METHOD FOR OPERATING A PLA ARM MOTOR

Description

[0001] The present invention relates to a method for operating a planar motor with a plane of motion in which a plurality of motion paths are defined, along which a plurality of transport units move, wherein at least two motion paths in the plane of motion are extended at least sectionally two-dimensionally around the respective motion path to form a motion lane in the plane of motion, by defining a width of the motion lane at least sectionally at each point of the respective motion path, and checking whether the at least two resulting motion lanes overlap, or whether one of the resulting motion lanes overlaps with itself, or whether one of the resulting motion lanes overlaps with an obstacle defined with respect to position and geometry in the plane of motion, in order to determine a conflict zone in an overlap area.where there is a risk of collision between transport units moving on movement paths involved in the conflict zone, or a risk of collision between a transport unit moving on a movement path involved in the conflict zone and the obstacle in the plane of movement, and the identified conflict zone is taken into account when controlling the movement of the transport units along the assigned movement path in order to avoid collisions between transport units moving on movement paths involved in the conflict zone or between a transport unit and the obstacle in the plane of movement.

[0002] In a planar motor, a primary part (stator) and at least one secondary part (rotor) are provided, which is arranged to be movable relative to the primary part. Drive coils are arranged on the primary part and drive magnets on the secondary part, or vice versa. The drive magnets are designed as permanent magnets, electrical coils, or short-circuit windings. The drive coils are electrical coils that are energized to generate an electromagnetic field. Through the interaction of the (electro)magnetic fields of the drive magnets and the drive coils, forces act on the secondary part, enabling it to move relative to the primary part. The drive coils are arranged on the primary part in one plane of motion. Designs are also known in which the drive coils are arranged on the primary part in several planes. The secondary part can move freely in the two directions of motion within the plane of motion.It is also possible to move the secondary part perpendicular to the plane of motion within certain limits. Rotational movements of the secondary part, particularly about an axis of rotation perpendicular to the plane of motion, can also be generated. Typically, the secondary part is held suspended by forces above the plane of motion.

[0003] Planar motors are used, for example, in electromagnetic transport systems where a transport unit is moved to perform a transport task. The transport unit is designed as a secondary component.

[0004] By energizing drive coils in the vicinity of the transport unit's drive magnets, for example by applying electrical voltages to the active drive coils, an electromagnetic field can be generated. This field interacts with the magnetic field of the drive magnets to generate a propulsive force (in the direction of movement in a plane of motion along the stator) and / or a normal force (in the direction perpendicular to the plane of motion) acting on the transport unit. The resulting forces can be influenced by controlling the individual drive coils involved to regulate the generated magnetic flux. This allows the transport unit to be moved as desired in the plane of motion by controlling the drive coils to generate a magnetic field moving in the desired direction.It is also possible to arrange a large number of transport units on the plane of motion, whose movements can be controlled individually and independently of each other by supplying current to the drive coils that interact with each transport unit as required, usually by applying an electrical voltage.

[0005] Such planar motors, their construction and their operation are well known and are described, for example, in WO 2013 / 059934 A1 or WO 2015 / 017933 A1.

[0006] Since multiple transport units can move freely within the plane of motion, it is necessary to plan the transport path of each unit within that plane. Multiple transport paths can exist within the plane, along which the transport units can move. The paths of different transport units can intersect, creating a risk of collision between units moving along these intersecting paths. Similarly, transport paths can come close to each other without intersecting, also creating a risk of collision between units moving along these paths. Therefore, it is advantageous to plan the transport paths in such a way that there are no, or as few as possible, intersections or near misses. However, mechanisms are also required to both detect the risk of collision and prevent potential collisions.However, such mechanisms require computing power on the one hand, and on the other hand, they can limit the throughput of transport units along the transport paths, and thus also the transport performance of a transport system with a planar motor, because the transport units must maintain certain distances.

[0007] US 10,926,418 B2 describes a planar motor with one-dimensional paths for the movement of transport units. Collision avoidance is achieved by checking for potential collisions in two dimensions. EP 3 095 739 A1 describes path planning on a planar motor. Potential collisions at path intersections are resolved using the first-come, first-served principle.

[0008] WO 2020 / 109276 A1 describes a planar motor with a predefined path network consisting of a number of paths along which the transport units can move. A path is defined as a one-dimensional line in the plane of motion. It is also possible for two paths to intersect. To prevent collisions at an intersection, rules or priorities are defined that determine how two transport units may move across an intersection to avoid a collision, for example, through priority rules, prioritization of transport units, or first-come-first-served approaches. If there is no risk of collision, there is no requirement for collision avoidance. For example, if a transport unit approaches an intersection without another transport unit nearby, this transport unit can pass through the intersection without checking the rules or priorities.WO 2020 / 109287 A1 describes a method for path planning on a planar motor using graphs consisting of nodes and edges. However, it does not address the avoidance of intersections or near misses of transport paths.

[0009] EP 433 522 A1 discloses a method for operating a planar motor according to the preamble of claim 1. The aforementioned document describes the use of motion paths for moving the transport units of a planar motor. Possible intersections of the two-dimensional motion paths are checked two-dimensionally to prevent potential collisions. It is an object of the present invention to provide a method for operating a planar motor that reduces the risk of collisions between a transport unit or between a transport unit and an obstacle in the plane of motion.

[0010] This problem is solved by a method for operating a planar motor according to claim 1.

[0011] According to the invention, a two-dimensional collision monitoring system is used to avoid collisions in a conflict zone. This system checks two-dimensionally whether, in the conflict zone and in the plane of motion, a transport unit moving in one of the conflict zones is at risk of collision with another transport unit moving in another of the conflict zones or with an obstacle in the plane of motion. On a path of motion outside a conflict zone, a one-dimensional collision monitoring system is used. This system checks in the direction of motion whether there is a risk of collision between two transport units moving one behind the other on the path of motion. This allows the complex two-dimensional collision monitoring system to be limited to the conflict zones that have already been defined. Collision monitoring is thus significantly simplified.Outside of a conflict zone, collision monitoring can thus be implemented in a particularly simple and one-dimensional manner with little computational effort.

[0012] By using movement paths, overlapping areas where there is a risk of collision can be easily identified. Knowledge of a conflict zone can then be used to control the movement of transport units along the movement paths in order to avoid collisions. This can be used for both collision detection and collision avoidance. Furthermore, the conflict zones enable access control for transport units to a conflict zone, also with a view to collision avoidance.

[0013] The width of the movement lane in the plane of motion is simply defined orthogonally to the respective movement path, which allows for a simple implementation of the movement lane concept. The width of the movement lane in the plane of motion can be defined asymmetrically to the movement path, at least in sections, thus taking into account specific movement states of a transport unit on the movement path.

[0014] In an advantageous embodiment of the width determination, a reference point is defined on a transport unit, and the path of motion is referenced to this point. At a position along the path of motion, viewed in the direction of movement of the transport unit, vectors are determined from the reference point to an outer contour of the transport unit in the plane of motion. These vectors are then projected onto a normal to the path of motion at that position, and the longest projections on each side are added together to determine the width of the path of motion at that point. This enables, in particular, a fully automated determination of the width at any desired point along the path of motion, based on knowledge of the position of the transport unit.

[0015] In a particularly advantageous embodiment, the identified conflict zone is taken into account when controlling the movement of transport units along the assigned path. This is achieved by replanning at least one of the routes involved in the conflict zone, at least partially, to eliminate the conflict zone, reduce its size, decrease the number of identified conflict zones, decrease the number of routes involved, and / or increase the distance between two conflict zones. The movement of transport units on the replanned path then proceeds along this replanned path.Such a replanning can take place after the conflict zone has been identified, but before the normal operation of the planar motor, so that the risk of collision can be reduced during operation.

[0016] A movement route can be easily redesigned by redesigning at least a section of the geometry of the movement path assigned to the movement route in the movement plane and / or by changing at least a section of the width of the movement route.

[0017] In a further advantageous embodiment, before a transport unit moving in a movement path involved in the conflict zone enters it, a check is performed to determine whether this transport unit can leave the conflict zone with its intended movement without colliding with another transport unit moving in a different movement path involved in the conflict zone. If this check is unsuccessful, entry is denied. The conflict zone can thus also be used by the planar motor's control system for an entry logic that controls the access of transport units to the conflict zone.

[0018] The present invention is described below with reference to the Figuren 1a bis 7 In more detail, the invention is explained, and exemplary, schematic, and non-restrictive embodiments are shown. This includes showing Fig.1a and Fig.1b different views on a possible design of a planar motor, Fig.2a bis 2e Possible arrangements of drive coils on the stator of a planar motor, Fig.3a bis 3f Possible arrangements of drive magnets on a transport unit of a planar motor, Fig.5 Motion paths of transport units in a motion plane of the planar motor, Fig.6 Movement paths around movement routes of transport units and conflict zones in a movement plane of the planar motor and Fig.7 an advantageous determination of the width of a movement lane.

[0019] In Fig.1a and 1b An exemplary embodiment of a transport device in the form of a planar motor 1 is shown in a simplified manner. This shows Fig.1a the planar motor 1 in a partially broken-up top view and Fig.1b The planar motor 1 is shown in a partially cutaway side view. The planar motor 1 has at least one transport segment 2 as a stator, which forms a plane of motion 3, and at least one transport unit TEn, which is movable in the plane of motion 3 at least two-dimensionally in two principal directions of motion H1, H2. "n" is used here as an index to distinguish different transport units, with the reference numeral TEn generally being used when no specific transport unit is being addressed. Within the scope of the invention, the plane of motion 3 is understood to be the flat surface of the transport segment 2, which is determined by the size and shape of the transport segment 2. The plane of motion 3 can be oriented arbitrarily in space. Fig.1a For the sake of simplicity, only one transport segment 2 is shown. However, multiple transport segments 2 (even different ones) could be connected to form the stator and a larger motion plane 3. This allows the transport device 1 to be built modularly, enabling the realization of motion planes 3 of various shapes and sizes. Of course, this modular design is optional, and it is also possible to use only a single transport segment 2 as a single assembly. Within the motion plane 3 of the transport segment 2, several different transport units TEs can be moved simultaneously and independently of each other.

[0020] On transport segment 2, a first coil group SG1 with several drive coils AS1, which defines the first main direction of movement H1, and a second coil group SG2 with several drive coils AS2, which defines the second main direction of movement H2, are arranged. The drive coils are generally also designated as ASi, where "i" is a subscript to distinguish them if necessary. The drive coils AS1 of the first coil group SG1 are arranged one behind the other in a specific direction, here in the X-direction of a Cartesian coordinate system, to form the first main direction of movement H1 for the movement of the transport unit TEn, which extends along the X-axis.The drive coils AS2 of the second coil group SG2 are arranged one behind the other in a specific direction, here the Y-direction of the Cartesian coordinate system, to form a second principal direction of movement H2 for the transport unit TEn, which here extends along the Y-axis. Preferably, the drive coils AS1, AS2 of the first and second coil groups SG1, SG2 are arranged as shown in [reference]. Fig.1a depicted, arranged relative to each other in such a way that the two main directions of movement H1, H2 are orthogonal to each other.

[0021] Several drive magnets 4 are arranged on at least one transport unit TEn, which interact electromagnetically with drive coils AS1, AS2 of at least one of the two coil groups SG1, SG2 in the area of ​​the transport unit TEn to move the transport unit TEn. The transport unit TEn typically has a base body 9, on the underside of which (facing the plane of motion 3) the drive magnets 4 are arranged, as shown in Fig.1b is evident. Fig.1a The base body 9 is shown largely broken open in order to reveal the arrangement of the drive magnets 4. As in Fig.1b The drive magnets 4 are indicated as arranged in several magnet groups MGa, MGb. The drive magnets 4 are usually arranged with alternating polarity, as shown in Fig.1b As indicated, the drive magnets 4 can also be oriented differently in the various magnet groups Mga, MGb.

[0022] In the example shown, two first magnet groups MGa and two second magnet groups MGb are arranged on the transport unit TEn. To move the transport unit TEn in the plane of motion 3, essentially only a single first magnet group MGa and a single second magnet group MGb per transport unit TEn are sufficient. Of course, more than two first magnet groups MGa and more than two second magnet groups MGb can also be arranged per transport unit TE. An unequal number of first and second magnet groups MGa, MGb would also be conceivable, for example, two first magnet groups MGa and one second magnet group MGb. Within the magnet groups MGa, MGb, several drive magnets 4 with different magnetization directions are provided, arranged side by side in a specific orientation. The orientation of the first magnet groups MGa corresponds to the X-direction, and the orientation of the second magnet groups MGb corresponds to the Y-direction.The arrangement directions are thus analogous to the main directions of motion H1, H2 and preferably orthogonal to each other. Preferably, the arrangement directions of the magnet groups MGa, MGb run as parallel as possible to the main directions of motion H1, H2 in order to enable the most efficient electromagnetic force generation. In the illustrated example, the drive magnets 4 on the transport unit TEn are a known 1-D arrangement, but a known 2D arrangement would also be possible, as shown in the figure below. Fig.4a-4d will be explained in more detail later.

[0023] With the depicted planar motor 1, for example, essentially unrestricted movement of a transport unit TEn in the two main directions of motion H1 and H2 would be possible in the plane of motion 3 of the transport segment 2. The transport unit TEn could, for example, move only along the X-axis or only along the Y-axis. However, the transport unit TEn can, of course, move simultaneously in both main directions of motion H1 and H2, e.g., along a two-dimensional motion path BPn lying in the plane of motion 3 with an X-coordinate and a Y-coordinate, as shown at the transport unit TEn in Fig.1a As indicated, with appropriate design of transport segment 2 and the respective transport unit TEn, the other four degrees of freedom can also be used, at least to a limited extent, in a known manner (translational movement in the vertical direction Z + rotation about the three axes X, Y, Z).

[0024] ASi drive coils can also be arranged one above the other when viewed in the normal direction (here in the Z-direction). In the design according to Fig.1b The drive coils AS1 of the first coil group SG1 are arranged closer to the plane of motion 3 in the normal direction (here in the Z direction) than the drive coils AS2 of the second coil group SG2.

[0025] In Fig.2a-2e The following are schematic, exemplary and non-restrictive representations of various possibilities for arranging drive coils ASi on a transport segment. Fig.2a +2b show so-called "single-layer" variants, in which the first and second coil groups SG1, SG2 are arranged in the same plane. Fig.2c-2e so-called "double-layer" or multi-layer designs are shown, in which the first and second coil groups SG1, SG2 are arranged in a vertical direction, as previously shown. Fig.1b was explained.

[0026] In Fig.2a A so-called "herringbone" arrangement of the drive coils AS1, AS2 of the two coil groups SG1, SG2 is shown. In contrast to the other versions of the Fig.2b-2e The two main directions of movement, H1 and H2, do not run parallel to the edges of transport segment 2 (here in the X and Y directions), but at an angle to them. Fig.2c A "double-layer" embodiment is shown in which "long" drive coils AS1, AS2 are provided in both the first coil group SG1 and the second coil group SG2. Fig.2d Figure 1 shows an embodiment with "long" drive coils AS1 in the first coil group SG1 and "short" drive coils AS2 in the second coil group SG2. Fig.2e shows an example with "short" drive coils AS1 in the first coil group SG1 and "short" drive coils AS2 in the second coil group SG2, with the coil groups arranged one above the other.

[0027] In Fig.3a-f and Fig.4a-d The diagram schematically illustrates various arrangements of drive magnets 4 on a transport unit TE. A fundamental distinction is made between a so-called 1D arrangement ( Fig.3a-3f ) and a 2D arrangement ( Fig.4a-4d In the 1D arrangement, at least one first magnet group MGa with several drive magnets 4 is provided for the first main direction of movement H1 (here X-axis), and at least one second magnet group MGb with several drive magnets 4 is provided for the second main direction of movement H2 (here Y-axis). The magnet groups MGa and MGb each have a specific number of drive magnets 4, in particular permanent magnets, arranged one behind the other in a specific orientation (here MGa in the X-direction and MGb in the Y-direction). Adjacent drive magnets 4 have different magnetization directions. For example, the magnetization direction of adjacent drive magnets 4 can be rotated by 180° relative to each other, i.e., alternating magnetic north and south poles, as indicated by the hatched and unhatched drive magnets 4.The drive magnets 4 of a magnet group MGi can also be arranged in the known Halbach configuration, whereby, for example, between drive magnets 4 with opposite magnetization directions (north pole, south pole), a drive magnet 4 with a magnetization direction rotated by 90° is provided. The Halbach configuration has the advantage that the magnetic flux on one side of the magnet group MGj (preferably the side facing the plane of motion 3) is greater than on the opposite side. The Halbach configuration is known in the prior art, which is why further details are omitted here.

[0028] In the 2D arrangement, individual drive magnets of four different magnetization directions are arranged on the transport unit TE in a pattern essentially resembling a checkerboard. The drive magnets of four different magnetization directions are arranged alternately and offset in two orientations (here X and Y directions). The two directions are preferably oriented relative to each other as the two main directions of movement H1 and H2, i.e., they are perpendicular to each other. It is immediately apparent that a multitude of different arrangement possibilities arise, with the most common variants being the 1D arrangement in Fig.3a-3f are shown and the most common variants of the 2D arrangement in Fig.4a-4d In the 2D arrangement, the first magnet group MGa corresponds to the drive magnets 4 arranged alternately in one direction (e.g., in the X-direction), and the second magnet group MGb corresponds to the drive magnets 4 arranged alternately in the opposite direction (e.g., in the Y-direction). Thus, in the 2D arrangement, the magnet groups MGa and MGb are not separate, as they are in the 1D arrangement; instead, the drive magnets 4 are part of both the first magnet group MGa and the second magnet group MGb.

[0029] The planar motor 1 also includes a control unit 10, with which the drive coils ASi of the transport segment 2 can be controlled for energizing, as shown in Fig.1a This is indicated. Essentially, this means that the drive coils ASi are energized by the control unit 10 in such a way that the transport unit TEn executes a desired motion path BPn in the plane of motion 3, whereby the motion path BPn is not limited to movement in the main directions of motion H1, H2, but can also specify movements in the four other degrees of freedom. The motion path BPn is usually predefined, for example, to implement a transport task with the planar motor 1 as a transport device or depending on a specific production process of a plant in which the planar motor 1 is integrated as a transport device.

[0030] The planar motor 1, more specifically the drive coils ASi of the planar motor 1, is controlled by the control unit 10 such that a transport unit TEn moves along the desired motion path BPn in the motion plane 3. A specific motion profile with motion parameters (also in different spatial directions) of the transport unit TEn, such as speed, acceleration, etc., can be predefined for the movement.

[0031] For the implementation of the motion path BPn in the control unit 10, an actual value of the movement of the transport unit TEn is typically used, for example, an actual position (also an actual orientation of the transport unit TEn) or an actual speed. Suitable sensors, such as position sensors, can also be arranged on the transport segment 2 for this purpose, and their measured values ​​are transmitted to the control unit 10 as actual values ​​or from which actual values ​​are determined in the control unit 10.

[0032] The control unit 10 can also be implemented as a distributed control system, for example with a number of coil control units 5, preferably one coil control unit 5 per drive coil ASi, and a higher-level plant control unit 6, which is connected to the number of coil control units 5, for example via a communication network. Alternatively, a segment control unit can be provided, which is connected on one side to the plant control unit 6 and on the other side to the number of coil control units 5, for example, each via a communication network. The coil control units 5, the plant control unit 6, and, if applicable, the segment control unit then divide the control of a transport unit TEn among themselves in a predefined manner. For example, the plant control unit 6 can execute the transport task and, for this purpose, specify target points for the transport unit TEn in the motion plane 3 to the segment control unit.The plant control unit 6 can also be used to detect and / or prevent potential collisions between transport units TEn. The segment control unit can then determine a motion path BPn for the transport unit TEn to approach the target point and, for the implementation of the motion path BPn, determine setpoints, such as target coil voltages or target coil currents, for the drive coils ASi involved in the movement. The setpoints are then transmitted to the coil control units 5 for the drive coils ASi involved in the movement, which then implement them. For this purpose, power electronics can also be provided on a transport segment 2, which generates the required coil voltages or coil currents and applies them to the drive coils ASi.It is also conceivable that for each transport segment 2, or for a group of transport segments 2, a segment control unit is provided, which is then responsible for realizing the movement path BPn on the assigned transport segment 2.

[0033] A control unit can be implemented as microprocessor-based hardware, for example as a computer, microcontroller, digital signal processor (DSP), programmable logic controller (PLC), etc., on which corresponding control programs run to implement the respective function. It can also be implemented as an integrated circuit, such as an application-specific integrated circuit (ASCI) or field-programmable gate array (FPGA).

[0034] By appropriately controlling the first drive coils AS1, a moving magnetic field is generated in the first main direction of movement H1. This moving magnetic field in the first main direction of movement H1 interacts primarily electromagnetically with the drive magnets 4 of the first magnet group(s) MGa to move the respective transport unit TEn in the first main direction of movement H1. Similarly, by controlling the second drive coils AS2, a moving magnetic field is generated in the second main direction of movement H2, which interacts primarily electromagnetically with the drive magnets 4 of the second magnet group(s) MGb to move the transport unit TEn in the second main direction of movement H2.Depending on the control of the drive coils AS1, AS2, a superposition of the moving magnetic fields results, which allows the transport unit TEN to be moved in the desired manner along the specified two-dimensional motion path BPn in the motion plane 3.

[0035] In addition to the two essentially unlimited translational degrees of freedom in the main directions of motion H1 and H2 in the plane of motion 3, a limited translational movement of a transport unit TEn in the normal direction to the plane of motion 3 is also possible, specifically in the direction of the Z-axis. Depending on the arrangement and design of the drive coils AS1 and AS2 of the coil groups SG1 and SG2, as well as the interacting first and second magnet groups MGa and MGb, a rotation of the transport units TEn around the three spatial axes X, Y, and Z, at least to a limited extent, is also possible. A complete rotation around the vertical axis Z can also be achieved.

[0036] The drive coils ASi are usually controlled in such a way that a force acts in the direction of the Z-axis on the transport unit TEn, with which the transport unit TEn above the plane of motion 3 to create an air gap L ( Fig.1b ) is held freely suspended (which is also possible during the standstill of the transport unit TEN).

[0037] By appropriately controlling the drive coils ASi, the air gap L can be increased and decreased to a limited extent as required, thereby allowing the transport unit TE to be moved upwards, here in the Z-direction, as indicated by the double arrow on the transport unit TEn. Fig.1b The size of the available range of motion in the vertical direction depends essentially on the design of the planar motor 1, in particular on the maximum achievable magnetic field of the drive coils ASi and the design and arrangement of the drive magnets 4, as well as the mass and load of the transport unit TEn.

[0038] The above explanations regarding the structure and function of a planar motor 1 serve only for illustrative purposes and are not to be understood as limiting; they are intended to facilitate understanding. For the present invention, the specific structure of the planar motor 1 is irrelevant. The crucial aspect of the invention is that a plurality of transport units TEn can be moved along motion paths BPn in the plane of motion 3 of the planar motor 1. At least two motion paths BPn are provided, and each transport unit TEn can, in principle, be moved along any of these motion paths BPn.

[0039] A movement path BPn can be an open path, i.e., a path whose beginning and end do not coincide, or a closed path, i.e., a path whose beginning and end coincide.

[0040] The motion paths BPn of the transport units TEn moved by the planar motor 1 are usually planned in advance, for example, to perform a specific transport task with the planar motor 1. Additionally or alternatively, a motion path BPn, or even a part thereof, can be determined or defined during operation to ensure greater flexibility. The motion paths BPn of the transport units TEn in the plane of motion 3 can, in any case, be assumed to be known for the purposes of carrying out the invention.

[0041] Since a motion path BPn can be freely defined in the motion plane 3, it is possible for two motion paths BPn to intersect or come close to each other, creating a risk of collision between two transport units TEn moving along the motion paths BPn. It is also conceivable that a motion path BPn might intersect itself or come too close to itself, or that a motion path BPn might be located within the area of ​​an obstacle defined in terms of position and size in the motion plane. In these cases, too, there is a risk of collision between a transport unit TEn and another transport unit TEn or with an obstacle. A collision is defined as any unwanted contact caused by the movement between two transport units TEn (which also includes any object O being transported by them) or between a transport unit TEn and an obstacle.Since the transport units TEs can move freely in the plane of motion 3, a collision can occur in virtually any direction. However, in the operation of the planar motor 1, for example as a transport device for moving objects O, such collisions are usually undesirable and should be avoided. In exceptional cases, situations can also arise in which transport units TEs come very close to each other in a desired manner or even touch. This is the case, for example, when several transport units TEs combine to transport higher forces or larger / heavier products. It is also conceivable that two transport units TEs, by moving relative to each other, exert a force on a workpiece and thus perform a work process step. Such "intentional collisions" are, of course, not undesirable and should therefore not be avoided.

[0042] The fundamental problem with unwanted collisions is in Fig.5 The stator of the planar motor 1 consists of at least one, and in this embodiment several, transport segments 2, which, as described above, form the plane of motion 3. Drive coils ASi and drive magnets 4 are not shown here for clarity. In the plane of motion 3, a first transport unit TE1 is to be moved along a first path of motion BP1. A second transport unit TE2 is to be moved simultaneously along a second path of motion BP2. However, the first path of motion BP1 and the second path of motion BP2 intersect, so that in the area of ​​the intersection point K there is a risk of an unwanted collision between the transport units TE1 and TE2 moving along the paths of motion BP1 and BP2. A collision can occur if the two transport units TE1 and TE2 are moving simultaneously near the intersection point K.A collision hazard also exists if the two movement paths BP1, BP2 come too close to each other in an approach zone A, but do not intersect, such that the transport units TE1, TE2 moving along them could touch if both transport units TE1, TE2 are moving simultaneously near the approach zone A. Such an approach zone A is defined in . Fig.5 A collision hazard also exists if a movement path BPn overlaps in the movement plane 3 in the area of ​​an obstacle H defined with respect to its position and geometry, as shown in Fig.5 This is illustrated using the example of movement path BP1. The direction in which transport units TE1 and TE2 move along their respective movement paths BP1 and BP2 is irrelevant to the risk of collision.

[0043] To avoid collisions between transport units TEn or between a transport unit TEn and an obstacle H, it is necessary, on the one hand, to detect a collision hazard and, on the other hand, to take appropriate steps to avoid a collision if a collision hazard is detected. Since collision detection and collision avoidance are computationally very complex, the invention intervenes earlier and attempts to plan the motion paths BPn in such a way as to prevent collisions altogether or at least to reduce the number of points in the motion plane 3 where a collision can occur.

[0044] To avoid collisions, or at least to reduce the risk of collisions, it is provided that each movement path BPn in the movement plane 3 is extended, at least section by section in the direction of movement, two-dimensionally around the movement path BPn to form a movement lane BSn in the movement plane 3. For this purpose, a width B1, B2 of the movement lane BS1, BS2 is specified at least section by section at each point of the movement paths BP1, BP2, as shown in Fig.6 The representation is shown section by section because the motion path BSn does not necessarily have to be defined along the entire length of the motion path BPn. In principle, it is sufficient if the motion path BSn is defined only along certain sections of the motion path BPn. For example, a motion path BSn does not need to be defined in sections where, due to the design of the planar motor 1 or other circumstances, it is known from the outset that there can be no collisions between transport units TEn on different motion paths BPn or with an obstacle H. This can be the case, for example, if only a single motion path BPn is generally provided for all transport units TEn in certain sections.

[0045] The width Bn is defined, for example configured, at every point along the motion path BPn where a motion route BSn exists, and is therefore known. A transport unit TEn (preferably including any object transported by it) that moves along a motion path BPn is preferably completely encompassed by a motion route BSn defined on it. This means that the transport unit TEn does not protrude from the motion route BSn at any point.

[0046] The width Bn can depend on other influencing factors besides the position along the motion path BPn, such as the type or size of the transport unit TEn, the extent of an object O transported by a transport unit TEn, the rotation of the transport unit TEn around a vertical axis (e.g., in the Z-direction) or another axis, the maximum expected positioning error (e.g., the deviation between a target position and an actual position) of the motion control, a maximum speed, a predefined safety distance, etc. However, the width Bn or the course of the width Bn along a motion path BPn can also simply be fixed, for example, in the control unit 10.

[0047] The width Bn in the plane of motion 3 is preferably orthogonal to the respective motion path BPn. On a straight line, it is therefore normal to the motion path BPn in the plane of motion 3, and on a curve, it is normal to the tangent to the motion path BPn.

[0048] However, the width Bn does not have to be specified symmetrically with respect to the movement path BPn, but can also be specified asymmetrically around the movement path BPn, i.e., the proportions of the width Bn on both sides (seen in the direction of movement) of the movement path BPn are different.

[0049] To determine the width Bn at a specific position along the movement path BPn, one possible embodiment can be implemented as with reference to Fig.7The procedure is explained below. It is assumed that the motion path BPn of a transport unit TEn, relative to a reference point RP of the transport unit TEn, is predefined and therefore known. The reference point RP can be any point on the transport unit TEn, for example, its geometric center or the location of its center of gravity in the plane of motion 3. Since the geometry of the transport unit TEn is known, vectors VL and VR can be determined on each side (relative to the motion path BPn) from the reference point RP to the outer contour of the transport unit TEn in the plane of motion 3 (possibly taking into account a transported object). These vectors VL and VR are then projected onto the normal N to the motion path BPn (or onto the tangent T to the motion path BPn).The longest projections PL and PR on each side are then added together, and the sum of these longest projections is used as the width Bn at that point on the movement path BPn, i.e., Bn = (PL + PR). This results, for example, in a width Bn that is asymmetrical with respect to the movement path BPn if the longest projections PL and PR are different. This procedure allows for the computational determination of the widths Bn of the movement path BSn for a transport unit TEn at any desired point on the movement path BPn. The dimensions of the transport unit TEn, and any object O being transported with it, as well as any rotation around the vertical axis (or other axes), are automatically taken into account, because the position and orientation of the transport unit TEn are factored into this calculation.Similarly, a safety margin can be easily incorporated by simply extending the vectors VL, VR, or their projections PL, PR, by a specific value. Such a safety margin can also depend on a movement parameter of a transport unit TEn, such as its speed or acceleration. When determining the widths Bn, the outer contour can also be simplified, for example, by placing a simple two-dimensional or three-dimensional geometric figure (or solid), such as a circle, rectangle, or polygon, around the outer contour of the transport unit TEn, and then determining the vectors VL, VR, and their longest projections PL, PR based on this geometric figure (solid). Determining the widths Bn can be done offline, for example, before starting the transport task.However, the widths Bn can also be recalculated online during operation if required, for example when a transport unit TEn is reloaded.

[0050] The width Bn of a motion path BSn can also be determined by simulating the movement of a transport unit TEn along a motion path BPn. Simulation tools are available for this purpose. Essentially, the simulation simulates the movement of a two-dimensional geometric figure or a three-dimensional body in the motion plane 3. Here, too, a simple geometric figure (body) can be placed around the outer contour of the transport unit TEn to simplify the simulation. The transport unit TEn (or the surrounding figure / body) sweeps out a specific area in the motion plane 3 (in a three-dimensional simulation, possibly projected onto the motion plane 3). This area will extend to both sides of the motion path BPn (viewed in the direction of movement), from which the width Bn can be determined at any desired point.The envelope of this surface in the plane of motion 3 can also be determined. The width Bn can then be calculated from the envelope at any point. A safety margin can also be taken into account in these cases.

[0051] It is immediately apparent that for different transport units TEn, e.g., different types or sizes, different transported objects O, different movement parameters of a transport unit TEn, etc., there can also be different motion paths BSn, which, however, does not change the fundamental approach according to the invention. If several motion paths BSn with different widths Bn result along a section of a motion path BPn, it can also be provided that the motion path BSn with the largest width Bn is generally used in such a section. Thus, if one wants to move different types of transport units TEn along a common motion path BPn, one can preferably generate only one motion path BSn by considering a maximum envelope of all types during its generation.Alternatively, a separate movement path BSn can be determined or specified for each pair of transport unit TEN and movement path BPn. Hybrid forms are also possible, of course.

[0052] All motion paths (BSn) for all motion paths (BPn) and all transport units (TEn) of the planar motor 1 can be determined in advance, for example, to implement a transport task. This can be done, for instance, after the motion paths (BPn) have been planned or before the planar motor 1 is put into operation for the first time or restarted. Additionally, reconfiguring a motion path (BPn) and / or a motion path (BSn) at runtime is conceivable, for example, by creating, modifying, or deleting a motion path (BSn) while the planar motor is operating. Such reconfiguration is preferably carried out within the remaining runtime of a predefined time step of the control unit (10) or on a separate control unit. Once the new configuration has been created and, preferably, all transport units (TEn) are also on a motion path (BSn) with respect to the new configuration, the control unit (10) can switch to this new configuration.Since the creation of the new configuration is completed before switching to the new operating mode, all movement paths (BSn) are known in advance in this case as well. However, an additional movement path (BSn) can also be temporary, meaning it might only be used for a single movement, for example, to initially transfer a transport unit (TEn) to another movement path (BSn).

[0053] The known movement paths BSn are now being used to test whether Whether movement paths BSn overlap in the movement plane 3, i.e., whether at least a first movement path BS1 and a second movement path BS2 intersect, or whether a movement path BSn overlaps with itself, or whether a movement path BSn and an obstacle H defined in the movement plane 3 overlap, to identify potential conflict zones of concentration camps in the overlap area. Of course, different overlaps are also possible simultaneously. An overlap area is therefore the area in which at least one of the overlaps described above occurs. This is in Fig. 6 The diagram is shown schematically, with conflict zones (KZ) in overlapping areas between movement routes (BSn) or in the area of ​​an obstacle (H) indicated by hatching. However, it is conceivable that more than two movement routes (BSn) may overlap in one overlapping area.

[0054] In general, a conflict zone KZ is understood to be a geometric area in the plane of motion 3 in which at least two transport units TEn moving on different or the same motion paths BPn could collide or in which a transport unit TEn could collide with an obstacle.

[0055] A movement path BSn can also be used to verify whether the movement path BSn is entirely within a predefined permissible movement area of ​​the movement plane 3. The permissible movement area can be naturally limited by the edges of the movement plane 3. Alternatively, obstacles H can be defined within the movement plane 3, which must be avoided by all or only some transport units TEn. These obstacles H are considered logical boundaries of the movement area. Within the scope of the invention, an overlap area of ​​a movement path BSn with the area outside the permissible movement area is also considered a conflict zone KZ, which must be avoided by transport units TEn on the movement path BPn.

[0056] If at least one conflict zone (KZ) has been found, this information can be further processed by either making it available to the user, for example in a graphical or textual output of a planning tool for the planar motor 1, which can be used to optimize the transport and processing process, or by using the information to improve the process flow of the transport task carried out with the planar motor 1, preferably fully automatically, for example by intervening in the control of the movements of the transport units (TEs).

[0057] In one aspect of the invention, to avoid collisions, the next step after identifying at least one conflict zone KZ is to redesign at least one of the movement paths BSn involved in a identified conflict zone KZ in order to reduce the size of the identified conflict zone KZ, preferably to eliminate it entirely, and / or to reduce the number of identified conflict zones, preferably to eliminate all conflict zones. At least one movement path BSn can also be redesigned to reduce the complexity of the conflict zones KZn by decreasing the number of movement paths BSn involved in a conflict zone KZ. Increasing the distance between two conflict zones KZn can also be provided.

[0058] A movement route BSn can be replanned, for example, by replanning a movement path BPn of a movement route BSn involved in the conflict zone KZ, at least section by section, preferably in the area of ​​the conflict zone KZ, in movement plane 3 (i.e., by changing the geometry of the movement path BPn) and / or by changing the width Bn of a movement route BSn, at least section by section, preferably in the area of ​​a conflict zone KZ. The width Bn of a movement route BSn can be changed, for example, by reducing or increasing a safety distance, by arranging an object O differently on the transport unit TEn, or by imposing a restriction on the objects O that can be transported along a movement path BPn.

[0059] This replanning of at least one movement path BSn involved in a conflict zone KZ is preferably carried out fully automatically according to predefined replanning rules using appropriate software, for example in a planning tool for the planar motor 1 or in the control unit 10. Thus, rules can be predefined for the replanning according to which a movement path BPn is changed, for example rules such as how a movement path BPn should be moved section by section in the movement plane 3 and with which geometry of the movement path BPn this should be carried out, or how a geometry of the movement path BPn should be changed.

[0060] However, it is also conceivable to redesign the movement paths (BSn) involved in at least one conflict zone (KZ) by means of optimization. For the optimization, a performance functional can be defined that is a function of the geometry of the movement paths (BPn) or movement routes (BSn) involved in a conflict zone and / or of a conflict zone (KZ). The performance functional can, for example, contain a performance term that evaluates the extent of a conflict zone (KZ), such as its area or its maximum length and width (relative to the movement path). The performance functional can also contain a performance term that evaluates the length of the movement paths (BPn) or movement routes (BSn) involved in a conflict zone in the direction of movement. A performance term can also evaluate the number of conflict zones (KZ). Such performance terms are weighted in a predefined manner within the performance functional (e.g., with a value between 0 and 1) and summed.The performance functional is then optimized, usually minimized or maximized, by varying the geometry of the movement paths (BPn) or movement routes (BSn) involved in a conflict zone (KZ). The movement paths (BPn) or movement routes (BSn) that optimize the performance functional are then used for replanning.

[0061] After replanning at least one movement path BSn, the planar motor 1 can then be put into operation with the transport units TEn, which are moved in a defined manner along the intended movement paths BPn, or it can be switched to the newly determined configuration (if the replanning takes place during operation).

[0062] Analogous to automated replanning, a movement path (BSn) can also be replanned manually by a user. The user can utilize the planning tool mentioned above to perform the replanning manually and thereby achieve an improved process flow. The planning tool provides information about the existence of conflict zones (KZ) (which are automatically determined as described above) and, preferably, their location. The location can be output, for example, using a representative point such as the intersection of movement paths (BPn) or the center of gravity of the conflict zone area. Further benefits include knowledge of the size of the conflict zone area (KZ), the movement paths (BPn) or movement paths (BSn) involved in a conflict zone, their intersection or approach points, and the projections of these points onto the involved movement paths (BPn).

[0063] Of course, a combination of manual replanning with automated replanning is also possible, for example, by allowing the user to interactively decide for each identified conflict zone (KZ) whether a better replanning solution than the automatically determined one should be sought for it.

[0064] If a conflict zone KZ can be completely eliminated, no collisions can occur at the location where the conflict zone KZ was located between transport units TEn on different movement paths BPn that were involved in the eliminated conflict zone, or with obstacles H in the movement plane 3. This simplifies collision monitoring in the control unit 10. Essentially, in this case, it may suffice to check for a collision between directly adjacent transport units TEn along their movement paths BPn in their direction of movement along the respective movement path BPn. This can be done simply in a one-dimensional analysis, without having to consider a two-dimensional (or spatial) extent of the transport units TEn in the movement plane 3. Such one-dimensional collision monitoring can be implemented with very little computational effort because a collision only needs to be checked in one direction.

[0065] In contrast, two-dimensional collision monitoring, i.e., essentially two-dimensional checks for collisions in all directions in the plane of motion 3, is considerably more complex and requires significantly more computing power than one-dimensional collision monitoring, especially because transport units TEn on different motion paths BPn must also be checked for collisions.

[0066] In a further aspect of the invention, the use of motion paths BSn, as described above, for determining conflict zones KZ of possible collisions can also be used for an advantageous embodiment of the collision monitoring of a planar motor 1. Based on the motion paths BSn and the determined conflict zones KZ, there can only be two types of collisions. Firstly, within a motion path BSn but outside a conflict zone KZ, collisions can only occur between transport units TEn moving one after the other within the motion path BSn. Secondly, within a conflict zone KZ, collisions between transport units TEn moving on different motion paths BPn, from and in different directions, or collisions of a transport unit TEn with an obstacle H are conceivable.

[0067] According to the invention, the collision monitoring of the planar motor 1 is designed such that, on a motion path BPn but outside a conflict zone KZ, only one-dimensional collision monitoring in the direction of motion is implemented between transport units TEn traveling in succession on the motion path BPn. By prior checking for conflict zones KZ between motion paths BSn or between a motion path BSn and an obstacle H, it can therefore be ruled out outside a conflict zone KZ that transport units other than those traveling in succession could collide.In a conflict zone KZ, a two-dimensional collision monitoring system is implemented. This system checks whether a transport unit TEn moving within a movement route BSn involved in the conflict zone KZ is at risk of collision with another transport unit TEn moving within a movement route BSn involved in the conflict zone KZ, or with an obstacle H. This simplifies collision monitoring within the conflict zone KZ compared to classical approaches, as the set of transport units TEn to be checked can be limited to those located on the movement routes BSn involved in the conflict zone KZ within a local area surrounding the conflict zone.

[0068] It is also evident that a reduction in the size of a conflict zone (KZ) or an increase in the distance between two conflict zones (KZ) has a positive effect on collision monitoring, because this limits the areas in which two-dimensional collision monitoring is required or the number of transport units (TEs) to be checked.

[0069] This allows for the implementation of an advantageous method for operating a planar motor with a motion plane in which at least two motion paths are defined, along which a plurality of transport units move. In this method, each motion path in the motion plane is extended two-dimensionally, at least section by section, to form a motion lane in the motion plane by defining a width for the motion lane at least section by section at each point along the motion paths. The resulting motion lanes are then checked to determine whether the two resulting motion lanes overlap, whether one of the resulting motion lanes overlaps with itself, or whether one of the resulting motion lanes overlaps with an obstacle defined in terms of position and size in the motion plane, in order to identify a conflict zone in the overlap area.Within the conflict zone, there is a risk of collision between transport units moving on paths within the conflict zone, or a risk of collision between a transport unit moving on a path within the conflict zone and an obstacle in the plane of motion. On a path outside the identified conflict zone, the planar motor uses one-dimensional collision monitoring, which checks in the direction of motion whether there is a risk of collision between two transport units traveling one behind the other on the path.In the identified conflict zone, a two-dimensional collision monitoring system is used, which checks in all directions in the plane of motion 3 whether, in the conflict zone, a transport unit moving in a movement path involved in the conflict zone is at risk of collision with a transport unit moving in another movement path involved in the conflict zone or with an obstacle H in the plane of motion 3.

[0070] Control unit 10 can also implement an entry logic for a conflict zone (KZ). This allows control over which transport unit (TE) may enter a conflict zone (KZ) first, or at all, if one or more transport units (TEs) wish to enter a conflict zone (KZ) simultaneously. This entry logic is independent of collision monitoring. In a preferred embodiment, a transport unit (TE) may only enter the conflict zone (KZ) if it can be ensured that the transport unit (TE) can leave the conflict zone (KZ) without a collision, for example, by ensuring that no other transport unit (TE) is in the conflict zone and that no backlog or deadlock occurs.

[0071] The entry logic preferably also takes into account a prioritization of the transport units TEs. The prioritization of the transport units TEs can, for example, be configured in control unit 10. Alternatively, the priority of the transport units TEs can be derived from the priority of the movement paths BPn involved in the conflict zone KZ, so that individual movement paths BPn can be given priority. The priority of the movement paths BPn can be configured for this purpose. The prioritization of the transport units TEs can also be based on other known principles for optimizing the process flow.For example, a ticketing system (such as a first-come-first-served principle, a time-based traffic light system, or a throughput ratio between movement paths BPn), optimization with regard to the waiting time of transport units TEn, or a system that prioritizes those movement paths BPn where more transport units TEn are waiting can be used. A combination of different prioritizations mentioned above is also possible. Of course, it is also conceivable to combine the collision avoidance implementation according to the invention with existing approaches. Within the movement paths BSn and the conflict zones KZ, the above-described [method / approach] can be used.

[0072] Collision monitoring is used in some areas, and in those areas where no motion path BSn is defined, classic, well-known approaches are used or collision monitoring is omitted. This allows, for example, the necessary flexibility to be maintained within a processing station arranged along a motion path BPn.

[0073] For collision avoidance, it is advantageous to generally prevent a transport unit TEn from entering a movement path BSn at any given time. For this purpose, a movement path BSn can be viewed, for example, analogous to the edges of transport segments 2, as a logical boundary of the permissible movement area. Entry into a movement path BSn by a transport unit TEn can be permitted at selected and predefined positions, preferably at the beginning of the movement path BPn or at selected, predefined transition points along the movement path BPn. Preferably, a movement path BSn may only be entered by a transport unit TEn at the selected position if collision-free entry is possible with respect to all transport units TEn assigned to the movement path BSn.

[0074] As mentioned above, the movement paths BPn and the dependent movement routes BSn are usually determined once in advance, or at least only if a movement path BPn is planned anew (even if only in sections) and thus reconfiguration is necessary.

[0075] Following a malfunction of the planar motor 1, where, for example, the transport units TEn coast uncontrollably and thus assume an uncontrolled end position in the motion plane 3 after coasting, or during the restart of the planar motor 1 after a system standstill, it can happen that a transport unit TEn is located next to, partially on, or even completely or partially on a different motion path BSn than intended, or completely outside of all motion paths. "Partially" on a motion path BSn means that a transport unit TEn is not entirely within the associated motion path BSn, but only partially.

[0076] This can lead to situations such as the following: The transport unit TEn is not next to a movement path BSn, but is on or partially on the wrong movement path BSn. The transport unit TEn is partly on movement path BSn and partly outside of movement path BSn. The transport unit TEn is partly on several movement paths BSn. The transport unit TEn is completely outside of movement path BSn.

[0077] Before the planar motor 1 can operate properly, it is therefore advantageous to restore a defined state, which can be performed, for example, by the control unit 10. The collision avoidance described above assumes that such a defined state exists. The following explains how such a defined state can be achieved.

[0078] For the proper operation of the planar motor 1, it is necessary that no transport unit TEn partially protrudes into a motion path BSn to which it is not assigned. Otherwise, the above-described method of one-dimensional collision monitoring on motion path BSn outside of conflict zones KZ may fail. If one-dimensional collision monitoring is not provided in a non-inventive embodiment, then this would not be strictly necessary, but would still be advantageous.

[0079] To restore a defined state of the planar motor 1, the transport units TEn, at least those located within or partially within a motion path BSn, must first be assigned to a motion path BPn or a motion path BSn. The assignment can be made to the last known motion path BPn of a transport unit TEn. Alternatively, an assignment can be made to a predefined initial motion path BPn, which, for example, is specified by the user. Finally, an assignment can be made to the nearest motion path BPn.

[0080] Preferably, during normal operation, all transport units TEn assigned to a movement path BSn are entirely within the movement path BSn, meaning they do not extend beyond it. To restore normal operation, those transport units TEn that are not entirely within the assigned movement path BSn (i.e., that extend at least partially beyond it) must be moved onto the assigned movement path BSn by means of a restoration movement. Temporary restoration paths or restoration paths can be defined for this purpose, along which such transport units move for the transfer. The starting point of such a temporary restoration path is the current position of the transport unit TEn, and the endpoint is a point within the movement path BSn into which the transport unit TEn is to be moved."Temporary" because these temporary recovery paths or recovery routes are no longer needed after the defined state has been established. This temporary state can be considered a separate mode of recovery, but preferably also follows the procedure described here, in that the recovery routes are treated in the same way as the movement routes BSn.

[0081] The restoration process can be carried out by manually entering a sequence of movement commands, but is preferably performed fully automatically by the control unit 10 without the need for user intervention.

[0082] During such an automatic recovery process, it is necessary to add recovery paths or routes, at least temporarily. This can result in recovery conflict zones, which can be handled with regard to controlling the movements of the transport units (TEs) and collision monitoring, as described above. The recovery paths can be chosen to connect to the intended movement routes (BSns) at arbitrary or predetermined points. When creating the recovery paths, it is preferable to ensure that recovery conflict zones only arise at the points where the movement routes (BSns) intersect, but not along the recovery paths themselves. Once the recovery process is complete, the recovery routes can be discarded.

[0083] To ensure the smoothest possible entry of transport units (TEs) onto their assigned movement paths (BSs) and to avoid deadlock situations wherever possible, it can be advantageous to enter the assigned movement path (BPn) in a defined sequence, i.e., to specify the order in which the transport units (TEs) take up their positions on the movement path (BPn). This can be achieved, for example, by first restoring those transport units (TEs) whose distance is smaller with respect to the orthogonal projection onto the intended entry point of the movement path (BPn) or the movement path (BSn). If necessary, these units can then move along the movement path (BPn) to create space for subsequent transport units (TEs). The distance can be determined, for example, with respect to a reference point (RP) or any other point (e.g., an extremum) on the transport unit (TE).However, the distance can also be determined using a metric other than the orthogonal projection, for example the shortest distance in a certain direction of the plane of motion 3, such as the x-direction of the planar motor alignment or the length of the respective recovery path.

[0084] Once the assignment and, preferably, the assignment sequence, and optionally the arrangement of the transport units TEs in the direction of movement along the movement path BPn, has been determined, the transport units TEs are moved along the assigned movement path BPn. This means, for example, that the respective reference point RP is positioned on the movement path BPn, optionally in the determined arrangement. If desired, the order along the movement path BPn can also be adjusted in this step by moving the already assigned transport units TEs.

[0085] The movement of the transport units TEs towards their respective movement paths BPs then takes place along the recovery paths, which are preferably created analogously to the metric used for the assignment sequence. It is essential to ensure that no collisions occur between transport units TEs.

[0086] Transport units (TEs) with a lower assignment priority, which determines the assignment sequence, preferably have a lower priority than transport units (TEs) with a higher assignment priority. The assignment priority can be predefined or defined for each transport unit (TE). This is advantageous when not all transport units (TEs) assigned to a movement path (BPn) can be positioned on the movement route (BSn) without collisions. Preferably, a movement route (BSn) may only be entered by a transport unit (TE) if movement to the respective movement path (BPn) can occur without conflict.

Claims

1. Method for operating a planar motor (1) having a movement plane (3) in which a plurality of movement paths (BPn) are prespecified along which a plurality of transport units (TEn) move, wherein at least two movement paths (BPn) in the movement plane (3) are expanded two-dimensionally around the respective movement path (BPn), at least in sections, to form a movement route (BSn) in the movement plane (3) by prespecifying at least in sections of the movement route (BSn) sections a width (Bn) at each point of the movement path (BPn), and wherein it is checked whether the at least two resulting movement routes (BSn) overlap, or one of the resulting movement routes (BSn) overlaps with itself, or whether one of the resulting movement routes (BSn) overlaps with an obstacle (H) in the movement plane (3), which obstacle is defined with respect to its location and geometry, in order to determine a conflict zone (KZ) in an overlap region in which there is a risk of collision between transport units (TEn) moving in the region of the conflict zone (KZ) on movement routes (BSn) involved in the conflict zone (KZ) or a risk of collision between a transport unit (TEn) moving on a movement route (BSn) involved in the conflict zone (KZ) and the obstacle (H) in the movement plane (3), and wherein the determined conflict zone (KZ) is taken into account when controlling the movement of the transport units (TEn) along the assigned movement path (BPn) in order to avoid collisions between transport units (TEn) moving on movement routes (BSn) involved in the conflict zone (KZ) or between a transport unit (TEn) and the obstacle (H) in the movement path (BPn), wherein the determined conflict zone (KZ) is taken into account when controlling the movement of the transport units (TEn) along the assigned movement path (BPn) by using two-dimensional collision monitoring for collision avoidance in a conflict zone (KZ), which two-dimensional collision monitoring checks whether there is a risk in the conflict zone (KZ) in the movement plane (3) that a transport unit (TEn) moving in a movement route (BSn) involved in the conflict zone (KZ) will collide with a transport unit (TEn) moving in another movement route (BSn) involved in the conflict zone (KZ) or with an obstacle (H) in the movement plane (3), characterized in that on a movement path (BPn) outside of a conflict zone (KZ) a one-dimensional collision monitoring is used, which one-dimensional collision monitoring checks in the movement direction whether there is a risk of a collision between two transport units (TEn) traveling behind one another on the movement path (BPn).

2. Method according to claim 1, characterized in that the width (Bn) of at least one movement route (BSn) in the movement plane (3) is prespecified orthogonally to the assigned movement path (BPn).

3. Method according to claim 1 or 2, characterized in that the width (Bn) of at least one movement route (BSn) in the movement plane (3) is prespecified asymmetrically to the movement path (BPn), at least in sections.

4. Method according to one of claims 1 to 3, characterized in that a reference point (RP) is determined on a transport unit (TEn), and the movement path (BPn) is related to the reference point (RP).

5. Method according to claim 4, characterized in that vectors (VL, VR) from the reference point (RP) to the outer contour of the transport unit (TEn) in the movement plane (3) are determined at a position of the movement path (BPn) on both sides of the transport unit (TEn) as viewed in the direction of movement of the transport unit (TEn), in that the determined vectors (VL, VR) are in each case projected onto a normal (N) on the movement path (BPn) at this position, and in that the longest projection (PR, PL) on each side are added to the width (Bn) of the movement route (BSn) at this position.

6. Method according to claim 5, characterized in that a prespecified geometric figure, which surrounds the transport unit (TEn) in the movement plane (3), is used as the outer contour.

7. Method according to one of claims 1 to 6, characterized in that the determined conflict zone (KZ) is taken into account when controlling the movement of the transport units (TEn) along the assigned movement path (BPn) in that, for collision avoidance, at least one of the movement routes (BSn) involved in the conflict zone (KZ) is replanned, at least in sections, in order to eliminate the conflict zone (KZ) and / or to reduce the size of the determined conflict zone (KZ) and / or to reduce a number of determined conflict zones (KZ) and / or to reduce the number of movement routes (BSn) involved in the conflict zone (KZ) and / or to increase a distance between two conflict zones (KZ).

8. Method according to claim 7, characterized in that a movement route (BSn) is replanned in that the movement path (BPn) assigned to the movement route (BSn) is replanned, at least in sections, and / or a width (Bn) of a movement route (BSn) is changed, at least in sections.

9. Method according to one of claims 1 to 8, characterized in that the determined conflict zone (KZ) is taken into account when controlling the movement of the transport units (TEn) along the assigned movement path (BPn) by checking, before a transport unit (TEn) moving on a movement route (BSn) involved in a conflict zone (KZ) enters the conflict zone (KZ), whether said transport unit (TEn) can exit the conflict zone (KZ) with the intended movement again without colliding with another transport unit (TEn) moving on a different movement route (BSn) involved in the conflict zone (KZ), and, in the negative case, entry is denied.

10. Method according to one of claims 1 to 9, characterized in that the determined conflict zone (KZ) is taken into account when controlling the movement of the transport units (TEn) along the assigned movement path (BPn) in that transport units (TEn) are assigned a priority, and a transport unit (TEn) having the highest priority is granted entry into a conflict zone (KZ) first.