FR3080189A1 - DEVICE FOR GEO-LOCATION OF A MOBILE OBJECT - Google Patents

Abstract

The invention relates to a geolocation device (DISP) configured to: - calculate at least one primary position (POS1) and at least one associated primary parameter (IP1); receiving messages (M) sent by at least one transmitter (DIFF) when the geolocation device (DISP) is in a convergence phase (ph); from a part of said received messages (M), determining a secondary position (POS2) of said mobile object (V1) and at least one associated secondary parameter (IP2); according to a comparison of said at least one secondary parameter (IP2) with at least one threshold (TH), using said secondary position (POS2) as an input parameter for calculating said next primary position (POS1).

Description

GENERAL DESCRIPTION OF THE INVENTION

To this end, the invention provides a geo-location device for a mobile object, according to which said geo-location device is configured to:

- calculate at least one primary position and at least one associated primary parameter;

- receive messages sent by at least one transmitter when the geolocation device is in a convergence phase;

- from a portion of said received messages, determining a secondary position of said mobile object and at least one associated secondary parameter;

- based on a comparison of said at least one secondary parameter with at least one threshold, use said secondary position as an input parameter for the calculation of said next primary position.

Thus, as will be seen in detail later, thanks to this secondary position and its use as an input parameter for the calculation of the primary position, the convergence phase will be considerably reduced. The secondary position is used if it is more precise than the primary position previously generated by the geolocation device and if its determination is reliable.

According to nonlimiting embodiments, the geolocation device can also include one or more additional characteristics among the following.

According to a nonlimiting embodiment, said messages sent by said at least one transmitter are cooperative perception messages.

According to a nonlimiting embodiment, said geolocation device is further configured to identify your cooperative perception messages which correspond to said mobile object.

According to a nonlimiting embodiment, said geolocation device is further configured to broadcast cooperative alert messages comprising said at least one primary position and said at least one associated primary parameter.

According to a nonlimiting embodiment, said messages sent by said at least one transmitter are unicast messages.

In the case of unicast messages, according to a nonlimiting embodiment, said geolocation device is configured to receive messages sent by at least one transmitter if the geolocation device is in a convergence phase.

According to a nonlimiting embodiment, said primary position is a geo-localized position.

According to a nonlimiting embodiment, said at least one threshold is said at least one primary parameter.

According to a nonlimiting embodiment,

- Said at least one primary parameter is a primary confidence level or a primary precision level; and

- Said at least one secondary parameter is a secondary confidence level or a secondary precision level.

According to a nonlimiting embodiment, said transmitter is part of another mobile object or of another stationary object.

According to a nonlimiting embodiment, said other mobile object is a vehicle or a portable telephone.

According to a nonlimiting embodiment, said other stationary object is a fixed infrastructure.

According to a nonlimiting embodiment, said geolocation device is configured to receive messages sent by a plurality of transmitters.

According to a nonlimiting embodiment, said geolocation device is part of said mobile object.

According to a nonlimiting embodiment, said geolocation device is a real-time kinematic positioning device or a precise point positioning device.

According to a nonlimiting embodiment, said geolocation device comprises:

- a geolocation unit configured to calculate a primary position and said at least associated primary parameter;

- a transmission unit configured to receive said messages sent by said at least one transmitter;

- an electronic control unit configured for:

- according to a comparison of said at least one secondary parameter with at least one threshold, use said secondary position as an input parameter for the calculation of said primary position.

According to a nonlimiting embodiment, said location unit or said electronic control unit are further configured for:

- determine said secondary position and said at least one associated secondary parameter from a portion of said messages received;

- comparing said at least one secondary parameter with said at least one threshold.

According to a nonlimiting embodiment, the primary position makes it possible to determine whether the geo-location device is in a convergence phase.

According to a nonlimiting embodiment, said geolocation device is configured to, from all of said received messages, determine a secondary position of said mobile object and at least one associated secondary parameter.

A mobile object is also proposed comprising a geolocation device, according to any one of the preceding characteristics.

A geo-localization process for a mobile object is also proposed, comprising:

- the calculation of at least one primary position and at least one associated primary parameter;

- the reception of messages sent by at least one transmitter when the geolocation device is in a convergence phase;

- from a part of said received messages, the determination of a secondary position of said mobile object and at least one associated secondary parameter;

- as a function of a comparison of said at least one secondary parameter with at least one threshold, the use of said secondary position as an input parameter for the calculation of said next primary position.

It is also proposed a transmitter configured for:

- send messages to a mobile object from which a secondary position of said mobile object and at least one associated secondary parameter can be determined, said messages being cooperative perception messages.

It is also proposed a transmitter configured for:

- receive cooperative alert messages broadcast by a geo-location device of a mobile object, said cooperative alert messages comprising a primary position and at least one associated primary parameter;

- from said cooperative alert messages received, determine whether said geolocation device is in the convergence phase;

- if so, send messages from which a secondary position of said mobile object and at least one associated secondary parameter can be determined, said messages being unicast messages.

BRIEF DESCRIPTION OF THE FIGURES

The invention and its various applications will be better understood on reading the description which follows and on examining the figures which accompany it.

- Figure 2 shows a geolocation device of a mobile object which is a motor vehicle, according to a non-limiting embodiment of the invention;

- Figure 3a shows a motor vehicle comprising said geolocation device of Figure 2 which receives messages sent by a transmitter which is part of another mobile object, said mobile object being another motor vehicle, according to a first mode non-limiting implementation;

- Figure 3b shows a motor vehicle comprising said geolocation device of Figure 2 which receives messages sent by a transmitter which is part of another stationary object, said other stationary object being a fixed infrastructure, according to a second mode non-limiting implementation;

FIG. 4 represents a diagram of a motor vehicle on a road comprising the geolocation device of FIG. 2, said motor vehicle sending cooperative alert messages, according to a nonlimiting embodiment;

- Figure 5 shows a motor vehicle comprising said geolocation device of Figure 2 which filters the messages received from said transmitter of Figures 3a or 3b which correspond to it, when the messages are cooperative perception messages, according to one embodiment not limiting;

- Figure 6 shows said motor vehicle of Figure 4 or 5 whose convergence phase of the geo-location device has been reduced through the use of a secondary position obtained from messages received from said transmitter of Figures 3a or 3b , according to a nonlimiting embodiment;

- Figure 7 illustrates a time diagram of a geolocation process implemented by the geolocation device of Figure 2, according to a first non-limiting embodiment;

- Figure 8 illustrates a time diagram of a geolocation process implemented by the geo-location device of Figure 2, according to a second non-limiting embodiment.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Identical elements, by structure or by function, appearing in different figures keep, unless otherwise specified, the same references.

The invention relates to a DISP geolocation device for a mobile object V1.

In a nonlimiting embodiment, said geo-localization device DISP is a real-time kinematic positioning device RTK or a precise point positioning device PPP whose position calculation is based on the carrier phase of signals transmitted by satellites GNSS (“Global Navigation Satellite System” in English), using RTK (“Real Time Kinematic” in English) or PPP (“Precise Point Positioning” in English) techniques, known to those skilled in the art.

In nonlimiting embodiments, the mobile object V1 is a vehicle or a mobile phone.

In a non-limiting variant, the vehicle is a motor vehicle or a vehicle without a motor (sail, solar cells, etc.). In a nonlimiting example, the motor vehicle is a motor vehicle.

In a nonlimiting variant embodiment, the portable telephone is a so-called intelligent “Smartphone” portable telephone. The mobile phone can be carried by a user of a motor vehicle, a bicycle or by a user who is a pedestrian.

In the following description, the motor vehicle is taken as a non-limiting example for the mobile object V1. This motor vehicle V1 is also called in the following description of the primary vehicle V1.

Said DISP geolocation device is described with reference to Figures 2 to 6.

In a nonlimiting embodiment, said geolocation device DISP is part of said mobile object V1.

As illustrated in Figures 2 to 6, the DISP geolocation device is configured to:

- calculate at least one primary position POS1 and at least one associated primary parameter IP1 (function illustrated in Figure 2 CALC (DISP, EQ (POS1), IP1));

- receive messages M sent by at least one DiFF transmitter when the DISP geolocation device is in a ph convergence phase (function illustrated in Figure 2 RX (DISP, DIFF, M, ph)) i

- from a part of said messages received, determining a secondary position POS2 of said motor vehicle V1 and at least one associated secondary parameter IP2 (function illustrated in FIG. 2 DET (DISP, POS2, IP2 ");

- as a function of a comparison of said at least one secondary parameter IP2 with at least one threshold TH, use said secondary position POS2 as an input parameter for the calculation of said following primary position POS1 (function illustrated in FIG. 2 CAL (DISP , EQ (POS1, POS2))).

The DIFF transmitter is a transceiver.

In a nonlimiting embodiment, said geolocation device DISP is further configured to calculate a primary position POS1 from a calculation equation EQ described below (function illustrated in FIG. 2 CALC (DISP, EQ, POS1) )).

In a nonlimiting embodiment, said geolocation device DISP is further configured to compare said at least one secondary parameter IP2 with a threshold TH (function illustrated in FIG. 2 COMP (DISP, IP2, TH)).

* Messages M o CPM cooperative perception messages

In a first non-limiting embodiment, the messages M sent by said at least one DIFF transmitter are cooperative perception messages CPM, otherwise called CPM messages.

More particularly, the DIFF transmitter broadcasts said CPM messages. The sending of a CPM message by the DIFF transmitter is carried out via a wireless communication protocol. In nonlimiting embodiments, the wireless communication protocol is a 5G or WIFI communication protocol.

Said DIFF transmitter periodically sends said CPM messages. In a nonlimiting embodiment, it sends them every 100 milliseconds.

CPM cooperative perception messages provide less saturation in V2X and I2X communications. There are indeed fewer messages to exchange than in the case of a UNIC unicast message described below. There is indeed no CAM cooperative alert message or unicast message exchanged.

In addition, the cooperative perception messages CPM allow a better reactivity of the acceleration of the convergence time. In fact, unlike the use of a unicast message described below, it is not necessary to wait for another mobile object V2 or stationary BS to realize that the primary vehicle V1 is in a phase of convergence ph and sends a message to said primary vehicle V1 to improve the convergence time of said primary vehicle V1. Thus, the primary vehicle V1 does not expect any particular action from the mobile object V2 or stationary BS and in particular the detection of the convergence phase ph.

The DIFF transmitter is thus configured to:

- send CPM messages from which a secondary position POS2 of said mobile object V1 and at least one associated secondary parameter IP2 can be determined.

The messages M here being cooperative perception messages CPM, the secondary position POS2 of said mobile object V1 and at least one associated secondary parameter IP2 are determined from said cooperative perception messages CPM.

Furthermore, in a nonlimiting embodiment, said geolocation device DISP is further configured to identify cooperative perception messages CPM which correspond to said mobile object V1 (function illustrated in FIG. 2 IDT (DISP, M (V1)) ). FIG. 5 illustrates the primary vehicle V1 which performs such an identification.

o UNIC unicast messages

In a second non-limiting embodiment, the messages M sent by said at least one DIFF transmitter are unicast UNIC messages, otherwise called point-to-point messages. Namely, these are messages that are dedicated only to the DISP geolocation device. Sending a UNIC unicast message by the DIFF transmitter is carried out via a wireless communication protocol. In nonlimiting embodiments, the wireless communication protocol is a 5G or WIFI communication protocol.

When the messages M are UNCI unicast messages, in a non-limiting embodiment, the geo-localization device DISP is also configured to:

- broadcast cooperative alert messages CAM comprising said at least one primary position POS1 and said at least one associated primary parameter IP1 (function illustrated in FIG. 2 TX (DISP, CAM (POS1, IP1)));

A CAM cooperative alert message, also known as a CAM message, is known in English as "Cooperative Waming Message".

In a nonlimiting embodiment, a cooperative alert message CAM includes a field which indicates whether the primary vehicle V1 is in the ph convergence phase.

FIG. 4 illustrates the motor vehicle V1 which sends cooperative alert messages CAM. In the following description, the cooperative CAM alert messages are also called CAM messages.

The DIFF transmitter is thus configured to:

- receive cooperative alert messages CAM broadcast by said geo-localization device DISP of said mobile object V1, said cooperative alert messages CAM comprising a primary position POS1 and at least one associated primary parameter IP1 (function illustrated in FIG. 2 RX (DIFF, DISP, CAM (POS1, IP1));

- from said cooperative alert messages CAM received, determine whether said geo-location device DISP is in the ph convergence phase (function illustrated in FIG. 2 DET (DIFF, ph));

- if so, send unicast UN IC messages from which a secondary position POS2 of said mobile object V1 and at least one associated secondary parameter IP2 can be determined.

Thanks to cooperative alert messages, a DIFF transmitter that communicates with the primary vehicle V1 will be able to know that the DISP geo-location device is in a ph convergence phase.

Thus, UNIC unicast messages are sent if said DISP geolocation device is in the ph convergence phase.

The DIFF transmitter determines whether the DISP geolocation device is in the ph convergence phase, either by looking at the history of the primary parameter IP1, ie its evolution over time, or by looking at the field associated with the ph convergence phase. in CAM messages if it exists. The messages M being here UNIC unicast messages, the secondary position POS2 of said mobile object V1 and at least one associated secondary parameter IP2 are determined from said UNIC unicast messages.

In a nonlimiting embodiment, the geolocation device DISP is activated when the primary vehicle V1 is started.

In order to perform the functions described above, as illustrated in FIG. 2, in a nonlimiting embodiment, the DISP geolocation device comprises:

- a LOCU location unit; and

- a COMU transmission unit; and

- an ECU electronic control unit;

The COMU transmission unit is a transceiver.

In a nonlimiting embodiment:

said at least one primary parameter IP1 is a primary confidence level IC1 or a primary precision level PR1; and

- Said at least one secondary parameter IP2 is a secondary confidence level IC2 or a secondary precision level PR2.

In nonlimiting embodiments, the primary position V1 is used for driving assistance or navigation, or autoguiding, or monitoring functions.

The driving assistance functions are in non-limiting examples, a collision avoidance function or a lane change function etc.

The tracking functions are used for an emergency call in the event of an accident, in a non-limiting example.

The various functions performed by the DISP geolocation device are described in detail below.

"CalcuLdeJa.ppsit ^

The primary position POS1 is calculated by the geolocation device DISP in the following manner.

In a nonlimiting embodiment, the electronic control unit ECU is configured to calculate the primary position POS1 of the primary vehicle V1.

The primary position POS1 is calculated from distances between said primary vehicle V1 and a plurality of satellites Sj.

In a nonlimiting embodiment, the calculation of the primary position POS1 comprises:

a calculation of distances Φν (Ι, j, k) between the primary vehicle V1 and several satellites sj, calculation which uses the carrier phase of the signals emitted by the satellites Sj, based on a calculation equation EQ;

a trilateration between the distances Φν (ί, j, k) obtained.

In a nonlimiting embodiment, the EQ calculation equation is the Verhagen equation which is as follows:

For each frequency v = v1, v2, each epoch tk and each receiver pair π transmitter sj we have:

Φν (ί, j, k) - Φν, ί (ΐκ) - Φν, ί (tk - t (i, j)) + Nv (i, j) + ev (i, j, k) [EQ]

Or

The transmitter Sj is a satellite.

The receiver n is said motor vehicle V1.

Φν (Ι, j, k) corresponds to the phase observations expressed in cycles, namely the distance between the satellite Sj and the primary vehicle V1.

0v, i (tk) corresponds to the phase of the signal emitted by the satellite Sj and measured by the receiver n at the instant tk.

Φν, ί (tk - t (i, j)): corresponds to the phase during transmission by the transmitter sj. t (i, j): corresponds to the duration of transmitter-receiver propagation (in seconds).

εν (ί, j, k) corresponds to the noise terms (in cycles).

In a nonlimiting embodiment, the frequency v1 = 1,575.42 MHz and the frequency v2 = 1,227.60 MHz.

Nv (i, j): corresponds to the whole number of wavelengths between the satellite Sj and the primary vehicle V1, otherwise called whole phase ambiguities. This number is an unknown to be resolved. It will be noted that the time to resolve this unknown is generally long, which leads to a phase of convergence ph which lasts a long time. Also, at start-up at an instant t of the geolocation device DISP, the primary position POS1 which is calculated is very far from the actual position POSr of the primary vehicle V1.

As we will see below, the secondary position POS2 is used to solve this unknown Nv (i, j) which will rapidly decrease the convergence phase ph.

In a nonlimiting embodiment, the LOCU locating unit comprises a GNSS satellite navigation system called “Global Navigation Satellite System” in English, such as in nonlimiting examples the GPSTM, GLONASSTM, GALILEOTM, BEIDOUTM etc. systems. , configured to receive satellite signals.

Thanks to this GNSS satellite navigation system and using correction signals generated and transmitted by reference stations, the LOCU locating unit makes it possible to calculate the distance between said primary vehicle V1 and a Sjen satellite based on the EQ equation.

Furthermore, the LOCU location unit makes it possible to determine said at least primary parameter IP1, namely said confidence level IC1 and / or said level of precision PR1. The determination of at least one primary parameter IP1, from satellite signals being known to those skilled in the art, it is not described here.

In a nonlimiting example, when the primary parameter IP1 is a primary confidence level IC1, it may be associated with a risk of internal failure or of cyber attack determined by the localization unit LOCU.

In a nonlimiting example, when the primary parameter IP1 is a primary precision level PR1, this can be a 2D confidence ellipse around the primary position POS1.

In the nonlimiting embodiment described and illustrated in FIG. 2, the location unit LOCU transmits the distance Φν (ί, j, k) and said at least one primary parameter IP1 to said electronic control unit ECU for the calculation from the primary position POS1.

The primary parameter IP1, in particular the primary precision level PR1 thus calculated at time t and at the preceding instants t-N. N> 1 makes it possible to know if the geo-localization device DISP is in a phase of ph convergence. Indeed, a DIFF transmitter will see that at the start the accuracy is very low and that it gradually improves over time.

In a nonlimiting embodiment, to calculate the primary position POS1, four satellites sj are used.

Four respective distances Φν (ΐ, j, k) are thus obtained between the primary vehicle V1 and the four satellites, the distances being represented by spheres around each satellite Sj. By making a trilateration over the four distances, namely by taking the intersection of said spheres, we obtain the primary position POS1. Trilateration being known to a person skilled in the art, it is not described in detail here.

* M reception function.

In a nonlimiting embodiment, said transmission unit COMU is configured to receive said messages M from said at least one DIFF transmitter.

The mobile object V1, here the primary vehicle V1 in the non-limiting example taken, is configured to carry out communication, via its transmission unit COMU, with at least one DIFF transmitter.

As illustrated in FIGS. 3a and 3b, in a nonlimiting embodiment, the DIFF transmitter is part of another mobile object V2 or of an immobile object BS.

In a first nonlimiting alternative embodiment illustrated in FIG. 3b, said other mobile object V2 is another motor vehicle V2. The other motor vehicle V2 is also called secondary vehicle V2 in the following description. In another non-limiting variant embodiment not illustrated, said other mobile object V2 is a portable telephone.

In a second nonlimiting alternative embodiment illustrated in FIG. 3a, said stationary object BS is a fixed infrastructure. In a nonlimiting exemplary embodiment, the fixed infrastructure BS is a base transmission station.

In a nonlimiting embodiment, the COMU transmission unit is configured to receive messages M from a plurality of DIFF transmitters. Thus, in a nonlimiting example, the primary vehicle V1 can receive messages M from a plurality of secondary vehicles V2, or from a plurality of secondary vehicles V2 and from at least one fixed infrastructure BS, or from a plurality secondary vehicles V2 and a plurality of fixed infrastructures BS etc.

It will be noted that a message M is produced by a direct propagation known as Adhoc. It therefore spreads through a tunnel, a bridge, or in an underground car park.

Thus, the primary vehicle V1 can receive a message M even when it passes through a tunnel, under a bridge, or when it is in an underground car park, namely when the satellite signals are lost.

In nonlimiting embodiments, the messages M are cooperative perception messages CPM or unicast messages UNIC. Said messages M are described below, according to the two nonlimiting embodiments.

Furthermore, in a nonlimiting embodiment, said transmission unit COMU is configured to transmit said CPM messages to said electronic control unit ECU (function illustrated in FIG. 2 TX (M (INFa, INFb, INFc)).

o CPM messages

In the first nonlimiting embodiment where the CPM message is a cooperative perception message, the COMU transmission unit is configured to carry out a communication:

- with a secondary vehicle V2, the communication is then a so-called V2V communication. The secondary vehicle V2 is a motor vehicle with higher performance capacities than the primary vehicle V1;

- with a fixed infrastructure BS, here the base transmission station, the communication is then a V2I communication.

In the nonlimiting embodiment where the CPM message is a cooperative perception message, in a manner known to those skilled in the art, a CPM message describes the perception of a communicating entity, here the DIFF transmitter, of its environment and therefore objects surrounding it such as in non-limiting examples of cars, pedestrians, traffic signs, etc. Said communicating entity shares its perception of its environment with other surrounding entities X, including here the primary vehicle V1. Thus, the DIFF transmitter is configured to perform V2X communication when it is a secondary V2 or I2X vehicle when it is a fixed infrastructure.

In one embodiment, the DIFF transmitter is configured to determine information about objects around it that are within a radius of one kilometer.

The DIFF transmitter is configured to broadcast CPM messages.

Note that the DISP geolocation device receives CPM messages when it is in the ph convergence phase or when it is no longer in the ph convergence phase.

In a nonlimiting embodiment. a CPM message notably includes INF information on the objects which surround the DIFF transmitter, such as:

a / primary INFa information:

- an identifier of an object. Said identifier is in a nonlimiting example the license plate:

- the type of object (truck, bicycle, light vehicle etc.);

- the speed of an object;

- the acceleration of an object;

- the course of an object;

- the dimensions of an object.

This INFa information will make it possible to identify the primary vehicle V1 among the other objects which surround the DIFF transmitter.

b / secondary information INFb:

- an absolute position of the DIFF transmitter in a geocentric reference frame for example and a relative position of the detected objects in a reference frame centered on the DIFF transmitter making it possible to deduce an absolute position POS2 ’of the detected objects. In a nonlimiting example, the relative position is given by measurements of angles and of distances relative to the DIFF transmitter; or

- an absolute position POS2 ’, in a common repository of objects detected by the DIFF transmitter.

c / tertiary information INFc on the detection capacity of the DIFF transmitter. In nonlimiting examples, this tertiary information INFc is:

- the field of vision of a sensor;

- the type of sensors used;

- the quality level of a sensor, for example an error rate.

Note that to determine a relative position of an object, the DIFF transmitter needs sensors such as in non-limiting examples a radar, a lidar, an image sensor such as a camera, an ultrasonic sensor, etc.

This tertiary information INFc will be used to calculate said at least one secondary parameter IP2 '. Thus, in a nonlimiting embodiment, for each secondary information INFb and tertiary INFc, a CPM message comprises at least one associated secondary parameter IP2 ′, namely a confidence level IC2 ^! and / or an associated precision PR2 '.

It will be noted that when the transmission unit COMU receives CPM messages from a plurality of DIFF transmitters, it will receive a plurality of absolute or relative positions POS2 ’with said at least one associated secondary parameter IP2’.

o UNIC unicast message

In a nonlimiting embodiment, a UNIC unicast message comprises:

a / primary INFa information:

- the identifier of the primary vehicle V1. Said identifier is in a nonlimiting example the license plate.

b / secondary information INFb:

- the secondary position POS2 corresponding to the primary vehicle V1 in the ph convergence phase.

In a non-limiting embodiment, for each secondary information INFb, and tertiary information INFb, a unicast message UNIC comprises at least one associated secondary parameter IP2, namely a confidence level IC2 and / or an accuracy PR2 associated.

Thus, a DIFF transmitter can send a UNIC unicast message which is dedicated only to the primary vehicle V1, indicating its license plate for example.

In a nonlimiting embodiment, the primary information INFa further comprises:

the type of object (truck, bicycle, light vehicle, etc.);

- the speed of an object;

- the acceleration of an object;

- the course of an object;

- the dimensions of an object.

In a nonlimiting embodiment, the secondary position POS2 is given by:

an absolute position of the DIFF transmitter in a geocentric reference frame for example and a relative position of the primary vehicle V1 in a reference frame centered on the DIFF transmitter making it possible to deduce an absolute position POS2 of the primary vehicle V1. In a nonlimiting example, the relative position is given by measurements of angles and of distances relative to the DIFF transmitter; or

- an absolute position POS2 of the primary vehicle V1, in a common repository of objects detected by the DIFF transmitter.

In a nonlimiting embodiment, a UNIC unicast message further comprises tertiary information INFc such as that described for a CPM message.

• Functioning of CAM message broadcasting

In a nonlimiting embodiment, said transmission unit COMU is configured to broadcast said CAM messages comprising the primary position POS1 calculated by said geo-location device DISP and said at least one associated primary parameter IP1.

A cooperative alert message CAM includes information on said primary vehicle V1.

In a nonlimiting embodiment, a cooperative alert message CAM notably includes the following information INFd;

- the primary position POS1 of said motor vehicle V1 and the associated primary parameter IP1;

- an identifier of said motor vehicle V1. Said identifier is in a nonlimiting example the license plate;

- the type of said motor vehicle V1 (truck, bicycle, light vehicle etc.);

- the speed of said motor vehicle V1;

- the acceleration of said motor vehicle V1;

- the heading of said motor vehicle V1;

- the dimensions of said motor vehicle V1.

The broadcast of a cooperative CAM alert message is carried out via a wireless communication protocol. In nonlimiting embodiments, the wireless communication protocol is a 5G or WIFI communication protocol.

The motor vehicle V1 periodically broadcasts said CAM messages. In a nonlimiting embodiment, it broadcasts them every HOOmilliseconds.

* Djdentifjcation function

This identification function is performed by the geolocation device when the messages M are cooperative perception messages CPM broadcast by said at least one DIFF transmitter.

Note that there is no identification when the M messages are UN IC unicast messages.

In a nonlimiting embodiment, said electronic control unit ECU is configured to identify the CPM messages which correspond to the primary vehicle V1.

In the nonlimiting examples of FIGS. 3a and 3b, the DIFF transmitter is surrounded by five objects 01 to 05 which are here motor vehicles, the object 01 being the primary vehicle V1.

The primary vehicle V1 must be able to recover the CPM messages which correspond to it, that is to say which describe it, from among all the CPM messages broadcast by the DIFF transmitter. It must sort through all the CPM messages it receives. In the nonlimiting examples illustrated in FIGS. 4a and 4b, it indeed receives from the DIFF transmitter the CPM messages which describe it but also those which describe the other objects 02 to 05.

In a non-limiting embodiment, the identification of CPM messages is carried out with at least one of the primary information INFa of said CPM message.

Thus, in a nonlimiting example, the identification can be done with the license plate.

Thus, in another nonlimiting example, if the type and / or dimensions in all the CPM messages except one only corresponds to trucks, the primary vehicle V1 will only take the only CPM message which includes a type of vehicle which is a light vehicle.

Thus, in another nonlimiting example, if the speed and / or heading, and / or acceleration in a CPM message is substantially equal to that of the primary vehicle V1 over time, the latter can deduce that it is a message Corresponding CPM. Otherwise, it can classify this CPM message as not describing you and thus not select you.

Note that the identification can be done on a set of CPM messages broadcast by a single DIFF transmitter or by a plurality of DIFF transmitters. Thus, the identification of the CPM messages which correspond to said primary vehicle V1 results from the analysis of the multiple CPM messages received over time and coming from one or different DIFF transmitters.

* EQnçtipn.de.determjnation de.Japosjtjpn.seçondaire.PQS2

In nonlimiting embodiments, said electronic control unit ECU is configured © to determine said secondary position P0S2 and said at least one associated secondary parameter IP2.

The secondary position POS2 thus corresponds to the real position POSr of the primary vehicle V1 or comes closest to said real position POSr.

The determination is made from a portion of said messages M received by the primary vehicle V1.

o CPM message

The determination is made from a portion of said CPM messages identified as corresponding to said primary vehicle V1.

It will be noted that if only the primary vehicle V1 is located in the environment of the DIFF transmitter, then all the CPM messages will be identified as corresponding to said primary vehicle V1 and all the CPM messages will be used for determining the secondary position POS2 and said at minus a secondary parameter IP2.

Said secondary position POS2 and said at least one associated secondary parameter IP2 are thus determined from secondary information INFb of said identified CPM messages.

Thus, the secondary position POS2 is:

- determined from the absolute position of the DIFF transmitter and the relative position of the object in the frame of reference centered on the DIFF transmitter making it possible to deduce an absolute position POS2 ’from the primary object V1; or

- determined from the absolute position POS2 ’of the primary object V1 in the common repository.

When it has several CPMs sent by several DIFF transmitters, the secondary position POS2 is determined from the set of absolute positions POS2 ’received. In a nonlimiting example, the secondary position POS2 'is equal to the barycenter of all the absolute positions POS2' given in the identified CPMs. Likewise, said at least secondary parameter IP2 is determined from all the secondary parameters IP2 ’associated with the absolute positions POS2’ received.

When the secondary parameter IP2 is a confidence level IC2, in nonlimiting embodiments, the confidence level IC2 is determined from:

- 1) tertiary information INFc, detection capacities / types of sensors of the DIFF transmitter (s) having detected the primary vehicle V1 and their quality / error rate) indicated in the CPM messages identified; eü'ou

- 2) on the number of different sources of CPM messages identified, namely the number of DIFF transmitters; and or

3) on the number of identified CPM messages received over time; and or

- 4) on a risk of cyber attack evaluated by the electronic control unit ECU ("corrupt CPM message"); and or

- 5) on the consistency (over time) and plausibility of the INF information received, evaluated by ECU (for example, a car detected by the DIFF transmitter does not suddenly disappear in the middle of the highway); and or

- 6) primary information INFa, secondary INFb, tertiary INFc.

It will be noted that the level of confidence POS2 calculated translates the reliability to be granted to the secondary position POS2 determined.

When the secondary parameter IP2 is a level of precision PR2, in nonlimiting embodiments, the level of precision PR2 is determined from the levels of precision PR2 ′ of the information INF mentioned in the CPM messages, for example, the precision on the measurement of the absolute position of the DIFF transmitter. Thus, in nonlimiting embodiments, the level of precision PR2 corresponds to:

- at the barycenter of precision information PR2 ’on at least one secondary information INFb, and / or tertiary information INFc, between several CPM messages sent by different DIFF transmitters. The latter have different detection capacities, and therefore different precision capacities; or

- at the barycenter of precision information PR2 ’on at least one secondary information INFb, and / or tertiary information INFc given between several CPM messages sent by the same DIFF transmitter over time; or

- in the worst case of precision information PR2 ’on at least one secondary information INFb, and / or tertiary INFc given deduced from the CPM messages sent by all the DIFF transmitters.

o UNIC unicast message

The determination is made from said UNIC unicast messages received by said primary vehicle V1. Said secondary position POS2 and said at least one associated secondary parameter IP2 are thus obtained directly from secondary information INFb, and tertiary INFc of said unicast UNIC messages received. Unlike CPM messages, the primary vehicle V1 does not have to identify the messages since it is the only one that can receive these UNIC unicast messages.

• Utijisatjon.de.laposi ^ P.QS.2 as the entry parameter

In a nonlimiting embodiment, said one electronic control unit ECU is configured to use, according to a comparison of said at least one secondary parameter IP2 with at least one threshold TH, to use said secondary position POS2 as an input parameter for the calculation of said primary position POS1.

To this end, in a non-limiting embodiment, said one ECU control unit or said one location unit are further configured to perform a comparison between said at least one secondary parameter IP2 and at least one threshold TH (function illustrated on Figure 1 COMP (DISP, IP2, TH)).

It will be noted that in the case where the location unit LOCU determines the secondary position POS2 and performs said comparison, in this case, as a function of said comparison, the location unit LOCU will transmit said secondary position POS2 to the unit of ECU electronic control so that it uses it as an input parameter for the calculation of the primary position POS1.

In a nonlimiting embodiment, said at least one threshold TH is said at least primary parameter IP1.

As illustrated in FIG. 1, when the geolocation device DISP is activated, the current primary position POS1 is different from the actual position POSr of the primary vehicle V1.

Thus in non-limiting embodiments:

- if said at least one secondary parameter IP2 is greater than or equal to the threshold TH (for example, the secondary confidence level IC2 and the secondary precision level PR2 are greater than or equal to a given respective secondary threshold (which may respectively be the level primary confidence IC1 and the primary level of precision PR1 in a nonlimiting example); or

- if the secondary precision level PR2 is greater than or equal to the threshold TH (which can be the primary precision level PR1 in a nonlimiting example) and the secondary confidence level IC2 is greater than or equal to a given threshold (which can be the primary confidence level IC1 in a nonlimiting example); or

- if the secondary confidence level IC2 is greater than or equal to a threshold TH (which may be the primary confidence level IC1 in a non-limiting example) and the primary precision level PR1 is less than a given threshold.

then, said secondary position POS2 is used as an input parameter for the calculation of the primary position POS1; otherwise it is not used as an input parameter and the calculation is done as usual according to the EQ calculation equation described above.

Thus, if the secondary position POS2 is better than the primary position POS1 at time t, said secondary position POS2 is chosen to reduce the convergence phase ph of the geo-location device DISP and thus to improve your performance in calculating the positions following POS1 primaries, namely from time t + 1. Thus, the primary position POS1 will approach the real position POSr more quickly.

For this purpose, the secondary position POS2 is used as an input parameter for the calculation of the primary position POS1 in the following manner.

We refer to the EQ calculation equation described above.

The secondary position POS2 is used for the resolution of the unknown Nv (i, j), called ambiguity resolution.

Thus, in a nonlimiting embodiment, Nv (i, j) = whole part of [geometric distance between the satellite Sj and the receiver V1] / [wavelength of the satellite signal transmitted].

The receiver V1 is the mobile object on which is installed the geolocation device DISP, of secondary position POS2 obtained, here the primary vehicle V1.

It will be noted that the geometric distance between the satellite sj and the receiver V1 is known because it is regularly broadcast by the satellite itself in the ephemeris or received from external infrastructures.

In a nonlimiting example, the satellite signal is broadcast at a frequency v1 of 1575.42MHz, which corresponds to a wavelength of 19cm (centimeters).

As described above, in a nonlimiting embodiment, to calculate the primary position POS1, at least four satellites are used sjOn thus obtains at least four respective distances, deduced from Φν (ί, j, k), between the primary vehicle V1 and the four satellites. By making a trilateration on the four distances, namely by taking the intersection of four spheres whose radius corresponds respectively to the previous four distances, we obtain the primary position POS1 at the instant t + 1.

Thus, thanks to the secondary position POS2 which is better (because more precise) than the primary position POS1 calculated at the previous instant t, we quickly manage to converge the primary position POS1 calculated at times t + 1 and following to the position real POSr of the primary vehicle V1.

FIGS. 7 and 8 illustrate a time diagram of a geolocation method PR implemented by the geolocation device DISP described above, respectively according to a first and a second nonlimiting embodiment.

The different elements of the DISP geo-localization device (COMU transmission unit, ECU electronic control unit, LOCU localization unit) which participate in the stages of the PR correction process are described below.

In this illustrated nonlimiting embodiment:

- the DIFF transmitter is another motor vehicle, namely here the secondary vehicle V2.

the threshold TH for the comparison is said at least one primary parameter IP1 including a primary confidence level IC1 and a primary precision level PR1.

- the electronic control unit ECU determines the secondary position POS2, performs the comparison and executes the EQ calculation equation;

In a nonlimiting embodiment, the geolocation method PR is executed as soon as the geolocation device DISP is activated.

The geolocation device is in a phase of ph convergence.

* Pr.emi.ei.fnode of realization

According to this first embodiment, your messages M are cooperative perception messages CPM broadcast by the DIFF transmitter.

In step 1), the geolocation device DISP calculates at least one primary position POS1 of the primary vehicle V1 with the equation EQ and calculates said at least associated primary parameter IP1.

In a nonlimiting example, the geolocation device DISP calculates a plurality of primary positions POS1 at times t-N until t, N> 1.

In step 2), the secondary vehicle V2 broadcasts CPM messages.

In I step 2), the transmission unit COMU receives CPM messages broadcast by the secondary vehicle V2 and sends it to the electronic control unit ECU in step 2 ”). The CPM messages include the primary information INFa, secondary INFb and tertiary INFc described above. The DISP geolocation device thus receives these CPM messages when it is in its ph convergence phase.

In step 3), the electronic control unit ECU filters the CPM messages received. It thus identifies the CPM messages which correspond to the primary vehicle V1 and recovers them.

In step 4), from said identified CPM messages, in particular from the information INF that they contain, the electronic control unit ECU determines a secondary position POS2 of the primary vehicle V1 and said at least one associated secondary parameter IP2.

In step 5), the electronic control unit ECU compares said at least one secondary parameter IP2 with said threshold TH which is said at least one primary parameter IP1.

In the nonlimiting exemplary embodiment described, the secondary confidence level IC2 is greater than the primary confidence level IC1 and the secondary precision level PR2 is greater than the primary precision level PR1. The secondary position POS2 thus has better reliability and better precision than the primary position POS1.

It will be taken into account in the EQ calculation equation of the primary position POS1.

In step 6), as a function of said comparison, the electronic control unit ECU uses the secondary position POS2 as an input parameter to calculate said next primary position POS1, namely at the next instant t + 1 and t + N, N> 1 following.

We stop using the secondary position POS2 as an input parameter in the EQ calculation equation of the primary position POS1, when the convergence phase ph has reached the desired precision, namely a few centimeters.

Thus, the calculation equation EQ integrates the secondary position POS2 to calculate the following primary position POS1, as described above.

The convergence phase ph is thus reduced, since the next new primary position POS1 is much more precise than the previous primary position POS1 (at time t) thanks to the use of the secondary position POS2. We thus arrive very quickly to calculate a primary position POS1 which is very close to or equal to the real position POSr of the primary vehicle V1.

This new primary position value POS1 will thus be used for the driving assistance or navigation functions for example. The latter will thus provide correct data to the user of the primary vehicle V1.

Thus, thanks to the DISP geolocation device, the ph convergence phase is reduced.

* Second mode of realization

According to this second embodiment, the messages M are unicast UNIC messages sent by the DIFF transmitter.

In step 1), the geolocation device DISP calculates at least one primary position POS1 of the primary vehicle V1 with the equation EQ and calculates said at least associated primary parameter IP1.

In a nonlimiting example, the geolocation device DISP calculates a plurality of primary positions POS1 at times t-N up to t. N> 1.

In step 2), the transmission unit COMU broadcasts CAM messages comprising said at least one primary position POS1 calculated by said geo-location device DISP and at least one associated primary parameter IP1 including the primary confidence level IC1 and a primary precision level PR1.

In step 2 ’), the secondary vehicle V2 receives said CAM messages. By observing the history of said at least one primary parameter P1, it can define whether the DISP geolocation device is in the ph convergence phase. So, for example, he will see that the primary precision level PR1 is gradually improving.

In step 3), the secondary vehicle V2 then sends UNIC unicast messages.

In step 3 '), the COMU transmission unit receives the UNIC unicast messages and transmits them to the electronic control unit ECU in step 3 ”).

In step 4), on the basis of said unicast UNIC messages, the electronic control unit ECU determines the secondary position POS2 of the primary vehicle V1 and said at least one associated secondary parameter IP2. In particular, it retrieves the secondary position POS2 and said at least one associated secondary parameter IP2 in the secondary information INFb.

The following steps 5) and 6) are the same as those described in the first embodiment of FIG. 7.

For the two embodiments of FIGS. 7 and 8, it will be noted that steps 1 to 6 are repeated if one returns to the phase of convergence ph, for example in the event of loss of the satellite signal requiring recalculation I unknown Nv (i, j ). The satellite signal is lost when the primary vehicle V1 passes under a bridge in a nonlimiting example. Note that what has been described in this embodiment with the secondary vehicle V2 can be applied for the base transmission station BS.

Of course, the description of the invention is not limited to the application, the embodiments and the examples described above. Thus, in another nonlimiting embodiment, the other mobile object V2 is a truck, a motorcycle, a bicycle, a boat, etc.

Thus, in another non-limiting embodiment, the mobile object V1 is a truck, a motorcycle, a bicycle, a boat, etc.

Thus, in another nonlimiting embodiment, the fixed infrastructure BS is a marine infrastructure.

Thus, in other nonlimiting embodiments, the broadcasting of a CPM message by the DIFF transmitter is carried out via a 3G / 4G / XG or Bluetooth ™ wireless communication protocol.

Thus, in other nonlimiting embodiments, the broadcasting of a CAM message by the mobile object V1 is carried out via a 3G / 4G / XG or Bluetooth ™ wireless communication protocol.

Thus, the invention described has the following advantages in particular:

- it is simple to implement;

thanks to exchanges of CPM and CAM messages, which are collaborative messages, it makes it possible to quickly arrive at obtaining a precise primary position POS1;

- It thus makes it possible to converge very quickly towards the real position POSr of a motor vehicle. This saves time when starting the geolocation device.

Claims (16)

1. Geo-location device (DISP) of a mobile object (V1), according to which said geo-location device (DISP) is configured to: - calculate at least one primary position (POS1) and at least one associated primary parameter (IP1); - receive messages (M) sent by at least one transmitter (DIFF) when the geolocation device (DISP) is in a convergence phase (ph); - from a part of said messages (M) received, determining a secondary position (POS2) of said mobile object (V1) and at least one associated secondary parameter (IP2); - according to a comparison of said at least one secondary parameter (IP2) with at least one threshold (TH), use said secondary position (POS2) as an input parameter for the calculation of said following primary position (POS1). 2. Geolocation device (DISP) according to claim 1, according to which said messages (M) sent by said at least one transmitter (DIFF) are cooperative perception messages (CPM). The geo-location device (DISP) according to claim 2, wherein said geo-location device (DISP) is further configured to identify cooperative perception messages (CPM) which correspond to said mobile object (V1). 4. Geo-location device (DISP) according to claim 1, according to which said geo-location device (DISP) is further configured to broadcast cooperative alert messages (CAM) comprising said at least one primary position (POS1 ) and said at least one associated primary parameter (IP1). 5. A geolocation device (DISP) according to claim 4, according to which said messages (M) sent by said at least one transmitter (DIFF) are unicast messages (UNIC). 6. Geo-location device (DISP) according to any one of claims 1 to 5, according to which said primary position (POS1) is a geo-localized position. 7. A geolocation device (DISP) according to any one of claims 1 to 6, according to which said at least one threshold (TH) is said at least one primary parameter (IP1). 8. Geo-location device (DISP) according to any one of claims 1 to 7, according to which: - Said at least one primary parameter (IP1) is a primary confidence level (IC1) or a primary precision level (PR1); and - Said at least one secondary parameter (IP2) is a secondary confidence level (IC2) or a secondary precision level (PR2). 9. Geo-location device (DISP) according to any one of claims 1 to 8, according to which said transmitter (DIFF) is part of another mobile object (V2) or another stationary object (BS). 10. A geolocation device (DISP) according to claim 9, according to which said other mobile object (V2) is a vehicle or a mobile telephone. 11. A geolocation device (DISP) according to claim 9 or claim 10, according to which said other immobile object (BS) is a fixed infrastructure. 12. Geolocation device (DISP) according to any one of claims 1 to 11, according to which said geolocation device (DISP) is part of said mobile object (V1). 13. Geolocation device (DISP) according to any one of claims 1 to 12, according to which said geolocation device (DISP) is a real time kinematic positioning device (RTK) or a precise point positioning device ( PPP). 14. Geolocation device (DISP) according to any one of claims 1 to 13, according to which said geolocation device (DISP) comprises: - a geolocation unit (LOCU) configured to calculate said at least one primary position (POS1) and said at least associated primary parameter (IP1); - a transmission unit (COMU) configured to receive said messages (M) sent by said at least one transmitter (DIFF); - an electronic control unit (ECU) configured for: - according to a comparison of said at least one secondary parameter (IP2) with at least one threshold (TH), use said secondary position (POS2) as an input parameter for the calculation of said primary position (POS1). 15. A geolocation device (DISP) according to claim 14, according to which said location unit (LOCU) or said electronic control unit (ECU) are further configured for: - determining said secondary position (POS2) and said at least one associated secondary parameter (IP2) from a portion of said messages (M) received; - compare said at least one secondary parameter (IP2) with said at least one threshold (TH). 16. Geolocation method (PR) of a mobile object (V1), comprising: - the calculation of at least one primary position (POS1) and at least one 5 associated primary parameter (IP1); - the reception of messages (M) sent by at least one transmitter (DIFF) when the geolocation device (DISP) is in a convergence phase (ph); - from a part of said messages (M) received, the determination 10 of a secondary position (POS2) of said moving object (V1) and at least one associated secondary parameter (IP2); - according to a comparison of said at least one secondary parameter (IP2) with at least one threshold (TH), the use of said secondary position (POS2) as an input parameter for the 15 calculation of said next primary position (POS1).