POSITION-LOCATING ARRANGEMENT

Abstract

The invention relates to a position-locating arrangement for detecting the position of a mobile object that can move inside a defined area and for processing data relative to the mobile object, said arrangement comprising a mobile identification tag (11) associated with the mobile object, and a stationary receiving device (12) configured to transmit a message from the stationary receiving device (12) to a position locating server (15) in response to receipt of an identification and data message broadcast by the mobile identification tag (11), the position-locating serves: (13), remote from the mobile identification tag (11), receiving the message from the stationary receiving device (11). The arrangement of the invention is suitable for remotely determining the position of the identification tag (11) inside the defined area and processing the data relative to the mobile object carrying same.

Claims

1. A position-locating and characterising arrangement for determining the position of a mobile object that can move inside a delimited area relative to the position-location arrangement comprising: a mobile identification tag (11) associated with the mobile object, a stationary receiving device (12) configured to transmit a stationary receiving device message to a position-locating server (13) in response to receipt of an identification and data message broadcast from the mobile identification tag (11) corresponding to the position of the identification tag itself, the position-locating server (13) remote from the mobile identification tag (11) is configured to receive the message from the stationary receiving device (12); characterised in that the stationary receiving device (12) is configured to receive a periodic identification and data message broadcast from a mobile identification tag (11); to generate a stationary receiving device message, comprising the unique identification number and data relating to the mobile object that carries the mobile identification tag (11), extracted from the identification and data message received; the stationary receiving device identification number and the RF signal strength level of the broadcast identification and data message; and to transmit the generated stationary receiving device message to the position-locating server (13); with said server being adapted to determine the position of the identification tag remotely inside the delimited area and to process the data relating to the mobile object associated with the mobile identification tag (11).

2. The arrangement according to claim 1, characterised in that the mobile identification tag (11) comprises a radio transceiver configured to broadcast, in multicast, periodic identification and data messages, including a unique identification number, to the stationary receiving device (12), when the identification tag switches from a deactivated state to an activated state.

3. The arrangement according to claim 2, characterised in that the mobile identification tag (11) periodically broadcasts unique identification and data messages to the stationary receiving devices (12) within a configurable periodic uplink transmission window.

4. The arrangement according to claim 2, characterised in that the mobile identification tag (11) comprises a magnetic sensor to couple the mobile identification tag (11) to a magnet to send an identification and data frame and to open a isolated receiving window when the magnet is brought into proximity of said magnetic sensor and coupled magnetically to the same.

5. The arrangement according to claim 4, characterised in that the magnetic sensor is configured to generate a command signal to send an identification and data frame and open a isolated receiving window.

6. The arrangement according to claim 3, characterised in that the mobile identification tag (11) comprises a push button configured to send an identification and data frame and to open a isolated receiving window when the push button is activated by pressing it.

7. The arrangement according to claim 2, characterised in that the mobile identification tag (11) includes a battery to power the mobile identification tag (11) which normally operates in standby mode until the mobile identification tag (11) switches from a deactivated state to an activated state periodically or isolatedally by means of the magnetic sensor or push button.

8. The arrangement according to claim 1, characterised in that the mobile identification tag (11) includes a plurality of sensors to supply data relating to the mobile object to which it is attached; such as the temperature, humidity, accelerometer or similar data; with the data generated by the sensors being sent within the payload of the identification and data message.

9. The arrangement according to claim 1, characterised in that the mobile identification tag (11) includes an attachment feature configured to affix the identification tag to the mobile object.

10. The arrangement according to claim 1, characterised in that the position-locating server (13) is configured to process the data received relating to the object carrying the mobile identification tag (11).

Description

BRIEF DESCRIPTION OF THE FIGURES

[0036] A more detailed explanation of the invention is given in the following description based on the attached figures:

[0037] FIG. 1 shows a block diagram of a position-locating and characterising arrangement for mobile objects to which a mobile identification tag has been attached;

[0038] FIG. 2 shows the transmission of a periodic identification and data message/frame from the mobile identification tag to a position-locating server of the position-locating and characterising arrangement for mobile objects; and

[0039] FIG. 3 shows a communications flow diagram, including the periodic transmission and receiving windows, of the position-locating and characterising arrangement for mobile objects.

DESCRIPTION

[0040] With regard to FIGS. 1 to 3, these show a position-locating and characterising arrangement to determine the position of a mobile identification tag 11 associated with a mobile object which can move within the area of coverage of a first wireless communications system.

[0041] The position-locating arrangement comprises a plurality of identification tags 11, with each identification tag 11 being configured to transmit and receive to and from a plurality of stationary devices 12 for receiving periodic identification and data messages via the first wireless communications system; in addition, each stationary receiving device 12 is configured to transmit and receive, to and from a computer-based position-locating server 13, stationary receiving device messages via a second communications system which has a transmission rate different from the transmission rate of the first wireless communications system, for the purpose of determining the position of the identification tags 11 within the area delimited by the coverage of the first wireless communications system and for processing the data relating to the mobile object.

[0042] The mobile identification tag 11 comprises a radio transceiver configured to broadcast, in multicast, periodic identification and data messages, including a unique identification number and data relating to the mobile object carrying the mobile identification tag, to the plurality of stationary receiving devices 12, when said tag 11 switches from a deactivated state to an activated state.

[0043] The periodic identification and data messages are broadcast through the first wireless communications system in the uplink direction of a communications channel established over the first wireless communications system.

[0044] The mobile identification tag 11 comprises a motion sensor configured to provide a motion signal such that the periodicity with which the periodic identification and data messages are broadcast is a function of the motion signal; i.e. as the speed of the movement of the mobile identification tag increases, the period of time between the broadcast of one transmitted periodic identification message and the next periodic identification message transmitted is shorter than the period of time between the broadcast of one transmitted periodic identification message and the following second periodic identification message transmitted when the mobile identification tag 11 is parked or stopped, in order to reduce the power consumption of a power supply included within the mobile identification tag.

[0045] The mobile identification tag 11 also comprises a magnetic sensor configured such that the tag itself switches from a deactivated state to an activated state when a magnet brought into proximity of the mobile identification tag 11, i.e. when the mobile identification tag 11 changes from the deactivated state to an activated state due to the magnetic sensor, it broadcasts at least one isolated identification and data message to the plurality of stationary receiving devices 12, and opens a similarly isolated receiving window, and it then returns to the deactivated state to save power from the mobile identification tag power supply.

[0046] The periodic identification and data message is broadcast as a radio signal and will be received by all of the stationary receiving devices 12 that receive a sufficiently strong radio signal.

[0047] The mobile identification tag 11 sends, in multicast (broadcast) mode, the identification and data message, which is received by the stationary receiving devices 12 within their corresponding areas of coverage; each stationary receiving device 12 which has received the identification and data message broadcast by the mobile identification tag 11 establishes communication with the position-locating server 13 to transmit a stationary receiving device message, including identification information, data, and RSSI.

[0048] If the same identification and data message is received simultaneously by the server from several stationary receiving devices 12, the server 13 uses the various RSSIs to calculate the position of the mobile identification tag 11.

[0049] In addition, it uses the data from the first message received, discarding the data from the other messages, to process the data relating to the mobile object that is carrying the mobile identification tag 11, for example, temperature level, alarm, battery level, etc.

[0050] The mobile identification tag 11 periodically broadcasts unique identification and data messages to the stationary identification devices. The sending period is configurable.

[0051] The identification tag 11 comprises a magnetic sensor that enables the tag to be configured to send an identification message with data outside the configurable sending period.

[0052] When a magnet is brought into proximity of the identification tag 11, the magnetic sensor is triggered, generating an event; this event is processed by the identification tag 11 such that it transmits a unique identification and data message and opens a receiving window.

[0053] The identification tag 11 comprises a push button that enables the tag to be configured to transmit an identification message with data and to open a receiving window outside the configurable sending period.

[0054] When a user presses the push button on the identification tag 11, said tag transmits an identification and data message.

[0055] The identification tag 11 also comprises at least one sensor for generation of data relating to the mobile object carrying it; temperature, humidity, accelerometer or similar type data. The plurality of sensors generate data that are sent within the payload of the identification and data message.

[0056] The stationary receiving device 12 is configured to transmit a stationary receiving device message to the position-locating server 13 in the uplink direction of a communications channel established over the second wireless communications system, in response to the receipt of an identification and data message broadcast from any identification tag.

[0057] The stationary receiving devices 12 act as a communications link between the mobile identification tags 11 and the position-locating server 13 to determine the position of the mobile identification tags 12, carried by mobile objects, within the area of coverage of the first wireless communications system.

[0058] The stationary receiving device 12 comprises a first wireless communications unit configured to receive and send messages in the uplink and downlink direction of a communications channel established in the first wireless communications system, to and from the identification tag 11, and it also comprises a second communications unit configured to send and receive messages in the uplink and downlink direction of a communications channel established in the second communications system, to and from the position-locating server 13.

[0059] Furthermore, the stationary receiving devices 12 comprise a detector unit configured to detect the RF signal strength of the broadcast identification and data message and a processing unit configured to generate a message from the stationary receiving device 12 comprising the unique identification number, extracted from the identification message received; the stationary receiving device identification number and the RF signal strength level of the broadcast identification message received by the stationary receiving device 12.

[0060] The stationary receiving device message comprises the unique identification number extracted from the identification message received; data relating to the mobile object also included in the identification message received; the stationary receiving device identification number and an RF signal strength level at which the identification and data message was received by the first wireless communications unit of the stationary receiving device, namely the Received Signal Strength Indicator, RSSI.

[0061] The position locating server 13 is configured to determine the position of the mobile identification tag 11 which broadcast the identification and data message, and to process the data broadcast from the identification tag 11.

[0062] The position-locating server 13 comprises a second communications unit configured to receive and send messages in the uplink and downlink direction of a communications channel established in the second communications system, to and from the stationary receiving devices 12; and a locator unit to determine the position of the mobile identification tag on the basis of the information data extracted from a stationary receiving device message received through the third communications unit.

[0063] The mobile identification tag 11 broadcasts, in multicast, periodic identification and data message frames, including a unique identification number and data relating to the mobile object, to the plurality of stationary receiving devices 12, within the uplink transmission window corresponding to the activated state of said tag; establishing communication with the position-locating server 13 through at least one first stationary receiving device 12. If the position-locating server 13 receives the same message from different stationary receiving devices 12, it processes the data only from the first message received and uses the RSSI data from all of the messages to calculate the position. This mode of operation is maintained as the mobile identification tag 11 moves within the area of coverage of the first wireless communications system.

[0064] According to the above, all of the stationary receiving devices 12 that receive the periodic identification and data message broadcast will generate and transmit the corresponding stationary receiving device 12 message; with the position-locating server 13 using, at each instant, the first stationary receiving device message for processing of the data relating to the object carrying the tag 11, and all of the RSSIs received being used for calculation of the location.

[0065] Therefore, the position-locating server 13, at each instant, processes the first stationary receiving device message to process the data, and all of the stationary device messages to determine the position of the mobile identification tag.

[0066] The stationary receiving devices 12 and the position-locating server 13 are connected by means of the second communications system via a wired communications connection or via a wireless communications connection.

[0067] Consequently, the first communications system does not have a roaming function or automatic transfer of a communication established between a first and a second stationary receiving device to maintain the communications established between the position-locating server and the first mobile identification tag which broadcast the periodic identification and data message.

[0068] The plurality of stationary receiving devices 12 are located at fixed positions inside the area delimited by the area of coverage of the first wireless communications system: for example, within a hospital-hype building to ensure that the position of any patient within said building can be determined.

[0069] The identification tag 11 also broadcasts non-periodic event messages to inform the position-locating server 13, for example, of the power supply or battery level or other information regarding the status of the mobile identification tag 11.

[0070] The position-locating server 13 transmits an event message frame within a periodic downlink receiving window; for example, a message to change the configuration of the periodic windows.

[0071] The position-locating arrangement 12 determines the location of a mobile identification tag in a monitored area; for example, it specifically identifies the location, room or area of a patient within a health care facility. The patient physically carries the identification tag.

[0072] The stationary receiving devices 12 can be connected to a communications network belonging to the health care facility.