Device and method for controlling the operation of a towed implement, which can be activated hydraulically, on a vehicle

Abstract

The disclosure relates to a device of a vehicle, in particular a tractor, having a hydraulic activation unit for controlling the operation of a towed implement on the vehicle, comprising at least one position detection unit with at least one camera, position detection marks, and an evaluation unit and a data-transmitting connection to a control unit which is assigned to the hydraulic activation unit. Furthermore, a method is proposed, wherein by means of such a position detection unit the position of the towed implement can be determined, and the position can be adjusted according to requirements by suitable operation of the hydraulic activation unit.

Claims

1. A device for a vehicle having a hydraulic activation unit configured to control an operation of a towed implement of the vehicle, the device comprising: at least one position detection unit having at least one camera; at least one position detection mark arranged on one of (i) the towed implement and (ii) the hydraulic activation unit configured to control an operation of the towed implement, wherein the at least one camera is directed toward the at least one position detection mark to generate image data indicative of the position of the at least one position detection mark; an evaluation unit connected to said at least one camera and configured and adapted to (i) determine a position of the towed implement from the image data, (ii) compare the position to a reference position, and (iii) activate the hydraulic activation unit to adjust the position of the towed implement in response to a difference in the position and the reference position; and a data-transmitting connection from the evaluation unit to a control unit that is assigned to the hydraulic activation unit.

2. The device according to claim 1, wherein the at least one camera is arranged on one of (i) the vehicle and (ii) the towed implement.

3. The device according to claim 1, wherein the at least one position detection mark includes a plurality of position detection marks that are spaced apart from one another.

4. The device according to claim 1, further comprising: a tensile force-measuring apparatus connected to the evaluation unit in a data-transmitting fashion.

5. The device according to claim 4, wherein: the tensile force-measuring apparatus is coupled to the at least one camera; and the at least one camera is directed toward a stress-optical material arranged on one of (i) the towed implement and (ii) the hydraulic activation unit configured to control the towed implement.

6. The device according to claim 5, wherein the stress-optical material is attached to one of (i) the towed implement and (ii) a lifting mechanism of the towed implement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure and the technical field are explained in more detail below with reference to figures. Here, identical components are characterized with the same reference signs. The illustrations are schematic and not provided for the illustration of size ratios. The explanations which are given with respect to individual details of the figure can be extracted and are freely combinable with contents from other figures or the description above, unless something else necessarily arises for a person skilled in the art or such a combination is explicitly prohibited here.

(2) In the drawings:

(3) FIG. 1 shows a schematic side view of a tractor with a hydraulic activation unit for controlling the operation of a towed implement comprising a camera for a position detection unit;

(4) FIG. 2 shows a side view according to FIG. 1 in which the camera mounted on the vehicle is directed towards the towed implement and position detection marks of the position detection unit and a stress-optical material of a tensile force-measuring apparatus are positioned on the towed implement;

(5) FIG. 3 shows a side view according to FIG. 1 in which the camera is directed towards the lifting mechanism, and on the lifting mechanism the position detection marks are positioned on the upper link, and the stress-optical material is positioned on the lower link;

(6) FIG. 4 shows a side view according to FIG. 1 in which the position detection unit is positioned with an integrated camera on the towed implement; and

(7) FIG. 4a shows a detail of the position detection unit with an integrated camera.

DETAILED DESCRIPTION

(8) FIG. 1 shows the basic illustration of the device 1 specified here on a vehicle 2, in particular of the type of a tractor during working of the soil with a towed implement 4, in particular with a plow. Here, the vehicle 2 tows the towed implement 4 behind it while driving in the driving direction 6 and through an upper layer of the ground. The general driving mode of the vehicle 2 can be influenced by means of a (if appropriate separate) vehicle controller 12. The position of the towed implement 4 can be set with a hydraulic activation unit 3 having a control unit 13 for actuating the hydraulic activation unit 3 and a lifting mechanism 15. The hydraulic activation unit 3 can be constructed, in particular, as follows: the pump 20 delivers a flow of oil to the regulating valve 21 which controls the lifting mechanism 15. Said lifting mechanism acts on the lower links 17, as a result of which the towed implement 4 can be raised, held in position or lowered.

(9) Furthermore, a camera 8 of a position detection unit 7 is provided which is attached to or on the vehicle 2. The camera 8 is directed towards the towed implement 4 (illustrated in a cut-away view and forming a plow here). The camera 8 can be e.g. a reversing camera which is suitable for optical measurements or a digital camera (high-resolution) which is installed specifically for the application purpose described here, and preferably with a polarization filter.

(10) In order to be able to determine the position of the plow in space and therefore also its depth or height (vertical position 25), according to FIG. 2 three visually salient position detection marks 9a, 9b and 9c are provided on each side of the plow. In addition, the geometry or the dimensions of the plow are known. In order to determine a tensile-force-equivalent value for the tensile force controller, a stress-optical material 19, suitable for stress-optical recordings, is fastened to the carrier 22 of the plow at the level of the first pair of blades, e.g. by means of adhesive. Owing to the deformation which is dependent on the tensile force during plowing and is caused by tensile stresses or bending stresses in the carrier 22, an equivalent of the tensile force is inferred through evaluation of the camera images.

(11) According to FIG. 3, the position detection marks 9a, 9b and 9c for determining the position or inclination of the lifting mechanism 14 are provided directly on the upper link 16 of the (vehicle-side) lifting mechanism 14. In addition, the stress-optical material 19 is fastened to the lower link 17 of the lifting mechanism 14. The arrangement has the advantage that it is independent of the selection of the towed implement 4. Therefore, the towed implements 4 do not have to be equipped with these position detection marks and/or stress-optical materials, and it is substantially easier to exchange the towed implements 4.

(12) In addition, in both variants according to FIGS. 2 and 3 light sources (not illustrated here explicitly) can be provided in the region of the stress-optical material 19 if the ambient light is not sufficient for visual evaluation. At least one optical position detection mark 9a, 9b, 9c can basically be embodied e.g. also as infrared LEDs. This permits use of the measurement principle even in the case of low ambient lighting (e.g. at night).

(13) In addition, by way of example a method for operating the vehicle 2 with a hydraulic activation unit for controlling the operation of a towed implement 4 is illustrated here. Firstly, the position detection marks 9a, 9b, 9c are detected by means of the camera 8 directed towards them. Then, the (current) vertical position 25 of the towed implement 4 is determined with respect to the ground 5 from the detected position of the position detection marks 9a, 9b, 9c and the known shape of the towed implement 4. The vertical position 25 which is determined in this way is then compared with a (stored or desired) reference vertical position 26. If the determined vertical position 25 differs from a reference vertical position 26 (more than desired or permitted), the hydraulic activation unit or the lifting mechanism 15 is activated and the towed mechanism 4 is pivoted.

(14) FIG. 4 shows the combination of the stress-optical material 19, a light source 23 and a camera 8 in a separate, enclosed unit 24 (see FIG. 4a). Said unit 24 is mounted on the towed implement 4 (or also on the lower link of the lifting mechanism 14 of the agricultural tractor) in such a way that the stress-optical material 19 is fastened directly to the carrier material and can therefore detect the stresses. The transmission of energy and data to the vehicle 2 (if it is not installed on the lower link of the lifting mechanism 14) is carried out e.g. by means of cables into which the data lines are integrated. In addition, optical stress sensors can be mounted either on the lower link 17 or on the carrier 22 of the plow in order therefore to infer the tensile force during plowing.

(15) In addition, by way of example a method for operating the vehicle 2 with a hydraulic activation unit for controlling the operation of a towed implement 4 is illustrated here. Firstly, the state of the stress-optical material 19 is detected by means of the camera 8 which is directed towards it. The (current) tensile force of the towed implement 4 is then determined from the detected state of the stress-optical material 19. The tensile force (load on the towed implement 4) which is determined in this way is then compared with a (stored or desired) tensile force. If the determined tensile force differs from the reference tensile force (more than desired or permitted), the hydraulic activation unit or the lifting mechanism 15 is activated and the towed implement 4 is pivoted. The driving speed of the vehicle 2 can also be adapted alternatively or cumulatively.

LIST OF REFERENCE NUMBERS

(16) 1 Device 2 Vehicle 3 Hydraulic activation unit 4 Towed implement 5 Ground 6 Driving direction 7 Position detection unit 8 Camera 9a First position detection mark 9b Second position detection mark 9c Third position detection mark 10 Evaluation unit 11 Data-transmitting connection 12 Vehicle controller 13 Control unit 14 Lifting mechanism 15 Lifting mechanism 16 Upper link 17 Lower link 18 Tensile force-measuring apparatus 19 Stress-optical material 20 Pump 21 Control valve 22 Carrier 23 Light source 24 Unit 25 Vertical position 26 Reference vertical position