>
As shown in FIG. 3, the battery state detection device according to this embodiment includes a current sensor 21 that detects the output current of the battery 1, a voltage sensor 23 that detects the output voltage of the battery 1, and a detection result of the voltage sensor 23. A processing unit (processing for determining whether the state of the battery 1 is normal (that is, normal for engine startability) and determining the capacity / deterioration of the battery 1 based on the detection result of the current sensor 21 Means, a cranking rotation number detecting means) 25, an output unit 29 for outputting the determination result of the processing unit 25, and data necessary for determining the state of the battery 1 by the processing unit 25 (the predetermined operable voltage value Vc, And a storage unit 27 that stores Vt, a predetermined ignition speed n01), and the like.

  The battery 1 has its negative electrode grounded and its positive electrode connected to the starter ST, the fuel injection / ignition system 7 and the engine control ECU 8 via the ignition switch 6. Thereby, when the ignition switch 6 is turned on, the power supply from the battery 1 is supplied to the starter ST, the fuel injection / ignition system 7 and the engine control ECU 8 via the ignition switch 6. Note that the fuel injection / ignition system 7 is an injector that performs fuel injection to the engine, an ignition plug that performs engine ignition, and a circuit for operating them. The engine control ECU 8 includes the fuel injection / ignition system 7. It is an ECU to be controlled.

  As shown in FIG. 4, the processing unit 25 determines the first condition (that is, whether or not the lower limit voltage VL immediately after the start of battery discharge is equal to or higher than a predetermined operable voltage value Vc for the engine control ECU 8). A condition determination unit 25a, a second condition determination unit 25b for determining a second condition (that is, whether or not the ignition time voltage Va is equal to or higher than a predetermined operable voltage value Vt for the fuel injection / ignition system 7); A third condition determination unit 25c for determining a third condition (that is, whether or not the cranking rotation speed at T02 at the time of engine ignition is equal to or higher than a predetermined ignition speed n01), and each of these condition determination sections 25a And a comprehensive determination unit 25 d that comprehensively determines whether or not the state of the battery 1 is normal based on the determination results at ˜25 c and outputs the comprehensive determination result to the output unit 29.

  The output unit 29 is configured as a display device such as a liquid crystal display panel, an audio output device, or the like, for example. In addition, when performing the interruption | blocking control of the various loads (for example, audio equipment etc.) mounted in the motor vehicle according to the state of the battery 1, the output part 29 is comprised also as a load power supply control unit.

<3. Operation>
Next, the operation of the battery state detection device will be described with reference to FIG. In this embodiment, in steps S1 to S12, it is determined whether or not the battery 1 is normal from the viewpoint of engine startability. If the determination result indicates that the battery is not normal, step S13 is performed. In step S15, the remaining capacity of the battery 1 is determined, and in steps S16 to S20, the deterioration state of the battery 1 is determined. In consideration of the determination results (remaining capacity and deterioration state), the battery 1 is finally normal. It is determined whether or not there is. Here, it is determined whether the first to third conditions are satisfied based on the waveform of the output voltage of the battery 1 when the engine is ignited.

  When the ignition switch 6 is turned on in step S1, the power supply from the battery 1 is supplied to the starter ST, the fuel injection / ignition system 7 and the ECU 8 via the ignition switch 6, and the battery 1 being supplied with power is supplied. The output voltage and output current are detected by the voltage sensor 23 and the current sensor 21. Then, based on the detection result of the voltage sensor 23, the processing unit 25 determines whether or not the engine has ignited. More specifically, referring to FIG. 2, the rising width ΔV1 from the nearest minimum value Pb of the waveform of the output voltage 13 of the battery 1 detected by the voltage sensor 23 is the voltage value at the nearest minimum value Pb. It is determined that the engine has ignited when a predetermined ratio (for example, 50%) of the voltage difference ΔV2 with respect to the battery open voltage value V0 before discharging at the time of engine start is reached. If it is determined in step S1 that the engine has ignited, the process proceeds to step S2. In step S2 and subsequent steps, it is determined whether the first to third conditions are satisfied based on the battery output voltage waveform obtained in step S1 (that is, the battery output voltage waveform when the engine is ignited). Is done.

  In step S2, the processing unit 25 detects the output voltage (ignition voltage) Va of the battery 1 at the time of engine ignition T02 based on the battery output voltage waveform when the engine is ignited. More specifically, the voltage value at the nearest minimum value P1 focused on when determining the engine ignition in step S1 is used as the ignition time voltage Va.

  In step S3, the processing unit 25 determines whether or not the ignition time voltage Va is equal to or higher than a predetermined operable voltage value Vt for the fuel injection / ignition system 7 (that is, the second condition is satisfied). Whether or not) is performed. As a result of the determination, if it is determined that the voltage is greater than or equal to the predetermined operable voltage value Vt, the process proceeds to step S4. On the other hand, if it is determined that the voltage is less than the predetermined operable voltage value Vt, step S11 is performed. Proceed to

  On the other hand, if the process proceeds to step S4, the processing unit 25 performs the above <1. The cranking rotational speed at the time of engine ignition T02 is detected as in (1-3. Third condition) of the principle>.

  In the next step S5, if the cranking rotation speed at the time of engine ignition T02 can be detected as a result of the detection at step S4, the process proceeds to step S6. On the other hand, the cranking rotation speed at the time of engine ignition T02 cannot be detected. If YES, go to step S7.

  When the process proceeds to step S6, the processing unit 25 determines whether or not the cranking rotational speed detected in step S5 is equal to or higher than a predetermined ignition-enabled rotational speed n01 (that is, the third condition is A determination is made as to whether or not it is satisfied. As a result of the determination, if it is equal to or higher than the predetermined ignition speed n01, the process proceeds to step S7. On the other hand, if it is lower than the predetermined ignition speed n01, the process proceeds to step S11.

  When the processing proceeds to step S7, the lower limit voltage value VL immediately after the start of discharging of the battery 1 is equal to or higher than a predetermined operable voltage value Vc for the ECU 8 set in advance by the processing unit 25 based on the battery output voltage waveform. Whether or not (that is, whether or not the first condition is satisfied) is determined. As a result of the determination, if it is determined that the voltage is greater than or equal to the predetermined operable voltage value Vc, the process proceeds to step S8. On the other hand, if it is determined that the voltage is less than the predetermined operable voltage value Vc, step S11 is performed. Proceed to

  In step S <b> 8, the processing unit 25 determines that the state of the battery 1 is normal (with respect to engine startability), and the determination result is output to the output unit 29. Next, in step S9, the balance of the charge amount of the battery 1 detected by the current sensor 21 is integrated by the processing unit 25, and predetermined processing such as full charge determination is performed by the control unit 25 in step S10. As a result of the processing, when the processing unit 25 determines that the battery is fully charged, the control unit 25 performs control for preventing overcharging by stopping charging of the battery 1 or the like.

  On the other hand, when the process proceeds from step S3, S6 or S7 to step S11, the processing unit 25 determines that the battery 1 needs attention, and the output unit 29 outputs information to that effect. Further, the output unit 29 performs a caution display indicating that the battery 1 needs attention, a voice output for prompting attention, and the like. Further, when a load power supply control unit is included as the output unit 29, the load power supply control unit performs cutoff control of various loads (for example, audio devices) mounted on the automobile according to the state of the battery 1. Is called. Then, the process proceeds to step S12.

  In step S12, the balance of the charge amount of the battery 1 detected by the current sensor 21 is integrated by the processing unit 25, and the process proceeds to step S13. In step S13, it is determined whether or not the charge balance of the battery 1 exceeds a predetermined value Pc considering dark current for a predetermined number of days (for example, one week) of the automobile. It is determined that the battery 1 is sufficiently charged even when the dark current for the number of days left is taken into consideration, and the process proceeds to step S14. In step S14, information indicating that the battery 1 is in a normal state is output to the output unit 29 through the general determination unit 25d. Thereafter, the processing after step S12 is repeated.

  On the other hand, if it is determined in step S12 that the charge balance of the battery 1 is equal to or less than the predetermined value Pc, the process proceeds to step S15, and it is first determined in step S16 whether the battery is fully charged.

  If it is determined in step S16 that the battery is not fully charged, the process returns to step S12 and the subsequent processing is repeated.

  On the other hand, if it is determined in step S16 that the battery is fully charged, the process proceeds to step S17, and it is determined again whether the charge balance of the battery 1 exceeds the predetermined value Pc. When it is determined that the charge balance of the battery 1 exceeds the predetermined value Pc, the battery 1 is sufficiently charged even when the dark current corresponding to the predetermined number of days to be left is taken into consideration. It progresses to step S18. In step S18, information indicating that the battery 1 is in a normal state is output to the output unit 29 through the comprehensive determination unit 25d. Thereafter, the processing after step S12 is repeated.

  On the other hand, when it is determined in step S17 that the charge balance of the battery 1 is equal to or less than the predetermined value Pc, it is determined that the amount of charge until the battery 1 is fully charged is small, and the battery 1 has a life. In step S19, information to that effect is output to the output unit 29. In this case, a warning display indicating that the battery 1 has reached the end of life, an audio output related to the warning, and the like are performed. Further, when a load power supply control unit is included as the output unit 29, etc., the load power supply control unit is used to cut off various loads (for example, audio devices) mounted on the vehicle according to the state of the battery 1 or the like. I do.

  According to the battery state detection device configured as described above, the output voltage of the battery 1 is detected by the voltage sensor 23, the engine cranking rotational speed is detected based on the waveform of the detected voltage, and the cranking rotation is detected. Since the state of the battery 1 is detected in consideration of the number, the battery 1 can be immediately adapted to the actual situation without taking into consideration various conditions such as the battery mounting environment such as the deterioration state and temperature and the vehicle type of the automobile. The state can be detected accurately.

  Further, when engine cranking is performed, engine cranking rotation is performed based on a waveform within a period of one waveform period or less including any one peak included in the waveform of the detection voltage detected by voltage sensor 23. In order to detect the number, even if the waveform pattern of the detected voltage of the voltage sensor 23 within the cranking period is a pattern that includes only one peak, the cranking rotation speed is determined based on the detected voltage waveform. Can be detected.

  Further, since the state of the battery 1 is detected in consideration of whether or not the cranking rotational speed is equal to or higher than a preset ignition possible rotational speed n01, the engine starting ability of the battery 1 can be accurately determined. .

  In the embodiment described above, all of the first to third conditions are determined. However, if at least the third condition is determined, the first and second conditions are determined. It may be omitted.

It is a graph which shows the measurement result which measured the open circuit voltage and the lower limit voltage at the time of engine starting about the battery from which a deterioration condition and charge remaining amount differ. It is a figure which shows the change of the output voltage of a battery in the case of engine starting. It is a block diagram which shows the battery state detection apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the process part of the battery state detection apparatus of FIG. It is a flowchart which shows operation | movement of the battery state detection apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery 23 Voltage sensor 25 Processing part n01 Predeterminable rotation speed Va ignition voltage Vc Predetermined operable voltage value for engine control ECU VL Lower limit voltage value immediately after start of battery discharge VO Battery open voltage value before discharge at engine start Vt Predetermined operable voltage value for fuel injection / ignition system

Claims (2)

A battery state detection device for managing the state of a battery mounted on an automobile,
A voltage sensor for detecting the output voltage of the battery;
In consideration of the detection voltage of the voltage sensor, a processing unit for detecting the state of the battery;
With
The processing unit is based on the waveform in a period of one waveform period or less including any one peak included in the waveform of the detection voltage detected by the voltage sensor when engine cranking is performed. A battery state detection device that detects a cranking rotational speed of the engine and detects the state of the battery in consideration of the cranking rotational speed. The battery state detection device according to claim 1,
The processing unit detects the state of the battery in consideration of whether or not the cranking rotational speed is equal to or higher than a preset reference rotational speed.

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