METHOD FOR CONTROLLING A PLANAR DRIVE SYSTEM, ROTOR, STATOR ASSEMBLY AND PLANAR DRIVE SYSTEM

A method for controlling a planar drive system includes transmitting a communication message with the aid of a main controller to a sub-controller via the communication system, where the communication message comprises a start command for starting the automation process to be carried out by the rotor and is configured to drive the sub-controller to control the automation process, and receiving a response message transmitted by the sub-controller to the main controller via the communication system, the response message comprising a status indication of a status of the automation process controlled by the sub-controller. The application also provides a rotor, a stator assembly and a planar drive system.

TECHNICAL FIELD

The application relates to a method for controlling a planar drive system, a rotor and a stator assembly of a planar drive system and a planar drive system which is set up to carry out the method for controlling a planar drive system.

BACKGROUND

Planar drive systems may be used in automation technology, in particular in production technology, handling technology and process engineering. Planar drive systems may be used to move or position a moving element of a system or of a machine in at least two linearly independent directions. Planar drive systems may comprise a permanently energized electromagnetic planar motor having a planar stator and a rotor that may move on the stator in at least two directions.

In a permanently energized electromagnetic planar motor, a drive force is exerted upon the rotor by creating a magnetic coupling between a magnetic field of the rotor and a magnetic field of a stator assembly. The magnetic field of the rotor may be generated via permanent magnets arranged on the rotor. The magnetic field of the stator assembly, on the other hand, may be generated by energizing a plurality of stator coils.

By controlling the current supply to the various stator coils accordingly, it is possible to drive the rotor via the magnetic coupling with the magnetic field of the rotor. Since both the magnetic field of the rotor and the controllable magnetic fields of the stator assembly have components that are oriented in parallel to a surface of the stator assembly, the rotor may be moved in any direction parallel to the surface of the stator assembly. By coupling components of the magnetic fields of the rotor and of the stator assembly that are oriented perpendicular with regard to the surface of the stator assembly, the rotor may be brought into a floating state above the surface of the stator assembly or held in this state.

For such planar drive systems, which are primarily used for the transportation of goods to be transported, it may be advantageous to carry out processes relating to the respective goods directly on the respective rotor during the transportation of the goods. These processes may include, for example, reorienting the goods to be transported on the rotor or processing the goods to be transported.

A method for controlling a planar drive system and a planar drive system is known from publication WO 2022/079070 A1.

SUMMARY

The present application provides an improved method for controlling a planar drive system, a rotor, a stator assembly and a planar drive system.

EXAMPLES

According to an aspect of the application, a method for controlling a planar drive system is provided, wherein the planar drive system comprises a main controller for controlling the planar drive system, a stator assembly with a plurality of stator coils for generating a stator magnetic field and at least one rotor with a plurality of magnet assemblies for generating a rotor magnetic field, wherein the rotor is drivable on the stator assembly via a magnetic coupling between the stator magnetic field and the rotor magnetic field, wherein a sub-controller is embodied on the rotor for controlling an automation process executable by the rotor, wherein the planar drive system further comprises a communication system for wireless data communication between the main controller and the sub-controller of the rotor, and wherein the method comprises:transmitting a communication message by the main controller to the sub-controller via the communication system in a transmitting step, the communication message comprising a start command for starting the automation process to be executed by the rotor and being configured to drive the sub-controller to control the automation process; andreceiving a response message sent by the sub-controller to the main controller via the communication system in a receiving step, wherein the response message comprises a status information about a status of the automation process controlled by the sub-controller.

This may achieve the technical advantage that an improved method for controlling a planar drive system may be provided. For this purpose, at least one rotor of the planar drive system is provided having a sub-controller, which is set up to control an automation process that may be executed on the rotor or by the rotor. The planar drive system also comprises a main controller, which is set up to control the entire planar drive system, including the drive of the at least one rotor, via a corresponding actuation of the stator assembly of the planar drive system. The main controller is also set up to cause the sub-controller, via a communication system of the planar drive system, to start the automation process that may be controlled by the sub-controller of the rotor and to control it accordingly.

The sub-controller is in this context set up to control the automation process independently of the main controller. The independent control of the automation process by the sub-controller in this context describes that the main controller is only set up to cause the sub-controller to start the execution of the automation process with a corresponding communication message and a start command contained therein. However, the main controller is not set up to intervene in the execution of the automation process or to start or end the automation process without the sub-controller. The sub-controller, on the other hand, is set up to start the automation process independently after receiving the start command, to control it and, if necessary, to end the automation process when the process target to be achieved is reached or to interrupt it if a malfunction is observed or if it becomes apparent that the target to be achieved by the automation process cannot be achieved.

The sub-controller of the rotor is also set up to send a response message to the main controller via the communication system, with the response message comprising status information relating to a status of the automation process controlled by the sub-controller. By outputting the response message, the automation process of the rotor controlled by the sub-controller may be integrated into the control of the entire planar drive system by the main controller. For this purpose, the status information may include process data of the automation process or start, stop or interruption information of the automation process controlled by the sub-controller. The status information of the automation process may be integrated into the control of the planar drive system by the main controller by controlling further processes executed by the planar drive system, taking into account the status information of the automation process carried out by the rotor.

This achieves the technical advantage that individual sub-processes of the main process to be carried out by the entire planar drive system may be outsourced to different rotors in a decentralized manner.

By controlling the automation process of the rotor through the sub-controller embodied on the rotor, the control of the entire planar drive system by the main controller may be simplified in that control processes that are required to control the automation process to be executed on the rotor are carried out exclusively by the sub-controller. The main controller therefore does not have to carry out these control processes.

Furthermore, it may be achieved that a reduction in the data volume of a data communication between the main controller and a processing device executing the automation process may be reduced. Only data communication between the sub-controller and the processing device carrying out the automation process is required to control the automation process. If this processing device is also embodied on the rotor, the data communication required to control the automation process may also be effected exclusively on the rotor.

The data communication between the rotor and the main controller may in this context be reduced to the sending of the response message, including the status information contained therein, by the sub-controller to the main controller. For the purposes of the application, the data communication between the main controller and the rotor describes in particular a data communication between the main controller and the sub-controller embodied on the rotor.

The reduced data volume of the data communication between the main controller and the rotor or the sub-controller embodied on the rotor allows for improved and accelerated control of the planar drive system, in that the bandwidth of the data communication within the planar drive system saved as a result may be used for other functionalities of the planar drive system.

DETAILED DESCRIPTION

According to an embodiment, the communication system comprises a plurality of communication units arranged in a distributed manner on the stator assembly and rotor communication units arranged in a distributed manner on the rotor, wherein the transmitting step carried out by the main controller comprises:determining at least one communication unit arranged adjacent to a position of the rotor on the stator assembly in a determining step; andcontrolling the communication unit adjacent to the position of the rotor to send the communication message in an actuating step.

This has the technical advantage of allowing for precise data communication between the main controller of the planar drive system and the sub-controller on the rotor. In order to control the rotor, the position of the rotor on the stator assembly is known to the main controller at all times. For this purpose, the planar drive system comprises a plurality of magnetic field sensors embodied in the stator assembly, via which the rotor magnetic field of the rotor may be detected and the position of the rotor on the stator assembly may be determined.

If the position of the rotor is known, only the communication units that are arranged in the stator assembly adjacent to the position of the rotor may thus be selected for transmission of the information message by the main controller to the sub-controller. Communication units adjacent to the position of the rotor may be characterized according to the application in that they do not exceed a predefined maximum distance from the determined position of the rotor.

The corresponding communication message is therefore sent to the rotor exclusively via the communication units of the stator assembly arranged adjacent to the rotor in the respective position. This allows for improved data communication between the main controller and the sub-controller on the rotor. Particularly in the case of a plurality of rotors that are actuated by the main controller on the stator assembly, the selection of the communication units for sending communication messages may ensure that the communication messages sent are only sent to the respective addressed sub-controllers of the rotors. This may prevent the main controller from sending messages to non-addressed sub-controllers.

According to an embodiment, the receiving step performed by the main controller comprises:determining at least one communication unit arranged adjacent to the position of the rotor on the stator module in a further determining step; andreading out the communication unit adjacent to the position of the rotor to receive the response message in a reading-out step.

This has the technical advantage of allowing for precise data communication between the sub-controller on the rotor and the main controller of the planar drive system. For this purpose, the main controller only reads out the communication units that are embodied in the stator assembly adjacent to the current position of the rotor after the response message has been sent by the rotor's sub-controller.

This means that it is not necessary to read out all the communication units in the stator assembly in order to receive the response message from the sub-controller. Particularly in the case of a plurality of rotors having corresponding sub-controllers, each of which transmits response messages to the main controller, the selection of the communication units of the stator assembly adjacent to the respective positions of the rotors is advantageous in that the different response messages transmitted by the sub-controllers of the different rotors may be clearly assigned to the respective rotor. Misinterpretation of the received response messages due to incorrect assignment of the messages to the respective sub-controllers of the rotors and the automation processes carried out on or by these may thus be avoided.

According to an embodiment, the data communication between the main controller and the sub-controller takes place during a driving of the rotor from a first position to a second position on the stator assembly, wherein the transmitting step carried out by the main controller comprises a transmitting step:determining at least one first communication unit arranged adjacent to the first position of the rotor on the stator assembly in a first communication unit determining step; anddriving the first communication unit adjacent to the first position of the rotor to transmit a first communication partial message in a first partial transmitting step, the first communication partial message representing a part of the communication message; anddetermining at least one second communication unit disposed adjacent to the second position of the rotor on the stator assembly in a second communication unit determining step; anddriving the second communication unit adjacent to the second position of the rotor to transmit a second communication partial message in a second partial transmitting step, wherein the second communication partial message represents a further part of the communication message; and/or wherein the receiving step carried out by the main controller comprises: determining at least one first communication unit arranged adjacent to the first position of the rotor on the stator assembly in a further first communication unit determining step; andreading out the first communication unit adjacent to the first position of the rotor to receive a first partial response message in a first partial reading-out step, the first partial response message representing a part of the response message; anddetermining at least one second communication unit arranged adjacent to the second position of the rotor on the stator assembly in a further second communication unit determining step; andreading out the second communication unit adjacent to the second position of the rotor for receiving a second partial response message in a second partial reading-out step, the second partial response message representing a further part of the response message.

This may achieve the technical advantage of allowing for precise data communication between the main controller and the sub-controller during a movement of the rotor between two positions on the stator assembly. For this purpose, the communication messages or response messages to be transmitted are divided up into at least two communication partial messages or two response partial messages and a corresponding first communication or response partial message is transmitted via first communication units adjacent to a first position of the rotor and a corresponding second communication or response partial message is transmitted via second communication units adjacent to a second position of the rotor.

For this purpose, the main controller first determines a first position of the rotor and first communication units are selected which are arranged in the stator assembly adjacent to the first position of the rotor, and a corresponding first communication partial message is sent to the sub-controller of the rotor via the selected first communication units or a corresponding first response partial message is received by reading out the selected first communication units.

At a later time, the second position of the rotor is determined and corresponding second communication units are selected, which are arranged adjacent to the second position in the stator assembly. By actuating the selected second communication units, a corresponding second partial communication message is sent to the sub-controller or, by reading out the selected second communication units, a second partial response message is received by the main controller.

The first and second communication partial messages are each parts of the entire communication message to be transmitted, while the first and second response partial messages represent corresponding parts of the entire response message to be transmitted.

In this way, it may particularly be achieved that, in the case of cyclical control of the planar drive system, in which the functionalities of the planar drive system are controlled by the main controller in corresponding control cycles, a communication message may be transmitted by the main controller or a response message may be received, the scope of which cannot be transmitted completely in one control cycle. For this purpose, the first communication partial message or the first response partial message is transmitted via the first communication units in a first control cycle, while the second communication partial message or the corresponding second response partial message, which in each case represents the remainder of the entire communication message or response message that could not be transmitted during the first control cycle, is transmitted via the second communication units in the immediately following later control cycle.

In this context, it is assumed that the rotor was moved from the first position to the second position in the subsequent control cycle as a result of the movement of the rotor.

This ensures that precise data communication between the main controller and the sub-controller may be achieved even when the rotor is moving and when the rotor is controlled cyclically, so that all data to be transmitted may be exchanged without errors.

According to an embodiment, the response message or partial response message received by the main controller via the communication unit is assigned to the sub-controller of the rotor based on a position of the communication unit on the stator assembly via which the response message or partial response message was received and the position of the rotor when the response message or partial response message was received by the main controller.

This has the technical advantage that the respective sub-controller of the respective rotor may be addressed via the position of the rotor known to the main controller. Explicit addressing of the rotor's sub-controller within the transmitted communication message is therefore not necessary. Similarly, a response message received by the main controller may be uniquely assigned to the sub-controller of this rotor based on the known position of the rotor. Explicit identification of the rotor's sub-controller is therefore also not necessary.

According to an embodiment, the status information of the response message received by the main controller comprises start information that the automation process has been started and/or stop information that the automation process has been stopped and/or process data of the completed automation process and/or process data as partial result information of the running automation process and/or an error message regarding an incorrect execution of the automation process.

This may achieve the technical advantage that precise information regarding the status of the automation process controlled by the sub-controller may be provided to the main controller. This allows for precise control of the planar drive system, in which the results of the automation process controlled by the sub-controller may be taken into account.

According to an embodiment, the main controller and the sub-controller each comprise a clock element, wherein the communication message further comprises a time stamp for synchronizing the clock elements of the main controller and of the sub-controller.

This has the technical advantage that the execution of the automation process may be precisely integrated into the control of the entire planar drive system. For this purpose, clock elements of the main controller and of the sub-controller are synchronized with one another based on the time stamp provided by the main controller. Based on the synchronized clock elements, a precise temporal classification of the execution of the automation process controlled by the sub-controller into the overall process of controlling the planar drive system may thus be achieved. This may further improve the control of the planar drive system.

According to an embodiment, the communication message comprises a start time for starting the execution of the automation process by the sub-controller.

This may achieve the technical advantage that a precise start time for the execution of the automation process may be defined. This in turn allows the timing of various sub-processes within the overall process of controlling the planar drive system to be achieved, which in turn helps to improve the control of the planar drive system.

According to a further aspect, a rotor for a planar drive system is provided with a stator module for generating a stator magnetic field for driving the rotor via a magnetic coupling with a rotor magnetic field of the rotor, wherein the rotor comprises a plurality of magnet assemblies for generating the rotor magnetic field, a sub-controller for controlling an automation process, a processing device with at least one actuator unit and/or a sensor unit for executing the automation process, and a rotor communication unit for executing data communication between the sub-controller of the rotor and a main controller of the planar drive system.

In this way, the technical advantage may be achieved that an improved rotor may be provided for a planar drive system, wherein the rotor is set up via a sub-controller embodied on the rotor to control an automation process individually and independently of the main controller of the planar drive system. Furthermore, the rotor is set up to communicate with the main controller of the planar drive system via a communication system of the planar drive system, consisting of rotor communication units arranged in a distributed manner on the rotor and communication units arranged in a distributed manner on the stator assembly. The sub-controller embodied on the rotor for controlling the automation process allows for decentralizing the control of an overall process of the planar drive system. The automation process controlled by the sub-controller represents a sub-process of the overall process of the planar drive system. By controlling the automation process via the sub-controller, the control processes of the main controller may be simplified in that the automation process is controlled exclusively by the sub-controller of the rotor.

According to an embodiment, the sub-controller is layered and evenly distributed over a surface of the rotor.

This has the technical advantage that the uniformly flat embodiment of the sub-controller on the rotor may achieve an even weight distribution of the rotor. The uniform weight distribution, in which the center of gravity of the rotor is arranged as far as possible in a geometric center of the rotor, allows for a more precise floating or flight behavior of the rotor above the stator surface of the stator assembly. The uniform weight distribution of the rotor due to the flat embodiment of the sub-controller means that tilting of the rotor relative to the stator surface of the stator assembly may be prevented.

According to an embodiment, the sub-controller is arranged below the processing device or to the side of the processing device.

This has the technical advantage of allowing for a space-saving arrangement of the sub-controller and the processing device on the rotor.

According to a further aspect, a stator assembly for a planar drive system with at least one rotor is provided, wherein the stator module comprises a plurality of stator coils for generating a stator magnetic field for driving the rotor via a magnetic coupling with a rotor magnetic field of the rotor and a plurality of communication units arranged in a distributed arrangement on the stator assembly for data communication between a main controller of the planar drive system and a sub-controller embodied on the rotor.

This may achieve the technical advantage that an improved stator assembly for a planar drive system may be provided, which allows for precise data communication between the main controller of the planar drive system and a sub-controller embodied on a rotor of the planar drive system. For this purpose, the stator assembly comprises a plurality of communication units which are embodied in an arrangement on the stator assembly and allow for data communication between the main controller and the sub-controller of the rotor.

According to an embodiment, a maximum distance between two neighboring communication units on the stator assembly of the arrangement is less than or equal to twice the maximum communication range of the communication unit.

This may achieve the technical advantage of allowing for seamless data communication between the main controller of the planar drive system and the sub-controller of the rotor for any position of the rotor on the stator assembly. For this purpose, the communication units in the arrangement on the stator assembly are arranged at distances from each other that are less than or equal to twice the communication range of the communication units.

By ensuring that the distances between the communication units of the stator assembly are equal to or smaller than twice the communication range of the communication units, it may be achieved that for any position of the rotor, the rotor communication unit embodied on the rotor is always positioned within the communication range of at least one communication unit of the stator assembly. This allows for continuous, uninterrupted data communication between the main controller of the planar drive system and the sub-controller of the rotor, which may also be provided while the rotor is moving. The communication range of the communication units describes a maximum distance to the respective communication unit within which error-free wireless data communication between the communication unit and the rotor communication unit may be guaranteed.

For the purposes of the application, a communication range of the communication units and of the rotor communication units is a maximum distance that two communication units or rotor communication units have to each other without interference with the data communication between the communication units and/or rotor communication units.

According to an embodiment, a maximum distance between two neighboring communication units on the stator assembly is less than or equal to a minimum planar extent of a rotor of a planar drive system.

This may achieve the technical advantage of allowing for seamless data communication between the main controller of the planar drive system and the sub-controller of the rotor. By creating distances between directly adjacent communication units of the stator assembly that are smaller than or equal to the smallest planar extension of the rotor, it is possible to ensure that the rotor at least partially covers at least one communication unit of the stator assembly for any position of the rotor. This allows for ensuring that the rotor or the at least one rotor communication unit embodied on the rotor is positioned within the communication range of at least one communication unit embodied in the stator assembly for each position of the rotor.

According to an embodiment, the stator coils are set up by a cyclical actuation to drive the rotor at a maximum speed over a maximum distance that may be covered within a control cycle, wherein the maximum distance that may be covered by the rotor in a control cycle is less than or equal to a communication range of the communication units and/or less than or equal to a maximum distance between two neighboring communication units.

This may achieve the technical advantage of ensuring seamless data communication between the main controller of the planar drive system and the sub-controller of the rotor. For this purpose, the distances between the communication units embodied in the stator assembly are smaller than or equal to a maximum distance that the rotor may cover relative to the stator assembly during a control cycle. This allows for ensuring that the rotor is positioned within a communication range of at least one communication unit of the stator assembly at all times, even while the rotor is moving relative to the stator assembly, thus ensuring data communication between the sub-controller of the rotor and the main controller of the planar drive system at all times.

According to an embodiment, the communication units of the stator assembly comprise transmitting/receiving units of a near-field communication and/or a Bluetooth communication and/or a ZigBee communication and/or a Z-wave communication.

The at least one rotor communication unit arranged on the rotor also comprises transmitting/receiving units. These comprise an embodiment that is compatible with the communication units in terms of the communication technology used.

According to an embodiment, the communication units of the stator assembly and the rotor communication units of the rotor are of the same type.

This may achieve the technical advantage of ensuring reliable data communication between the main controller of the planar drive system and the sub-controller of the rotor. The technical advantage of near-field communication lies in the favorable embodiment of the communication units or rotor communication units, as well as in the technically less complex embodiment of the communication protocol. In particular, data communication may take place without a handshake between the two communication partners, the main controller and the sub-controller.

According to an embodiment, the communication units are embodied in a communication foil, with the communication foil being embodied on a stator surface of the stator module.

The has the technical advantage of allowing for the communication units to be embodied on the stator assembly in a simple manner. For this purpose, the communication units may be arranged in a communication foil, which in turn may be positioned on the stator surface of the stator assembly. This allows for simple and cost-effective production of the communication system. By arranging the communication units on the stator surface, the communication units are arranged directly between the rotor and the stator surface. This prevents shielding of the communication units by the stator coils of the stator assembly and ensures interference-free data communication via the communication units of the stator assembly and the rotor communication units of the rotor. The communication units and the communication foil may in turn be made correspondingly thin so that the magnetic coupling of the rotor magnetic field of the rotor and the stator magnetic fields of the stator coils is not weakened. The communication foil, which may be produced from a plastic material, may also serve as a protective layer for the stator surface.

According to an embodiment, the communication units are integrated into the stator module.

This may achieve the technical advantage that the communication units are robust and secured to the stator assembly. By integrating the communication units into the stator assembly, the communication units are protected against damage. This in turn may improve data communication.

According to a further aspect, a planar drive system is provided which comprises a main controller for controlling the planar drive system, a rotor according to one of the preceding embodiments and a stator module according to one of the preceding embodiments, wherein the planar drive system is set up to carry out the method according to the application according to one of the preceding embodiments.

This may achieve the technical advantage that an improved planar drive system with a rotor according to the application with the above-mentioned technical advantages and a stator assembly according to the application with the above-mentioned technical advantages may be provided, which is set up to carry out the method according to the application for controlling a planar drive system with the above-mentioned technical advantages.

According to an embodiment, the communication system comprises at least one external communication unit, wherein the external communication unit is arranged at a distance from the stator assembly.

This may achieve the technical advantage that the external communication unit, which is positioned at a distance from the stator assembly, allows for interference-free communication between the main controller and the sub-controllers of the rotors for any position of the rotors on the stator assembly. For this purpose, the external communication unit may be arranged next to or above the stator assembly and have a communication range that is suitable for encompassing the rotors in any position on the stator assembly.

FIG.1shows a schematic view of a planar drive system200having a stator assembly300and a rotor400.

According to the embodiment inFIG.1, the planar drive system200comprises a main controller201, a stator assembly300and a rotor400. The main controller201is connected to the stator assembly300via a data connection203. The main controller201is set up to actuate the stator assembly300by sending corresponding control signals via the data connection203to the stator assembly300to move the rotor400accordingly. The main controller201is also set up to carry out a method100according to the application for controlling a planar drive system200.

According to the application, the rotor400comprises a sub-controller401and a processing device403. The sub-controller401is embodied to control an automation process which is carried out by the processing device403. For this purpose, the processing device403comprises at least an actuator unit405and/or a sensor unit407, with the aid of which the automation process may be executed. The automation process may be embodied as a partial process of a superordinate process to be executed by the entire planar drive system200. The sub-controller401of the rotor400is in this context set up to control the automation process independently and to have it executed by the processing device403. The sub-controller401and the processing device403are connected to each other by data technology for this purpose, so that the processing device403may be actuated by the sub-controller401. The sub-controller401may, for example, be embodied as a programmable logic controller PLC, and the automation process may be controlled cyclically.

The automation process controlled by the sub-controller401may, for example, be an arrangement or orientation process in which a good to be transported by the rotor400is brought into a desired arrangement or orientation on the rotor400. For this purpose, the processing device403may, for example, comprise a gripper arm with the aid of which the orientation or arrangement of the goods on the rotor400may be changed.

As an alternative or in addition, the automation process may comprise a loading process. For example, objects or items may be unloaded from the rotor400with the aid of a gripper arm of the processing device403or another loading device and positioned on other rotors400or on positioning devices of the planar drive system200provided for this purpose. The gripper arm of the processing device403may also be used to load goods from one rotor400onto a further rotor400. Alternatively, the gripper arm may also be positioned on the rotor400and goods not positioned on the rotor400may also be moved by the gripper arm. For example, the gripper arm may be used to place goods on the rotor400, on another rotor or at a position provided for this purpose that is not arranged on the stator assembly.

As an alternative or in addition, the processing device403may comprise a camera unit, with the aid of which processes may be observed that are executed on the same rotor400or on other rotors400of the planar drive system200. The observation process may be executed via the sub-controller401. The camera unit may, for example, be embodied as a smart camera that allows for recognizing objects with the aid of appropriately trained artificial intelligence.

As an alternative or in addition, the automation process may comprise a manufacturing or processing process in which processing of a good to be transported or manufacturing of an object or item from the good to be transported is achieved. For example, the automation process may comprise a heating or cooling process in which the goods to be transported are heated or cooled to or maintained at a predetermined temperature. For this purpose, the processing device403may comprise at least one heating or cooling element and a temperature sensor. By heating or cooling, for example, the aggregate state of the goods to be transported may be changed and, if necessary, a mixing or segregation of different components of the goods to be transported may be achieved. As an alternative or in addition, the processing device403may also merely be used to monitor the temperature of the goods to be transported, wherein this is maintained at a constant temperature, for example.

As an alternative or in addition, the processing device403may be configured to carry out a weighing process to determine a mass of the goods to be transported.

The automation process to be controlled by the sub-controller401may be carried out while the rotor400is moving between two positions on the stator assembly300. Alternatively, the rotor400may be moved to a position provided for this purpose on the stator assembly300in order to carry out the automation process. Alternatively, the automation process to be controlled may also be executed by the movement of the rotor400itself, for example by rotating the rotor at a defined speed in order to mix transported liquids with one another or to separate them from one another in accordance with a centrifuge.

In order to integrate the automation process controlled by the sub-controller401of the rotor400into the superordinate automation process to be controlled or carried out by the entire planar drive system200, the planar drive system200further comprises a communication system500, with the aid of which communication between the main controller201of the planar drive system200and the sub-controller401of the rotor400is made possible. Via the communication between the main controller201and the sub-controller401of the rotor400, a start command or a stop command of the main controller201may initiate a start or stop of the automation process. Furthermore, status information regarding the executed automation process and/or process data may be provided by the sub-controller401of the main controller201.

The data communication between the main controller201and the sub-controller401of the rotor400may also include cyclical data communication. For this purpose, corresponding messages may be transmitted or received in predetermined communication cycles by the main controller201or the sub-controllers401at predetermined times. The communication cycles may be given by control cycles, according to which cyclic control of the planar drive system200or the executed automation process takes place.

For example, the rotor400or the sub-controller401of the rotor400may permanently send sensor values or other information in corresponding messages to the main controller301for the specified communication cycles. The data transmitted cyclically by the sub-controller401may then be processed by the main controller201and its information integrated into the control of the automation process to be controlled. For this purpose, the main controller may cyclically send corresponding communication messages to the sub-controller401of the rotor400.

Alternatively, the main controller may transmit a communication message to the sub-controller401of the rotor400once, with the aid of which the rotor400is requested to transmit the corresponding data cyclically. Alternatively, the sub-controller401may also be triggered to send data cyclically to the main controller201independently, i.e. without a prior communication message from the main controller201.

As the case may be, based on the data from the sub-controller401, corresponding subsequent commands may be sent to the sub-controller401in corresponding communication messages by the main controller201. In particular, commands or instructions or information may be exchanged between the main controller201and the sub-controller401in the prescribed cycle times of the communication cycles.

In order to provide communication, the communication system500comprises a plurality of communication units501distributed on the stator assembly300and at least one rotor communication unit402embodied on the rotor400.

In the embodiment shown, the rotor400comprises four rotor communication units402arranged at the four edges of the square shaped rotor400. In deviation therefrom, the rotor400may comprise any number of rotor communication units402embodied at any positions on the rotor400. According to an embodiment, the rotor communication units402each comprise antenna units for receiving and transmitting messages and evaluation units for evaluating the received messages. The antenna units and evaluation units of a rotor communication unit402may each be embodied at different positions on the rotor400.

For a detailed description of the method according to the application for controlling a planar drive system200, please refer to the description ofFIG.5toFIG.8.

In the embodiment shown, the stator assembly300comprises a plurality of stator modules301arranged side by side along an X-direction and a Y-direction of the stator assembly300and forming a contiguous planar stator surface303of the stator assembly300. In the embodiment shown, the stator assembly300comprises six stator modules301. However, the number of interconnected stator modules301of a stator assembly300is not intended to be limited to this and may vary as desired. In the embodiment shown, the main controller201is connected to each stator module301via the data connection203, so that each stator module301may be actuated individually. Control signals and/or communication messages of the main controller201may be forwarded from one stator module308to another stator module308via the data connection203.

Each of the stator modules301comprises four stator segments308. Each stator segment308comprises X-coil groups and Y-coil groups, each of which is oriented along the X-direction or the Y-direction. For a detailed description of the coil groups, please refer toFIG.3. Alternatively, a stator module301may comprise any number of stator segments308.

In the embodiment shown, the stator segments308are square and are arranged in alignment along the X-direction and the Y-direction. A rectangular or otherwise shaped configuration of the stator segments308is also possible. Each stator segment308comprises a plurality of energizable stator conductors309, which are combined in the coil groups as described inFIG.4and are oriented along the X-direction or along the Y-direction.

InFIG.1, only stator conductors309oriented along the X direction are shown. Stator magnetic fields may be generated by energizing the stator conductors309of the coil groups. With the aid of a magnetic coupling between the stator magnetic fields and a rotor magnetic field of the rotor400, the rotor400may be driven in a floating manner along the X-direction and the Y-direction via the stator surface303. By moving the rotor400both in the X-direction and in the Y-direction, the rotor400may be moved in any direction over the stator surface303. It is also possible to move the rotor400in a Z-direction oriented perpendicular with regard to the X-direction and the Y-direction. In this way, the distance between the rotor400and the stator surface303may be varied, i.e. the rotor400may be raised or lowered above the stator surface303. It is also possible to rotate the rotor400about an axis of rotation oriented perpendicular with regard to the stator surface303or to tilt the rotor400about an axis of rotation oriented in parallel to the stator surface303.

The stator modules301each comprise a stator module housing305, in which control electronics are arranged to control the stator module301. Furthermore, magnetic field sensors for detecting the rotor magnetic field of the rotor400are arranged in the stator module housing305. Each stator module301comprises corresponding connection lines307for supplying power and data to the control electronics.

In the embodiment shown, the communication system500comprises a plurality of communication units501embodied on the stator assembly300. The rotor400comprises rotor communication units402. The communication units501thus allow for communication between the main controller201and the rotor400or the sub-controller401arranged on the rotor400in communicative connection with the rotor communication units402.

In the embodiment shown, the communication units501are evenly distributed over the entire stator assembly300. In the embodiment shown, the communication units501are arranged in a communication foil507. The communication foil507may be made of a plastic material and positioned on the stator surface303of the stator assembly300. For this purpose, the communication foil507may be glued or otherwise fixed to the stator surface303. The communication units501are also electrically or data-technically connected to the respective stator modules301of the stator assembly300. The connection of the communication units501to the stator modules301also provides a data connection between the communication units501and the main controller201, so that the communication units501may be actuated or read out by the main controller201. In an alternative embodiment, the communication units501may also be connected independently to an electrical supply and directly to the main controller201in terms of data technology.

In the embodiment shown, a communication unit501is arranged on each stator segment308. This is merely exemplary and the communication units501may be arranged on the stator assembly300as desired. In particular, a plurality of communication units501may be arranged on each stator module301. Also, in contrast to the arrangement inFIG.1, the communication units501may not be arranged in the geometric center of the respective stator segment308, but rather, for example, at the edge of the stator segment308.

Preferably, the communication units501are arranged on the stator assembly300in such a way that for any position of the rotor400on the stator assembly300, the rotor400is arranged within communication range of at least one communication unit501. In this way, seamless communication between the main controller201and the rotor400or the sub-controller401of the rotor400may be achieved. Positions of the rotor400in which communication is prevented therefore do not exist on the stator assembly300.

For seamless communication, the communication units501may be arranged on the stator assembly300in such a way that a distance between two immediately adjacent communication units501is less than or equal to twice the maximum communication range of the communication units501. As an alternative or in addition, the distances at which the communication units501are arranged on the stator module300in relation to one another may be related to the dimensions of the rotor400. Thus, distances between directly adjacent communication units501may be smaller than or equal to the maximum dimensions of the rotor400, in particular the widths of the rotor400in the X and/or Y directions. The distances between the communication units501here refer to the X and Y directions running parallel to the stator surface303.

By spacing the communication units501in this way, it may be provided that even with short communication ranges of the communication units501, the rotor400is arranged in any position on the stator assembly300within the communication range of at least one communication unit501.

According to the application, the rotor400is also provided with at least one rotor communication unit402. In the embodiment shown, the rotor400comprises four rotor communication units402, each of which is arranged on the four edges of the substantially rectangularly shaped rotor400. Alternatively, the rotor400may have a higher or lower number of rotor communication units402. For example, only a single rotor communication unit402may be arranged in a geometric center of the rotor400on the rotor400.

For seamless communication between the communication units501and the rotor communication units402, the communication units501may additionally or alternatively be arranged on the stator assembly300in such a way that the rotor400cannot be moved out of the communication range of a communication unit501during a control cycle when the rotor400is cyclically actuated and the main controller201cyclically communicates with the sub-controller401via the communication units501on the stator assembly300and the rotor communication units402on the rotor400.

For this purpose, the communication units501may be arranged on the stator assembly300at distances from one another that are less than or equal to a maximum distance that the rotor400may travel at a maximum speed of the rotor400within a control cycle on the stator assembly300. However, other arrangements of the communication units501on the stator assembly300are also conceivable and advantageous for fulfilling the described purpose. In particular, arrangements according to the previous description. In addition, it is advantageous for this purpose that the rotor400is embodied with a plurality of rotor communication units402, so that at any time during the control cycle at least one rotor communication unit402of the rotor400is arranged within range of at least one communication unit501of the stator assembly300.

According to an embodiment, the communication units501of the stator assembly300and the rotor communication units402of the rotor400are of the same type. In particular, the communication units501and rotor communication units402may be embodied as transmitting/receiving units that allow for both transmitting and receiving communication messages and response messages. In this way, messages may be sent from the main controller201to the sub-controller401and received by the sub-controller401. Conversely, messages may be sent from the sub-controller401to the main controller201and received by the main controller201.

The communication units501and rotor communication units402may, for example, be embodied as transmitting/receiving units of a near-field communication, a Bluetooth communication, a ZigBee communication or a Z-Wave communication. In general, the communication units501and rotor communication units402are advantageously embodied as radio-based transmitting/receiving units.

As an alternative to the formation of the communication units501in a communication foil507, the communication units501may also be arranged in a communication layer. The communication layer may, for example, be embodied as an additional layer of the stator modules301of the stator assembly300. For example, the communication layer may be made of a plastic material in which the communication units501are embedded. The communication layer may, for example, be the uppermost layer of each stator module301and thus form the stator surface303of the stator assembly300. Alternatively, the communication layer may be integrated into the respective stator module301and be located inside of the stator module301. If the communication layer is integrated into the stator assembly300and thus does not form the stator surface303, the communication layer is preferably arranged directly below the stator surface. For example, the communication layer may also be embodied as an integrated circuit in a control board and integrated in the stator assembly300.

According to a further embodiment, at least one communication unit501of the communication system500may be embodied as an external communication unit501which is arranged externally to the stator assembly300in the planar drive system200. The external communication unit501may, for example, be arranged laterally next to the stator assembly300or mounted above the stator assembly300on a holder provided for this purpose. A communication range of the external communication unit501may be embodied to be correspondingly greater than that of the communication units501arranged on the stator assembly300, in order to enable interference-free data communication with rotors400positioned at any point on the stator assembly300.

FIG.2shows a schematic view of a stator module301of the stator assembly300inFIG.1.

The stator module301comprises four stator segments308having stator conductors309oriented along the X direction. InFIG.2, only an uppermost layer of stator conductors309is shown. Below the layer of stator conductors309shown, at least one further layer of stator conductors309is arranged according to the application, which is not visible inFIG.2. According to the application, the stator conductors309of the at least one further layer are oriented along the Y-direction. Furthermore, a stator module301may also comprise more or fewer than the four stator segments308shown.

The stator conductors309are electrically insulated from one another. The four stator segments308are square in shape and form a square stator surface303. Alternatively, the stator segments308may also comprise a rectangular shape or any other shape. The stator segments308are connected to one another via a contact structure311. In the embodiment shown, each stator segment308comprises a communication unit501. The communication units501are each arranged in the geometric center of the stator segment308. In the embodiment shown, the communication units501are arranged in a communication foil507, which is arranged on the stator surface303of the stator module301in analogy to the embodiment inFIG.1. Alternatively, the communication units501may also be arranged in a communication layer. This may, for example, be integrated as an additional layer in the stator module301.

According to an embodiment, the communication units501each comprise an antenna unit, and an evaluation unit. According to an embodiment, the antenna unit and the evaluation unit of a communication unit501may be arranged at different positions on the stator assembly300.

In the embodiment shown, the communication units501each have an X distance Dxalong an X axis, a Y distance Dyalong a Y axis and an XY distance Dxyalong an XY direction. In this context, the X-axis and the Y-axis refer to a coordinate system that is fixedly connected to the stator assembly300, wherein the XY plane of the coordinate system is oriented in parallel to the stator surface303of the stator assembly300.

FIG.3shows a schematic depiction of an underside of a rotor400according to an embodiment.

During operation of the planar drive system200, the underside of the rotor400is arranged facing the stator surface303of the stator assembly300. The rotor400comprises a magnet arrangement409with a plurality of magnet assemblies413on the underside. The magnet assemblies413are each aligned in pairs along two mutually perpendicular directions x, y of the rotor400and each comprise a plurality of magnetic elements415arranged next to one another. The magnet arrangement409is embodied to generate the rotor magnetic field of the rotor400, via which a magnetic coupling with the stator magnetic fields of the stator assembly300may be achieved. A drive of the rotor400relative to the stator assembly300may be achieved via the magnetic coupling.

In operation, the underside of the rotor400with the magnet arrangement409is oriented essentially in parallel to the stator surface303and is arranged facing the stator surface303.

With the aid of the magnet assemblies413arranged along the X-direction and Y-direction, X-components, Y-components and Z-components of the rotor magnetic field may be generated. With the aid of a coupling with correspondingly oriented stator magnetic fields of the stator assembly300, the rotor400may be brought into a beat over the stator surface303of the stator assembly300, in which no contact of the rotor400with the stator assembly300occurs. With the aid of a corresponding control of the stator coils, the rotor400may be driven in the floating state relative to the stator assembly300.

FIG.4shows a schematic exploded view of a stator segment308of a stator assembly300.FIG.4shows four separate stator layers, each of which is part of the stator segment308.

According to the embodiment shown, the stator segment308comprises a first stator layer313, a second stator layer315, a third stator layer317and a fourth stator layer319arranged one above the other in the Z direction. The first stator layer313and the third stator layer317each exclusively comprise stator conductors309extending in the X direction. The second stator layer315and the fourth stator layer319, on the other hand, each exclusively comprise stator conductors309extending in the Y direction.

The stator conductors309of the first stator layer313correspond to the stator conductors309shown inFIG.1andFIG.2, which are arranged on the stator surface303. The stator conductors309of the other stator layers are arranged in the Z direction below the first stator layer313.

The embodiment of the stator segment308is exemplary for the stator segments308shown inFIG.1andFIG.2, which also have the embodiment shown inFIG.4.

The stator conductors309of the individual stator layers313,315,317,319are each combined to form coil groups321. In the embodiment shown, each stator layer313,315,317,319comprises three coil groups321arranged next to one another. The first and third stator layers313,317comprise three X coil groups323oriented along the X direction, while the second and fourth stator layers315,319comprise three Y coil groups325oriented along the Y direction. By corresponding energization, the X coil groups323are set up to generate a stator magnetic field with a Z component and a Y component, while the Y coil groups are set up to generate a stator magnetic field with a Z component and an X component. The corresponding X, Y or Z components of the stator magnetic field may be used to achieve translational movements of the rotor400in X, Y and Z axes and rotational movements about axes of rotation aligned parallel to the X, Y and Z axes.

The six stator conductors309in each coil group321may in particular be combined as a three-phase system, in which two interconnected stator conductors309each form one of the three phases U, V, W of the three-phase system.

FIG.4also shows a further layer of the stator segment308, which comprises a plurality of communication units501. In the embodiment shown, five communication units501are arranged in a communication layer509. The communication layer509is here arranged as an uppermost layer of the stator segment308in the Z-direction. The communication layer509may thus be embodied in such a way that the stator surface303of the stator module301or the stator assembly300is embodied by the communication layer509. Alternatively, a further layer may be arranged above the communication layer509, which forms the stator surface303. The communication layer509may e.g. be embodied as a circuit board. The communication layer509may be embodied from a plastic material, in particular in such a way that the stator module301or the stator assembly300is sealed by the communication layer509.

In the embodiment shown, five communication units501are arranged in the stator segment308shown. This is merely exemplary and is not intended to limit the invention. According to the application, any number of communication units501may be arranged per stator segment308. In particular, the number of communication units501per stator segment308may depend on the communication range of the respective communication units501, so that a larger communication range of the communication units501allows for a smaller number of communication units501per stator segment308, since the individual communication units501may each be arranged at larger distances from one another. The same applies to the entire stator assembly300or the stator modules301. Depending on the number of stator modules301that are integrated into the stator assembly300, and thus depending on the size of the stator assembly300, any number of communication units501may be integrated into the stator assembly300. This number may in turn depend on the respective communication range of the communication units501.

FIG.5shows a flow chart of a method100for controlling a planar drive system200according to an embodiment.

The method100according to the application for controlling a planar drive system200may be implemented by a planar drive system200with a main controller201, a stator assembly300and at least one rotor400with a sub-controller401according to the embodiments inFIGS.1to4. For this purpose, the planar drive system200further comprises a communication system500having a plurality of communication units501and at least one rotor communication unit402. A plurality of the communication units501is embodied on the stator assembly300, while at least one rotor communication unit402is arranged on the rotor400. The rotor400may further comprise a processing device403for executing the automation process to be controlled by the sub-controller401.

As described above, the stator assembly300comprising a plurality of stator coils321for generating a stator magnetic field. The rotor400itself comprises a plurality of magnet assemblies413for generating a rotor magnetic field. The rotor400may be driven on the stator assembly300via a magnetic coupling between the stator magnetic field and the rotor magnetic field. The main controller201of the planar drive system200is set up to control the planar drive system200and, in particular, to control the movement of the at least one rotor400on the stator assembly300. The sub-controller401of the rotor400, on the other hand, is set up to control the automation process that may be carried out by the processing device403.

The automation process may in this process be seen as a partial process of an overall process carried out by the planar drive system200. Here, the overall process may comprise the movement of the various rotors400or of the at least one rotor400on the stator assembly300for transporting various goods by the at least one rotor400. Furthermore, the overall process may include the automation process as described above, which may include, for example, a processing or manufacturing process of a good transported by the rotor400. The control of the planar drive system200may thus comprise, according to the application, the movement of the rotor400between different positions on the stator assembly300, as well as the execution of the automation process by the processing device403of the rotor400and the control of the automation process by the sub-controller401of the rotor400.

According to the application, in order to control the planar drive system200, the main controller201first transmits a communication message to the sub-controller401of the rotor400via the communication system500in a transmitting step101. The communication message in this context comprises a start command for starting the automation process to be executed by the rotor400or by the processing device403of the rotor400. In this case, the communication message is set up by the start command to cause the sub-controller401of the rotor400to start the automation process when it is received.

According to the application, after receipt of the communication message by the sub-controller401of the rotor400, the automation process to be carried out is controlled by the sub-controller401.

After receipt of the communication message by the sub-controller401of the rotor400, a response message transmitted by the sub-controller401to the main controller201via the communication system500is received by the main controller201in a receiving step103according to the application.

In this context, the response message comprises a status information about a status of the automation process controlled by the sub-controller401. The status information of the response message may, for example, comprise start information with the aid of which feedback is provided to the main controller201that the automation process has been started by the sub-controller401in accordance with the start command of the communication message. As an alternative or in addition, the status information may comprise stop information indicating that the automation process has been stopped.

Stopping the automation process may include, for example, ending the automation process by reaching the desired goal of the automation process. Stopping the automation process may also describe an interruption of the automation process, for example due to a malfunction of the automation process. As an alternative or in addition, the status information may comprise process data of the automation process which, for example, describe a final result or partial results of the executed automation process. The final or partial results may in turn comprise process data describing the progress of the controlled automation process. As an alternative or in addition, the status information may include an error message in which a faulty execution of the automation process is indicated. The status information may provide a precise description of the state of the automation process controlled by the sub-controller401and executed by the processing device403.

The main controller201may take the status information of the response message into account when controlling the planar drive system200. For example, the main controller201may initiate additional subsequent processes upon successful completion of the automation process executed by the processing device403. For example, after successful completion of the automation process, the main controller201may move the rotor400to a designated position on the stator assembly300, for example to load or remove from the rotor400the goods processed or produced by the automation process. Alternatively, further measures may also be initiated by the main controller201. Overall, the bidirectional data communication between the main controller201and the sub-controller401allows the results of the automation process controlled by the sub-controller401to flow into the overall control of the planar drive system200.

According to an embodiment, the main controller201and the sub-controller401each comprise a clock element. Furthermore, the communication message transmitted by the main controller201comprises a timestamp defined by the main controller201. Alternatively, not every communication message comprises a time stamp. Instead, communication messages are only provided with time stamps at predetermined time intervals and thus the controllers are synchronized at the predetermined time intervals.

With the aid of the time stamp, synchronization of the two clock elements of the main controller201and the sub-controller401may be achieved. By synchronizing the two clock elements of the main controller201and the sub-controller401, synchronized time recording of the two controllers201,401may be achieved. By synchronizing the two clock elements of the main controller201and the sub-controller401, a communication message sent out may include a start time predefined by the main controller201in addition to the start command for executing the automation process. In this way, it may be achieved that the automation process is started by the sub-controller401at the predetermined start time, which in turn may be arranged at any time later than the receipt of the communication message by the sub-controller401. In addition, the synchronization between the main controller201and the sub-controllers401of the rotors400allows data exchanged to be assigned to exact points in time.

Without synchronization of the clock elements of the two controllers201,401, the automation process may alternatively be started by the sub-controller401immediately after receipt of the communication message including the start command contained therein. Alternatively, a command may be provided to the sub-controller401to start or stop the automation process at the end of a predetermined period of time after receipt of the respective start command.

FIG.6shows a further flow chart of the method100for controlling a planar drive system200according to a further embodiment.

The embodiment of the method100according to the application shown inFIG.6is based on the embodiment inFIG.5and comprises all the method steps described therein. A further detailed description is therefore not provided below.

In the embodiment shown, the transmitting step101carried out by the main controller201comprises a determining step105. To transmit the communication message, a communication unit501of the stator assembly300is first determined in the determining step105for a position of the rotor400on the stator assembly300, which is arranged adjacent to the respective position of the rotor400.

According to the application, the main controller201for controlling the planar drive system200and in particular for moving the rotor400on the stator assembly300is aware of a current position of the rotor400on the stator assembly300at all times. For this purpose, the stator assembly300comprises, for example, a plurality of magnetic field sensors with the aid of which the rotor magnetic field of the rotor400may be detected.

By detecting the rotor magnetic field in this way, the position of the rotor400on the stator assembly300may be determined accordingly. By knowing the position of the rotor relative to the stator assembly300, the main controller201may determine at least one communication unit501for each position of the rotor400on the stator assembly300, which is arranged on the stator assembly300adjacent to the respective position of the rotor400. Here, a communication unit501is adjacent to the position of the rotor400if the respective communication unit501has a distance to the respective position of the rotor400that is less than a predetermined limit value. For this purpose, the main controller201is in turn aware of each position of each communication unit501of the stator assembly300.

After determining the communication units501of the stator assembly300arranged adjacent to the current position of the rotor400on the stator assembly300, the main controller201actuates the selected communication unit501to transmit the communication message to the sub-controller401of the rotor400in an actuating step107for transmitting the communication message. Alternatively, a plurality of communication units501of the stator assembly300adjacent to the rotor400in the current position may be determined in the determining step105. Accordingly, in the activating step107, the various selected communication units501may be actuated simultaneously to transmit the communication message.

As described above, the rotor400also comprises at least one rotor communication unit402, which is embodied on the rotor400. Via the at least one rotor communication unit402, the rotor400is able to receive the communication message transmitted by the main controller201. If the rotor400according to the embodiment inFIG.1comprises a plurality of rotor communication units402, the communication message may be received via each or via a plurality of the rotor communication units402of the rotor400.

In the embodiment shown, the receiving step103carried out by the main controller201further comprises a further determining step109. In the further determining step109, the communication units501arranged adjacent to the current position of the rotor400in the stator assembly300are determined and selected by the main controller201. According to an embodiment, the determining step105and the further determining step109may be carried out in a common method step. The adjacent communication units501of the stator assembly300for transmitting the communication message to the position of the rotor400may also be used for receiving the response message in the receiving step103.

This is possible in particular if the position of the rotor400has remained unchanged between the transmission of the communication message in the transmitting step101and the receipt of the response message in the receiving step103. However, if the position of the rotor400is changed by moving the rotor400on the stator assembly300, other communication units501are determined in the further determining step109than were determined for transmitting the communication message in the determining step105. In particular, other communication units501are determined if the rotor400is outside a communication range of the originally determined communication unit501.

In a reading-out step111carried out by the main controller201, after determining the current position of the rotor400, adjacent communication units501of the stator assembly300are read out and the response message is received by the main controller201.

FIG.7shows a further flow chart of the method100for controlling a planar drive system200according to a further embodiment.

In the embodiment shown, the case of a communication between the main controller201and the sub-controller401arranged on the rotor400during a drive of the rotor400and a movement of the rotor400between a first position P1and a second position P2is described. Furthermore, the case is described in which the rotor400is actuated cyclically in that the rotor400is actuated in corresponding control cycles for moving between the first and second positions P1, P2by the main controller201.

The cyclic control of the planar drive system200further comprises the data communication between the main controller201and the sub-controller401of the rotor400. In the embodiment shown, the case is described here in which the transmission of the communication message in the transmitting step101by the main controller201to the sub-controller401is not fully completed during a control cycle, so that the transmission of the entire communication message must be distributed over two consecutive control cycles. Similarly, the case is described in which the receipt of the response message transmitted by the sub-controller401by the main controller201may also not be completely executed in one control cycle, so that the receipt of the entire response message must also be executed distributed over two consecutive control cycles.

For this purpose, in the embodiment shown, the transmitting step101carried out by the main controller201comprises a first communication unit determining step113. In the first communication unit determining step113, first communication units503of the stator assembly300are determined, which are arranged adjacent to a first position P1of the rotor400on the stator assembly300.

In a first partial transmitting step115, the determined first communication units503are then triggered to transmit a first partial communication message to the sub-controller401of the rotor400. The first communication partial message here describes a part of the complete communication message and, in particular, the part that may be transmitted completely by the correspondingly determined first communication units503in a first control cycle of the planar drive system200.

Since the rotor400is moved from the first position P1to the second position P2on the stator assembly300during the data communication, second communication units505are determined in a second communication unit determining step117, which are arranged in the stator assembly300adjacent to the second position P2of the rotor400. Depending on the distance between the first and second positions P1, P2, the second communication units505may be at least partially identical to the first communication units503. On the other hand, if the rotor400has been moved a large distance between the first position P1and the second position P2, the first communication units503differ from the second communication units505.

Subsequently, in a second partial transmitting step119, the second communication units505adjacent to the second position P2of the rotor400are controlled to transmit a second partial communication message. The second communication partial message describes a further part of the original communication message, in particular the part of the original communication message that could not be transmitted in the first control cycle. The second communication unit determining step117as well as the second partial transmitting step119are thus carried out in the further control cycle following the first control cycle. In the embodiment shown, the transmitting step101and the transmission of the communication message are distributed over two successive control cycles. By moving the rotor400from the first position P1to the second position P2, the first and second communication partial messages may thus be transmitted by at least partially different first and second communication units503,505.

Similarly, a response message transmitted by the sub-controller401of the rotor400is received in the receiving step103carried out by the main controller201over two control cycles that follow one another in time.

For this purpose, the receiving step103comprises a further first communication unit determining step121. In the further first communication unit determining step121, the first communication units503arranged adjacent to the first position P1are determined.

In a first partial reading-out step123, the determined first communication units503are read out by the main controller201and a first partial response message is received.

In a further second communication unit determining step125, second communication units505are again determined, which are arranged adjacent to the second position P2of the rotor400in the stator assembly300.

In a second partial reading-out step127, the determined second communication units505are read out and a second partial response message is received by the main controller201.

The first and second partial response messages each describe parts of the original response message to be transmitted, in particular the parts that could be transmitted by the sub-controller401in the two consecutive control cycles.

The first and second communication units503,505adjacent to the first and second positions P1, P2may be determined by ensuring that the corresponding communication units501do not exceed a predefined maximum distance to the corresponding position.

The shown transmission of the communication message in the transmitting step101and the receipt of the response message in the receiving step103may each be carried out in a distributed manner over two immediately consecutive control cycles. Alternatively, the transmission of the two communication partial messages in the transmitting step101or the receiving of the two response partial messages in the receiving step103may each be executed in a distributed manner over two control cycles of the planar drive system200, which do not immediately follow one another in time and between which at least one further control cycle was executed.

It is also conceivable that the communication message and/or the response message could be divided up into more than two communication partial messages or more than two response partial messages. In this case, more control cycles are used for the procedure described above.

FIG.8shows a schematic depiction of the method100for controlling a planar drive system200according to the embodiment inFIG.7.

FIG.8shows a plan view of an embodiment of the planar drive system200fromFIG.1. The planar drive system200comprises all the features described there. A further detailed description is therefore not provided below.FIG.8also shows a movement of a rotor400in a direction of travel D between a first position P1and a second position P2.

According to the embodiment of the method100inFIG.7, first communication units503adjacent to the first position P1are determined. As shown, the first communication units503of the stator assembly300are characterized in that they have a distance as small as possible to the rotor communication units402arranged at the respective four edges of the square-shaped rotor400. The first communication units503may be identified in particular by the fact that they have a distance to the first position P1of the rotor400that is less than a predetermined limit value. By knowing the first position P1of the rotor400, which is defined with respect to a geometric center of the rotor400as shown, and by knowing the arrangement of the individual rotor communication units402on the rotor400, the first communication units503may be identified as the communication units501of the stator assembly300with the smallest distance to one of the rotor communication units402of the rotor400.

In the embodiment shown, data communication between the main controller201and the sub-controller401of the rotor400may thus take place via the determined first communication units503of the stator assembly300and the corresponding rotor communication units402of the rotor400. In the illustration shown, a transmission of a response message by the rotor communication units402of the rotor400to the determined first communication units503of the stator assembly300is shown. By a corresponding readout of the first communication units503of the stator assembly300by the main controller201, the transmitted response message may be received by the main controller201. According to the embodiment inFIG.7, the transmitted response message may be embodied as a first partial response message and describe only a part of the response message to be transmitted, which may be transmitted during a first control cycle.

In the embodiment shown, the communication units501are arranged in the stator assembly300in such a way that distances between directly adjacent communication units501are smaller than the extensions of the rotor400. In particular, an X distance DXrunning along an X axis is smaller than an X width Lx of the rotor400along the defined X direction. Similarly, a Y-distance DYbetween two directly adjacent communication units501of the stator assembly300along a Y-direction is smaller than a corresponding Y-width Ly of the rotor400. An XY-distance DXYbetween two directly adjacent communication units501along an XY-direction is also smaller than the planar dimensions of the square-shaped rotor400in the embodiment shown.

By moving the rotor400along the direction of travel D, the rotor400is positioned in a temporally subsequent control cycle in a second position P2relative to the stator assembly300, which differs from the first position P1. According to the embodiment inFIG.7, corresponding second communication units505are determined, which are adjacent to the second position P2of the rotor400. In the embodiment shown, the second communication units505are again characterized in that they have a minimum distance to the rotor communication units402of the rotor400arranged respectively at the four edges of the square-shaped rotor400. Also, for the second position P2,FIG.8again shows the transmission of a second response message from the rotor communication units402of the rotor400to the determined second communication units505of the stator assembly300. By reading out the corresponding second communication units505, the main controller201may receive the transmitted second response partial message accordingly.

In the embodiment shown, a situation is shown in which the first and second partial response messages were not transmitted in two immediately consecutive control cycles. Rather, the situation is shown in which the two control cycles are timed apart by a plurality of further executed control cycles. This is only done for the sake of clarity of the illustration shown and is not intended to limit the present application. In the case of two control cycles immediately following each other in time, the distance between the first and second positions P1, P2is smaller and the first and second communication units503,505may be at least partially identical.

In the illustration shown, the transmission of the response message by the sub-controller401of the rotor400is shown. According to the embodiment of the method100inFIG.7, the transmission of the communication message by the main controller201takes place analogously via the correspondingly determined first and second communication units503,505in two consecutive control cycles.

FIG.9shows a schematic depiction of a rotor400of the planar drive system200according to an embodiment.

In the embodiment shown, the sub-controller401is embodied flat on the rotor400. In the embodiment shown, the processing device403for executing the automation process is also embodied flat and arranged above the sub-controller401. In the embodiment shown, the processing device403comprises a first functional module406and a second functional module408, which are also positioned one above the other in layers. The two functional modules406,408may carry out different functions of the automation process to be controlled. Alternatively, the processing device403may comprise any number of different functional modules. The sub-controller401and the first and second functional modules406,408each comprise connection elements410, with the aid of which an electrical and data connection between the sub-controller401and the processing device403is made possible.

FIG.10shows a further schematic depiction of a rotor400of the planar drive system200according to a further embodiment.

FIG.10is based on the embodiment of the rotor400inFIG.9and includes all the features described there. A further detailed description is thus not provided below. In contrast to the embodiment inFIG.9, in the embodiment inFIG.10the first and second functional modules406,408of the processing device403are arranged in a step-wise manner on the sub-controller401embodied flat on the rotor400.

FIG.11shows a further schematic depiction of a rotor400of the planar drive system200according to a further embodiment.

FIG.11shows a top view of a rotor400with a flat and, in particular, rectangularly shaped sub-controller401arranged in the center of the rotor400on the rotor400. In the embodiment shown, connecting elements410are arranged around the rectangularly shaped sub-controller401. The connection elements are arranged on the four sides of the rectangular sub-controller401. The connection elements410can, for example, be embodied as I/O connection elements, with the aid of which a connection of the actuator units405or sensor units407of the processing device403is made possible.

According to an embodiment, the sub-controller401and/or the processing device403and/or the I/O connection elements of the embodiments shown inFIGS.9-11are comprised by a housing unit. The housing unit may be embodied in such a way that further modules, for example further processing devices403, may be inserted into the housing unit. For example, the housing unit may have slide-in recesses into which corresponding modules may be inserted. Furthermore, the housing unit may be embodied with contacting elements so that the various modules may be electrically and/or data-technically connected to one another via contacting with the contacting elements. The housing unit may also be connected to the rotor via a back plate.

FIG.12shows schematic depictions of various embodiments of a sub-controller401of a rotor400.

Diagram a) shows a top view of a rotor400with an sub-controller401. In the embodiment shown in diagram a), the sub-controller401is embodied in two parts and is arranged on an edge region of the rotor400. In particular, the sub-controller401is embodied in an impact protection element417embodied on the outer edges of the rotor400. The impact protection element417serves as impact protection for the rotor400and prevents damage to the rotor400in the event of collisions of the rotor400with other rotors400or other objects. In the embodiment shown, the two-part sub-controller401extends over two edges of the rotor400. It is also conceivable that only one sub-controller401is embodied on one edge of the rotor400. However, it is also conceivable that the sub-controller401is divided up into more than two parts, in particular into four parts, and that a part of the sub-controller401is arranged on all four edges of the rotor400. In this way, the installation space requirement and the weight distribution may be optimized.

Diagram b) shows a bottom view of a rotor400with an sub-controller401. In the embodiment shown in diagram b), the sub-controller401is positioned centrally between the four magnet assemblies413. Such an arrangement of the sub-controller is very space-saving and optimal in terms of weight distribution on the rotor400.

Diagram c) shows a top view and a side view of a rotor400with a sub-controller401. In the embodiment shown in diagram c), the sub-controller401is embodied as a flat layer element on the rotor400. For this purpose, the sub-controller401may be embodied as a control board.

Further components, connection elements, control elements and/or objects/products to be transported may then be placed on the flat sub-controller401and thus moved by the rotor400.

According to an embodiment, the sub-controller401is embodied as a programmable logic controller PLC. In particular, the sub-controller401may be embodied as an industrial PC.

According to an embodiment, the data communication between the main controller201and the sub-controller401may be carried out via a fieldbus protocol. In particular, the fieldbus protocol may be embodied as an EtherCAT protocol.

A control cycle of the cyclic control of the planar drive system200may describe a time duration in the microsecond range.

Although the invention has been further illustrated and described in detail by embodiments, the invention is not limited by the disclosed examples and other variations may be derived therefrom by those skilled in the art without departing from the protective scope of the invention.