EP4200680A1

EP4200680A1 - Method for diagnosing an open- and/or closed-loop control system, and open- and/or closed-loop control system

Info

Publication number: EP4200680A1
Application number: EP21759090.0A
Authority: EP
Inventors: Christian FIEBIGER; David Wagner-Stürz
Original assignee: Samson AG
Current assignee: Samson AG
Priority date: 2020-08-20
Filing date: 2021-08-13
Publication date: 2023-06-28
Also published as: WO2022038060A1; DE102020121890A1; US20240028023A1; CN116097187A

Abstract

In a method for diagnosing an open- and/or closed-loop control system of a process engineering plant having a plurality of actuating units (1i) for setting a process fluid and a central unit, the following steps are provided: (a) detecting (200) at least one actuating-unit-specific control raw datum, such as a setpoint value (w), an actual value (s), a setpoint-actual difference value (d) or a control value (g); (b) generating (300) at least one more particularly local diagnosis code (D_j, D_ij) by one of the plurality of actuating units (1i) on the basis of the at least one detected control raw datum; (c) transmitting (400) the at least one diagnosis code (D_j, D_ij) from the respective actuating unit (1i) to a central unit (3); (d) transforming (304, 404) a local diagnosis code (D_j), which comes from a particular actuating unit (1_i) and/or relates to a particular actuating unit (1i), into a global diagnosis code (D_ij) in that the local diagnosis code (D_j, D_ij) is linked to an actuating-unit-specific identifier (I_i), (e) defining (603) at least one logical condition for a diagnosis deduction logic (γ) such that when the at least one logical condition is applied to at least one diagnosis code (D_j, D_ij), the diagnosis deduction logic (γ) determines a predetermined deduction result (K), and (f) determining (500) at least one deduction result (K) by means of the diagnosis deduction logic (γ) on the basis of the at least one diagnosis code (D_j, D_ij) in the central unit (3).

Description

Method for diagnosing a control and/or regulation system and control and/or regulation system

The invention relates to a control and/or regulation system for a process engineering plant, such as a chemical plant, for example a petrochemical plant, a power plant, for example a nuclear power plant, a food processing plant, for example a brewery, or the like. The invention also relates to methods for diagnosing a control and/or regulation system.

Typical applications in process control use field devices with control valves, so-called actuators, in order to influence a downstream process towards a specified stationary or dynamic target via changes in the volume or mass flows passing through. Process controllers used for process control do not directly control the mechanical position of the control valve. This is implemented using control routines of subordinate actuators. In a controller cascade formed in this way, the control difference formed as the difference between a process setpoint signal and an actual process value is supplied as an input signal to the higher-level, figuratively the outer control loop, of the process controller. A control method implemented in the process controller is used to generate an output variable from the process control difference, which can be referred to as the process control signal and describes the target position of the control valve. This process control signal is fed to the control device. In addition, the actuator detects a signal representing the actual position of the control valve. From this, the control electronics of the control device determine a control signal for controlling an actuator, for example a control drive of a process fluid pump or a control valve. The control routine of the actuator is set up to compensate for local disturbance variables.

EP 1 451 649 B1 relates to the detection and differentiation of instabilities in an actuator. For an actuator installed in a process environment with position controller, actuator and control valve should be able to detect whether an undesired vibration occurs due to a mechanical fault in the control system or due to an incorrect configuration of a positioner. To this end, EP 1 451 649 Bi proposes detecting signals within the actuator and using an assessment unit to determine the presence and source of instabilities. In order to detect the presence of an instability, the assessment unit should carry out statistical analyses. In order to identify the cause of the detected instability, the assessment unit should use phase angles of causally correlated signals to check whether there is a limit cycle in the control circuit of the actuator. If necessary, the time lag between the signal pressure and the valve position should be determined in order to localize the cause of the error in the actuator. The diagnostic routines described in EP 1 451 649 Bi are typically aimed at causes of errors located within the actuator.

Effects resulting from the interaction of an actuator and its peripherals, for example other actuators or a higher-level process controller, can often only be taken into account incompletely. This makes it difficult to diagnose the causes of the problem in situations in which several control loops in a controller cascade show undesirable behavior. In addition, the diagnosis of an error that is supposedly located in a specific actuator can be an artefact as a result of a malfunction of another actuator or as a result of an operating behavior imposed on the actuator via the process controller. Such artifacts can affect operator confidence in the diagnostic capability of a particular device. Furthermore, such artifacts can result in troubleshooting efforts being directed to an inappropriate approach. Under certain circumstances, this can result in a time delay in troubleshooting or in unnecessary effort due to the erroneous replacement of an actuator that is actually intact. In some cases, experienced operating personnel are able, based on their personal experience and taking into account other circumstances, to guess that an artefact is present which indicates an unstated cause of the problem in another part of the technical infrastructure. Accordingly, a problem or error diagnosis appears desirable, which also allows inexperienced operating personnel to identify the actual cause of the error more accurately. US 7,085,610 B2 relates to an industrial process diagnostic device for identifying a source or root cause of an anomaly in an industrial process. A diagnosis of the process control loops in a process plant is to be determined based on a plurality of process signals in a process plant (including process variables, control signals and diagnostic signals) using a root cause calculation device. The root cause calculation device should carry out an analysis to determine the root cause of an anomaly, for example based on rules or by means of regressive learning, fuzzy logic or a neural network. The root cause calculation device is to be implemented in any process device of a process engineering installation, for example in a transmitter, a controller, a mobile communication device or a computer in a central control room. Often, however, there is not a sufficient number of communication interfaces available for the transmission of a wide variety of process signals. Even if all the required interfaces were available, many process signals cannot be provided arbitrarily due to the limited bandwidth available in typical communication networks of process engineering systems, especially not in real time.

It can therefore be seen as an object of the invention to overcome the problems of the prior art, in particular to provide a diagnostic method and/or a control and/or regulation system that, on the basis of a limited amount of available data, makes an accurate statement about the causes of errors Allowed both within a process engineering system and / or problem or error diagnosis desirable, which allows a more targeted troubleshooting, in particular taking into account empirical values.

The object of the independent claims solves this problem.

Accordingly, a method is provided for diagnosing a control and/or regulation system of a process engineering installation with a plurality of actuators for adjusting a process fluid and a central unit. A process plant can be a chemical plant, for example a petrochemical plant, a power plant, for example a nuclear power plant, a food processing plant, for example a brewery, or the like. A process engineering system includes a central unit and a large number of active and/or passive field devices which are connected to the central unit, in particular unidirectionally or bidirectionally, for signal transmission. An active field device can be implemented, for example, by an actuator for adjusting a process fluid of the process plant. Active field devices are generally set up as actuators to intervene directly or indirectly in a process or sub-process of the process plant in order to influence a process state, for example to stabilize a process state or to bring about a change in the process. An example of an actuator is a valve actuator. A valve actuator comprises a control valve or an open/close valve, it being possible for the control valve to be designed as a lift valve that can be moved in translation or as a swivel valve that can be moved in rotation. A process fluid flow can be interrupted or set to a desired desired value, for example a desired pressure, a desired temperature, a desired speed, a desired volume flow or the like, with a control valve. The process plant can have passive field devices, for example in the form of sensors related to one or different status variables of the process plant or parts thereof. The multiple active field devices of the process engineering system include multiple actuators for adjusting a process fluid. A control device generally has a computing unit, for example position controller electronics, a microcontroller or the like. The central unit also has at least one computing unit, such as a processor. According to one embodiment, the computing units in the multiple actuators or the central unit can be designed to exchange data with one another. If data from a specific processing unit of a specific actuator is processed exclusively by this specific actuator and/or the origin of the data is not clearly recognizable for another processing unit as originating from the specific actuator, the term “local” data is used in the following. Insofar as it is clearly determined throughout the plant, for example with the help of a special identifier, a clear signal transmission path or the like, for at least one other actuating device or the central unit, which specific actuating device has a date or is to be assigned to such a thing, one can speak of a "global" date in the following. Those skilled in the art understand that when a general reference is made to a value, a signal, a datum or the like without express designations of the same as “global” or “local”, the datum described in the particular context, or the like, according to appropriate means, can optionally be local or treated as a global date etc.

The procedure for diagnosing a control and/or regulation system of a process plant with multiple actuators includes the following steps:

According to a step (a), it is provided that at least one actuator-specific raw control data, such as a target value, an actual value, a target/actual difference value or a control value is recorded. A control device can be set up to receive a setpoint value, for example, from the central unit of a central control room of the process engineering installation or from a higher-level controller in a cascade-like manner. The actuator can be set up to record an actual value, for example based on a process state, such as a state of a process medium, for example the process fluid, or a state of a part of the process plant or a component thereof. An actual value can be determined, for example, by a sensor and made available to the actuator. The sensor can be part of the actuator. An example of an actual value can be a position of a valve actuator, a temperature, a pressure, a noise level, a volume flow or the like, for example of the process fluid. A target/actual differential value can be determined using a comparison or differential value formation based on a target value and an actual value. A target/actual difference value can be, for example, a qualitative value such as "too large" or "too small" or "within a permissible range", or a quantitative target/actual difference value, for example a numerical difference between a numerically specified target value and a numerically specified actual value. The control device is set up to determine a control value that is transferred to an actuator of the control device in order to bring about a desired setting of a process fluid. For example, a control value may be determined based on a target value according to a predetermined control routine. It is conceivable that a control value is determined based on a target/actual difference using a control routine. Alternatively, a control value can be calculated directly on the basis of a Nes target value and an actual value are determined according to another control routine. The control raw data is generally actuator-specific insofar as it relates to a section of the process plant or process that interacts with the specific actuator. In particular, such raw control data are actuator-specific with regard to a specific actuator, which undergo processing on a computing device of the specific actuator. A control device-specific raw control data of a specific control device is preferably sent by the specific control device and/or received by the specific control device and/or generated by the specific control device.

The method for diagnosing a control and/or regulation system also includes a step (b) according to which at least one preferably local diagnosis code relating in particular to an anomaly is generated by one of the multiple actuators on the basis of the at least one detected raw regulation data. The local diagnosis code relates to the one specific one of the several actuators that generates the local diagnosis code. Step (b) is preferably carried out subsequent to step (a). It should be appreciated that a variety of raw control data may be generated according to step (a) before a local diagnostic code is generated according to step (b). The generation of a local diagnostic code can be based on one or more raw control data previously generated by the actuator. A diagnostic code may contain a qualitative or quantitative diagnostic statement related to the particular actuator. In a particularly simple case, the local diagnostic code can correspond to a simple binary diagnostic statement such as “error-free” or “incorrect”. The local diagnosis code can refer to the entire actuator, the entire function of the actuator, a part of the actuator or a partial function of the actuator. A diagnostic code can include a quantitative diagnostic statement, for example the behavior of an actuator designed as a control valve during a partial stroke test (so-called partial stroke test, PST) or a full stroke test (full stroke test, FST). characterized. A diagnosis code can characterize the response behavior of the actuator, in particular a regulation routine or a control routine of the actuator, for example with regard to an oscillating, for example overshooting, behavior being recognizable when the actuator is used; regarding the reaction on time between the specification of a specific target value or target value profile with regard to an intended actual value or actual value profile; for example a step response or the like. A large number of different diagnostic methods and/or diagnostic statements relating to actuators are known to those skilled in the art. A diagnosis code can be related to a particularly critical malfunction of the actuator, for example an interruption, such as a break in the actuator rod or/and shaft. A diagnostic code may relate to a process variable that is outside of a permissible range, for example a pneumatic supply pressure, a supply voltage, a temperature, vibration or the like. The diagnostic code preferably includes an anomaly-specific diagnostic statement that identifies the anomaly.

Furthermore, the method for diagnosing a control and/or regulation system includes a step (c), the at least one diagnosis code being transmitted from the respective specific actuator to the central unit. In the method, the step (c) of transmitting is performed following a step (b) of generating the diagnostic code by one of the plurality of actuators. It can be preferred that the transmission according to step (c) takes place immediately, ie in a short time after a generation step (b) has been completed, for example within less than an hour, in particular less than 30 minutes, preferably less than 10 minutes. more preferably less than 1 minute, more preferably less than 30 seconds and most preferably less than 5 seconds. It is clear that a large number of diagnostic codes can be generated in a process engineering system before at least one specific diagnostic code is transmitted from a respective actuator to the central unit. Alternatively, each diagnosis code generated by the actuators of the process engineering system can be transmitted from the respective actuator to the central unit. It is conceivable that a first group consisting of one or more critical actuators is set up to transmit each diagnosis code generated by the group of actuators from the respective critical actuator to the central unit. Alternatively or additionally, it is conceivable that a second group consisting of at least one or more other actuators is set up to transmit the respective diagnosis code of the other actuator to the central unit only if a specific further transmission criterion is present. to transmit, for example in response to a request to the actuator, preferably from the central unit, in response to the presence of a predetermined diagnostic code, in the presence of a combination of predetermined diagnostic codes, at predetermined time intervals or at predetermined times, or a combination of the above sending criteria. The respective control device can be set up to transmit a local or a global diagnosis code to the central unit.

The method for diagnosing a control and/or regulation system also includes a step (d), wherein a local diagnostic code originating from a specific actuator and/or relating to a specific actuator is transformed into a global diagnostic code by the local diagnostic code with a actuator-specific identifier is linked. It is conceivable that the central unit is set up to link a transmitted local diagnostic code with an actuator-specific identifier, for example if the central unit can clearly assign a received diagnostic code to a specific actuator using a particular time and/or syntactic assignment . The provision of an identifier and the linking of a unique identifier with local diagnostic codes in order to upgrade a local diagnostic code to a global diagnostic code is particularly useful in process engineering systems in which the central unit is connected to several identical or similar actuators which, for example, have the same design, can be of the same type or similar and/or are formatted similarly or in the same way in their respective local diagnostic codes

In addition, the method for diagnosing a control and/or regulation system according to step (e) includes defining at least one logical condition for a diagnosis deduction logic, so that with the diagnosis deduction logic when the at least one logical condition is applied to the at least one diagnosis code, preferably to multiple diagnostic codes, a predetermined diagnostic result is determined. In a simple case, a deduction logic can be defined according to an if-then logic, the deduction logic being based on the presence of a specific diagnostic code, in particular a specific global diagnostic code considers an if-condition as fulfilled and determines an associated then-deduction result.

Logical conditions for the diagnosis deduction logic can be defined according to a binary logic, a so-called fuzzy logic, or the like. A diagnostic deduction logic can be defined, for example, based on two-way match rules, three-way match rules, multiple match rules, non-match rules, group (wildcard) rules, etc. according to one or more logical conditions. A two-match rule can, for example, assign a specific deduction result to the presence of two specific diagnosis codes. The same applies to a rule of three or other multiple matches. A non-match rule can define as logical conditions that a predetermined inference result is assigned to the non-existence of a combination of different specific diagnosis codes. A group (wildcard) rule can, for example, define logical conditions such that when a predetermined minimum number of a predetermined set of specific diagnostic codes is present, for example at least two specific diagnostic codes of a predetermined set consisting of three specific diagnostic codes, an associated specific deduction result is determined. The diagnosis deduction logic preferably implements a persistent mapping of expert knowledge. Defining diagnostic deduction logic includes providing machine-coded rule descriptions, in particular based on expert knowledge, for describing the behavior of one or more components of a process engineering installation, in particular in interaction with one another.

According to the method for diagnosing a control and / or regulation system, after defining the one or more logical condition (s) for the diagnosis deduction logic in step (e) based on the definition made in step (f) at least one deduction result by means of the inference logic based on the at least one diagnostic code in the central unit. The central processing unit is set up to implement the diagnosis deduction logic. At least one deduction result is determined by the central unit using the diagnostic deduction logic on the basis of the local or preferably global diagnostic codes that are available to the central unit. The central unit applies the one logical condition or the several ren logical conditions of the diagnosis deduction logic on at least one, preferably several, in particular related to anomalies, diagnosis code to determine one or more deduction results.

According to one embodiment, step (f) includes the determination of at least one deduction result that the determination takes into account at least a first global diagnostic code from a first actuator and at least a second global diagnostic code from a second actuator. In particular, a large number of different global diagnostic codes from a large number of different actuators can be taken into account in step (f) determining.

According to another embodiment, which can be combined with the previous one, step (f) determining at least one inference result can include the central unit considering a set of global diagnostic codes in order to form an inference result from a modified set of the diagnostic codes considered. The modified set of diagnostic codes corresponds to the set of global diagnostic codes minus at least one of the global diagnostic codes of the set and/or plus at least one central diagnostic code. A modified set of diagnostic codes can be formed from an existing set of global diagnostic codes by deleting a global diagnostic code and/or adding a central diagnostic code by the central unit and/or replacing a global diagnostic code with a central diagnostic code. The deduction logic can, for example, be equipped with a logical condition which, given a predetermined constellation of specific global diagnosis codes, recognizes that a diagnosis result is falsely positive and deletes the global diagnosis codes recognized as falsely positive. Alternatively or additionally, the deduction logic could be set up to recognize a predetermined constellation of global diagnostic codes in a set of global diagnostic codes that there is another error that is not manifested in the global diagnostic codes, and to assign a new central diagnostic code with regard to this additional error respectively. According to a further embodiment, step (b) includes generating that the at least one local or global diagnosis code is related to an anomaly on the basis of the at least one raw control data. Step (b) also includes an anomaly description step, in which at least one indication of the anomaly is determined on the basis of raw control data. Step (b) generating the at least one diagnostic code includes that the diagnostic code is given information, in particular a diagnostic statement, about the type of anomaly, the cause of the anomaly and/or about a diagnostic and corrective measure relating to the anomaly will. Under certain circumstances, the central unit can use the diagnostic statement as an identifier of the diagnostic code for clear assignment to a specific actuator.

According to one embodiment, the method also includes a quality determination step, in which at least one quality index is calculated on the basis of raw control data, step (b) generating the at least one diagnostic code including a quality index being impressed on the diagnostic code. A quality index can, for example, be a statistical control deviation, reaction time, a number of overshoots, an amplitude of a maximum overshoot, an integral value with regard to the amount of the control deviation, a statistical moment, in particular the nth statistical moment of the control deviation and/or fuzzy Set assignments affect. A quality number can be related to a local time or a global time. Generating the diagnostic codes, which are in particular local, can include the calculation of at least one quality number or a plurality of quality numbers from the raw control data, in particular after the raw control data have been recorded. The diagnosis deduction logic can be set up to take a quality index into account. Using a diagnostic routine to generate a diagnostic code can include loading data for describing analysis rules from a particularly local memory of an actuator, preferably a valve position controller, and processing a quality index according to the loaded analysis rules.

According to one embodiment of the method, the global diagnosis code is formed by the actuator when generating or sending the local diagnosis code. Alternatively, in the method described above, the global diagnostic code can be changed from a Communication device are preferably formed when transmitting the local diagnostic code in particular re from the actuator to the central unit. Alternatively, the global diagnosis code is formed by the central unit when receiving a local diagnosis code or when determining the at least one deduction result. It is conceivable that an actuator is set up to link the diagnostic code to an actuator-specific identifier as early as step (b) of generating a diagnostic code, so that the diagnostic code is already in step (c) of transmitting the diagnostic code from the specific actuator the central unit is implemented as a global diagnosis code and can thus be clearly assigned by the central unit to the actuator on whose actuator-specific raw control data it is based. Alternatively or additionally, the transformation of the local diagnostic code related to a specific actuator or originating from a specific actuator can take place during step (c) when the diagnostic code is transmitted to the central unit, for example by sending the diagnostic code via a dedicated signal transmission line from one actuator to the receiving central unit is transmitted, so that based on the signal input of the central unit, an identifier is available for the central unit, which can be used to understand a clear assignment of a diagnostic code to a specific actuating device for the central unit. It is conceivable that the transformation of a local diagnostic code according to step (d) takes place between the generation of the local diagnostic code according to step (b) and its transmission according to step (c), for example by a generated diagnosis code is linked to an identifier.

According to one embodiment of a method according to the invention, step (b) generating the at least one diagnosis code includes taking into account a temporal relationship, such as simultaneity, sequence or time series, of at least two control raw data for generating the diagnosis code. A sequence can in particular relate to at least three, at least five, at least seven or more control raw data occurring one after the other. It is clear that a time relation can be related to a global time, which is taken into account by the central unit, for example, or to a local time of a specific actuator. According to one embodiment, the at least one in particular local diagnostic code generated by a specific actuator can be correlated to an actuator-specific local time, in particular in step (b) of generating the diagnostic code. A local time can be defined by a timer of the actuator itself, for example. A local time can be defined as a local point in time, for example using an actuator-specific time stamp, as a local time period, for example from a local start time to a local end time, as a local time window after an actuator-specific event and/or as a local periodic time interval. The central unit can be set up to apply at least one temporal condition, for example based on a simultaneity, an order or a succession of diagnostic codes based on a local time on the respective specific actuator. The central deduction logic can be set up, for example, to diagnose diagnostic codes of the same actuator over time, for example over the course of a month or a year, taking local time information into account, in order to detect a change in the behavior of the actuator during its service life.

According to one embodiment of the method, at least one diagnostic code is correlated to a global, in particular absolute, time. A global time can relate to a global time stamp, a global time period from a global start time to a global end time, a global time window after a specific event or a specific periodic time interval. The correlation of a diagnostic code to a global time can be performed when generating (b) the diagnostic code, when transmitting (c) the diagnostic code or when determining (d) the inference result. In a method in which diagnostic codes are correlated to a global time, it can be preferred that all diagnostic codes taken into account by the deduction logic or at least some of the diagnostic codes taken into account by the deduction logic are correlated to a respective global time. The diagnosis of the deduction logic can in particular be designed to apply at least one or more logical rules with time criteria (for example relating to simultaneity, a sequence or the like) exclusively to global diagnosis codes in particular that are correlated to a global time. In this way, for example, an error cascade can be detected early, which is in the Occurrence of certain system component errors in a certain sequence.

According to one embodiment, step (f) determining at least one inference result includes the diagnostic inference logic being associated with and applied to a set of global diagnostic codes, the diagnostic inference logic taking into account at least one temporal condition related to global time, for example a temporal one Simultaneity, sequence or time series of at least two predetermined global diagnostic codes. The inference logic can be set up to apply temporal conditions related to global diagnostic codes of the same actuator. Alternatively or additionally, the deduction logic can be set up to apply at least one temporal condition related to at least two global diagnosis codes of different actuators.

According to a development of the method, the local time can be defined as a local time window with an opening time that is determined as a function of a predetermined process signal result or raw control data, for example a predetermined signal curve of a setpoint value, such as a step response, a sine response or a ramp response or, for example, a predetermined signal curve of an actual signal, such as a sudden change in load. The local time window can also be defined with an opening period.

According to another development that can be combined with the previous one, a local time can be defined as a particularly periodically recurring local time interval, such as a discrete control cycle of a digital control device, with a constant manipulated variable of one control being used in particular during the discrete control cycle - And/or control electronics of the controller are provided to a controller actuator of the controller. In particular, the manipulated variable is calculated using a target value, an actual value, a system deviation defined by the difference between the actual value and the target value, and a control routine that takes the system deviation into account, such as a PID control routine. According to one embodiment of a method, a computing unit of an individual specific actuator is used both for generating (b) at least one diagnostic code, in particular local, and for determining (f) a deduction result, taking into account at least one other diagnostic code from at least one other actuator. In other words, an actuator of the process engineering system can be used in functional union both as an actuator and as a central unit.

The invention also relates to an open-loop and/or closed-loop control system for a process engineering installation that includes a number of actuators, a central unit and a communication unit for transmitting at least one diagnostic code from the number of actuators to the central unit. Each actuator comprises a control valve for setting a process fluid flow and a computing unit that is set up to actuate the control valve on the basis of at least one raw control data according to a control and/or regulation routine. The arithmetic unit is also set up to generate at least one, in particular local, diagnosis code, preferably relating to an anomaly, on the basis of at least one raw control data item according to a diagnosis routine. The central unit is set up to receive at least one logical condition for application to at least one diagnosis code as diagnosis deduction logic and to determine a diagnosis deduction result according to the diagnosis deduction logic on the basis of the diagnosis codes provided by the multiple actuators.

According to a further development of a control and/or regulation system, the central unit is integrated in one of the actuators, in particular in an arithmetic unit specific to the actuator. According to another embodiment of a control and/or regulation system, the central unit is implemented separately from the actuators in a computer, such as a process control computer, a remote server, a workstation computer, a tablet computer or the like. The central processing unit can be configured in such a way that the diagnostic deduction logic is only applied after the central processing unit has a predetermined minimum number of, in particular, global diagnostic codes. A minimum threshold can be defined, for example, as the product of the number of actuators that communicate with the central unit with a a predetermined factor such as 5, 10, 50, 100 or 1000 in relation to the number of diagnostic codes from the actuator. Alternatively or additionally, a minimum threshold value can be defined on the basis of a minimum period of time, such as an hour, a day, a week or a month, within which the diagnostic codes were continuously transmitted from the control devices of the process engineering system to the central unit.

According to another embodiment of a control and/or regulation system, which can be combined with the previous ones, the control and/or regulation system is configured to carry out the method described above.

Further features, properties and advantages of the invention are made clear by the following description of a preferred embodiment of the invention, in which:

FIG. 1 shows a schematic representation of a control and/or regulation system;

FIG. 2 shows a schematic representation of a method for diagnosing a control and/or regulation system; and

FIG. 3 shows an exemplary input mask of a user interface of a control and/or regulation system.

In the following description of the preferred embodiment with reference to the figures, the same or similar reference symbols are used for the same or similar components.

The invention generally relates to carrying out a control loop analysis based on diagnostic codes from different actuators, which were generated in the individual actuators based on raw control data from the respective actuator. The control loop analysis is to apply a deduction logic to the diagnosis codes for diagnosis in order to infer a diagnosis deduction result. It won't be the real one Control raw data but diagnostic codes of the control loop analysis based. In many cases, the raw control data is either not available at all or the technical effort required to acquire the raw control data cannot be implemented for economic or technical reasons, for example because the required bandwidth for transmitting the raw control data is not available in the process plant or because the available bandwidth is absolutely necessary for the operational control and/or regulation of the components of the process engineering system. The diagnosis deduction logic maps expert knowledge relating to a process plant. The expert user maps his knowledge of relationships between diagnosis codes of the actuators, in particular valve position controllers, persistently in the form of one or more logical conditions and actions derived therefrom, which form the diagnosis deduction logic. Using the diagnosis deduction logic, a consolidated diagnosis statement about an appropriate overall measure at a hierarchical level of the process plant, for example for troubleshooting or prevention, can be derived on the basis of a collection of received and stored, in particular global, diagnosis codes in a central unit. The application of diagnostic deduction logic to one or more diagnostic codes thus implements a type of meta-diagnosis in order to support the user of a central unit, for example monitoring personnel in a control room, in assessing a system status.

FIG. 1 shows a schematic representation of a process plant 100 by way of example. The representation of the process engineering plant is reduced to selected components for monitoring and influencing the plant process. It is clear to the person skilled in the art that the process engineering system includes numerous other components, not shown, for carrying out the system process, such as safety devices, containers, heaters, reactors and pipelines, which are not shown in detail here.

The process engineering system 100 includes a plurality of actuators 1i, 1x, 1y, IZ and a central unit 3 connected thereto. The actuators 1 shown in FIG. The index i, with which the control devices 1 and their components 13, 15 are labeled, is a placeholder for a to understand actuator-specific identifiers. The indices x, y and z designate different actuators 1.

A control device 1i is preferably set up as a control valve lii for setting a process fluid flow. A computing unit 13i or control and/or regulation electronics is set up to actuate the control valve 11i on the basis of raw control data according to a control and/or regulation routine. For this purpose, the arithmetic unit 13i can provide a pneumatic control signal g, for example, to a pneumatic control actuator 15i, for example, which causes a control travel and/or a control force of the control valve lii. The arithmetic unit 13i can have one or more sensors, not shown in detail, which detect actual values s, such as an actual position of the control valve 11i.

The actuator 1i can be connected to a central control room 103 which provides the actuator 1i with a command signal w via the communication network 5 . The computing unit 13i can be designed to generate the control signal g on the basis of the reference signal w and an actual signal s. In this example, the actual signal s, the command signal w or setpoint signal and the control signal g produce raw control data for the control valve 11i. It is conceivable that a computing unit (not shown in more detail) upstream of the actuating device 1i receives the setpoint variable or the command signal w from the control room 103 and an actual value s from a sensor in order to calculate a setpoint-actual difference d to form, which can be transferred to the processing unit 13i. The arithmetic unit 13i can be designed to carry out a control routine R on the basis of a received target/actual difference d in order to determine the control signal. A target/actual difference d can also be considered as raw control data of the actuating device 1i. The signal processed by the arithmetic unit 13i, for example an actual signal s, a target signal w, a target/actual difference d and a control signal g, are raw control data specific to the actuator 1i.

The computing unit 13i is also designed to carry out one or more diagnostic routines R in order to generate diagnostic codes Dj, Dij based on the raw control data. The diagnostic codes relate to the actuator 1i and can, for example, indicate either correct or incorrect behavior of the actuator 1i cha- characterize. A diagnostic code Dj, Dij specific to the actuator 1i can describe the behavior of the entire actuator 1i or only part of the components and/or functions of the actuator 1i.

The computing unit 13i can include a processor 133 and a memory 130 as well as a network interface 134, for example. The computing device 13i can be implemented as a microcontroller, for example. The arithmetic unit 13i of the actuator 1i is set up to perform various functions, for example a control routine R and at least one diagnostic routine(s) D. Both the control routine R and the diagnostic routines D are executed by the arithmetic unit 13i on the basis of the raw control data w , s, d and g performed.

The diagnostic routine D can, as shown in FIG. The quality index Q can characterize the quality of the control routine R, for example. In the present example, the diagnostic routine D can be related, for example, to the step response of a control signal g to a step-like changing target signal w over the course of the global time T between a global start time Tstart and a global end time Tend.

In an exemplary embodiment, the valve actuating device 11i can comprise the electrically controllable supply and/or discharge of a medium, in particular a pneumatic fluid, to and/or from the in particular pneumatic actuator 15i. For this purpose, the position controller electronics 13i can comprise an electropneumatic converter and/or a pneumatic relay. According to an alternative embodiment, an electric actuator such as an electric setting drive can be provided as the actuator 15i. According to another alternative embodiment, a hydraulic actuator such as a hydraulic servo drive can be provided as actuator 15i.

The control room 103 of the process plant 100 also has a central processing unit 113. The central processing unit 113 includes a memory 140 and a processor 141. Processor 141 and memory 140 of the central processing unit 113 the numerous actuators 1i, 1x, 1y, 1Z can be set up to implement process control functions R _p and/or control circuit diagnosis functions D _p that are higher in level. The central processing unit 113 can generate one or more reference variables w by using a process control routine R _p . The reference variables w are made available to the individual control devices 1i via the communication network 5 from the control room 103 .

The control devices 1i can transmit their local or global diagnostic codes Dj, Dijj to the control room 103, which are stored in a central memory 140 of the control room 103 as a set of diagnosis codes can be stored. The set of diagnostic codes of the in the memory 140 of the control room 103 according to FIG. 1 is stored in such a way that each diagnostic code Dijj is assigned an actuator-specific identifier L, so that it is a global diagnostic code Dijj. The global diagnosis codes Dijj are each assigned global time information T, with the example shown in FIG.

The global diagnosis codes D stored as a set by the control room 103 are generated by the actuators 1i in the examples shown in FIG. 1 and linked to an actuator-specific identifier li when generated by the respective actuator 1i and assigned a global time Tstart, Tend. The diagnostic codes Dijj generated in this way are transferred from the actuating device 1i to the communication network 5 for transmission to the control room 103 by means of a network interface 134 of the processing unit 13i.

The process engineering installation 100 has a central unit 3 with a control database RDB, in which a diagnosis deduction logic γ manifests itself. The diagnostic deduction logic γ can be defined as a set of logical rules or conditions BED, with each of the logical rules being assigned a predetermined action AKT. By applying the diagnosis deduction logic γ to the set including numerous diagnosis codes D the conditions BED of the diagnosis deduction logic γ are applied to the diagnosis codes D. If one or more of the conditions BED is met by the set of diagnosis codes D, each of a specific condition is BED associated action AKT implemented to determine a diagnosis deduction result K.

In the example according to FIG. i, the central unit 3 is formed as a separate unit relative to the actuating devices 1i. It should be clear that a central unit 3 can also be implemented as part of a specific one of the many actuators, for example the actuator 1z marked with the index z, which can be referred to as the central actuator. Alternatively, the central unit 3 can be implemented as part of the processing unit 113 of the control room 103 . It is conceivable that a central unit 3 is implemented by a workstation computer 105, for example.

An expert and other users of the process plant can interact with the process plant 100 using one or more workstation computers 105 . To simplify the illustration, the workstation computer 105 in the previous example according to FIG. 1 is connected to the same communication network 5 as the other parts of the process engineering installation 100 shown. summarize, hierarchically structured networks, or can have a different network topology than the one shown. For example, the control room 103 can be connected to the workstation computer 105 via a first network and to the actuators 1i via a second network. In Figure 1, the communication network 5, which connects the actuators 1i and the control room 103 is shown according to a bus topology. It is clear that the communication network 5 can be partially or fully implemented according to another topology, for example ring-shaped, linear, meshed, star-shaped or tree-shaped. The communication between the actuators 1i and the control room 103 can be implemented as direct single-hop communication from each individual actuator to the control room or as multi-hop communication, with one or more actuators as a communication link between the Control room 103 and the specific actuator are provided. It should be clear that mixed forms of topology and/or signal transmission can also be implemented. The bandwidth available for data transmission is particularly limited in the case of process engineering systems that work at least partially with multi-hop signal transmission limited by the actuators to a central unit 3, so that the diagnostic method according to the invention can be useful.

The diagnosis deduction logic γ can be defined by an expert user with the aid of the workstation computer 105, for example. The definition of the diagnostic deduction logic γ can be implemented by defining a logical condition that determines an assignment of one or more diagnostic codes Dijj to a deduction result K. The diagnosis deduction logic γ can include a multiplicity of different logical conditions BED. Each logical condition BED can be associated with an action AKT, which indicates the deduction result K of the respective condition BED. The sum of the actions AKT determines the entire deduction result K.

The number of actuators 1i, in particular the valve actuators lii, and process computer 103 and the topological design of the network 5 are examples and should not be understood as a limitation of the method according to the invention for diagnosing the system 100. Process computer 103 can be implemented as a DCS or PLC, for example.

The central processing unit 3 and the management device 103 can be set up to exchange data between the diagnosis deduction routine and the control program. A data exchange between the central unit and the central computing device 113 can be implemented in particular when the control room 103 and the central unit 3 are implemented in a functional union. For example, the diagnosis deduction routine can be designed to accept and/or store process data from the control program RP ZU and/or to correlate, in particular with diagnosis codes, for example in terms of time, and to use this as a basis for determining a diagnosis deduction result K.

The logical conditions BED and the actions AKT assigned to them can be stored as machine-coded rule descriptions in the rule database RDB of the central unit 3 . In embodiments, the machine coding can be implemented by externally structured and, in particular, firmly formatted data records or by explicitly structured data records such as XML, for example. The diagnostic deduction logic γ can be defined, for example, on the basis of conditions that determine the behavior of multiple diagnostic codes with a logical relationship, such as an "AND" relationship, a logical "OR" relationship, a logical "EXCLUSIVE-OR" link relationship. Logical conditions BED of the diagnostic deduction logic γ can include logical operators such as “NOT” or “EXCLUSIVELY” in relation to at least one diagnostic code Dijj. Logical conditions BED of the diagnostic deduction logic γ can include links, groupings, parentheses and other semantic structuring.

A control program Rp can be contained in the memory 140 of the control room 103 or another central unit 3, which is continuously executed in order to monitor and/or influence the system process or a part thereof. The control room 103 can provide reference variables w for the various actuators on the basis of the control program Rp. The memory 140 of the control room 103 can also contain a diagnostic program which implements functions A for receiving local diagnostic codes Dj and/or global diagnostic codes Dijj and rule processing. Furthermore, a reporting unit C can be provided, with which a diagnosis result can be further processed into a desired representation, for example for a workstation computer 105 . At least one diagnostic result K can be displayed on the workstation computer 105 in an obvious graphical representation. The diagnosis result K can be supplemented by data elements with which a direct influencing of the process plant 100 can be effected by machine processing.

FIG. 2 shows a schematic flowchart of an embodiment of a method according to the invention for diagnosing a control and/or regulation system of a process engineering installation. The flowchart shown in FIG. 2 represents a greatly simplified sequence in which only the method steps carried out by a first actuator 1i and a central unit 3 are shown. It should be clear that the steps or similar steps shown here only with regard to a single exemplary actuator 1i can be implemented by the many different actuators 1i, 1x, 1y, IZ, et cetera of the process engineering system 100. The steps carried out by the various units of the system, ie the many different actuators and the central unit 3, can be carried out independently of one another by independent computing units of the various system components, in particular independently of one another in terms of time, for example simultaneously or one after the other. It should be clear that method steps that are carried out in cooperation by several system components, namely the communication 400 between a control device 1i and a central unit 3, take place in particular with the components involved being coordinated in terms of time.

The step 400 of communication or transmission of at least one diagnostic code Dijj from the actuator 1i to the central unit 3 includes the sending 401 of the diagnostic code Dijj by the actuator 1i and the reception 403 of the diagnostic code Dijj by the central unit 3. The transmission step 400 or its sub-steps Sending 401 and/or receiving 403 include that an actuator-specific identifier Ii is impressed 404 on a transmitted local diagnostic code Dj in order to upgrade the diagnostic code to a global diagnostic code Dijj.

The linking of the actuator-specific identifier Ii to the local diagnostic code Dj can be performed on the software side, for example by a transformation routine linking a local diagnostic code Dj without an identifier to one on the actuator li to which the local diagnostic code Dj belongs. Alternatively or in addition, the transformation step can be performed on the hardware side, for example by transmitting a local diagnostic code Dj from a specific actuator 1i to the central unit 3 by means of a dedicated signal input of the central unit 3 or one of the central unit 3 upstream, not shown Component takes place, so that the receipt of a local diagnostic code Dj without a device-specific identifier at a signal input exclusively assigned to the control device 1i causes a transformation of the local diagnostic code into a global diagnostic code Dij. Before a local diagnosis code Dj is transmitted from the actuating device 1i to the central unit 3 in accordance with step 400, the position controller 13 must first be made available for dispatch 401.

By connecting a local diagnosis code Dj to a device-specific identifier Ii, the diagnosis codes are upgraded to global diagnosis codes Dijj, which can be traced back to a specific device 1i within the process engineering system 100. The central unit 3 can use the identifier Ii to classify a global diagnosis code Dijj in a technical context, which can be assigned, for example, to a model of the overall technical process of the process engineering installation 100 or parts thereof. In this way, a causality between an observed behavior of different actuators 1i can be derived. In this way, it is easier to draw conclusions about the causation of an abnormal behavior of an actuator than with exclusively local data. For example, a reference to a specific actuator 1i, on which abnormal behavior is observed, can simplify a diagnosis with regard to the question of whether the abnormal behavior of the specific actuator is solely due to its specific deviation from a good state for the anomaly is the cause or whether a contribution from another actuator or another area of the process engineering system is at least partly the cause.

According to one embodiment of a method according to the invention, it can be provided that first of all a local time t is defined by the actuating device. In the case of an actuator 1i with an actuator electronics 13i that uses a microcontroller or the like, this can be done, for example, by using a timer or the like of the computing unit 13i. For the sake of completeness, it should be noted that it is conceivable that the control unit 1i can be provided with a definition of a global time T by the central unit 3 or the process control room 103, in particular at regular intervals or at specific times or events 1i can serve as an alternative to or in addition to a local time t (not shown in detail). At least one raw control data item specific to the control device is detected in a detection step 200 by the control device 1i. It is clear that an actuator 1i can carry out a large number of detection steps 200 . In terms of the present inventive method, the composition 200 can, for example, receive a target value w, receive or measure an actual value s, receive or determine a target-actual difference value d and/or determine a Control value g include in particular by means of a control routine or a control routine R.

The control routine R can be implemented in a method step 250 together with the detection 200 or subsequent thereto. As explained above, the regulation generally takes place in that a control value g is calculated on the basis of a target value w and, if applicable, an actual value s or on the basis of a prepared target/actual difference d. The control value g can be calculated, for example, according to a so-called proportional-integral-derivative control (PID control).

The actuator 1i also carries out a method step according to which a diagnosis code Dj, Dij is generated. FIG. 2 shows an example of how a local diagnosis code Dj is generated with the actuator 1i in step 300 and its substeps. It should be understood that generating 300 the diagnostic code can include, as an optional step 304, transforming the diagnostic code Dj generated by the actuator with an actuator-specific identifier Ii so that the actuator immediately generates a global diagnostic code Dij.

The diagnosis code can be generated 300 by means of a diagnosis routine D. It is clear that the actuator 1i can be set up to carry out at least one diagnostic routine D or a large number of different diagnostic routines relating to the entire actuator or only to parts of the actuator or partial functions of the actuator. In the exemplary embodiment shown here, to generate 300 the local diagnostic code Dj, the local time t previously defined by the actuator is correlated to the diagnostic code Dj. In many digital actuators, in many cases, work in control cycles, with a diagnostic routine within be carried out in a control cycle and can thus be assigned to it, with a diagnostic routine R being able to correspond to a sequence of several control cycles. By correlating the control routine R to one or more control cycles or a locally (or global) time t (or T) defined in some other way, the diagnostic code Dj (or Dij)j generated by the diagnostic routine D can be generated at a local time t ( or a global time T) can be correlated.

A diagnosis code can be correlated to a local time t, for example, in relation to a time t or a very special periodically recurring time interval d or a time window with an opening time tFij and an opening duration dtFij.

Based on the correlation at a particular local time t, the diagnostic routine D can be set up to take into account a temporal relationship between a number of different raw control data relative to one another in a diagnostic step 309 . An exemplary example is a diagnostic routine that relates a time profile of a setpoint value w or a control difference d on the one hand to an actual value s or a control signal g on the other hand for a predetermined point in time or period of time, in particular for a diagnosis with regard to the control response effected in the actuating device 1i to a specified setpoint signal curve. Another example of a consideration 309 of a temporal correlation of raw control data can include that at regular intervals, in particular, an assignment of certain target signals w (e.g. a target position) to the control signal g generated by the associated actuator 1i (e.g. a control pressure for a pneumatic Stellaktor 15i) is considered to check whether the behavior of the control valve 11i changes over time. For example, signs of wear on the actuator mechanism or leaks in the pneumatic supply can be detected. In many cases, the consideration 309 of the temporal relationship of raw control data can be connected with the collection 303 of an indication of an anomaly, for example in the form of a diagnostic statement.

When performing a diagnostic routine D in step 300, the actuator can determine an anomaly from the raw control data and according to diagnostic routine step 303 impress a diagnostic code on one or more specific detected anomalies, for example as a diagnostic statement. It is clear that a diagnosis routine D can alternatively come to the conclusion as a result of the diagnosis and thus as a diagnosis code that there is normal behavior and therefore no anomaly. An anomaly generally describes a deviation from error-free normal behavior of an actuator. An anomaly can be present, for example, in the form of a control response to a setpoint value w or a control difference d (for example, the control response can exhibit overshooting behavior). Alternatively, an anomaly can be detected if the control response to a specified target signal w or a control difference d is slower than expected. The diagnostic routine D can be implemented, for example, as a partial stroke test, it being possible to determine whether, for example, there is an undesired behavior of the mechanics and/or the pneumatics of a control valve lii.

The diagnosis routine D can include a quality determination step 307, in which a quality index Q is calculated on the basis of the raw control data and is applied to the diagnosis code Dj, Dijj. The quality indicator Q can characterize the quality of the controls implemented in practice compared to an ideal situation. It is clear that the diagnostic routine for generating a single diagnostic code can determine several quality indicators Q and impress them on the diagnostic code Dijj. For example, in step 307 a predetermined number of quality indicators Q can be calculated. As an alternative or in addition, the calculation of one or more further quality indicators Q can be carried out as a function of conditions on the previously calculated quality indicators Q. The assignment of one or more calculated quality parameters Q to one or more diagnosis codes Dj can be implemented by using a local memory 130 of the electronic control system 13i as a program part or a decision tree stored as a parameter set. For example, for valve positioner 13, reference is made to Samson TROVIS VIEW and Samson SAM CHEMICALS for exemplary diagnostic routines. The product names may be registered trademarks. After the actuating device 1i has generated one or more diagnosis codes Dijj in at least one or a multiplicity of generation steps 300, the transmission 400 of diagnosis codes Dijj described above can be carried out.

The initial definition 609 of at least one global time T is carried out with the central unit 3 . A global time T can be implemented in a simple case using an unambiguous date and time specification. Numerous other approaches are conceivable. For example, a global time T can be defined as a system time depending on a global event relating to the process plant 100, for example an initiation event, a maintenance time or the like.

Several different local diagnosis codes of different actuators 1i, 1y, 1x, 1Z from the same test period can be aggregated by the central unit 3 to form a data packet. This data packet can contain additional information about a time, for example a time interval of the acquisition of the underlying raw process data, in order to allow a chronological classification of the various diagnostic codes relative to the absolute time T or to a synchronized time based on a local time t - ben, which can be used as a common pseudo-global time of the various actuators.

In a step 603, a diagnosis deduction logic Y is defined with the inclusion of the central unit 3. The definition 603 of the diagnosis deduction logic γ comprises the assignment of at least one logical condition BED to at least one preferably global diagnosis code Dijj and at least one action AKT resulting from the present condition BED for generating a diagnosis deduction result K. The definition 603 of the diagnosis deduction logic γ can include that a multiplicity of conditions BED related to one or more diagnostic codes Dijj and actions AKT resulting from the presence of the respective conditions are determined.

The central unit 3 is set up to carry out a determination of a diagnosis result K in a method step 500 . When determining 500 becomes the diagnostic deduction logic γ is applied to the diagnostic codes Dijj present in the central unit in order to determine which conditions BED are met and to derive the resulting actions AKT. The diagnosis deduction result K results from all of the actions AKT to be implemented.

To determine 500 the diagnosis result K, the diagnosis code Dijj is assigned to a respective diagnosis code-specific global time T. A global time T for a respective diagnosis code Dijj can be defined, for example, as at least one point in time T, a regularly recurring interval, or using a one begin at a specific point in time Tstart and a time window lasting for a specific period of time dT can be defined. The assignment 506 of a global time T to a diagnosis code Dijj can be omitted within the framework of the determination 500 if a corresponding assignment has already taken place, for example, in the individual actuators 1i.

The determination 500 also includes forming a set of jj from particular global diagnosis codes in order to apply the diagnosis deduction logic γ to this diagnosis code set.

The determination 500 of the diagnostic result K includes in particular the application 505 of at least one condition BED to the at least one diagnostic code Dijj and the implementation 509 of the resulting actions AKT. An action AKT can specify, for example, that one or more predetermined diagnostic codes Dijj be deleted when a specific condition BED is present. This can be useful, for example, to eliminate diagnostic codes recognized as false positives. Alternatively or additionally, an action AKT can determine that a specific central diagnosis code D _c is generated by the central unit 3 when a specific condition BED is present. Such a generation of a central diagnosis code can be expedient, for example, if it is clear from expert knowledge that the presence of one or more specific diagnosis codes _Dijj is another or another undesired state in the process plant 100 to which the central diagnosis code Dc relates. Another action can cause the replacement of a diagnostic code Dijj with a central diagnostic code D _c in the presence of certain conditions BED, which can be considered a combination of the deletion and addition described above. Such an action can be implemented, for example, as part of the determination of a diagnosis deduction result K if it is clear to the expert based on existing diagnosis codes Dijj that a different state than that specified in the specific global diagnosis code Dijj is present, which is evident from the Combination of this specific diagnostic code Dijj with one or more other predetermined diagnostic codes Dijj can be seen.

FIG. 3 shows an exemplary input mask for display on a workstation computer 105. With the input mask according to FIG.

According to one example, an expert user can recognize that two changes made in the configuration of different actuators 1x, 1y that are closely correlated in terms of time have often proven to be incompatible. Based on this finding, a rule BED can be generated with which, when global diagnosis codes Dyj, DXj occur with regard to the actuators 1y, 1x, which indicate the incompatible measure, an action AKT is derived with the aid of the diagnosis deduction logic, which has a central Diagnostic code D _c is generated, which as a diagnostic statement includes a measure that promises success in order to eliminate an undesired system status. Based on this condition BED, the global diagnosis codes D _yi , D _zj , which indicate the incompatible measures, can also be deleted from the actuators 1y, 1z.

According to another case, an expert user may have recognized that following a change to the configuration of a specific actuator 1z, observing the relevant diagnostic code D _ZJ , further changes to the configuration of other actuators 1y, 1x were regularly required in order to ensure trouble-free operation to ensure or restore. In such a case, the diagnostic sededuction logic γ are defined such that starting from the diagnostic code DZj related to the actuating device 1z as action AKT, both a diagnostic statement for rectifying the anomaly in this actuating device 1z as well as supplementary central diagnostic statements relating to the other actuating devices 1y, 1x are generated.

According to a third example, oscillating valves can develop an air consumption that jeopardizes the compressed air supply in the plant part of these actuators. In such a case, one or more of the actuators 1x, 1y, 1z can report a supply air pressure that is too low with a corresponding diagnostic code as a diagnostic code. As an alternative or in addition, there can be messages from the actuators 1x, 1y and/or 1z that indicate vibrations. Sometimes a user would hide these diagnostic codes indicating vibrations because in some situations a vibrating valve is acceptable. In the event of such a fault constellation, a user of the process engineering system 100 could incorrectly assume the cause of the drop in air pressure to be in the air supply to the actuators. In such a risk situation, an expert user can define rules in the diagnostic deduction logic γ to the effect that, if at least one diagnostic code is present, related to one or more actuators with a common pneumatic supply, which indicate that the pneumatic supply air pressure is too low, in combination with at least a diagnostic code that indicates an oscillating valve that an action AKT generates a central diagnostic code D _c that informs the user that a fault cause for the low supply air pressure can be caused by the oscillating valve behavior.

The exemplary input mask shown in FIG. 3 can be displayed on a screen terminal on a workstation computer 103. With the help of the input mask, the expert user can select rule descriptions including conditions BED and associated actions AKT. An operating part is displayed in the upper part of the input mask, while an action part is shown below the horizontal line. For example, selection lists in the form of drop-down menus or the like can be offered to the expert user in order to define the conditions BED in a permissible manner. In the example according to FIG. 3, the condition for the presence of two specific diagnosis codes is established in order to trigger the defined action AKT by the diagnosis deduction logic. First of all, the actuator, which is identified here with the identifier I _x "GT-003819", must have the predetermined diagnosis code "high-frequency continuous oscillation: reduce P component". Furthermore, because of the selected logical "AND" operation, a second actuator with the identifier I _y "VS-1203819" must also have a diagnostic code of the same type. When these conditions BED are present, the action AKT is to delete the two aforementioned diagnostic codes relevant to the condition from the entire set of diagnostic codes Traj. A new central diagnosis code D _c is also added, which refers to another actuator with the identifier I _z "GT-0200790".

A time relation of simultaneity other than that described here can, for example, relate to the occurrence of two specific diagnosis codes within a specified period of time, for example “And then in 2 to 5 seconds”.

Various examples of diagnostic codes with their associated diagnostic statements are listed below:

The features disclosed in the above description, the figures and the claims can be important both individually and in any combination for the realization of the invention in the various configurations.

References:

1i, 1X, 1y actuator

3 central unit

5 communication network

11i control valve

13i setting and/or control electronics

15i actuator

100 process engineering plant

103 control room

113 central processing unit

130. 140 memories

131. 141 processor

134, 144 network connection

200 Capture

250 presses

300 generate

303 anomaly description

304, 404 Transform

306 correlate to local time

307 quality determination

309 consideration of a temporal relation

400 Submit

401 sending

403 received

500 determine

503 Modified Set Form

505 apply condition

506 correlate to global time

509 perform action

601 define local time

603 define diagnosis deduction logic

609 define global time

35 ACT action

BED Condition d target/actual difference value

D diagnostic routine

Dc central diagnosis code

D _P Loop diagnostic routine

Dj local diagnostic code

Dij, Dxj, Dyj global diagnostic code Set of diagnostic codes Modified quantity g Control signal li, Ix, ly, Iz actuator-specific identifier

K deduction result

Q quality index

R control routine

Rp process control routine

RBD rule database s actual signal ti local time tFy local time window dtFy local opening time local time interval

T global time

Tstart Start time

Tend end time w target signal γ diagnosis deduction logic

Claims

Expectations:

1. Method for diagnosing a control and/or regulation system of a process engineering plant with a plurality of actuators (1i) for adjusting a process fluid and a central unit, comprising the steps of a) detecting (200) at least one actuator-specific raw control data, such as a target value (w ), an actual value (s), a target/actual differential value (d) or a control value Cg); b) generating (300) at least one, in particular local, diagnostic code (Dj, Dij) by one of the plurality of actuators (1i) on the basis of the at least one detected raw control data item; c) transmission (400) of the at least one diagnosis code (Dj, Dij)j from the respective actuator (1i) to a central unit (3); d) transforming (304, 404) a local diagnostic code (Dj) originating from a specific actuator (1i) and/or relating to a specific actuator (1i) into a global diagnostic code (Dij)j, in that the local diagnostic code (Dj , Dij)j is linked to an identifier (Ii, Dij )j a predetermined deduction result (K) is determined, f) determining (500) at least one deduction result (K) using the diagnostic deduction logic (y) on the basis of the at least one diagnostic code (Dj, Dij)j in the central unit (3).

2. The method of claim 1, wherein the step of determining (500) at least one consolidation result (K) comprises determining at least a first global diagnostic code (Di=xj) from a first actuator (ii= _x ) and at least a second global diagnostic code (Di=yj) is taken into account by a second actuator (ii= _y ).

3. The method of claim 1 or 2, wherein the step of determining (500) comprises at least one deduction result (K) that the central unit (3) a set of global Diagnostic codes (Dij) are taken into account in order to form a deduction result (K) from a modified set of the global diagnostic codes (Dij)j taken into account,

37 where the modified set is the set minus at least one global Diagnostic code and / or plus at least one central diagnostic code (Dzj) can correspond. Method according to Claim 3, in which the deduction logic is equipped with a logical condition which, given a predetermined constellation of specific global diagnosis codes, recognizes that a diagnosis result is false positive and deletes the global diagnosis code recognized as false positive. Method according to one of the preceding claims, wherein a central unit applies the one or more logical conditions to a plurality of diagnostic codes in order to determine a deduction result. Method according to one of the preceding claims, wherein the step of determining (500) comprises at least one deduction result (K). that the central processing unit (3) takes into account a set (Dij) of global diagnosis codes (Dij) in order to produce a deduction result (K) from a modified set of the global diagnosis codes (Dij) taken into account form, where the modified amount the sentence plus at least one Central Diagnostic Trouble Code (Dzj) may match. Method according to one of the preceding claims, wherein the step of generating (300) comprises that the at least one diagnostic code (Dj,Dij) is related to an anomaly on the basis of the at least one raw control data; further comprising an anomaly description step (303), in which at least one indication of the anomaly is determined on the basis of raw control data, the step of generating (300) the at least one diagnosis code (Dj, Dij) comprising that the diagnosis code (Dj, Dij) a diagnostic statement, such as an indication of the type of anomaly, the cause of the anomaly and/or a diagnostic and remedial measure with regard to the anomaly, is impressed. Method according to one of the preceding claims, further comprising a quality determination step (307) in which at least one quality index (Q) is calculated on the basis of raw control data, the step generating (300) the at least one diagnosis code (Dj, Dij) comprising that Diagnostic code (Dj, Dij) a quality index (Q) is impressed, which characterizes in particular the quality of the control routine (R). Method according to one of the preceding claims, wherein the global diagnosis code (Dij ) is formed

38 (i) by the actuator (1i) when generating (300) or when sending (401) the local diagnostic code (Dj),

(ii) by a communication device (5) when transmitting (400) the local diagnostic code (Dj), or

(iii) by the central unit upon receiving (403) a local diagnosis code (Dj) or upon determining (500) the at least one inference result (K). Method according to one of the preceding claims, wherein the step of generating (300) the at least one diagnostic code (Dj, Dij) comprises that for generating the diagnostic code (Dj, Dij) a temporal relation, such as a simultaneity, sequence or time series, of at least two Control raw data is taken into account. Method according to one of the preceding claims, wherein at least one diagnosis code (Dj, Dij) is correlated to a global, in particular absolute time (T). The method of claim 11, wherein the step of determining (500) at least one deduction result (K) comprises that the diagnostic deduction logic (y) is assigned a set of global diagnostic codes (Dij) a deduction result (K), wherein the diagnostic deduction logic (y) at least one temporal Condition related to global time (T) taken into account. The method of claim 12, wherein the step of determining (500) a deduction result (K) comprises assigning a deduction result (K) to the diagnostic deduction logic (y) to a set of global diagnostic codes (Dij), the diagnostic deduction logic (y) having at least one temporal condition with regard to a temporal simultaneity, sequence or time series, of at least two predetermined global diagnosis codes (Dij) based on the global time (T) is taken into account. Method according to one of the preceding claims, wherein the at least one in particular local diagnostic code (Dj, Dij) generated by an actuator (ii), in particular in the step of generating (300) the diagnostic code (Dj, Dij), at an actuator-specific local time (ti ) is correlated. The method of claim 14, wherein the local time (ti) is defined as a time window with an opening time (tFij), which is determined as a function of a predetermined process signal event, for example a predetermined signal curve of a target value, such as a step response, a Sine response, or a ramp response, or a predetermined waveform of an actual signal, such as a sudden change in load, and with an opening duration (dtFij). 9erfahrn according to claim 14 or 15, wherein the local time (ti) is defined as a particularly periodically recurring time interval (dfi), such as a discrete control cycle of a digital actuator, wherein in particular during the discrete control cycle a constant manipulated variable of a manipulated and / or Control electronics (13i of the control device (1i) to a control actuator (15i of the control device (10), with the control variable being calculated in particular using a setpoint value (w), an actual value (s), a value determined by the difference between the actual value and A control deviation defined as a desired value, and a control routine which takes into account the control deviation, such as a PID control routine. Method according to one of the preceding claims, in which a computer unit (13z) of an individual specific actuating device (1z) is both responsible for generating (300) at least one diagnosis code ( Di=zj) and for the determination (500) of a deduction result (K) taking into account at least one diagnostic codes (Di* _z ,j) are used by at least one other actuator (1iǂz). Control and/or regulation system (100) for a process plant, comprising a plurality of actuators (10, a central unit (3) and a communication device (5) for transmitting at least one diagnostic code (Dj, Dij) from the actuators (10 to the central unit (3 ), Each control device (10) comprising a control valve (ui) for adjusting a process fluid flow and a computing unit (13i) which is set up to control the control valve (11i) on the basis of at least one control raw data according to a control and/or control routine ( 250), and wherein the computing unit (13i) is also set up to generate diagnostic codes (Dj, Dji), in particular local diagnostic codes (Dj), preferably relating to an anomaly, based on at least one raw control data item according to a diagnostic routine (300). the central unit (3) is set up to apply at least one logical condition to at least one diagnostic code (Dj, Dij) as a diagnostic deduct to obtain ion logic, and to determine a deduction result (K) according to the diagnosis deduction logic (y) on the basis of, in particular, at least two of the diagnosis codes (Dj, Dij) provided by the actuators (1i). Control and/or regulation system according to claim 18, wherein the central unit (3) is integrated in one of the actuators (1i=z), in particular the actuator-specific computing unit (13i=z), or wherein the central unit (3) is separate from the actuators ( 1i) is implemented in a computer, such as a process control computer (103), a workstation computer (105), a tablet computer or the like. Control and/or regulation system according to one of claims 18 or 19, wherein the control and/or regulation system (100) is configured to carry out the method according to one of claims 1 to 17.