JPH04336606A - Process controller - Google Patents

Abstract

PURPOSE:To perform not only the control but the diagnoses in a process controller by providing a diagnostic inference part requiring a high-speed end high- accuracy signal input operation into a microprocessor application device of the process controller and also preparing the knowledge necessary for the diagnosis. CONSTITUTION:A microprocessor application device 3 of a process controller 2 for a process 1 is provided with a control arithmetic part 4' which calculates a control signal 6 from the filament signal received from the process 1, a diagnostic knowledge base 8 which stores the knowledge necessary for diagnoses, a data collecting part 9 which collects the data on the process 1 and the part 4', and a diagnostic inference part 10 which carries out the inference based on those collected knowledges and data, the decision for presence or absence of a trouble, and the identification of the trouble area. The part 10 also performs a high-speed and high-accuracy diagnosis with use of a feedback signal 5 of an accuracy/updating cycle required by the part 4' for the process control and an actual control signal 6 which controls the process 1.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process control device for controlling a process.

0002

[Background Art] In recent years, with the progress of digitalization of control devices due to the development of microprocessors, fault diagnosis and fault location identification of control devices and processes have become increasingly complex, using expert systems to make inferences based on previously experienced knowledge. Increasingly, this is achieved through statistical estimation using a large amount of estimation data. Compared to conventional self-diagnosis that uses only simple correlations, expert systems use knowledge to make inferences or estimate through statistical analysis of data to detect failure factors that have more complex relationships. It is becoming possible to derive the

[0003] Such failure diagnosis is often realized using a separate device configuration from the process control device. FIG. 2 shows an example of the configuration of a process control device including a conventional failure diagnosis device. A process control device 2a that controls the process 1 to be controlled is a microprocessor application device 3a such as a computer.
The control calculation unit 4 calculates a control signal 6 from the feedback signal 5 from the process 1 and outputs the control signal 6 to the process 1. On the other hand, the diagnostic function is realized by a microprocessor application device 3b as a process diagnostic device 7, which is configured separately from the process control device 2, and is a collection unit for the knowledge 8b for diagnosis and data obtained from the process 1 and the process control device 2a. 9b, the diagnostic reasoning unit 10b determines the presence or absence of a failure and the location of the failure. Further, the result of inference made by the inference section 10b is output to a man-machine display device 11 such as a CRT, and is notified to the operator. Further, the operator can add or modify the knowledge 8, which is experience, via the man-machine display device 11 as necessary.

As shown in FIG. 2, the conventional process control device and diagnostic device were configured as separate devices in order to prevent the process control device that actually controls the process from becoming abnormal due to an abnormality in the diagnostic device. Ta. For this reason, diagnostic devices often diagnose entire plants having a plurality of processes and process control devices, and are increasingly connected to a plurality of process control devices 2.

[0005]

[Problems to be Solved by the Invention] However, as the diagnosis and inference speed of diagnostic equipment becomes faster and it becomes possible to perform processes such as process control signals and process transfer function identification that require momentary changes in process signals, diagnostic equipment The required information requires the same degree of accuracy and update time as that required by process control equipment, and the amount of information required is increasing, requiring significant functional improvements in diagnostic equipment and the addition of additional equipment. . In addition, in such a case, a large amount of the above information must be transmitted from the process control device to the diagnostic device with the same degree of precision and time as required for process control, so process control, including the signal transmission interface, must be It is also necessary to add equipment to the equipment and increase the computational load. Furthermore, in terms of price, since high-performance equipment is required separately for diagnosis and process control equipment, there is a strong possibility that the price will further increase.

As mentioned above, in the past, the process control device and the diagnostic device were configured separately, so the diagnosis and reasoning of the diagnostic device has become more sophisticated, and the accuracy and update cycle of the process control device has become more sophisticated. If signals become necessary, it becomes necessary to add significant equipment and increase the load not only for diagnostic equipment but also for process control equipment, making the system larger and more expensive, and the interface between both equipment becomes more sophisticated.・There was a fear that things would become complicated. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a process control device that can solve the above problems and construct a process monitoring control system having advanced diagnostic functions. [Structure of the invention]

[0007]

[Means for Solving the Problems] The present invention takes into account the increasing speed and capacity of microprocessors, and provides diagnostics that require high-speed and high-precision signal input into microprocessor-applied devices in process control devices. A reasoning section and the knowledge necessary for its diagnosis are provided, and not only control but also diagnosis is performed within this process control device. In addition, the diagnosis results from each process control device are transmitted to a separate diagnostic device, and this diagnostic device performs a conventional diagnosis of a plant consisting of multiple processes, thereby improving the interface between the process control device and the diagnostic device. This is a simplification.

[0008]

[Operation] The microprocessor application device constituting the process control device is provided with not only a control calculation section that performs process control, but also a diagnostic inference section related to signals handled by the process control device, and a knowledge and data collection section for this purpose. Therefore, signals with the same accuracy and update period as those used for control calculations can be easily used for diagnosis. In addition, by outputting diagnostic results from high-speed, high-precision signals within the process control device to the diagnostic device, the diagnostic device can diagnose the entire plant. In addition, the interface between the process control device and the diagnostic device can be simplified.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an embodiment of a process control apparatus according to the present invention. In the microprocessor application device 3 constituting the process control device 2 that controls the process 1, there is a control calculation unit 4' that calculates the control signal 6 from the filament signal 5 from the process 1, and a diagnosis that stores knowledge for diagnosis. A data collection section 9 that collects data from the knowledge base 8, the process 1 and the control calculation section 4', and a diagnostic inference section 10 that makes inferences from these knowledge and data to determine the presence or absence of a failure and identify the location of the failure. The diagnostic inference unit 10 in the process control device 2 uses the accuracy/update cycle feedback signal 5 required by the control calculation unit 4' for process control and the actual control signal 6 that controls the process 1.・It is designed to enable highly accurate diagnosis. Diagnosis results from the process control device 2 are output to the man-machine display device 11 and can also be transmitted to the plant diagnosis device 7. Further, the operator can modify and add to the knowledge 8 in the process control device 2 via the man-machine display device 11, similar to conventional diagnostic devices.

The process control device 2 of the present invention performs diagnosis for each process using signals that are directly connected to the control of each process with high accuracy and a quick update cycle, making it unnecessary to diagnose multiple processes. However, a hierarchical configuration can be constructed in which diagnosis of the entire plant is performed by the plant diagnostic device 7, which does not require highly sophisticated processing of individual signal accuracy or update period. Therefore, on the diagnostic equipment side, there is no particular need to add equipment for advanced signal processing or to strengthen the interface with the process control equipment, making it possible to construct a compact diagnostic and control system for the entire plant.

Furthermore, with the recent increase in speed and capacity of microprocessors in process control devices, it has become possible to construct diagnostic inferences that require knowledge within one microprocessor application device. Furthermore, when it is desired to take action on control based on the process diagnosis results in the process control device, it can be easily and quickly implemented.

As described above, although the above-mentioned embodiment has been described as an example realized by one microprocessor application device, the same effect can be obtained even if it is implemented by two or more microprocessor application devices sharing a bus. is obtained. In this case, for example, two microprocessor-applied devices are installed in a process control device, one for process control and the other for diagnostics, and these two microprocessor-applied devices share a bus, allowing communication between the two devices. This can be achieved by allowing free exchange of signals.

[0013]

[Effects of the Invention] As explained above, according to the present invention,
In addition to process control, process control equipment also provides high-accuracy and high-speed fault diagnosis related to process control, making the entire plant monitoring and control system more compact and without significantly increasing costs. can do. In addition, it is possible to achieve high-accuracy and high-speed diagnosis that is directly connected to control, and to reflect it in control.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a process control device showing an embodiment of the present invention.

[Figure 2] System configuration diagram using conventional process control equipment

[Explanation of symbols]

1... Process, 2, 2', 2a, 2a'... Process control device, 3, 3a, 3b... Microprocessor application device,
4, 4'...Control calculation unit, 5...Feedback signal, 6...
Control signal, 7... Process diagnostic device, 8, 8b... Diagnostic knowledge base, 9, 9b... Data collection section, 10, 10b... Diagnostic inference section, 11... Man-machine display device.

Claims (1)

[Claims] 1. A process control device configured with a microprocessor application device and controlling a process, comprising: a control calculation unit that performs process control calculations; a data collection unit for process signals and control signals used for process control; A diagnostic knowledge base that stores past diagnostic experience regarding signals as knowledge, and diagnostic reasoning that uses the data and knowledge to determine failures and identify failure locations in process control loops related to the signals using empirical methods and statistical analysis methods. Diagnosis that requires high speed and high accuracy using signals related to process control is performed by the diagnostic inference section of one process control device, and the diagnostic results are sent to a diagnostic device that diagnoses the entire plant. A process control device characterized by outputting.