JP2007188425A - Control method and controller for sensor terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method and a controller for a sensor terminal, capable of prolonging a life of a battery for operating the sensor terminal. <P>SOLUTION: This controller 10 is provided with the sensor terminal 12 attached to measuring objective equipment, and a server 30 communication-connected with the sensor terminal 12. The sensor terminal 12 is provided with a sensor 14 for measuring a physical quantity of the measuring objective equipment, the battery 22, and a communication circuit 18 for receiving a measuring request from the server 30, and for transmitting a measured data of the physical quantity to the server 30. The server 30 is provided with a communication processing part 40 for transmitting the measuring request to the sensor terminal 12, and for receiving the measured data of the physical quantity transmitted from the sensor terminal 12, and a determination part 32 for judging an integrated operation time of the measuring objective equipment, and a size of the measured data input via the communication processing part 40, to determine a measuring period of the sensor terminal 12, and for outputting the measuring request of requesting measurement execution and the transmission of the measured data to the sensor terminal 12, to the communication processing part 40, with the measuring period. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sensor terminal control method and a control apparatus.

  Rotating devices such as pumps and fans are used in industrial plants such as water treatment facilities and air conditioning facilities. When a failure occurs in the rotating equipment, the industrial plant must be stopped, and abnormality diagnosis of the rotating equipment is performed periodically. This abnormality diagnosis is performed by the operator measuring the sound, vibration, temperature, etc. of the rotating equipment.

Some have also introduced online monitoring to save labor and to remotely monitor rotating equipment. For example, the facility diagnosis system disclosed in Patent Document 1 is a sensor network terminal having a sensor, a power source, a wireless transmission / reception circuit, and the like, and a system that inputs data wirelessly transmitted from the sensor network terminal and stores it in a control information DB And a control device. The equipment diagnostic system then measures the strain of the casing by attaching the sensor net terminal to the casing of the pump, wirelessly transmits this strain data to the system control device, processes the strain data by the system control device, and determines the pump frequency. When a low frequency frequency indicating the deterioration of the pump is detected, it is determined that maintenance is necessary, and a warning is displayed on the screen. When the sensor network terminal used in this diagnostic system communicates for t seconds to transmit strain data, the sensor network terminal rests for a while to charge the communication power and communicates for t seconds to transmit strain data. repeat.
JP 2005-164315 A

When a sensor terminal for abnormality diagnosis is attached to various devices such as the rotating device described above, abnormality diagnosis cannot be performed when the battery mounted on the sensor terminal is exhausted. For this reason, it is necessary to manage the battery life of all sensor terminals. However, since the number of sensor terminals required per industrial plant is very large, it is very difficult to manage this. Although it is conceivable to replace the battery mounted on the sensor terminal with a solar battery or replace it with a vibration power generation element, the cost of the sensor terminal increases and a technical problem arises.
An object of this invention is to provide the control method and control apparatus of a sensor terminal which aim at the lifetime extension of the battery which operates a sensor terminal.

  The sensor terminal control method according to the present invention has the following features. That is, a sensor terminal is attached to a device (measurement target device), and a physical quantity of the device is measured by the sensor terminal. The cumulative operating time of the device can be divided into a plurality of stages, a stable period of the failure probability of the device and a period of high failure probability before and after the stable period. The measurement period of the sensor terminal is set for each of the stable period and the period when the failure probability is high, and the measurement period when the failure probability is high is set to a measurement period shorter than the stable period. Note that the measurement period when the failure probability is high is obtained in advance.

  Further, the control method of the sensor terminal according to the present invention includes the cumulative operation time of the measurement target device to which the sensor terminal is attached, the time when the initial failure probability of the measurement target device is high, the subsequent stable period of the failure probability, and the stable It is divided into each stage with a high probability of failure after the period, and the cumulative operating time is divided into the magnitude relationship between the value of the measurement data obtained by the sensor terminal and the preset threshold value. The measurement period of the sensor terminal obtained in advance is set at each stage.

  The sensor terminal control apparatus according to the present invention has the following characteristics. That is, the control device for the sensor terminal includes a sensor terminal attached to the measurement target device and a server for communication connection with the sensor terminal. The sensor terminal includes a sensor that measures a physical quantity of the measurement target device, a battery that supplies power, and a communication circuit that receives a measurement request from the server and transmits measurement data of the physical quantity to the server. The server transmits a measurement request to the sensor terminal and receives the measurement data of the physical quantity transmitted from the sensor terminal, and the measurement data input via the accumulated operation time of the measurement target device and the communication processing unit. And a determination unit that determines a measurement cycle of the sensor terminal and outputs a measurement request to the sensor terminal for measurement execution and transmission of measurement data to the communication processing unit at the measurement cycle.

  According to the control method and control device for the sensor terminal, the measurement cycle is changed according to the accumulated operating time of the measurement target device, so that the battery mounted on the sensor terminal can be effectively used, and the battery length Life can be extended. When the physical quantity (measurement data) measured by the sensor terminal becomes larger than the threshold value, the measurement cycle is changed by determining the magnitude relationship between these values. For this reason, the battery mounted in the sensor terminal can be effectively used. In addition, since the battery life can be extended in accordance with the life of the measurement target device, it is possible to save labor for the operator to manage the battery life of the sensor terminal. Furthermore, since the battery mounted on the sensor terminal does not need to be a solar battery or a vibration power generation element, problems such as an increase in the cost of the sensor terminal do not occur.

  In the following, the best embodiment of the control method and control apparatus of the sensor terminal according to the present invention will be described. FIG. 1 is a schematic block diagram of a control device for a sensor terminal. The control device 10 for the sensor terminal 12 includes a server 30 and a plurality of sensor terminals 12. The sensor terminal 12 is attached to these devices (measurement target devices) and performs various measurements in order to diagnose abnormalities of various devices used in the industrial plant. The sensor terminal 12 includes a sensor 14, a communication circuit 18 including an antenna 16, a control unit 20, and a battery 22.

  The sensor 14 measures a physical quantity of the measurement target device and outputs the measurement result (measurement data). This physical quantity is, for example, vibration, temperature, acceleration, frequency, or the like of the measurement target device. The communication circuit 18 provided with the antenna 16 wirelessly transmits data (measurement data) measured by the sensor 14 to the server 30 and receives a measurement request sent from the server 30. The control unit 20 controls the operation of the communication circuit 18 and the sensor 14. And the control part 20 can operate the sensor 14 according to the measurement request | requirement transmitted from the server 30. FIG. The battery 22 supplies power to the control unit 20, the communication circuit 18, and the sensor 14. The measurement by the sensor 14 may be performed by operating the sensor 14 intermittently according to the measurement request transmitted from the server 30. When the sensor 14 is intermittently operated, power is intermittently consumed, so that the consumption of the battery 22 can be delayed compared to the case of continuous operation.

  The server 30 includes a determination unit 32 and a communication processing unit 40. The determination unit 32 determines the measurement period of the sensor 14 according to the accumulated operation time of the measurement target device to which the sensor terminal 12 is attached and the data (measurement data) measured by the sensor terminal 12. The determination unit 32 includes a calculation unit 38, a storage unit 36, and a measurement cycle determination unit 34. The calculating means 38 calculates the measurement cycle of the sensor terminal 12 based on the inputted conditions. The storage unit 36 stores the measurement cycle obtained by the calculation unit 38. Further, the measurement cycle determining unit 34 determines a measurement cycle from a plurality of measurement cycles stored in the storage unit 36 according to the accumulated operating time of the measurement target device and measurement data.

  A plurality of routers 44 each having an antenna 42 are connected to the communication processing unit 40. The communication processing unit 40 inputs measurement data transmitted from the sensor terminal 12 via the antenna 42 and the router 44 and outputs the measurement data to the determination unit 32. The communication processing unit 40 measures the physical quantity of the measurement target device with the sensor terminal 12 and wirelessly transmits a measurement request for sending the measurement data to the sensor terminal 12 via the router 44 and the antenna 42. is there.

  Next, the operation of the control device 10 (method for controlling the sensor terminal 12) will be described. FIG. 2 is a graph showing the relationship between the failure probability of the device to be measured and the cumulative operating time of this device. The relationship between the failure probability of the measurement target device and the cumulative operating time of the device becomes a bathtub curve indicating the transition of the failure probability of the measurement target device. This bathtub curve shows that the failure probability is low and stable after many initial failures of the measurement target device occur, and thereafter many failures of the measurement target device occur. In other words, the bathtub curve has a high failure probability during the cumulative operation time from zero to t1, a low failure probability during the cumulative operation time from t1 to t2 (stable period), and the cumulative operation time t2. From t to t3, it is shown that the unstable period in which the failure probability increases again. The cumulative operation time t3 is the expected life of the battery 22 mounted on the sensor terminal 12.

  FIG. 3 is a flow for determining the measurement cycle of the sensor terminal and battery replacement. First, as the above conditions, the calculation means 38 of the server 30 is estimated from the measurement target device to which each sensor terminal 12 is attached, the measurement period T1 in the stable period (between the cumulative operation time t1 and t2), and the battery life. The number of possible measurements N of the sensor terminal 12, the safety factor w, and the threshold value P are input. Note that the failure probability of the measurement target device is associated with the accumulated operation times t1, t2, and t3 in advance. Based on these conditions, the calculation means 38 obtains a measurement cycle between the accumulated operating time from zero to t1 and from t2 to t3, and the measurement data Y exceeds the threshold value P. Obtain the measurement period. And the memory | storage means 36 preserve | saves these measurement periods.

  Then, the operation of the measurement target device is started. At this time, the server 30 starts counting the cumulative operation time of the measurement target device. Then, the server 30 determines whether or not the accumulated operation time t of the measurement target device has reached the stable period, that is, t <t1 (S100). If the cumulative operating time t does not reach t1, the measurement cycle determining unit 34 of the server 30 measures the measurement cycle according to the cumulative operating time from among a plurality of measurement cycles stored in the storage unit 36. T2 is selected (S110), and a measurement request is transmitted to the sensor terminal 12 at this measurement cycle T2. Upon receiving this measurement request, the sensor terminal 12 measures the physical quantity of the measurement target device, for example, the vibration of the measurement target device, and outputs the measurement data Y to the server 30.

  On the other hand, in the determination of S100, when the accumulated operation time t of the measurement target device exceeds No, the server 30 determines whether or not the cumulative operation time t of the measurement target device has reached an unstable period, that is, t. <T2 is determined (S120). If it is determined in S120 that the accumulated operating time t has not reached t2, the server 30 causes the value of the measurement data Y sent from the sensor terminal 12 to exceed a preset threshold value P. It is judged whether it is (S130). In the determination of S130, when the measurement data Y does not exceed the threshold value P, the measurement cycle determination unit 34 of the server 30 determines the measurement cycle T1 from the plurality of measurement cycles stored in the storage unit 36. Is selected (S140), and a measurement request is transmitted to the sensor terminal 12 every measurement cycle T1. If the measurement data Y exceeds Yes in the determination of S130, the measurement cycle determination unit 34 of the server 30 determines the measurement cycle T2 from the plurality of measurement cycles stored in the storage unit 36. Alternatively, the measurement cycle T3 is selected (S150), and a measurement request is transmitted to the sensor terminal 12 at the measurement cycle T2 or the measurement cycle T3. The measurement period T1 is longer than the measurement periods T2 and T3.

  If the cumulative operating time t reaches No in the determination of S120, the server 30 determines that the cumulative operating time t is equal to or longer than the expected battery life t3, or the number of times the sensor terminal 12 is sensed. It is determined whether or not the number of measurable times N ′ (N ′ = measurable number of times N × safety factor w) of the sensor terminal 12 in consideration of the safety factor w is greater (S160). Note that this S160 determines the replacement time of the battery 22 mounted on the sensor terminal 12. That is, since it is desirable to replace the battery 22 at the same time as maintenance of the measurement target device, if the measurement data Y does not exceed the threshold value P, the measurement cycle is set so that the battery can be replaced at the same time as the maintenance of the measurement target device. Has been. However, when the measurement data Y exceeds the threshold value P during the cumulative operating time of the measurement target device from t1 to t2 (stable period), the battery life is shorter than the battery life t3 that is assumed in advance. For this reason, a counter (not shown) that counts the number of times the sensor terminal 12 is sensed is provided in the server 30. When this exceeds the measurable number N ′, the battery 22 is replaced regardless of the state of the measurement target device. Judgment is made.

  If the accumulated operating time t is equal to or greater than t3 as a result of the determination in S160 or the number of sensing times is equal to or greater than the measurable number N ', the server 30 replaces the battery 22 of the sensor terminal 12. An urging warning is issued (S170). Note that this warning may be any warning display on a display means (not shown) provided in the server 30, for example, or by a sound or voice from a speaker (not shown) provided in the server 30. Anything that issues a warning may be used.

  On the other hand, as a result of the determination in S160, if the accumulated operation time t is less than the battery life t3 or the number of sensing times is less than the measurable number N ′, the server 30 before the end of the stable period (before t2) ), It is determined whether or not the measurement data Y has exceeded the threshold value P (S180). As a result of the determination in S180, when the measurement data Y has exceeded the threshold value P, the measurement cycle determination unit 34 of the server 30 selects from the plurality of measurement cycles stored in the storage unit 36. A measurement cycle T2 or T4 is selected (S190), and a measurement request is transmitted to the sensor terminal 12 at the measurement cycle T2 or T4. Note that the measurement period T1 is longer than the measurement period T4. When the measurement data Y has not exceeded the threshold value P as a result of the determination in S180, the measurement cycle determining unit 34 of the server 30 selects from a plurality of measurement cycles stored in the storage unit 36. A measurement cycle T2 is selected (S200), and a measurement request is transmitted to the sensor terminal 12 at this measurement cycle T2.

  Next, a specific example of the operation of the control device 10 described above (control method of the sensor terminal 12) will be described. First, a first specific example will be described. FIG. 4 is a graph illustrating the relationship between the failure probability and measurement data of the measurement target device and the cumulative operation time of the measurement target device, explaining the first specific example. In FIG. 4, the bathtub curve indicated by a solid line indicates the failure probability of the measurement target device, and the broken line indicates data (measurement data) measured by the sensor terminal 12.

First, if the accumulated operating time of the measurement target device is between zero and t1, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T2 based on the flow of S100 and S110 shown in FIG. Each time the sensor terminal 12 receives this measurement request, the sensor terminal 12 measures the physical quantity of the measurement target device and transmits the measurement data to the server 30. The measurement period T2 is obtained from Equation 1 based on the above conditions.

  And if the accumulation operation time of a measuring object apparatus is the stable period between t1 and t2, the server 30 will output a measurement request | requirement to the sensor terminal 12 by the measurement period T1 based on the flow of S120-S150. In the case shown in FIG. 4, since the measurement data Y does not exceed the threshold value P in the stable period, the measurement period T1 remains unchanged. If the accumulated operating time of the measurement target device is an unstable period between t2 and t3, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T2 based on the flow of S160 to S200. Note that the number of sensing times of the sensor terminal 12 is not greater than or equal to the measurable number of times N ′ considering the safety factor w.

  Next, a second specific example will be described. FIG. 5 is a graph showing the relationship between the failure probability and measurement data of the measurement target device, and the cumulative operation time of the measurement target device, explaining the second specific example. In FIG. 5, the solid line indicates the failure probability of the measurement target device, and the broken line indicates the measurement data. First, if the accumulated operating time of the measurement target device is between zero and t1, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T2 based on the flow of S100 and S110 shown in FIG. Each time the sensor terminal 12 receives this measurement request, the sensor terminal 12 measures the physical quantity of the measurement target device and transmits the measurement data to the server 30. And if the accumulation operation time is the stable period between t1 and t2, the server 30 will output a measurement request | requirement to the sensor terminal 12 with the measurement period T1 based on the flow of S120-S150.

  In the case shown in FIG. 5, since the measurement data Y exceeds the threshold value P in the stable period, the server 30 that has received the measurement data Y exceeding the threshold value P uses the measurement period determination unit 34 to store the storage unit 36. One of the measurement periods T2 and T3 is selected and determined from the plurality of measurement periods stored in, and the measurement period T1 is changed to the measurement period T2 or the measurement period T3.

ここでｔ２’は測定データＹがしきい値Ｐを超えた後において、最初にセンサ端末１２が測定したときの時間である。またＮ”は、測定可能回数Ｎから安全係数ｗを考慮した測定可能回数Ｎ’を引いた値（Ｎ”＝Ｎ−Ｎ’）である。そしてサーバ３０は、累積稼働時間がｔ２からｔ３の間の不安定期であれば、Ｓ１６０〜Ｓ２００のフローに基づいて、測定周期Ｔ２または測定周期Ｔ４で測定要求をセンサ端末１２に出力する。 The measurement period T3 is obtained from Equation 2 based on the above conditions.

Here, t2 ′ is the time when the sensor terminal 12 first measures after the measurement data Y exceeds the threshold value P. N ″ is a value (N ″ = N−N ′) obtained by subtracting the measurable frequency N ′ in consideration of the safety factor w from the measurable frequency N. If the accumulated operation time is an unstable period between t2 and t3, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T2 or the measurement cycle T4 based on the flow of S160 to S200.

  Next, a third specific example will be described. FIG. 6 is a graph illustrating the relationship between the failure probability and measurement data of the measurement target device and the cumulative operation time of the measurement target device, explaining a third specific example. In FIG. 6, the solid line indicates the failure probability of the measurement target device, and the broken line indicates the measurement data. First, if the accumulated operating time of the measurement target device is between zero and t1, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T2 based on the flow of S100 and S110 shown in FIG. Each time the sensor terminal 12 receives this measurement request, the sensor terminal 12 measures the physical quantity of the measurement target device and transmits the measurement data to the server 30.

  And if the accumulation operation time is the stable period between t1 and t2, the server 30 will output a measurement request | requirement to the sensor terminal 12 with the measurement period T1 based on the flow of S120-S150. In the case shown in FIG. 6, as in the case shown in FIG. 5, since the measurement data Y exceeds the threshold value P in the stable period, the server 30 that has received the measurement data Y exceeding the threshold value P is The measurement cycle determining unit 34 selects and determines one of the measurement cycle T2 and the measurement cycle T3 from the plurality of measurement cycles stored in the storage unit 36, and sets the measurement cycle T1 to the measurement cycle T2 or the measurement cycle T3. change. If the accumulated operation time is an unstable period between t2 and t3, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T2 or the measurement cycle T4 based on the flow of S160 to S200.

  Next, a fourth specific example will be described. FIG. 7 is a graph illustrating the relationship between the failure probability and measurement data of the measurement target device, and the cumulative operation time of the measurement target device, explaining a fourth specific example. In FIG. 7, the solid line indicates the failure probability of the measurement target device, and the broken line indicates the measurement data. First, if the accumulated operating time of the measurement target device is between zero and t1, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T2 based on the flow of S100 and S110 shown in FIG. Each time the sensor terminal 12 receives this measurement request, the sensor terminal 12 measures the physical quantity of the measurement target device and transmits the measurement data to the server 30.

  And if the accumulation operation time is the stable period between t1 and t2, the server 30 will output a measurement request | requirement to the sensor terminal 12 with the measurement period T1 based on the flow of S120-S150. In the case shown in FIG. 7, the measurement data Y exceeds the threshold value P once in the stable period, and then falls below the threshold value P. For this reason, the server 30 that has received the measurement data Y exceeding the threshold value P has any one of the measurement period T2 and the measurement period T3 among the plurality of measurement periods stored in the storage unit 36 by the measurement period determining unit 34. One of them is selected and determined, and the measurement cycle T1 is changed to the measurement cycle T2 or the measurement cycle T3. Then, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T2 or the measurement cycle T3. In addition, the server 30 that has received the measurement data Y below the threshold value P selects and determines the measurement period T1 from the plurality of measurement periods stored in the storage unit 36 by the measurement period determination unit 34, and the measurement period T2 or measurement cycle T3 is changed to measurement cycle T1. Then, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T1.

ここでｔ４は測定データＹがしきい値Ｐを下回った後において、最初にセンサ端末１２が測定したときの時間である。なお数式３の分母において、カッコ内の（ｔ４−ｔ２’）／Ｔ２の測定周期Ｔ２は測定周期Ｔ３に置き換えられてもよい。 If the accumulated operation time is an unstable period between t2 and t3, the server 30 outputs a measurement request to the sensor terminal 12 at the measurement cycle T2 or the measurement cycle T4 based on the flow of S160 to S200. The measurement period T4 is obtained from Equation 3 based on the above conditions.

Here, t4 is a time when the sensor terminal 12 first measures after the measurement data Y falls below the threshold value P. In the denominator of Equation 3, the measurement period T2 in parentheses (t4-t2 ′) / T2 may be replaced with the measurement period T3.

  According to such a control method and control device 10 for the sensor terminal 12, since the measurement cycle is changed according to the failure probability of the measurement target device, the battery 22 mounted on the sensor terminal 12 is effectively used. Thus, the life of the battery 22 can be extended. Further, when the physical quantity (measurement data) measured by the sensor terminal 12 becomes larger than a preset threshold value, the measurement cycle is changed by judging the magnitude relationship between these values. For this reason, the battery 22 mounted on the sensor terminal 12 can be effectively used, and the life of the battery 22 can be extended.

  In addition, the server 30 counts the cumulative operation time of the measurement target device and counts the number of sensings of the sensor terminal 12, so that a warning may be issued before the battery 22 mounted on the sensor terminal 12 is exhausted. it can. Accordingly, it is possible to prevent the abnormality diagnosis of the measurement target device from being performed, and it is possible to save labor for the operator to manage the battery life of the sensor terminal 12.

  Further, since the battery 22 mounted on the sensor terminal 12 does not need to be a solar battery or a vibration power generation element, problems such as an increase in the cost of the sensor terminal 12 do not occur.

ここでＴ’は、ｔ３／Ｎである。このような故障確率の決定方法では故障確率に応じて、すなわち累積稼働時間のその時点において測定周期を計算するので、細かい測定周期の設定が可能になる。 Note that the method for determining the measurement cycle is not limited to the above-described form. FIG. 8 is a graph illustrating the relationship between the failure probability of the measurement target device and the cumulative operation time of the measurement target device, explaining a modification. In the measurement cycle determination method according to this modification, the measurement cycle is set so as to be inversely proportional to the failure probability of the measurement target device. That is, if the failure probability is high, the measurement cycle is short, and if the failure probability is low, the measurement cycle is long. If the failure probability is constant, the measurement cycle is also constant. Specifically, when the failure probability is X, the measurement cycle T5 is obtained from Equation 4.

Here, T ′ is t3 / N. In such a failure probability determination method, the measurement cycle is calculated according to the failure probability, that is, at the time of the accumulated operation time, so that a fine measurement cycle can be set.

  A specific example of the above-described embodiment will be described below. The sensor terminal 12 described in this embodiment is capable of performing wireless recognition (RFID) communication about 100,000 times. When the sensor terminal 12 is attached to a measurement target device (air supply fan) having a design expected life of 15 years, the conventional technology in which an equal measurement interval is assigned regardless of the accumulated operation time, performs measurement at a frequency of 18 times / day. If communication is performed, the battery 22 of the sensor terminal 12 will be exhausted in 15 years.

  In contrast, in the present embodiment, it is assumed that the sensor terminal 12 is used 50,000 times in consideration of the safety factor, and the accumulated operating time of the bathtub curve is calculated from statistical failure data of the measurement target device (air supply fan). Assuming that t1 = 1 year, t2 = 13 years, and t3 = 15 years, the measurement and communication interval (measurement cycle) is initialized as follows according to the accumulated operation time. That is, the measurement cycle between zero and t1 is 54 times / day, the measurement cycle between the cumulative operation time t1 and t2 is once / day, and the measurement time is between t2 and t3. Set the cycle to 34 times / day.

  Thereby, in the period when the failure frequency of the measurement target device is high, that is, the cumulative operation time is between zero and t1, and between t2 and t3, compared to the case of assigning an equal measurement period as in the prior art, In the case, the frequency of measurement and communication can be increased, and the reliability can be improved.

  In addition, when the value of the measurement data gradually increases during the period between t1 and t2 of the measurement target device and exceeds the threshold value P, the point in time t2 ′ (for example, the cumulative operation time is 11 years). To t2 between measurement and communication (measurement cycle T3) is obtained from T3 = (t2−t2 ′) / 50,000 times, and the measurement cycle is 68 times / day. As a result, if the cumulative operation time from the time when the value of the measurement data exceeds the threshold to t2 is within 7.6 years, this embodiment is compared with the case where an equal measurement period is assigned as in the prior art. In this case, the frequency of measurement and communication can be increased, and the reliability can be improved.

It is a schematic block diagram of the control apparatus of a sensor terminal. It is a graph which shows the relationship between the failure probability of a measuring object apparatus, and the accumulation operation time of this apparatus. It is a flow which determines the measurement period and battery replacement of a sensor terminal. It is a graph which shows the relationship between the failure probability and measurement data of the measuring object apparatus in a 1st specific example, and the accumulation operation time of a measuring object apparatus. It is a graph which shows the relationship between the failure probability and measurement data of the measuring object apparatus in a 2nd specific example, and the accumulation operation time of a measuring object apparatus. It is a graph which shows the relationship between the failure probability and measurement data of a measuring object apparatus in the 3rd example, and the accumulation operation time of a measuring object apparatus. It is a graph which shows the relationship between the failure probability and measurement data of a measuring object apparatus in the 4th example, and the accumulation operation time of a measuring object apparatus. It is a graph which shows the relationship between the failure probability of the measuring object apparatus explaining the modification, and the accumulation operation time of a measuring object apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ......... Control apparatus, 12 ......... Sensor terminal, 14 ......... Sensor, 18 ......... Communication circuit, 30 ......... Server, 32 ......... Determining part, 40 ......... Communication processing part.

Claims (3)

The cumulative operating time of a device to which a sensor terminal is attached and the physical quantity is measured by this sensor terminal is divided into a plurality of stages of a stable period of failure probability of the device and a high probability of failure before and after the stable period. ,
In addition to setting the measurement period of the sensor terminal in the stable period, obtaining a measurement period shorter than the measurement period in the stable period in advance, and setting this short measurement period to a time with a high probability of failure,
A control method for a sensor terminal. The cumulative operating time of the measurement target device to which the sensor terminal is attached is divided into the following stages: a time when the initial failure probability of the measurement target device is high, a stable period of the subsequent failure probability, and a high probability of failure after this stable period Divided into
The step of dividing the cumulative operating time and the magnitude relationship between the value of the measurement data obtained at the sensor terminal and a preset threshold value are determined, and the measurement cycle of the sensor terminal obtained in advance is determined as Set to stage,
A control method for a sensor terminal. A sensor terminal control device comprising a sensor terminal attached to a measurement target device and a server that is connected to communicate with the sensor terminal,
The sensor terminal includes a sensor that measures a physical quantity of the measurement target device, a battery that supplies power, and a communication circuit that receives a measurement request from the server and transmits measurement data of the physical quantity to the server. ,
The server transmits a measurement request to the sensor terminal and receives the measurement data of the physical quantity sent from the sensor terminal, the accumulated operating time of the measurement target device, and the communication processing unit. Determining the measurement period of the sensor terminal by determining the size of the measurement data input in response to the measurement request to the sensor terminal for measurement execution and transmission of the measurement data to the communication processing unit in the measurement period A determination unit for outputting,
The control apparatus of the sensor terminal characterized by the above-mentioned.

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