METHOD FOR ASSISTED OPERATING SUPPORT OF A SOIL COMPACTION MACHINE

Description

[0001] The invention relates to a method for assisted operating support of a soil compaction machine.

[0002] Soil compaction machines of this type are known, for example, from DE 102018 007 825 A1 and DE 10 2019 002 442 A1 of the applicant. They are typically used in road and path construction as well as 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 may, for example, also have two roller drums, which are arranged separately from each other and one behind the other, particularly in the working direction of the soil compaction machine, so that when the soil compaction machine moves forward, a specific position on the subsoil is successively traversed by both roller drums arranged one behind the other.The working direction of the soil compaction machine corresponds to a longitudinal axis or a front / back direction. The actual working direction can be forward or reverse, with reversing operation being the norm. The roller drums are typically hollow metallic cylinders, for example made of steel, which may have a smooth outer surface. During operation, the soil compaction machine is moved with its at least one or two roller drums over the soil to be compacted, for example, an asphalt layer laid by a paver. The drive energy required for operating 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.To increase soil compaction by the roller drums beyond the machine's own weight, it is also known to provide a vibration exciter in or on the roller drum, which can set the roller drum into vibration. Depending on the type of vibrations, their frequency, and their amplitude, the desired adjustment of the compaction by the roller drum can be made.

[0003] Soil compaction machines of this type typically have a driver's cab from which the operator controls the soil compaction machine. The operator controls, in particular, the movement of the soil compaction machine over the soil to be compacted. For example, both the direction of travel and the 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, in some cases, their frequency and / or amplitude can be varied. Generic soil compaction machines typically have a control device, which may, for example, be an on-board computer or part of an on-board computer. 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 status of one or more vibration exciters, an acceleration value, a value associated with soil stiffness, a travel distance, etc. Furthermore, soil compaction machines of this type typically have a display device connected to the control unit, for example, a screen or a display. This display can show, for example, the sensor readings. In addition, the control unit can be configured to receive control commands from the operator—for example, via the display device, which may include a touchscreen, supplementary and / or separate input devices, etc.—and to control the soil compaction machine based on these commands.

[0004] 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 travel over the same area of ​​soil multiple times. The objective of soil compaction machines is generally to create and leave behind a soil surface that is as smooth and homogeneously compacted as possible. For example, the evenness of a roadway is an essential, remuneration-relevant criterion, which is therefore of great practical and economic interest.

[0005] However, it is unavoidable that the roller drums of the soil compaction machine will leave a bump in the surface being compacted when reversing (i.e., changing direction) on soil that is still deformable under the machine's own weight, for example, when the asphalt temperature is still relatively high. This bump then typically needs to be smoothed out as much as possible during subsequent passes to achieve the desired quality of the road surface. To simplify this process, operators of soil compaction machines are typically instructed to steer the vehicle shortly before the machine comes to a complete stop when reversing, so that the roller drums, and therefore the bump they leave behind, are angled to the working direction.Such slanted waves can be smoothed out much more easily and quickly during subsequent passes than waves that run perpendicular to the direction of travel.

[0006] Furthermore, the operator of the soil compaction machine typically has to ensure that the operation of the vibration exciter(s) is controlled in such a way that excessive vibration energy or too many impulses per defined distance are not introduced into the ground, for example, the asphalt layer, at any one point or over too short a distance. This, too, can promote the formation of undesirable ground undulations. Therefore, the vibration input into the ground must 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 at a sufficient speed.

[0007] 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 they control the soil compaction machine. However, achieving high-quality work results requires a considerable degree of experience and skill from the operator. Situations therefore 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 a way that achieves optimal evenness of the compacted soil, for example of the roadway. Furthermore, the operator is usually unable to determine the achieved evenness during operation. Measuring the evenness of the soil during the work process is technically complex and is therefore not typically carried out.It is therefore not possible for the operator to adapt his driving style based on the current or most recently achieved result, ideally during ongoing operation.

[0008] Against this background, the object of the present invention is to provide a method and a soil compaction machine with which the evenness of the compacted soil can be improved. In particular, driving errors that can occur when reversing the soil compaction machine are to be reduced. Preferably, feedback on the work result should be provided during and / or after compaction operation without requiring a measurement of the evenness of the soil. The feedback on the previous work process should make it possible to improve future work processes with regard to optimal evenness of the compacted soil.

[0009] The problem is solved using a method according to the independent claim. Preferred further developments are specified in the dependent claims.

[0010] 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 conventional manner by entering appropriate control commands, for example regarding travel direction, travel speed, activation and / or adjustment of one or more vibration exciters, etc. Therefore, a conventional working mode of a soil compaction machine of this type takes place, 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 paver, which is still hot or still sufficiently warm for surface deformation by the soil compaction machine and from which, for example, a roadway or similar is created after compaction. Controlling the soil compaction machine therefore particularly comprises 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 vibrated by a vibration exciter in order to achieve dynamic soil compaction.This can include, for example, vibrations or oscillations, or any combination thereof. In this context, operator control of the soil compaction machine is understood to include, in particular, semi-autonomous operation. For instance, an automatic reversing system could be used, in which the operator initiates a reversing process by means of a control input, such as pressing a button. The braking, reduction of vibration input, acceleration in the opposite direction, and subsequent increase of vibration input are then carried out automatically by the control unit. The operator can start the automatic reversing process, for example, at their own discretion or after reaching a marker, such as a light spot projected onto the ground, which can be positioned at a predetermined distance before the reversing point, as required for the reversing process.It is important to note that the driver naturally retains full control of the machine and can intervene at any time, thereby immediately terminating the automatic reversing function and restoring complete control of the machine to the operator. These instances, in which the operator resumes control, are of particular interest for the method according to the invention, as the automatic reversing function already takes optimal driving styles into account. For this reason, the automatic reversing function is preferably designed to control only the braking and subsequent acceleration in the opposite direction of travel, especially up to a desired target speed, but not steering operations, which must preferably be controlled exclusively manually.

[0011] In the method according to the invention, at least one change in driving speed is detected. For this purpose, the soil compaction machine preferably comprises at least one suitable detection device, for example at least one sensor, which directly or indirectly detects at least the change in driving speed and in particular forwards it to the control device. The detection and determination of various parameters, variables, times, or locations can preferably also include, throughout the present description, the detected or determined values ​​being stored for later use, for example in a memory, in particular an electronic memory, of the control device. In principle, one sensor of the detection device can be provided which detects several parameters or variables, or a separate sensor can be provided for each parameter or variable.Since soil compaction machines typically already determine the travel speed directly or indirectly, the value of this parameter, for example, is usually already available and can be used for the method according to the invention. The change in travel speed, in turn, can also be calculated from a repeatedly or continuously measured travel speed. Furthermore, it is also possible to measure the movement or acceleration of the soil compaction machine, for example, using an electronic compass or an IMU (inertial measurement unit). inertial measurement unit ). The use of GNSS systems (Global Navigation Satellite System, engl. global navigation satellite system) for the repeated or continuous recording of the location of the soil compaction machine and / or its temporal comparison is possible. In addition, the movement of the soil compaction machine can also be inferred from its optical recording of the surroundings. For example, a camera or the image from a camera can be used to infer the movement of the soil compaction machine. The aforementioned variables, which are not directly related to the driving speed, the change in driving speed and / or a reversal of driving direction, can preferably be used to infer these. Alternatively, the aforementioned variables can also be used directly in the next step of the process.

[0012] From at least the detected change in driving speed, a point in time at which the soil compaction machine reverses is determined. In other words, the reversal point of the soil compaction machine is determined. It is therefore preferable to determine when a reversal of travel direction occurs, or when the driving speed first drops to zero and then increases again in the opposite direction. This is referred to herein 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 of the soil compaction machine at the time the reversal occurs is also determined. This location can therefore also be used as a starting point for the further process.

[0013] Ideally, below a certain operating speed of the soil compaction machine, and especially when stationary, no vibration is transmitted into the ground by the exciter unit, meaning no vibration energy is transferred to the ground. Such localized compaction caused by vibrations can otherwise quickly lead to excessive ripple formation. Operators of soil compaction machines are therefore required to reduce the vibration transmitted into the ground well before the machine comes to a standstill during reversing, ideally to zero. This can be achieved, for example, by switching off the exciter or by reducing the amplitude of the generated vibration, particularly to zero, for instance, by rotating the exciter to a horizontal position. When the exciter is switched off, it typically passes through a resonance range in which the amplitude of the generated vibrations increases.A sufficiently high driving speed of the soil compaction machine must therefore be ensured, particularly when passing through the resonance range. Furthermore, as already explained at the beginning, the machine should be steered before coming to a standstill, so that the undulation inevitably left in the soil when reversing is oriented at an angle to the straight-ahead working direction. The method according to the invention therefore provides for detecting a steering angle of the soil compaction machine and, preferably additionally, a vibration input from a vibration exciter into the soil or a variable correlated with the steering angle or the vibration input. For this purpose, one or more sensors can be provided on the soil compaction machine as part of the detection device; these sensors detect the respective parameters or variables and transmit their values ​​to the control device.For example, a sensor can be provided that directly or indirectly detects the steering angle or the vibration input via a correlating parameter. Repeated or continuous measurements of the soil compaction machine's position, based on the distance traveled, can also indicate any tilting of the machine, which in turn correlates with the steering angle. Alternatively, the braking distance and the steering movement performed during braking can be used to infer the tilting of the soil compaction machine. The vibration input is a measure of how much energy is transferred from the vibration source to the ground. This depends significantly on the frequency and amplitude of the vibration source, which is typically one or more unbalanced 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 a reduction in the frequency, in particular down to zero. In addition or alternatively, the amplitude of the vibration exciter can be adjusted, in particular down to zero, for example by changing the eccentricity of the flywheel masses of the vibration exciter. This also makes it possible to change the vibration input into the ground. Parameters that correlate with the vibration input are, 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 is also particularly preferred for this purpose. impacts per foot), which indicates how often a vibration exciter impacts the ground in a specific section of the track. Details on the IPF value can be found, for example, in the applicant's DE 10 2018 007 825 A1. In particular, the amplitude refers to the vertically directed portion of the vibration. Additionally or alternatively, the amplitude of the horizontally directed portion of the vibration can also be considered.

[0014] 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 the control of the soil compaction machine both before and after reversing. According to the invention, the steering angle and preferably additionally the vibration input or the variables correlating therewith are therefore recorded within a time interval and preferably additionally within a distance around the already determined time of reversing and preferably additionally around the already determined location of the soil compaction machine at this time. Therefore, the aforementioned parameters or variables are recorded before and after reversing.The steering angle, and preferably additionally the vibration input or correlated quantities, are therefore linked, depending on which measurements are performed, either temporally or spatially with the also determined parameters of change in driving speed, and preferably additionally driving speed, and / or reversal of driving direction or correlated quantities. Thus, for example, the steering angle and preferably additionally the vibration input are recorded together with each driving speed of the soil compaction machine. The interval, and preferably additionally the distance traveled, can initially be chosen arbitrarily and, for example, encompass the entire work operation or the entire construction site of the soil compaction machine. It is important that they include the considered reversing process of the soil compaction machine. Preferred, more specific intervals / distances are explained in more detail below.

[0015] A key aspect of the method according to the invention consists of comparing the measured or determined steering angle and, preferably additionally, the vibration input within the interval and, preferably, additionally, the travel distance, with predetermined reference values ​​for a target steering angle and, preferably, additionally, a target vibration input. As mentioned at the outset, it is known that waves oriented obliquely to the working direction in the soil yet to be compacted, which arise during reversing, can be better compensated for in subsequent passes. Furthermore, it is known that excessive vibration input over an insufficient travel distance also contributes to wave formation. From these relationships, a target steering angle and / or a target vibration input can therefore be derived. These can, for example, be related to a travel speed, a change in travel speed, or similar parameters of the soil compaction machine.For example, a target steering angle can specify how far the operator should steer the roller to a standstill when reversing, in order to position the resulting bump at such an angle to the working direction that it can be optimally smoothed out on subsequent passes. A target vibration input can, for example, specify the maximum permissible vibration input at a given travel speed of the soil compaction machine. Specifically, such reference values ​​for a target steering angle and / or a target vibration input are stored in memory and accessible to the control unit. These can be fixed, predefined limits.The reference values ​​can be, for example, point-based, such as "from a driving speed X, only a maximum of Y vibration input," or continuous, such as in the form of characteristic maps that specify a wide range of driving speeds and, in each case, the maximum permissible vibration input. Furthermore, 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 typically always proceeds in a nearly identical manner during operation, at least in comparable work situations, the reference values ​​can alternatively be based on a time interval and / or a distance before and / or after the reversing instead of the driving speed.Such reference values ​​could therefore, for example, provide information such as "switch off the vibration exciter no later than X seconds or Y meters before reversing" or "switch on the vibration exciter no earlier than 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 soil compaction machine operator before, during, and after reversing corresponds and / or corresponded to the specifications for optimal evenness of the compacted soil. The result of the comparison can be purely qualitative or quantitative.The result can therefore be, for example, information on whether the steering angle and / or vibration input set by the operator corresponds to the reference values ​​or not. Furthermore, the result can also include, in particular, 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 on how much smaller the steering angle set by the operator is when reversing the soil compaction machine compared to the target steering angle. Since an excessively tight steering angle when reversing can also be detrimental to soil evenness, the target steering angle can also be an interval that 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 greater than the upper limit specified by the target steering angle when reversing the soil compaction machine. This occurs in particular in addition to the monitoring of the lower limit already described. Additionally or alternatively, 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" refers here to the interval and / or the distance around the determined time of reversing and / or the location of the soil compaction machine at that time.Overall, the result of the comparison therefore includes information about how closely the control performed by the operator of the soil compaction machine corresponds to optimal control in terms of optimal evenness of the compacted soil.

[0016] Finally, the method according to the invention also comprises outputting and preferably additionally storing the result of the comparison or comparisons. For example, the result can be output or displayed visibly for the operator of the soil compaction machine on a display device. Additionally or alternatively, an acoustic output is also conceivable. In this way, the operator receives direct feedback as to whether or not their control of the soil compaction machine during the previous reversing was optimal with regard to the resulting evenness of the compacted soil. If appropriate, the operator also receives feedback from the result as to the extent to which their control of the soil compaction machine deviated from optimal control during the previous reversing.This information can be used by the operator to perform future reversing of the soil compaction machine more optimally. Although the result of the comparison according to the invention only provides the operator with information about the already completed sequence of the last reversing, this information can, however, be used positively to improve each subsequent reversing, thereby providing overall assisted operation of the soil compaction machine and improving the overall evenness of the ground after completion of the compaction work. Since this is a professional work environment, it can be assumed that the operator will implement corresponding instructions wherever possible. The result can also be saved, for example, stored in a memory of the control unit.The operator can then, for example, view the results after completing a job and receive feedback on the workflow. This can then also be used for future jobs to improve the resulting evenness of the compacted soil. Furthermore, the stored results can be 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 soil compaction machine's control. In this way, the operator can determine, for example, whether the operator requires additional driver training. This also allows the evenness of the soil to be improved in future jobs.In order 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.

[0017] In principle, it would suffice to repeatedly record the parameters of travel speed, change in travel speed, and / or reversal of travel direction, as well as steering angle and / or vibration input, or quantities correlated with these parameters, at discrete intervals, particularly in terms of time and / or location. As long as the discrete intervals are chosen to be sufficiently close to determine the point at which the soil compaction machine reverses with sufficient accuracy, the method can be carried out with such data. However, it is preferably provided that the recording of at least one of the parameters of travel speed, change in travel speed, and / or reversal of travel direction, or at least one quantity correlated with one of these parameters, and / or the recording of the steering angle and / or the vibration input, or a quantity correlated therewith, is carried out continuously.In this way, the point at which the reversal occurs can be determined with particular precision. Furthermore, the values ​​of the respective parameters can be determined with particular accuracy, for example, at a point in time when a certain driving speed is present or when a certain vibration input occurs.

[0018] 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 process. Accordingly, the interval and preferably additionally the travel distance can be defined such 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 travel distance can be defined separately for each individual case, for example based on functional criteria. Preferably, the interval or the travel distance can be defined such that the start is predetermined by the travel speed of the soil compaction machine falling below a threshold value that signals that operation at a working speed in one direction of travel is being terminated.The working speed describes the travel speed at which the soil compaction machine is typically operated during work while traveling straight ahead over the soil to be compacted. Such typical working speeds depend on the type of soil compaction machine and are known to those skilled in the art. Similarly, the end of the interval or distance can be specified by the travel speed of the soil compaction machine rising above the threshold value, signaling that acceleration is returning to the working speed. The start and end can be specified by the same threshold value or by different threshold values. The threshold value can be, for example, 3 km / h, 5 km / h, or 7 km / h.The working speed can be fixed and, for example, also correspond to the threshold value or lie above the threshold value by a fixed value, for example 1 km / h or 2 km / h or 3 km / h. The interval and / or the distance are preferably 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 comprises 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. Additionally or alternatively, the distance can be set such that it comprises 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 the reversing.To determine the interval or distance in this way, the time or location of the reversal must, of course, already be established. This means that, at least for those parameters and quantities that need to be recorded before reversing, previously recorded values ​​must be accessed once the reversal time is known. Even if the method then only uses values ​​that fall within the considered interval or distance, it is still preferable for the values ​​to be recorded over the entire operating period of the soil compaction machine. However, since not all of this data is required, it may be preferable, for example, to retain or store the data only until the time of the next reversal has been determined.From this point on, it is sufficient to retain only the data within the interval or distance under consideration. Previous data, however, can be deleted. For this purpose, a type of rolling memory can preferably be used, 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 distance before the reversal. Data from further back can, however, be overwritten.

[0019] As already mentioned, it is preferable that the reference values ​​used for comparison include a target steering angle, which specifies the minimum steering angle that should be at the determined point of reversing. In other words, the target steering angle indicates how sharply the operator of the soil compaction machine should steer before the machine comes to a standstill during reversing. The direction of the steering angle is initially irrelevant to the effect on the evenness of the compacted soil. Therefore, it is immaterial whether the steering is to the left or right. This can be freely chosen depending on the conditions of the construction site. Thus, only the magnitude of the steering angle as a deviation from driving straight ahead is considered. Accordingly, the target steering angle also refers to the magnitude of the steering angle as a deviation from driving straight ahead.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 coming to a standstill at the reversal point when reversing from the rolling direction at this reversal point during at least one preceding or subsequent pass in which the soil compaction machine does not reverse. To assess this, position data is collected, for example, throughout the entire working sequence of the soil compaction machine. 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 may also be located in a curve. The steering angle then accounts for the deviation caused by turning away from the curvature of the curve.Particularly when the soil to be compacted is in a curve, it is also preferable for the steering to occur in the opposite direction to the curve. This can also be monitored according to the invention and included in the evaluation. The target steering angle can also refer 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°.

[0020] The vibration input into the soil must be reduced or slowed down in good time before reversing. In particular, it must be prevented that the soil compaction machine, when traveling at particularly low speeds shortly before coming to a standstill, still introduces significant vibration into the soil. After reversing, the vibration input may only be increased again once the soil compaction machine has already accelerated back to a sufficiently high travel speed. It is therefore preferable 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 the maximum vibration input, in particular in relation to the travel speed of the soil compaction machine.Additionally, it is preferred that after reversing, the vibration input is increased, particularly from zero, and that the reference values ​​used for comparison include a target vibration input specifying the maximum desired vibration input, especially in relation to the travel speed of the soil compaction machine. As already mentioned, the IPF value is preferably used as a measure of the vibration input. Additionally or alternatively, the frequency, amplitude, eccentricity, and / or the vibration energy supplied by the vibration exciter can be used. For example, the target vibration input can specify the travel speed of the soil compaction machine before reversing at which no vibration input should occur and / or the travel speed of the soil compaction machine after reversing at which vibration input should resume.For example, reducing the vibration input to zero while maintaining a constant travel speed, such as the working speed, can be considered optimal. However, it's important to note that the working speed isn't always constant and can differ 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 travel speed. Therefore, the target vibration input can, for example, include an IPF value as a limit. However, a slight deviation from this is also considered optimal. For example, a deviation of a maximum of 20%, preferably a maximum of 15%, 10%, or 5% from the IPF value stored as the reference value for the target vibration input can still be considered optimal.This can be taken into account when comparing the procedures and also in the evaluation.

[0021] As previously mentioned, vibration exciters, especially circular exciters, inevitably go through a resonant frequency when switching on and off. At this frequency, vibration amplitudes are briefly increased, resulting in higher vibration induction into the soil. This, in turn, leads to waves in the soil. The effect is particularly noticeable when the vibration exciter is switched off, i.e., before the soil compaction machine reverses. To smooth these waves as much as possible during reversal, optimal control of the soil compaction machine ensures that the resulting waves are passed over again with the highest possible compaction power after reversing. This means that, ideally, the waves should also be passed over with high vibration induction, for example, at the maximum intended operating power 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 a position of the maximum vibration input before reversing is determined within the interval and / or the distance, 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 reducing the vibration input.Determining this position can be achieved, for example, via the travel speed, changes in travel speed, or location tracking, such as using GNSS, as described above. For instance, the target vibration input can specify that this position should be traversed with a nominal vibration input, such as the maximum compaction power of the vibration exciter, after reversing. The nominal vibration input refers specifically to a vibration input with which the vibration exciter operates optimally at the given position of the soil to be compacted. This can be determined automatically, for example, by the applicant's "Asphalt Manager." 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.

[0022] If the soil compaction machine has a front and a rear roller drum spaced apart along the machine's length, optimal control of the machine requires that the rear roller drum, in the current direction of travel or work, passes the point of maximum vibration input from the front roller drum before reversing. As explained above, when the vibration input is reduced, the vibration exciter of the front roller drum passes through its resonant frequency, exhibiting increased vibration input that leads to wave formation. Ideally, these waves should be passed over by the rear roller drum before reversing. For this to occur, it is crucial that the vibration input is reduced in time before reversing, for example, by switching off the vibration exciter just before the machine reverses.To also 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.

[0023] The actual effect of the operator's control of the soil compaction machine on the evenness of the compacted soil is also influenced by external factors. These are referred to here as operating conditions. For example, the consistency of an asphalt layer laid by a paver depends significantly on its temperature. The hotter the asphalt, the more easily undesirable waves form, so that deviations from the reference values ​​result in greater unevenness than with cooler asphalt. At the same time, the temperature of the asphalt is also influenced by external factors, such as the weather. Soil stiffness, which also depends on the properties of the soil beneath the asphalt, plays a role here as well. Furthermore, whether the soil to be compacted has a slope makes a difference.A gradient, for example, can positively or negatively influence the effects of braking on an asphalt layer, depending on the direction of travel. It is therefore generally preferred that at least one external operating condition is also taken into account when comparing the recorded values ​​with the reference values, wherein the operating condition includes, for example, a soil temperature and / or soil stiffness and / or weather conditions and / or a transverse and / or longitudinal gradient of the soil. The external operating conditions 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 conditions. The measurement results from the sensors are forwarded accordingly to the control device, which can then take the external operating conditions into account when comparing.Additionally or alternatively, the external operating conditions can also be entered by the operator at the control unit. Preferably, the control unit adjusts the reference values ​​based on the operating condition(s). For example, it may be necessary to apply stricter reference values ​​if the soil temperature is particularly high. Conversely, if the soil temperature is particularly low, the reference values ​​can be chosen less strictly, since the influence of the soil compaction machine's driving maneuvers on cool soil or asphalt is less. The adjustment of the reference values ​​based on the external operating conditions can also be qualitative or quantitative. For example, the reference values ​​can be increased or decreased by a fixed predefined value if corresponding external operating conditions exist, such as particularly hot asphalt.Alternatively, and preferably, the adjustment of the reference values ​​can be 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 soil temperature, outside temperature, precipitation amount, slope angle, etc., and adjusted to deviating external operating conditions using a calculation rule. In this case, the reference values ​​are dynamically and quantitatively adjusted to the external operating conditions or the current conditions of the construction site.

[0024] Outputting the result of the comparison can include a display for the operator of the soil compaction machine. As already explained, based on this feedback, the operator can adapt the control of the soil compaction machine for future reversing in order to achieve optimal results with regard to the evenness of the compacted soil. Preferably, if a deviation of the steering angle and preferably additionally of the vibration input within the interval and preferably additionally of the distance from the reference values ​​is detected, 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 provided with information on how he can specifically optimize the control of the soil compaction machine.This also applies to all other aspects of the soil compaction machine's control described herein that may be included in the evaluation. These aspects can also be used to display instructions for the operator to improve the machine's control. Such instructions might include, for example, "switch off the vibration exciter earlier," "switch on the vibration exciter later," or "steer more sharply when reversing." Several such instructions can be displayed simultaneously if multiple deviations from the reference values ​​are detected during the underlying reversing process. These instructions can be displayed visually, particularly in text form, on the display devices. Additionally or alternatively, the instructions can also be provided audibly, for example, via a voice output.In this way, the operator of the soil compaction machine receives automatic assistance during operation, providing insights into the effects of the machine's controls on the evenness of the compacted soil—insights typically only available to highly experienced operators. Even inexperienced operators can thus achieve improved soil evenness, while experienced operators can further refine their expertise.

[0025] To provide even more information to the operator, it can preferably be provided that the operator is shown a note along with the instruction if an external operating condition has led to an adjustment of the reference value(s), which increases a deviation of the steering angle and / or vibration input within the interval and / or the distance from the reference value(s). This therefore always applies when external operating conditions exist that increase the impact of the operator's driving behavior on the evenness of the ground. Such notes could, for example, be "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 provided with additional specialist knowledge in addition to improving the current work results.

[0026] In principle, the result of the comparison can be displayed numerically. Specifically, the numerical deviation of the recorded steering angle and / or vibration input from the reference value(s) could be shown. However, to avoid burdening the operator with having to consider the severity of the displayed deviation while simultaneously fulfilling all their other duties during operation, it is preferable for the comparison result to be automatically evaluated. Therefore, it is preferable for the comparison result to be assigned a rating that worsens with a greater deviation from the reference value(s) or the optimal control of the soil compaction machine, and this rating should also be displayed or saved.For example, different levels could be defined that represent a spectrum from no deviation to slight deviation to high deviation. A standard grading system, for example, from 1 (very good) to 6 (unsatisfactory), could be used here. Alternatively, a rating in fewer levels, for example three, would also be possible. These could be, for example, "no deviation," "minor deviation," and "high deviation." The respective limit values ​​for the individual levels can either be fixed or adjustable by the operator or operator of the soil compaction machine. This allows, for example, the fact that different construction sites may have different requirements regarding the evenness of the compacted soil to be taken into account.To make it even easier for the operator to read the rating, it may be possible to display the rating in the form of a symbol, for example a pictogram or a smiley face with a facial expression corresponding to the rating.

[0027] In addition to the criteria mentioned, the procedure can also monitor other factors that may influence the evenness of the compacted soil. As already described, the soil compaction machine must be decelerated for reversing and then accelerated again. Both the deceleration and acceleration of the soil compaction machine should be as smooth as possible, i.e., without jerky or abrupt changes in travel speed. Such jerky changes in travel speed can also lead to undulations in the soil. It is therefore preferred that jerky changes in travel speed are also detected and included in the evaluation. In particular, jerky changes in travel speed within the interval and / or within the distance traveled are detected.Such cases are characterized by a rapid increase in the ground speed and / or acceleration, i.e., a change in ground speed, of the soil compaction machine. Threshold values ​​can also be provided for this purpose to detect sudden changes in ground speed. If such sudden changes are detected, this can be included in the evaluation and, in particular, taken into account in the instructions. For example, a warning message indicating that braking or acceleration should be applied more gently is then displayed.

[0028] In principle, assisted operation and a related improvement in the evenness of the compacted soil can be achieved if the method according to the invention is applied to only a single reversing operation of the soil compaction machine. The operator can then use the resulting feedback to optimize future reversing operations if necessary. However, it is preferred that the method be carried out for several, in particular all, reversing operations 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 a working period of an operator on a specific construction site. In principle, however, smaller work intervals could also be conceivable, for example one or more hours of a workday or work assignment.In particular, it may be possible to generate an overall score from the individual scores of all reversing operations within the work interval, which is then also displayed or saved. The overall score can, for example, follow the same grading scheme as the score for a single reversing operation. A school grading system or similar could be used. The overall score is, for example, the average of all scores within the work interval. The operator can use the overall score to determine whether their control of the soil compaction machine was appropriate for the current construction site and / or whether their control of the soil compaction machine has improved or deteriorated. At the same time, the operator of the soil compaction machine can identify which operators require additional training or instruction.

[0029] The method described above preferably determines one or more of the aforementioned parameters, identifies a reversing process from this (for example, by determining a change in direction), then compares the actual reversing process with one or more of the aforementioned parameters to an optimal reversing process (for example, by comparing it to one or more characteristic maps, formulas, etc.), and evaluates, based on this comparison, how closely the actual reversing process comes to the theoretically optimal reversing process, as described above. This evaluation result can then be displayed to the driver, who thus receives an indication, even during operation, of how to further optimize their driving style in this operating situation.

[0030] It is possible to configure a soil compaction machine, in particular a tandem roller or single-drum roller, with at least one roller drum and a control device for carrying out the method. In particular, the control device can be configured to carry out the method, naturally with the exception of the step of controlling the soil compaction machine by the operator. The soil compaction machine can be equipped like the soil compaction machine described above. All features, effects, and advantages described for the method according to the invention also apply, in a figurative sense, to such a soil compaction machine, and vice versa. Reference is made to the respective other embodiments merely to avoid repetition.

[0031] The invention is explained in more detail below with reference to the exemplary 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 occurrence of waves in the soil during reversing without steering; Figure 4: the occurrence of oblique waves in the soil during reversing with steering; Figure 5: the occurrence of waves in the soil due to reducing the vibration input too late; Figure 6: the avoidance of waves in the soil by reducing the vibration input early; Figure 7: the course of various parameters during reversing; Figure 8: the output of a positive rating and a course of action; Figure 9: the output of a medium rating and a course of action; Figure 10: the output of a poor rating and a course of action; and Figure 11: a flowchart of the procedure.

[0032] Identical or similarly functioning components are numbered with the same reference symbols in the figures. Repeating components are not individually labeled in each figure.

[0033] In the Figures 1 and 2 Two soil compaction machines 1 are shown. Specifically, it shows 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 platform 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 2preferably has a front roller drum 5 and, on the rear frame, preferably wheels 7. 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 paver, 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 to influence the compaction performance. The soil compaction machines 1 further 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.be present, via which the driver of the soil compaction machine can issue control commands, for example with regard to the driving speed, steering specifications, settings for an excitation device, etc. Furthermore, 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 designed to detect a change in driving speed and preferably additionally to detect the driving speed and / or the reversal of direction and / or the steering angle and / or the vibration input or variables correlating 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 additionally have a data transmission device 12, which can be designed, for example, to transmit data via the Internet or via another wireless data connection.

[0034] In Figure 3The reversing of the soil compaction machine 1 is shown. In particular, illustrations a) to e) show the same soil compaction machine 1 on the same construction site section in a top-down, bird's-eye view, but in successive snapshots. In illustration a), the soil compaction machine 1 is traveling at a speed v in the working direction R, where the speed v in illustration a) corresponds to the working speed of the soil compaction machine 1, at which it typically compacts the soil 8. In illustration b), the soil compaction machine 1 has already been partially decelerated, so that the speed v is lower than that in illustration a). In illustration c), the soil compaction machine 1 has come to a standstill.The time shown in diagram c) is therefore the time of reversal or the turning point of the soil compaction machine 1, when the machine, as shown in d), starts moving again in the opposite direction of travel. At the time shown in diagram d), the soil compaction machine 1 has already been accelerated in the opposite direction of travel, i.e., opposite to 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 of the soil compaction machine 1. In the situation shown in diagram e), the soil compaction machine 1 has been accelerated again to a travel speed v that corresponds to the working speed.The distance L to which the procedure can refer, for example, can be defined as the distance from the turning point of the soil compaction machine 1 to the point where the soil compaction machine 1 has again reached a travel speed v corresponding to the specified working speed. Alternatively, the distance L can also be defined by a fixed distance, for example 30 m.

[0035] As in Figure 3 As shown in illustrations d) and e), the soil compaction machine 1, or rather its roller drums 5, leaves a soil ridge 13 at the point of reversal or at the reversal point of the soil compaction machine 1. In the case of the Figure 3These bumps 13 are aligned perpendicular to the working direction R, since no steering was applied during reversing. Such bumps 13 are only poorly smoothed during subsequent passes of the soil compaction machine 1. Therefore, there is an increased risk that the bumps 13 will continue to negatively affect the evenness of the soil 8 even at the end of the work. Figure 4 shows the same process as Figure 3 The only difference is that the operator of the 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 diagonally 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, therefore, the procedure according to Figure 4 a significantly more level, compacted soil 8.

[0036] 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 The effects 14 of vibrations of the rolling bands 5 on the floor 8 are now shown. The effects 14 can be Impacts be understood in the sense of an IPF value. For example, an action 14 indicates a location where the vibration of the rolled bandage 5 presses it onto the ground 8. In other words, vibration energy is transferred to the ground 8 at the locations of the actions 14. The distance between the actions 14 is a measure of the vibration input, with actions 14 shown closer to each other indicating a higher vibration input. Of course, the Figures 5 and 6These are merely schematic diagrams intended to make the underlying processes understandable, but do not represent them in a realistic manner.

[0037] In Figure 5Two separate operating errors by the operator are shown. In particular, illustrations a) to c) show the case where the vibration input into the soil 8 is reduced too late before the soil compaction machine 1 reverses, for example, to zero. The reduction of the vibration input is achieved, for example, by switching off the vibration exciter 10 or the vibration of the roller drum 5. The reduction of the vibration input only occurs at a point in time when the soil compaction machine 1 has already been decelerated to a travel speed v that is so low that too many impacts 14, or an excessive amount of vibration, occur over a short distance. This is shown by the closely spaced impacts 14 in illustration c).Where the influences 14 are too close together or the vibration input is too great, soil undulations can arise that are detrimental to the evenness of the soil 8 left behind after work. In illustrations d) and e), on the other hand, 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, the vibration exciter 10 or the vibration of the roller drum 5 is switched on, for example. In particular, the vibration input is increased at a time when the soil compaction machine 1 has only been accelerated to a travel speed v that is too low, so that the influences 14 are again too close together, at least over a partial section, or the vibration input is too great, which in turn can cause soil undulations.This is also shown in illustrations d) and e) by the closely spaced effects 14. In the worst case, the cases shown in illustrations a) to c) and d) to e) occur together during a single reversal of the soil compaction machine 1. Of course, the two cases can also occur individually during a single reversal of the soil compaction machine 1. This will be taken into account in the evaluation of the reversal, if applicable.

[0038] Also in Figure 6 The process of reversing soil compaction machine 1 is shown. Figure 6As shown in figures a) to c), the soil compaction machine 1 decelerates to reverse, with the vibration input being reduced in a timely manner before coming to a standstill. For example, the vibration exciter 10 is switched off sufficiently early so that the decrease in the travel speed v of the soil compaction machine 1 is compensated for by a decrease in the vibration input, for example, by a decrease in the frequency of the vibration exciter 10. The vibration input therefore decreases essentially to the same extent as the travel speed v, and no sections are created where the vibration input is too high, i.e., where compaction is too intensive. This is illustrated by the uniform spacing of the loads 14. In this way, no, or at least no significant, bumps are created that would impair the evenness of the compacted soil 8 at the end of operation.In representations d) and e) of the . Figure 6 Figure 1 depicts the case in which the soil compaction machine 1 accelerates again after reversing its direction of travel. However, the vibration input into the soil 8 is only increased again at a point in time when the travel speed v of the soil compaction machine 1 is already sufficiently high, so that no sections with excessively high vibration input occur. For example, the vibration exciter 10 is only switched on again after the soil compaction machine 1 has reached a sufficiently high travel speed v. In this way, the formation of soil undulations is prevented, which is represented by the uniform spacing of the impacts 14. Figure 6Therefore, a reversal is depicted, where optimal control is achieved both before and after the reversal point. As already explained, errors can also occur separately before or after the reversal point, which will be taken into account accordingly in the evaluation.

[0039] The Figures 4 and 6 The optimized processes are also particularly preferred to be 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.

[0040] Figure 7The figure shows the temporal relationship between the driving speed v, the change in driving speed a, the steering angle w, and the vibration input S of the soil compaction machine 1. For this purpose, diagrams for these respective values ​​are superimposed, with the abscissa representing the time t elapsed across all diagrams. Figure 7 The data is synchronized across the diagrams. The corresponding values ​​of the mentioned parameters are then plotted on the ordinate of each diagram.

[0041] The top diagram of the Figure 7The figure shows, for example, the travel speed v of the soil compaction machine 1. From left to right, it depicts the soil compaction machine 1 accelerating from a standstill until it reaches a constant travel speed v, for example, the working speed. After the soil compaction machine 1 has covered a distance at this travel speed v, it is decelerated back to a standstill. It is then accelerated again in the same direction as before until it reaches a constant travel speed v once more. This process therefore involves deceleration and subsequent acceleration of the soil compaction machine 1, without a change in direction. While this process can also influence the evenness of the soil 8 after the work is completed, it does not involve reversing the soil compaction machine 1, which is particularly important in this context.After traveling a distance at a constant travel speed v, the soil compaction machine 1 is decelerated 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 reversed here. The time period around the reversing 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 decelerated from the working speed before reversing and accelerated back to the working speed after reversing. The soil compaction machine 1 then travels at an essentially constant travel speed v, for example the working speed, and is then reversed again.The soil compaction machine 1 is therefore braked to a standstill again and then accelerated in the opposite direction. This reversing also takes place within a time interval T. This second interval T can in principle be of the same length as the first interval T. However, it is also conceivable for the intervals T to be of different lengths, for example in particular if they are defined functionally, 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 deduced from the travel speed v or a reversal of travel direction. This results in particular from a reversal of the sign of the travel speed v.

[0042] Directly below the diagram of the driving speed v shows Figure 7A diagram of the acceleration or change in travel speed a of the soil compaction machine 1. As shown, the change in travel speed a can also be used to identify a reversing of the soil compaction machine 1. In particular, during reversing, a double change in travel speed a in the same direction occurs, separated by the machine's standstill, from which a reversing can be inferred. As can be seen from the left part of the diagram, such a double change in travel speed a in the same direction does not occur during an interrupted straight-line travel in one direction.

[0043] Below the diagram of the change in driving speed a is in Figure 7A diagram of the steering angle w is shown. Since the direction of steering during reversing is irrelevant, at least with regard to the evenness of the ground 8 after operation, only the magnitude of the steering angle w is shown. Furthermore, the diagram only shows steering angles w that correspond to steering during reversing within the intervals T. Other steering angles w occurring during the operation of the soil compaction machine 1 are not shown. In particular, the diagram shows that the steering angle w remains below a threshold value represented by the dashed line parallel to the abscissa in the first interval T shown on the left.This means that the operator did not steer sufficiently during this reversal of the soil compaction machine 1, so that the soil ridges 13 created at the reversal point are not sufficiently inclined to the working direction R to be optimally smoothed in subsequent passes of the soil compaction machine 1. In other words, there is a deviation from a reference value, which 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 reversal of the soil compaction machine 1 by the operator. The situation of the reversal in the first interval T shown on the left therefore corresponds to that according to [reference missing]. 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 represented by the dashed line parallel to the abscissa. Here, the operator has thus steered sufficiently far when reversing the soil compaction machine 1, which results in the bumps 13 created at the reversal point being aligned at an angle to the working direction R such that they can be optimally smoothed 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 .

[0044] The lowest in Figure 7The diagram shown relates to the vibration input S. In order to avoid excessive compaction of the soil 8 in some places, as this would lead to the formation of waves, it is provided that during the working operation of the soil compaction machine 1 the vibration input S is only increased, or the vibration exciter 10 is only operated with an energy transfer to the soil 8, when the soil compaction machine 1 is traveling at a sufficient travel 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 the working operation of the soil compaction machine 1.As shown in the intervals T around the reversal 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 reversal of travel direction, the vibration input S is then typically increased again. However, it can also happen that a vibration input S is only used or present before or only after reversing. Even then, the method can be applied to reducing the vibration input S before reversing or to increasing 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 well in advance of reversing so that the travel speed v is sufficiently high as long as a vibration input S is still present.Furthermore, the vibration input S is only increased again when the soil compaction machine 1 has reached a sufficient driving speed v. Therefore, no sections arise in which excessive compaction of the soil 8 occurs 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 . Figure 6Furthermore, 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 during reversing. The vibration input S is still at its maximum even when the travel 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, this results in undulations in the soil, which negatively affect 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 preceding interval T, so that the vibration input S is only increased when the travel 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 representations a) to c) of the diagram. Figure 5and the representations d) and e) of the Figure 6 .

[0045] 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, for example, be a screen or a display which is connected to the control device 6. The output of the result of the comparison can, for example, be carried out 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, indicates, for example, 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 operation. If necessary, the operator can adjust the control of the soil compaction machine 1 for future reversing operations. To assist or support the operator, an instruction 16, for example in written form, can be displayed on the display device 9 in addition to the rating symbol 15. Alternatively, the instruction 16 could also be issued audibly. The instruction 16 preferably includes specific information on which reference values ​​were not met during the last reversing operation and / or how the deviation from the reference values ​​can be avoided or at least reduced during future reversing operations.

[0046] Figure 11finally 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 during reversing has an increased influence on the resulting evenness of the soil 8. For this reason, the method 20 provides for detection 22 of at least the change in travel speed a and, additionally, preferably at least one of the parameters travel speed v and / or reversal of travel direction or at least one variable correlating with one of the aforementioned parameters.Such parameters are often already recorded on soil compaction machines 1 anyway, so that the sensors 11 required for this purpose may already be present in some cases. Next, a time at which a reversal of the soil compaction machine 1 takes place is determined 27 from the at least one recorded parameter or the at least one recorded variable. This preferably also records the location of the soil compaction machine 1 at this time when a position or distance detection takes place. By determining when a reversal of the soil compaction machine 1 takes place, the control of the soil compaction machine 1 by the operator can be checked around the reversal.For this purpose, a steering angle w of the soil compaction machine 1 and, additionally, preferably, 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, additionally, preferably, a distance L around the determined time of reversing and, additionally, preferably, a location of the soil compaction machine 1 at this time are recorded 23. Recommendations exist 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 being complied with is determined by comparing 24 the detected steering angle w and, additionally, preferably, the vibration input S within the interval T and, additionally, preferably, the distance L with predefined reference values ​​for a target steering angle and, additionally, preferably, for a target vibration input. In particular, this directly determines whether or not the operator is complying with the recommendations when controlling the soil compaction machine 1. Furthermore, it is also possible to quantitatively determine the extent to which the recommendations are not being complied with. In order to obtain assisted operation support or assistance for the operator, the result of the comparison 24 is output 25 and, additionally, preferably, saved 26.The operator and, if applicable, 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 they control the soil compaction machine 1 in the future and improve their work results. The operator, in turn, can determine the extent to which 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

1. A method (20) for assisted operating support for a ground compaction machine (1), comprising the steps of: a) controlling (21) the ground compaction machine (1) by an operator; b) detecting (22) of at least a change in travel speed the method being characterized with the additional steps c) determining (27) a time at which a reversal of the ground compaction machine (1) takes place from the parameter detected in step b); d) detecting (23) a steering angle (w) of the ground compaction machine (1) within a time interval (T) around the time determined in step c); e) comparing (24) the steering angle (w) within the interval (T) with predetermined reference values for a target steering angle; f) outputting (25) a result of the comparison (24).

2. The method (20) according to claim 1, characterized in that detecting (22, 23) in steps b / or d) is performed continuously.

3. The method (20) according to any one of the preceding claims, characterized in that the interval (T) is set such that the reversal is in the middle of the interval (T).

4. The method (20) according to any one of the preceding claims, characterized in that the reference values used for comparing (24) in step e) comprise a target steering angle indicating how large the steering angle (w) should at least be at the time of the reversal as determined in step c).

5. The method (20) according to any one of the preceding claims, characterized in that reducing the vibration input (S), in particular to zero, is performed before the reversal, and that the reference values used for comparing (24) in step e) comprise a target vibration input indicating how large the maximum vibration input (S) should be, in particular in relation to the travel speed (v) of the ground compaction machine (1), and that increasing the vibration input (S), in particular starting from zero, is performed after reversing, and that the reference values used for comparing (24) in step e) comprise a target vibration input indicating how large the maximum vibration input (S) should be, in particular in relation to the travel speed (v) of the ground compaction machine (1).

6. The method (20) according to any one of the preceding claims, characterized in that that within the interval (T) a position of a maximum vibration input (S) before reversing is determined, and that the reference value for the target vibration input indicates a minimum vibration input (S) with which this position is to be passed over after reversing.

7. The method (20) according to any one of the preceding claims, characterized in that that within the interval (T) a position of a maximum vibration input (S) of a front roller drum (5) of the ground compaction machine (1) before reversing is determined, and that it is monitored whether a rear roller drum (5) of the ground compaction machine (1) passes over this position before reversing.

8. The method (20) according to any one of the preceding claims, characterized in that in step e), at least one external operating condition is additionally taken into account, the operating condition comprising a ground temperature.

9. The method (20) according to any one of the preceding claims, characterized in that outputting (25) the result of the comparison (24) in step f) comprises displaying to the operator of the ground compaction machine (1), wherein in a case where a deviation of the steering angle (w) within the interval (T) from the reference values has been detected, an instruction (16) is displayed to the operator as to how the deviation can be reduced in the future.

10. The method (20) according to claims 8 and 9, characterized in that an indication is displayed to the operator along with the instruction if an external operating condition has resulted in an adjustment of the reference values which increases a deviation of the steering angle (w) within the interval (T) from the reference values.

11. The method (20) according to any one of the preceding claims, characterized in that in step e), the result of the comparison (24) is assigned a rating which becomes worse with a higher deviation from the reference values.

12. The method (20) according to the preceding claim, characterized in that jerky changes in travel speed (v) are also detected and included in the rating.

13. The method (20) according to any one of claims 11 or 12, characterized in that the method (20) is carried out for all reversing operations within a work interval, wherein the individual ratings from step e) are used to create an overall rating, which is likewise output or stored in step f).