KR102416583B1 - Event Logging system for IoT-Driven Rare-Event Applications and Event Logging method for IoT-Driven Rare-Event Applications - Google Patents

Abstract

The present invention comprises: an event information output step; an important event extraction step of extracting an important event by monitoring the event information output from the MUX unit; An IoT-based intermittent event logging method, characterized in that it includes; a logging step of storing the extracted important events in the frame buffer and logging the important events to the flash memory unit at a time when the set size is reached. Provide an IoT-based intermittent event logging method can According to the above description, it is possible to effectively reduce the internal flash memory access current.

Description

IoT-based intermittent event logging system and IoT-based intermittent event logging method {Event Logging system for IoT-Driven Rare-Event Applications and Event Logging method for IoT-Driven Rare-Event Applications}

The present invention relates to an IoT-based intermittent event logging system and an IoT-based intermittent event logging method, and more particularly, for event logging that occurs intermittently in an IoT sensor node, periodic ADC circuit driving current and built-in flash memory access current are reduced It relates to an IoT-based intermittent event logging system and an IoT-based intermittent event logging method for

In general, connection-based IoT sensor systems are difficult to install with large batteries due to the size and price of small systems compared to their effectiveness. Although it can operate for days or months, and there is a demand to operate for several years, the technology development is slow.

On the other hand, when an IoT sensor system senses an event that occurs intermittently and logs it to the built-in flash, a chain circuit of the sensor, ADC, DSP, and flash access is made at regular intervals and it has to operate continuously without stopping, so it consumes little power. Even in this case, energy (integral value of power) consumption of a non-negligible magnitude occurs over time.

Therefore, operating the IoT sensor system for a long time is the most technically important issue. Accordingly, in general, the problem has been solved by using a large-capacity battery for such energy consumption or by paying the cost of replacing the battery from time to time.

However, such a conventional IoT sensor system is difficult or expensive to access again after installation, for example, in the desert, the South Pole, the sensor inside the car that does not reach the power line, the ceiling, the electric pole, the inside of an airplane, and a machine driven by high heat and high voltage. In the case of the interior, there was a problem that the battery replacement method was also limited.

Republic of Korea Patent Publication No. 10-1584600

The present invention is a flash memory access algorithm that intermittently observes only important events and collects them to access the flash memory at once, unlike the conventional method that focused on reducing the operating current and lowering the operating voltage as a method of reducing peak power as a power consumption reduction method The purpose of presenting is to provide an IoT-based intermittent event logging system and an IoT-based intermittent event logging method that can achieve efficient power consumption reduction by reducing energy consumption corresponding to the integral of power consumption over time.

In addition, the present invention is an IoT-based intermittent event logging system and IoT-based that can present a cooperative logging method by preventing the logging of duplicate events by determining whether the currently observed sensing value is being logged in duplicate even in the adjacent IoT sensor system It aims to provide an intermittent event logging method.

According to one aspect of the present invention, the present invention provides a pad unit including a plurality of input/output pads (PAD I/O) for discriminating an event signal that occurs intermittently in an IoT sensor node, and a plurality of input/output pads. a data range control unit configured to include a MUX unit for selectively outputting the received event information; The integral control unit that loads the event information output from the MUX unit, and the event information accumulated by the integral control unit is monitored for a set time to extract event information of the set sensor level, and the amount of change between the current value and the past value of the sensor level is compared A data analysis unit comprising an event extraction control unit that extracts an important event by doing this, and a differential control unit for sampling time information at the time of change after calculating the amount of change by differentially controlling the sensor event value according to time from the event information Wow; It includes a buffer memory unit that stores important events extracted from the data analysis unit in the frame buffer and logs the important events at once when they reach the buffer size of the flash memory unit, and a flash memory unit that logs and stores important events from the buffer memory. It is possible to provide an IoT-based intermittent event logging system, characterized in that it includes; a data storage unit, characterized in that it is configured.

In addition, according to another aspect of the present invention, in the present invention, an event signal that occurs intermittently in an IoT sensor node is divided using a plurality of input/output pads (PAD I/O), and received from the plurality of input/output pads an event information output step of selectively outputting event information using a MUX (multiplexer) unit; The event information output from the MUX unit is loaded, the accumulated event information is monitored for a set time, and event information of the set sensor level is extracted, and the amount of change in the current value and the past value of the sensor level according to time from the extracted event information an important event extraction step of extracting an important event by comparing and sampling event information at a changed singularity; A logging step of storing the extracted important events in the frame buffer, and logging important events to the flash memory unit at once when the important events reach the buffer size of the flash memory; An intermittent event logging method can be provided.

Here, the important event extraction step may be configured to dynamically adjust the level of event information to be monitored next by selectively and dynamically setting based on the accumulated event information.

In addition, the important event extraction step extracts event information from the accumulated event information based on the set sensor level of at least one of maximum, minimum and average for a set time as a dynamic reference, and extracts event information from the extracted event information according to time After calculating the amount of change by differential control of the sensor event value, it may be configured to extract important events by sampling time information at the time of change.

In addition, in the important event extraction step, the amount of change is calculated by firstly differentially controlling the sensor event value according to time from the extracted event information, and the time information at the time of change is obtained by differential control secondarily with respect to the calculated amount of change. can be configured to extract.

On the other hand, when a plurality of adjacent IoT sensor nodes sense one target, the important event extraction step may be configured to determine whether event information is sampled by comparing the extracted important event with a comparison event received from the gateway.

At this time, in the important event extraction step, when the important event is included within the set range of the comparison event, it is determined that the situation around the target is stable and sampling is stopped, and when the important event exceeds the set range of the comparison event, sampling is performed can be configured to perform again.

And the important event extraction step may be configured to perform sampling again when a set time is exceeded after stopping sampling.

The IoT-based intermittent event logging system and IoT-based intermittent event logging method according to the present invention can effectively reduce the ACC drive and built-in flash memory access current for data logging that is the most frequent operation of the IoT sensor system and consumes the most power. , it can provide an effect that can be used more effectively for intermittent event logging of applications running for a long time.

1 is a block diagram showing a schematic configuration of an IoT-based intermittent event logging system according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a logic circuit of a conventional logging method that continuously accesses a flash memory using a conventional analog ADC.
3 is a flowchart illustrating an IoT-based intermittent event logging method according to an embodiment of the present invention.
4 is a diagram illustrating a logic circuit of an IoT-based intermittent event logging method according to an embodiment of the present invention.
5 is a logic circuit illustrating a method of observing an intermittent event in an IoT-based intermittent event logging method according to an embodiment of the present invention, storing the intermittent event in a buffer, and then accessing the flash memory unit.
5 is a diagram schematically illustrating a cooperative sensing method between IoT adjacent sensor nodes in an IoT-based intermittent event logging method according to an embodiment of the present invention.

Hereinafter, the terms used in the present invention have been selected as currently widely used general terms as possible while considering the functions in the present invention, which may vary depending on the intention or precedent of a person skilled in the art, the emergence of new technology, and the like. In addition, in a specific case, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the corresponding invention. Therefore, the term used in the present invention should be defined based on the meaning of the term and the overall content of the present invention, rather than the name of a simple term. In the entire specification, when a part "includes" a certain element, this means that other elements may be further included, rather than excluding other elements, unless otherwise stated. In addition, terms such as "...unit", "module", and "means" described in the specification mean a unit that processes at least one function or operation, which is implemented in hardware or software, or is a combination of hardware and software. can be implemented. In addition, in the following description, terms such as 1st, 2nd, etc. are terms used to describe various components, and their meanings are not limited, and are used only for the purpose of distinguishing one component from other components. do.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, similar reference numerals are attached to similar parts throughout the specification, and the same reference numbers used throughout the present specification refer to the same components. indicates. And, in the description of the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, an IoT-based intermittent event logging system (1000, hereinafter referred to as an 'IoT-based logging system') according to an embodiment of the present invention will be described with reference to FIG. 1 .

Specifically, the logging system 1000 according to an embodiment of the present invention may include a data range control unit 100 , a data analysis unit 200 , and a data storage unit 300 .

The IoT-based logging system 1000 according to an embodiment of the present invention may have a configuration integrated into the IoT module 1 . That is, the data range control unit 100 , the data analysis unit 200 , and the data storage unit 300 may be any one of a plurality of components constituting the IoT module. In addition, the data range control unit 100 , the data analysis unit 200 , and the data storage unit 300 may be independently provided in the IoT module, or some or all of the above-described components may be integrated. Here, the sensor unit of the IoT module 1 may sense the surrounding environment of the location where the IoT module 1 is disposed, and the sensed event information may be transmitted to the data range control unit 100 through the communication unit.

The data range control unit 100 is configured to selectively output an event signal that occurs intermittently in the IoT sensor node, and may include a pad unit 110 and a MUX unit 120 . .

The pad unit 110 may be configured to output an event signal intermittently generated in the IoT sensor node to a plurality of input/output pads (PAD I/O).

The MUX unit 120 may be configured to selectively output event information received from a plurality of input/output pads.

The data analysis unit 200 may be configured to accumulate and analyze event information received from the data range control unit 100 and to extract an important event from the event information. The data analysis unit 200 may include an integral control unit 210 , an event extraction control unit 220 , and a differential control unit 230 .

The integral control unit 210 may be configured to load event information output from the MUX unit 120 .

The event extraction control unit 220 monitors the event information accumulated by the integral control unit 210 for a set time, extracts event information of a set sensor level, and compares the amount of change between the current value and the past value of the sensor level for an important event may be configured to extract

The differential control unit 230 may be configured to differentially control a sensor event value according to time from the event information to calculate a change amount and then sample the time information at the change time point.

The data storage unit 300 stores important events received from the data analysis unit 200 , and may include a buffer memory unit and a flash memory unit.

The buffer memory unit may be configured to store important events extracted from the data analysis unit 200 in a frame buffer and log the important events to the flash memory unit at once when the important events reach the buffer size of the flash memory unit.

The flash memory unit is configured such that important events are logged and stored from the buffer memory.

Meanwhile, a detailed description of each configuration of the IoT-based logging system 1000 for an embodiment of the present invention will be described in more detail in the following IoT-based intermittent event logging method.

Hereinafter, an IoT-based intermittent event logging method according to an embodiment of the present invention will be described.

Prior to this, referring to FIG. 2 , FIG. 2 shows a conventional IoT-based event logging method. Continuous data sampled for every event of the IoT sensor node that occurs intermittently is driven every time using an analog ADC, and the built-in It takes a method of accessing each time to write to the flash memory. However, since this conventional IoT-based event logging method has to operate continuously without stopping by driving a series of circuits of sensor, ADC, DSP, and flash access at regular intervals, even with small power consumption, the amount of energy that cannot be ignored over time ( power consumption).

Accordingly, the IoT-based intermittent event logging method (hereinafter referred to as 'IoT-based logging method') according to an embodiment of the present invention does not use an analog ADC and only plural input/output pads (Digital Input PAD) having different VIH/VIL levels In order to determine whether a specific level of the sensor signal has been reached, the past accumulated sample pattern is observed for a long time, and VIH/VIL is selectively set dynamically to observe only the desired sensor level threshold. By comparing the change amount of the value and the past value and sampling the time value at the time of the level change, the singularity of the level value on the time axis and the voltage value on the space axis is recognized at the same time, as if a digital signal after a lot of sampling using ADC The effect of recognizing an event can be obtained through processing. On the other hand, this event logging method is applicable only to an application in which an intermittent event occurs.

Furthermore, in the IoT-based logging method according to an embodiment of the present invention, only the extracted important events are collected separately and collected in the flash memory frame buffer, and the previously sampled data is continuously deleted until the data of a predetermined pattern is collected, so that the frame buffer becomes full. It can provide the effect of significantly reducing the frequency of accessing the flash memory when it is filled.

On the other hand, Figure 3 is a view showing an IoT-based logging method according to an embodiment of the present invention, the IoT-based logging method of the present invention, specifically, the event information output step (S10), the important event extraction step (S20), It may be configured to include a logging step (S30).

In the event information output step (S10), an event signal that occurs intermittently in the IoT sensor node is divided using a plurality of input/output pads (PAD I/O), and event information received from the plurality of input/output pads is MUX (Multiplexer) is used to selectively output.

In the important event extraction step (S20), the event information output from the MUX unit 120 is loaded, the accumulated event information is monitored for a set time to extract event information of a set sensor level, and time from the extracted event information A significant event is extracted by sampling event information at the changing singularity by comparing the change amount of the current value and the past value of the sensor level.

Here, the important event extraction step (S20) may be configured to dynamically adjust the level of event information to be monitored next by selectively and dynamically setting based on the accumulated event information.

In addition, the important event extraction step (S20) extracts event information from the accumulated event information based on the set sensor level of at least one of the maximum, minimum, and average for a set time as a dynamic reference, and from the extracted event information After calculating the amount of change by differentially controlling the sensor event value according to time, it may be configured to extract important events by sampling time information at the time of change.

In addition, in the important event extraction step (S20), the amount of change is calculated by firstly differentially controlling the sensor event value according to time from the extracted event information, and secondarily, the differential control is performed with respect to the calculated amount of change to determine the change at the time of change. It may be configured to extract time information.

In the logging step (S30), the extracted important events are stored in the frame buffer, and when the important events reach the buffer size of the flash memory, the important events are logged in the flash memory unit at a time.

On the other hand, when a plurality of adjacent IoT sensor nodes sense one target, the important event extraction step may be configured to determine whether event information is sampled by comparing the extracted important event with a comparison event received from the gateway.

At this time, in the important event extraction step, when the important event is included within the set range of the comparison event, it is determined that the situation around the target is stable and sampling is stopped, and when the important event exceeds the set range of the comparison event, sampling is performed can be configured to perform again.

And the important event extraction step may be configured to perform sampling again when a set time is exceeded after stopping sampling.

4 is a logic circuit illustrating an IoT-based logging method according to an embodiment of the present invention, and the present invention will be described in detail with reference to the drawings.

Referring to FIG. 4 , the IoT-based logging method according to an embodiment of the present invention does not use ADC-based continuous sampling/flash logging, and multiple VIH using a plurality of input/output pads (PAD I/O). /VIL (threshold) effect can be implemented, and simple low-resolution ADC function is also possible.

On the other hand, the output signals of the plurality of input/output pads are selectively output by the Mux and transmitted to the data analysis unit 200. Accordingly, the data analysis unit 200 dynamically converts VIH/VIL while watching the trend of sensor values from the past to the present. to dynamically adjust the next level to be observed based on the accumulated event information so far. At this time, the time information is extracted through the differential control of the change point of the sensor event value according to time. This differential control extracts the change amount through the primary differentiation of the event information and the change time point through the secondary differentiation of the extracted change amounts. extract the time information of

When important events are extracted through this process, the extracted important events are not directly accessed to the flash memory unit, but intermittent important events are extracted with low power without ADC operation, and a certain amount is stored in the frame buffer, and the important events are stored in the flash memory buffer When the size is reached, the flash memory unit is accessed at once.

5 is a diagram illustrating a logic circuit for intermittent event observation in the present invention. Referring to the drawing, whenever an event occurs, the sensor, circuit, signal processing, and flash memory are not driven, but the event occurrence trend is observed for a long period of time and stored only in the buffer. Access the memory unit and perform programming.

Meanwhile, the following shows the intermittent event extraction algorithm. Referring to this, whenever an event occurs, it is loaded into the queue, and trends are observed from the data loaded in the queue for a long time by methods such as maximum, minimum, and average, and when a defined condition is reached, it is recognized as an intermittent event and only this data is extracted ( dequeue) and store it in the flash framebuffer. Through this process, significant event generation is required until the flash frame buffer is filled, so the frequency of flash access can be greatly reduced, and the energy consumption for writing (programming) data to the flash memory can be extremely reduced.

On the other hand, the IoT-based logging method according to an embodiment of the present invention can reduce the frequency of flash access by preventing overlapping event logging through cooperative sensing between adjacent IoT adjacent sensor nodes. In this regard, referring to the algorithm below and FIG. 6 , when the data that has undergone ADC sampling of the node is Ds and the data transmitted from the gateway is ??Dg, the value varies depending on the purpose of the sensor network transmitted by the gateway, as shown in FIG. The figure on the left of Figure 6 shows a case where it is assumed that the conditions around the sensor are stable and that the value that is considered unnecessary for sampling is transmitted. In the algorithm, if the sampled data Ds is within the range of M % of Dg, the situation around the sensor is considered stable, so sampling is stopped. Conversely, if it exists outside the range, sampling is activated again. At this time, to adjust the time when sampling is stopped, use cnt to restart sampling after a certain time has elapsed.

As described above, the IoT-based logging method according to an embodiment of the present invention does not access the data continuously sampled by driving the ADC for intermittently generated sensor signals to write to the flash memory every time, but a plurality of input/output pads Using only (Digital I/O PAD), it is possible to observe the pattern of a certain event on the time axis and voltage level axis for a long time with pure digital circuitry. By keeping the flash write buffer from filling up as much as possible by erasing it, the frequency of writing to the flash memory can be greatly reduced, effectively reducing the access current of the built-in flash memory for data logging, which is the most frequent operation of the IoT sensor system and consumes the most power. can be reduced

The present invention is a sensor system that needs to be operated for a long time (more than 1 year) based on a battery without constant power, such as an environmental sensor, a sensor inside a car (all parts that do not reach the power line, such as a tire pressure sensor), and access it again after installation. It can be effectively applied to difficult sensors (ceilings, electric poles, inside airplanes, high heat, inside machines driven by high voltage, etc.), and can be applied to intermittent signal changes that do not change quickly, but is not limited thereto. On the other hand, in the present invention, a part of the configuration of the buffer memory unit 310 and the flash memory unit 320 of the data storage unit 300 is supported by the National Research Foundation of Korea with funding from the government (Ministry of Science and ICT) in 2019. (No. NRF-2019R1A2C2005099), 「Efficient Flash Memory Power Consumption Reduction Technique Optimized for IoT-Based Intermittent Event Logging Application」 of Journal of the Korean Society of Embedded Engineers, Vol. ) can be referred to.

Although the present invention has been described with reference to the embodiment shown in the drawings, which is merely exemplary, it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: data range control unit
110: pad part
120: MUX unit
200: data analysis unit
210: integral control unit
220: event extraction control unit
230: differential control unit
300: data storage unit
310: buffer memory unit
320: flash memory unit
1000: IoT-based intermittent event logging system

Claims (8)

A pad unit including a plurality of input/output pads (PAD I/O) having different VIH/VIL levels for discriminating intermittent event signals from the IoT sensor node, and event information received from the plurality of input/output pads a data range control unit configured to include a MUX unit for selectively outputting the data;
An integral control unit for loading event information output from the MUX unit, and monitoring the event information accumulated by the integral control unit for a set time, extracts event information of a set sensor level to observe only a desired sensor level threshold, and a sensor An event extraction control unit that extracts an important event by comparing the amount of change between the present value and the past value of the level, and differential control of the sensor event value according to time from the event information to calculate the amount of change and then sample the time information at the time of change a data analysis unit configured to include a differential control unit;
A buffer memory unit that stores the important events extracted from the data analysis unit in a frame buffer and logs the important events at once when the important events reach a set buffer size, and a flash memory unit in which important events are logged and stored from the buffer memory A data storage unit characterized in that it is configured to include;
The data analysis unit,
In order to dynamically adjust the level of the next event information to be monitored by selectively dynamically setting the accumulated event information based on the accumulated event information, at least one of the maximum, minimum, and average sensor levels from the accumulated event information for a set time is measured. Extracting event information on a dynamic basis,
In order to extract an important event by sampling the sensor event value over time from the extracted event information, the amount of change is calculated by differentially controlling the sensor event value over time from the extracted event information, and the calculated change amount is IoT-based intermittent event logging system, characterized in that it is configured to extract time information at the time of change by secondary differential control. The event signal that occurs intermittently in the IoT sensor node is divided using a plurality of input/output pads (PAD I/O) having different VIH/VIL levels, and event information received from the plurality of input/output pads is divided into MUX ( an event information output step of selectively outputting using a multiplexer);
The event information output from the MUX unit is loaded, the accumulated event information is monitored for a set time, and event information of a set sensor level is extracted to observe only a desired sensor level threshold value, and from the extracted event information, according to time an important event extraction step of extracting an important event by sampling event information at a changed singularity by comparing the amount of change between the current value and the past value of the sensor level;
A logging step of storing the extracted important events in a frame buffer, and logging the important events to a flash memory unit at a time when the important events reach a buffer size of a flash memory;
The important event extraction step is
In order to dynamically adjust the level of the next event information to be monitored by selectively dynamically setting the accumulated event information based on the accumulated event information, at least one of the maximum, minimum, and average sensor levels from the accumulated event information for a set time is measured. Extracting event information on a dynamic basis,
In order to extract an important event by sampling the sensor event value over time from the extracted event information, differential control of the sensor event value over time is primarily differentially controlled from the extracted event information to calculate the amount of change, and An IoT-based intermittent event logging method, characterized in that it is configured to extract time information at the time of change by secondary differential control. delete delete delete 3. The method of claim 2,
When a plurality of adjacent IoT sensor nodes sense a single target,
The important event extraction step is
IoT-based intermittent event logging method, characterized in that it is configured to determine whether to sample the event information by comparing the extracted important event with the comparison event received from the gateway. 7. The method of claim 6,
The important event extraction step is
When the important event is included within the set range of the comparison event, it is determined that the situation around the target is stable and sampling is stopped,
IoT-based intermittent event logging method, characterized in that it is configured to perform sampling again when the important event exceeds the set range of the comparison event. 8. The method of claim 7,
The important event extraction step is
IoT-based intermittent event logging method, characterized in that it is configured to perform sampling again when the set time is exceeded after stopping sampling.

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