JP2005331518A - Residual capacity measurement method and device for storage battery mounted on vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a practical idling stop processing device for a vehicle and a residual capacity measurement device for a lead-acid battery. <P>SOLUTION: A residual capacity of a storage battery is defined as a criterion for stopping idling. A first level: a battery capacity necessary for restarting an automobile after stopping idling. A second level: a battery capacity found by adding the battery capacity necessary for restarting the automobile after stopping idling and a consumption battery capacity necessary during stopping idling for a fixed time together. An addition level: a battery capacity found by adding a predetermined battery capacity to the battery capacity at the second level. These levels are stored in a memory means 21. A residual capacity measurement means 22 for the storage battery measures a residual capacity of a lead-acid battery. A determination means 23 determines a level of the residual capacity measured by the measurement means 22. The measurement means 22 for the storage battery uses data previously computed for calculating a residual capacity and relationship between the measured discharge current value and a terminal voltage to calculates the residual capacity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method and apparatus for measuring the remaining capacity of a storage battery.
In particular, the present invention relates to a method and an apparatus for measuring the remaining capacity of a storage battery mounted on a vehicle, which is preferably applied to processing or the like as to whether to perform idling stop for stopping an internal combustion engine when the vehicle is temporarily stopped in a vehicle mounted with a storage battery. .

Automobiles that have an idling stop function that stops the internal combustion engine (engine) when the car is temporarily stopped for traffic lights at intersections or when it is stopped due to traffic jams in order to reduce environmental pollution and improve automobile fuel economy It has been known.
When performing such an idling stop, it is necessary that the in-vehicle storage battery has a remaining capacity as much as possible to restart the automobile after the idling stop. Therefore, when the idling is stopped, it is necessary to know that the storage battery has enough remaining capacity to restart the automobile after the idling is stopped.

Various methods for measuring the remaining capacity of a storage battery have been tried. However, until now, there has been no known method for detecting the remaining capacity of an on-vehicle storage battery that is suitable for determination of idling stop.
Hereinafter, an overview of the known methods for measuring the remaining capacity of a storage battery will be given.

  The simplest and most reliable method for measuring the remaining capacity of a storage battery is a method in which the storage battery is completely discharged, the capacity is measured, and the deterioration state is determined from the capacity. However, this method cannot be used to determine idling stop in real time. Moreover, since this method takes a long time to discharge, there is a problem that the measurement time becomes long.

  Next, a method for measuring the remaining capacity of the storage battery in a relatively short time without discharging the storage battery will be described.

  Since lead acid batteries produce water by discharging and produce sulfuric acid by charging, the specific gravity of the sulfuric acid aqueous solution is reduced when discharged, and the specific gravity of the sulfuric acid aqueous solution is restored by charging. Using this phenomenon, a method of estimating the remaining capacity using the specific gravity of the electrolyte as an index is known. However, since the concentration distribution of the electrolyte contained in the lead storage battery often becomes non-uniform, this method cannot always accurately estimate the remaining capacity of the lead storage battery. In recent years, sealed lead-acid batteries with very little electrolyte have been adopted. For such a sealed lead-acid battery, it is difficult to measure the specific gravity of the electrolyte itself, so the remaining capacity of the lead-acid battery cannot be estimated.

In Patent Document 1, (1) a transient current value of an alternator generated when an engine start key is turned is measured as a current flowing through a resistor interposed between the alternator and an in-vehicle lead storage battery (battery). Further, the terminal voltage of the battery is also measured, and these measurement results are calculated by an operational amplifier to obtain the initial remaining capacity of the battery immediately before traveling. (2) Further, the charging amount or charging / discharging amount during traveling is obtained, (3) A method of calculating the remaining capacity of the battery by comparing the initial remaining capacity and the charge / discharge amount is disclosed.
However, this method is based on the initial remaining capacity at a specific timing when the automobile is started, and cannot be applied to the idling stop as it is. In addition, since a resistor is provided for current measurement, there is a disadvantage that battery capacity is consumed.

Patent Document 2 (1) actually measures the terminal voltage drop of the battery with respect to the amount of discharge charge during engine start-up in a new battery when the battery is first installed in the automobile. (2) Thereafter, engine stop and start The terminal voltage of the battery with respect to the amount of discharge charge during engine start-up every time the vehicle is driven on condition that the time required for the battery static characteristics to revive during A method is disclosed in which the amount of drop is measured and (3) the battery life is predicted by calculating using the initial voltage drop and the voltage drop after running.
However, this method also uses the drop in the battery terminal voltage at a specific timing, such as when the automobile is started, as a reference for detecting the remaining capacity, and is not suitable for idling stop determination. In addition, this method is not applicable to the determination of idling stop because the above-described conditions are imposed.

Patent Document 3 detects (1) a battery discharge current at a plurality of time points indicating different values during a large current discharge such as when a starter is started, and a terminal voltage of the battery when each discharge current flows out, (2) The internal resistance value and power of the battery are calculated from the detected current and voltage values, and (3) the internal resistance calculated using a function representing a correlation system between the battery capacity, the internal resistance, and the electromotive force obtained experimentally in advance. A method for calculating the remaining capacity of a battery from an electromotive force is disclosed.
However, since this method is also based on the starter start-up condition, it is not appropriate for determining idling stop. Furthermore, the processing of this method is complicated.

Patent Document 4 discloses an invention that uses internal impedance to detect the remaining capacity of a lead-acid battery. That is, in the present invention, (1) the internal impedance of the lead storage battery is measured, and (2) the measured internal impedance of the lead storage battery is converted into an inductance component L, an electrolyte resistance RΩ, a charge transfer resistance Rct, Apply an equivalent circuit consisting of multilayer capacitance Cd, Warburg impedance W, and Warburg coefficient σ to find an optimal solution. (3) Compare at least one of L, RΩ, Rct, Cd, W, and σ with the initial value The life of the lead storage battery is determined from the difference.
However, the present invention cannot be applied to the remaining capacity of a vehicle-mounted lead storage battery that is charged from the generator to the lead storage battery as the vehicle travels. The reason is that it is difficult to measure the internal impedance of the lead storage battery due to the influence of the generator on the lead storage battery and the load fluctuation of the equipment mounted on the automobile. If the internal impedance of the lead-acid battery cannot be measured, it cannot be compared with the initial value and the life cannot be determined. Further, when the present invention is implemented, the configuration of the measuring apparatus is complicated, the size is increased, and the price is increased. Therefore, there is a problem in applying the present invention to ordinary automobiles such as passenger cars.

A method is also known in which a current value discharged or charged from a storage battery is constantly measured, and the measured current value is integrated to determine the remaining capacity of the storage battery. Hereinafter, this method is referred to as “current integration method”.
In such a current integration method, the error of the integrated value gradually increases due to the measurement error of the current value, and the state of the storage battery cannot be obtained accurately. Therefore, methods that improve the “current integration method” have been proposed in Patent Literature 5, Patent Literature 6, and the like.

The invention described in Patent Document 5 measures the remaining capacity of a lead-acid battery for an electric vehicle by performing data processing using both the current integration method and the internal resistance detection method. That is, (1) First, the remaining capacity of a lead storage battery mounted on an electric vehicle is calculated by a current integration method. (2) Further, when the full charge of the lead storage battery for an electric vehicle is completed and when the vehicle is temporarily stopped The internal impedance of the lead storage battery is measured, and (3) the value of the remaining capacity of the storage battery obtained by the current integration method is corrected by the discharge rate derived from the internal impedance.
This method is useful as a method for inspecting the remaining capacity of a storage battery for automobiles, and is an important technique in an electric vehicle that needs to know the remaining capacity of a lead storage battery accurately.
However, according to the present invention, in addition to the measurement by the current integration method, it is also necessary to perform the measurement by the internal impedance. When a measuring device that realizes this method is manufactured, the device price becomes high. In particular, the present invention cannot be applied to an idling stop of an automobile equipped with an internal combustion engine because it is difficult to measure the internal impedance described above.

The invention disclosed in Patent Document 6 is a technique for calculating a remaining capacity of a storage battery by a current integration method and correcting the remaining capacity. To calculate the corrected remaining capacity, a data table of terminal voltage and remaining capacity in constant current discharge at a specific discharge current value is prepared in advance, and it is detected that the specific discharge current value continues for a certain period of time while the vehicle is running. Then, the terminal voltage of the storage battery at that time is measured, and the remaining capacity of the storage battery for correction is obtained by referring to the measured terminal voltage in the data table.
Then, the remaining capacity of the current integration method obtained in advance is corrected with the calculated remaining capacity for correction.
The present invention is a technique suitable for measuring the remaining capacity of a storage battery (battery) mounted on an electric vehicle such as an electric vehicle. The reason is that, in an electric vehicle, there are many opportunities to obtain the remaining capacity of the storage battery by setting the discharge current value at the traveling speed that the vehicle normally uses to the above-mentioned specific discharge current value.
However, the present invention is not suitable for the remaining capacity of a storage battery mounted on an automobile (normal automobile) operating with an internal combustion engine. The reason for this is that in normal automobiles, there are few opportunities for a specific current value that frequently continues for a certain period of time to occur during vehicle driving, so there are very few opportunities to determine the remaining capacity of the storage battery, and the residual that should be corrected This is because the capacity cannot be obtained.

As a method for solving the above-described problem of the invention disclosed in Patent Document 6, for example, a plurality of terminal voltage and remaining capacity data tables may be prepared and the remaining capacity may be determined using a plurality of current values.
However, in order to implement such a method, it is necessary to prepare a plurality of data tables, and the processing becomes complicated. In order to accurately measure the remaining capacity, if the relationship between the terminal voltage of the storage battery and the remaining capacity changes depending on the temperature and the deterioration state, it is necessary to prepare more data tables accordingly. It is assumed that a complicated device is required to store and process the data. In addition, it is troublesome to create such a large amount of data. It is also difficult to judge the deterioration state of the storage battery.
JP-A-53-127646 JP 63-27776 A JP-A-1-39068 Japanese Patent No. 2536257 (Japanese Patent Laid-Open No. 4-95788) Japanese Patent No. 2791751 (Japanese Patent Laid-Open No. 8-19103) Japanese Patent Laid-Open No. 9-171065

  Various conventional techniques have been discussed above. However, these techniques have problems when applied to an idling stop of an automobile equipped with an internal combustion engine, and cannot be applied as they are.

  Another object of the present invention is to provide a method and apparatus for measuring the remaining capacity of a storage battery mounted on a vehicle, which is suitable for application to idling stop processing of a vehicle.

According to the first aspect of the present invention, the relationship between the discharge current in a plurality of discharge capacities and the terminal voltage of the storage battery is obtained in advance, and the terminal voltage is obtained using the discharge current as a variable. Obtaining an approximate expression; and
During the operation of the vehicle, a measurement process for continuously measuring the actual discharge current of the in-vehicle storage battery and the actual terminal voltage of the storage battery;
An estimated terminal voltage calculation step of calculating an estimated value of a plurality of terminal voltages by substituting the measured discharge currents into the obtained plurality of approximate equations;
A determination step of comparing the measured terminal voltage of the storage battery with the calculated plurality of estimated terminal voltages to determine which range of estimated terminal voltages are present;
Measuring the remaining capacity of the storage battery, comprising determining a discharge capacity corresponding to the estimated terminal voltage within the range of the plurality of discharge capacities and determining the discharge capacity as the remaining capacity of the storage battery. A method is provided.

In the step of obtaining the approximate expression, (1) a storage battery having a fully charged battery capacity larger than any of the plurality of discharge capacities, with a plurality of constant first discharge currents, until the battery voltage drops to a predetermined terminal voltage. A first measurement step of continuously discharging and measuring the terminal voltage and discharge elapsed time of the storage battery at that time, and (2) the discharge capacity that is the product of the respective constant discharge current value and discharge time elapsed, A first characteristic calculation step of obtaining a first characteristic indicating a relationship with the terminal voltage measured for each discharge elapsed time for the plurality of discharge currents; and (3) the storage battery that has dropped to the predetermined terminal voltage. Until the voltage drops to the predetermined terminal voltage, the discharge is continued at a constant second discharge current lower than the plurality of discharge currents, and the terminal voltage and elapsed discharge time of the storage battery at that time are measured. (4) For each of the plurality of discharge capacities A, as a product of a plurality of constant first discharge currents Id1 and a discharge elapsed time T1 at that time in the first measurement step A first discharge capacity defined, a second discharge capacity defined as a product of a constant second discharge current Id2 in the second measurement step and a discharge elapsed time T2 at that time, and the discharge capacity A For, calculate the third discharge capacity by the following calculation,
(Id1 × T1) + (Id2 × T2) −A
(5) By applying the calculated third discharge capacity to the discharge capacity / terminal voltage characteristics obtained in the first characteristic calculation step, the corresponding terminal voltage is calculated, and for each discharge capacity, the discharge current and the terminal voltage are calculated. And a second characteristic calculating step for obtaining a second characteristic indicating the relationship with (6), and (6) an approximation step for expressing the result of the second characteristic in an approximate expression.

  In the approximation step, for each discharge capacity, the relationship between the discharge current and the terminal voltage is approximated by a linear expression.

  According to the second aspect of the present invention, the relationship between the discharge current in the plurality of discharge capacities and the terminal voltage of the storage battery is obtained in advance, and the terminal voltage is obtained using the discharge current as a variable. Means for obtaining an approximate expression; an ammeter for measuring the discharge current of the storage battery; a voltmeter for measuring a terminal voltage of the storage battery; and the discharge current measured by the ammeter is substituted into the obtained approximate expressions An estimated terminal voltage calculating step of calculating an estimated value of a plurality of terminal voltages, and comparing the terminal voltage of the storage battery measured with the voltmeter with the calculated estimated terminal voltages, to which range of estimated terminal voltages Determining means for determining whether there is a remaining capacity determining means for determining a discharge capacity corresponding to an estimated terminal voltage within the range among the plurality of discharge capacities, and determining the discharge capacity as a remaining capacity of the storage battery And To the measuring apparatus of the remaining capacity of the storage battery is provided.

  According to the present invention, the outline of the remaining capacity of the storage battery can be calculated by a simple method. Since the method for calculating the remaining capacity of the storage battery is simple, the measurement apparatus for the remaining capacity of the lead storage battery can be manufactured at a low price and in a small size, and is easy to handle.

  As a first embodiment of the present invention, the remaining capacity of a storage battery mounted on an automobile having a so-called idling stop function for stopping an internal combustion engine (engine) while the automobile is running is temporarily stopped due to a traffic jam or an intersection. A vehicle idling stop processing method and apparatus for measuring and performing idling stop processing will be described.

FIG. 1 is a configuration diagram of a vehicle idling stop processing apparatus according to the present embodiment.
The vehicle idling stop processing device 20 according to the present embodiment includes a memory means 21, a storage battery remaining capacity measuring means 22, an idling stop determination means 23, an idling stop processing means 24, and a restarting means 25. .

The memory means 21 stores the level data described below.
The storage battery remaining capacity measuring means 22 is means for detecting the remaining capacity of the storage battery, which will be described in detail with reference to FIG.
The idling stop determination means 23 is means for determining whether or not the remaining capacity of the storage battery detected by the storage battery remaining capacity measuring means 22 is at a level at which idling can be stopped.
The idling stop processing means 24 is means for stopping the engine and setting the idling stop state when the idling stop determining means 23 determines that idling can be stopped.
The restart means 25 is means for restarting the engine and running the vehicle after the idling stop.

  The memory means 21, the idling stop determination means 23, the idling stop processing means 24, and the restarting means 25 can be integrally configured, for example, in a control computer that controls the automobile.

The criteria for determining the remaining capacity of the present invention stored in the remaining capacity determination level memory means 21 will be described. The inventor of the present application has formulated the following criteria for producing a practical method and apparatus for determining the remaining capacity.
That is, the present invention specifies the determination level of the remaining capacity of the lead storage battery as illustrated in FIG. 2 under the limitation of measuring the remaining capacity of the lead storage battery of an automobile having an idling stop function. The level and the corresponding battery capacity are stored in the memory of an idling stop processing device for a vehicle, which will be described later, and used for determining the remaining capacity of the storage battery.

(1) First level: Battery capacity required for vehicle restart after idling stop (2) Second level: Battery capacity required for vehicle restart after idling stop and required for idling stop for a specific time (3) Third level: battery capacity obtained by adding first predetermined battery capacity to second level battery capacity (4) Fourth level: third level battery capacity (5) Fifth level: battery capacity obtained by adding the third predetermined battery capacity to the fourth level battery capacity

  Describe the meaning of the first level and the reasons for its definition. When idling is stopped, the engine is stopped during the temporary stop, so it is necessary to restart the engine starter and the like when the vehicle starts running again from the temporary stop. The first level is a value for determining that the battery capacity necessary for restarting remains in the storage battery.

Describe the meaning of the second level and the reasons for its definition. When making a decision to stop the engine immediately before stopping the engine, the battery capacity (first level) when starting running again after the engine stops, and restarting the starter after stopping the engine Until the vehicle is started again, it is necessary that the battery capacity including the battery capacity necessary for operating the equipment of the automobile remains in the storage battery.
In order to obtain the battery capacity required to operate the equipment of the automobile between the time when the engine is stopped and the time when the engine is restarted, the time from when the engine is stopped to when the engine is restarted, that is, It is necessary to specify the idling stop time. Furthermore, it is necessary to know the amount of power consumed by the automobile equipment that is operated during idling stop.
However, it is difficult to determine the idling stop time and the power consumption during that period before the idling stop.
Therefore, in the embodiment of the present invention, the standard idling stop time and the battery capacity consumed during that time are estimated. These are stored in the memory means 21.

  The idling stop determination means 23 monitors the level of the remaining capacity of the storage battery, but when the actual idling stop time exceeds the estimated standard idling stop time and / or during the idling stop period. When the consumed battery capacity exceeds the estimated standard battery capacity, there is a possibility that the battery capacity necessary for restarting the engine is insufficient and the engine cannot be restarted.

Therefore, before the idling stop time exceeds the specified time and / or before the battery capacity consumed during the idling stop period exceeds the standard battery consumption capacity, the reduction in the remaining capacity of the storage battery is suppressed, or It is desirable to apply a method for increasing the battery capacity of the storage battery.
Therefore, the idling stop processing means 24 restarts the engine immediately after the standard idling stop time has elapsed or immediately after the power consumption exceeds the standard battery capacity during the idling stop period, for example. To charge the storage battery, or to stop some of the operating equipment during the idling stop period.

  When the idling stop processing means 24 operates to stop idling, the battery capacity of the second level must be present in the lead storage battery as the remaining capacity at a minimum. However, the second level alone is not enough. Therefore, it is desirable to provide an additional level. Additional levels are described below.

  As a method for measuring the remaining capacity of the lead storage battery for determining the above-mentioned level, the method described as the prior art can be applied in addition to the preferred embodiment of the present invention described below. However, in the method of calculating the remaining capacity using the internal impedance, as described above, it is difficult to measure the internal impedance of the storage battery when the engine is operating and the generator is operating. The capacity cannot be determined. In such a method, when there are only the first and second determination levels, if the measurement for determining the remaining capacity of the storage battery cannot be performed for a long time, the determination of the remaining capacity level of the storage battery is not possible. Become accurate.

  For example, a car equipped with a storage battery whose remaining capacity is determined to be at the second level in a certain situation then traveled at a low speed while using an air conditioner or heater in a situation such as traffic jams, so the discharge state from the storage battery When idling is stopped for a long time, it is difficult to determine whether the remaining capacity of the storage battery at that time is at the second level or below the second level, and it is difficult to determine idling stop. Therefore, it is desirable to have an additional level for judging a remaining capacity larger than the second level at least 1, preferably 1 to 3. These levels are stored in the memory means 21.

  When the remaining capacity larger than the second level is set as the third level, the vehicle equipped with the storage battery determined to be at the third level travels in the state described above and the discharge state from the storage battery continues for a long time, When idling is stopped, the remaining capacity of the difference between the second level and the third level and the estimated value of the discharge amount during traveling are compared to determine whether the engine is at the second level. It becomes possible.

Furthermore, considering the safety for avoiding the shortage of the remaining capacity, it is desirable to set the fourth level.
A plurality of additional levels can be set in this way. However, if a large number of such additional levels are set, the remaining capacity measuring device becomes complicated and the price increases. Furthermore, the recognition of the remaining capacity of the storage battery is complicated for a user such as a driver.
From such a viewpoint, the additional level is preferably about 1 to 3 for practical use. Therefore, the total level is about 3-5.

The values of these levels are determined in consideration of the capacity of the storage battery, the starter starting power, the power consumption of the in-vehicle equipment, and the like.
An example of determining the level will be described in detail later as an example.

In the idling stop processing apparatus 20 for a vehicle according to the present embodiment, the absolute value of the remaining capacity of the storage battery or the ratio of the remaining capacity of the storage battery to the capacity at the time of full charge, as conventionally performed, is not obtained. As described above, a plurality of levels are provided for the remaining capacity, and the remaining capacity is determined based on the remaining capacity of the storage battery to be measured.
Compared with the conventional method for obtaining the absolute value of the remaining capacity or the ratio of the remaining capacity to the capacity at the time of full charge, in the vehicle idling stop processing device 20 according to the embodiment of the present invention, which of the three to five levels is selected. Since it is only determined whether it is in the standard, the apparatus can be simplified, the cost can be reduced, the outer shape of the apparatus can be reduced, and the practical effect is extremely high.

Means 22 for measuring the remaining capacity of the storage battery
When performing idling stop in the idling stop processing means 24, in order to determine whether or not the in-vehicle lead storage battery has a remaining capacity of the second level or higher, the remaining capacity of the storage battery is determined by the remaining capacity measuring means 22 of the storage battery. I need to know.
As means for measuring the remaining capacity 22 of such a storage battery, Japanese Patent Laid-Open No. 53-127646, Japanese Patent Laid-Open No. 63-27776, Japanese Patent Laid-Open No. 1-339068, Japanese Patent No. 2536257 (Japanese Patent Laid-Open No. 4-36257). No. 95788), Japanese Patent No. 2791751 (Japanese Patent Laid-Open No. 8-19103), Japanese Patent Laid-Open No. 9-171065, etc., can be applied.
However, a preferred method and apparatus according to the present embodiment will be described with reference to FIG. 3 as the preferred means for measuring the remaining capacity 22 of the storage battery according to the present embodiment.

FIG. 3 is a block diagram of a measuring apparatus for measuring the remaining capacity of an in-vehicle lead storage battery as the first embodiment as the means for measuring the remaining capacity 22 of the storage battery according to the present invention.
The lead-acid battery remaining capacity measuring device illustrated in FIG. 3 includes an electric equipment 4 such as a starter 1, a generator 2, a lead-acid battery 3, an air conditioner, a heater, a lighting device, an operation guide device, a music device, and a radio. An ammeter 6, a voltmeter 7, an arithmetic processing device 8 that performs arithmetic processing using the measured values of the ammeter 6 and the voltmeter 7, and a display that displays results such as a liquid crystal display 9
FIG. 3 also illustrates a control computer 10 that performs various controls of the automobile. As the control computer 10, the memory means 21, the idling stop determination means 23, the idling stop processing means 24, and the restarting means 25 of the vehicle idling stop processing device 20 illustrated in FIG. 1 can be incorporated.

In order to calculate the remaining capacity of the lead storage battery 3 and determine the level, the ammeter 6, the voltmeter 7, the arithmetic processing unit 8, the control computer 10 and the like are always supplied with power from the lead storage battery 3 and operate. It needs to be possible. Therefore, in addition to the power consumed by the electrical equipment 4 described above, the power consumed by the ammeter 6, the voltmeter 7, the arithmetic processing unit 8, and the control computer 10 is also considered as the battery capacity required for the second level There is a need to.
In general, the battery capacity consumed by the ammeter 6, the voltmeter 7, the arithmetic processing unit 8, and the control computer 10 is smaller than the battery capacity consumed by the electrical equipment 4 or the like.
In the present embodiment, for convenience, the battery capacity of the electrical equipment 4 considered as the second level battery capacity is changed to the ammeter 6, the voltmeter 7, the arithmetic processing unit 8, and the control computer 10. It shall include the battery capacity consumed.

The ammeter 6 measures the charge / discharge current of the lead storage battery 3.
The voltmeter 7 measures the terminal voltage of the lead storage battery 3.
As the ammeter 6 and the voltmeter 7, known measuring meters can be used.

The arithmetic processing unit 8 calculates the remaining capacity of the lead storage battery 3, determines the level illustrated in FIG. 2 based on the result, and determines idling stop in cooperation with the control computer 10.
Information relating to the operation (including stopping) and operation of the automobile related to the method for measuring the remaining capacity of the lead storage battery of the present embodiment is transmitted to the arithmetic processing unit 8 from the computer 10 for controlling the automobile. Therefore, it is assumed that the arithmetic processing unit 8 holds information necessary for calculating the remaining capacity of the lead storage battery 3 and determining the level described above.
Although the arithmetic processing unit 8 and the control computer 10 can be integrated, in the present embodiment, the case where the arithmetic processing unit 8 and the control computer 10 are independent from each other will be described.

  The arithmetic processing unit 8 includes, for example, a memory, a computer such as a microcomputer, and an A / D converter for inputting measurement signals from the ammeter 6 and the voltmeter 7. The arithmetic processing described below is performed by a computer. Data for calculating the remaining capacity of the lead storage battery 3 described below is stored in the memory.

  The display device 9 is not added in the present embodiment, and it is desirable to use it together with a display device already mounted on the automobile. That is, the display output of the display unit 9 described below is a case where it is displayed as the remaining capacity display mode of the storage battery on the panel portion of the automobile, for example, on a part of the existing display unit that performs speed display, failure display, etc. is there.

  With reference to FIG. 4, the process of the measuring apparatus for the remaining capacity of the lead storage battery illustrated in FIG. 3 will be described. FIG. 4 is a flowchart showing the operation of the lead-acid battery remaining capacity measuring apparatus illustrated in FIG.

Step 1: Pre-preparation process, preparation of data for calculating remaining capacity The car designer, in advance, for each of the first to third levels, the first to fourth levels, or the first to fifth levels, Data relating the discharge current value of the lead storage battery 3 and the terminal voltage value of the lead storage battery 3 corresponding to each level of battery capacity is obtained and stored in a memory as a table.
Thus, in the present embodiment, the relationship between the discharge current value of the lead storage battery 3 and the terminal voltage of the lead storage battery 3 indicating the specific remaining capacity corresponding to the plurality of levels of battery capacity is prepared as data. The data is stored as a data table in a memory in the arithmetic processing unit 8. That is, the present embodiment is characterized in that the relationship between the discharge current value and the terminal voltage during constant current discharge is used.

  An outline of a method for obtaining the relationship between the discharge current and the terminal voltage will be described with reference to FIG. A specific example will be described later as an example.

Step 21: First measurement step For a storage battery having a battery capacity that is larger than any of the discharge capacities defined by a plurality of levels at the time of full charge, a plurality of first constants are maintained until the battery voltage drops to a predetermined terminal voltage. Discharge is continued with the discharge current of, and the terminal voltage of the storage battery and the elapsed discharge time are measured.
The value of the constant first discharge current is a value that is assumed to be discharged at each level of battery capacity.
The predetermined terminal voltage is a terminal voltage at which the lead storage battery 3 can operate normally even when discharged.

Step 22: First characteristic calculation step The first characteristic indicating the relationship between the terminal voltage measured for each discharge elapsed time with respect to the discharge capacity, which is the product of the respective constant discharge current value and discharge time elapsed, The plurality of discharge currents are obtained.
Such a characteristic can be shown, for example, as a graph illustrated in FIG.

Step 23: Second measurement step For the storage battery that has dropped to the predetermined terminal voltage, the discharge is continued at a constant second discharge current lower than the plurality of discharge currents until the storage battery drops to the predetermined terminal voltage. The terminal voltage and discharge elapsed time of the storage battery at that time are measured.

Step 24: Second characteristic calculation step For each of the plurality of discharge capacities A, it is defined as the product of a plurality of first discharge currents Id1 that are constant in the first measurement step and the discharge elapsed time T1 at that time. The first discharge capacity, the second discharge capacity defined as the product of the constant second discharge current Id2 in the second measurement step and the discharge elapsed time T2 at that time, and the discharge capacity A, A third discharge capacity is calculated by the following calculation.

        (Id1 × T1) + (Id2 × T2) −A

  Further, the calculated third discharge capacity is applied to the discharge capacity / terminal voltage characteristics obtained in the first characteristic calculation step to calculate a corresponding terminal voltage, and the discharge current and the terminal voltage are calculated for each discharge capacity. A second characteristic indicating the relationship is obtained.

Step 25: Approximation process The result of the second characteristic is expressed in an approximate expression.

According to the experiment by the present inventor, when the lead storage battery 3 is used as the storage battery, it has been found that the relationship between the discharge current value and the terminal voltage can be approximated by a linear expression. Therefore, the data stored in the memory may be tilt data and intercept data. A plurality of such sets of inclination data and intercept data are prepared for the discharge capacity of the lead storage battery 3 corresponding to the battery capacity defining the above level, and stored in the memory.
Thus, it was found that the relationship between the discharge current value of the lead storage battery 3 and the terminal voltage, which shows a specific remaining capacity, can be approximated by a linear expression. The approximation by the linear expression requires very little data to be stored in the memory and simplifies the subsequent arithmetic processing. As a result, there is an advantage that the arithmetic processing device 8 can be easily manufactured and can be manufactured at a low price.
Also from such a viewpoint, it is preferable as the measuring device 22 for the remaining capacity of the lead storage battery of the present embodiment and for the remaining capacity of the storage battery of the idling stop processing device 20 of the vehicle.

Step 2: The charge / discharge current of the lead storage battery 3 is measured with the measurement ammeter 6, and the terminal voltage of the lead storage battery 3 is measured with the voltmeter 7 in the same manner. This measurement process is continuously performed regardless of the operation of the arithmetic processing unit 8. The discharge current measured by the ammeter 6 and the terminal voltage of the lead storage battery 3 detected by the voltmeter 7 are output as a continuous analog signal, for example, a voltage signal.

Step 3: The computer of the terminal voltage estimation arithmetic processing unit 8 inputs the current measurement value of the ammeter 6 and the voltage measurement value of the voltmeter 7 converted into a digital signal by the A / D converter at a predetermined sampling period. .
The arithmetic processing unit 8 uses the slope data a and the intercept data b for each level of discharge capacity stored in the memory, and the measured value m of the ammeter 6 is (m × a) + b. Is calculated to estimate the terminal voltage of the lead storage battery 3. This estimated terminal voltage is calculated for each discharge capacity.

Step 4: The discharge capacity estimation calculation processing device 6 compares the terminal voltage measured by the voltmeter 7 with the estimated plurality of terminal voltages, and the measured terminal voltage approximates any of the estimated terminal voltages. Or which terminal voltage is close.
Then, the arithmetic processing unit 8 estimates the discharge capacity corresponding to the estimated terminal voltage that is most approximated as the remaining capacity of the lead storage battery 3. From the characteristics illustrated in FIG. 6, the remaining capacity of the lead storage battery 3 at that time can be estimated.
The remaining capacity of the lead storage battery 3 estimated in this way corresponds to the battery capacity that defines the above-mentioned level.
Therefore, the remaining capacity calculated by the arithmetic processing unit 8 can be easily used for the determination in the idling stop determination means 23 of the idling stop processing unit 20 of the vehicle illustrated in FIG.

The discharge current value of the storage battery takes various values depending on the life of the storage battery, season, time, weather, driver, and driving state.
Therefore, it is practically very useful that the remaining capacity of the storage battery can be determined over a wide range of current values as in the embodiment of the present invention.

First Embodiment Hereinafter, a first embodiment of the idling stop processing device 20 for a vehicle and a measurement device for the remaining capacity of a lead storage battery will be described.
As a first example of a vehicle idling stop processing device 20 and a lead-acid battery remaining capacity measuring device according to an embodiment of the present invention, in an automobile having an idling stop function and having a lead-acid battery as a battery, FIG. The capacity of the lead storage battery necessary for starting the engine was tested under various temperature conditions using the measurement apparatus for the remaining capacity of the lead storage battery shown in FIG.

As the first-level determined lead-acid battery 3, one having a capacity of 20 Ah at full charge was used.
As a result of actual measurement, the capacity of the lead storage battery necessary for starting the engine by starting the starter 1 was 8 Ah with a margin. Therefore, 8Ah was set as the first level.
The battery capacity at the first level was 40% of the battery capacity at full charge.

The standard time for performing the idling stop at the second level was assumed to be 3 minutes, and it was assumed that a maximum current of 30 A would flow from the lead storage battery 3 to the in-vehicle electrical equipment 4 during the idling stop period. Therefore, the standard value of the battery capacity consumed by the electrical equipment 4 when idling is stopped is 1.5 Ah.
Since the battery capacity of the first level is 8 Ah and the power consumption of the electrical equipment 4 during the idling stop period is 1.5 Ah, the total is 9.5 Ah, but with a margin, the battery capacity of the second level is 10 Ah. did.

Third and Fourth Level Determination Between the second level 10Ah and the fully charged battery capacity 20Ah, the third level battery capacity 13Ah and the fourth level battery capacity 18Ah were set.
In this experimental example, the additional levels were only the third and fourth levels.

Collection of characteristic data in FIG. 6 A lead storage battery having a capacity of 20 Ah at the time of full charge was used as a sample (sample), and discharging was performed by a known method, and the voltage between terminals of the test storage battery at that time was measured.
Constant current discharge was performed at 5A, 10A, 20A, and 30A on the test lead-acid batteries. Such a constant current discharge value is assumed to be an appropriate value between 0A and 30A because a maximum of 30A flows from the lead-acid battery to the vehicle-mounted electrical equipment.
FIG. 6 is a graph showing the relationship between the terminal voltage and the discharge current value of the test lead-acid battery obtained in the above experiment.
The horizontal axis of FIG. 6 shows the discharge capacity D of a lead acid battery, and the vertical axis | shaft shows the terminal voltage of a lead acid battery.
As illustrated in FIG. 6, when discharging at a constant current, the drooping characteristics of the terminal voltage at that time differ depending on the difference in the current value.

Extraction of characteristic data of FIG. 7 The constant current discharge was continued until the terminal voltage of the lead storage battery decreased to 10.5 V, and the time T1 when the constant current discharge was performed was measured. The first discharge capacity D1 was obtained by multiplying the time T1 and the current value of each constant current discharge.
The 12V lead acid battery is configured by connecting 6 cells in series of approximately 2V per cell. When the battery of 1 cell is discharged to 1.75 V or less, the battery itself is damaged due to overdischarge. Therefore, 10.5 V, which is 6 times 1.75 V, was set as the lower limit voltage in discharging.

Next, the lead storage battery whose terminal voltage reached 10.5 V by each constant current discharge continuously performed a constant current discharge at a current lower than the above-described constant current discharge, for example, 4A.
When the constant current discharge at 4 A was started, the terminal voltage of the lead storage battery temporarily increased, but the discharge was continued until the terminal voltage decreased to 10.5 V again. The time T2 during which constant current was discharged at 4A was measured.
The second discharge capacity D2 was obtained by multiplying the time T2 and the discharge current value = 4A.

  The values of the first discharge capacity D1 and the second discharge capacity D2 were different depending on the current value of constant current discharge.

  The following calculation was performed about each experimental result of constant current discharge value 5A, 10A, 20A, 30A.

D1 + D2-8 = D3 ₈

The symbol D3 ₈ means the third discharge capacity D3 with respect to the first level battery capacity 8Ah.
According to FIG. 6, the terminal voltage Vd ₈ corresponding to the calculated discharge capacity D3 ₈ was read. The current value of the constant current discharge read here and the voltage Vd ₈ were plotted to obtain the characteristics shown in FIG.

The third discharge capacity D3 ₁₀ for the second level battery capacity 10Ah is obtained by performing the following calculation.

D1 + D2-10 = D3 ₁₀

According to FIG. 6, the terminal voltage Vd ₁₀ corresponding to the calculated discharge capacity D3 ₁₀ was read. By plotting the current and voltage Vd ₁₀ of the constant current discharge was read here, give the characteristics shown in FIG. 7 (B).

In the same manner, it reads the terminal voltage Vd ₂₀ corresponds to the discharge capacity D3 _20, obtains the characteristic of FIG. 7 (C) to plot the results, read the terminal voltage Vd ₃₀ corresponds to the discharge capacity D3 _30, The results were plotted to determine the characteristics shown in FIG.

FIG. 7A is a graph illustrating a characteristic curve L1 showing the relationship between the discharge current value of 8 Ah, the remaining capacity of the test lead storage battery being the first level battery capacity, and the terminal voltage of the lead storage battery.
FIG. 7B is a graph illustrating a characteristic curve L2 showing the relationship between the discharge current value of 10 Ah, in which the remaining capacity of the test lead-acid battery is the second-level battery capacity, and the terminal voltage of the lead-acid battery.
FIG. 7C is a graph illustrating a characteristic curve L3 showing the relationship between the discharge current value of 13 Ah, the remaining capacity of the test lead storage battery being the third level battery capacity, and the terminal voltage of the lead storage battery.
FIG. 7D is a graph illustrating a characteristic curve L4 showing the relationship between the discharge current value of 18 Ah, in which the remaining capacity of the test lead-acid battery is the fourth level battery capacity, and the terminal voltage of the lead-acid battery.

The characteristic curves shown in FIGS. 7A to 7D are results obtained by approximating the relationship between the plotted discharge current value and the terminal voltage by the least square method, and each can be represented as a substantially straight line.
The curve L1 showing the relationship between the discharge current value and the terminal voltage when the remaining capacity of the test lead-acid battery illustrated in FIG. 7A is 8 Ah is shown with a slope of a1 and a vertical axis intercept b1. Is a straight line that can be expressed by the following equation.

      L1 = a1 · x + b1 (1)

  Similarly to the above, the curves in FIGS. 7B to 7D can also be represented by the following formulas showing straight lines.

L2 = a2 · x + b2 (2)
L3 = a3 · x + b3 (3)
L4 = a3 · x + b4 (4)

The relationship between the discharge current and the terminal voltage obtained in this way was organized as battery capacity, and stored in the form of a table in the memory of the arithmetic processing unit 8 illustrated in FIG. Actually, it was stored in the memory as a pair with an inclination, for example, a1 and an intercept value, for example, b1. Thus, since the data stored in the memory is only the parameters described above, the amount of memory used is very small.
Thus, the remaining capacity can basically be expressed by a linear relational expression between the discharge current and the terminal voltage.
The above processing is the preparatory work of Step 1 illustrated in FIG.

  After the preparatory work described above, the lead storage battery was actually mounted on the automobile, and the operations after Step 2 in FIG. 4 were performed.

  As the lead storage battery 3 mounted on the automobile, a lead storage battery was discharged by a known method and the remaining capacity was adjusted to 17 Ah.

  While the automobile engine was stopped, the ammeter 6 was used to perform constant current discharge at a current value Am for 2 seconds, during which time the terminal voltage of the lead storage battery was measured with the voltmeter 7 to obtain a voltage value Vm.

In the computer of the arithmetic processing unit 8, the inclination data a1 to a4 and the intercept data b1 to b4 of the straight lines L1 to L4 described above are read from the memory, and the current value Am measured by the ammeter 6 is used as the discharge current value x. Substituting and calculating the estimated voltage Um _{1 to} Um ₄ of the terminal voltage.

  Then, the following determination was performed about the voltage value Vm measured with the voltmeter 7. FIG.

Vm> Um ₄
Um ₄ >Vm> Um ₃
Um ₃ >Vm> Um ₂
Um ₂ >Vm> Um ₁

By this comparison and determination, it is possible to know where the terminal voltage measured by the voltmeter 7 is located. For example, if Um ₄ >Vm> Um ₃ , the lead storage battery 3 has a third level remaining capacity.

Next, the electrical equipment 4 was operated with the engine stopped, that is, with the generator 2 stopped, and left for a certain period of time.
Thereafter, the operation of the electric equipment 4 was stopped.
During this time, the arithmetic processing unit 8 accumulated the measurement values of the ammeter 6 and integrated the current values discharged from the lead storage battery 3. According to experiments, the value corresponded to 7 Ah.

  Thereafter, with the engine stopped, a constant current discharge with a current value An was performed for 3 seconds, during which the terminal voltage of the lead storage battery 3 was measured with a voltmeter 7 to obtain a voltage value Vn.

In the computer of the arithmetic processing unit 8, the inclination data a1 to a4 and the intercept data b1 to b4 of the straight lines L1 to L4 described above are read from the memory, and the current value An measured by the ammeter 6 is used as the discharge current value x. Substituting and calculating terminal voltage estimated values Un _{1 to} Un ₄ .

  Then, the following determination was performed about the voltage value Vn measured with the voltmeter 7. FIG.

Vn> Un ₄
Un ₄ >Vn> Un ₃
Un ₃ >Vn> Un ₂
Un ₂ >Vn> Un ₁

By this comparison and determination, it is possible to know where the terminal voltage measured by the voltmeter 7 is located. For example, if Un ₃ >Vn> Un ₂ , the lead storage battery 3 has a second level remaining capacity.

When the remaining capacity of the lead storage battery 3 is at the second level, the remaining capacity necessary for starting the engine is present in the lead storage battery 3.
Then, after that, when an engine start experiment was conducted, the engine could be started.

After a certain amount of time had elapsed since the engine was started, the engine was stopped.
With the engine stopped, a constant current discharge with a current value Ap was performed for 5 seconds, during which time the terminal voltage of the lead storage battery 3 was measured with a voltmeter 7 to obtain a voltage Vp.

In the computer of the arithmetic processing unit 8, the inclination data a1 to a4 and the intercept data b1 to b4 of the straight lines L1 to L4 described above are read from the memory, and the current value Ap measured by the ammeter 6 is used as the discharge current value x. Substituting and calculating terminal voltage estimated values Up _{1 to} Up ₄ .
Then, the following determination was performed about the voltage value Vp measured with the voltmeter 7. FIG.

Vp> Up ₄
Up ₄ >Vp> Up ₃
Up ₃ >Vp> Up ₂
Up ₂ >Vp> Up ₁

By this comparison and determination, it is known where the terminal voltage Vp measured by the voltmeter 7 is located. For example, if Up ₃ >Vp> Up ₂ , the lead storage battery 3 has a second level remaining capacity.

  Thereafter, the remaining capacity of the lead storage battery was measured by a known method for measuring the remaining capacity of the lead storage battery, for example, an invention described in Japanese Patent Application Laid-Open No. Hei 9-171065 improved by a current integration method. The remaining capacity of the storage battery 3 was 11 Ah. Since this remaining capacity is not less than the above-mentioned second level battery capacity and not more than the third level battery capacity, the lead storage battery 3 exhibited the second level remaining capacity.

  Thus, as shown in the present embodiment, (1) In advance, the relationship between the discharge current and the terminal voltage of the lead storage battery 3 in a specific discharge capacity is represented by a straight line, and the slope data indicating those straight lines. And (2) are stored in the memory of the arithmetic processing unit 8, and (3) are measured by the ammeter 6 and the voltmeter 7 immediately before the automobile is actually started and stopped. (4) In the arithmetic processing device 8, the predicted value of the terminal voltage is calculated by substituting the discharge current measured by the ammeter 6 into the slope data and intercept data stored in the memory. (5) By comparing the predicted value of the calculated terminal voltage with the voltage value measured by the voltmeter 7, depending on where the terminal voltage of the lead storage battery 3 measured by the voltmeter 7 is located in the predicted terminal voltage Determines the level of remaining capacity of lead-acid battery 3 Kill.

  The level thus determined is sent from the arithmetic processing unit 8 to the memory means 21 of the idling stop processing unit 20 of the vehicle. The idling stop determination means 23 of the vehicle idling stop processing device 20 refers to the remaining capacity level data to determine whether or not to perform idling stop when the automobile is temporarily stopped, and the idling stop processing means 24 performs idling stop. .

  Information displayed on the display unit 9 from the arithmetic processing unit 8 can be provided to the driver.

In this embodiment, the absolute value of the remaining capacity of the lead storage battery 3 is not calculated. However, since the state of the remaining capacity of the lead storage battery 3 for determining whether or not to perform the idling stop is known as a level, the idling stop is performed. Applicable to automobiles with functions.
In the method of this embodiment, the processing performed by the arithmetic processing unit 8 using the measurement results of the ammeter 6 and the voltmeter 7 after the preparatory work shown in step 1 shown in FIG. Is easy. Therefore, the measurement apparatus for the remaining capacity of the lead storage battery of the present embodiment having the ammeter 6, the voltmeter 7 and the arithmetic processing unit 8 illustrated in FIG. 3 can be easily mass-produced at a low price. It can be installed and applied.

  As described above, the case where the lead storage battery 3 is used as the storage battery has been described, but this embodiment does not use the specific gravity of the electrolyte as an index, does not use the internal impedance, and does not perform the processing specified for the lead storage battery. As a secondary battery, it is applicable also to storage batteries other than a lead storage battery.

When using a lead storage battery having a characteristic in which the relationship between the discharge current amount and the terminal voltage value at the level of the remaining capacity of the lead storage battery 3 changes depending on the deformation mode temperature or the deterioration state, the remaining capacity to be determined as necessary. It is desirable to prepare a data table of discharge current values and terminal voltage values according to temperature and / or deterioration state at each level, and to correct the above-described values based on the results.
When preparing additional data tables according to temperature and / or deterioration state, there is a possibility that the cost of the apparatus increases due to an increase in the number of data tables to be prepared. In this case, it is desirable to obtain a correction parameter based on the temperature and / or the deterioration state in advance, and to correct the relationship between the discharge current value and the terminal voltage value for each level of the remaining capacity of the lead storage battery using the correction parameter. By doing so, it is only necessary to prepare one data table for each level to be determined, and the cost of the apparatus can be suppressed.

Second Embodiment As a second embodiment of the present invention, when the level of the remaining capacity of the lead storage battery according to the first embodiment described above is determined and the remaining capacity equal to or higher than the second level is found, in the next stop Until the measurement device for the remaining capacity of the lead storage battery performs the above-described level determination operation, the discharge current value continuously measured by the ammeter 6 is accumulated in the arithmetic processing device 8, as in a known technique, The level of the remaining capacity of the storage battery can be determined using the accumulated current value accumulated.
According to the second embodiment, in addition to the closest remaining capacity determination level, the determination is made based on the integrated value of the charge / discharge current from the determination time to the determination time. It becomes possible to increase the accuracy of the.

Third Embodiment In the third embodiment, instead of the method and apparatus described with reference to FIGS. 3 to 7, a method disclosed in Japanese Patent Laid-Open No. 9-171065 is applied to The remaining capacity is calculated and the level is determined.
In the method disclosed in Japanese Patent Laid-Open No. 9-171655, (1) a data table showing the relationship between the terminal voltage of the storage battery and the remaining capacity in constant current discharge at a specific discharge current value is prepared in advance. (2) The arithmetic processing device 8 detects when the current value measured by the ammeter 6 becomes a specific discharge current, and the arithmetic processing device 8 obtains the remaining capacity of the storage battery.

In this method and apparatus, it is necessary to prepare a data table of terminal voltage and remaining capacity in constant current discharge at a specific discharge current value. As in the first embodiment, the relationship between the terminal voltage and remaining capacity is obtained. Since it is difficult to express with a primary or secondary expression, the processing is more complicated than in the first embodiment.
However, the remaining capacity of the storage battery can be calculated according to the third embodiment, and the arithmetic processing unit 8 can determine the level by determining the result.

Fourth Embodiment As a fourth embodiment, the invention described in Japanese Patent Laid-Open No. 53-127646, Japanese Patent Publication No. 1555466, Japanese Patent Publication No. 1927445, that is, when the engine start key is turned. The remaining capacity of the storage battery is calculated using the relationship between the generated current and voltage.
The remaining capacity of the storage battery is calculated by the processing unit 8.

In the point of using the relationship between the current and voltage of the fourth embodiment, it is the same as the processing of the remaining capacity measuring device of the lead storage battery of the first embodiment, but the first embodiment is in constant current discharge. Whereas the relation between the current value of the constant current discharge indicating the predetermined remaining capacity and the terminal voltage is used, the fourth embodiment has a transient current value generated when the engine start key is turned. The voltage value relationship is used.
However, the remaining capacity of the storage battery can be calculated according to the fourth embodiment, and the arithmetic processing device 8 can determine the level by determining the result.

  The remaining capacity of the storage battery calculated in the present invention indicates detection accuracy sufficient to determine the level of the remaining capacity of the storage battery that determines whether or not idling can be stopped, for example. Therefore, when the invention of the second aspect of the present invention is applied to the invention of the first aspect, it is particularly preferable for application to a vehicle operating with an internal combustion engine having an idling stop function due to a synergistic effect of both.

FIG. 1 is a configuration diagram of a vehicle idling stop processing apparatus according to the present invention. FIG. 2 is a diagram illustrating a level representing the remaining capacity of the storage battery according to the embodiment of the present invention. FIG. 3 is a block diagram of an apparatus for calculating the remaining capacity of an in-vehicle storage battery as an embodiment of the present invention. FIG. 4 is a flowchart showing processing and preparatory operations in the arithmetic processing unit of the apparatus for measuring the remaining capacity of the lead storage battery shown in FIG. FIG. 5 is a flowchart illustrating the process in step 1 of FIG. FIG. 6 is a graph showing the discharge characteristics of the storage battery. 7A to 7D are graphs showing the relationship between the discharge current and the terminal voltage used in the measurement apparatus for the remaining capacity of the lead storage battery illustrated in FIG.

Explanation of symbols

1 .... Starter 2 .... Generator 3 .... Lead battery 4 .... Electrical equipment 6 .... Ammeter 7 .... Voltmeter 8 .... Processing unit 9 .... Display 10 .... Control computer 20 .... Vehicle Idling stop processing equipment
21 .. Memory means
22..Measuring means for remaining capacity of storage battery
23..Idling stop determination means
24 .. Idling stop processing means
25 .. Restart means

Claims (6)

In advance, the relationship between the discharge current in the plurality of discharge capacities and the terminal voltage of the storage battery, the terminal voltage is obtained using the discharge current as a variable, and the step of obtaining a plurality of approximate expressions corresponding to the plurality of discharge capacities,
During the operation of the vehicle, a measurement process for continuously measuring the actual discharge current of the in-vehicle storage battery and the actual terminal voltage of the storage battery;
An estimated terminal voltage calculation step of calculating an estimated value of a plurality of terminal voltages by substituting the measured discharge currents into the obtained plurality of approximate equations;
A determination step of comparing the measured terminal voltage of the storage battery with the calculated plurality of estimated terminal voltages to determine which range of estimated terminal voltages are present;
A remaining capacity determination step of determining a discharge capacity corresponding to an estimated terminal voltage within the range of the plurality of discharge capacities and determining the discharge capacity as the remaining capacity of the storage battery. Method. In the step of obtaining the approximate expression,
For a storage battery having a battery capacity at full charge that is greater than any of the plurality of discharge capacities, discharging is continued with a plurality of constant first discharge currents until the terminal voltage drops to a predetermined terminal voltage, and the terminals of the storage battery at that time A first measuring step for measuring voltage and discharge elapsed time;
A first characteristic indicating a relationship between the terminal voltage measured at each discharge elapsed time with respect to a discharge capacity that is a product of the respective constant discharge current value and discharge time elapsed is obtained for the plurality of discharge currents. A first characteristic calculating step;
With respect to the storage battery that has dropped to the predetermined terminal voltage, until the voltage drops to the predetermined terminal voltage, the discharge continues with a constant second discharge current lower than the plurality of discharge currents, and the terminal voltage of the storage battery at that time A second measuring step for measuring the elapsed discharge time;
For each of the plurality of discharge capacities A, a first discharge capacity defined as a product of a plurality of constant first discharge currents Id1 and a discharge elapsed time T1 in the first measurement step, The second discharge capacity defined as the product of the constant second discharge current Id2 and the discharge elapsed time T2 at that time in the measurement step 2, and the discharge capacity A, the third discharge capacity by the following calculation And
(Id1 × T1) + (Id2 × T2) −A
By applying the calculated third discharge capacity to the discharge capacity / terminal voltage characteristics obtained in the first characteristic calculation step, the corresponding terminal voltage is calculated, and the relationship between the discharge current and the terminal voltage for each discharge capacity. A second characteristic calculating step for obtaining a second characteristic indicating
An approximation step for expressing the result of the second characteristic in an approximate expression,
The method for measuring the remaining capacity of the storage battery according to claim 1. In the approximating step, for each discharge capacity, the relationship between the discharge current and the terminal voltage is approximated by a linear expression.
The method for measuring the remaining capacity of the storage battery according to claim 1. In advance, the relationship between the discharge current in the plurality of discharge capacities and the terminal voltage of the storage battery, the terminal voltage is obtained using the discharge current as a variable, and the means for obtaining a plurality of approximate expressions corresponding to the plurality of discharge capacities,
An ammeter for measuring the discharge current of the storage battery;
A voltmeter for measuring the terminal voltage of the storage battery;
An estimated terminal voltage calculation step of calculating an estimated value of a plurality of terminal voltages by substituting the discharge current measured by the ammeter into the plurality of approximate expressions obtained;
A determination means for comparing the terminal voltage of the storage battery measured with the voltmeter with the calculated plurality of estimated terminal voltages to determine which range of the estimated terminal voltage is present;
Of the plurality of discharge capacities, a discharge capacity corresponding to an estimated terminal voltage within the range is determined, and a remaining capacity determination means for determining the discharge capacity as the remaining capacity of the storage battery, measuring device. The means for obtaining the approximate expression is:
For a storage battery having a battery capacity at full charge that is greater than any of the plurality of discharge capacities, discharging is continued at a plurality of constant first discharge currents until the battery voltage drops to a predetermined terminal voltage. Measure the voltage and elapsed discharge time,
A first characteristic indicating a relationship between the terminal voltage measured for each discharge elapsed time with respect to a discharge capacity, which is a product of the respective constant discharge current value and discharge time elapsed, is obtained for the plurality of discharge currents,
With respect to the storage battery that has dropped to the predetermined terminal voltage, until the voltage drops to the predetermined terminal voltage, the discharge continues with a constant second discharge current lower than the plurality of discharge currents, and the terminal voltage of the storage battery at that time Measure the elapsed discharge time,
For each of the plurality of discharge capacities A, a first discharge capacity defined as the product of a plurality of first discharge currents Id1 and a discharge elapsed time T1 at that time, and a constant second discharge current For the second discharge capacity defined as the product of Id2 and the discharge elapsed time T2 at that time, and the discharge capacity A, a third discharge capacity is calculated by the following calculation:
(Id1 × T1) + (Id2 × T2) −A
By applying the calculated third discharge capacity to the obtained discharge capacity / terminal voltage characteristics to calculate the corresponding terminal voltage, the second characteristic indicating the relationship between the discharge current and the terminal voltage is obtained for each discharge capacity,
The result of the second characteristic is expressed in an approximate expression.
The measuring apparatus of the remaining capacity of the storage battery of Claim 4. The storage battery is a lead storage battery,
In the approximating means, for each discharge capacity, the relationship between the discharge current and the terminal voltage is approximated by a linear expression, and slope data and intercept data approximated by the linear expression are stored in the storage means.
The measuring apparatus of the remaining capacity of the storage battery of Claim 5.

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