DE102018007825A1 - Method for controlling a soil compaction machine and soil compaction machine - Google Patents

Abstract

The invention relates to a method (22) for controlling a soil compaction machine (1), in particular to avoid compaction errors, comprising the steps: excitation (23) of a vibration with a vibration frequency (f) in at least one compaction bandage (5) by means of an excitation device (13 ), Moving (24) the soil compaction machine (1) over a soil (8) to be compacted at a driving speed (v), and changing (28) the driving speed (v) and / or the vibration frequency (f), with a determination and monitoring (25) the number of vibrations per travel distance (IPF) from the driving speed (v) and the vibration frequency (f), a comparison (26) of the determined number of vibrations per travel distance (IPF) with predetermined limit values (IPF, IPF, IPF) and a reduction (27) of the vertical vibration amplitude (A) of the compression bandage (5) if the size exceeds or falls below at least one values (IPF, IPF, IPF). The invention also relates to a soil compaction machine (1) with a control unit (15) which is designed to carry out the method (22) and / or carries it out.

Description

The invention relates to a method for controlling a soil compaction machine, in particular to avoid compaction errors. In addition, the invention relates to a soil compaction machine with a control unit which is designed to carry out the method and / or carries it out.

Generic soil compaction machines are designed, for example, as road rollers, in particular tandem rollers or single drum rollers. They are used in road and path construction to compact the subsurface, for example hot layers of asphalt or soil. For this purpose, the soil compaction machines typically have compaction bandages that are designed, for example, as roller bandages with a hollow cylindrical base body. The compression bandages can either have smooth, round surfaces, or can also be designed polygonally or with projections projecting beyond the circumference of the hollow cylindrical base body as breaker bandages. One or more compaction bandages can be provided on a soil compaction machine. It is also possible that a compaction bandage is used in combination with wheels or other running gear. The generic soil compaction machines are in particular designed to be self-propelled and comprise a drive motor, which is typically a diesel internal combustion engine. This drives the compaction bandage, among other things, so that during the working operation of the soil compaction machines the soil compaction machine is moved at a driving speed over a soil to be compacted.

In order to increase the compaction performance of the generic soil compaction machines, a vibration is typically excited with a vibration frequency in at least one compaction bandage by means of an excitation device. The excitation device is also referred to as a vibration exciter and comprises, for example, one or more circular exciters and can in particular be designed as a directional oscillator. By exciting a vibration on the compaction bandage, the compaction performance can be increased many times over simply crossing the soil compacting machine over the soil to be compacted. A generic excitation device is for example from the EP 2 172 279 A1 known to the applicant.

The working speed of the soil compaction machines often changes the driving speed and / or the vibration frequency. This can lead to undesired effects or even compaction errors. If, for example, the driving speed is reduced while the vibration frequency remains the same, the compaction drum performs an increased number of vibrations due to the vibrations over a shorter distance. In this way, compaction is more intensive on this shorter route than if the roller were traveling faster at the same vibration frequency. This goes so far that the roller literally presses dents into the soil to be compacted at too slow speed and / or particles in the substrate material to be compacted are appreciably destroyed and thereby reduced. If, on the other hand, the soil compacting machine runs too fast at a given vibration frequency, relatively too few vibrational vibrations are carried out over a long distance, which leads to the individual vibrating vibrations or impacts being too far apart. This can lead to the formation of waves in the ground. The problem with this is that it is hardly possible to compensate for these bumps once they have arisen. Even if the affected areas are crossed several times, it cannot always be ensured that the compaction errors have been eliminated. This is made even more difficult by the fact that too much compression is disadvantageous, so that it is not possible to drive over the affected area as often as desired. During the compaction work, the operator of the soil compaction machine must devote a large part of his attention to ensuring that no compaction errors occur. This distracts him from the actual work of compaction.

This problem occurs particularly in hybrid systems, which are used more and more frequently due to the increasingly strict environmental regulations. Soil compacting machines, which are designed, for example, as hydraulic or electrical hybrids, typically have a drive motor designed for lower power, which is supported during work when power peaks occur with energy from an intermediate store, for example a hydraulic pressure store or an electrical store. However, if the energy contained in the buffer is not sufficient to bridge a power peak, either because the peak power is too large or too long, the requested power exceeds the maximum power made available by the drive motor. In this case, the driving speed and / or the vibration frequency of the soil compacting machine must typically be reduced. In this way, hybrid systems increasingly experience the problem described above that driving is too fast or too slow for a given vibration frequency or that the vibration frequency is too high or too low for a given driving speed.

It is therefore the object of the present invention to provide a method for controlling a soil compaction machine and a soil compaction machine in which the formation of unevenness in the soil to be compacted, up to compaction errors, is reliably avoided. At the same time, this should be possible for the operator of the soil compacting machine with as little effort as possible and, in particular, improve the use of hybrid systems.

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 to a method mentioned at the outset is achieved by determining and monitoring the number of vibrations per covered route from the driving speed and the vibration frequency, comparing the determined number of vibrations per covered route with predetermined limit values and reducing the vertical vibration amplitude of the compression bandage when or falling below at least one of the limit values. In the present case, a period of those vibrations is referred to as a vibration shock, in which the compression bandage is placed by the excitation device. A vibration shock therefore includes, for example, a vibration in the vertical direction of a lowering of the compaction bandage from a neutral position downwards, then a lifting of the compaction bandage back to the neutral position and upwards beyond this, followed by a further lowering of the compaction bandage to the neutral position . The number of such vibration shocks per distance traveled is then specified, for example, as vibration shocks per meter or per foot and is referred to as the IPF value (from the English: “impacts per foot”). The term IPF value is used here regardless of the length unit used, so that the unit used in each case must be specified for specific values. A value that indicates the vibration shocks per meter is therefore also referred to as the IPF value.

A basic idea of the invention is therefore based on determining and monitoring the IPF value. As a result, the IPF value can be used as a control variable in the process. The number of vibrations per distance traveled is calculated from the known variables of the driving speed and the vibration frequency. Specifically, the IPF value corresponds to the division of the vibration frequency by the driving speed. Since the driving speed and the vibration frequency are typically measured continuously, the IPF value can also be continuously determined and monitored. Knowing the IPF value makes it possible to compare the current value with a setpoint, a setpoint range or with limit values. For example, limit values can be specified, such as a maximum IPF value and a minimum IPF value, between which the currently measured IPF value, which is therefore present on the soil compacting machine, should ideally be found during work. In this area, the number of vibration shocks per distance traveled is set so that the vibration shocks applied to the soil to be compacted are both far enough apart to not carry out excessive compaction at one point and close enough to one another that the soil is compacted uniformly without waves.

If, on the other hand, this range of the permissible IPF value is left, since the current IPF value either exceeds the maximum limit value or falls below the minimum limit value, the vertical vibration amplitude of the compression bandage is reduced in the method according to the invention. The vertical vibration amplitude corresponds to that part of the compression bandage that vibrates or is aligned in the vertical direction. “Vertical” here means perpendicular to an essentially flat ground. In particular, this vertical vibration or vertical vibration amplitude brings a particularly high level of compaction performance into the soil, so that an IPF value outside the optimal range threatens compaction errors. In the case of a circular oscillator that vibrates equally strongly in all directions, the vertical vibration amplitude therefore corresponds to the current overall amplitude. In the case of a directional oscillator, for example, the direction of the oscillation can be freely adjusted so that the oscillation can be adjusted, for example, between complete vertical alignment and complete horizontal alignment. A vibration of a directional oscillator can always be seen as a superposition of a horizontal and a vertical vibration. In the case of such a directional oscillator, the vertical vibration amplitude always corresponds to that part of the vibration which is oriented in the vertical direction. By reducing the vertical vibration amplitude it is achieved according to the invention that a lower compaction power is applied to the ground. This prevents compaction errors, since too much selective compaction is ruled out if the IPF value is too large or too small. In the case of a directional oscillator in particular, this also leads to the fact that it can continue to be operated at a constant frequency, as a result of which the vibration frequency is reduced and the drive must then be started again Excitation device is not required. This has advantages both with regard to the drive motor, which can thereby be operated more precisely in the optimal power range, and with regard to comfort for an operator.

The method according to the invention is carried out, for example, by a control unit of the soil compaction machine. The control unit can either be designed as a separate control unit or can be integrated, for example, in an on-board computer of the soil compaction machine. In particular, the method is carried out automatically by the control unit without an operator having to enter further control commands. However, the control unit can be designed, for example, to switch the method according to the invention on and off. Either the control unit itself or the on-board computer of the soil compaction machine therefore has a control element by means of which the method can be switched on or off. This control element can be both a switch and only part of a digital or virtual user interface. The control unit can also include a display device which, for example, displays to an operator the current IPF value and / or the steps currently taken by the control unit as part of the method. This display device can also be implemented, for example, on a screen of the on-board computer.

In principle, the vertical vibration amplitude can be reduced with any excitation device capable of this. For example, excitation devices can be used which have different discrete stages with different vibration frequencies. These levels can then be used if the corresponding limit values are fallen short of or exceeded. However, it is particularly advantageous and therefore preferred that the vertical vibration amplitude is reduced continuously. This is the case, for example, with an excitation device such as that used by the applicant's “BOMAG Asphalt Manager”. The present invention can be used particularly flexibly with such an excitation device. For example, an optimum range between a maximum IPF value and a minimum IPF value can be set here as limit values for the IPF value, in which the method does not yet reduce the vertical vibration amplitude. If these limit values are exceeded or undershot, a sharp reduction in the vertical vibration amplitude does not have to be carried out abruptly, but instead, for example, the vertical vibration amplitude can be reduced, the amount by which the vibration amplitude is reduced being proportional to the overshoot or undershoot of the limit value by the current measured IPF value. In this way, the method adjusts the compaction performance by the vibration of the compaction bandage in a particularly flexible manner to the respective operating situation of the soil compaction machine.

It has been shown that an optimal compression, in which no reduction in the vertical vibration amplitude is necessary, for example in a range of 30-55 Vibrations per meter, preferred 35-50 Vibration shocks per meter and very particularly preferred by 40-45 Vibration shocks can occur per meter. Another preferred area is also 30-42 Vibrations per meter. These values are therefore preferred, in particular also in pairs, as indicated, for the minimum and the maximum limit value of the IPF value. Preferred values for the minimum limit are therefore 25th , 30th , 35 or 40 Vibrations per meter and for the maximum limit 55 , 50 , 45 or 40 Vibrations per meter. If the maximum limit value is exceeded or the minimum limit value is undershot, the vertical vibration amplitude is reduced according to the invention. The maximum limit is in the present application as IPF _max , the minimum limit as IPF _min designated.

In extreme cases, the vertical vibration amplitude can be reduced until the vertical vibration amplitude completely disappears. In particular, it is preferred that the vertical vibration amplitude is reduced to zero when a critical limit value for the number of vibration shocks per distance traveled is exceeded or undershot. In the present case, the critical limit is also called IPF _end designated. Since the invention provides that the vertical vibration amplitude is reduced both when the current IPF value is too low and when the current IPF value is too high, there is both a low critical limit value, below which the vertical vibration amplitude is reduced to zero also a high critical limit value, if exceeded, the vertical vibration amplitude is reduced to zero. The low critical limit is, for example 30th , prefers 25th , particularly preferred 20th , Vibration shocks per meter. The high critical limit is, for example 55 , prefers 60 , particularly preferred 65 , Vibration shocks per meter. A particularly preferred embodiment of the present invention provides that reducing the vertical vibration amplitude between the maximum limit IPF _max and the high critical limit and / or between the minimum limit IPF _min and the low critical limit is linear between the maximum possible vertical vibration amplitude that can be set on the excitation device and a vertical vibration amplitude of zero. Another The advantage of reducing the vertical vibration amplitude to zero is that the invention then implements an automatic shutdown in which, for example, when the machine stops and is at a standstill, the vertical vibration amplitude is automatically set to zero, that is to say completely switched off. In this way, an operator can easily bring the machine to a standstill while driving and does not have to remember to switch off the vibration in order not to compact any dents in the ground. This effect also occurs in the case of reversing runs which frequently occur in the working operation of the soil compaction machines, in which the operator does not have to constantly switch the excitation device on and off as a result of the invention. This increases the ease of use of the soil compaction machine.

During the operation of the soil compacting machine, power peaks occur, for example when starting up the machine and when, for example, slopes or embankments are driven up. If, due to such an operating situation, more power is suddenly required from the soil compaction machine, it often happens that the driving speed and / or the vibration frequency have to be changed, in particular reduced, in order to meet the power requirement. In these situations, the method according to the invention can considerably simplify the control of the soil compaction machine. It is therefore preferred that the changing of the driving speed and / or the vibration frequency takes place due to an increased requested performance of the soil compacting machine. Particularly in the case of these changes, which are sometimes difficult to predict by the operator, it is particularly practical if, in case of doubt, the method automatically reduces the vertical vibration amplitude without the operator having to take any action. In this way, compaction errors can be avoided efficiently.

As already explained at the beginning, the problem of occurring power peaks and the resulting excessive overloading of the drive motor is problematic, in particular in hybrid systems. It is precisely these systems which therefore benefit particularly greatly from the present invention, which ensures that no compression errors occur even when power peaks occur and the machine's reactions to a change in the driving speed and / or the vibration frequency. In a preferred embodiment, the soil compaction machine is thus designed as a hybrid, in particular an electrical or hydraulic hybrid. In particular, the soil compacting machine comprises an intermediate store, and additional power is released by the intermediate store before the change in driving speed and / or the vibration frequency when the required power of the soil compacting machine is increased. The intermediate store can be, for example, an electrical store, such as a rechargeable battery, or a hydraulic store, for example a pressure store. The release of additional power therefore takes place either by the release of additional electrical energy or, for example, by the release of hydraulic fluid which is received in the intermediate store and is under pressure. In this way, power peaks that typically occur in hybrid systems are to be bridged.

However, the energy stored in the buffer store is often not sufficient to completely bridge the peak power. For example, the uphill journey takes longer than it can be maintained by the drive motor and the buffer under the current operating parameters. In order to fully exploit the entire potential of the hybrid system, it is preferred in this case that the driving speed and / or the vibration frequency are only changed after the energy stored in the intermediate store has been completely used up, if there is still an increased requested output of the soil compacting machine. In this way, the method only then reduces the vertical vibration amplitude, so that it is possible to work longer with a high vertical vibration amplitude and thus high compression performance. In this way, the method according to the invention is particularly efficient, particularly in interaction with a hybrid system.

In a preferred embodiment of the invention, it is also provided that the state of charge of the intermediate store is also used to control the method. The state of charge of the buffer store is therefore detected by means of a suitable sensor. On the basis of the state of charge, a decision is then made, for example by the control unit, as to whether a peak power can be bridged by using the energy stored in the intermediate store or whether a reduction in the vertical vibration amplitude is necessary immediately. In particular, the transition from releasing additional power or energy from the intermediate store to reducing the vertical vibration amplitude can be controlled by the control unit on the basis of the measured state of charge of the intermediate store. Regardless of the state of charge of the buffer, the necessary measure is always taken to avoid compression errors.

In principle, the method can be used in such a way that only and only one Reducing the vertical vibration amplitude is done. In other words, the vertical vibration amplitude can only be increased by the operator himself, for example using a control command. This can serve as an additional safety measure, so that it is not suddenly compacted again without the operator's will. In order to further relieve the operator, however, it is alternatively preferred that the vertical vibration amplitude be increased when the at least one limit value is again exceeded or undershot. If, for example, the currently measured IPF value is again above the minimum critical limit value or below the maximum critical limit value, the vertical vibration amplitude can be increased again from zero. The continuous adjustment of the vertical vibration amplitude between the critical limit values and the maximum or minimum limit value can be carried out essentially the other way around as the reduction already described above. In this way, the compaction performance currently applied to the soil is always adapted to the current operating situation without an operator having to intervene.

In particular, the potential of the machine is best exploited if maximum compression is carried out in the optimal range between the maximum and the minimum limit value. This means, in particular, that the vertical vibration amplitude is adjusted to its maximum value when the number of vibrations per distance traveled is within a predetermined optimal range, in particular between the limit values IPF _max and IPF _min , is located. If the soil compaction machine is in the desired optimal range, this condition is also used for maximum compaction performance.

The method according to the invention reduces the vertical vibration amplitude which is caused by the excitation device on the compaction drum. This reduction typically also reduces the power consumption of the excitation device. If, for example, only a horizontal vibrator is excited by a directional oscillator, the power consumption of the excitation device can decrease by half compared to the case in which only vertical vibrations are excited. In this way, additional power is released in the drive train of the soil compacting machine, which can then be used for other purposes. In a preferred embodiment it is provided, for example, that the power saved by reducing the vertical vibration amplitude is used to increase the driving speed and / or the vibration frequency. In this way, a slowdown of the soil compaction machine and / or a reduction in the vibration frequency can be at least partially counteracted. Overall, the speed of the soil compaction machine is reduced less strongly, for example, which in turn makes the work operation more efficient.

Here too, however, the particular efficiency of the invention when used with a hybrid system is again evident. A particularly preferred embodiment provides that the power saved by reducing the vertical vibration amplitude is used to charge the buffer store. In particular in the case of a long-lasting peak in power, in which the energy stored in the intermediate store has already been used up, the intermediate store is correspondingly empty. If the vertical vibration amplitude then has to be reduced as a result of a change in the driving speed and / or the vibration frequency on the basis of the current IPF value then measured, the power released can at least be used to charge the buffer store. In this way, a charged buffer is available again at the next peak performance, so that the efficiency of the hybrid system increases.

Starting and braking the excitation device in particular can be disruptive in the working operation of the soil compacting machine. It is therefore preferred that the vibration frequency of the vibration of the at least one compression bandage is kept substantially constant. In particular, this is kept constant. Essentially, in the present case means that there may be operational fluctuations, but no externally induced or controlled changes to the vibration frequency are made. In this way, the excitation device can always be driven in the same way and, for example, it does not have to be coupled when reversing. Of course, at the same time, this means that the driving speed is reduced in order to bridge these during peak loads. In the method according to the invention, therefore, preferably only the driving speed is changed and the vibration frequency is kept constant. Alternatively, it is also possible to change the vibration frequency and in particular the vibration frequency and the driving speed. The vibration frequency can also be reduced in order to bridge a power peak. However, care must be taken to ensure that the vibration frequency is not reduced to the resonance frequency of the drum, so that the machine is not damaged. Even if the vibration frequency changes, it is therefore preferred that it is changed only in such a way that the excitation device is operated in a supercritical manner in working mode. In particular, it is preferred to reduce the vibration frequency when the vertical Vibration amplitude is essentially zero, that is, for example, the vibration is only aligned horizontally. In this case, reducing the vibration frequency can also reduce wear. In this case, the damage otherwise to be feared for the work result is also less. By changing the vibration frequency and / or the driving speed, the control unit can regulate and control compliance with the optimal IPF value in a particularly flexible manner.

In addition, the present invention also makes it possible to always operate the drive motor as close as possible to its optimal power point, since a possibility is given to overcome load peaks without changing a power output by the drive motor. It is therefore preferred that an output or the speed of a drive motor of the soil compacting machine is kept substantially constant. In particular, the power output or the speed is kept constant. Here, too, essentially means that, although operational fluctuations are possible, for example, no externally induced or controlled changes in the power output or the speed are carried out. Such optimal operation of the drive engine extends its service life and at the same time reduces fuel consumption.

The above-mentioned object is also achieved by a soil compaction machine with a control unit which is designed to carry out and / or carry out the method according to the invention. The method according to the invention is therefore used to control the floor milling machine, which is designed for this use and comprises at least one control unit which is able to carry out the method. All of the features, effects and advantages described above for the method apply in the figurative sense to the soil compaction machine according to the invention. At the same time, all of the features, effects and advantages described for the soil compaction machine apply equally to the method according to the invention. It is therefore only to avoid repetition that reference is made to the other statements.

The soil compaction machine comprises in particular a machine frame, a drive motor, at least one compaction drum, an excitation device for exciting a vibration on the compaction drum with a vibration frequency, as well as a frequency sensor for measuring the vibration frequency and a route sensor for measuring the distance traveled. The frequency sensor and the route sensor are connected to the control unit and, in particular continuously, supply the latter with corresponding measured values of the vibration frequency and the distance traveled. These are used by the control unit when carrying out the method.

As has also already been explained above, the soil compaction machine is very particularly preferably designed as a hybrid, in particular a hydraulic hybrid, with an intermediate store. The present invention is particularly advantageous in the case of such a hybrid system.

• 1: eine Seitenansicht einer Tandemwalze;
• 2: eine Seitenansicht eines Walzenzuges;
• 3: ein Schema des Antriebs und der Steuereinheit einer Bodenverdichtungsmaschine;
• 4: den zeitlichen Ablauf des Verfahrens bei stufenweiser Erhöhung der Fahrgeschwindigkeit;
• 5: den zeitlichen Ablauf des Verfahrens bei stufenweiser Verringerung der Fahrgeschwindigkeit;
• 6: den zeitlichen Ablauf des Verfahrens beim Einsatz eines Hybridsystems; und
• 7: ein Ablaufdiagramm des Verfahrens.

The invention is explained in more detail below on the basis of the exemplary embodiments shown in the figures. They show schematically:

• 1 : a side view of a tandem roller;
• 2nd : a side view of a single drum roller;
• 3rd : a diagram of the drive and the control unit of a soil compacting machine;
• 4th : the chronological sequence of the procedure with a gradual increase in driving speed;
• 5 : the timing of the procedure with a gradual reduction in driving speed;
• 6 : the timing of the procedure when using a hybrid system; and
• 7 : a flow chart of the process.

The same or equivalent components are denoted in the figures with the same reference numerals. Repeating components are not identified separately in each figure.

The 1 and 2nd show generic and soil compaction machines according to the invention 1 . The soil compaction machine 1 of the 1 is the tandem roller, the one 2nd trained as a single drum roller. The soil compaction machines 1 include a driver's cab 2nd and a machine frame 3rd , as well as a drive motor 4th , which is typically a diesel internal combustion engine. The drive motor 4th among other things drives a chassis that has at least one via a drum holder 6 on the machine frame 3rd attached compaction bandage 5 includes. In the case of the tandem roller 1 has a compression bandage on both the front and rear 5 on. The single drum roller according to 2nd has a front compression bandage 5 and includes two wheels on its rear chassis axle 7 . In operation of the soil compaction machine 1 this is over the soil to be compacted 8th driven, for example in the forward direction a. Of course, it is also possible to compress against the forward direction a, i.e. backwards. In at least one of the Compaction bandages 5 of soil compaction machines 1 an excitation device is arranged, which the respective compression bandage 5 vibrated, especially vibrations. In this way the compaction performance is increased. At the respective vibration frequency of the compaction drum 5 the soil compaction machines have to measure 1 Frequency sensors 33 on, in particular a frequency sensor 33 per compaction bandage 5 . In addition, the soil compaction machines 1 able to detect which distance they have covered. For this they have a route sensor 34 on. This can either determine the route from the vehicle speed or, for example, as a rotation sensor on the wheels 7 or the compaction bandages 5 be trained. In addition, the soil compaction machines include 1 a control unit 15 that with the frequency sensor 33 and the route sensor 34 connected is. The control unit 15 is designed to carry out the method according to the invention or carries it out. In particular, the method according to the invention is used for each compression bandage 5 individually or alternatively for all compaction drums 5 a soil compaction machine 1 executed together.

3rd shows schematically the drive of the soil compaction machine 1 and their interconnection with the control unit 15 . On the drive motor 4th are a driving pump 9 and a vibration pump 10th arranged. Both are powered by the engine 4th driven. The driving pumps 9 is with a hydraulic lines 19th with the traction motor 11 connected to the at least one wheel 7 or at least a compaction bandage 5 the soil compaction machine 1 drives. The vibration pump 10th is also via a hydraulic lines 19th with a vibration motor 12th connected via a mechanical coupling 20th the excitation device 13 energized so that the excitation device 13 the compaction bandage in work mode 5 vibrated. At the excitation device 13 is also via a mechanical coupling 20th an amplitude control 14 provided, via which the vibration amplitude, in particular the vertical vibration amplitude of the compression bandage 5 by the excitation device 13 is caused, is adjustable. According to a particularly preferred embodiment, the soil compaction machine is 1 designed as a hybrid system. For this purpose, it is provided that the drive motor 4th also a pump / motor unit 16 is arranged via hydraulic lines 19th with a loading / unloading valve 17th and over this with a buffer 18th , for example a hydraulic pressure accumulator, is connected. Is in the drive train of the soil compaction machine 1 Excess power available, so the pump / motor unit works 16 as a pump and loads the buffer 18th via the loading / unloading valve 17th . In the event of power peaks, the power output of the drive motor 4th can exceed, however, in the buffer 18th stored energy via the charge / discharge valve 17th are delivered so that the pump / motor unit 16 works as a motor and initiates additional power, for example in the form of a torque, into the drive train. Power peaks can be bridged as long as those in the buffer 18th stored energy is sufficient.

3rd also shows the control unit 15 and their connection to the frequency sensor 33 and to the route sensor 34 . In addition, the control unit 15 with control lines 21 however also connected to other components of the drive. The control lines 21 In the present case there are, for example, electrical lines via which both control commands and recorded measured values can be transported. The control unit 15 is designed, for example, in particular for the vibration frequency of the excitation unit 13 , for example via the frequency sensor 33 , and the distance traveled, for example via the route sensor 34 , to eat. In addition, the control unit 15 trained to control the amplitude 14 to be controlled in such a way that, according to the method, the vertical vibration amplitude is reduced or increased as a function of the measured or calculated current IPF value.

4th shows the system and its reaction over time with a gradual increase in driving speed v . The abscissa of all the diagrams indicated indicated the time t. The diagrams are arranged in such a way that the individual marked times along the abscissa coincide in all diagrams. This also applies to the 5 and 6 . At the beginning of the 4th shown procedure, in the diagram to the left of the time t ₁ , the soil compaction machine is located 1 in normal working mode and runs at a constant driving speed v over the soil to be compacted 8th . The excitation device 13 excites a vibration on the compaction drum 5 whose vibration frequency f will remain essentially constant throughout the process. The peak power is therefore compensated for in the exemplary embodiments shown by adapting the driving speed v as described below. Alternatively, however, the vibration frequency could also be used f , either alone or together with the driving speed v , to be changed. At the time t ₁ accelerates the operator of the soil compaction machine 1 . The driving speed v increases until a constant, increased driving speed v was achieved. Because of the vibration frequency f remains constant and the driving speed v elevated the number of vibrations per distance traveled, i.e. the IPF value (see diagram below). However, the IPF value remains above a minimum limit IPF _min , so that, as shown in the diagram above, the vertical vibration amplitude A also remains constant, for example at its maximum at the excitation device 13 adjustable value. At the time t ₂ the operator accelerates the soil compaction machine 1 continue. This time the driving speed increases v such that due to the constant vibration frequency f the IPF value below the specified minimum limit IPF _min sinks. This is happening at the time t ₃ . The control unit that takes the IPF value from the vehicle speed v and the vibration frequency f calculated, noticed that the IPF value the minimum limit IPF _min has fallen below and therefore leads at the time t ₃ reducing the vertical vibration amplitude A as shown in the top diagram. The change in the vertical vibration amplitude A is therefore carried out (in all the exemplary embodiments shown in the figures) as a function of the IPF value by the control unit. The change in the vertical vibration amplitude A is therefore slightly shifted in time to change the IPF value and occurs later because of the vertical vibration amplitude A is regulated or controlled depending on the IPF value. The soil compaction machine 1 by the operator until this point t ₄ accelerated further until a constant driving speed v is reached. Reducing the vertical vibration amplitude A by the control unit 15 is therefore also up to date t ₄ continued, in which the IPF value also no longer changes. Between the times t ₄ and t ₅ becomes the floor sealing machine 1 or the excitation device 13 with a reduced vertical vibration amplitude A operated. This remains essentially constant between these two times. At the time t ₅ becomes the soil compaction machine 1 however accelerated again. This time the acceleration goes so far that at the time t ₆ the IPF value below the critical limit IPF _end falls off. Up to this point, the control unit 15 continuously the vertical vibration amplitude A reduced in proportion to the drop in the IPF value. The method according to the invention is now either designed so that when the critical limit value is reached IPF _end the vertical vibration amplitude of the A is just zero, or the inventive method is designed so that the control unit 15 the vertical vibration amplitude A via the amplitude control for 10th when the critical limit is reached IPF _end zero, no matter what the previous value of the vertical vibration amplitude A was. In the exemplary embodiment shown, the vertical vibration amplitude is reached A even if the IPF value is the critical limit, in this case the low critical limit IPF _end , falls below. Only at the time t ₇ becomes the driving speed v the soil compaction machine 1 reduced again by the operator so that the IPF value at the time t ₈ again over the critical limit IPF _end increases. From this point on, the vertical vibration amplitude A increased again, from zero in the exemplary embodiment shown. Between the times t ₆ and t ₈ becomes the excitation device 13 with a constant vibration frequency f but with vertical vibration amplitude A operated zero. For example, the excitation device generates 13 during this time only horizontal vibrations. The increase in the vertical vibration amplitude A corresponds proportionally to the increase in the IPF value up to the point in time t ₉ the soil compaction machine 1 was slowed down in such a way that the IPF value again exceeded the minimum limit IPF _min increases. From this point on, the vertical vibration amplitude A increased until it returns to its maximum value from the beginning of the process shown. The soil compaction machine 1 is in optimum operating condition and brings the maximum compaction performance to the soil to be compacted 8th on.

5 shows the course of a similar situation as 4th , where in 5 the case of a gradual reduction in driving speed v is shown. Such a reduction in driving comfort v can occur, for example, in order to achieve peak performance of the soil compaction machine 1 to bridge, for example if it has to drive up a slope. In a figurative sense, the above statements apply to 4th also for the 5 , which is why only the differences are discussed. At the time t ₁ becomes the soil compaction machine 1 according to 5 slowed down. The driving speed v remains so high, however, that the IPF value increases, but still below the maximum limit IPF _max remains. For this reason there is also the slowed down compaction machine 1 still in the optimal range, so the vertical vibration amplitude A remains constant. Only through that at the time t ₂ further slowdown then occurs at the time t ₃ the maximum limit IPF _max of the IPF value is exceeded, so that here too the vertical vibration amplitude is reduced A by the control unit 15 is initiated. It also follows here between the times t ₄ and t ₅ an operation of the soil compaction machine 1 with constant, reduced vertical vibration amplitude A , because the currently calculated IPF value is between the maximum limit IPF _max and the critical limit IPF _end , especially the high critical limit. By further reducing the driving speed v from the time t ₅ The IPF value then finally rises at the time t ₆ over the critical limit IPF _end addition, causing the vertical vibration amplitude A is zeroed. This also avoids compaction errors. From the time t ₇ becomes the soil compaction machine 1 accelerated again, so at the time t ₈ the critical limit IPF _end undershot and from the time t ₉ also the maximum limit IPF _max is undercut. From falling below the critical limit IPF _end becomes the vertical vibration amplitude A again increased in proportion to the increase in the IPF value. From falling below the maximum limit IPF _max represents the control unit 15 then the maximum vertical vibration amplitude again A on. The compaction in the optimal operating condition of the soil compaction machine 1 can then continue.

In 6 the particularly advantageous integration of the method according to the invention in a hybrid system is illustrated. The top four diagrams correspond to those of the 4th and 5 , and show the vertical vibration amplitude A , the vibration frequency f , the driving speed v and the IPF value. In particular, the sequence shown corresponds to the case with a reduction in the driving speed v according to 5 , although the process is simplified. At the beginning of the 6 shown procedure is the soil compaction machine 1 in normal work, it runs at a constant speed v and compacted the soil 8th with a constant vibration frequency f . As shown in the bottom diagram, the drive motor 4th with constant power output E or operated at constant speed. The one for the entire operation of the soil compaction machine 1 necessary performance, that is, the requested performance L at this time is lower than that of the drive motor 4th achieved output E . At the time t ₁ the requested performance increases L the soil compaction machine 1 on. The reason for this can be, for example, that the soil compaction machine 1 must compress uphill. As long as the requested service L under the power output generated by the drive motor E remains, nothing happens for the time being. At the time t ₂ however, the requested performance exceeds L the power output E of the drive motor 4th . At this point, the hybrid system of the soil compacting machine is starting 1 noticeable. Specifically, the cache is there 18th free additional energy or power and feed this into the drive train of the soil compacting machine 1 on. The power output H the cache 18th rises. Through the additional power output H from the cache 18th can the increased power requirement of the soil compaction machine 1 be covered. For this reason, the soil compactor 1 continue their work unimpeded. At the time t ₃ however, the energy reserves of the buffer store are approaching 18th their end and the power delivery H from the cache 18th subsides. From this point in time, the required performance of the soil compaction machine 1 no longer through the combination of the drive motor E and the cache 18th be covered. In order to maintain work, the power required must be reduced elsewhere. According to the invention, this is preferably done at the driving speed v that from the time t ₃ is reduced in order to absorb the increased power requirement. Because the vibration frequency f remains constant, increases as the driving speed decreases v also the IPF value. As previously related to 5 explained, the IPF value exceeds at the time t ₄ the maximum limit IPF _max , so that from this point on the control unit 15 reducing the vertical vibration amplitude A is carried out by the time t ₄ was kept constant. The driving speed v is reduced until the available power for the operation of the soil compacting machine 1 is sufficient. At the time t ₅ this is achieved so the driving speed v can be kept constant from here. The increase in the IPF value therefore also ends at the time t ₅ so that also reducing the vertical vibration amplitude A at the time t ₅ is stopped. The vertical vibration amplitude A can now remain constant. Later, the increased power requirements decrease again, for example because of the floor exposure machine 1 from an embankment to a level, so at the time t ₆ the requested service L again under that of the drive motor 4th delivered power E falls. At this point, the driving speed can then v be increased again, which leads to a decrease in the IPF value and an associated increase in the vertical vibration amplitude A , as already described, leads.

6 shows another advantage of the method. As already explained above, the excitation device takes 13 less power when the vertical vibration amplitude A is reduced. The power available can be used elsewhere on the soil compacting machine 1 be used. So are in 6 two different options are shown as examples. On the one hand, the power released can be used to drive speed v the soil compaction machine 1 reduce less. This is indicated by the dashed line in the driving speed diagram v shown. The dashed curve shows the course of the driving speed v if that by reducing the vertical vibration amplitude A released power is used to achieve a higher driving speed v maintain. The solid line, on the other hand, shows the case in which the additional power is not in the driving speed v is invested. By using the by reducing the vertical vibration amplitude A released performance can therefore a higher driving speed v can be set so that the compression process as a whole becomes more efficient. As an alternative to this, however, it is also possible to reduce the vertical vibration amplitude A free performance to use the cache 18th to load. This is shown in the diagram of the power output H from the cache 18th also indicated by the dashed line. The dashed line illustrates a loading process of the buffer 18th , since the dashed line below the zero line of the power output running parallel to the time axis H runs. The negative power output shown corresponds to a charging process. The loading process of the cache 18th takes place over the entire period in which the vertical vibration amplitude A is reduced because of the excitation device over this entire period 13 less power is required and the excess power is therefore used to load the cache 18th is available. In this way, the cache 18th directly after the energy stored in it has been completely used up, at least partially recharged, so that at the next peak power, an at least partially charged intermediate store is again again 18th is available.

7 shows an exemplary flow chart of the method according to the invention 22 . The procedure 22 includes excitation 23 a vibration on a compaction drum 5 through the excitation device 13 and moving 24th the soil compaction machine 1 across the floor 8th . If the soil compactor 1 is designed as a hybrid system, can be used to bridge a peak power in the crotch 22 Power or energy from an intermediate store 18th be released. For various reasons, there can be a change in work 28 the driving speed v and / or the vibration frequency f come, for example when the energy in the buffer 18th not for completely bridging the increased power requirements of the soil compaction machine 1 is sufficient. Because of a change 28 the driving speed v and / or the vibration frequency f the current IPF value of the soil compaction machine also changes 1 who in the crotch 25th is determined and monitored. The determined IPF value is then in the step 26 with predetermined limit values IPF _max , IPF _min , IPF _end compared. If the measured IPF value lies in an optimal range between the minimum limit value IPF _min and the maximum limit IPF _max , so nothing happens and the work continues uninterrupted. On the other hand, the measured IPF value is below the minimum limit IPF _min or above the maximum limit IPF _max , a reduction follows in the first case 27 the vertical vibration amplitude A and in the second case an increase 29 the vertical vibration amplitude A . In the case of increasing the vertical vibration amplitude A the process begins 22 again from the beginning. In contrast, is in the step 27 the vertical vibration amplitude A reduced, the power consumption of the excitation device goes 13 back and due to the reduced power requirement, excess energy is available, for example in the step 30th can be used to drive speed v and / or the vibration frequency f increase or at least buffer their reduction. Alternatively, it is also possible to save the energy saved in the step 31 for charging the cache 18th to use. All in all, the present invention succeeds in the occurrence of compaction errors in the working operation of the soil compaction machine 1 prevent efficiently. At the same time, almost no operator attention is required, which makes the soil compacting machine easier to use 1 is increased. These advantages are particularly apparent when used with a hybrid system.

QUOTES INCLUDE IN THE DESCRIPTION

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Patent literature cited

• EP 2172279 A1 [0003]

Claims (15)

Method (22) for controlling a soil compaction machine (1), in particular for avoiding compaction errors, comprising the steps: a) excitation (23) of a vibration with a vibration frequency (f) in at least one compaction bandage (5) by means of an excitation device (13), b) moving (24) of the soil compacting machine (1) over a soil (8) to be compacted at a driving speed (v), and c) changing (28) the driving speed (v) and / or the vibration frequency (f), characterized by the d) determining and monitoring (25) the number of vibrations per travel distance (IPF) from the vehicle speed (v) and the vibration frequency (f), e) comparing (26) the determined number of vibrations per travel distance (IPF) with predetermined ones Limit values (IPF _max , IPF _min , IPF _end ) and f) At _least reduce (27) the vertical vibration amplitude (A) of the compression bandage (5) if the pressure falls below and / or falls below one of the limit values (IPF _max , IPF _min , IP-F _end ). Method (22) according to Claim 1 , characterized in that the reduction (27) of the vertical vibration amplitude (A) is carried out continuously. Method (22) according to one of the preceding claims, characterized in that the vertical vibration amplitude (A) is reduced to zero when a critical limit value (IPF _end ) of the number of vibration shocks per distance traveled (IPF) is exceeded or undershot. Method (22) according to one of the preceding claims, characterized in that the changing (28) of the driving speed (v) and / or the vibration frequency (f) takes place on the basis of an increased requested power (L) of the soil compacting machine (1). Method (22) according to one of the preceding claims, characterized in that the soil compaction machine (1) comprises an intermediate store (18) and before the change (28) the driving speed (v) and / or the vibration frequency (f) at an increased requested power (L) the soil compaction machine (1) releases (18) additional power through the intermediate store (18). Method (22) according to Claim 5 , thereby I net that only after the complete consumption of the energy stored in the buffer (18) the change (28) of the driving speed (v) and / or the vibration frequency (f) takes place, if an increased requested power (L) continues Soil compaction machine (1) is present. Method (22) according to one of the preceding claims, characterized in that the vertical vibration amplitude (A) is increased (29) when the at least one limit value (IPF _max , IPF _min , IPF _end ) is again exceeded or undershot. Method (22) according to one of the preceding claims, characterized in that the vertical vibration amplitude (A) is adjusted to its maximum value when the number of vibrations per distance traveled (IPF) is within a predetermined optimal range, in particular between the limit values (IPF _max , IPF _min ). Method (22) according to one of the preceding claims, characterized in that the power saved by reducing (27) the vertical vibration amplitude (A) is used to increase (30) the driving speed (v) and / or the vibration frequency (f) . Method (22) according to one of the preceding claims, characterized in that the power saved by reducing (27) the vertical vibration amplitude (A) is used for charging (31) the intermediate store (18). Method (22) according to one of the preceding claims, characterized in that the vibration frequency (f) of the vibration of the at least one compression bandage (5) is kept substantially constant. Method (22) according to one of the preceding claims, characterized in that a power output (E) of a drive motor (4) of the soil compacting machine (1) is kept substantially constant. Soil compacting machine (1) with a control unit (15) which is designed to carry out the method (22) according to one of the preceding claims and / or carries it out. Soil compaction machine (1) Claim 13 , with a machine frame (3), a drive motor (4), at least one compression bandage (5), an excitation device (13) for exciting a vibration on the compression bandage (5) with a vibration frequency (f), a frequency sensor (33) for measurement the vibration frequency (f) and a route sensor (34) for measuring the distance traveled. Soil compacting machine (1) according to one of the Claims 13 or 14 that as a hybrid, in particular hydraulic hybrid, with an intermediate store (18).

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