Abstract:
The maintenance of a technical installation may be effected in an optimized manner with regard to time and costs. To this end, a method, a computer program product and a computer system are provided for maintenance, by way of which wear behavior of installation components may be predicted and a maintenance time and/or a maintenance action may be determined from this prediction.

Description:
[0001]    This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/EP01/12725 which has an International filing date of Nov. 2, 2001, which designated the United States of America and which claims priority on European Patent Application number EP 00124548.9 filed Nov. 9, 2000 the entire contents of which are hereby incorporated herein by reference.  
         FIELD OF THE INVENTION  
         [0002]    The present invention generally relates to a method, a computer program product and a computer system for maintenance of a technical facility that includes two or more system components.  
         BACKGROUND OF THE INVENTION  
         [0003]    Technical systems are being introduced in various fields of industry which are used, for example, for producing a specific product, for further processing or for refinement of raw materials, for carrying out what were formerly manual activities in an automated manner, or, in particular, for producing electrical power.  
           [0004]    Technical facilities such as these generally have two or more system components which carry out the individual functions of the technical facility. Many of these system components are subject to mechanical wear during their operating life. During the life of the technical facility, the wear to its system components represents a major problem, since the operation of the technical facility, or at least of some of its functions, is no longer ensured when a wear limit is exceeded.  
           [0005]    If the system component which is adversely affected by wear is not replaced in good time, then its excessive wear in general leads to at least a partial failure of the technical facility, and hence to undesirable downtimes, which can in turn lead to production failures, loss of profit and, in some circumstances, to very costly repairs to the technical facility.  
           [0006]    In order to avoid failures caused by wear, it is known for servicing procedures to be carried out on specific system components, as soon as these have reached a specific operating life, that is to say, for example, when a motor has been run for 10 000 operating hours, a valve has carried out 5 000 switching operations, for example, or a car has been driven, for example, for 15 000 km. In this case, a so-called preventative maintenance is carried out by statistical evaluation, without taking into account actual loads on the basis of experience.  
           [0007]    This procedure, which is known from the prior art, has the disadvantage that components are in this case often serviced or replaced which would in fact be suitable by virtue of their actual condition for ensuring their continued operation at least for a certain period of time. Such servicing, which is often superfluous, thus leads to high financial penalties, in order to ensure safe and reliable operation of the system components.  
           [0008]    It is also known for system components to be serviced or to be replaced when they indicate conspicuous features in their operating behavior.  
           [0009]    In order to identify conspicuous features, sensors are installed on the system components or in their vicinity, and are connected to monitoring devices. These produce monitoring signals, which can then in general be interpreted by servicing personnel for a technical facility. This interpretation is then used to draw an appropriate conclusion with regard to the servicing measures that are supposed to be necessary. This procedure can lead to servicing measures being initiated too late, since the monitoring is often carried out only on the basis of secondary measured values, and the primary cause of damage is thus identified too late, if at all. One typical example of this is cavitation damage in a pump, which cannot be measured as a primary factor and can be identified only on the basis of secondary measured values, for example the medium pressure, the medium temperature or the medium flow rate.  
           [0010]    Furthermore, monitoring devices which are based on classical, analog measurement methods relating to pressure, temperature, rotation speed, flow rate, etc. do not make use of the entire range of information, for example that contained in the noise on the signals and power flows. It thus fails to make use of a wide range of information for monitoring and diagnosis of the behavior of components.  
           [0011]    The major disadvantage of servicing measures that are initiated too late is that they necessarily lead to a system shutdown.  
           [0012]    The initiation of servicing measures on the basis of sensor data can also lead to servicing procedures being initiated unnecessarily, since the monitoring on the basis of the previously mentioned secondary measured values does not reflect the actual wear or damage pattern, but only its symptoms, which need not necessarily correspond to one another.  
           [0013]    Servicing procedures which are initiated unnecessarily lead to work on and/or replacement of system components which are intrinsically still serviceable, and thus to unnecessary ongoing financial costs.  
         SUMMARY OF THE INVENTION  
         [0014]    The present invention is based on an object of providing a method, a computer program product and a computer system for maintenance of a technical facility which includes two or more system components, to substantially guarantee timely and cost-effective servicing of the technical facility.  
           [0015]    With regard to a method according to an embodiment of the present invention, an object is achieved by a method for maintenance of a technical facility which includes two or more system components, having the following steps:  
           [0016]    1. The wear behavior of at least one system component is simulated.  
           [0017]    2. The wear behavior is associated with at least one wear parameter.  
           [0018]    3. The future development of the value of the at least one wear parameter is predicted.  
           [0019]    4. The predicted future development of the value of the at least one wear parameter is used to derive at least one servicing time and/or at least one servicing action for the relevant system component.  
           [0020]    The advantage of a method according to the present invention is, in particular, that the servicing time and/or the servicing action are/is related to the wear that has actually occurred. The prediction of the wear behavior makes it possible to define the servicing time and/or the servicing action specifically, when the wear to one or more system components has exceeded a permissible tolerance threshold. This prevents servicing from being initiated too early or too late, that is to say prevents unnecessary costs from being incurred for unnecessary servicing measures, while preventing maintenance operations from being carried out to an excessive, unnecessary extent.  
           [0021]    In one advantageous refinement of the present invention, the current process data which is stored in at least one databank and/or archived long-term stored process data are/is used to simulate the wear behavior.  
           [0022]    This makes the simulation of the wear behavior more accurate since, firstly, this results in the simulation including wear-relevant process data based on the actual current situation. Secondly, possible future loads which will govern the wear behavior can be anticipated better since the archived values of process data stored over a long time includes process data governing the wear behavior that has actually taken place in the past. If, for example, the archived long-term stored process data is now found to contain previous process data which matches the current process data well, for example in terms of the operating situation existing at that time, then there is a high probability that the current process data will in the future behave in a similar way to the identified, archived long-term stored process data. This archived long-term stored process data can then be included in the simulation, thus considerably improving the prediction of the wear behavior.  
           [0023]    The servicing time and/or the servicing action is advantageously derived with the aid of a diagnosis system. The diagnosis system is in this case a specialized system which, based on current values of input data—such as the predicted future development of the value of a wear parameter—draws a conclusion relating to the presence of a specific current or future wear situation, and uses this, if appropriate, to derive measures, such as the production of a warning signal, the production of a defect signal or else the determination of a servicing time as the latest time at which the system or system component must be serviced. The identification of a current or future wear situation by the diagnosis system can also at the same time be linked to corresponding action proposals.  
           [0024]    As in the case of commercially available diagnosis systems, the diagnosis system according to the present invention advantageously records and links expert knowledge relating to the technical system, frequently with the assistance of fuzzy logic and “self-learning” neural network methods.  
           [0025]    The present invention also leads to a computer program product which can be loaded directly into the internal memory of a digital computer and includes software code sections by way of which steps of the present invention are carried out when the program is running on a computer.  
           [0026]    The present invention leads to a computer system for maintenance of a technical facility which includes two or more system components, with the computer system including a simulation system for simulation of the wear behavior of at least one system component and being suitable for predicting the future development of the value of at least one wear parameter which is associated with the wear behavior, and for using this to derive at least one servicing time and/or at least one servicing action.  
           [0027]    In one embodiment of the present invention, this computer system inludes a databank, in which current process data and/or archived long-term stored process data are/is stored.  
           [0028]    Moreover, according to an embodiment of the present invention, process data such as this can be included in the simulation and prediction, in order to improve their reliability.  
           [0029]    In an embodiment of the present invention, the computer system includes a diagnosis system which can be used to derive the servicing time and/or the servicing action.  
           [0030]    Known diagnosis systems which, for example, use fuzzy logic methods, are particularly suitable for acquiring expert knowledge relating to the behavior of the technical facility in widely differing operating situations. The simulation and prediction data in the simulation system can then be included as input data in the diagnosis system, which uses this data and the acquired expert knowledge to derive a servicing time and/or a servicing action.  
           [0031]    The computer system advantageously includes a training system which can be used to test simulations and to conceive new simulation tasks.  
           [0032]    The training system is used for working interactively with the simulation system and, for example, for developing, modifying, validating and verifying self-learning mechanisms. The training system is thus a test platform, by way of which the simulations, predictions, etc., can be tested before being used for actual operation of the technical facility. Furthermore, the training system can be used to train operators, in order to make them familiar with the maintenance system. Since the training system is decoupled from the actual technical process, the functions of the computer system for maintenance can be tested and learned without this being associated with any intervention, which in some circumstances may be dangerous, in the operation of the technical facility.  
           [0033]    The computer system advantageously also includes an engineering system, which can be used to handle the entire computer system.  
           [0034]    The engineering system ensures the technological, engineering handling of the computer system, preferably at a graphics level. This includes, for example, the installation of the overall system, the incorporation of the technological objective, the incorporation of data and parameters, the definition of the displays and communications via the man-machine interface, any link to a process control system and, if appropriate, linking to internal and external networks as well as other electronic data processing systems.  
           [0035]    The computer system furthermore advantageously includes a multimedia system, which is used to support the process of carrying out servicing tasks.  
           [0036]    In the case of servicing procedures or additional diagnosis measures, the user is provided with multimedia functions, such as video and audio information, at the location of the activity via appropriate output devices, such as a screen, laptop, headset, loudspeaker, etc., to assist and follow the work. The system can also be designed to be interactive and, for example, to store procedures in order to make these available later once again in comparable situations.  
           [0037]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the present invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0038]    The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:  
         [0039]    [0039]FIG. 1 illustrates a technical facility which is connected to a computer system for maintenance, and  
         [0040]    [0040]FIG. 2 illustrates an outline sketch of a computer system for maintenance.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0041]    [0041]FIG. 1 shows a technical facility  1  which includes two or more system components  3 ,  5 ,  7 , . . . , n. The technical facility  1  is connected via a data link  2  to a computer system  20  for maintenance. The wear behavior of the system components  3 ,  5 ,  7 , . . . , n is simulated in a simulation module  101  of a simulation system  10  of the computer system  20 , and this wear behavior is associated with at least one wear parameter  102 . To simulate the wear behavior, the simulation system  10  makes use of current process data  151  and archived long-term stored process data  152  stored in a databank  15 .  
         [0042]    Data  105  to predict the future development of the wear parameter  102  is determined in a prediction module  103 .  
         [0043]    This data  105  relating to the predicted profile of the wear parameter  102  is passed to a downstream diagnosis system  12 . The diagnosis system  12  contains an expert knowledge base  121 , in which knowledge from experience of operation of the technical facility is acquired and linked, for example with the aid of fuzzy logic methods.  
         [0044]    The diagnosis system  12  uses the predicted development of the wear parameter  102  to determine a servicing time  110  and/or a servicing action  120 , for the relevant system components.  
         [0045]    [0045]FIG. 2 shows a computer system  40  for maintenance, comprising a number of component elements. The component elements of the computer system  40  are linked to one another via a communications link  41 .  
         [0046]    Servicing-relevant aspects relating to all the components and systems in the technical facility are simulated in a simulation system  50 . To do this, the simulation system  50  receives current and archived process data from a databank  45 . In order to obtain this data from the processes in the technical facility, the databank  45  is linked via a gateway  43  by way of a communications link  410  to the process control system  415  of the technical facility. Since the simulation system  50  has access to the current and archived process data stored in the databank  45 , the prediction of the wear behavior as determined by the simulation system  50  is very reliable, since the simulation system can match its simulation results to the actual current or stored process data.  
         [0047]    If classical simulation methods, for example the modeling of the wear behavior with the aid of mathematical equations, are used in the simulation system  50 , the validity of the simulation results is very high from the start. However, it is also possible to use more modern simulation methods, such as neural fuzzy technology with corresponding self-learning mechanisms. These more modern methods are particularly appropriate when the wear behavior cannot be mathematically recorded exactly. The validity reliability of such methods then increases only over the course of time, as the number of learning circles carried out increases.  
         [0048]    The simulation results from the simulation system  50  are evaluated in the diagnosis system  52  and are processed to produce information, decision bases and action statements.  
         [0049]    The diagnosis system  52  is also linked to a man-machine interface  48 . The man-machine interface  48  is connected via a communications link  400  to units—for example a screen unit  310 , a printer  320  or communications devices  340 —which can be used by the operator to control the computer system  40 . Furthermore, the computer system  40  can also communicate with remote electronic data processing systems via satellites S, the Internet I or mobile radio M, by way of a gateway  46  which is likewise connected to the communications link  400 .  
         [0050]    An engineering system  44 , which is connected to the communications link  41 , is used mainly to set up the software for the overall structure and functions of the computer system  40 , to modify it, and to adapt it to the respective technical situation and to the requirements of the technical facility. The engineering system is also used, inter alia, for servicing and for quality management of the entire computer system  40 .  
         [0051]    A multimedia system  46 , which is likewise connected to the communications link  41 , contains multimedia information such as video and audio information relating to the servicing measures to be carried out in the technical facility. This information may, for example, be video information which, for example, can display the servicing action on a specific facility component in the form of a film, and can thus be used to instruct the servicing personnel on the action.  
         [0052]    Via appropriate communications links within the technical facility, this multimedia information can be transmitted as required to the respective location of the servicing measure, thus assisting the servicing personnel. The multimedia system  46  may also be interactive and, for example, store servicing measures that have been carried out in order to make them available once again later on as required, for example where a servicing measure is being carried out.  
         [0053]    Exemplary embodiments being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.