Method for supporting a charging process

Abstract

Method for assisting a loading process, in which a front loader (16) arranged on a commercial vehicle (14) is provided, which front loader comprises a loading tool (18) for receiving a load (20) and a hydraulically adjustable loader linkage (22) for pivoting and for raising or lowering the loading tool (18).In this case, a control unit (56) monitors a wheel slip variable, which represents a wheel slip occurring at driven wheels (52) of the commercial vehicle (14), and / or an engine load variable, which represents a current load of a drive motor (46) comprised by the commercial vehicle (14), wherein, at the instigation of the control unit (56), by controlling the hydraulically adjustable loader linkage (22), a loading movement, in particular dependent on a forward travel of the commercial vehicle (14), is carried out along a predetermined loading trajectory for picking up load (20) from a load supply (42), wherein the control unit (56) interrupts the forward travel of the commercial vehicle (14) by intervening in a drive management system (80) in the event that the wheel slip represented by the wheel slip variable and / or the load of the drive motor (46) represented by the engine load variable exceeds a respective predetermined limit value reached.

Description

[0001] The invention relates to a method for supporting a loading process, in which a front loader arranged on a commercial vehicle is provided, which comprises a loading tool for receiving a load and a hydraulically adjustable loader linkage for pivoting and for raising or lowering the loading tool.

[0002] Such front loaders are used to load, among other things, loose cargo using a loading tool, particularly designed as a shovel, which is located at one free end of the front loader. The loading tool or shovel can be adjusted in terms of its height relative to the ground and its inclination about a pivot axis running transversely to the longitudinal extent of the commercial vehicle by actuating hydraulic adjusting devices that are part of the loader linkage. This allows the shovel to be immersed in a specific load for the purpose of filling the shovel. The front loader is attached to the front of an agricultural tractor, for example, as a removable attachment, but it can also be designed as a shovel excavator, telescopic loader, or other similar loading vehicle from the construction or agricultural sectors.The cargo is primarily loose goods such as grain, corn, gravel, sand, earth or the like.

[0003] Efficiently picking up the load using the loading attachment places increased demands on the operator due to the required coordination between controlling the commercial vehicle's travel movement, i.e., maneuvering the commercial vehicle, and the loading movement of the loading attachment, which is carried out by appropriately controlling the hydraulically adjustable loader linkage. Depending on the type of load, less experienced operators may therefore encounter resistance when the loading attachment is inserted into the load that exceeds the capacity of the commercial vehicle's drive motor and / or excessive wheel slip may occur on its driven wheels.Since the drive motor also serves to operate a hydraulic system of the commercial vehicle, which supplies the hydraulic control devices of the front loader with hydraulic energy, such operating conditions can lead to a collapse in the performance of the hydraulic supply, which significantly impairs the execution of the loading process.

[0004] In view of this, it is the object of the present invention to provide a method of the type mentioned at the outset in such a way that it supports an operator in the efficient execution of a loading process with a front loader.

[0005] This object is achieved by a method for supporting a charging process having the features of patent claim 1.

[0006] In the method provided to support a loading process, a front loader is arranged on a commercial vehicle, which comprises a loading tool for receiving a load and a hydraulically adjustable loader linkage for pivoting and for raising or lowering the loading tool.In this case, a control unit monitors a wheel slip variable, which represents a wheel slip occurring on driven wheels of the commercial vehicle, and / or an engine load variable, which represents a current utilization of a drive motor included in the commercial vehicle, wherein, at the instigation of the control unit, a loading movement, which is dependent in particular on a forward travel of the commercial vehicle, is carried out by controlling the hydraulically adjustable loader linkage along a predetermined loading trajectory for picking up load from a load supply, wherein the control unit interrupts the forward travel of the commercial vehicle by intervening 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 engine load variable reaches a respective predetermined limit value.

[0007] By appropriately specifying the limit values, operating conditions that could lead to a drop in the hydraulic supply's performance due to excessive wheel slip on the commercial vehicle's driven wheels or an impending overload of the drive motor used both for the traction drive and the hydraulic system can be reliably avoided. If the drive motor is an internal combustion engine, its current load is capped by appropriately specifying the corresponding limit value, reliably preventing overload-related stalling.

[0008] In this context, it should be mentioned that the use of the method according to the invention is not limited to a commercial vehicle equipped with an internal combustion engine, but rather it can also be any other drive motor that can be part of an electric or hybrid drive system.

[0009] The wheel slip value is determined, for example, based on a comparison performed by the control unit between the wheel speed occurring at the driven wheels of the commercial vehicle and the current speed of the commercial vehicle. The latter can be derived, for example, by detecting the vehicle's movement relative to the ground using a radar sensor or a GPS navigation system. When determining the engine load value, however, the control unit can evaluate corresponding information from an engine control unit intended for operating the drive motor, which is part of the drive management system.

[0010] The front loader is used for loading, among other things, loose cargo using a loading tool designed as a shovel or similar, which is located at one free end of the front loader. The loading tool can be adjusted in height relative to the ground and its inclination about a pivot axis running transversely to the longitudinal extent of the commercial vehicle by actuating hydraulic adjusting devices that are part of the loader linkage. This allows the loading tool to be immersed in a specific load for the purpose of filling the loading tool. The front loader is attached to the front of an agricultural tractor, for example, as a removable attachment; however, it can also be designed as a shovel excavator, telescopic loader, or other similar loading vehicle from the construction or agricultural sectors.The cargo is primarily loose goods such as grain, corn, gravel, sand, earth or the like.

[0011] The method can optionally be extended so that the execution of the loading movement according to the specified loading trajectory is automatically coordinated by the control unit depending on the distance traveled when driving the loading tool into the load storage area. The loading trajectory specified for the corresponding actuation of the hydraulic actuating devices can be stored in a memory unit assigned to the control unit. The loading trajectory typically involves pivoting the loading tool from a (horizontally oriented) pickup position to a (vertically oriented) transport position while simultaneously raising the loader boom. The assistance function created in this way further relieves the operator, who only needs to concentrate on maneuvering the commercial vehicle.

[0012] Advantageous further developments of the method according to the invention emerge from the subclaims.

[0013] To interrupt forward travel, the control unit preferably brings the commercial vehicle to a standstill by intervening in the drive management system. To do this, the control unit can first bring the commercial vehicle to a standstill by driver-independently actuating the associated wheel brakes and then hold it in its current position. In a commercial vehicle equipped with a manual transmission, the control unit can simultaneously disconnect the drive connection to the driven wheels by disengaging an associated drive clutch. Automatic or continuously variable transmissions, on the other hand, are placed in a drive-neutral state by the control unit.

[0014] Furthermore, it is possible for the control unit to monitor the loader linkage to determine whether the loading tool is being lifted from the load supply. In such a case, the control unit suspends the loading movement in order to determine the weight of the load already picked up by the loading tool using a weighing device. For this purpose, the loading tool can be pivoted up from its current pick-up position into the transport position. The static state of the loader linkage assumed by suspending the loading process allows for particularly precise weight determination of the load in the loading tool through sensory detection and evaluation of the pressure conditions prevailing in the hydraulic actuating devices in conjunction with the current position of the loader linkage or the loading tool.

[0015] It is conceivable that the loader linkage is monitored by the control unit for the occurrence of a change in actuating force characteristic of lifting the loading tool from the load reservoir. A characteristic of this is a noticeable decrease in actuating force when raising the loader linkage, caused by the sudden loss of the resistance on the load side that opposes the loading tool during filling.

[0016] The corresponding change in actuating force can be reliably detected by the control unit, in particular by evaluating a sensor-detected hydraulic pressure in a hydraulic cylinder intended for lifting the loading tool, which is a component of the hydraulic actuating devices of the loader linkage.

[0017] If the weighing process indicates that a desired target weight has not (yet) been reached, the loading process is continued by the control unit either automatically or after prior authorization from the operator via a user interface connected to the control unit. This can be achieved by lowering or pivoting the loading tool back into the pick-up position and by continuing the loading movement along the specified loading trajectory while simultaneously driving the commercial vehicle forward. For this purpose, the control unit engages the drive clutch and releases the wheel brakes.

[0018] The desired target weight can, for example, be specified manually via the user interface connected to the control unit within the scope of the respective loading capacity of the loading tool.

[0019] For the purpose of simplified and intuitive specification of the desired target weight, it can be provided that this is based on a partial or full target loading state of the loading tool, which can be selected via the user interface, and is then calculated by the control unit based on a specific mass density of the load 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 regarding the mass density specific to the respective load can be entered or selected via the user interface. In the case of harvested crops such as grain or corn, the residual moisture content is important for their mass density. The residual moisture content of the harvested crop can be determined using a crop analyzer and transmitted to the control unit.Such a crop analyzer is offered by John Deere under the name "HarvestLab 3000".

[0020] The method according to the invention for supporting a charging process is explained in more detail below with reference to the accompanying drawings. They show: Fig. 1 shows an embodiment of the method according to the invention for supporting a loading process with a front loader, shown as a flow diagram, and Fig. 2 shows an agricultural tractor with an arrangement for carrying out the method shown in Fig. 1 reproduced inventive method.

[0021] Fig. 1 shows an embodiment of the method according to the invention for supporting a loading process with a front loader, shown as a flow chart, which is described below with reference to the arrangement provided for its implementation according to Fig. 2 should be described.

[0022] Starting from Fig. 2the arrangement 10 is a component of a commercial vehicle 14 designed as an agricultural tractor 12 with a front loader 16 arranged thereon, wherein the front loader 16 is attached in the front area of ​​the agricultural tractor 12 as a removable additional device and comprises a loading tool 18 for receiving a load 20 and a hydraulically adjustable loader linkage 22 for pivoting and for raising or lowering the loading tool 18.

[0023] More precisely, the front loader 16 serves, among other things, to load loose cargo 20, for which the loading tool 18 is designed as a bucket 28 located at a free end 24 of the front loader 16 or a loader boom 26. The bucket 28 can be adjusted in its height relative to the ground 36 and its inclination about a pivot axis 40 running transversely to the longitudinal extent 38 of the agricultural tractor 12 by actuating hydraulic adjusting devices 30 in the form of associated hydraulic cylinders 32, 34, which are part of the loader linkage 22, so that a targeted immersion of the bucket 28 into a cargo supply 42 for the purpose of filling the bucket 28 is possible. The cargo 20 primarily comprises loose goods such as grain, corn, gravel, sand, earth, or the like.A drive motor 46, designed as an internal combustion engine 44, is part of a drive system 48 of the agricultural tractor 12 and is connected to driven rear wheels 52 of the agricultural tractor 12 via a vehicle transmission 50. The drive motor 46 also serves to operate a hydraulic system 54 of the agricultural tractor 12, which, among other things, supplies the hydraulic actuating devices 30 of the front loader 16 with hydraulic energy.

[0024] Furthermore, the arrangement 10 comprises a microprocessor-controlled control unit 56, to which data from at least one wheel speed sensor 60 for detecting a wheel speed occurring at the driven rear wheels 52 of the agricultural tractor 12, a GPS navigation system 62 for determining the current position of the agricultural tractor 12, and a radar sensor 64 for detecting the vehicle's movement relative to the ground 36 are provided via a CAN bus 58. Furthermore, the control unit 56 communicates with a user interface 68 embodied as a touch-sensitive display 66, an internal storage unit 70, and, via a wireless interface 72a, 72b, with an external storage unit 74 in the form of a data cloud 76.

[0025] Furthermore, a hydraulic control 78 for actuating the hydraulic cylinders 32, 34 of the front loader 16 and a drive management system 80 are provided, which allows the implementation of targeted interventions in wheel braking devices 84 included in a braking system 82 of the agricultural tractor 12 as well as in an engine control unit 86 provided for operating the drive motor 46 or a transmission control 88. The latter enables the control unit 56, in the case of an agricultural tractor 12 equipped with a manual transmission 90, to disconnect the drive connection to the driven rear wheels 52 by opening an associated drive clutch 92.

[0026] Feedback regarding the operating state of the loader linkage 22 is provided to the control unit 56 by means of sensors, shown schematically only as functional block 94, for detecting the pressure conditions in the hydraulic cylinders 32, 34 as well as the current position of the loader arm 26 and bucket 28.

[0027] A weighing device 96, not shown in detail, is also provided, by means of which the weight of the load 20 located in the bucket 28 can be determined.

[0028] The process, which is executed by the control unit 56 and stored as corresponding program code in the internal memory unit 70, is initiated by the operator in a start step 100 by calling up the corresponding assistance function via the user interface 68. Following this, in a first main step 102, the operator is prompted via the user interface 68 or the display 66 included therein to begin the loading process. This is typically done by lowering the loader arm 26 or by pivoting the bucket 28 into a horizontally oriented pick-up position POS_A while simultaneously starting travel or driving forward in the direction of the load supply 42.

[0029] The actual execution of the loading movement is automatically coordinated by the control unit 56 according to a predetermined loading trajectory, depending on the path traveled when driving the bucket 28 into the load storage area 42. The path traveled is derived by the control unit 56 based on a change in position of the agricultural tractor 12 determined by 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 storage unit 70 and provides for pivoting the bucket 28 from the horizontally oriented pickup position POS_A into a vertically oriented transport position POS_T while simultaneously raising the loader arm 26.Generally speaking, at the instigation of the control unit 56, by controlling the hydraulically adjustable loader linkage 22, a loading movement is carried out along the predetermined loading trajectory, dependent on the forward travel of the agricultural tractor 12, to pick up load 20 from the load supply 42. The assistance function thus created leads to a corresponding relief for the operator, who only needs to concentrate on maneuvering the agricultural tractor 12.

[0030] In addition, in a second main step 104, the control unit 56 determines a wheel slip value, which represents a wheel slip occurring at the driven rear wheels 52 of the agricultural tractor 12. The wheel slip value is determined based on a comparison performed 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 travel 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 based on a position change determined by the GPS navigation system 62.The wheel slip represented by the wheel slip quantity is monitored by the control unit 56 in a third main step 106 to determine whether it reaches a predetermined limit value that is characteristic of the occurrence of excessive wheel slip at the driven rear wheels 52 of the agricultural tractor 12.

[0031] If it emerges in the third main step 106 that the predefined limit value has not been reached, the process continues with a fourth main step 108, in which the control unit 56 further determines an engine load variable that represents a current utilization of the drive motor 46 included in the agricultural tractor 12. In determining the engine load variable, the control unit 56 evaluates corresponding information from the engine control unit 86 provided for operating the drive motor 46. The utilization of the drive motor 46 represented by the engine load variable is monitored by the control unit 56 in a fifth main step 110 to determine whether it reaches a predefined limit value that corresponds to an impending overload-related stalling of the drive motor 46, which is designed as an internal combustion engine 44.

[0032] If it emerges in the third main step 106 or the fifth main step 110 that one of the two limit values ​​has been reached or exceeded, the process continues with a first sub-step 120, in which the control unit 56 interrupts the forward travel of the agricultural tractor 12 by intervening in the drive management system 80. More precisely, the control unit 56 brings the agricultural tractor 12 to a standstill by intervening in the drive management system 80, in that the control unit 56 first brings the agricultural tractor 12 to a standstill by actuating the wheel brake devices 84 independently of the driver and then holds the agricultural tractor 12 in its current position.If the agricultural tractor 12 is equipped with a vehicle transmission 50 designed as a manual transmission 90, as in this case, the control unit 56 simultaneously disconnects the drive connection to the driven rear wheels 52 by disengaging the drive clutch 92. If, however, the vehicle transmission 50 is an automatic or continuously variable transmission, the control unit 56 places it in a drive-neutral state. By appropriately specifying the limit values, operating conditions leading to a drop in the performance of the hydraulic supply can be reliably avoided. These operating conditions could occur due to excessive wheel slip on the driven rear wheels 52 of the agricultural tractor 12 or an impending overload of the drive motor 46, which serves both for the purposes of the travel drive 48 and the operation of the hydraulic system 54.

[0033] The loading process is accordingly continued in a subsequent second sub-step 122 with the provision of "full" hydraulic power. In a fourth sub-step 126, the control unit 56 monitors the loader linkage 22 to determine whether the bucket 28 is being lifted out of the load storage 42, thus leaving it. For this purpose, the loader linkage 22 or the loader arm 26 is monitored by the control unit 56 for the occurrence of a change in actuating force characteristic of the bucket 28 being lifted out of the load storage 42. A characteristic feature in this respect is a noticeable decrease in actuating force when the loader arm 26 is raised, caused by the sudden loss of the resistance on the load side that opposes the bucket 28 during filling.The corresponding change in actuating force is detected by the control unit 56 in the fourth sub-step 126 by evaluating a hydraulic pressure of the hydraulic cylinders 32 provided for lifting the loader arm 26, which hydraulic pressure was detected by sensors in the function block in a previous third sub-step 124.

[0034] If this is the case, the execution of the loading movement is suspended or stopped by the control unit 56 in a fifth sub-step 128 in order to determine the weight of the load 20 already picked up by the bucket 28 by means of the weighing device 96 in a sixth sub-step 130. Otherwise, the loading movement is continued without interruption by returning to the second sub-step 122.

[0035] In the sixth sub-step 130, the bucket 28 is first pivoted upwards from its current pick-up position into the transport position POS_T at the instigation of the control unit 56 by controlling the relevant hydraulic cylinders 34. The actual weight determination then takes place by evaluating the pressure conditions prevailing in the hydraulic cylinders 32, 34 in conjunction with the current position of the loader arm 26 or bucket 28, based on the sensor detection performed in function block 94.

[0036] If, in a seventh sub-step 132, the previously performed weighing process indicates that a desired target weight has not (yet) been reached, the loading process is continued by the control unit 56 automatically or after prior authorization by the operator via the user interface 68 connected to the control unit 56. This occurs in an eighth sub-step 134 by lowering or pivoting back the bucket 28 into the pick-up position POS_A and by continuing the loading movement along the predetermined loading trajectory while simultaneously driving the agricultural tractor 12 forward. For this purpose, in a ninth sub-step 136, the control unit 56 closes the drive clutch 92 while releasing the wheel brake devices 84. The method then returns to the first main step 102 to be executed again.

[0037] The desired target weight is specified manually via the user interface 68 within the respective loading capacity of the bucket 28.

[0038] In order to simplify and intuitively specify the desired target weight, it is intended that this is based on a partial or full target loading state of the bucket 28, which can be selected via the user interface 68, and is calculated by the control unit 56 based on a specific mass density of the load 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 regarding the mass density specific to the respective load 20 can be entered or selected via the user interface 68. If the load is a harvested crop, such as grain or corn, the residual moisture content is important for its mass density.In such a case, the residual moisture content of the crop is determined using a crop analyzer and uploaded to the external storage unit 74, so that the control unit 56 can access the relevant information via the wireless interface 72a, 72b. Such a crop analyzer is offered by John Deere under the name "HarvestLab 3000."

[0039] If, on the other hand, the seventh sub-step 132 shows that the desired target weight has been reached or exceeded as a result of the weighing process carried out, the loading process is terminated by the control unit 56 in a final step 200.

[0040] If it is determined in the third main step 106 or the fifth main step 110 that neither of the two limit values ​​has been reached, the control unit 56 monitors the loader linkage 22 in a seventh main step 114 to determine whether the bucket 28 is being lifted out of the load material supply 42, thus leaving it. The occurrence of the corresponding change in actuating force on the loader linkage 22 or on the loader boom 26 is detected by the control unit 56 in the seventh main step 114 by evaluating the hydraulic pressure of the hydraulic cylinder 32 provided for raising the loader boom 26, which pressure was detected by a sensor in the function block 94 in a preceding sixth main step 112.

[0041] If this is the case, the forward travel of the agricultural tractor 12 is interrupted by the control unit 56 in a tenth sub-step 138 by intervening in the drive management system 80. More precisely, the agricultural tractor 12 is first brought to a standstill by the control unit 56, again by driver-independent actuation of the wheel brake devices 84, and held in its current position, whereupon the process continues with the fifth sub-step 128, in which the execution of the loading movement is suspended or stopped by the control unit 56 in order to determine the weight of the load 20 already picked up by the bucket 28 in the manner already described.

[0042] If it turns out in the seventh main step 114 that the bucket 28 is still located within the load supply 42, the method returns to the first main step 102 to be run through from the beginning.

[0043] For the sake of completeness, it should be added that use of the method according to the invention is not limited to a commercial vehicle 14 equipped with an internal combustion engine 44, but rather it can also be any other drive motor 46, which can, for example, also be part of an electric or hybrid drive system.

Claims

1. A method for supporting a loading process, in which a front loader (16) is provided on a commercial vehicle (14), which front loader comprises a loading tool (18) for receiving a load (20) and a hydraulically adjustable loader linkage (22) for pivoting and for raising or lowering the loading tool (18), wherein a control unit (56) monitors a wheel slip variable, which represents a wheel slip occurring at driven wheels (52) of the commercial vehicle (14), and / or an engine load variable, which represents a current load of a drive motor (46) included in the commercial vehicle (14), wherein, at the instigation of the control unit (56), by controlling the hydraulically adjustable loader linkage (22), a loading movement, in particular dependent on a forward travel of the commercial vehicle (14), along a predetermined loading trajectory for receiving load (20) from a load supply (42),wherein the control unit (56) interrupts the forward travel of the commercial vehicle (14) by intervening in a drive management system (80) in the event that the wheel slip represented by the wheel slip variable and / or the load of the drive motor (46) represented by the engine load variable reaches a respective predetermined limit value.

2. Method according to claim 1, characterized in that the commercial vehicle (14) is brought to a standstill by the control unit (56) by intervening in the drive management system (80) in order to interrupt the forward travel.

3. Method according to claim 1 or 2, characterized in thatthe control unit (56) monitors the loader linkage (22) to determine whether the loading tool (18) is lifted out of the load supply (42), wherein in such a case the execution of the loading movement is suspended by the control unit (56) in order to carry out a weight determination of the load (20) already picked up by the loading tool (18) by means of a weighing device (96).

4. Method according to claim 3, characterized in that the loader linkage (22) is monitored by the control unit (56) with regard to the occurrence of a change in actuating force characteristic of lifting the loading tool (18) out of the load supply (42).

5. Method according to claim 4, characterized in thatthe change in actuating force is detected by the control unit (56) by evaluating a sensor-detected hydraulic pressure in a hydraulic cylinder (32) provided for lifting the loading tool (18), which is a component of hydraulic actuating devices (30) of the loader linkage (22).

6. Method according to at least one of claims 3 to 5, characterized in that the loading process is continued by the control unit (56) if the weighing process carried out shows that a desired target weight has not been reached.

7. Method according to claim 6, characterized in that the desired target weight is specified manually via a user interface (68) connected to the control unit (56).

8. Method according to claim 7, characterized in thatthe desired target weight is based on a partial or complete target loading state of the loading tool (18) that can be selected via the user interface (68) and is calculated therefrom by the control unit (56) based on a specific mass density of the load (20) to be picked up.

Images