EP2862979B1 - Method and device for determining a dimension representing a contact state of a compressor roller with a base to be compacted - Google Patents

Description

The present invention relates to a device and to a method for determining a contact state of a compactor roller with a base to be compacted representing a rump.

For the compaction of underground, for example, soil, different types of rock or asphalt in road construction, are generally, as in the WO 2013/087783 A1 shown, self-propelled soil compactors used with one or more compressor rollers run over the substrate to be compacted and lead by pressure loading, possibly in conjunction with oscillatory or vibratory movements to compaction of the building material of the substrate to be compacted. Due to the pressure load exerted on the substrate, a compacting roller which is generally much stiffer in comparison with the substrate to be compacted will generally produce a settling depression in the substrate to be compacted. The stiffer or already more compacted such substrate is, the less deep the compressor roller will use in the building material of the substrate, with the result that decreases with increasing rigidity or increasing the degree of compacting a contact width of the compactor roller on the substrate to be compacted ,

It is the object of the present invention to provide an apparatus and a method for determining a contact state of a compacting roller with compacting surface to be compacted Aufstandsgröße which allow a simple and reliable way to draw conclusions about the compression state of the building material of the substrate to be compacted.

According to a first aspect of the present invention, this object is achieved solved by a device for determining a contact state between a compacting roller and a compacting subsurface representing Aufstandsgröße, comprising at least one detection peripheral region of a compacting roller rotational axis rotatable compressor roller at least one contact signal generating a contact sensor, wherein the contact signal is a contact start and a contact end of a detection scope with the compacted underground.

By means of the device constructed according to the invention, information is provided which, for example, based on a complete revolution of the compressor roller, in association with a detection circumferential region, represents that portion in which a detection peripheral region is in contact with the substrate to be compacted. The greater this proportion, ie the greater the distance between contact start and contact end, the greater the extent of contact between the compactor roller and the substrate to be compacted, which indicates that the compactor roller penetrates comparatively deep into the material of the substrate to be compacted and this Therefore, it is relatively compact. With increasing degree of compaction, the compactor roller penetrates less deeply into the building material of the substrate to be compacted, which means that, relative to an entire revolution or the entire circumference of the compactor roller, that portion in which contact with the substrate to be compacted decreases. The contact patch to be determined with the device according to the invention therefore permits a conclusion as to the degree of compaction of the substrate to be compacted and can thus be used to define further compaction or machining measures on the substrate to be compacted.

In order to be able to determine the contact patch more precisely or more often during the compressor roller movement with the device according to the invention, it is proposed that a plurality of detection peripheral areas each having at least one contact sensor distributed around the roller axis of the compressor preferably in the same axial area of the compactor roller is provided. It is particularly advantageous if the detection peripheral areas are arranged with substantially the same circumferential distance, preferably about 90 ° to each other. By a uniform spacing of the detection perimeter areas, a periodic detection pattern of the various detection perimeter areas can be provided with a defined time offset and used for the evaluation.

• akustischer Sensor, vorzugsweise Ultraschallsensor oder Pfeifensensor, oder
• Tastsensor, oder
• Drucksensor.

Impairment of contact sensors during the compression operation can be avoided by providing at least one contact sensor on an inner side of a roller shell of the compressor roller in at least one, preferably each detection peripheral region. For example, such a contact sensor may be formed as:

• acoustic sensor, preferably ultrasonic sensor or whistle sensor, or
• Pushbutton sensor, or
• Pressure sensor.

These are sensors which, with a comparatively simple structure, reliably permit a conclusion as to whether or not the region in which a respective contact sensor is positioned, that is to say a respective detection peripheral region, is in contact with the substrate to be compacted.

In order to be able to provide a more detailed evaluation of a signal supplied by a contact sensor, it is further proposed that a rotational positioning detection arrangement for detecting a rotational positioning of the compressor roller is provided. The provision of information about the rotational positioning of the compressor roller in relation to the output from a respective contact sensor contact signal can be used in a particularly advantageous manner, information about an asymmetric contact behavior of the compactor roller with the substrate to be compacted, in particular the emergence of a by the Voranbewegung In general, the compressor roller generated generated bow wave in the underground to be compacted.

For this purpose, it can be provided, for example, that the rotational positioning detection arrangement comprises at least one contact sensor and at least one rotation positioning reference region which is in detection interaction with the at least one contact sensor and can not rotate with the compressor roller about the compressor roller rotational axis.

Since the present invention utilizes the rotation of the compacting roller about its compressor roller axis of rotation to determine information on contacting or terminating the contact of a respective detection perimeter area in the course of such rotational movement, according to a particularly advantageous variant, the pedestal size can be combined with the substrate to be compacted Contact represent standing peripheral portion of the compressor roller. This peripheral region can be represented by a length dimension, that is, for example, circumferential length region, or an angular segment.

According to a further aspect of the present invention, the above object is achieved by a method for determining a contact patch representing a contact state of a compacting roller with a substrate to be compacted, preferably by means of a device constructed according to the invention, comprising detecting a contact between at least one detection peripheral region of the compactor roller and to be compacted Subsurface during rotation of the compactor roll around a compactor roll axis of rotation.

Also in this method according to the invention is advantageously the contact between a compactor roller and the substrate to be compacted or contact size representing this contact based on the occurring during the rotation of the compactor contact between at least one detection range and the scope compacting ground and the contact end. In the period between the contact start and the contact end, a respective detection peripheral area is in contact with the substrate to be compacted, while after the contact end until the next contact start, the detection peripheral area is not in contact with the substrate to be compacted.

In order to be able to determine a geometrical variable representing the contact state in a simple manner based on the start of contact and the end of contact or time, it is proposed that the contact patch be further determined based on a speed of movement of the compactor roller and / or a radius of the compactor roller ,

In a variant of the method according to the invention which is functional in particular also with only a single contact sensor, it is possible for the contact patch size to be based on a ratio between a first movement duration indicative of contact of at least one detection scope with the substrate to be compacted and a second movement duration indicative of no contact Rotation of the compressor roller to the compressor roller axis of rotation or / and a one revolution of the compressor roller indicating second movement time is determined. In this procedure, therefore, that duration during which a respective detection peripheral area moves in contact with the substrate to be compacted is set in relation to the time period in which such a contact does not exist or at the time of one complete revolution of the compactor roller. Both possibilities lead in a simple way to the information as to which angular component of the compacting roller is actually in contact with the substrate to be compacted, which, as already stated, allows a conclusion as to how deep the compactor roller penetrates into the material of the substrate to be compacted.

Also, in the course of the advancement of a soil compactor or a compressor roller of a soil compactor resulting bow wave, so in the direction of movement of a soil compactor in front of a respective compressor roller accumulation of material to be compacted, allows a conclusion on the state of the substrate to be compacted. The emergence of such a bow wave basically leads to the fact that the contact of a compactor roller with the substrate to be compacted is asymmetrical, since in the direction of movement of the compactor roller behind the same region such a bow wave or accumulation of material to be compacted substrate to this extent not arises. This aspect exploits the present invention in that the contact patch is composed of a first contact patch part between the start of contact of at least one detection peripheral area with the ground to be compacted and a contact reference position and a second contact patch part between the contact reference position and the contact end.

For example, this contact reference position may represent a deepest positioning of the detection peripheral area in the course of the circumferential movement of a detection peripheral area with respect to a perpendicularly orthogonal to the substrate to be compacted, where the first footprint is a bow-sided part of the barrier and the second pad is a rear-side part of the pad. In the case of a substantially horizontally oriented substrate to be compacted and a correspondingly horizontally moving compressor roller, therefore, such a contact reference position may comprise a contact region located substantially directly below the axis of rotation of the compactor roller in the vertical direction. The preceding part in the direction of movement is considered to be bow-side and will generally have a greater extension than the trailing rear-side part due to the presence of the above-mentioned bow wave.

In order to obtain information in the rotational method according to the invention in which rotary positioning is the compressor roller or a respective Erfasungsumfangsbereich, it is proposed that the contact reference position is determined based on at least one Drehpositionierungsreferenz. Such a rotational positioning reference may be generated, for example, by interaction of at least one detection perimeter area with a rotational positioning reference area.

When multiple detection coverage areas are used, it can be advantageously carried out such that a first detection coverage area essentially generates a rotational positioning reference by interaction with a rotational positioning reference area when a second detection peripheral area is in the contact reference position.

The contact patch, which can be determined by the method according to the invention, can represent a peripheral region of the compactor roller that is in contact with the substrate to be compacted. From this peripheral area can then be determined for example by orthogonal projection onto a plane defined by the substrate to be compacted a contact patch of the compactor on the substrate to be compacted, which in turn can be used by mathematical operations information about various physical variables such. B. the modulus of elasticity or transverse Poisson of the underground to be determined.

Fig. 1

in prinzipieller Darstellung eine Verdichterwalze auf zu verdichtendem Untergrund während der Bewegung der Verdichterwalze auf dem Untergrund;

Fig. 2

ein Zeitdiagramm, welches von vier bei der Verdichterwalze der Fig. 1 vorgesehenen Kontaktsensoren gelieferte Kontaktsignale darstellt;

Fig. 3

in vereinfachter Art und Weise die Ermittlung einer Aufstandsbreite einer Verdichterwalze auf dem zu verdichtenden Untergrund;

Fig. 4

die Hertzsche Formel, welche den Zusammenhang zwischen einer Aufstandsbreite und der Materialsteifigkeit von zu verdichtendem Material wiedergibt;

Fig. 5

in prinzipartiger Darstellung einen an der Innenseite eines Walzenmantels einer Verdichterwalze vorgesehenen und in Form eines Pfeifensensors aufgebauten Kontaktsensors;

Fig. 6

eine der Fig. 5 entsprechende Darstellung eines als Ultraschallsensor aufgebauten Kontaktsensors;

Fig. 7

eine der Fig. 5 entsprechende Darstellung eines als Tastsensor aufgebauten Kontaktsensors;

Fig. 8

eine der Fig. 5 entsprechende Darstellung eines als Drucksensor aufgebauten Kontaktsensors.

The present invention will be described below in detail with reference to the accompanying drawings. It shows:

Fig. 1

in principle, a compressor roller to be compacted surface during the movement of the compacting roller on the ground;

Fig. 2

a time chart, which four of the compressor roller of Fig. 1 provided contact sensors supplied contact signals;

Fig. 3

in a simplified manner, the determination of a contact width of a compacting roller on the substrate to be compacted;

Fig. 4

the Hertz formula, which represents the relationship between a riot width and the material stiffness of material to be compacted;

Fig. 5

in principle a representation provided on the inside of a roll shell of a compressor roller and constructed in the form of a pipe sensor contact sensor;

Fig. 6

one of the Fig. 5 corresponding representation of a constructed as an ultrasonic sensor contact sensor;

Fig. 7

one of the Fig. 5 corresponding representation of a touch sensor constructed as a contact sensor;

Fig. 8

one of the Fig. 5 corresponding representation of a pressure sensor constructed as a contact sensor.

The Fig. 1 shows a schematic side view and cross-sectional view relative to a compressor roller axis of rotation D a generally designated 10 device with which a reproduced in the example shown in angular scale Aufstandsgröße a compressor roller 12 can be determined on to be compacted substrate 14. The device 10 comprises four contact sensors 1, 2, 3, 4 in the inner space 16 enclosed by a roll shell 13 of the compressor roll 12. The contact sensor 1 is arranged in a detection peripheral region 18 of the compacting roll 12. The contact sensor 2 is disposed in a detection peripheral area 20. Of the Contact sensor 3 is disposed in a detection peripheral region 22, while the contact sensor 4 is disposed in a detection peripheral region 24. Each of these contact sensors 1, 2, 3, 4 provides a contact signal S1, S2, S3, S4 which varies depending on whether a respective detection perimeter area 18, 20, 22, 24 is in contact with the building material of the substrate 14 to be compacted, which is the case in the illustrated example only for the detection scope 22 or the contact sensor 3, or is not in contact with the building material of the substrate to be compacted 14, which in the example shown for the detection scope areas 18, 20 and 24 and the contact sensors provided therein 1, 2, 4 is the case.

In the in Fig. 1 illustrated embodiment, the four contact sensors 1, 2, 3, 4 to each other at the same angular distance of 90 °. That is, the contact sensor 1 is diametrically opposed to the contact sensor 3 with respect to the compressor roller rotational axis D while the contact sensor 2 is diametrically opposed to the contact sensor 4 with respect to the compressor roller rotational axis D.

In the movement of such a compactor roller 12 having soil compactor in the direction of movement V and the concomitant rotation of the compactor roller 12 about the roller axis D in the direction R is formed in the direction of movement V in front of the compactor roller 12, a generally referred to as bow wave 26 accumulation of material. In the area of this bow wave 26, the contact of the roll mantle 13 with the building material of the subfloor 14 to be compacted begins. This area is in Fig. 1 represented by a dashed line A. In an area indicated by a dashed line E, the contact of the roll mantle 13 ends with the substrate 14 to be compacted. Only in the area lying between the lines A and E, defined here by the angle α, does contact between the Compressor roller 12 and the substrate to be compacted 14th

A rotational positioning reference region 30 formed, for example, as a reference wheel 28 abutting the outer circumference of the roll mantle 13 can be used in the manner described below to generate a rotational positioning reference for the compactor roll 12 in cooperation with the contact sensors 1, 2, 3, 4. Whenever one of these contact sensors 1, 2, 3, 4 moves past the rotation positioning reference area 30, a change indicating this movement will occur in the contact signal S1, S2, S3, S4 of the respective contact sensor 1, 2, 3, 4, which indicates that at this time, this contact sensor generating a respective contact signal has moved past the rotation positioning reference area 30. It should be noted that this rotational positioning reference region 30 need not necessarily be formed as a reference wheel. Also on a proximity switch moving past projections on the compressor roller 12 can be used to determine a respective rotational positioning of the compactor roller 12. In the Fig. 1 illustrated variant in which the rotational positioning reference can also be generated with the inclusion of the Konaktsensoren 1, 2, 3, 4, is particularly advantageous due to the structurally simple design, which requires no additional sensors.

One recognizes in Fig. 1 Further, in the illustrated example, the rotational positioning reference region 30 is positioned in a height direction directly above the rotational axis D of the compacting roller 12. This means that on the spanned by the substrate to be compacted 14 level, z. B. a horizontal plane, orthogonal vertical S on the one hand, the Drehpositionierungsreferenzbereich 30 and on the other hand, the compactor roller rotational axis D intersects. This vertical S defined in the lying between the lines A and E peripheral region, so that peripheral region in which the compressor roller 12 is in contact with the substrate to be compacted 14, a contact reference position K. This contact reference position K divides the between the two lines A and E. spanned angle α at an angle α _bow , which extends between the line A, so the contact start, and the contact reference position K, and an angle α _tail , which extends between the contact reference position K and the line E, so the contact end. Due to the fact that during the advance of the compressor roller 12 in the direction V, the bow wave 26 is formed, in general, the part α _{bow of} the angle α will be greater than the trailing part a _tail . Only in a state in which such a bow wave would not be present, these two parts α _bow and α _tail would be substantially equal to each other, so the contact of the compressor roller 12 with the substrate 14 to be compacted with respect to the contact reference position K symmetrical. It should be noted in this context that of course the compressor roller 12 in a plane to the Fig. 1 In this respect, the contact reference position K, as well as the positions defined by the dashed lines A and E, are to be considered as respective lines which extend substantially parallel to the compressor roller rotational axis D along the compacting roller 12.

The Fig. 2 shows the time course of the generated by the contact sensors 1, 2, 3, 4 contact signals S1, S2, S3, S4. These contact signals S1, S2, S3, S4 are only examples of a variety of waveforms, which respectively indicate whether one of the detection scope in question 18, 20, 22, 24 in contact with the substrate 14 to be compacted or, for example, past the rotational positioning reference 30 moved or not. In the illustrated example, whenever a material is opposed to a respective detection peripheral region, the signal level decreases, whereas if no material is opposed to a respective detection peripheral region, the signal level is at a high level.

In the following, based on the contact signals S1 and S3 generated by the two contact sensors 1 and 3 in the detection scope regions 18 and 22, the mode of operation of the device 10 or the procedure for determining a contact patch representing the contact between the compactor roller 12 and the substrate 14 to be compacted, for example, represented by the angle α, explained.

In the course of a complete revolution of the compressor roller 12 about its compressor roller rotational axis D represented by the arrow U, the detection peripheral region 22 moves with its contact sensor 3 in the region of the line A, ie at a point in time t _A in FIG Fig. 2 , in contact with the substrate 14 to be compacted. At this time, the signal level of the contact signal S3 drops significantly. For example, the point in time at which the contact signal S3 assumes its minimum value can be selected as the time for the contact to occur. In the course of the further movement of the detection scope 22 reaches the area or to the line E, so that at the time t _{E of} the detection peripheral area 22 out of contact with the substrate to be compacted 14 occurs and consequently the signal level increases again. Here, for example, the timing of the rise of the signal level may be taken as the timing of the termination of the contact between the detection scope 22 and the ground 14 to be compacted. This means that between the two times t _A and t _E, the detection perimeter area 22 was in contact with the material to be compacted. The time t ₁ indicates the state of Fig. 1 again.

The circumferential length or the angular range α, in which the compressor roller 12 is in contact with the substrate 14 to be compacted, can therefore be calculated in a simple manner by the ratio of the length of the interval t ₀ between the times t _E and t _A to the length of the total Umdrehug U are determined. By this ratio, the angle α, which ultimately represents a fraction or an angle segment of the total angle of 360 °, can be determined in a simple manner without further mathematical operations. Taking into consideration a radius r of the compressor roller 12 and the total circumference of the same so computable, the circumferential length in which the compressor roller 12 is in contact with the substrate 14 to be compacted can be determined. To compensate for variations in the speed of movement in the direction of V and hence also resulting variations in the rotational speed in the direction of rotation R. Furthermore, the movement speed or the angular velocity in the movement of the compacting roller 12 can also be taken into account. However, under the simplified assumption that during a revolution U of the compressor roller 12 it moves at a substantially constant speed, such a speed compensation is basically not required.

In the manner described above, the extent of the contact area between the compacting roller 12 and the substrate to be compacted can be determined. With further consideration of the already mentioned contact reference position K, a more precise division of the angle α, that is to say of the entire circumferential region of the compressor roller 12 in contact with the substrate 14 to be compacted, can take place in the two parts α _bow and α _tail . The Fig. 2 shows that between times t _E and t _A , when the detection scope 22 moves over the contact reference position K, the detection peripheral area 18 with its contact sensor 1 moves past the rotation positioning reference area 30. That is, when the detection scope 22 moves past the contact reference position K, the contact signal S1 of the contact sensor 1 will spontaneously vary, for example, fall to a low level. The time at which this drop of the contact signal S1 occurs or this is, for example, to a minimum level can be used as Drehpositionierungsfrequenz to assign to the contact signal S3 of the contact sensor 3, a division of the interval t ₀ in the two in Fig. 1 in the two units also indexed, namely, the bow-end, or the precedent first occurring in temporal terms, part α _bow and the _stern trailing part α make.

Using the device described above, it is thus not only possible to determine the circumferential length or the angular segment in which the compressor roller 12 is in contact with the substrate 14 to be compacted, but it can also relate to an asymmetry of the contact be determined on the contact reference position K, which in turn allows a conclusion on the upstream of the compactor roller 12 forming bow wave 26.

One recognizes in Fig. 2 in that, in a corresponding manner, even when the detection peripheral region 18 is in contact with the substrate 14 to be compacted, the movement of the contact sensor 3 past the rotational positioning reference region 30 indicates that the contact reference position K has been reached. The same occurs in the ratio of the two contact sensors 2 and 4 or the contact signals S2 and S4 generated thereby. This means that in the course of a single revolution U of the compressor roller 12 about its compressor roller rotational axis D, four detections of the angle α or of the portions α _bow and α _tail emerge, which results in the detection of these variables with high precision or high repetition rate and accordingly also correspondingly allows frequent consideration of these variables in the case of compaction processes to be carried out.

It should be noted in this context that, of course, the above with reference to the Fig. 1 and 2 illustrated operating principle can also be used when a different number of detection scope and a different relative positioning of the same is selected. For example, three detection perimeter areas could be provided with an angular spacing of 120 °. It would also be possible to work with, for example, only two detection perimeter ranges which have an arbitrary circumferential distance from each other. It should be noted in each case that, advantageously, when one of the detection perimeter areas is in the contact reference position K, another detection perimeter area cooperates with the rotational positioning reference area 30 to generate the rotational positioning reference. Also, a single detection perimeter area could result in the desired result by interacting with a rotational positioning reference area. In this case, however, additionally the movement speed or angular speed of the compressor roller 12 would have to be considered to determine when a detection peripheral area moving past the rotation positioning reference area is in the contact reference position. Regardless of how many detection scope or contact sensors are used, there is basically the possibility to position the rotation positioning reference at any point in a soil compactor where this is possible or advantageous for structural reasons. For example, in the in Fig. 1 For example, the rotational positioning reference area 30 about the compressor roller rotational axis D can be shifted forwards or backwards by 90 ° so that, for example, the contact signal S4 or S2 of the contact sensor 4 or of the contact sensor 2 could be used in association with the detection circumference area 22 or the contact sensor 3.

The Fig. 3 illustrates a simplified example that, or as in the case of a represented by the angle α Aufstandsgröße a riot width b can be determined. In the in Fig. 3 illustrated case, no bow wave 26 is present, so that the two in Fig. 1 mentioned shares α _Bug and α _Heck would be basically the same. The circumferential length range represented by the angle α can be converted into the contact width b by orthogonal projection onto a plane spanned by the substrate 14 to be compacted. At the in Fig. 3 illustrated idealized, symmetrical case without bow wave, the proportions α _Bug and α _{tail are the} same size and the total angle α corresponds to twice the contact distance 2b. The riot width b in turn can be found in the Fig. 4 Taking into account the known per se variables r, ie radius of the compressor roller 12, I, ie length of the compressor roller 12 in the direction of the compressor roller rotational axis D, and F, ie the force exerted by the compactor roller 12 gravitational force, a conclusion on Material properties, such as the modulus of elasticity E or the transverse strain number v to obtain. It should be noted that in particular in the case of the occurrence of a bow wave and with respect to the contact reference position K unbalanced contacting the substrate to be compacted 14 for the two parts α _bow and α _tail, for example using a vector decomposition to make each separate calculations of the ridge widths. Basically, however, it is also possible to determine by experiments a connection between the physical properties of the material to be compacted and the resulting contact conditions, which are represented by the above-described contact sizes, and store this relationship, for example, in tabular form or in a database, so that in the Course of a compression process by comparing the ascertainable using the contact signals Aufstandsgröße can be concluded with corresponding values determined in the experiment on the compression state of the substrate 14.

The Fig. 5 to 8 show various examples of contact sensors used in the Fig. 1 generally shown device 10 can be used. That's how it shows Fig. 5 a known as a pipe sensor acoustic contact sensor 1. this is fed via an air line 30 with air L, which generates a whistling sound in the contact sensor 1. This in turn can be picked up by a microphone 32. The contact sensor 1 is open to the environment via an opening 34 in the roll shell 14, so that depending on whether the opening 34 is covered or not, different frequencies of the sound generated in the contact sensor 1 will adjust, whereby a passing of the detection scope 18, for example on Rotational positioning reference region 30 or can be detected on the substrate 14 to be compacted.

The Fig. 6 shows the configuration of the contact sensor 1 as an ultrasonic sensor. This generates an ultrasonic signal which, depending on whether or not the detection peripheral region 18 is covered with material, is reflected differently and received in a corresponding receiver, for example also provided in the contact sensor 1, at a different level.

The Fig. 7 shows a constructed as a mechanical tact sensor contact sensor 1. This has an opening 34 in the roll shell 14 passing through the push-button 36, which, when the detection peripheral region 18 is covered by material, is displaced inwards. The probe 36 may be formed, for example, as a plunger, so that its displacement in the contact sensor 1 leads to the generation of a corresponding signal.

The Fig. 8 shows a trained as a pressure sensor contact sensor 1. Via a compressed air line 38 compressed air L is supplied. This compressed air L can escape via a, for example, a throttling function unfolding opening 34 in the roll shell 14, as long as the opening 34 is not covered. If the material is covered by the detection scope 18, which prevents or impedes the outflow of the compressed air L through the opening 34, this is detected by a pressure sensor provided in the contact sensor 1.

It should be noted that, of course, the in Fig. 1 Contact sensors 2 to 4 can be constructed accordingly. It should also be pointed out that in the device 10 contact sensors of different types can be combined.

Claims (19)

1. Device for determining a contact area dimension (α) representing a contact state of a compactor roller and ground to be compacted, comprising at least one contact sensor (1, 2, 3, 4) generating a contact signal (S1, S2, S3, S4) arranged on at least one detection circumferential area (18, 20, 22, 24) of a compactor roller (12) which can be rotated about a compactor roller rotation axis (D), and wherein the contact signal (S1, S2, S3, S4) indicates a beginning of contact (A) and an end of contact (E) of a detection circumferential area (18, 20, 22, 24) with the ground to be compacted (14).
2. Device according to claim 1,
   characterized by a plurality of detection circumferential areas (18, 20, 22, 24) being provided with at least one contact sensor (1, 2, 3, 4) each, distributed around said compactor roller rotation axis (D), preferably in the same axial area of the compactor roller (12).
3. Device according to claim 2,
   characterized by the detection circumferential areas (18, 20, 22, 24) being arranged substantially with the same circumferential spacing from each other, preferably about 90°.
4. Device according to one of claims 1 to 3,
   characterized by at least one contact sensor (1, 2, 3, 4) being provided in at least one, preferably each detection circumferential area (18, 20, 22, 24) at an inner side of the roller shell (13) of the compactor roller (12).
5. Device according to one of claims 1 to 4,
   characterized by at least one contact sensor (1, 2, 3, 4) being adapted as:

   - an acoustic sensor, preferably an ultrasonic sensor or a pipe sensor, or

   - a tactile sensor, or

   - a pressure sensor.
6. Device according to one of claims 1 to 5,
   characterized by a rotation positioning detection arrangement (1, 2, 3, 4, 30) being provided for detecting a rotation positioning of the compactor roller (12).
7. Device according to claim 6,
   characterized by said rotation positioning detection arrangement (1, 2, 3, 4, 30) comprising at least one contact sensor (1, 2, 3, 4) and at least one rotation positioning reference area (30) in detection interaction with the at least one contact sensor (1, 2, 3, 4) which cannot be rotated about said compactor roller rotation axis (D) with the compactor roller (12).
8. Device according to one of claims 1 to 7,
   characterized by the contact area dimension (α) representing a circumferential area in contact with the ground to be compacted (14), preferably a circumferential longitudinal area or an angle segment of the compactor roller (12).
9. Method for determining a contact area dimension (α) representing a contact state of a compactor roller (12) and ground to be compacted (14), preferably by means of a device according to one of the preceding claims, comprising the detection of a contact between at least one detection circumference area (18, 20, 22, 24) of the compactor roller (12) and ground to be compacted (14) during rotation of the compactor roller (12) about a compactor roller rotation axis (D).
10. Method according to claim 9,
    characterized by the contact area dimension (α) being determined on the basis of the beginning of contact (A) in the course of the rotation of said compactor roller (12) between at least one detection circumference region (18, 20, 22, 24) and the ground to be compacted (14) and the end of contact (E).
11. Method according to claim 10,
    characterized by said contact area dimension (α) being furthermore determined on the basis of a speed of movement of said compactor roller (12) or/and a radius (r) of said compactor roller (12).
12. Method according to claim 10 or 11,
    characterized by said contact area dimension (α) being determined on the basis of a ratio between a first duration of movement (t₀) indicating a contact of at least one detection circumference region (18, 20, 22, 24) with the ground to be compacted (12) and a second time of movement in the course of a revolution of the compactor roller (12) about said compactor roller rotation axis (D) not indicating any contact or/and a second duration of movement indicating a revolution (U) of the compactor roller (12).
13. Method according to one of claims 9 to 12,
    characterized by said contact area dimension (α) consisting of a first contact area dimension part (α _Bug ) between the beginning of contact (A) of at least one detection circumference region (18, 20, 22, 24) with the ground to be compacted (14) and a contact reference position (K), and a second contact area dimension part (α _Heck ) between the reference position (K) and the end of contact (E).
14. Method according to claim 13,
    characterized by said contact reference position (K) representing the deepest positioning of said detection circumference regions (18, 20, 22, 24) during the circumferential movement of a detection circumference region (18, 20, 22, 24) in relation to a vertical line (S) which is substantially orthogonal to the ground to be compacted (14), said first contact area dimension part (α _burg ) being a bow-sided part of said contact area dimension (α) and the second contact area dimension part (α _Heck ) being a stern-sided part of said contact area dimension (α).
15. Method according to one of claims 13 or 14,
    characterized by said contact reference position (K) being determined on the basis of at least one rotation positioning reference.
16. Method according to claim 15,
    characterized by said rotation positioning reference being generated by an interaction of at least one detection circumference region (18, 20, 22, 24) with a rotation positioning reference region (30).
17. Method according to claim 16,
    characterized by a first detection circumference region (18, 20, 22, 24) generating a rotation positioning reference substantially by an interaction with a rotation positioning reference region (30) when a second detection circumference region (22, 24, 18, 20) is in the contact reference position (K).
18. Method according to one of claims 9 to 17,
    characterized by said contact area dimension (α) representing a circumferential region in contact with the ground to be compacted, preferably a circumferential longitudinal direction or an angle segment, of the compactor roller (12).
19. Method according to one of claims 9 to 18,
    characterized by a contact area width (b) of said compactor roller (12) on the ground to be compacted (14) being determined on the basis of said contact area dimension (α).

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