EP2514873B1 - Method and system for applying a paving composition - Google Patents

Description

The present invention relates to a method for applying a road surface according to the preamble of claim 1.

When creating a road surface is an extremely complex work process. This work process usually involves not only many different work machines, such as a mixer, trucks, feeders, pavers and rollers, but also many different people with sometimes varying degrees of experience. In addition, the production of a road surface is influenced by many factors, such as the temperature and composition of the paving material, the duration of transport of the paving material to the site, the paving speed, the setting of the compaction units on the paver or optionally on the subsequent roller, as well as environmental influences like wind, temperature and humidity. All these influences, individually or in combination, can influence the quality of the pavement produced. However, the goal is always to produce a road surface with the highest possible quality, in particular with a defined degree of compaction of the paving material or with a high stability.

Many suggestions have already been made in the past on how to better monitor, control or document road paving procedures and systems for more consistent work results. For example, the DE 101 51 942 B4 A work machine management system that allows construction vehicles to communicate with each other and with a site office. The exchanged data may relate, for example, to theft information, construction project costs, parts demand forecasts, service requirement forecasts, weather data or fuel consumption. The DE 60 2004 011 968 T2 describes another system for information exchange on construction sites. A data exchange between mobile construction vehicles and a construction site office takes place there by means of an Internet Protocol. The DE 10 2008 054 481 A1 describes an asphalting system in which the navigation of construction vehicles is based on a so-called positional temperature model. Based on the initially estimated and then measured asphalt temperature, the system determines where compactors are used most cheaply.

According to the US 2004/0260504 A1 For example, asphalt-related measurement data can be transmitted in a wireless communication system. The DE 101 51 942 B4 describes that each construction vehicle is assigned a specific identification. Another fleet management system for construction vehicles comes from the US Pat. No. 6,862,521 B1 out. The WO 00/70150 A1 describes a measurement of the asphalt temperature on a paver. The measured temperature data is forwarded to a compressor following the paver.

The DE 197 44 772 A1 describes the determination of a local compaction level to tell a compressor how often it has to travel over the specified area. The DE 694 16 006 T2 describes a further variant for controlling a compressor, for example a roller. The navigation of a compaction roller as a function of the degree of compaction in road construction is also in the EP 1 897 997 A2 treated.

The DE 10 2008 058 481 A1 , the DE 60 2004 011 968 T2 and the DE 101 51 942 B4 reveal the inclusion of climate and weather data in construction site processes. An automatic traffic control system, which, however, has no relation to construction site processes, goes out of the DE 195 47 574 out. An automatic navigation of construction vehicles taking into account their position, for example, from the DE 197 44 772 , of the DE 60 2004 011 968 T2 , of the DE 199 40 404 or the DE 197 55 324 A1 out.

A fleet management system that displays data from mobile work machines and their location on an Internet site is in the EP 1 314 101 A1 described. The EP 1 550 096 discloses a system that measures the quality of asphalting or the quality of the asphalt. A system for determining the compaction of an asphalt is described in US Pat EP 0 698 152 B2 addressed. This document discloses specifications for a speed of a paver before the subsequent rollers or other compaction machines.

The US 3,608,446 discloses another material supply system with trucks that bring asphalt to a paver.

The object of the present invention is to improve a method and system for applying a road surface to the effect that road coverings can be produced with even higher quality.

This object is achieved by a method having the features of claim 1 or by a system having the features of claim 10. Advantageous developments of the invention are specified in the subclaims.

Although conventional fleet management systems for construction site operation can occasionally detect the position of individual trucks that deliver the paving material to the construction site. However, this does not prevent, for example, in case of delays in the installation process, several trucks accumulate in front of the paver, so that the mounting material on the truck undesirably cools down strongly. If too much cooling, the paving material may even become unusable, so it must be disposed of consuming. Conventionally, if at all the logistics process of the supply chain (which may include several trucks) is controlled, this is done conventionally according to the so-called "push principle" in which a mixer produces a certain amount of paving material (for example, asphalt) and this asphalt mass flow over the Supply chain transported, for example, in the truck shuttle to the construction site. The paver must then be guided by the delivered mass flow of the paving material.

The invention is based on the idea that it is much cheaper for the quality of the pavement produced when the site logistics is controlled by the so-called "pull principle". This "pull principle" focuses on the paver. It specifies the paving speed of the road surface and determines the required properties and the amount of paving material. For this purpose, the paver generates request commands and transmits them to the mixer. This is then set up, depending on the respective request commands, to set the rate of production of the paving material in the mixer and / or the temperature of the paving material produced in the mixer.

The advantage of the method according to the invention is that influences such as weather, defects, congestion, pauses or work-related changes in the speed of the paver are directly recognized directly on the paver and can now be used to control the mixing plant. For example, if delays in the installation process result from jams or defects, the rate of manufacture of the paving material in the mixer can be slowed or the mass flow delivered to the paver can be reduced. This prevents that too much paving material is produced or transported to the construction site, which can not be installed or jams at the construction site and cools down too much. Conversely, it prevents the paving train comes to a standstill. A significant improvement in quality is achieved by the most uniform installation process possible. Qualitatively equally serious as the cooling of the asphalt on the truck are gaps in coverage, where no truck is on site. As a result, the already applied asphalt cools directly behind the paver, without it being possible to recompress it. When restarting, there is also the risk that bumps are generated transversely to the direction of travel. Thus, quality losses or returns as well as the time-consuming disposal of excess produced paving material can be avoided. In addition, it is not necessary to schedule a reserve that will not ultimately be used for installation. This saves resources, costs and energy. The use therefore seems both ecologically and economically sensible. If it is recognized on the paver that a quick installation of the supplied paving material can take place, the temperature of the paving material produced in the mixer can be reduced, since this material cools less because of the rapid installation. This in turn saves energy.

In the method according to the invention, a single mixing plant may be used or, alternatively, a plurality of mixing plants may be used which deliver the paving material produced by them to one or more construction sites. For the purposes of the invention, a supply chain comprises at least one, preferably several transport vehicles, which transport the installation material from the mixing plant or the mixing plants to the road paver. Another case may involve a transport chain to several road pavers, where the road pavers incorporate different asphalt mix, which must be delivered in the correct order (just-in-sequence).

Preferably, a demand preview is created on the paver, and the request commands are generated in response to this demand preview. The demand preview can be created either manually or by means of a suitable computer program. It estimates what amount of paving material can be processed in a given period of time in the future.

In particular, this demand preview can take into account a work schedule, faults in the installation process or supply chain, defects, congestion and / or weather data. The work plan specifies the intended work result, ie the location, the dimensions and the quality of the road surface to be produced. It can be taken into account that more complicated geometries, such as manhole covers, tight curves or gyros, will reduce the speed of the paver's installation. This expected, reduced installation speed can be taken into account in the demand preview and lead to changes at the mixing plant and / or in the supply chain by means of the request commands.

If a plurality of mixing plants are provided, preferably a change in the requested by the paver amount of paving material is divided according to a key proportional to the maximum capacity of the individual mixing plants or proportional to the ordered by the individual mixers daily amount of paving material to the individual mixing plants. This promotes a smooth operation of the construction process.

In an advantageous embodiment of the method, in certain situations or at regular intervals, feedback is given about the condition of the mixing plant and / or the supply chain to the road paver. In this way, the road paver can be signaled both a smooth operation of the mixing plant or the supply chain, as well as disturbances in the operation of the mixing plant and / or the supply chain.

It is particularly advantageous if the road paver currently located in the supply chain mass flow is displayed on paving material. An operator of the paver can then adjust the paving speed of the paver to this future incoming mass flow. In this way, for example, in the case of an impending shortage of built-in material, the speed of installation can be throttled in order to prevent a standstill of the paver and consequent quality losses.

It is expedient if at least one operating parameter of the paver is set as a function of a feedback of the mixing plant or the supply chain with respect to the temperature or the amount of paving material present in the feed to the paver. The operating parameters may be a paving speed of the paver and / or an operating parameter of a compaction unit of the paver, for example the speed of tampers or the operating parameters of pressure bars. In this way, the method according to the invention leads to a system which operates primarily according to the "pull principle", However, this allows feedback and consequent optimization of the operation of the paver.

In a further variant of the method, means of transport of the supply chain at the mixing plant and / or on a construction site can be identified by a marking. This marking may be a mark that can be read optically or with electromagnetic radiation, which is detected automatically in particular. As a result, the installation process can be further optimized, as more accurate information about the position of the individual means of transport and over the duration of transport from the mixer to the paver can be obtained.

The invention also relates to a system for applying a road surface. In this system, the paver comprises a controller having a communication module adapted to generate request commands and to communicate to the mixer via a (preferably wireless) communication channel. The mixer is configured to adjust the temperature of the paving material produced in the mixer and / or the rate of manufacture of the paving material depending on the received request commands. This results in the advantages described above with regard to the method according to the invention.

It is expedient if the controller of the road paver has a demand forecast determination module by means of which a future demand of the quantity and / or the temperature of the installation material can be estimated. For example, this demand forecasting module may consider a work schedule stored in the controller. Depending on the determined requirement of the quantity and / or the temperature of built-in material suitable request commands can be generated and transmitted via the communication channel to the mixer.

Preferably, an indicator is provided on the road paver or elsewhere on the construction site, for example, a screen by means of which the currently located in the supply chain mass flow of mounting material can be displayed. This allows the paver operator to see how much paving material will be available in future periods.

It is particularly favorable if the controller is set up to automatically adjust the paving speed and / or at least one other operating parameter of the road paver in dependence on a feedback received via the communication channel about the state of the mixing plant or the supply chain. In this way, the operation of the paver and thus ultimately the quality of the road surface can be optimized.

The controller may store a plurality of data sets, each representing a group of matched operating parameters. These datasets can cover most of the situations commonly encountered in paver operation and provide an optimized set of operational parameters for each of these situations. In this way, the operation of the paver is further optimized.

Figur 1

eine vereinfachte Darstellung des erfindungsgemäßen Systems,

Figur 2

eine Darstellung des Straßenfertigers im erfindungsgemäßen System,

Figur 3

ein Flussdiagramm bezüglich der Erfassung von Temperaturwerten,

Figur 4

das Ergebnis einer Asphalttemperaturmessung und Mittlung am Straßenfertiger,

Figur 5

die zeitliche Entwicklung der Verladetemperatur am Mischwerk, und

Figur 6

die gemessene Auslieferungstemperatur des Einbaumaterials an der Baustelle.

In the following, an advantageous embodiment of the invention is explained in detail with reference to a drawing. In detail show:

FIG. 1

a simplified representation of the system according to the invention,

FIG. 2

a representation of the paver in the system according to the invention,

FIG. 3

a flowchart relating to the detection of temperature values,

FIG. 4

the result of an asphalt temperature measurement and averaging on the paver,

FIG. 5

the temporal evolution of the loading temperature at the mixer, and

FIG. 6

the measured delivery temperature of the paving material at the construction site.

Identical components are each provided with the same reference numerals in the drawings.

FIG. 1 shows a schematic view of an inventive system 1 for applying a road surface 2. The system 1 comprises a mixing plant 3, in the paving material 4 (for example, asphalt) is produced. This mounting material 4 has a specific Temperature when it has been produced at the mixer 3. In the case of asphalt, for example, this temperature can be between 130 ° and 170 ° Celsius.

At the mixing plant 3, the built-in material 4 is transferred to a supply chain 5. This supply chain 5 comprises a plurality of transport vehicles 6, for example trucks. The conveyor chain 5 transports the paving material 4 from the mixer 3 to a paver 7. The paver 7 processes the paving material 4 into a paving 2, which can then optionally be further compacted by compaction vehicles such as rollers (not shown).

The inventive system 1 further comprises a communication channel 8, via which the paver 7 wirelessly - for example, via an Internet Protocol, Bluetooth, infrared interfaces or the exchange of SMS messages - can communicate with the mixer 3 and the supply chain 5. Part of this communication channel 8 is a central server 9 with suitable communication interfaces. This server 9 may be located, for example, in a construction site office. He accepts the road paver 7 sent request commands, manages these request commands and forwards them to the mixer 3 and to the transport vehicles 6 of the supply chain 5 on. The mixer is adapted to adjust the rate of manufacture of the paving material 4 and the temperature of the paving material 4 produced in the mixer 3 in response to the request commands received via the communication channel 8, i. change if necessary. On the other hand, the supply chain 5 is set up to set the mass flow of paving material 4 delivered per unit of time to the road paver 7 as a function of the request commands received.

Each transport vehicle 6 of the supply chain 5 is provided with a marking 10 which represents an identification (ID) of the respective transport vehicle 6. The marking 10 can be, for example, an RFID tag, alternatively a visually recognizable marking, for example a one- or two-dimensional barcode or the official identifier. In the illustrated embodiment, the currently located on the paver 7 truck 6 is provided with the mark "17".

For reading the mark 10 of the respective transport vehicle 10 suitable detection means or readers 11 are provided both at the mixing plant 3, as well as at the construction site. These detecting means 11 automatically detect the mark 10 of one The identification of the detected transport vehicle 6 and the time at which this transport vehicle 6 has passed the detection means 11 are transmitted by the detection means 11 wirelessly to the central server 9 to be managed there. The identification of the vehicle can also be recorded at other points of interest for the process, eg at construction site accesses.

FIG. 2 schematically shows a road finisher used in the system according to the invention 7. This paver comprises in a conventional manner a chassis 12, a Gutbunker 13 for receiving the built-in material 4, an operator's station 14, provided for compacting the road surface 2 screed 15 and a transverse distributor screw 16, in front of the Screed 15 is arranged. A central controller 17 of the paver controls the operation of the paver 7. This controller 17 includes, inter alia, a memory 18, a demand forecasting module 19 and a communication module 20. At the control station 14, a display 21 is provided, for example in the form of a screen. In the vicinity of the transverse distributor screw 16, for example on the screed 15, one or more temperature sensors 22 are provided which detect the temperature of the paving material 4 at the transverse distributor screw 16 and transmit it to the controller 17. Alternatively, the asphalt temperature distribution may be recorded by a plurality of sensors mounted behind the screed, or by a scanner mounted rearward to the roof of the paver, which scans the roadway width.

The operation of the system 1 according to the invention or the sequence of the method according to the invention will be explained below by means of an example.

Before starting the construction work, a work plan is created and stored in a computer. This work plan specifies the geometry, the thickness, the degree of compaction and all other relevant parameters for describing the road surface 2 to be produced. The work plan is transmitted to the paver 7 to be stored there in the memory 18 of the controller 17.

The mixer 3 produces paving material 4, such as asphalt. The transport vehicles 6 of the supply chain 5 are loaded at the mixer with the paving material 4, then the paving material 4 to the site and in particular to the road paver 7 to transport. The controller 17 controls the paver 7 so that it can produce the road surface with the fastest possible installation speed. The temperature sensors 22 monitor during installation the temperature of the paving material 4 at the transverse distributor auger 16 (or at any other location on the paver 7, if deemed appropriate). From the current installation speed and the temperature measured at the temperature sensors 22 asphalt temperature and taking into account the stored work plan and possibly external influences such as weather data calculates the demand forecasting module 19 of the controller 17 a demand preview. This indicates how much paving material 4 is required at what temperature in which future periods of time in order to run the paving process as evenly as possible. For example, the demand forecasting module 19 could calculate how much paving material 4 is needed at what temperature within the next 30 minutes, within the subsequent 30 minutes, and so on.

From the demand preview 17 request commands are generated in the controller, which are transmitted via the communication channel 8 to the central server 9. From there, the request commands are transmitted via the communication channel 8 on to the mixing plant 3 and / or to the supply chain 5. In response to the request commands, the mixer 3 may increase or decrease the temperature of the built-in material 4 being produced. For example, the temperature of the paving material 4 can be increased if it appears that the transport vehicles 6 take longer or suspect for transport to the construction site. With this temperature requirement, it can be taken into account that asphalt on a truck, for example, cools down at around 8 ° Celsius per hour. If the demand forecast shows that a slower installation of the road surface 2 is to be expected in future periods, for example on tight bends or complicated road geometries, a lower mass flow of paving material 4 can be requested for this future period to avoid unnecessary waiting times of the paving material 4 at the construction site to avoid. In these future periods, the supply chain 5 would therefore deliver less installation material 4 to the road paver 7.

For temperature measurement on the road paver, an averaging is preferably used, based on FIG. 3 is explained. This averaging has the purpose to prevent a request change by outliers. In step 30 begins the method with a first temperature measurement at the temperature sensor 22. The counter n is given the value n = 1.

In step 31, an average value T _middle (n) is formed from all the previously recorded temperature measurement _values . In step 32, a query is made as to whether the number n of the previously recorded temperature measured values is already 10 (or another value, if more or less measured values are to be averaged). If this is not the case, a new temperature measurement takes place, the number n of the measurements is increased by 1, and in step 31 averaging is again carried out.

After the predetermined number of temperature measurements (in the example ten), the method proceeds to step 33. There, it is checked whether the average temperature T _medium (n) corresponds to a setpoint T _soll , at least within predetermined tolerance ranges. If this is the case, the method begins again with a new temperature measurement in step 30. If, however, the average temperature deviates from the predetermined desired value T _soll , a temperature _correction value T _{corr is} calculated in the following step. This is the difference between the temperature value T _set and _means the average value T, to which a reserve temperature T _res may be added in addition. This temperature reserve T _res takes into account a reserve for possible delays in the delivery of the paving material 4 to the paver. The correction _value T _korr is then transmitted in step 35 from the communication module 20 of the controller 17 via the communication channel 8 to the responsible person on the construction site and to the mixer 3, whereupon the mixer 3 changes the temperature of the paving material 4 produced. The identifiable trucks and their associated mixing plants allow the production temperatures of several mixing plants to be monitored in parallel and the installation temperature to be homogenized.

In one example, the mixer produces 3 Asphalt 4 at a temperature of 142 ° Celsius. A truck 6 transports this asphalt material 4 to the construction site with a journey time of 45 minutes. At a cooling rate of 8 ° Celsius per hour, the installation material 4 cools during transport by 6 °, so it still has a temperature of 136 ° Celsius when it arrives at the paver. However, the setpoint temperature at the paver 7 during installation is T _soll = 120 ° Celsius. The built-in material 4 could therefore be produced at a temperature lower by 16 ° Celsius at the mixer 3. However, now a temperature reserve T _res of 2 ° for possible delays taken into account in the journey time of the truck 6 by 15 minutes. The correction value T _corr sent to the mixer 3 is therefore (120 - 136 + 2) degrees Celsius = -14 ° Celsius. In response to receiving this request command, the mixer 3 thus produces the asphalt 4 4 at a new temperature of 128 ° Celsius.

Especially in so-called low-temperature asphalt, maintaining the correct temperature plays a significant role, both in terms of quality and ecology.

FIG. 4 shows in a temperature-time diagram both the temperature measurement curve 40 at the temperature sensors 22, as well as the time evolution of the averaging according to FIG. 3 41. The temperature measurement curve 40 shows three "break-ins" at which the measured temperature drops sharply. These temperature drops in each case characterize the end of the tilting operation of a transport vehicle 6. The formation of an average value 41 compensates for these temperature drops. The decrease in the mean temperature T _medium with time is due to the storage of the manufactured installation material 4 at the mixer 3 and the resulting cooling of the built-in material. 4

The current temperature of the installation material 4 at the mixing plant 3 can either be detected at the mixing plant 3 itself during loading and fed via an interface to the system 1, or it can be entered manually later on the information on the delivery note.

FIG. 5 shows the development of the mean temperature 50 with time, now the times of arrival of the individual transport vehicles 6 are indicated on the paver 7 by dots.

FIG. 6 again shows the time evolution of the mean 41 of the measured temperature. On the X-axis is in FIG. 6 not only the time specified, but also a location. It designates the length (technical term: stationing) a, by which the installation process has already advanced since a certain zero point. A vertical bar at the time of 1:00 pm or at the location "30 m" indicates the current time. From the previous course of the mean temperature curve 41 is now extrapolated into the future, so as to estimate the further development of the average temperature curve 41 'beyond the current time. At the same time shows FIG. 6 a minimum temperature 51. The built-in material 4 can only be processed if it has at least the minimum temperature 51. The intersection of the extrapolated average temperature curve 41 'and the minimum temperature 51 designates the point in time in the future, to which the installation process can be continued.

Diagrams like those in the FIGS. 4 to 6 Diagrams shown can be displayed to the operator of the paver 7 on the display device 21, so that the operator receives an overview of the development of the temperature of the paving material 4. In addition, the supply chain 5 can provide the paver 7 via the communication channel 8 information about what amount of paving material 4 is currently traveling to the paver 7 and when the arrival of the individual transport vehicles 6 is expected at the site. The mixer 3 may also transmit data relating to the temperature and amount of the built-in material 4 produced as well as the delivery of certain delivery quantities to the transport vehicles 6 by means of the communication channel 8 to the paver 7. The controller 17 of the road paver 7 processes this information and informs the operator of the paver 7 by means of the display device 21 about the amount of paving material 4 expected in future time intervals. Taking this information into account, either the controller 17 can automatically or the operator manually set the paver operating parameters 7 , in particular its installation speed, adapt. If faults occur, such as traffic congestion or failure of trucks 6 along the supply chain 5, or a failure or production bottlenecks at mixers 3, the installation process of the paver 7 can be slowed down to prevent quality-degrading interruptions in the installation process.

If a plurality of mixing units 3 are provided, a change in the mass flow of paving material 4 requested by the road paver 7 can be divided among the individual mixing plants 3 according to a key proportional to the maximum capacity of the individual mixing plants 3 or proportional to the daily amount of paving material 4 ordered by the individual mixing plants 3 ,

Claims (14)

1. Method of applying a road surface (2) using at least one mixing plant (3) for producing laying material (4), a road finishing machine (7) processing the laying material (4) to a road surface (2), and a supply chain (5) transporting the laying material (4) from the mixing plant (3) to the road finishing machine (7), characterized in that request commands are transmitted from the road finishing machine (7) to the mixing plant (4), and that, depending on these request commands, the production rate of the laying material (4) in the mixing plant (3) and/or the temperature of the laying material (4) produced in the mixing plant (3) are adjusted.
2. Method according to claim 1, characterized in that a demand forecast is established and the request commands are established depending on the demand forecast.
3. Method according to claim 2, characterized in that the demand forecast takes into consideration a work schedule, troubles in the laying process or the supply chain, defects, traffic jams and/or weather data.
4. Method according to one of the preceding claims, characterized in that, if several mixing plants (3) are provided, a change of the mass flow (5) of laying material (4) requested by the road finishing machine (7) is distributed to the individual mixing plants (3) according to a key proportionally to the maximum capacity of the individual mixing plants (3) or proportionally to the daily amount of laying material ordered from the individual mixing plants (3).
5. Method according to one of the preceding claims, characterized in that a feedback on the condition of the mixing plant (3) and/or the supply chain (5) is given to the road finishing machine (7).
6. Method according to claim 5, characterized in that the mass flow of laying material (4) currently located in the supply chain (5) is displayed at the road finishing machine (7).
7. Method according to one of claims 5 or 6, characterized in that at least one operating parameter of the road finishing machine (7) is adjusted depending on a feedback of the mixing plant (3) or the supply chain (5) on the temperature or the amount of the laying material (4) located in the supply at the road finishing machine (7).
8. Method according to claim 7, characterized in that the operating parameter is a laying speed of the road finishing machine (7) and/or an operating parameter of a compacting unit (15) of the road finishing machine (7).
9. Method according to one of the preceding claims, characterized in that transport means (6) of the supply chain (5) are detected at the mixing plant (3) and/or on a construction site by a marking (10).
10. System (1) for applying a road surface (2) with a road finishing machine (7) for applying a road surface (2) of laying material (4), a mixing plant (3) for producing the laying material (4), and a supply chain (5) for transporting the laying material (4) from the mixing plant (3) to the road finishing machine (7), characterized in that the road finishing machine (7) comprises a control (17) with a communication module (20) which is adapted to generate request commands and transmit them, via a communication channel (8), to the mixing plant (3), and that the mixing plant (3) is adapted to adjust, depending on these request commands, the temperature of the laying material (4) produced in the mixing plant (3) and/or the production rate of the laying material (4) in the mixing plant (3).
11. System according to claim 10, characterized in that the control (17) comprises a demand forecast assessment module (19) which is adapted to assess a future demand of the amount and/or temperature of laying material (4).
12. System according to one of claims 10 or 11, characterized in that a display (21) is provided at the road finishing machine (7) by means of which the mass flow of laying material (4) currently located in the supply chain (5) can be displayed at the road finishing machine (7).
13. System according to one of claims 10 to 12, characterized in that the control (17) is adapted to automatically adjust the laying speed and/or at least one other operating parameter of the road finishing machine (7) depending on a feedback on a condition of the mixing plant (3) or the supply chain (5) received via the communication channel (8).
14. System according to one of claims 10 to 13, characterized in that in the control (17), a plurality of data records is stored which each represent a group of operating parameters adapted to each other.

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