EP4072809A1 - Computer-assisted method and device for controlling a concrete mixing facility - Google Patents

Abstract

The invention relates to a computer-assisted method and to a device for controlling a concrete mixing facility for producing ready-mixed concrete (1) or pre-mixed pouring concrete which is mixed at least from the components cement (6a; 6b) and aggregates (8a, 8b, 8c) with addition of water (9) in a motor-driven mixer unit (3). Prior to the start of the mixing process, at least the required mixing time (tM) of the mixer unit (3) is calculated by means of an electronic predictive unit (10), which takes into account the current moisture content (F) of at least the aggregates (8a, 8b, 8c) to be added, measured by means of at least one humidity sensor (11), and the component temperature (TK), the mixer temperature (TM) and/or the external temperature (TA), measured or determined by means of at least one temperature sensor (12; 13; 14) or thermal imaging camera, in order to determine the required mixing time (tM) of the mixer unit (3) on the basis of a predefined concrete formula (18), taking into account the various measured values determined by the sensors.

Description

Computer-aided process and device for controlling a concrete mixing plant

Reference to related applications

The present application claims the priority of German patent application No. 102019219373.0, filed on December 11, 2019, which is incorporated in its entirety by reference into this document.

The present invention relates to a computer-aided method for controlling a concrete mixing plant for the production of ready-mixed concrete or mixed concrete, which is mixed at least from the components cement and aggregates with the addition of water in a motor-driven mixer unit. In addition, the invention also relates to a data processing device executing the control method and a computer program embodying the method. Furthermore, the invention comprises a special data format generated by the device for a documentation data record of the concrete quality produced and delivered by a concrete mixing plant.

The field of application of the invention extends both to concrete mixing plants and to the transport logistics between a concrete mixing plant for the production of ready-mixed concrete and the construction site on which the ready-mixed concrete is delivered and installed.

LK: State of the art

A concrete mixing plant usually consists essentially of several silos and outdoor storage areas on which the components to be mixed are stored. Powdered cement is stored in silos, protected from moisture, and the aggregates, preferably gravel and sand, are stored outdoors in the form of bulk material heaps. From here, depending on the type of concrete mixing plant, the aggregates can also be conveyed into silos, for example using a conveyor belt system. Different grain groups of aggregates are stored separately in assigned silos. The components get from the silos into the mixer unit according to a concrete recipe to be produced with the appropriate addition of water.

The mixer unit can be designed, for example, as a drum mixer, free-fall mixer, ring trough mixer, plate mixer, plate mixer or the like. After a mixing time, which is usually dictated by the recipe, the ready-mixed concrete is filled into truck mixers, which are supposed to transport it to the construction site as punctually as possible.

So-called concrete additives are also used as additional components for the production of ready-mixed concrete, which must be stored separately from the aforementioned components. The same applies analogously to so-called concrete additives, for example fly ash, limestone powder or the like.

According to the generally known state of the art, the above-mentioned components are usually metered by an operator in the control room of the concrete mixing plant and is carried out in a semi-automated manner in accordance with written mixing instructions, i.e. the concrete recipe. For batch sizes of more than 1 m ^3, strict rules apply to the metering of the components. The components cement, aggregates, water and additives must be dosed with a tolerance of ± 3% of the required amount in order to achieve the desired concrete quality. The dosing process is computer-assisted according to instructions and when controlling the mixing time, care must be taken that changes in the properties of the components, such as the moisture of the aggregates, trigger a corresponding adjustment of the added quantities.

The mixing of the components must be carried out by the motor-driven mixer unit until the mixture appears uniform. This period is the mixing time ΪM, which is usually determined on the basis of empirical values and is at least 30 seconds for normal concrete and at least 90 seconds for lightweight concrete. Of course, the required mixing time Ϊ _M also depends on the shape and movement of the mixer unit, for example on the speed of a drum mixer. These parameters differ depending on the concrete mixing plant and the mixer technology used there. Therefore, the aforementioned empirical values are not generally applicable. If too long a mixing time is selected to be on the safe side, an optimal mixing of the components is achieved, but the longer system time requires a correspondingly higher effort and, for example, due to the fact that the transport concrete is also too long due to the dust, the quality of the ready-mixed concrete can also suffer from premature setting.

In addition, longer mixing times may be required for the production of concretes with special requirements, for example self-compacting concretes, high-strength concretes, exposed concrete or when using air entrainment patterns. Concrete admixtures usually need to be added during the mixing process. If superplasticizer is added during the mixing process, the concrete must be mixed further until the superplasticizer has been completely distributed in the mixture. Depending on the system technology, concrete admixtures are added either together with the Water supply or immediately afterwards. Usually the effect depends on the time of addition.

In addition, other circumstances also influence the required mixing time Ϊ _{M of} the mixer unit and the associated quality of the ready-mixed concrete produced. For example, aggregates that have been heated up by solar radiation in summer can lead to ready-mixed concrete that is much too hot, which may begin to set before the end of the transport period. Although this can be counteracted by adding dry ice or watering the rock formations, the achievable results cannot always be reliably achieved due to the other influencing parameters mentioned above.

It is therefore the object of the present invention to create a method and a device for computer-aided control of a concrete mixing plant, which ensures the most uniform possible concrete quality for different concrete formulations despite different or changing influencing parameters.

Disclosure of the invention

The object is achieved by a computer-aided method according to claim 1. Reference is made to claim 10 with regard to a data processing device executing the method. Claim 16 relates to a concrete mixing plant for the production of ready-mixed concrete, which includes such a device. In addition, a special data format for a documentation data record of a concrete mixing plant is proposed and claim 18 relates to a computer program embodying the method according to the invention. The invention includes the procedural teaching that the required mixing time Ϊ _{M of} the mixer unit as a quality-determining factor for a ready-mixed concrete produced in a concrete mixing plant is calculated using an electronic forecast unit from the relevant influencing parameters before the start of the mixing process A moisture sensor measured current moisture F at least of the added aggregates, but also the component temperature TK measured or determined via at least one temperature sensor or a thermal imaging camera, the mixer temperature TM and / or the outside temperature TA also taken into account in order to be based on a specified concrete recipe taking into account the Sensor technology determined various measured values to determine the required mixing time Ϊ _{M of} the mixer unit as well as the expected concrete quality for each batch size. If a thermal imaging camera is used instead of a temperature sensor, it can be installed below or next to a mixer drum or the like, for example, to detect the mixer temperature TK. In this way, existing concrete mixing plants can also be retrofitted with the technology according to the invention in terms of the required hardware with reasonable effort.

In other words, the solution according to the invention contains an optimal prediction of the mixing time Ϊ _{M of} a concrete mixing plant as a quality-determining factor for a ready-mixed concrete to be produced by comparing measured values from various sensors, in particular a moisture sensor for determining the moisture content of the aggregates and at least one temperature sensor for determining process temperatures and / or sensors for other process parameters. It has been found that these essential measured variables have a decisive influence on the concrete quality that can be _{achieved, so that the concrete quality can be made uniform by setting the mixing time Ϊ M accordingly.} For example, when the outside temperature is high, the mixing process can be shortened by increasing the amount of water added. Preferably done i.e. the prognosis of the required mixing time Ϊ _M , taking into account further correction characteristics for parameters relevant to the recipe.

It is also proposed that the required mixing duration Ϊ _{M be} transmitted from the forecasting unit directly to the control unit of the mixer unit for controlling the same. In addition, the control unit can also vary the speed of rotation of a drum-shaped mixer unit in order to subsequently extend or shorten the predicted required mixing duration Ϊ _M. If, for example, temperature measured values rise unusually strongly during the mixing process, the normal speed of the mixer unit can be increased in order to subsequently shorten the mixing time. This also shortens the heat exposure. The control unit also adjusts the amount of water added to the measured moisture content of the aggregate.

For example, temperature / mixing time correction characteristics, speed / mixing time correction characteristics and the like are used as correction characteristics for parameters relevant to the recipe. These characteristics are used to vary the mixing time Ϊ _M as a function of parameters such as the temperature or the speed of a drum-shaped mixer unit, which influence the quality of the concrete.

According to a further measure improving the invention, it is proposed that the electronic forecasting unit not only _{calculate the mixing time Ϊ M} , but also forecast the transport time for the ready-mixed concrete from the concrete mixing plant to the construction site. Since the delivery location and the desired delivery time are also known from the order information for the ready-mixed concrete, the electronic forecasting unit can use a route planning unit to estimate the current travel time of a truck mixer due to the traffic. As a further influencing parameter, the electronic forecasting unit can also take into account the estimated transport temperature curve based on the outside temperature and optionally also an estimated waiting time until the ready-mixed concrete is installed on the construction site. A waiting time can result, for example, from the fact that a formwork has not yet been completed on the construction site or the installation of earlier deliveries of ready-mixed concrete is delayed. Since the outside temperature also has a decisive influence on the quality of the concrete during transport, this is also taken into account. Using a forecast unit, the concrete quality can be predicted along the entire production chain, from the storage of the material, the start of the mixing process to the installation on the construction site, and if necessary influenced in order to achieve uniform quality. If, for example, a longer transport time is required due to congestion, the forecasting unit reacts by specifying concrete additives to extend the pot life of the ready-mixed concrete, which can be added within the framework of the given concrete recipe during the mixing process according to the control unit.

Since the forecast unit is able to determine the concrete quality that can be achieved under the given circumstances on the basis of the measured values determined by the sensors and other process-influencing parameters for the concrete recipe to be implemented, this can be communicated to the person responsible on the construction site before mixing and subsequent transport so that they can decide whether the concrete quality that can be achieved under the given circumstances should be used or not. In this way, incorrect deliveries can be avoided.

This process can advantageously be carried out by a computer-aided comparison unit connected to the forecast unit, which compares the forecast, realizable concrete quality with the specification required for the construction site. before the mixing unit is filled with the components to be mixed, the mixing process is started.

According to a further measure improving the invention, it is proposed that at least the information generated by the sensors, the forecasting unit, the control unit and the comparison unit on a mixing and delivery process for ready-mixed concrete is stored in a documentation database so that it can be called up. For this purpose, a special data format for a documentation data record is proposed which comprises at least the following essential data fields assigned to an order identifier as a data record key: concrete recipe used,

Measured temperature values during the mixing and / or transport process, measured moisture values of at least one component of the concrete formulation used,

Quantities of all components used in the concrete formulation, you forecast _{the mixing time Ϊ M of} the mixer unit, and transport time to and waiting time on the construction site.

This special data format thus includes the core information, which is decisive for the concrete quality of a delivery. In addition, further data can of course also be added to the documentation data record. Furthermore, with a correspondingly large amount of data, such documentation data sets can be analyzed to determine the conditions under which optimal concrete quality could be achieved in order processes. From this, a pattern identifier can automatically suggest countermeasures to eliminate negative influences in the context of machine learning in order to ensure a higher probability of optimal concrete quality in the future. Such a countermeasure can, for example, result in an increased addition of water slow speeds, a shortened mixing time at low temperatures or the like. All such countermeasures are not readily recognizable at all on the basis of the human understanding with the wealth of experience of a specialist.

The documentation data set can also be linked to other construction-related data using blockchain technology and stored in a forgery-proof documentation database for all those involved in a construction project.

Detailed description based on the drawing

Further measures improving the invention are shown in more detail below together with the description of a preferred exemplary embodiment of the invention with reference to the figures. It shows:

1 shows a schematic representation of a concrete mixing plant with a computer-aided control device implemented therein,

FIG. 2 shows a schematic flow chart of a method for controlling the concrete mixing plant according to FIG. 1, and

3 shows a data format of an order data record for the concrete mixing plant.

According to Fig. 1, a concrete mixing plant for the production of ready-mixed concrete 1, which is transported from there by truck mixer 2 to a construction site - not shown here - for shoring, essentially consists of a mixer unit 3, which is designed here as a drum mixer, which can be set in rotary motion via an electric drive motor 4 for mixing. For the supply of components to be mixed, the mixer unit 3 is connected to cement silos 5a to 5c, which contain different types of cement 6a; 6b; 6c, which are blown into the mixer unit 3 in a valve-controlled manner via a compressed air delivery device. In addition, the mixer unit 3 is in material flow connection with a dump area 7, on which dumps of bulk material with different aggregates 8a to 8c, that is different gravel and sands, are stored. These are transported to the mixer unit 3 by a conveyor belt device. In addition, the mixer unit 3 can be connected to a connection for water 9.

In order to calculate a required mixing time Ϊ _M for operating the mixer unit 3, an electronic forecast unit 10 is provided as part of the control of the concrete mixing plant. On the input side, in this exemplary embodiment, the electronic forecasting unit 10 has a moisture sensor 11 for measuring the current moisture F of the aggregate 8a to be supplied; 8b; 8c in connection. In addition, the temperature sensor 12, the component temperature T _{K of} the aggregate to be fed 8a; 8b; 8c measured. In addition, the process temperature within the mixer unit 3 is monitored via a further temperature sensor 13 and the outside temperature TA is also monitored via a temperature sensor 14. At this point, it should be pointed out again that only a partial selection of these sensors or additional sensors are provided within the scope of the solution according to the invention can report which measured values relevant to the mixing time to the electronic forecasting unit 10.

The electronic forecasting unit 10 determines, based on a ready-mixed concrete order 16 stored in an order database 15 and to be processed, the associated concrete recipe 18 stored in a recipe database 17, for example for a special lightweight concrete. In addition, the different types of measurement values determined by the sensor system described above are fed to the prognosis unit 10. Proceeding from this, the prognosis unit 10 determines at least the required mixing duration Ϊ _{M of} the mixer unit 3 at a specific nominal speed. In addition, other control data can also be forecast.

When determining the control data, the prognosis unit 10 also takes into account correction characteristics 19, which are stored in a correction line database 20 and can be called up. For example, a temperature / mixing time correction characteristic curve can be used, for example in the case of the use of unusually dry and heated components, to extend _{the mixing time unter M with increased addition of water.} In the opposite case, the same applies analogously.

_{The required mixing duration Ϊ M} predicted by the forecast unit 10 is then transmitted to the control unit 21 of the mixer unit 3 for controlling the motor 4 at a defined nominal speed. In addition, it is also possible for the control unit 21 to reduce or increase the speed of the electric motor 4 in order to _{vary the predicted required mixing duration t MZ} u. For example, if a truck mixer 2 is not yet available for the removal of the ready-mixed concrete 1, the rotational speed of the mixer unit 3 can be reduced during the waiting time.

In addition, in this exemplary embodiment, the electronic forecasting unit 10 also takes into account a transport time fr from the stationary concrete mixing plant to the construction site, which is forecast using a route planning unit 22 and which results from the route planning data. This can also be used to vary _{the required mixing time M accordingly.} In addition, concrete admixtures that extend the pot life can be added within the framework of the concrete formulation if it turns out that the delivery of the ready-mixed concrete 1 to the construction site would be extended due to traffic. This ensures that a concrete quality that is as uniform as possible is used.

A comparison unit 23, which is also connected to the forecast unit 10, compares the forecast, realizable concrete quality with the specification required for the construction site, which results from the order 16 for ready-mixed concrete. If this specification cannot be achieved, there is a possibility that the start of the filling and mixing process will be prevented, as it is foreseeable that the required concrete quality cannot be achieved in view of the extreme heating of components in the summer or a transport time delayed due to traffic jams. This information generated by the comparison unit 23 can, for example, also be transmitted to the construction site for the purpose of changing the construction schedule.

It is also provided that the information generated by the sensor system, the prognosis unit 10, the control unit 21 and the comparison unit 23 on a mixing and delivery process for ready-mixed concrete 1 can be retrieved in a documentation database 24, which ensures later traceability.

According to FIG. 2, the method for controlling a concrete mixing plant for the production of ready-mixed concrete 1 comprises at least the following steps:

In a step A, the concrete recipe to be produced is first loaded for the execution of a ready-mixed concrete order. In a step B, various current state measurement values of the required components are read in via the sensors of the concrete mixing plant. On the basis of this, in a step C, at least the required mixing time is forecast. In a step D, this result is corrected by further logistical influencing parameters. In a step E, it is filled into a truck mixer for transport to the construction site. According to FIG. 3, a data format of an order data record 25 for a concrete mixing plant for the production of ready-mixed concrete comprises the following data fields assigned to an order identifier 26, which are also archived in the documentation database 24:

The concrete formulation 18 used is stored in a data field I, the measured temperature values T during the mixing and / or transport process are stored in a data field II, the measured moisture values F of at least one component of the concrete formulation used are stored in a data field III, and the actual quantities M of all components used according to the concrete recipe are stored, the predicted mixing time der _{M of} the mixer unit is stored in a data field V and the entire transport and waiting time t of the ready-mixed concrete to or on the construction site is stored in a data field VI.

This concentrated data set documents essential quality information about an ordered and installed ready-mixed concrete, which is also accessible for a later evaluation in the sense of pattern recognition, damage analysis, recipe improvements and the like.

The invention is not limited to the preferred exemplary embodiment described above. Rather, modifications thereof are also conceivable, which are also covered by the scope of protection of the following claims. For example, it is also conceivable, in addition to or instead of the control parameter of the required mixing duration t _M that determines the quality of the concrete, to also predict other or further variables, such as the actually required quantities of the individual components of the concrete. In cold weather conditions on the construction site, the concrete mix can also be specifically preheated, for example. Thanks to the solution according to the invention, the quality of a concrete delivery can also be met in a contractual condition that can be met make a so-called smart contract and secure it along the production and use chain using blockchain technology.

List of reference symbols

Ready-mixed concrete

Truck mixer

Mixer unit

Electric motor

silo

cement

Dump area

Rock flow

water

Forecast unit

Humidity sensor first temperature sensor second temperature sensor third temperature sensor

Order database

Ready-mixed concrete order

Recipe database

Concrete recipe

Correction curve

Correction characteristics database

Control unit

Route planning unit

Adjustment unit

Documentation database

Documentation data set

Order identifier

Claims

Expectations 1. Computer-aided method for controlling a concrete mixing plant for the production of ready-mixed concrete (1) or mixed concrete, which consists of at least the components cement (6a; 6b) and aggregates (8a, 8b, 8c) with the addition of water (9) in one motor-operated mixer unit (3), characterized in that at least the required mixing time (ΪM) of the mixer unit (3) is calculated before the start of the mixing process via an electronic forecast unit (10), which is the current measured via at least one moisture sensor (11) Moisture (F) of at least the aggregates (8a, 8b, 8c) to be added and the component temperature (TK), the mixer temperature (TM) and / or the outside temperature (TA) measured or determined by at least one temperature sensor (12; 13; 14) or thermal imaging camera ) are taken into account, based on a specified concrete recipe (18) taking into account the various types of measurement determined by the sensors rte to determine the required mixing time (ΪM) of the mixer unit (3). 2. The method according to claim 1, characterized in that the prognosis of the required mixing time (ΪM) is carried out with further consideration of correction characteristics (19) for parameters relevant to the recipe. 3. The method according to claim 1, characterized in that the required mixing time (ΪM) is transmitted from the forecast unit (10) to the control unit (21) of the mixer unit (3) for control. 4. The method according to claim 1, characterized in that the control unit (21) varies the speed of rotation of a drum-shaped mixer unit (3) for the subsequent extension or reduction of the predicted required mixing time (ΪM). 5. The method according to claim 1, characterized in that by the electronic forecasting unit (10) a transport time (fr) from the stationary concrete mixing plant to a construction site and / or an estimated transport temperature profile of the ready-mixed concrete (1), which is predicted using a route planning unit (22) and / or an estimated waiting time until the ready-mixed concrete (1) is installed on the construction site is taken into account in the calculation. 6. The method according to claim 1, characterized in that by the control unit (21) the addition of water (9) according to the concrete recipe (18) and taking into account the measured moisture at least the aggregates to be added (8a, 8b, 8c) or others Components is controlled. 7. The method according to claim 1, characterized in that the prognosis unit (10) for the concrete recipe (18) to be implemented on the basis of the measured values determined by the sensors determines the concrete quality that can be achieved under the given circumstances. 8. The method according to claim 1, characterized in that a comparison unit (23) compares the predicted realizable concrete quality with the specification required for the construction site before the start of the mixing process. 9. The method according to claim 1, characterized in that at least the information generated by the sensors, the forecast unit (10), the control unit (21) and the adjustment unit (22) on a mixing and delivery process of ready-mixed concrete (1) in a documentation -Database (24) is stored in a retrievable manner. 10. Device for data processing for the control of a concrete mixing plant for the production of ready-mixed concrete (1) or mixed concrete, which a motor-driven mixer unit (3) from at least the components cement (6a; 6b) and aggregates (8a, 8b, 8c) with addition generated by water (9), the components being stored in respective silos (5a, 5b) in material flow connection with the mixer unit (3) and / or on at least one dump area (7), characterized in that an electronic forecasting unit (10) to calculate the required mixing time (M) of the mixer unit (3) is provided, which the current humidity (F) measured by at least one humidity sensor (11) of at least the aggregates (8a; 8b; 8c) to be added and the by at least one temperature sensor (12 ; 13; 14) or thermal imaging camera take into account the component temperature (TK), the mixer temperature (TM) and / or the outside temperature (TA) ichtigt in order to determine the required mixing time (ΪM) of the mixer unit (3) on the basis of a concrete recipe (18) taking into account the measured values determined by the sensors. 11. Device according to claim 10, characterized in that different concrete recipes (18) are stored in a recipe database (17) connected to the forecast unit (10). 12. Device according to claim 10, characterized in that the correction characteristics (19) for parameters relevant to the recipe are stored in a correction line database (20) connected to the prognosis unit. 13. Device according to claim 10, characterized in that the correction characteristics (19) for recipe-relevant parameters are selected from a group of characteristics, comprising: temperature-mixing time correction characteristic curve, speed-mixing time correction characteristic curve. 14. Device according to claim 10, characterized in that the components to be mixed also include concrete additives and / or concrete additives, the properties of which are also taken into account by the forecast unit (10) due to the formulation. 15. Device according to claim 10, characterized in that the information on a mixing and delivery process, including the concrete recipe (18) used, temperature measurements during the mixing and / or transport process, moisture measurements of at least one component used in the concrete recipe (18), amounts of used components of the concrete recipe (18), the predicted mixing time (ΪM) and correction values for this and / or the subsequent transport and waiting time in the form of a documentation data record (25) are stored in a documentation database (24) and can be called up. 16. Concrete mixing plant for the production of ready-mixed concrete (1), comprising an electronic device according to one of claims 10 to 15. 17. Data format of a documentation data set (25) for a concrete mixing plant for the production of ready-mixed concrete (1) or mixed concrete, at least comprising the following data fields (I - VI) assigned to an order identifier (26): concrete recipe (18) used, Measured temperature values (T) during the mixing and / or transport process, measured moisture values (F) of at least one component used in the concrete formulation (18), actual quantities (M) of all components used according to the concrete formulation (18), forecast mixing time (ΪM) of the mixer unit (3) , and transport time to with waiting time (t) at the construction site. 18. A computer program comprising instructions which, when the program is executed by a computer-aided device according to one of claims 10 to 15, cause the latter to execute the method according to one of claims 1 to 9.