FR2934687A1 - Automatically guided vehicle e.g. industrial truck, guiding system control method for use in logistics field, involves controlling guiding system based on routing action to be executed by system, corresponding to read information - Google Patents

Abstract

The method involves arranging radio frequency identification tags (30) in determined zones (21-29) of a path. One of digital information (1-14) stored in the respective tags is read from a moving vehicle i.e. industrial truck (40). A guiding system of the vehicle is controlled based on a pre-established routing action to be executed by the system, corresponding to the read information. The information stored in each tag defines a tag number to locate the corresponding tag in a univocal manner among the tags arranged in the path. An independent claim is also included for an automatically guided vehicle comprising an on-board radio frequency identification reader.

Description

The present invention relates to the field of vehicles with automatic guidance, known as AGV, according to the English terminology for Automatically Guided Vehicle.

The invention more particularly relates to a control method of a guidance system of a vehicle whose movement is controlled automatically along a path, and a vehicle designed for the implementation of the method.

An AVG, in particular a industrial truck, is therefore designed to move automatically in an installation, following a predetermined path corresponding to a circuit along which certain operations must be performed, such as loading and unloading operations. trolley at different workstations arranged successively along the path. The advantages of automatically guided industrial trucks are well known, particularly in the field of logistics for optimizing material flows processed by a production process, allowing the handling of equipment, tools or any other object of a point to another in a workshop.

The course of the vehicle is generally materialized by guide elements. According to the automatic guiding technology used, it may be a conductive wire implanted in the ground and traversed by a variable electric current creating an electromagnetic field in the vehicle path, in the case of a guided vehicle, pads magnets positioned in certain areas of the course in the case of a magnetoguided vehicle, or even a paint or reflective tape placed on the ground in the case of an optoguided vehicle.

A guidance system mounted on the vehicle then comprises a suitable sensor, designed to detect the elements in question, wire, magnetic studs, reflectors or paint, and thus control the drive members of the carriage, so as to follow the course of the path materialized by the guiding elements detected. Prior to its automatic operation, the vehicle guidance system is programmed with detailed instructions corresponding to the route to be followed and the specific operations to be performed along the route, such as walking, stopping, slowing down, etc. This programming guidance instructions allowing the vehicle to follow a defined path by performing certain operations is however complex when the guidance environment is located in large facilities, possibly requiring several vehicles in operation simultaneously.

In this context, the routes to be set up may include multiple referrals, which then require the choice for the vehicle of a direction to be taken, or crossroads or convergences of two or more tracks, which then require Manage priorities between vehicles to avoid collisions.

A guide course is also required to evolve during the lifetime of an installation, as well as the operations to be performed by each vehicle.

An object of the invention is to provide a method of controlling a vehicle whose movement is controlled automatically along a path, which is of great simplicity of implementation, including in complex applications , and even if changes are later made to the route and / or operations to be performed by the vehicle. Another aim is to provide great flexibility in the management of the course of a vehicle by facilitating the steps of modification of the course and / or operations to be performed by each vehicle. Another aim is to allow the implementation of such changes in real time, without additional costs, or production interruption due for example to ground infrastructure work for the installation of wires, magnets, etc.. To aim at all or part of these aims, the control method according to the invention, moreover in conformity with the generic definition given in the preamble above, is more particularly characterized in that it consists in of certain determined areas of the RFID tags, to read from the moving vehicle digital information stored in a label and to control the vehicle guidance system according to at least one predetermined routing action to run by the vehicle guidance system, corresponding to the digital information read. According to one embodiment, at least one destination is selected for the vehicle, the execution of the preset routing action being conditioned by the prior checking of the presence of a destination parameter associated with the preset routing action and by comparing this parameter with the selected destination of the vehicle.

In particular, the preset routing action is systematically executed if no destination parameter is associated with said action. In particular, the preset routing action is executed only if the destination parameter associated with said action corresponds to the selected destination of the vehicle. Preferably, the method according to the invention comprises a step of setting up the vehicle, comprising: programming a routing table, consisting of a description of the preset routing actions associated with each digital information stored in a radiofrequency label arranged on the along the route, and - the download of the routing table programmed in a vehicle memory. Advantageously, the digital information stored in each radiofrequency label disposed along the path defines a tag number adapted to uniquely identify the tag among the other tags arranged along the path.

Preferably, the radiofrequency tags are disposed in a cavity dug in the ground substantially in the axis of a trace defining the path along which the vehicle is guided.

Preferably, the vehicle is guided along the route by optoguidage. The invention also relates to a vehicle with automatic guidance, characterized in that it comprises an on-board radio frequency identification reader adapted to obtain digital information stored by a radio frequency identification tag and a control module of a system. for guiding the vehicle adapted to control the guidance system according to at least one predetermined routing action to be performed by the guidance system, corresponding to a digital information obtained by the reader. In particular, the vehicle according to the invention comprises means for selecting a destination of the vehicle, the control module being adapted to compare the selected destination with a destination parameter associated with the preset routing action, so as to control the execution of said action only when the destination parameter is equal to the selected destination.

Advantageously, the control module comprises means for storing a routing table describing preset routing actions associated with each digital information obtained by the on-board reader of the vehicle.

Advantageously, the control module comprises a wired and / or wireless communication interface adapted to download the routing table. Preferably, the vehicle according to the invention is an optoguided vehicle. Other features and advantages of the present invention will emerge more clearly on reading the following description given by way of illustrative and nonlimiting example and with reference to the appended figures in which: FIG. 1 is a representation of a example of a guidance path with the location and routing terminals arranged along the path according to the invention, FIG. 2 is a representation of an example of modification of the guidance path according to FIG. 1, with the modification of the routing. associated, and - Figure 3 shows a simplified block diagram of an automatic guided vehicle according to the invention. The automatic vehicle guidance system such as industrial trucks, comprises, in the example of Figure 1, a carriage 40 moving in the arrow direction along the path 20 defining a guide path for the carriage between three positions 21, 22 and 23, loading respectively for one and unloading for the other two. According to a preferred embodiment of the invention, the trolley guidance system is an optoguidance installation. The path 20 for guiding the carriage 40 is for example made by a ground trace of black paint on a light background, adapted to be viewed by a camera on the truck. In a manner known in itself, with reference to FIG. 3 illustrating a simplified block diagram of a trolley 40 designed for the implementation of the present invention, the on-board camera 41 comprises means 42 for interpreting the image acquired for indicate to a control module 43 of the trolley guidance system, microcontroller type, the position of the trace relative to its axis. The guidance system of the carriage can thus correct the trajectory of the carriage by acting on the motor members 44 of the latter, so that the trace visualized is always in the axis of the camera. The actual guidance of the carriage is therefore conventionally provided by optoguidage using the on-board camera, then fulfilling only the tracking function.

In addition to this guiding of the trolley by tracing the trace with the aid of the camera, the invention provides for locating and routing terminals along the path 20, represented in FIG. 1 by points 30, to ensure both a tracing of the trolley along the path and the management of actions to be performed along the route by the trolley. Each terminal 30 comprises a radiofrequency identification tag, also known by the name of RFID (or Radio Frequency Identification) tag (or marker), corresponding to a chip / antenna pair, storing digital information intended to be read. by the cart when passing nearby. In the present application, the tags 30 are advantageously readable and writable tags. The information stored in the various tags 30 arranged along the path 20 correspond to integers, defining tag numbers numbered 1 to 10 according to the example of FIG.

It is planned to implant the tags in a cavity dug in the ground substantially in the axis of the trace defining the path, or in the immediate vicinity thereof, by a simple piercing. After implantation of the tag in the cavity thus dug, the latter can be closed for example by a resin or a plug taken by force. The implementation of tags along the route is thus made extremely simple, fast and advantageously makes it possible to make the installation evolve very easily according to the routing requirements of the carriages. Again with reference to FIG. 3, each carriage according to the invention then comprises an embedded RFID reader, consisting of a circuit 45 adapted to emit electromagnetic energy through an antenna arranged in the lower part of its chassis, and to an associated RFID module 46, which receives and decodes the information sent by a tag 30, as the carriage progresses along the path.

The RFID reader embedded on the carriage is connected to the control module 43 of the carriage, which is adapted to process the data acquired by the RFID reader according to a description table of the information stored in the tags, called the routing table, stored in a memory 47 of the carriage and to which the control module refers to order the motor members of the carriage accordingly, as will be discussed in more detail later. The tags 30 are arranged at strategic locations of the path 20, corresponding to each location of the route where a routing action must be performed by the carriage, such as for example: - in front of a switch 24, 25, to make the choice of a direction to be taken, - at a workstation 21, 22, 23 to stop, - before a junction 26, 27 (or a convergence of at least two tracks), to manage priorities in order to avoid collisions, at a loading station 21, to stop to allow for example the selection of a destination for the carriage, at a place where a change of speed is necessary, in order to manage a slowing or acceleration of the truck for example, etc. In general, therefore, it is expected to have a tag in any area of the course to make a decision as to a routing action to be performed or not for a carriage before it crosses the area in question. By routing action of a trolley, generally means any action resulting in any control action on the drive members of the carriage, such as turning right, left, stop, accelerate, slow down, etc. The tags 30 arranged along the path, each of which can be successively uniquely identified by the whole number that it memorizes, thus allow a truck to know where it is on the route, similarly to a milestone along a route, and also allow to trigger routing actions programmed in the routing table downloaded into a memory of the carriage. To launch a trolley on the route, one can first select at least one destination of the trolley. The selected destination may correspond, for example, to an unloading station to which the truck must go and may be selected by an operator at a loading station. The destination can be selected by push buttons on the truck if there are few possible destinations or via a more complex selection interface in the case of more destinations (eg via an embedded barcode reader on the cart). When the cart is started, its routing is then managed through the tags and routing table to which the control module of the cart refers to what action must be ordered to each tag detected along the route. The routing table contains the following elements. Action number 1 action 2 Parameter Secondary secondary tag destination associated 1 AR VOP CHGMT VIT 25 2 TRN DR 4 3 4 Tag number: The tag numbers correspond to the integer numbers 10 stored in the tags along the path. Actions 1 and 2: Actions 1 and 2 make it possible to determine the routing actions that the carriage will perform when the latter will detect the tag with which these actions are associated. These parameters are selected from a predefined list of actions that the cart can interpret, such as for example: stop, slow down, speed up, turn left, turn right, and so on.

For each tag number, two actions are for example programmed, respectively a main action, such as: Stop with restart by operator validation (AR VOP); and a secondary action, such as: Speed change on restart (CHGMT VIT). Associated parameter: The associated parameter is used to define certain values that may be necessary to perform an action. For example, to a CHGMT VIT action, it is necessary to associate a speed value, for example 25 m / min.

This parameter is therefore only to be filled in for certain actions requiring a numerical value such as slowing down, accelerating, timed shutdown, etc. Destination: The destination parameter of the routing table makes it possible to condition the execution of the actions to be performed by the truck at the destination of the truck, which can be selected by the operator at a loading station for example.

The action associated with the tag number is thus performed by the carriage if and only if the destination parameter associated with the action in the routing table is equal to the selected destination of the carriage.

If the destination parameter is not specified for a given tag number in the routing table, the routing action of the carriage associated with this tag is then systematically executed. This mode of operation therefore makes it possible to route the carriages according to the destinations selected for the carriage. For example, with reference to the table above, if tag number 2 (that is, the tag storing the value 2) is associated with a right turn action (TRN DR) and that this action makes it possible to go to destination 4 (that is to say where tag 4 is located), as illustrated in the path of FIG. 1, then the value 4 must be written in the destination parameter of the routing table associated with tag # 2.

In this way, a carriage launched on the course, to which the destination 4 will have been selected and which will read the tag n ° 2, will execute the action associated with this tag and will therefore turn right. Other trolleys whose destination is not destination 4 and read tag # 2 will ignore the action associated with tag # 2 in the routing table and go straight. This destination parameter is to be entered in the routing table for each tag involved in the routing of a destination to which an action such as turn right, turn left, stop ... is associated. All the destinations that can be selected by the operator at a loading point must be taken into account in this parameter so that the carriages can get there.

However, it is also possible, particularly for more complex applications involving multiple stops and branches, to manage the routing without selecting a destination for the trolley.

In the case where no destination is selected but a routing set by the routing table is used, this destination parameter is not used. In any case, each trolley must therefore be parameterized with the routing table before it is launched. The setting of a trolley can be carried out using a parameterization terminal, for example a mobile terminal, adapted to program the routing table and to download it into the trolley via a connection to the control module of the trolley, for example by a wired Ethernet type connection or via a wireless interface type infrared or radio frequency, the control module of the carriage then being equipped with a corresponding communication interface, referenced 48 in Figure 3. The parameter table is advantageously programmed once on the setting terminal, then downloaded once and for all in all carts, at the time of creation of the course or after a modification of the course, in order to take account of it. The programming of the routing table at the parameter terminal is in the form of an Excel type table. The programming is done in a very simple and intuitive way and consists of selecting the boxes one by one and then entering a numeric value or selecting an entry in a drop-down list according to the type of information required for each element of the routing table. as defined above.

The following table gives an example of a routing table to be programmed and downloaded into the carriages, with reference to the example run of Figure 1. Number Order 1 Order 2 Parameter Associated tag destination 1 Loading 2 Turn right 4 3 Priority on the right 4 Stop 4 5 Priority 6 Turn right 7 7 Stop 7 8 Priority right 9 Priority Slow down 30m / min The functional description accompanying this routing table 10 is as follows. A carriage stops at tag # 1 (loading point), the operator loads the cart and then selects a destination on the cart, eg destination 7.

The carriage starts, when it encounters the tag n ° 2, the value 2 stored in this tag is read by the on-board reader and the control module of the carriage then refers to the routing table previously downloaded into the carriage and controls the destination parameter associated with tag # 2 in the table. Since this parameter has the value 4 in the example, the carriage does not execute the action associated with tag 2 in the routing table (because its destination is 7), and it continues straight on the path. When the carriage encounters tag # 3, the value 3 is read and the control module refers back to the routing table. Since no value of the destination parameter is associated with tag # 3 in the routing table, the carriage therefore executes the action associated with tag # 3, consisting in checking that there is no carriage on its right to continue its progression. When the carriage encounters the tag No. 6, the control module of the carriage then commands the guidance system to execute the action turn right, because the destination parameter associated with tag No. 6 in the stored routing table is in this case equal to the destination selected for the carriage. At tag # 7, corresponding to the location of the unloading station 23, the carriage stops because the destination parameter associated with tag # 7 in the routing table is equal to the selected destination. The stop action is executed. The operator then unloads the truck and for example presses an on-board push button operator validation to restart the carriage that will return to the loading station 21. Upon its return to the loading station the carriage will read and execute the predetermined actions in the table of routing under the same conditions as before.

FIG. 2 illustrates an example of a modification of the path of FIG. 1, with modification of the associated routing (the elements in common with those of FIG. 1 bear the same references). The modification procedure can be done very easily and quickly, since it simply includes steps of: - painting of the new trace, - implementation of the new tags, - setting all the trolleys of the circuit to load the new routing table programmed. Such a procedure can advantageously be performed while maintaining production at the facility. According to the example of FIG. 2, the modifications of course consist in adding a fifth strand of unloading to the course with a new unloading station 29 and are materialized by the disposition of the following tags at the level of the new trace, in order to be able to manage the routing of carts accordingly: tag # 11, which allows to add the action of turning left and slow down for the carts of this destination, tag # 12, which allows to add the stop at the new position unloading 29, tag n ° 13, which makes it possible to add the action of management of the priority on the right and of acceleration with 40 m / mn, tag n ° 14, which makes it possible to add the action of management of trolley priority (temporary slowdown).

This is followed by the programming modification of the routing table to be downloaded into the carts: Number Order 1 Order 2 Parameter Associate destination ro tag 1 Loading 2 Turn right 4 3 Priority right 4 Stop 4 Priority 6 Turn right 7 7 Stop 7 8 Priority right 9 Priority Slow 30m / min 11 Turn left Change 20m / min 12 speed 12 Stop 12 13 Priority right Change 40m / min speed 14 End of priority In this example, it has been added a destination (tag # 12) with a switch then the tags # 11, # 13 and # 14 necessary for the proper operation of the circuit, specifically: - the tag # 11 to manage the switch, - the tags # 13 and # 14 to manage priorities. After having made the modification of the route, the routing table must be modified on the parameterizing terminal and then downloaded into all the carriages so that these can take into account the modification.

A cart that has not been modified will ignore tags added on the course.

Claims (13)

REVENDICATIONS1. A method of controlling a guide system of at least one vehicle (40) whose movement is controlled automatically along a path (20), characterized in that it consists in arranging at certain zones determined (21-29) of the route of the radio frequency identification tags (30), to read from the moving vehicle digital information (1-14) stored in a label and to control the vehicle guidance system according to at least one predetermined routing action to be performed by the vehicle guidance system, corresponding to the read digital information. 2. Method according to claim 1, characterized in that it consists in selecting at least one destination for the vehicle (40) and in that the execution of the preset routing action is conditioned by the prior checking of the presence a destination parameter associated with the preset routing action and comparing this parameter with the selected destination of the vehicle. 3. Method according to claim 2, characterized in that the preset routing action is systematically executed if no destination parameter is associated with said action. Method according to claim 2 or 3, characterized in that the preset routing action is executed only if the destination parameter associated with said action corresponds to the selected destination of the vehicle (40). 5. Method according to any one of the preceding claims, characterized in that it comprises a step of setting up the vehicle (10), comprising: programming a routing table, consisting of a description of the predetermined preset routing actions each digital information stored in a radio frequency tag (30) arranged along the path, and - downloading the routing table programmed in a memory (47) of the vehicle (40). 6. Method according to any one of the preceding claims, characterized in that the digital information stored in each radiofrequency label disposed along the path defines a tag number adapted to identify the label unequivocally among the other labels arranged. along the route. 7. Method according to any one of the preceding claims, characterized in that the 521 radiofrequency tags are disposed in a cavity dug in the ground substantially in the axis of a trace defining the path along which the vehicle is guided. 8. Method according to any one of the preceding claims, characterized in that the vehicle (40) is guided along the route by optoguidage. 10 9. Vehicle (40) with automatic guidance, characterized in that it comprises an on-board radio frequency identification reader (45, 46), adapted to obtain digital information stored by a radiofrequency identification tag and a radio frequency identification module. control (43) of a vehicle guidance system adapted to control the guidance system according to at least one predetermined routing action to be performed by the guidance system, corresponding to a digital information obtained by the reader. 10. Vehicle according to claim 9, characterized in that it comprises means for selecting a destination of the vehicle, the control module being adapted to compare the selected destination with a destination parameter associated with the routing action. preset, so as to control the execution of said action only when the destination parameter is equal to the selected destination. 30 22 11. Vehicle according to claim 9 or 10, characterized in that the control module comprises means (47) for storing a routing table describing preset routing actions associated with each digital information obtained by the on-board reader of the vehicle. . 12. Vehicle according to claim 11, characterized in that the control module comprises a wired and / or wireless communication interface (48) adapted to download the routing table. 13. Vehicle according to any one of claims 9 to 12, characterized in that it is an optoguided vehicle.