AGRICULTURAL MACHINE AND METHOD FOR OPERATION THEREOF

Description

[0001] The present invention relates to an agricultural machine with an improved system for machine diagnostics having the features of independent claim 1. The invention also relates to a method for operating such an agricultural machine having the features of independent method claim 9.

[0002] In agriculture, a wide variety of machines are used to cultivate agricultural land, for example, to spread or harvest agricultural crops, or to pull agricultural machinery across the field for field work. Such machines are referred to as tractors, harvesters, or distribution machines. What all such machines have in common is that they each have a variety of actuators, control elements, sensors, actuators, or the like, preferably electrically controlled or operated, by means of which the respective work to be performed is carried out, positions and working positions are evaluated, and the corresponding work tools are controlled.

[0003] For the distribution of agricultural materials such as seeds, fertilizers, or the like, crop protection sprayers, seed drills, precision seed drills, fertilizer spreaders, or the like are used. These typically each have at least two functional units, such as row units, nozzle units, or the like, by means of which the material to be distributed is spread over an agricultural area. For this purpose, the row units or nozzle units can have a variety of actuators, sensors, control elements, actuators, or the like, which are controlled via pneumatic, hydraulic, but especially via electrical signals or which can output electrical signals.

[0004] An agricultural distribution machine is known from DE 10 2006 038 688 A1. To ensure simple and safe activation and deactivation of the individual spray nozzles of a multi-nozzle unit, the control line or control system of this machine is designed as a CAN bus (Controller Area Network) system.

[0005] Another agricultural machine or another agricultural distribution machine is described in DE 10 2010 061 241 A1. In order to avoid having to assign at least one microprocessor, one energy storage device, and one CAN bus connection to each actuating element and actuator, groups of actuators are formed, each controlled via a common control unit, thereby increasing the maximum number of controllable actuators. Communication takes place via a CAN bus system. To determine the position of the control units in the CAN bus system, another electrical control line is provided parallel to the CAN bus, as well as a switch in each control unit, via which the microprocessor can pass the control line on to the next control unit. In the initial step, the control line may not be connected through in all devices or control units.This means that a signal applied to the control line can only be received by the first control unit, which then communicates with a control computer because the control computer is now receiving a signal. The control computer can now identify the control unit and assign it an address in the CAN bus system and thus a position on the agricultural machine. The control unit can then be given the command to switch the control line on. This can also happen automatically. The next control unit in the series can then receive the signal applied to the control line. From here, the same process can begin as with the first control unit. By repeating this procedure, all devices on the CAN bus can be assigned a unique position.

[0006] Another agricultural distribution machine is disclosed in DE 10 2010 061 241 A1. The agricultural distribution machine comprises at least one control unit, preferably several control units. Groups of actuators or several electrical actuators or units for switching metering devices on and off or adjusting them, or for recording sensor data, as well as for switching or regulating electrical consumers or current-carrying lines for operating electrical elements, are assigned to the control unit(s). The plurality of control units can be connected to a control computer or a central unit via a bus. At the same time, each actuator can be directly connected to one of the control units via electrical connections. Optionally, the actuators can also be connected to the control unit via another bus system, which can be a CAN bus system.

[0007] Various agricultural machines are already known from the state of the art that feature a CAN bus system, which allows a defined arrangement or sequence of controlling individual actuators, sensors, or the like. These CAN bus systems typically have a linear structure, at the end of which a terminal resistor is usually installed, which is required for the proper functioning of the CAN bus system. Such systems or linear structures are also referred to as "daisy chains."

[0008] However, the "daisy chain" systems known from the prior art have the disadvantage that addressing of the individual control units is usually very slow due to the serial switching, which means that such systems can only be used to a limited extent for fast switching processes, especially for so-called section control applications, during operation. This slowing effect is further amplified by the one-sided input of messages and signals. In particular, practical experience has shown that communication in the CAN bus system is generally too slow during operation of machines with large working widths.

[0009] Furthermore, the known "daisy chain" systems have the disadvantage that if the "daisy chain" is interrupted at any point, the subsequent control units or control devices can no longer be reached. This can lead to a complete failure of the CAN bus system, especially since the terminal resistor located at the end of the "daisy chain" and required for proper function can no longer be reached or is no longer present. Possible causes for this, such as faulty bus control or whether there are further problems with the control devices on the agricultural machine after an interruption point, cannot be determined or diagnosed by the system. Likewise, fault localization or machine diagnostics, as well as continued operation of the machine, are not possible, which generally makes rapid troubleshooting impossible.

[0010] In addition to a CAN bus system, agricultural machines generally also require a power supply system to operate their functional units. This can be integrated into a CAN bus system, or it can be separate from it or even exist without a CAN bus system. These power supply systems are also generally designed as a line structure. However, even in these systems, a cable break at any point in the line structure can cause the power supply to fail throughout the entire system, making continued operation of the machine impossible. Furthermore, machine diagnostics are therefore also impossible because the specific defective location cannot be located.

[0011] To improve this, power supply systems or CAN bus systems with an additional redundant system are already known. One such system with a redundant CAN bus system is described, for example, in EP 0 864 457 B1. However, such redundant systems are very complex and expensive due to the generally required duplicate system structure, and they also require a lot of installation space. Furthermore, such redundant systems can only be used when precise positioning of control units on the agricultural machine is not required, since the redundant systems each operate independently and each perform "independent" addressing. Thus, such redundant systems are of limited use, particularly in crop protection sprayers, seed drills, precision grain machines, or the like.

[0012] Another redundant system or redundant CAN data bus is described in DE 103 24 724 A1. This redundant CAN data bus is designed in the form of a CAN data bus ring open at one point for "n" devices. The data bus ring consists of "n" CAN data bus segments arranged between the devices, which can be connected to or disconnected from the data bus via switching means provided in the devices. During operation, an active data bus is used, in which the devices are connected to one another via a chain of "n-1" of the "n" CAN data bus segments. The unused CAN data bus segment represents a redundant data bus segment, which can be added to the remaining chain of data bus segments as a replacement in the event of the failure of one of the "n-1" CAN data bus segments.

[0013] DE 103 10 302 B4 discloses an initialization method for a ring-shaped data bus arrangement, in particular for a vehicle braking system, in which defects in the power lines of the participants are taken into account. The ring structure comprises power lines for the participants, with two central power switching elements arranged in at least one power line. A local power switching element is also provided for at least some of the participants. When a data bus section and the respective power section and participant are connected, a check is first performed to determine whether or not a fault is present. Depending on the test result, further steps are initiated.

[0014] WO 2013 / 103937 A1 discloses a bus system for monitoring and detecting errors in a device used for agricultural purposes. The system comprises several modules, each containing several sensors connected to each other in a loop. The loops assigned to the individual modules are, in turn, connected to each other in a linear structure or "daisy-chain configuration."

[0015] However, such systems have proven to be disadvantageous due to their complex and costly design, so that they are rarely or not at all used in agricultural machinery.

[0016] The invention is based on the object of realizing an agricultural machine and / or providing a method for operating an agricultural machine that enables simplified machine diagnostics and increases reliability without requiring an additional redundant system. These objects of the invention are achieved by an agricultural machine having the features of independent claim 1 or by a method having the features of independent method claim 9, with further advantageous embodiments and refinements of the invention emerging from the respective dependent claims.

[0017] To achieve the stated aim, the invention proposes an agricultural machine, in particular an agricultural distribution machine such as a crop protection sprayer, a seed drill, a precision grain machine, a fertilizer spreader or the like, by means of which seeds, fertilizers, crop protection products or the like can be distributed on an agricultural area. The machines each have at least two functional units such as row units, nozzle units or the like, by means of which the material to be distributed is distributed or by means of which the required work is carried out. Such functional units can also be understood or referred to as assemblies, whereby a larger number of similar assemblies can normally be present, as is the case, for example, with seed drills with a larger working width and a corresponding number of sowing units, so-calledrow units or application units.

[0018] For example, at least one main control unit and / or one voltage supply unit are assigned to the machine, whereby the voltage supply unit can also be part of the main control unit, and whereby the voltage can also be supplied by the main control unit or whereby the main control unit can also be part of the voltage supply system. Each functional unit is assigned an electrical control unit which is activated by the main control unit or is controlled and / or regulated by it. This electrical control unit is used to switch dosing devices and / or actuating elements on and off and / or to record sensor data and / or to switch, control and / or regulate electrical consumers and / or to switch and / or control and / or regulate current-carrying lines for operating electrical elements. The connection orCommunication between the main control unit and / or the power supply unit and the at least two electrical control units, or between the at least two control units, takes place via a CAN bus system or via a power supply system. In order to achieve simplified machine diagnostics without a redundant system, the invention provides that the CAN bus line and / or the power supply line is designed as a ring line, wherein the ring line is composed of a plurality of connecting lines and a two-way feed of signals and / or messages is made from the main control unit and / or the power supply unit in the direction of the at least two control units.

[0019] A CAN bus topology, a power supply system, or a "daisy chain" makes it possible to detect, diagnose, and / or localize failures of individual functional units or control units, or line breaks, and determine which functional unit, row unit, nozzle unit, control unit, and / or point in the daisy chain is specifically affected. Identifying the defect, e.g., a connecting cable between two control units or a control unit itself, allows the remaining functional functional units to continue to be used, rather than all functional units remaining nonfunctional from the point of failure onward, as was previously the case. These units were previously connected via a CAN bus line and associated spur lines without redundancy and the possibility of machine diagnostics or fault diagnosis.

[0020] In contrast to CAN bus systems and / or power supply systems previously designed as a line structure with a one-sided signal and message feed and generally only a one-sided terminating resistor, the invention provides for a two-sided feed of signals and messages, starting from the main control unit and / or from the power supply unit into the CAN bus system or into the power supply system, which is achieved in particular by a CAN bus line or power supply line designed as a ring line, whereby, for example, in the event of a line break or a fault between two control units, control or power supply can still take place from a side facing away from the defective point.

[0021] It should be noted that the ring line may be connected to the main control unit. It is conceivable that the ring line is located in the area of ​​the control units, but this ring line is interrupted by the main control unit or the power supply unit. In the event of such an interruption of the ring line, particularly the CAN bus system, the main control unit may be assigned corresponding terminating or termination resistors.

[0022] The daisy chain also provides for the system to be divided into a plurality of individual, independently functional CAN bus systems, corresponding to the number of control units or functional units present. The resulting plurality of individual CAN bus systems is then connected to form an entire CAN bus system using a hardware gateway. The resulting CAN bus system or daisy chain can theoretically be extended indefinitely, as the respective CAN bus lines or connecting lines between two control units or between a control unit and the main control unit only have a length from one control unit to the next or only a length from one control unit to the main control unit. Such a theoretically infinite extension of the CAN bus system was previously not possible with the systems known from the prior art, as their length is limited.Thanks to the existing CAN bus system and daisy chain, agricultural machines with a large working width and a multitude of, for example, twelve or more functional units can also be implemented. In particular, the daisy chain eliminates the need for repeaters or similar signal amplification devices.

[0023] According to a useful option, the invention can further provide that the ring line of the CAN bus system and / or the power supply system is formed by a plurality of connecting lines, wherein the number of connecting lines results in particular from the sum of existing control units and the existing main control units + 1. Thus, the connection between the main control unit and the control units or between the control units is not made via a single ring line in the form of a CAN bus line and / or a power supply line, but according to the option of the invention there is only one connection with the direct local neighbor. This ultimately results in many small, self-functioning CAN bus systems which are inherently stable because the individual connecting lines can be made comparatively very short. In contrast, in classic CAN bus systems orIn classic daisy chain systems, the cables are laid along the entire system.

[0024] In order to achieve sufficient speed when addressing or controlling the control units, these can each be connected via a hardware gateway, or such a hardware gateway can be arranged on the control units, which can then serve as a CAN bus interface. In contrast to a software solution, such hardware gateways have a sufficiently fast forwarding of the CAN messages or CAN signals. In addition, a processor on the control units is not burdened. This can be further illustrated by the following mathematical relationship. For example, if an agricultural machine has 36 functional units, each of which is controlled by a software gateway, and each of these functional units requires, for example,a processing time of around ten milliseconds (10ms) until the signal is responded to and forwarded, this results in a time delay to the outermost functional unit of around 360 milliseconds. If this is converted to a driving speed of the agricultural machine of, for example, 15km / h, this results in a typical distance difference of around 150 centimeters between the first functional unit and the last functional unit. This time difference or distance difference is particularly unacceptable for so-called section control applications, which in turn mean that the time between a response and forwarding of the signal from a functional unit should be as short as possible. By implementing it as a hardware gateway, the time between response and forwarding can be significantly reduced, e.g.to only about one millisecond (or within that range), resulting in a distance difference of only 15 cm, which is also sufficient for a section control system. This allows signal processing and control times to be reduced by a factor of 10 using hardware gateways.

[0025] If a fault occurs in one of the control units or in one of the connecting lines of the CAN bus system and / or in the power supply system, this fault or defect can be localized by feeding signals or messages to the control units from both sides, from the perspective of the main control unit or the power supply unit, thus narrowing down the fault. By means of a signal or by means of a display device or by means of a CAN message from the main control unit, an operator can now be shown which control unit or connecting line on the agricultural machine has failed or is no longer functioning. Furthermore, the system according to the invention allows work to continue with the functioning control units on both sides of the fault, since all control units are still addressable and / orbe supplied with power, either from one side or the other of the main control unit or the power supply unit.

[0026] The connecting lines forming a ring line can, for example, be combined into a six-core cable, with some cables being designed as so-called twisted pairs. A possible distribution would be as follows: CAN − L = CAN Low = CAN Signalleitung CAN − H = CAH High = CAN Signalleitung CAN − EN = CAN Enable = CAN Adressleitung CAN − GND = CAN Ground

[0027] For example, the CAN-L and CAN-H lines are each designed as twisted-pair cables, and the CAN-EN and CAN-GND lines are each designed as twisted-pair cables. Two additional wires can be laid parallel to these, for example, serving as power supply lines, for example, for voltages of 0V and +12V. However, any other configuration of the connecting cables would also be possible or conceivable.

[0028] In the event of a malfunction, the CAN-EN line can be used, in particular, for diagnostic purposes. This can be achieved, for example, by initiating a test signal from the main control unit and then passing it sequentially to all control units, up to the main control unit and back again. This can be accomplished very quickly thanks to the connection via hardware gateways and the two-way power supply. In the event of a fault, the fault can then be localized or diagnosed, either in one of the control units or in one of the connecting lines, since the sequential forwarding allows for an evaluation of the control unit up to which fault-free forwarding is possible.

[0029] Since, according to the invention or an option according to the invention, the CAN bus connections each consist of only two control units or of a control unit and a main control unit, in the event of faults in the two CAN signal lines (CAN-H & CAN-L), a precise conclusion can always be drawn about the faulty location. The fault is therefore located either in the control unit itself or in a connecting line. This fault detection takes place, for example, directly using a CAN controller assigned to the control unit. Since the respective control units are separated by a gateway, preferably implemented as a hardware gateway, which only forwards valid CAN signals, other control units are not affected by faults. Due to the two-way connection, the fault or error can thus be reported to the main control unit and displayed by the main control unit, for example, using a display device to an operator.Apart from the defect, the functional unit remains fully functional, which represents a significant improvement over the systems known from the state of the art, in which all control units are connected to a single CAN bus line or power supply line.

[0030] In addition to the CAN bus line, a power supply line assigned to the control units can also be designed as a ring line and, for example, supply the respective control units with power from both sides, starting from the main control unit. This means that an interruption in this line does not represent or trigger a malfunction of the machine, i.e. the resulting topology represents redundancy with regard to an interruption in the power supply. Only when a second interruption in this line occurs during operation does the function of the intermediate functional units cease to exist. The power supply line, like the CAN bus line, can also be integrated into the twisted pair cable. Furthermore, it should be noted that the inventive design of the power supply as a ring line can also be used in agricultural machines without a CAN bus system.It would also be conceivable to use a voltage or current source other than a main control unit, the function being identical in each case, and in this embodiment the main control unit can also be integrated into the ring line of the voltage supply system.

[0031] The main control unit serves, for example, as a voltage supply unit or as a current source, which supplies a constant voltage of, for example, +12V and which provides an electrical current of, for example, +1.5A, or it is designed, for example, so that up to 1.5A can be drawn from it, whereby this current is fed from both sides of the main control unit or from the voltage supply unit towards the control units. If all control units are connected together, a certain current is drawn from each side of the main control unit or from a voltage supply unit. However, if a line break occurs, e.g. between two control units, the current consumption between the two sides of the voltage supply unit changes. Based on a corresponding comparison between actual values ​​and target values, it can then be determined how many consumers are still being supplied from each side of the voltage supply unit.Based on the difference between the two values, it is then possible to determine between which control units or functional units, for example, a line break has occurred, thus significantly simplifying machine diagnostics. This offers a significant advantage over prior art systems because, even in the event of a line break in the power supply system, all functional units continue to function and the specific line break can be precisely located. In contrast, prior art systems always resulted in the failure of all functional units without providing any indication of the defective location.

[0032] To achieve the above-mentioned object, the present invention further proposes a method for operating an agricultural machine, in particular an agricultural distribution machine, which has at least one main control unit for controlling and regulating a plurality of electrical control units, each of which is assigned to a functional unit of the machine. By means of said control units, a wide variety of metering devices and / or actuating elements can be switched on and / or off and / or adjusted. Sensor data can also be optionally recorded in this way. In addition, electrical consumers can be switched, switched on and / or off or regulated by means of said control units. In addition, current-carrying lines can be switched, switched on and / or off as required. Furthermore, a wide variety of electrical elements can be operated by means of said control units.In all of these options, the electrical and / or signaling connections between the main control unit and the plurality of control units are formed by a CAN bus system and / or by a power supply system. The method also provides for the electrical and / or signaling connections of the CAN bus system and / or the power supply system to be designed as a ring line. It is further provided that this ring line is composed of a plurality of connecting lines, each of which provides a two-way feed of signals and / or messages from the main control unit and / or from the power supply unit to the control units or the plurality of control units.

[0033] A variant of the method according to the invention can provide that the CAN bus system is divided into a plurality of individual, functional CAN bus systems, corresponding to the number of existing control units.

[0034] In addition, it can optionally be provided that the individual, functional CAN bus systems are connected and / or communicate with each other via a hardware gateway.

[0035] The method can also be characterized in that, for machine diagnosis, a test signal is initiated bilaterally by the main control unit and is then passed on sequentially to all control units and back again.

[0036] Furthermore, the method can assign at least one resistor to each control unit. Optionally, this resistor can also be integrated into the hardware gateway. Alternatively, the hardware gateway could be designed in such a way that no such resistor is required.

[0037] Finally, the method can also provide that in the event of a line break, the power supply system carries out a comparison between actual values ​​and target values, on the basis of which it is determined how many control units are supplied from which side of the two-sided connection to a power supply unit and / or a main control unit.

[0038] All of these above-mentioned method variants and aspects mentioned in connection with the method according to the invention or one of its embodiment variants are also to be considered as disclosed in connection with the agricultural machine according to the invention or one of its embodiment variants. Therefore, if a feature or aspect is mentioned or disclosed in connection with the method, this aspect or connection can also be combined with one of the embodiment variants of the agricultural machine. The same applies vice versa. Therefore, if a feature or aspect is mentioned or disclosed in connection with the agricultural machine according to the invention, this aspect or connection can also be combined with one of the embodiment variants of the method.

[0039] It should also be noted that the CAN bus system or power supply system according to the invention can be used in any agricultural machine with a plurality of electrically operated functional units, for example also in tractors, harvesters or the like. The same also applies to the method according to the invention for operating such an agricultural machine.

[0040] In the following, exemplary embodiments will explain the invention and its advantages in more detail with reference to the accompanying figures. The relative sizes of the individual elements in the figures do not always correspond to the actual sizes, as some shapes are simplified and others are enlarged relative to other elements for better illustration. Fig. 1 shows a plan view of an agricultural machine designed as a single-grain machine with a plurality of attached functional units. Fig. 2 shows a schematic view of a CAN bus system and / or a power supply system with a main control unit or a power supply unit and three control units, each of which is connected to a ring line composed of a plurality of connecting lines. Fig. 3 shows a functional diagram of a CAN bus system or a power supply system with a main control unit and four control units, each of which is connected to a ring line composed of a plurality of connecting lines. Fig. 4 shows a functional diagram of a CAN bus system or a power supply system with a main control unit and four control units, each of which is connected to a ring line composed of a plurality of connecting lines and wherein there is a fault in the CAN-H line between two control units. Fig. 5shows a functional diagram of a CAN bus system or a power supply system with a main control unit and four control units, each of which is connected to a ring line composed of a plurality of connecting lines and wherein there is a line break in the power supply line between two control units.

[0041] For identical or equivalent elements of the invention, the Figures 1 to 5 Identical reference numerals are used in each case. Furthermore, for the sake of clarity, only those reference numerals are shown in the individual figures that are necessary for the description of the respective figure. The illustrated embodiments merely represent examples of how the agricultural machine according to the invention can be designed and do not represent a conclusive limitation.

[0042] A variant of an agricultural machine 10 is shown in Fig. 1 , which is designed as a single-seed machine. The machine 10 has a storage container 12 for carrying and providing agricultural material for distribution. The storage container 12 is mounted on a carrier vehicle 14, which carrier vehicle 14 essentially consists of a drawbar 16 for connecting the agricultural machine 10 to a towing vehicle (not shown here), a frame 18, and a chassis 22 provided with wheels 20. At the rear end, the carrier vehicle 14 or the agricultural machine 10 is assigned a coulter bar 24 with a plurality of functional units 26 in the form of row units 28 attached thereto at regular intervals.

[0043] The row units 28 are generally used to distribute the agricultural material to be spread, with each row unit 28 being assigned an electrical control unit 30 for this purpose, by means of which the metering devices and / or adjusting elements required for a desired distribution can be switched on and off and / or adjusted and / or by means of which sensor data can be recorded or by means of which electrical consumers can be switched or regulated and / or by means of which current-carrying lines can be switched.

[0044] The outermost control units 30 are each connected to a main control unit 36 ​​via a CAN bus system 34 and / or a power supply system 35. The connection is made by means of a plurality of connecting lines 38, which in turn form a ring line 32. Likewise, the control units 30 are each connected to one another by means of a connecting line 38, wherein the connection of the control units 30 and the main control units 36 is made in such a way that only the local neighbor is connected by means of the connecting line 38. As the arrows in the Fig. 1 As can be seen, starting from the main control unit 36, a two-way feed of messages and signals takes place in the direction of the outermost control units 30 and from these a two-way feed in the direction of a directly adjacent inner control unit 30 and main control unit 36.

[0045] The Fig. 1The CAN bus system 34 and the power supply system 35 shown again come from the Fig. 2 The main control unit 36 ​​is equipped with a total of three control units 30 or CAN bus interfaces or functional units 26 (AS1; AS2; ASn), two of which are connected directly to the main control unit 36 ​​for communication with the control units 30. Thus, in contrast to CAN bus systems known from the prior art, in which communication between the main control unit 36 ​​and the control units 30 is only possible via one interface, communication within the CAN bus system 34 from both sides with the control units 30 is possible, which is achieved in particular by the CAN bus lines designed as a ring line 32, the ring line 32 having a plurality of connecting lines 38 between two control units 30 or between the main control unit 36 ​​and a control unit 30.

[0046] It should also be noted that the connecting lines 38 of the voltage supply system 35 are also designed without interruption (cf. Figures 3 , 4 and 5 ).

[0047] A functional diagram of a CAN bus system 34 or a voltage supply system 35 with a main control unit 36 ​​and four control units 30, each of which is connected to a ring line 32 composed of a plurality of connecting lines 38, is shown in the Figures 3 , 4 and 5 , whereby this in Fig. 3 without defects, in Fig. 4 with a defect 46 in the CAN bus line or in a connecting line 38 between two control units 30, as well as in Fig. 5 with a line break 48 in the voltage supply system 35 between two control units 30 or functional units 26.

[0048] The CAN bus system 34 and the voltage supply system 35 each have a main control unit 36 ​​in which two identical supply or signal systems are provided. Each of these includes a +12V direct current voltage supply, which is made up of a +12V and a 0V line. During normal operation of the CAN bus system, +1A or -1A is tapped or provided from this voltage supply, the respective current flow direction being shown by arrows. In addition, the main control unit 36 ​​also provides the CAN bus lines required for the CAN bus, which include CAN-GND; CAN-EN; CAN-H and CAN-L. In addition, the main control unit 36 ​​has two interfaces 40, each of which can be connected to a connecting line 38 leading to a control unit 30. This ensures a two-sided signal or message feed or output.Voltage supply from the main control unit 36 ​​to a control unit 30. For clarity, the connecting lines 38 are each depicted as individual wires. However, these could also be combined into a single cable, which could, for example, be a so-called twisted-pair cable. Likewise, the control units 30 each have interfaces for connecting to the connecting lines 38, although these interfaces are also not shown for clarity.

[0049] The CAN interfaces present on the control units 30 are each implemented as hardware gateways 42. This has the advantage that, in contrast to a software solution, the CAN messages are quickly forwarded to the respectively addressed control units 30 within the CAN bus system 34.

[0050] A resistor 44 is arranged next to each hardware gateway 42, although these could also be integrated into the hardware gateway 42 or the hardware gateway 42 could be designed such that it is not required. This resistor 44 forms a terminating resistor in the event of, for example, a line break in a connecting line 38, so that even in the event of a fault 46 or a line break 48, a closed CAN bus system is present. However, due to the two-sided control, this does not result in the failure of a control unit 30 or a functional unit 26.

[0051] As the Figures 3 , 4 and 5 As can be seen, the ring line 32 is closed via the main control unit 36, or the CAN-H and CAN-L outputs of the main control unit 36 ​​are each assigned terminating or terminating resistors in such a way that a closed CAN bus system is again produced.

[0052] A fault 46 in the CAN bus system is due to Fig. 4 , showing a fault 46 in the CAN-H line between two control units 30. This fault 46 can be localized by feeding signals or messages to the control units 30 from both sides, as seen from the main control unit 36, thus narrowing down the fault 46. A signal or CAN message from the main control unit 36 ​​can now indicate to an operator which control unit 30 on the agricultural machine 10 has failed. Furthermore, work can continue on both sides of the fault 46 with the functional control units 30, since all control units 30 are still addressable, either from one side or the other of the main control unit 36, thanks to the two-sided feed and the many small, self-contained CAN bus systems.

[0053] Compared to CAN bus systems 34 previously designed as linear systems, the invention provides for a two-sided feed of signals or messages or the power supply into the CAN bus system 34 or the power supply system 35, which is achieved in particular by a ring line 32 composed of a plurality of connecting lines 38. Such a configuration ensures that in the event of a line break 48 or a fault 46 between two control units, the control unit 30 or the functional unit 26 can still be controlled from the side facing away from the defective location.

[0054] The CAN bus line 32, or the individual connecting lines 38, can be composed, for example, of a CAN-L; CAN-H; CAN-EN and a CAN-GND line and can be designed, for example, as a so-called twisted-pair cable. In the event of a malfunction, the CAN-EN line can be used for diagnostics by initiating a test signal from the main control unit 36 ​​and then passing it sequentially to all control units up to the main control unit 36 ​​and back again. In the event of a fault, this subsequently enables localization or machine diagnosis of the fault, either in one of the control units 30 and / or a connecting line 38.

[0055] Since the respective control units 30 are each separated by a hardware gateway that only transmits valid data, other control units 30 are not affected by faults, and due to the two-way connection, the faulty location can be reported to the main control unit 36. Apart from the fault location 46 or the line break 48, the functional unit 26 remains fully functional, which represents a significant improvement over the systems known from the prior art.

[0056] The Fig. 5 also shows the identical functional plan according to the Figures 3 and 4but with a line break 48 in the voltage supply system 35 between two control units 30 or functional units 26. The voltage supply line, like the CAN bus line, is designed as a ring line 32, which is also composed of a plurality of connecting lines 38. The main control unit 36 ​​provides identical voltage supplies on both sides, or the same amount of current A can be drawn from the main control unit 36 ​​in each case. If a line break 48 occurs between two control units 30, a current evaluation is used to compare the amount of current drawn on the left side of the main control unit 36 ​​and the amount of current drawn on the right side of the main control unit 36.On the basis of a corresponding actual value and target value comparison, it can then be determined how many control units 30 are still supplied from the left side of the main control unit 36 ​​and how many from the other side, whereby a line break 48, for example, between two control units 30 can be narrowed down and thus the machine diagnosis is simplified accordingly.

[0057] The invention has been described with reference to a preferred embodiment. However, it is conceivable to a person skilled in the art that modifications or variations of the invention can be made without departing from the scope of the following claims. List of reference symbols

[0058] 10Agricultural machine 12Storage container 14Carrier vehicle 16Drawbar 18Frame 20Wheel 22Chassis 24Shaver bar 26Functional unit 28Row unit 30Control unit 32Ring line 34CAN bus system 35Power supply system 36Main control unit 38Connecting line 40Interface 42Hardware gateway 44Resistance 46Defect 48Cable break

Claims

1. An agricultural distribution machine, with at least one main control device (36) for controlling and regulating a plurality of electrical control devices (30), which are each assigned to a functional unit (26) of the machine (10), wherein the functional unit (26) is designed in the form of a row unit, nozzle unit, or the like, by means of which the material to be distributed is spread on an agricultural area, wherein, by means of the control devices (30), in each case - various different metering organs and / or actuating elements can be switched on and / or switched off and / or be adjusted, - and / or sensor data can be detected, - and / or electrical loads can be switched, switched on and / or switched off, or be regulated, - and / or current-carrying lines can be switched, switched on and / or switched off, - and / or various different electrical elements can be operated, wherein the electrical and / or signal connections between the main control device (36) and the plurality of control devices (30) are formed by a CAN bus system (34) and / or by a power supply system (35), characterised in that the electrical and / or signal connections of the CAN bus system (34) and / or of the power supply system (35) is / are designed as a ring circuit (32), which ring circuit (32) is composed of a plurality of connecting lines (38), wherein a two-sided feed of signals and / or messages is carried out in each case from the main control device (36) and / or from the power supply unit in the direction to the control devices (30) or to the plurality of control devices (30).

2. The agricultural machine according to claim 1, characterised in that a separate connecting line (38) is in each case arranged between the main control device (36) and a control device (30), or in that a separate connecting line (38) is in each case arranged between two control devices (30).

3. The agricultural machine according to claim 1 or 2, characterised in that the sum of connection lines (38) results from the sum of control devices present (30) added to the number of main control devices (36), or from the sum of power supply units present added to the number 1.

4. The agricultural machine according to one of the previous claims, characterised in that the CAN bus system (34) is or will be divided into a plurality of individual, self-sufficiently functional CAN bus systems the number of which corresponds to the number of control devices (30) present.

5. The agricultural machine according to one of the previous claims, characterised in that the individual, self-sufficiently functional CAN bus systems are connectable by means of a hardware gateway (42).

6. The agricultural machine according to one of the previous claims, characterised in that, for the purpose of machine diagnostics, a test signal from the main control device (36) is initiated on both sides and is then passed on sequentially to all control devices (30) and back again.

7. The agricultural machine according to one of the previous claims, characterised in that, at least one resistor (44) is assigned to each control device (30), or that it is integrated into the hardware gateway (42), or that the hardware gateway (42) is designed in such a manner that no resistor (44) is required.

8. The agricultural machine according to one of the previous claims, characterised in that, in the event of a line break (48), the power supply system (35) performs an actual / target value comparison based on which it is determined how many control devices (30) are supplied from which side of the two-sided connection to a power supply unit and / or to a main control device (36).

9. A method for operating an agricultural distribution machine, which has at least one main control device (36) for controlling and regulating a plurality of electrical control devices (30), which are each assigned to a functional unit (26) of the machine (10), wherein the functional unit (26) is designed in the form of a row unit, nozzle unit, or the like, by means of which the material to be distributed is spread on an agricultural area, wherein, by means of the control devices (30), in each case - various different metering organs and / or actuating elements can be switched on and / or switched off and / or be adjusted, - and / or sensor data can be detected, - and / or electrical loads can be switched, be switched on and / or switched off, or be regulated, - and / or current-carrying lines can be switched, switched on and / or switched off, - and / or various different electrical elements can be operated, wherein the electrical and / or signal connections between the main control device (36) and the plurality of control devices (30) are formed by a CAN bus system (34) and / or by a power supply system (35), characterised in that the electrical and / or signal connections of the CAN bus system (34) and / or of the power supply system (35) is / are designed as a ring circuit (32), which ring circuit (32) is composed of a plurality of connecting lines (38), wherein a two-sided feed of signals and / or messages is carried out in each case from the main control device (36) and / or from the power supply unit in the direction to the control devices (30) or to the plurality of control devices (30).

10. The method according to claim 9, in which the CAN bus system (34) is divided into a plurality of individual, self-sufficiently functional CAN bus systems the number of which corresponds to the number of control devices (30) present.

11. The method according to claim 9 or 10, in which the individual, self-sufficiently functional CAN bus systems are connected and / or communicate with each other by means of a hardware gateway (42).

12. The method according to one of the claims 9 to 11, in which, for the purpose of machine diagnostics, a test signal from the main control device (36) is initiated on both sides and is then passed on sequentially to all control devices (30) and back again.

13. The method according to one of the claims 9 to 12, in which at least one resistor (44) is assigned to each control device (30), or in which this resistor (44) is integrated into the hardware gateway (42), or in which the hardware gateway (42) is designed in such a manner that no resistor (44) is required.

14. The method according to one of the claims 9 to 13, in which, in the event of a line break (48), the power supply system (35) performs a comparison between actual values and target values based on which it is determined how many control devices (30) are supplied from which side of the two-sided connection to a power supply unit and / or a to main control device (36).