Conveyor system, motor roller controller, and method for operating a conveyor system

Abstract

In a method for operating a motor roller controller, a first value indicating the number of amperes at the input power port of a first motor roller controller is measured by a measuring instrument of the first motor roller controller, and the first value is transmitted to at least one second motor roller controller via a signal bus port of the first motor roller controller. At least one second value indicating the number of amperes at the input power port of the at least one second motor roller controller is received at the signal bus port. A nominal value for the number of amperes at the input power port of the first motor roller controller is determined depending on the first value and the at least one second value, and the motor roller control port of the first motor roller controller is operated by an output current to the motor roller such that the number of amperes at the input power port reaches the nominal value.

Description

Technical Field

[0001] The subject matter of the present application relates to a method for operating a motor roller controller, particularly for a conveyor system, for transporting articles, packages, and the like. Further, this subject matter relates to a conveyor system having a motor-driven conveyor driven by motor rollers. This subject matter further relates to a motor roller controller within such a conveyor system.

Background Art

[0002] A motor-driven conveyor roller, also known as a motor roller, includes a roller body rotatably mounted around a roller shaft. The roller body is typically a hollow tube. A motor is disposed within the roller body. The motor is an electric motor configured to generate a rotational movement around the roller shaft between the shaft and the roller body.

[0003] For purposes of understanding, in the following, the term motor roller may be used for the motor alone within the roller body, for a drive unit including the motor within the roller body and a control circuit corresponding to the motor, or for the roller body including the motor or the drive unit. In the following, the term motor may be used for such a motor or for a drive unit including such a motor and a control circuit corresponding to the motor.

[0004] It is well known that a motor roller is operated by a control unit, also known as a controller, disposed externally outside the roller body. The controller exchanges control signals with the motor inside the roller body.

[0005] A motor-driven conveyor driven by this type of motor roller is used in a conveyor system. In such a conveyor system, a single motor roller is used to operate a plurality of roller bodies within a conveyor zone. Conveyor systems often have a plurality of conveyor zones, and the object to be conveyed passes through those conveyor zones in sequence. As described, within each conveyor zone, at least one motor-driven conveyor roller operates a plurality of rollers.

[0006] The controller has a wired power inlet (input power port) for receiving power, which is preferably DC power. However, the input power port may be an AC port, and in this case, a rectifier for converting the input AC power to DC power may be arranged on the controller. Further, 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 powered through the motor roller control port using, for example, a pulse width modulation (PWM) signal for at least controlling the rotation speed of the motor. In addition, state information and control signals can be exchanged between the motor roller and the controller using the motor roller control port. The state information and / or control signals can particularly include the actual motor speed, the set motor speed, the actual conveyor speed, the set conveyor speed, the actual rotation direction, the set rotation direction, the actual operation mode, the set operation mode, the temperature, the error message, the gear ratio of the motor gear, the serial number, the product number, the manufacturing date, etc. In particular, the motor roller control port is a four-wired motor roller control port according to Patent Document 1.

[0007] Conventional controllers include wired I / O (input / output) ports. This I / O port is configured to exchange control information with a central control center such as a central PLC (SPS) control unit. The I / O port can be configured using, for example, a dedicated protocol. However, the I / O port can also be configured using standardized I / O protocols such as those based on CAN, DeviceNet (registered trademark), Ethernet (registered trademark) Powerlink, INTERBUS, Fieldbus, LIN, M-Bus (M-Bus), PROFIBUS, and VARAN. In addition to such conventional controllers, wireless controllers that operate similarly to wired controllers are known. Descriptions for wired controllers and wireless controllers can be used for both, except that the I / O bus of the wireless controller is a wireless bus with an appropriate wireless protocol.

[0008] The controller is configured to exchange motor controller signals with the motor controller at the motor controller port, exchange motor controller status signals with the motor controller at the motor controller port, and exchange motor controller signals for the motor controller with the central control unit at the I / O port. The exchange of relevant control signals and status signals is well-known and does not require further explanation. Note that all ports and inlets of the wired controller are preferably wired ports, and wiring is required between the motor controller and the controller and between the controller and the centralized control center. Wiring is usually required to provide stable communication in an industrial environment. The wireless controller also has wiring to the motor controller and the power inlet, but has a wireless I / O port.

[0009] For the purpose of understanding, a motor roller controller, also known as a controller, may be arranged to control the motor roller. For this purpose, at least one microprocessor may be provided in the controller to operate the motor roller within the conveyor system, more specifically to operate at least one motor roller within the conveyor system.

[0010] The conveyor system is typically constructed by a plurality of conveyor zones. That is, the next conveyor zone follows one conveyor zone. Within each conveyor zone, at least one, preferably just one motor roller is provided. In addition, at least two spatially adjacent motor rollers may be operated by a single motor roller controller.

[0011] Preferably, all motor rollers or every other motor roller are controlled by separate motor roller controllers. 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 DC, but this subject also relates to AC power supplies when possible. In a typical conveyor system, especially when there is human interaction, the power supply has a low voltage. The low voltage in this case can be understood as a voltage less than 100V, especially less than 50V, such as 48V, 24V, or 12V. To provide sufficient power to the motor, a higher supply current is required. To keep the resistance losses in the supply line low, these high currents require a cross-section of the supply cable to be, for example, larger than 1.5mm 2 more, especially 2.5mm 2 , 4mm 2It is necessary to make it larger. These larger cross-sections require more metal per meter of cable, increasing the cost of the cable. To keep costs low, the wiring is calculated based on the minimum requirements. However, due to resistive losses, a voltage drop is introduced along the supply line, i.e., from the power source to the controller. In situations with high power requirements, this can result in under voltages at the controller and the motors connected to this controller. This under voltage can sometimes cause malfunctions in the controller and / or the motor. According to the prior art, the problem of under voltage is usually solved by issuing an error signal from the controller or temporarily stopping the motor being controlled. Both of these solutions cause negative side effects to the entire system. From the perspective of system integration, this problem is frustrating and causes a dead end.

[0013] Furthermore, a conveyor system usually has a power source with a rated current that satisfies the most reasonable operating conditions. However, there are cases with higher current requirements, i.e., when the item to be transported is heavier than predicted during the design of the conveyor system, which causes overcurrent and thus activates the power protection. This will also cause malfunctions in the conveyor system.

[0014] The above definitions and descriptions can be understood as part of the following disclosure, i.e., they form an integral part of the claimed subject matter.

Prior Art Documents

Patent Documents

[0015]

Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0016] To improve the availability of the system and overcome problems due to under-voltage and / or over-current, this subject matter relates to the method of claim 1.

[0017] A conveyor system is arranged, in particular, for transporting articles, packages, etc. along a transport line. The transport system may include at least two transport zones, each of which is driven using one motor roller. For purposes of understanding, the terms conveyor, conveyor zone, or conveyor line may be understood as synonyms. The conveyor system may include at least two conveyor zones. A transport zone may include at least one motor roller and at least two, preferably six or more, passive rollers. Each of the motor roller and the passive roller includes a preferably cylindrical tube rotatably connected to a rack via a shaft. By driving the motor roller, the passive rollers are also driven to rotate in a desired direction.

[0018] To operate the motor roller, a motor roller controller is required. The motor roller controller is arranged to supply power to the motor roller and further control the operation of the motor roller, in particular to control start / stop, direction, torque, rotational speed, revolutions per minute (RPM). Further, the motor roller controller may be arranged to detect the motor roller state. Supplying power to the motor roller and / or detecting the motor roller state may be achieved using the motor roller control port of the motor roller controller. The motor roller is wired to the motor roller controller along the motor roller control port. Thus, the motor roller control port of the motor roller controller is a wired port. To operate a plurality of motor roller controllers, the motor roller controllers are next connected to a control bus. Conventional systems include a plurality of motor roller controllers each connected to a wired control bus.

[0019] Here, a method for operating a motor roller controller is proposed.

[0020] When operating the motor, the controller draws current from an input power port such as the power inlet described above. The current is provided to the input power port through wiring. The wiring can connect two or more controllers to a common power source. The wiring has at least two wires. At the input power port, a first value indicating the number of amperes at the input power port of the first motor roller controller is measured. For this purpose, at the input power port, preferably as part of the controller, an instrument indicating current, i.e., an ampere measuring instrument, can be provided. This instrument is arranged to detect information indicating the number of amperes at the input power port. The instrument may output a first value indicating the detected number of amperes. "Indicating" may also be understood as "representing". The term "instrument" can be understood as a measurement sensor. The terms "measuring", "measuring", "determining", "detecting", or "acquiring" can be used interchangeably.

[0021] In a system according to this subject matter, at least two controllers are connected to a common power source. The controllers connected to the power source may communicate with each other via a signal bus port. The signal bus port may be an I / O port or any other communication port, particularly the communication port of each 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 used for communication. The controllers may be connected to such a bus for communication. The communication may be direct two-way communication between the controllers or indirect communication via a communication hub. The signal bus port may be the I / O port described above or any other communication port. The terms "communicating", "transmitting", "transmitting", "receiving" can be used interchangeably. In particular, values can be transmitted, transmitted, communicated. This includes polling and / or pushing data between communication partners.

[0022] After the first value is obtained, 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 the central controller. Since at least one second controller is constructed and operates identically or at least similarly to the first controller, the description of the first controller also applies to the second controller and preferably any other controller along the conveyor line or conveyor system.

[0023] In the second motor roller controller, a second value indicating the number of amperes at the input power port of at least one second motor roller controller may be measured. The second value may be sent from the second controller. As described, the first controller and the second controller may operate similarly, particularly with respect to the measurement and transmission of the first value / second value.

[0024] The second value may be received at the signal bus port of the first motor roller controller in particular. The second value may be received at the central controller. For example, all controllers along the conveyor line or within the conveyor system may measure and send their first values. Further, in other controllers, these first values may be received as second values. Thus, the controller recognizes its own first value and the first values of other controllers received as second values. The terms first and second are used only to improve the legibility of the claims. The transmission and / or reception of values may be understood as the transmission and / or reception of data indicating the values.

[0025] In the controller, it is not necessary to obtain only one first value. The controller preferably obtains a plurality of first values at different times, for example, periodically or triggered by an event. In the controller, it is not necessary to receive only one second value. The controller preferably receives a plurality of second values at different times, for example, periodically or triggered by an event. The controller may be either a motor roller controller or a central controller.

[0026] The controller may enable the controller to calculate the sum of one first value and one second value at a specific time or within a specific time interval by inputting information indicating time together with the first value and the second value into a list. This sum may indicate the total amperage of these controllers in a common power supply for the controller. These controllers may be connected to the same power supply.

[0027] Under most conditions, especially in conditions where a high amperage is required over a specific time in a specific controller to enable the conveyor system to operate perfectly, it is proposed here to determine the nominal value for the amperage at the input power port of the first motor roller controller depending on the first value and at least one second value. The controller usually has the maximum current required to operate perfectly. The nominal value may limit such a maximum current. Thus, even when the motor would require a higher current, the current available to the motor may be reduced to the nominal value.

[0028] In addition, the controller may control the motor such that the motor draws a specific current from the motor roller controller port. The current at the motor roller controller port may depend on the impedance of the motor. The impedance of the motor may depend on the torque of the motor. The controller may control the motor such that the motor draws only the nominal current.

[0029] The nominal value may be understood as a setpoint or an indication for the number of amperes of the controller at the input power port. The nominal value may be determined inside or outside the controller. The term "determined" may be understood as calculated, computed, or obtained.

[0030] The nominal value may be determined individually for each controller along the conveyor line. The nominal value may be determined commonly for two or more of the plurality of controllers along the conveyor line. The nominal value may be understood as a setpoint or an indication for the number of amperes of the controller at the motor roller control port. The nominal value may be understood as a setpoint or an indication for the number of amperes of the motor within the motor roller. The nominal value may be determined in one or any or the central controller of the motor roller controllers. The nominal value may be transmitted from one motor roller controller to another motor roller controller via a bus, or may be transmitted from the central controller to any one of the motor roller controllers.

[0031] For example, for a specific time or time interval, particularly the instant time, the controller may take into account the instantaneously measured first value and the received second value to determine the nominal value. For example, for a specific time or time interval, particularly the instant time, the central computer may take into account the instant first value and the second value to determine the nominal value for a specific controller.

[0032] After the nominal value for the first controller is determined, the motor roller control port of the first motor roller controller is operated by the output current for the motor roller such that the number of amperes at the input power port reaches the nominal value. The motor is controlled in such a way that the motor draws current from the motor roller control port according to the nominal value. The current drawn at the motor roller control port may be different from the nominal value, but the change in the number of amperes from the instantaneous current is towards the nominal value, that is, when the nominal value is lower than the instantaneous current, the number of amperes of the motor is reduced.

[0033] According to an embodiment, the first value indicating the number of amperes 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. Instead of measuring at the input power port of the controller, the number of amperes may also be measured at the motor roller control port. The motor roller is supplied with power from the controller at the motor roller control port. The current drawn from the input power port by the controller is mainly the current provided to the motor at the motor roller control port. Only a small amount of power is consumed in the controller itself. Thus, the current at the motor roller control port may also indicate the current at the input power port. The same applies to the second value indicating the number of amperes at the input power port of the second motor roller controller. The second value may also be determined at the motor roller control port of the second motor roller controller.

[0034] According to an embodiment, information representing membership of a first motor roller controller in a common group, in particular a group ID of the common group, is assigned to the first motor roller controller. As described above, at least two or more controllers may be connected to a common power supply. Controllers connected to the common power supply may form a group. In particular, controllers connected electrically in parallel with the common power supply may form a common group. Where controllers along a common wiring belong to a common group, it may also be possible that controllers of a second group are connected to the same power supply using a different wiring in parallel therewith.

[0035] Voltage drops along the wiring may cause a voltage shortage. When grouping two or more controllers into a common group, it may be possible to determine the number of amperes along the wiring of this common group. Information representing the group may be used by the controllers within the group to determine whether a received second value is relevant. Only second values generated from controllers in the same group as the receiving controller may be used. Information representing the group may be assigned to both the first motor roller controller and at least one second motor roller controller.

[0036] The information representing membership may be a group identifier (ID). The information representing membership may be a numerical or alphanumerical value. The information representing membership may also be understood as information representing the group.

[0037] Information representing membership can be manually assigned to a controller, for example, using a DIP switch or the like, such as at the time of initial installation. It may also be possible to electronically assign information representing membership to a controller using an I / O port. The controller can also autonomously determine information representing its own membership. For example, the power supply may issue a signal indicating specific information representing membership along the wiring to the connected controller. In addition, the controller may vary its amperage in a specific pattern during initialization, and all controllers connected to the same wiring may measure this pattern of amperage and may also detect their membership in a specific group.

[0038] According to an embodiment, the first value is transmitted together with information representing membership by a motor roller controller. This enables the receiving controller to determine whether the received second value is relevant. This may be the case even if the communication link between the controllers is different from the power wiring. Thus, the second value of a controller belonging to the second group may be received by a controller belonging to the first group. Such second values originating from controllers belonging to different groups may be discarded at the receiving controller.

[0039] According to an embodiment, only the second value received together with information representing membership corresponding to the assigned information representing membership is used to determine the nominal value. As explained, the nominal value is used to prevent under-voltage and / or over-current. The nominal value enables each controller to adjust its own amperage, such as the amperage output at the motor roller control port, so as to limit the total current within the group without degrading the performance of the entire conveyor line.

[0040] Depending on various parameters such as the power limit of the power supply, the cross-section of the wiring, and the length of the wiring, a limit value for the sum of the first value and the second value of all motor roller controllers assigned to a common group can be determined. The limit value can be such that overcurrent does not substantially occur within the group.

[0041] The limit value can be determined manually. In particular, when setting up a conveyor system, the detrimental parameters of the limit value can be determined and the limit value can be calculated. The limit value can also be determined automatically. The limit value can be set manually within the controller or communicated to the controller.

[0042] Not only the first value and the second value, and especially only their sum, are related to the nominal value, but the nominal value can also be determined depending on, in particular, the limit value in addition thereto. The nominal value can be determined dynamically, for example, within continuous time intervals. The relative and / or absolute difference between the sum of the first value and the second value and the limit value may indicate the nominal value. In addition, the gradient of the relative and / or absolute difference between the sum of the first value and the second value and the limit value may indicate the gradient of the nominal value.

[0043] For at least one controller, preferably individual correction factors indicating the combination of the nominal value and the above-mentioned difference may be set. That is, some controllers may be set to be more responsive to changes in the difference than others. For example, some controllers control motors that are more important for the function of the conveyor line than others. These controllers have lower correction factors than controllers with a lower importance for the function of the conveyor line.

[0044] According to an embodiment, the nominal value is determined by a processor of at least one motor roller controller within a common group. That is, at least one controller within the group may be responsible for determining the nominal value for at least one other motor roller controller within the group, particularly the nominal value for all motor roller controllers within the group. However, the nominal value may also be determined individually by the processor of the motor roller controller for this individual controller. Similar to the first value, the nominal value may also be communicated within the group.

[0045] The nominal value for one controller within the group may depend on the nominal values of other controllers within the group. In particular, the sum of the nominal values within the group is less than the limit value for that group. Thus, the sum of the nominal values within the group may also be related to the nominal values of the controllers within the group.

[0046] According to an embodiment, the current slope for changing the value of the output current to the motor roller in the direction of the nominal value is determined depending on the first value, the second value, the sum of the first value and the second value, and / or the limit value. Further, the slope may depend on the sum of the nominal values of the group. It is preferable that the current slope is controlled to control the sum of the currents within the group. The current slope may be controlled such that the slope of the change in the sum of the currents is attenuated.

[0047] According to an embodiment, the current slope for changing the value of the output current to the motor roller in the direction of the nominal value is determined by a P, PD, PI, or PID controller using the difference between the first value and the nominal value.

[0048] According to an embodiment, the nominal value may be calculated identically for each motor roller controller in the group. For example, some motor roller controllers, such as those that control mergers and diverters, may not be included in the calculation of the nominal value, that is, these motor roller controllers are supplied with a current without the restrictions described in this specification. The calculation of the nominal value for all other motor roller controllers may be the same.

[0049] The nominal value and the slope of the nominal value, such as the current slope of the change in the nominal value, may depend on the number of motor roller controllers in the group, particularly the number of motor roller controllers in the group involved in the current restrictions described in this specification.

[0050] The change in the nominal value may be linear or non-linear. Depending on the application of a particular motor roller controller in the conveying line, the change in the nominal value may follow a linear slope or a non-linear slope.

[0051] According to an embodiment, a priority among at least two different priorities is assigned to the motor roller controller. Similar to the coupling factor, the priority may be used to distinguish the controllers. Some controllers may be more relevant to the function of the system than others. In addition, some controllers control the conveyor line, and those controllers are more tolerant of changes in their own current than others. For example, a merger or a diverter is very sensitive to changes in current related to the function of the conveyor line. That is, for example, a merger and a diverter may be considered not to have restrictions on the nominal value for their own current, or at least to be restricted as the last controller in the conveyor system. Thus, they may have a higher priority than the conveyors along the conveyor line. When the current decreases, the articles are transported at a lower speed, but the conveyor line still operates.

[0052] As described above, it is proposed that the nominal value be determined based on the assigned priority. For example, a controller with a high priority will be assigned a nominal value lower than the current it requires, after a controller with a low priority. That is, when it is necessary to control the current within a group, first the nominal value for the controller with the first low priority is determined and used in these controllers. Thereafter, only when it is still necessary to control the current within the group, the nominal value for the controller with the second higher priority is determined first and used in these controllers.

[0053] According to an embodiment, the motor roller controllers of a common group are supplied with power from a common power supply. The common power supply has a specific rated current. The total current in the controllers is made not to exceed this rated current.

[0054] As described above, some controllers are more relevant to the function than others. It may be preferable to completely exclude one or more controllers from the current control as described using the nominal value. Therefore, it is proposed that at least one motor roller controller within a common group be configured not to limit its first value in the direction of the nominal value.

[0055] The upper limit of the nominal value of the current for the motor may be the maximum allowable current for that motor. The lower limit for the nominal value for the motor roller controller may be such that the current for the motor roller is higher than the minimum required value for rotating the motor roller. This ensures that the roller rotates at a lower speed but still rotates and the conveyor line still operates.

[0056] To facilitate communication between the motor roller controllers of different common groups, those motor roller controllers may be connected to the same serial bus.

[0057] Each controller may be able to maintain a list of the controllers within the group. According to an embodiment, when a second value is received along with the unique identification of the motor roller controller to which it corresponds, this list may be used to determine whether the received second value is related to that group. This unique identification can be compared with what is stored in the list, whereby it may be determined whether the corresponding second value is related. The unique identification may depend on the MAC address of the communication module within the controller. The unique identification may be composed of the MAC address, a part of the MAC address, or a value determined from the MAC address.

[0058] According to an embodiment, a list having all the second values received along with information representing membership in a common group is stored within the motor roller controller. This enables the controller to determine the nominal value by additionally using at least its own first value.

[0059] For example, in order to prevent excessive traffic on a communication channel such as a communication bus, the first value should be communicated based on a rule. Thus, it may be possible to transmit the first value depending on the absolute value of the change in the first value. For example, the first value may be transmitted only when the absolute change in the first value is higher than a threshold. In such a case, the second value of the received controller is valid while a new second value is being received.

[0060] It may also be possible to transmit the first value depending on the relative value of the change in the first value. For example, the first value may be transmitted only when the relative change in the first value is higher than a threshold. In such a case, the second value of the received controller is valid while a new second value is being received.

[0061] The first value may be compared to the last transmitted first value in each case. This transmitted first value may be stored in the controller while a new first value is being transmitted. The absolute and / or relative change of the first value may be determined from the immediately determined first value and the stored first value. This absolute and / or relative change may be compared to a threshold value, and when it is higher than such a threshold value, the value may be transmitted.

[0062] The derivative of the first value may also be determined. When the absolute derivative of the first value is higher than a threshold value, it may be possible to transmit the first value. In such cases, the motor current is subject to a steep change, and thereby it will be necessary to set the nominal value so as to reduce the immediate operation, i.e., the sum of the currents within the group.

[0063] According to an embodiment, the threshold value for comparison may be different for different controllers. For example, the motor roller controller may be configured by individual threshold values, and / or at least two controllers of a common group may be configured by a common threshold value. This enables fine-tuning of the system. Further, the threshold value may be different depending on the sign of the value of the change and / or derivative. For example, when the current value is dropping, it may be preferable for the nominal value to change more slowly in these cases than when the current value is rising. Thus, the threshold value for a negative change in value may be higher than the threshold value for a positive change in value, or vice versa.

[0064] The motor roller controller may be configured as a master controller or a slave controller. Within the master controller, the above-described calculations for the slave controller may be performed, and the result of the calculation may be transmitted to the slave controller. Thereby, the need for "intelligent" controllers within the conveyor system is reduced.

[0065] A "keep-alive" function should be provided to ensure that the controller is active in current control. For example, the first value may be transmitted depending on the elapsed time since the previous transmission of the first value. Thus, other controllers may monitor whether the second value is received within such time intervals, thereby indicating that the controller that transmitted this value is still active (alive). If a controller does not receive the second value of one other controller within a specified time interval, those controllers may issue a warning signal.

[0066] These and other aspects of this subject matter will be described in more detail with reference to the following drawings.

Brief Description of the Drawings

[0067]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0068] FIG. 1 shows a conventional wired motor roller controller 2 for a motor roller. The controller 2 has a power inlet 4. The power inlet 4 (input power port) is a DC power inlet 4, particularly a 12V or 24V power inlet, but 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.

[0069] 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. The motor roller may be supplied with at least electrical energy via the motor roller control port 6. In addition, the motor roller may 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.

[0070] Finally, the controller 2 has an I / O port 8. The I / O port 8 can be a communication port for wired communication and / or wireless communication, especially as described above, for example, compliant with industry standards. Further, the I / O port 8 can support any dedicated protocol. Control signals and / or status information can be exchanged between the controller 2 and the central control center via the port 8.

[0071] The controller 2 further has a central processor 26 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. The programming may be understood as setting parameters for the motor roller. According to the programming, the motor roller is instructed to rotate in a specific direction at a specific speed via the motor roller control port 6. Any of the other parameters described above can be parameterized and programmed. The processor 26 can be programmed to operate according to any of the methods disclosed herein.

[0072] It is possible to set the parameters of the controller 2 and read out the status information from the controller 2 via the port 8. In addition, the controller 2 may have a memory 30.

[0073] During operation, the central processor 26 outputs a control signal to the motor roller via the motor roller control port 6. The signal output, as well as the amperage and voltage of the output signal, etc., depend on the settings (parameters) of the controller 2 according to the method described in this specification. In particular, the processor 26 may be programmed to obtain a first value from an amperage sensor. Further during operation, the central processor 26 reads status information from the motor roller via the motor roller control port 6.

[0074] An amperage sensor (meter) 4a may be arranged at the power input port 4. Additionally or alternatively, an amperage sensor (meter) 6a may be arranged at the motor roller controller 6. The amperage for the first value and / or the second value can be measured by either the sensor 4a or the sensor 6a. Additionally, both sensors 4a and 6a may measure the amperage. The first value and / or the second value can be determined from the arithmetic mean or geometric mean of these values. Additionally, it may also be possible to measure the amperage over a specific period and then calculate the arithmetic mean or geometric mean of these values as the first value and / or the second value.

[0075] The conventional conveyor shown in FIG. 2 may include a motor roller 14 and rollers 16. The conveyor line 12 may have two or more conveyor zones 12a. Within each conveyor zone 12a, in particular by means of a V - belt or a poly - V - belt, etc., one motor roller 14 is mechanically coupled to at least one, preferably 2 to 7 rollers 16. Other mechanical couplings are also possible.

[0076] The motor roller 14 is arranged rotatably on a rack 18 and includes a motor within a hollow tube. The motor within the hollow tube is connected to the controller 2 via the motor roller control port 6 of the controller 2.

[0077] For each of these zones 12a, a separate controller 2 is provided to control the respective motor roller 14. The controller 2 is connected to a power and control bus via its own power inlet 4 and I / O port 8.

[0078] Figure 3 shows a conveyor system having a plurality of controllers 2. Each controller is connected to a power bus via a cable 5. Each power bus is powered by a power supply 3. Insufficient voltage may occur due to resistive losses along the cable 5 due to overcurrent. In addition, the rated power of the power supply 3 may be less than the power drawn by all the controllers 2 connected to the power supply 3 via the same power bus.

[0079] As can be seen, the controllers 2 are communicatively connected via a communication bus 7. The communication bus 7 can be connected to the I / O port 8. It may be possible for the controllers 2 of different power buses to be communicatively connected via the same communication bus 7. The communication bus 7 may connect the controllers 2 to a central controller 9. As defined above, the communication bus 7 may be wired or wireless.

[0080] A first value of the number of amperes used by the controller 2 is proposed to be stored in the controller 2 as value A and transmitted as value B by this controller. The controller 2 may receive various values B1, B2,... Bn, where n is the number of controllers 2 connected to the same power bus.

[0081] The controller 2 may have a synchronized time base. The controller 2 may acquire the first value and / or the second value within a time interval. The value is acquired at the end of the time interval or a threshold value of the acquired value has been reached. The threshold value can be, for example, the absolute amount of change in the value, the relative amount of change in the value, the slope of the value, the absolute or relative value of the derivative of the value over time, etc.

[0082] When m is the number of intervals, within specific intervals T1, T2, T3... Tm, the controller acquires its first value A, transmits these values as value B, and receives other values B. As shown in Figure 4, for each time interval, the controller 2 may store the acquired and received values A and B in storage. Such storage may be applied in each controller 2, a specific master controller 2, and / or a central controller 9. The options for application in each controller 2 are described below, but may be understood as related to any option. However, in the latter two options, the calculated values are transmitted from the master controller 2 or the central controller 9 to other controllers 2.

[0083] For example, as shown in Figure 5, the time intervals T1... Tm have equal lengths. Additionally, the time intervals may have varying lengths.

[0084] Within each time interval T, the sensor 4a and / or the sensor 4b acquires the first value A. Within each time interval T or at the end of the time interval T, each controller acquires and stores the first value A. The first value is transmitted as a second value B at the end of each of the time intervals T or when those values are acquired.

[0085] Thus, the controller 2 receives the second value B of other controllers within each time interval T, at least at the end of the time interval T. As described above, the controllers are grouped into common groups. The grouping may be done by assigning a group ID to the controllers. The second value B may be transmitted together with the group ID. The receiving controller 2 may evaluate whether the received value B is assigned to the same group ID as the group ID of the receiving controller 2. In that case, the received value B is stored, otherwise the received value B may be discarded. The group ID is shown in Figure 3. As can be seen, the controller 2 connected to the power supply 3a via the same power bus has the group ID1, and the controller 2 connected to the power supply 3b via the same power bus has the group ID2.

[0086] At the end or during the time interval T, each time a new value A is acquired or a new value B is received, the controller 2 may determine the nominal value for the number of amperes at the motor roller control port 6 or the power inlet 4.

[0087] As shown in FIG. 5, the value A1 is acquired at the end of the interval T1. The reason is that the measured values within the time interval T1 did not change significantly. However, during the interval T2, the measured values change substantially. The absolute amount of change in the value when compared with the last acquired value A1 may be decisive for acquiring the value A2. When the measured values change substantially again during the interval T2 when compared with the value A2, for example, when the change is greater than a threshold value, a new value A2x will be acquired in the interval T2.

[0088] Since the value A2 is acquired in the time interval T2, no new value is acquired at the end of the interval T2 in order not to increase the communication traffic.

[0089] At the beginning of the time interval T3, here the value changes substantially again when compared with the last value A2, and a new value A3 is acquired.

[0090] There is no substantial change in the time interval T4, thus a new value A4 is acquired at the end of the interval T4.

[0091] The values A1 to A4 are stored in the controller 2 and transmitted as values B1 to B4 to other controllers within the common group.

[0092] This nominal value may be determined based on the first value A and the second value B that are current, that is, the latest received values, initially.

[0093] In order to determine whether the value B for all the controllers 2 within the group is available, it may be advantageous for the controller 2 to recognize the number of controllers 2 within the same group.

[0094] The controller 2 may calculate the total based on the value A and the value B.

[0095] In addition, the controller 2 may recognize the limit value of the group. The limit value may be set for the group, for example. For example, the limit value may be.

[0096] Within each time interval T, particularly at the end of the time interval T, the controller 2 calculates the total from the current values A and B.

[0097] The total can be compared with the limit value. The limit value for the group may depend on the rated power of the power supplies 3a, 3b and / or the information in the wirings 5a, 5b, or the infrastructure, etc.

[0098] When the total reaches the limit value, the above-described current limiting strategy may be applied individually to the controller 2 (individually) or commonly to at least two controllers 2 (common) within the group.

[0099] First, a lower threshold value for the number of amperes may be set for the individual or common controller 2. This may be a value for the number of amperes such that the motor still operates but the rotation becomes slow. This ensures the operation of the conveyor system.

[0100] Next, an individual or common nominal value may be set. The nominal value may be the upper limit of the number of amperes. The nominal value may be fixed or set dynamically depending on the total.

[0101] The nominal value may be used to limit the number of amperes of the controller 2 compared with the measured current value A. The nominal value is usually lower than the current value A.

[0102] When the total is higher than the limit value, it may be checked whether the current value A is higher than the nominal value. If not, the amperage of the controller 2 cannot be changed. If the current value A is higher than the nominal value, the amperage of the controller 2 can be changed towards the nominal value.

[0103] It may be advantageous for the slope of the change to be set individually or commonly. The slope may determine the speed of change of the amperage.

[0104] It may be possible to determine the nominal value depending on the limit value and the second value. When the total becomes higher than the limit value, it may be possible to dynamically determine the nominal value. Then it may be checked whether the reason for the total becoming higher than the limit value lies in the actual controller 2 or in another controller. Thus, something about the total of the second value B may be determined. When the total of the second value is within the range of the limit value, i.e., when the distance is less than the lower threshold, the reason for the overcurrent may lie in another controller 2. Then the nominal value is not set individually. However, when the total of the second value B has a distance from the limit value higher than the said threshold, the reason for the overcurrent may lie in the actual controller 2. Then the nominal value is set.

[0105] However, it should be noted that the nominal value may be set when the total of A and B reaches or exceeds the limit value.

[0106] The nominal value may be set for a common group of controllers. That is, depending on which type of motor roller or conveyor line is controlled by the group, the nominal value may be different. For example, there may be a controller 2 that controls a merger or a diverter, etc. The current of these controllers 2 is not limited, i.e., they do not have a set nominal value. Other controllers 2 may be more important, and for that reason the nominal value becomes higher than the nominal value for a "normal" controller 2.

[0107] It may also be possible to assign priorities to the controllers 2. In such a case, when the total reaches the limit value, the nominal value is first assigned to the controller 2 with the lowest priority. In that case, some of the first controllers 2 may change their amperage. At the end of the time interval, it may be checked whether the total is lower than the limit value. If so, the controller 2 with the next higher priority sets the nominal value. This continues until the last priority or until the total is less than the limit value.

[0108] In addition, it may be possible to assign a coupling coefficient to the controller 2. That is, the higher the coupling coefficient, the steeper the slope of the change in amperage towards the nominal value. This allows some of the controllers 2 to react faster than others, if necessary, and to change their amperage more quickly.

[0109] By the above method, the amperage of the group can be changed when the total current in the group exceeds the limit value. Then, it may be possible to change the amperage, the absolute value of the amperage, and the slope of the amperage, etc. for the controller 2 individually or in common. This allows the conveyor system to operate even if the amperage of the system usually exceeds the rated power of the power supply. The amperage changes to a lesser extent than turning off the controller 2 in the case of overcurrent. Still, the controller can still operate the motor with a current that is probably sufficient for operation but less than normal.

[0110] It should be noted that the use of singular terms may be understood to include plural forms and vice versa. The term "and" may be understood as "or" and vice versa. Any enumeration is to be considered non-exhaustive.

Claims

1. A method for operating a motor roller controller, comprising: - A first value indicating the number of amperes at the input power port of a first motor roller controller is measured by a measuring instrument of the first motor roller controller; - The first value is transmitted from the first motor roller controller to at least one second motor roller controller; - At least one second value indicating the number of amperes at the input power port of the at least one second motor roller controller is received at the first motor roller controller; - A nominal value for the number of amperes at the input power port of the first motor roller controller is determined depending on the first value and the at least one second value; - The motor roller control port of the first motor roller controller is operated by an output current for the motor roller such that the number of amperes at the input power port reaches the nominal value.

2. The method according to claim 1, characterized in that the first value indicating the number of amperes at the input power port of the first motor roller controller is measured at the motor roller control port of the first motor roller controller and / or the second value indicating the number of amperes at the input power port of the second motor roller controller is measured at the motor roller control port of the second motor roller controller.

3. - 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, and / or - Information representing the membership of the second motor roller controller in the common group, in particular the group ID of the common group is assigned to the second motor roller controller, and / or - The first value is transmitted together with the information representing the membership by the motor roller controller, and / or - At least one second value is received together with the information representing the membership in the motor roller controller The method according to claim 1 or 2, characterized in that.

4. Only the second value received together with the information representing the membership corresponding to the assigned information representing the membership is used to determine the nominal value, The method according to claim 3 or 4, characterized in that.

5. - A limit value for the sum of the first and second values of all motor roller controllers assigned to a common group is determined, and / or - The motor roller controllers of the common group are configured by the limit value The method according to any one of claims 1 to 4, characterized in that.

6. - The nominal value is determined depending on the limit value and the at least one second value, and / or - The nominal value is determined by a processor of at least one motor roller controller within a common group The method according to any one of claims 1 to 5, characterized in that.

7. - A current slope for changing the value of the output current to the motor roller in the direction of the nominal value depends on the first value, the second value, the sum of the first value and the second value, and / or the limit value and is determined, and / or - A current slope for changing the value of the output current to the motor roller in the direction of the nominal value is determined by a P, PD, PI, or PID controller using the difference between the first value and the nominal value The method according to any one of claims 1 to 6, characterized in that.

8. - At least two different priorities are assigned to the motor roller controller, and / or - The nominal value is determined based on the assigned priority The method according to any one of claims 1 to 7, characterized in that.

9. - Motor roller controllers in a common group are powered from a common power source, and / or - At least one motor roller controller within the common group is configured not to limit its own first value in the direction of the nominal value The method according to any one of claims 1 to 8, characterized in that.

10. The nominal value for the motor roller controller is such that the current for the motor roller is higher than the minimum required value for rotating the motor roller, according to the method according to any one of claims 1 to 9.

11. The method according to any one of claims 1 to 10, characterized in that the second value is received together with a unique identifier of the corresponding motor roller controller.

12. The method according to any one of claims 1 to 11, characterized in that a list having all the second values received together with the information representing the membership in the common group is stored in the motor roller controller.

13. - The first value is transmitted depending on the absolute value of the change, the relative value of the change when compared to the previous transmission of the first value, or the derivative of the first value, and / or - The first value is transmitted depending on the elapsed time from the previous transmission of the first value, and / or - The value of the change or the derivative is compared with a threshold value The method according to any one of claims 1 to 12, characterized in that.

14. The method according to any one of claims 1 to 13, characterized in that the motor roller controllers are constituted by individual threshold values and / or at least two controllers of a common group are constituted by a common threshold value.

15. The method according to any one of claims 1 to 14, characterized in that the first value is transmitted from the signal bus port of the first motor roller controller.

16. The method according to any one of claims 1 to 15, characterized in that the second value is transmitted from the second motor roller controller, in particular from the signal bus port of the second motor roller controller.

17. The method according to any one of claims 1 to 16, characterized in that the nominal value for the amperage at the input power port of the first motor roller controller is determined depending on the first value and the at least one second value in the first motor roller controller or the central controller.

18. The method according to any one of claims 1 to 17, characterized in that the first value and the second value are received in a central controller.

19. A motor roller controller configured to operate according to the method according to any one of claims 1 to 18.

20. A conveyor system for transporting, for example, articles and packages, comprising at least two motor roller controllers according to claim 19 and a common power supply.

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