CN116575288A

CN116575288A - Leveling system for construction machine

Info

Publication number: CN116575288A
Application number: CN202310099562.5A
Authority: CN
Inventors: 阿尔方斯·霍恩
Original assignee: MOBA Mobile Automation AG
Current assignee: MOBA Mobile Automation AG
Priority date: 2022-02-08
Filing date: 2023-02-08
Publication date: 2023-08-11
Also published as: EP4223932A1; DE102022201294A1; US20230250595A1

Abstract

Leveling system for a construction machine, in particular a road construction machine or road finishing machine (10), comprising: a layer thickness measurement system (110, 14) configured to measure a current layer thickness and to determine respective actual layer thickness values for a plurality of locations; a processor (130) configured to determine a layer thickness value (S) based on a layer thickness value (S) _set1 、S _set2 The actual layer thickness values of the layer thickness profile (120) and of these locations are determinedPosition-dependent control values for height adjustment of a tool of a construction machine are defined.

Description

Leveling system for construction machine

Technical Field

Embodiments of the present invention relate to a leveling system for a construction machine, in particular a road construction machine, such as a road finishing machine or a road milling machine. The preferred embodiments relate to a leveling system having a layer thickness measurement system.

Further embodiments relate to a construction machine (road construction machine, such as a road finishing machine or a road milling machine) with a corresponding leveling system. A further embodiment relates to an apparatus for determining a layer thickness profile. Further embodiments relate to a corresponding method for leveling and for determining a layer thickness profile and to a corresponding computer program.

Background

For example, leveling systems are used in road construction machines, such as road finishing machines or road milling machines. By using a leveling system, for example, in a road finishing machine, the height and inclination (transverse gradient) of the placement tool (placement screed) are controlled such that the placed layers are placed with corresponding layer thicknesses and inclinations. By means of the leveling system, the unevenness of the subsurface is correspondingly leveled. Here, during the placement process, the respective actual height of the road finishing machine or of the placement tool (screed) relative to the ground or relative to the already laid layer is scanned, so that the placement tool can be controlled accordingly as a function of the ground change. Thus, in a leveling system, a sensor holder is used that runs parallel to the direction of travel, which extends for example across a length of 12 m. Such a sensor holder is shown in fig. 1 a. Fig. 1a shows a road finishing machine 10 with a sensor holder 12 and four sensors 14a-14d. Here, the sensor 14b is arranged behind the screed 10 b. With the sensor holder shown with four sensors 14a-14d, waves in the range of 4m to 8m can be scanned well and then leveled.

For correspondingly longer waves, additional height adjustment may be made by the total station, as shown in fig. 1 b. Fig. 1b shows a road finishing machine 10 with a screed 10 b. Height adjustment of the screed is controlled at the traction point 10z via the traction point cylinder 10zz, as already explained in the context of fig. 1 a. Additionally or alternatively, the height of screed 10b may also be controlled through the use of assemblies 14la1 and 14la2 and 14 t. The total station 14t incorporates an external reference that emits a laser beam at a predetermined height. For example, a laser beam emitted parallel to the ground or reference is then received directly by the height sensor 14la1, or indirectly after being reflected by the 360 ° prism 14la 2. Thus, the actual height of the screed relative to a fixed reference height may be determined. Because of the fixed reference height, the actual height is not affected by long wave variations, which cannot be detected by the sensor arrangement of fig. 1 a. In addition, by using the total station as a virtual reference, other references, such as ropes and the like, can be omitted. The disadvantage of using total stations is that the total station has to be calibrated expensive and that usually one total station is not sufficient, especially for longer screeds. Thus, there is a need for an improved method.

Disclosure of Invention

The object of the present invention is to provide leveling or generally height adjustment for construction machines, thereby providing an improved compromise of ergonomics, accuracy and adjustability for long waves.

The object of the invention is solved by the subject matter of the independent claims.

Embodiments of the present invention provide a leveling system for a construction machine, in particular a road construction machine or road finishing machine or road milling machine. The leveling system includes a layer thickness measurement system and a processor. The layer thickness measurement system is configured to measure a layer thickness currently to be applied or to be removed and to determine corresponding (predicted) actual layer thickness values for a plurality of locations (e.g., along a direction of travel of the work machine). Here, for example, several current layer thickness values are obtained for a plurality of (successive) positions. In other words, the plurality of layer thickness values may be referred to as an actual layer thickness profile. The processor is configured to determine a control value according to a (further) position for height adjustment of a tool (e.g. screed or milling wheel) of the construction machine based on a layer thickness profile (set layer thickness profile) comprising a plurality of set layer thickness values assigned to a plurality of positions and a (predicted) actual layer thickness value of the respective position.

It should be noted that depending on the measuring system, the actual layer thickness value can be predicted from the currently measured layer thickness, since the individual sensors scan the subsurface in front of the screed without any applied layer. The prediction is based on measured altitude values according to location. If not adjusted, the predicted actual layer thickness will be generated at the corresponding location. For example negative during layer removal (road milling machine) or positive during layer application (road finishing machine). A change can occur, wherein a corresponding adjustment is made on the basis of the layer thickness values set as described above.

According to an embodiment, a position-dependent control value is determined for the height adjustment of the tool, so that the tool is controlled in accordance with the set layer thickness profile. Furthermore, according to an embodiment, the tool is controlled by the control value such that the deviation between the actual layer thickness value profile and the set layer thickness value profile or the actual layer thickness value and the set layer thickness value is adjusted as a function of the respective position.

According to an embodiment, the position-dependent control value is selected such that, in the steady state of the tool, the position-dependent actual layer thickness value substantially corresponds to the set layer thickness value. By "substantially" is meant, for example, ±20%, ±10%, ±5%, ±3% or ±1%, i.e. the allowable maximum deviation is ±1%, ±3%, ±5%, ±10% or ±20% (depending on the variation). To this end, according to an embodiment, the control value is derived such that the height adjustment of the tool is performed by taking into account the adjustment path of the tool along the travelling direction of the construction machine (the offset between the adjustment position and the completed adjustment, e.g. the offset between the pivot point or virtual pivot point or the screed rear edge and the traction point). According to an embodiment, some type of correction value according to the position is determined based on the deviation between the set layer thickness value and the actual layer thickness value. The correction value is used, wherein, due to the interpreted offset, the correction value is not applied to the current position (actual layer thickness value), but to a "future" or further position. In this way, for a "future" position, the height of the tool is determined on the basis of the correction value for the respective further position and the set layer thickness value. For example, the control value according to the "farther" position is selected such that when the "farther" position is reached, the tool is raised and/or lowered according to the set layer thickness profile in order to be moved to the set layer thickness value according to the position at the respective position. Furthermore, the control value according to the further position can be selected such that the current deviation between the actual layer thickness value and the set layer thickness value is compensated or taken into account.

Thus, embodiments of the present invention are based on the finding that instead of or in addition to the adjustment at a fixed height value, in order to compensate for the long wave unevenness, an adjustment of the height value that is set is performed in accordance with the layer thickness profile. Here, starting from a pre-scanned unevenness, for example, a set layer thickness profile is scanned, which, when applied to the unevenness, forms a flat road surface together with the unevenness. For example, at the location of uneven hills, a set layer thickness is provided that is thinner than at the location of uneven valleys. This applies in particular to road finishing machines or other construction machines for laying road surfaces. In the case of road milling machines or more generally machines for removing road surfaces, the set layer thickness profile corresponds to the profile to be removed from the road surface. Here, more material is removed on uneven hills than on uneven valleys.

As a result, in both cases, a flat road surface is provided, especially for long-wave unevenness. Drift is prevented by continuous (set/actual) adjustment. In addition, the field work is reduced because measures such as total stations can be omitted.

According to an embodiment, this means that the above-mentioned processor is configured to derive the control values from the layer thickness profile such that the layer to be smoothed by the tool or to be applied by the tool forms a flat road surface on the (uneven or wavy) subsurface profile along the travelling direction of the working machine. As described above, this is advantageously performed even for long-wave unevenness. Here, it should be noted that the layer to be applied (to be placed) or the layer to be smoothed may also have a second dimension transverse to the direction of travel, in addition to the first dimension along the direction of travel. Control values are derived from the layer thickness profile such that the layer to be applied (to be placed) or to be smoothed by the tool on the subsurface profile forms a flat road surface along the spanned plane. The plane extends along a first dimension and a second dimension. According to an embodiment, this is performed such that the height of the tool may be controlled, for example, on both the first side and the second side (left and right) of the construction machine. Tools such as screeds extend from the first side to the second side of the work machine, or beyond the first and second sides of the work machine, and provide a flat road surface. The inclination adjustment is performed according to the height of the two actuators of the tool or according to the relative height of the two actuators of the tool. According to a further embodiment, the control values of the two actuators are determined from the set inclination and from the two-dimensional subsurface profile. This means that, according to an embodiment, the layer thickness measurement system forms together with the processor a first control circuit for the first side (left or right side of the tool). The layer thickness measurement system (or another layer thickness measurement system) forms together with the processor a second control circuit for a second (different) side of the tool. According to a further embodiment, the two control circuits interact in order to control the tool correspondingly for an intermediate position between the first side and the second side of the tool, such that the actual layer thickness substantially corresponds to the set layer thickness for the intermediate position in the steady state.

According to a simple variant, the layer thickness measuring system can be formed by two height sensors, wherein a first height sensor is arranged, for example, behind the screed and also measures the deposited or leveled layer and determines the corresponding height value, while a second height sensor is applied in front of the screed and determines the height value relative to the underground or not yet leveled layer. For example, if a simple case of comparable applied heights is assumed, the layer thickness can be determined by differentiation. In the case of different applied heights, either offset can be used, which results in very accurate results when the distance between the sensor and the pivot point along the direction of travel is the same. Regarding the pivot point, it should be noted that the pivot point may be formed by, for example, the screed rear edge. By taking into account the intersection theorem, it is apparent that arrangements of different distances are possible. According to an embodiment, the two height sensors are firmly connected to the screed, wherein "firmly" should be interpreted as a predetermined geometrical relationship between the screed and the sensors is given. By hanging, both sensors move together with the screed, i.e. rotate together and undergo the same lifting movement (similar to a screed).

According to an embodiment, the sensor arrangement comprises at least two, even at least three or even at least four sensors arranged on a carrier extending in the travelling direction of the construction machine. According to a further embodiment, a layer thickness measurement system may be integrated in the sensor arrangement.

According to an embodiment, the layer thickness profile is determined from the subsurface profile. The subsurface profile also has a first dimension along the direction of travel, and may have a second dimension transverse to the direction of travel. According to an embodiment, the subsurface contour is scanned beforehand, so that a corresponding determination of the layer thickness contour can also be made (in advance or in real time) using the layer thickness values set as a function of the position. Thus, the layer thickness profile can have a set layer thickness value that varies across positions and/or along the direction of travel.

As described above, each set layer thickness value is assigned to a position for which the actual layer thickness value can be determined. The determination of the respective position is performed, for example, with a position sensor or a GNSS sensor. The sensor may be coupled to a tool/screed, or alternatively, may be coupled to a work machine, depending on the embodiment. The position sensor or GNSS sensor is configured to determine the position of the actual layer thickness value, in particular the position along the direction of travel.

Hereinafter, other aspects regarding the adjustment will be explained. It should be noted that according to an embodiment, a minimum layer thickness may be provided in the layer thickness profile. The minimum layer thickness defines a set layer thickness value at the peak of the subsurface profile. From the position, a control value is derived from the predetermined minimum layer thickness.

Thus, advantageously, the above-described method allows leveling the layer thickness, for example, adjusting the layer to be applied or the layer to be removed, in particular of long-wave unevenness. In a basic variant, such leveling requires non-conventional leveling techniques of conventional leveling systems. According to further embodiments, the explained leveling system may be combined with or integrated in a conventional leveling system. In other words, this means that the leveling system described above may include the functionality of a conventional leveling system. According to an embodiment, this also means that the processor of the leveling system described above comprises a flatness adjuster configured to determine a control value by using the sensor value, thereby generating a flat road surface. As already discussed in the context of the prior art, the flatness adjuster may for example comprise several distance sensors arranged transversely to the direction of travel of the work machine and measuring the distance to the ground. Advantageously, for example, the layer thickness measuring system to be used uses comparable or identical distance sensors. According to an embodiment, the layer thickness measurement system may be based on two distance sensors arranged around the pivot point of the screed, i.e. one distance sensor in front of the screed and one distance sensor behind the screed, and the layer thickness is determined, for example, by the difference of the two height values. Further implementations with other constellations will be discussed below. According to a further embodiment, the processor may comprise an adjustment path comprising, for example, a P component and/or an IT component and/or a PT component. Additionally or alternatively, the adjustment path may also be adjusted by a predictive model. This predictive model is particularly advantageous for the above-described leveling method based on layer thickness values, since there is a time offset between the adjustment time and the actually performed change in the applied layer thickness profile, or in particular a spatial offset of a few centimeters or even meters. The offset depends on parameters such as screed inclination, work machine speed, asphalt temperature, asphalt thickness, etc. These dependencies can also be taken into account by using a predictive model.

Further embodiments relate to a construction machine, a road construction machine or a road finishing machine with a corresponding leveling system. According to a further embodiment, a road milling machine or a construction machine with a milling function and a corresponding leveling system may be provided.

A further embodiment relates to a device for determining a layer thickness profile (comprising a plurality of layer thickness values assigned to a plurality of positions) and a computing unit. The apparatus includes an interface and a computing unit. The interface is configured to receive a subsurface profile (e.g., a scanned subsurface profile) that includes a plurality of height values assigned to a plurality of locations. Furthermore, at least one set height or set depth is received by the interface or another interface. For example, the set height may be defined by a set height value or several set height values assigned to several positions. In conventional leveling systems or layer thickness measuring systems, a minimum layer thickness has been determined. This also corresponds to a set height, for example. The calculation unit is configured for determining the layer thickness profile based on a difference between a plurality of height values assigned to the plurality of positions and at least one set height or set depth or a reference of the at least one set height or set depth. According to a further embodiment, the device comprises an output interface for providing or outputting a layer thickness profile to the construction machine. Here again, it should be noted that according to a further embodiment, the set height may also be defined by several set height values assigned to the plurality of positions, or the at least one set depth may be defined by several set depth values assigned to the plurality of positions. This is particularly important when, for setting the inclination, there are different set heights on the left and right or along the direction of travel. According to an embodiment, several or one set height value defines a plane or 3D plane of the layer to be smoothed or created (to be placed).

According to a further embodiment, a leveling method for a construction machine is provided. The method comprises the following steps:

measuring the current layer thickness to be applied or removed and determining the corresponding (predicted) actual layer thickness values for a plurality of positions,

-determining a position-dependent control value for height adjustment of a tool of the construction machine based on a layer thickness profile comprising a plurality of set layer thickness values assigned to a plurality of positions and a (predicted) actual layer thickness value of the position.

A further embodiment relates to a method for determining a layer thickness profile, comprising:

-receiving a subsurface profile comprising a plurality of elevation values assigned to a plurality of locations;

-receiving at least one set height or set depth; and

-determining a layer thickness profile based on the difference between a plurality of height values assigned to a plurality of positions and at least one set height or set depth or a reference defined by at least one set height or set depth.

According to a further embodiment, the method may be computer implemented.

Drawings

Hereinafter, embodiments of the present invention will be discussed based on the drawings. These figures show:

FIG. 1a is a schematic illustration of a work machine having a measurement system for a leveling system;

FIG. 1b is a schematic illustration of a work machine having a leveling system;

FIG. 2a is a schematic block diagram of a leveling system according to a basic embodiment;

FIG. 2b is a schematic diagram of a layer thickness measurement system according to an embodiment;

FIGS. 2c and 2d are schematic diagrams of leveling systems by using a layer thickness measurement system according to an extended embodiment;

FIG. 2e is a schematic diagram of a layer thickness measurement system according to an embodiment;

FIGS. 3a and 3b are schematic diagrams for explaining the subsurface profile and layer thickness profile of an embodiment;

FIG. 4 is a schematic diagram of the subsurface profile used in the discussion of the embodiments in combination with a set layer thickness profile having dispensing parameters;

FIGS. 5a and 5b are schematic block diagrams of leveling systems according to an extended embodiment;

fig. 6a and 6b are schematic views for explaining an adjustment behavior of a screed plate as a tool of a construction machine;

FIGS. 7a and 7b are schematic diagrams of a leveling system during use of a milling machine according to an embodiment;

FIGS. 8a and 8b are schematic diagrams for explaining long wave compensation together with measured values according to an embodiment; and

fig. 9 is a schematic block diagram for explaining a calibration process in the leveling system according to the embodiment.

Detailed Description

Before embodiments of the invention are discussed below based on the drawings, it should be noted that like elements and structures are provided with like reference numerals and thus descriptions of like elements and structures are applicable or interchangeable.

Embodiments of the present invention provide a leveling system. The leveling system can be advantageously used in a construction machine, in particular a road finishing machine 10 as shown in fig. 1a and 1 b.

The leveling system 100 is schematically shown in fig. 2 a. Leveling system 100 includes a layer thickness measurement system 110 and a processor 130. Layer thickness measurement system 110 is again illustratively depicted herein. The system comprises, for example, a carriage 12 which is arranged at a screed 10b of the construction machine and carries two distance measuring devices 14a and 14b, for example ultrasonic sensors. First ultrasonic sensingThe applicator 14a is arranged in front of the screed in the direction of travel, while the second ultrasonic sensor 14b is arranged behind the screed in the direction of travel. Each of these sensors 14a and 14B determines a distance a or B relative to the subsurface or relative to the sedimentary layers. By forming the difference between the two distances a and B, the layer thickness can be determined. Details of this will be discussed below. For the positions P1, P2 along the travel direction, the determined layer thickness values S1, S2 … are transmitted to the processor 130. In addition, the processor 130 receives the (set) layer thickness profile 120. The layer thickness profile 120 comprises correspondingly positioned set layer thickness values S _set1 、S _set2 A. As shown in block 120 or fig. 3a, layer thickness profile 120 includes different heights applied across separate locations that form a planar layer with subsurface 122. As shown in fig. 3b, the subsurface 122 comprises waves, here long waves in the range of 15 to 100 m. The trough is marked by 122t and the peak is marked by 122 b. A larger layer thickness is provided in the region of the wave trough 122t, while a smaller layer thickness is provided in the region of the wave crest 122 b.

The processor 130 determines the control values C1, C2 assigned to the individual positions such that the tool (here the screed 10 b) is controlled to the respective heights for movement to the respective set values S of the positions _set1 、S _set2 . The control values C1, C2 act on the traction point adjustment and as a result raise or lower the screed. For example, the control value may be a specific distance indication of how much the traction point is offset. In this case both positive control values as well as negative control values are possible, since the traction point can be both raised and lowered. For example, such a control value may be proportional to a determined difference between the set layer thickness and the actual layer thickness. According to an embodiment, the translation ratio is considered, since the traction point offset results in x longitudinal units (screed offset x, e.g. between 0.1 and 10 or between 0.01 and 100), depending on the geometry of the screed suspension. Depending on the geometry, an indirect ratio may be provided. According to a further variant, the control value may also merely indicate that a traction point increase or a traction point decrease is required. For example, this is a binary adjustment or an adjustment with three states (-1 decrease, +1 increase, 0 traction point unchanged). Control values of this type may also be identical to those discussed above In combination, such that for example for lowering and raising two or three (typically more) possible control values indicating the degree of change are possible. As already seen on the basis of fig. 1b, the height of the traction point 10z is adjusted via the traction point cylinder 10zz, however, the traction point cylinder has only an indirect influence on the height of the screed 10b or in particular the screed rear edge 10 bk.

Starting from control 130, a perfect road surface is theoretically formed by taking into account the layer thickness profile 120. Since in practice the height of the tool and thus the applied layer thickness depends on further parameters in addition to the adjustment height at the traction point cylinder 10zz (current traction point adjustment), according to an embodiment also the actual layer thicknesses S1, S2 according to position are considered. It should be noted here that the values referred to as actual layer thickness values are measured with respect to the subsurface, for example, before the application of the layer, so that these values are predicted actual layer thickness values or in general also height values. In this way, the term actual layer thickness value is considered synonymous with the term actual height value. As can be seen from the arrangement of the measuring system of fig. 1a in front of the screed (see sensor arrangements 14a, 14c and 14 d), scanning is performed with respect to the subsurface in front of the screed, i.e. the position assigned to the fixed length offset starts from the screed in the direction of travel or from the screed rear edge in the direction of travel.

Here, it should be noted that, according to an embodiment, for example, at the position P1, the set value S is maintained _set1 And the layer thickness height S1 at the position P1 can be compared, wherein then a control signal C is output _{1+ offset} . The background is that when the height S1 can be determined, a traction point adjustment of another position has been made, which adjustment is by adjusting the path offset. In this way, the derived control signal C _{1+ offset} Is considered as a compensation signal of some kind, wherein for another (offset) position P _{1+ offset} (e.g., P3), a corresponding set height S _set3 Also with compensation signal C _{1+ offset} Considered together.

This results in the control signal of the other position depending on the constellation of the setting-actual comparison of the first position P1, wherein the setting height of the other position is also taken into account, e.g. S _set3 . Here, it should be noted that the other position (here P3) is offset from the first position P1 by an offset which may be constant at least during operation and is preferably considered constant. As mentioned above, the offset is dependent on different parameters such as the speed of the construction vehicle, the asphalt temperature, the asphalt mixture, the tilt angle of the screed, etc.

The principle can be applied, for example, to road finishing machines having a layer height to be applied, but also to road milling machines having a layer depth to be removed. In road finishing machines, the set layer thickness/set height is determined as a function of position, and in road milling machines, the set layer depth/set depth is determined.

This offset becomes more pronounced based on the position of the layer thickness adjustment tool 10b, the traction point adjuster 10zz, as shown in the top view of fig. 2 b.

In this embodiment, FIG. 2b shows a work machine 10 having screed 10b and layer thickness measurement system 14r including first sensor 14a and second sensor 14 b. These sensors are mounted to the screed 10b by brackets 12 such that a first sensor 14a is measured in front of the screed and a second sensor 14b is measured behind the screed. The first sensor 14a measures with respect to the subsurface and the second sensor 14b measures with respect to the applied layer.

In addition, according to an embodiment, another layer thickness measurement system 14l may be provided, which is similar in structure to layer thickness measurement system 14r. The layer thickness measuring system 14r is located, for example, on the right side of the screed 10b, while the layer thickness measuring system 14l is arranged on the left side of the screed 10 l. As described above, layer thickness measurement systems 14l and 14r measure height relative to the subsurface. Assuming that both sensors 14a and 14b are arranged at the same applied height, the layer thickness can be determined starting from the difference of the two height values. When tilting the screed, the distance will also vary indirectly in proportion. In the case of identical leveling arm (lever arm) lengths, i.e. identical horizontal distances of the sensors 14a and 14b with respect to the pivot point, the layer thickness can still be determined based on this difference. According to an embodiment, the intersection theory may be considered in case of leveling arms of different lengths. Different measuring methods for determining the layer thickness by means of a distance sensor are explained, for example, in EP 2921588 or EP 3048199 or EP 3228981. In addition, according to further embodiments, other methods for layer thickness measurement are contemplated. However, a particular advantage of the layer thickness measurement discussed above is that distance sensors also used in conventional leveling systems can be used.

Here, it should be noted that the layer thickness is generally determined in the region of the screed. This position is marked by reference number 140. According to a further embodiment, a position sensor, such as a GNSS sensor, may be provided at the position 140 to assign positions to the layer thicknesses, which improves the comparison of the set layer thicknesses with the actual layer thicknesses according to the positions. In addition to this, a further position sensor 142 can be provided, which is arranged, for example, in the region of the towing point. As described above, the position of the traction points is shifted, and then the screed approaches these positions in consideration of the shift. The use of two position sensors advantageously allows assigning a position to an offset between the current (screed) position and the other position (position where the traction point is offset). According to the embodiment, it is apparent that only one sensor may be provided, and the offset may be calculated based on the running speed or the like. In addition to the layer thickness measuring system 14, according to an embodiment, a further sensor arrangement, here a sensor arrangement 24, may be provided. The sensor arrangement 24 further comprises a distance sensor measuring the distance to the ground. These sensor arrangements 24 are directly connected to the chassis of the road construction machine 10 and scan for unevenness. The sensor arrangement may be provided on one side of the construction machine or on both sides of the construction machine.

Starting from the arrangement of fig. 2c, the leveling system will be explained. The constellation of fig. 2c shows a construction machine 10 with a screed 10b and two layer thickness measurement systems 14l and 14r for two different sides of the screed 10 b. For example, consider each side individually and receive the set point S via database 150 _set . The database 150 may be installed on a notebook 152, for example, or may be retrieved via a notebook. The notebook 152, or a portion of a leveling system typically having a communication device or interface, provides the setting data S to the two control circuits 130l and 130r _set . Note-bookThe set value S according to the position of the screed in the future _set And the deviation of the current screed position obtained, the traction points currently on the left and right (not shown) are controlled.

Fig. 2d shows a further variant. Here, one of the two control circuits 130l or 130r is instructed to function as a master circuit, and the other control circuit functions as a slave circuit. It can be seen that control circuit 130l receives the distance value from measuring device 14l, and control circuit 130r receives the distance value from measuring device 14 r. In this embodiment, the arrangement 14l (i.e. the measuring arrangement 14 r) comprises three distance sensors 14a, 14b and 14c, respectively. 14a are located between 14b and 14c and measure, for example, the height of the area in front of the screed or the area of the traction point 10z, while 14c is measured further towards the ground in the direction of travel. The layer thickness measuring systems 14l, 14r may use two sensors 14a and 14b by forming a difference, or may also use the sensors 14c, 14b, or alternatively, may use all three sensors. Here, for example, the distance values are measured by the sensors 14a and 14c, averaged, and the difference value is combined with the distance value of the distance sensor 14 b.

The entire sensor arrangement 14 can also be extended, for example, by using more than three sensors. This is shown for example in fig. 2 e.

Fig. 2e shows work machine 10 with corresponding control circuit 130 and sensor arrangement 14. The construction machine includes four sensors 14a, 14b, 14c and 14d mounted on a common carrier 12. The sensors shown herein may be configured as so-called superski sensors, each comprising a plurality of sensor heads.

The sensors 14a and 14b together form a layer thickness measurement system 14. The sensors 14a, 14b can also be used to determine measured values (for short waves) of the function of a conventional leveling system. Here, it is advantageous to use additional sensors, for example, in the direction of travel in front of the sensors 14a and 14 b. This means that the sensor arrangement 14 (14 l, 14 r) can be used both in conventional leveling systems and in the described leveling system for long waves in a solution with two sensors 14a and 14b each or in a solution with more than two sensors 14a to 14d. Obviously, the layer thickness can be determined directly by the sensors (14 a, 14 b).

According to an embodiment, the system is configured as described above in order to compensate for long wave unevenness. According to a further embodiment, in addition, short and uneven properties can be compensated for, for example, based on conventional leveling techniques.

Fig. 4 shows a layer thickness profile 120' of a flat road surface 125 for producing a layer to be applied. For example, the pre-scanned subsurface profile 122 includes elevations and depressions. For example, scanning is performed at a distance of 3m, wherein a tilt angle or the like may be included in addition to the height with respect to the reference. From deviations from a reference (see Δh _set ) Initially, a layer thickness profile (see "left thickness" or "right thickness") is derived for the two control circuits, respectively. The deviation of the two points from the reference (deltah can also be taken into account _{Two of} )。

Referring to fig. 5a, the control circuit 103 is extended by a flatness adjuster. The actual layer thickness S1, the layer thickness is determined on the basis of the actual height value by means of the layer thickness control circuit 130 and compared with the set layer thickness (see comparator 131). By taking into account the predictive model 137, the adjustment may be performed as described above. In addition, according to an embodiment, a flatness adjuster 142 may be provided. This also adjusts the flatness in the traction point area with the P-component or PT-component according to the height sensor, e.g. the height sensor 14 a.

In the screed area, flatness is maintained by using a P-component or a PT-component. This flatness adjustment occurs without consideration of the predictive model 137.

Referring to fig. 5b, the model will be explained in detail again. Figure 5b shows screed 10b pulled across traction point 10 z. The flatness is again adjusted by the flatness adjuster 142. The flatness adjuster 142 adjusts the traction point cylinders similarly to the IT1 component behavior. As a feedback loop, the height sensor value is determined in the region of the traction point and fed back to the flatness adjuster 142 after optional filtering (see filter 144). This is an auxiliary control circuit of the flatness control circuit. As already mentioned, the flatness control circuit includes a P component and an IT1 component. Starting from this, the screed plate showing PT2 behavior is adjusted. This results in a height at the rear edge of the screed which may be determined by the sensor 14b or generally by the sensor arrangement 14. After optional filtering by the filter 146, the actual height value is compared with the set height value so that traction point adjustment can be performed in another control circuit by using the predictive model 137. By means of the sensor arrangement 14 connected to the filter 146, a superimposed control circuit is provided, which corresponds to the control circuit 130 described above.

As mentioned above, adjusting the traction point does not lead to an immediate change in the layer thickness height. The background is the so-called stabilization process. The same is shown in fig. 6 a. At point P1, the traction point is adjusted accordingly to reach other screed heights, as shown based on curve 60. Here too, in the case of a certain transient, the traction point adjustment is performed. The screed moves with a certain hysteresis following the traction point, which is why so-called "overshoots" or "undershoots" occur, i.e. the screed turns in the other direction shortly after point P1, which is shown on the basis of curve 62. The height adjustment of the screed 10b ends at the latest at a point P2, which is approximately one trailing arm length from the point P1.

In addition, the stabilization process can also be considered with respect to time. Adjustment of the traction point 10z takes, for example, half a second, here 0.4 seconds. From here on, the layer thickness in the screed region varies with a time factor of 0.5 seconds. When the system mainly implies that a rotation takes place around the screed rear edge 10bk, it should be noted that the pivot point is slightly moved in the direction of the traction point, as shown in the lower half of fig. 6 b. The lower half represents the kinematics of the overall system, wherein the position of the pivot point can also be varied depending on the current conditions. Even when the conventional leveling control circuit is activated, a change occurs in the path (time) of travel (for example, in the range between 1 minute and 20 minutes).

The above principle has been explained in particular in the case of road finishing machines (layer thicknesses to be applied), wherein it is obvious that the above principle can also be applied to other machines, for example road construction machines, which lead to planarization. For example, the road milling machine may be height-adjustable by the system. Fig. 7a shows the adjustment of a road milling machine with a milling wheel 10f and two height sensors 14l and 14 r. The road milling machine measures a specific height from its offset relative to the ground 11. When the wheel 10f takes material from the subsurface 11, the measured height is reduced, as is shown on the basis of fig. 7 b. This height gives an indication of the removed layer and may therefore be referred to as a layer thickness system. Since the subsurface contour can also be predetermined for a road milling machine, by the same principle as described above, the layer thickness to be removed in the sense of the layer to be removed can be predetermined and can then be kept constant by using the measuring system shown in order to remove in particular long waves.

Fig. 8a and 8b show the layer thickness values at individual positions 1 to 15. Here, for example, the position distances are equidistant. Assume an average desired height, here 5.0. In one position, here position 1, the desired average layer thickness is determined as the reference layer thickness and applied substantially parallel to the subsurface. Determining the individual layer thickness values such that the minimum layer thickness h is not undercut or exceeded _min And a maximum layer thickness h _max . Since the layer thickness values are also determined such that layer thickness variations are possible without changing the subsurface (see positions 8 and 9), the transverse gradient can be adjusted.

Here, it should be noted that a distinction is made between a control unit or man-machine interface MM2 (manual control unit) and a global control SSI (control computer).

Fig. 9 shows a calibration process. In the beginning, the height is set to the correct height level and is determined as the reference level. Furthermore, a time setpoint is introduced into the system such that the corresponding layer thickness profile for compensating for the long-wave screed unevenness and/or the desired lateral gradient is known to the leveling system.

A further embodiment relates to a method for determining a set layer thickness profile. Here, for example, as discussed, the subsurface profile is scanned to determine a set layer thickness profile from which to begin. Minimum and maximum values are also contemplated herein.

Here, it should be noted that the process of determining and using the set layer thickness profile is particularly useful for the sub-structure layer. Because of the low thickness of the adhesive layer and the cover layer, long wave unevenness cannot generally be compensated for in these layers.

Although some aspects have been described in the context of apparatus, it is evident that these aspects also represent descriptions of corresponding methods so that a block or apparatus of an apparatus also corresponds to a respective method step or feature of a method step. Similarly, aspects described in the context of method steps also represent descriptions of corresponding blocks or details or features of corresponding apparatus. Some or all of the method steps may be performed by (or using) hardware devices such as microprocessors, programmable computers, or electronic circuits. In some embodiments, some or several of the most important method steps may be performed by such an apparatus.

The encoded signals of the present invention, such as audio signals or video signals or transmission current signals, may be stored on a digital storage medium or may be transmitted over a transmission medium, such as a wireless transmission medium or a wired transmission medium, for example, the internet.

The encoded audio signal of the present invention may be stored on a digital storage medium or may be transmitted over a transmission medium, such as a wireless transmission medium or a wired transmission medium, such as the internet.

Embodiments of the invention may be implemented in hardware or software, depending on certain implementation requirements. The implementation may be performed using a digital storage medium, such as a floppy disk, DVD, blu-ray disc, CD, ROM, PROM, EPROM, EEPROM, or flash memory, hard disk drive, or another magnetic or optical storage having electronically readable control signals stored thereon, which cooperate or are capable of cooperating with a programmable computer system, such that the corresponding method is performed. Thus, the digital storage medium may be computer readable.

Some embodiments according to the invention include a data carrier comprising electronically readable control signals capable of cooperating with a programmable computer system, thereby performing a method as described herein.

In general, embodiments of the invention may be implemented as a computer program product having a program code operable to perform a method when the computer program product is run on a computer.

For example, the program code may be stored on a machine readable carrier.

Other embodiments include a computer program for performing a method described herein, wherein the computer program is stored on a machine-readable carrier.

In other words, an embodiment of the inventive method is therefore a computer program comprising a program code for performing one of the methods described herein when the computer program runs on a computer.

Thus, a further embodiment of the inventive method is a data carrier (or digital storage medium or computer readable medium) having embodied thereon, recorded thereon, a computer program for performing one of the methods described herein. The data carrier, digital storage medium, or computer readable medium is typically tangible or non-volatile.

Thus, a further embodiment of the inventive method is a data stream or signal sequence representing a computer program for executing a method as described herein. The data stream or signal sequence may, for example, be configured for transmission via a data communication connection (e.g., via the internet).

Further embodiments include a processing device, e.g., a computer or programmable logic device, configured or adapted to perform one of the methods described herein.

Further embodiments include a computer having a computer program installed thereon for performing one of the methods described herein.

Further embodiments according to the invention include an apparatus or system configured to transmit a computer program for performing at least one method described herein to a receiver. For example, the transmission may be electronic or optical. The receiver may be, for example, a computer, mobile device, storage device, or the like. For example, the apparatus or system may comprise a file server for transmitting the computer program to the receiver.

In some embodiments, a programmable logic device (e.g., a field programmable gate array FPGA) may be used to perform some or all of the functions of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor to perform one of the methods described herein. In general, the method is preferably performed by any hardware device. This may be universally applicable hardware such as a Computer Processor (CPU) or hardware specific to the method such as an ASIC.

The apparatus described herein may be implemented, for example, by using hardware means or by using a computer or by using a combination of hardware means and a computer.

The apparatus described herein, or any component of the apparatus described herein, may be implemented at least in part in hardware and/or software (computer programs).

The methods described herein may be implemented, for example, by using hardware devices or by using a computer, or by using a combination of hardware devices and a computer.

The methods described herein, or any components of the methods described herein, may be implemented at least in part by hardware and/or software (computer programs).

The above-described embodiments are merely illustrative of the principles of the present invention. It is to be understood that modifications and variations of the arrangements and details described herein will be apparent to other persons skilled in the art. It is therefore the intention that the invention be limited only by the scope of the claims appended hereto and not by the specific details presented by way of description and explanation of the embodiments herein.

Claims

1. Leveling system for a construction machine, in particular a road construction machine or road finishing machine (10) or road milling machine, comprising:

a layer thickness measurement system (110, 14) configured to measure a layer thickness currently to be applied or to be removed and a respective actual layer thickness value (S1, S2,) of a plurality of positions (P1, P2,) or a respective predicted actual layer thickness value (S1, S2,),

a processor (130) configured to determine a layer thickness value (S _set1 、S _set2 -determining a control value according to position (P1, P2), -a layer thickness profile (120) of the tool (10 b) of the construction machine (10), and-the actual layer thickness value (S1, S2), -or the predicted actual layer thickness value (S1, S2), -of the position (P1, P2), -to determine a control value according to position (P1, P2), -to the height adjustment of the tool (10 b).

2. Leveling system according to claim 1, wherein the control values (C1, C2, according to positions (P1, P2) are selected such that the tool (10 b) is raised and/or lowered according to the layer thickness profile (120) in order to adjust the position of the tool in the layer thickness profile (S _set1 、S _set2 The term,) is moved according to the position (P1, P2).

3. Leveling system according to claim 1, wherein the control values according to positions (P1, P2) are selected such that the actual layer thickness value or the predicted actual layer thickness value (S1, S2) is considered to be equal to the set layer thickness value (S _set1 、S _set2 A.c.) determined deviation between the two.

4. The leveling system according to claim 1, wherein the processor (130) is configured to determine the leveling value by taking into account the other position (P _{1+ offset} ) To determine control values (C1, C2,) for said other location; and/or

Wherein the other position (P _{1+ offset} ) Offset by an offset amount relative to the corresponding position.

5. Leveling system according to claim 1, wherein the control values according to position are chosen such that in steady state the actual layer thickness values according to position or the predicted actual layer thickness values (S1, S2.) substantially (±20%, ±10%, ±5%, ±3%, ±1%) correspond to the set layer thickness values according to position (S _set1 、S _set2 、...)。

6. Leveling system according to claim 1, wherein the control value is derived such that the height adjustment of the tool (10 b) is performed by taking into account an adjustment path (offset) of the tool along the travel direction of the work machine.

7. The leveling system according to claim 1, wherein the processor (130) is configured to derive the control value from the layer thickness profile (120) such that a layer to be smoothed or applied by the tool forms a flat road surface on an underground profile (122) along a direction of travel of the work machine; and/or

Wherein the layer to be applied or the layer to be smoothed comprises a first dimension along the travelling direction and a second dimension transverse to the travelling direction, and wherein the first dimension and the second dimension span a plane, and wherein the control value is derived from the layer thickness profile (120) such that the layer to be applied (placed) by the tool or the layer to be smoothed by the tool comprises a flat road surface on the subsurface profile (122) along the spanned plane.

8. Leveling system according to claim 1, comprising a position sensor or GNSS sensor, in particular coupled to the tool or to the work machine, and wherein the position sensor or GNSS sensor is configured to determine a position of the actual layer thickness value or the predicted actual layer thickness value (S1, S2,) in particular along a travelling direction.

9. Leveling system according to claim 1, wherein the layer thickness profile (120) comprises a layer thickness value (S _set1 、S _set2 The use of the term,; and/or

Wherein the layer thickness profile (120) is determined from the subsurface profile (122).

10. The leveling system according to claim 1, wherein the processor (130) is configured to determine the control value such that a minimum layer thickness is set as a function of position.

11. The leveling system according to claim 1, wherein the processor (130) comprises a flatness adjuster configured to determine the control value by using a sensor value, thereby generating a flat road surface.

12. The leveling system of claim 1, wherein the processor (130) comprises: including the conditioning paths of the P component, the IT component, the PT component, and/or the conditioning paths with predictive models.

13. The leveling system according to claim 1, wherein the layer thickness measurement system (110, 14) forms together with the processor (130) a first control circuit for a first side (left or right) of the tool; and/or wherein the layer thickness measurement system (110, 14) or another layer thickness measurement system (110, 14) forms together with the processor (130) a second control circuit for a second side of the tool.

14. The leveling system of claim 13, wherein the first and second control circuits interact to control the tool accordingly for an intermediate position between the first and second sides of the tool such that an actual layer thickness substantially corresponds to a set layer thickness of the intermediate position in a steady state.

15. Leveling system according to claim 1, wherein the layer thickness measuring system (110, 14) comprises at least one sensor (14 a) located in front of the screed (10 b) and at least one sensor (14 b) located behind the screed (10 b), and wherein the layer to be determined is determined by forming a difference.

16. The leveling system of claim 1, wherein the leveling system comprises a sensor arrangement comprising at least two, at least three, or at least four sensors arranged on a bracket extending along a direction of travel of the work machine; or alternatively

Wherein the leveling system comprises a sensor arrangement comprising at least two, at least three or at least four sensors arranged on a carrier extending along the travel direction of the construction machine, and wherein the sensor arrangement comprises the layer thickness measuring system (110, 14).

17. Construction machine (10), in particular a road construction machine or road finishing machine (10) or road milling machine, having a leveling system according to claim 1.

18. An apparatus for determining a layer thickness profile (120) comprising a plurality of layer thickness values (S1, S2) assigned to a plurality of locations, comprising:

An interface for receiving a subsurface contour (122) comprising a plurality of elevation values assigned to the plurality of locations;

an interface for receiving at least one set height or at least one set depth; and

a calculation unit for determining the layer thickness profile (120) based on a difference between the plurality of height values assigned to the plurality of positions and the at least one set height or the at least one set depth or a reference defined by the at least one set height or the at least one set depth.

19. The device according to claim 18, comprising an output interface for providing/outputting the layer thickness profile (120) to a construction machine, in particular a road construction machine or a road finishing machine (10).

20. The apparatus of claim 18, wherein the at least one set height is defined by a few set height values assigned to the plurality of locations;

wherein the at least one set depth is defined by several set depth values assigned to the plurality of locations.

21. The apparatus of claim 18, wherein the at least one set height and/or several set height values define a plane or 3D plane of layers to be smoothed or generated (placed).

22. Leveling method for a construction machine, in particular a road construction machine or road finishing machine (10) or road milling machine, comprising:

measuring the current layer thickness to be applied or removed and determining corresponding actual layer thickness values or predicted actual layer thickness values (S1, S2),

based on a layer thickness value (S _set1 、S _set2 The actual layer thickness profile (120) and the actual layer thickness value of a position or the predicted actual layer thickness value (S1, S2.) to determine a position-dependent control value for a height adjustment of a tool of the construction machine.

23. For determining a layer thickness value (S) comprising a plurality of settings assigned to a plurality of positions _set1 、S _set2 A layer thickness profile (120), comprising:

receiving a subsurface profile (122) comprising a plurality of elevation values assigned to the plurality of locations;

receiving at least one set height or at least one set depth; and

the layer thickness profile (120) is determined based on a difference between the plurality of height values assigned to the plurality of locations and the at least one set height or the at least one set depth or a reference defined by the at least one set height or the at least one set depth.

24. A computer program for performing the method of claim 22 or 23 when the method is run on a computer.