WO2018041978A1

WO2018041978A1 - Device for determining a speed limit, on-board system comprising such a device, and method for determining a speed limit

Info

Publication number: WO2018041978A1
Application number: PCT/EP2017/071917
Authority: WO
Inventors: Charles-Henri QUIVY; Emilie WIRBEL
Original assignee: Valeo Schalter Und Sensoren Gmbh Fr
Priority date: 2016-08-31
Filing date: 2017-08-31
Publication date: 2018-03-08
Also published as: FR3055287A1; FR3055287B1

Abstract

The invention relates to a device (2) for determining a speed limit (L) on a travel lane used by a vehicle, said device comprising an interface (26) for receiving first speed limit information (I₁) from a navigation system (6), an analysis module (20) designed to estimate the respective relative speeds (V_i) of a plurality of third-party vehicles and to generate second speed limit information (I₂) according to said respective relative speeds (V_i), and a merging module (22) designed to determine said speed limit (L) according to the first speed limit information (I₁) and the second speed limit information (I₂). The invention also relates to an on-board system comprising such a device, and to a method for determining a speed limit.

Description

Device for determining a speed limitation, embedded system comprising such a device and method for determining a speed limitation

speed limit

TECHNICAL FIELD TO WHICH THE INVENTION RELATES The present invention relates to driving assistance systems.

It relates more particularly to a device for determining a speed limit, an onboard system comprising such a device and a method for determining a speed limitation.

The invention applies particularly advantageously in the case where it is desired to determine in advance the speed limitation to come on a traffic lane.

BACKGROUND

Vehicle driving assistance systems are known in which the speed limitation (or maximum permitted speed) is determined by means of a navigation unit, depending on the detected position of the vehicle within an electronic card. then, when approaching a traffic sign, based on an acknowledgment of the speed limit indicated on this sign.

The determination of speed limitation with the aid of an electronic card is, however, rather imprecise. Recognition on the road sign can only be done at a short distance from the road sign concerned (generally at a distance of between 60 m and 80 m) and therefore imposes a sudden change of speed (in particular in the case of a deceleration where the new maximum speed must be adopted as soon as the vehicle passes at the level of the panel).

OBJECT OF THE INVENTION

In this context, the present invention proposes a device for determining a speed limit relating to a traffic lane used by a vehicle, comprising an interface for receiving a first speed limitation information from a parking system. navigation, an analysis module designed to estimate respective relative speeds of a plurality of third-party vehicles (preceding said vehicle on the taxiway) and to generate a second speed-limiting information as a function of said respective relative speeds, and a fusion module designed to determine said speed limitation according to the first speed limitation information and the second speed limit information.

This is used to determine the speed limit information derived from the relative speeds of third vehicles observable from the vehicle equipped with the determination device. Such information is available at a distance of about 150 m to 200 m from the third vehicles concerned, ie before detection and recognition of a speed limit sign located on the edge of the taxiway.

The speed limitation to be determined is thus anticipated in advance, which makes it possible to take adequate measures early enough, such as an anticipated deceleration, and thus to avoid abrupt changes of speed during the change of speed limit.

According to other characteristics that can be envisaged as optional (and therefore not limiting):

the analysis module is designed to estimate said respective relative speeds by analyzing data supplied by a sensor (such as an image sensor or a flight time sensor);

the analysis module is designed to generate the second speed limitation information on the basis of a central tendency measurement (for example a median or an average) applied to said respective relative speeds;

the determination device comprises a panel detection module designed to generate (for example on the basis of an image acquired by a sensor) a third speed limitation information;

the fusion module is designed to determine said speed limitation as a function of the first speed limitation information, the second speed limitation information and the third speed limitation information (for example by selecting one of said speed limitation information and / or on the basis of confidence indices respectively associated with said speed limitation information).

The invention also proposes an on-board vehicle system comprising a device for determining a speed limitation as presented above, and a control unit designed to issue a command according to the determined speed limitation.

The control unit is for example designed to transmit said control based on a comparison between the determined speed limit and an instantaneous vehicle speed.

In practice, the command may be an alarm generation command for a vehicle driver, or a command (for example deceleration) for an actuator of the vehicle.

The embedded system may include said navigation system; said navigation system may further be adapted to determine a position of the vehicle and to generate said first speed limitation information as a function of the determined position.

The invention finally proposes a method for determining a speed limitation relative to a traffic lane used by a vehicle, comprising the following steps:

receiving first speed limitation information from a navigation system;

estimating respective relative speeds of a plurality of third-party vehicles;

generating a second speed limiting information as a function of said respective relative speeds;

determining said speed limit as a function of the first speed limitation information and the second speed limitation information.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT The following description with reference to the accompanying drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be implemented.

In the accompanying drawings:

- Figure 1 shows schematically elements of a system embedded in a vehicle; and

FIGS. 2 to 4 illustrate an example of use of the system of FIG.

Figure 1 shows schematically the elements of a system embedded in a vehicle useful for understanding the invention.

This system comprises a speed limitation determination device 2, a flight time sensor 4, an image sensor 5, a flight control system navigation 6, a control unit 8, a measuring unit 9 of instantaneous speed V and an actuator 10.

The speed limitation determination device 2 aims to determine (in the manner described below) the speed limit L relative to the traffic lane used by the vehicle, for the current position and the future positions of the vehicle in order to be able to anticipate a change of speed limit and control the necessary actions (eg a deceleration of the vehicle).

The flight time sensor 4 is for example a scanning laser rangefinder (or "laser scanner according to the English name sometimes used) or, alternatively, an obstacle sensor (typically infrared or laser).

The flight time sensor 4 is placed in the vehicle so as to capture data D describing the external environment of the vehicle, located at the front of the vehicle.

The environment here comprises the traffic lane used by the vehicle and the vehicles (third parties) which precede on the driving lane the vehicle equipped with the onboard system of FIG.

Such a flight time sensor 4 makes it possible to measure, for each of a plurality of directions in the environment facing the vehicle, the free distance to the first obstacle encountered in the direction in question, generally by counting down the time set by a light ray (or more generally an electromagnetic wave) emitted in the direction concerned to be detected at the time of flight sensor 4 after reflection on the first obstacle encountered. The data D are here representative of the free distances associated with the different measurement directions.

The image sensor 5 is for example a video camera. The image sensor 5 is placed in the vehicle so as to capture an IMG image of the outside environment of the vehicle, located at the front of the vehicle (that is to say, met by the vehicle when the latter is moving forward) in a solid angle A corresponding to the field of view of the image sensor 5.

The navigation system 6 includes a vehicle location device 12, a navigation unit 14 and a map database 16.

The device for locating the vehicle 12 is, for example, a device geolocation (typically GPS type for "Global Positioning System"). The vehicle location device 12 thus generates POS data representative of the position of the vehicle in a given reference frame (here the terrestrial reference).

The navigation unit 14 receives the POS data produced by the location device 12 and can thus determine the current position of the vehicle within a card C stored in the map database 1 6, and extract data from the map C associated with this current position, in particular a speed limitation information ^ associated with the traffic lane currently taken by the vehicle (according to POS position data). The navigation unit 14 may also produce a confidence index associated with the speed limitation information ^ (for example depending on the age of the data of the map C).

The actuator 10 makes it possible to control at least part of the trajectory of the vehicle. Thus, the actuator 10 may be for example a braking system, a powertrain or a steering control system.

The control unit 8 is designed to control the actuator 10 by means of a control signal CMD, and this in particular according to the speed limitation L determined by the determination device 2 and the instantaneous speed V of the vehicle measured by the unit of measurement 9.

The control unit 8 can control the actuator 10 for the purpose of driving assistance (the control unit 8 being for example designed to control a deceleration or even a braking of the vehicle, if the driver does not respect the speed limitation determined L), or for the purpose of automatic steering of the vehicle (case of an autonomous vehicle).

For example, as explained below, the speed limitation L delivered by the determining device 2 is for example relating to a portion of the taxiway located at the front of the vehicle, for example a portion of track located at a fixed distance (typically between 100 m and 200 m) at the front of the vehicle or a portion of lane located at a variable distance (which is then for example specified in data generated by the determination device 2 and which can be annexed to the speed limit L).

In this case, if the speed limitation L received from the generation device 2 indicates an increase in the authorized speed, the control unit 8 waits reaching the portion at the front (and possibly confirmation of this increase in the speed allowed by detection of a corresponding panel, as described below) before transmitting to the actuator 10 a CMD command d acceleration of the vehicle.

If the speed limitation L received from the generation device 2 indicates a decrease in the authorized speed, the control unit 8 immediately sends a deceleration command CMD to the actuator 10 so as to allow a smooth deceleration up to at the new speed allowed. The control unit 8 determines, for example, the magnitude of the deceleration as a function of the instantaneous speed V, the speed limit L received (relative to the portion situated at the front of the vehicle) and the distance of the portion the channel concerned by this speed limitation L (this distance may, for example, as already indicated be specified in data appended to the speed limitation L).

According to one conceivable variant, the command CMD generated by the control unit 8 is an activation command of an alarm (for example audible or visual) indicating to the driver of the vehicle an exceeding of the authorized speed (the control unit 8 emitting such a command when the instantaneous speed V measured by the measurement unit 8 is greater than the speed limit L determined by the determining device 2).

The speed limiting determination device 2 comprises a plurality of modules and functional blocks which are described hereinafter.

Each module or functional block corresponds to a particular functionality implemented by the determination device 2. Several (or even all) modules and functional blocks can, however, in practice be implemented by the same physical entity, for example a processor on which executes program instructions stored in a memory associated with the processor (each module or function block being then in this case implemented by the execution of a particular set of instructions stored in said memory).

The speed limiting determination device 2 comprises an analysis module 20, a panel detection module 21, a fusion module 22, an interface 24 for receiving the data D acquired by the time-of-flight sensor 4, interface for receiving IMG images acquired by the image sensor 5, an interface 26 for receiving a speed limitation information ^ transmitted by the navigation system 6 and an interface 28 for transmitting the speed limitation L determined.

FIG. 1 shows the various interfaces 24, 26, 28 as distinct (in functional terms), but these interfaces 24, 26, 28 could be implemented physically by the same circuit, for example a bus.

The analysis module 20 comprises an estimation block 30 and a synthesis block 32.

The estimation block 30 is designed to estimate, from the data D received via the interface 24, the respective relative speeds V, of the third vehicles situated at the front of the vehicle and detected by the flight time sensor 4.

For each third-party vehicle, the relative speed V of the third-party vehicle concerned is for example estimated (by shunting) on the basis of the distances measured between the flight time sensor 4 and the third-party vehicle concerned at successive acquisition times.

The estimation block 30 transmits the respective relative speeds V, of the third vehicles (and possibly the distances of these third-party vehicles) to the synthesis block 32.

The synthesis block 32 is designed to derive speed limitation information 1 ₂ based on these relative velocities V, and instantaneous velocity V using statistical calculations.

The speed limitation information I ₂ calculated by the synthesis block 32 is for example determined using a measure of central tendency applied to the set of relative velocities V i. The speed limitation information I ₂ calculated by the synthesis block 32 is typically the sum of this measure of central tendency and the measured instantaneous speed V.

In the example described here, the speed limitation information I ₂ calculated by the synthesis block 32 is determined based, for example, on the median of the relative velocities V 1. The speed limitation information I ₂ calculated by the synthesis block 32 is then, for example, the sum of the median of the relative speeds V, and the measured instantaneous speed V.

Alternatively, the speed limitation information ₁₂ calculated by the synthesis block 32 could be determined on the basis of the average of the relative velocities V 1. In practice, reliable speed limitation information 12 is obtained on the basis of relative velocities V, of third vehicles situated at about 150 m (or even 200 m), or less, at the front of the vehicle equipped with the vehicle's on-board system. figure 1 .

The synthesis block 32 can moreover also produce a confidence index associated with the speed limitation information 1 ₂ (confidence index determined, for example, as a function of the number of third-party vehicles used by the synthesis block 32 to determine the speed limitation information l ₂ ).

The synthesis block 32 can also determine the distance (at the front of the vehicle) for which this speed limitation information l ₂ is estimated (this distance being for example determined on the basis of the distances of the third vehicles possibly received from the block of estimate 30 as already indicated).

The synthesis block 32 transmits the speed limitation information l ₂ (as well as possibly the associated confidence index and / or the associated distance) to the fusion module 22.

The merging module 22 also receives via the interface 26 the speed limitation information ^ 1 emitted by the navigation system 6 (as well as possibly a confidence index associated with this speed limitation information h).

When the determination module 2 is designed to determine the speed limitation at a fixed distance to the front of the vehicle, the speed limitation information received from the navigation system 6 is the maximum authorized speed stored in the card C. for the track portion located at this fixed distance to the front of the vehicle (whose position POS in the map C is determined as already indicated by the locating device 12).

In the case where the determination module 2 is designed to determine the speed limitation at a variable distance to the front of the vehicle, it can be provided for example that the distance for which the speed limitation information l ₂ is estimated by the synthesis block 32 is communicated to the navigation system 6 so that the navigation system 6 transmits as speed limiting information ^ (via the interface 26) the maximum authorized speed stored in the card C for the portion of the track located at that distance in front of the vehicle.

The panel detection module 21 is designed to analyze the IMG images successively received from the image sensor 5 (via the interface 25) and to possibly identify in these images (typically by shape recognition) a warning sign relating to a speed limitation and, in this case, to determine ( for example by character recognition) the maximum authorized speed prescribed by this sign.

The panel detection module 21 can thus produce speed limitation information ₁₃ , which is transmitted to the fusion module 22.

Such speed limitation information ₁₃ is produced in practice at a distance of between 60 m and 80 m from the panel.

The panel detection module 21 can produce a confidence index associated with the speed limitation information ₁₃ (confidence index determined, for example, during the implementation of the recognition algorithms within the panel detection module 21 ).

The panel detection module 21 can also estimate and provide the distance (at the front of the vehicle) of the detected panel.

The fusion module 22 receives the speed limitation information h,

1 ₂ , 1 ₃ respectively provided by the navigation system 6, the analysis module 20 and the panel detection module 21, and determines, on the basis of this information h, l ₂ , I 3, the speed limit L to be transmitted to the control unit 8 via the interface 28.

The fusion module 22 is for example designed to select one of the speed limiting information h, l ₂ , I 3 as a function of the confidence indices respectively associated with the speed limiting information h, l ₂ ,

1 ₃ . A merger based on the Dempster-Shafer algorithm is an example of implementation. Another possible embodiment consists of a confirmation of λ by l ₂ as a function of the confidence index associated with the speed information l ₂ .

The selected information is transmitted as a determined speed limitation L via the interface 28 (possibly including the distance associated with the selected speed limiting information).

The speed limitation L thus determined is used by the control unit 8 as already explained above.

An example of use of the onboard system of FIG. 1 will now be described with reference to FIGS. In these figures, the arrows represent the relative speed of the third-party vehicle concerned with respect to the vehicle E equipped with the onboard system of FIG.

Figures 2 to 4 respectively show three successive instants of a situation where the vehicle E is traveling on a first portion of road on which the speed is limited to 1 30 km / h. The navigation system 6 delivers a corresponding speed limit information ^ (h = 130 km / h).

In FIGS. 2 to 4, the zone in which the third-party vehicles are detectable and which allow the analysis module to generate reliable speed limitation information 1 ₂ has been noted in FIGS. This zone Z ^ corresponds in practice to a range of 150 m and 200 m.

Z ₂ in FIGS. 2 to 4 has also been noted the zone in which a panel must be located in order to be validly analyzed by the panel detection module 21. This zone Z ₂ corresponds in practice to a range of between 60 m and 80 m.

At the first instant considered represented in FIG. 2, the third vehicles Ti, T ₂ , T ₃ , T ₄ , T ₅ detectable by the flight time sensor 4 travel at approximately the same speed (although sometimes higher, sometimes lower) than the speed V of the vehicle E.

In the case of FIG. 2, the analysis module 20 thus generates speed limitation information l ₂ of the same order as that delivered by the navigation system 6; the speed limitation L (here L = 130 km / h) delivered by the fusion module 22 is unchanged.

Note that another third T ₆ vehicle has slowed down significantly because it enters a second stretch of road, limited to 90 km / h. This third vehicle T ₆ is however located more than 200 m ahead of the vehicle E and is therefore not detected by the flight time sensor 4 and / or the analysis module 20 so that its relative speed does not affect the determined speed limit L.

In FIG. 2, no panel is also located in the zone Z ₂ and the panel detection module 21 therefore delivers no speed limitation information l ₃ .

At the second moment (after the first instant) represented in FIG. 3, certain third vehicles T ₃ , T ₄ , T ₅ approach or enter the second portion of the road (limited to 90 km / h) and have therefore slowed down to a speed of the order of 90 km / h. Their relative speed V, with respect to the vehicle E is therefore negative. The analysis module 20 therefore generates a speed limitation information l ₂ influenced by these relative speeds of the order of 90 km / h. The speed limitation information l ₂ is thus less than 130 km / h and can be for example 105 km / h (or about 90 km / h if all the third vehicles treated in the analysis module 20 were close or in the second portion, limited to 90 km / h).

The melting module 22 therefore produces a speed limitation L equal to the speed limitation information I ₂ (here for example 105 km / h), which results, as explained above, in the emission by the control unit 8 of a deceleration control for the actuator 10.

This results in an anticipated deceleration of the vehicle E, while no panel is detectable by the panel detection module 21.

At the third instant (after the second instant) shown in FIG. 4, the vehicle E has sufficiently approached the limitation panel P (at 90 km / h) of the second road portion for the panel detection module 21 to detect this panel P.

The panel detection module 21 thus generates speed limit information indicative of the ₃ this limitation to 90 km / h. The fusion module 22 receives this information and therefore selects this information 13 as a speed limit L.

The control unit 8 receives this new speed limitation value L and thus sends (to the actuator 10) a deceleration control of the vehicle E so as to reach this new limit speed L (here 90 km / h) at the passage of the panel P. Due to the anticipated deceleration of the vehicle made at the second instant (shown in Figure 3) as explained above, the deceleration to reach the new speed limit L is not abrupt.

Claims

1. Device (2) for determining a speed limitation (L) relating to a traffic lane used by a vehicle (E), comprising an interface (26) for receiving a first speed limitation information (h) in from a navigation system (6),

characterized by :

an analysis module (20) designed to estimate the respective relative speeds (V,) of a plurality of third-party vehicles (Ti, T ₂ , T ₃ , T ₄ , T ₅ ) and to generate a second limitation information velocity (l ₂ ) according to said respective relative velocities (V,);

a melting module (22) designed to determine said speed limitation (L) as a function of the first speed limiting information (h) and the second speed limiting information (l ₂ ).

2. Determination device according to claim 1, wherein the analysis module (20) is designed to estimate said respective relative velocities (V,) by data analysis (D) provided by a sensor (4).

The determining device according to claim 1 or 2, wherein the analysis module (20) is adapted to generate the second speed limitation information (1 ₂ ) based on a measure of central tendency applied to said speeds. respective relative (V,).

4. Determination device according to one of claims 1 to 3, comprising a panel detection module (21) designed to generate a third speed limitation information (l ₃ ), the fusion module (22) being designed to determining said speed limit (L) according to the first speed restriction information (h), the second speed limitation information (l ₂ ) and the third speed limitation information (l ₃ ).

Vehicle on-board system comprising a speed limiting device (2) according to one of claims 1 to 4, and a control unit (8) for issuing a control (CMD) in accordance with according to the determined speed limit (L).

An on-board system according to claim 5, wherein the control unit (8) is adapted to transmit said command (CMD) based on a comparison between the determined speed limitation (L) and an instantaneous speed (V). of the vehicle (E).

7. Embedded system according to claim 5 or 6, wherein the control (CMD) is an alarm generating command for a driver of the vehicle (E).

8. Embedded system according to claim 5 or 6, wherein the control (CMD) is a command for an actuator (10).

9. Embedded system according to one of claims 5 to 8, including said navigation system (6), said navigation system being designed to determine a position (POS) of the vehicle (E) and to generate said first limitation information of speed (h) according to the determined position (POS).

10. A method for determining a speed limitation (L) relating to a traffic lane used by a vehicle (E), comprising the following steps:

receiving first speed limiting information (h) from a navigation system (6);

estimating respective relative speeds (V,) of a plurality of third-party vehicles (Ti, T ₂ , T ₃ , T ₄ , T ₅ );

- generating a second speed limiting information (l ₂ ) according to said respective relative speeds (V,);

determining said speed limitation (L) as a function of the first speed limiting information (h) and the second speed limiting information (l ₂ ).