Method and road construction system for dynamically controlling a installation speed of a road finisher

Abstract

The invention relates to a method for dynamically controlling the paving speed (v) of at least one road paver (3) for a paving process (E), wherein, based on a control system (2) functionally connected to the road paver (3), a paving speed (v) adapted to the determined material delivery rate (PL) of a material supply chain (L) supplying the road paver (3) with paving material (M) is determined as a function of a variable material delivery rate (PL) of a material supply chain (L) supplying the road paver (3) with paving material (M), and wherein a pre-compaction performance (VL) of at least one pre-compaction element (6) of a screed (7, 7') of the road paver (3) is adapted as a function of the determined paving speed (v) in order to maintain a constant pre-compaction (V) achieved by means of the pre-compaction element (6).Furthermore, the invention relates to a road construction system (1) for an installation process (E) for producing a constant pre-compaction (V) at varying installation speeds (v).

Description

[0001] The present invention relates to a method for dynamically controlling a paving speed of at least one road paver for a paving process according to claim 1. Furthermore, the invention relates to a road construction system for a dynamic paving process according to claim 14.

[0002] EP 2 514 871 A1 discloses a road construction system comprising a material supply chain, a road paver supplied with paving material from the material supply chain for precompacting a newly produced paving layer, and a compactor vehicle following the road paver for final compaction of the newly produced paving layer. Furthermore, the road construction system has an electronic material density module configured to detect the precompaction achieved by the road paver and to communicate with the compactor vehicle, which adjusts its final compaction performance based on the received data representing the precompaction in order to achieve a desired final compaction of the newly produced paving layer.

[0003] DE 10 2019 116 853 A1 discloses a system and method for controlling the speed of a road paver. For this purpose, a feed rate of the paving material delivered from an asphalt mixing plant to a construction site is determined, and the paving speed of at least one road paver used on the construction site is adjusted depending on the determined feed rate. Alternatively, the speed of the road paver, in particular its maximum paving speed, can be varied based on a detected maximum compaction rate of the compaction machines following the road paver.

[0004] EP 2 325 392 A2 discloses a road paver with a compaction unit whose stroke can be automatically adjusted to the paving speed, resulting in largely constant pre-compaction even when the paver's speed changes. The automatic adjustment of the stroke is performed by means of a speed-dependent characteristic control. Comparable characteristic control systems are disclosed in EP 3 138 961 A1, EP 2 366 831 A1, and EP 2 366 832 A1.

[0005] The invention is based on the object of providing an installation process with improved installation quality and improved installation performance.

[0006] This object is achieved by a method according to claim 1 and by means of a road construction system according to claim 14. Advantageous further developments of the invention are given by the respective subject matters of the subclaims.

[0007] The invention relates to a method for dynamically controlling a paving speed of at least one road paver for a paving process. A control system functionally connected to the road paver determines a paving speed for the road paver that is adjusted to the determined material delivery rate based on a variable material delivery rate of a material supply chain supplying the road paver with paving material. By having the road paver perform the paving process at the determined paving speed adjusted to the material delivery rate, material supply bottlenecks or interruptions in the material supply at the road paver's construction site can be prevented. Furthermore, an oversupply of material at the construction site can be counteracted.

[0008] According to the invention, the precompaction performance of at least one precompaction element of a paving screed of the road paver is adjusted depending on the paving speed, which is adjusted to the material delivery rate, in order to maintain a constant precompaction achieved by the precompaction element. According to the invention, the precompaction performance performed directly on the road paver is thus varied depending on the speed for the road paver, which is dynamically determined based on the determined material delivery rate, in order to maintain a constant precompaction in the paving layer laid by the road paver. This allows the precompaction to remain constant even if the paving speed of the road paver changes due to a varying material delivery rate.

[0009] This allows, on the one hand, the speed of the paver to be optimized taking into account the feed rate or material delivery rate to achieve improved paving performance. On the other hand, this optimization allows consistent pre-compaction using the screed, meaning the paver is able to produce a paving layer with consistent pre-compaction despite the paving speed being adjusted to the material delivery rate. This results in improved paving quality.

[0010] The invention further promotes a continuous material supply throughout the material supply chain, as the operation of the road paver is adjusted to the determined material delivery rate, meaning that there is no oversupply or undersupply of paving material on the construction site. Furthermore, the invention allows for a continuous paving process, as the paving layer can be created without interruptions using the road paver, taking the material delivery rate into account. Fluctuations in the material supply can be easily compensated for using the invention without affecting the pre-compaction quality.

[0011] In principle, the invention allows the paving process to proceed more slowly as the material delivery rate decreases and more quickly as the material delivery rate increases, without this dynamic leading to a change in pre-compaction. This results in a continuous, i.e., uninterrupted, paving process on the construction site, leading to constant pre-compaction, beyond the material supply chain.

[0012] The invention derives the pre-compaction performance of the paving screed of the road paver from the material delivery performance of the material supply chain. The material delivery performance determines the paving speed of the road paver, on which the pre-compaction performance depends. This leads to a homogeneous, consistent pre-compaction result with uninterrupted paving. The inventive concept of correlating the material delivery performance with the pre-compaction performance via the adjusted paving speed enables an overall more efficient and higher-quality paving process.

[0013] Preferably, a user enters a maximum paving speed for the paving process in the control system as a limit condition. This allows expert knowledge to set limits on the paver's speed control on the construction site.

[0014] In particular, the user can make the input in the control system dependent on the type of paving screed of the road paver on the construction site, especially its maximum pre-compaction performance. This allows the paver's paving speed to be increased only to the extent that constant pre-compaction is still possible.

[0015] It would be conceivable for the control system to be functionally linked to the paving screed and, when the paving screed of the road paver is changed, which may change a possible maximum pre-compaction performance, to prompt the user to confirm or update the maximum paving speed stored by the user as a limit condition in the control system.

[0016] According to a variant of the invention, the control system determines the maximum possible paving rate by the road paver, taking into account the determined material delivery rate, and thus calculates a separate maximum paving speed for the road paver depending on the layer thickness and layer width to be produced by the paving screed. The control system is thus capable of calculating a separate maximum paving speed for the road paver for any structure specification, adapted to the material delivery rate. This separately determined maximum paving speed can, in principle, be lower than, equal to, or higher than the maximum paving speed stored by the user in the control system.

[0017] In particular, according to one variant of the invention, the maximum paving speed calculated using the control system is stored as the paving speed target value in a vehicle control system of the road paver that is functionally connected to the control system if this is less than or equal to the maximum paving speed entered by the user. Alternatively, it would be possible for the maximum paving speed entered by the user to be stored as the paving speed target value in the vehicle control system of the road paver that is functionally connected to the control system if the maximum paving speed calculated using the control system is greater than the maximum paving speed entered by the user. The first alternative described above results in a paving process that is as accelerated as possible depending on the determined material delivery rate, without risking an interruption in paving.This allows for a maximum paving rate adapted to the material delivery rate. The second alternative mentioned above sets limits on the speed increase of the paving process through specialist knowledge, for example, with regard to the maximum pre-compaction rate achievable by the screed. This allows for the maximum paving speed to be determined even at very high material delivery rates in such a way that the pre-compaction rate can be adjusted to maintain a constant pre-compaction, even if the determined material delivery rate would actually allow for a higher maximum paving rate. In both alternatives, the pre-compaction therefore remains constant.

[0018] According to one embodiment of the invention, the control system, by detecting a changing material delivery rate, calculates a correspondingly adjusted, new maximum paving speed for the road paver and determines a time at which the new maximum paving speed is stored in the road paver's vehicle control system. This ensures that the speed adjustment of the paving process is only carried out on the road paver when a correspondingly detected, increased, or reduced material delivery rate of the material supply chain is noticeable on the construction site. Thus, the road paver only reacts to an increased or reduced material delivery rate when it actually arrives at the construction site, i.e., when it affects the amount of material stored there.

[0019] In particular, the control system can vary the time at which the new maximum paving speed is stored in the road paver's vehicle control system depending on the magnitude of the required paving speed change. In principle, with a small change in paving speed with regard to a changing material delivery rate, the new maximum paving speed in the road paver's vehicle control system tends to be stored or activated later than with a large change in paving speed with regard to a changing material delivery rate. This principle can lead to only short-term, minor changes in material delivery rate being ignored, i.e., not being unnecessarily transferred to the operation of the road paver. This promotes energy-efficient operation of the road paver.

[0020] Preferably, the new maximum paving speed calculated using the control system is stored as the new paving speed target value in the vehicle control system of the road paver, which is functionally connected to the control system, if this is less than or equal to the maximum paving speed entered by the user. Alternatively, it would be possible for the maximum paving speed entered by the user to be stored as the paving speed target value in the vehicle control system of the road paver, which is functionally connected to the control system, or for this speed to remain set if the new maximum paving speed calculated using the control system is (still) greater than the maximum paving speed entered by the user. In both alternatives, it can be ensured that, based on the determined material delivery rate, a maximum paving rate combined with consistent pre-compaction is possible.In the first alternative, the main consideration is that the maximum paving speed is set with regard to the material delivery capacity in such a way that the road paver only accelerates the paving process when the material supply is low to the extent that it can carry out the paving process continuously, i.e. disadvantages associated with a material supply bottleneck and a resulting stoppage of the road paver, such as the sinking of the paving screed during the stop and / or impairments of the layer thickness surface quality, for example due to imprints, can be avoided.The other alternative, whereby the maximum paving speed is operated according to the user-set maximum paving speed, ensures that the paver does not operate at an excessive paving speed. While this would in principle be possible with the determined material delivery rate, it would no longer be possible to compensate for it with the maximum pre-compaction rate adjustable on the paving screed to achieve constant pre-compaction. Thus, with these variants, the control system always instructs the paver to accelerate the paving process to such an extent that the paver never stops on the construction site and paving is always carried out with consistent pre-compaction.

[0021] Preferably, the control system adjusts the paving speed setpoint, in particular the new paving speed setpoint, as a function of a preselected minimum material supply and / or as a function of a preselected maximum material supply of paving material present in the immediate vicinity of the road paver, i.e. on the construction site, in such a way that the minimum material supply is not fallen below and / or the maximum material supply is not exceeded during the paving process. This provides additional security to ensure that there is always a sufficient material buffer available for the road paver on the construction site, i.e. there is never too little or too much paving material. This promotes a continuous paving process by preventing the road paver from having to stop during the paving process due to insufficient or insufficient material supply.Furthermore, this prevents excess paving material from being stored on site. This would have the disadvantage of cooling down the excess paving material on site. This downstream speed correction of the paving speed target, determined based on the material delivery rate, is limited by the control system. The resulting speed adjustment or acceleration of the road paver only occurs under the condition that the pre-compaction remains constant.

[0022] It would be useful to define an initial paving speed for the paver before the start of the paving process, and to store a target layer thickness and target pre-compaction as process parameters in the control system, for example, through user input. The initial paving speed can, for example, be selected so that the paver can start slowly at the beginning of the paving process. This means that the paver temporarily performs the paving process at a "warm-up speed," at least at the beginning of the paving process, and is not immediately controlled at maximum paving speed.These basic settings selected on the road paver before the start of the paving process can be transmitted from the road paver to the control system as a basic data set, preferably when they are detected on the road paver at the start of the paving process and / or in the paving result, whereby this initiates the inventive operation on the control system for maintaining a constant pre-compaction at maximum paving speed. It would be conceivable for the inventive operation for maintaining a constant pre-compaction at maximum paving speed to be activated only after a predetermined warm-up time has elapsed, for example, 5 minutes after the start of the paving process, so that the drives and units installed on the road paver reach a desired operating temperature before the road paver adapts its speed to the changing material delivery capacity of the material supply chain supplying it.

[0023] It would be conceivable that the initial paving speed of the road paver could be dampened by means of its vehicle control system using a ramp function to the maximum paving speed adjusted to the material delivery rate or to the maximum paving speed set by the user, so that the working units of the road paver, which are still cold at the beginning of the paving process, including in particular the speed-dependent pre-compaction device, can slowly start up.

[0024] One variant provides that the initial paving speed at the start of the paving process is stored in the vehicle control system as a paving speed target value, whereby a speed change detected on the road paver or determined by means of the control system, in particular a speed change from the initial paving speed to the maximum paving speed entered by the operator or to the maximum paving speed calculated on the basis of the material delivery rate, causes the control system to calculate a correction factor for adjusting the pre-compaction performance for the natural change in pre-compaction that is foreseeable due to the speed change and to store this correction factor in a screed control system of the road paver, which uses the correction factor to adjust the operation of the compaction element in such a way, in particular at a specific time,that the pre-compaction achieved with the speed change essentially corresponds to the target pre-compaction defined for the initial paving speed. The speed change initiated by the control system therefore determines the extent of the resulting correction factor, by which the pre-compaction performance is adjusted to compensate for the natural change in pre-compaction. This allows the pre-compaction performance to be adjusted based on the correction factor to compensate for the changed target paving speed, despite a material supply-dependent change in the target paving speed of the road paver compared to the initial paving speed, thus ensuring constant pre-compaction.

[0025] In particular, the correction factor is used by the screed control system to vary the stroke of the compaction element, to vary the achievable contact pressure of the compaction element, and / or to vary the speed of the compaction element. Varying these process parameters can be combined as desired to enable pre-compaction performance using the screed to be adjusted to the change in speed.

[0026] It would be conceivable that real-time measurement of the actual layer thickness could be used to calculate a layer thickness deviation from the target layer thickness, based on which a layer thickness correction factor would be determined and used by the screed control system to adjust the height of the screed. Although it can be assumed that the layer thickness will remain constant with changing paving speeds and correspondingly adjusted precompaction performance, which enables constant precompaction, any exceptionally detected layer thickness deviations can be easily compensated for via the height control of the screed using the layer thickness correction factor, so that a constant layer thickness can be achieved in addition to constant precompaction.

[0027] One variant provides for a pre-compaction deviation from the target pre-compaction to be determined through real-time measurement. A system used for post-compaction, for example, a roller following the road paver, compensates for the pre-compaction deviation by means of dynamic post-compaction modulation, so that the overall residual compaction deviation is minimized. Although the invention results in a substantially consistent pre-compaction result along the paving section, i.e., constant, deviations from the target pre-compaction that are determined in exceptional cases can be easily compensated for by the subsequent post-compaction system.The post-compaction system benefits from a constant pre-compaction created by the road paver essentially along the entire paving section, so that it can compensate for any isolated, detected deviations from the target pre-compaction without great effort.

[0028] According to an advantageous embodiment, at least part of the control system can, as a cloud-based application, record predetermined construction planning values, for example from a control center connected to it, and / or dynamic paver and screed process data of the road paver determined during the paving process and, based thereon, calculate at least one target process value for the paving process, in particular the paving speed adapted to the varying material delivery rate and / or at least one correction factor, in particular the correction factor for adjusting the pre-compaction performance, and transmit it to another part of the control system, which stores the calculated target and correction values ​​of the vehicle control system and / or the screed control system.

[0029] Preferably, the part of the control system configured as a cloud-based application can record dynamic material delivery process data determined during the material delivery process carried out on the basis of the material delivery chain and, based on this, calculate the material delivery performance of the material delivery chain, in particular in real time, as well as the paving speed to be adjusted thereto and transmit this to the other part of the control system, which maintains the adjusted paving speed of the vehicle control of the road paver.

[0030] Using the cloud-based variants mentioned above, IT resources can be outsourced as a web application. This makes it possible, in particular, to connect multiple installation processes carried out on different construction sites with the part configured as a cloud-based application. The cloud-based part of the control system could thus be used universally for many construction projects simultaneously.

[0031] According to one embodiment of the invention, the control system is not only partially but entirely available as a cloud-based application and calculates all target process values ​​and correction values ​​for the paving process at least as a function of the variable material delivery rate and makes these available directly to the vehicle control system and / or the screed control system of the road paver in order to achieve constant pre-compaction.

[0032] The invention further relates to a road construction system for a paving process. The road construction system comprises a control system, at least one road paver functionally connected to the control system, at least one logistics system functionally connected to the control system, and at least one material supply chain supplying the road paver with paving material, the variable material delivery rate of which can be recorded using the logistics system and made available to the control system. The control system is designed to determine a paving speed for the road paver that is adapted to the determined material delivery rate. According to the invention, a pre-compaction rate of at least one pre-compaction element of a paving screed of the road paver is adaptable depending on the paving speed that is adapted to the determined material delivery rate. This enables the paving process to be carried out continuously, i.e.This allows paving to proceed without interruption and with constant pre-compaction. A change in speed caused by the material delivery rate is thus compensated for by adjusting the pre-compaction rate in such a way that the pre-compaction achieved by the screed remains constant. The material delivery rate thus has a direct influence on the achieved pre-compaction.

[0033] Preferably, the control system is designed to determine a maximum paving performance that can be achieved by the road paver, taking into account the material delivery performance displayed to it by the logistics system, in order to calculate a maximum paving speed for the road paver as a function of a layer thickness and layer width to be produced by means of the paving screed, and to store the maximum paving speed calculated using the control system as a paving speed target value in a vehicle control system of the road paver that is functionally connected to the control system, if this is less than or equal to a maximum paving speed entered by a user on the control system as a limit condition.Alternatively, the control system is designed to store the maximum paving speed entered by the user as a limit condition as the paving speed setpoint in the road paver's vehicle control system, which is functionally connected to the control system, if the maximum paving speed calculated using the control system is greater than the maximum paving speed entered by the user. Both of the above-mentioned alternatives achieve uninterrupted, maximum paving performance combined with constant pre-compaction, thus ensuring both maximum acceleration and optimal quality paving results.

[0034] It would be useful for the control system to be configured to detect a changing material delivery rate, calculate a correspondingly adjusted (new) maximum paving speed for the road paver, and determine a time at which the (new) maximum paving speed is to be stored in the road paver's vehicle control system. This would allow the speed adjustment of the road paver to be delayed on the construction site until the changing material delivery rate is noticeable, or to be carried out precisely when the road paver reacts to the changed material delivery rate only when this would lead to an undesirable change in the existing material stocks on the construction site.This variant thus makes it possible to ignore only short-term, negligible changes in the material supply, so that the road paver travels at as constant a paving speed as possible.

[0035] In particular, the control system can be configured to vary the time at which the new maximum paving speed is stored in the vehicle control system of the road paver depending on the magnitude of the required paving speed change. In particular, the control system can follow a logic such that, in principle, in the case of a small change in paving speed with regard to a changing material delivery rate, the new maximum paving speed in the vehicle control system of the road paver tends to be stored at a later time than in the case of a large change in paving speed with regard to a changing material delivery rate. This principle can lead to only short-term, minor changes in material delivery rate being ignored, i.e., not being unnecessarily transferred to the operation of the road paver.This promotes energy-efficient operation of the road paver.

[0036] An advantageous embodiment of the invention provides that the control system is configured to adapt the paving speed setpoint as a function of a preselected minimum material supply and / or as a function of a preselected maximum material supply of paving material present in the immediate vicinity of the road paver, i.e. on the construction site, such that during the paving process there is no less paving material than the minimum material supply and / or no more paving material than the maximum material supply in the immediate vicinity of the road paver. This means that the road paver only accelerates the paving process in such a way that there is no undersupply or oversupply of material on the construction site. A material undersupply would carry the risk of the road paver having to interrupt the paving process.Overstocking of paving material would lead to the paving material cooling down.

[0037] Preferably, a target layer thickness and a target pre-compaction can be stored as process parameters in the control system for an initial paving speed of the road paver defined before the start of the paving process.The initial paving speed at the start of the paving process is stored in the vehicle control system of the road paver as the initial paving speed setpoint, and the control system is designed to calculate a correction factor for adjusting the pre-compaction performance in response to a speed change detected on the road paver or determined by means of the control system, in particular a speed change from the initial paving speed setpoint to a maximum paving speed entered for the paving process as the paving speed setpoint or to a maximum paving speed calculated on the basis of the material delivery rate, in view of a natural change in the pre-compaction that is foreseeable due to the speed change, and to store this correction factor in a screed control system of the road paver.The screed control system thus adjusts the precompaction performance of the compaction element using the correction factor in such a way that the precompaction achieved with the speed change essentially corresponds to the target precompaction defined for the initial paving speed. The process parameters stored at the beginning of the paving process for the predetermined initial paving speed thus remain constant even if the paver's speed is detected or determined using the correction factor. In particular, this allows the paver to accelerate the paving process to the maximum without interrupting the paving process, which is carried out with constant precompaction. This results in a particularly economical paving process with consistent paving quality.

[0038] Preferably, the screed control system is configured using the correction factor to vary a stroke of the compaction element, to vary an executable contact force by the compaction element, and / or to vary a speed of the compaction element. It would be conceivable to use correction factors determined separately by the control system to vary the respective process parameters. In particular, the process parameters can be changed in combination to achieve a constant pre-compaction result.

[0039] An advantageous embodiment of the invention provides that the road paver is configured to carry out a real-time measurement of the produced layer thickness, whereby a layer thickness correction factor resulting from a detected layer thickness deviation from the target layer thickness can be determined and made available to the screed control for height control of the screed, and / or the road paver is configured to carry out a real-time measurement of a produced pre-compaction, wherein depending on a pre-compaction deviation from the target pre-compaction determined therefrom, a post-compaction system compensating for the pre-compaction deviation by means of dynamic post-compaction modulation can be controlled such that a total residual compaction deviation is minimized.The use of these correction functions is the absolute exception, since a substantially constant pre-compaction also results in a constant layer thickness, and deviations from the target pre-compaction tend to be very small. Should these compensation functions be triggered, the associated effort to compensate for the deviations is very minimal.

[0040] The control system can be integrated into the logistics system and the road paver as a cloud-based application or as a server-based network. One variant involves integrating the control system into a portable device used by an operator on the construction site. It would be conceivable for the logistics system to be integrated into another portable device, carried by at least one truck driver in the material supply chain, as a cloud- or network-based application.

[0041] According to a preferred variant, at least part of the control system is available as a cloud-based application configured to capture predetermined construction planning values, e.g., from a control center connected to it, and / or dynamic paver and screed process data of the road paver determined during the paving process. Based on this, it calculates at least one target process value, in particular the paving speed adjusted to the varying material delivery rate, and / or at least one correction factor, in particular the correction factor for adjusting the pre-compaction rate, and transmits it to another part of the control system, which stores the calculated target and correction values ​​of the vehicle control system and / or the screed control system. This allows certain IT resources, in particular storage space, computing power, and / or software, to be used as a web-based application.

[0042] Preferably, the part of the control system configured as a cloud-based application is further configured to record dynamic material delivery process data determined during the material delivery process carried out on the basis of the material delivery chain and, based thereon, to calculate the material delivery performance of the material delivery chain, in particular in real time, and to transmit this to the other part of the control system, which, based on the calculated material delivery performance, determines the paving speed to be adjusted thereto and makes it available to the vehicle control of the road paver.

[0043] According to one embodiment of the invention, the control system is not only partially but entirely a cloud-based application and is configured to calculate all target process values ​​and correction values ​​for the paving process at least as a function of the variable material delivery rate and to make these available directly to the vehicle control and / or the screed control of the road paver in order to achieve constant pre-compaction.

[0044] The invention is explained in more detail with reference to the following figures. They show: Figure 1 shows a road construction system in a schematic representation for carrying out a paving process, Figure 2 shows a paving screed of a road paver in a sectional view according to a first embodiment, Figure 3 shows another paving screed of a road paver in a sectional view according to a second embodiment, Figure 4 shows the inventive principle of a speed and pre-compaction performance adapted on the basis of changing material delivery performance for producing constant pre-compaction, Figure 5 shows a schematic representation relating to varying material storage on the construction site, Figure 6 shows a schematic diagram of a changing paving speed of the road paver during the paving process, and Figure 7 shows a schematic diagram of a pre-compaction performance adapting to the varying paving speed of the road paver during the paving process.

[0045] Technical components are provided with the same reference symbols throughout the figures.

[0046] Figure 1 shows a schematic representation of a road construction system 1 that is configured as a site management system to control a paving process E. The road construction system 1 comprises a control system 2, a road paver 3 functionally connected to the control system 2, a logistics system 4 functionally connected to the control system 2, and a material supply chain L that supplies the road paver 3 with paving material M, the material delivery performance PL of which can be recorded using the logistics system 4 and made available to the control system 2.

[0047] The control system 2 is designed to determine a paving speed v for the road paver 3 that is adapted to the determined material delivery rate PL. Figure 1shows in a schematic representation that the control system 2 uses the material delivery performance PL provided to it by the logistics system 4 in order to calculate the paving speed v of the road paver 3 on the basis of this and to store this in a vehicle control 5 provided on the road paver 3.

[0048] Furthermore, Figure 1 in a schematic representation that a pre-compaction performance VL provided can be adjusted by means of at least one pre-compaction element 6 of a paving screed 7 attached to the road paver 3 as a function of the determined paving speed v.

[0049] Furthermore, the control system 2 is configured to determine, in addition to the paving speed v adjusted based on the material delivery rate PL, a time tx at which the paving speed v is stored in the vehicle control system 5 of the road paver 3. This time tx can also be stored accordingly in a screed control system 8 of the paving screed 7 in order to simultaneously adjust the speed v of the road paver 3 and the pre-compaction rate VL of the compaction element 6.

[0050] During the Figure 1In the schematically illustrated paving process E, an asphalt layer D is produced on a construction site. The road construction system 1 comprises a mixing plant W, which belongs to the material supply chain L and delivers paving material M to a truck 9. The paving material M is produced with a specific composition and temperature by the mixing plant W and transported to the construction site by truck 9. The truck(s) 9 pour the paving material M either directly into a material hopper 10 of the road paver 3 or into a material hopper of a feeder 11 for the road paver 3, which is traveling in the paving direction R in front of the road paver 3. A compactor vehicle 12 configured for post-compaction travels behind the road paver 3 in the paving direction R. The compactor vehicle 12 is in Figure 1 also functionally connected to control system 2.

[0051] Figure 1indicates that a user enters a maximum paving speed VB for the paving process E of the road finisher 3 in the control system 2 as a boundary condition. Furthermore, Figure 1 in a schematic representation that the control system 2, taking into account the determined material delivery rate PL, determines a paving rate PE possible by the road paver 3 and thus, taking into account a visible thickness S and a layer width T, calculates the paving speed v, in particular a separate, maximum paving speed V max for the road paver 3.

[0052] In particular, the control system 2 is able to store the maximum paving speed v max calculated using the control system 2 as the paving speed target value v target in the vehicle control 5 of the road paver 3, which is functionally connected to it, if this is less than or equal to the maximum paving speed v B entered by the user. Alternatively, the maximum paving speed v B entered by the user is stored in the vehicle control 5 as the paving speed target value v target if the maximum paving speed v max calculated using the control system 2 is greater than the maximum paving speed v B entered by the user.

[0053] The control system 2 can be configured in whole or in part as a cloud-based application C and / or as a server-based network in order to control the respective vehicles and working units functionally integrated in the road construction system 1 in such a way that an uninterrupted, maximally accelerated paving process E leading to a constant pre-compaction of the paving layer D is achieved.

[0054] Figure 2shows a sectional view of the paving screed 7 of the road paver 3 according to a first embodiment. The paving screed 7 is an extending screed with a base screed section 14 and laterally movable extending screeds 15, which allow a change in the layer width T. Alternatively, the paving screed 7 could also be provided without a variable paving width. The base screed section 14, as well as each extending screed 15, has a bottom-side screed plate 16, on which at least one vibration device 17 operable at a selectable speed is arranged, so that the screed plate 16 is used as a compaction element 6 on the paving screed 7. A further compaction element 6 is a tamper having at least one tamper bar 18 with an eccentric drive 19, the speed v' and / or eccentricity, ie the stroke H, of which can be selected, wherein the tamper produces the foremost pre-compaction stage on the screed 7 in the paving direction R for pre-compacting the paving material M.

[0055] The Figure 3 The screed 7' shown in addition to the configuration of the screed 7 Figure 2 at least one pressure bar 20 as a further compaction element 6, which can be operated via a hydraulic drive 21 with vertical pressure pulses and optionally adjustable acceleration and further pre-compacts in the paving direction R behind the screed plate 16 with a selectable contact pressure F.

[0056] The Figures 2 and 3 The compaction elements 6 deployed on the respective paving screeds 7, 7' are controlled by the screed control system 8 in such a way that they generate a desired pre-compaction performance VL. This can be controlled as a function of the paving speed v driven by the road paver 3 in such a way that a constant pre-compaction V corresponding to a target pre-compaction V target stored in the control system 2 is achieved in the produced paving layer D.

[0057] The pre-compaction performance VL is varied by means of a correction factor f(v), which is calculated by the control system 2 on the basis of a changing paving speed v, in particular with regard to a predicted change in pre-compaction V caused by speed adjustment, and is fed into the screed control 8 either directly or indirectly via the vehicle control 5. This ensures that the compaction elements 6 working on the respective paving screeds 7, 7' adapt their pre-compaction performance VL to the paving speed v, in particular to the entered maximum paving speed VB or to the maximum paving speed v max calculated as a function of the material delivery rate PL, in such a way that a constant pre-compaction V is produced by the paving screed 7, 7'.

[0058] Figure 4shows a schematic representation of the inventive concept, according to which the paving speed v, in particular the maximum paving speed v max, adapts with a time delay tx to a changing material delivery rate PL and this is accompanied by a change in the pre-compaction rate VL in order to keep the pre-compaction V constant.

[0059] Figure 4 shows in particular that with increasing material delivery rate PL the paving speed v, or the maximum entered or calculated paving speed v B , v max at the time tx , is also stored in the vehicle control 5 with a time delay and, in accordance with this delay, the pre-compaction performance VL is adjusted in the screed control 8 by means of the correction factor f(v) in such a way that a constant pre-compaction V can be achieved.

[0060] The time axis t in Figure 4In the event that the material delivery rate PL decreases, an increasing pre-compaction rate VL, adapted to the material delivery rate PL, could be reduced with a time delay together with a decreasing paving speed v, adapted to the material delivery rate PL, in order to keep the pre-compaction V constant.

[0061] Figure 5 shows a schematic diagram of a material supply Q present in the immediate vicinity of the road paver 3, which can vary depending on the material delivery rate PL and the paving speed v of the road paver 3. The material supply Q can correspond to the quantity of paving material M held in the material hopper 10 of the road paver 3. If a feeder 11 is used on the construction site, the material supply Q results from the sum of the paving material M contained in the respective material hoppers of the feeder 11 and the road paver 3.

[0062] For a constant material delivery rate PL, it can be assumed that on the construction site the material stock Q decreases with increasing paving speed v and the material stock Q increases with decreasing paving speed v. Figure 5 shows that the material supply Q in the immediate vicinity of the road paver 3 does not exceed a maximum material supply Q max and does not fall below a minimum material supply Q min. The control system 2 can be designed to select the paving speed setpoint v soll stored in the vehicle control system 5, in particular the maximum paving speed v max, such that the minimum material supply Q min is not undershot and / or the maximum material supply Q max is not exceeded.

[0063] The Figure 5The fluctuations in material stock levels Q shown may be the result of disturbances in the material supply chain L. For example, the fluctuations in material stock levels M could be caused by unexpectedly high traffic volumes on the way from the mixing plant W to the construction site.

[0064] Figure 6 shows a schematic representation of the paving speed v controlled on the road finisher 3 during the paving process E. In particular, Figure 6that the road paver 3 is initially controlled from time t 1 to time t 2 with an initial paving speed v. At time t 2, a changing material delivery rate PL for the paving process E is recorded by means of the control system 2. The control system 2 then determines a new paving speed v, here a new maximum paving speed v max, which from time t 3 corresponds to the maximum paving speed B entered by the operator. This is due to the fact that the material delivery rate PL at time t 2 is so high that a maximum paving speed v max determined by the control system 2 is greater than the maximum paving speed v B entered by the operator, so that the latter is stored by the control system 2 in the vehicle control system 5 of the road paver 3.

[0065] Between time t 2 and time t 3 , a ramp function y derived from time tx determined by means of the control system 2 is used to continuously increase the speed until the paving speed v corresponds to the maximum paving speed v B entered by the user in the control system 2.

[0066] At time t 4 , the control system 2 detects a further change in the material delivery rate PL, namely a lower rate than that prevailing before time t 4 . A resulting maximum paving speed v max calculated by the control system 2 is stored in the vehicle control system 5 of the road paver 3 from time t 5 . This maximum paving speed v max is lower than the maximum paving speed VB entered by the user, corresponding to the reduced material delivery rate PL, and can therefore be stored in the vehicle control system 5 of the road paver 3 as calculated by the control system 2.

[0067] At time t 6 , an even further reduced material delivery rate PL is detected by the control system 2. The appropriate maximum paving speed v max from time t 7 onwards is therefore even lower in order to carry out the paving process E even more slowly in accordance with the further reduced material delivery rate PL.

[0068] Between the respective Figure 6 Ramp functions y are used for the intervals of maximum paving speeds v max shown to implement the speed changes with a respective gradient. The gradient can be selected depending on the magnitude of the speed change. In particular, the gradient can be set so flat that the acceleration does not exceed maximum values ​​due to the inertia of the systems and components.

[0069] Figure 7shows in a schematic representation that the pre-compression power VL is determined according to the Figure 6 illustrated speed curve in such a way that a constant pre-compaction V is achieved by the paving screed 7, 7'. The respective compaction elements 6 on the paving screed 7, 7' are controlled during their operation depending on the paving speed v of the road paver 3.

Claims

1. Method for dynamically controlling a paving speed (v) of at least one road paver (3) for a paving process (E), wherein a paving speed (v) for the road paver (3) adapted to the determined material delivery rate (PL) is determined by means of a control system (2) functionally connected to the road paver (3) as a function of a variable material delivery rate (PL) determined thereby for a material supply chain (L) supplying the road paver (3) with paving material (M), characterized in that, a pre-compaction performance (VL) of at least one pre-compaction element (6) of a paving screed (7, 7') of the road paver (3) is adapted as a function of the paving speed (v) adapted to the variable material delivery rate (PL) in order to keep a pre-compaction (V) achieved by means of the pre-compaction element (6) constant.

2. Method according to claim 1, characterized in that a user enters a maximum paving speed (vB) for the paving process (E) of the road paver (3) in the control system (2) as a limit condition.

3. Method according to claim 2, characterized in that the control system (2), taking into account the determined, variable material delivery rate (PL), determines a maximum possible paving performance (PE) by the road paver (3) and thus calculates a separate, maximum paving speed (vmax) for the road paver (3) as a function of a layer thickness (S) and layer width (T) to be produced by means of the paving screed (7, 7').

4. Method according to claim 3, characterized in that the maximum paving speed (vmax) calculated by means of the control system (2) is stored in a vehicle control (5) of the road paver (3), which is functionally connected to the control system (2), as the paving speed set value (vsoll) if this is less than or equal to the maximum paving speed (vB) entered by the user, or in that the maximum paving speed (vB) entered by the user is stored as the paving speed set value (vsoll) in the vehicle control (5) of the road paver (3), which is functionally connected to the control system (2), if the maximum paving speed (vmax) calculated by means of the control system (2) is greater than the maximum paving speed (vB) entered by the user.

5. Method according to claim 4, characterized in that the control system (2), by determining a changing material delivery rate (PL), calculates both a correspondingly adapted new maximum paving speed (vmax) for the road paver (3) and determines a time (tx) at which the new maximum paving speed (vmax) is stored in the vehicle control (5) of the road paver (3).

6. Method according to claim 5, characterized in that the new maximum paving speed (vmax) calculated by means of the control system (2) is stored in the vehicle control (5) of the road paver (3), which is functionally connected to the control system (2), as the new paving speed set value (vsoll), if this is less than or equal to the maximum paving speed (vB) entered by the user, or in that the maximum paving speed (vB) entered by the user is stored as the paving speed set value (vsoll) in the vehicle control (5) of the road paver (3), which is functionally connected to the control system (2), if the new maximum paving speed (vmax) calculated by means of the control system (2) is greater than the maximum paving speed (vB) entered by the user.

7. Method according to one of claims 4 to 6, characterized in that the control system (2) adapts the paving speed set value (vsoll), in particular the new paving speed set value (vsoll), as a function of a pre-selected minimum material stockpile (Qmin) and / or as a function of a pre-selected maximum material stockpile (Qmax) of a paving material (M) available in the direct vicinity of the road paver (3) in such a way that the minimum material stockpile (Qmin) is not undercut and / or the maximum material stockpile (Qmax) is not exceeded during the paving process (E).

8. Method according to one of the preceding claims, characterized in that an initial paving speed (vinitial) of the road paver (3) is defined before the beginning of the paving process (E) and a target layer thickness (Ssoll) and a target pre-compaction (Vsoll) are stored as process parameters in the control system (2) for the initial paving speed (vinitial).

9. Method according to claim 8, characterized in that the initial paving speed (vinitial) is stored in the vehicle control (5) as paving speed set value (vsoll) at the beginning of the paving process (E), wherein a change in speed detected on the road paver (3) or a change in speed determined by means of the control system (2), in particular a maximum paving speed (vB, vmax) entered by the user as a set value (vsoll) for the paving process (E) or calculated on the basis of the material delivery rate (PL), causes the control system (2) to calculate a correction factor (f(x)) for adapting the pre-compaction performance (VL) for the natural change in pre-compaction (V) which can be predicted on the basis of the change in speed, and to store this correction factor in a screed control (8) of the road paver (3) which uses the correction factor (f(x)) to adapt the operation of the compaction element (6) such that a pre-compaction (V) achieved with the change in speed essentially corresponds to the target pre-compaction (Vsoll) defined for the initial paving speed (vinitial).

10. Method according to claim 9, characterized in that the correction factor (f(x)) is used by means of the screed control (8) to vary a stroke (H) of the compaction element (6), to vary an executable contact pressure (F) by the compaction element (6) and / or to vary a speed (v') of the compaction element (6).

11. Method according to claim 9 or 10, characterized in that a layer thickness deviation from the target layer thickness (Ssoll) is calculated by real-time measurement of the produced layer thickness (S), on the basis of which a layer thickness correction factor (f(S)) is determined and used by the screed control (8) for height control of the paving screed (7, 7').

12. Method according to one of claims 9 to 11, characterized in that a pre-compaction deviation from the target pre-compaction (Vsoll) is determined by real-time measurement, wherein a compactor vehicle (12) used for post-compaction compensates for the pre-compaction deviation by means of dynamic post-compaction modulation such that an overall residual compaction deviation is minimized.

13. Method according to one of the preceding claims, characterized in that at least one part of the control system (2) as a cloud-based application (C) detects predetermined construction planning values, for example from a control center connected thereto, and / or dynamic paver and screed process data of the road paver (3) determined during the paving process (E) and, based thereon, calculates at least one target process value, in particular the pre-compaction performance (VL) adapted to the varying material delivery rate (PL), and / or at least one correction factor, in particular the correction factor (f(x)) for adapting the pre-compaction performance (VL), and transmits it to another part of the control system (2), which provides the calculated target and correction values for the vehicle control (5) and / or the screed control (8).

14. Road construction system (1) for a paving process (E), comprising a control system (2), at least one road paver (3) functionally connected to the control system (2), at least one logistics system (4) functionally connected to the control system (2), and at least one material supply chain (L) supplying the road paver (3) with paving material (M), the variable material delivery rate (PL) of which can be detected by means of the logistics system (4) and can be kept available to the control system (2), wherein the control system (2) is configured to determine a paving speed (v) for the road paver (3) which is adapted to the material delivery rate (PL) determined, characterized in that a pre-compaction performance (VL) of at least one pre-compaction element (6) of a paving screed (7, 7') of the road paver (3) can be adapted as a function of the paving speed (v) adapted to the material delivery rate (PL) determined in order to keep a pre-compaction (V) achieved by means of the pre-compaction element (6) constant.

15. Road construction system according to claim 14, characterized in that the control system (3) is configured to determine a maximum possible paving performance (PE) by the road paver (3), taking into account the material delivery rate (PL) indicated to it by the logistics system (4), and to calculate therefrom a maximum paving speed (vmax) for the road paver (3) as a function of a layer thickness (S) and layer width (T) to be produced by means of the paving screed (7, 7'), and to store the maximum paving speed (vmax) calculated by means of the control system (2) as the paving speed set value (vsoll) in a vehicle control (5) of the road paver (3) functionally connected to the control system (2), if this is less than or equal to a maximum paving speed (vB) entered by a user on the control system (2) as a limit condition, or in that the control system (2) is configured to store the maximum paving speed (vB) entered by the user as a limit condition in the vehicle control (5) of the road paver (3), which is functionally connected to the control system (2), as the paving speed set value (vsoll) if the maximum paving speed (vmax) calculated by means of the control system (2) is greater than the maximum paving speed (vB) entered by the user.

16. Road construction system according to claim 15, characterized in that the control system (2) is configured to calculate both a correspondingly adapted new maximum paving speed (vmax) for the road paver (3) by determining a changing material delivery rate (PL) and to determine a time (tx) at which the new maximum paving speed (vmax) is to be stored in the vehicle control (5) of the road paver (3).

17. Road construction system according to claim 15 or 16, characterized in that the control system (2) is configured to adapt the paving speed set value (vsoll) as a function of a pre-selected minimum material stockpile (Qmin) and / or as a function of a pre-selected maximum material stockpile (Qmax) of a paving material (M) available in the direct vicinity of the road paver (3) in such a way that during the paving process (E) no less paving material (M) than the minimum material stockpile (Qmin) and / or no more paving material (M) than the maximum material stockpile (Qmax) is available in the direct vicinity of the road paver (3).

18. Road construction system according to one of claims 14 to 17, characterized in that a target layer thickness (Ssoll) and a target pre-compaction (Vsoll) can be stored as process parameters in the control system (2) for an initial paving speed (vinitial) of the road paver (3) defined before the beginning of the paving process (E), wherein the initial paving speed (vinitial) at the beginning of the paving process (E) is stored in the vehicle control (5) of the road paver (3) as the paving speed set value (vsoll), and wherein the control system (2) is configured, in response to a change in speed detected on the road paver (3) or a change in speed determined by means of the control system (2), in particular a paving speed set value (vsoll) entered for the paving process (E) or calculated on the basis of the material delivery rate (PL), to calculate a correction factor (f(x) for adjusting the maximum paving speed (vB, vmax) in view of a natural change in pre-compaction (V) which can be predicted on the basis of the change in speed, and to store this in a screed control system (8) of the road paver (3), so that the screed control (8) adapts the operation of the compaction element (6) by means of the correction factor (f(x)) such that a pre-compaction (V) achieved with the speed change essentially corresponds to the target pre-compaction (Vsoll) defined for the initial paving speed (vinitial).

19. Road construction system according to claim 18, characterized in that the screed control (8) is configured using the correction factor (f(x)) for varying a stroke (H) of the compaction element (6), for varying an executable contact pressure (F) by the compaction element (6) and / or for varying a speed (v') of the compaction element (6).

20. Road construction system according to one of claims 14 to 19, characterized in that the road paver (3) is configured to carry out a real-time measurement of the produced layer thickness (S), whereby a layer thickness correction factor (f(S)) resulting as a function of a layer thickness deviation from the target layer thickness (Ssoll) detected therefrom can be determined and can be provided to the screed control (8) for a height control of the paving screed (7, 7'), and / or the road paver (3) is configured to carry out a real-time measurement of a pre-compaction produced, wherein, as a function of a pre-compaction deviation from the target pre-compaction (Vsoll) determined therefrom, a compressor vehicle (12) compensating for the pre-compaction deviation by means of dynamic post-compaction modulation can be controlled such that a total residual compaction deviation is minimized.

21. Road construction system according to one of claims 14 to 20, characterized in that at least one part of the control system (2) is available as a cloud-based application (C) and is configured to detect predetermined construction planning values, for example from a control center connected to it, and / or dynamic paver and screed process data of the road paver (3) determined during the paving process (E) and, based thereon, to determine at least one target process value, in particular the pre-compaction performance (VL) adapted to the varying material delivery rate (PL), and / or at least one correction factor, in particular the correction factor (f(x)) for adapting the pre-compaction performance (VL), and to transmit this to another part of the control system (2), which provides the calculated target and correction values to the vehicle control (5) and / or the screed control (8).

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