CH719194A2 - Computer-implemented method for optimizing a building infrastructure. - Google Patents

Abstract

In a computer-implemented method for optimizing a building infrastructure (1), the building infrastructure (1) comprising a plurality of infrastructure components (2.1, 2.2), the method comprises a modeling process (P1) within which a computer model (4) of the building infrastructure (1) is created, with each infrastructure component (2.1, 2.2) being assigned a unique identification number (3.1, 3.2). The method can include an operational optimization process, within which a virtual infrastructure parameter of an infrastructure component (2.1, 2.2) is modified in the computer program and the corresponding real infrastructure parameter is then modified accordingly.

Description

technical field

The invention relates to a computer-implemented method for optimizing a building infrastructure according to the preamble of claim 1. The invention also relates to a system, a computer program and a computer-readable medium according to the independent claims.

State of the art

[0002] Digitization is generally regarded as a suitable means of helping to solve the technical challenges of the coming decades, for example stopping climate change, improving the energy efficiency of technical systems or improving the CO2 balance of technical systems.

[0003] Especially in the building sector, which is typically responsible for a large part of the energy requirements and the CO2 emissions of cities and communities, there is great potential for optimization in the areas mentioned. Although methods of digitization are already being used in the building sector, the use of such methods has so far e.g. B. not led to a sufficient reduction in energy demand and CO2 emissions from buildings.

[0004] In particular, further solutions are required in order to be able to carry out the planning, operation, maintenance and servicing of building infrastructure in as resource-efficient a manner as possible.

object of the invention

It is the object of the invention to eliminate or at least mitigate the disadvantages of the aforementioned prior art.

solution of the task

This object is achieved by a computer-implemented method for optimizing a building infrastructure, the building infrastructure comprising a plurality of infrastructure components, the method comprising a modeling process within which a computer model of the building infrastructure is created, each infrastructure component being assigned a unique identification number.

In this context, the term "optimize" is to be understood broadly. In advantageous embodiments, “optimization” means, for example, that the computer model of the building infrastructure is supplemented and/or brought into line with the actual building infrastructure and/or kept in line on a computer on which the modeling process runs. Furthermore, in advantageous embodiments, “optimize” means, for example, that operation of the building infrastructure is optimized, that is, for example, energy consumption of the building infrastructure is minimized, for example in relation to the consumption of electrical energy or thermal energy. In typical embodiments, “optimization” also includes an improvement in the building infrastructure to the effect that infrastructure components are exchanged, modified and/or reprogrammed in such a way that the energy efficiency of the building infrastructure is improved.

The term "infrastructure components" is also to be understood broadly. In advantageous embodiments, infrastructure components within the meaning of this description are, for example, heating components, ventilation components, air conditioning components, electrical components, sensors, actuators or other types of technical components. Such infrastructure components can be arranged inside buildings or outside of buildings, for example in the form of technical installations that are used by several buildings, such as heat pumps, electricity infrastructure components or underground lines in districts.

A "modeling process" is typically understood to mean a computer-implemented process in which the computer model of the building infrastructure is created and/or extended and/or adapted to the actual, real building infrastructure and/or modified in some other way. For example, a CAD component and/or a CAD computer program product is used in a typical modeling process.

It can therefore be said that the real building infrastructure includes a plurality of real infrastructure components and that these infrastructure components are of course also present in the computer model of the building infrastructure. The infrastructure components in the computer model can also be referred to as virtual infrastructure components and/or as virtual images of the real infrastructure components. For the sake of simplicity, no distinction is usually made below between the real infrastructure components in the real building infrastructure and the virtual infrastructure components in the computer model, since these infrastructure components correspond. The topic of the correspondence between the building infrastructure on the one hand and the computer model on the other is briefly taken up again in a few places only for a better understanding.

[0011] A "creating" of the computer model of the building infrastructure is typically to be understood as meaning both the initial creation and the described adaptation, supplementation or other modification of the computer model.

The “unique identification number” is typically a string of digits and/or letters, for example a string of at least 8, at least 12, at least 16, at least 20, at least 24 or at least 36 characters.

The inventors have found that when optimizing building infrastructure, it is often problematic that in the overall area of the actual, real building infrastructure on the one hand and the modeling process of the building infrastructure in a computer on the other hand, a clear identification of infrastructure components is often not available, which then leads to efficiency problems in the planning, monitoring, optimization, operational control and/or modification of the building infrastructure. Because each infrastructure component of the building infrastructure and thus also each infrastructure component of the building infrastructure correspondingly mapped in the computer model is assigned a unique identification number, a simple and clear exchange between the building infrastructure and the computer model is made possible, which ultimately leads to an optimization of the building infrastructure itself.

In advantageous embodiments, the method includes a monitoring process within which a technical operating state of at least one of the infrastructure components is monitored, and the method includes an updating process within which the technical operating state in the computer model is updated. A "technical operating state" should in principle be understood to mean any technical property of an infrastructure component, for example the current temperature of a temperature sensor, the opening state of a window, the opening state of a valve, the current operating state of an actuator, a measured humidity value, current power consumption or the like. As part of the monitoring process, the respective technical operating status of at least some of the infrastructure components is typically continuously queried in the building infrastructure. The results of this continuous polling are then fed into the computer model. The corresponding technical operating states of the virtual infrastructure components in the computer model are then updated in the computer model as part of the updating process, so that the technical operating states of the infrastructure components in the building infrastructure are essentially correctly represented in the computer model at all times. Such a combination of a monitoring process and an update process has the advantage that the technical operating states of the infrastructure components can be taken into account at least essentially at any time in the modeling process, which typically runs parallel to the monitoring process and the update process.

In advantageous embodiments, the technical operating status is continuously and automatically queried as part of the monitoring process, preferably via the Internet, with all continuously queried technical operating statuses typically being updated continuously in the computer model as part of the updating process, with each technical operating status preferably being assigned a corresponding identification number becomes. This ensures a standardized and efficient exchange between the building infrastructure and the computer model.

In advantageous embodiments, the method includes a database query process within which database data, preferably infrastructure element data and/or building data and/or neighborhood data and/or heating data and/or electricity data and/or insurance data are queried from at least one database , preferably via the Internet, the queried database data being advantageously inserted into the computer model as part of the modeling process after being queried from the at least one database. "Infrastructure element data" means in particular technical characteristics and/or technical parameters of infrastructure elements. "Quarter data" includes, in particular, technical features and/or technical parameters and/or statistical data and/or plans and/or operational data of lodgings such as e.g. B. districts, neighborhoods and / or other building clusters. In typical embodiments, the database is a GIS database, where "GIS" stands for "Geographical Information System". In typical embodiments, the database is an EGID database, where “EGID” stands for “Federal Building Identifier”. In typical embodiments, the database is a building and dwelling register database. In typical embodiments, the database query process includes a query step, in the context of which a data package comprising the database data is queried from one or more of the databases described or other databases. In typical embodiments, the database query process includes a benchmark step, within which the queried database data is compared with one or more of the technical operating states. Such a database query process has the advantage that it is possible to compare the building infrastructure, which is optimized using the method, with pre-recorded data from databases and thus get an impression of how great a current optimization potential there is in the examined building infrastructure .

In typical embodiments, the method includes an operation optimization process, wherein within the operation optimization process in the computer model, at least one virtual infrastructure parameter of at least one infrastructure component is preferably modified in such a way, preferably automatically, that the technical operating state of this infrastructure component in the computer model changes from a critical operating state to a normal operating state Operating state transitions, advantageously then, preferably automatically and / or via the Internet, typically a virtual infrastructure parameter corresponding real infrastructure parameter is modified accordingly in the building infrastructure.

In advantageous embodiments, real infrastructure parameters are at least partially modified by a robot. “At least in part” is to be understood in such a way that the robot works, for example, fully autonomously and/or partially autonomously, with the robot being remotely controlled and/or monitored at least temporarily by a human in certain embodiments.

[0019] An “infrastructure parameter” of an infrastructure component is to be understood, for example, as a sensitivity value of an infrastructure component or some other setting of an infrastructure component. Such an operation optimization process has the advantage that in a case where it is determined in the computer model that an infrastructure component is not working as desired, a modification can be made in the computer model to the virtual counterpart of the infrastructure parameter of the infrastructure component in such a way that a normal Function (or in other words: non-critical function) of the infrastructure component stops. As soon as this has been achieved, the corresponding real infrastructure parameter can then be modified accordingly in the real building infrastructure. In typical embodiments, the operation optimization process interacts with the modeling process and/or the monitoring process and/or the updating process and/or the database query process.

In advantageous embodiments, the method includes an infrastructure optimization process within which the computer model is automatically determined, preferably with the participation of the modeling process and/or the monitoring process and/or the updating process and/or the database query process and/or the operation optimization process. how a modification of a specific infrastructure component affects the technical operating parameters of this infrastructure component and/or other technical operating parameters of the building infrastructure. Such an infrastructure optimization process has the advantage that, based on a result of the infrastructure optimization process, a modification can be made to the building infrastructure, for example replacing a specific infrastructure component and/or changing the setting of a specific infrastructure component, so that the building infrastructure is optimized. In typical embodiments, the infrastructure optimization process includes a swapping step in which a particular infrastructure component is replaced with another infrastructure component in the computer model. Then, in a simulation step, it is determined how this exchange affects at least one technical operating parameter of the building infrastructure. If it is apparent that the technical operating parameters have changed for the better as a result of the exchange, then in a recommendation step the recommendation is issued that this exchange should also be carried out in the real building infrastructure. In advantageous embodiments, the exchange is then carried out in an exchange step in the real building infrastructure. In advantageous embodiments, the replacement step is performed at least in part by a robot. “At least in part” is to be understood in such a way that the robot works, for example, fully autonomously and/or partially autonomously, with the robot being remotely controlled and/or monitored at least temporarily by a human in certain embodiments.

In advantageous embodiments, the method includes an artificial intelligence process, within which using one or more methods from the field of artificial intelligence, the modeling process and / the monitoring process and / or the update process and / or the database query process and/or the operational optimization process and/or the infrastructure optimization process is/are supported. In the following, "artificial intelligence" is also referred to with the usual abbreviation "AI".

[0022] The object is also achieved by a system for optimizing a building infrastructure, comprising means for carrying out a method according to one of the exemplary embodiments described above.

In advantageous embodiments, the system comprises a modeling module and/or an identification number generation module and/or a monitoring module and/or an update module and/or a database query module and/or an operation optimization module and/or an infrastructure optimization module and/or an artificial intelligence module. In typical embodiments, each of these modules is capable of performing a corresponding one of the above processes. In typical embodiments, the identification number generation module is capable of assigning each infrastructure component a unique identification number.

At least some of the aforementioned modules are advantageously implemented in the system by means of computer program code.

In one embodiment of the invention, a computer program comprises instructions which, when the computer program is executed by a computer, cause the latter to execute one of the aforementioned methods. The computer program can also be referred to as a computer program product.

In one embodiment of the invention, a computer-readable medium comprises computer program code for performing one of the aforementioned methods. In typical embodiments, a computer program according to an embodiment of the invention is stored on the computer-readable medium. The term “computer-readable medium” is to be understood in particular, but not exclusively, as hard drives and/or servers and/or memory sticks and/or flash memories and/or DVDs and/or Blu-rays and/or CDs. In addition, the term “computer-readable medium” also means a data stream, such as that created when a computer program and/or a computer program product is downloaded from the Internet.

FIGURE DESCRIPTION

The invention is described in more detail below with the aid of drawings, which show: FIG. 1: schematic representation of a method according to the invention according to a first embodiment, FIG Method according to a third embodiment, FIG. 4: schematic representation of a method according to the invention according to a fourth embodiment, FIG. 5: schematic representation of a method according to the invention according to a fifth embodiment, and FIG. 6: schematic representation of a method according to the invention according to a sixth embodiment.

Description of preferred embodiments

FIG. 1 shows a schematic representation of a method according to the invention according to a first embodiment. A building infrastructure 1 is shown in FIG. 1, which comprises two infrastructure components 2.1, 2.2. The first infrastructure component 2.1 includes an identification number 3.1 and the second infrastructure component 2.2 includes an identification number 3.2. Each of the infrastructure components 2.1, 2.2 of the building infrastructure 1 thus includes a unique identification number 3.1, 3.2. A computer model 4 is also shown in FIG. In addition, a modeling process P1 is shown in FIG. In the exemplary embodiment shown in FIG. 1, the modeling process P1 has already created the computer model 4. The infrastructure components 2.1, 2.2 of the building 1 with their respective identification numbers 3.1, 3.2 are represented in virtual form in the computer model 4. As part of the process, each infrastructure component 2.1, 2.2 was therefore assigned a unique identification number 3.1, 3.2. The modeling process P1, which has already created the computer model 4 as a virtual version of the building infrastructure 1, communicates with the computer model 4 on the one hand and with the building infrastructure 1 on the other hand, each represented by a double arrow. If changes are made to the computer model 4 and/or to the building infrastructure 1, these changes are typically taken into account as part of the modeling process 1, so that the building infrastructure 1 and the computer model 4 correspond at least essentially.

FIG. 2 shows a schematic representation of a method according to the invention according to a second embodiment. The building infrastructure 1 and the computer model 4 are again shown in FIG. The infrastructure components 2.1, 2.2 already shown in FIG. 1 with their respective identification numbers 3.1, 3.2 are also shown in FIG. In addition, technical operating states 5.1, 5.2 are shown in the exemplary embodiment in FIG. 2 in each infrastructure component. The modeling process P1 is also shown in FIG. The exemplary embodiment in FIG. 2 also includes a monitoring process P2 and an updating process P3. The monitoring process P2 interacts with the building infrastructure 1, which is symbolized by the double arrow between the building infrastructure 1 and the monitoring process P2. The monitoring process P2 continuously monitors the technical operating states 5.1, 5.2 of the infrastructure components 2.1, 2.2 in the building infrastructure 1. For example, it is possible for the technical operating states 5.1, 5.2 to be queried continuously as part of the monitoring process P2, for example using an endless loop.

The update process P3 interacts with the computer model 4, which is symbolized by the double arrow between the update process P3 and the computer model 4. In addition, the monitoring process P2 and the updating process P3 interact with one another. Based on information that the update process P3 receives from the monitoring process P2, in particular continuously and/or periodically, the update process P3 ensures that the technical operating states 5.1, 5.2 in the computer model 4 are continuously updated, so that the technical operating states 5.1, 5.2 in the building infrastructure 1 on the one hand and in the computer model 4 on the other hand essentially constantly correspond. In principle it is also possible for the monitoring process P2 and/or the updating process P3 to communicate with the modeling process P1. However, for the sake of a better overview, such a communication is not shown in FIG.

FIG. 3 shows a schematic representation of a method according to the invention according to a third embodiment. FIG. 3 again shows the building infrastructure 1 and the computer model 4 with the respective infrastructure components 2.1, 2.2. In contrast to the exemplary embodiments shown above, the explicit representation of identification numbers and technical operating states has been dispensed with. However, these features are also present in the building infrastructure 1 and in the computer model 4 in the exemplary embodiment in FIG. The modeling process P1 is still in exchange with the building infrastructure 1 and the computer model 4. A database query process P4 is also shown in FIG. The database query process P4 interacts on the one hand with the computer model 4 and on the other hand with a database 7. The database query process ensures that a data stream with database data 6 (represented by a thick arrow) between the database 7 and the Computer model 4 is initiated. The database data 6 can include, for example, building data and/or district data and/or heating data and/or electricity data and/or insurance data. The database data 6 are typically inserted into the computer model 4 and/or are taken into account as part of the modeling process P1 and/or as part of the monitoring process P2 and/or as part of the update process P3. The updating process P3 and the monitoring process P2 are also shown in FIG. 3 in order to show that these processes can also run in the exemplary embodiment in FIG. For the sake of a better overview, their interactions, which are in principle possible with all other processes in FIG. 3 and/or with the computer model 4 and/or the building infrastructure 1, are not represented by arrows or the like.

FIG. 4 shows a schematic representation of a method according to the invention according to a fourth embodiment. In particular, FIG. 4 again shows a building infrastructure 1 and a computer model 4. Both the computer model 4 and the building infrastructure 1 include the infrastructure component 2.1, which in turn includes an identification number 3.1 and a technical operating status 5.1. In addition, the infrastructure component 2.1 includes an infrastructure parameter 8. This infrastructure parameter 8 can also be present in the exemplary embodiments illustrated in FIGS. 1 to 3, but has not yet been discussed. The infrastructure parameter 8 can be, for example, a setting, a sensitivity or the like of the infrastructure component 2.1. In addition, FIG. 4 shows an operation optimization process P5 which is suitable for interacting with the computer model 4 and the building infrastructure 1 . FIG. 4 shows an exemplary embodiment in which the technical operating state 5.1 has assumed a critical value, for example overheating, an unwanted opening state or the like. In response to this critical operating state, the operation optimization process P5 carries out a virtual infrastructure parameter modification 9 on the infrastructure parameter 8 in the computer model 4 . In typical embodiments, the virtual infrastructure parameter modification 9 is carried out in a loop until the technical operating state 5.1 has returned to a normal value, for example an acceptable temperature or an acceptable opening. The operation optimization process P5 then ensures that the corresponding infrastructure parameter 8 is modified accordingly in the building infrastructure 1 as well, so that the technical operating state 5.1 also transitions into a normal range in the building infrastructure 1. For this purpose, the operation optimization process P5 in the building infrastructure 1 preferably automatically carries out a real infrastructure parameter modification 10 . In addition to the operation optimization process P5, Figure 4 also shows the modeling process P1, the monitoring process P2, the updating process P3 and the database query process P4, in order to symbolize that all processes P1 to P5 in this exemplary embodiment are also carried out simultaneously and/or can be performed in an overlapping and/or parallel manner.

FIG. 5 shows a schematic representation of a method according to the invention according to a fifth embodiment. FIG. 5 shows an infrastructure optimization process P6 as a sub-process of a method according to the invention. This infrastructure optimization process P6 interacts with the computer model 4. The computer model 4 includes an infrastructure component 2.1, within which a technical operating state 5.1 is shown. The infrastructure optimization process P6 ensures that a modification 11 is made in the computer model 4, in which the infrastructure component 2.1 is replaced by an infrastructure component 2.1a. This infrastructure component 2.1a then has a technical operating status 5.1a. In the infrastructure optimization process P6, the modification 11 is typically carried out in an exchange step. The exchange step can be followed by a simulation step (this is not shown explicitly in FIG. 5) in which it is determined how the modification 11 affects at least one technical operating parameter of the building infrastructure or the computer model 4 . Based on the result of such a simulation step, a recommendation for an exchange in a real building infrastructure can then be issued in a recommendation step (likewise not shown). In typical embodiments, the exchange can then be carried out in an exchange step in the real building infrastructure (this is also not shown in FIG. 5 for the sake of a better overview). In addition to the infrastructure optimization process P6, the exemplary embodiment in FIG. 5 also shows the modeling process P1, the monitoring process P2, the updating process P3, the database query process P4 and the operation optimization process P5. The double arrows show that each of these processes P1 to P5 can interact and/or communicate with the infrastructure optimization process P6 if necessary. In principle, it is also possible for these processes P1 to P5 to communicate with one another. However, this is not shown in FIG. 5 for the sake of a better overview.

FIG. 6 shows a schematic representation of a method according to the invention according to a sixth embodiment. The method includes a modeling process P1, a monitoring process P2, an updating process P3, a database query process P4, an operation optimization process P5, an infrastructure optimization process P6 and an artificial intelligence process P7. The artificial intelligence process P7 is suitable for the other processes P1 to P6 by using methods of artificial intelligence, for example the systematic analysis of large amounts of data and/or methods of machine learning and/or fuzzy logic processes in their respective to support activities.

In typical embodiments, several or all processes P1 to P7 interact at least temporarily with one another and/or with the building infrastructure 1 and/or with the database 7 and/or with the computer model 4 as part of the above-mentioned methods.

In typical embodiments, one or more infrastructure components are addressed using IP addressing as part of the method, for example as part of the monitoring process P2 and/or the update process P3 and/or the operation optimization process P5 and/or the infrastructure optimization process P6. In typical embodiments, at least one infrastructure component is accessed using the so-called “Internet of Things” (“IoT” for short). In typical embodiments, the computer model includes a computer model database in which at least some, preferably all, infrastructure components and/or at least some, preferably all, identification numbers and/or at least some, preferably all, technical operating states and/or at least some, preferably all, infrastructure parameters are stored. In typical embodiments, the computer model database includes benchmark data. In typical embodiments, the computer model database includes pricing information for operations and/or components. In typical embodiments, the computer model has a simulation accuracy, ie a maximum deviation from the building infrastructure and/or from technical processes in the building infrastructure, of between 3 and 10 percent, preferably between 5 and 8 percent. In typical embodiments, the method includes a plan output step, within which a plan of the computer model and/or the building infrastructure is automatically created and output to a user. In typical embodiments, the plan is an electrical plan, a heating plan or a sanitary plan.

In principle, all of the exemplary embodiments described can be combined with one another, unless this is technically impossible in exceptional cases.

The invention is not limited to the exemplary embodiments described. The scope of protection is defined by the patent claims.

In principle, all methods described in the description or in the claims can be carried out by devices which include means for carrying out the respective method steps of these methods.

Reference List

1 building infrastructure 2.1, 2.1a, 2.2 infrastructure component 3.1, 3.2 identification number 4 computer model 5.1, 5.1a, 5.2 technical operating state 6 database data 7 database 8 infrastructure parameters 9 virtual infrastructure parameters modification 10 real infrastructure parameters modification 11 modification P1 modeling process P2 monitoring process P3 Update Process P4 Database Query Process P5 Operations Optimization Process P6 Infrastructure Optimization Process P7 Artificial Intelligence Process

Claims (10)

1. Computer-implemented method for optimizing a building infrastructure (1), the building infrastructure (1) comprising a plurality of infrastructure components (2.1, 2.1a, 2.2), characterized in that - The method includes a modeling process (P1) within which a computer model (4) of the building infrastructure (1) is created, - Where each infrastructure component (2.1, 2.1a, 2.2) is assigned a unique identification number (3.1, 3.2). 2. The method according to claim 1, characterized in that - The method includes a monitoring process (P2) within which a technical operating state (5.1, 5.1a, 5.2) of at least one of the infrastructure components (2.1, 2.1a, 2.2) is monitored, and - The method includes an update process (P3), within which the technical operating state (5.1, 5.1a, 5.2) in the computer model (4) is updated. 3. The method according to claim 2, characterized in that - As part of the monitoring process (P2), the technical operating status (5.1, 5.1a, 5.2) is automatically queried continuously, preferably via the Internet, - wherein typically as part of the update process (P3) all continuously queried technical operating states (5.1, 5.1a, 5.2) are continuously updated in the computer model (4), with each technical operating state (5.1, 5.1a, 5.2) preferably having a corresponding identification number ( 3.1, 3.2) is assigned. 4. The method according to any one of the preceding claims, characterized in that the method comprises a database query process (P4) within which database data (6), preferably infrastructure element data and/or building data and/or district data and/or heating data and /or electricity data and/or insurance data are queried from at least one database (7), preferably via the Internet, the queried database data (6) after being queried from the at least one database (7) advantageously as part of the modeling process (P1 ) are inserted into the computer model (4). 5. The method according to any one of claims 2 to 4, characterized in that the method comprises an operation optimization process (P5), wherein within the operation optimization process (P5) in the computer model (4) preferably at least one virtual infrastructure parameter (8) of at least one infrastructure component (2.1 , 2.1a, 2.2) is modified in such a way that the technical operating state (5.1, 5.1a, 5.2) of this infrastructure component (2.1, 2.1a, 2.2) in the computer model (4) changes from a critical operating state to a normal operating state Advantageously, a real infrastructure parameter (8) corresponding to the virtual infrastructure parameter (8) is then advantageously modified accordingly, preferably automatically and/or via the Internet, in the building infrastructure (1). 6. The method according to any one of the preceding claims, characterized in that the method comprises an infrastructure optimization process (P6), within which in the computer model (4) is automatically determined, preferably with the participation of the modeling process (P1) and / or the monitoring process (P2) and/or the update process (P3) and/or the database query process (P4) and/or the operation optimization process (P5), how a modification (11) of a specific infrastructure component (2.1, 2.1a, 2.2) affects the technical Operating parameters (5.1, 5.1a, 5.2) of this infrastructure component (2.1, 2.1a, 2.2) and / or other technical operating parameters (5.1, 5.1a, 5.2) of the building infrastructure (1) affects. 7. The method according to any one of the preceding claims, characterized in that the method comprises an artificial intelligence process (P7), within which the modeling process (P1 ) and/or the monitoring process (P2) and/or the update process (P3) and/or the database query process (P4) and/or the operation optimization process (P5) and/or the infrastructure optimization process (P6) is/are supported. 8. System for optimizing a building infrastructure (1), comprising means for performing a method according to any one of the preceding claims. 9. A computer program comprising instructions which, when the computer program is executed by a computer, cause the latter to execute a method according to one of the preceding claims. 10. Computer-readable medium, comprising computer program code for performing one of the aforementioned methods.