Conveyor system, motor roller controller, and method of operating conveyor system

Abstract

A method for operating a motor roller controller in which: a first value indicative of a current intensity at an input power port of a first motor roller controller is measured by a meter of the first motor roller controller, the first value is sent to at least one second motor roller controller via a signal bus port of the first motor roller controller, receiving, at the signal bus port, at least one second value indicative of the current intensity at the input power port of at least one second motor roller controller, determining a nominal value of the current intensity at the input power port of the first motor roller controller as a function of the first value and the at least one second value, and operating a motor roller control port of the first motor roller controller with the output current to the motor roller such that the current intensity at the input power port reaches a nominal value.

Description

Technical Field

[0001] The present subject matter relates to a method for operating a motor roller controller, in particular for operating a conveyor system, for example for conveying goods, packages, etc. In addition, the present subject matter relates to a conveyor system having a motor-driven conveyor driven by a motor roller. The present subject matter also relates to a motor roller controller in such a conveyor system. Background Art

[0002] The motor-driven conveyor roller (also called motor roller) comprises a roller body rotatably mounted about a roller axis. The roller body is usually a hollow tube. The motor is arranged inside the roller body. The motor is an electric motor configured to generate a rotational motion about the roller axis between the roller axis and the roller body.

[0003] For ease of understanding, hereinafter, the term "motor roller" may be used to refer to only the motor in the roller body, to refer to the drive unit including the motor and the corresponding control circuit of the motor in the roller body, or to refer to the roller body including the motor or the drive unit. hereinafter, the term "motor" may be used to refer to the motor itself and to refer to the drive unit including the motor itself and the corresponding control circuit of the motor.

[0004] As is well known, the motor roller is operated by a control unit (also referred to as a controller) which is arranged outside the roller body. The controller exchanges control signals with the motor inside the roller body.

[0005] Motor-driven conveyors driven by motor rollers of this type are used in conveyor systems. In such conveyor systems, a single motor roller is used to operate several roller bodies in a conveying zone. Conveyor systems usually have several conveying zones through which the objects to be conveyed pass one after another. As described above, in each conveying zone, at least one motor-driven conveyor roller operates several rollers.

[0006] The controller has a wired power inlet (input power port) for receiving power (preferably DC power). However, the input power port can also be an AC port, in which case a rectifier can be arranged on the controller for converting the input AC power into DC power. In addition, the controller has a wired motor roller control port. The wired motor roller control port is configured to provide drive power to the motor roller. The motor can be fed through the motor roller control port using, for example, a pulse width modulation (PWM) signal to at least control the speed of the motor. In addition, the motor roller control port can be used to exchange state information and control signals between the motor roller and the controller. The state information and / or control signals can include, in particular, actual motor speed, set motor speed, actual conveyor speed, set conveyor speed, actual rotation direction, set rotation direction, actual operating mode, set operating mode, temperature, error message, transmission ratio of the motor gear, serial number, article number, production date, etc. In particular, the motor roller control port is a four-wire motor roller control port consistent with EP 3100340B1.

[0007] Conventional controllers include wired I / O (input / output) ports. Such I / O ports are configured to exchange control information with a central control center (e.g., a central PLC (SPS) controller). For example, a proprietary protocol can be used to configure the I / O ports. However, the I / O ports can also be configured using standardized I / O protocols, such as according to CAN, DeviceNet, Ethernet Powerlink, INTERBUS, Fieldbus, LIN, M-bus, PROFIBUS, VARAN, etc. In addition to such conventional controllers, wireless controllers that operate similarly to wired controllers are also known. The explanation of wired controllers and wireless controllers can be used for both, except that the I / O bus or wireless controller is a wireless bus with an appropriate wireless protocol.

[0008] The controller is configured to exchange motor roller control signals with the motor roller at the motor roller control port, exchange motor roller status signals with the motor roller at the motor roller control port, and exchange motor roller control signals for the motor roller with the central controller at the I / O port. The exchange of relevant control and status signals is well known and requires no further description. It should be noted that all ports and inlets of a wired controller are preferably wired ports, requiring wiring between the motor roller and the controller and between the controller and the centralized control center. Wiring is generally necessary to provide stable communications in an industrial environment. A wireless controller also has wiring connected to the motor roller and power inlet, but also has a wireless I / O port.

[0009] For ease of understanding, a motor roller controller (also referred to as a controller) may be configured to control a motor roller. In this way, within the controller, at least one microprocessor may be configured to operate the motor roller within the conveyor system, and more particularly, to operate at least one motor roller within the conveyor system.

[0010] Conveyor systems usually consist of several conveyor zones. That is, one conveyor zone is followed by the next conveyor zone. In each conveyor zone, at least one, preferably only one, motor roller is provided. At least two spatially adjacent motor rollers can also be operated by a single motor roller controller.

[0011] Preferably, each motor roller or at least every other motor roller is controlled by a separate motor roller controller.The motor roller controllers are connected to each other and to the central controller using a serial bus.

[0012] The controller of the conveyor system is powered by a central power supply. The power supply is preferably a DC power supply, however, where possible the present subject matter also relates to an AC power supply. In typical conveyor systems, in particular where human-machine interaction is involved, the power supply has a low voltage. In this sense, low voltage is to be understood as a voltage below 100 V, in particular below 50 V, such as 48 V, 24 V or 12 V. In order to provide sufficient power to the motors, higher supply currents are required. In order to keep the ohmic losses in the supply lines low, these high currents require a cross-section of the supply cable greater than, for example, 1.5 mm 2 , especially greater than 2.5mm 2 , 4mm 2 . These higher cross-sections require more metal per meter of cable, which increases the cost of the cable. In order to keep costs low, the cabling is calculated to the minimum requirements. However, ohmic losses lead to a voltage drop along the supply line, i.e. from the power supply to the controller. In the case of high power demands, this can lead to an undervoltage at the controller and therefore to an undervoltage at the motor connected to the controller. The undervoltage can lead to malfunctions of the controller and / or the motor. According to the prior art, the undervoltage problem is usually solved by sending an error signal from the controller or by a momentary stop of the controlled motor. Both solutions have a negative impact on the entire system. From a system integration point of view, this problem is both irritating and annoying.

[0013] Furthermore, conveyor systems are usually equipped with power supplies whose rated current meets the most reasonable operating conditions. However, there are situations with higher current requirements, namely when the goods to be transported are heavier than expected during the design of the conveyor system, which leads to overcurrent and thus activation of the power supply protection. This can also lead to malfunctions in the conveyor system.

[0014] The above definitions and description are to be understood as being part of the following disclosure, ie the above definitions and description form an integral part of the claimed subject matter. Summary of the invention

[0015] In order to increase system availability and overcome undervoltage and / or overcurrent problems, the subject matter relates to the method of claim 1 .

[0016] A conveyor system is particularly arranged for conveying goods, parcels, etc. along a conveyor line. The conveyor system may include at least two conveying zones, each of which is actuated using a motor roller. For ease of understanding, the terms conveyor, conveying zone or conveying line may be understood as synonyms. The conveyor system may include at least two conveying zones. The conveying zone may include at least one motor roller and at least two, preferably six or more passive rollers. The motor roller and the passive roller each include a preferably cylindrical tube, which is rotatably connected to a frame by means of an axis. By actuating the motor roller, the passive roller is also actuated and rotates in the desired direction.

[0017] In order to operate the motor roller, a motor roller controller is required. The motor roller controller is arranged to provide electrical energy to the motor roller, and is also used to control the action of the motor roller, in particular to control start / stop, direction of rotation, rotational torque, number of revolutions, revolutions per minute (RPM). In addition, the motor roller controller can be arranged to sense the state of the motor roller. The motor roller control port of the motor roller controller can be used to power the motor roller and / or sense the state of the motor roller. The motor roller is connected to the motor roller controller via the motor roller control port. Therefore, the motor roller control port of the motor roller controller is a wired port. In order to operate multiple motor roller controllers, the motor roller controller is in turn connected to a control bus. Conventional systems include multiple motor roller controllers, each of which is connected to a wired control bus.

[0018] Now, a method for operating a motor roller controller is proposed.

[0019] When operating the motor, the controller draws current from an input power port, such as a power inlet as described above. The current is provided to the input power port via a cable. The cable can connect two or more controllers to a common power supply. The cable has at least two wires. At the input power port, a first value indicating the current intensity at the input power port of the first motor roller controller is measured. Thus, at the input power port, a meter indicating the current, i.e. an ammeter, can be provided, preferably as part of the controller. The meter is arranged to sense information indicating the current intensity at the input power port. The meter can output a first value indicating the sensed current intensity. Indication can also be understood as representation. The term meter can be understood as a measuring sensor. The terms metering, measuring, determining, sensing or obtaining can be used interchangeably.

[0020] In a system according to the present subject matter, at least two controllers are connected to a common power supply. The controllers connected to the power supply can communicate with each other via a signal bus port. The signal bus port can be an I / O port or other communication port, in particular a communication port of a corresponding controller. The term signal bus port can be understood as a port for communication on a signal bus. The signal bus can be any type of bus for communication. The controller can be connected to such a bus for communication. The communication can be a direct two-way communication between the controllers, or an indirect communication via a communication hub. The signal bus port can be an I / O port as described above or any other communication port. The terms communicate, send, transmit, receive can be used interchangeably. In particular, values ​​can be sent, transmitted, communicated. This includes polling and / or pushing data between communication partners.

[0021] After obtaining the first value, the controller may send this value. According to one aspect, the first value is communicated to at least one second controller. The first value may also be sent to a central controller. The at least one second controller may be configured and operated identically or at least similarly to the first controller, so the description of the first controller applies to the second controller, and preferably also to any other controller along the conveyor line or conveyor system.

[0022] A second value indicative of current intensity at an input power port of at least one second motor roll controller may be measured in the second motor roll controller. The second value may be sent from the second controller. As described above, the first controller and the second controller may operate similarly, particularly in terms of measuring and sending the first value / second value.

[0023] The second value can be received in the first motor roller controller, in particular at the signal bus port. The second value can be received in the central controller. For example, all controllers along a conveyor line or in a conveyor system can meter and transmit their first values. In addition, these first values ​​can be received as second values ​​in other controllers. Therefore, the controller knows its own first value and the first values ​​of other controllers that are received as second values. The terms first and second are only used to improve the readability of the claims. Sending and / or receiving a value can be understood as sending and / or receiving data indicating a value.

[0024] In the controller, not only one first value can be obtained, but preferably, the controller obtains multiple first values ​​at different times (e.g., periodically or triggered by an event). In the controller, not only one second value can be received, but preferably, the controller receives multiple second values ​​at different times (e.g., periodically or triggered by an event). The controller can be any one of a motor roller controller or a central controller.

[0025] The controller may populate the list with the first value and the second value and information indicating the time so that the controller can calculate the sum of the first value and the second value at a specific moment or within a specific time interval. The sum may indicate the total current intensity of the controllers at the power supply common to the controllers. The controllers may be connected to the same power supply.

[0026] In order to allow the conveyor system to operate flawlessly in most cases, in particular in cases where high current intensities are required at certain controllers at certain times, it is now proposed to determine a nominal value for the current intensity at the input power port of the first motor roller controller based on a first value and at least one second value. The controller usually has a required maximum current to operate flawlessly. The nominal value can impose a limit on this maximum current. Thus, even if the motor requires a higher current, the current available to the motor can be reduced to the nominal value.

[0027] It should be noted that the controller can control the motor so that the motor draws a certain current from the motor roller control port. The current at the motor roller control port can depend on the impedance of the motor. The impedance of the motor can depend on the torque of the motor. The controller can control the motor so that the motor only draws a nominal value of current.

[0028] The nominal value may be understood as a set value or an indication of the current intensity of the controller at the input power port. The nominal value may be determined within the controller or external to the controller. The term "determine" may be understood as calculate, estimate or obtain.

[0029] The nominal value may be determined individually for each controller along the conveyor line. The nominal value may be determined jointly for more than one of a plurality of controllers along the conveyor line. The nominal value may be understood as a set value or an indication of the current intensity of the controller at the motor roller control port. The nominal value may be understood as a set value or an indication of the current intensity of the motor in the motor roller. The nominal value may be determined in one or any of the motor roller controllers or in the central controller. The nominal value may be sent from one motor roller controller to another motor roller controller or from the central controller to any of the motor roller controllers via a bus.

[0030] For example, for a certain time or time interval, in particular for an instantaneous time, the controller may take into account the instantaneous measured first value and the received second value to determine the nominal value. For example, for a certain time or time interval, in particular for an instantaneous time, the central computer may take into account the instantaneous first value and the second value to determine the nominal value of a specific controller.

[0031] After the nominal value of the first controller has been determined, the motor roller control port of the first motor roller controller is operated with the output current to the motor roller so that the current intensity at the input power port reaches the nominal value. The motor is controlled in such a way that the motor draws a current from the motor roller control port that is consistent with the nominal value. The current drawn at the motor roller control port may be different from the nominal value, however, the current intensity changes from the instantaneous current towards the nominal value, i.e., when the nominal value is lower than the instantaneous current, the current intensity of the motor is reduced.

[0032] According to an embodiment, a first value indicating the current intensity at the input power port of the first motor roller controller is determined at the motor roller control port of the first motor roller controller. Rather than measuring at the input power port of the controller, the current intensity is measured at the motor roller control port. The motor roller is powered by the controller at the motor roller control port. The current drawn by the controller from the input power port is mainly the current provided to the motor at the motor roller control port. The controller itself consumes only a small amount of power. Therefore, the current at the motor roller control port can also indicate the current at the input power port. The same applies to a second value indicating the current intensity at the input power port of the second motor roller controller. The second value can also be determined at the motor roller control port of the second motor roller controller.

[0033] According to an embodiment, information representing the membership of the first motor roller controller in a common group, in particular the group ID of the common group, is assigned to the first motor roller controller. As described above, at least two or more controllers can be connected to a common power supply. Controllers connected to a common power supply can form a group. In particular, controllers electrically connected in parallel with a common power supply can form a common group. It is also possible that controllers along a common cable belong to a common group, wherein a second group of controllers in parallel therewith can be connected to the same power supply, but using a separate cable.

[0034] The voltage drop along the cable may cause undervoltage. When multiple controllers are grouped into a common group, the current intensity along the cable of the common group can be determined. The controllers within the group can use the information representing the group to determine whether the received second value is relevant. Only those second values ​​from controllers of the same group as the receiving controller can be used. The first motor roller controller and at least one second motor roller controller can each be assigned information representing the group.

[0035] The information representing membership may be a group ID. The information representing membership may be a numeric value or an alphanumeric value. The information representing membership may also be understood as information representing a group.

[0036] The information representing the membership can be assigned to the controller manually, for example, using DIP switches, for example, during the first installation. It is also possible that the information representing the membership can be assigned to the controller electronically using an I / O port. The controller can also determine the information representing the membership of the controller autonomously. For example, the power supply can send a signal along the cable indicating specific information representing the membership to the connected controller. In addition, the controllers can change their current intensity in a certain pattern during initialization, and all controllers connected to the same cable can measure the current intensity of this pattern and can detect their membership of a certain group.

[0037] According to an embodiment, a first value is sent by the motor roller controller together with information representative of membership. This allows the receiving controller to determine whether a received second value is relevant. The communication link between the controllers may be different from the power cable. Thus, a second value belonging to a controller of a second group may be received in a controller belonging to a first group. Such a second value originating from a controller belonging to a different group may be discarded in the receiving controller.

[0038] According to an embodiment, only those second values ​​received together with the information representing the membership corresponding to the information representing the assigned membership are used to determine the nominal value. As described above, the nominal value is used to prevent undervoltage and / or overcurrent. The nominal value allows each controller to adjust its current intensity, such as the current intensity output at the motor roller control port, so that the total current within the group can be limited without reducing the overall performance of the conveyor line.

[0039] The limit value of the sum of the first and second values ​​of all motor roller controllers assigned to a common group can be determined based on various parameters, such as power limit of the power supply, cable cross section, cable length, etc. This limit value enables almost no overcurrent to occur within the group.

[0040] The limit values ​​can be determined manually. In particular, when setting up a conveyor system, parameters which are detrimental to the limit values ​​can be determined and the limit values ​​can be calculated. The limit values ​​can also be determined automatically. The limit values ​​can be set manually in the controller or can be transmitted to the controller.

[0041] Not only the first value and the second value, in particular their sum, are related to the nominal value, but the nominal value can also, in particular additionally, be determined from the limit value. The nominal value can be determined dynamically, for example, over successive time intervals. The relative and / or absolute difference between the sum of the first value and the second value and the limit value can indicate the nominal value. Likewise, the gradient of the relative and / or absolute difference between the sum of the first value and the second value and the limit value can indicate the gradient of the nominal value.

[0042] For at least one controller, a preferred individual correction factor may be set, indicating the coupling between the nominal value and the above-mentioned difference. That is, some controllers may be set to be more sensitive to changes in the difference than other controllers. For example, some controllers control motors that are more important to the operation of the conveyor line than other motors. These controllers have lower correction factors than controllers that are less important to the operation of the conveyor line.

[0043] According to an embodiment, the nominal value is determined by a processor of at least one motor-roll controller within a common group. That is, at least one controller within the group may be responsible for determining the nominal value of at least one other motor-roll controller in the group, in particular the nominal value of all motor-roll controllers in the group. However, the nominal value may also be determined individually by a processor of a motor-roll controller for the individual controller. Like the first value, the nominal value may also be communicated within the group.

[0044] The nominal value for one controller in a group can depend on the nominal values ​​of other controllers in the group. In particular, the sum of the nominal values ​​in a group should be less than the limit value of the group. Therefore, the sum of the nominal values ​​in a group can also be related to the nominal values ​​of the controllers in the group.

[0045] According to an embodiment, a current slope for changing the output current value to the motor roller in the direction of the nominal value is determined according to the first value, the second value, the sum of the first value and the second value and / or the limit value. In addition, the slope may depend on the sum of the nominal values ​​of the group. In order to control the sum of the currents within the group, it is preferred to control the current slope. The current slope may be controlled so that the slope of change of the sum of the currents decreases.

[0046] According to an embodiment, the difference between the first value and the nominal value is used by a P, PD, PI or PID controller to determine a current slope for changing the output current value to the motor roller in the direction of the nominal value.

[0047] According to an embodiment, the nominal value may be calculated similarly for each motor roll controller within the group. Some motor roll controllers, such as those controlling combiners and splitters, may not be part of the nominal value calculation, i.e., these controllers are supplied with current without the limitations described herein. All other motor roll controllers may have the same nominal value calculation.

[0048] The nominal value and the slope of the nominal value, eg the current slope of the varying nominal value, may depend on the number of motor roll controllers in the group, in particular the number of motor roll controllers in the group that participate in the current limiting described herein.

[0049] The change in nominal value can be linear or non-linear. Depending on the application of a motor roller controller within a conveyor line, the change in nominal value can follow a linear slope or a non-linear slope.

[0050] According to an embodiment, a motor roller controller is assigned one of at least two different priorities. Like the coupling coefficient, priorities can be used to distinguish controllers. Some controllers may be more relevant to the operation of the system than other controllers. In addition, conveyor lines controlled by some controllers are more tolerant of changes in their current than other conveyor lines. For example, a combiner or a diverter is very susceptible to changes in the current associated with the operation of the conveyor line. That is, as an example, the current of the combiner and the diverter should perhaps not be limited by the nominal value, or at least should be subject to the same current limit as the last controller in the conveyor system. Therefore, combiners and diverters can have a higher priority than conveyors on the conveyor line. As the current decreases, the goods are transported at a lower speed, but the conveyor line is still running.

[0051] As mentioned above, it is proposed to determine the nominal value according to the assigned priority. For example, a controller with a high priority will be assigned a nominal value lower than its required current later than a controller with a low priority. That is, in the case where it is necessary to control the current within a group, the first nominal value of the controller with the first low priority is first determined and used in these controllers. Only when the current within the group still needs to be controlled thereafter, the first nominal value of the controller with the second higher priority is first determined and used in these controllers.

[0052] According to an embodiment, the motor roller controllers of a common group are powered by a common power supply. The common power supply has a certain current rating. The sum of the currents on the controllers must not exceed the current rating.

[0053] As previously mentioned, some controllers are more relevant to operation than others. As explained, it may be appropriate to exclude one or more controllers completely from current control using the nominal value. Therefore, it is proposed to configure at least one motor roller controller within the common group to not limit its first value in the direction of the nominal value.

[0054] The upper limit of the nominal value of the motor current may be the maximum allowed current of the motor. The lower limit of the nominal value of the motor roller controller may be such that the current of the motor roller is higher than the minimum value required to rotate the motor roller. In this way, it is ensured that the roller still rotates at a lower speed, but the conveyor line can still operate.

[0055] To facilitate communication between motor roller controllers of different common groups, these motor roller controllers may be connected to the same serial bus.

[0056] A list of controllers within a group may be maintained in each controller. Using this list, it may be determined whether a received second value is relevant to the group, and according to an embodiment, whether the second value is received together with a unique identification of a corresponding motor roller controller. The unique identification may be compared with those stored in the list, and it may therefore be determined whether the corresponding second value is relevant. The unique identification may depend on a MAC address of a communication module within the controller. The unique identification may include a MAC address, a portion of a MAC address, or a value determined from the MAC address.

[0057] According to an embodiment, a list is stored within the motor roller controller, the list having all second values ​​received and information representative of membership of a common group. This allows the controller to determine the nominal value by additionally using at least its own first value.

[0058] In order to prevent excessive traffic on a communication channel (e.g., a communication bus), the first value should be communicated based on a rule. Therefore, the first value can be sent based on the absolute value of the change of the first value. For example, the first value can be sent only when the absolute change of the first value is above a threshold. In this case, the received second value of the controller is valid as long as a new second value is received.

[0059] The first value may be sent based on the relative value of the change in the first value. For example, the first value may be sent only when the relative change in the first value is above a threshold. In this case, the received second value of the controller is valid as long as a new second value is received.

[0060] The first value can be compared in each case with the last first value sent. Whenever a new first value is sent, the sent first value can be stored in the controller. An absolute change and / or a relative change of the first value can be determined based on the instantaneously determined first value and the stored first value. The absolute change and / or the relative change can be compared with a threshold value and, if above the threshold value, the value can be sent.

[0061] The derivative of the first value may also be determined. The first value may be sent when the absolute derivative of the first value is above a threshold value. In this case, a sharp change in the motor current may occur, which may require immediate action, namely setting a nominal value to reduce the sum of the currents in the group.

[0062] According to an embodiment, the thresholds used for comparison may be different for different controllers. For example, a motor roller controller may be configured with an individual threshold and / or at least two controllers of a common group may be configured with a common threshold. This allows fine tuning of the system. Furthermore, the thresholds may be different depending on the sign of the change value and / or the derivative. For example, for cases where the current value drops, it may be preferred that the nominal value changes more slowly in these cases than in cases where the current value rises. Thus, the threshold for a negative change may be higher than the threshold for a positive change and vice versa.

[0063] The motor roller controller can be configured as a master controller or a slave controller. The above calculations can be performed within the master controller for the slave controller, and the results of the calculations can be sent to the slave controller. This reduces the need for "intelligent" controllers in the conveyor system.

[0064] In order to ensure that the controller is active in current control, a "keep alive" function should be provided. For example, a first value can be sent based on the time that has passed since the previous sending of the first value. Thus, other controllers can monitor whether they receive a second value within such a time interval, and if so, indicate that the controller sending the value is still active. If these controllers do not receive the second value within the specified time interval of another controller, these controllers can issue a warning signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] These and other aspects of the present subject matter will be explained in more detail with reference to the following figures.

[0066] As shown in the figure:

[0067] Figure 1 is a motor roller controller according to an embodiment;

[0068] Figure 2 is a conventional conveyor according to an embodiment;

[0069] Figure 3 is a conveyor system including a plurality of controllers according to an embodiment;

[0070] Figure 4 is a memory according to an embodiment;

[0071] Figure 5 is a schematic diagram of values ​​stored and output by a controller over time according to an embodiment. DETAILED DESCRIPTION

[0072] Figure 1A conventional wired motor roller controller 2 for a motor roller is shown. The controller 2 has a power inlet 4. The power inlet 4 (input power port) is a DC power inlet 4, in particular a 12V or 24V power inlet, however the power inlet 4 may also be an AC inlet. The power inlet 4 receives power for operating the controller 2. The power inlet 4 may also receive power for operating the motor roller.

[0073] The motor roller can be connected to the motor roller control port 6. The motor roller control port 6 has at least two, preferably four connectors for connecting the motor roller. Via the motor roller control port 6, the motor roller can be supplied with at least electrical energy. In addition, the motor roller can be controlled by exchanging control signals and / or status information signals via the motor roller control port 6. Such control of the motor roller is well known and will not be described in more detail.

[0074] Finally, the controller 2 has an I / O port 8. The I / O port 8 may be a communication port for wired / wireless communication, for example according to industrial standards, in particular according to the standards described above. Furthermore, the I / O port 8 may support any proprietary protocol. Control signals and / or status information may be exchanged between the controller 2 and a central control center via the port 8.

[0075] The controller 2 also has a central processor 26, which is connected to the power inlet 4, the motor roller control port 6 and the I / O port 8. The central processor 26 can be programmed. Programming can be understood as setting parameters for the motor roller. According to the programming, the motor roller is instructed to rotate at least at a specific speed in a specific direction via the motor roller control port 6. Any other parameters as described above can be parameterized and programmed. The processor 26 can be programmed to operate according to any method disclosed herein.

[0076] Parameters of the controller 2 can be set, and status information can be read from the controller 2 via the port 8 . In addition, the controller 2 can have a memory 30 .

[0077] During operation, the central processor 26 outputs a control signal for the motor roller via the motor roller control port 6. The signal output, current intensity, voltage, etc. of the output signal depend on the settings (parameters) of the controller 2 according to the method described herein. In particular, the processor 26 can be programmed to obtain a first value from the current sensor. In addition, during operation, the central processor 26 reads status information from the motor roller via the motor roller control port 6.

[0078] A current sensor (meter) 4a may be arranged at the power input port 4. Furthermore, additionally or alternatively, a current sensor (meter) 6a may be arranged at the motor roller controller 6. The first value and / or the second value of the current intensity may be measured by the sensor 4a or the sensor 6a. Furthermore, both sensors 4a, 6a may measure the current intensity. The first value and / or the second value may be determined from the arithmetic or geometric mean of these values. It is also possible to measure the current intensity over a certain time span and then calculate the arithmetic or geometric mean of these values ​​as the first value and / or the second value.

[0079] like Figure 2 The conventional conveyor shown may include a motor roller 14 and a roller 16. The conveyor line 12 may have more than two conveying zones 12a. In each conveying zone 12a, a motor roller 14 is mechanically coupled to at least one roller 16, preferably to two to seven rollers 16, in particular by a mechanical coupling such as a V-belt or a multi-V belt. Other mechanical couplings are also possible.

[0080] The motor roller 14 is rotatably arranged on the frame 18 and includes a motor located in a hollow tube. The motor in the hollow tube is connected to the controller 2 via the motor roller control port 6 of the controller 2.

[0081] For each of these conveying zones 12a, a separate controller 2 is provided to control the corresponding motor roller 14. The controller 2 is connected via its power inlet 4 and I / O port 8 to the power and control bus.

[0082] Figure 3 A conveyor system with multiple controllers 2 is shown. Each controller is connected to a power bus via a cable 5. Each power bus is powered by a power supply 3. Undervoltages may occur due to ohmic losses along the cables 5 caused by overcurrent. In addition, the power rating of the power supply 3 may be less than the power drawn by all controllers 2 connected to the power supply 3 via the same power bus.

[0083] As can be seen, the controller 2 is communicatively connected via a communication bus 7. The communication bus 7 may be connected to an I / O port 8. Controllers 2 of different power buses may be communicatively connected via the same communication bus 7. The communication bus 7 may connect the controller 2 to a central controller 9. As described above, the communication bus 7 may be wired or wireless.

[0084] A first value of the current strength proposed to be used by the controller 2 is stored in the controller 2 as value A and sent out by the controller as value B. The controller 2 can receive various values ​​B1, B2, ... Bn, where n is the number of controllers 2 connected to the same power bus.

[0085] The controller 2 may have a synchronized time reference. The controller 2 may obtain the first value and / or the second value within the time interval. Either the value is obtained at the end of the time interval, or the obtained value has reached a threshold value. The threshold value may be, for example, an absolute change in the value, a relative change in the value, a slope of the value, an absolute or relative value of a derivative of the value over time, etc.

[0086] In certain time intervals T1, T2, T3 ... Tm, m being the number of time intervals, the controller obtains their first values ​​A, sends these values ​​out as values ​​B, and receives other values ​​B. For each time interval, the controller 2 can store the obtained and received values ​​A, B in a manner such as Figure 4 In the memory shown. This storage can be applied in each controller 2, certain master controllers 2 and / or central controller 9. The application options in each controller 2 will be described below, but the following content can also be understood to be related to any option. However, in the latter two options, the calculated values ​​are sent from the master controller 2 or the central controller 9 to the other controllers 2.

[0087] For example, Figure 5 As shown, the time intervals T1 ... Tm have equal lengths. The time intervals can also have different lengths.

[0088] In each time interval T, the sensor 4a and / or 4b obtains a first value A. In each time interval T or at the end of the time interval T, each controller obtains and stores the first value A. At the end of each time interval T or as soon as the first value is obtained, it is sent as a second value B.

[0089] Thus, the controller 2 receives the second value B of the other controllers in each time interval T, at least at the end of the time interval T. As described above, the controllers are grouped into a common group. This can be done by assigning a group ID to the controllers. The second value B can be sent together with the group ID. The receiving controller 2 can evaluate whether the received value B is assigned to the same group ID as the group ID of the receiving controller 2. In this case, the received value B is stored, otherwise, the received value B can be discarded. Figure 3 The group ID is shown in . It can be seen that the controller 2 connected to the power supply 3a via the same power supply bus has the group ID1, and the controller 2 connected to the power supply 3b via the same power supply bus has the group ID2.

[0090] At the end of the time interval T or on an ongoing basis, each time a new value A is obtained or a new value B is received, the controller 2 may determine the nominal value of the current intensity at the motor roller control port 6 or the power inlet 4 .

[0091] from Figure 5It can be seen that the value A1 is obtained at the end of the time interval T1. The reason is that during the time interval T1, the measured value did not change significantly. However, during the time interval T2, the measured value changes significantly. The absolute amount of the value change compared to the last obtained value A1 can be decisive for obtaining the value A2. If during the time interval T2, the measured value changes significantly again compared to the value A2, for example exceeds a threshold value, a new value A2x will be obtained in the time interval T2.

[0092] Since the value A2 is obtained in the time interval T2, no new value is obtained at the end of the time interval T2 so as not to increase the communication traffic.

[0093] At the beginning of the time interval T3, the value changes significantly again compared to the now most recent value A2, and a new value A3 is obtained.

[0094] During the time interval T4, there are no significant changes, so at the end of the time interval T4, a new value A4 is obtained.

[0095] Values ​​A1-A4 are stored in controller 2 and sent as values ​​B1-B4 to the other controllers in the common group.

[0096] The nominal value may first be determined based on the current first value A and second value B, ie the most recently received values.

[0097] It may be advantageous if the controller 2 knows the number of controllers 2 within the same group in order to determine whether the value B is available for all controllers 2 in the group.

[0098] Using the values ​​A and B, the controller 2 can calculate the sum.

[0099] In addition, the controller 2 may know the limit value of the group. For example, the limit value may be set for the group. For example, the limit value may be

[0100] In each time interval T, in particular at the end of the time interval T, the controller 2 calculates a sum from the current values ​​A, B.

[0101] This sum can be compared with a limit value.The limit value of the group can depend on the rated power of the power sources 3a, 3b and / or information about the cables 5a, 5b, the infrastructure or the like.

[0102] If the sum reaches the limit value, the current limiting strategy as described above may be applied to the controller 2 individually (individual) or applied jointly to at least two controllers 2 in the group (common).

[0103] Firstly, a lower threshold value of the current intensity can be set for the individual or common controller 2. This can be a current intensity value at which the motor still works, but at a lower speed. This ensures the operation of the conveyor system.

[0104] Then, individual or common nominal values ​​can be set. The nominal value can be an upper limit for the current intensity. Depending on the sum, the nominal value can be fixed or dynamically set.

[0105] The nominal value can be used to limit the current intensity of the controller 2 compared to the currently measured value A. The nominal value is usually lower than the current value A.

[0106] If the sum is above the limit value, it can be checked whether the current value A is above the nominal value. If not, the current intensity of the controller 2 is not changed. If the current value A is above the nominal value, the current intensity of the controller 2 is changed towards the nominal value.

[0107] It may be advantageous to set the slope of the change individually or together. The slope may determine the rate of change of the current intensity.

[0108] The nominal value can be determined based on the limit value and the second value. Once the sum is higher than the limit value, the nominal value can be determined dynamically. Then, it can be checked whether the reason why the sum is higher than the limit value lies in the actual controller 2 or in other controllers. Therefore, it can be determined what the sum of the second values ​​B is. If the sum of the second values ​​is within the range of the limit value, that is, the difference is less than the lower threshold, the cause of the overcurrent may lie in other controllers 2. Therefore, the nominal value is not set separately. However, if the difference between the sum of the second values ​​B and the limit value is higher than the threshold, the cause of the overcurrent may lie in the actual controller 2. Therefore, the nominal value is set.

[0109] However, it should be noted that once the sum of the values ​​A and B reaches or exceeds the limit value, a nominal value may be set.

[0110] Nominal values ​​can be set for controllers of a common group. That is, depending on the type of motor rollers or conveyor lines controlled in the group, the nominal values ​​can be different. For example, there can be controllers 2 that control combiners, splitters, etc. The current of these controllers should not be limited, i.e. these controllers do not have set nominal values. Other controllers 2 may be more important and therefore have higher nominal values ​​than the "standard" controller 2.

[0111] The controllers 2 can be assigned priorities. In this case, once the sum reaches the limit value, the controller 2 with the lowest priority is first assigned the nominal value. In this case, some of the first controllers 2 can change their current intensity. If at the end of the time interval, it can be checked whether the sum is below the limit value. If so, the nominal value is set for the controller 2 with the next higher priority. This will continue until the last priority or until the sum is less than the limit value.

[0112] It is also possible to assign a coupling coefficient to the controllers 2. That is, the higher the coupling coefficient, the steeper the slope of the change in current intensity towards the nominal value. This results in some controllers 2 being able to react faster than others and, if necessary, being able to change their current intensity more quickly.

[0113] Using the above method, once the total current in a group exceeds the limit value, the current intensity of the group can be changed. Then the current intensity, the absolute value of the current intensity, the slope of the current intensity, etc. of the controller 2 can be changed individually or collectively. This results in the conveyor system being able to operate even if the current intensity of the system would normally exceed the rated power of the power supply. In the event of an overcurrent, the degree of change in the current intensity is less than shutting down the controller 2. However, the controller may still operate the motor with a current that is sufficient for operation, but less than usual.

[0114] It should be noted that the use of singular terms may be understood to include the plural and vice versa. It should be noted that the term "and" may be understood as "or" and vice versa. It should be noted that any list should be considered non-exhaustive.

Claims

1. A method for operating a motor roller controller, wherein - measuring, by an instrument of a first motor-roll controller, a first value indicative of the current intensity at an input power port of said first motor-roll controller, - sending said first value from said first motor-roll controller to at least one second motor-roll controller, - receiving at said first motor-roll controller at least one second value indicative of the current intensity at an input power port of said at least one second motor-roll controller, - determining a nominal value of the current intensity at the input power port of the first motor-roll controller as a function of the first value and the at least one second value, and - operating the motor roller control port of the first motor roller controller with the output current to the motor roller so that the current intensity at the input power port reaches the nominal value.

2. The method according to claim 1, Features - measuring the first value indicating the current intensity at the input power port of the first motor roller controller at the motor roller control port of the first motor roller controller, and / or measuring the second value indicating the current intensity at the input power port of the second motor roller controller at the motor roller control port of the second motor roller controller.

3. The method according to claim 1 or 2, It is characterized in that - assigning to the first motor-roller controller information representing the first motor-roller controller's membership of a common group, in particular a group ID of the common group, and / or - assigning to the second motor-roller controller information representing the membership of the second motor-roller controller to the common group, in particular the group ID of the common group, and / or - said first value and said information representative of said membership are sent by said motor roller controller, and / or - receiving at said motor-roll controller said at least one second value and said information representative of said membership.

4. The method according to claim 3 or 4, It is characterized in that - Only those second values ​​which are received together with said information representative of said membership corresponding to the information representative of said membership which is assigned are used for determining said nominal value.

5. The method according to any one of the preceding claims, It is characterized in that - determining a limit value for the sum of the first value and the second value of all motor roller controllers assigned to a common group, and / or - configuring a common set of said motor-roller controllers with said limit values.

6. The method according to any one of the preceding claims, It is characterized in that - determining said nominal value as a function of said limit value and said at least one second value, and / or - said nominal value is determined by a processor of at least one motor roller controller within a common group.

7. The method according to any one of the preceding claims, It is characterized in that - determining a current slope for changing the output current value to the motor roller in the direction of the nominal value according to the first value, the second value, the sum of the first value and the second value and / or the limit value, and / or - using the difference between said first value and said nominal value by a P, PD, PI or PID controller to determine a current slope for changing the output current value to said motor roller in the direction of said nominal value.

8. The method according to any one of the preceding claims, It is characterized in that - assigning one of at least two different priorities to the motor roller controller, and / or - The nominal value is determined according to the assigned priority.

9. The method according to any one of the preceding claims, It is characterized in that - a common group of motor roller controllers powered by a common power supply, and / or - configuring at least one motor roller controller within the common group to not constrain its first value in the direction of a nominal value.

10. The method according to any one of the preceding claims, It is characterized in that - The nominal value of the motor roller controller is such that the current of the motor roller is higher than the minimum value required to rotate the motor roller.

11. The method according to any one of the preceding claims, It is characterized in that - receiving said second value together with a unique identification of a corresponding motor-roll controller.

12. The method according to any one of the preceding claims, It is characterized in that - within the motor-roller controller, storing a list with all second values ​​received and information representative of said membership of said common group.

13. The method according to any one of the preceding claims, It is characterized in that - transmitting said first value according to an absolute value of a change compared to said first value transmitted last, a relative value of a change or a derivative of said first value, and / or - sending said first value according to the time that has passed since a previous sending of said first value, and / or - Comparing the change value or said derivative with a threshold value.

14. The method according to any one of the preceding claims, It is characterized in that The motor roller controllers are configured with individual threshold values ​​and / or at least two controllers of a common group are configured with common threshold values.

15. The method according to any one of the preceding claims, It is characterized in that - sending out said first value from a signal bus port of said first motor roller controller.

16. The method according to any one of the preceding claims, It is characterized in that - The second value is emitted from the second motor-roll controller, in particular from a signal bus port of the second motor-roll controller.

17. The method according to any one of the preceding claims, It is characterized in that - Determining said nominal value of the current intensity at the input power port of said first motor-roll controller in said first motor-roll controller or in a central controller as a function of said first value and said at least one second value.

18. The method according to any one of the preceding claims, It is characterized in that - Receiving said first value and said second value at a central controller.

19. A motor roller controller arranged to operate according to the method of any preceding claim.

20. A conveyor system, for example for conveying goods, parcels, etc., comprising at least two motor roller controllers according to claim 19 and a common power supply.

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