EP4357525A1 - Method for assisted operation assistance of a soil compaction machine and soil compaction machine - Google Patents

Abstract

Method (20) for assisted operation of a soil compaction machine (1), comprising the steps: controlling (21) the soil compaction machine (1) by an operator; detecting (22) at least one of the parameters travel speed (v), change in travel speed (a) and/or reversal of travel direction or at least one variable correlating with one of the said parameters; determining (27) a point in time at which a reversal of the soil compaction machine (1) takes place from the at least one parameter detected in step b) or the at least one variable detected in step b); Detecting (23) a steering angle (w) of the soil compaction machine (1) and/or a vibration input (S) of a vibration exciter (10) into the soil (8) or a variable correlating with the steering angle (w) or with the vibration input (S) within a time interval (T) and/or a distance (L) around the point in time determined in step c) and/or around a location of the soil compaction machine (1) at this point in time; comparing (24) the steering angle (w) and/or vibration input (S) detected in step d) within the interval (T) and/or the distance (L) with predetermined reference values for a target steering angle and/or a target vibration input; outputting (25) and/or storing (26) a result of the comparison (24).

Description

The invention relates to a method for assisted operation of a soil compaction machine. Furthermore, the invention relates to a soil compaction machine, in particular a tandem roller or a roller train, with at least one roller drum and a control device.

Generic soil compaction machines are, for example, from the EN 10 2018 007 825 A1 known to the applicant. They are typically used in road and path construction and in the construction of runways and airfields. These are usually self-propelled machines, which in particular have a machine frame supported by a chassis. The chassis typically comprises at least one roller drum and optionally wheels. The chassis can also have, for example, two roller drums, which are separated from one another and arranged one behind the other, in particular in the working direction of the soil compaction machine, so that when the soil compaction machine moves forward, a certain position on the ground is successively driven over by both roller drums arranged one behind the other. The working direction of the soil compaction machine corresponds to a longitudinal machine axis or a front/back direction of the soil compaction machine. The current working direction can be a forward or an opposite backward direction, with a reversing working mode usually being present. The roller drums are typically metallic hollow cylinders, for example made of steel, which can in particular have a smooth outer surface. When soil compaction machines are in operation, they are moved with at least one or two roller drums over a soil to be compacted, for example an asphalt layer laid by a road finisher. The drive energy required to operate the soil compaction machine is typically provided by a drive motor, for example an internal combustion engine, usually a diesel engine, or an electric motor. In order to increase the compaction of the soil by the roller drums beyond the machine's own weight, It is also known that a vibration exciter is provided in or on the rolling band, via which the rolling band can be set into vibration. Depending on the type of vibration, its frequency and its amplitude, a desired adjustment of the compaction of the rolling band can be set.

Such soil compaction machines usually have a driver's cab for an operator, from which the soil compaction machine is controlled by the operator. The operator controls in particular the travel of the soil compaction machine over the soil to be compacted. For example, both the direction of travel and the travel speed are specified by the operator. At the same time, the operator typically controls the operation of the vibration exciter(s) in the roller drum(s). These can be switched on and off and sometimes varied in terms of their frequency and/or amplitude. Soil compaction machines of this type typically have a control device, which can be an on-board computer or part of an on-board computer, for example. The control device is typically equipped with at least one sensor that records at least one parameter of the operation of the soil compaction machine. Such a parameter can be the direction of travel, the travel speed, the steering angle, the operating state of one or more vibration exciters, an acceleration value, a value associated with the soil stiffness, a travel path, etc. In addition, soil compaction machines of this type typically have a display device connected to the control device, for example a screen or a display. The measured values of the sensor can be shown on this display, for example. In addition, the control device can be designed to receive control commands from the operator - for example via the display device, which can include a touchscreen, additional and/or separate input devices, etc. - and to control the soil compaction machine using these control commands.

Soil compaction machines are typically driven over an area to be compacted several times. This usually requires the soil compaction machine to be reversed several times. In other words, the direction of travel is reversed several times so that the soil compaction machine moves back and forth over the soil to be compacted. The soil compaction machine can therefore drive over the same spot several times. The aim of soil compaction machines is usually to create and leave behind a soil surface that is as smooth and homogeneously compacted as possible. For example, the evenness of a road is an important criterion relevant to remuneration, which is therefore of great practical and economic interest.

However, it is unavoidable that the roller drums of the soil compaction machine will leave a bump in the surface to be compacted when reversing, i.e. when changing direction, if the ground is still deformable under the machine's own weight, for example when the asphalt temperature is still relatively high. This bump then typically has to be smoothed out as well as possible on subsequent passes in order to obtain a road surface of the desired quality. To make this easier, the operators of the soil compaction machines are typically instructed to turn shortly before the soil compaction machine comes to a standstill when reversing, so that the roller drums and thus also the bump left by them are aligned at an angle to the working direction when reversing. Such diagonal bumps can be smoothed out much more easily and quickly on subsequent passes than bumps that run perpendicular to the working direction.

In addition, the operator of the soil compaction machine must typically ensure that the operation of the vibration exciter(s) is controlled in such a way that too much vibration energy or too many impulses per defined distance are not introduced into the soil, for example the asphalt layer, at one point or over too short a distance. This can also promote the formation of undesirable ground waves. The vibration input into the soil must therefore be reduced in good time before or during the braking of the soil compaction machine before reversing, for example by switching off the vibration exciter in good time while the soil compaction machine is still traveling sufficiently fast.

Overall, the operator can therefore actively influence the waviness or evenness of the compacted soil left behind by the machine and thus the quality of the work result through the way in which he controls the soil compaction machine. However, in order to achieve high-quality work results, a considerable amount of experience and skill is required on the part of the operator. Situations often arise in which operators with sufficient training are not available, so that due to a lack of specialist knowledge, the soil compaction machine is not used in such a way that the compacted soil, for example the roadway, is optimally even. In addition, the operator is usually unable to recognize the levelness achieved during operation. Measuring the evenness of the soil during operation is technically complex and is therefore typically not carried out. There is therefore no possibility for the operator to adapt his driving style based on the current or last achieved result, ideally during operation.

Against this background, the object of the present invention is to provide a method or a soil compaction machine with which which the evenness of the compacted soil can be improved. In particular, driving errors that can occur around the reversing of the soil compaction machine should be reduced. Preferably, feedback on the work result should be provided during and/or after compaction operation without the need to measure the evenness of the soil. The feedback on the previous work process should make it possible to improve future work processes with regard to the optimal evenness of the compacted soil.

The problem is solved with a method and a soil compaction machine according to the independent claims. Preferred developments are specified in the dependent claims.

Specifically, the solution is achieved with a method for assisted operation of a soil compaction machine. In other words, it is a method for controlling the compaction process during compaction operation of the soil compaction machine or a method for monitoring the operation of the soil compaction machine during compaction operation by the operator. The method is based on the control of the soil compaction machine by an operator. This is done in a known manner by entering appropriate control commands, for example with regard to direction of travel, speed of travel, activation and/or setting of one or more vibration exciters, etc. A soil compaction machine of this type therefore operates in a conventional manner, in which the operator guides it over the soil to be compacted. The soil to be compacted is in particular an asphalt layer laid by a road finisher, still hot or still sufficiently warm for surface deformation by the soil compaction machine, from which, for example, a roadway or similar is created after compaction. Controlling the soil compaction machine therefore includes, in particular, driving over the soil to be compacted several times or reversing the soil compaction machine several times. The soil compaction machine is preferably repeatedly braked, in particular to a standstill, and then accelerated again in a direction opposite to the original direction of travel. Preferably, at least one roller drum of the soil compaction machine is at least partially set into vibration by a vibration exciter in order to achieve dynamic soil compaction. This can be, for example, vibration or oscillation vibrations or any superposition of these. Controlling the soil compaction machine by an operator is understood in this case to mean, in particular, semi-autonomous operation. For example, an automatic reversing system could be used in which an operator triggers a reversing process by means of a control input, for example by pressing a button, whereby braking, reducing the vibration input, accelerating in the opposite direction and subsequent increase in the vibration input is carried out automatically by the control device. The operator can start the automatic reversing, for example, according to his own judgment or, for example, after reaching a mark, for example a light spot projected onto the ground, which can be arranged at a set distance from the reversing point that is necessary for the reversing process. It is important, however, that the driver naturally still retains control of the machine and can intervene in the process at any time, whereby the automatic reversing immediately ends and the operator takes over control of the machine completely. In particular, these cases in which the operator takes over control again are of interest for the method according to the invention, since the automatic reversing already takes optimal driving styles into account. For this reason, the automatic reversing is particularly preferably designed in such a way that it only controls the braking and subsequent acceleration in the opposite direction of travel, in particular up to a desired target speed, but does not take over steering processes, which preferably have to be controlled exclusively manually.

In the method according to the invention, at least one of the parameters of driving speed, change in driving speed and/or reversal of driving direction is recorded. Alternatively, another variable that correlates with one of the parameters mentioned can also be recorded. For this purpose, the soil compaction machine preferably comprises at least one suitable recording device, for example at least one sensor, which records the respective parameter or variables directly or indirectly and in particular forwards it to the control device. The recording and determination of various parameters, variables, times or locations can preferably also include, throughout the present description, that the recorded or determined values are stored for later use, for example in a memory, in particular an electronic one, of the control device. In principle, a sensor of the recording device can be provided that records several parameters or variables, or a separate sensor can be provided for each parameter or variable. Since soil compaction machines usually already determine the driving speed directly or indirectly, the value of this parameter is usually already available, for example, and can be used for the method according to the invention. The change in driving speed can in turn also be calculated from a repeatedly or continuously measured driving speed. In addition, it is also possible to record the movement or acceleration of the soil compaction machine, for example, using an electronic compass or an IMU ( inertial measurement unit ). The use of GNSS systems (global navigation satellite system ) to repeatedly or continuously record the location of the soil compaction machine and/or their temporal comparison is possible. In addition, the movement of the soil compaction machine can also be determined by optically recording the surroundings of the soil compaction machine. For example, a camera or the image from a camera can be used to determine the movement of the soil compaction machine. The variables mentioned, which are not directly the driving speed, the change in driving speed and/or a reversal of the direction of travel, can preferably be used to determine these. Alternatively, the variables mentioned can also be used directly in the next step of the process.

From the at least one recorded parameter or the at least one recorded size, a point in time is then determined at which the soil compaction machine reverses. In other words, the turning point of the soil compaction machine is determined. It is therefore preferably determined when a reversal of direction takes place or when a driving speed first drops to zero and then increases again in the opposite direction. This is referred to here as reversing the soil compaction machine. If the position of the soil compaction machine is also recorded, for example by a distance measurement or by a GNSS system, the location at which the soil compaction machine is located at the time at which the reversal takes place is also determined. This location can therefore also be used as a starting point for the further process.

It is optimal if, below a certain driving speed of the soil compaction machine and especially when it is at a standstill, no more vibrations are introduced into the ground by the exciter unit, i.e. no more vibration or oscillation energy is transferred to the ground. Such localized compaction due to the vibrations can otherwise quickly lead to excessive wave formation. The operators of the soil compaction machines are therefore required to reduce the vibrations introduced into the ground in good time before the machine comes to a standstill during reversing, in particular to zero. To do this, the vibration exciter can be switched off, for example, or the amplitude of the vibration generated can be reduced, in particular to zero, for example by turning the amplitude to the horizontal. When the exciter is switched off, it typically passes through a resonance range in which the amplitude of the vibrations generated increases. A sufficiently high driving speed of the soil compaction machine must therefore be ensured, especially when passing through the resonance range. In addition, as already explained at the beginning, the machine should be turned before it comes to a standstill, so that the wave in the ground that is inevitably left behind when reversing is aligned at an angle to the straight-ahead working direction. The method according to the invention therefore provides for the detection of a steering angle of the soil compaction machine and/or a vibration input from a vibration exciter into the ground or a vibration related to the steering angle. or a quantity correlating with the vibration input. For this purpose, one or more sensors can be provided on the soil compaction machine as part of the recording device, which record the respective parameters or quantities and forward their values to the control device. For example, a sensor can be provided which records the steering angle or the vibration input directly or indirectly via a correlating parameter. From a repeated or continuous measurement of the location of the soil compaction machine, it can also be concluded that the soil compaction machine is inclined based on the distance traveled, which in turn correlates with the steering angle. Alternatively, the braking distance covered and the steering movement carried out during this can be used to conclude that the soil compaction machine is inclined. The vibration input is a measure of how much energy is transferred from the vibration exciter to the ground. This depends largely on the frequency and amplitude of the vibration exciter, which is usually one or more unbalance exciters. Accordingly, the vibration input can be influenced by adjusting the frequency and/or the amplitude of the vibration exciter. Switching off the vibration exciter, for example, leads to the frequency decreasing, in particular to zero. In addition or alternatively, the amplitude of the vibration exciter can be adjusted, in particular to zero, for example by changing the eccentricity of the flywheel masses of the vibration exciter. This can also change the vibration input into the ground. Values that correlate with the vibration input are therefore, for example, the frequency and/or the amplitude and/or the eccentricity of the flywheel masses of the vibration exciter. The so-called IPF value ( impacts per foot ) is also particularly preferred for this purpose, as it indicates how often a vibration exciter impacts the ground in a certain section of the route. Details of the IPF value can be found, for example, in the EN 10 2018 007 825 A1 from the applicant. In particular, the amplitude refers to the portion of the vibration directed in the vertical direction. In addition or alternatively, the amplitude of the portion of the vibration directed in the horizontal direction can also be taken into account.

As explained at the beginning, the control of the soil compaction machine during reversing or around reversing is particularly important for the evenness of the compacted soil. Of interest here is therefore both the control of the soil compaction machine before reversing and after reversing. The steering angle and/or the vibration input or the variables correlated with this are therefore recorded according to the invention within a time interval and/or within a distance around the already determined time of reversing and/or around the already determined location of the soil compaction machine at this time. The parameters or variables mentioned are therefore recorded before and after reversing. The steering angle and/or the vibration input or the quantities correlating with it are therefore, depending on which measurements are carried out, linked in time or place with the parameters of driving speed, change in driving speed and/or reversal of direction or the quantities correlating with it. For example, it is recorded which steering angle and/or which vibration input is present together with which driving speed of the soil compaction machine. The interval and/or the distance can initially be chosen arbitrarily and can, for example, cover the entire working period or the entire construction site of the soil compaction machine. It is important that they cover the reversing process of the soil compaction machine under consideration. Preferred, more specific intervals/distances are explained in more detail below.

A key point of the method according to the invention is a comparison of the recorded or determined steering angle and/or vibration input within the interval and/or the distance with specified reference values for a target steering angle and/or a target vibration input. As mentioned at the beginning, it is known that waves in the soil that is still to be compacted that are aligned at an angle to the working direction and that arise when reversing can be better compensated for in subsequent passes. In addition, it is known that excessive vibration input on a distance that is too short also contributes to wave formation. A target steering angle and/or a target vibration input can therefore be derived from these relationships. These can, for example, be related to a driving speed, a change in driving speed or similar of the soil compaction machine. For example, a target steering angle can indicate a value for how much the operator should steer until the roller comes to a standstill when reversing in order to arrange the resulting ground wave at an angle to the working direction so that it can be optimally smoothed out in subsequent passes. A target vibration input can, for example, specify a value for how high the maximum vibration input can be at which driving speed of the soil compaction machine. Specifically, such reference values for a target steering angle and/or a target vibration input are stored in a memory that is accessible to the control device. These can be fixed limit values. The reference values can, for example, be punctual, for example in the sense of "from a driving speed X only a maximum of Y vibration input", or continuous, for example in the sense of characteristic maps that specify a wide range of driving speeds and the maximum permissible vibration input in each case. In addition, the reference values can also include a calculation rule from which the target steering angle and/or the target vibration input can be determined for a given driving speed and/or acceleration around the reversing. Since the reversing of the soil compaction machine in operation, at least in comparable work situations, always proceeds almost the same, the reference values can alternatively be based on a time interval and/or a distance before and/or after reversing instead of the driving speed. Such reference values could therefore, for example, provide information such as "switch off the vibration exciter at the latest X seconds or Y meters before reversing" or "switch on the vibration exciter at the earliest X seconds or Y meters after reversing". By comparing the steering angle and/or vibration input with the reference values for the target steering angle and/or the target vibration input, it can be determined to what extent the steering angle or vibration input set by the operator of the soil compaction machine before, during and after reversing corresponds and/or corresponded to the specifications for optimal evenness of the compacted soil. The result of the comparison or comparison can be purely qualitative or quantitative. The result can therefore, for example, be information about whether the steering angle and/or vibration input set by the operator corresponds to the reference values or not. In addition, the result can also include how much the steering angle and/or vibration input set by the operator deviates from the reference values. For example, the result can include information about how much the steering angle set by the operator is smaller than the target steering angle when reversing the soil compaction machine. Since a steering angle that is too narrow when reversing can also be bad for the evenness of the ground, the target steering angle can also be an interval, which therefore specifies both a lower and an upper limit for the steering angle. Accordingly, the result can also include information about how much the steering angle set by the operator is larger when reversing the soil compaction machine than the upper limit specified by the target steering angle. This is done in particular in addition to the monitoring of the lower limit already described. In addition or as an alternative, the result can also include information about how much the vibration input set by the operator around the reversing is greater than the target vibration input. "Around the reversing" here refers to a reference to the interval and/or the distance around the determined time of the reversing and/or the location of the soil compaction machine at that time. Overall, the result of the comparison therefore includes information about the extent to which the control carried out by the operator of the soil compaction machine corresponds to an optimal control in terms of optimal evenness of the compacted soil.

Finally, the method according to the invention also includes outputting and/or storing the result of the comparison or comparisons. For example, the result can be output or displayed on a display device so that it is visible to the operator of the soil compaction machine. In addition or Alternatively, an acoustic output is also conceivable. In this way, the operator receives immediate feedback as to whether or not his control of the soil compaction machine during the previous reversing was optimal in relation to the resulting evenness of the compacted soil. If necessary, the operator also receives feedback from the result as to the extent to which his control of the soil compaction machine during the previous reversing deviated from optimal control. This information can be used by the operator to carry out future reversing of the soil compaction machine more optimally. The result of the comparison according to the invention therefore only provides the operator with information about the sequence of the last reversing that has already been completed. However, this information can be used positively to improve each subsequent reversing, thereby providing overall assisted operation of the soil compaction machine and improving the evenness of the soil overall after the compaction work has been completed. Since this is a professional working environment, it can be assumed that the operator will implement corresponding instructions wherever possible. In addition or alternatively, the result can also be saved, for example stored in a memory of the control device. The operator can then, for example, view the result after completion of the work and thus receive feedback on the workflow. This can also be used for future work to improve the resulting evenness of the compacted soil. In addition, it can be provided that the saved results are read out, for example by an operator of the soil compaction machine, who does not necessarily have to be the operator. This provides the operator with feedback on the quality of the control of the soil compaction machine. In this way, the operator can determine, for example, whether the operator requires additional driver training or not. This can also improve the evenness of the soil in future work. To further simplify this process, it can be provided, for example, that the soil compaction machine has a device for remote data transmission and the result or results of the comparison are automatically transmitted to the operator, for example uploaded to a central server of the operator.

In principle, it would be sufficient if the recording of the parameters of driving speed, change in driving speed and/or reversal of driving direction as well as steering angle and/or vibration input or quantities correlating with the parameters mentioned were repeated at discrete, in particular temporal and/or spatial, intervals. As long as the discrete intervals are chosen close enough to determine the time of reversing of the soil compaction machine with sufficient accuracy, the method can be carried out with such data. However, it is preferably provided that the detection of at least one of the parameters driving speed, change in driving speed and/or reversal of driving direction or at least one variable correlating with one of the parameters mentioned and/or the detection of the steering angle and/or the vibration input or a variable correlating therewith is carried out continuously. In this way, the time of reversing can be determined particularly precisely. In addition, the value of the respective parameters can be determined particularly precisely, for example at a time when a certain driving speed is present or when a certain vibration input occurs.

As already mentioned, the focus of the method according to the invention is to optimize the control of the soil compaction machine around the reversing. Accordingly, the interval and/or the distance can be set in such a way that only the control of the soil compaction machine in the immediate temporal and/or spatial vicinity of the reversing is considered. For example, the size of the interval or the distance can be defined separately for each individual case, for example based on functional criteria. Preferably, the interval or the distance can be set in such a way that the start is specified by the driving speed of the soil compaction machine falling below a threshold value that signals that operation with a working speed in one direction of travel is terminated. The working speed describes a driving speed at which the soil compaction machine is typically operated in working mode while it travels straight ahead over soil to be compacted. Such typical working speeds depend on the type of soil compaction machine and are known to the person skilled in the art. Similarly, the end of the interval or the distance can be specified by the driving speed of the soil compaction machine increasing above the threshold value, thus signaling that acceleration is being returned to the working speed. The start and the end can be specified by the same threshold value or by different threshold values. The threshold value can be, for example, 3 km/h or 5 km/h or 7 km/h. The working speed can be fixed and, for example, also correspond to the threshold value or be a fixed value, for example 1 km/h or 2 km/h or 3 km/h, above the threshold value. Preferably, the interval and/or the distance are set such that the reversing is in the middle of the interval and/or the distance. For example, the interval can be set such that it covers a maximum of 20 seconds, preferably a maximum of 15 seconds or a maximum of 10 seconds and particularly preferably a maximum of 5 seconds before and/or after the reversing. In addition or alternatively, the distance can be set such that it covers a maximum of 50 m, preferably a maximum of 40 m or a maximum of 30 m or a maximum of 20 m or a maximum of 10 m and particularly preferably a maximum of 5 m before and/or after reversing. In order to determine the interval or the In order to determine the distance in this way, the time or location of the reversal must of course already have been determined. This means that at least for those parameters and sizes that have to be recorded before the reversal, values recorded in the past must be used at the time when it is determined when the reversal took place. Even if the method then only uses values that lie in the interval or distance under consideration, it is nevertheless preferable that the values are recorded over the entire working operation of the soil compaction machine. However, since not all of this data is required, it can preferably be provided, for example, that the data is only retained or stored until the time of the subsequent reversal has been determined. From this moment on, it is then sufficient to only retain the data that lies within the interval or distance under consideration. Previous data can, however, be deleted. A type of rolling memory can also preferably be used for this, which always contains the most recently recorded data or values of the recorded parameters. The rolling memory can be designed in such a way that it is at least large enough to store the data from that part of the interval and/or the distance before reversing. Data from further back can, however, be overwritten.

As already indicated, it is preferred that the reference values used for comparison include a target steering angle that indicates how large the steering angle should be at the determined time of reversing. In other words, the target steering angle indicates how much the operator of the soil compaction machine should or should steer before the soil compaction machine comes to a standstill when reversing. The effect on the evenness of the compacted soil does not initially depend on the direction of the steering angle. It is therefore irrelevant whether the steering is to the left or to the right. This can therefore be freely selected depending on the conditions on the construction site. For example, only the amount of the steering angle in deviation from straight ahead driving is considered. Accordingly, the target steering angle also refers to the amount of the steering angle in deviation from straight ahead driving. The target steering angle and/or the steering angle can be defined in particular as the deviation of the rolling direction of the soil compaction machine shortly before it comes to a standstill at the reversal point when reversing from the rolling direction at this reversal point in at least one previous or subsequent pass in which the soil compaction machine does not reverse. In order to be able to assess this, position data is collected over the entire work sequence of the soil compaction machine, for example. The rolling direction corresponds in particular to the current travel or working direction of the soil compaction machine. In this way, it is also taken into account, for example, that the soil to be compacted can also lie in a curve. can. The steering angle then takes into account the deviation from the curvature of the curve caused by steering. In particular, when the soil to be compacted is in a curve, it is also preferred that the steering takes place against the direction of the curve. This can also be monitored according to the invention and included in the evaluation. The target steering angle can also relate to the front and/or rear roller drum and/or to an inclined position of the soil compaction machine. It is, for example, at least 20°, preferably at least 25° or at least 30° or at least 35° or at least 40°, particularly preferably at least 45° or at least 50° or at least 55° or at least 60°.

The vibration input into the ground must be reduced or decreased in good time before reversing. In particular, it must be prevented that the soil compaction machine, when traveling particularly slowly, makes a significant vibration input into the ground shortly before coming to a standstill. After reversing, the vibration input may only be increased again when the soil compaction machine has already accelerated to a sufficiently high driving speed. It is therefore preferred that the vibration input is reduced, in particular to zero, before reversing and that the reference values used for comparison include a target vibration input that indicates how large the vibration input should be at most, in particular in relation to the driving speed of the soil compaction machine. In addition or alternatively, it is preferred that the vibration input is increased, in particular starting from zero, after reversing and that the reference values used for comparison include a target vibration input that indicates how large the vibration input should be at most, in particular in relation to the driving speed of the soil compaction machine. As already mentioned, the IPF value is preferably used as a measure of the vibration input. In addition or as an alternative, the frequency, amplitude, eccentricity and/or the vibration energy provided by the vibration exciter can be used. For example, the target vibration input can indicate the driving speed of the soil compaction machine at which no more vibration input should be made before reversing and/or the driving speed of the soil compaction machine at which vibration input should be made again after reversing. For example, reducing the vibration input to zero while the driving speed, for example the working speed, is still constant can be considered optimal. However, it should be noted that the working speed does not always have to be the same and can also be different before and after reversing. One advantage of the IPF value is that it relates the vibration input to the distance traveled and is therefore initially independent of the driving speed. Therefore, the target vibration input can, for example, include an IPF value as a limit value. Preferably However, a slight deviation from this is still considered optimal. For example, a deviation of a maximum of 20%, preferably a maximum of 15% or a maximum of 10% or a maximum of 5%, from the IPF value stored as a reference value for the target vibration input can still be considered optimal. This can be taken into account when comparing the procedure and also in the evaluation.

As already mentioned, vibration exciters, especially circular exciters, inevitably pass through a resonance frequency when switched on and off, at which increased vibration amplitudes occur for a short time and therefore also a higher vibration input into the ground. This therefore also leads to waves in the ground. The effect occurs particularly when the vibration exciter is switched off, i.e. before the soil compaction machine reverses. In order to smooth out these waves as well as possible when reversing, optimal control of the soil compaction machine therefore provides that the waves that have arisen are driven over again after reversing with the highest possible compaction power. This means that in the best case the waves should also be driven over with a high vibration input, for example the maximum intended work output of the vibration exciter. When accelerating the soil compaction machine after reversing, the vibration exciter must therefore be switched on again earlier or closer to the reversal point than it was switched off before reversing. This can also be monitored by the method according to the invention and included in the evaluation explained in more detail below. For this purpose, it can preferably be provided that within the interval and/or the distance, a position of the maximum vibration input is determined before reversing, and that the reference value for the target vibration input indicates the minimum vibration input with which this position should be passed after reversing. The position of the maximum vibration input refers in particular to the position at which the vibration exciter passes through its resonance frequency when the vibration input is reduced. This position can be determined, for example, via the driving speed, the change in driving speed or a location determination, for example via GNSS, as already described above. For example, the target vibration input can specify that this position should be passed after reversing with a nominal vibration input, for example the maximum compaction power of the vibration exciter. The nominal vibration input refers in particular to a vibration input with which the vibration exciter works optimally at the given position of the soil to be compacted. This can be specified, for example, by an automatic system, such as the applicant's "Asphalt Manager". Particularly preferably, the position of the maximum vibration input is determined separately for each roller drum of the soil compaction machine and considered individually as described above.

If the soil compaction machine has a front and a rear roller drum that are spaced apart from each other in the longitudinal direction of the machine, it is also important for optimal control of the soil compaction machine that the roller drum that is at the rear in the current direction of travel or working direction rolls over the position of the maximum vibration input of the front roller drum before reversing. As already explained above, when the vibration input is reduced, the vibration exciter of the front roller drum goes through its resonance frequency and has an increased vibration input, which leads to the formation of waves. These waves should therefore ideally be rolled over by the rear roller drum before reversing, for which it is important that the vibration input is reduced in good time before reversing, for example that the vibration exciter is switched off in good time before reversing. In order to take this into account in the method according to the invention, it is preferred that within the interval and/or the distance a position of the maximum vibration input of a front roller drum of the soil compaction machine is determined before reversing, and that it is monitored whether a rear roller drum of the soil compaction machine passes this position before reversing. Whether or not this succeeds and, if so, to what extent, can then also be included in the evaluation explained in more detail below.

The actual effect of the described control of the soil compaction machine by the operator on the evenness of the compacted soil is also influenced by external circumstances. These are referred to here as operating conditions. For example, the consistency of an asphalt layer laid by a road paver depends largely on its temperature. The hotter the asphalt, the easier it is to form undesirable waves, so that a deviation from the reference values results in greater unevenness than with cooler asphalt. At the same time, the temperature of the asphalt is also influenced by external circumstances, such as the weather. Soil stiffness, which also depends on the properties of the soil beneath the asphalt, also has an influence here. It also makes a difference whether the soil to be compacted has a slope. A slope can, for example, have a positive or negative influence on the effects of braking on an asphalt layer, depending on the direction of travel. It is therefore preferred that when comparing the recorded values with the reference values, at least one external operating state is also taken into account, the operating state including, for example, a soil temperature and/or a soil stiffness and/or weather conditions and/or a transverse and/or longitudinal gradient of the soil. The external operating states can either be recorded by sensors, for which purpose the soil compaction machine is preferably equipped with one or more sensors that can detect the respective operating states. The measurement results of the sensors are transmitted accordingly to the control device, which can then take the external operating conditions into account when making comparisons. In addition or as an alternative, the external operating conditions can also be entered by the operator on the control device. Preferably, the control device adapts the reference values based on the operating condition or conditions. For example, it may be necessary to use stricter reference values if the ground temperature is particularly high. If, on the other hand, the ground temperature is particularly low, the reference values can be selected to be less strict, since the influence of the driving maneuvers of the soil compaction machine on cool ground or asphalt is less. The reference values can also be adapted qualitatively or quantitatively based on the external operating conditions. For example, the reference values can be increased or decreased by a fixed value if corresponding external operating conditions exist, for example particularly hot asphalt. Alternatively and preferably, it can be provided that the adaptation of the reference values is gradually modified according to the external operating conditions. For example, the reference values can be specified for a specific initial value of the external operating conditions, such as ground temperature, outside temperature, amount of precipitation, slope angle, etc., and adapted to external operating conditions that deviate from these using a calculation rule. In this case, the reference values are dynamically and quantitatively adapted to the external operating conditions or the current conditions on the construction site.

Outputting the result of the comparison can include a display for the operator of the soil compaction machine. As already explained, the operator can use this feedback to adapt the control of the soil compaction machine for future reversing in order to achieve optimal results in terms of the evenness of the compacted soil. Preferably, if a deviation of the steering angle and/or the vibration input within the interval and/or the distance from the reference values is determined, the operator is shown instructions on how the deviation can be reduced or avoided in the future. In addition to the pure result of the comparison, the operator is also given information on how he can specifically optimize the control of the soil compaction machine. This also applies to all other aspects of the control of the soil compaction machine that are described here and that can be included in the evaluation. These can also be used to display tips on how the operator can improve the control of the soil compaction machine. Such instructions can be, for example, "switch off the vibration exciter earlier", "switch on the vibration exciter later" or "steer more strongly when reversing". Several such instructions can also be displayed simultaneously if several deviations from the reference values were detected during the underlying reversing. These instructions can be displayed, for example, visually, in particular in writing, on the display devices. displayed. In addition or as an alternative, it is also possible to provide the information acoustically, for example via a voice output. In this way, the operator of the soil compaction machine is automatically assisted during operation, providing him with insights into the effects of the control of the soil compaction machine on the evenness of the compacted soil, which is usually only available to very experienced operators. Even inexperienced operators can thus achieve increased evenness of the soil. Experienced operators, in turn, can further perfect their specialist knowledge.

In order to provide the operator with even more information, it can preferably be provided that the operator is shown a note with the instruction if an external operating condition has led to an adjustment of the reference value(s) that increases a deviation of the steering angle and/or the vibration input within the interval and/or the distance from the reference value(s). This therefore always comes into play when external operating conditions exist that increase the effects of the operator's driving behavior on the evenness of the ground. Such notes can therefore be, for example, "steer more when reversing due to the high ground temperature", "steer more when reversing due to the steep gradient" or "switch off the vibration exciter even earlier due to the low ground stiffness". In this way, the operator is given additional specialist knowledge in addition to improving the current work result.

In principle, the result of the comparison can be output numerically. In concrete terms, the numerical deviation of the recorded steering angle and/or vibration input from the reference value(s) could be output. In order not to burden the operator with having to think about how bad the displayed deviation actually is while carrying out all the other duties he has to perform during work, it is preferable that the result of the comparison is automatically evaluated. It is therefore preferable that the result of the comparison is assigned a rating that becomes worse with greater deviation from the reference value(s) or the optimal control of the soil compaction machine, and that this is also output or saved. For example, different levels could be defined that represent a spectrum from no deviation to slight deviation to high deviation. Here, for example, a standard grading system could be used, for example in levels from 1 (very good) to 6 (unsatisfactory). Alternatively, a rating in fewer levels, for example in three levels, would also be possible. These could be, for example, "no deviation", "low deviation" and "high deviation". The respective limit values of the individual stages can either be fixed or adjustable by the operator or operator of the soil compaction machine. For example, it can be taken into account that with different Construction sites may have different requirements for the evenness of the compacted soil. To make it even easier for the operator to read the rating, the rating can be displayed in the form of a symbol, for example a pictogram or a smiley with a facial expression corresponding to the rating.

In addition to the criteria mentioned, the method can also monitor other points that can influence the evenness of the compacted soil. As already described, the soil compaction machine must be braked to reverse and then accelerated again. Both the braking and the acceleration of the soil compaction machine should be as gentle as possible, i.e. without jerky or sudden changes in the driving speed. Such jerky changes in the driving speed can also lead to waves in the ground. It is therefore preferably provided that jerky changes in the driving speed are also recorded and included in the evaluation. In particular, jerky changes in the driving speed within the interval and/or within the distance are recorded. Such cases are characterized by a rapid increase in the amount of the driving speed and/or acceleration, i.e. the change in the driving speed, of the soil compaction machine. Threshold values can also be provided for this, which serve to detect jerky changes in the driving speed. If such jerky changes are recorded, this can be included in the evaluation and in particular also taken into account in the instructions for action. For example, a message will be displayed telling you to brake or accelerate more gently.

In principle, assisted operating support and an associated improvement in the evenness of the compacted soil can be achieved if the method according to the invention is only applied to a single reversal of the soil compaction machine. The operator can then use the resulting feedback to optimize future reversals if necessary. However, it is preferred that the method is carried out for several, in particular all, reversing processes within a work interval. In this way, the operator is continuously assisted and an optimal work result is achieved. A work interval describes, for example, an operator's working day or an operator's working time on a specific construction site. In principle, however, smaller work intervals could also be considered, for example one or more hours of a work day or work assignment. In particular, it can be provided that an overall rating is created from the individual ratings of all reversing processes in the work interval, which is also output or saved. The overall rating can, for example, follow the same pattern as the rating of an individual reversal. For example, a school grading system can also be used here. or similar. The overall rating is, for example, the average of all ratings for the work interval. The overall rating can be used by the operator to find out whether the control of the soil compaction machine he carried out was appropriate for the current construction site and/or whether his control of the soil compaction machine has improved or worsened. At the same time, an operator of the soil compaction machine can determine whether and which operators need additional training.

The method described above therefore preferably determines one or more of the parameters mentioned, identifies a reversing process from them, for example by determining a reversal of the direction of travel, then compares the actual reversing process with an optimal reversing process with regard to one or more of the parameters mentioned, for example by comparing it with one or more characteristic maps, formulas, etc., and uses this comparison to evaluate how close the actual reversing process comes to the theoretically optimal reversing process in the manner described above. This evaluation result can then be displayed to the driver, for example, who in this way receives an indication while driving on how he can further optimize his driving style in this operating situation.

The solution to the problem mentioned at the beginning is also achieved with a soil compaction machine, in particular a tandem roller or roller train, with at least one roller drum and a control device, whereby the soil compaction machine is designed to carry out the method. In particular, the control device is designed to carry out the method, of course with the exception of the method step of controlling the soil compaction machine by the operator. The soil compaction machine can be equipped like the generic soil compaction machine described at the beginning. All features, effects and advantages described for the method according to the invention also apply in a figurative sense to the soil compaction machine according to the invention and vice versa. Reference is made to the other embodiments only to avoid repetition.

Figur 1:

eine Seitenansicht einer Tandemwalze;

Figur 2:

eine Seitenansicht eines Walzenzuges;

Figur 3:

das Auftreten von Wellen im Boden beim Reversieren ohne Einlenken;

Figur 4:

das Auftreten von schrägen Wellen im Boden beim Reversieren mit Einlenken;

Figur 5:

das Auftreten von Wellen im Boden durch zu spätes Reduzieren des Schwingungseintrags;

Figur 6:

die Vermeidung von Wellen im Boden durch frühzeitiges Reduzieren des Schwingungseintrags;

Figur 7:

den Verlauf verschiedener Parameter beim Reversieren;

Figur 8:

die Ausgabe einer positiven Wertung und einer Handlungsanweisung;

Figur 9:

die Ausgabe einer mittleren Wertung und einer Handlungsanweisung;

Figur 10:

die Ausgabe einer schlechten Wertung und einer Handlungsanweisung; und

Figur 11:

ein Ablaufdiagramm des Verfahrens.

The invention is explained in more detail below with reference to the embodiments shown in the figures. They show schematically:

Figure 1:

a side view of a tandem roller;

Figure 2:

a side view of a roller train;

Figure 3:

the appearance of waves in the ground when reversing without turning;

Figure 4:

the appearance of oblique waves in the ground when reversing with steering;

Figure 5:

the occurrence of waves in the ground due to reducing the vibration input too late;

Figure 6:

the prevention of waves in the ground by reducing the vibration input at an early stage;

Figure 7:

the course of various parameters during reversing;

Figure 8:

the issuing of a positive evaluation and an instruction for action;

Figure 9:

the issuance of an average rating and an instruction for action;

Figure 10:

the issue of a bad rating and an instruction for action; and

Figure 11:

a flow chart of the procedure.

Identical components or components with the same effect are numbered with the same reference numerals in the figures. Repeating components are not designated separately in each figure.

In the Figures 1 and 2 Two soil compaction machines 1 are shown. Specifically, Figure 1 a tandem roller and Figure 2 a roller train. The soil compaction machines 1 preferably have a machine frame 3 and a driver's cab 2. The tandem roller according to Figure 1 preferably has a front and a rear roller drum 5, while the roller train according to Figure 2 preferably has a front roller drum 5 and preferably wheels 7 on the rear frame. During operation, the soil compaction machines 1 preferably travel in or against the working direction R over the soil 8, for example an asphalt layer laid by a road finisher, and compact it. For this purpose, they preferably have a drive motor 4, which can be, for example, an internal combustion engine or an electric motor. The roller drums 5 can each be equipped with a vibration exciter 10, which causes the respective roller drum 5 to vibrate in order to influence the compaction performance. The soil compaction machines 1 also preferably comprise a control device 6, which in particular carries out the essential steps of the method. For this purpose, the control device 6 can also be connected to a display device 9, for example a display. Furthermore, input devices such as buttons, levers, etc. can be present, via which the driver of the soil compaction machine can carry out control commands, for example with regard to the driving speed, steering specifications, settings for an excitation device, etc. In addition, the control device 6 can be connected to a sensor 11 or to several sensors 11 of one or more detection devices which is or are preferably designed to detect the driving speed and/or the change in driving speed and/or the reversal of the direction of travel and/or the steering angle and/or the vibration input or quantities correlated therewith. In order to be able to transmit the result of the comparison according to the invention wirelessly, for example to a central server, the soil compaction machine 1 can also have a data transmission device 12 which can be designed, for example, to transmit data via the Internet or via another wireless data connection.

In Figure 3 a reversing of the soil compaction machine 1 is shown. In particular, representations a) to e) show the same soil compaction machine 1 on the same construction site section in a bird's eye view, but in chronologically successive snapshots. In representation a), the soil compaction machine 1 travels at a travel speed v in the working direction R, whereby the travel speed v in representation a) corresponds to a working speed of the soil compaction machine 1 at which it usually compacts the soil 8. In representation b), the soil compaction machine 1 has already been partially braked, so that the travel speed v is lower than that of representation a). In representation c), the soil compaction machine 1 has come to a standstill. The time shown in representation c) is therefore the time of reversing or the turning point of the soil compaction machine 1 when the machine starts moving again in the opposite direction, as shown in d). At the time of representation d), the soil compaction machine 1 has already been accelerated in the opposite direction of travel, i.e. against the working direction R, and is traveling at a travel speed v which, however, is still below the working speed or the working speed to be achieved by the soil compaction machine 1. In the situation according to representation e), the soil compaction machine 1 has been accelerated again to a travel speed v which corresponds to the working speed. The distance L to which the method can refer, for example, can run through the distance from the turning point of the soil compaction machine 1 to the location at which the soil compaction machine 1 has again reached a travel speed v which corresponds to the predetermined working speed. Alternatively, the distance L can also be specified by a distance, for example 30 m.

As in Figure 3 As shown in the illustrations d) and e), the soil compaction machine 1 or its roller drums 5 leave a soil wave 13 at the location of reversing or at the turning point of the soil compaction machine 1. In the case of Figure 3 these bumps 13 are aligned perpendicular to the working direction R, since no steering was used when reversing. Such bumps 13 are only poorly smoothed out during subsequent passes of the soil compaction machine 1. There is therefore an increased risk that the bumps 13 will still affect the evenness of the ground at the end of the work. 8 negatively influence. Figure 4 shows the same process as Figure 3 The only difference is that the operator of soil compaction machine 1 in Figure 4 when reversing, as shown in particular in illustration c). As a result of the reversing, the resulting bumps 13 are no longer aligned perpendicular to the working direction R with regard to the longitudinal course of their trough, but obliquely to the working direction R. Such bumps 13 are smoothed out significantly more efficiently during subsequent passes of the soil compaction machine 1 than the bumps 13 according to Figure 3 , as they are driven over at an oblique angle. Overall, the procedure according to Figure 4 a much more level compacted soil 8.

The Figures 5 and 6 show the process of reversing the soil compaction machine 1, analogous to the Figures 3 and 4 . In the Figures 5 and 6 now the effects 14 of vibrations of the rolling bands 5 on the ground 8 are shown. The effects 14 can be understood as impacts in the sense of an IPF value. For example, an effect 14 indicates a location where the vibration of the rolling band 5 presses it onto the ground 8. In other words, vibration energy is transferred to the ground 8 at the locations of the effects 14. The distance between the effects 14 is a measure of the vibration input, whereby effects 14 shown closer to each other mean a higher vibration input. Of course, the Figures 5 and 6 merely schematic diagrams intended to make the underlying processes understandable, but do not represent them in a realistic manner.

In Figure 5 two separate errors in operation by the operator are shown. In particular, illustrations a) to c) show the case where the vibration input into the ground 8 is reduced too late before the soil compaction machine 1 is reversed, for example to zero. The reduction in the vibration input is achieved, for example, by switching off the vibration exciter 10 or the vibration of the roller drum 5. The reduction in the vibration input only takes place at a time when the soil compaction machine 1 has already been braked to a travel speed v that is so low that too many influences 14 or too great a vibration input occur over a short distance. This is shown by the influences 14 arranged closely together in illustration c). Where the influences 14 are too close together or the vibration input is too great, ground waves can arise that are detrimental to the evenness of the soil 8 left behind after the work. In the illustrations d) and e), however, the case is shown in which the vibration input into the soil 8 is increased again too soon after the soil compaction machine 1 has been reversed, for example starting from zero. For this purpose, for example, the vibration exciter 10 or the vibration of the roller drum 5 is switched on. In particular, the vibration input is increased at a time when the soil compaction machine 1 has only accelerated to a driving speed v that is too low, so that the influences 14 are too close together, at least over a section of the route, or the vibration input is too great, which in turn can cause bumps in the ground. This is also shown in illustrations d) and e) by the influences 14 being close to one another. In the worst case, the cases shown in illustrations a) to c) and d) to e) occur together when the soil compaction machine 1 is reversed just once. Of course, the two cases can also occur alone when the soil compaction machine 1 is reversed. This is taken into account when evaluating the reversing.

Also in Figure 6 the process of reversing the soil compaction machine 1 is shown. In Figure 6 In the illustrations a) to c) it is shown that the soil compaction machine 1 brakes to reverse, whereby here in particular the vibration input is reduced in good time before the machine comes to a standstill. For example, the vibration exciter 10 is switched off sufficiently early so that the reduction in the driving speed v of the soil compaction machine 1 is compensated by a reduction in the vibration input, for example by a reduction in the frequency of the vibration exciter 10. The vibration input therefore decreases essentially to the same extent as the driving speed v and there are no sections on which the vibration input is too great, i.e. on which too much compaction takes place. This is shown by the even spacing of the influences 14. In this way, no or at least no significant ground waves are created that are detrimental to the evenness of the compacted soil 8 at the end of the working operation. In the illustrations d) and e) of the Figure 6 the case is shown in which the soil compaction machine 1 accelerates again after reversing the direction of travel. However, the vibration input into the soil 8 is only increased again at a time when the driving speed v of the soil compaction machine 1 is already sufficiently high, so that here too no sections with excessive vibration input arise. For example, the vibration exciter 10 is only switched on again after the soil compaction machine 1 has reached a sufficiently high driving speed v. In this way, the formation of ground waves is prevented, which is shown by the uniform spacing of the influences 14. In Figure 6 A reversal is therefore shown, where optimal control is provided both before and after the reversal point. As already explained, however, errors can also occur separately before or after the reversal point, which is taken into account accordingly in the evaluation.

The Figures 4 and 6 The optimized processes are also particularly preferably combined with each other, ie an oblique steering is preferred, as in Fig.4 shown, and a sufficiently early and late switching on and off of the vibration exciters, as in Fig.6 shown.

Figure 7 shows the temporal relationship between the driving speed v, the change in driving speed a as well as the steering angle w and the vibration input S of the soil compaction machine 1. For this purpose, diagrams are shown one above the other for these respective values, the abscissa of which indicates the time t that is spread over all diagrams of the Figure 7 The corresponding values of the parameters mentioned are then plotted on the ordinate of the respective diagrams.

The top diagram of the Figure 7 shows, for example, the driving speed v of the soil compaction machine 1. From left to right it is shown that the soil compaction machine 1 is accelerated from a standstill until it has reached a constant driving speed v, for example the working speed. After the soil compaction machine 1 has covered a distance at this driving speed v, it is braked again to a standstill. It is then accelerated again in the same direction as before until it has again reached a constant driving speed v. This process therefore involves braking and subsequent acceleration of the soil compaction machine 1, whereby the direction of travel has not changed. Although this process can also influence the evenness of the ground 8 after work, it does not involve reversing the soil compaction machine 1, which is what is particularly important here. After a distance at a constant driving speed v, the soil compaction machine 1 is braked again to a standstill, but then accelerated in the opposite direction, for example back to the working speed, only in the opposite direction. In other words, the soil compaction machine 1 has been reversed here. The time period around the reversal is referred to as interval T. This can, for example, have a fixed amount or, alternatively, can be determined, for example, by when the soil compaction machine 1 was braked from the working speed before reversing and accelerated back to the working speed after reversing. In the further course, the soil compaction machine 1 travels at an essentially constant travel speed v, for example the working speed, and is then reversed again. The soil compaction machine 1 is thus braked again to a standstill and then accelerated in the opposite direction. This reversal also takes place within a time interval T. This second interval T can in principle be just as long as the first interval T. However, it is also conceivable that the intervals T are of different sizes, for example in particular when they are functionally determined, for example based on a value of the travel speed v. The diagram of the travel speed v also shows how a reversal of the soil compaction machine 1 can be concluded based on the travel speed v or a reversal of the direction of travel. This results in particular from a reversal of the sign of the driving speed v.

Directly below the diagram of the driving speed v shows Figure 7 a diagram of the acceleration or the change in driving speed a of the soil compaction machine 1. As shown, the change in driving speed a can also be used to identify a reversal of the soil compaction machine 1. In particular, when reversing, there is a double change in driving speed a in the same direction, separated by the machine coming to a standstill, from which it can be concluded that reversing has occurred. As can be seen from the left part of the diagram, such a double, identically directed change in driving speed a does not occur when driving straight ahead in one direction without interruption.

Below the diagram of the driving speed change a is Figure 7 a diagram of the steering angle w is shown. Since the direction of the steering when reversing is not important, at least with regard to the evenness of the ground 8 after work, only the amount of the steering angle w is shown. In addition, the diagram only shows steering angles w that correspond to a steering during reversing within the intervals T. Other steering angles w that occur while the soil compaction machine 1 is traveling are not shown. In particular, the diagram shows that the steering angle w in the first interval T shown on the left remains below a threshold value shown by the dashed line parallel to the abscissa. This means that the operator did not steer sufficiently during this reversing of the soil compaction machine 1, so that the bumps 13 in the ground that arise at the reversal point are not aligned sufficiently obliquely to the working direction R in order to be optimally smoothed out in subsequent passes of the soil compaction machine 1. In other words, there is a deviation from a reference value that is given, for example, by the indicated threshold value. The relevant deviation can be determined quantitatively and is included in a corresponding evaluation of the reversing of the soil compaction machine 1 by the operator. The situation of reversing in the first interval T shown on the left therefore corresponds to that according to Figure 3 . In contrast, the diagram shows that the steering angle w in the second interval T shown on the right is above the threshold value shown by the dashed line parallel to the abscissa. Here, the operator has therefore turned sufficiently far when reversing the soil compaction machine 1, which means that the bumps 13 created at the reversal point are aligned at an angle to the working direction R in such a way that they can be optimally smoothed out during subsequent passes of the soil compaction machine 1. In this way, the overall evenness of the compacted soil 8 left behind by the soil compaction machine 1 is positively influenced. The situation of reversing in the second interval T shown on the right therefore corresponds to that according to Figure 4 .

The lowest in Figure 7 The diagram shown relates to the vibration input S. In order to avoid excessive compaction of the soil 8 in certain places, as this would lead to the formation of waves, it is provided that the vibration input S is only increased during operation of the soil compaction machine 1, or the vibration exciter 10 is only operated with energy transfer to the soil 8, when the soil compaction machine 1 is traveling at a sufficient speed v. This is also shown, for example, on the left in the diagram when the soil compaction machine 1 is paused in its forward travel. Here too, however, the reversing of the soil compaction machine 1 has a special significance, if only because it occurs particularly frequently during operation of the soil compaction machine 1. As shown in the intervals T around the reversing of the soil compaction machine 1, the vibration input S is reduced before the machine comes to a standstill, in particular to zero. After the direction of travel is reversed, the vibration input S is then typically increased again. However, it can also happen that a vibration input S is used or is present only before or only after reversing. Even then, the method can be applied to reduce the vibration input S before reversing or to increase the vibration input S after reversing. In particular, the diagram in the first interval T shown on the left shows that the vibration input S is reduced early before reversing so that the driving speed v is sufficiently high as long as a vibration input S is still present. In addition, the vibration input S is only increased again when the soil compaction machine 1 has reached a sufficient driving speed v. This means that there are no sections of the route in which excessive compaction of the soil 8 takes place or in which excessive vibration input S is present. The control of the soil compaction machine 1 in this interval T is therefore optimal with regard to the evenness of the soil 8 left behind. The situation therefore corresponds to that of the Figure 6 . In addition, the diagram in the second interval T shown on the right shows that the vibration input S is reduced too late before the machine comes to a standstill when reversing. The vibration input S is still at a maximum even when the driving speed v of the soil compaction machine 1 has already decreased to such an extent that the soil 8 driven over by the soil compaction machine 1 is compacted too much. In this case, there are therefore undulations in the ground that have a negative effect on the evenness of the soil 8 left behind. After the reversal point, however, the increase in the vibration input S corresponds to that of the previous interval T, so that the vibration input S is only increased when the driving speed v of the soil compaction machine 1 is already sufficiently high. The situation shown in the second interval T shown on the right is therefore composed of analogous situations to the representations a) to c) of the Figure 5 and the representations d) and e) of the Figure 6 .

The Figures 8, 9 and 10 show by way of example how a display of the result of the comparison could look during the output on the display device 9. The display device 9 can be, for example, a screen or a display which is connected to the control device 6. The result of the comparison can be output, for example, via a rating symbol 15 which symbolizes the rating determined by the comparison. In the example shown, the rating symbol 15 is a smiley which, depending on the result of the comparison or the quality of the rating, for example indicates compliance with the reference values ( Figure 8 ), a slight deviation from the reference values ( Figure 9 ) or a significant deviation from the reference values ( Figure 10 ). In this way, an operator can immediately see at a glance whether the control of the soil compaction machine 1 complied with the specifications during the previous reversing or not. If necessary, he can adapt the control of the soil compaction machine 1 for future reversing. In order to assist or support the operator during operation, an instruction 16, for example in written form, can be output on the display device 9 in addition to the evaluation symbol 15. Alternatively, the instruction 16 could also be output acoustically. The instruction 16 preferably includes concrete information about which reference values were not adhered to during the last reversing and/or how the deviation from the reference values can be avoided or at least reduced during future reversing.

Figure 11 finally shows a flow chart of the method 20. This begins with the control 21 of the soil compaction machine 1 by an operator. The operator operates the soil compaction machine 1 on a construction site to compact a soil 8. Typically, several passes of the soil compaction machine 1 are required to compact the soil 8. This results in repeated reversing of the soil compaction machine 1, whereby the manner in which the operator controls the soil compaction machine 1 when reversing has a greater influence on the resulting evenness of the soil 8. For this reason, the method 20 provides for the detection 22 of at least one of the parameters travel speed v, change in travel speed a and/or reversal of travel direction or at least one variable correlating with one of the parameters mentioned. Such parameters are often already detected on soil compaction machines 1 anyway, so that the sensors 11 required for this may already be present in some cases. Next, a point in time at which the soil compaction machine 1 is reversed is determined 27 from the at least one recorded parameter or the at least one recorded size. This preferably also records the location of the soil compaction machine 1 at this point in time when a position or path detection takes place. By determining when the soil compaction machine 1 is reversed takes place, the control of the soil compaction machine 1 by the operator around the reversing can be checked. For this purpose, a steering angle w of the soil compaction machine 1 and/or a vibration input S of a vibration exciter 10 in the soil 8 or a variable correlating with the steering angle w or with the vibration input S is recorded within a time interval T and/or a distance L around the determined time of reversing and/or around a location of the soil compaction machine 1 at this time. There are recommendations for the steering angle w at the time of reversing and for the vibration input S around the reversing, which are intended to ensure optimal evenness of the soil 8 after the work process. Whether the recommendations are adhered to can be determined by comparing 24 the recorded steering angle w and/or vibration input S within the interval T and/or the distance L with predetermined reference values for a target steering angle and/or a target vibration input. In particular, it can be seen directly from this whether or not the operator is complying with the recommendations when controlling the soil compaction machine 1. In addition, it can also be determined quantitatively to what extent the recommendations are not being complied with. In order to obtain assisted operating support or assistance for the operator, the result of the comparison 24 is output 25 and/or saved 26. The operator and possibly also an operator of the soil compaction machine 1 therefore receive overall feedback on the extent to which the control of the soil compaction machine 1 during reversing corresponds to the recommendations for optimal evenness of the compacted soil 8. The operator can therefore adapt the way in which he controls the soil compaction machine 1 in the future and improve his work results. The operator, in turn, can determine to what extent an operator needs training or instruction. All in all, the method 20 according to the invention therefore enables an improvement in the evenness of the compacted soil 8 without having to detect this evenness using sensors.

Claims (14)

Method (20) for assisted operation of a soil compaction machine (1), comprising the steps: a) controlling (21) the soil compaction machine (1) by an operator; b) detecting (22) at least one of the parameters driving speed (v), driving speed change (a) and/or reversal of driving direction or at least one variable correlating with one of said parameters; c) determining (27) a point in time at which a reversal of the soil compaction machine (1) takes place from the at least one parameter detected in step b) or the at least one variable detected in step b); d) detecting (23) a steering angle (w) of the soil compaction machine (1) and/or a vibration input (S) of a vibration exciter (10) into the soil (8) or a variable correlating with the steering angle (w) or with the vibration input (S) within a time interval (T) and/or a distance (L) around the time determined in step c) and/or around a location of the soil compaction machine (1) at this time; e) comparing (24) the steering angle (w) and/or vibration input (S) detected in step d) within the interval (T) and/or the distance (L) with predetermined reference values for a desired steering angle and/or a desired vibration input; f) Outputting (25) and/or storing (26) a result of the comparison (24). Method (20) according to claim 1,
characterized,
that the detection (22, 23) in steps b) and/or d) is carried out continuously. Method (20) according to one of the preceding claims,
characterized,
that the interval (T) and/or the distance (L) is determined such that the reversing is in the middle of the interval (T) and/or the distance (L). Method (20) according to one of the preceding claims,
characterized,
that the reference values used for comparison (24) in step e) include a target steering angle which indicates how large the steering angle (w) should at least be at the time of reversing determined in step c). Method (20) according to one of the preceding claims,
characterized, that before reversing, a reduction, in particular to zero, of the vibration input (S) takes place and the reference values used for comparison (24) in step e) comprise a target vibration input which indicates how large the vibration input (S), in particular in relation to the driving speed (v) of the soil compaction machine (1), should be at most and/or that after reversing, an increase, in particular starting from zero, of the vibration input (S) takes place and the reference values used for comparison (24) in step e) comprise a target vibration input which indicates how large the vibration input (S) should be at maximum, in particular in relation to the driving speed (v) of the soil compaction machine (1). Method (20) according to one of the preceding claims,
characterized,
that within the interval (T) and/or the distance (L) a position of the maximum vibration input (S) is determined before reversing, and that the reference value for the target vibration input indicates the minimum vibration input (S) with which this position is to be passed after reversing. Method (20) according to one of the preceding claims,
characterized,
that within the interval (T) and/or the distance (L) a position of the maximum vibration input (S) of a front roller drum (5) of the soil compaction machine (1) is determined before reversing, and that it is monitored whether a rear roller drum (5) of the soil compaction machine (1) passes this position before reversing. Method (20) according to one of the preceding claims,
characterized,
that in step e) at least one external operating state is additionally taken into account, wherein the operating state comprises, for example, a soil temperature and/or a soil stiffness and/or weather conditions and/or a transverse and/or longitudinal gradient of the soil (8), wherein in particular the reference values are adapted based on the operating state. Method (20) according to one of the preceding claims,
characterized,
that the output (25) of the result of the comparison (24) in step f) comprises a display for the operator of the soil compaction machine (1), wherein in the case in which a deviation of the steering angle (w) and/or the vibration input (S) within the interval (T) and/or the distance (L) from the reference values was determined, the operator is shown an instruction (16) on how the deviation can be reduced or avoided in the future. Method (20) according to claims 8 and 9,
characterized,
that the operator is given a message with the instruction to act if an external operating condition has led to an adjustment of the reference values which increases a deviation of the steering angle (w) and/or the vibration input (S) within the interval (T) and/or the distance (L) from the reference values. Method (20) according to one of the preceding claims,
characterized,
that in step e) the result of the comparison (24) is assigned a rating which becomes worse with greater deviation from the reference values and which is in particular also output or stored in step f). Method (20) according to the preceding claim,
characterized,
that sudden changes in driving speed (v) are also recorded and included in the evaluation. Method (20) according to one of claims 11 or 12,
characterized,
that the method (20) is carried out for all reversing processes within a working interval, whereby an overall rating is created from the individual ratings from step e), which is also output or stored in step f). Soil compaction machine (1), in particular tandem roller or roller train, with at least one roller drum (5) and a control device (6),
characterized,
that the soil compaction machine (1) for carrying out the method (20), and in particular the control device (6) for carrying out steps b) to f) of the method (20), is designed according to one of the preceding claims.

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