METHOD FOR SUPPORTING A LOADING OPERATION

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to European Patent Application No. 24164092.9, filed Mar. 18, 2024, which is hereby incorporated by reference.

FIELD OF THE DISCLOSURE

The disclosure relates to a method for supporting a loading operation

BACKGROUND

In the agriculture, construction, and forestry industries, various work machines, such as front loaders, may be utilized in lifting and moving various materials. In certain examples, a front loader may include a bucket pivotally coupled by loader arms to the vehicle chassis. One or more hydraulic cylinders move the loader arms and/or the bucket between positions relative to the chassis to lift and move materials.

SUMMARY

The disclosure relates to a method for supporting a loading operation, in which a front loader, which is arranged on a utility vehicle and comprises a loading tool for picking up a load material and a hydraulically adjustable loader linkage for pivoting and for raising and lowering the loading tool, is provided.

Front loaders of this kind are used to transfer, inter alia, bulk load material by means of a loading tool, for example a loading tool designed as a bucket, which is located on a free end of the front loader. In this case, the loading tool or bucket can be adjusted in height relative to the ground and in its inclination about a pivoting axis running transversely to the longitudinal extent of the utility vehicle by actuating hydraulic actuating devices, which are component parts of the loader linkage, thus allowing targeted penetration of the bucket into a load material supply for the purpose of filling the bucket. The front loader is attached as a removable accessory unit in the front region of an agricultural tractor, for example, but the latter can also be designed as a bucket excavator, a telescopic loader or some other corresponding loading vehicle from the construction or agricultural sector. The load material primarily comprises bulk materials such as cereals, maize, gravel, sand, soil or the like.

Owing to the required coordination between the control of the driving movement of the utility vehicle, that is to say the maneuvering of the utility vehicle, and the loading movement of the loading tool which is to be carried out by appropriate actuation of the hydraulically adjustable loader linkage, picking up the load material by means of the loading tool in an efficient way imposes increased demands on the operator. In the case of less experienced operators, it may happen that, depending on the type of load material, the resistance which opposes the driving of the loading tool into the load material exceeds the capacity of the drive motor of the travel drive of the utility vehicle and/or excessive wheel slip occurs at the driven wheels thereof. Since the drive motor is simultaneously used for the operation of a hydraulic system of the utility vehicle which supplies the hydraulic actuating devices of the front loader with hydraulic energy, such operating states can lead to a dip in the power of the hydraulic supply, considerably impairing the execution of the loading operation.

In view of this situation, it is the object of the present disclosure to specify a method of the type stated at the outset such that this method supports an operator in the efficient execution of a loading operation by means of a front loader.

This object is achieved by a method for supporting a loading operation having the features of one or more of the embodiments disclosed herein.

In the method provided to support a loading operation, a front loader, which is arranged on a utility vehicle and comprises a loading tool for picking up a load material and a hydraulically adjustable loader linkage for pivoting and for raising and lowering the loading tool, is provided. In this method, a wheel slip variable, which represents a wheel slip occurring at driven wheels of the utility vehicle, and/or a motor load variable, which represents a current utilization of a drive motor with which the utility vehicle is equipped, are/is monitored by a control unit (e.g., a controller including a processor and memory), wherein, at the request of the control unit, a loading movement, for example a loading movement dependent on a forward travel of the utility vehicle, is carried out along a predetermined loading trajectory by actuation of the hydraulically adjustable loader linkage in order to pick up load material from a load material supply, wherein the forward travel of the utility vehicle is interrupted by the control unit by intervention in a drive management system in the event that the wheel slip represented by the wheel slip variable and/or the utilization of the drive motor represented by the motor load variable reach/reaches a respectively predetermined limit value.

By appropriate specification of the limit values, it is possible to reliably avoid operating states that lead to a dip in the power of the hydraulic supply caused by excessive wheel slip at the driven wheels of the utility vehicle or an imminent overload on the drive motor used both for the purposes of the travel drive and the operation of the hydraulic system. If the drive motor is an internal combustion engine, its current utilization is capped by appropriate specification of the associated limit value in such a way that stalling due to overloading can be reliably excluded.

In this context, it should be mentioned that use of the method according to the disclosure is not restricted to a utility vehicle equipped with an internal combustion engine; on the contrary, it may be any other drive motor, which may be a component part of an electric or hybrid drive system.

The wheel slip variable is determined, for example, on the basis of a comparison carried out by the control unit between the wheel speed occurring at the driven wheels of the utility vehicle and the current speed of movement of the utility vehicle. The latter can be derived, for example, by detecting the vehicle movement relative to the ground by means of a radar sensor or a GPS navigation system. In determining the motor load variable, on the other hand, corresponding information from a motor control unit which is provided for the operation of the drive motor and is a component part of the drive management system can be evaluated by the control unit.

The front loader is used to transfer inter alia bulk load material by means of a loading tool designed as a bucket or the like, which is located on a free end of the front loader. In this case, the loading tool can be adjusted in height relative to the ground and in its inclination about a pivoting axis running transversely to the longitudinal extent of the utility vehicle by actuating hydraulic actuating devices, which are component parts of the loader linkage, allowing targeted penetration of the loading tool into a load material supply for the purpose of filling the loading tool. The front loader is attached as a removable accessory unit in the front region of an agricultural tractor, for example, but the latter can also be designed as a bucket excavator, a telescopic loader or some other corresponding loading vehicle from the construction or agricultural sector. The load material primarily comprises bulk materials such as cereals, maize, gravel, sand, soil or the like.

The method can optionally be extended such that the execution of the loading movement in accordance with the predetermined loading trajectory is automatically coordinated by the control unit in dependence on the distance travelled as the loading tool is driven into the load material supply. In this case, the loading trajectory specified for the corresponding actuation of the hydraulic actuating devices can be stored in a memory unit associated with the control unit. The loading trajectory typically provides for pivoting of the loading tool out of a (horizontally oriented) pickup position into a (vertically oriented) transport position while simultaneously raising the loader linkage. The assistance function thus created leads to a further relief of the load on the operator, who may only then have to concentrate on the maneuvering of the utility vehicle.

Advantageous developments of the method according to the disclosure can be found in the one or more embodiments disclosed herein.

The utility vehicle is for example brought to a standstill by the control unit by intervention in the drive management system in order to interrupt the forward travel. For this purpose, the utility vehicle can first of all be brought to a halt and held in its instantaneous position by the control unit by driver-independent actuation of associated wheel brake devices. In the case of a utility vehicle equipped with a shift transmission, the control unit can simultaneously interrupt the drive connection to the driven wheels by opening an associated driving clutch. In contrast, automatic or continuously variable transmissions are put into a neutral drive state by the control unit.

There is furthermore the possibility that the loader linkage is monitored by the control unit as to whether the loading tool is being raised from the load material supply, wherein, in such a case, the execution of the loading movement is suspended by the control unit in order to carry out a weight determination on the load material already picked up by the loading tool by means of a weighing device. For this purpose, the loading tool can be pivoted up out of its current pickup position into the transport position. The static state of the loader linkage adopted due to the suspension of the loading operation allows particularly accurate determination of the weight of the load material located in the loading tool by sensing and evaluation of the pressure conditions prevailing in the hydraulic actuating devices in combination with the current position of the loader linkage and/or of the loading tool.

In this context, it is conceivable for the loader linkage to be monitored by the control unit in respect of the occurrence of a change in actuating force characteristic of lifting of the loading tool out of the load material supply. An obvious decrease in the actuating force as the loader linkage is raised, on account of the sudden decrease in the resistance posed to the loading tool by the load material during filling, is characteristic in this regard.

The corresponding change in actuating force can be reliably detected by the control unit by evaluation of a sensed hydraulic pressure in a hydraulic cylinder, which is provided for the purpose of raising the loading tool and is a component part of hydraulic actuating devices of the loader linkage.

If the weighing operation shows that a desired target weight has not (yet) been achieved, the loading operation is continued by the control unit, either automatically or after first being enabled by the operator via a user interface connected to the control device. This can be accomplished by lowering or pivoting back the loading tool into the pickup position and by continuing the loading movement along the predetermined loading trajectory while simultaneously driving the utility vehicle forward. For this purpose, at the request of the control unit, the driving clutch is closed by the control unit, while the wheel brake devices are released.

The desired target weight can be specified manually, for example, via the user interface connected to the control unit, within the limits of the respective loading capacity of the loading tool.

With a view to simplified or intuitive specification of the desired target weight, provision can be made for the said weight to be set with reference to a partial or complete target loading state, selectable via the user interface, of the loading tool and, proceeding from this, to be calculated by the control unit on the basis of a specific mass density of the load material to be picked up. For the sake of simplicity, the target weight can be specified as a percentage and divided into fractions of 100% of the loading capacity of the loading tool used.

Information on the mass density specific to the respective load material can be input or selected via the user interface. If it is crop material, such as cereals or maize, the residual moisture content thereof is significant for its mass density. The residual moisture content of the crop material can be determined by means of a crop analyzer and communicated to the control unit. Such a crop analyzer is offered by John Deere under the name “HarvestLab 3000”.

The above and other features will become apparent from the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The method according to the disclosure for supporting a loading operation will be explained in more detail below on the basis of the appended drawings. In the drawings:

FIG. 1 shows an example embodiment, illustrated as a flow diagram, of the method according to the disclosure for supporting a loading operation with a front loader; and

FIG. 2 shows an agricultural tractor with an arrangement for carrying out the method according to the disclosure illustrated in FIG. 1.

DETAILED DESCRIPTION

The embodiments or implementations disclosed in the above drawings and the following detailed description are not intended to be exhaustive or to limit the present disclosure to these embodiments or implementations.

FIG. 1 shows an example embodiment, illustrated as a flow diagram, of the method according to the disclosure for supporting a loading operation with a front loader, wherein this method will be described below with reference to the arrangement according to FIG. 2 provided for carrying it out.

Starting from FIG. 2, the arrangement 10 is a component part of a utility vehicle 14, which is designed as an agricultural tractor 12 and has a front loader 16 arranged thereon, wherein the front loader 16 is attached as a removable accessory unit in the front region of the agricultural tractor 12 and comprises a loading tool 18 for picking up a load material 20 and a hydraulically adjustable loader linkage 22 for pivoting and for raising and lowering the loading tool 18.

In some embodiments, the front loader 16 is used to transfer, inter alia, bulk load material 20, for which purpose the loading tool 18 is designed in the present case as a bucket 28 located on a free end 24 of the front loader 16 or a loader boom 26. The bucket 28 can be adjusted in height relative to the ground 36 and in its inclination about a pivoting axis 40 running transversely to the longitudinal extent 38 of the agricultural tractor 12 by actuating hydraulic actuating devices 30 in the form of associated hydraulic cylinders 32, 34, which are component parts of the loader linkage 22, thus allowing targeted penetration of the bucket 28 into a load material supply 42 for the purpose of filling the bucket 28. The load material 20 primarily comprises bulk materials such as cereals, maize, gravel, sand, soil or the like.

A drive motor 46 designed as an internal combustion engine 44 is a component part of a travel drive 48 of the agricultural tractor 12 and is connected via a vehicle transmission 50 to driven rear wheels 52 of the agricultural tractor 12. The drive motor 46 is simultaneously used to operate a hydraulic system 54 of the agricultural tractor 12, which inter alia supplies the hydraulic actuating devices 30 of the front loader 16 with hydraulic energy.

Furthermore, the arrangement 10 comprises a microprocessor-controlled control unit 56, which can be supplied via a CAN bus 58 with data from at least one wheel speed sensor 60 for the detection of a wheel speed at the driven rear wheels 52 of the agricultural tractor 12, from a GPS navigation system 62 for the determination of the current position of the agricultural tractor 12, and from a radar sensor 64 for the detection of the vehicle movement relative to the ground 36. In addition, the control unit 56 communicates with a user interface 68 designed as a touch-sensitive display 66, with an internal memory unit 70, and, via a wireless interface 72a, 72b, with an external storage unit 74 in the form of a data cloud 76.

In addition, there is a hydraulic controller 78 for the actuation of the hydraulic cylinders 32, 34 of the front loader 16, and a drive management system 80, which allows the execution of targeted interventions both into wheel brake devices 84 included in a brake system 82 of the agricultural tractor 12 and into an engine control unit 86 provided for the operation of the drive motor 46, or into a transmission controller 88. The latter makes it possible, in the case of an agricultural tractor 12 equipped with a shift transmission 90, for the control unit 56 to interrupt the drive connection to the driven rear wheels 52 by opening an associated driving clutch 92.

Feedback on the state of actuation of the loader linkage 22 to the control unit 56 is provided by means of sensors, depicted schematically as a function block 94, for detecting the pressure conditions in the hydraulic cylinders 32, 34 and the instantaneous position of the loader boom 26 and bucket 28.

There is also a weighing device 96 (not illustrated specifically), by means of which it is possible to determine the weight of the load material 20 located in the bucket 28.

The method executed by the control unit 56 and stored as corresponding program code in the internal memory unit 70 is started by the operator in a starting step 100 by calling up the corresponding assistance function via the user interface 68, whereupon, in a first main step 102, the operator is requested via the user interface 68 or via the display 66 included in the latter to start the loading operation. This is typically accomplished by lowering the loader boom 26 or by pivoting the bucket 28 into a horizontally oriented pickup position POS_A while simultaneously starting to drive or driving forwards in the direction of the load material supply 42.

The actual execution of the loading movement is coordinated automatically by the control unit 56 in accordance with a predetermined loading trajectory in dependence on the distance travelled as the bucket 28 is driven into the load material supply 42. The distance travelled is derived by the control unit 56 from a change in the position of the agricultural tractor 12 determined by means of the GPS navigation system 62. The loading trajectory specified for the corresponding actuation of the hydraulic actuating devices 30 or hydraulic cylinders 32, 34 is stored in the internal memory unit 70 and provides for pivoting of the bucket 28 out of the horizontally oriented pickup position POS_A into a vertically oriented transport position POS_T while simultaneously raising the loader boom 26. In general terms, therefore, at the request of the control unit 56, a loading movement dependent on a forward travel of the agricultural tractor 12 is carried out along the predetermined loading trajectory by actuation of the hydraulically adjustable loader linkage 22 in order to pick up load material 20 from the load material supply 42. The assistance function thus created leads to a corresponding relief of the load on the operator, who may only then have to concentrate on the maneuvering of the agricultural tractor 12.

In addition, in a second main step 104, the control unit 56 determines a wheel slip variable, which represents a wheel slip at the driven rear wheels 52 of the agricultural tractor 12. The wheel slip variable is determined on the basis of a comparison carried out by the control unit 56 between the wheel speed detected at the driven rear wheels 52 by means of the at least one wheel speed sensor 60 and the current speed of movement of the agricultural tractor 12. The latter is derived by detecting the vehicle movement relative to the ground 36 by means of the radar sensor 64 or because of a change in position determined by means of the GPS navigation system 62. The wheel slip represented by the wheel slip variable is monitored by the control unit 56 in a third main step 106 as to whether it reaches a predetermined limit value characteristic of the occurrence of excessive wheel slip at the driven rear wheels 52 of the agricultural tractor 12.

If it is found in the third main step 106 that the predetermined limit value is not reached, the procedure continues with a fourth main step 108, in which the control unit 56 additionally determines a motor load variable, which represents a current utilization of the drive motor 46 included in the agricultural tractor 12. In determining the motor load variable, the control unit 56 evaluates corresponding information from the motor control unit 86 provided for the operation of the drive motor 46. The utilization of the drive motor 46 represented by the motor load variable is monitored by the control unit 56 in a fifth main step 110 as to whether it reaches a predetermined limit value, which corresponds to imminent overload-induced stalling of the drive motor 46, which is designed as an internal combustion engine 44.

If it is found in the third main step 106 or in the fifth main step 110 that one of the two limit values is reached or exceeded, the procedure continues with a first substep 120, in which forward travel of the agricultural tractor 12 is interrupted by intervention in the drive management system 80 by the control unit 56. In some embodiments, for this purpose the agricultural tractor 12 is brought to a standstill by the control unit 56 by intervention in the drive management system 80 in that the agricultural tractor 12 is first of all brought to a halt and held in its instantaneous position by the control unit 56 by driver-independent actuation of the wheel brake device 84. If, as here, the agricultural tractor 12 is equipped with a vehicle transmission 50 designed as a shift transmission 90, the control unit 56 simultaneously interrupts the drive connection to the driven rear wheels 52 by opening the driving clutch 92. If, on the other hand, the vehicle transmission 50 is an automatic or continuously variable transmission, it is put into a neutral drive state by the control unit 56. By appropriate specification of the limit values, it is possible to reliably avoid operating states that lead to a dip in the power of the hydraulic supply caused by excessive wheel slip at the driven rear wheels 52 of the agricultural tractor 12 or by an imminent overload on the drive motor 46 used both for the purposes of the travel drive 48 and the operation of the hydraulic system 54.

The loading operation is accordingly continued with the provision of the “full” hydraulic power in a subsequent second substep 122, wherein, in a fourth substep 126, the control unit 56 monitors the loader linkage 22 as to whether the bucket 28 is being raised from the load material supply 42, and therefore is leaving the latter. For this purpose, the loader linkage 22 or loader boom 26 is monitored by the control unit 56 in respect of the occurrence of a change in actuating force characteristic of lifting of the bucket 28 out of the load material supply 42. An obvious decrease in the actuating force as the loader boom 26 is raised, on account of the sudden decrease in the resistance posed to the bucket 28 by the load material during filling, is characteristic in this regard. The corresponding change in actuating force is detected by the control unit 56 in the fourth substep 126 by evaluation of a hydraulic pressure, sensed in the function block in a preceding third substep 124, in the hydraulic cylinders 32, which are provided for the purpose of raising the loader boom 26.

If this is the case, the execution of the loading movement by the control unit 56 is suspended or stopped in a fifth substep 128 in order, in a sixth substep 130, to carry out a weight determination by means of the weighing device 96 on the load material 20 already picked up by the bucket 28. Otherwise, the loading movement is continued without interruption by returning to the second substep 122.

In the sixth substep 130, at the request of the control unit 56, the bucket 28 is first of all pivoted up out of its current pickup position into the transport position POS_T by actuation of the relevant hydraulic cylinders 34. The actual weight determination is then performed by evaluating the pressure conditions prevailing in the hydraulic cylinders 32, 34 in combination with the current position of the loader boom 26 or bucket 28, more specifically on the basis of the sensor determination performed in function block 94.

If, in a seventh substep 132, it is found on the basis of the previously performed weighing operation that a desired target weight has not (yet) been achieved, the loading operation is continued by the control unit 56, either automatically or after first being enabled by the operator via the user interface 68 connected to the control unit 56. This is accomplished in an eighth substep 134 by lowering or pivoting back the bucket 28 into the pickup position POS_A and by continuing the loading movement along the predetermined loading trajectory while simultaneously driving the agricultural tractor 12 forwards. For this purpose, in a ninth substep 136, the driving clutch 92 is closed, while the wheel brake devices are released 84, by the control unit 56. The method then returns to the first main step 102 in order to be run through again.

The desired target weight is specified manually via the user interface 68 within the limits of the respective loading capacity of the bucket 28.

With a view to simplified or intuitive specification of the desired target weight, provision is made for the said weight to be set with reference to a partial or complete target loading state, selectable via the user interface 68, of the bucket 28 and, proceeding from this, to be calculated by the control unit 56 on the basis of a specific mass density of the load material 20 to be picked up. For the sake of simplicity, the target weight can be specified as a percentage and divided into fractions of 100% of the loading capacity of the loading tool 18 used. Information on the mass density specific to the respective load material 20 can be input or selected via the user interface 68. If it is crop material, such as cereals or maize, the residual moisture content thereof is significant for its mass density. In such a case, the residual moisture content of the crop material is determined by means of a crop material analyzer and uploaded to the external storage unit 74, allowing the control unit 56 to access the appropriate information via the wireless interface 72a, 72b. Such a crop analyzer is offered by John Deere under the name “HarvestLab 3000”.

If, on the other hand, in the seventh substep 132, it is found on the basis of the weighing operation performed that the desired target weight has been achieved or exceeded, the loading operation is ended by the control unit 56 in a final step 200.

If it is observed in the third main step 106 or in the fifth main step 110 that neither of the two limit values is achieved, then, here too, in a seventh main step 114, the control unit 56 monitors the loader linkage 22 as to whether the bucket 28 is being raised from the load material supply 42 and is therefore leaving the latter. The occurrence of the corresponding change in actuating force at the loader linkage 22 or the loader boom 26 is detected by the control unit 56 in the seventh main step 114 by evaluation of the hydraulic pressure, sensed in the function block 94 in a preceding sixth main step 112, in the hydraulic cylinder 32, which is provided for the purpose of raising the loader boom 26.

If this is the case, the forward travel of the agricultural tractor 12 is interrupted by the control unit 56 in a tenth substep 138 by intervention in the drive management system 80. In some embodiments, the agricultural tractor 12 is once again brought to a halt and held in its instantaneous position by the control unit 56 by driver-independent actuation of the wheel brake devices 84, whereupon the procedure continues with the fifth substep 128, in which the execution of the loading movement is suspended or stopped by the control unit 56 in order, in the manner already described, to carry out a weight determination on the load material 20 already picked up by the bucket 28.

If it is found in the seventh main step 114 that the bucket 28 is still within the load material supply 42, the method returns to the first main step 102 in order to be run through again from the start.

For the sake of completeness, it should be added that use of the method according to the disclosure is not restricted to a utility vehicle 14 equipped with an internal combustion engine 44; on the contrary, it may be any other drive motor 46, which may also be a component part of an electric or hybrid drive system, for example.

The terminology used herein is for the purpose of describing example embodiments or implementations and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the any use of the terms “has,” “includes,” “comprises,” or the like, in this specification, identifies the presence of stated features, integers, steps, operations, elements, and/or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Those having ordinary skill in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” “top,” “bottom,” etc., are used descriptively for the drawings, and do not represent limitations on the scope of the present disclosure, as defined by the appended claims. Furthermore, the teachings may be described herein in terms of functional and/or logical block components or various processing steps, which may include any number of hardware, software, and/or firmware components configured to perform the specified functions.

Terms of degree, such as “generally,” “substantially,” or “approximately” are understood by those having ordinary skill in the art to refer to reasonable ranges outside of a given value or orientation, for example, general tolerances or positional relationships associated with manufacturing, assembly, and use of the described embodiments or implementations.

As used herein, “e.g.,” is utilized to non-exhaustively list examples and carries the same meaning as alternative illustrative phrases such as “including,” “including, but not limited to,” and “including without limitation.” Unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (e.g., “and”) and that are also preceded by the phrase “one or more of” or “at least one of” indicate configurations or arrangements that potentially include individual elements of the list, or any combination thereof. For example, “at least one of A, B, and C” or “one or more of A, B, and C” indicates the possibilities of only A, only B, only C, or any combination of two or more of A, B, and C (e.g., A and B; B and C; A and C; or A, B, and C).

While the above describes example embodiments or implementations of the present disclosure, these descriptions should not be viewed in a restrictive or limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the appended claims.