JP6599049B2 - Data collection device - Google Patents

Description

  The present invention relates to a technique for collecting data from a plurality of nodes.

With the spread of IoT (Internet of Things), various devices such as various devices and various computers are connected to a network, and various data can be collected from the connected devices.
For example, by collecting the power consumption remotely via a smart meter, it is possible to expect an improvement in prediction accuracy related to power demand. In addition, it is possible to visualize the usage amount for power consumers and encourage energy saving activities.
In such a data collection system, a large amount of data is often handled as a whole, and not only a communication load but also a processing load of a collection device that accumulates data increases. In a case where data is aggregated and transmitted from each device, the size of the data to be transmitted becomes large, and processing resources such as a CPU (Central Processing Unit) or a memory on the collection device are more likely to become a bottleneck than communication. For this reason, in order to process a large amount of data, it is necessary to secure sufficient processing resources in the collection device on the center side. However, increasing processing resources increases the cost of server equipment and the cost of using cloud services. Therefore, in a large-scale data collection system, it is required to efficiently use the processing resources of the collection device.
If the distribution of the amount of data sent from nodes such as connected devices is random or biased, it is not a processing resource that can process the average amount of data in the distribution, but a large load on the distribution. Processing resources that can process In order to efficiently use processing resources, it is required that the data collection load for each node be smoothed.

Patent Document 1 discloses a method for scheduling transmission timing by a collection device according to the communication characteristics of each node.
Patent Document 2 discloses a method of adjusting the transmission timing so that the transmission processing of the sensor module corresponding to each node does not overlap.
Both methods are methods for suppressing overlapping of transmission processes by instructing the connected nodes from the collection device with data transmission timing.

JP2013-123250A JP 2012-195705 A

  In the data collection system, the processing load of the collection device changes according to the input data size. For example, the CPU usage, the memory usage, or the disk input / output amount corresponds to the processing load. Data transmitted from connected nodes is not necessarily the same data size. For example, when data transmission fails and data transmission is performed including the failure, the size of the transmitted data increases. In addition, when a relay device connected to a plurality of devices transmits data to the collection device, the size of data transmitted to the collection device changes according to the number of devices connected to the relay device.

  When there is a deviation in data size, even if the transmission timing of each node is equally spaced, the processing load increases when the size of the transmitted data is large. For this reason, the data size must be considered in determining the transmission timing of each node. The prior art document describes a method of adjusting the transmission timing based on the number of devices and communication characteristics, but does not indicate the size of data to be transmitted and the processing cost of the collection device.

  An object of the present invention is to make it possible to determine an appropriate collection schedule even if there is a difference in the data amount of each node.

The data collection device of the present invention comprises:
A receiving unit that receives data amount information indicating a data amount per unit time for each node from which data is obtained;
A schedule determination unit that determines a collection schedule for collecting data from each node based on the data amount information for each node.

  According to the present invention, the collection schedule is determined based on the data amount information for each node. Therefore, it is possible to determine an appropriate collection schedule even if there is a difference in the data amount of each node.

1 is a configuration diagram of a data collection system 100 according to Embodiment 1. FIG. 1 is a configuration diagram of a data collection device 200 according to Embodiment 1. FIG. FIG. 3 is a configuration diagram of a node 300 in the first embodiment. 3 is a flowchart of a data collection method according to the first embodiment. FIG. 5 is a diagram showing a specific example of node information 110 in the first embodiment. FIG. 6 is a diagram showing a specific example of the node management table 120 in the first embodiment. FIG. 5 is a diagram showing a specific example of schedule information 130 in the first embodiment. FIG. 6 is a diagram showing a specific example of collected data 140 in the first embodiment. 5 is a flowchart of a schedule determination method in the first embodiment. FIG. 6 shows a specific example of load amount data 150 in the first embodiment. The figure which shows the change of the uncollected data amount in Embodiment 1, and a collection interval data amount. FIG. 4 shows an image of a collection schedule in the first embodiment. FIG. 6 shows a specific example of a collection schedule in the first embodiment. 1 is a diagram illustrating a configuration example of a data collection system 100 according to Embodiment 1. FIG. FIG. 3 is a configuration diagram of a data collection system 100 in a second embodiment. The block diagram of the data collection device 200 in Embodiment 2. FIG. 10 is a flowchart of a schedule determination method according to the second embodiment. FIG. 9 shows a node group in the second embodiment. FIG. 6 shows an image of a collection schedule in the second embodiment. FIG. 10 shows a specific example of a collection schedule in the second embodiment. The hardware block diagram of the data collection device 200 in embodiment.

  In the embodiments and the drawings, the same reference numerals are assigned to the same elements and corresponding elements. Description of elements having the same reference numerals will be omitted or simplified as appropriate. The arrows in the figure mainly indicate the flow of data or the flow of processing.

Embodiment 1 FIG.
The data collection system 100 will be described with reference to FIGS.

*** Explanation of configuration ***
Based on FIG. 1, the structure of the data collection system 100 is demonstrated.
The data collection system 100 is a system for collecting data from a plurality of nodes 300.

The data collection system 100 includes a data collection device 200.
Furthermore, the data collection system 100 includes a plurality of nodes 300.
In the first embodiment, the data collection system 100 includes five nodes 300 from the node (1) to the node (5).

The plurality of nodes 300 are connected to the data collection device 200 via the network 101.
The network 101 may be a wired line or a wireless line.

The node 300 is a device that obtains data.
Specifically, the node 300 is a measurement device. The measurement device obtains a measurement value by performing measurement. For example, the measurement device is a power meter, a pulse sensor, a heart rate sensor, a thermal sensor, or an optical sensor. The measuring device may be an information processing device that acquires information on information processing load or operating status.

  The data collection device 200 is a computer that collects data from a plurality of nodes 300.

The configuration of the data collection device 200 will be described with reference to FIG.
The data collection device 200 includes hardware such as a processor 201, a memory 202, an auxiliary storage device 203, and a communication interface 204. These hardwares are connected to each other via signal lines.
The data collection device 200 may include hardware such as a display interface and an input interface. The display interface is connected to the display. The input interface is connected to the keyboard and mouse.

The processor 201 is an IC (Integrated Circuit) that performs arithmetic processing, and controls other hardware. For example, the processor 201 is a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or a GPU (Graphics Processing Unit).
The memory 202 is a volatile storage device. The memory 202 is also called main memory or main memory. For example, the memory 202 is a RAM (Random Access Memory). Data stored in the memory 202 is stored in the auxiliary storage device 203 as necessary.
The auxiliary storage device 203 is a nonvolatile storage device. For example, the auxiliary storage device 203 is a ROM (Read Only Memory), an HDD (Hard Disk Drive), or a flash memory. Data stored in the auxiliary storage device 203 is loaded into the memory 202 as necessary.
The communication interface 204 is a device that performs communication, that is, a receiver and a transmitter. For example, the communication interface 204 is a communication chip or a NIC (Network Interface Card).

  The data collection device 200 includes software elements such as a control unit 210 and a schedule determination unit 220. A software element is an element realized by software.

The auxiliary storage device 203 stores a data collection program for causing the computer to function as the control unit 210 and the schedule determination unit 220. The data collection program is loaded into the memory 202 and executed by the processor 201. Of the data collection programs, a program for causing a computer to function as the schedule determination unit 220 is referred to as a schedule determination program.
Furthermore, the auxiliary storage device 203 stores an OS (Operating System). At least a part of the OS is loaded into the memory 202 and executed by the processor 201.
That is, the processor 201 executes the data collection program while executing the OS.
Data obtained by executing the data collection program is stored in a storage device such as the memory 202, the auxiliary storage device 203, a register in the processor 201, or a cache memory in the processor 201.

The auxiliary storage device 203 functions as a storage unit 291 and a storage unit 292. However, other storage devices may function as the storage unit 291 and the storage unit 292 instead of the auxiliary storage device 203 or together with the auxiliary storage device 203.
The communication interface 204 functions as a reception unit 293 and a transmission unit 294.

  The data collection device 200 may include a plurality of processors that replace the processor 201. The plurality of processors share the role of the processor 201.

  The data collection program can be stored in a nonvolatile storage medium such as a magnetic disk, an optical disk, or a flash memory. The nonvolatile storage medium is a computer-readable recording medium.

The configuration of the node 300 will be described based on FIG.
The node 300 includes hardware such as a processor 301, a memory 302, an auxiliary storage device 303, a communication interface 304, and a sensor interface 305. These hardwares are connected to each other via signal lines.

The processor 301 is an IC that performs arithmetic processing, and controls other hardware. For example, the processor 301 is a CPU.
The memory 302 is a volatile storage device. The memory 302 is also called a main storage device or a main memory. For example, the memory 302 is a RAM. Data stored in the memory 302 is stored in the auxiliary storage device 303 as necessary.
The auxiliary storage device 303 is a nonvolatile storage device. For example, the auxiliary storage device 303 is a ROM, an HDD, or a flash memory. Data stored in the auxiliary storage device 303 is loaded into the memory 302 as necessary.
The communication interface 304 is a device that performs communication, that is, a receiver and a transmitter. For example, the communication interface 304 is a communication chip or a NIC.

  The node 300 includes a control unit 311. The control unit 311 is realized by software.

The auxiliary storage device 303 stores a node program for causing the computer to function as the control unit 311. This node program is loaded into the memory 302 and executed by the processor 301.
Further, the auxiliary storage device 303 stores an OS. At least a part of the OS is loaded into the memory 302 and executed by the processor 301.
That is, the processor 301 executes the node program while executing the OS.
Data obtained by executing the node program is stored in a storage device such as the memory 302, the auxiliary storage device 303, a register in the processor 301, or a cache memory in the processor 301.

The auxiliary storage device 303 functions as the storage unit 391. However, another storage device may function as the storage unit 391 instead of the auxiliary storage device 303 or together with the auxiliary storage device 303.
The communication interface 304 functions as a transmission unit 392 and a reception unit 393.
The sensor interface 305 functions as the measurement unit 394.

  The node 300 may include a plurality of processors that replace the processor 301. The plurality of processors share the role of the processor 301.

  The node program can be stored in a nonvolatile storage medium such as a magnetic disk, an optical disk, or a flash memory. The nonvolatile storage medium is a computer-readable recording medium.

*** Explanation of operation ***
The operation of the data collection system 100 corresponds to a data collection method. Further, the procedure of the data collection device 200 in the data collection method corresponds to the procedure of the data collection program.

A data collection method will be described with reference to FIG.
In step S <b> 101, each node 300 transmits a collection request to the data collection device 200.
Specifically, the control unit 311 generates a collection request, and the transmission unit 392 transmits the collection request to the data collection device 200.
The collection request includes node information 110.
The node information 110 is data information obtained by the node 300.

The node information 110 includes a node identifier, an uncollected data amount, a measurement interval, and data amount information.
The node identifier is an identifier that identifies the node 300.
The amount of uncollected data is the amount of data that has not been collected.
The measurement interval is a time indicating an interval at which measurement is performed.
The data amount information indicates the data amount per unit time. Specifically, the data amount is the number of data items.
The node information 110 is stored in the storage unit 391.

FIG. 5 shows a specific example of the node information 110.
The first node information 110 is the node information 110 of the node (1). In the node information 110 of the node (1), the amount of uncollected data is 0, and the measurement interval is 1 second. Further, the data amount information is 10 cases every 10 seconds.
The second node information 110 is the node information 110 of the node (2). In the node information 110 of the node (2), the amount of uncollected data is 0, and the measurement interval is 1 second. The data amount information is 50 every 10 seconds.
The third node information 110 is the node information 110 of the node (3). In the node information 110 of the node (3), the amount of uncollected data is 0, and the measurement interval is 1 second. The data amount information is 40 cases every 10 seconds.
The fourth node information 110 is the node information 110 of the node (4). In the node information 110 of the node (4), the amount of uncollected data is 0, and the measurement interval is 1 second. The data amount information is 40 cases every 10 seconds.
The fifth node information 110 is the node information 110 of the node (5). In the node information 110 of the node (5), the amount of uncollected data is 44, and the measurement interval is 1 second. The data amount information is 20 cases every 10 seconds.
Assume that the nodes (1) to (4) are existing nodes 300, and the node (5) is a newly connected node 300. Since node (5) is a newly connected node 300, node (5) has uncollected data.

Returning to FIG. 4, the description will be continued from step S102.
In step S <b> 102, the data collection device 200 receives a collection request from each node 300.
Specifically, the receiving unit 293 receives the collection request, and the storage unit 291 registers the node information 110 included in the collection request in the node management table 120. The node management table 120 is a table stored in the storage unit 291.

FIG. 6 shows a specific example of the node management table 120.
The node management table 120 includes columns for a node identifier, a previous collection time, an uncollected data amount, a measurement interval, and data amount information.
A node identifier is registered in the node identifier column.
The previous collection time is registered in the previous collection time column. The previous collection time is the previous time when data was collected.
In the uncollected data amount column, the uncollected data amount included in the node information 110 is registered.
The measurement interval included in the node information 110 is registered in the measurement interval column.
Data amount information included in the node information 110 is registered in the data amount information column.

Returning to FIG. 4, the description of step S102 will be continued.
Next, the data collection device 200 determines a collection schedule.
Specifically, the schedule determination unit 220 determines a collection schedule based on the node information 110 for each node 300.
The collection schedule is a schedule for collecting data from each node 300.
A method for determining the collection schedule will be described later.

Then, the data collection device 200 transmits a collection response to each node 300.
Specifically, the schedule determination unit 220 generates schedule information 130 based on the collection schedule. Next, the control unit 210 generates a collection response including the schedule information 130. Then, the transmission unit 294 transmits a collection response.
The collection response includes schedule information 130.
The schedule information 130 is information indicating a collection schedule.

The schedule information 130 includes a node identifier, a next collection time, and a next data amount.
The node identifier is an identifier that identifies the node 300.
The next collection time is the time when the next collection is performed.
The next data amount is the amount of data collected next time.

FIG. 7 shows a specific example of the schedule information 130.
The first schedule information 130 is the schedule information 130 of the node (1).
The second schedule information 130 is the schedule information 130 of the node (2).
The third schedule information 130 is the schedule information 130 of the node (3).
The fourth schedule information 130 is the schedule information 130 of the node (4).
The fifth schedule information 130 is the schedule information 130 of the node (5).
The next collection time and the next data amount are set in the schedule information 130 of each of the nodes (1) to (4).
Since the node (5) is the newly connected node 300, the next collection time and the next data amount are not set in the schedule information 130 of the node (5).

Returning to FIG. 4, the description will be continued from step S103.
In step S <b> 103, each node 300 receives a collection response from the data collection device 200.
Specifically, the receiving unit 393 receives the collection response, and the storage unit 391 stores the schedule information 130 included in the collection response.

In step S <b> 104, each node 300 transmits a collection request to the data collection device 200.
Specifically, the control unit 311 generates a collection request including the collection data 140 having the same amount as the next data amount indicated by the schedule information 130. Then, the transmission unit 392 transmits a collection request to the data collection device 200 at the next collection time indicated by the schedule information 130.
The collection request includes collection data 140 and node information 110.
The collected data 140 is data obtained by the node 300 and collected by the data collection device 200.

The collected data 140 includes a measurement time, a measurement value, and a device identifier.
The measurement time is the time when the measurement was performed.
The measured value is a value obtained by measurement. There may be one or more measurement values.
The device identifier is an identifier for identifying a measurement device that has performed measurement.

FIG. 8 shows a specific example of the collected data 140.
Each collected data 140 is data obtained by the measurement device (10000001), and includes measurement time, measurement value, and device identifier.

Returning to FIG. 4, the description will be continued from step S105.
In step S <b> 105, the data collection device 200 receives a collection request from each node 300.
Specifically, the receiving unit 293 receives the collection request, and the storage unit 291 registers the node information 110 included in the collection request in the node management table 120.

Then, the data collection device 200 determines whether the collection schedule needs to be changed.
Specifically, the schedule determination unit 220 determines whether the collection schedule change condition is satisfied based on the node information 110 for each node 300.
For example, when a large amount of collected data is retained, it is necessary to change the collection schedule. For example, the collection schedule change condition is a condition that the ratio of the uncollected data amount to the data amount indicated by the data amount information exceeds a threshold value.
If the collection schedule needs to be changed, the process proceeds to step S106.
If it is not necessary to change the collection schedule, the process proceeds to step S107.

In step S106, the data collection device 200 determines a collection schedule.
Specifically, the schedule determination unit 220 determines a collection schedule based on the node information 110 for each node 300.
A method for determining the collection schedule will be described later.

In step S107, the data collection device 200 accumulates the collected data 140 of each node 300.
Specifically, the storage unit 292 stores the collected data 140 included in the collection request for each node 300.

Then, the data collection device 200 transmits a collection response to each node 300.
Specifically, the schedule determination unit 220 generates schedule information 130 based on the collection schedule. Next, the control unit 210 generates a collection response including the collection result and the schedule information 130. Then, the transmission unit 294 transmits a collection response.
The collection response includes a collection result and schedule information 130.
The collection result indicates the result of data collection.

In step S <b> 108, each node 300 receives a collection response from the data collection device 200.
Specifically, the receiving unit 393 receives the collection response, and the storage unit 391 stores the schedule information 130 included in the collection response.

  After step S108, data collection is repeatedly performed in the same procedure as the procedure from step S104 to step S108.

A schedule determination method will be described with reference to FIG.
In the schedule determination method, the schedule determination unit 220 determines a collection schedule based on the node information 110 for each node 300.

In step S <b> 201, the schedule determination unit 220 calculates a collection interval range based on the reference data amount and the data amount information of each node 300.
The collection interval range is the range of the collection interval i. The lower limit of the collection interval range is written as min, and the upper limit of the collection interval range is written as max.
The collection interval i is a time indicating an interval for collecting data from each node 300.
The reference data amount is a predetermined number as the lower limit of the data amount collected at one time.

Specifically, the schedule determination unit 220 calculates the collection interval range as follows.
First, the schedule determination unit 220 selects data amount information with the smallest data amount per unit time from the node management table 120. In FIG. 6, the selected data amount information is the data amount information of the node (1). The data amount information of the node (1) is 10 cases every 10 seconds.
Then, the schedule determination unit 220 calculates the time necessary to obtain the reference data amount using the selected data amount information. The calculated time is the lower limit of the collection interval range. When the reference data amount is 10, the lower limit of the collection interval range is 10 seconds.
The upper limit of the collection interval range is a predetermined time. For example, the upper limit of the collection interval range is 60 seconds.

In step S202, the schedule determination unit 220 selects a collection interval i from the collection interval range.
Specifically, the schedule determination unit 220 sets the lower limit of the collection interval range as the collection interval i.

Here, the collection interval will be described.
In general, when the collection interval is short, the collection process is divided into small parts, so that the entire collection load is easily smoothed.
However, the processing load for the data amount is not necessarily proportional to the data amount. In general, the larger the amount of data processed at one time, the higher the processing efficiency, and the lower the amount of data processed at one time, the lower the processing efficiency.
For this reason, if the collection interval is short and the amount of data processed at a time is small, the processing efficiency is lowered.
Therefore, the lowering of the processing efficiency is suppressed by providing a lower limit (reference data amount) of the data amount collected at one time.

Also, if the collection interval is long, the time required for the data collection device 200 to collect data from each node 300 tends to be long.
Thus, the upper limit of the collection interval is determined based on the time requirement for collecting data from each node 300.

The description will be continued from step S203.
In step S203, the schedule determination unit 220 compares the collection interval i with the upper limit of the collection interval range.
If the collection interval i is less than or equal to the upper limit of the collection interval range, the process proceeds to step S204.
If the collection interval i is greater than the upper limit of the collection interval range, the process ends without determining the collection schedule. In this case, data cannot be collected from each node 300.

In step S <b> 204, the schedule determination unit 220 calculates the collection interval data amount for each node 300 based on the data amount information for each node 300.
The collection interval data amount is the amount of data obtained during the collection interval i.
For example, when the data amount indicated by the data amount information is 10 cases every 10 seconds and the collection interval i is 10 seconds, the collection interval data amount is 10 seconds.

In step S <b> 205, the schedule determination unit 220 calculates a load amount for the collection interval data amount for each node 300. Then, the schedule determination unit 220 calculates the total load amount using the load amount for each node 300.
The load amount is an amount of load required for processing data. Specifically, the load amount is CPU time required for processing on data. Examples of the load amount include a memory usage amount and a disk input / output amount in addition to the CPU time. The amount of load is also called processing cost.
The total load amount is the total load amount. Specifically, the total load amount is the total CPU time.

Specifically, the schedule determination unit 220 extracts a load amount corresponding to the collection interval data amount from the load amount data 150 for each node. And the schedule determination part 220 totals the load amount for every node. The load amount obtained by the sum is the total load amount.
The load amount data 150 is data in which the data amount and the load amount are associated with each other. For example, the load amount data 150 is a graph, a table, or an equation.

FIG. 10 shows a specific example of the load amount data 150.
As shown in FIG. 10, the load amount is not necessarily proportional to the data amount.
In general, the larger the amount of data processed at one time, the higher the processing efficiency, and the lower the amount of data processed at one time, the lower the processing efficiency.

Returning to FIG. 9, the description will be continued from step S206.
In step S206, the schedule determination unit 220 compares the total load amount with the allowable load amount.
The allowable load amount is an allowable load amount. When the total load amount is the total CPU time, the allowable load amount is the collection interval i. That is, the schedule determination unit 220 compares the total CPU time with the collection interval i.
If the total load amount is less than or equal to the allowable load amount, the process proceeds to step S208.
If the total load amount is greater than the allowable load amount, the process proceeds to step S207.

In step S207, the schedule determination unit 220 newly selects a collection interval i.
Specifically, the schedule determination unit 220 adds the additional time Δ to the collection interval i. That is, the schedule determination unit 220 selects the collection interval i in ascending order of time.
For example, the additional time Δ is a time obtained by dividing the collection interval range into N. When the collection interval range is 50 seconds from 10 seconds to 60 seconds, and the collection interval range is divided into 10, the additional time Δ is 5 seconds.
After step S207, the process proceeds to step S203.

In step S208, the schedule determination unit 220 calculates a margin amount using the total load amount and the allowable load amount, and compares the margin amount with a margin threshold.
The margin amount is the remainder of the allowable load amount with respect to the total load amount.
The margin threshold value is a predetermined value as a threshold value to be compared with the margin amount.

  Specifically, the schedule determination unit 220 calculates the surplus time by subtracting the total CPU time (total load amount) from the collection interval i (allowable load amount), and calculates the ratio of the surplus time to the collection interval i. The calculated ratio is a margin. For example, if the collection interval i is 10 seconds and the total CPU time is 7 seconds, the extra time is 3 seconds and the margin is 30 percent. When the margin threshold is 25%, the margin amount is larger than the margin threshold.

If the margin amount is equal to or greater than the margin threshold, the process proceeds to step S209.
If the margin amount is less than the margin threshold, the process proceeds to step S210.

  In step S <b> 209, the schedule determination unit 220 determines whether the total load amount after adding the uncollected data amount for each node 300 to the collection interval data amount for each node 300 does not exceed the allowable load amount. An uncollected data amount for each node 300 is added to the collection interval data amount.

Specifically, the schedule determination unit 220 adds an uncollected data amount as follows.
(1) The schedule determination unit 220 selects one node 300 whose non-collected data amount is not zero from the node management table 120.
(2) Next, the schedule determination unit 220 calculates the total load amount when the uncollected data amount of the selected node 300 is added to the collection interval data amount of the selected node 300.
(3) Next, the schedule determination unit 220 compares the total load amount with the allowable load amount.
(4) When the total load amount is equal to or less than the allowable load amount, the schedule determination unit 220 adds the uncollected data amount of the selected node 300 to the collection interval data amount of the selected node 300. Then, the process returns to (1).
(5) When the total load amount is larger than the allowable load amount, the schedule determination unit 220 does not add the uncollected data amount of the selected node 300 to the collection interval data amount of the selected node 300. Alternatively, the schedule determination unit 220 adds a part of the uncollected data amount of the selected node 300 to the collection interval data amount of the selected node 300. Then, the process ends.

  After step S209, the process proceeds to step S210.

FIG. 11 shows a specific example of the collection interval data amount and the load amount before and after step S209.
When there is uncollected data in the node (5) and there is a margin in processing resources, it is possible to add the uncollected data amount of the node (5) to the collection interval data amount of the node (5). When the uncollected data amount of the node (5) is added to the collection interval data amount of the node (5), the load amount of the node (5) increases.

Returning to FIG. 9, step S210 will be described.
In step S210, the schedule determination unit 220 determines a collection schedule using the collection interval i. The storage unit 291 stores the collection schedule.
Specifically, the schedule determination unit 220 determines the collection schedule as follows.
First, the schedule determination unit 220 determines the entire collection time zone using the collection interval i. The total collection time zone is a time zone having a time as long as the collection interval i.
Next, the schedule determination unit 220 determines the collection order of each node 300. For example, the schedule determination unit 220 arranges the newly connected node 300 and the node 300 having uncollected data in front, and behind that, arranges the remaining nodes 300 in the same order as the previous time.
Next, the schedule determination unit 220 calculates the collection time length for each node 300 using the collection interval data amount. The collection time length is a time required for collecting data of the collection interval data amount.
Next, the schedule determination unit 220 calculates the total collection time length, calculates the difference between the total collection time zone and the total collection time length, and calculates the insertion time by dividing the difference by the number of nodes. The insertion time is a time inserted during the collection time of each node 300.
Then, the schedule determination unit 220 determines the collection time zone of each node 300 in the entire collection time zone. The collection time zone is a time zone having a collection time length. The start time of the collection time zone is called the collection time.

FIG. 12 shows an image of the collection schedule.
The collection interval is 10 seconds, and collection is performed in the order of the node (5), the node (4), the node (3), the node (2), and the node (1). Each collection interval data amount is 64 cases, 40 cases, 40 cases, 50 cases, and 10 cases. An insertion time Tw is inserted between each collection time zone.

FIG. 13 shows a specific example of the collection schedule.
The node identifier identifies the node 300.
The next collection time is the time when the next collection is performed.
The next data amount is the amount of data collected next time.
The next collection time is a time when the next collection is performed, and is determined based on the next collection time.
The successive data amount is the amount of data collected one after another.

*** Effects of Embodiment 1 ***
In the data collection method for collecting data from a plurality of nodes 300, the data collection device 200 receives information such as the amount of uncollected data and the amount of data per unit time from each node 300 and collects the amount of data collected from each node 300. Schedule collection according to As a result, the data collection device 200 can smooth the collection load.

*** Other configurations ***
The accumulation unit 292 may be outside the data collection device 200. That is, the database in which the collected data is stored may be provided in the data collecting apparatus 200 or may be provided outside the data collecting apparatus 200.

  The data collection device 200 may be composed of a plurality of computers. For example, the data collection device 200 may be configured by two computers: a computer that functions as the control unit 210 and the storage unit 292, and a computer that functions as the schedule determination unit 220.

The node 300 may be a relay device.
The relay device relays data between the measurement device and the data collection device 200. That is, the relay device receives data from each measurement device and transmits the received data to the data collection device 200. For example, the relay device is a concentrator for a power meter.

FIG. 14 illustrates an example of a data collection system 100 including a node 300 that is a relay device.
The data collection system 100 includes three measurement devices 102, two nodes 300, and a data collection device 200.
Node (1) is a relay device. Three measuring devices 102 are connected to the node (1). The node (1) receives data from each measuring device 102.
Node (2) is a measuring device.
The data collection device 200 collects data from the node (1) and the node (2).

Embodiment 2. FIG.
A mode in which a plurality of nodes 300 are grouped and a collection schedule is determined for each group will be described mainly based on FIGS. 15 to 20 with respect to differences from the first embodiment.

*** Explanation of configuration ***
The configuration of the data collection system 100 will be described based on FIG.
The data collection system 100 includes a data collection device 200 and a plurality of nodes 300 as in the first embodiment.
Specifically, the data collection system 100 includes nine nodes 300 from the node (1) to the node (9).

The configuration of the data collection device 200 will be described based on FIG.
The data collection device 200 includes a plurality of processors 201. Specifically, the data collection device 200 includes two processors 201.
Other configurations of the data collection device 200 are the same as those in the first embodiment.

*** Explanation of operation ***
The overall flow of the data collection method is the same as that of the first embodiment (see FIG. 4).

Based on FIG. 17, a schedule determination method will be described.
Steps S201 to S204 and step S207 are as described in the first embodiment (see FIG. 9).

  In step S <b> 221, the schedule determination unit 220 calculates a load amount for the collection interval data amount for each node 300. The method for calculating the load amount is the same as the method in step S205 (see FIG. 9 of the first embodiment).

Next, the schedule determination unit 220 divides the plurality of nodes 300 into a plurality of node groups.
Specifically, since the data collection system 100 includes nine nodes 300 and the data collection device 200 includes two processors 201, the schedule determination unit 220 divides the nine nodes 300 into two node groups.

  Then, for each node group, the schedule determination unit 220 calculates the total load amount by adding the load amounts of the nodes 300 belonging to the node group.

FIG. 18 shows the node group, the node information of the node 300 belonging to the node group, and the load amount of the node 300 belonging to the node group.
Five nodes 300 from node (1) to node (5) belong to the first node group.
In the second node group, four nodes 300 from node (6) to node (9) belong.
The total load amount of the first node group is 4754.7 milliseconds, the total load amount of the second node group is 3274.7 seconds, and the total load amount of both node groups is less than 5 seconds.

Returning to FIG. 17, the description will be continued from step S222.
In step S222, the schedule determination unit 220 compares the total load amount with the allowable load amount for each node group.
If the total load amount of any node group is equal to or less than the allowable load amount, the process proceeds to step S223.
If the total load amount of at least one of the node groups is larger than the allowable load amount, the process proceeds to step S207.

  In FIG. 18, the total load amount of any group is less than 5 seconds. Therefore, when the collection interval i is 5 seconds, the total load amount of any node group is equal to or less than the allowable load amount (collection interval i).

Returning to FIG. 17, the description will be continued from step S223.
In step S223, the schedule determination unit 220 calculates a margin amount for each node group, and compares the margin amount with a margin threshold for each node group. The method for calculating the margin is the same as the method in step S208 (see FIG. 9 of the first embodiment).
If the margin amount of at least one of the node groups is greater than or equal to the margin threshold, the process proceeds to step S224.
If the margin amount of any node group is less than the margin threshold, the process proceeds to step S225.

In step S224, the schedule determination unit 220 adds an uncollected data amount for the margin node group.
The margin node group is a node group having a margin amount equal to or greater than a margin threshold.
The addition of the uncollected data amount is the process described in step S209 (see FIG. 9 of the first embodiment).

  In step S225, the schedule determination unit 220 determines a collection schedule for each node group. The method for determining the collection schedule is the same as the method in step S210 (see FIG. 9 of the first embodiment).

FIG. 19 shows an image of the collection schedule.
The collection interval is 5 seconds.
In the first node group, nodes (5), (4), (3), (2), and (1) are collected in this order. Each collection interval data amount is 20 cases, 40 cases, 40 cases, 50 cases, and 10 cases. An insertion time Tw1 is inserted between the respective collection time zones.
In the second node group, data is collected in the order of the node (9), the node (8), the node (7), and the node (6). The respective collection interval data amounts are 30, 40, 20, and 20. An insertion time Tw2 is inserted between the respective collection time zones.

FIG. 20 shows a specific example of the collection schedule.
The collection schedule is determined for each node group.

*** Effects of Embodiment 2 ***
A plurality of nodes 300 can be grouped and a collection schedule can be determined for each group.

*** Supplement to the embodiment ***
Based on FIG. 21, the hardware configuration of the data collection device 200 will be described.
The data collection device 200 includes a processing circuit 990.
The processing circuit 990 is hardware that implements the control unit 210, the schedule determination unit 220, and the storage unit 291.
The processing circuit 990 may be dedicated hardware or a processor 901 that executes a program stored in the memory 902.

When the processing circuit 990 is dedicated hardware, the processing circuit 990 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.
ASIC is an abbreviation for Application Specific Integrated Circuit, and FPGA is an abbreviation for Field Programmable Gate Array.
The data collection device 200 may include a plurality of processing circuits that replace the processing circuit 990. The plurality of processing circuits share the role of the processing circuit 990.

  A part of the functions of the data collection device 200 may be realized by dedicated hardware, and the rest may be realized by software or firmware.

  Thus, the processing circuit 990 can be realized by hardware, software, firmware, or a combination thereof.

  The embodiments are exemplifications of preferred forms and are not intended to limit the technical scope of the present invention. The embodiment may be implemented partially or in combination with other embodiments. The procedure described using the flowchart and the like may be changed as appropriate.

  100 data collection system, 101 network, 102 measurement device, 110 node information, 120 node management table, 130 schedule information, 140 collection data, 150 load data, 200 data collection device, 201 processor, 202 memory, 203 auxiliary storage device, 204 communication interface, 210 control unit, 220 schedule determination unit, 291 storage unit, 292 storage unit, 293 reception unit, 294 transmission unit, 300 node, 301 processor, 302 memory, 303 auxiliary storage device, 304 communication interface, 305 sensor interface 311 control unit, 391 storage unit, 392 transmission unit, 393 reception unit, 394 measurement unit, 990 processing circuit.

Claims (4)

A receiving unit that receives data amount information indicating a data amount per unit time for each node from which data is obtained;
A data collection device comprising: a schedule determination unit that determines a collection schedule for collecting data from each node based on data amount information for each node ;
The schedule determination unit
Select a collection interval to collect data from each node from the collection interval range,
Based on the data amount information for each node, calculate the collection interval data amount obtained during the selected collection interval for each node,
Calculate the load amount for the collection interval data amount for each node,
Calculate the total load using the load for each node,
The data collection device that determines the collection schedule using the collection interval when the total load amount is smaller than an allowable load amount . The data collection device according to claim 1 , wherein the schedule determination unit newly selects a collection interval when the total load amount is greater than the allowable load amount. The data collection device according to claim 2 , wherein the schedule determination unit selects a collection interval in ascending order of time. The receiving unit further receives an uncollected data amount for each node having uncollected data,
The schedule determination unit determines whether the total load amount after adding the uncollected data amount for each node to the collection interval data amount for each node is within the collection interval data amount for each node within a range that does not exceed the allowable load amount. data acquisition apparatus according to add the uncollected amount of data, the collection interval data amount for each node claims 1 to include in the collection schedule in any one of claims 3 per.

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