Battery-powered communication device, program, and method for monitoring the battery level of a battery-powered communication device.

Abstract

To predict battery replacement time in a battery-powered communication device.SOLUTION: Every time an IoT terminal 1 measures battery voltage, the IoT terminal calculates the rate of change in battery voltage based on the latest voltage value of battery voltage and measurement date and time thereof, and a voltage value of reference voltage and measurement date and time thereof. If the calculated rate of change is negative, the IoT terminal uses a linear function of time-battery voltage having this rate of change as a coefficient (slope) and the voltage value of the reference voltage or the latest voltage value of the battery voltage as a constant, and calculates a predicted value of time required for the voltage value of the battery voltage to decrease to a predetermined battery replacement voltage value. The IoT terminal adds the calculated predicted value of time to the measurement date and time of the reference voltage or the measurement date and time of the latest battery voltage to predict a battery replacement time. The IoT terminal then updates the voltage value and measurement date and time of the reference voltage to the latest voltage value and measurement date and time of the battery voltage.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a battery remaining amount monitoring technology for battery-powered communication devices, and particularly to a battery remaining amount monitoring technology for battery-powered IoT (Internet of Things) terminals.

Background Art

[0002] In recent years, battery-powered IoT terminals have become widespread as IoT terminals that wirelessly relay sensor data detected by sensors to a server. Battery-powered IoT terminals do not require wiring for power supply and have a high degree of freedom in the installation location. However, in order to continuously operate a battery-powered IoT terminal, it is necessary to replace the battery before the battery remaining amount runs out. Therefore, it is necessary to accurately monitor the battery remaining amount in battery-powered IoT terminals.

[0003] Patent Document 1 discloses a battery remaining amount determination device in a battery-powered device. This battery remaining amount determination device measures the battery voltage in a no-load state and the battery voltage in a maximum-load state, calculates the voltage drop amount from these voltage values, and compares the calculated voltage drop amount with a threshold value for remaining amount determination to determine the presence or absence of the battery remaining amount. When the battery remaining amount is present, a remaining amount display is performed, and when there is none, a battery replacement display is performed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, if the battery level indicator displayed by the battery level determination device described in Patent Document 1 is left on for an extended period, it may cause the battery of a battery-powered device to run out. On the other hand, even if the battery level indicator is displayed, the operator does not know how much longer the device can operate with the displayed battery level. Therefore, the operator has to frequently check whether the battery needs to be replaced, which is cumbersome.

[0006] This invention has been made in view of the above circumstances, and the object of this invention is to enable the prediction of when to replace the battery in a battery-powered communication device. [Means for solving the problem]

[0007] To solve the above problems, the present invention calculates the rate of change of the battery voltage each time the battery voltage is measured, based on the latest voltage value and measurement date and time of the battery voltage and the reference voltage value and measurement date and time. If the calculated rate of change of voltage is negative, the rate of change of the battery voltage is used as a coefficient (slope), and a linear function of time-battery voltage is used, with the reference voltage value or the latest voltage value of the battery voltage as a constant, to calculate a predicted time required for the battery voltage value to decrease to a predetermined battery replacement voltage value. Then, the calculated predicted time value is added to the measurement date and time of the reference voltage or the latest measurement date and time of the battery voltage to predict the battery replacement time. After that, the voltage value and measurement date and time of the reference voltage are updated to the latest voltage value and measurement date and time of the battery voltage.

[0008] Here, the calculated rate of change of the battery voltage may be corrected by a reference slope, and the corrected rate of change may be used as a coefficient (slope). A linear function of time-battery voltage may be used, where the voltage value of the reference voltage or the voltage value of the latest battery voltage is a constant, to calculate the predicted time required for the battery voltage value to drop to the battery replacement voltage value. In this case, the reference slope is then updated to the corrected rate of change.

[0009] For example, the present invention is A battery-powered communication device, A voltage measuring means for repeatedly measuring battery voltage, A reference information storage means that stores the voltage value of the reference voltage and the date and time of measurement, Each time the battery voltage is measured by the voltage measuring means, a slope calculation means calculates the rate of change of the battery voltage based on the latest voltage value and measurement date and time of the battery voltage, and the voltage value and measurement date and time of the reference voltage stored in the reference information storage means. When the rate of change calculated by the slope calculation means is negative, a replacement timing prediction means predicts the battery replacement timing based on the rate of change and the voltage value and measurement date and time of the reference voltage stored in the reference information storage means or the latest voltage value and measurement date and time of the battery voltage. When the battery replacement time is predicted by the replacement time prediction means, the reference information update means updates the voltage value and measurement date and time of the reference voltage stored in the reference information storage means to the latest voltage value and measurement date and time of the battery voltage. In a coordinate system where the vertical axis represents voltage and the horizontal axis represents time, a measured area storage means stores the measured area of ​​battery consumption, If the rate of change calculated by the slope calculation means is negative, the measured area update means calculates the area of ​​the region enclosed by the coordinates specified by the latest voltage value and measurement date and time of the battery voltage, the coordinates specified by the voltage value and measurement date and time of the reference voltage, the coordinates specified by a predetermined battery replacement voltage value and the latest measurement date and time of the battery voltage, and the coordinates specified by the battery replacement voltage value and the measurement date and time of the reference voltage, and adds the calculated area as the measured area of ​​the battery consumption to the measured area storage means. When the battery replacement time is predicted by the replacement time prediction means, the battery remaining amount calculation means calculates the area of ​​the region enclosed by the coordinates specified by the latest voltage value and measurement date and time of the battery voltage, the coordinates specified by the latest measurement date and time of the battery voltage and the battery replacement voltage, and the coordinates specified by the battery replacement voltage value and the battery replacement time as the predicted area of ​​battery consumption, and calculates the battery remaining amount as the ratio of the predicted area of ​​battery consumption to the sum of the measured area of ​​battery consumption and the predicted area of ​​battery consumption stored in the measured area storage means. It has, The aforementioned replacement timing prediction means is Using a linear time-battery voltage function with the aforementioned rate of change as a coefficient and the voltage value of the reference voltage or the latest voltage value of the battery voltage as a constant, the voltage value of the battery voltage is calculated. The aforementioned The estimated time required for the battery voltage to drop to the battery replacement voltage value is calculated, and the calculated estimated time is added to the measurement date and time of the reference voltage or the latest measurement date and time of the battery voltage to predict the battery replacement time. [Effects of the Invention]

[0010] This invention predicts the battery replacement time, eliminating the need for operators to frequently check whether battery replacement is necessary. Furthermore, this invention predicts the battery replacement time each time the battery voltage is measured, based on the latest battery voltage value and measurement date and time, and the reference voltage value and measurement date and time. Here, the reference voltage is updated each time the battery replacement time is predicted, based on the latest battery voltage value and measurement date and time. Therefore, according to this invention, in a battery-powered communication device, the battery replacement time can be predicted with high accuracy from the recent voltage drop trend of the battery. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic diagram of a wireless data sensing system to which the IoT terminal 1 according to the first embodiment of the present invention is applied. [Figure 2] Figure 2 is a schematic functional configuration diagram of IoT terminal 1 according to the first embodiment of the present invention. [Figure 3] Figure 3 is a flowchart illustrating the battery replacement timing prediction process of IoT terminal 1 according to the first embodiment of the present invention. [Figure 4] Figure 4 is a flowchart illustrating the battery replacement timing prediction process of IoT terminal 1 according to the first embodiment of the present invention, and is a continuation of Figure 3. [Figure 5] Figure 5 is a flowchart illustrating the battery replacement timing prediction process of IoT terminal 1 according to the first embodiment of the present invention, and is a continuation of Figure 3. [Figure 6] Figure 6 is a schematic functional configuration diagram of IoT terminal 1A according to a second embodiment of the present invention. [Figure 7] Figure 7 is a flowchart illustrating a part of the battery replacement timing prediction process for IoT terminal 1A according to a second embodiment of the present invention. [Figure 8] Figure 8 is a flowchart illustrating a part of the battery replacement timing prediction process for IoT terminal 1A according to a second embodiment of the present invention. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0013] [First Embodiment] First, the first embodiment of the present invention will be described.

[0014] FIG. 1 is a schematic configuration diagram of a wireless data sensing system to which the IoT terminal 1 according to the present embodiment is applied.

[0015] As shown in the figure, the wireless data sensing system is for managing the operating status of facilities 4 such as factories using IoT, measures sensor values related to the operating status of facilities 4, and outputs sensor data including the sensor values and their measurement dates and times. It includes a sensor 2, an IoT server device 3 that collects and manages the sensor data output from the sensor 2, and the IoT terminal 1 according to the present embodiment.

[0016] The IoT terminal 1 houses the sensor 2 and is wirelessly connected to a wireless access point (wireless AP) 5, and relays the sensor data output from the sensor 2 to the IoT server device 3 via the wireless access point 5. Further, the IoT terminal 1 is a battery-powered IoT terminal, predicts the battery life so that the battery replacement operation can be performed at an appropriate timing, and outputs the prediction result. Note that the wireless access point 5 may be a gateway (GW).

[0017] FIG. 2 is a schematic functional configuration diagram of the IoT terminal 1 according to the present embodiment.

[0018] As shown in the figure, the IoT terminal 1 includes a battery power source 100, a sensor interface unit 101, a wireless interface unit 102, a relay unit 103, a voltage measurement unit 104, a reference information storage unit 105, a slope calculation unit 106, a replacement timing prediction unit 107, a reference information update unit 108, a display unit 109, and a main control unit 110.

[0019] The battery power supply 100 has a replaceable battery, and supplies power to each part 101-110 of the IoT terminal 1 from this battery.

[0020] The sensor interface unit 101 is an interface for connecting to the sensor 2 and receives sensor data from the sensor 2.

[0021] The wireless interface unit 102 is an interface for wirelessly connecting to the wireless access point 5, and wirelessly transmits sensor data to the IoT server device 3 via the wireless access point 5.

[0022] The relay unit 103 relays data between the sensor interface unit 101 and the wireless interface unit 102. As a result, the sensor data from sensor 2 received by the sensor interface unit 101 is wirelessly transmitted from the wireless interface unit 102 to the wireless access point 5, and then transmitted from the wireless access point 5 to the IoT server device 3.

[0023] The voltage measurement unit 104 periodically measures the battery voltage of the battery power supply 100.

[0024] The reference information storage unit 105 stores the voltage value of the reference voltage, the measurement date and time, and the reference slope. The reference voltage and reference slope are used by the slope calculation unit 106 and the replacement timing prediction unit 107.

[0025] The slope calculation unit 106 calculates the rate of change (average rate of change) of the battery voltage each time the battery voltage is measured by the voltage measurement unit 104, based on the latest voltage value and measurement date and time of the battery voltage, and the voltage value and measurement date and time of the reference voltage stored in the reference information storage unit 105.

[0026] The replacement timing prediction unit 107 predicts the battery replacement timing based on the rate of change of voltage calculated by the slope calculation unit 106, the latest voltage value and measurement date and time of the battery voltage, and the reference slope stored in the reference information storage unit 105, when the rate of change of voltage calculated by the slope calculation unit 106 is negative.

[0027] When the battery replacement time is predicted by the replacement time prediction unit 107, the reference information update unit 108 updates the reference voltage value, measurement date and time, and reference slope of the reference voltage stored in the reference information storage unit 105.

[0028] The display unit 109 consists of a liquid crystal panel or the like and displays the battery replacement time predicted by the replacement time prediction unit 107.

[0029] The main control unit 110 then comprehensively controls each of the IoT terminal 1's components 100-109.

[0030] The functional configuration of IoT terminal 1 shown in Figure 2 may be implemented in hardware using integrated logic ICs such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays), or it may be implemented in software using a computer such as a DSP (Digital Signal Processor). Alternatively, in a computer system equipped with a CPU (Central Processing Unit), memory, auxiliary storage, and a communication interface, each of the above functional components may be implemented as a process by the CPU loading a predetermined program from the auxiliary storage into memory and executing it.

[0031] Figures 3 to 5 are flowcharts illustrating the battery replacement timing prediction process of the IoT terminal 1 according to this embodiment.

[0032] When a periodic measurement timing arrives (YES in S100), the voltage measurement unit 104 measures the battery voltage of the battery power supply 100 (S101). It then outputs the measured battery voltage value along with the measurement date and time to the slope calculation unit 106.

[0033] In response, if the reference voltage value and measurement date and time are not registered in the reference information storage unit 105 (NO in S102), the slope calculation unit 106 registers the battery voltage value and measurement date and time received from the voltage measurement unit 104 as the reference voltage value and measurement date and time in the reference information storage unit 105 (S103).

[0034] On the other hand, if the reference voltage value and measurement date and time are already registered in the reference information storage unit 105 (YES in S102), the slope calculation unit 106 calculates the rate of change of the battery voltage using the battery voltage value and measurement date and time received from the voltage measurement unit 104 and the reference voltage value and measurement date and time registered in the reference information storage unit 105 (S104). The calculated rate of change of voltage is then output to the replacement timing prediction unit 107 along with the battery voltage value and measurement date and time received from the voltage measurement unit 104. If the battery voltage value and measurement date and time are Vc and Tc respectively, and the reference voltage value and measurement date and time are Vs and Ts respectively, the rate of change of the battery voltage A can be calculated by the following equation 1.

[0035]

number

[0036] Next, the replacement timing prediction unit 107 determines whether the sign of the rate of change A of the battery voltage is negative (S105). If the rate of change A of the battery voltage is positive, that is, if the battery voltage is rising (NO in S105), it is possible that the battery voltage was not measured correctly, so this rate of change A is not adopted and the process returns to S100.

[0037] On the other hand, if the slope A of the battery voltage is negative, that is, if the battery voltage is decreasing (YES in S105), the replacement timing prediction unit 107 refers to the reference information storage unit 105 and checks whether a reference slope is registered in the reference information storage unit 105 (S106).

[0038] Here, if no reference slope is registered in the reference information storage unit 105 (NO in S106), the replacement timing prediction unit 107 sets a linear function of time-battery voltage as the voltage drop characteristic equation, using the voltage value Vc of the battery voltage received from the slope calculation unit 106 as a constant and the rate of change of the battery voltage A as a coefficient (slope) (S107). If time is T and battery voltage is V, the voltage drop characteristic equation can be expressed by the following equation 2.

[0039]

number

[0040] Next, the replacement timing prediction unit 107 uses the set voltage drop characteristic formula to calculate the predicted time (drop time) Tx required for the battery voltage V to drop to the battery replacement voltage Ve, which is pre-registered as the battery voltage value at which the battery should be replaced (S108). Then, the replacement timing prediction unit 107 adds the drop time Tx to the measurement date and time Tc of the battery voltage received from the slope calculation unit 106 to calculate the battery replacement timing Te (S109). The battery replacement timing Te is then output to the main control unit 110 along with the battery voltage Vc, the measurement date and time Tc, and the rate of change of the battery voltage (the rate of change used as the slope A of the voltage drop characteristic formula).

[0041] In response, the main control unit 110 displays the battery replacement time Te received by the replacement time prediction unit 107 on the display unit 109 (S110). The main control unit 110 also passes the battery voltage value Vc, measurement date and time Tc, and the rate of change of the battery voltage (the rate of change used as the slope A of the voltage drop characteristic formula) received by the replacement time prediction unit 107 to the reference information update unit 108. The reference information update unit 108 then updates the reference voltage value Vs and measurement date and time Ts stored in the reference information storage unit 105 with the battery voltage value Vc and measurement date and time Tc received from the main control unit 110, respectively, and registers the rate of change A of the battery voltage received from the main control unit 110 as the reference slope (S111). The process then returns to S100.

[0042] Furthermore, in S106, if a reference slope is registered in the reference information storage unit 105 (YES in S106), the replacement timing prediction unit 107 corrects the rate of change of the battery voltage using this reference slope (S112). Specifically, the rate of change of the battery voltage A is corrected so that it becomes the slope of the line that bisects the angle between the line with the rate of change of the battery voltage A as its slope and the line with the reference slope. If the reference slope is As, the corrected rate of change of the battery voltage A' can be expressed by the following equation 3.

[0043]

number

[0044] Next, the replacement timing prediction unit 107 sets a linear function of time-battery voltage as the voltage drop characteristic equation, using the voltage value Vc of the battery voltage received from the slope calculation unit 106 as a constant and the rate of change A' of the corrected battery voltage as the coefficient (slope) (S113). When time is T and battery voltage is V, the voltage drop characteristic equation can be expressed by the following equation 4.

[0045]

number

[0046] Next, the replacement timing prediction unit 107 uses the set voltage drop characteristic formula to calculate the drop time Tx required for the battery voltage value V to drop to the battery replacement voltage value Ve, which is pre-registered as the battery voltage value at which the battery should be replaced (S114). Then, the replacement timing prediction unit 107 adds the drop time Tx to the measurement date and time Tc of the battery voltage received from the slope calculation unit 106 to calculate the battery replacement timing Te (S115). The battery replacement timing Te is then output to the main control unit 110 along with the battery voltage value Vc received from the slope calculation unit 106, the measurement date and time Tc, and the rate of change of the corrected battery voltage (the rate of change used as the slope of the voltage drop characteristic formula) A'.

[0047] In response, the main control unit 110 displays the battery replacement time Te received by the replacement time prediction unit 107 on the display unit 109 (S116). The main control unit 110 also passes the battery voltage value Vc, measurement date and time Tc, and the corrected rate of change of the battery voltage (slope of the voltage drop characteristic formula) A' received by the replacement time prediction unit 107 to the reference information update unit 108. The reference information update unit 108 then updates the reference voltage value Vs, measurement date and time Ts, and reference slope As stored in the reference information storage unit 105 with the battery voltage value Vc, measurement date and time Tc, and the corrected rate of change of the battery voltage (slope of the voltage drop characteristic formula) A' received from the main control unit 110, respectively (S117). After that, the process returns to S100.

[0048] The first embodiment of the present invention has been described above.

[0049] The IoT terminal 1 according to this embodiment predicts and outputs the battery replacement time Te, so the operator does not need to frequently check whether the battery needs to be replaced. Furthermore, each time the battery voltage is measured, the battery replacement time is predicted based on the latest battery voltage value Vc and measurement date and time Tc, and the reference voltage value Vs and measurement date and time Ts. Here, the reference voltage is updated to the latest battery voltage value Vc and measurement date and time Tc each time the battery replacement time Te is predicted. Therefore, according to this embodiment, the battery replacement time Te can be predicted with high accuracy from the recent voltage drop trend of the battery.

[0050] Furthermore, the IoT terminal 1 according to this embodiment corrects the rate of change A of the battery voltage, which is obtained from the latest battery voltage value Vc and measurement date and time Tc, and the reference voltage value Vs and measurement date and time Ts, using a reference slope As. The corrected rate of change A' of the battery voltage is used as a coefficient (slope), and the latest battery voltage value Vc is used as a constant. This linear function of time-battery voltage is used to predict the battery replacement time Te. Specifically, the rate of change A of the battery voltage is corrected so that it becomes the slope of the line that bisects the angle between the line with the rate of change A as the slope and the line with the reference slope As. Thus, according to this embodiment, the reference slope As is reflected in the rate of change A of the battery voltage, which is obtained from the latest battery voltage value Vc and measurement date and time Tc, and the reference voltage value Vs and measurement date and time Ts. Therefore, when this rate of change A changes significantly from the reference slope As, it is possible to prevent the battery replacement time Te from fluctuating significantly from the previously predicted battery replacement time Te, thereby reducing the variability of the battery replacement time Te.

[0051] In this embodiment, the latest battery voltage value Vc is used as a constant, and the rate of change of the battery voltage A or its corrected rate of change A' is used as a coefficient (slope). A linear function of time-battery voltage is used as the voltage drop characteristic equation (see Equations 2 and 4) to calculate the drop time Tx required for the battery voltage value V to drop to the battery replacement voltage value Ve. This drop time Tx is then added to the latest battery voltage measurement date and time Tc to calculate the battery replacement time Te. However, the present invention is not limited to this. Alternatively, the voltage value Vs of the reference voltage is used as a constant, and the rate of change of the battery voltage A or its corrected rate of change A' is used as a coefficient (slope). A linear function of time-battery voltage is used as the voltage drop characteristic equation (the equation obtained by replacing Vc with Vs in Equations 2 and 4) to calculate the drop time Tx required for the battery voltage value V to drop to the battery replacement voltage value Ve. This drop time Tx is then added to the reference voltage measurement date and time Ts to calculate the battery replacement time Te.

[0052] Furthermore, in this embodiment, the rate of change A of the battery voltage, obtained from the latest battery voltage value Vc and measurement date and time Tc, and the reference voltage value Vs and measurement date and time Ts, is corrected so that it becomes the slope of the line that bisects the angle between the line with the rate of change A as its slope and the line with the reference slope As, and the battery replacement time Te is predicted using the corrected rate of change A'. However, the present invention is not limited to this. It is sufficient to correct the rate of change A of the battery voltage, obtained from the latest battery voltage value Vc and measurement date and time Tc, and the reference voltage value Vs and measurement date and time Ts, with the reference slope As. For example, the rate of change A of the battery voltage may be corrected by assigning predetermined weights to the rate of change A of the battery voltage and the reference slope As, and then taking a weighted average. Alternatively, without correcting the rate of change A of the battery voltage with the reference slope A', the battery replacement time may be predicted using a linear function of time-battery voltage with the rate of change A as a coefficient (slope) and the latest battery voltage value Vc as a constant. Even in this case, after predicting the battery replacement time Te, the reference voltage value Vs and measurement date and time Ts are updated to the latest battery voltage value Vc and measurement date and time Tc, allowing for accurate prediction of the battery replacement time Te based on the recent voltage drop trend of the battery.

[0053] [Second Embodiment] Next, a second embodiment of the present invention will be described.

[0054] The IoT terminal 1A according to this embodiment can be used in place of the IoT terminal 1 according to the first embodiment of the present invention in the wireless data sensing system shown in Figure 1.

[0055] Figure 6 is a schematic functional configuration diagram of IoT terminal 1A according to this embodiment.

[0056] The differences between the IoT terminal 1A according to this embodiment and the IoT terminal 1 according to the first embodiment shown in Figure 2 are the addition of a measured area storage unit 111, a measured area update unit 112, and a battery level calculation unit 113, and the addition of a main control unit 110a instead of a main control unit 110. The other configurations are the same as those of the IoT terminal 1 according to the first embodiment shown in Figure 2.

[0057] The measured area storage unit 111 stores the measured area representing the battery consumption of the battery power supply 100 in a TV standard system where the vertical axis is the voltage value V of the battery voltage and the horizontal axis is time T.

[0058] When the rate of change A of the battery voltage calculated by the slope calculation unit 106 is negative, the measured area update unit 112 calculates the area of ​​a rectangular region enclosed by the coordinates (Tc,Vc) specified by the latest voltage value Vc and measurement date and time Tc of the battery voltage measured by the voltage measurement unit 104 in the above-mentioned TV coordinate system, the coordinates (Ts,Vs) specified by the voltage value Vs and measurement date and time Ts of the reference voltage, the coordinates (Tc,Ve) specified by the battery replacement voltage value Ve and the latest measurement date and time Tc of the battery voltage, and the coordinates (Ts,Ve) specified by the battery replacement voltage value Ve and the measurement date and time Ts of the reference voltage, and adds the calculated area to the measured area storage unit 111 as the measured area indicating the above-mentioned battery consumption.

[0059] When the battery replacement time Te is predicted by the replacement time prediction unit 107, the battery remaining charge calculation unit 113 calculates the area of ​​the triangular region enclosed by the coordinates (Tc,Vc) specified by the latest voltage value Vc and measurement date and time Tc of the battery voltage measured by the voltage measurement unit 104 in the above-mentioned TV standard system, the coordinates (Tc,Ve) specified by the battery replacement voltage value Ve and the latest measurement date and time Tc of the battery voltage, and the coordinates (Te,Ve) specified by the battery replacement voltage value Ve and battery replacement time Te, as the predicted area of ​​battery consumption. Then, using the measured area of ​​battery consumption and the predicted area of ​​battery consumption stored in the measured area storage unit 111, the remaining battery charge of the battery power supply 100 is calculated.

[0060] The main control unit 110a comprehensively controls the various parts 100-109 and 111-113 of the IoT terminal 1A.

[0061] The functional configuration of IoT terminal 1A shown in Figure 6 may be implemented in hardware using integrated logic ICs such as ASICs and FPGAs, similar to the functional configuration of IoT terminal 1 according to the first embodiment shown in Figure 2, or it may be implemented in software using a computer such as a DSP. Alternatively, in a computer system equipped with a CPU, memory, auxiliary storage device, and communication interface, each functional component may be implemented as a process by the CPU loading a predetermined program from the auxiliary storage device into memory and executing it.

[0062] The battery replacement timing prediction process for IoT terminal 1A according to this embodiment is the same as the battery replacement timing prediction process for IoT terminal 1 according to the first embodiment shown in Figures 3 to 5, with S200 and S201 shown in Figure 7 performed between S110 and S111, and S202 to S206 shown in Figure 8 performed between S116 and S117.

[0063] In S200 shown in Figure 7, the main control unit 110a obtains the voltage drop characteristic equation shown in Equation 2 from the replacement timing prediction unit 107. This voltage drop characteristic equation, along with the latest measurement date and time Tc of the battery voltage and the measurement date and time Ts of the reference voltage received from the replacement timing prediction unit 107, is then passed to the actual area update unit 112.

[0064] In response, the measured area update unit 112 uses the voltage drop characteristic formula received from the main control unit 110a, the latest measurement date and time Tc of the battery voltage, the measurement date and time Ts of the reference voltage, and the battery replacement voltage value Ve to calculate the area Sc of the rectangular region enclosed by the coordinates (Tc,Vc) specified by the latest voltage value Vc of the battery voltage and the measurement date and time Tc, the coordinates (Ts,Vs) specified by the voltage value Vs of the reference voltage and the measurement date and time Ts of the reference voltage, the coordinates (Tc,Ve) specified by the battery replacement voltage value Ve and the measurement date and time Tc of the battery voltage, and the coordinates (Ts,Ve) specified by the battery replacement voltage value Ve and the measurement date and time Ts of the reference voltage. If the voltage drop characteristic formula shown in Equation 2 is f(T), this area Sc can be calculated by Equation 5 below.

[0065]

number

[0066] Next, the measured area update unit 112 stores the area Sc of the rectangular region calculated by equation 5 above as the measured area for battery consumption in the measured area storage unit 111 (S201).

[0067] Furthermore, in S202 shown in Figure 8, the main control unit 110a obtains the voltage drop characteristic formula shown in Equation 4 from the replacement timing prediction unit 107. This voltage drop characteristic formula is then passed to the actual area update unit 112 along with the latest measurement date and time Tc of the battery voltage and the measurement date and time Ts of the reference voltage, which were received by the replacement timing prediction unit 107.

[0068] In response, the measured area update unit 112 uses the voltage drop characteristic formula received from the main control unit 110a, the latest measurement date and time Tc of the battery voltage, the measurement date and time Ts of the reference voltage, and the battery replacement voltage value Ve to calculate the area Sc of the rectangular region enclosed by the coordinates (Tc,Vc) specified by the latest voltage value Vc of the battery voltage and the measurement date and time Tc, the coordinates (Ts,Vs) specified by the voltage value Vs of the reference voltage and the measurement date and time Ts, the coordinates (Tc,Ve) specified by the latest measurement date and time Tc of the battery voltage and the battery replacement voltage value Ve and the coordinates (Ts,Ve) specified by the measurement date and time Ts of the reference voltage. If the voltage drop characteristic formula shown in Equation 4 is denoted as f'(T), this area Sc can be calculated by Equation 6 below.

[0069]

number

[0070] Next, the measured area update unit 112 adds the area Sc of the rectangular region calculated by equation 6 above to the measured area storage unit 111 (S203).

[0071] Next, the main control unit 110a passes the voltage drop characteristic formula shown in equation 4, the latest measurement date and time Tc of the battery voltage, and the battery replacement time Te, which it received from the replacement timing prediction unit 107, to the battery remaining capacity calculation unit 113.

[0072] In response, the battery remaining charge calculation unit 113 uses the voltage drop characteristic formula, the latest measurement date and time Tc of the battery voltage, the battery replacement time Te, and the battery replacement voltage value Ve received from the main control unit 110a to calculate the area Se of the triangular region enclosed by the coordinates (Tc,Vc) specified by the latest voltage value Vc and measurement date and time Tc of the battery voltage, the coordinates (Tc,Ve) specified by the battery replacement voltage value Ve and the latest measurement date and time Tc of the battery voltage, and the coordinates (Te,Ve) specified by the battery replacement voltage value Ve and battery replacement time Te, as the predicted area of ​​battery consumption (S204). This area Se can be calculated using the following equation 7.

[0073]

number

[0074] Then, the battery level calculation unit 113 calculates the remaining battery level W (%) of the battery power supply 100 using the total value of the measured battery area Sc and the predicted battery area Se that have been stored in the measured area storage unit 111 up to that point (S205). Specifically, the battery level W is calculated as the ratio (%) of the predicted battery area Se to the sum of the total value of the measured battery area Sc and the predicted battery area Se. The remaining battery level W can be calculated using the following equation 8.

[0075]

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[0076] Next, the battery level calculation unit 113 outputs the battery level W to the main control unit 110a. In response, the main control unit 110a displays the battery level W received from the battery level calculation unit 113 on the display unit 109 along with the currently displayed battery replacement time Te (S206).

[0077] The second embodiment of the present invention has been described above.

[0078] According to this embodiment, the IoT terminal 1A displays not only the battery replacement time Te but also the remaining battery level W, allowing the user to easily determine the timing for battery replacement. Other effects are the same as those of the IoT terminal 1 according to the first embodiment.

[0079] It should be noted that the present invention is not limited to the embodiments described above, and numerous modifications are possible within the scope of its essence.

[0080] For example, in each of the embodiments described above, the battery replacement time Te (in the second embodiment, the battery replacement time Te and the remaining battery level W) is displayed on the display unit 109 of the IoT terminals 1 and 1A. However, the present invention is not limited thereto. Instead of displaying on the display unit 109, or in addition to displaying on the display unit 109, the battery replacement time Te may be transmitted from the wireless interface unit 102 to the IoT server device 3 or a dedicated management terminal and displayed on the IoT server device 3 or a dedicated management terminal.

[0081] Furthermore, the present invention can be widely applied to battery-powered communication devices. [Explanation of symbols]

[0082] 1, 1A: IoT terminal 2: Sensor 3: IoT server device 4: Equipment 5: Wireless access point 100: Battery power supply 101: Sensor interface unit 102: Wireless interface unit 103: Relay unit 104: Voltage measurement unit 105: Reference information storage unit 106: Slope calculation unit 107: Replacement timing prediction unit 108: Standard information update section 109: Display section 110, 110a: Main control unit 111: Measured area storage unit 112: Actual measurement area update unit 113: Battery remaining charge calculation unit

Claims

1. A battery-powered communication device, A voltage measuring means for repeatedly measuring battery voltage, A reference information storage means that stores the voltage value of the reference voltage and the date and time of measurement, Each time the battery voltage is measured by the voltage measuring means, a slope calculation means calculates the rate of change of the battery voltage based on the latest voltage value and measurement date and time of the battery voltage, and the voltage value and measurement date and time of the reference voltage stored in the reference information storage means. When the rate of change calculated by the slope calculation means is negative, a replacement timing prediction means predicts the battery replacement timing based on the rate of change and the voltage value and measurement date and time of the reference voltage stored in the reference information storage means or the latest voltage value and measurement date and time of the battery voltage. When the battery replacement time is predicted by the replacement time prediction means, the reference information update means updates the voltage value and measurement date and time of the reference voltage stored in the reference information storage means to the latest voltage value and measurement date and time of the battery voltage. In a coordinate system where the vertical axis represents voltage and the horizontal axis represents time, a measured area storage means stores the measured area of ​​battery consumption, If the rate of change calculated by the slope calculation means is negative, the measured area update means calculates the area of ​​the region enclosed by the coordinates specified by the latest voltage value and measurement date and time of the battery voltage, the coordinates specified by the voltage value and measurement date and time of the reference voltage, the coordinates specified by a predetermined battery replacement voltage value and the latest measurement date and time of the battery voltage, and the coordinates specified by the battery replacement voltage value and the measurement date and time of the reference voltage, and adds the calculated area as the measured area of ​​the battery consumption to the measured area storage means. When the battery replacement time is predicted by the replacement time prediction means, the battery remaining amount calculation means calculates the area of ​​the region enclosed by the coordinates specified by the latest voltage value and measurement date and time of the battery voltage in the coordinate system, the coordinates specified by the battery replacement voltage value and the latest measurement date and time of the battery voltage, and the coordinates specified by the battery replacement voltage value and the battery replacement time as the predicted area of ​​battery consumption, and calculates the ratio of the predicted area of ​​battery consumption to the sum of the actual area of ​​battery consumption and the predicted area of ​​battery consumption stored in the actual area storage means as the remaining battery amount. The aforementioned replacement timing prediction means is Using a linear function of time-battery voltage, with the aforementioned rate of change as a coefficient and the voltage value of the reference voltage or the latest voltage value of the battery voltage as a constant, a predicted time is calculated for the battery voltage to decrease to the battery replacement voltage. The calculated predicted time is added to the measurement date and time of the reference voltage or the latest measurement date and time of the battery voltage to predict the battery replacement time. A battery-powered communication device characterized by the following features.

2. A battery-powered communication device according to claim 1, The aforementioned reference information storage means stores the reference slope, The aforementioned replacement timing prediction means is The rate of change calculated by the slope calculation means is corrected to the slope of a line that bisects the angle between a line whose slope is the rate of change and a line of the reference slope stored in the reference information storage means, and the time required for the voltage value to decrease to the battery replacement voltage value is calculated using a linear time-battery function with the corrected rate of change as a coefficient and the voltage value of the reference voltage or the latest voltage value of the battery voltage as a constant. The aforementioned reference information update means is: When the battery replacement time is predicted by the replacement time prediction means, the reference slope stored in the reference information storage means is updated to the corrected rate of change. A battery-powered communication device characterized by the following features.

3. A program that enables a computer to function as a battery-powered communication device. Voltage measuring means for repeatedly measuring battery voltage, Reference information storage means for storing the voltage value and measurement date and time of the reference voltage, Each time the battery voltage is measured by the voltage measuring means, a slope calculation means calculates the rate of change of the battery voltage based on the latest voltage value and measurement date and time of the battery voltage and the voltage value and measurement date and time of the reference voltage stored in the reference information storage means. If the rate of change calculated by the slope calculation means is negative, a replacement timing prediction means predicts the battery replacement timing based on the rate of change and the voltage value and measurement date and time of the reference voltage stored in the reference information storage means or the latest voltage value and measurement date and time of the battery voltage. When the battery replacement time is predicted by the replacement time prediction means, the reference information update means updates the voltage value and measurement date and time of the reference voltage stored in the reference information storage means to the latest voltage value and measurement date and time of the battery voltage. In a coordinate system where the vertical axis represents voltage and the horizontal axis represents time, a measured area storage means stores the measured area of ​​battery consumption. If the rate of change calculated by the slope calculation means is negative, the measured area update means calculates the area of ​​the region enclosed by the coordinates specified by the latest voltage value and measurement date and time of the battery voltage, the coordinates specified by the voltage value and measurement date and time of the reference voltage, the coordinates specified by a predetermined battery replacement voltage value and the latest measurement date and time of the battery voltage, and the coordinates specified by the battery replacement voltage value and the measurement date and time of the reference voltage, and adds the calculated area as the measured area of ​​the battery consumption to the measured area storage means, and When the battery replacement time is predicted by the replacement time prediction means, the computer functions as a battery remaining amount calculation means, which calculates the area of ​​the region enclosed by the coordinates specified by the latest voltage value and measurement date and time of the battery voltage, the coordinates specified by the latest measurement date and time of the battery voltage, and the coordinates specified by the battery replacement voltage value and the battery replacement time as the predicted area of ​​battery consumption, and calculates the ratio of the predicted area of ​​battery consumption to the sum of the actual area of ​​battery consumption and the predicted area of ​​battery consumption stored in the actual area storage means as the remaining battery amount. The aforementioned replacement timing prediction means is Using a linear function of time-battery voltage, with the aforementioned rate of change as a coefficient and the voltage value of the reference voltage or the latest voltage value of the battery voltage as a constant, a predicted time is calculated for the battery voltage to decrease to the battery replacement voltage. The calculated predicted time is added to the measurement date and time of the reference voltage or the latest measurement date and time of the battery voltage to predict the battery replacement time. A program characterized by the following features.

4. A method for predicting the remaining battery level of a battery-powered communication device, The battery voltage is repeatedly measured, and each time the battery voltage is measured, the rate of change of the battery voltage is calculated based on the latest voltage value and measurement date and time of the battery voltage and the voltage value and measurement date and time of a pre-registered reference voltage, and the measured area of ​​battery consumption is stored in a coordinate system with voltage on the vertical axis and time on the horizontal axis. If the calculated rate of change is negative, a linear function of time-battery voltage is used, with the rate of change as a coefficient and the voltage value of the reference voltage or the latest voltage value of the battery voltage as a constant, to calculate a predicted time required for the battery voltage to drop to a predetermined battery replacement voltage. The calculated predicted time is added to the measurement date and time of the reference voltage or the latest measurement date and time of the battery voltage to predict the battery replacement time. In addition, the area of ​​the region enclosed by the coordinates specified by the latest voltage value and measurement date and time of the battery voltage in the coordinate system is calculated, and the area of ​​the region enclosed by the coordinates specified by the voltage value and measurement date and time of the reference voltage, the coordinates specified by the battery replacement voltage value and the latest measurement date and time of the battery voltage, and the coordinates specified by the measurement date and time of the battery replacement voltage value and the reference voltage is added to the measured area of ​​battery consumption. When the battery replacement time is predicted, the previously registered reference voltage value and measurement date and time are updated to the latest battery voltage value and measurement date and time. In the coordinate system, the area enclosed by the coordinates specified by the latest battery voltage value and measurement date and time, the coordinates specified by the battery replacement voltage value and the latest measurement date and time of the battery voltage, and the coordinates specified by the battery replacement voltage value and the battery replacement time is calculated as the predicted battery consumption area. The ratio of the predicted battery consumption area to the sum of the actual battery consumption area and the predicted battery consumption area is calculated as the remaining battery capacity. A method for predicting the remaining battery level of a battery-powered communication device, characterized by the following features.

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