Distribution System

Abstract

A method of operating a distribution system is described. The distribution system comprises a plurality of carriers, each adapted to carry one or more articles. A transfer surface of the distribution system supports the carriers. A controller controls the drive means. During initialization of the distribution system, the controller predefines a pattern of safety points on the transfer surface, on which the carriers can be positioned. After initialization of the distribution system, the controller calculates partial routes of the carriers such that the end position of each partial route is either one of the safety points or has a free path to one of the safety points reachable in the next partial route.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION SUMMARY OF THE INVENTION Embodiments of the present invention relate to a method for a distribution system for calculating routes for carriers moving on a transport surface, a distribution system, and in particular a routing method. [Background technology]

[0002] Background of the Invention WO2012158520 discloses a laboratory product transport element for a laboratory transport system, comprising an energy receptor and / or energy accumulator for providing a driving force. The laboratory product transport element comprises at least one signal receiver for receiving control signals, a control unit for generating a driving signal as a function of the at least one control signal obtained from the at least one signal receiver, and a moving device for independently moving the laboratory product transport element on a transport path as a function of the driving signal of the control unit, the driving device being driven by a driving power, and at least one holder holding a laboratory product to be transported. A transport path configuration is also described.

[0003] WO2013064656 describes a laboratory sample distribution system including a plurality of container carriers, each of which is equipped with at least one magnetically active device, preferably at least one permanent magnet, and adapted to carry sample vessels containing samples. The transfer device includes a transfer surface adapted to carry the plurality of container carriers and a plurality of electromagnetic actuators fixedly disposed below the transfer surface. The electromagnetic actuators are adapted to move the container carriers disposed on the transfer surface by applying magnetic forces to the container carriers. A control device is adapted to control the movement of the container carriers above the transfer surface by driving the electromagnetic actuators, and the control device is adapted to control the movement such that three or more container carriers can be moved simultaneously and independently of one another.

[0004] EP 3385893 discloses a system, method, and machine-executable coded instruction set for controlling the movement of a transport device and / or operations performed at various workstations. In particular, the present disclosure provides a method, system, and computer-readable medium for controlling the movement of a transport device configured for fully and / or partially automated handling of articles and / or for controlling operations performed at various workstations.

[0005] "Ma Tao, A. Elssamadisy, N. Flann, and B. Abbott, "Optimal route re-planning for mobile robots: a massively parallel incremental A* algorithm," Proceedings of International Conference on Robotics and Automation, Albuquerque, NM, USA, 1997, pp. 2727-2732, vol. 3, doi:10.1109 / ROBOT.1997.619372. discloses the primary advantages of an incremental A* algorithm for precomputing and maintaining routes for mobile robotic vehicles, which are the completeness and optimality of the approach. However, complexity is limited by the domain modeled, so when large worlds are modeled or fine resolution is required, the computational burden becomes unreasonable. This challenge is exacerbated when multiple vehicles and multiple targets are involved, since a route from each vehicle to each target must be maintained. A massively parallel incremental A* algorithm suitable for VLSI implementation is disclosed. The number of iterations of the parallel algorithm is limited by the optimal path length, providing significant speedup for large worlds. Empirical studies combined with feasible VLSI designs estimate that path computation for a 1000x1000 world can be completed in about 110 ms in the worst case.

[0006] EP 3 537 159 A1 describes a method for operating a laboratory sample distribution system comprising: a plurality of sample container carriers, the sample container carriers being adapted to carry laboratory sample containers; a transport surface, the transport surface being adapted to support the sample container carriers; and a plurality of drive elements, the drive elements being adapted to move the sample container carriers on the transport surface, the method comprising: a) planning a movement path for one of the sample container carriers from a start to a destination on the transport surface, the transport surface being logically modelled by a plurality of nodes, the nodes being free for at least one time window. The present invention describes a method for planning a sample container carrier, the method comprising: -a) planning a sample container carrier on a transport surface along the reserved movement path by controlling at least one of the drive elements; -b) planning a sample container carrier on a transport surface along the reserved movement path by controlling at least one of the drive elements; -c) planning a sample container carrier on a transport surface along the reserved movement path by controlling at least one of the drive elements; -d) planning a sample container carrier on a transport surface along the reserved movement path by controlling at least one of the drive elements;

[0007] U.S. Patent Application Publication No. 2019 / 152057 describes a robotic load handler coordination system including a robotic load handler configured, in use, to traverse a plurality of cells arranged in a grid formation. The load handler is configured to receive instructions related to execution of a selected, determined route from a start cell to a destination cell. Processing resources are configured to support a movement optimizer, the movement optimizer being configured to iteratively determine a plurality of routes using an A* pathfinding algorithm to respectively determine a number of sets of routes from several of the plurality of cells to the destination cell. The number of the plurality of cells includes a start cell, and the movement optimizer is configured to select an optimal route to the destination cell from the set of routes relative to the start cell. Summary of the Invention

[0008] The object of the present invention is to provide a reliable method for operating a distribution system. This is achieved by the method according to claim 1.

[0009] A first aspect of the invention relates to a method of operating a distribution system, the distribution system comprising a number of carriers, the carriers adapted to carry one or more articles, a transfer surface adapted to support the carriers.

[0010] A drive means is adapted to move the carrier on the transfer surface, and a controller controls the drive means.

[0011] The method comprises: During initialization of the dispensing system, a controller predefines a pattern of safety points on the transfer surface and carriers are placed on the safety points; and a step in which, after initialization of the distribution system, the control device calculates the partial routes of the carrier so that the end position of each partial route is either one of the safety points or has a free path to one of the safety points reachable in the next partial route.

[0012] This avoids or minimizes the occurrence of deadlocks, which means blocking of carriers on the transport surface. A safe point is a position on the transport surface where a carrier can be placed and from which it can leave again. A safe point therefore has at least one adjacent position on the transport surface that is not a safe point, so that a carrier on a safe point can be removed from the safe point even if all safe points in the vicinity of this safe point are occupied by other carriers.

[0013] This placement at or reachability of safe points ensures that in the event of a jam of carriers on the transport surface, the carriers are placed at a safe point and still allow a free path.

[0014] Typically, the route of a carrier on a transfer surface from its starting location to its final destination location is divided into one or more partial routes to intermediate destinations.

[0015] The transport surface includes multiple logical locations. The term "logical location" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. This term can specifically, but not exclusively, refer to any location on the transport surface adapted to support carriers. The representation of the transport surface can be multiple logical locations or a graph having multiple logical locations and allowable connections between them. The transport surface may be mathematically mapped to a graph of logical locations or a graph of logical locations and allowable connections between them. Routing of carriers on the logical locations, e.g., route discovery, may be performed using the graph. Safe points may be defined from these logical locations. The logical locations may be defined on the transport surface by hardware requirements and / or software. Each logical location may be configured to be occupied by only one carrier. Therefore, two carriers cannot share a logical location. The distribution system may be configured to move multiple carriers on the transport surface via respective calculated partial routes, each of which may lead from a first logical location to a second logical location, i.e., the end location of each partial route. However, if each carrier's partial route has unlimited access to each logical location, multiple carriers on the transport plane may cause congestion. In the worst case, carriers may interfere with or block each other's movement, preventing the route from being completed. Therefore, the present invention proposes boundary conditions and / or constraints on the end positions of carrier partial routes, in particular, that the end position of each partial route be one of the safe points or have a free path to one of the safe points reachable in the next partial route. Therefore, other logical locations not predefined as safe points may not be considered as end positions of partial routes at all, or may be considered by the control device to calculate the partial route only if the carrier has a free path to one of the safe points reachable in the next partial route.These boundary conditions and / or constraints for calculating partial routes can ensure that carriers are placed at safe points in the event of a jam of carriers on the transport surface, while still allowing carriers to move to complete each calculated partial route. Thus, in the event of a jam, the jam leaves free paths from each safe point. Jams still exist, but these jams leave free paths from each safe point. The occupied safe points within a "jam" represent a pattern of safe points on the transport surface. As traffic decreases, the jams can be resolved without carriers blocking each other. Blocking results in an endless computing loop. According to the present invention, only safe points are allowed in the event of a jam. Therefore, if all safe points ahead are occupied, a carrier cannot move because it cannot reach a safe point or cannot reach it on its next move.

[0016] As outlined above, during initialization of the distribution system, the logical locations may be predefined by the control device as a pattern of safety points and other logical locations. The other logical locations may be defined as aisles and / or empty spaces around the safety points. The control device may be configured to select a pattern of safety points from the entire set of logical locations. The term "safety point" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. This term may specifically, but is not limited to, refer to a logical location selected taking into account the range of movement of a carrier occupying the logical location. The range of movement may be such that a carrier can be positioned at a safety point and then moved away again, particularly in the next partial route. A safety point and a route to the safety point may be reserved for a carrier, while other carriers can travel through the safety points. However, these carriers may not be able to stop at the safety points. The pattern of safety points may be selected so that even if all safety points in the pattern are occupied by carriers moving from the safety points, it is still possible. The pattern of safety points can be selected such that each safety point has at least one adjacent location on the transport surface that is not a safety point. For example, the pattern of safety points may be selected such that each safety point has at least two adjacent locations on the transport surface that are not safety points. For example, the pattern of safety points may be selected such that the safety points are not adjacent logical locations on the transport surface. For example, the pattern of safety points may be selected such that the safety points are separated by at least one logical location that is not a safety point. Thus, a carrier at a safety point can be removed from a safety point even if all safety points in the vicinity of the safety point are occupied by other carriers. The controller can be configured to calculate partial routes with boundary conditions such that all carriers can only stop at safety points and cannot stop in aisles and / or empty spaces, or have at least a free path to a safety point in the next partial route.The controller can be configured to calculate partial routes with a boundary condition that all carriers are at a safe point for every movement before the carriers can begin their movement. The controller may also be configured to calculate partial routes with a boundary condition that a safe point must be defined and reachable for every partial route, so that in high traffic situations, only the safe points can be occupied.

[0017] Various patterns of safety points may be possible. For example, the pattern of safety points may be direction-dependent, e.g., relative to a particular direction of travel. An advantage of having direction-dependent safety points is that two carriers placed at two adjacent safety positions may not have opposite directions. One of the carriers must move around the other to continue moving. The pattern may include multiple clusters of safety points. A movement path according to a preferred direction of movement may be arranged around each cluster of safety points. The transfer surface may comprise multiple transfer modules. A certain number of safety points may be used for each transfer module. The movement direction of the carrier towards the next inside corner may determine which safety point in the transfer module may be used.

[0018] In a further embodiment of the method, the control device calculates partial routes such that the carriers stop at a safety point if the traffic on the transport surface exceeds a predetermined density, for example if 50% of the transport surface is covered by carriers, or in case of congestion, i.e. if there is no free safety point on the routed path.

[0019] A further aspect of the method of operating the distribution system is that, at initialization of the distribution system, handover positions are defined on the transport surface for handing over items, and safety points are predefined such that there is a free path along the safety points between the handover positions.

[0020] Another aspect of the method of operating the distribution system is that the control device, during initialization of the distribution system, defines movement directions, in particular as straight lines on the transport surface in at least two directions perpendicular to each other, and the calculated route uses these movement directions.

[0021] This reduces the degrees of freedom in the calculation of the route and therefore makes the calculation faster. In particular, the carrier moves only in a straight line and stops, especially if the carrier changes direction only with an angular resolution of 90 degrees.

[0022] A further aspect of the disclosed method of operating dispensing is that logical locations are defined on the transfer surface and the safety points are logical locations.

[0023] A logical position can be defined on a transport surface by hardware requirements or by software alone. The former is the case, for example, in transport systems that have electromagnetic coils below the transport surface to push or pull carriers using active magnetic devices. Thus, the position at which the carrier can be clearly defined is located above the electromagnetic coil. The latter is the case for automatically driven carriers on any transport surface, such as the floor of a work area. In this case, a logical position can be defined by software at a specific location on the transport surface.

[0024] In a further embodiment, for each logical location, the control device calculates, during initialization of the distribution system, a partial route from each logical location to the next safe point, in particular a safe point reachable while traveling n logical locations, which are stored in a look-up table, where N is an integer in the range of 3 to 60, in particular in the range of 12 to 30, and more particularly 24.

[0025] Another aspect of the method of operating the distribution system is that the transport surface is made up of tile elements connected to each other, and during initialization of the distribution system, the control system maps the layout of the transport surface by identifying boundaries by creating vectors for each edge of the tile elements, canceling all vectors based on adjacent vectors of adjacent tile elements, and combining remaining vectors that are adjacent and have the same direction. Thus, easy and reliable boundary mapping of the transport surface is possible, and can be easily repeated if the tile geometry changes.

[0026] A further aspect of the method for operating a distribution system is that during mapping of the distribution system, inner corners are identified by identifying changes in direction of adjacent remaining vectors, calculating their vector product, and mapping inner or outer corners to negative or positive vector products, respectively, depending on the initial direction of the vectors, which allows for reliable detection of inner corners.

[0027] In the plane of the transfer surface, a logical position can be characterized by the number of adjacent logical positions. An inner logical position can have four neighboring and / or adjacent logical positions, allowing for movement in four directions. The term "corner" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. This term can specifically, but not be limited to, a logical position that cannot have neighboring and / or adjacent logical positions in at least one direction of movement. The term "inner corner" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. This term can specifically, but not be limited to, a logical position that cannot have neighboring and / or adjacent logical positions in one direction of movement. An inner corner can have three neighboring and / or adjacent logical positions. The term "outer corner" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term can specifically refer to, but is not limited to, a logical position that cannot have neighboring and / or adjacent logical positions in two directions of movement. An outside corner can have two neighboring and / or adjacent logical positions.

[0028] A further aspect of the method of operating the distribution system is that the adjacent inside corners are determined during initialization.

[0029] Two inner corners are adjacent if the rectangle spanned by the corners lies entirely on the transport surface, or in other words, if the rectangle does not include any portion from the transport surface.

[0030] Another aspect of the method for operating a distribution system is that a route is calculated to maintain the distance to the inner corner while the carrier passes through the inner corner. While this means that the carrier does not travel on the shortest path around the corner, it improves the overall throughput of the distribution method and avoids contention between carriers, and therefore deadlocks, which may result in carriers blocking each other. Corners, such as inner or outer corners, can be potential bottlenecks for carrier movement because corners limit the range of movement of carriers in at least one direction. Therefore, detecting inner and outer corners can be advantageous for preventing congestion. The present invention proposes identifying corners and taking them into account when calculating partial routes. For example, a carrier route can be calculated to maintain the distance to the inner corner while the carrier passes through the inner corner. The control device can be configured to calculate partial routes by considering that the carrier does not travel as close to the inner corner as possible. The control device can be configured to calculate partial routes by considering that the waypoint before the change of direction takes into account the distance between the starting position and the outer boundary of the transport surface, also referred to as the system boundary, that is closest to the inner corner. The inner corner may be formed by two outer boundaries of the transport surface. At a starting position, the carrier may face one of the outer boundaries and have a first distance to the outer boundary. The control device may be configured to calculate a partial route of the carrier around an inner corner by considering that the first distance is preserved during the movement of the carrier. The control device may be configured to calculate a partial route of the carrier around the inner corner by considering only logical positions having a distance corresponding to the first distance from the outer boundary that forms the inner corner. In the case of multiple carriers, this may ensure that multiple carriers are evenly spaced around the inner corner before changing direction of movement to avoid congestion at the inner corner.

[0031] A further aspect of the method for operating a distribution system is that during initialization, the Manhattan distance between adjacent inside corners is determined. The Manhattan distance is the distance between two points measured along perpendicular axes. For example, in a plane where point A is at (x1, y1) and point B is at (x2, y2), the Manhattan distance can be |x1-x2|+|y1-y2|.

[0032] A further aspect of the method of operating the distribution system is that during initialization a node network is generated that indicates the paths and Manhattan distances between at least two, and in particular all, adjacent inside corners.

[0033] In a further embodiment of the method, during initialization, a lookup table is created that takes two inside corners as input parameters and outputs a path between the input inside corners as a list of intermediate inside corners, and also outputs the Manhattan distance along the path.

[0034] This allows for fast and reliable route calculation: if two routes have the same distance, the one with fewer intermediate nodes is preferred.

[0035] Another aspect of a method of operating a distribution system is a method of operating a distribution system, comprising: 1. Follow a straight line, if that's not possible, follow an L-shaped path, if that's not possible, 3. Determine the next intermediate destination location using the A* algorithm, and if not possible, 4. If the carrier remains at its current position for less than n seconds, wait for a change in the neighborhood; If a change occurs, restart at 1. b. If the carrier waits longer than n seconds, c. Search for the next safe point and use the A* algorithm to reach this safe point, if not possible, d. Wait for a change in the neighborhood, and if a change occurs, resume at 1. With n being a number between 1 and 10, particularly 3, the distance to the next intermediate destination is determined by the Manhattan distance between the current location and the destination location.

[0036] This allows for reliable and easy routing of carriers.

[0037] The destination location can be the location to which the carrier must ultimately travel to perform its task. An intermediate location can be a location on the carrier's way to the destination location. For an intermediate location, the constraint must be met that it is one of the safe points or that the carrier has a free path from the intermediate location to one of the safe points reachable in the next partial route. An intermediate location can also be the end point of a partial movement.

[0038] A further aspect of the method of operating the distribution system is that the determined partial route is reserved for a carrier until the carrier reaches its intermediate or final destination, meaning that no other carrier can use the reserved route or while the respective carrier is traveling.

[0039] This allows the method to take into account the routes and locations of other carriers when calculating the route of one carrier.

[0040] A further aspect of the method of operating the distribution system is that for each carrier the next intermediate destination location is determined one after the other until the final destination location is reached, which means that the entire route of the carrier is divided into smaller partial routes.

[0041] This allows for better consideration of other carriers and increases the flow of all carriers towards their final destinations.

[0042] A further aspect of the method of operating the distribution system is that the positioning system determines the position of the carrier on the transport surface and sends a position update message to the controller, which triggers the release of reserved logical fields that the carrier has already passed through in its current movement.

[0043] This allows for faster release of reserved logical positions on a route or partial route and therefore more efficient routing of all carriers which increases the overall throughput of the method.

[0044] Another aspect of the method of operating the distribution system is that the carrier does not travel longer than m logical positions, where m is an integer between 3 and 50, particularly between 10 and 30, and more particularly 24.

[0045] This allows for an increase in the overall throughput of the method.

[0046] However, other embodiments are possible that involve combinations of the features disclosed herein.

[0047] In summary, without excluding further possible embodiments, the following embodiments can be envisaged:

[0048] Embodiment 1. A method of operating a distribution system, comprising: a plurality of carriers adapted to carry one or more items; a transfer surface adapted to support the carrier; drive means adapted to move the carrier on the transfer surface; a control device adapted to control the drive means; The method is During initialization of the dispensing system, a controller predefines a pattern of safety points on the transfer surface and carriers are placed on the safety points; A method for operating a distribution system, comprising: after initialization of the distribution system, a step in which the control device calculates partial routes of the carrier so that the end position of each partial route is either one of the safety points or has a free path to one of the safety points reachable in the next partial route.

[0049] Embodiment 2. A method of operating a distribution system as described in the previous embodiment, wherein handover positions are defined on the transport surface for handing over articles, and safety points are predefined such that a free path exists along the safety points between the handover positions.

[0050] Embodiment 3. A method of operating a distribution system according to the previous embodiment, in which the control device, during initialization of the distribution system, defines the direction of movement as a straight line on the transport surface, in particular in at least two directions perpendicular to each other, and the calculated route uses these directions of movement.

[0051] Embodiment 4. A method of operating a dispensing system according to any one of the previous embodiments, wherein a logical position is defined on the transfer surface and the safety point is the logical position.

[0052] Embodiment 5. A method of operating a distribution system described in any one of the previous embodiments, wherein the transport surface consists of tile elements connected to each other, and during initialization of the distribution system, the control system maps the layout of the transport surface by identifying boundaries by creating vectors for each edge of the tile elements, cancels all vectors based on adjacent vectors of adjacent tile elements, and combines remaining vectors that are adjacent and have the same direction.

[0053] Embodiment 6. A method of operating a distribution system according to the previous embodiment, wherein during mapping of the distribution system, inner corners are identified by identifying changes in direction of adjacent remaining vectors, calculating their vector products, and mapping inner or outer corners to negative or positive vector products respectively depending on the initial direction of the vectors.

[0054] Embodiment 7. A method of operating a dispensing system according to the previous embodiment, wherein during initialization, adjacent inside corners are determined.

[0055] Embodiment 8. A method of operating a distribution system according to the previous embodiment, wherein the route of the carrier is calculated to maintain the distance to the inside corner while the carrier passes through the inside corner.

[0056] Embodiment 9. A method of operating a distribution system according to the previous embodiment, wherein the Manhattan distance between adjacent inside corners is determined.

[0057] Embodiment 10. A method of operating a distribution system according to the previous embodiment, wherein a node network is generated showing paths and Manhattan distances between at least two, and in particular all, adjacent inside corners.

[0058] Embodiment 11. A partial route of a carrier is 1. Follow a straight line, if that's not possible, follow an L-shaped path, if that's not possible, 3. Determine the next intermediate destination location using the A* algorithm, if not possible, 4. If the carrier remains at its current position for less than n seconds, wait for a change in the neighborhood; 4.1. If a change occurs, restart at 1. 5. If the carrier waits longer than n seconds, 5.1. Search for the next safe point and use the A* algorithm to reach this safe point, if not possible, 5.2. Wait for a change in the neighborhood, and if a change occurs, resume at 1. A method of operating a distribution system as described in the previous embodiment, wherein the distance to the next intermediate destination location is determined by the Manhattan distance between its current location and the destination location, where n is a number between 1 and 10, in particular 3.

[0059] Embodiment 12. A method of operating a distribution system according to the previous embodiment, wherein the determined route is reserved for the carrier until the carrier reaches its intermediate or final destination.

[0060] Embodiment 13. A method of operating a distribution system according to the previous embodiment, wherein for each carrier, the next intermediate destination location is determined, one after the other, until the final destination location is reached.

[0061] Embodiment 14. A method of operating a distribution system according to any one of the previous embodiments, wherein the positioning system determines the position of the carrier on the transport surface and sends a position update message to the controller, which triggers the release of reserved logical fields that the carrier has already passed through in its current movement.

[0062] Embodiment 15. A method of operating a distribution system according to any one of the previous embodiments, wherein the carrier does not move for more than m logical positions, and m is an integer between 3 and 50, particularly between 10 and 30, and more particularly 24. [Brief explanation of the drawings]

[0063] Further optional features and embodiments of the present invention are disclosed in more detail in the subsequent description of preferred embodiments, preferably in conjunction with the dependent claims. Here, each optional feature can be realized independently as well as in any possible combination, as will be understood by those skilled in the art. The scope of the present invention is not limited by the preferred embodiments. The embodiments are illustrated schematically in the figures, where the same reference numerals in these figures refer to identical or functionally comparable elements.

[0064] The diagram is as follows:

[0065] [Figure 1] FIG. 1 is a perspective view of a distribution system. [Figure 2] 1 shows a schematic diagram of a possible layout of the transfer surface and the determination of its boundaries; [Figure 3] 1 shows a portion of a transfer surface having an inside corner. [Figure 4] 4 shows a diagram of the inside corner shown in FIG. [Figure 5] 10 shows a schematic of how a carrier moves around an inside corner. [Figure 6] 3 partially illustrates the defined directions of movement of the transfer surface layout shown in FIG. 2; [Figure 7] Shown are three possible patterns of safe spots on the tiles of the transport surface. [Figure 8] 1 shows a flowchart for determining a carrier route. DETAILED DESCRIPTION OF THE INVENTION

[0066] Detailed Description of the Invention FIG. 1 shows a schematic perspective view of a distribution system 10, such as a diagnostic laboratory transport system, particularly for obtaining patient test results.

[0067] The distribution system 10 generally comprises two components:

[0068] First, a transport system 11 that executes the movement of the carrier 14 according to a given plan, calculated by the router software. The transport system communicates all or predefined position changes and potential errors of the carrier 14 to the software system.

[0069] Second, a software system that receives status updates regarding the carrier's position and errors and calculates new plans for the next move based on the status updates and new requests to transport the carrier 14 to its destination. These plans are sent to the transport system and executed.

[0070] The distribution system 10 is required to transport objects 16, such as tubes containing biological sample fluids and / or consumables, between stations 18 of the distribution system 10, such as analytical instruments, pre-analysis stations, or post-analysis stations. Additionally, other species, such as tissues, reagents, waste, or disposables, can be transported between stations 18. The stations 18 may also be diagnostic laboratory modules, such as aliquot generation stations, centrifuges, or analytical modules that perform single analyses. In other embodiments, the distribution system 10 may be a warehouse distribution system that distributes items as objects 16 between stations 18, such as shelves and packing stations, or a manufacturing site where the objects 16 are raw or semi-finished products that need to be transferred between work stations, such as in a machine shop. Furthermore, if desired, a transfer surface can be used within the stations 18 to transport carriers within the stations 18.

[0071] The distribution system 10 includes a transport surface 12 and a carrier 14 that is moved, moves itself, or even hovers on the transport surface 10. To move the carrier 14, the distribution system 10 includes a drive system. The drive system can be realized by an electromagnetic coil below the transport surface and a permanent magnet within the carrier 14. The magnetic field generated by the coil can then push and / or pull the permanent magnet within the carrier 14, causing the carrier 14 to slide or hover on the transport surface 12. To locate the carrier 14 on the transport surface 12, sensors such as optical, magnetic, or inductive sensors can be embedded in the transport surface 12. Another option can be a camera system with image analysis software for locating the carrier 14.

[0072] Other drive systems are possible in other embodiments, such as self-propelled carriers 14 that include sensors, motors, and energy storage such as batteries, especially rechargeable batteries. These self-propelled carriers 14 can therefore also travel autonomously on the transfer surface 12. In this case, the control device can be part of the carrier or can be distributed on the carrier 14. Alternatively, a robotic load handler is possible that can traverse multiple cells arranged in a grid.

[0073] A control system 20 is part of the distribution system to control the movement of the carrier 14. The control system 20 can, for example, control the drive current of the coils or collect position information of the carrier 14. The control system 20 is therefore connected to the transport system 11, in particular to the drive system and the camera 21.

[0074] The dashed lines in FIG. 1 represent a graph or possible movement paths between their intersections, which define the logical positions. In this embodiment, the graph forms a rectangular mesh. However, other models are also possible, for example, with curved movement paths. In some drive systems, the logical positions are given by the technically possible start-stop positions on the transport surface 12. This is the case, for example, for drive systems with coils below the transport surface 12. On the other hand, in the case of self-propelled carriers, the carriers can start and stop at any position on the transport surface 12, so logical positions defined purely by software are possible. At least the logical positions must be far enough apart on the transport surface 12 that two carriers 14 can be positioned adjacent to each other. The carriers 14 move along the logical positions on the transport surface.

[0075] Carriers 14 transport objects 16 between stations 18 on a transfer surface 21. The objects are either handed over to stations 18 or the carrier moves into stations 18 using a similar transfer system within the station 18. The location before a station 18 on the transfer system can be defined as the final destination of the carrier if the objects 16 on the carrier 14 must be moved to the respective station 18.

[0076] For example, in one embodiment as a diagnostic laboratory at one final destination location, tubes containing biological fluids are placed in carriers forming a pre-analytical system. A further final destination location can be located at station 18, such as an analyzer, where the tubes are grasped and placed in the analyzer or a portion of the fluid can be pipetted at the final destination location.

[0077] For stations 18 that themselves have the same or similar transport system, the final destination location may be a logical location on the transport surface 12 to which the carrier 14 can move into the station.

[0078] The transfer surface 12 can be realized from tiles such as transfer modules 24 .

[0079] The routing software module may be implemented within the control system 20 or within any other computing device, not shown, connected to the control system 20. The routing software module implements the distribution method of the distribution system 10 by calculating partial routes for the carriers 14 along their logical locations toward their final destination or the station 18 to which they need to go.

[0080] 1, the routing software module or controller defines a pattern of safety points 701 during initialization. After initialization of distribution system 10, controller 20 calculates partial routes for carrier 14 such that the end location of each partial route is either one of the safety points 701 or has a free path to one of the reachable safety points 701 on the next partial route. The end locations and safety points are logical positions on transfer surface 12.

[0081] FIG. 2 illustrates an example of a particular embodiment of layout mapping during initialization to identify layout boundaries and inner corners.

[0082] The layout of the transport surface 12 constructed from the transport modules 24 can be given to the software module by a "config" file from a higher software layer. In an initialization phase, the software module creates four vectors 201 for each transport module 24 in a counterclockwise rotation around the boundary of each transport module 24. In a next step, each vector is added to the vector of the adjacent boundary of the transport module 24 next to this boundary. This cancels all vectors based on their proximity except for the vector with the entire boundary of the transport surface 12. All vectors that do not cancel and follow the same direction are combined to construct the boundary vector 202.

[0083] Where there is a change in direction, corners of the layout are identified. The corners are grouped into inner and outer corners. The vector product between adjacent boundary vectors is calculated by the software module. For example, for a selected counterclockwise rotation of vector 201, the vector product of boundary vector 202 at inner corner 203 is negative and at outer corner 204 is positive.

[0084] A change in the layout of the transfer surface 12 due to a change in a hardware signal indicating a fault will result in a new layout initialization and the software module will recalculate the route affected by the layout change.

[0085] 3 illustrates a portion of another embodiment having a transfer surface 12 with inside corners A, B, C, D, and E. After inside corners A, B, C, D, and E have been identified as described above, adjacent inside corners are defined. Two inside corners are adjacent if the rectangle extending between them lies entirely on the transfer surface 12. For example, rectangle 301 extending between inside corners A and C lies within the open space between inside corners B and D; therefore, inside corners A and C are not adjacent inside corners.

[0086] In the next step, the software module determines the true heuristic distance, for example the Manhattan distance, between adjacent inside corners.

[0087] Figure 4 shows the node network between the inside corners of the inside corners shown in Figure 3. The node network is generated by a software module that shows the paths and Manhattan distances between all the inside corners.

[0088] Finally, the software module generates and stores a table using the node network connecting all nodes to each other, listing the shortest distances between nodes. If there are multiple paths with the same total distance connecting two nodes, the path with the fewest number of intermediate nodes is prioritized. The node network and node distance table from the layout portion of Figure 3 are shown in Table 1 below.

[0089] [Table 1]

[0090] For example, the Manhattan distance between inside corners A and B is 5. Any distance unit can be used, or for example, the number of logical positions the carrier must move. Because inside corners A and C are not adjacent inside corners, the Manhattan distance of inside corners A, D, and C is used.

[0091] The software module uses a node network based on the inside corners as a rough plan / direction on how to reach each logical location within the transport plane, e.g., the final destination of the carrier 14. Additionally, a table is used to determine a true distance heuristic. This speeds up calculations and allows for avoiding unnecessary calculations during routing, i.e., calculating the route / movement of the carrier 14 on the transport plane 12.

[0092] In the event of a hardware failure or redesign within the transport plane 12, layout initialization and heuristic distance determination are re-performed. A single logical location failure can be treated as an obstruction, so that the logical location can be blocked and does not require re-initialization.

[0093] Once initialization is complete, routing of the individual carriers 14 on the transport surface 12 is possible. Routing decisions are made based on the initial position of the carrier 14 and its final destination. A software module determines the route for each carrier individually, one after the other.

[0094] The route of the carrier 14 is determined based on the available or unreserved portion of the transport surface 12, specifically the shortest distance between free and unreserved logical positions.

[0095] Having identified the initial position of the carrier 14 on the transport surface 12 along with its final destination, the shortest paths between all combinations of initial adjacent nodes and destination adjacent nodes in the node network as shown in Figure 4 are determined using respective tables such as Table 1. The calculated route minimizes the true heuristic distance from the initial position of the carrier 14 on the transport surface 12 to its final destination on the transport surface 12.

[0096] In this method embodiment, the software module defines sub-routes of the calculated route by reserving portions of the transport surface, specifically each logical position along which the carrier 14 will travel. Once a sub-route is defined, the carrier 14 begins moving without having to wait for the route determination of other carriers. The sub-route is calculated such that intermediate destinations are closer to the final destination than the current location.

[0097] Carrier 14 position update messages are sent by the transport system 11 or drive system firmware during carrier 14 movement, which triggers the release of reserved portions of the transport surface 12, in particular logic fields that have already been driven during carrier 14 movement.

[0098] As shown in FIG. 5, carriers 14 do not move as close to inside corner A as possible, but their waypoint before changing direction takes into account the distance between their starting location and the system boundary closest to inside corner A. Carriers 14 closer to the boundary move along dotted arrow line 501. Carriers 14 farther from the boundary move along dashed dotted line 502. Both maintain their distance to inside corner A. This is done so that multiple carriers 14 are evenly spaced around the inside corner before changing direction of movement. This results in a higher overall throughput of the distribution method.

[0099] In one embodiment, the route consists of either straight or L-shaped movements with a maximum movement length of 24 logical positions.

[0100] In a further embodiment of the dispensing method, the movement of the carriers is monitored in real time by a sensor such as the camera 21 shown in Figure 1 or by a sensor system in the transfer plane 12 as described above. Each time a carrier 14 crosses from one transfer module 24 to another, Each time the carrier 14 changes direction, By a signal when the carrier 14 stops after a partial route, it is transmitted to the control device 20 in one, some or each of the cases.

[0101] In a further embodiment shown in Figure 6, for the layout of the transport surface 12 shown in Figure 2, the directions of movement are defined on the transport surface by the controller 20 during initialization as arrows 601, 602, 603, 604. Note that the arrows are not labeled, and not all necessary arrows are shown. Only for transfer module 624 (highlighted with bolder lines) are all necessary arrows present. For this transfer module 624, each intersection of the arrows represents a logical position on the transport surface 12.

[0102] During initialization as shown in Figure 7, safety points 701 are defined on the transfer surface 12. Figure 7 shows three transfer modules 24 with different patterns of safety points on the transfer module 24. Each used transfer module 24 that makes up the transfer surface 12 has the same or a different pattern of safety points 701.

[0103] In an embodiment, the safe point 701 corresponds to a logical position. The controller, and therefore the software module, calculates a partial route for the carrier so that the partial route ends at the safe point or the safe point can be reached within the next partial route.

[0104] Therefore, for each partial route of the carrier, one safety point is reserved on the transfer surface.

[0105] For each pattern of safe points 701, as shown in FIG. 7, there is a free path along the safe points 701 for travel on the transfer module.

[0106] In a further embodiment, these safe points 701 are used for the partial route calculation that are on the defined direction of travel 601, 602 of this partial route.

[0107] In a further embodiment, the handover location is not used as the safe point 701 .

[0108] This makes it possible to avoid deadlocks, which block carriers from moving with each other, meaning that partial routes can no longer be calculated.

[0109] In a further embodiment, there is at least one logical position to allow free movement around the safety point.

[0110] In another embodiment, each safe point has at least one adjacent logical location connected to an adjacent logical location that is not a safe point but defines a free path between handover locations.

[0111] A handover location may be a location on the transfer surface 12 where an object 16 is handed over to a station 18 or where a carrier 14 can be positioned so that the carrier 14 can enter or exit a station 18 .

[0112] In another embodiment of the dispensing method, the controller defines a certain number of safe points for each transfer module 24, 624 during initialization.

[0113] Figure 8 shows a flow diagram of how the controller and / or software module calculates the next partial route for a carrier 14. 1. The partial route for a carrier is calculated by: 1. Follow a straight line, if not possible, 2. Follow the L-shaped route, if not possible, 3. Determine the next intermediate destination location using the A* algorithm, and if not possible, 4. If the carrier remains at its current position for less than n seconds, wait for a change in the neighborhood; If a change occurs, restart at 1.. If the carrier waits longer than n seconds, 5. Search for the next safe point and use the A* algorithm to reach this safe point, if not possible, 4. Wait for a change in the neighborhood, and if a change occurs, resume at 1. A method of operating a distribution system as described in the previous embodiment, wherein the distance to the next intermediate destination location is determined by the Manhattan distance between its current location and the destination location, where n is a number between 1 and 10, in particular 3.

[0114] The neighborhood can be defined as an area having a radius of k logical positions around the location of the carrier 14 or the transfer module 24, 624 in which the carrier 214 is currently located, where K is in the range of 2 to 50, particularly 6 to 40, and more particularly 10 to 25.

[0115] In particular, each partial route is calculated to travel no more than 24 logical positions.

[0116] In a further embodiment, the controller 20 generates a waiting list of carriers that have been waiting for more than m seconds, where m is greater than or equal to 20 seconds. In particular, this list is generated for the entire transport layout. The waiting list is updated each time a carrier exceeds the waiting time m, and the carrier 14 is listed at the end of the list.

[0117] When a free path or safe point becomes available again in the vicinity, the carrier 14 in this vicinity that is highest on the list is moved next and a partial route for this carrier 14 is calculated as shown in FIG.

[0118] Carriers 14 carrying high priority objects 16 are always set to the top of the list or are arranged in the list according to the priority of the objects 16 .

[0119] In another embodiment of the method, logic fields next to the defective logic field are emptied of any carriers placed at possible safe points 701. Possible safe points 701 are cleared and carriers can still travel through these fields, although they can no longer stop there.

Claims

1. A method of operating a distribution system for moving a plurality of carriers on a transfer surface, the distribution system comprising: a plurality of carriers adapted to carry one or more items; a transfer surface adapted to support the carrier, logical positions defined on the transfer surface; drive means adapted to move the carrier on the transfer surface; a control device adapted to control the drive means; The method comprises: During initialization of the distribution system, the control device predefines a pattern of safety points on the transport surface from the logical positions, the safety points being logical positions selected taking into account the range of movement of carriers occupying the logical positions so that carriers can be positioned on the safety points and then moved away again; a step in which, after initialization of the distribution system, the control device calculates partial routes of the carrier so that the end position of each partial route is either one of the safety points or has a free path to one of the safety points that can be reached in the next partial route, and if all of the safety points ahead are occupied, the carrier cannot move because it cannot reach the safety point or cannot reach it in the next move.

2. 2. The method of operating a distribution system of claim 1, wherein handover locations are defined on the transport surface for handing over the article, and the safety points are predefined such that a free path exists along the safety points between the handover locations.

3. 3. The method of operating a distribution system of claim 2, wherein the controller defines directions of movement as straight lines on the transfer surface during initialization of the distribution system, and the calculated route uses these directions of movement.

4. 3. The method of operating a distribution system of claim 2, wherein the controller defines directions of movement as straight lines on the transfer surface in at least two directions during initialization of the distribution system, and the calculated route uses these directions of movement.

5. 3. The method of operating a distribution system of claim 2, wherein the control device defines, during initialization of the distribution system, directions of movement as straight lines on the transfer surface in at least two directions perpendicular to each other, and the calculated route uses these directions of movement.

6. A method of operating a distribution system described in any one of claims 1 to 5, wherein the transport surface consists of tile elements connected to each other, and during initialization of the distribution system, a control system maps the layout of the transport surface by identifying boundaries by creating vectors for each edge of the tile elements, cancels all vectors based on adjacent vectors of adjacent tile elements, and combines remaining vectors that are adjacent and have the same direction.

7. 7. The method of operating a distribution system of claim 6, wherein during mapping of the distribution system, inner corners are identified by identifying changes in direction of adjacent remaining vectors, calculating their vector products, and mapping inner or outer corners to negative or positive vector products, respectively, depending on the initial direction of the vectors.

8. The method of operating a distribution system of claim 7, wherein the adjacent inside corners are determined during initialization.

9. 9. The method of operating a distribution system of claim 8, wherein the route of the carrier is calculated to maintain a distance to the inside corner while the carrier passes the inside corner.

10. 10. The method of operating a distribution system of claim 9, wherein a Manhattan distance between adjacent inside corners is determined.

11. 11. The method of operating a distribution system of claim 10, wherein a node network is generated that indicates paths and Manhattan distances between at least two adjacent inside corners.

12. 11. The method of operating a distribution system of claim 10, wherein a node network is generated showing paths and Manhattan distances between all adjacent inside corners.

13. The partial route of the carrier is 1. Follow a straight line, if not possible, 2. Follow the L-shaped route, if not possible, 3. Determine the next intermediate destination location using the A* algorithm, if not possible:

4. If the carrier remains at the current position for less than n seconds, wait for a change in the neighborhood; 4.

1. If a change occurs, restart at 1.

5. If the carrier waits longer than n seconds, 5.

1. Search for the next safe point and use the A* algorithm to reach this safe point, if not possible, 5.

2. Wait for a change in the neighborhood, and if a change occurs, resume at 1.

13. A method of operating a distribution system as claimed in claim 11 or 12, wherein the distance to the next intermediate destination location is determined by the Manhattan distance between the current location and the destination location, where n is a number from 1 to 10.

14. 14. The method of operating a distribution system of claim 13, wherein n is 3.

15. 15. A method of operating a distribution system as claimed in claim 13 or 14, wherein the determined route is reserved for said carrier until said carrier reaches its intermediate or final destination location.

16. 16. The method of operating a distribution system of claim 15, wherein for each carrier, the next intermediate destination location is determined in succession until a final destination location is reached.

17. 17. A method of operating a distribution system according to any one of claims 1 to 16, wherein a position determination system determines the position of the carrier on the transport surface and sends a position update message to the control device, which triggers the release of reserved logical positions that the carrier has already passed through in its current movement.

18. 18. A method of operating a distribution system according to any one of claims 1 to 17, wherein the carrier does not travel longer than m logical positions, where m is an integer between 3 and 50.

19. 20. The method of operating a distribution system of claim 18, wherein m is an integer between 10 and 30.

20. 20. The method of operating a distribution system of claim 18, wherein m is 24.

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