METHOD FOR DETERMINING SOIL CONDITIONS

Description

[0001] The invention relates to a method for determining soil properties.

[0002] Knowledge of the soil composition of a field surface to be cultivated is essential for the correct application of agricultural cultivation methods and techniques. This is reflected, among other things, in the selection of suitable tillage equipment and working parameters, such as determining the working depth of soil-penetrating implements on a plow, cultivator, seed drill, or similar equipment, as well as in determining the appropriate tire inflation pressure, the optimal sowing and harvesting time, and efficient and environmentally friendly weed control.

[0003] Soil quality is determined by factors including soil structure, soil organisms (biological activity), moisture content, and the degree of soil surface compaction. Normally, this is assessed visually by the agricultural user, which requires relevant experience, or based on random soil measurements taken using stationary or mobile analysis equipment.

[0004] In view of this, the object of the present invention is to provide a method of the type mentioned at the outset in such a way that a continuous provision of the soil condition of a field surface to be cultivated is possible. A method for determining a soil condition according to the preamble of claim 1 is known from US 2021 / 173399 A1.

[0005] This problem is solved by a method for determining soil properties with the features of claim 1. Advantageous embodiments of the method according to the invention are set forth in the dependent claims.

[0006] The inventive method for determining soil properties provides that a detection device is used to observe the kinematic behavior of a crawler track caused by sinking when driving over a compressible subsoil, wherein an evaluation device is used to infer at least one parameter characterizing the soil properties from the observed kinematic behavior of the crawler track.

[0007] This approach takes advantage of the fact that, with increasing demands for soil conservation, agricultural and forestry machinery and equipment are increasingly being equipped with crawler tracks. These typically consist of a track belt made of fiber-reinforced rubber, which is guided on a chassis over a multitude of driven or freely rotating deflection, tensioning, and support rollers. Depending on the complexity of the chassis, at least some of the rollers are articulated or sprung so that the track belt's path can adapt to the unevenness of the terrain. The type of linkage or suspension of the rollers has a significant influence on the pressure distribution between the track belt and the ground, which is usually asymmetrical under the influence of the drive torques acting on the track belt. Therefore, each type of crawler track or...Each tracked undercarriage model exhibits a specific or characteristic signature regarding its compression effect on the surface it traverses. In this way, it is possible to continuously infer the soil conditions or the relevant parameters by recording the kinematic behavior of the tracked undercarriage as it sinks into the ground during operation of a tracked machine or implement. For this purpose, the kinematic behavior observed by the recording device is fed into a predictive model predefined for the respective tracked undercarriage, which in turn provides a basis for making a statement about the soil conditions.

[0008] Since the compression effect caused by the respective crawler track also depends on the extent of the traction torque occurring at the track belt relative to the ground due to the drive and / or the axle load acting at a pivot point of the crawler track relative to a vehicle chassis due to weight, corresponding information from a drive system and / or an axle load sensor can be taken into account to improve the accuracy of the prediction model and to account for the aforementioned influences.

[0009] The predictive model is trained in advance based on empirically conducted test and measurement series and uploaded to a processor unit designed for executing the method according to the invention, which is part of the evaluation device. The predictive model establishes a clear correlation between the observed kinematic behavior of the crawler track and the respective ground conditions. The use of appropriate AI methods (AI - Artificial Intelligence) is also recommended to improve the predictive accuracy.

[0010] The machine used can be an agricultural tractor, a harvester, or a forestry vehicle. In addition, the method according to the invention can also be used with agricultural or forestry equipment such as powered loading trailers or the like.

[0011] The kinematic behavior results from a deflection that occurs during travel at a chassis component of the tracked undercarriage that is movably mounted relative to the ground. According to the invention, the undercarriage is pivotally mounted to a vehicle chassis via a base part and a pivot joint, so that the observed deflection results from a change in angle about the pivot axis, which can be detected by the sensor. A traction torque occurring at the track belt relative to the ground due to the drive causes the tracked undercarriage to sink asymmetrically in the opposite direction of travel, which manifests itself as a corresponding change in angle. As already mentioned, complex undercarriage arrangements may also include other movable chassis components that serve for suspension and / or tensioning of the track belt by means of associated deflection, tensioning, and support rollers.The comprehensive sensory recording of the movements occurring in this respect results in a complex and therefore particularly distinctive deflection pattern, which allows for an accurate conclusion to be drawn about the respective soil condition.

[0012] Furthermore, the kinematic behavior may result from normal and / or tangential acceleration occurring on a section of the track belt facing the ground due to driving motion. The evaluation system can use this normal and / or tangential acceleration to determine the orientation of the relevant belt section relative to the ground. This approach is largely independent of the specific design of the chassis and can be used redundantly for a deflection-based assessment of the crawler track's kinematic behavior.

[0013] Normal and / or tangential acceleration can be determined by means of an accelerometer embedded in the belt section as part of the detection device, with a data stream representing this acceleration being wirelessly transmitted to the evaluation device. Preferably, the accelerometer is protected from mechanical influences and housed or embedded on the inside of the drive belt. The accelerometer and a radio interface for data transmission can be powered by an integrated accumulator, which can be charged inductively and thus contactlessly from the outside, or by a generator that produces electricity when the drive belt moves. The accelerometer, radio interface, and accumulator or power-generating generator are, for example, integrated into a single acceleration measurement module.

[0014] The vehicle chassis typically serves as the reference system for determining the orientation of the belt section. For this purpose, it is equipped with its own acceleration sensor to establish a reference orientation.

[0015] Since the drive belt is deflected several times along its path, it is conceivable to arrange a number of acceleration sensors corresponding to the deflection points along the drive belt in order to continuously detect the normal and / or tangential acceleration.

[0016] To achieve the most accurate possible determination of the ground conditions, the observed kinematic behavior of the crawler tracks can be adjusted by the evaluation system to account for ground irregularities oriented in the direction of travel. These irregularities can be detected using forward-looking sensor systems for three-dimensional environmental perception, such as a stereo camera or lidar.

[0017] Typically, the parameters characterizing soil properties include information regarding soil moisture, soil structure, soil compaction, and / or soil type. Determining soil properties can also be limited to a selection of the aforementioned parameters, whereby information regarding current moisture content, i.e., soil moisture, can be obtained from alternative data sources and thus contribute to improved accuracy of the remaining parameters. Moisture content can be derived, for example, from weather information or on-site soil measurements.

[0018] To make the information obtained regarding soil conditions usable, especially when driving over the same field again, the determined parameters can be located using a navigation system communicating with the evaluation device by linking them to a corresponding map position and transmitting them as a data set to a central data server. From there, users can download this data for purposes of field planning or process optimization.

[0019] The inventive method for determining soil properties is described in more detail below with reference to the drawings. Identical reference numerals refer to components that are identical or comparable in function. The drawings show: Fig. 1 shows an arrangement located in an agricultural tractor for carrying out the method according to the invention for determining soil properties, and Fig. 2 shows an embodiment of the method according to the invention illustrated as a block diagram.

[0020] Fig. 1 Figure 1 shows an arrangement housed in an agricultural tractor for carrying out the inventive method for determining soil properties.

[0021] The agricultural tractor 10 is an articulated four-track tractor 12, in which a first pair of driven tracks 16a, 16b is assigned to a front axle 14 and a second pair of driven tracks 16c, 16d to a rear axle 18. Due to the chosen view, only the tracks 16a, 16c on the left side of the agricultural tractor 10 are visible; the tracks 16b, 16d on the right side are obscured along the line of sight and are arranged as a mirror image of the two tracks 16a, 16c.

[0022] The arrangement 20 comprises a processor unit 22, which is part of an evaluation unit 26 communicating with a detection device 24, and a storage unit 28, as well as a first wireless interface 30 with a central data server 32 or a second wireless interface 34 with a radio interface 36 of a first accelerometer 40 embedded in a drive belt 38 made of fiber-reinforced rubber (see Fig. 2 ) is in a data exchange connection.

[0023] According to the representation of a single caterpillar track 16i (i = a,...,d) in Fig. 2 The drive belt 38 is guided on a chassis 42 over a multitude of driven or freely rotating deflection, tensioning and support rollers 44. Depending on the complexity of the chassis 42, at least some of the rollers 44 are articulated or sprung in such a way that the path of the drive belt 38 can adapt to the unevenness of a surface 46 being driven over.

[0024] In addition, a second acceleration sensor 48 connected to the processor unit 22 is present. This is attached to a vehicle chassis 50 of the agricultural tractor 10 and, together with the first acceleration sensor 40, forms part of the detection device 24.

[0025] The first accelerometer 40 and the radio interface 36 are integrated into a common accelerometer module 52 and are supplied with electrical energy by means of a built-in accumulator 54, which can be charged inductively and thus contactlessly from the outside. The accelerometer module 52 is embedded on the inside of the drive belt 38, protected from mechanical influences.

[0026] How best to Fig. 2 As can be seen, the chassis 42 of the crawler track 16i is pivotably attached to the vehicle chassis 50 by means of a base part 56 via a swivel joint 58, whereby an angle change α occurring along a swivel joint axis 60 is sensorially detected by means of an incremental rotary encoder 62, which is also encompassed by the detection device 24.

[0027] Furthermore, a GPS-based navigation system 64 serves to determine a current cartographic position of the agricultural tractor 10, whereby the respective determined cartographic position is transmitted to the processor unit 22 in the form of corresponding position information.

[0028] For example, forward-looking sensor devices 68 are mounted in the front area 66 of the agricultural tractor 10. These are designed in the form of a stereo camera or a lidar and serve to pre-detect a surface contour 70 of the ground 46 to be driven on. The detected surface contour 70 is made available to the processor unit 22 in the form of corresponding contour information.

[0029] In addition, the processor unit 22 has access to information from a drive system 74 and / or an axle load sensor 76 of the agricultural tractor 10 via a CAN data bus 72.

[0030] In Fig. 2 An embodiment of the method according to the invention, illustrated as a block diagram, is shown below with reference to Fig. 1 The invention will be explained below. A single track unit 16i (i = a,...,d) is shown as a representative example. However, to improve the quality of the soil condition determination, the method according to the invention is preferably carried out using all existing track units 16a,...,16d of the agricultural tractor 10.

[0031] The procedure can essentially be divided into two functional blocks. In a first functional block 78, the detection device 24 observes the kinematic behavior of the crawler track 16i caused by sinking when driving over the subsoil 46, which is assumed to be compressible. Subsequently, in a second functional block 80, the evaluation device 26, or the processor unit 22 it comprises, uses the observed kinematic behavior of the crawler track 16i to infer at least one parameter characterizing the soil properties.

[0032] The latter is done by feeding the kinematic behavior observed by means of the detection device 24 into a prediction model 82 specified for the relevant crawler track 16i, on the basis of which a statement is made regarding the soil condition.

[0033] The prediction model 82, which is ultimately an algorithm, is trained in advance based on empirically conducted test and measurement series and uploaded to the processor unit 22, more precisely to the associated memory unit 28. The prediction model 82 establishes a clear correlation between the observed kinematic behavior of the crawler track 16i and the respective soil conditions.

[0034] As an example, the kinematic behavior of the crawler track 16i results from a deflection that occurs due to driving at a chassis component of the crawler track 16i, more precisely the base part 56, which is mounted to move relative to the ground 46. In this case, this leads to a change in angle α about the pivot axis 60, which is detected by the incremental rotary encoder 62. Thus, a traction torque occurring at the drive belt 38 relative to the ground 46 causes an asymmetrical sinking of the crawler track 16i against the direction of travel 84, which manifests itself in a corresponding change in angle α (see Fig. 2 ).

[0035] In contrast, complex running gear arrangements may include, in addition to the base part 56, further movable chassis components that serve for suspension and / or tensioning of the running gear belt 38 by means of associated deflection, tensioning, and support rollers 44. The comprehensive sensory recording of the movements occurring in this respect results in a complex and therefore particularly distinctive deflection pattern, which allows for a precise conclusion to be drawn about the respective ground conditions.

[0036] Additionally or alternatively, the kinematic behavior of the crawler track 16i results from a normal and / or tangential acceleration that occurs during travel at a section 86 of the track belt 38 facing the ground 46. The processor unit 22 uses the knowledge of the normal and / or tangential acceleration to determine the orientation of the relevant belt section 86 relative to the ground 46.

[0037] The normal and / or tangential acceleration is determined by means of the first acceleration sensor 40, whereby the radio interface 36 wirelessly transmits a data stream representing this to the second wireless interface 34 and from there to the processor unit 22. The vehicle chassis 50 serves as a reference system for determining the orientation of the belt section 86, for which purpose the processor unit 22 determines a corresponding reference orientation by means of the second acceleration sensor 48.

[0038] Since the drive belt 38 is deflected several times along its path, a number of acceleration measurement modules 52 corresponding to the deflection points 88 are arranged along the drive belt 38 to ensure uninterrupted measurement of the normal and / or tangential acceleration. In the present case, a total of three identical acceleration measurement modules 52 are present. Contrary to the illustration in Fig. 2 The acceleration measurement modules 52 are mounted equidistantly along the drive belt 38.

[0039] To determine the soil conditions as accurately as possible, the observed kinematic behavior of the crawler track 16i is corrected by the processor unit 22 with regard to ground irregularities 90 lying in the direction of travel 84. The ground irregularities 90 are detected by means of the forward-looking sensor devices 68.

[0040] Typically, the parameters characterizing soil properties include information regarding soil moisture, soil structure, soil compaction, and / or soil type. In the present example, the determination of soil properties is based on a Fig. 2The selection of parameters listed above is limited (soil structure, soil compaction, and soil type), whereby information regarding the current moisture content, i.e., soil moisture, is obtained from alternative data sources, thus contributing to improved accuracy of the remaining parameters. The moisture content is derived, for example, from weather information, or better yet, from an on-site soil measurement. The soil measurement results are uploaded to the storage unit 28 via the first wireless interface 30, so that the processor unit 22 can access them.

[0041] To make the information obtained regarding soil conditions usable, particularly when driving over the same field again, the determined parameters are located by linking them with the position information provided by the navigation system 64 and transmitted as a data set via the first wireless interface 30 to the central data server 32. From there, they can be downloaded by a user for the purposes of field planning or process optimization.

[0042] Since the compression effect caused by the respective crawler track 16i also depends on the extent of the traction torque occurring on the drive belt 38 against the ground 46 due to the drive and / or the axle load acting at the pivot point of the crawler track 16i formed by the pivot joint 58 against the vehicle chassis 50 due to weight, the processor unit 22 also takes into account corresponding information from the drive system 74 and / or the axle load sensor 76 via the CAN data bus 72 to improve the accuracy of the prediction model 82.

[0043] For the sake of completeness, it should be noted that the use of the method according to the invention is not limited to agricultural tractors; rather, it can also be used with any other working machines or implements, provided they are equipped with a crawler track.

Claims

1. Method for ascertaining a soil condition, in which a kinematic behaviour of a track drive (16a, ..., 16d) caused by sinking when driving on a compressible underlying surface (46) is observed by means of a detection device (24), wherein at least one parameter characterizing the soil condition is concluded by an assessment device (26) starting from the observed kinematic behaviour of the track drive (16a, ..., 16d), wherein the kinematic behaviour results due to a deflection, which occurs because of travel on a chassis component of the track drive (16a, ..., 16d) mounted so it is movable in relation to the underlying surface (46), characterized in that the chassis component is a base part (56) attached via a pivot joint (58) in a pivotable manner on a vehicle chassis (50), such that the observed deflection results from a change of angle (α) of the base part (56) about the pivot joint axis (60) as detectable using sensors by means of the detection device (24).

2. Method according to Claim 1, characterized in that the kinematic behaviour results redundantly due to a normal and / or tangential acceleration, which occurs because of travel on a section (86) of the drive belt (38) facing towards the underlying surface (46).

3. Method according to Claim 2, characterized in that the normal and / or tangential acceleration is determined by means of an acceleration sensor (40) embedded in the belt section (86) as part of the detection device (24), wherein a data stream representing this is transmitted wirelessly to the assessment device (26).

4. Method according to Claim 3, characterized in that the drive belt (38) is deflected multiple times along its course, wherein a number of acceleration sensors (40) corresponding to the deflection points (88) is arranged distributed along the drive belt (38).

5. Method according to at least one of the preceding claims, characterized in that the observed kinematic behaviour of the track drive (16a,...,16d) is filtered by the assessment device (26) with respect to soil irregularities (90) located in the travel direction (84).

6. Method according to at least one of the preceding claims, characterized in that the parameters characterizing the soil condition are items of information with respect to a soil moisture, a soil structure, a soil compaction, and / or a soil type.

7. Method according to at least one of the preceding claims, characterized in that the ascertained parameters are located by means of a navigation system (64) communicating with the assessment device (26) by linking to an associated cartographic position and transmitted as a data set to a central data server (32).