JPH0722432B2 - Distributed monitoring method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a distributed monitoring method for efficient data transmission.

[Background of the Invention]

Conventionally, various methods have been proposed for monitoring, including a method of sending data when a request is made, a method of sending data at regular intervals, or a combination of both.
Alternatively, there is a method of sending when a failure occurs.

However, in the above three methods, when the amount of transmission data extremely increases, or when there is a sudden change in the state, the change cannot be monitored in real time, and the response may be delayed. Also, in the case of sending when a failure occurs, the trigger can be triggered by the failure occurrence signal from the target,
Even if a sign of a failure appears, nothing is sent until the failure occurs, so it cannot be confirmed and it cannot be prevented.

[Object of the Invention]

An object of the present invention is to provide a method for reducing the transmission amount of a signal transmitted from a monitoring terminal in a decentralized monitoring system and rapidly transmitting the information amount without reducing it.

[Outline of Invention]

In the present invention, when the status and the amount of change thereof satisfy the preset criteria in the monitoring terminal, not only the necessary information can be collected earlier by sending the information and the related information to the central monitoring device. It is not necessary to send unnecessary information.
Furthermore, the information can be sent in response to a request from the central monitoring device, and the information is sent in a long cycle to prevent the lack of data. In addition, the predetermined standard can be set from the central monitoring device.

Example of Invention

 Hereinafter, the present invention will be described with reference to examples.

FIG. 1 shows an example of a loop structure as a transmission system of this monitoring system. However, this system is not particularly limited to the loop structure, and may be a multidrop bus type.

In FIG. 1, a monitoring terminal arranged corresponding to a plurality of monitored objects is connected to a transmission line having a loop structure.
Furthermore, one central monitoring device is connected to the loop transmission line. The central monitoring terminal collects and processes information from each monitoring terminal. The monitoring terminal processes the data from each monitored object and transmits it to the transmission line if necessary.

FIG. 2 shows the program flow of the monitoring terminal.
The data is collected in a short cycle to, the reference is performed, and when it is satisfied, the transmission processing is performed in a long cycle To. The reference can be set by the central monitoring device when needed. Two timers are activated and referenced for sampling at a fixed period to, To.

Hereinafter, FIG. 2 will be described in detail.

At the time of program start, first, _two timers, a timer Ti ₂ for keeping the data sampling period constant and a timer Ti ₁ for keeping the data transmission period constant, are started. Next, data indicating the state of the monitored object is collected from the monitored object in a form that can be arithmetically processed. This data is judged to meet the criteria set beforehand by the central monitoring device. If the criteria are met, the data along with relevant information is processed for transmission and sent to the central monitoring unit. When the criterion is not satisfied, it is determined whether the timer Ti ₁ has reached the transmission cycle To. If Ti ₁ has reached To, the timer Ti ₁ is reset, and then the same transmission processing as in the case where the above criteria are met is performed. If Ti ₁ does not reach To or the transmission process ends, timer Ti ₂
Wait until the data collection cycle becomes to, and when it becomes to Ti
Reset ₂ After that, the process returns to the data collection again, and the data is collected from the monitoring target, and the monitoring is performed by repeating the following as described above.

Fig. 3 shows the current value collected by data collection, which is an example of the current monitor configuration of the electric motor in a part of the train monitoring system, samples the current value after A / D conversion at the period to, compares it with the upper and lower limits, and falls outside that range. When it is judged that the data has come out, the data, the data from a little before, and the data related thereto are sent out. It also receives and sets the new standards sent by the central monitoring unit.

FIG. 4 shows an example of a current monitor of an electric motor of an actual train monitoring system. FIG. 11A shows an example of change in current, and the horizontal axis represents time.

The vertical axis is the current, and the upper and lower limits are reference values preset from the central monitoring device, and are boundaries of the current range. It is set to send data when the current goes out of this range.

FIG. 1B shows the transmission timing in the conventional method of sending at a fixed cycle. The horizontal axis is time. Moreover, the same figure (c)
Indicates the transmission timing in this system. The horizontal axis is time. In addition to going out of the upper and lower limits, send data at the cycle To. By doing so, the state can be confirmed even during normal traveling. This To does not increase the amount of data to be transmitted without making a mistake by preventing the continuation of similar data by taking a little longer.

First, the train starts from the stopped state, the current increases, exceeds the lower limit value, and normal running starts. Even during normal driving, data is sent at a fixed cycle To, indicating normal. Information is also sent when the train stops and drops below the lower limit. When something goes wrong during normal driving and the current rises and exceeds the upper limit, or the breaker works and the current reaches zero, first to notify that the upper limit has been exceeded, and then to notify that the lower limit has been exceeded. To transmit information from a while ago related to it.

Although FIG. 4 was considered as the value of the current, it is also possible to determine the upper limit and the lower limit by taking the derivative or integral of the value. For example, it is not just failure information, such as sending information when the acceleration differential that makes the ride comfortable exceeds a certain value. This will be described in the description of FIG.

Further, if the current rises as a sign of a failure and the current value is about to exceed the upper limit, that information is also sent to notify that there is a possibility of failure. This can prevent a failure from occurring.

FIG. 5 shows digital data and its transmission timing. (A) is an example of digital data showing the opening and closing of the door. The ON (ON) level is the door open state, OFF (OFF)
The level is a door closed state. (B) shows the transmission timing when the state change is set as the data transmission reference. In addition to the case where there is a state change, data is transmitted with a long cycle To. What is indicated by the arrow here is from ON
It is the change of state from OFF or OFF to ON, and the mark indicates that there is no change.

FIG. 6 is an example of the standard set for the differentiation of the state. (A) is a change in speed until the train starts and reaches a constant speed, which gradually rises to a constant value. In (b), the acceleration when the speed changes in (a) smoothly rises, reaches its maximum value, then smoothly falls to zero. (C) is a change in the differential value of acceleration. It rises first, then falls to the minus side, and then returns to zero. An upper limit and a lower limit can be set for the derivative of this acceleration.

FIG. 7 shows an example in which a plurality of reference values are set. (A)
Is the set reference value and state quantity or their integrals and derivatives. (B) is the transmission timing in the case of (a).
Although a plurality of reference values are set here, the reference value (1) is transmitted when the value that is lower than the reference value exceeds the reference value. The reference value (3) is transmitted when the value that exceeds the reference value is lower than the reference value. The reference value (2) is transmitted both when the reference value changes from top to bottom and from bottom to top. Since a plurality of reference values can be freely set in this way, it is possible to perform monitoring that matches the nature of the monitored object.

Although the train monitoring system has been described above as an example, it can be applied to other monitoring systems.

〔The invention's effect〕

According to the present invention, unnecessary data can be prevented from being transmitted, so that the amount of transmission can be reduced, the cost of the transmission line can be reduced, and an economical monitoring system can be constructed. Also, if the transmission amount is the same, many other necessary data can be sent.

[Brief description of drawings]

1 is a block diagram of the monitoring system, FIG. 2 is a flow chart of the monitoring terminal program of the monitoring system, FIG. 3 is a block diagram of the train monitoring system, and 4
Figure is a data transmission timing chart, Figure 5 is a data transmission timing chart for digital information, Figure 6 is a state diagram of reference values set for state differentiation, and Figure 7 is a case where multiple reference values are set. 6 is a data transmission timing chart of FIG. To …… Data transmission cycle, to …… Data acquisition cycle, Ti ₁ ,
Ti ₂ ...... timer, t ...... time.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Miyamoto 1099, Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Inside the Hitachi, Ltd. System Development Laboratory (56) Reference JP 62-77673 (JP, A) Special Kohei 3-10265 (JP, B2) Japanese Kohei 3-32954 (JP, B2)

Claims (8)

[Claims] 1. A monitoring terminal, which is arranged in a distributed manner corresponding to an object to be monitored, a central monitoring device for collecting and processing data sent from the monitoring terminal, and the monitoring terminal and the central monitoring device. What is claimed is: 1. A distributed monitoring method in a distributed monitoring system comprising a transmission system to be coupled, wherein a standard for determining whether or not to transmit the data from the monitoring terminal to a central monitoring device is set on the central monitoring device side, and the monitoring terminal A distributed monitoring method, comprising transmitting the data to the central monitoring device when the data on the side satisfies the criterion. 2. The distributed monitoring method according to claim 1, wherein the reference is an upper limit value or a lower limit value that can be set from the central monitoring device side. 3. The distributed monitoring method according to claim 1, wherein the standard is dynamically updated on the side of a central monitoring device. 4. The distributed monitoring method according to claim 2, wherein the upper limit value or the lower limit value is the upper limit value or the lower limit value of the differentiation or integration of the state quantity of the monitored object, respectively. 5. The distributed monitoring method according to claim 1, wherein the setting process comprises a process of setting at least one of the changes from ON to OFF or OFF to ON of the digital data. . 6. The setting process includes a case where a criterion having a value lower than a preset specific value is higher than the specific value and a criterion having a value higher than the specific value is lower than the specific value. The distributed monitoring method according to claim 1, comprising processing to be set for both cases when an attempt is made. 7. The distributed monitoring method according to claim 1, wherein a plurality of the standards are set. 8. The distributed monitoring method according to claim 1, wherein the transmitting process comprises a process of transmitting data after a time point before the time when the criterion is satisfied to the central monitoring device.