Control mechanism for a sprinkling system

The invention relates to a control for an irrigation system consisting of pipelines supported by towers and coupled to one another, each tower being assigned a drive motor and an electrical control unit as well as a scanning device that is operatively connected to the control unit for determining the relative position to the neighboring towers .

It is a correction control for an irrigation system consisting of pipelines supported by towers, coupled to one another, which are moved at right angles to the pipe axis. The movement can also take place in such a way that a point on the pipeline is held and it moves around this point in a circle. Such systems are known under the name CENTER PIVOT or LINEAR-MOVE SYSTEMS. Whose

They are usually driven by electric motors that are mounted on the individual towers. The straight alignment of these systems is achieved by switching the individual motors on and off.

A sprinkling system for targeted irrigation or fertilization of a field with different areas, for example different soil properties, is known from US Pat. No. 5,246,164 A and WO 00/15987 A1. Such an irrigation system includes sensors for the detection of damp or dry areas, the type and size of the vegetation, or the soil composition. According to the evaluation of the resulting data, the valves of the individual sprinklers are controlled by a common control unit.

No. 5,246,164 A provides more detailed information about the straight alignment of the main arm.

The outermost tower is the control tower, which is decisive for the movement of the other towers. Electromechanical devices monitor the relative alignment or the angle between individual towers and set the motor of the respective tower in motion until a straight line with the adjacent tower is given. In this way, the towers align themselves one after the other in a straight line with the control tower.

In a similar way, the irrigation system of WO 00/15987 A1 includes so-called “alignement senors”. Electronically controlled motors respond to these sensors independently of one another in order to guarantee a linear alignment of the individual units. This type of alignment of the individual units with one another is completely independent of the control unit, which is used in particular to control the sprinklers and to evaluate data relating to the nature of the soil.

US Pat. No. 6,045,066 A, US Pat. No. 6,085,999 A and US Pat. No. 4,569,481 A are a

Irrigation system that allows efficient watering of the corners of a square field. Such an irrigation system has an additional irrigation arm (extension boom), the deflection of which with respect to the main arm is detected by a computer via a sensor for determining the angle. In order to reach most of the corner areas of a square field, a computer controls the movement of the additional irrigation arm. Pre-programmed “sprinkler sequences” ensure that these corner areas are watered evenly. The towers that support the main arm of the irrigation system are kept essentially in a straight line. The way in which this alignment of the main arm is achieved is not discussed in any more detail.

For this control of the drive motors it is necessary that the displacement of the respective tower from the ideal linear alignment is detected with scanning devices (transmission part, switching cam). Electromechanical switching elements (microswitches, contactors) are then operated via these scanning devices.

AT413 065B

With the conventional systems this is solved as follows:

On each tower there is an elekr. Control unit that is connected to the central control cabinet (control center), which is usually located at the pivot point of the system, via a supply cable. The main circuit for the drive motors and the control voltage for the control units are transmitted via this cable. The main parts of the control center are a transformer for the control voltage, a main switch that creates the electrical supply to the system, a switch for the forward and reverse flow of the system, a percentage timer for the speed control of the last tower and a switch that connects the system

Movement sets or stops.

Since the speed of each drive motor is fixed, each tower would run at the same speed when the system is set in motion. With CENTER PIVOT systems, however, the tower located further inside must travel a proportionally shorter distance in order to complete a 360 ° rotation. Therefore, the tower located further inside has to run a proportionally shorter period of time in order to keep the system straight. As already mentioned, the percentage timer is built into the control center, which sets the speed of the system. If this is set to 100%, the contactor of the last tower drive motor closes, which means that 400 volts are continuously supplied to the drive motor and the tower runs continuously. For reasons of irrigation technology, it is necessary to let the system run at lower speeds, the percentage timer being set to 50%, for example, which means that the end tower 1 is in operation for 30 seconds within one minute and is at a standstill for 30 seconds. This Entturm is also known as the control tower. No scanning device is arranged on this, since there is no need to register any deflection of a subsequent tower.

The inner towers have a scanning device that transmits the degree of angulation between two towers to two microswitches via a transmission part and a switching cam, one switch serving as a work switch and the second as a safety switch.

If the last tower now moves forward, the transmission part with the switching cam is also moved forward on the penultimate tower; At a certain angle, the switch cam actuates the microswitch, whereupon the contactor is closed and the drive motor sets the tower in motion. This runs until it is in a straight line with the last tower.

This alignment is repeated for each tower over the entire length of the system.

Since the last tower only stands still for a short time, it can start moving again before the inward alignment is completed. Each tower can therefore move at any point in time; it just depends on how the towers are angled to each other. If a tower remains due to a defect or rushes ahead and the permissible angulation is exceeded, the safety switch is actuated, which then switches off the entire system (buckling). The realignment of a system in the knee run is done via the control center and is done "manually". This type of correction control has the disadvantage that not all towers can be controlled centrally from one point, that all towers can run at the same time, the cause and the exact position of the error cannot be identified centrally in the case of a break, and the realignment after such a break Must be done "manually".

The object of the present invention is to be able to control all towers centrally from one point, to determine the maximum number of towers starting up, to adjust the towers that are in operation at the same time, to obtain information from the towers,

Send information from the control center, the alignment of the overall system and

AT 413 065 Β the automatic realignment after a break.

According to the invention, this object is achieved with a controller of the type mentioned at the outset in that the controller has a central control unit which communicates with the control units assigned to the driving towers, which send messages, in particular data about the relative positions of the driving towers, to the central control unit or from the central control unit receives commands and carries them out.

In a preferred embodiment, the central control unit communicates with the control units assigned to the io driving towers via a serial bus system CAN (Controller Area

Network).

The invention is explained in more detail below with reference to the drawing. They show

Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5 show an irrigation system with different positions of the towers,

6 shows a tower with control unit and scanning device, and FIG. 7 shows a control unit with CAN nodes.

The individual positions of an irrigation system are to be explained with reference to FIGS. 1 to 5:

Fig. 1 shows the starting position. The speed setting on the percentage timer, for example 50%, corresponds to a driving speed of 72.5 m / h (max. 145 m / h). The percent timer works in a time sequence of one minute, ie if the timer is set to 50%, the system runs for 30 seconds. The central pivot point is designated by 1.

Start of the end tower: The end tower moves until it has reached the maximum angle of 0.15 ° (Fig. 2, corresponds to a path of 153 cm for a 58.5 m span).

Start of the 1st tower. The first tower moves until it has reached the maximum deflection of 0.15 ° (Fig. 3).

Start of the 2nd tower. The second tower moves until it has reached the maximum deflection of 0.15 ° (Fig. 4).

Start of the 3rd tower. The third tower moves until it is in a straight line with the second tower (Fig. 5). Alignment is complete.

The invention relates to a correction control for movable circular irrigation systems, consisting of coupled pipelines carried by towers 3, 4, 5, 6, these towers 3, 4, 5, 6 being aligned with one another via a control unit 7 mounted centrally on the tower. In each of these control units 7 there is now an intelligent control which communicates with a central control unit (control center 2) via the transmission medium CAN-BUS and which sends messages or receives commands and executes them. The serial bus system CAN (Controller Area Network), originally developed by Bosch / Intel for automotive applications, is multi-master capable, ie several CAN participants can request the BUS at the same time. The message with the higher priority (determined by the identifier) ​​asserts itself without any loss of time. As a result, each of these control points can be called "CAN - NODE" from the control center 2 ON - or

Turned off.

The inputs of these CAN nodes 10 are actuated by microswitches and this information is transmitted to the control center 2 via the CAN bus. Furthermore, information is transmitted from the control center 2 via the CAN bus to the CAN node 10 and to the

Drive motors or indicator lights are output. The advantages of this system over other systems is that each CAN node 10 can be controlled centrally, which opens up new possibilities for controlling a CENTER PIVOT, determining the maximum approaching towers and setting the towers that are in operation at the same time. A new way of aligning the entire system with all towers 3, 4, 5, 6 by the control center 2 means that all towers 3, 4, 5, 6 have no angular displacement, that is, the entire CENTER PIVOT from the central control in a straight line Line from the center of the system to the last tower 3 is aligned.

io This is necessary for the normal operation of the CENTER PIVOT, since too large an angular displacement between two towers leads to the switch-off of the CENTER PIVOT and the output of an error message with the cause of the error and the exact position of the error (at which CAN node 10) is reported will.

Such information is only possible through the CAN nodes 10 mounted on the tower 3, 4, 5, 6, which report this information to the control center 2.

Fig. 6 shows a tower with scanning device 8 and control unit 7. The scanning device 8 transmits the degree of angulation between two towers via a transmission part and a switching cam 9 to two microswitches, one switch serving as a work switch 12 and the second as a safety switch 13.

The control unit 7 is shown in detail in FIG. 7. It comprises a switch cam 9, a microswitch as a work switch 12 and a microswitch as a safety switch 13, a

Contactor 11 and a CAN node 10.