METHOD FOR EFFICIENT ROUTE PLANNING OF VEHICLES IN A SORTING SYSTEM

Description

[0001] The present invention relates to a sorting system, a sorting system control device, and methods for operating the same. The present invention particularly relates to a method for efficient route planning of vehicles in the sorting system.

[0002] In vehicle-based sorting systems, such as those in US2020 / 293063 A1, the transport performance must be provided by a large number of vehicles traveling at high speed and acceleration in a confined space to ensure sufficient overall system performance. Each individual vehicle picks up a load at a source at low speed, travels along a precalculated trajectory with high acceleration and braking behavior close to maximum speed to the drop-off point, and delivers the load there at low speed.

[0003] In a sorting system, several different types of obstructions can occur, especially in multi-robot systems that are used in the Fig. 4a bis 4f are shown. Fig. 4a shows an exemplary scenario in which two vehicles 120 1 and 120 2 move towards each other along a trajectory 140, for example along opposite directions of travel, which can lead to a so-called head-to-head collision.

[0004] Fig. 4b shows a scenario in which the vehicles 120 1 and 120 2 are traveling along the same direction on the same trajectory 140, but a vehicle 120 1 traveling behind the vehicle 120 2 is traveling at a speed V 1 that is greater than the speed V 2 , so that catching up with the vehicle 120 2 can result in a so-called head-to-tail collision. Fig. 4a und 4b show possible scenarios for collisions.

[0005] Fig. 4c shows a scenario in which vehicles 120 1 and 120 2 or 120 3 and 120 4 , which are traveling on different trajectories 140 1 and 140 2 , but the trajectories combine at a meeting point 160 to form a trajectory 140 g , so that a traffic jam can occur during sorting, for example because the meeting point 160 can only be used by one vehicle at a time, but a larger number arrive from trajectories 140 1 and 140 2 . This can lead to queues.

[0006] Fig. 4d shows a scenario in which vehicles 120 1 and 120 2 on trajectory 140 1 are to merge onto trajectory 140 2, on which vehicles 120 3 to 120 6 are already traveling, so that there is insufficient space for the merge. Based on right-of-way rules, it may happen that the vehicles on trajectory 140 1 have to wait until a flow of vehicles from trajectory 140 2 has sufficient distance before meeting point 160 or comes to a standstill. Fig. 4b thus indicates a partial or local vehicle standstill, a so-called livelock.

[0007] The Fig. 4e und 4f In contrast, show a non-local deadlock in Fig. 4e or a local total standstill in Fig. 4f .

[0008] Each of these scenarios requires resolution of the problem or avoidance of the scenario in order to maintain smooth operations.

[0009] In traditional sorting systems with conveyor belts or tilting trays, goods are transported at high speed on the conveyor belt or tilting trays. Guardrails prevent them from falling during curves. At technically complex infeeds, the goods are accelerated to the main speed of the sorting circuit and brought to a free location or tray. Discharge at the drop-off point is achieved by simply wiping or tilting the tray. Thanks to the fixed circuit and targeted infeed and outfeed, there are no interferences between the goods being transported.

[0010] Existing sorting systems with autonomous vehicles and free movement operate at low speeds of, for example, a maximum of three meters per second and with large safety distances. Alternatively, the vehicles travel on fixed routes with block-based reservations or on a checkerboard grid, which significantly reduces the algorithmic complexity of coordinating many vehicles. Almost all existing algorithms are based on modifications of the A* algorithm, which enable the simultaneous optimization of paths for multiple vehicles. This problem is also known as "multi-agent pathfinding," i.e., pathfinding for multiple participants.

[0011] There is therefore a need for flexible sorting systems that can transport goods at high speeds.

[0012] An object of the present invention is therefore to provide a sorting system, a sorting system control device, methods for operating the same and computer program products for implementing such methods, which enable goods to be moved in a sorting system at high speeds on flexible routes.

[0013] This problem is solved by the subject matter of the independent patent claims.

[0014] A core idea of ​​the present invention is the recognition that a pre-determination of trajectories between starting points and end points, each with an associated speed profile or speed specification, can be subsequently modified as needed to avoid potential collisions between multiple trajectories and to adapt the travel order. This makes it possible to utilize the different trajectories to achieve a high degree of flexibility in the sorting system and also to implement high speeds, since the computational effort for adapting the travel orders is low and can, for example, be limited to vehicles that are not yet moving, allowing vehicles that are moving to travel at high speed.

[0015] According to one embodiment, a sorting system comprises a plurality of vehicles configured to move along trajectories in the sorting system. The sorting system comprises a calculation device configured to determine a third number of trajectories between a first number of starting points and a second number of end points, wherein each trajectory is assigned a speed specification for a vehicle along the trajectory. The sorting system comprises a coordination device configured to transmit travel orders to the plurality of vehicles, wherein each travel order comprises a trip from one of the starting points to one of the end points along one of the trajectories.The sorting system comprises a collision avoidance device configured to examine a trajectory for possible collisions with another vehicle of the sorting system for a new travel order in order to obtain collision information indicating a possible collision, so that the collision avoidance device changes the speed specification assigned to the trajectory based on the collision information in order to obtain a changed speed specification and to avoid the possible collision. The sorting system is configured to transmit the new travel order, comprising an instruction that includes the trajectory and the changed speed specification, to the vehicle or the vehicle control system.

[0016] According to one embodiment, the calculation device is configured to determine a plurality of trajectory candidates between a starting point of the first number of starting points and an end point of the second number of end points, and the coordination device is configured to select one of the trajectory candidates as the trajectory for the new travel order. This enables a high degree of flexibility, since several possible paths are considered.

[0017] According to one embodiment, the calculation device is configured to determine the plurality of trajectory candidates taking into account a trajectory curvature. The calculation device is configured to determine a predefined number of trajectory candidates with minimal curvature and / or a number of trajectory candidates that have trajectory curvatures of at most a predefined curvature threshold. This makes it possible to keep the computational effort within predetermined limits.

[0018] According to one embodiment, the calculation device is configured to calculate the trajectory based on splines. This enables high calculation efficiency.

[0019] According to one embodiment, the calculation device is configured to determine a distance for control points between the starting point and the end point of the trajectory, which distance indicates the distance between neighboring trajectory candidates. This allows the calculation of trajectories that cannot be realized later to be avoided, or additional safety aspects can be taken into account.

[0020] According to one embodiment, the calculation device is configured to calculate the speed specification cinema-dynamically as a time-optimized speed specification. This makes it possible, on the one hand, to utilize high to maximum vehicle speeds while, at the same time, limiting the speed specification adjustment to a reduction of the high speed because it enables low computational effort.

[0021] According to one embodiment, the trajectory is configured to comprise a number of trajectory sections. The calculation device is configured to calculate a section speed specification for each trajectory section and to calculate the speed specification based on a combination of the section speed specifications. This enables a time-variant speed profile.

[0022] According to one embodiment, the calculation device is configured to calculate a maximum speed for each trajectory section based on a curvature of the trajectory section and a maximum acceleration of a vehicle, which speed may be associated with the respective vehicle type. Based on the maximum speed, a speed specification at the beginning of the trajectory section, and a speed specification at one end of the trajectory section, the section speed specification can be calculated by the calculation device. This enables effective utilization of possible maximum accelerations to achieve the highest possible, even maximum, speed on the section.

[0023] According to one embodiment, the coordination device is configured to select the trajectory for the new travel order from a plurality of trajectory candidates. The plurality of trajectory candidates takes into account trajectories already assigned to vehicles in existing travel orders. This enables efficient avoidance of blockages by avoiding trajectory overload, for example, taking into account vehicles that are already on the move or are about to depart.

[0024] According to one embodiment, the collision avoidance device is configured not to adjust the speed specification for already assigned trajectories of existing travel orders. This allows for a significant reduction in possible calculations, allowing results to be obtained quickly.

[0025] According to one embodiment, the coordination device is configured to consider vehicles on already assigned trajectories as potential obstacles for the trajectory selection. This allows for a reduction in the selection space for possible further decisions and thus lower computational costs.

[0026] According to one embodiment, the collision avoidance device is configured to obtain a plurality of corresponding trajectories for a plurality of new travel orders as a respective time-optimal speed specification for traversing the trajectory, and to determine possible collisions between the vehicles for the plurality of new trajectories, and to avoid the possible collisions within the new travel orders by adjusting at least one of the speed specifications. This enables the coordination of new travel orders with one another so that they can take each other into account.

[0027] According to one embodiment, time-optimized, collision-free travel orders are obtained globally for the majority of vehicles by changing the speed specifications. This not only optimizes individual vehicles, but also optimizes the overall throughput of the sorting system.

[0028] According to one embodiment, the collision avoidance device is configured to determine for which of the vehicles involved in the potential collision the speed specification needs to be adjusted. Such a balancing of factors makes it possible to maintain the overall throughput of the sorting system at a high level, even if individual vehicles are slowed down significantly.

[0029] According to one embodiment, the collision avoidance device is configured to use at least one of a predefined priority, an exhaustion method, and a combination thereof to determine for which of the vehicles involved in the potential collision the speed specification should be adjusted. This enables the optimization of the overall throughput based on appropriate criteria, for example, since even with a desired high overall throughput, there may be transport orders that require priority.

[0030] According to one embodiment, the collision avoidance device is configured to determine potential collisions for a plurality of new travel orders and to coordinate the speed specifications with the speed profiles assigned to the travel orders by the coordination device. Previously transmitted speed profiles remain unchanged. This enables the adaptation of new trips to existing or coordinated trips.

[0031] According to one embodiment, the collision avoidance device is designed to treat already changed speed specifications that have already been determined on vehicles as unchangeable until the travel order on the assigned trajectory is completed.

[0032] According to one embodiment, the starting point and / or an end point is a fixed area in the sorting system. Alternatively or additionally, one of the starting points and / or one of the end points can be based on the trajectory and thus be variable across different trajectories. This enables a high degree of planning flexibility.

[0033] According to one embodiment, the majority of vehicles are holonomic vehicles or at least include such vehicles. Holonomic vehicles are particularly suitable for the flexible trajectories and high speeds possible with the described embodiments.

[0034] According to one embodiment, the coordination device is configured to transmit the new travel order as a joint travel order to a vehicle convoy or vehicle formation for a joint journey of several vehicles along the trajectory. This also enables the transport of large and / or heavy objects.

[0035] A further embodiment of the present invention provides a sorting system control device. This device comprises, for example, the coordination device and the collision avoidance device described herein, as well as an interface for outputting the new travel order.

[0036] Further embodiments relate to methods for operating a sorting system or a sorting system control device.

[0037] Further advantageous embodiments are the subject of dependent patent claims.

[0038] Particularly preferred embodiments are explained in more detail below with reference to the accompanying drawings. In the drawings: Fig. 1 shows a schematic block diagram of a sorting system according to an embodiment; Fig. 2 shows a schematic representation of a part of a sorting system according to an embodiment, in which exemplary regions are shown that can be used as a starting point and / or end point for a trajectory; Figs. 3a-c show schematic graphs for explaining a determination of a speed specification for a trajectory according to an embodiment; and Figs. 4a-f show schematic representations of known obstructions in a sorting system.

[0039] Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally identical or equivalent elements, objects and / or structures in the different figures are provided with the same reference numerals, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.

[0040] The embodiments described below are described in conjunction with numerous details. However, embodiments may also be implemented without these detailed features. Furthermore, for clarity, embodiments are described using block diagrams instead of detailed illustrations. Furthermore, details and / or features of individual embodiments may be readily combined with one another, unless explicitly described otherwise.

[0041] Embodiments described herein relate to the movement of vehicles along trajectories. In some of the embodiments described herein, such a trajectory is described from a starting point to an end point, such that, for example, a transport item can be picked up at the starting point and delivered at an end point. However, the embodiments described herein are not limited to this. Rather, a starting point or end point can also be a differently designed point or area in the sorting system, for example a path at which a change takes place in another spatial area of ​​the sorting system, for example an exit or entrance of a transport item hall or warehouse.The starting points or end points or starting areas or end areas can also be considered dynamically and, for example, be a start or an end of a partial trajectory on a path from a transport goods pick-up point to a transport goods drop-off point, so that such starting points or end points can also be distributed arbitrarily in space and along trajectories.

[0042] Embodiments and the core inventive idea are based on considerations of using kinodynamic path planning in vehicle-based sorting systems. This means that in some of the embodiments described herein, kinodynamic path planning is used to calculate trajectories and speeds. Compared to conventional methods, kinodynamic path planning not only determines a collision-free path through an environment with obstacles, which represents a kinematic boundary condition, but also takes into account the physically maximum possible speeds and accelerations along this path, i.e., dynamic boundary conditions. This is intended, in particular, to solve the problem of determining which combination of speed and trajectory results in the minimum possible travel time at which the vehicle just does not swerve uncontrollably.Cinema dynamic path planning includes a planning component, predictive path planning, which can be performed offline, and a reactive component, which can be performed online during operation to enable control of the stability of the vehicle's movement during execution. Overall, it places high demands on the performance of the algorithms and on-board computers used, because the determined route must be collision-free and the vehicle's trajectory along the route must satisfy the dynamic constraints. Furthermore, the determined route should be optimal, for example, provide the shortest route to the destination. One requirement is that such calculations be provided reliably and in real time.

[0043] Embodiments are aimed at solving the technical problem of coordinating many vehicles with their complex cinema-dynamic path planning, i.e. trajectories and speed profiles, in such a way that no obstructions arise between the vehicles, as is the case in connection with the Fig. 4a bis 4f described, while at the same time achieving the required logistical performance in terms of packages transported per hour. An additional challenge is presented by convoys of several vehicles traveling in formation, for example, to jointly complete a larger transport order or the transport of bulky goods.

[0044] Fig. 1 shows a schematic block diagram of a sorting system 10 according to an embodiment. The sorting system 10 has a plurality of vehicles 12 1 and 12 2 that are configured to move in the sorting system 10 along trajectories 14 1 and 14 2. The number of vehicles 12 1 and 12 2 is arbitrary and can be two or more, five or more, ten or more, twenty or more, or even one hundred or more. The number of trajectories 14 is independent of this, even if in Fig. 1 Only two trajectories 14 1 and 14 2 are shown. These are chosen by way of example such that the trajectory 14 1 connects a starting point 16 1 and an end point 18 2 to each other and describes a route between the points 16 1 and 18 2. Similarly, the trajectory 14 2 describes a path or a route between a starting point 16 2 and an end point 18 1. The starting points and end points can be arranged arbitrarily beside one another or distributed from one another in the sorting system. Further possible trajectories are, for example, a connection between the starting point 16 2 and the end point 18 2 and / or between the starting point 16 1 and the end point 18 1.However, it is not necessary that a trajectory be provided in the sorting system 10 between each starting point and each end point, nor is it necessary that only one trajectory between a specific pair from a starting point to an end point is possible; rather, a plurality or multiplicity of trajectory candidates may be possible, which will be discussed in detail later.

[0045] Each trajectory 14 1 and 14 2 can be assigned a speed specification 22 1 or 22 2 , which can also be referred to as a speed profile. The speed specification 22 1 and / or 22 2 can have a specification for a speed v, which can be constant or variable over a path x of the trajectory 14 1 or 14 2 . The speed specification 22 1 and 22 2 can include an instruction to the vehicle regarding a speed to be set, reached, or traveled along the trajectory or a section thereof.

[0046] The sorting system 10 comprises a calculation device 24 configured to calculate a number of trajectories 14 between the starting points 16 and the end points 18. Each trajectory is assigned a speed specification 22 for a vehicle 12 of the sorting system along the trajectory 14. It is possible to use different vehicles in the sorting system 10 for the use of different vehicles, for example, different vehicles with different speeds, transport volume, transport weight, energy consumption, or the like, so that different speed specifications can exist for the same route depending on the different vehicles, particularly with regard to the optional configuration as cinema-dynamic route planning.

[0047] The sorting system 10 further comprises a sorting system control device 26, which may have a coordination device 28 and a collision avoidance device 32. The coordination device 28 and the collision avoidance device 32 may also be implemented independently of the sorting system control device 26, for example, as individual components and / or as components of vehicles. Alternatively or additionally, the calculation device 24 may also be part of the sorting system control device, although this should not exclude embodiments in which the information about the trajectories and / or speed specifications is obtained from a possibly remotely located computing system. This may include both computing units of a possibly remotely located service provider and distributed computing services, for example, so-called cloud services.Even if a calculation of the trajectory is carried out in part on external computing units, embodiments nevertheless relate to sorting systems with a calculation device that adapts the corresponding calculation results to the existing sorting system.

[0048] The coordination device 28 is designed to transmit travel orders 34 1 and 34 2 to the vehicles 12 1 and 12 2 . Each of the travel orders 34 1 and 34 2 describes, defines, or comprises a journey from one of the starting points 16 i to one of the end points 18 j along one of the trajectories 14 k . As part of the travel orders 34, which can also be referred to as transport orders, the speed specifications 22 1 and 22 2 can also be transmitted to the vehicles. Alternatively, information designed to identify information pre-stored in the vehicles can also be transmitted to the vehicles, so that the route and / or the speed profile are already pre-stored on the vehicles and can be selected in the vehicles using the travel orders 34, for example, using an identifier, an identifier, or another designator.Alternatively or additionally, the vehicles can also have advance information about available routes, so that the travel order 34 can be understood as a selection of a possible trip or a trajectory from those known in advance. A speed specification for the trip can already be stored in a memory of the vehicle, for example, in the same memory in which the possible trips are stored. Alternatively, the travel order, i.e., the trajectory and / or the speed specification, can be transmitted to the vehicle, for example, using radio technology.

[0049] The collision avoidance device 32 can be implemented at least partially as part of a sorting system controller and / or at least partially in one or more vehicles, for example, comprising a processor, a microcontroller, a field-programmable gate array (FPGA), or the like. When implemented at least partially in a vehicle, each of the vehicles in question can, for example, be configured to avoid a collision for its own travel order and, if necessary, also to perform corresponding investigations and / or provide instructions for other vehicles.

[0050] The collision avoidance device 32 is configured to examine, for a new driving order, that is to say, an added driving order, the trajectory of this driving order for possible collisions with another vehicle of the sorting system. The other vehicle can be a vehicle for which a driving order or a driving plan is also carried out, or it can be a vehicle that is already on the way. For example, the vehicle 12 1 may already have a completed plan of its trajectory and the driving order 34 2 can be considered as a new driving order in this scenario. The collision avoidance device is configured to obtain collision information indicating a possible collision of the driving order 34 2 with the driving order 34 1, where any possible type of mutual blocking is understood as a collision for this purpose, examples of which are given in the Fig. 4a bis 4f are written.

[0051] The collision avoidance device 32 is designed to change the speed specification 22 2 assigned to the trajectory of the new travel task 34 2 based on the collision information in order to obtain a changed speed specification 22' 2 in order to thus avoid the possible collision. A change in the speed specification can, for example, mean an at least temporary increase or decrease in the speed specification 22 2 . In the case of cinematic dynamic path planning, where an attempt is made to implement the maximum accelerations in each case, the change can mean a reduction in the acceleration and / or speed. This makes it clear that the speed specification 22 is not necessarily directed at specifying an actual speed, but can also refer to other parameters, such as acceleration, energy to be provided to the drive, or other manipulated variables.

[0052] In any case, embodiments provide that the collision avoidance device 32, alternatively or in addition to adapting the speed specification 22 2, adapts the speed specification 22 1 by a modified speed specification 22' 1. In principle, it is possible to avoid a detected collision, which is represented by the collision information, by changing one or more speed specifications of vehicles involved in the collision.

[0053] The sorting system, such as the collision avoidance device, is designed to transmit the new travel order 34 2 comprising an instruction that includes the trajectory, such as 14 2 , and the changed speed specification 22' 2 , to the vehicle 12 2 or its control system or vehicle control system. For this purpose, wireless transmission technologies such as 5G, WLAN (Wireless Local Area Network) can be used, but possibly also wired or other transmission methods. Different configurations of the exemplary embodiments can be mentioned here regarding differences with regard to transmission to the vehicle or its control system, which are based, for example, on how and at which location the collision avoidance device 32 is implemented and / or which concept or strategy for collision avoidance or prioritization is implemented.

[0054] Often, the updated speed profiles can be transmitted remotely to the vehicle, for example, if the collision avoidance device 32 is implemented at a remote location. However, even if implemented in the vehicle, transmission can occur within the vehicle, i.e., to its control system, to the vehicle.

[0055] Although it is possible, for example, if the collision avoidance device 32 is implemented on the vehicles themselves and round-robin scheduling is used, which will be explained in more detail in connection with prioritization, and the lower-priority vehicle checks the corresponding collision and, furthermore, only two vehicles are involved in a collision, this step can also be omitted. However, since such knowledge is rarely available a priori, a check and / or transmission can still take place. In many or all other variants, it cannot be guaranteed that only exactly one vehicle requires a changed speed profile, especially when the exhaustion method is used as a prioritization strategy, and that this vehicle is still the checking vehicle.Therefore, within the framework of a separate implementation of the collision avoidance device 32 and the vehicle's control device, it is intended to provide a corresponding transmission to the vehicle / vehicle control system, even if this does not require a corresponding signal to come from outside the vehicle. Even if, for example, the collision avoidance device 32 is at least partially implemented in software running in the vehicle, this represents a separate software component from the control / motion device of the robot / vehicle, so that the information must also be "transmitted" here, even if the transmission then takes place within the vehicle, between these two software components.

[0056] It becomes clear from this that the sorting system 10 is designed to calculate the routes and speeds in advance and, only in the case of possible collisions, to avoid these collisions by ensuring that newly added driving orders do not cause any collisions by setting their speed specifications accordingly.Although this can also lead to embodiments in which a vehicle, once on the way, travels at a predefined speed until it delivers its cargo, for example, it is also possible to set the starting points 16 and / or the end points 18 in such a way that they are based, for example, on a certain time interval and / or on a certain route and a redetermination, possibly taking global optimization criteria into account, of the speed profiles for one or more or all vehicles that are already on the way takes place before they deliver their cargo, which can also be understood as meaning that several trajectories are traversed starting from a point in time at which the cargo is picked up to a point in time at which the cargo is dropped off.

[0057] It should also be noted that although the sorting system 10 makes a distinction between the start point and the end point of a trajectory, a corresponding point can be used both as a start point and as an end point, for example for different trajectories.

[0058] Reference is made below to the planning phase, during which the trajectories are determined. For example, the calculation device 24 can be configured to calculate a plurality of trajectory candidates between a starting point of a number of possible starting points and an end point of a possible number of end points.

[0059] Reference is made to the Fig. 2 , which is a schematic representation of a part of a sorting system 20 according to an embodiment. Regions 36 1 to 36 l are shown as examples, some, some, or all of which can be considered both as a starting point and as an end point for a trajectory.

[0060] The areas 36 can describe a stationary area in the sorting system as a starting point and / or end point or, alternatively, can be based on the trajectory. A total set of areas can also be constructed combinatorially, so that some areas are stationary and other areas are based on the trajectory, such as a beginning and / or end of a portion of an overall travel route, a hall entrance, a hall exit, or the like.

[0061] By way of example, several trajectory candidates 38 m,n are shown, where m describes a trajectory identifier, which in the present exemplary embodiment is 1 or 2, and n describes an indexing of the respective trajectory candidate within the trajectory or path connection to be selected. For example, the calculation device 24 can be designed to use the area 36 19 as the starting point and the area 36 31 as the end point for candidates 38 1,n, and to use the area 36 31 as the starting point and the area 36 1 as the end point for trajectory candidates 38 2,m. It should be noted at this point that the number n of trajectory candidates for different path areas is the same in the present example, but can also be different from one another and can be at least 2, at least 3, at least 5, at least 10, or at least 20 or more.

[0062] The coordination device 28 can be configured to select one of the trajectory candidates as the trajectory for the new travel order. This means that the coordination device can select one of several possible paths. For example, different candidates for a path of 38 m can make it possible to have several vehicles travel at short intervals, since they can then travel side by side rather than one behind the other.

[0063] The calculation device can be designed to calculate the plurality of trajectory candidates 38 m,n taking into account a trajectory curvature. The calculation device 24 can, for example, be designed to determine a predefined number of trajectory candidates that have a minimal curvature, optionally taking into account additional boundary conditions such as distances between the trajectories or the like. Determining a predetermined number of most suitable trajectory candidates can make it possible to have a certain degree of flexibility with regard to several different trajectory candidates, i.e., a certain number of options are always available. Alternatively or additionally, the calculation device 24 can be designed to determine a number of trajectory candidates that have trajectory curvatures of at most one predefined curvature threshold.This means that it is possible to determine all trajectory candidates that satisfy certain curvature boundary conditions, since excessive curvatures may potentially lead to low accelerations and / or low velocities. From this perspective, for example, a different number of trajectory candidates can be obtained for the path between the areas 36 31 and 36 1 than for the path between the areas 36 19 and 36 31 . Both criteria can also be easily combined with one another, so that, for example, a fixed number of trajectory candidates is calculated that satisfy a certain curvature condition. Other or additional boundary parameters, such as a specific path length, a distance to other objects, or the like, can also be taken into account.It should be noted that, with regard to curvature, the vehicle's maximum acceleration, i.e., its acceleration capability, can make a particularly important contribution. The maximum possible acceleration in relation to the curvature can be relevant to or determine the physical maximum possible speed along the path.

[0064] According to one embodiment, the calculation device is configured to calculate the trajectory based on splines. Optionally, the calculation device 24 can be configured to determine a distance 44 for control points between the starting point and the end point, for example, for adjacent vertices 42 1 and 42 2 , which distance indicates a distance between adjacent trajectory candidates. This distance does not necessarily have to be maintained across the entire trajectory and can, for example, be selected differently in the area of ​​the starting point and / or the end point, or can be omitted.

[0065] In principle, a high degree of freedom exists when determining the trajectory candidates. The trajectory candidates enable the available free space in the sorting system 10 to be utilized effectively or even maximally, so that, for example, several lanes can be formed in a wider aisle that can be driven in parallel. Furthermore, multiple candidates for connecting two areas also offer the possibility of switching to other candidates if a blockage or collision is detected.

[0066] For each of the candidates 38 m,n, a speed profile, ie, a speed target, can be calculated, for example in the form of a time-optimal speed profile. This is done using the Figuren 3a-c explained by example.

[0067] So in Fig. 3a a schematic graph is shown, where a total path length at location x 6 of one of the candidates is 38 m,n from Fig. 2 are divided into several trajectory sections, each having path lengths Δx 1 to Δx 6. Possibly but not necessarily, the trajectory sections Δx 1 to Δx 6 are equidistant, i.e., they cover the same path length.

[0068] For each of the trajectory sections Δx 1 to Δx 6 , the number of which can be at least 1, at least 2, at least 3, at least 5, at least 10 or more, the calculation device can calculate a section speed specification in order to calculate the speed specification 22 based on a combination of the section speed specifications. Furthermore, a maximum speed is calculated for each of the sections, as shown in Fig. 3a is shown. Speeds V1 to V7 correspond to the maximum speeds at the respective waypoints. For this purpose, the curvatures on the respective sections are considered or taken into account, and the maximum speeds V1 to V7 are calculated from these.

[0069] In other words, Fig. 3a a determination of the maximum speed at the sections of the trajectory curve.

[0070] In Fig. 3b A further step for determining the speed specifications is shown. For this purpose, the sections Δx 1 to Δx 6 are iterated sequentially, for example starting from distance 0 to the end x 6, for example taking into account the acceleration of the vehicles. This results in deviations, for example at the start (x = 0) of the journey, in that the acceleration, shown as a straight line 46, is plotted based on the actual speed. At the start of the path (x = 0), the speed is 0, for example, but this is not mandatory for other embodiments. At other starts and distances, the speed can also be different from 0. The gradient of the straight line 46 determines which maximum speed V2' can actually be reached at location x1, so that a correction is made here, just as for the speed V3' at x 2 .Furthermore, based on the gradient of the constant acceleration 46, a correction is made at x 5 , so that an adjusted speed V 6 ' is obtained here. It is understood that although the acceleration 46 can be represented as a straight line, other vehicles may have different acceleration profiles, such as curved paths.

[0071] In other words, the sections are iterated from start to finish and the maximum speed is calculated based on the acceleration. Fig. 3b a calculation of the maximum speed that can actually be achieved.

[0072] In Fig. 3c It also shows how negative acceleration and deceleration are taken into account in order to reach the target speed, 0 in this example, at x 6, for example. In other examples, the final speed may be non-zero, for example when driving from one area to another and a new trajectory begins in the new area.

[0073] For example, starting from x 6 to x 0, taking into account a potentially maximum negative acceleration 48, the braking capability can be taken into account by plotting corresponding exemplary but vehicle-dependent straight lines, which also involves an iteration. This allows the speed specification 22 to be determined combinatorially in the individual sections and for the trajectory as a whole.

[0074] In other words, at the end the sections are run through backwards, so that the maximum achievable speed also takes into account the braking maneuvers, as in Fig. 3c As a result, for each trajectory section, the calculation device uses the curvature of the trajectory section and the maximum acceleration of the vehicle, both as positive and negative acceleration, to calculate a maximum speed. Based on maximum speeds, a speed specification at the beginning of the trajectory section, Fig. 3b , and a speed specification at one end of the trajectory section, Fig. 3c , the section speed target can be calculated by subtracting the maximum achievable or desired speed from the original target from Fig. 3a is adjusted. The Fig. 3c shows a calculation of the maximum achievable speed taking into account braking maneuvers.

[0075] According to one embodiment, the calculation device can be configured to calculate the speed specification cinema-dynamically as a time-optimized speed specification. This means that for each trajectory, the speed specification is determined such that the shortest possible time is required to traverse the trajectory.

[0076] According to one embodiment, the coordination device is configured to select the trajectory for the new travel order from a plurality of trajectory candidates, for example, one of the n candidates for a specific route. The plurality of trajectory candidates can take into account trajectories already assigned to vehicles in existing travel orders. This means that vehicles that are about to depart or are already en route can already occupy trajectory candidates, which is taken into account by the coordination device.

[0077] According to one embodiment, the collision avoidance device 32 is designed not to adapt the speed specification for the already assigned trajectories of existing travel orders, so that, for example, a reduction in the speed as a result of the Fig. 3c The speed specification received is only used for the speed specifications to be newly added or updated in transfer sections.

[0078] According to one embodiment, the coordination device 28 is configured to consider vehicles on already assigned trajectories for selecting the trajectory as a potential obstacle. These can be taken into account by selecting corresponding trajectories that pass the potentially moving obstacle and / or by adjusting the speed specification.

[0079] According to one exemplary embodiment, the collision avoidance device is designed to obtain a plurality of corresponding trajectories as a time-optimized speed specification for traversing the trajectory for a plurality of new travel orders, i.e., multiple vehicles are to be supplied with travel orders. The collision avoidance device 32 can determine possible collisions between the vehicles within the new travel orders for the plurality of new trajectories and avoid the possible collisions within the new travel orders by adjusting at least one of the speed specifications. This enables mutual consideration of the travel orders while existing travel orders can remain unaffected. At this point, the goal is not only to control a single vehicle in a time-optimized manner and simply avoid collisions with the remaining vehicles.Rather, the objective of the embodiments described herein is to optimize the time for all vehicles while taking into account the constraint of collision-free operation. Even if new speed profiles / orders are adjusted relative to existing orders, the existing orders can still be adjusted in a subsequent iteration, such as a subsequent route segment or a subsequent time segment, when an updated calculation is performed. With reference to FIG. Figuren 3b and 3c This is possible, for example, for trajectories where the initial velocity and / or the final velocity is not equal to 0.

[0080] According to one embodiment, a set of time-optimized collision-free travel orders is thus obtained globally for the majority of vehicles by means of changed speed specifications.

[0081] The collision avoidance device 32 can be configured to determine for which of the vehicles involved in the potential collision the speed limit needs to be adjusted. In this case, with a new travel order, the speed limit can be adjusted for one of the two vehicles involved or for both of the vehicles involved, for example, reduced in sections. This is also possible without restrictions for a number of more than two vehicles that would be involved in a potential collision.

[0082] The collision avoidance device 32 can be configured to implement at least one predefined priority, an exhaustive search method, or a combination of the two. For example, a priority can take into account the priority of the goods and / or the priority can be assigned to the vehicle. This enables a fixed ranking or sequence so that, based on the sequence, it is always clear which vehicle's travel order requires an adjustment. This information can be known to the vehicles and is known at least to the central coordination point, the collision avoidance device. An example of such a predefined prioritization is so-called round-robin scheduling.

[0083] According to one embodiment, the collision avoidance device is designed to determine possible collisions for a plurality of new travel orders and to coordinate the speed specifications of the speed profiles assigned to the travel orders by the coordination device, wherein optionally already transmitted speed profiles or adjusted speed profiles can remain unchanged.

[0084] According to one embodiment, the collision avoidance device 32 is configured to treat previously changed speed specifications as unchangeable until the travel task for the assigned trajectory is completed. In some embodiments, this may also refer only to the partial section of the overall route to be traveled.

[0085] According to one exemplary embodiment, the coordination device 28 is configured to determine the new travel order as a joint travel order for a vehicle convoy or vehicle formation for a joint journey along the trajectory, for example, for particularly heavy goods and / or particularly bulky goods. The trajectory can be selected such that vehicles in the formation are arranged offset from the trajectory based on the formation, for example, one vehicle slightly to the left and one vehicle slightly to the right, or that vehicles move along or parallel to the trajectory at a constant distance from one another.

[0086] The embodiments described herein are particularly suitable for holonomic vehicles whose drive systems include, for example, so-called "omni-wheels." In particular, the embodiments described herein provide significant advantages when combined with a calculation of the speed specification as a cinema-dynamic calculation to obtain time-optimized speed specifications.

[0087] With reference again to the Fig. 1 Embodiments also provide for the implementation of a sorting system control device, which, for example, comprises a coordination device, such as coordination device 28, which is configured to transmit travel orders to a plurality of vehicles, wherein each travel order comprises a journey from a starting point to an end point along a respective trajectory. Each trajectory is assigned a speed specification for a vehicle along the trajectory.Furthermore, the sorting system control device 26 comprises a collision avoidance device, such as the collision avoidance device 32, which is designed to examine an associated trajectory for a new travel order for possible collisions with a travel order, to obtain collision information indicating a possible collision, and to change the speed specification assigned to the trajectory based on the collision information in order to obtain a changed speed specification in order to avoid the possible collision. The sorting system control device comprises an interface for outputting the new travel order comprising an instruction that includes the trajectory and the changed speed specification.This means that the sorting system control device 26 can also be implemented or delivered independently of other components of the sorting system 10 and only later combined to form an overall system.

[0088] According to one embodiment, the sorting system control device 26 comprises a calculation device, such as the calculation device 24, which is designed to determine a third number of trajectories between a first number of starting points and a second number of end points, such as a plurality of trajectory candidates or only one trajectory, wherein the coordination device is designed to assign travel orders to the trajectories.

[0089] The considerations regarding the exemplary embodiments described herein will be explained again in other terms with reference to a specific exemplary embodiment. As a background for these explanations, the following conditions are assumed for the vehicles described herein, which can also be referred to as LoadRunners, and the respective application location: The vehicles, i.e., the Load Runners, are capable of high speeds and high accelerations. For example, the vehicles can reach top speeds of 10 m per second and more and exhibit accelerations of 4 to 5 m / s 2 or more. This has the disadvantage that these vehicles cannot, or can only react with difficulty, to dynamically occurring obstacles, such as a person walking across the area or roadway, since a braking distance of approximately 10 to 12 m or more can occur at maximum speed. This means that the vehicles cannot easily be operated reactively and with "swarm heuristics," but rather work with pre-planned trajectories. By using omni-wheels, a Load Runner is a so-called "holonomic robot." This means that the number of controllable degrees of freedom is equal to the total number of degrees of freedom available in the system.A holonomic robot can be understood as a device that is capable of traversing any trajectory in the so-called "configuration space" (i.e., effectively the space formed by the three degrees of freedom with the positions X, Y, and rotation), as long as the boundary condition of acceleration is met. In the case of a flying device, the z-component can also be considered. In contrast, there are vehicles such as a car, which are not able to drive sideways into a parking space. Here, relatively complex trajectories must be selected to move the vehicle 2 m sideways, for example, because the car only has two controllable degrees of freedom.For this purpose, it is assumed that systems of vehicles traveling on the ground have a total of three degrees of freedom, two for the position X and Y and one for rotation. In order to use vehicles in a sorting system, it is important, among other things, that the trajectories between the feed points, i.e. the location where a new parcel is picked up, and the end points are optimal. As a rule, optimal trajectories from and to arbitrary points in space are not required, since only the sorting circuit is important and can specify the points. In addition, it is possible to provide a large free travel area in the layout of the sorting system. This point can be of particular importance because it eliminates the major disadvantage that the trajectories have to be statically pre-calculated for a certain time according to exemplary embodiments.One of the core ideas of the solution method is that both of these conditions are utilized and the multi-agent pathfinding problem, which is fundamentally very difficult to solve, especially with kinodynamic path planning, is somewhat alleviated by placing the path planning according to kinodynamic boundary conditions at the beginning, for example by the calculation device and the coordination device, and the actual collision avoidance of the vehicles is realized via the speed profiles along these paths, for example by the collision avoidance device.

[0090] A method according to the invention can be fundamentally divided into the following three steps: 1. For a period of time T, all paths that can be used in the next steps are determined. For a sorting scenario, this means, specifically, the paths from all sources used in the period T to all sinks used in the period T, including the return of the vehicles to, for example, a charging station or a buffer zone. Typically, several candidates for a connection can be generated; see the explanations in Fig. 2 in order to offer more alternative routes. The time period T can be comparatively long and, for example, at least 1 minute, at least 5 minutes, or at least 10 minutes. 2. The allocation of transport orders to the vehicles. This determines which vehicle has to travel "from where to where." Each vehicle checks all available candidates for its transport order. The selection of a trajectory candidate can thus be implemented centrally or decentrally, which means that the sorting system control device 26 or the coordination device 28 can also be implemented locally in a vehicle. In such a case, it can report the selection made back to the sorting system control device or also carry out collision avoidance. 3. Collision avoidance by adapting the speed profiles with possible collision candidates. This step preferably takes place before the vehicle has started moving orthe current trajectory begins. .

[0091] In the first step, determining trajectories, several path candidates 38 m,n are calculated for each source / sink combination used. These path candidates have the smallest possible curvature so that the highest possible accelerations and associated velocities can be achieved. For example, to stay in lane on a curved path, the centrifugal force must be counteracted. This means that the vehicle uses part of its maximum possible acceleration only to stay in lane and not to accelerate along the path. For maximum acceleration along the path, all paths with the smallest possible curvature are therefore desirable or preferred. When generating the paths, splines are used, for example, where the control points at the start and end are always fixed.For the checkpoints between start and end, an interval is defined depending on the length, which determines how far apart the checkpoints of the individual candidates should be from each other, for example by the distance 44. This ensures that necessary points at pick-up and drop-off points are always passed through exactly and that the free space in the open area is used evenly or according to other specifications, as is the case, for example, in . Fig. 2 is shown.

[0092] For each candidate, a time-optimal velocity profile can be calculated. The trajectory sections are divided equidistantly, and the curvature and resulting maximum velocity are calculated for each section, see Fig. 3a . The sections are then iterated from start to finish and the maximum speed is calculated based on the acceleration, see Fig. 3b . The sections are then run through backwards so that the maximum achievable speed also takes the braking maneuvers into account, see Fig. 3c .

[0093] Furthermore, transport orders are assigned to the vehicles. This determines which vehicle has to travel from where to where. Each vehicle checks all available or selected candidates for its transport order.

[0094] In the second step, the transport orders are assigned to the available vehicles, thereby determining which journey candidates are suitable for the vehicle. It should be noted that of all transport orders and associated trajectories, a portion is always fixed, i.e., unchangeable, while another portion is in the planning stage. This means, for example, that the trajectories that are either currently being traveled by a vehicle or are about to start have a fixed speed profile that cannot be changed by the collision avoidance (see point 3) of the other participants. This results, on the one hand, from the long braking distances, but also from the communication and processing time required to calculate the optimal profiles. In the current step, these vehicles are viewed as static obstacles and taken into account when selecting a path candidate.For the current task, a path is chosen that contains as few obstacles as possible.

[0095] In the third step, which is carried out after the second step, the speed profiles for the paths are determined, with each vehicle initially starting with a time-optimal profile. Since the paths were planned as time-optimal trajectories in step 1, it is always possible to travel through them at the maximum possible speed without deviating from the path. In this embodiment, collision avoidance simply slows the vehicles down, not speeds them up. This ensures that the paths can always be traveled precisely, since lower speeds also reduce the centrifugal forces that influence acceleration. First, all collisions that could occur with the current speed profiles are determined. Since all routes are known in advance through step 1, it is known for each vehicle which vehicles it could theoretically collide with.This provides enormous savings in computing time, as the scenarios to be considered can be limited to these. Collisions are avoided by a vehicle intelligently adjusting its speed profile.

[0096] To adapt the speed profile, various implementation examples provide different strategies: a) The use of a fixed prioritization, for example, round-robin scheduling. This is a simple and fast variant. Here, in the event of a collision, it is determined in advance which vehicle will adjust its speed. This can be determined either by a fixed ranking (e.g., vehicle A always has right of way over vehicle B), by the arbitrary order in which the collisions are checked (the collision of vehicle B with vehicle A was checked before the collision of vehicle A with vehicle B, which is why, for example, vehicle B is given right of way), by the timestamp of the transport order, so that, for example, vehicle A, which starts earlier, is given right of way over vehicle B, by the priority of the order (vehicle A must arrive before vehicle B, therefore vehicle A has right of way), or by any selection procedure.The only thing that is relevant at this point is that both vehicles have all the information they need to know, recognize, or consistently determine the sequence. This concept has the advantage that only one of the two vehicles has to adjust its speed profile and check for collisions with other vehicles, which means a solution can be found quickly. A potential disadvantage is that the solution found may not be optimal for the entire sorting system, for example, vehicle A always has right of way over vehicle B, but both would be faster if vehicle A waited for vehicle B. b) Exhaustive Search, exhaustion method: In this variant, several options for conflict avoidance or collision avoidance are played out. For example, if vehicle A collides with vehicle B, both evasive options (vehicle A brakes for vehicle B or vehicle B brakes for vehicle A) are simulated.This may result in new collisions with other candidates that are currently being planned. All of these possibilities are sorted in a tree structure. The leaves of the tree represent collision-free trajectories for all vehicles involved. This determines a truly optimal solution for collision avoidance for all participants. However, this process comes at the expense of execution time, as the tree to be searched may be very large and complex. c) A combination of these: here an attempt is made to combine the best of both methods A and B. If collisions are possible, the possibility tree is built up again, but only to a certain depth, i.e. the search has a time limit. If an optimal solution cannot be found quickly enough, the system falls back to the predefined sequence according to option a).

[0097] The planning phase, for example, is terminated as soon as an optimal or suboptimal solution has been found for the candidates. From this point on, the trajectory is fixed, meaning that subsequent vehicle planning can no longer influence it, for example, or only when predetermined priorities are reached or other predefined exceptional situations occur.

[0098] Steps 2 and 3, allocating transport orders and adjusting speed profiles, are repeated one after the other for each vehicle. As soon as the situation in the warehouse requires a new route network, the process begins again with the determination of the trajectories in step 1.

[0099] A special application of holonomic vehicles is that several individual vehicles can form a formation that behaves like a single, larger vehicle. Such formation travel can also be realized using the solution described above. For this purpose, the first step is to create a trajectory for the entire formation, from which the trajectories of the individual vehicles are formed using the known offset of each vehicle from the formation center. Steps 2 and 3, i.e., the travel task assignment and the speed adjustment, can be carried out analogously to all other participants, with the restriction or additional boundary condition that the speed profiles of all formation vehicles are always adjusted together and the trajectories start simultaneously.

[0100] The embodiments described herein allow the specific technical advantages of holonomic vehicles to be exploited in such a way that high accelerations and speeds can be achieved through cinematic path planning. In contrast to known methods, reactive evasion and large safety distances can be dispensed with, allowing a large number of vehicles to carry out transport tasks simultaneously.

[0101] Examples of implementation can be used in particular in the implementation of sorting systems or sorting plants with autonomously driving transport vehicles.

[0102] Embodiments also provide methods for operating a sorting system and for operating a sorting system control device.

[0103] A method for operating a sorting system to move a plurality of vehicles in the sorting system along trajectories comprises calculating a number of trajectories between a first number of starting points and a second number of end points, such that each trajectory is assigned a speed specification for a vehicle along the trajectory. Furthermore, travel orders are transmitted to the plurality of vehicles, such that each travel order comprises a journey from one of the starting points to one of the end points along one of the trajectories. Furthermore, a trajectory for a new travel order is examined for possible collisions with another vehicle of the sorting system in order to obtain collision information indicating a possible collision.The method includes changing the speed command assigned to the trajectory based on the collision information in order to obtain a modified speed command and avoid the potential collision. Furthermore, the new travel order, comprising an instruction that includes the trajectory and the modified speed command, is transmitted to a vehicle.

[0104] A method for operating a sorting system control device comprises transmitting travel orders to a plurality of vehicles, such that each travel order comprises a journey from a starting point to an end point along a respective trajectory, such that each trajectory is assigned a speed specification for a vehicle along the trajectory. The method comprises examining, for a new travel order, an associated trajectory for possible collisions with a travel order in order to obtain collision information indicating a possible collision. Furthermore, the speed specification assigned to the trajectory is changed based on the collision information in order to obtain a changed speed specification and to avoid the possible collision. The new travel order is output, comprising an instruction that includes the trajectory and the changed speed specification.

[0105] Although some aspects have been described in connection with a device, it should be understood that these aspects also represent a description of the corresponding method, so that a block or component of a device can also be understood as a corresponding method step or as a feature of a method step. Analogously, aspects described in connection with or as a method step also represent a description of a corresponding block, detail, or feature of a corresponding device.

[0106] Depending on specific implementation requirements, embodiments of the invention may be implemented in hardware or software. The implementation may be performed using a digital storage medium, such as a floppy disk, a DVD, a Blu-ray Disc, a CD, a ROM, a PROM, an EPROM, an EEPROM, or a FLASH memory, a hard disk, or other magnetic or optical storage device storing electronically readable control signals that can interact or cooperate with a programmable computer system to perform the respective method. Therefore, the digital storage medium may be computer-readable.Some embodiments according to the invention thus comprise a data carrier having electronically readable control signals capable of interacting with a programmable computer system such that one of the methods described herein is carried out.

[0107] In general, embodiments of the present invention can be implemented as a computer program product with program code, wherein the program code is effective to perform one of the methods when the computer program product is run on a computer. The program code can also be stored, for example, on a machine-readable medium.

[0108] Other embodiments include the computer program for performing one of the methods described herein, wherein the computer program is stored on a machine-readable carrier.

[0109] In other words, one embodiment of the method according to the invention is thus a computer program comprising program code for performing one of the methods described herein when the computer program is run on a computer. Another embodiment of the method according to the invention is thus a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program for performing one of the methods described herein is recorded.

[0110] A further embodiment of the method according to the invention is thus a data stream or a sequence of signals that represents the computer program for carrying out one of the methods described herein. The data stream or the sequence of signals can be configured, for example, to be transferred via a data communication connection, for example via the Internet.

[0111] A further embodiment comprises a processing device, for example a computer or a programmable logic device, which is configured or adapted to carry out one of the methods described herein.

[0112] A further embodiment comprises a computer on which the computer program for performing one of the methods described herein is installed.

[0113] In some embodiments, a programmable logic device (e.g., a field programmable gate array, an FPGA) can be used to perform some or all of the functions of the methods described herein. In some embodiments, a field programmable gate array can cooperate with a microprocessor to perform one of the methods described herein. Generally, the methods are performed by any hardware device in some embodiments. This can be a general-purpose hardware such as a computer processor (CPU) or hardware specific to the method, such as an ASIC.

[0114] The above-described embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

Claims

1. A sorting system control means comprising: coordinating means (28) configured to transmit drive requests to a plurality of vehicles (12), wherein each drive request includes a drive from a start point to an end point along a respective trajectory (14); wherein a speed specification (22) for a vehicle (12) along the trajectory (14) is allocated to each trajectory (14); collision avoidance means (32) configured to examine, for a new drive request, an allocated trajectory (14) for possible collisions with a drive request to obtain collision information indicating a possible collision; and to amend the speed specification (22) allocated to the trajectory (14) based on collision information to obtain an amended speed specification (22'); and to prevent the possible collision; an interface for outputting the new drive request including an instruction that includes the trajectory (14) and the amended speed specification (22'). wherein the speed specification associated with the trajectory is a speed specification based on a predetermination and includes a speed profile for a speed (v) across a path (x) of the trajectory (14); and the collision avoidance means (32) is configured to adapt the speed specification subsequently and prior to transmission of the drive request by the amended speed specification (22') to avoid the possible collision.

2. The sorting system control means according to claim 1, wherein the coordinating means (24) is configured to select, for the new drive request, the trajectory (14) from a plurality of trajectory candidates (38); wherein the plurality of trajectory candidates (38) considers trajectories (14) already allocated to vehicles (12) in existing drive requests.

3. The sorting system control means according to claim 1 or 2, wherein the collision avoidance means (32) is configured to not adapt the speed specification (22) for already allocated trajectories (14) of existing drive requests.

4. The sorting system control means according to claim 2 or 3, wherein the coordinating means (28) is configured to consider vehicles (12) on already allocated trajectories (14) for the selection of the trajectory (14) as potential obstacles.

5. The sorting system control means according to any of the preceding claims, wherein the collision avoidance means (32) is configured to obtain, for a plurality of new drive requests, a plurality of corresponding trajectories (14) as respective time-optimum speed specification (22) for traversing the trajectory (14) and to determine, for the plurality of the new trajectories (14), possible collisions among the vehicles (12) and to prevent the possible collisions within the new drive requests by adapting at least one of the speed specifications (22).

6. The sorting system control means according to claim 5, wherein, by means of amended speed specifications, overall time-optimized collision-free drive requests are obtained globally for the plurality of vehicles (12).

7. The sorting system control means according to any of the preceding claims, wherein the collision avoidance means (32) is configured to determine possible collisions for a plurality of new drive requests and to match the speed specifications of the speed profiles allocated to the drive requests by the coordinating means (28); wherein already transmitted speed profiles remain unamended.

8. The sorting system control means according to any of the preceding claims, wherein the collision avoidance means (32) is configured to treat already amended speed specifications (22') as unamendable until the drive request on the allocated trajectory (14) is terminated.

9. The sorting system control means according to any of the preceding claims, comprising: calculating means (24) configured to determine a third number of trajectories (14) between a first number of start points and a second number of end points, wherein the coordinating means (28) is configured to allocate drive requests to the trajectories (14).

10. The sorting system control means according to claim 9, wherein the calculating means (24) is configured to calculate a plurality of trajectory candidates (38) between a start point of the first number of start points and an end point of the second number of end points; wherein the coordinating means (28) is configured to select one of the trajectory candidates (38) as trajectory (14) for the new drive request.

11. The sorting system control means according to any of the preceding claims, wherein the trajectory (14) describes a continuous path or a continuous route between a start point and an end point.

12. The sorting system control means according to any of the preceding claims, wherein the trajectory (14) includes a plurality of trajectory portions, wherein the calculating means (24) is configured to calculate a portion speed specification for each trajectory portion; and to calculate the speed specification (22) based on a combination of the portion speed specifications.

13. The sorting system control means according to claim 12, wherein the calculating means (24) is configured to calculate a maximum speed for each trajectory portion based on a curvature of the trajectory portion and a maximum acceleration of a vehicle (12); and to calculate the portion speed specification (22) based on the maximum speed, a speed specification (22) at the start of the trajectory portion and a speed specification (22) at an end of the trajectory portion.

14. A method for operating a sorting system control means, comprising: transmitting drive requests to a plurality of vehicles (12) such that each drive request includes a drive from a start point to an end point along a respective trajectory (14); such that a speed specification (22) for a vehicle (12) along the trajectory (14) is allocated to each trajectory (14); examining, for a new drive request, an allocated trajectory (14) for possible collisions with a drive request to obtain collision information indicating a possible collision; and amending the speed specification (22) allocated to the trajectory (14) based on the collision information to obtain an amended speed specification (22'); and to prevent the possible collision; outputting the new drive request including an instruction that includes the trajectory (14) and the amended speed specification (22'); such that the speed specification associated with the trajectory is a speed specification based on a predetermination and includes a speed profile for a speed (v) across a path (x) of the trajectory (14); and the collision avoidance means (32) is configured to adapt the speed specification subsequently and prior to transmission of the drive request by the amended speed specification (22') to avoid the possible collision.

15. A computer program having program code for performing the method according to claim 26 when the program runs on a computer.