JPS60231215A - Abnormality predicting device of sequence control system - Google Patents

Abstract

PURPOSE:To detect the sign of abnormality between an operation command output terminal and a response signal input terminal by sequentially storing a response waiting the time of each state in each execution of a sequence control cycle and collectively deciding the length of the waiting time, the coefficient of variation, etc. CONSTITUTION:A response time trend processor 1 detects a period from the sending of an operation command from a sequence control device 2 to its response by a response time measuring timer 17 on the basis of a transient signal from a state transient timing receiver 15 and stores the detected result in a memory 16. The memory 16 stores the trend data corresponding to the past n times. If the wairing time trends toward increase from the transition of the waiting time, a detection processor 4 divides the difference between the limit value of the waiting time and the response waiting time at the current state by the coefficient of variation of the response waiting time measured at the current point of time by using a diagnosis parameters storing memory 25. Then, the processor 4 compares the obtained forecasting value for a margin time up to the generation of a trouble with a reference value for alarm generation and then outputs an alarm signal.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an abnormality prediction device in a sequence control system that includes a controlled object and a sequence control device that controls the controlled object.

In conventional sequence control systems, the sequence proceeds by repeating the following sequence: after initiating a control action on a controlled object, waiting for a response event caused by that action, and after confirming the occurrence of that event, moving to the next state. Go.

For this reason, changes in response waiting time for each state often sensitively indicate deterioration or abnormal conditions in the mechanical system that is controlled by that state.

Problems to be Solved by the Invention Conventionally, as a method of abnormality detection in such sequence control systems, a limit value of response waiting time, which is the maximum waiting time of each state, is fixedly determined, and the response within that time is If not, in most cases, an abnormal display such as a time-out error was displayed. For this reason, by the time an abnormality is detected, there have often been cases in which a failure has already occurred to the extent that it is impossible to carry out the sequence.

Furthermore, the object of judgment in this case is limited to the current response waiting time, and predictions are not made based on the rate of change in the response waiting time, etc., making it difficult to predict abnormal conditions.

Purpose of the Invention Therefore, the present invention solves the above-mentioned problems by sequentially storing the response waiting time in each state every time a control cycle is executed, and comprehensively determining the length, rate of change, etc. It is an object of the present invention to provide an abnormality prediction device for a sequence control system capable of detecting abnormality signs of parts and subsystems existing between an operation command output terminal and a response signal input terminal, and predicting abnormality progress status.

Composition of the Invention According to the abnormality prediction device for a sequence control system according to the present invention, there is provided a response time trend calculation section that calculates the rate of change in response waiting time for each state in real time, and a response time trend calculation section that calculates the rate of change in response waiting time for each state in real time. An anomaly prediction and detection section that predicts and detects anomalies by inputting response waiting time and rate of change and comparing them with a preset response waiting time limit value, and an alarm that displays the output from this anomaly prediction and detection section.・The feature is that it is equipped with a display section.

Example DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to illustrated embodiments.

As shown in Figure 1, controlled object 3! A sequence control device 2 is connected to this, and an operation command is output from the sequence control device 2 to the controlled object 3 for each state of the sequence, and when that state is achieved, the control object 3 outputs an operation command to the controlled object 3. A response is output to the sequence control device 2. An abnormality prediction device A is connected to the sequence control device 2, and the abnormality prediction device A is connected to the sequence control device 2. It is configured.

The response time trend processor 1 includes an OPU 6, a memory 9 connected to the processor bus 12 of the CPU 6, a trend display information transmitter 18, a response time measurement timer 17, a response time trend φ memory 16, and state transition timing. It is composed of a receiver 15.

The state transition timing receiver 15 receives the state transition signal from the sequence control device 2, and the response time measuring timer 17 counts the time every time the state transition signal is input to the state transition timing receiver 15. This count value is stored in response time trend memory 16 and new data is added sequentially. The trend display information transmitter 18 outputs the data in the response time trend memory 16 to the trend display information receiver of the alarm and display processor 5. The operations of these parts are controlled by a CPU 6 equipped with a memory 9.

Further, the abnormality prediction/detection processor 4 includes a memory 11 connected to the apva processor bus 14, a prediction/detection information transmitter 26, and a diagnostic parameter storage memory 25. The processor bus 14 is connected to the output of a response time trend memory 16, and is supplied with response time count value data for each state. The diagnostic parameter storage memory 25 contains diagnostic parameters such as threshold waiting time and rate of change values.
The PUA processes data input from the processor bus 14. The processing results are output from the prediction/detection information transmitter 26 to the alarm/display processor 5.

Further, the alarm/display processor 5 includes a trend display information receiver 19 connected to the processor bus 13 of the 0PU7, a memory 10, a display controller 24,
Alarm device 1/721 and prediction/detection information receiver 20
It consists of

The trend display information receiver 19 outputs the data from the trend display information transmitter 18 to the processor bus 15, and the prediction/detection information receiver 20 outputs the data from the prediction/detection information transmitter 26 to the processor bus 16. do. Also,
The display controller 24 is equipped with a CRT 24 and functions as an interface for displaying data supplied on the processor bus 15 on the ORT 24. Similarly, alarm device I/? 21 is equipped with a buzzer 26, and the buzzer 26 is activated based on data input from the prediction/detection information receiver 20 to the processor bus 15.
An alarm can be issued from

In the configuration above the operation, 81.82 as shown in Figure 2
．． A case will be described in which abnormality prediction is performed for a sequence that changes in each of the 85 states.

response time trend processor 1 receives the state transition signal via state transition timing receiver 15;
When the sequence control device 2 sends an operation command to the controlled object 3 and learns that it is waiting for a response, the response time measurement timer 17
Start. In this state, when the controlled object 3 makes a response to the sequence control device 2, the state transition signal is inputted from the sequence control device 2 to the state transition timing receiver 15 again. Therefore, the CPU 6 stops the response time measurement timer 17 to complete the response time measurement, and stores the measured value in the response time trend memory 16. This response time trend memory 16 records response wait times of states over the past n times, and is updated every time new data is stored.

Step 81, 132.85 No. 1 shown in Figure 2 IC
rs? for each execution cycle from ~n? ), Tag
'.

Self 11, Ts(P) and Ts≦1), TB(I)
, e a a Tl1F' e and TB≦1).

rsk'..., each data of TJFI is stored.

This abnormality prediction/detection processor 4 has a response time trend φ
The response time trend memory 16 of the processor 1 is directly accessed to compare the stored trend data with diagnostic parameters such as thresholds and rate of change values stored in the diagnostic parameter storage memory 25.

As shown in the data shown in FIG. 3(a), each response time T8 up to 1, 2.5**fist and n cycles for state S1
~゛ゝ, Ts(",..., Ta?" are approximately equal, it is determined to be normal.

In addition, as shown in Fig. 3(b), the stay) 82 is
: Ts! "・1・So..., T, ?+" when each response time tends to increase is stored in the diagnostic parameter storage memory 25 in advance.

T1m1t: Limit value of response waiting time, TJ: Response waiting time of state Sm at present (J), d(-0: Failure occurrence at present (1) due to response waiting time parameter measured at present (L)) Expected value of reserve time up to T(0 to T"= ('rxm1t -'1'8n?))/ll"
Calculated by

The expected value T0 of the margin time calculated in this way is compared with the alarm generation reference value TWARN, and if T≦TWARN, the prediction/detection information transmitter 26 sends an alarm signal indicating a deterioration abnormality to the alarm/display processor 5. Output.

Also, as shown in FIG. 3(0), the response time TB, 6).

Which of GaP,...Tl38° is the limit waiting time T1m1
If the case exceeds t, the prediction/detection information transmitter 26 is immediately transmitted.
From there, an alarm signal indicating a catastrophic abnormality is output to the prediction/detection information receiver 20 of the alarm meeting display processor 5.

The alarm/display processor 5 receives response time trend information via the trend display information receiver 19 and abnormality prediction/detection information via the prediction/detection information receiver 20 and displays them on the ORT 24 from the display controller 22. Then, the alarm unit 21 activates the buzzer 23 to transmit the alarm to the operator. The trend display at 0RT 24 can prompt the operator to make a judgment regarding abnormalities that cannot be automatically predicted using only the parameters stored in the diagnostic parameter storage memory 25.

In this way, by sequentially calculating the rate of change in response time for each state of the sequence using the latest one waiting time, the expected failure time is constantly updated, and the response time is approaching the limit value. It is possible to predict deterioration and deterioration.

Also, in this embodiment, response time trend processor 1
, the anomaly prediction/detection processor 4, and the alarm/display processor 5 are each controlled by a CPU equipped with a memory, but the entire anomaly prediction device is configured with a single processor, and a software program that performs the same operation is configured. It is also possible to implement it as an independent task.

Furthermore, this embodiment includes a response time measurement timer that measures the time from waiting for a response until receiving a response;
Although the response time trend memory and the response time trend memory for sequentially recording temporal changes in response wait time are provided separately to perform a dedicated function, the timer and memory, which are the basic components of a microprocessor system, are also used. You can also.

Effects of the Invention The embodiment of the abnormality prediction device for a sequence control system according to the present invention is as described above, and can provide the following effects.

By sequentially storing the response waiting time in each state every time the control cycle of the sequence is executed, and comprehensively determining the length and rate of change, etc., the parts existing between the operation command output terminal and the response signal input terminal, It is possible to detect signs of abnormality in subsystems and predict the progress of the abnormality.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a chart showing states and execution cycles, and FIG. 3(a)
, (b) and (C) are response time/cycle graphs. A. Abnormality prediction device, 1. Response time trend processor, 2. Sequence control device, 3. Controlled object, 4
...Anomaly prediction/detection processor, 5...Alarm/display processor, '179B, CPU, 9, 10
, 11...Memory, 12,13,14...Processor bus, 15...State transition timing receiver%
16・φ response time trend memory, 17・・Response time measurement timer, 18・0 trend display information transmitter, 19
・・Trend display information receiver, 20-"Prediction/detection information receiver, 21.Fist alarm device engineer/F, 22.0 display controller, 23e.F"j'-,24.oO
RT0

Claims (1)

[Claims] In a sequence control system comprising a controlled object and a sequence control device that controls the controlled object, a response is returned to the sequence control device from the time when the sequence control device outputs an operation command to the controlled object. Input the sequence transition timing for each state up to and measure the response waiting time for each state, and store it sequentially.
A response time trend calculation unit that calculates the rate of change in the sequentially stored response waiting time in real time, and a response time trend calculation unit that inputs the latest response waiting time and rate of change from this response time trend calculation unit and calculates the rate of change in the response waiting time set in advance. An abnormality prediction/detection section that performs abnormality prediction and detection by comparing the time limit value and the input value, and an alarm/display section that inputs the output from this abnormality prediction detection section and displays an alarm. An abnormality prediction device for a sequence control system characterized by comprising: