JP5789480B2 - Electronic cash register - Google Patents

Description

  The present invention relates to a technique for predicting an operable time of an electronic cash register driven by a battery.

Some users, such as street vendors, require battery-powered electronic cash registers. A battery-driven electronic cash register generally measures a battery voltage value during operation with a battery and displays a battery voltage value or information corresponding to the battery voltage value. When the voltage of the battery falls below a voltage value that can drive the electronic cash register, the electronic cash register operates and transaction processing cannot be performed. Display of information corresponding to the battery voltage value to inform the user of the margin of the voltage value until such operation stop and prompt the user to charge the battery or switch to AC drive while there is still a margin is necessary.
The information corresponding to the voltage value is, for example, dividing the range of the battery voltage of the device into a plurality of ranges and displaying which level the current battery voltage value belongs to. This is a rounded battery voltage value and is essentially information corresponding to the battery voltage value.

  As a technology related to warning of a battery-powered device, data that monitors the frequency of communication and standby is stored, and used to calculate the remaining battery level to obtain continuous standby and continuous talk time, respectively (for example, Patent Document 1). In Patent Document 1, the control unit monitors the occurrence frequency Fc of handover during communication and the occurrence frequency Fi of celery selection during standby for a certain time (step S5). Then, the mobility parameters α and β respectively corresponding to the occurrence frequencies Fc and Fi are obtained from the table of the storage unit (step S6), and the remaining battery level of the terminal and the continuous call are obtained using the mobility parameters α and β. Each is converted into possible time (step S7).

JP 2007-267067 A

  However, the measurement and display of the voltage values as described above merely indicate the state of the battery at the moment when the battery voltage is measured, and do not directly indicate how long the device can be used. . This is because the device operable time varies depending on the use state of the device and the deterioration state of the battery. That is, the battery voltage drop depends on the deterioration state of the battery and the usage state of the electronic cash register. For example, the voltage drop is faster if the electronic cash register is operating for a long time due to a transaction operation or the like. However, if the electronic cash register is not used, the voltage drop is slow. Therefore, the remaining time cannot be determined only by the voltage state at that time.

  However, the information that the user wants to display the remaining battery capacity is not about the state of the battery, but about how long the device in use can be used. Among various electronic devices, an electronic cash register performs processing directly related to money transactions. It is desirable to be able to accurately predict how long the equipment will be operational for.

  The present invention has been made in consideration of the above-mentioned circumstances, and considering how long the device can be operated in consideration of the usage status of the device that affects the transition of the battery voltage and the deterioration state of the battery. It is an object of the present invention to provide an electronic cash register capable of accurately predicting such a situation.

  The present invention relates to a battery for driving a device, a measuring unit that measures the voltage of the battery, a time measuring unit that provides the date and time when the measurement was performed, and a storage unit that stores data related to the voltage and the date and time A process for repeatedly measuring the battery voltage in the measurement unit, a process for obtaining the date and time related to each measurement from the time measuring unit, and a change in voltage between each measured battery voltage and the previous measurement. Is stored in the storage unit as a battery voltage log in association with the date and time related to measurement, a process for predicting battery voltage at a series of times after the current time based on the stored battery voltage log, and a predicted battery A control unit that performs a process of calculating as the operable time until the voltage drops to a predetermined threshold, and a display unit that performs a display relating to the operable time, and the control unit presents a current value to the measuring unit. Battery voltage is measured, the date and time of measurement is obtained from the timekeeping unit, and the battery voltage at each time is within a predetermined range for predicting the battery voltage at each time, and the measurement was performed on the previous day Provided is an electronic cash register characterized by making a prediction based on a voltage log.

  In the electronic cash register of the present invention, the control unit repeatedly performs processing for causing the measurement unit to measure the battery voltage, processing for obtaining the date and time related to each measurement from the time measuring unit, and each measured battery voltage The process of associating the change in voltage between the previous and subsequent measurements with the date and time related to the measurement and storing it in the storage unit as a battery voltage log, and the battery voltage at a series of times after the current time based on the stored battery voltage log Performs the process of predicting and calculating the operation time until the predicted battery voltage drops to a predetermined threshold, causing the measuring unit to measure the current battery voltage, and measuring from the time measuring unit When predicting the battery voltage at each time, the prediction is based on the battery voltage log that is within a predetermined range from each time and measured on the previous day. Based on the battery voltage log measured at approximately the same time of the day out of the battery voltage log that reflects the usage status of the device that affects the battery voltage transition and the battery deterioration state, how long the device will remain It is possible to accurately predict whether it can be operated. By displaying the operable period, it is possible to accurately predict and inform the user when the battery needs to be charged. In particular, it is possible to inform the user who uses the electronic cash register in an environment where AC power cannot be secured and AC driving or charging of the battery cannot be ensured, such as a street vendor, when it is necessary to replace the spare battery or close the store.

In the present invention, the battery may be rechargeable or replaced after it is used up, and the material and shape are not limited.
The measurement unit measures the voltage of the battery when the battery is driving the device. In an embodiment described later, a circuit that converts a terminal voltage of a battery by an A / D converter and causes a control unit to read the voltage corresponds to the measurement unit.
The timekeeping section provides the current date and time. A specific example is a real-time clock circuit, for example.

The storage unit stores data and variables in a readable / writable manner. Specific examples thereof include a semiconductor memory such as a RAM and a flash memory, or a storage device such as a hard disk device. In the embodiments described later, the storage unit corresponds to a nonvolatile memory.
A control part performs the prediction process of an operable voltage. In addition, money calculation processing as an electronic cash register is performed. Specific examples thereof include a CPU and a microcomputer.
The display unit performs display related to the operable voltage. Specific examples thereof include a liquid crystal display device and an LED display device. The display unit may display the result of the monetary calculation.

It is a block diagram which shows the electrical structural example of the electronic cash register of this invention. It is a graph which shows the 1st aspect regarding the measurement of the battery voltage which concerns on this invention. It is explanatory drawing which shows the example of the battery voltage measurement data of FIG. It is a graph which shows the 2nd aspect regarding the measurement of the battery voltage which concerns on this invention. It is explanatory drawing which shows the example of the battery voltage measurement data of FIG. It is explanatory drawing which shows an example of the battery voltage log information table which concerns on this invention. It is explanatory drawing which shows an example of the average voltage drop amount table which concerns on this invention. It is a graph for demonstrating the additional conditions which concern on this embodiment. It is explanatory drawing which shows an example of the prediction of the battery voltage which concerns on this invention. It is a 1st flowchart which shows the procedure of the process which the control part which concerns on this invention performs. In this process, the battery voltage is measured at the beginning and end of each time block to generate a battery voltage log information table. It is a 2nd flowchart which shows the procedure of the process which the control part which concerns on this invention performs. In this process, the battery voltage is repeatedly measured at intervals shorter than the period of each time block to generate a battery voltage log information table. It is a 3rd flowchart which shows the procedure of the process which the control part which concerns on this invention performs. This is processing related to generation of an average voltage drop amount table. It is a 4th flowchart which shows the procedure of the process which the control part which concerns on this invention performs. This is processing related to generation of an average voltage drop amount table. It is a 5th flowchart which shows the procedure of the process which the control part which concerns on this invention performs. This is a process related to the prediction of the operable time. It is a 6th flowchart which shows the procedure of the process which the control part which concerns on this invention performs. This is a process related to the prediction of the operable time. It is a 7th flowchart which shows the procedure of the process which the control part which concerns on this invention performs. This is processing related to the first additional condition. It is an 8th flowchart which shows the procedure of the process which the control part which concerns on this invention performs. This is processing related to the second additional condition.

Hereinafter, preferred embodiments of the present invention will be described.
The time measuring unit provides the date and day of the week when the measurement was performed, and when the control unit predicts the transition of the battery voltage from the current time, the time related to the measurement is close to the current time and the day of the week related to the measurement is predicted. You may make it estimate based on the same battery voltage log as the day of the week concerning. In this way, for example, when there is a certain tendency in the usage situation for each day of the week, such as a lot of sales on the weekend, it is possible to make a prediction in consideration of the tendency.

  In addition, when the control unit predicts the transition of the battery voltage from the current time, the control unit divides the measured battery voltage into predetermined voltage classifications, the time related to the measurement is close to the current time, and the voltage classification is the current battery. You may make it estimate based on the same battery voltage log as a classification of a voltage. Due to the normal characteristics of the battery, the amount of voltage drop differs between the fully charged state, the insufficient charge state, and the state between them. In this way, the voltage drop is based on the battery voltage log close to the current battery state. The amount can be accurately predicted.

  Further, the control unit divides the day into a plurality of predetermined periods, determines which period each of the time and current time related to the measurement of the battery voltage log belongs to, and determines the time and current time related to the measurement. May be determined to be within a predetermined range when they belong to the same period. In this way, it is possible to determine whether or not the time related to the measurement is close to the current time based on a clear standard.

  The control unit causes the measurement unit to measure the battery voltage at time block intervals obtained by dividing the day into predetermined intervals, and changes the initial battery voltage and the change in the initial and final battery voltages of the time block. You may store as a battery voltage log. In this way, the battery voltage log can be generated by measuring the battery voltage at time block intervals.

  Alternatively, the control unit repeatedly causes the measurement unit to measure the battery voltage at intervals shorter than the time block interval obtained by dividing the day into predetermined intervals, and minimizes the battery voltage measured in the time block. The battery voltage at the start and end of the time block may be calculated by applying the square method, and the battery voltage at the start and the change in the battery voltage at the start and end may be stored as a battery voltage log. In this way, the battery voltage can be measured at intervals shorter than the time block, and the voltage drop amount in the time block can be obtained with high accuracy, and the obtained voltage drop amount can be stored as a battery voltage log.

Further, the division of the plurality of periods and the division of the time block may coincide with each other.
Preferred embodiments of the present invention include combinations of any of the plurality of embodiments shown here.
Hereinafter, the present invention will be described in more detail with reference to the drawings. In addition, the following description is an illustration in all the points, Comprising: It should not be interpreted as limiting this invention.

≪Configuration of electronic cash register≫
FIG. 1 is a block diagram showing an example of the electrical configuration of the electronic cash register of the present invention. As shown in FIG. 1, the electronic cash register 11 of the present invention includes a control unit 21, a RAM 23, a display unit 31, a ROM 33, an RTC 35, a nonvolatile memory 37, a battery 41, and an A / D converter 43. . Although not shown, the configuration includes an input unit such as a keyboard for inputting an amount of money and an instruction from the user.
The control unit 21 is a processor that performs processing such as calculation of an operable time described below. Specifically, a CPU or a microcomputer is used. The control unit 21 performs money processing, which is the main function of the electronic cash register,

The RAM 23 is a memory that provides a work area for the control unit 21 to process data, and stores an average voltage drop amount table 53 and various temporary variables. For example, a semiconductor memory element such as an SRAM or a DRAM is used. The temporary variables include, for example, an array variable of the battery voltage measurement data VB [], a battery voltage log reference address pointer L, a battery voltage measurement data index counter Di, and a voltage drop Vd during the time block.
The display unit 31 displays the operable time obtained by the calculation of the control unit 21, and for example, a liquid crystal display device or an organic EL is used. The display unit 31 may display the result of the monetary calculation in the electronic cash register 11, but may be configured to display the result of the monetary calculation on another display device (not shown).
The ROM 33 stores a processing program to be executed by the control unit 21 in advance, and for example, a flash memory is used.

The RTC 35 is a real-time clock that provides the current date and time.
The non-volatile memory 37 is a memory that stores data in a readable / writable manner and holds the stored data regardless of whether the electronic cash register 11 is turned on or off. For example, a flash memory is used. The nonvolatile memory 37 stores a battery voltage log information table 51. Furthermore, the battery voltage log head address pointer Lt and the battery voltage log tail address pointer LI used for referring to the battery voltage log information table 51 are stored.
The battery 41 is a power source for driving the electronic cash register 11, and specifically, for example, a lithium ion battery is used. The operable time is an estimate of how long the battery 41 can drive the electronic cash register 11 from the present time.
The A / D converter 43 is a circuit used when the control unit 21 reads the battery voltage of the battery 41.

≪Measurement of battery voltage-Measurement of base voltage and voltage drop for each time block≫
The electronic cash register according to the present invention is driven by a battery. However, it may be driven by an AC power source. The operable time indicates how long the electronic cash register 11 can be driven when the battery 41 is driven.

When the electronic cash register 11 is driven by the battery 41, the control unit 21 measures the battery voltage transition of the battery 41 as a battery voltage log. Then, it is stored in the battery voltage log information table 51 of the recording nonvolatile memory 37. This is because the operable time is accurately calculated using the stored battery voltage log. The battery voltage log is recorded in units of a predetermined time block. In one example, a time block is a unit of one hour. However, the present invention is not limited to this, and the unit of the time block may be shorter or longer than one hour.
In this embodiment, the control unit 21 measures the battery voltage at the beginning and the end of each time block, and changes in the battery voltage in the time block by repeatedly measuring the battery voltage at intervals shorter than the period m of each time block. Each of the embodiments for more faithfully fitting will be described.

First Mode: Method for Measuring Battery Voltage at the Start and End of Each Time Block FIG. 2 is a graph showing a first mode relating to the measurement of battery voltage according to the present invention. In FIG. 2, the horizontal axis indicates the transition of time, t _b is the start time of a time block, and m is the period from the start to the end of the time block. Therefore, (t _b + m) is the end time of the time block. A reference time t ₀ within one day is determined in advance. In one example, the reference time t ₀ is midnight, the beginning of the day. The start of the time block is a time around the base time t ₀ by an integer multiple of m. That is,
t _b = t ₀ + m × n (where n is an integer)
The relationship is established.

The vertical axis in FIG. 2 is the battery voltage of the battery 41. The battery voltage V _{b at} time t _b is the base voltage of the time block. A difference between the base voltage V _b and the battery voltage V _{b + m at} time (t _b + m) is a voltage drop amount V _d . The relationship V _d = V _b −V _{b + m} is established.
The control unit 21 measures the battery voltage of the battery 41 at time t _b , and sets the time t _b acquired from the RTC 35 and the value of the measured battery voltage V _b in the array variable, battery voltage measurement data VB [ ] Is stored in VB [0]. That is,
VB. t [0] = t _b
VB. V [0] = V _b

Further, the control unit 21 measures the battery voltage V _{b + m} battery 41 at time t _b + m of the period of the time blocks, the value of the time t _b + m and the battery voltage V _{b + m} reserved RAM23 battery The voltage measurement data VB [1] is stored in the memory area. That is,
VB. t [1] = t _b + m
VB. V [1] = V _{b + m}

FIG. 3 is an explanatory diagram showing an example of the battery voltage measurement data of FIG. As shown in FIG. 3, the time t _b = 12: 00: battery voltage at _{00 V b = 7.580 (V)} , the time _{t b + m = 13: 00} : 00 the battery voltage at V _b + m = 7.396 (V). Therefore, the battery voltage measurement data is
VB. t [0] = 12: 00
VB. V [0] = 7.580 (V)
VB. t [1] = 13: 00
VB. V [1] = 7.396 (V)
It is. The voltage drop V _d is
V _d = 7.580-7.396 = 0.184 (V)
It is.

Second Aspect: Technique for Repetitively Measuring Battery Voltage at Intervals Shorter than the Period m of Each Time Block FIG. 4 is a graph showing a second aspect relating to the measurement of the battery voltage according to the present invention. As in FIG. 2, the horizontal axis of FIG. 4 shows the transition of time, t _b is the start time of a time block, and (t _b + m) is the end time of the time block. The vertical axis represents the magnitude of the battery voltage. The control unit 21 repeatedly measures the battery voltage at intervals shorter than the time block period m, and stores the time and the value of the battery voltage at that time in the memory area of the battery voltage measurement data VB [] secured in the RAM 23. To do.

FIG. 5 is an explanatory diagram showing an example of the battery voltage measurement data of FIG. As shown in FIG. 5, the control unit 21 repeats the battery voltage measurement 120 times during a one-hour time block. That is, the battery voltage is measured every 30 seconds. As a result, the battery voltage measurement data in FIG.
VB. t [0] = 12: 00
VB. V [0] = 7.580 (V)
VB. t [1] = 12: 00: 30
VB. V [1] = 7.579 (V)
VB. t [2] = 12: 00: 01: 00
VB. V [2] = 7.577 (V)
::
VB. t [120] = 13: 00: 00: 00
VB. V [120] = 7.396 (V)
It is.

And the control part 21 calculates | requires the regression line based on battery voltage measurement data, and calculates | requires the average voltage drop amount and base voltage in the time block. Base voltage V _b is the voltage of the regression line at the time t _b. The voltage drop amount V _d is a difference between the base voltage V _b and the voltage V _{b + m} of the regression line at time (t _b + m). The relationship V _d = V _b −V _{b + m} is established.

≪Battery voltage log information table-storage of history for each time block≫
The control unit 21 acquires the battery voltage log of the battery 41 every time the time block elapses and stores it in the battery voltage log information table 51 of the recording nonvolatile memory 37. The battery voltage log is made up of the start time, date and day of the week, base point voltage V _b, and voltage drop V _d for each time block.
FIG. 6 is an explanatory diagram showing an example of a battery voltage log information table according to the present invention. As shown in FIG. 6, the control unit 21 adds the newly obtained battery voltage log to the end of the battery voltage log information table 51. When adding, the battery voltage log tail address pointer LI is used. After the battery voltage log is stored until the capacity of the battery voltage log information table 51 is full, the battery voltage log at the head of the battery voltage log information table 51 may be overwritten. That is, the battery voltage log information table 51 is used as a ring buffer to store the battery voltage log. When overwriting the first battery voltage log, the control unit 21 uses the battery voltage log first address pointer Lt.

≪Creation of average voltage drop amount table-Future battery voltage transition prediction≫
As pre-processing when calculating the operable time, the control unit 21 creates an average voltage drop amount table indicating the transition of the future battery voltage in units of time blocks with the current time block as a base point. When creating the average voltage drop amount table, the control unit 21 refers to the battery voltage log information table 51. The battery voltage log reference address information L is a pointer used when the control unit 21 refers to the battery voltage log stored in the battery voltage log information table 51.

  FIG. 7 is an explanatory diagram showing an example of an average voltage drop amount table according to the present invention. In the average voltage drop amount table shown in FIG. 7, “Relative time” in the left column is a time block from the current time t to 24 hours, that is, from “0:00” to “23:00”. Is divided in units of time blocks. In the example of FIG. 7, as in FIG. 6, the time block period m is 1 hour.

  The average voltage drop amount in the right column in FIG. 7 indicates how much the battery voltage will drop from the beginning to the end of each time block with the current battery voltage as the base point (zero), and indicates the predicted value of the voltage drop amount. Yes. It is rare that the current time is the time corresponding to the beginning of the time block. The relative time “0:00” indicates how much the battery voltage drops at the current time before the end of the time block including the current time arrives.

The control unit 21 creates the average voltage drop amount table 53 as follows. First, an average voltage drop amount storage area VA. An initial value is written in V _ad [] (initialization process). As the initial value, a voltage drop amount in time block units in a typical use state can be measured in advance before shipment from the factory, and the value can be used.
Subsequently, the control unit 21 associates the time block including the current time with the relative time 0:00 from the time block related to the battery voltage log information table 51 of FIG. 7, and then from 0:00 to 23:00. An average value V _ad of the voltage drop amount V _d corresponding to each time block of relative time is calculated based on the battery voltage log stored in the battery voltage log information table 51. V _ad corresponding to each time block from relative time 0:00 to 23:00 can be said to be a voltage drop amount reflecting an average usage frequency of the electronic cash register 11 in the time zone of the day. The control unit 21 uses the calculated average voltage drop amount V _ad to store the corresponding relative time storage area VA. Each is stored in V _ad [].
When the average voltage drop amount V _ad is calculated using each battery voltage log stored in the battery voltage log information table 51, the above-described extraction condition as to whether or not to extract the battery voltage log as an element for calculating the average value is described above. In addition to the time block matching, for example, the following conditions can be added.

First addition condition: addition of day of the week A condition is added so that only information on the same day of the week as the current date and time is referred to.
Some users have different usage frequencies on certain days of the week, such as a lot of sales on weekends. In the case of a user who frequently uses a specific day of the week, the amount of battery voltage drop depends on the day of the week. By extracting only the data for the same day of the week, the accuracy of predicting the voltage drop can be improved.

Second addition condition: addition of battery voltage range A condition is added so as to refer only to a time block having a base voltage in a range close to the current battery voltage.
FIG. 8 is a graph for explaining additional conditions according to this embodiment. As shown in FIG. 8, due to the normal characteristics of the battery, the voltage drop amount varies even in the same usage frequency in the fully charged state, the state near the charge shortage, and the state between them. By dividing the voltage section for each voltage characteristic of the battery and referring to the voltage drop amount in the same voltage section, the prediction accuracy of the battery voltage is increased. In FIG. 8, the fully charged state is divided into a voltage section A, a state near a charge shortage is divided into a voltage section C, and a state between them is divided into a voltage section B.
The control unit 21 applies the above additional conditions alone or in combination, or calculates the average voltage drop amount V _ad corresponding to each time block without the additional conditions.

It can be considered that the prediction accuracy of the battery voltage is improved as the combination of conditions increases. However, it is assumed that a sufficient number of battery voltage logs are stored in the battery voltage log information table 51, and that a sufficient number of battery voltage logs corresponding to the extraction condition exist.
V _ad is not calculated for a time block for which there is no battery voltage log corresponding to the extraction condition. Therefore, V _ad is not stored in the average voltage drop amount table 53 for the time block, and the initial value is used as a result. Further, even if there are corresponding battery voltage logs, if the number is small, for example, if there is only one corresponding battery voltage log, it cannot be said that the prediction accuracy is improved. Therefore, if there are many combinations of extraction conditions, it cannot be said that the prediction accuracy is improved. Whether or not the condition is added may be selectable by the user by setting. Alternatively, the control unit 21 may determine and change whether to combine conditions and / or add conditions based on whether or not the number of battery voltage logs corresponding to the extraction condition is equal to or greater than a threshold value. .

≪Calculation of operating time≫
When the basic average voltage drop amount table 53 is created as described above, the control unit 21 calculates the operable time as follows using the created average voltage drop amount table.
The control unit 21 measures the battery voltage at the current time t. This time t is the time of the base point of the average voltage drop amount table 53. That is, the control unit 21 measures the battery voltage V _t when the average voltage drop amount table 53 is created.
Control unit 21, battery voltage estimated value VA of the relative time "0:00" of the obtained battery voltage V _t the average voltage drop amount table. Store in V _b [0]. V _t is a measured value rather than the predicted value, convenience to this.

Subsequently, the control unit 21 determines the average voltage drop amount VA. At the relative time “0:00” of the average voltage drop amount table 53 that has already been obtained. V _ad [0] end time block relative time "0:00" using, i.e., calculates the estimated value of the battery voltage of the beginning of time block "1:00" in the following relative time. What should be noted here is that the current time t does not normally coincide with the start time t _b of the relative time “0:00” and is between the start time and the end time. Therefore, the average voltage drop amount VA. Multiply V _ad [0] by the ratio of the remaining time until the final time t _b + m to the total time m of the time block to obtain the voltage drop until the final time. Then, by subtracting the resulting voltage drop from the current battery voltage V _t and the predicted value of the battery voltage at the end of the relative time "0:00". This can be said to be a predicted value of the base voltage at the relative time “10:00”. The control unit 21 calculates the battery voltage predicted value VA. At the relative time “10:00” in the average voltage drop amount table 53. The obtained value is stored as V _b [1].

When the calculated predicted value is _{equal to} or higher than a threshold voltage _Vlmt determined in advance as a voltage at which the electronic cash register 11 can operate, the control unit 21 further starts the relative time “1” from the base voltage at the relative time “ _10:00 ”. : 0:00 ”is subtracted from the average voltage drop amount, and the predicted value of the base voltage at the relative time“ 2:00 ”is calculated and stored. If the calculated predicted value is _greater than or equal to V _1mt , the control unit 21 further calculates and stores the predicted value of the base voltage at the relative time “3:00”. Thereafter, the calculation of the predicted value of the base voltage is repeated until “23:00”. On the other hand, when the calculated predicted value is smaller than V _1mt , the calculation of the predicted value is aborted and the immediately preceding relative time is output as the remaining operable time. If the predicted value of the base voltage of the last time block “23:00” is equal to or greater than V _1mt , the fact that the battery life is sufficient is output.

FIG. 9 is an explanatory diagram showing an example of battery voltage prediction according to the present invention. In FIG. 9, the current time is 13:30, the time block starts at 10:00 in hour units, the current battery voltage measurement is 7.541 V, and the threshold voltage V at which the electronic cash register 11 can operate It is assumed that _lmt is 6.5V.

The control unit 21 stores the current battery voltage measurement value in the predicted battery voltage value at the relative time “0:00”. According to the already obtained average voltage drop amount table, the average voltage drop amount at the relative time “0:00” is 0.186V. The end of the time block including the current time is 14:00. Until that end, half of the time block period remains, so the amount of voltage drop until the end of the relative time “0:00” is
0.186 (V) x 30 (min) / 60 (min) = 0.093 (V)
It is. The control unit 21 subtracts this voltage drop amount from the current battery voltage.
7.541−0.093 = 7.448 (V)
And it stores as a battery voltage prediction value of relative time “10:00”. Since the obtained predicted value is 6.5 V or more of V _lmt , the control unit 21 further calculates and stores the predicted battery voltage value at the relative time “2:00”. This calculation is obtained by subtracting the average voltage drop at the relative time “10:00” from the predicted battery voltage at the relative time “10:00”.
7.448−0.151 = 7.297 (V)
Since the obtained predicted value is 6.5 V or more of V _lmt , the control unit 21 repeats the same calculation until the predicted battery voltage value at the relative time “9:00” is reached.

The battery voltage predicted value 6.477 (V) at the relative time “9:00” is lower than 6.5 V of V _lmt , so the control unit 21 stops the calculation of the battery voltage predicted value here. Then, the operable time is calculated as follows.
First, the time until the end of the relative time “0:00” is obtained. This time is 30 minutes. Further, the total of time blocks in which the base voltage is V _lmt or higher is _obtained . Here, it is 7 hours from the relative time “10:00” to “7:00”. Furthermore, a period during which the battery voltage drops to V _1mt during the relative time “8:00” is calculated. _Assuming that the voltage drop characteristic is expressed by a linear function, the period during which the battery voltage drops to V _1mt is obtained by the following calculation from the predicted battery voltage values at the beginning and end.
60 × (6.577-6.500) / (6.577-6.477) = 46 (minutes)

Therefore, the predicted value of the operable time with the current time t as a base point is obtained as a sum of these values. That is,
30 (minutes) +7 hours + 46 (minutes) = 8 hours and 16 minutes is the expected operation time. Since the current time is 13:30, it is predicted to operate until 21:46.
The control unit 21 displays the operable time on the display unit 31.

≪Flowchart≫
10 to 17 are flowcharts showing a procedure of processing executed by the control unit 21 according to the present invention. Among these, FIG. 10 and FIG. 11 show processing relating to measurement of the base voltage and voltage drop amount for each time block and generation of the battery voltage log information table. More specifically, FIG. 10 shows a mode in which the battery voltage is measured at the beginning and end of each time block, and FIG. 11 shows a mode in which the battery voltage is repeatedly measured at an interval shorter than the period of each time block. . 12 and 13 show processing relating to generation of the average voltage drop amount table. FIG. 14 and FIG. 15 show processing related to the prediction of the operable time. 16 and 17 show processing relating to the additional conditions.
Hereinafter, the process which the control part 21 performs is demonstrated along a flowchart.

Measurement of Battery Voltage and Generation of Battery Voltage Log Information Table First, the process of FIG. 10 will be described. In this process, the battery voltage is measured at the beginning and end of each time block, and a battery voltage log information table is generated. As shown in FIG. 10, as an initialization process, the control unit 21 first sets the battery voltage log head address pointer Lt so as to refer to the head address of the battery voltage log information table (step S11). Further, the battery voltage log tail address pointer LI is initialized so as to refer to the address immediately before the battery voltage log head address pointer Lt (step S13). This initial value allows for the increment of the battery voltage log tail address pointer LI in step S31 described later. Initially, since the battery voltage log is not stored, the initial values of the leading and trailing pointers are almost the same. The above is the initialization process.

Next, the control unit 21 sets zero as the initial value of the battery voltage measurement data index counter Di (step S15). Di is a counter used for referring to battery voltage measurement data VB [] that is an array variable.
Subsequently, the control unit 21 acquires the current date, day of the week, and time from the RTC 35 (step S17). Then, the acquisition date T of the next battery voltage log is calculated in light of the base point and unit of the predetermined time block (step S19). Then, while sequentially referring to the RTC (step S21), it waits for the acquisition date T to arrive (step S23).

  When the acquisition date and time T has arrived (Yes in step S23), the control unit 21 measures the current battery voltage V via the A / D converter 43 (step S25). And the battery voltage V measured and the acquisition date T when the measurement was performed are stored in battery voltage measurement data VB [Di] (step S27). Subsequently, Di is incremented (step S29). In FIG. 10, when the battery voltage is measured at the beginning and end of each time block, when Di is zero, it corresponds to the measurement at the beginning, and when Di is 1, it corresponds to the measurement at the end. Therefore, when the result of incrementing Di is 1 (No in step S23), this corresponds to the state where the initial measurement is completed. In this case, the routine proceeds to step S19 and calculates the acquisition date and time T for performing the final measurement. Then, the same processing as the initial measurement is repeated in steps S21 to S29.

On the other hand, when Di is larger than 1 (Yes in step S31), it corresponds to the case where the final measurement is completed. In this case, the control unit 21 increments the battery voltage log tail address pointer LI used for storing the battery voltage log (step S33). Then, the voltage drop amount V _d is obtained by subtracting the battery voltage at the beginning and the end (step S35).
The control unit 21 stores the year / month / day, day of the week, and time associated with the measurement of the base voltage stored in the battery voltage measurement data VB [] in the battery voltage log information table 51 referred to by the battery voltage log tail address pointer LI. Data VB. t [0] is stored as the date, day, and time of the battery voltage log. Further, the obtained voltage drop amount V _d is stored as the voltage drop amount of the battery voltage log. Further, the base voltage data VB. Stored in the battery voltage measurement data VB []. V [0] is stored as the base voltage of the battery voltage log (step S37). The routine then returns to step S15 and repeats the processing for the next time block in the same manner. The above is the processing shown in FIG.

On the other hand, FIG. 11 repeatedly measures the battery voltage not only at the start and end of each time block but also at intervals shorter than the time block period.
In FIG. 11, steps S41, S43, S45, S47 and S49 correspond to steps S11, S13, S15, S17 and S19 of FIG. The acquisition date T acquired in step S49 is the start of the next time block and the end of the current time block.
Following the processing of step S49, the control unit 21 measures the current battery voltage V (step S51). And the battery voltage V measured and the acquisition date T when the measurement was performed are stored in the battery voltage measurement data VB [Di] (step S53). Subsequently, Di is incremented (step S55).

  The control unit 21 acquires the current date, day of the week, and time t from the RTC 35 (step S57). It is checked whether or not the time t has reached the acquisition date T, that is, the end of the time block (step S59). If the end of the time block has not been reached, the routine proceeds to step S51 and repeats the measurement of the battery voltage V and the addition of the battery voltage measurement data. In this way, the battery voltage data is sequentially stored in the array variable of the battery voltage measurement data VB []. If the measurement interval of the battery voltage V is too short, a timer setting corresponding to the measurement cycle and a process for waiting for the end of the timer may be added to this repeated loop.

When the current time t reaches the end of the time block (Yes in step S59), the control unit 21 increments the battery voltage log tail address pointer LI used for storing the battery voltage log (step S61). Then, to calculate the regression line from the data stored in the battery voltage measurement data VB [], determine its time base voltage V _b of the block and the voltage drop V _d during the time block (step S63).

The control unit 21 stores the year / month / day, day of the week, and time associated with the measurement of the base voltage stored in the battery voltage measurement data VB [] in the battery voltage log information table 51 referred to by the battery voltage log tail address pointer LI. Data VB. t [0] is stored as the date, day, and time of the battery voltage log. Further, the voltage drop amount V _d obtained in step S63 is stored as the voltage drop amount of the battery voltage log, and further, the base voltage V _b obtained in step S63 is stored as the base voltage of the battery voltage log ( Step S65). Then, the routine returns to step S45, and the next time block processing is repeated in the same manner. The above is the processing shown in FIG.

Generation of Average Voltage Drop Amount Table Next, processing related to generation of the average voltage drop amount table 53 shown in FIGS. 12 and 13 will be described.
In a state where the electronic cash register 11 is driven by the battery 41, the control unit 21 causes the display unit 31 to display the predicted value of the operable voltage. When the display update time comes, the control unit 21 creates an average voltage drop amount table 53 with the time as a base point.
The control unit 21 first determines the average voltage drop VA.VA stored in the average voltage drop amount table 53. The data of V _ad [] is initialized (step S71). This is because the value of the average voltage drop amount table created immediately before remains before initialization.

Then, the current date, day of the week, and time are acquired from the RTC 35 (step S73). Further, the current battery voltage V is measured via the A / D converter 43 (step S75). In addition, a time block including the current date, day of the week, and time t, that is, the start time T0 of the time block corresponding to the relative time “0:00” is calculated (step S77).
Subsequently, the control unit 21 sets zero as the initial value of the pointer Tr indicating the relative time to be targeted in the average voltage drop amount table 53 (step S79). Further, zero is set as the initial value of the average voltage drop amount table reference counter Ca (step S81). The initial value of the pointer Tr indicates the start time of the relative time “0:00”. Further, the initial value of the average voltage drop amount table reference counter Ca indicates that the target relative time is the relative time “0:00”.

Thereafter, the control unit 21 performs processing for extracting data used for calculating the average voltage drop amount from the battery voltage log information table 51. First, Lt is set to the battery voltage log reference address pointer L as an initial value (step S83). Lt indicates the head of the battery voltage log information table 51. Further, zero is set to the cumulative voltage drop amount Vs, and zero is set to the corresponding log counter CI (step S85). The CI is a counter that stores the number of battery voltage logs corresponding to the condition and calculates an average value of the voltage drop amount.
The control unit 21 obtains the time T indicated by the battery voltage log referenced by the battery voltage log reference address pointer L in the battery voltage log information table 51 and the time indicated by the pointer Tr (for example, the initial value is obtained in step S77). It is checked whether or not the time T0 matches (step S87). If they do not match, it is determined that the battery voltage log is not used for calculating the average voltage drop amount (No in step S87), and the routine proceeds to step S97 described later. Note that the time indicated by the pointer Tr is a time corresponding to the target relative time. The relative time that is the target is the relative time indicated by the average voltage drop amount table reference counter Ca.

On the other hand, if they match (Yes in step S87), the process shown in FIG. 16 or FIG. 17 is executed to further check the additional conditions (step S89). In addition, what is necessary is just to skip to the process of step S93 when not attaching additional conditions.
Here, the processing of FIG. 16 and FIG. 17 related to the processing of step S89 will be described. FIG. 16 shows a process in the case of extracting data using the coincidence of the day of the week as an additional condition. FIG. 17 shows a process in the case where data is extracted with a voltage classification close to the current battery voltage V as an additional condition. When both are combined, the processes of FIGS. 16 and 17 are both performed, and when each determination corresponds to “applicable”, the final determination result is “corresponding”. Otherwise, the final determination result is “ “Not applicable”.

  In the process illustrated in FIG. 16, the control unit 21 matches the time T indicated by the battery voltage log referenced by the battery voltage log reference address pointer L in the battery voltage log information table 51 with the day of the week associated with the pointer Tr. This is checked (step S141). The day of the week related to the pointer Tr is the day of the relative time that is the current target (for example, the initial value is the day of the week related to the time T0). If the two match, “applicable” is returned as the determination result (step S145), and if not, “not applicable” is returned as the determination result (step S143). The above is the contents of the processing shown in FIG.

Further, in the process shown in FIG. 17, the control unit 21, the voltage division of base voltage V _b of battery voltage log referenced by the battery voltage log reference address pointer L belongs voltage interval A shown in FIG. 8, B and C It is checked which one corresponds (step S151). Further, it is examined which of the voltage sections A, B, and C corresponds to the base point voltage related to the time indicated by the pointer Tr, that is, the relative time that is currently targeted (step S153). Then, it is checked whether or not the two voltage classifications match (step S155). If they match, “relevant” is returned as the determination result (step S159). If they do not match, “not applicable” is returned as the determination result (step S157). The above is the contents of the processing shown in FIG.

  Returning to the description of FIG. The control unit checks whether the result of step S89 is “applicable” or “not applicable” (step S91). If the result is “not applicable”, it is determined that the battery voltage log is not used for calculation of the average voltage drop amount (No in step S87), and the routine proceeds to step S97 described later.

On the other hand, when the result is “appropriate”, the control unit 21 adds the voltage drop amount V _d of the battery voltage log referred to by the battery voltage log reference address pointer L to the cumulative voltage drop amount Vs (step S93). Further, the corresponding battery voltage log counter CI is incremented (step S95). Then, it is checked whether or not the battery voltage log reference address pointer L points to the end of the battery voltage log information table 51 (step S97). If it is not the end (No in step S97), the battery voltage log reference address pointer L is incremented to refer to the next battery voltage log in the battery voltage log information table 51 (step S99), and then from step S87. Repeat the process. The battery voltage log stored in the battery voltage log information table 51 is sequentially referred to by the repeated processing of steps S87 to S99.

In step S97, when the battery voltage log reference address pointer L points to the end of the battery voltage log information table 51 (Yes in step S97), the battery voltage log stored in the battery voltage log information table 51 is displayed. In this case, the routine proceeds to step S101, and the number of battery voltage logs to be used for calculating the average value of the voltage drop amount related to the target relative time in the average voltage drop quantity table 53 is determined. The number is counted in the process of step S95 and stored in the corresponding log counter CI.
If the corresponding log counter CI is zero (No in step S101), it means that there is no corresponding log. Therefore, the voltage drop amount at the current relative time is not changed to the initial value, and the routine is stepped. The process proceeds to S105.

On the other hand, if the corresponding log counter CI is not zero (Yes in Step S101), the control unit 21 determines the relative time VA. As indicated by the current relative time, that is, the average voltage drop amount table reference counter Ca. The average voltage drop amount of t [Ca] is calculated, and the result is calculated as the average voltage drop amount VA. V _ad [Ca] is stored (step S103). Here, the average voltage drop VA. V _ad [Ca] is obtained by dividing the cumulative voltage drop amount Vs by the corresponding log counter CI.
VA. V _ad [Ca] = Vs / CI

  The control unit 21 increments the average voltage drop amount table reference counter Ca to refer to the next relative time. Further, the relative time VA. Indicated by the average voltage drop amount table reference counter Ca. The time block interval m is added to the start time of the time block of t [Ca] (step S105). As a result, the Ca and Tr are updated so as to indicate the next relative time in a synchronized state.

Subsequently, the control unit 21 determines the relative time VA. Referenced by the average voltage drop amount table reference counter Ca. It is checked whether or not t [Ca] exceeds 24 hours (step S107). Specifically, it is checked whether the value obtained by multiplying the time block interval m by the value of the average voltage drop amount table reference counter Ca is greater than 24 hours. If it does not exceed 24 hours (No in step S107), the routine returns to S87 and repeats the process. By this iterative process, the average voltage drop amount is calculated with reference to the battery voltage log information table 51 for the next relative time, and the obtained average voltage drop amount is stored in the average voltage drop amount table 53.
On the other hand, when it exceeds 24 hours (Yes of step S107), the operation | workable time demonstrated below is estimated.

Prediction of operable time When the above-described determination in step S107 is Yes, the control unit 21 predicts an operable time. This is the process shown in FIGS.
First, the control unit 21 initializes a temporary variable Tw for storing the operable time to zero (step S111). Then, zero is set to the average voltage drop amount table reference counter C (step S113). The initial value of the average voltage drop amount table reference counter C indicates the relative time “0:00”.

Next, the control unit 21 determines the time Tw until the end of the time block at the relative time “0:00” and the predicted value of the battery voltage at the end, that is, the predicted value VA. Of the battery voltage at the start of the next time block. V _b [1] is calculated (step S115). In the calculation, the current time t acquired in step S73 and the battery voltage V at that time are used as a base point.

Since the start time of the time block of relative time “0:00” is T0, the time Tw until the end is
Tw = T0 + mt
Is required. Further, the predicted value VA. Of the battery voltage at the end, that is, at the start of the next time block. V _b [1] is
VA. V _b [1] = V−VA. V _ad [0] × Tw / m

Then, when the relative time indicated by the average voltage drop amount table reference counter C ends, that is, when the end of the time block indicated by C arrives, the control unit 21 operates the threshold voltage V _{lmt at} which the battery voltage can operate. It is determined whether it is below (step S117). If not lower (No in step S117), the average voltage drop amount table reference counter C is incremented to refer to the next time block (step S119).

Next, the control unit 21 compares the relative time VA. The time Tw until the end of the time block t [C] and the predicted value VA. of the battery voltage at the end, that is, the start of the next time block. V _b [C] is calculated (step S121). The time Tw until the end is obtained by adding the time block interval m to the end time Tw of the immediately preceding time block,
Tw = Tw + m
Is required. Further, the predicted value VA. Of the battery voltage at the end, that is, at the start of the next time block. V _b [C + 1] is
VA. V _b [C + 1] = VA. V _b [C] -VA. V _ad [C]
Is required.

Then, when the end of the time block indicated by the average voltage drop amount table reference counter C comes, the control unit 21 determines whether the battery voltage falls below the _operable threshold voltage _Vlmt (step S131). If not lower (No in step S123), the average voltage drop amount table reference counter C is incremented to refer to the next time block (step S125).
Further, the relative time VA. It is checked whether t [Ca] exceeds 24 hours (step S127). Specifically, it is checked whether the value obtained by multiplying the time block interval m by the value of the average voltage drop amount table reference counter Ca is greater than 24 hours. If it exceeds 24 hours (Yes in step S127), a display indicating that the operating time is 24 hours or longer is displayed on the display unit 31 (step S129), and the process is terminated.

On the other hand, if it exceeds 24 hours (No in step S127), the routine returns to S121 and repeats the process. By this iterative process, when the end of the next relative time _comes , the determination as to whether the battery voltage falls below the _operable threshold voltage _Vlmt is sequentially repeated.
On the other hand, if it is determined in step S117 or S123 described above that the battery voltage falls below the _operable threshold voltage _Vlmt when the end of the time block _comes , the routine proceeds to step S131, and the time Time Tw until the battery voltage reaches the operable voltage in the block is calculated. The time Tw is obtained by adding the time block interval m multiplied by the following ratio to Tw obtained as the time until the end of the previous time block processing. The ratio is the battery voltage predicted value VA. The difference between V _b [C] and V _lmt is _calculated as the average voltage drop VA. It is a value divided by V _ad [C].
Then, the calculated operable time Tw is displayed on the display unit 31 (step S133), and the process ends.
The above is the process of the control unit 21.

  In addition to the embodiments described above, there can be various modifications of the present invention. These modifications should not be construed as not belonging to the scope of the present invention. The present invention should include the meaning equivalent to the scope of the claims and all modifications within the scope.

11: Electronic cash register 21: Control unit 23: RAM
31: Display unit 33: ROM
35: RTC
37: Non-volatile memory 41: Battery 43: A / D converter 51: Battery voltage log information table 53: Average voltage drop amount table

Claims (5)

A battery for driving the device;
A measurement unit for measuring the voltage of the battery;
A timekeeping section that provides the date and time when the measurement was made;
A storage unit for storing data relating to the voltage and the date and time;
Process for repeatedly measuring the battery voltage by the measurement unit, processing for obtaining the date and time related to each measurement from the time measuring unit, and measuring each battery voltage measured and a change in voltage between the previous and subsequent measurements The process of storing the battery voltage log in the storage unit in association with the date and time related to the process, the process of predicting the battery voltage at a series of times after the current time based on the stored battery voltage log, and the predicted battery voltage A control unit that performs a process of calculating the operable time until it falls to a predetermined threshold;
A display unit for performing display related to the operable time,
The control unit causes the measurement unit to measure the current battery voltage, obtains the date and time of measurement from the timekeeping unit, and predicts the battery voltage at each time at a time within a predetermined range from each time. Battery voltage log measured on the same day , and further based on the battery voltage log corresponding to the same voltage category as the current battery voltage when each measured battery voltage is divided into predetermined voltage categories Electronic cash register characterized by The timekeeping section provides the date and day of the measurement and the day of the week,
The control unit, when predicting the transition of the battery voltage from the current time, the time for measurement is within a predetermined range from the current time, and the day of the week for measurement is predicted based on the same battery voltage log as the day of the week for prediction Item 2. The electronic cash register according to Item 1. The control unit divides a day into a plurality of predetermined periods, sequentially predicts battery voltage transitions from the present time by dividing the period, and predicts battery voltage transitions during a certain period of time for measurement. There electronic cash register according to claim 1 or 2 carried out on the basis of the battery voltage logs belonging to the same period. The control unit causes the measurement unit to measure the battery voltage at time block intervals obtained by dividing the day into predetermined intervals, and changes the initial battery voltage and the change in the initial and final battery voltages of the time block. The electronic cash register according to claim 3 , wherein the electronic cash register is stored as a battery voltage log. The control unit repeatedly causes the measurement unit to measure battery voltage at intervals shorter than an interval of time blocks obtained by dividing a day into predetermined intervals, and uses the least-squares method for the battery voltage measured in the time block. 4. The electronic cash register according to claim 3 , wherein a battery voltage at the beginning and end of the time block is calculated by applying and a change in the battery voltage at the beginning and at the beginning and end is stored as a battery voltage log.