Method for adapting the operating and / or actuation characteristics of a front loader control

Abstract

Method for adapting the operating and / or actuation characteristics of a front loader control (10), which has a hand control lever (70), a control unit (46) for evaluating a deflection detected by a sensor on the hand control lever (70), and an actuating device (32) that can be hydraulically controlled by the control unit (46) according to the deflection detected by the sensor for raising and lowering a front loader boom (30) with a loading tool (26) for picking up a load (22), wherein a functional relationship between the deflection detected by the sensor on the hand control lever (70) and a hydraulic flow generated for the hydraulic actuating of the actuating device (32) can be adapted by the control unit (46).In this process, the functional relationship of the control unit (46) is adjusted depending on a determined material property parameter that represents an immersion resistance opposite to that of the loading tool (26) when picking up the load (22).

Description

[0001] The invention relates to a method for adapting the operating and / or actuation characteristics of a front loader control system, which has a hand control lever, a control unit for evaluating a deflection detected by a sensor on the hand control lever, and an actuating device for raising and lowering a front loader boom with a loading tool for picking up a load, which can be hydraulically controlled by the control unit according to the deflection detected by the sensor, wherein a functional relationship between the deflection detected by the sensor on the hand control lever and a hydraulic flow generated for the hydraulic actuating of the actuating device can be adapted by the control unit.

[0002] Front loaders are used, among other things, for loading materials using a loading tool, such as a bucket or forks, located at the free end of a front loader boom. The loading tool's height relative to the ground and its angle can be adjusted by hydraulically controlled actuators, which are part of the loader linkage. This allows the loading tool to be precisely lowered into the material for loading. The front loader is typically attached to the front of an agricultural tractor as a detachable attachment, but it can also be a backhoe, telescopic handler, or other similar loading vehicle used in construction or agriculture. The materials being loaded include straw, hay, silage, manure, grain, corn, gravel, sand, soil, and the like.

[0003] The front loader is typically operated using a hand control lever designed as a joystick. Depending on the direction of deflection of the control lever, the front loader boom can be raised or lowered. The degree of deflection determines the hydraulic flow generated to actuate the corresponding actuator. To accommodate the varying material properties of the load being handled and ensure efficient loading, assistance systems are also available. These systems allow the operator to select different operating and / or actuation characteristics for the front loader control via a user interface. The respective operating and / or actuation characteristic results from a functional relationship between the sensor-detected deflection of the hand control lever and the generated hydraulic flow.

[0004] Selecting the appropriate operating and / or actuation characteristics for loading the cargo in question requires corresponding experience on the part of the operator. Therefore, less experienced operators may find that, depending on the type of cargo, the loading process is less efficient due to an incorrect choice.

[0005] In view of this, the object of the present invention is to provide a method of the type mentioned above in such a way that the operator is actively supported in the efficient execution of a loading process with a front loader.

[0006] This problem is solved by a method for adapting the operating and / or actuation characteristics of a front loader control system with the features of claim 1.

[0007] In a method for adapting the operating and / or actuation characteristics of a front loader control system, the front loader control system comprises a hand control lever, a control unit for evaluating a deflection detected by a sensor on the hand control lever, and an actuator for raising and lowering a front loader boom with a loading tool for picking up a load. This actuator can be hydraulically controlled by the control unit according to the sensor-detected deflection. The control unit allows for the adaptation of a functional relationship between the sensor-detected deflection at the hand control lever and a hydraulic flow generated for the hydraulic actuation of the actuator. This adaptation of the functional relationship by the control unit depends on a determined material property parameter that represents an immersion resistance opposite to that of the loading tool when picking up the load.

[0008] Since the immersion resistance significantly influences the hydraulic power required to pick up the load, inefficient operating conditions of the front loader control system can be reliably avoided by appropriately adjusting or limiting the hydraulic flow generated for the hydraulic control of the associated actuator. This adjustment or limitation is achieved by selecting a functional relationship corresponding to the respective immersion resistance, thus requiring no further input from the operator and actively supporting them in the efficient execution of a loading operation with a front loader.

[0009] Advantageous further developments of the method according to the invention are set out in the dependent claims.

[0010] Preferably, based on the determined material property parameter, the control unit assigns the collected load to either a first material class characterized by soft material properties or a second material class characterized by hard material properties, with the functional relationship being adjusted accordingly. Dividing the load into only two material classes reduces the computational effort required by the control unit and is sufficient for most applications. For example, soft materials (especially those consisting of stem-like plant parts) such as straw, hay, silage, or manure exhibit a measurably lower immersion resistance compared to hard materials (generally free-flowing or granular) such as grain, corn, gravel, sand, or soil.

[0011] Furthermore, the functional relationship of the control unit can be adjusted to generate the hydraulic flow linearly, progressively, or in a mixed linear-progressive manner. The hydraulic flow is then linear or progressive if it increases proportionally or (quasi-)exponentially with the sensor-detected deflection of the hand control lever. A linear increase in hydraulic flow when picking up soft materials, and a linear-progressive or progressive increase when picking up hard materials, has proven advantageous.

[0012] Furthermore, it is conceivable that, to determine the material property parameter, the control unit could detect the actuating torque exerted on the loading tool when picking up the load. This would allow a reliable conclusion to be drawn about the immersion resistance encountered by the loading tool during loading and could, for example, be estimated based on the sensor-detected pressure conditions in another hydraulically controlled actuator, which serves to tilt the loading tool on the front loader boom. Alternatively, direct measurement could also be carried out using a strain gauge located at a suitable point on the loader linkage.

[0013] Based on this, the control unit can compare the recorded actuation torque with a corresponding class-specific value range to assign the picked-up load to one of the two material classes. The class-specific value range is determined empirically, by evaluating and classifying a large number of goods to be loaded with regard to the actuation torques occurring during picking up at the loading tool.

[0014] Additionally, it can be provided that, to verify the classification of the loaded material into one of the two material classes, the control unit relates the recorded actuation torque to a velocity value representing the immersion speed of the loading tool into the load and compares this with a further class-specific value range. The velocity value can be estimated with good approximation from the current forward speed of the loading vehicle. This allows the actuation torque exerted on the loading tool to be evaluated with regard to speed-dependent influences, which enables further refinement and precision in the classification of the loaded material into one of the two material classes.

[0015] Furthermore, to verify the assigned classification of the load to one of the two material classes, the control unit can determine the weight of the load picked up by the loading tool and compare it with the corresponding class-specific weight range. This takes into account the fact that there are usually significant differences in mass density between soft and hard materials, which can be used to further refine the classification of the load to one of the two material classes. The weight determination can be carried out, for example, using a weighing device as described in detail in EP 2 843 378 A1.

[0016] The specification of the respective class-specific further value range or weight range is also carried out empirically through appropriate evaluation and classification of a large number of goods to be loaded.

[0017] The method according to the invention is explained in more detail below with reference to the accompanying drawings. These show: Fig. 1 shows an embodiment of the inventive method for adapting the operating and / or actuation characteristics of a front loader control, illustrated as a flowchart, and Fig. 2 shows a schematically illustrated arrangement for carrying out the inventive method for adapting the operating and / or actuation characteristics of a front loader control.

[0018] Fig. 1 Figure 1 shows an embodiment of the inventive method for adapting the operating and / or actuation characteristics of a front loader control 10, presented as a flowchart, and is subsequently described with reference to the arrangement 12 provided for its implementation. Fig. 2 to be described.

[0019] Starting from Fig. 2 The arrangement 12 is part of a loading vehicle 14 in the form of an agricultural tractor 16 with a front loader 18 attached to it, wherein the front loader 18 is attached as a removable attachment in the front area 20 of the agricultural tractor 16.

[0020] More precisely, the front loader 18 serves to load material 22 by means of a loading tool 26, in this case designed as a bucket 24 (or also as a loading fork), which is located at a free end 28 of a front loader boom 30. The loading tool 26 can be adjusted in height relative to the ground 42 and in its inclination by means of first and second hydraulically controlled adjusting devices 32, 34 in the form of associated hydraulic cylinders 36, 38, which are part of a loader linkage 40, so that the loading tool 26 can be precisely inserted into a material supply 44 for the purpose of picking up the material 22. The material 22 consists of goods such as straw, hay, silage, manure, grain, corn, gravel, sand, soil or the like.

[0021] The arrangement 12 comprises a microprocessor-controlled control unit 46, which is connected via a CAN data bus 48 to several wheel speed sensors 50, 52, which serve to provide information regarding the wheel speeds occurring at associated wheels 54, 56 of the agricultural tractor 16.

[0022] Furthermore, the control unit 46 communicates via the CAN data bus 48 with a valve arrangement 60 supplied with hydraulic fluid from a hydraulic system 58 of the agricultural tractor 16 for controlling the first and second actuators 32, 34, a user interface 64 designed as a touch-sensitive display 62 and a storage unit 66.

[0023] The front loader 18 is operated by means of a hand control lever 70 designed as a joystick 68, which is also connected via the CAN data bus 48 to the control unit 46 for evaluating a deflection detected by a sensor on the hand control lever 70. The first actuating device 32 for raising and lowering the front loader boom 30 is hydraulically controlled by the control unit 46 according to the sensor-detected deflection. The hand control lever 70, the control unit 46, the valve assembly 60, and the two hydraulically controlled actuating devices 32, 34 constitute the core components of the front loader control system 10.

[0024] More precisely, the front loader boom 30 can be raised or lowered depending on the deflection direction of the control hand lever 70, whereby the extent of the deflection determines a hydraulic flow generated for the hydraulic control of the first actuating device 32, which is provided via the valve arrangement 60 according to a functional relationship that can be adapted by the control unit 46.

[0025] Feedback regarding the actuation status of the loader linkage 40 to the control unit 46 is provided based on information supplied by a sensor arrangement 72 for detecting the pressure conditions in the two actuating devices 32, 34 as well as the current position of the front loader boom 30 and the loading tool 26.

[0026] According to Fig. 1 In a start step 100, the procedure carried out by the control unit 46 and stored as corresponding program code in the memory unit 66 is started by the operator by calling up the corresponding assistance function via the touch-sensitive display 62 of the user interface 64, whereupon in a first main step 102, the control unit 46 determines a material property parameter that represents an immersion resistance opposite to the loading tool 26 when picking up the load 22.

[0027] The derivation of the immersion resistance required to determine the material property parameter is achieved by detecting an actuating torque exerted on the loading tool 26 when picking up the load 22. In the first main step 102, the control unit 46 estimates the actuating torque based on the information provided by the sensor arrangement 72 regarding the pressure conditions in the second actuating device 34, which is intended for tilting the loading tool 26. Alternatively, direct detection is carried out using a strain gauge arranged at a suitable point on the loader linkage 40 (in Fig. 1 (not shown).

[0028] Subsequently, the control unit 46, based on the material property parameter determined in the first main step 102, performs a multi-stage verification assignment of the received cargo 22 to a first material class characterized by soft material properties or a second material class characterized by hard material properties.

[0029] In this process, the actuation torque recorded in the first main step 102 is first evaluated by the control unit 46 in a second main step 104 on the basis of a corresponding comparison to determine whether it can be assigned to a respective class-specific value range.

[0030] In the first case, the process continues with a third main step 106, and in the second case with a first sub-step 108, with the aim of verifying the assigned classification of the loaded material 22 to one of the two material classes. For this purpose, the control unit 46 relates the detected actuation torque to a velocity value representing the immersion speed of the loading tool 26 into the loaded material 22. In the first sub-step 108, this value is compared with a further class-specific value range assigned to the first material class, and in the third main step 106, with a further class-specific value range assigned to the second material class. If an assignment to the relevant further class-specific value range is possible, the process continues with a second sub-step 110 or a fourth main step 112, respectively. Otherwise, the procedure returns to the beginning without further action and is repeated from the start.

[0031] The verification described above allows the actuating torque exerted on the loading tool 26 to be further evaluated with regard to speed-dependent influences, which enables a further narrowing down or more precise classification of the loaded material 22 into one of the two material classes. The speed parameter used for this purpose is derived, to a good approximation, from the current forward speed of the agricultural tractor 16, which in turn is determined based on the information provided via the CAN data bus 48 regarding the wheel rotation speeds occurring at the corresponding wheels 54, 56 of the agricultural tractor 16.

[0032] In the second sub-step 110 or fourth main step 112, a further verification of the assigned load 22 to one of the two material classes is provided, for which the control unit 46 determines the weight of the load 22 picked up by the loading tool 26 and compares it in the second sub-step 110 with a class-specific weight range assigned to the first material class or in the fourth main step 112 with a class-specific weight range assigned to the second material class.

[0033] This takes into account the fact that there are usually significant differences in mass density between soft and hard materials, which can be used for the purposes of further narrowing down or refining the assignment of the loaded material 22 to one of the two material classes. The weight is determined based on the information provided by the sensor arrangement 72 for detecting the pressure conditions in the two actuating devices 32, 34, as well as the current position of the front loader boom 30 and the loading tool 26, for example, using a weighing device as described in detail in EP 2 843 378 A1.

[0034] If an assignment to the relevant class-specific weight range is possible, the process continues with a third sub-step 114 or a fifth main step 116, in which the functional relationship between the sensor-detected deflection of the hand control lever 70 and the hydraulic flow generated for the hydraulic actuation of the first actuator 32 is adjusted with regard to whether the hydraulic flow is generated linearly, progressively, or in a mixed linear-progressive manner. If necessary, the flow is limited accordingly. Otherwise, the process returns to the beginning without further action and is repeated from the start. In this context, the generation of the hydraulic flow is linear or progressive if it increases proportionally or (quasi-)exponentially with the sensor-detected deflection of the hand control lever 70.

[0035] The specification of the class-specific value or weight ranges stored in storage unit 66 as the associated data record is carried out empirically, for which a corresponding evaluation and classification of a large number of goods to be loaded is carried out beforehand.

[0036] Finally, it should be noted that the illustration of a front loader 18 designed as a detachable attachment on an agricultural tractor 16 is merely exemplary; it can just as well be designed as a backhoe, telescopic loader or a corresponding other loading vehicle from the construction or agricultural sector.

Claims

1. Method for adapting the operating and / or actuation characteristics of a front loader control system, which has a hand control lever (70), a control unit (46) for evaluating a deflection detected by a sensor on the hand control lever (70), and an actuating device (32) that can be hydraulically controlled by the control unit (46) according to the deflection detected by the sensor for raising and lowering a front loader boom (30) with a loading tool (26) for picking up a load (22), wherein a functional relationship between the deflection detected by the sensor on the hand control lever (70) and a hydraulic flow generated for the hydraulic actuating of the actuating device (32) can be adapted by the control unit (46), characterized by the fact thatthe adjustment of the functional relationship of the control unit (46) depending on a determined material property parameter, which represents an immersion resistance opposite to the loading tool (26) when picking up the load (22), takes place.

2. Method according to claim 1, characterized by the fact that The control unit (46) assigns the received cargo (22) to a first material class characterized by soft material properties or a second material class characterized by hard material properties based on the determined material property parameter, whereby the adjustment of the functional relationship is made on the basis of this assignment.

3. Method according to claim 1 or 2, characterized by the fact that the functional relationship of the control unit (46) is adapted with respect to a linear, progressive or mixed linear-progressive generation of the hydraulic flow.

4. Method according to at least one of the preceding claims, characterized by the fact that To determine the material property size, the control unit (46) detects an actuating torque exerted on the loading tool (26) when picking up the load (22).

5. Method according to claim 2, characterized by the fact that To assign the received load (22) to one of the two material classes, the control unit (46) compares the recorded actuation torque with a corresponding class-specific value range.

6. Method according to claim 5, characterized by the fact that To verify the assignment of the load (22) to one of the two material classes, the control unit (46) relates the detected actuation torque to a velocity value representing the immersion speed of the loading tool (26) into the load (22) and compares it with a further class-specific value range assigned to each.

7. Method according to claim 5 or 6, characterized by the fact that To verify the assignment of the load (22) to one of the two material classes, the control unit (46) determines the weight of the load (22) picked up by the loading tool (26) and compares it with a class-specific weight range assigned to each.

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