System for sorting products, wherein the system comprises an efficient communication topology

Abstract

System for sorting products comprising a number of combinations (1) of an elongated carrying body (2) and a pusher body (3), located one after another, which combinations are movable in a direction of movement following a path along which a number of sorting locations are provided, wherein the carrying bodies extend parallel to each other and perpendicular to the direction of movement and wherein the carrying bodies are configured for carrying the products to be sorted, wherein the pusher body is arranged for pushing a product carrier by the carrying body off of the carrying body, wherein said system comprises an improved communication topology for communication between controllers associated with said combinations.

Description

[0001] Title: System for sorting products, wherein the system comprises an efficient communication topology.

[0002] Description

[0003] The present disclosure relates to a system for sorting products comprising a number of successive combinations of an elongated carrying body and a pusher body, located one after another, movable in a direction of movement following a path along which a number of sorting locations are provided, wherein the carrying bodies extend parallel to each other and substantially perpendicular to the direction of movement and wherein the carrying bodies are configured for carrying the products to be sorted, a displacing device for moving the combinations in the direction of movement along the path, wherein each combination is further provided with a further displacing device comprising an electric motor for moving the pusher body in a sorting direction along the carrying body, the sorting direction extending perpendicularly to the direction of movement, for pushing a product carried by the carrying body off of the carrying body with the pusher body, and a plurality of controllers, wherein each of the plurality of controllers is provided on a combination of the elongated carrying body and the pusher body.

[0004] In the PCT patent application having the International Patent Publication Number WO 2020 / 022896 A1 , a system of this kind is described. This particular patent application focuses on the concept that the system comprises a distance-determining device that is configured for determining a distance parameter that is related to the, or at least a, distance viewed in the sorting direction between a pusher body of a combination, of which the carrying body carries a product to be sorted and the product to be sorted carried by the carrying body and for sending the distance parameter to an on-board control system, wherein the on-board control system is configured for controlling an on-board driving device of the combination on the basis of this distance data.

[0005] The system described above has the drawback that the communication topology is left in the middle and especially the communication topology between different controller associated with the combinations of an elongated carrying body and a corresponding pusher body. The central server is to provide data to the controllers associated with the combinations, but there is no effective topology described to accomplish communication between the controllers.

[0006] The present invention aims to provide a system for sorting products having an effective communication topology for exchanging data between the controllers.

[0007] As such, in a first aspect, there is provided a system for sorting products comprising: a number of combinations of an elongated carrying body and a pusher body, located one after another, which combinations are movable in a direction of movement following a path along which a number of sorting locations are provided, wherein the carrying bodies extend parallel to each other and perpendicular to the direction of movement and wherein the carrying bodies are configured for carrying the products to be sorted, wherein the pusher body is arranged for pushing a product carrier by the carrying body off of the carrying body; a displacing device for moving the combinations in the direction of movement along the path, wherein each combination is further provided with a further displacing device comprising an electric motor for moving the pusher body in a sorting direction along the carrying body, the sorting direction extending substantially perpendicularly to the direction of movement, for pushing a said product carried; by the carrying body off of the carrying body with the pusher body , a plurality of controllers , wherein each controller is provided on a combination of an elongated carrying body and the pusher body, and wherein each one of the plurality of controllers is arranged to control at least one of the further displacing devices by receiving destination data from a central control server relating to a sorting location where a product to be sorted should be pushed off of the carrying body and for driving the electric motor in accordance with the received destination data; wherein said plurality of controllers are divided in neighbouring groups of controllers such that each controller belongs to a single group, and wherein there is provided: a bus oriented communication network for connecting controllers of a group to one another using a communication bus dedicated for said group such that said controllers of said group are connected to said communication bus dedicated for said group, wherein said controllers of said group are arranged to use said communication bus oriented network for communicating latency sensitive data; a point-to-point oriented communication network for connecting said controllers of said group to one another such that neighbouring controllers of said group have a direct, dedicated, connection to one another, wherein said controllers of said group are arranged to use said point-to-point oriented communication network for communicating latency insensitive data.

[0008] It is noted that, typically, the length of a system may range from tens of meters to even hundreds of meters. Each of the elongated carrying bodies may be coupled to one another, or may be situated next to one another, to form a closed circuit. The result is that thousands of elongated carrying bodies may be provided, given typical dimensions for the elongated carrying body in the direction of movement, for example 50 to 200 mm. For example, in one example discussed with respect to the figures it is assumed that a system comprises 3200 elongated carrying bodies. Other possibilities may also be applicable, for example a system having 1600 or 2000 elongated carrying bodies.

[0009] Products to be sorted may be pushed onto, or placed on top of, the elongated carrying bodies. The dimensions of the elongated carrying bodies may be such that a product may span multiple consecutively situated elongated carrying bodies.

[0010] An elongated carrying body is provided with a pusher body, wherein the pusher body is able to move, with respect to the carrying body, in the sorting direction. An electric motor, for example a Direct Current, DC, motor, is provided for each combination of elongated carrying body with its pusher body for moving the pusher body in the sorting direction along the carrying body. In operation, the pusher body is pushed against the product to be sorted such that the product to be sorted is pushed from its corresponding elongated carrying body.

[0011] As mentioned above, a product may span multiple consecutively situated elongated carrying bodies such that at least two pusher bodies are to be controlled together for pushing the product off of the corresponding elongated carrying bodies.

[0012] The above paragraphs describe the mechanical actions required for pushing a particular product to be sorted from its corresponding elongated carrying bodies.

[0013] The inventors have found that it might be beneficial to obtain communication directly between controllers, even though each controller is provided on a combination of an elongated carrying body and a pusher body.

[0014] It is noted that the controllers thus also move in the direction of movement following a path along which a number of sorting locations are provided, at least during use. This complicates the communication between the controllers, as the implementation of the communication topology is thus, in use, also moving along the same path.

[0015] The alternative solution is, according to the inventors, that each controller is arranged to wirelessly transmit to an access point that is placed stationary along the path. This allows communication between controllers to occur via that particular stationary access point. This is, however, undesired as this involves risks related to, for example, reliability of the communication and the latency aspects of the communication.

[0016] On top of the above, such an alternative communication topology may be considered undesired when data transmission between controllers is ramping up. This may lead to congestion issues which negatively impacts latency requirements of data communicated between the controllers.

[0017] Instead of the alternative solution as explained above, the inventors have found a way to effectively implement the communication topology between the controller on a non-stationary, i.e. , a moving, platform.

[0018] That is, the bus oriented communication network as well as the point- to-point oriented communication network are implemented such that the controllers are able to communicate to each other, without signals to traverse via a stationary communication device, for example the stationary access point.

[0019] The above allows for more reliable communication between the controllers and allows for data to be communicated with less latency. On top of the above, the inventors have found an implementation of the communication topology between the controllers that is tailored to the use case. This is explained in more detail here below.

[0020] In order to grasp the disclosure in a clear manner, it is defined that the plurality of controllers is divided in neighbouring groups of controllers such that each controller belongs to a single group. For example, the system comprises 3200 controllers, divided into 100 groups of 32 controllers. Each controller is then associated with one group. So, 32 neighbouring, i.e., directly adjacent to one another, controllers form part of a single group.

[0021] Communication between the controllers within the group is made possible by utilizing a bus oriented communication network and a point-to-point oriented communication network.

[0022] The inventors have found that it is beneficial two create two separated communication networks, one directed to communicating latency sensitive data and one directed to communicating latency insensitive data. This is explained as follows.

[0023] First, a bus oriented communication network is provided for connecting the controller of a group to one another using a communication bus dedicated for that particular group. Each of the controllers in the group is thus connected to the communication bus.

[0024] The advantage of using such a bus oriented communication network is that there are no delays between each controller, as it is a multi-dop network, wherein each of the controllers receive the same message on the communication bus at the same time. This allows for low latency traffic exchanged between the controllers of the group. Enabling low-latency communication might be advantageous as this enables accurate synchronization between the controllers, and it enables last-minute decisions to be communicated in time.

[0025] The inventors have found that utilizing just a bus oriented communication network is not sufficient. The bus oriented communication network may not be used for, for example, automatic topology detection. The controllers cannot determine the order in which they are placed in the network I system relative to one another.

[0026] As such, the inventors have found to introduce a second communication network, being the point-to-point oriented communication network. In such a network, each controller of the group is connected to its neighbouring controller of that group (except for the two controllers at both ends of the group). The controllers are then connected to one another via intermediate controllers. The controllers are thus connected to one another in a concatenated fashion. The point-to-point communication can be used to determine the order of the controllers withing the group. Using only a point-to-point communication network may not be sufficient as such a point-to-point communication network may not support low-latency traffic between the controllers, as the messages need to traverse intermediate controllers before the messages end up with the intended recipient, i.e. , intended controller.

[0027] In an example, each of said groups of controllers comprises a host controller, wherein said bus oriented communication network is further arranged for: connecting controllers of a first group to a host controller of a second group using a different communication bus of said bus oriented communication network, said first group being different from said second group.

[0028] The inventors have found that it may be beneficial to introduce different kinds of redundancy to ensure that communication between controllers is still possible even when the communication bus malfunctions for whatever reason.

[0029] It was found to introduce another communication bus, i.e., a physically different communication bus. This means that the controllers are connected to one another via the communication bus that is dedicated for that particular group, but that the controller are also connected to one another via the further communication bus.

[0030] In order to further improve the redundancy aspects of the communication topology, the inventors have found that it may be beneficial to connect this further communication bus to a host controller of another group. This would allow that host controller of the another group to control communications over that further communication bus between the controller of the first group when the host controller of the first group malfunctions for whatever reason.

[0031] As such, the redundancy aspect described above covers, for example, the situations where there is a broken communication bus, i.e., a broken cable of the communication bus, and covers the situation in which the host controller of the first group malfunctions for whatever reason.

[0032] In an example, each of said groups of controllers comprises a host controller, wherein said bus oriented communication network is further arranged for: connecting controllers of a first group to one another such that said controllers of said first group are connected in parallel to said communication bus, and for switchably connecting a host controller of a second group to said bus, said first group being different from said second group, such that said host controller of said second group is able to take over coordination of said communication bus.

[0033] In order to improve the redundancy of the communication topology, the inventors have found that it might be beneficial to switchably connect the dedicated communication bus to a host controller of a second group. That is, the host controller of the second group is not, or not actively, connected to the dedicated communication bus of the first group but may step in whenever required. For example, whenever the host controller of the first group malfunctions, the host controller of the second group may decide to take over the function of the host controller of the first group.

[0034] The host controller of the second group may decide, upon receiving information that the host controller of the first group is malfunctioning, to take over the host function.

[0035] In a further example, each of said groups of controllers comprises a host controller, wherein said point-to-point oriented communication network is further arranged for: connecting controllers of a first group to a host controller of a second group, said first group being different from said second group.

[0036] The last controller of the first group may, for example, be directly connected to a first controller of the second group, said first controller of the second group being the host controller for that particular group.

[0037] The advantage hereof is that redundancy is provided for the point-to- point oriented communication network. The host controller of the first group may malfunction such that communication from, and to, the central server is no longer possible, especially communication directed to the topology detection, or other type of overhead signalling. This problem is solved in that the host controller of the second group may take over this responsibility, wherein the host controller of the second group is then made responsible for the controllers of the first group.

[0038] In yet another example, each of said host controllers of said groups comprises a wireless transceiver for communicating with said central control server. In a further example, each of said host controllers is arranged for topology detection using said point-to-point communication network.

[0039] The point-to-point communication network may be used for a variety of application, one of which is topology detection. Topology detection means that the network is able to determine the physical order in which the controllers are located in the system and thus also the order of the combinations of elongated carrying bodies and pusher bodies in the system. This allows the system to initialize itself.

[0040] The point-to-point communication network may be used for a variety of non-latency sensitive traffic, for example overhead signalling. This may reduce any load on the bus communication network, such that the bus communication network may be used for latency sensitive communication as much as possible.

[0041] In a further example, each controller of said first group comprises: a first bus driver for connecting said controller to said communication bus; a second bus driver for connecting said controller to said different communication bus.

[0042] In order to even further improve the redundancy of the bus oriented communication network, the inventors have found that it might be beneficial to create two, physically separated, bus drivers in a particular controller. The first driver may connect the controller to the communication bus and the second driver may connect the controller to the different communication bus.

[0043] This improves the redundancy of the system as, in case one of the two bus drivers start to malfunction, there is always a backup bus driver to connect the respective controller to a communication bus. This allows the controller to still participate in the communication regime of the bus oriented communication network.

[0044] In yet another example, each controller of said first group comprises: a first point-to-point driver for providing a direct connection to a first neighbouring controller; a second point-to-point driver for providing a direct connection to a second neighbouring controller.

[0045] In order to even further improve the redundancy of the point-to-point communication network, the inventors have found that it might be beneficial to create two, physically separated, point-to-point drivers in a particular controller. The first point-to-point driver may connect the controller to a neighbouring controller at a first (left) side, and a second point-to-point driver may connect the controller to a further neighbouring controller at a second (right) side.

[0046] In yet another example, the bus oriented communication network comprises a Controller Area Network, CAN, based communication network.

[0047] In another example, the point-to-point oriented communication network comprises an RS485 communication network.

[0048] In a further example, each of said groups of controllers comprises a host controller and wherein said system further comprises: at least one stationary Access Point, AP, wherein the at least one AP is arranged to wirelessly communicate with said host controllers of said groups.

[0049] The at least one AP is stationary meaning that the AP is not to move, in operation, like the plurality of controllers and like the bus oriented communication network and the point-to-point communication network. The inventors have found that the communication between the stationary AP and the plurality of moving host controllers of the different groups may be effectively dealt with in a couple of manners, which is elucidated in more detail later below.

[0050] Following the above, a system that comprises 3200 combinations, and a maximum of 1600 controllers, may comprise 4 Access Points or the like.

[0051] In a further example, the system further comprises: at least one stationary placed leaky coax cable extending along the direction of movement along the path, and wherein the leaky coax cable is connected to the at least one stationary AP for communication with said host controller.

[0052] The communication topology is divided, physically, in a part that is stationary and a part that is moving during operation. The stationary placed leaky coax cable enables the communication to go from a static, stationary environment to a moving environment. The moving environment comprises the controllers, the communication topology between the controller, i.e. , the bus oriented communication network and the point-to-point communication network, while the static, stationary environment comprises the at least one AP and the central control server.

[0053] In yet another example, each of said groups of controllers comprises a host controller and wherein said system further comprises: said control server arranged for transmitting destination data relating to the sorting location where a product to be sorted should be pushed off of the carrying body, to one or more of the plurality of controllers via the at least one stationary AP.

[0054] In a second aspect of the present disclosure, there is provided a method of sorting a product to be sorted, using a system in accordance with any of the previous claims, wherein the method comprises the steps of: communicating, by one of said controllers of a group, latency sensitive data using said bus oriented communication network, and communicating, by one of said controller of said group, overhead data using said point-to-point oriented communication network.

[0055] It is noted that the advantages and definitions as disclosed with respect to the embodiments of the first aspect of the invention also correspond to the embodiments of the second aspect of the invention, being the method of sorting a product to be sorted.

[0056] In an example, the method comprises the steps of: determining, by said host controller of said second group, that it has to take over coordinating said bus oriented communication network for said controllers of said first group; coordinating, by said host controller of said second group, communication between said controllers of said first group using said different communication bus.

[0057] In a further example, the method comprises the steps of: determining, by said host controller of said second group, that it has to take responsibility for said point-to-point communication network for said controllers of said first group; coordinating, by said host controller of said second group, communication to, and from, said controllers of said first group.

[0058] In a third aspect of the present disclosure, there is provided a computer program product comprising a computer readable medium having instructions stored thereon which, when executed by a controller, cause said controller to implement a method in accordance with any of the previous examples. The invention will be explained in more detail hereunder on the basis of the description of a number of possible embodiments of the invention, referring to the following figures.

[0059] Brief description of the figures

[0060] Fig. 1 discloses an example of a combination of an elongated carrying body and a pusher body;

[0061] Fig. 2 discloses an example of a system in accordance with the present disclosure;

[0062] Fig. 3 discloses a system comprising a communication topology, in accordance with the present disclosure;

[0063] Fig. 4 discloses a host controller in accordance with the present disclosure;

[0064] Fig. 5 discloses a controller in accordance with the present disclosure.

[0065] Detailed description

[0066] Fig. 1 shows the end portion of a combination 1 of an elongated carrying body 2, to be denoted hereinafter with the term slat, and a pusher body 3, to be denoted hereinafter with the term pusher shoe. Pusher shoe 3 is movable along slat 2 in two opposite sorting directions according to double-headed arrow 4 that extends parallel to the longitudinal direction of slat 2, in a manner that will be explained in more detail on the basis of Figs. 2 and 3. Combination 1 is one of a large number of identical combinations which together form a closed circuit and form part of a system for sorting products.

[0067] The slats 2 extend parallel to each other for example as is also shown in Fig. 3. The closed circuit comprises an upper part and a lower part located directly thereunder. The upper part and the lower part extend as horizontal surfaces with a length of typically tens of metres. The upper part and the lower part are joined to each other at their ends via semi-arcuate parts of the closed circuit. This type of sorting devices is well known in the art. The slats 2 are, at their longitudinal ends, coupled to chains that also run along the closed circuit. Gears engage with the chains at least at the site of the arcuate parts of the closed circuit. At least some of these gears are driven by one or a number of electric motors so that the successive combinations 1 can be moved in a direction of movement 5 that extends perpendicular to the sorting directions 4, along an endless transport path that is of identical shape to the shape of the closed circuit of the combinations 1.

[0068] Slat 2 may be an extruded aluminium profile.

[0069] Fig. 1 shows a combination 1 , with a carrying surface 6 with four equally spaced carrying ribs 7 extending in the longitudinal direction of slat 2, for a product to be carried thereon.

[0070] In use, a product to be sorted, such as a parcel, is supplied at the site of the upstream end of the sorting path, to a combined carrying surface such as is formed by a number of successive carrying surfaces 6 located one after another. This combined carrying surface supports the product during movement of the respective combinations 1 in the direction of movement 5. The respective product is intended, at the site of a sorting location, where typically a chute or roller table is provided along the path of the combinations 1 , to be pushed off of the combined carrying surface by means of the pusher shoes 3 that form part of the associated combinations 1. Logically, the product to be sorted is located on the side a corresponding pusher bodies 3 that is facing the respective sorting location. The central control system of the sorting system is in possession of data relating to the aforementioned sorting location for the respective product to be sorted.

[0071] Fig. 2 shows a high level design of the system 31 , in a top view, for sorting products in accordance with the present disclosure.

[0072] The system 31 for sorting products comprises a number of successive combinations 36 of an elongated carrying body and a pusher body, located one after another. Such a combination is explained in more detail with respect to the first figure.

[0073] The combinations are movable in a direction of movement 5 following a path along which a number of sorting locations are provided, wherein the carrying bodies extend parallel to each other and substantially perpendicular to the direction of movement 5 and wherein the carrying bodies are configured for carrying the products to be sorted.

[0074] Here, the sorting locations are connected to the exit feeds as indicated with reference numeral 32.

[0075] The sorting system 31 further comprises a displacing device 47 for moving the combinations in the direction of movement 5 along the path.

[0076] Each combination is further provided with a further displacing device, for example comprising an electric motor 33 for moving the pusher body in a sorting direction 4 along the carrying body, the sorting direction 4 extending perpendicularly to the direction of movement 5, for pushing a product carried by the carrying body off of the carrying body with the pusher body.

[0077] Figure 2 discloses that the products are sorted in a single direction as indicated with reference numeral 4. It is noted that the present disclosure is also directed to systems that are able to sort the products in both directions, such that the products may be sorted at a first side - as indicated with reference numeral 4, but also at a second side opposite to the first side. The second side is then directly opposite to the first side.

[0078] A plurality of controllers is provided, wherein each controller is provided on a combination of the elongated carrying body and the pusher body. The communication topology between these controllers is elaborated on with respect to figure 3.

[0079] The system 31 may further comprise at least one stationary Access Point, AP, 37 wherein the at least one AP 37 is arranged to communicate with host controllers of a particular group, and with a central control server 38.

[0080] The central control server 38 may be arranged for transmitting destination data relating to the sorting location where a product to be sorted should be pushed off of the carrying body, to one or more of the host controllers via the at least one stationary placed AP 37.

[0081] Here below, a specific implementation of the system 31 is provided. The present disclosure is not to be limited to this specific implementation.

[0082] A leaky coaxial antenna 46 may be provided on of the side frames of the system 31. As an alternative, the coaxial antenna 46 may be provided somewhere in the middle part under the combinations of the pusher body and the elongated carrying body. The leaky coaxial antenna 46 makes it possible to communicate between moving parts of the system 31 and stationary parts of the system. As such, antennas may be provided on each host controller, which antennas also move, in operation, in the direction of movement 5. The antennas are able to transfer message between the host controllers and the leaky coaxial cable 46.

[0083] Preferably, there is a fixed clear line of sight between the antennas of the host controllers and the leaky coax antenna 46 to ensure a stable connection.

[0084] Fig. 3 discloses a system 51 comprising a communication topology, in accordance with the present disclosure.

[0085] First, a number of combinations of an elongated carrying body and a pusher body are shown. One of such combination is indicated by reference numeral 54. For clarity purposes the combinations are drawn such that there is a free spacing in between them. In practice, these combinations may be oriented much closer to one another to form a solid support area for the products that are being carried and sorted.

[0086] The combinations 54 are thus located one after another, wherein the combinations are movable in a direction of movement following a path along which a number of sorting locations are provided. This is not shown in figure 3 but is shown in figure 2.

[0087] A displacing device may be provided for moving the combinations in the direction of movement along the path. This displacing device is, for example, an electric motor or the like.

[0088] In accordance with the present disclosure, each combination is further provided with a further displacing device, for example an electric motor, for moving the pusher body in a sorting direction along the carrying body.

[0089] A plurality of controllers 55, 56a, 56b, 56c, 61 is provided, wherein each controller is provided on a combination of an elongated carrying body and a corresponding pusher body. There may be a 1 -to- 1 mapping, such that there are the same number of controllers as there are carrying bodies. It is also possible that some controllers control multiple pusher bodies, i.e. , a controller is responsible for activating and deactivating multiple pusher bodies of multiple carrying bodies.

[0090] The plurality of controllers 55, 56a, 56b, 56c, 61 are divided in neighbouring, non-overlapping, groups 52, 60 of controllers. It is noted that just the first part of the group having reference numeral 60 is shown in figure 3. In this particular case, the first group 52 of controllers comprises a host controller 55 and a plurality of controller as indicated with reference numerals 56a, 56b and 56c. Typically about 31 or 32 controllers may be connected to a single host controller 55. The host controller 55 may act as a master device, and the remaining controllers of the group may act as a slave controller.

[0091] The host controller of a group, for example the host controller 55 of the first group and the host controller 61 of the second group, are responsible for communicating with the outside world. For example, communicating with a central control server.

[0092] The central control sever may communicate data towards a host controller 55, 61 via a wireless antenna 53, 62. The data may, for example, comprise destination data relating to a sorting location where a product to be sorted should e pushed off of the corresponding carrying body.

[0093] The system further comprises two communication networks.

[0094] A bus oriented communication network 58, 57 is provided for connecting controllers 55, 56a, 56b, 56c of a group 52 to one another using a communication bus 58 dedicated for said group 52 such that said controllers 55, 56a, 56b, 56c of said group 52 are connected to said communication bus 58 dedicated for said group, wherein said controllers 55, 56a, 56b, 56c of said group 52 are arranged to use said communication bus oriented network for communicating latency sensitive data.

[0095] The latency sensitive data may, for example, comprise the destination data related to where products are to be sorted out. The latency sensitive data may be directed to data that is to be exchanged during operational phase of the system, i.e. , for correctly operating the system.

[0096] Other examples include time synchronization between fixed and moving world, exchange of velocity and position of the decks, positions where sorting is allowed, status of each deck, errors and warnings per deck and per segment and permission to sort from the fixed world.

[0097] Further, a point-to-point oriented communication network 59a, 59b, 59c is provided for connecting said controllers 55, 56a, 56b, 56c of said group 52 to one another such that neighbouring controllers of said group have a direct, dedicated, connection to one another, wherein said controllers 55, 56a, 56b, 56c of said group 52 are arranged to use said point-to-point oriented communication network 59a, 59b for communicating latency insensitive data.

[0098] The latency insensitive data may, for example, comprise topology information. The point-to-point oriented communication network 59a, 59b may be used, by the controllers, to determine the particular order in which they are located within the system 51 .

[0099] In this particular scenario, in order to improve redundancy, the controllers of the first group 52 are connected to a host controller 61 of a second group using a different communication bus 57 of said bus oriented communication network, said first group being different from said second group.

[0100] The bus oriented communication network may comprise several redundancy aspects. For example, in case the communication over the communication bus 58 fails, for whatever reason, the host controller 61 of the second group 60 may step in and may coordinate the data exchanged over the bus oriented communication network in the first group 52 by utilizing the different communication bus 57.

[0101] The point-to-point oriented communication network may also comprise several redundancy aspects. For example, in case the communication between the different controllers over the dedicated connections 59a, 59b, between the controllers fails, for whatever reason, the host controller 61 of the second group 60 may step in. That is, the controllers 55, 56a, 56b, 56c of the first group 52 are connected to the host controller 61 of the second group, via a same dedicated connection. The host controller 61 of the second group 60 will, typically, not use that particular connection for communicating with the controllers of the first group 52, only in case some sort of malfunction occurs in which the host controller 55 of the first group 52 is not able to use said point-to-point communication network to contact the controllers of the first group 52.

[0102] The bus oriented communication network may comprise a Controller Area Network, CAN, bus. The CAN bus may be a multi-drop single-pair network topology, where multiple controllers are connected in parallel on the same signal line, i.e. , cable. The CAN communication protocol may be a carrier-sense, multiple access protocol with collision detection and message priority arbitration, i.e., CSMA / CD+AMP. CSMA means that each controller connected to the bus must wait a prescribed period of inactivity before attempting to send a message. Using a CAN bus may be advantageous, for example in view of using an ethernet solution, as the CAN bus may save on purchase costs and energy consumption. Energy consumption is especially of interest as the controllers are moving, in use, such that the provision of energy to these controllers should be limited as much as possible. The electrical energy may be provided to the controllers using, for example, sliding contacts or wireless charging. Reducing energy consumption in the controllers is thereby beneficial to loosen the requirements for these energy transfer means.

[0103] The inventors have found that such a CAN bus cannot be used for automatic topology detection. The controllers cannot use such a CAN bus to determine the order in which they are placed in the network relative to one another. In order to know in which order the controllers are connected in series with one another, a point- to-point communication network is utilized between the different controllers. It was found that RS485 can be advantageous, as common available microcontrollers are typically equipped with a universal asynchronous receiver-transmitter port that is able to support RS485.

[0104] Combining the CAN bus and the RS485 may be performing using an ethernet cable, for example CAT5 or higher. Such an ethernet cable comprises 8 wire pairs, such that these wire pairs can be used for two CAN busses and two full-duplex RS485 signals. As mentioned above, by using two CAN buses and two full-duplex RS485 signal busses, redundancy is obtained, wherein each controller is able to receive and sent any data via two sides, i.e. , a host controller of a first group as well as a host controller of a second group.

[0105] The CAN bus can be used for hard-real-time low-latency process data and the RS485 can be used for configuration data, comprising automatic topology detection, heartbeat and log data, such that signalling overhead does not disrupt the sorting process.

[0106] As for power transmission, power rails may be fitted on one of the side frames of the sorter. Current collectors may be fitted on the moving carriers and connected to the power pickup units that are fixed on the carriers.

[0107] Fig. 4 discloses a host controller in accordance with the present disclosure. The host controller 84 may be considered the coordinator of a particular group. The host controller 84 may be responsible for communicating to the outside world, for example using a transceiver 84. The transceiver 84 may use an antenna to wireless communicate data from, and to, a central control server.

[0108] Using wireless communication is preferred, as all the controllers are actually moving, in use. The controllers follow the path of movement.

[0109] The host controller may comprise two, physically separated, RS485 transceivers as indicated with reference numerals 82 and 83. The first RS485 transceiver is arranged to provide duplex point-to-point communication with a controller directly adjacent to said host controller at a left side. The second RS485 transceiver is arranged to provide duplex point-to-point communication with a controller directly adjacent to said host controller at a right side.

[0110] The host controller comprises a Main Control Unit 85, for controlling the operation of the RS485 transceivers 82, 83, and for controlling the operation of two CAN bus drivers 86, 87. The first can bus driver 87 may be operational during use and may be connected to a dedicated CAN bus 88. This dedicated CAN bus 88 is used for providing communication between the controllers of the group to which the host controller 81 belongs.

[0111] The second bus driver 86 may be used as a backup bus driver in case something is faulty with the communication over a bus that is dedicated for the controllers at the left hand side of the host controller. In that case, the host controller 81 may take over and coordinate communication over that bus, i.e. , in that different group, as well.

[0112] Fig. 5 discloses a controller 101 in accordance with the present disclosure. The controller comprises a Main Control Unit, MCU, 104 arranged for controlling a motor 105, wherein the motor 105 is arranged to drive a corresponding shoe for sorting a particular product.

[0113] The MCU 104 is connected to two RS485 transceiver 102, 103, and to two CAN bus drivers 106, 107.

[0114] To reduce the number of claims, certain aspects of the technology are presented below in certain claim forms, but the applicant contemplates the various aspects of the technology in any number of claim forms. For example, while some aspect of the technology may be recited as a computer-readable medium claim, other aspects may likewise be embodied as a computer-readable medium claim, or in other forms, such as being embodied in a means-plus-function claim.

[0115] In the description above, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of implementations of the disclosed technology. It will be apparent, however, to one skilled in the art that embodiments of the disclosed technology may be practiced without some of these specific details.

[0116] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope thereof.

Claims

CLAIMS1. System for sorting products comprising: a number of combinations of an elongated carrying body and a pusher body, located one after another, which combinations are movable in a direction of movement following a path along which a number of sorting locations are provided, wherein the carrying bodies extend parallel to each other and perpendicular to the direction of movement and wherein the carrying bodies are configured for carrying the products to be sorted, wherein the pusher body is arranged for pushing a product carrier by the carrying body off of the carrying body; a displacing device for moving the combinations in the direction of movement along the path, wherein each combination is further provided with a further displacing device for moving the pusher body in a sorting direction along the carrying body, the sorting direction extending substantially perpendicularly to the direction of movement, for pushing said product carried; a plurality of controllers, wherein each controller is provided on a combination of an elongated carrying body and the pusher body, and wherein each one of the plurality of controllers is arranged to control at least one of the further displacing devices by receiving destination data from a central control server relating to a sorting location where a product to be sorted should be pushed off of the carrying body and for driving the displacing device in accordance with the received destination data; wherein said plurality of controllers are divided in neighbouring groups of controllers such that each controller belongs to a single group, and wherein there is provided: a bus oriented communication network for connecting controllers of a group to one another using a communication bus dedicated for said group such that said controllers of said group are connected to said communication bus dedicated for said group, wherein said controllers of said group are arranged to use said communication bus oriented network for communicating latency sensitive data; a point-to-point oriented communication network for connecting said controllers of said group to one another such that neighbouring controllers of saidgroup have a direct, dedicated, connection to one another, wherein said controllers of said group are arranged to use said point-to-point oriented communication network for communicating latency insensitive data.

2. System in accordance with claim 1 , wherein each of said groups of controllers comprises a host controller, wherein said bus oriented communication network is further arranged for: connecting controllers of a first group to a host controller of a second group using a different communication bus of said bus oriented communication network, said first group being different from said second group.

3. System in accordance with any of the previous claims, wherein each of said groups of controllers comprises a host controller, wherein said bus oriented communication network is further arranged for: connecting controllers of a first group to one another such that said controllers of said first group are connected in parallel to said communication bus, and for switchably connecting a host controller of a second group to said bus, said first group being different from said second group, such that said host controller of said second group is able to take over coordination of said communication bus.

4. System in accordance with any of the previous claims, wherein each of said groups of controllers comprises a host controller, wherein said point-to-point oriented communication network is further arranged for: connecting controllers of a first group to a host controller of a second group, said first group being different from said second group.

5. System in accordance with any of the claims 2 - 4, wherein each of said host controllers of said groups comprises a wireless transceiver for communicating with said central control server.

6. System in accordance with any of the claims 2 - 5, wherein each of said host controllers is arranged for topology detection using said point-to-point communication network.

7. System in accordance with any of the previous claims, and at least in accordance with claim 2, wherein each controller of said first group comprises: a first bus driver for connecting said controller to said communication bus; a second bus driver for connecting said controller to said different communication bus.

8. System in accordance with any of the previous claims, wherein each controller of said first group comprises: a first point-to-point driver for providing a direct connection to a first neighbouring controller; a second point-to-point driver for providing a direct connection to a second neighbouring controller.

9. System in accordance with any of the previous claims, wherein said bus oriented communication network comprises a Controller Area Network, CAN, based communication network.

10. System in accordance with any of the previous claims, wherein said point-to-point oriented communication network comprises an RS485 communication network.

11. System in accordance with any of the previous claims, wherein each of said groups of controllers comprises a host controller and wherein said system further comprises: at least one stationary Access Point, AP, wherein the at least one AP is arranged to wirelessly communicate with said host controllers of said groups.

12. System in accordance with claim 11 , wherein said system further comprises:at least one stationary placed leaky coax cable extending along the direction of movement along the path, and wherein the leaky coax cable is connected to the at least one stationary AP for communication with said host controller.

13. System in accordance with any of the previous claims, wherein each of said groups of controllers comprises a host controller and wherein said system further comprises: said control server arranged for transmitting destination data relating to the sorting location where a product to be sorted should be pushed off of the carrying body, to one or more of the plurality of controllers via the at least one stationary AP.

14. A method of sorting a product to be sorted, using a system in accordance with any of the previous claims, wherein the method comprises the steps of: communicating, by one of said controllers of a group, latency sensitive data using said bus oriented communication network, and communicating, by one of said controller of said group, overhead data using said point-to-point oriented communication network.

15. A method in accordance with claim 14 in combination with claim 2, wherein said method comprises the steps of: determining, by said host controller of said second group, that it has to take over coordinating said bus oriented communication network for said controllers of said first group; coordinating, by said host controller of said second group, communication between said controllers of said first group using said different communication bus.

16. A method in accordance with any of the claims 14 - 15, wherein said method comprises the steps of: determining, by said host controller of said second group, that it has to take responsibility for said point-to-point communication network for said controllers of said first group;coordinating, by said host controller of said second group, communication to, and from, said controllers of said first group.

17. Computer program product comprising a computer readable medium having instructions stored thereon which, when executed by a controller, cause said controller to implement a method in accordance with any of the claims 14 - 16.

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