COMMUNICATION CONNECTION DETERMINATION METHOD, COMMUNICATION CONNECTION DETERMINATION DEVICE AND SENSOR SYSTEM

1 - 8 . (canceled)

9 . A communication connection determination method, the method comprising:

receiving, by a sensor accommodating terminal, first data from a sensor terminal, and storing a first time stamp;

determining whether a reception number of pieces of the first data has reached a first specified number;

calculating a mean deviation reference value using a first time stamp interval obtained from the first time stamp in response to a determination that the reception number of pieces of the first data has reached the first specified number;

receiving, by the sensor accommodating terminal, second data from the sensor terminal, and storing a second time stamp;

determining whether a reception number of pieces of the second data has reached a second specified number;

calculating a mean deviation evaluation value using a second time stamp interval obtained from the second time stamp in response to a determination that the reception number of pieces of the second data has reached the second specified number; and

testing whether there is a threshold difference between the mean deviation reference value and the mean deviation evaluation value and determining that there is a communication connection abnormality in response to a determination that there is the threshold difference.

10 . The method according to claim 9 , wherein testing whether there is the threshold difference comprises testing for a presence or an absence of the threshold difference by a Wilcoxon signed-rank test.

11 . The method according to claim 10 , wherein the mean deviation reference value satisfies equation (A) and equation (B) below, wherein the mean deviation evaluation value satisfies equation (C) and equation (D) below,

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and wherein d 1,i represents the first time stamp interval, n 1 represents the reception number of pieces of the first data, σ stamp represents the mean deviation reference value, d 2,i represents the second time stamp interval, n 2 represents the reception number of pieces of the second data, and σ eval is the mean deviation evaluation value.

12 . The method according to claim 11 , wherein:

the sensor terminal is provided in plural;

the method further comprises selecting a first sensor terminal from the plural sensor terminals as a normally communicating sensor terminal based on a communication interval of each of the plural sensor terminals and a time stamp interval of each piece of data received from the plural sensor terminals; and

the first data is received from the first sensor terminal.

13 . The method according to claim 9 , wherein the mean deviation reference value satisfies equation (A) and equation (B) below, wherein the mean deviation evaluation value satisfies equation (C) and equation (D) below,

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and wherein d 1,i represents the first time stamp interval, n 1 represents the reception number of pieces of the first data, σ stamp represents the mean deviation reference value, d 2,i represents the second time stamp interval, n 2 represents the reception number of pieces of the second data, and σ eval is the mean deviation evaluation value.

14 . The method according to claim 9 , wherein:

the sensor terminal is provided in plural;

the method further comprises selecting a first sensor terminal from the plural sensor terminals as a normally communicating sensor terminal based on a communication interval of each of the plural sensor terminals and a time stamp interval of each piece of data received from the plural sensor terminals; and

the first data is received from the first sensor terminal.

15 . A communication connection determination device, the device comprising:

one or more processors; and

a storage device storing a program to be executed by the one or more processors, the program including instructions for:

measuring an arrival time of data from a sensor terminal;

acquiring a time stamp based on the arrival time;

storing the time stamp or a time stamp interval obtained from the time stamp; and

statistically determining a communication connection status between the sensor terminal and a sensor accommodating terminal based on the time stamp interval.

16 . The device according to claim 15 , wherein the program further includes instructions for:

receiving the time stamp interval;

calculating a mean deviation reference value and a mean deviation evaluation value based on the time stamp interval;

storing the mean deviation reference value; and

determining whether to disconnect a communication connection based on the mean deviation reference value and the mean deviation evaluation value.

17 . The device according to claim 16 , wherein the sensor terminal is provided in plural, and wherein the program further includes instructions for selecting a first sensor terminal of the plural sensor terminals as a normally communicating sensor terminal based on a communication interval of each of the plural sensor terminals and a time stamp interval of each piece of data received from the plural sensor terminals.

18 . The device according to claim 15 , wherein the sensor terminal is provided in plural, and wherein the program further includes instructions for selecting a first sensor terminal of the plural sensor terminals as a normally communicating sensor terminal based on a communication interval of each of the plural sensor terminals and a time stamp interval of each piece of data received from the plural sensor terminals.

19 . A sensor system comprising:

a sensor terminal; and

a sensor accommodating terminal comprising a communication connection determination device, the communication connection determination device comprising:

one or more processors; and

a storage device storing a program to be executed by the one or more processors, the program including instructions for:

measuring an arrival time of data from a sensor terminal;

acquiring a time stamp based on the arrival time;

storing the time stamp or a time stamp interval obtained from the time stamp; and

statistically determining a communication connection status between the sensor terminal and a sensor accommodating terminal based on the time stamp interval.

20 . The sensor system according to claim 19 , wherein the program further includes instructions for:

receiving the time stamp interval;

calculating a mean deviation reference value and a mean deviation evaluation value based on the time stamp interval;

storing the mean deviation reference value; and

determining whether to disconnect a communication connection based on the mean deviation reference value and the mean deviation evaluation value.

21 . The sensor system according to claim 20 , wherein the sensor terminal is provided in plural, and wherein the program further includes instructions for selecting a first sensor terminal of the plural sensor terminals as a normally communicating sensor terminal based on a communication interval of each of the plural sensor terminals and a time stamp interval of each piece of data received from the plural sensor terminals.

22 . The sensor system according to claim 19 , wherein the sensor terminal is provided in plural, and wherein the program further includes instructions for selecting a first sensor terminal of the plural sensor terminals as a normally communicating sensor terminal based on a communication interval of each of the plural sensor terminals and a time stamp interval of each piece of data received from the plural sensor terminals.