Irrigation system

Abstract

Irrigation system comprehensive - at least one driven guide carriage (2) with, • at least one first electric motor (5), • at least one wheel (4) driven by the first electric motor (5), and • a power control unit (14) controlling the first electric motor (5) with a control power, - at least one subordinate chassis (3) with • at least one second electric motor (15), • at least one wheel (4) driven by the second electric motor (15), • a detection unit (16) for detecting an angular deviation of the subordinate chassis (3) to the leading chassis (2), and • a switching unit for switching the second electric motor (15) on and off depending on the detected angular deviation, and - a pipeline (7) stretched from the leading chassis (2) to the subordinate chassis (3) with water outlet openings for irrigation, characterized in that the power control unit (14) is designed to drive the first electric motor (5) with a permanently constant, adjustable control power.

Description

[0001] The present invention relates to an irrigation system, in particular for sprinkling or irrigating fields, according to the preamble of claim 1 and a method for controlling the irrigation system.

[0002] The current state of the art distinguishes between two basic irrigation systems. The first system irrigates circular fields. A stationary tower is located in the center of the field. Several trolleys move in circles around the tower. A pipeline is stretched from the stationary tower over the trolleys to the outermost trolley. Water outlets for irrigation are provided on the pipeline. The second system is used to irrigate rectangular fields. The trolleys move side by side on parallel lines. The pipeline is stretched over all trolleys, and water outlets are also provided in the pipeline for irrigating the field. An irrigation system of this type is known, for example, from DE 28 51 425 A1. A problem with previously known irrigation systems is always the drive control of the individual trolleys, which must ensure that the pipeline is not bent too sharply.

[0003] In current irrigation systems, the travel speed and thus the rainfall amount are controlled via a start-stop cycle on all trolleys. Typically, a percentage timer with a time period of 1 minute is used to control the lead trolley, with a setting between 15% and 30% for normal irrigation. A setting of 15% means that the lead trolley moves for 15% of the time period (e.g., 9 seconds) and remains stationary for 85% of the time period (e.g., 51 seconds). The subordinate trolleys follow the lead trolley according to a master-slave principle.

[0004] The object of the present invention is to provide an irrigation system that enables effective irrigation with cost-effective production and assembly, and in particular largely avoids bending of the pipeline. The control of the carriages should be robust and simple.

[0005] This problem is solved by the features of the independent claims. The dependent claims relate to preferred developments of the invention.

[0006] The problem is thus solved by an irrigation system comprising at least one driven lead chassis and at least one subordinate chassis. The lead chassis is driven by at least one electric motor. At least a second electric motor is used to drive each subordinate chassis. According to the master-slave principle, a control power is specified via a line control unit for the first electric motor. The angular deviation of the subordinate chassis from the lead chassis or from the nearest subordinate chassis is determined by means of a detection unit. Depending on the detected angular deviation, the second electric motor or the plurality of second electric motors of the subordinate chassis are switched on and off. If it is detected based on the angular deviation that a certain subordinate chassis is slower than the lead chassis, the second electric motor is switched on.If, in contrast, it is detected that the subordinate chassis is ahead, the corresponding second electric motor is switched off. A pipeline extends from the lead chassis through the subordinate chassis. Water outlet openings for irrigation are provided in the pipeline. According to the invention, the first electric motor on the lead chassis is no longer controlled by a start-stop cycle. In the present invention, the power control unit for driving the first electric motor is designed with a permanently constant, adjustable control power. Depending on the desired speed and thus also on the desired irrigation volume, the control power of the first electric motor or the power control unit is set by the user. This control power then remains permanently constant until the next intervention by the user.The continuous movement of the leading carriage enables a more even water distribution along the entire irrigation system. At the same time, the mechanical loads on the leading carriage are reduced. The subordinate carriages retain the very simple yet robust control system by switching the second electric motors on and off.

[0007] A complex and intelligent control system for all of the irrigation system's electric motors would result in a maintenance-intensive and complicated device. However, particularly in the areas where irrigation systems are used, the system must be designed as simply as possible so that even non-experts can operate and partially repair the systems. Within the scope of the invention, it was recognized that subordinate chassis operated with a start-stop cycle dependent on the angular deviation follow a continuously moving lead vehicle much better than a lead vehicle operated with a start-stop cycle. The subordinate chassis can therefore continue to be operated with the simple start-stop cycle.

[0008] For the sake of simplicity, it is therefore intended that the second electric motors preferably have only one power level. The second electric motors can therefore either be off or drive the subordinate landing gear at this single power level.

[0009] The power control unit for controlling the first electric motor on the guide carriage is designed, in particular, for continuously adjusting the control power, and thus for continuously adjusting the speed or irrigation volume. When operating with alternating current, this is achieved, in particular, by using a frequency converter or a corresponding component for phase-cut control or trailing-edge control.

[0010] Preferably, the first electric motor is continuously operated at a constant drive power throughout an entire irrigation process or irrigation cycle. Such an irrigation process lasts several minutes, in particular several hours. During this time, the drive power of the first electric motor does not change.

[0011] The invention is particularly suitable for circular irrigation systems. Here, a stationary tower is located in the center of the irrigation system. The pipeline extends from the tower to the guide carriage. The guide carriage is located at the very outer edge.

[0012] Alternatively, the invention can also be used in irrigation systems with two leading carriages. These irrigation systems irrigate rectangular fields. The two leading carriages are located on the outside and set the speed for the subordinate carriages located inside.

[0013] There are several options for detecting the angular deviation. For example, three states can be detected using a switch with at least three switching positions. Alternatively, a control cable is stretched between the individual landing gears, which detects the angular deviation. Alternatively, a laser can be used to measure the angular deviation between the landing gears. Furthermore, the respective position and thus the angular deviation can be determined using a GPS sensor on the landing gear.

[0014] Preferably, several subordinate landing gears are provided, each with a detection unit for detecting an angular deviation of the respective subordinate landing gear relative to the lead landing gear or to another subordinate landing gear. In particular, the angular deviation is detected relative to the nearest landing gear.

[0015] The invention further comprises a method for controlling an irrigation system. The dependent claims and advantageous embodiments described in the context of the irrigation system according to the invention find correspondingly advantageous application to the method according to the invention. The method according to the invention provides that the angular deviation of the subordinate chassis relative to the leading chassis is detected. Furthermore, the first electric motor is driven with a permanently constant control power, and the second electric motor is switched on and off depending on the detected angular deviation.

[0016] In particular, the control power is kept constant throughout the entire irrigation process. Furthermore, it is preferably provided that the second electric motor is only switched on and off, and not operated at different power levels.

[0017] The invention is explained in more detail below using two exemplary embodiments shown in the figures. Fig. 1 an irrigation system according to the invention for a circular field according to a first embodiment, Fig. 2 an irrigation system according to the invention for a rectangular field according to a second embodiment, and Fig. 3 a detection unit for the angular deviation of the irrigation system according to the invention for both embodiments.

[0018] Fig. 1 shows an irrigation system 1 according to a first embodiment.

[0019] The irrigation system 1 comprises a central, stationary tower 9, a leading carriage 2, and a subordinate carriage 3 arranged between the leading carriage 2 and the tower 9. A pipeline 7 extends from the tower 9 via the subordinate carriage 3 to the leading carriage 2. Water outlets for irrigation are provided in the pipeline 7. At the tower 9, the pipeline 7 is connected to a water supply line 10.

[0020] The leading chassis 2 and the subordinate chassis 3 each comprise two wheels 4. In the example shown, a first electric motor 5, designed as a hub motor, is integrated into each wheel 4 of the leading chassis 2. A second electric motor 15, also designed as a hub motor, is integrated into each wheel 4 of the subordinate chassis 3. As an alternative to using hub motors, it is also possible to use only one electric motor 5, 15 per chassis 2, 3. The torque is transmitted to the wheels 4 via a corresponding gearbox with a fixed ratio.

[0021] The line control unit 14 of the guide carriage 2 is adjusted by the system operator according to the area to be irrigated. Using a continuous adjustment, the system operator can specify a constant value for the control power of the first electric motor 5. This control power is then maintained until further intervention by the operator or until an automatic shutdown due to a fault. As a result, the guide carriage 2 moves with a constant control power and thus at an approximately constant speed. The second electric motors 15 can only be operated in two different states. The second electric motors 15 are either on or off.

[0022] The subordinate chassis 3 further comprises a detection unit 16 (see Fig. 3). This detection unit measures an angular deviation α (see Fig. 3), in this embodiment, a rotational angle deviation, is measured relative to the guide carriage 2. To allow for a certain, small angular deviation α, joints 8 are provided in the pipeline 7. Depending on the measured angular deviation α, the second electric motors 15 are switched on and off in order to keep the angular deviation α as small as possible, so that the pipeline 7 is not bent too sharply.

[0023] Furthermore, a central control unit 11 is installed in the tower 9. Using this control unit 11, the user can set the desired control power for the first electric motor 10.

[0024] Fig. Figure 2 shows a linear irrigation system 1 according to the second embodiment, which is used particularly for rectangular fields. Identical or functionally identical components are provided with the same reference numerals in all embodiments. Two guide carriages 2 are provided here. The two guide carriages 2 are located at the outermost positions. Four subordinate carriages 3 are located between the two guide carriages 2. The pipeline 7 extends over all carriages 2, 3.

[0025] The task of controlling the second electric motors 15 in the second embodiment is again to prevent the pipeline 7 from becoming bent. The angular deviation α of the subordinate trolleys 3 is detected in relation to the next, outer trolley 2, 3.

[0026] Fig.Figure 3 shows, in a top view of a subordinate chassis 3, a detection unit 16 for the angular deviation α of the irrigation system 1 for both exemplary embodiments. Two pipe segments of the pipeline 7 connected via the joint 8 are shown. A switch 12 is located on one pipe segment, and a sensor 13 corresponding to the switch 12 is located on the other pipe segment.

Claims

[1] Irrigation system comprehensive - at least one driven guide carriage (2) with, • at least one first electric motor (5), • at least one wheel (4) driven by the first electric motor (5), and • a power control unit (14) controlling the first electric motor (5) with a control power, - at least one subordinate chassis (3) with • at least one second electric motor (15), • at least one wheel (4) driven by the second electric motor (15), • a detection unit (16) for detecting an angular deviation of the subordinate chassis (3) to the leading chassis (2), and • a switching unit for switching the second electric motor (15) on and off depending on the detected angular deviation, and - a pipeline (7) stretched from the leading chassis (2) to the subordinate chassis (3) with water outlet openings for irrigation, characterized bythat the power control unit (14) is designed to drive the first electric motor (5) with a permanently constant, adjustable control power. [2] Irrigation system according to claim 1, characterized by that the second electric motor (15) can only be operated in one power level. [3] Irrigation system according to one of the preceding claims, characterized by that the power control unit (14) is designed for continuously adjusting the control power of the first electric motor (5). [4] Irrigation system according to one of the preceding claims, characterized by that the power control unit (14) is designed to keep the control power constant over an entire irrigation process, preferably over at least 10 minutes. [5] Irrigation system according to one of the preceding claims, characterized bythat the control power in the power control unit (14) can be adjusted by means of frequency conversion or phase control or phase trailing edge control. [6] Irrigation system according to one of the preceding claims, characterized by a stationary tower (9), wherein the pipeline (7) extends from the tower (9) over all the chassis (2, 3). [7] Irrigation system according to one of claims 1 to 5, characterized by two guide chassis (2) and at least two subordinate chassis (3) positioned between the guide chassis (2), wherein the detection units (16) are designed to detect the angular deviation from the nearest guide chassis (2) and / or from the nearest outer subordinate chassis (3). [8] Method for controlling an irrigation system (1), comprising the following steps: - Providing at least one driven guide chassis (2) with at least one first electric motor (5), at least one subordinate chassis (3) with at least one second electric motor (15) and a pipeline (7) stretched from the guide chassis (2) to the subordinate chassis (3) with water outlet openings for irrigation; - detecting an angular deviation of the subordinate chassis (3) from the leading chassis (2); - driving the first electric motor (5) with a permanently constant control power, and - Switching the second electric motor (15) on and off depending on the detected angular deviation. [9] Method according to claim 8, characterized by that the control power is kept constant throughout the entire irrigation process, preferably for at least 10 minutes. [10] Method according to one of claims 8 or 9, characterized bythat the second electric motor (15) is only switched on and off and is not operated at different power levels.

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