WO2022189886A1

WO2022189886A1 - Tracking system of the position of objects in a work environment

Info

Publication number: WO2022189886A1
Application number: PCT/IB2022/051736
Authority: WO
Inventors: Georg CAMPANA; Paolo LIONETTI
Original assignee: Stetel S.R.L
Priority date: 2021-03-08
Filing date: 2022-02-28
Publication date: 2022-09-15
Also published as: IT202100005318A1

Abstract

It is provided a tracking system (1) of the position of objects (1a) in an environment comprising tags (4) each configured to be applied to one of said objects (1a); a server (2); and nodes (3) located in said environment and defining a communication network (1b) with the server (2); each node (2) defines a local network (1c) with the tags (3); in which the server (2) provides a database positions associated to each node (3) a position and connected to the communication network (1b) so as to receive the position of said node (3) and thus define the position of the object (1a); the tag (4) comprises a first connector (41) configured to connect the tag (4) to said local network (1c); a second connector (42) configured to connect the tag (4) to the communication network (1b); and a control board (45) defining a first configuration in which the second connector (42) is deactivated and the first connector (41) is active and a second configuration in which both connectors (41, 42) are active.

Description

DESCRIPTION

TRACKING SYSTEM OF THE POSITION OF OBJECTS IN A WORK ENVIRONMENT

The present invention relates to a tracking system of the type specified in the preamble of the first claim.

In particular, the invention relates to a device configured to track the position of objects in a working environment such as an industrial plant for example equipped for production.

As is known, these systems (also referred to as real time location systems (RTLS) or real time tracking systems) are used to automatically identify and track the position of objects in real time usually within a building or other contained area.

Examples of applications of these real-time localisation systems include tracking cars through an assembly line, locating pallets of goods in a warehouse or finding medical equipment in a hospital. Other possible applications may include locating and managing assets within a facility, notifying new locations, combining the identity of multiple items placed in a single location such as on a pallet.

These systems usually involve the use of wireless RTLS tags attached to objects, and in most RTLS fixed reference points receive wireless signals from the tags to determine their location. The technologies used to perform tracking can be of various types such as RFID, infrared, ultrasonic identification, optical tracking.

The known technique described includes some important drawbacks.

In particular, a first drawback lies in the fact that the known object location tracking systems impose a measured design to the working environment and/or to the flow of objects to be tracked. They therefore require installation and usage procedures specific to each working environment, thus imposing high purchase and usage costs.

This makes tracking systems particularly expensive and, above all, difficult to adapt to the evolution of the working environment. In fact, a working environment can often change (e.g. expand) and the system is not able to adapt to these changes, thus imposing costly and laborious procedures to adapt the tracking system. It should be noted that in most cases the stiffness of the system means that this adaptation is not possible and a new tracking system has to be designed. In this situation, the technical task at the basis of the present invention is to devise a tracking system capable of substantially obviating at least part of the aforementioned drawbacks.

In the context of said technical task, it is an important scope of the invention to obtain a tracking system that is easily adaptable to any work environment and/or to the flow of objects to be tracked. In particular, it is an important scope of the present invention to obtain a tracking system that is easily and quickly adaptable to the changing work environment.

Another important purpose of the invention is to achieve a tracking system of low purchase and usage costs. The technical task and the specified purposes are achieved by a tracking system as claimed in the annexed claim 1 . Examples of preferred embodiments are described in the dependent claims.

The features and advantages of the invention are hereinafter clarified by the detailed description of preferred embodiments of the invention, with reference to the annexed figures, wherein: the Fig. 1 shows a tracking system according to the invention; and the Fig. 2 illustrates the tracing system of Fig. 1 at a different time.

In the present document, the measurements, values, shapes and geometric references (such as perpendicularity and parallelism), when associated with words like “about” or other similar terms such as “approximately” or “substantially”, are to be considered as except for measurement errors or inaccuracies due to production and/or manufacturing errors, and, above all, except for a slight divergence from the value, measurements, shape, or geometric reference with which it is associated. For instance, these terms, if associated with a value, preferably indicate a divergence of not more than 10% of the value.

Moreover, when used, terms such as “first”, “second”, “higher”, “lower”, “main” and “secondary” do not necessarily identify an order, a priority of relationship or a relative position, but can simply be used to clearly distinguish between their different components.

The measurements and data reported in this text are to be considered, unless otherwise indicated, as performed in the International Standard Atmosphere ICAO (ISO 2533).

Unless otherwise specified, as results in the following discussions, terms such as “treatment”, “computing”, “determination”, “calculation”, or similar, refer to the action and/or processes of a computer or similar electronic calculation device that manipulates and/or transforms data represented as physical, such as electronic quantities of registers of a computer system and/or memories in, other data similarly represented as physical quantities within computer systems, registers or other storage, transmission or information displaying devices.

With reference to the Figures, the tracking system according to the invention is globally referred to as 1.

The tracking system 1 is configured to track and identify the position of objects 1a in a working environment such as an industrial plant equipped for production. In detail, it is configured to define the absolute position of an object 1a, i.e. the position of the object 1 a with respect to the environment.

The tracking system 1 may comprise a server 2; one or more nodes 3 dislocated in the environment 1a and defining a communication network 1b placing in data connection the nodes 3 with the server 2; and tags 4 each of which is configured to be applied, appropriately in solidarity, to an object 1 a. Each node 3 may comprise a node identifier.

Each tag 4 may comprise a tag identifier so as to allow server 2 to identify the tag 4 and thus the object 1 a with which it is associated.

The position of an object 1 a in the environment is determined by the position of the tag 4 and the position of the node 3 to which the tag 4 is connected. The position of tag 4 identifies the position of tag 4 with respect to node 3, while the position of node 3 identifies the position of node 3 with respect to server 2 i.e. the environment.

The server 2 may comprise an object database associating to each tag 4 (in detail to each identification code) a position of the tag 4 with respect to the server 2 and therefore to the environment. Preferably, the object database associates an object 1a with each identification code and thus with a tag 4.

The server 2 may comprise a map of the environment in which to perform the tracking of the objects 1a. This map identifies the areas of possible location of objects 1a (i.e. tag 4) and those of not possible location of an object 1 a.

Server 2 may comprise a position database associating to each node 3 (in detail to each node identifier 3) the position of node 3 in the environment. The position database may be defined by an operator at the time of installation of the tracking system 1 . Alternatively or additionally, it may be defined (or at least updated as described below) automatically by the server 2.

The communication network 1 b may be a wireless network and in particular WiFi. It may define a coverage radius and thus a coverage area.

The communication network 1 b may allow a direct connection of the nodes 3 with the server 2 or, alternatively, an indirect connection of the nodes 3 with the server 2, i.e. through other nodes 3.

Suitably, the tracking system 1 comprises at least three nodes 3 so as to allow the server 2 to trilateral the position of the tag 4.

In addition to the communication network 1 b, each node 3 is configured to define a local network 1c with at least one tag 4 so that node 2 can identify the position of the tag 4 (and thus the object 1 a) with respect to node 3.

The local network 1c is a data connection between tag 4 and node 3 preferably wirelessly.

In detail, the local area network 1c is a pulse network, i.e. exploiting, appropriately periodic, pulses of radiofrequency energy of extremely reduced time duration usually of the order of a few tens of picoseconds or a few nanoseconds. More in detail, the local area network 1 c is a UWB (ultra wideband) network. Alternatively or additionally, the local network 1c is a WiFi network and in particular a WiFi Tof 802.11 me network. In detail, the local network 1 c is a WiFi Tof 802.11 me network or other wireless network such that the distance of the nodes 3 can be measured using round trip delay. Preferably, the local network 1c is a WiFi network at a different frequency from the communication network 1 b. Preferably the system 1 exploits a communication network 1 b either WiFi (in particular a Tof 802.11 me WiFi network) or pulsed (such as UWB) allowing the same system 1 to exploit the most appropriate type of communication network 1 b.

The local networks 1 c may at least partially overlap so that a tag 4 can connect to multiple nodes 3. The communication networks 1 b may at least partially overlap so that a node 3 may connect to one or more nodes 3.

The one or more communication networks may not overlap with the server 2 and thus a node 3 may connect to the server 2 via one or more nodes 3.

Each node 3 identifies a fixed reference point for the tracking system 1 , i.e., a point that is substantially stationary with respect to the environment and whose position is therefore easily identifiable with precision.

Each node 3 may comprise a first antenna configured to define the local area network 1 c; and a second antenna configured to define said communication network 1 b.

Each tag 4 may comprise a first connector 41 configured to connect the tag to the local area network 1 c and thus to at least one node 3, and a second connector 42 configured to directly connect said tag 4 to the communication network 1 b and thus to the server 2.

Each tag 4 may comprise at least one sensor 43 for detecting displacement/movement of the tag 4. The at least one sensor 43 may comprise at least one geolocation sensor configured to identify the location of the tag 4 and thus its movements. Alternatively or additionally it may comprise at least one inertial sensor such as an accelerometer configured to detect a linear acceleration and thus a linear velocity of the tag 4 and/or a gyroscope configured to detect an angular acceleration and thus tilt of the tag 4. Each tag 4 may comprise a clock 44 configured to measure the passage of time. Each tag 4 may comprise a board 45 for controlling the operation of the tag 4.

In particular, the board 45 defines for the tag 4 a first configuration in which the tag 4 functions as a tracker and allows the object 1a to be identified, and a second configuration in which the tag 4 functions as a fixed reference point (i.e., as a node 3). In the first configuration the second connector 42 is disabled and therefore the tag 4 is not connected to the communication network 1 b and therefore to the server 2 only through at least one node 3.

In this first configuration, the first connector 41 is active and therefore the tag 4 is connected to the local network 1 c and therefore to at least one node 3. Therefore, the tag 4 communicates with one or more nodes 3 which, having determined the position of the tag 4 with respect to the node 3, send the position of the tag 4 with respect to the node 3 to the server 2.

In the second configuration, the second connector 42 is active so that the tag 4 is directly connected to the communication network 1 b and thus to the server 2. The tag 4 thus functions as a node 3 by varying the coverage of the communication network

1 b.

In the second configuration, the first connector 41 is active allowing the tag 4 to receive the relative position from at least one tag 4 with respect to the tag 4 in the second configuration. In detail, in this configuration the first connector 41 defines a local network 1 c that can extend the coverage of the local networks 1 c of the nodes 3.

The board 45 is configured to command the passage in the second configuration preferably if the sensor 43 does not detect a movement for at least a time limit, i.e. if the tag 4 remains stationary for a predefined time frame detected by the clock 44. Preferably, it is configured to command passage in the second configuration if for at least a limit time the sensor 43 detects a displacement substantially less than a movement threshold.

The time limit may be at least 1 minute and in detail 5 minutes.

The motion threshold may be substantially less than 1 m and in detail substantially between 0.5 m and 0.1 m.

When a tag 4 changes configuration, the server 2 updates the position database.

In particular, if a tag 4 changes to a second configuration, the server 2 inserts the tag 4 in the positions database in the second configuration and in particular associating to it (to be precise to its identification code) the position of said tag 4 in the environment.

It should be noted that the position of tag 4 in the second configuration is calculated during the time period defined by the time limit. It is therefore calculated several times with tag 4 in the first configuration, allowing an accurate detection of its position and thus ensuring greater accuracy of the position database.

If a tag 4 passes in the first configuration, server 2 updates the position database by removing from it this tag 4 passed in the first configuration.

Finally, each tag 4 may comprise a battery or other power supply system for the tag itself.

The operation of the tracking system 1 described above in structural terms defines a new procedure for tracking objects 1 a.

Hereinafter, for the sake of clarity, nodes 3 and tags 4 in the second configuration will be referred to as "nodes 3" and only tags 4 in the first configuration as "tags 4".

The procedure may comprise at least one tracing phase in which the server 2, through one or more nodes 3, identifies the position of the tag 4 and therefore of the object 1 a with which said tag 4 is associated.

In the tracing phase, each tag 4 sends to one or more nodes 3 a first signal comprising at least its own identification code. Each node 3 receiving said first signal, sends to the server 2 the first signal and a second signal including at least the identifier of said node. It is shown that all the nodes 3 receiving said first signal send back the first signal to the server 2.

The server 2 identifies the position of the tag 4 with respect to the node 3 according to the first signal and the position of the node 3 according to the position database and in particular the position associated with the identifier of the node 3. The position of an object 1a in the environment is therefore determined by the server according to the positions of the tag 4 and the node 3 and appropriately to the object database.

The tracking phase may be performed without interruption or at regular intervals for example every 30 seconds.

The process may include a permutation phase in which a tag 4 may change configuration.

In detail, a tag 4 and, to be precise, the board 45 commands the permutation phase, that is, the passage in second configuration of the tag 4, if for at least the aforementioned time limit the sensor 43 does not detect a displacement and, to be precise, detects a displacement substantially lower than said movement threshold. The tag 4 thus begins to operate as a node 3.

Alternatively, a tag 4 may switch to the first configuration if the sensor 43 detects a displacement suitably at least equal to the movement threshold. In this case, the tag 4 stops operating as a node 3 and returns to operating as a tag 4.

At this point, the procedure may comprise at least one verification phase in which the coverage of the environment by the nodes 3 is verified.

In the verification phase, the server 2, identifying the change in configuration of at least one tag 4, updates the positions database. In detail, if a tag 4 passes to the second configuration, server 2 updates the positions database by inserting the new node 3 (i.e. to the tag 4 passed to the second configuration) associated to its position in the environment. Alternatively or additionally, if a tag 4 passes into first configuration, server 2 updates the positions database by removing it from said association database. The swap phase may be simultaneous with the tracking phase. Therefore, the position of this tag 4 can be calculated with high accuracy by taking advantage of its position calculation occurring several times in the tracing phase.

Alternatively or additionally, in this phase the server 2, for example on the basis of the position database, can verify the position of the nodes 3 and to be precise the mutual positioning of the nodes 3. On the basis of this positioning the server 2 can define the coverage of each server 2 and thus command the deactivation of one or more servers

2 if their coverage area is substantially fully overlapping with those of one or more other servers 2.

Alternatively or additionally, the server 2 may command deactivation of part of the nodes 3 sending the same first signal (i.e., a first signal from the same tag 4). Preferably, the server 2 commands the deactivation of one or more nodes 3 whose first signal has less power than the others.

As a further alternative or addition, the server 2 may command the deactivation of part of the nodes 3 based on their position with respect to the same server and with respect to one or more nodes 3. For example, the server 2 may command the deactivation of a node 3 if it identifies the position of said node 3 substantially in line with other nodes

3 (i.e., if the server 2 identifies at least one other node 3 (e.g., with a higher signal strength) on the line/axis joining the server 2 to the tag 4 under investigation).

It is highlighted that, in some cases, the procedure may include periodic verification phases of the environment coverage. The tracking system 1 according to the invention achieves important advantages.

In fact, the possibility of using the tags 4 as nodes 3 allows, in a simple, fast and economic way, to adapt the coverage of the system 1 to any changes in the environment. Another advantage is given by the particular protocols of the local network 1c. In particular, the use of UWB is particularly advantageous in the case of tag 4 within the coverage of a node 3, while Wifi is preferable with nodes 3 and therefore local network 1 c not very visible or absent. Furthermore, the adoption of a WiFi type 1 c local network (in particular 802.11 me) gives the tag the possibility to be detected by third party devices such as smartphones/Android tablets.

Another advantage is given by the high accuracy of the tracking system 1 . This aspect can be accentuated with, for example, the use of the environment map that allows to identify possible errors (identification of the position of the tag 4 in an area of no possible location) giving the system 1 a higher accuracy. Other advantages include the fact that system 1 allows real-time control of supplies to the assembly line with high precision and reliability.

A not secondary advantage is to be identified in the fact that the tracking system 1 presents a low cost and, at the same time, a high precision.

The invention is susceptible to variations within the scope of the inventive concept as defined by the claims.

For example, passing a tag in the second configuration may be defined when a tag 4 is not connected to any node 3.

In particular, a tag 4 may switch to the second configuration upon detection of an alert signal issued by a second tag 4. A tag 4 and in detail a first connector 41 may emit an alert signal if it does not detect any local network emitted by a node 3. Consequently, a permutation phase may occur and in particular the passage into the second configuration of a tag 4 when said tag 4 receives an alert signal from a second tag 4.

In this context, all details are replaceable by equivalent elements and materials, shapes and sizes can be any.

Claims

1. Tracking system (1 ) of the position of objects (1 a) in a work environment characterised by comprising:

- a server (2);

- tags (4) each of which configured to be applied to one of said objects (1 a);

- nodes (3) placed in said environment and defining a communication network (1 b) of said nodes (3) with said server (2); each of said nodes (2) defining a local data network (1 c) with at least one of said tags (3) so as to identify the relative position with respect to said tag (3) of said node (3) and therefore of said object (1a);

- said server (2) comprising a database positions associating to each node (3) a position in said environment and connected to said communication network (1 b) so as to receive said relative position from said node (3) and therefore define the position of said object (1 a) in said environment as a function of said relative position and of said position database; by that said tag (4) comprises

- a first connector (41 ) configured to connect said tag (4) to said local network (1 c);

- a second connector (42) configured to directly connect said tag (4) to said communication network (1 b);

- at least one sensor (43) for detecting the displacement of said tag;

- a clock (44) configured to measure the passage of time; and

- a control board (45) defining o a first configuration wherein said second connector (42) is deactivated and said first connector (41 ) is active allowing said tag to connect exclusively to said local network (1 c) so as to communicate said relative position to said node and o a second configuration wherein said second connector (42) is active so that said tag (4) functions as one of said nodes (4) and therefore connects to said communication network (1 b) modifying the coverage of said communication network (1 b) and said first connector (41 ) is active allowing relative position reception from at least one of said tags (41 ); by that said board (45) commands said tag (4) to switch from said first configuration to said second configuration when said sensor (43) does not detect a movement at least for a time limit; and by that said server (2) is configured to update said position database by entering the position in said environment of each of said tag (4) in said second configuration.

2. Tracking system (1) according to claim 1 , wherein said time limit is at least equal to 5 minutes.

3. Tracking system (1 ) according to at least one previous claim, wherein said board (45) commands said tag (4) to switch from said first configuration to said second configuration when said sensor (43) detects a displacement substantially lower than a threshold of movement.

4. Tracking system (1 ) according to the preceding claim, wherein said movement threshold is substantially comprised between 0.5 m and 0.1 m.

5. Tracking system (1 ) according to at least one previous claim, comprising at least three of said nodes (3) so as to allow the server (2) to trace the position of said tag (4).

6. Tracking system (1) according to at least one preceding claim, wherein said board (45) commands said tag (4) to switch from said first configuration to said second configuration upon detection of an alert signal emitted by a second tag (4).

7. Tracking system (1) according to at least one preceding claim, wherein said local network (1c) is a pulse network.

8. Tracking system (1) according to at least one previous claim, wherein said local network (1c) is a WiFi network.

9. Tracking system (1) according to claims 8 and 9, wherein said local network (1c) is at least one between a WiFi Tof 802.11 me network and a UWB network.

10. Tracking process comprising

- a tracking system (1) according to at least one preceding claim; - a tracking phase wherein said server (2), through said nodes (3), identifies the position of said tag (4) and therefore of said object (1a) to which said tag (4) is associated; and characterised by comprising

- an exchange phase in which said sensor (43) does not detect a displacement for at least said time limit and therefore said board (45) controls the passage in said second configuration;

- a verification phase wherein said server (2) updates said position database by inserting as a new node (3) the tag 4 passed in said second configuration associated with the position in the environment defined in said tracing phase.