JP2012007995A - Device, method, and program for estimating battery remaining amount - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive cost reduction and downsizing of a device for estimating a battery remaining amount while keeping high accuracy.SOLUTION: The device for estimating the battery remaining amount includes: a capacitor 14 which is connected in parallel with a load 16 of a battery 11; a voltage holding circuit 12; and a control part 13. The voltage holding circuit 12 holds voltage corresponding to output voltage of the battery 11 when voltage drop is generated resulting from charge current which flows from the battery 11 to the capacitor 14. The control part 13 controls execution of processing for estimating the battery remaining amount of the battery 11, namely, battery remaining amount estimation processing based on the voltage held by the voltage holding circuit 12. In other words, the device for estimating the battery remaining amount of such a configuration estimates the battery remaining amount of the battery 11 based on the voltage drop of the battery 11 resulting from a dummy load of the battery 11 by considering the load by the charge current of the capacitor 14 as the dummy load.

Description

  The present invention relates to a remaining battery level estimation device and method, and a program, and more particularly, to a technology capable of reducing the cost and size of a remaining battery level estimation device while ensuring high accuracy.

  Conventionally, various electronic devices have been miniaturized, and portable electronic devices such as digital cameras are becoming widespread. Such a portable electronic device can use a battery as a power source so that it can operate even in a place where a commercial power source does not exist.

However, unlike a commercial power source, a battery cannot continue to supply power permanently. That is, when a portable electronic device uses a battery as a power source, there is a risk that the operation is suddenly stopped when power necessary for the operation is not supplied from the battery.
For this reason, the remaining battery level is widely used as an index indicating how much battery power can be supplied in the future. The remaining battery level is the amount of power held by the battery and is also called the remaining battery capacity.
Further, several devices for estimating the remaining battery level (hereinafter referred to as “battery remaining level estimation device”) have been proposed.

FIG. 8 is a diagram illustrating an example of a schematic configuration of a conventional battery remaining amount estimation apparatus.
The conventional battery remaining amount estimation apparatus shown in FIG. 8 includes a battery 101, a control unit 102 that estimates the remaining battery amount of the battery 101, and a load 103 that operates using the battery 101 as a power source.
The control unit 102 is provided with a voltage detection unit 111 that detects the output voltage of the battery 101.
The control unit 102 monitors the detection voltage of the voltage detection unit 111, identifies the voltage drop amount of the battery 101, and estimates the remaining battery level of the battery 101 based on the voltage drop amount.

The conventional battery remaining amount estimation apparatus shown in FIG. 8 has the following problems.
That is, when the load 103 is a light load or when the load 103 is not operating, there is a problem that it is difficult for the control unit 102 to estimate the remaining battery level. This is because the load current flowing from the battery 101 to the load 103 is small, and as a result, the amount of voltage drop is small, and a potential difference is hardly generated.

FIG. 9 is an example of a schematic configuration of a conventional battery remaining amount estimation apparatus that can solve such a problem, and is a diagram illustrating an example different from FIG. 8.
9 includes a battery 121, a control unit 122 that estimates the remaining battery capacity of the battery 121, a resistor 123 as a dummy load, and a dummy load connected to the circuit. A switch circuit 124 for cutting off and a load 125 are provided.
In the example of FIG. 9, a series connection of a resistor 123 and a switch circuit 124 and a load 125 are connected in parallel.
The control unit 122 is provided with a voltage detection unit 131 that detects the output voltage of the battery 121 and a connection control unit 132 that controls on / off switching of the switch circuit 124.
When the control unit 122 starts estimating the remaining battery level of the battery 121, the control unit 122 controls the connection control unit 132 to turn on the switch circuit 124. Thereby, the resistor 123 as a dummy load is connected to the circuit, and a certain amount of current flows from the battery 121 to the resistor 123. In this state, the control unit 122 monitors the detection voltage of the voltage detection unit 131, identifies the voltage drop amount of the battery 121, and estimates the remaining battery level of the battery 121 based on the voltage drop amount.
Here, if the resistor 123 as a dummy load is always connected to the circuit, wasteful power consumption increases, and as a result, the battery life of the battery 121 is shortened. Therefore, when the estimation of the remaining battery level is completed, the control unit 102 controls the connection control unit 132 to turn off the switch circuit 124, thereby cutting off the resistor 123 as a dummy load from the circuit.

  Similarly to the example of FIG. 9, Patent Literature 1 also discloses a battery remaining amount estimating device (battery remaining amount monitoring device) that employs a resistor as a dummy load.

JP 09-297164 A

  However, in order to mount the battery remaining amount estimating device in the portable electronic device, it is required to reduce the cost and size while ensuring high accuracy. It was difficult to meet this demand.

  That is, in the conventional battery remaining amount estimation apparatus shown in FIG. 8, it is difficult to ensure high accuracy in the first place as described above.

On the other hand, in the conventional battery remaining amount estimating device shown in FIG. 9 and the battery remaining amount estimating device described in Patent Document 1, as described above, a resistor is employed as a dummy load, so that high accuracy is ensured. It is possible.
However, if a resistor is used as the dummy load, power consumption increases and countermeasures against heat generation of the resistor are required. Therefore, an increase in cost and an increase in size are inevitable from the standpoint of the remaining battery level estimation device.
Here, as described above, a measure for providing a switch circuit is effective for the point that the power consumption is large. That is, by turning on and off the switch circuit, the dummy load can be connected to the circuit only when the remaining battery level is estimated, and the dummy load can be cut off from the circuit at other times. As a result, the power consumption can be suppressed. it can.
However, in terms of measures against heat generation of the resistance, which is a dummy load, it is necessary to consider safety in the event of an abnormality such as when the switch circuit is short-circuited. Therefore, even if a switch circuit can be provided to reduce power consumption, it is not possible to reduce the size and cost in order to firmly take measures against heat generation of the resistance that is a dummy load.

  In addition, there is no battery remaining amount estimation device that has been reduced in cost and size while ensuring high accuracy.

  The present invention has been made in view of such a situation, and an object of the present invention is to reduce the cost and the size of the remaining battery level estimation device while ensuring high accuracy.

According to one aspect of the invention,
A capacitor connected in parallel with the battery load;
Voltage holding means for holding a voltage corresponding to the output voltage of the battery when a voltage drop occurs due to a charging current flowing from the battery to the capacitor;
Estimating means for estimating a remaining battery level of the battery based on the voltage held in the voltage holding means;
A battery remaining amount estimation device is provided.

  According to another aspect of the present invention, there is provided a method and a program corresponding to the above-described battery remaining amount estimating apparatus according to one aspect of the present invention.

  According to the present invention, it is possible to reduce the cost and the size of the battery remaining amount estimation device while ensuring high accuracy.

It is a figure which shows the structural example of the battery residual amount estimation apparatus which concerns on 1st Embodiment of this invention. 3 is a flowchart for explaining a flow of a battery remaining amount estimation process executed by a control unit when the battery remaining amount estimating apparatus in FIG. 1 performs an operation of estimating a battery remaining amount. An example of the structure of the data table stored in the memory of the battery remaining power estimation apparatus of FIG. 1 is shown. It is a figure which shows the structural example of the battery remaining charge estimation apparatus which concerns on 2nd Embodiment of this invention. 6 is a flowchart for explaining a flow of a battery remaining amount estimation process executed by a control unit when the battery remaining amount estimating apparatus of FIG. 4 performs an operation of estimating a battery remaining amount. FIG. 5 shows an example of the structure of a data table stored in the memory of the remaining battery level estimation device of FIG. 4. FIG. It is a block diagram which shows an example of the hardware constitutions of the control part of the battery remaining charge estimation apparatus of FIG. 1 or FIG. It is a figure which shows an example of schematic structure of the conventional battery remaining charge estimation apparatus. It is an example of schematic structure of the conventional battery remaining charge estimation apparatus, Comprising: It is a figure which shows the example different from FIG.

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

[First Embodiment]
FIG. 1 is a diagram illustrating a configuration example of a battery remaining amount estimating apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, the remaining battery level estimation device according to the first embodiment includes a battery 11, a voltage holding circuit 12, a control unit 13, a capacitor 14, a switch circuit 15, and a load 16. Yes.

  The battery 11 can supply electric power necessary for the operation of the load 16 when the remaining battery level is equal to or higher than a certain level. However, when the remaining battery level becomes less than a certain level, the electric power necessary for the operation of the load 16 is supplied. It becomes impossible to supply.

The voltage holding circuit 12 includes a resistor 21, a diode 22, and a capacitor 23.
One end of the capacitor 23 is connected to the negative end of the battery 11, and the other end is connected to one end of the resistor 21 and the anode of the diode 22. The other end of the resistor 21 and the cathode of the diode 22 are connected to the positive end of the battery 11.
In other words, the resistor 21 and the diode 22 are connected in parallel, the parallel connection and the capacitor 23 are connected in series, and the series connection is connected between the positive electrode end and the negative electrode end of the battery 11. .
Although details will be described later, the voltage holding circuit 12 can hold a voltage corresponding to the output voltage of the battery 11 in which the voltage has dropped transiently by having such a configuration. The “voltage corresponding to the output voltage of the battery 11” is a voltage including the output voltage of the battery 11 itself and is a voltage that varies in conjunction with the output voltage of the battery 11.

The control unit 13 is configured by, for example, a microcomputer, and includes a voltage detection unit 31, a connection control unit 32, a memory 33, and a timer 34.
The voltage detection unit 31 detects the voltage held in the voltage holding circuit 12, that is, the voltage corresponding to the output voltage of the battery 11 that has dropped transiently.
The connection control unit 32 controls on / off switching of the switch circuit 15.
The memory 33 stores various information necessary for the control unit 13 to execute various processes, and stores, for example, a data table of FIG.
When the timer 34 is initialized, the timer 34 starts a time measuring operation. When the timer 34 measures time for a preset time, the timer 34 stops the time measuring operation. In addition, in this way, “when the time is measured for a preset time, the time measurement operation is stopped” is expressed as “time is up”.

The capacitor 14 is a capacitor element that functions as a dummy load.
The switch circuit 15 is configured to include, for example, a switching element. When the switch circuit 15 is turned on, a capacitor 14 as a dummy load is connected to the circuit including the battery 11 and the load 16. The capacitor 14 as a dummy load is cut off from the circuit.
In the example of FIG. 1, the capacitor 14 and the switch circuit 15 are connected in series, and the series connection and the load 16 are connected in parallel.

  The load 16 is composed of various parts of a portable electronic device, for example, and operates with the electric power when a certain level of electric power is supplied from the battery 11.

Next, referring to FIG. 2 as appropriate, the operation of the battery remaining power estimation apparatus of the first embodiment having the configuration of FIG. 1 will be described.
FIG. 2 shows a flow of processing (hereinafter referred to as “battery remaining amount estimation processing”) executed by the control unit 13 when the battery remaining amount estimating apparatus according to the first embodiment performs an operation of estimating the remaining amount of battery. It is a flowchart to explain.

  For example, when a predetermined condition is satisfied after a portable electronic device (not shown) on which the battery remaining amount estimating apparatus according to the first embodiment is mounted is turned on, the remaining battery amount estimating process in FIG. Start.

In step S <b> 1, the control unit 13 controls the connection control unit 32 to turn on the switch circuit 15 for connecting the capacitor 14.
In step S <b> 2, the control unit 13 initializes the timer 34 to start the time counting operation of the timer 34.
In step S3, the control unit 13 determines whether or not the timer 34 has counted up.
If the timer 34 has not yet counted up, it is determined as NO in step S3, and the process returns to step S3. That is, until the timer 34 counts up, the determination process in step S3 is repeatedly executed, so that the operation of the control unit 13 enters a standby state.

When attention is paid to the operation other than the control unit 13 during this period, when the switch circuit 15 is turned on in the process of step S <b> 1, the battery 11 and the capacitor 14 are connected, and a large charging current flows through the capacitor 14. The load of this charging current becomes a dummy load of the battery 11, and a voltage drop occurs according to the internal state of the battery 11. As a result, the output voltage of the battery 11 also decreases.
Here, as the capacitor 14 is charged, the charging current decreases and finally becomes 0, so the voltage drop of the battery 11 is transient. It is difficult to detect such a transient voltage drop.
Therefore, the voltage holding circuit 12 holds a voltage corresponding to the output voltage of the battery 11 when a voltage drop occurs due to the charging current flowing in the capacitor 14 as a dummy load for a certain time.
Based on the voltage held in the voltage holding circuit 12 in this way, that is, the voltage corresponding to the output voltage of the battery 11 at the time of heavy load by the dummy load (capacitor 14), the control unit 13 performs the battery remaining of the battery 11. Estimate the amount. Details of the processing of the control unit 13 will be described later as processing after step S2.

Here, the voltage holding function of the voltage holding circuit 12 will be described in more detail.
Assuming that the state before the switch circuit 15 is switched from OFF to ON is an initial state, the capacitor 23 is charged until it has substantially the same potential as the positive terminal of the battery 11 in the initial state.
Thereafter, as described above, when the switch circuit 15 is turned on by the process of step S1 of the control unit 13, a voltage drop of the battery 11 occurs. That is, the potential at the positive electrode end of the battery 11 is lowered. At this time, the potential of the capacitor 23 (the potential at the end on the side of the resistor 21 and the diode 22) is also reduced to a potential at which the potential difference from the positive end of the battery 11 becomes the voltage VF (the forward voltage VF of the diode 22). The capacitor 23 is discharged immediately.
Thereafter, when charging of the capacitor 14 as the dummy load proceeds, the output voltage of the battery 11 increases as described above. That is, the potential of the positive electrode end of the battery 11 increases.
However, even if the potential at the positive terminal of the battery 11 rises, the potential of the capacitor 23 of the voltage holding circuit 12 rises slowly due to the charging time constant with the resistor 21. Thereby, even if the potential of the positive electrode end of the battery 11 decreases transiently, the voltage holding circuit 12 uses the decreased potential (more precisely, the potential corresponding to the forward voltage VF of the diode 22). It becomes possible to hold for a certain period of time.

The set time of the timer 34 is set within such a fixed time, that is, within a range not exceeding a fixed time in which the voltage holding circuit 12 can hold the potential after the decrease of the positive terminal of the battery 11.
For this reason, at the stage where the voltage holding circuit 12 holds the potential after the decrease of the positive end of the battery 11, the timer 34 counts up, it is determined as YES in step S3, and the process proceeds to step S4. move on.

In step S <b> 4, the control unit 13 reads the voltage value detected by the voltage detection unit 31.
That is, at the time of processing in step S4, the voltage holding circuit 12 holds the output voltage after the voltage drop of the battery 11 (more precisely, the voltage obtained by adding the forward voltage VF of the diode 22) as described above. Yes. The voltage value held by the voltage holding circuit 12 is detected by the voltage detector 31. The voltage value detected by the voltage detector 31 in this way is read in the process of step S4.

  In step S <b> 5, the control unit 13 refers to the data table stored in the memory 33 and acquires an estimated value of the remaining battery level.

FIG. 3 shows an example of the structure of the data table stored in the memory 33.
In the first embodiment, since the data table has a matrix structure, the collection of items in the horizontal direction in FIG. 3 is hereinafter referred to as “row”, and the collection of items in the vertical direction in FIG. "
In the data table of FIG. 3, “voltage reading (V)” and “battery remaining amount (%)” are stored in association with each row.
That is, a predetermined voltage value that can be detected by the voltage detection unit 31 and read by the control unit 13 is stored in the item “voltage reading value (V)” of a predetermined row. In the “battery remaining amount (%)” item of the predetermined row (same row), an estimated value of the battery remaining amount when the predetermined voltage value is read is stored.
Note that the estimated value of the remaining battery level stored in the data table may be a calculated value calculated according to a predetermined algorithm, or may be an actually measured value acquired by prior evaluation or the like.
Specifically, for example, it is assumed that “4.19 V” is read as a voltage value in the process of step S4 of FIG. In this case, in step S5, the control unit 13 refers to the row in which “4.19V” is stored in the item “voltage reading (V)”, and “battery remaining amount (%)” in the row. The stored value of the item, that is, “99.8%” is acquired as the estimated value of the remaining battery level.
For example, it is assumed that “2.48V” is read as the voltage value in the process of step S4. In this case, in step S <b> 5, the control unit 13 refers to the row in which “2.48 V” is stored in the item “voltage reading (V)”, and “battery remaining amount (%)” in the row. The stored value of the item, that is, “5.2%” is acquired as the estimated value of the remaining battery level.

Thus, when the estimated value of the remaining battery level is acquired in the process of step S5, the process proceeds to step S6.
In step S6, the control unit 13 outputs the estimated value of the remaining battery level to a predetermined part or the like of a portable electronic device (not shown).
Then, the portable electronic device (not shown) presents the estimated value of the remaining battery level to the user by displaying it as an image.

In step S <b> 7, the control unit 13 controls the connection control unit 32 to turn off the switch circuit 15 for connecting the capacitor 14.
As a result, the battery remaining amount estimation process ends, and the capacitor 14 serving as the dummy load is disconnected from the circuit, so that it is possible to prevent wasteful consumption of electric power except when the battery remaining amount estimation process is executed. Shortening of the battery life of the battery 11 is prevented.

As described above, the remaining battery level estimation device of the first embodiment includes the capacitor 14, the voltage holding circuit 12, and the control unit 13 (FIG. 1).
The capacitor 14 is connected in parallel with the load 16 of the battery 11.
The voltage holding circuit 12 holds a voltage corresponding to the output voltage of the battery 11 when a voltage drop occurs due to the charging current flowing from the battery 11 to the capacitor 14.
The control unit 13 estimates the remaining battery level of the battery 11 based on the voltage held in the voltage holding circuit 12.
In other words, the battery remaining amount estimation device according to the first embodiment uses the capacitor 14 as a dummy load, and the battery of the battery 11 based on the voltage drop of the battery 11 caused by the charging current flowing through the dummy load. Estimate the remaining amount.
Thus, as the dummy load, a resistor 14 that does not generate heat is used instead of a resistor that generates heat (such as the conventional resistor 123 in FIG. 9). For this reason, even if an abnormality occurs, such as a short circuit failure in the switch circuit (conventionally the switch circuit 124 in FIG. 9, switch circuit 15 in the first embodiment) that connects or disconnects the dummy load to the circuit, it is safe. Sex can be secured. As a result, there is no need to increase the size of parts or take measures against heat generation as in the conventional case, and it is possible to easily reduce the cost and size.
Further, the capacitor 14 is a very inexpensive and simple element, and in some cases, the components in the portable electronic device in which the battery remaining amount estimating device of the first embodiment is mounted can be used as it is. This point also greatly contributes to the low cost and easy miniaturization.
Moreover, since the dummy load is used, the remaining battery level of the battery 11 can be estimated while ensuring high accuracy.
In summary, it is possible to easily provide a battery remaining amount estimation device that can be reduced in cost and size while ensuring high accuracy.

  In addition, from the viewpoint of diverting the components in the portable electronic device in which the battery remaining amount estimating device of the first embodiment is mounted, the switch circuit for the power switch of the portable electronic device can be diverted as the switch circuit 15 There is also. For example, in the case of a soft switch type portable electronic device having a standby state, connecting a power source is different from turning on (starting operation) and increasing current consumption. The switch circuit for the power switch of the portable electronic device can be used as the switch circuit 15. Thereby, cost reduction and size reduction are achieved further.

Heretofore, the remaining battery level estimation device according to the first embodiment of the present invention has been described.
Next, the remaining battery level estimation apparatus according to the second embodiment of the present invention will be described.

[Second Embodiment]
FIG. 4 is a diagram illustrating a configuration example of the remaining battery level estimation apparatus according to the second embodiment of the present invention.
In FIG. 4, the same reference numerals are given to the same parts as those of the first embodiment shown in FIG. 1.

  In order to compare the battery remaining amount estimating device of the second embodiment shown in FIG. 4 with the battery remaining amount estimating device of the first embodiment shown in FIG. 1, a battery 11, a voltage holding circuit 12, a capacitor 14, The point provided with the switch circuit 15 and the load 16 is in agreement. Further, these connection forms also coincide. Therefore, the description of these matching points is omitted.

On the other hand, the difference is that the control unit 13 is provided in the battery remaining amount estimating device of the first embodiment shown in FIG. 1, whereas the control is performed in the battery remaining amount estimating device of the second embodiment shown in FIG. The point 41 is provided.
However, the control part 41 of 2nd Embodiment is comprised, for example with the microcomputer etc., and as shown in FIG. 4, the voltage detection part 31, the connection control part 32, the memory 33, and the timer 34 are included. I have. The configuration up to this point is basically the same as that of the control unit 13 of the first embodiment shown in FIG.
Therefore, only differences from the control unit 41 of the second embodiment with respect to the control unit 13 of the first embodiment will be described below.

The control unit 41 according to the second embodiment further includes a battery temperature detection unit 51, a voltage detection unit 52, and a determination unit 53 in addition to the voltage detection unit 31 to the timer 34.
The battery temperature detection unit 51 detects the temperature of the battery 11 (hereinafter referred to as “battery temperature T”).
The voltage detector 52 detects the voltage value of the capacitor 14 (hereinafter referred to as “capacitor voltage value Vc2”).
In addition to the voltage value detected by the voltage detection unit 31 (hereinafter referred to as “voltage value Vc1”), the determination unit 53 further detects the battery temperature T detected by the battery temperature detection unit 51 and the voltage detection. The battery voltage of the battery 11 is estimated by comprehensively determining the capacitor voltage value Vc2 and the like detected by the unit 52.

That is, as a factor determining the battery remaining amount of the battery 11, first, the voltage drop amount of the battery 11 described above exists, and this is the main factor. Further, as sub-factors, there are a battery temperature T, a capacitor voltage value Vc2 before the switch circuit 15 is turned on (capacitor voltage value Vc2 due to the residual charge of the capacitor 14), and the like. In other words, even if the voltage drop amount of the battery 11 that is the main factor is the same, if these sub-factors are different, the remaining battery level of the battery 11 is different.
Therefore, the control unit 41 of the second embodiment determines the voltage drop amount of the battery 11 as a main factor, and further comprehensively determines one or more sub-factors that are not considered in the first embodiment. Thus, the remaining battery level of the battery 11 is estimated with higher accuracy.
As a sub-factor determining the remaining battery level of the battery 11, only the combination of the battery temperature T and the capacitor voltage value Vc2 before the switch circuit 15 is turned on will be described here. It is. That is, any one of the battery temperature T and the capacitor voltage value Vc2 before the switch circuit 15 is turned on may be adopted alone. Alternatively, an arbitrary number of arbitrary types of sub-factors may be adopted among a plurality of sub-factors including the battery temperature T and the capacitor voltage value Vc2 before the switch circuit 15 is turned on.

Next, with reference to FIG. 5, the battery remaining amount estimation process which the control part 41 of such 2nd Embodiment performs is demonstrated.
FIG. 5 is a flowchart illustrating the flow of the remaining battery level estimation process executed by the control unit 41 when the remaining battery level estimation apparatus according to the second embodiment performs the operation of estimating the remaining battery level.

  For example, when a predetermined condition is satisfied after a portable electronic device (not shown) equipped with the battery remaining amount estimating device of the second embodiment is turned on, the remaining battery amount estimating process in FIG. Start.

  In step S <b> 21, the control unit 13 reads the battery temperature T detected by the battery temperature detection unit 51.

  In step S22, the control unit 13 reads the capacitor voltage value Vc2 detected by the voltage detection unit 52.

In step S23, the control unit 13 determines whether or not the capacitor voltage value Vc2 is within a predetermined range.
For example, when the residual charge of the capacitor 14 is above a certain level, that is, when the capacitor voltage value Vc2 is above a certain level, the charging current does not sufficiently flow through the capacitor 14 even when the switch circuit 15 is turned on. The amount of descent is smaller. In such a case, it becomes difficult to accurately estimate the remaining battery level of the battery 11. In other words, the capacitor voltage value Vc2 needs to be within a predetermined range in order to ensure the estimation accuracy of the battery remaining amount of the battery 11 to a certain level or more.
Therefore, if the capacitor voltage value Vc2 is not within the predetermined range, it is determined NO in step S23, and the process returns to step S22. That is, until the capacitor voltage value Vc2 falls within the predetermined range, the loop process of steps S22 and S23 is repeatedly executed, so that the operation of the control unit 41 enters a standby state. In this case, the residual charge may be discharged by a discharge circuit (not shown) so that the residual charge of the capacitor 14 is below a certain level.
Thereafter, when the capacitor voltage value Vc2 falls within the predetermined range, it is determined as YES in Step S23, and the process proceeds to Step S24.

  As can be easily understood by comparing FIG. 5 and FIG. 2, the flow of processing in steps S24 to S30 in the second embodiment is basically the same as the flow of processing in steps S1 to S7 in the first embodiment. Therefore, the description of the processing flow of steps S24 to S30 of the second embodiment is omitted.

However, the data table referred to in step S28 of the second embodiment is different from the data table (FIG. 3) referred to in step S5 (FIG. 2) of the first embodiment.
Therefore, hereinafter, the data table referred to in the process of step S28 of the second embodiment and the process of step S28 executed with reference to the data table will be described.

FIG. 6 shows an example of the structure of the data table stored in the memory 33 (FIG. 4) of the second embodiment.
As shown in FIG. 6, in the second embodiment, each of the data tables 61 to 64 is stored in the memory 33 for each capacitor voltage value Vc2 before the switch circuit 15 is turned on.
In FIG. 6, for convenience of explanation, four data tables 61 to 64 are shown, but this is an example. That is, when the capacitor voltage value Vc2 is discretely divided into N pieces (within N being an integer value of 1 or more) within the “predetermined range” used in the process of step S23, N data tables are stored. Stored in the memory 33.
In this case, in the process of step S28, among the N data tables (N = 4 data tables 61 to 64 in the example of FIG. 6), it corresponds to the capacitor voltage value Vc2 read in the immediately previous process of step S22. The data table to be referenced is referenced.

Here, in FIG. 6, the entire structure of the data table 61 is illustrated, but only a part of the structures of the other data tables 62 to 64 are illustrated. Therefore, focusing on the data table 61, only the structure of the data table 61 will be described below.
However, this is for convenience of explanation. In the second embodiment, any of the N data tables including the data tables 61 to 64 shown in FIG. 6 is a data table 61 described below. It has the same structure as

Since the data table 61 in FIG. 6 has a matrix structure, the collection of items in the horizontal direction in FIG. 6 is called “row”, and the collection of items in the vertical direction in FIG. This is called “column”.
In the data table 61 of FIG. 6, “voltage reading value Vc1 (V)” and “battery remaining amount (%)” for each of a plurality of battery temperatures T (reference temperature T) are associated with each row. Stored.
That is, a predetermined voltage value that can be detected by the voltage detection unit 31 and read by the control unit 41 is stored in the item “voltage reading value (V)” of a predetermined row. In each of the plurality of “battery remaining amount (%)” items on the right side of the predetermined row (same row), the battery remaining when the predetermined voltage value is read for each of the plurality of battery temperatures T is displayed. Contains an estimate of the quantity.
Note that the estimated value of the remaining battery level may be a calculated value calculated according to a predetermined algorithm, or may be an actually measured value acquired by prior evaluation or the like.
Specifically, for example, “49 ° C.” is read as the battery temperature T in the process of step S21, and “4.19V” is read as the voltage value Vc1 in the process of step S27. In this case, in step S <b> 28, the control unit 13 refers to the row in which “4.19 V” is stored in the item “voltage reading (V)” and the reference temperature T [° C.] of the row is “ 49 ”is acquired as an estimated value of the remaining battery level, that is,“ 99.8% ”.
For example, it is assumed that “−9 ° C.” is read as the battery temperature T in the process of step S21, and “2.48V” is read as the voltage value Vc1 in the process of step S27. In this case, in step S <b> 28, the control unit 13 refers to the row where “2.48 V” is stored in the item “voltage reading (V)”, and the reference temperature T [° C.] of the row is “ The stored value of the item “remaining battery (%)” that is “−8”, that is, “5.2%” is acquired as an estimated value of the remaining battery.

As described above, the remaining battery level estimation device of the second embodiment includes the capacitor 14, the voltage holding circuit 12, and the control unit 41, as in the first embodiment.
Therefore, the remaining battery level estimation apparatus of the second embodiment also provides the same battery level estimation apparatus that can achieve the same effect as the first embodiment, that is, cost reduction and downsizing while ensuring high accuracy. It is possible to achieve the effect of being able to.

Furthermore, the battery remaining amount estimation device of the second embodiment not only considers the voltage drop amount of the battery 11 which is the main factor that determines the remaining battery amount of the battery 11, but also determines the remaining battery amount of the battery 11. The remaining battery level of the battery 11 is estimated in consideration of one or more sub-factors to be attached.
As sub-factors, for example, the battery temperature T and the capacitor voltage value Vc2 before the switch circuit 15 is turned on (capacitor voltage value V2 resulting from the residual charge of the capacitor 14) can be employed. As described above, these sub-factors are merely examples.
As described above, in the second embodiment, the main factor is used as a basis for the determination, and the sub-factor that is not considered in the first embodiment can also be comprehensively determined. Can be estimated with higher accuracy.

  In addition, this invention is not limited to the above-mentioned embodiment, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.

  For example, in the above-described embodiment, the voltage holding circuit 12 has the configuration shown in FIGS. 1 and 4, but is not particularly limited to this configuration. That is, the voltage holding circuit 12 has an arbitrary function as long as it has a function of holding a voltage corresponding to the output voltage of the battery 11 when a voltage drop occurs due to the charging current flowing from the battery 11 to the capacitor 14. Can take the configuration.

For example, in the above-described embodiment, the control unit 13 in FIG. 1 or the control unit 41 in FIG. 4 uses the voltage held in the voltage holding circuit 12 and the data table in FIG. 3 or FIG. The amount was estimated.
However, the method for estimating the remaining battery level is not particularly limited to the example of the above-described embodiment, and any method that uses the voltage held in the voltage holding circuit 12 is sufficient.
For example, a method for estimating and calculating the remaining battery capacity according to a predetermined algorithm without using a data table may be employed.
Further, for example, a method of preliminarily holding correction data different from the data table and estimating the remaining battery level based on the correction data may be employed.

Further, for example, in the above-described embodiment, the case where the battery remaining amount estimation apparatus to which the present invention is applied is configured to be mounted on a portable electronic device has been described as an example.
However, the present invention is not particularly limited to this, and can be widely applied to a battery remaining amount estimation device that is generally mounted or connected to a device that can employ a battery as a power source.

  The series of processes described above can be executed by hardware or can be executed by software.

FIG. 7 is a block diagram illustrating an example of a hardware configuration of the control unit 13 (FIG. 1) and the control unit 41 (FIG. 4) when the above-described series of processing is executed by software.
That is, the control unit 13 and the control unit 41 are configured as microcomputers in the above-described example, but are not particularly limited to this, for example, can be configured as dedicated hardware (not shown), It can also be configured as a computer shown in FIG.
Here, the computer itself shown in FIG. 7 may be a device on which the battery remaining amount estimating device is mounted. In other words, the control unit 13 and the control unit 41 may be configured by diverting components (in this case, the CPU 71) of equipment on which the battery remaining amount estimation device is mounted.

  The control unit 13 and the control unit 41 include a CPU (Central Processing Unit) 71, a ROM (Read Only Memory) 72, a RAM (Random Access Memory) 73, a bus 74, an input / output interface 75, and an input unit 76. , An output unit 77, a storage unit 78, a communication unit 79, and a drive 80.

The CPU 71 executes various processes according to programs recorded in the ROM 72. Alternatively, the CPU 71 executes various processes according to a program loaded from the storage unit 78 to the RAM 73.
The RA 73 also appropriately stores data necessary for the CPU 71 to execute various processes.

  For example, in the case of the control unit 13 (FIG. 1) of the first embodiment, programs that realize the functions of the voltage detection unit 31, the connection control unit 32, and the timer 34 are stored in the ROM 72 and the storage unit 78. . Therefore, each function of the voltage detection unit 31, the connection control unit 32, and the timer 34 can be realized by the CPU 71 executing processing according to these programs.

  For example, in the case of the control unit 41 (FIG. 4) of the second embodiment, in addition to the voltage detection unit 31, the connection control unit 32, and the timer 34, the battery temperature detection unit 51, the voltage detection unit 52, and A program for realizing each function of the determination unit 53 is stored in the ROM 72 or the storage unit 78. Therefore, the CPU 71 executes processing according to these programs, so that in addition to the voltage detection unit 31, the connection control unit 32, and the timer 34, the battery temperature detection unit 51, the voltage detection unit 52, and the determination unit 53 functions can be realized.

  The CPU 71, ROM 72, and RAM 73 are connected to each other via a bus 74. An input / output interface 75 is also connected to the bus 74. An input unit 76, an output unit 77, a storage unit 78, and a communication unit 79 are connected to the input / output interface 75.

The input unit 76 includes an operation unit such as various buttons, and accepts user instruction operations and inputs various types of information.
The output unit 77 includes a display unit such as a display and an audio output unit such as a speaker, and outputs various types of information, for example, information indicating an estimation result of the remaining battery level.
The storage unit 78 includes a hard disk, a DRAM (Dynamic Random Access Memory), and the like, and stores various data. For example, the storage unit 78 is provided with the memory 33 of FIGS. 1 and 4 described above, and stores the data tables shown in FIGS. 3 and 6.
The communication unit 79 controls communication performed with other devices (not shown) via a network including the Internet.

  A drive 80 is connected to the input / output interface 75 as necessary, and a removable medium 81 made of a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory or the like is appropriately attached. The program read from the removable medium 81 by the drive 80 is installed in the storage unit 78 as necessary. The removable medium 81 can also store various data stored in the storage unit 78 in the same manner as the storage unit 78.

  When a series of processing is executed by software, a program constituting the software is installed on a computer or the like from a network or a recording medium. The computer may be a computer incorporated in dedicated hardware. The computer may be a computer capable of executing various functions by installing various programs, for example, a general-purpose personal computer.

  A recording medium including such a program is provided not only to the removable medium 81 distributed separately from the apparatus main body in order to provide the program to the user, but also to the user in a state of being preinstalled in the apparatus main body. Recording medium. The removable medium 81 is composed of, for example, a magnetic disk (including a floppy disk), an optical disk, a magneto-optical disk, or the like. The optical disk is composed of, for example, a CD-ROM (Compact Disk-Read Only Memory), a DVD (Digital Versatile Disk), or the like. The magneto-optical disk is configured by an MD (Mini-Disk) or the like. In addition, the recording medium provided to the user in a state of being preliminarily incorporated in the apparatus main body includes, for example, a ROM 72 in which a program is recorded, a hard disk included in the storage unit 78, and the like.

  In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in time series along the order, but is not necessarily performed in time series, either in parallel or individually. The process to be executed is also included.

  DESCRIPTION OF SYMBOLS 11 ... Battery, 12 ... Voltage holding circuit, 13 ... Control part, 14 ... Capacitor 15 ... Switch circuit, 16 ... Load, 21 ... Resistance, 22 ... Diode , 23 ... Capacitor, 31 ... Voltage detection unit, 32 ... Connection control unit, 33 ... Memory, 34 ... Timer, 41 ... Control unit, 51 ... Battery temperature detection unit 52 ... Voltage detection unit, 53 ... Judgment unit

Claims (8)

A first capacitor connected in parallel with the load of the battery;
Voltage holding means for holding a voltage corresponding to the output voltage of the battery when a voltage drop occurs due to a charging current flowing from the battery to the first capacitor;
Estimating means for estimating a remaining battery level of the battery based on the voltage held in the voltage holding means;
A battery remaining amount estimation device comprising: The voltage holding means is
A second capacitor having one end connected to the negative electrode end of the battery;
One end is connected to the other end of the second capacitor and the other end is connected to the positive end of the battery;
A diode connected in parallel with the resistor so that the anode is on the other end side of the second capacitor;
With
The estimation unit uses a parallel connection of the resistor and the diode and a potential at a connection point of the other end of the second capacitor as the voltage held in the voltage holding unit.
The battery remaining amount estimation apparatus according to claim 1. The estimation means uses the voltage held in the voltage holding means as a main factor for determining the battery remaining amount of the battery, and further uses one or more sub-factors for determining the battery remaining amount of the battery. And estimating the remaining battery capacity of the battery,
The battery remaining amount estimation apparatus according to claim 1 or 2. The estimation means uses at least a battery temperature of the battery as the sub-factor.
The battery remaining power estimation apparatus according to claim 3. The estimation means uses at least the voltage of the first capacitor before charging current flows from the battery as the sub-factor,
The battery remaining amount estimation apparatus according to claim 3 or 4. The switch means for connecting the first capacitor to the load circuit of the battery when turned on, and disconnecting the first capacitor from the load circuit of the battery when turned off. The battery remaining power estimation apparatus according to any one of 5. A first capacitor connected in parallel with the load of the battery;
Voltage holding means for holding a voltage corresponding to the output voltage of the battery when a voltage drop occurs due to a charging current flowing from the battery to the first capacitor;
A battery remaining amount estimating method of a battery remaining amount estimating apparatus comprising:
A battery remaining capacity estimating method comprising: an estimating step of estimating a battery remaining capacity of the battery based on the voltage held by the voltage holding means. A first capacitor connected in parallel with the load of the battery;
Voltage holding means for holding a voltage corresponding to the output voltage of the battery when a voltage drop occurs due to a charging current flowing from the battery to the first capacitor;
In a computer that controls a battery remaining amount estimating device comprising:
The program which implement | achieves the estimation function which estimates the battery remaining charge of the said battery based on the said voltage hold | maintained at the said voltage holding means.

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