JP2009055709A - Monitoring device for state of charge of battery and engine controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately grasp the state of charge of a battery through simple configuration with respect to a monitoring device for the state of charge of batteries and an engine controller favorably applicable to vehicles having an idle stop/start function. <P>SOLUTION: The monitoring device includes: an engine 1; a generator 2 connected to the engine 1; a battery 3 electrically connected to the generator 2; an electrical apparatus that is electrically connected to the battery 3 and operates on power supplied from the battery 3 and/or the generator 2; and an electrical apparatus controlling means 4 that controls the operation of the electrical apparatus. Based on the voltage applied by the battery 3, the electrical apparatus controlling means 4 estimates whether a current is flowing from the generator 2 into the battery 3 or a current is flowing from the battery 3 out to the electrical apparatus and thereby determines the state of charge of the battery 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a battery charge state monitoring device and an engine control device suitable for use in a vehicle having an idle stop start function, and more particularly to a battery charge state monitoring device for monitoring a battery state based on a balance of battery current. And an engine control device for controlling the operation of the engine based on the battery state.

In recent years, a vehicle having an idle stop start (hereinafter referred to as ISS) device that automatically stops or restarts an engine at a stop such as waiting for a signal has been put into practical use due to an increase in environmental awareness.
In a vehicle having such an ISS device, the engine is automatically stopped when a predetermined engine stop condition such as accelerator off, vehicle speed 0, battery SOC (charge rate or charge capacity) is greater than a predetermined value and less than a predetermined electric load is satisfied. In addition, the engine is restarted when an engine restart condition such that the accelerator is on, the brake is off, or the electric load is equal to or greater than a predetermined value is satisfied. By executing such an idle stop, the emission of carbon dioxide gas from the vehicle is reduced and the fuel efficiency is improved.

On the other hand, recent vehicles are equipped with various electrical components, and power consumption tends to increase. Further, in a vehicle equipped with the above-mentioned ISS device, the number of engine starts also increases, so in a vehicle with an ISS device, the load on the battery increases.
The battery mounted on the vehicle is always charged by the alternator while the engine is running. However, if the power consumption is larger than the amount of charge, the remaining capacity of the battery decreases. Further, since the output of the battery depends on the remaining capacity of the battery, if the remaining capacity of the battery is reduced while the engine is stopped by the ISS device, sufficient output for starting the engine cannot be obtained, and restarting after the engine is stopped cannot be performed. There is a fear.

Therefore, in order to keep the ISS device in an operable state, the state of charge of the battery is reliably estimated, and if it is determined that the output required for starting the engine cannot be obtained, the ISS is prohibited (automatic engine operation). Stop).
In addition, even for a vehicle not equipped with an ISS, it is extremely important to accurately grasp the state of charge of the battery. For this reason, various techniques for accurately knowing the remaining capacity of the battery have been proposed. Yes.

For example, in a lead battery, it is known that the specific gravity of the battery fluid varies depending on the state of charge of the battery. Based on such characteristics, a specific gravity sensor is provided in the battery, and the specific gravity sensor is used. Techniques for detecting or estimating the state of charge of a battery are known.
In addition to this, for example, the following Patent Document 1 discloses a technique for calculating the internal capacity of a lead battery from the current and voltage changes when the engine is restarted to calculate the remaining capacity of the lead battery. ing.
JP 2004-42799 A

However, in the conventional technology, since it is necessary to obtain the battery circuit voltage at the time of key-on and to obtain the current and voltage characteristics at the time of starting the engine, it is possible to calculate the state of charge with a simple configuration and good accuracy. I couldn't.
The present invention has been devised in view of such a problem, and is a battery charge state monitoring device capable of grasping a battery charge state with a simple configuration, and an engine operation control according to the battery charge state. It is an object of the present invention to provide an engine control device that performs the above-described operation.

  For this reason, the state-of-charge monitoring device for a battery of the present invention according to claim 1 includes an engine, a generator mechanically connected to the engine, a battery electrically connected to the generator, and the battery. An electrical device that is electrically connected to the battery and / or operated by supplying power from the generator, and electrical device control means for controlling the operation of the electrical device, the electrical device control means comprising: Based on the voltage applied by the battery, it is estimated whether the current from the generator is flowing into the battery or the current is flowing from the battery to the electrical device, and the estimation It is characterized in that the state of charge of the battery is determined based on the result.

According to a second aspect of the present invention, the battery charge monitoring apparatus according to the present invention calculates the current balance of the battery by repeating the determination of the current inflow / outflow state of the battery every predetermined time and accumulating the determination results. Thus, the state of charge of the battery is determined.
The battery charge monitoring device of the present invention according to claim 3 sets the first counter value when the voltage of the battery is equal to or higher than a predetermined value, and sets the second counter value when the voltage of the battery is lower than the predetermined value. It is characterized in that it is determined whether or not the state of charge of the battery is lowered by comparing a value obtained by sequentially adding the first and second counter values with a predetermined threshold value. .

The battery charge monitoring apparatus of the present invention according to claim 4 is characterized in that the first counter value is a positive value and the second counter value is a negative value.
In the battery charge monitoring apparatus of the present invention according to claim 5, the first and second counter values are set based on the electric load of the electric device and the power generation capacity of the generator. It is characterized by.

According to a sixth aspect of the present invention, there is provided the battery charge monitoring apparatus according to the present invention, wherein a ratio of absolute values of the first and second counter values is set to 1: 2.
The battery charge monitoring apparatus of the present invention according to claim 7 is characterized in that an upper limit value and a lower limit value are provided for the integrated value of the counter value.
The engine control apparatus of the present invention according to claim 8 is an idle stop start that automatically stops the operation of the engine when a predetermined condition is satisfied, and restarts the engine when a predetermined return condition different from the predetermined condition is satisfied. An engine control device that performs control, predicting a current balance of a battery that supplies power when the engine is restarted based on a voltage applied to the engine control device, and charging the battery based on the prediction result The state is determined, and automatic stop of the operation of the engine is permitted or prohibited based on the determination result.

  An engine control device according to a ninth aspect of the present invention is an engine control device that controls the engine speed during idling of the engine, and is based on the voltage applied to the engine control device. The present invention is characterized in that a current balance of a battery that supplies electric power is predicted, a state of charge of the battery is determined based on the prediction result, and an idle speed of the engine is changed based on the determination result.

  According to the battery state-of-charge monitoring apparatus of the present invention, since the state of charge of the battery is monitored based on the balance of battery current, there is an advantage that the state of charge of the battery can be accurately grasped. Further, there is no need to add a new sensor or the like, and it can be realized only by adding software, and there is an advantage that there is almost no increase in cost. In addition, the count value is set according to the voltage value of the battery, and the state of charge of the battery is estimated based on the value obtained by adding the count value. Therefore, there is an advantage that the logic is simple and the calculation load is light. .

Further, according to the engine control device of the present invention, when the state of charge of the battery is lowered, the battery can be charged by increasing the idle rotation speed, and the battery can be prevented from running out. There is an advantage.
Further, when the state of charge of the battery is lowered, the engine idle stop start control is prohibited, so that there is an advantage that a situation where the engine cannot be restarted after the engine is stopped can be avoided.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a battery charge state monitoring apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a main part configuration of a vehicle including the apparatus, and FIG. FIG. 3 is a schematic block diagram, FIG. 3 is a diagram for explaining the relationship between the current balance and voltage of the battery, FIG. 4 is a flowchart for explaining the operation, and FIG. 5 is a time chart for explaining the operation.

In FIG. 1, reference numeral 1 denotes an engine mounted on a vehicle. Further, an alternator (generator) 2 is mechanically connected to the engine 1 via a belt (not shown), and the alternator 2 is driven by the rotational driving force of the engine 1 to generate electric power. The rated output of the alternator 2 is 28.5 [V] in this embodiment.
Further, a battery (charger) 3 is electrically connected to the alternator 2, and the electric power generated by the alternator 2 is supplied to the battery 3, an electrical component described later, and the like. The battery 3 is a lead battery having a rating of 24 V in this embodiment.

  Further, the battery 3 and the alternator 2 include various electrical components (for example, an air conditioner, a car stereo, a headlight, etc.) and a vehicle control system (for example, an idle stop start (ISS) device, a fuel injection amount control device, an automatic transmission control). Device, etc.), and an ECU (electric equipment control means) for controlling the operation of these electrical components and the vehicle control device (collectively referred to as electrical equipment). FIG. 1 shows an ISS-ECU 4 that controls the operation of the ISS device, an AT-ECU 5 that controls the operation of the automatic transmission, and an engine ECU 6 that controls the operation of the engine 1 as representative examples of the ECU.

  In this device, the state of charge of the battery 3 is monitored based on the voltage detected by the ECUs 4 to 6. In particular, in the present embodiment, in the ISS-ECU 4 among the ECUs 4 to 6 described above, The charging state of the battery 3 is monitored based on the battery voltage V. Note that the charge state of the battery 3 may be monitored in any ECU as long as the voltage applied from the battery 3 can be detected.

  The ISS-ECU 4 is in a state where current is flowing into the battery 3 from the alternator 2 based on the voltage of the battery 3 detected by the ISS-ECU 4, or current is flowing out from the battery 2 to an electrical device such as an ISS device. It is determined whether the battery is in a state, and the state of charge of the battery 3 is predicted or monitored based on the determination result. Specifically, the determination of the current inflow / outflow state of the battery 3 is repeatedly performed at predetermined time intervals, and the current balance of the battery 3 is calculated by accumulating the determination results to calculate the current balance of the battery 3. Based on this, the state of charge of the battery 3 is monitored.

Next, the configuration of the main part of the present apparatus will be described with reference to FIG. 2. In the ECU 4, a counter setting unit 7, an integrating unit 8, and a determining unit 9 are functionally provided. 9, the state of the battery 3 is determined.
Here, the counter setting unit 7 sets a counter value for performing later-described calculation based on the battery voltage detected by the ECU 4, and specifically, the battery voltage every predetermined control period (for example, 5 seconds). Each time, the detected battery voltage is compared with a predetermined value (for example, 25 V), and if the battery voltage is equal to or higher than the predetermined value, the first counter value a (> 0, 1 in this embodiment) is obtained. The second counter value b (<0, -2 in the present embodiment) is set if it is less than the predetermined value. The counter value is a numerical value indicating inflow or outflow of current from the battery 3, and is used as a parameter indicating the state of the battery. The relationship with the battery voltage will be described in detail later.

  The accumulating unit 8 is means for sequentially adding the counter values set by the counter setting unit 7, and the counting of the counter values is always executed from the key-on to the key-off of the engine 1. At the time of key-off, the last calculated counter value is stored in a nonvolatile memory (not shown), and at the time of key-on, integration is started with the counter value stored at the previous key-off as an initial value. . Also, the initial value is set to 0 only when the first key is turned on after the vehicle is manufactured and when the first key is turned on after the battery 3 is replaced.

  Further, the determination unit 9 compares the value (integrated value) calculated by the integration unit 8 with a predetermined threshold value, and determines that the battery is sufficiently charged if it is equal to or greater than the predetermined threshold value. . On the other hand, if the integrated value calculated by the integrating unit 8 is less than a predetermined threshold value, it is determined that the remaining capacity of the battery 3 is decreasing, and the determination result is output to another ECU (for example, the engine ECU 6). It is supposed to be. In this embodiment, 0 is set as the predetermined threshold value. In other words, the predetermined threshold value is set to the same value (= 0) as the initial value set at the first key-on after the battery 3 is replaced, and a value indicating the state of the battery 3 when it is new is set as the threshold value. The Then, based on the state when the battery is new, when the current balance with respect to the battery 3 falls below this reference value, it is determined that the state of charge of the battery has decreased.

  Next, setting of the counter values a and b relating to the current balance based on the battery voltage will be described. FIGS. 3A and 3B are graphs showing the relationship between the current flowing out from the battery 3 and the battery voltage, and FIG. 3A is a state in which the battery 3 is in a good state of charge (a state in which the remaining capacity is high = almost). (B) shows test results in a state where the charge state of the battery 3 is not good (state where the remaining capacity is low). 3A and 3B, if the horizontal axis is a positive value, it indicates that current is flowing from the alternator 2 to the battery 3, and if it is negative, the current is supplied from the battery 3. Indicates that it has been released.

  3 (a) and 3 (b), the engine speed (that is, the generated power of the alternator 2) is changed for each predetermined electric load, and the battery voltage detected by the ECU 4 and the actual inflow / outflow of the battery 3 are changed. The result of measuring the current is plotted. In the figure, the shape of the plot points is changed for each electric load. In addition, the electrical load was set to 0 [A], 10 [A], 20 [A], 30 [A], 40 [A], and 50 [A], respectively.

  As a result, as shown in FIG. 3A, when the battery 3 is almost fully charged, almost no current flows from the battery 3 when the electrical load is low (0 [A] to 30 [A]). It was confirmed that no current was flowing out or a current was flowing in from the alternator 2 slightly. In other words, in this case, it was found that the electric load is almost covered by the electric power from the alternator 2 and almost no electric power is supplied from the battery 3.

On the other hand, when the electric load is increased (especially, refer to the electric loads 40 [A] and 50 [A]), it has been found that current is discharged from the battery 3 regardless of the engine speed. This is because the power supply from the battery 3 covers the power consumption of the electrical equipment that cannot be covered by the power supply from the alternator 2.
Further, as shown in FIG. 3B, it has been found that when the battery 3 is in a poorly charged state, current flows into the battery 3 when the electrical load is relatively low. This is because, when the state of charge of the battery 3 is lowered, the surplus power generated by the alternator 2 is used for charging the battery 3. In this case, the current value supplied to the battery 3 tends to increase as the electrical load decreases. This is presumably because the electric load is covered by the electric power generated by the alternator 2, so that the smaller the electric load, the larger the surplus electric power.

On the other hand, when the electrical load increases, current is also released from the battery 3 as in the characteristics shown in FIG. In this case, since the electric load cannot be covered only by the generated current from the alternator 2, even if the state of charge of the battery 3 is not good, the current is taken from the battery 3 to supply power to the electric load. is there.
By the way, when looking at FIG. 3 (a) as a whole, the battery current becomes negative when the voltage of the battery becomes less than a predetermined voltage (here, about 25 [V]) regardless of the difference in electric load or engine speed. It turns out that it becomes a value and the battery 3 will be in a discharge state. Similarly, if the voltage of the battery 3 is equal to or higher than a predetermined voltage, the battery current tends to be a positive value and the battery 3 tends to be charged.

  Considering this tendency further, even if the state of charge of the battery 3 shown in FIG. 3 (b) is not good, the voltage of the battery 3 remains at a predetermined voltage regardless of the difference in the electrical load and the engine speed. When it is less than (25 [V]), the battery current becomes a negative value, and the current is released from the battery 3. Further, it can be seen that the battery current becomes a positive value above the predetermined voltage, and the current flows into the battery 3.

Therefore, from the test results shown in FIGS. 3A and 3B, “the current from the alternator 2 is supplied to the battery 3 if the voltage of the battery 3 is equal to or higher than a predetermined voltage regardless of the state of charge of the battery 3. It can be concluded that if the battery voltage is less than the predetermined voltage, the battery current is discharged.
For this reason, it is possible to estimate whether the battery 3 is in a charged state or a discharged state without using a current sensor by detecting the battery voltage and comparing the battery voltage with a predetermined voltage.

  Therefore, in this apparatus, if the battery voltage is greater than or equal to a predetermined value in the counter setting unit 7, a counter value a (> 0) indicating that current is flowing into the battery is set, and if less than the predetermined value, A counter value b (<0) indicating that current is flowing out from the battery is set, and these counter values are integrated to sequentially calculate the current balance of the current of the battery.

  When the integrated value falls below a predetermined threshold value, it is determined that the remaining capacity of the battery 3 is reduced. Note that the values of a and b are set to 1 and -2 in this embodiment, respectively, but this can be tuned by experiment or the like, depending on the power generation characteristics, power generation capacity, and electric load of the alternator 2. It can be changed accordingly. Specifically, by performing calibration so as to match the actual current balance, the integrated value of the counter value can be set to the current balance.

In this embodiment, the ratio of the absolute values of the first and second counter values a and b is 1: 2. This is the current balance of the battery 3 during actual charging and discharging. This can be changed according to the power generation characteristics, power generation capacity, and electric load of the alternator 2.
By the way, in this embodiment, in order to prevent the difference between the integrated value of the counter value and the balance of the actual current value of the battery, an upper limit value and a lower limit value are provided for the integrated value of the counter value. In the embodiment, the upper limit value 255 and the lower limit value -255 are set. When the integrated value of the counter value becomes the upper limit value 255 or more, the integrated value is held at 255. Similarly, when the integrated value becomes the lower limit value −255 or less, the value is similarly held at −255.

  Since the battery state-of-charge monitoring apparatus according to one embodiment of the present invention is configured as described above, its operation will be described below with reference to the flowcharts of FIGS. 4 (a) and 4 (b). FIG. 4A is a flowchart of voltage acquisition, which starts with key-on (power ON). Then, after the control is started, the voltage V applied from the battery 3 to the ISS-ECU 4 is read at predetermined time intervals Δt (step S101), and then the voltage V is calculated N times (for example, N = 5) as the moving average V_ave. Obtained (step S102). This is repeated until key-off (power-off) is reached (step S103).

  FIG. 4B is a main flowchart of the present apparatus. First, in step S1, the counter integrated value Count_v obtained in the previous last control cycle is read from the memory. Next, the moving average V_ave of the battery voltage obtained in step S102 of the voltage acquisition flowchart is acquired (step S2). Then, the battery voltage V_ave is compared with a predetermined value Vth (= 25 [V]) (step S3), and if the battery voltage V_ave is larger than the predetermined value Vth, a predetermined value a (= 1) is added to Count_v ( In step S4), if the battery voltage V_ave is smaller than the predetermined value Vth, the predetermined value b (= −2) is added to Count_v (step S5).

Next, the counter integrated value Count_v and the upper limit value Count_max are compared (step S6). If the counter integrated value Count_v exceeds the upper limit value Count_max, the counter integrated value Count_v is held at the upper limit value Count_max (step S7). ).
If the counter integrated value Count_v is lower than the upper limit value Count_max, the counter integrated value Count_v is compared with the lower limit value Count_min (step S8), and the counter integrated value Count_v is smaller than the lower limit value Count_min. If so, the counter integrated value Count_v is held at the lower limit value Count_min (step S9). On the other hand, if the counter integrated value Count_v is larger than the lower limit value Count_min in step S8, the counter integrated value is maintained as it is (step S10).

  Next, it is determined whether or not the counter integrated value Count_v is larger than a predetermined threshold value Threshold (= 0) (step S11). Here, if the counter integrated value Count_v is larger than a predetermined threshold Threshold, it is determined that the state of charge of the battery 3 is good. In this case, the ECU 4 permits ISS (idle stop start) control (step S12). Thus, the engine is automatically stopped when a predetermined engine automatic stop condition is satisfied, and the engine is restarted when a predetermined engine restart condition is satisfied.

On the other hand, if the counter integrated value Count_v is smaller than the predetermined threshold Threshold, it is determined that the state of charge of the battery 3 is lowered, and ISS control is prohibited (step S13).
Thereafter, the routines after step S2 are repeated, and when the power is turned off (step S14), the counter integrated value Count_v at that time is stored in the memory (step S15), and the process ends.

By repeatedly executing the above operation, the actual current balance of the battery 3 can be simulated by the integrated value of the counter value set based on the battery voltage, and the current of the battery 3 can be obtained without using a current sensor. In addition to estimating the balance, the state of charge of the battery can be estimated based on the current balance of the battery 3.
Here, FIG. 5 is a graph comparing the actual current balance of the battery with the result obtained by integrating the counter value set based on the battery voltage described above, and the line a represents the actual battery voltage ( (Actually measured value), line b indicates the battery voltage detected by the ECU, line c indicates the actual current balance [A], and line d indicates the simulation result (integrated value of the counter value) by this apparatus. The voltage is indicated on the scale on the left side of the graph, and the counter integrated value is indicated on the scale on the right side of the graph.

As shown in FIG. 5, the current balance of the battery 3 indicated by the line c and the simulation (calculation balance, that is, the counter integrated value) indicated by the line d substantially coincide with each other, and the counter value integration as described above is performed. It was confirmed that the battery state was estimated well.
More specifically, at time t = 0 (initial state), the current balance of the battery 3 is 0, and the calculated balance (counter integrated value) is also 0. When the key is turned on in this state, in the case of this embodiment, a predetermined voltage or higher is maintained until time t1 (see line b). For this reason, the counter value is always added, and the counter integrated value of the line c has a characteristic of increasing to the right. In addition, the actual current balance of the battery 3 also corresponds to the counter integrated value, and the simulation result matches the actual current balance. As shown by line a, the battery voltage actually exceeds 28V, but the ECU 4 cannot recognize 28V or more, so the detected voltage has an upper limit of 28V.

Then, when the detected voltage becomes equal to or lower than the predetermined voltage at time t1, a negative counter value is added, so that the counter integrated value of line d decreases. In addition, the actual current balance is also lowered as shown by the line c, and the actual current balance of the battery 3 and the simulation result coincide with each other.
Although such a simulation was confirmed after time t1, as shown in FIG. 5, the simulation result and the actual current balance of the battery are substantially the same, and the battery 3 can be satisfactorily achieved with the simple logic as described above. It was confirmed that the current balance can be estimated.

  Since the unit of current balance of the battery is ampere and the unit of the counter integrated value is dimensionless, it is not possible to directly compare the two. However, appropriate values are set for the counter values a and b by calibration. Further, by multiplying the integrated value of the counter value by an appropriate coefficient (fixed value), as shown in FIG. 5, the shape of the characteristic indicating the current balance of the battery and the characteristic of the current balance obtained by simulation Can be substantially matched, and can be expressed as counter value≈current balance (current value) of the battery 3.

  As described above, according to the battery state-of-charge monitoring apparatus according to the embodiment of the present invention, the current is flowing into the battery 3 based on the voltage applied from the battery 3 or from the battery 3. The current balance of the battery 3 can be easily estimated without providing a new current sensor or the like with a simple configuration that estimates whether the current is flowing out and estimates the state of charge of the battery 3 based on the result. The state of the battery 3 can be accurately monitored based on the current balance.

Moreover, since the charge state of the battery 3 can be grasped | ascertained favorably, it can apply to judgment of permission or prohibition of the action | operation of an ISS apparatus. As a result, it is possible to reliably avoid a situation in which the state of charge of the battery is reduced while the engine is stopped by the ISS device, and the engine cannot be restarted after the engine is stopped.
Further, it is not necessary to add a new sensor or the like, and it can be realized only by adding software and there is almost no increase in cost. In addition, since the count value is set according to the voltage value of the battery 3 and the state of charge of the battery is estimated based on the value obtained by adding the count value, there is an advantage that the logic is simple and the calculation load is light. is there.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, 0 is used as a threshold value for determining whether or not the remaining capacity of the battery 3 is reduced. For this threshold value, the power generation capability of the alternator 2 and the electric equipment mounted on the vehicle are used. It can be appropriately changed in consideration of the total electric load and the like.

  Moreover, although the above demonstrated the case where this invention was applied to the engine control apparatus which prohibits ISS when it determines with the charge condition of the battery 3 falling, when the charge condition of the battery 3 is falling If it is determined, the power generation amount of the alternator 2 may be increased by increasing the idle speed of the engine 1. In this case, it is preferable that the engine ECU 6 detects the voltage applied from the battery 3.

  In addition to the above, the present invention may be applied as an automatic transmission control device. That is, when it is determined that the state of charge of the battery 3 has decreased, the engine speed is increased by delaying the shift-up timing of the automatic transmission or lowering the gear position, and the alternator 2 The amount of power generation may be increased. In this case, it is preferable to detect the voltage applied from the battery 3 in the AT-ECU 5.

It is a schematic diagram which shows the principal part structure of the vehicle provided with the charge condition monitoring apparatus of the battery which concerns on one Embodiment of this invention. It is a typical block diagram shown about the principal part structure of the charge condition monitoring apparatus of the battery which concerns on one Embodiment of this invention. It is a figure explaining the relationship between the current balance of a battery and the voltage in the charge condition monitoring apparatus of the battery which concerns on one Embodiment of this invention. It is a flowchart for demonstrating the effect | action of the charge condition monitoring apparatus of the battery which concerns on one Embodiment of this invention. It is a time chart for demonstrating an effect | action of the charge condition monitoring apparatus of the battery which concerns on one Embodiment of this invention.

Explanation of symbols

1 Engine 2 Alternator (generator)
3 Battery 4 ISS-ECU (electric equipment control means)
5 AT-ECU (electric equipment control means)
6 Engine ECU (electric equipment control means)
7 Counter setting part 8 Accumulating part 9 Judgment part

Claims (9)

An engine, a generator mechanically connected to the engine, a battery electrically connected to the generator, and a power supply electrically connected to the battery and / or the generator And an electric device control means for controlling the operation of the electric device,
The electric device control means is in a state where a current from the generator is flowing into the battery or a current from the battery to the electric device based on a voltage applied by the battery. A battery state-of-charge monitoring device, wherein the state of charge is estimated and the state of charge of the battery is determined based on the estimation result. The determination of the current flow state of the battery is repeated every predetermined time, the current balance of the battery is calculated by accumulating the determination results, and the charge state of the battery is determined. Item 2. The battery charge state monitoring device according to Item 1. When the voltage of the battery is equal to or higher than a predetermined value, a first counter value is set, and when the battery voltage is lower than the predetermined value, a second counter value is set.
The value obtained by sequentially adding the first and second counter values is compared with a predetermined threshold value to determine whether or not the state of charge of the battery is lowered. The battery charge state monitoring device according to 1 or 2. 4. The battery state-of-charge monitoring apparatus according to claim 3, wherein the first counter value is a positive value and the second counter value is a negative value. 5. The battery according to claim 3, wherein absolute values of the first and second counter values are set based on an electric load of the electric device and a power generation capacity of the generator. 6. Charge state monitoring device. The battery charge state monitoring device according to any one of claims 3 to 5, wherein a ratio of absolute values of the first and second counter values is set to 1: 2. The battery charge state monitoring device according to any one of claims 3 to 6, wherein an upper limit value and a lower limit value are provided for the cumulative value of the counter value. An engine control device that performs idle stop start control that automatically stops the operation of the engine when a predetermined condition is satisfied, and restarts the engine when a predetermined return condition different from the predetermined condition is satisfied,
Based on the voltage applied to the engine control device, predicting the current balance of the battery that supplies power when the engine is restarted,
An engine control device that determines a state of charge of the battery based on the prediction result, and permits or prohibits automatic stop of the operation of the engine based on the determination result. An engine control device for controlling the engine speed during idling of the engine,
Based on the voltage applied to the engine control device, predict the current balance of the battery that supplies power to the engine control device,
An engine control apparatus, comprising: determining a state of charge of the battery based on the prediction result; and changing an idle speed of the engine based on the determination result.

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