JP6462214B2 - How to detect remaining battery capacity - Google Patents

Description

  The present invention relates to a battery life determination method for a portable device driven by a primary battery.

  One of the most effective treatments for respiratory diseases such as emphysema and chronic bronchitis is oxygen inhalation therapy. When carrying a portable oxygen cylinder when going out, it is synchronized with the user's breathing and only during inspiration A breath-tuned regulator that efficiently supplies oxygen is used. In such portable devices, a primary battery, particularly an alkaline dry battery that is inexpensive and easily available, is often used as a power source, and the remaining amount of the battery is accurately and more easily measured, and the battery remaining is prompted to the user at an appropriate timing. It is necessary to inform the quantity and the replacement time. Especially in the case of medical devices such as breath-synchronized regulators, stopping the device due to running out of the battery directly leads to a decrease in the therapeutic effect, so a system that can accurately check the remaining amount and continue operation as much as possible is required. .

JP 2007-280935 A Japanese Patent Laid-Open No. 10-172583 JP 2006-162402 A

  A breath-tuned regulator that operates with a primary battery that is used when carrying a portable oxygen cylinder when going out is designed to prevent patients from shutting down due to running out of battery while going out. It is necessary to replace the battery before prompting replacement and stopping. Further, even when the battery is exhausted and the apparatus is stopped, informing the patient that the cause of the device stop is that the battery is out of capacity leads to safe and reliable use of the apparatus.

As disclosed in Patent Document 1, there is a method for detecting the battery remaining amount of a primary battery by measuring the battery voltage and setting the lifetime of the primary battery when the measured voltage is equal to or lower than a predetermined voltage.
However, the battery voltage fluctuates depending on the operating state of the load and the usage history, and the actual battery consumption state and the battery voltage may not be proportional.
In addition, when the battery type is different (for example, a manganese battery, a lithium battery, etc.), the voltage, wear characteristics, and voltage fluctuation value with respect to the load differ depending on the battery type. is there.

On the other hand, Patent Literature 2 discloses a battery remaining amount notification device that identifies a type of battery and has a plurality of detection threshold values corresponding to the identification result, and Patent Literature 3 discloses a specific load. There is a disclosure of a method for determining a remaining battery level based on a voltage difference between when current is not supplied and when current is supplied. However, in the case of a system in which the load generation timing or load size varies depending on the user, or when there is a difference in the voltage that can be operated between individuals due to variations in the load or battery, voltage determination alone is still not possible. Even if it is operable, it may be determined that the battery has run out, and the apparatus operable time may be determined to be short.
An object of the present invention is to solve such problems and to provide a method for accurately determining battery life with a simple circuit configuration.

As means for solving this problem, the following battery remaining amount detection method has been found.
In particular, it is applied to portable devices that operate with a primary battery and has a function of displaying the remaining battery level. The remaining battery level is detected using A / D conversion means mounted on the control board. The battery voltage measurement from the substrate is performed at regular time intervals and every two or more generated load patterns, the voltage threshold set for each load pattern, and the threshold of the voltage drop amount at light load and high load To determine the remaining battery level.

When the battery runs out, the central processing unit is reset by sending a reset signal from the power supply voltage monitoring IC due to depletion of the primary battery. At the next startup, the flag at the previous startup stored in the storage device is checked. Thus, it is determined whether the operation switch has been stopped by turning off or the central processing unit has been reset due to battery consumption. Whether the central processing unit is reset, the voltage value measured for each load pattern and a preset voltage threshold value, the voltage drop amount during light load and high load, and the set threshold value are compared, and the remaining battery level is detected.
Further, at the time of start-up after the occurrence of battery exhaustion, the voltage threshold value used for determining the remaining battery level is set higher than normal.

The following apparatus is provided as an apparatus using such a method.
(1) In a device equipped with a power supply voltage monitoring means that operates on a primary battery and detects the remaining battery level, when the device stops due to a voltage drop due to battery consumption, a reset signal transmitted from the power supply voltage monitoring means Comprising storage means for storing a flag for which the central processing unit has been reset;
An apparatus having a remaining battery level detection function for determining whether the battery has run out from both the presence / absence of the flag stored in the storage means at the next startup and whether the remaining battery level is equal to or higher than a predetermined voltage threshold.
(2) The power supply voltage monitoring means uses the A / D conversion means mounted on the control board of the device, and the battery voltage value measured for each of two or more generated load patterns, or at light load and The apparatus according to (1) above, which is a means for determining a remaining battery level from a comparison result of a voltage drop amount at a high load and a preset threshold value.
(3) If the storage means has a flag for resetting the central processing unit, the voltage threshold value used for determining the remaining battery level is a value set higher than the voltage threshold value during normal operation. (2) The apparatus according to (2) above.

According to the present invention, with a simple circuit configuration having an A / D detection means, a battery voltage is acquired at a certain time interval and at a plurality of specific load generation timings, and a voltage threshold and a light load set for each load generation pattern are obtained. By determining the remaining amount of the battery based on the voltage drop amount at the time and at the time of high load, it becomes possible to more accurately determine the remaining amount of the battery.
Furthermore, the determination of battery exhaustion is realized not by voltage setting but by resetting the CPU, which is the limit of actual operation, so that the operation of the apparatus can be further extended to the limit of battery use.

Criteria for battery level. The flowchart of battery remaining charge determination.

Embodiment examples of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing the criteria for determining battery voltage according to the present invention. The measurement of the battery voltage is performed by an A / D converter, and the measurement timing of the battery voltage is performed every predetermined time and every specific load generation timing. FIG. 1 shows a consumption curve of a battery that outputs a voltage value acquired for each load pattern for three patterns having different load generation amounts from a light load to a heavy load. The obtained battery voltage value is stored in a certain number of buffers for each load pattern, and the moving average value A in each buffer is compared with the determination threshold voltage of the remaining battery level set for each load pattern. Judge the remaining battery level.

Furthermore, by calculating the voltage drop amount B from the moving average value A1 of the battery voltage value acquired at the time of light load and the moving average value of the battery voltage value A3 acquired at the time of high load, and comparing it with the determination threshold value of the voltage drop amount, Perform battery level judgment. The battery exhaustion determination is performed based on whether or not the power supply voltage that is the minimum reference value for the remaining capacity determination is equal to or higher than the battery exhaustion determination threshold.
In addition to the above, the determination of the battery exhaustion is performed by determining whether the battery remaining amount or the battery is exhausted based on the presence or absence of the occurrence of CPU reset due to the battery voltage drop C generated during the operation.

  FIG. 2 shows a flowchart for determining the remaining battery level. Whether or not a CPU reset has occurred is determined by the state of the activation flag. First, when the operation switch (operation SW) is turned on and the apparatus is activated, the battery voltage is measured to determine the remaining battery level. If the start flag is ON at this time, a CPU reset due to a voltage drop occurred during the previous start, and it is determined that the process ended abnormally as it is. The remaining battery level is determined with a voltage obtained by adding an arbitrary value in consideration of the recovery amount. When the condition of the determination threshold value + α is not satisfied, it is determined that the battery has run out, and a battery running alarm is issued.

When the activation flag is OFF, the activation flag is turned ON and, for example, the remaining battery level is determined based on the predetermined threshold voltage for the remaining battery level for each load pattern. Inform the user of the remaining battery level with an LED lamp. Further, when the battery voltage falls below the minimum reference voltage for determining the remaining battery level, it is determined that the battery has run out, and a battery running out alarm is issued. While the apparatus is starting up, it is preferable to save power by turning off the battery remaining amount display such as the LED lamp. Even when the activation flag is ON and the criterion of the battery exhaustion determination threshold value + α or more is satisfied, the battery remaining amount determination is performed in the same manner.

  The activation flag is stored in a non-volatile memory such as an EEPROM after the remaining battery level is determined, and when there is a termination command due to the operation SW OFF, the activation flag is erased and terminated. In this way, it is possible to check whether or not there is a start flag at the time of start-up, and it is possible to determine whether the end by the operation SW OFF has been performed at the previous end or whether the abnormal end has been performed by the CPU reset.

  In addition, the return condition after the occurrence of battery exhaustion is that the battery voltage may rise apparently if the battery is left unloaded for a while after the occurrence of battery exhaustion. By setting the determination threshold value higher, it is possible to prevent an erroneous determination with respect to the voltage recovery due to the passage of time.

  During the operation of the apparatus, if a CPU reset occurs due to a voltage drop, the process returns to the initial stage to determine the remaining battery level and battery exhaustion. Whether or not the power supply voltage is equal to or higher than the battery exhaustion determination threshold is constantly monitored, and it is determined whether or not the power supply voltage is equal to or higher than the determination threshold for the battery exhaustion power set for each load pattern. When the battery is exhausted, a battery exhaustion alarm can be issued, but of course, the device stops and malfunctions. When it falls below, it is preferable to issue an alarm for prompting battery replacement or a battery exhaustion alarm such as a lamp.

  The present invention can be applied as a method for detecting the remaining battery level of a device driven by a primary battery, in particular, a portable medical device such as a breath-tuned regulator used when carrying a portable oxygen cylinder, and accurately determines battery consumption. Thus, a device with improved safety can be supplied.

Claims (4)

In a device that operates with a primary battery and includes a power supply voltage monitoring unit that detects a remaining battery level, the storage unit stores a flag that determines whether the central processing unit has been reset,
A function to detect the case where the central processing unit is reset due to a voltage drop due to battery consumption and the device does not end normally by having the flag at the start of the device and leaving the flag off at the normal end. Prepared,
The power supply voltage monitoring means uses the A / D conversion means mounted on the control board of the apparatus and is set for each load pattern and the battery voltage value measured for each of two or more generated load patterns. Voltage drop amount and voltage drop amount determination threshold obtained by subtracting the moving average value of the battery voltage value acquired at high load from the moving average value of the battery voltage value acquired at light load as a result of comparison with the voltage determination threshold value Is a means for determining the remaining battery level from the result of comparison with
The battery voltage value and / or the voltage drop amount exceeds a predetermined determination threshold, and has a battery remaining amount detection function for determining whether the battery is exhausted ,
When the storage means has a flag for determining whether or not the central processing unit has been reset, the voltage threshold used for determining the remaining battery level is a value obtained by adding an arbitrary value to the predetermined voltage threshold. . The device of claim 1 , wherein the device is a portable device. The device of claim 2 , wherein the device is a respiratory tuned regulator. Two or more load patterns generated by measuring the battery voltage at a fixed time and every two or more load patterns generated using A / D conversion means mounted on the control board of a device that operates with a primary battery Battery voltage value obtained at high load from the result of comparison between the battery voltage value measured for each load pattern and the voltage judgment threshold set for each load pattern and / or the moving average value of battery voltage values obtained at light load The remaining amount of the battery is determined from the result of the comparison between the voltage drop amount obtained by subtracting the moving average value and the determination threshold value of the voltage drop amount,
By checking the flag at the time of previous activation when the device is activated, it is determined whether the operation switch has been stopped by turning off or the central processing unit has been reset due to battery consumption,
Whether the battery voltage value and / or the voltage drop amount exceeds a predetermined determination threshold value, or if the central processing unit is reset, the battery voltage exceeds a value obtained by adding an arbitrary value to the predetermined voltage threshold value A battery capacity remaining amount detection method for determining whether the battery has run out from both sides.

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