Method and device for controlling an adaptive cruise control system of a vehicle

Description

Technical field

[0001] The present invention relates to methods and devices for controlling an adaptive cruise control system of a vehicle, in particular a motor vehicle. The present invention also relates to a method and device for regulating the speed of a vehicle. The present invention also relates to a method and device for controlling a vehicle, in particular an autonomous vehicle. Technological background

[0002] Some contemporary vehicles are equipped with functions or systems or driving assistance, called ADAS (from the English "Advanced Driver-Assistance System" or in French "Advanced Driving Assistance System").

[0003] Among these systems, the adaptive cruise control system, known as ACC (from the English "Adaptive Cruise Control"), has as its primary function the automatic, adaptive regulation of the speed of vehicles equipped with it according to their environment. Such an ACC system determines one or more acceleration instructions according to a speed instruction and information relating to the vehicle's environment, the acceleration instruction(s) being capable of regulating the speed of the vehicle adaptively, that is to say by taking into account the vehicle's environment.

[0004] This environmental information corresponds, for example, to the distance between the vehicle equipped with the ACC system and a vehicle traveling in front, to the speed (for example, relative) of the vehicle traveling in front, to the acceleration of the vehicle traveling in front and / or to a regulatory speed limit. Such a vehicle is called a target vehicle or target object of the ACC system. The acceleration setpoint(s) are, for example, determined from a control law based on estimates of the torque supplied by a powertrain (for example, a thermal or electric engine) to one or more wheels of the vehicle and the current acceleration of the vehicle.

[0005] A vehicle's environmental information is obtained, for example, from sensors embedded in the vehicle, such as radars. This information is particularly important for a vehicle, for example to improve the vehicle's safety by taking into account the surrounding environment, particularly other vehicles.

[0006] Passenger comfort is another important factor, particularly for the acceptance of driver assistance systems. For example, excessive acceleration or deceleration can cause discomfort for vehicle passengers, especially when acceleration is controlled by an ACC system. Significant acceleration or deceleration is sometimes due to late deselection of the target vehicle. The compromise between passenger comfort and safety is sometimes difficult to find.

[0007] Furthermore, the state of the art is known from document FR3087732A1, corresponding to the preamble of claim 1. Summary of the present invention

[0008] An object of the present invention is to solve at least one of the problems of the technological background described above.

[0009] Another object of the present invention is to improve the operation of an ACC system of a vehicle.

[0010] According to a first aspect, the present invention relates to a method for controlling an adaptive cruise control system, called ACC system, of a first vehicle, the method comprising the following steps: determining a first piece of information representative of a longitudinal speed and a second piece of information representative of a lateral speed of a second vehicle corresponding to a target vehicle of said ACC system; characterized in that the method comprises the steps of: determining a probability indicator that the second vehicle will make a turn having a radius of curvature determined as a function of a ratio of the first information to the second information; determining a relevance indicator associated with the second vehicle as a function of the probability indicator; controlling the ACC system as a function of the relevance indicator.

[0011] According to one variant, the probability indicator is a function of a coefficient corresponding to the ratio of the sum of the lateral speed and a constant to the absolute value of the longitudinal speed.

[0012] According to another variant, the constant is equal to 2 m / s.

[0013] According to a further variant, the probability indicator takes a determined minimum value for any value greater than a determined maximum value of the coefficient and the probability indicator takes a determined maximum value for any value less than a determined minimum value of the coefficient.

[0014] According to a further variant, the minimum determined value of the coefficient is equal to 1.33 and the maximum determined value of the coefficient is equal to 2.

[0015] According to an additional variant, the control of the ACC system includes an adjustment of a set inter-vehicle time value depending on the relevance indicator.

[0016] According to another variant, the adjustment of the set inter-vehicle time value is obtained by determining an adjusted speed of the second vehicle, the adjusted speed being determined as a function of a current speed of the second vehicle and a difference between a set speed of the ACC system and the current speed, the difference being weighted by a weighting coefficient depending on the relevance indicator.

[0017] According to a further variant, the relevance indicator being between 0 and 1, the weighting coefficient being between 0 and a maximum value, the weighting coefficient being equal to its maximum value when the relevance indicator is between 0 and a determined value less than 1, the weighting coefficient being according to a decreasing function of the relevance indicator when the relevance indicator is between the determined value and 1.

[0018] According to a second aspect, the present invention relates to a device for controlling an adaptive vehicle speed regulation system, the device comprising a memory associated with a processor configured to implement the steps of the method according to the first aspect of the present invention.

[0019] According to a third aspect, the present invention relates to a vehicle, for example of the automobile type, comprising a device as described above according to the second aspect of the present invention.

[0020] According to a fourth aspect, the present invention relates to a computer program which comprises instructions adapted for executing the steps of the method according to the first aspect of the present invention, in particular when the computer program is executed by at least one processor.

[0021] Such a computer program may use any programming language, and may be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0022] According to a fifth aspect, the present invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the method according to the first aspect of the present invention.

[0023] On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium may include a storage medium, such as a ROM memory, a CD-ROM or a microelectronic circuit type ROM memory, or a magnetic recording medium or a hard disk.

[0024] Furthermore, this recording medium may also be a transmissible medium such as an electrical or optical signal, such a signal being able to be conveyed via an electrical or optical cable, by conventional or hertzian radio or by self-directed laser beam or by other means. The computer program according to the present invention may in particular be downloaded from a network such as the Internet.

[0025] Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to perform or to be used in performing the method in question. Brief description of the figures

[0026] Other characteristics and advantages of the present invention will emerge from the description of the particular and non-limiting exemplary embodiments of the present invention below, with reference to figures 1 to 5 annexed, on which: [ Fig. 1] schematically illustrates a first vehicle following a second vehicle, according to a particular and non-limiting exemplary embodiment of the present invention; [ Fig. 2 ] schematically illustrates an indicator of the probability of the presence of a turn in the trajectory of the second vehicle of the figure 1 , according to a particular and non-limiting exemplary embodiment of the present invention; [ Fig. 3 ] schematically illustrates a weighting coefficient determined according to the probability indicator of the figure 2 , according to a particular and non-limiting exemplary embodiment of the present invention; [ Fig. 4 ] schematically illustrates a device configured to control an adaptive cruise control system of the first vehicle of the figure 1 , according to a particular and non-limiting exemplary embodiment of the present invention; [ Fig. 5] illustrates a flowchart of the different stages of a method for controlling an adaptive cruise control system of the first vehicle of the figure 1 , according to a particular and non-limiting embodiment of the present invention. Description of examples of implementation

[0027] A method and a device for controlling an adaptive cruise control system of a vehicle will now be described in the following with joint reference to figures 1 to 5 The same elements are identified with the same reference signs throughout the description which follows.

[0028] According to a particular and non-limiting example of embodiment of the present invention, the control of an adaptive cruise control system, called ACC system, of a first vehicle having as target a second vehicle traveling in front of the first vehicle comprises the determination of a first information representative of a longitudinal speed of the second vehicle and a second information representative of a lateral speed of the second vehicle, for example from data received from sensors on board the first vehicle. A probability indicator that the second vehicle makes a turn having a determined radius of curvature is determined according to a ratio of the first information to the second information. A relevance indicator associated with the second vehicle is determined according to the probability indicator. The ACC system of the first vehicle is then controlled according to this relevance indicator.

[0029] The relevance indicator corresponds, for example, to a factor or a value representing the probability that the second vehicle remains the target vehicle of the ACC system at a given time interval, for example 1, 2, 3, 5 or 10 seconds.

[0030] The relevance indicator also represents a probability that the second vehicle will remain in the lane of the first vehicle, for example, the second vehicle will initiate a turn to leave the current lane while the first vehicle wishes to continue on the current lane.

[0031] The detection of a change in trajectory of the second vehicle is obtained by determining a probability indicator that the second vehicle is in a bend or is entering a bend having a determined radius of curvature (for example a 90° bend). The relevance indicator of the second vehicle is then determined by taking into account the probability that the second vehicle is in a bend indicating a change in trajectory or traffic lane for example, which allows, if necessary, to reduce the value of the relevance indicator and to deselect the second vehicle as a target object of the ACC system more quickly. A faster deselection of the second vehicle allows the first vehicle to brake less by allowing a smaller inter-vehicle distance for a determined and short duration, the second vehicle being in a bend and deviating from the trajectory of the first vehicle.

[0032] Such adaptation of the speed regulation of the first vehicle reduces unnecessary and excessive braking, especially when the longitudinal speed of the target vehicle (i.e. the second vehicle) decreases due to the turn taken by the second vehicle.

[0033] There figure 1 schematically illustrates a first vehicle 10 following a second vehicle 11 on a portion of road in an environment 1, according to a particular and non-limiting exemplary embodiment of the present invention.

[0034] There figure 1 illustrates a first vehicle 10, for example a motor vehicle, carrying one or more sensors configured to detect the presence of objects in the environment 1 of the first vehicle 10. According to other examples, the first vehicle 10 corresponds to a coach, a bus, a truck, a utility vehicle or a motorcycle, that is to say a vehicle of the motorized land vehicle type.

[0035] The first vehicle 10 corresponds to a vehicle traveling under the full supervision of a driver or traveling in an autonomous or semi-autonomous mode. The first vehicle travels according to a level of autonomy equal to 0 or according to a level of autonomy ranging from 1 to 5 for example, according to the scale defined by the American federal agency which has established 5 levels of autonomy ranging from 1 to 5, level 0 corresponding to a vehicle having no autonomy, the driving of which is under the full supervision of the driver, level 1 corresponding to a vehicle with a minimal level of autonomy, the driving of which is under the supervision of the driver with minimal assistance from an ADAS system, and level 5 corresponding to a completely autonomous vehicle.

[0036] According to the example of the figure 1, the first vehicle 10 travels on a section of road with two traffic lanes 1001, 1002. The first vehicle 10 travels for example on the right traffic lane 1001, the two traffic lanes 1001 and 1002 being in the same direction of travel.

[0037] According to the example of the figure 1 , the first vehicle 10 follows a second vehicle 11, at a determined distance which can vary over time (depending on the dynamic behavior of the first vehicle 10 and the second vehicle 11), the second vehicle 11 traveling on the same traffic lane 1001 as the first vehicle 10 and in the same direction as the first vehicle 10. The second vehicle 11 corresponds to the target object selected by the ACC system of the first vehicle 10.

[0038] According to the example of the figure 1, the second vehicle 11 begins a right turn, for example a 90° turn, to join a traffic lane 1003. According to this example, the second vehicle 11 is in the process of maneuvering to leave the traffic lane 1001 which is followed by the first vehicle 10 and which corresponds to the path followed by the first vehicle 10. When the maneuver of the second vehicle 11 is completed, that is to say when the second vehicle is completely on the traffic lane 1003, the path followed by the second vehicle 11 will be different from the path followed by the first vehicle 10 and their respective trajectories will be different.

[0039] An object of the present invention is thus to quickly detect the change in trajectory of the second vehicle 11 when the latter begins a turn in order to quickly deselect the second vehicle 11 as the target object of the ACC system of the first vehicle 10 and thus avoid excessive braking of the first vehicle 10 which would be unnecessary.

[0040] The first vehicle 10 for example carries one or more of the following sensors: one or more millimeter wave radars arranged on the first vehicle 10, for example at the front, at the rear, on each front / rear corner of the vehicle; each radar is adapted to emit electromagnetic waves and to receive the echoes of these waves returned by one or more objects (for example the second vehicle 11 located in front of the first vehicle 10 according to the example of the figure 1), for the purpose of detecting obstacles and their distances from the first vehicle 10; and / or one or more LIDAR(s) (from the English “Light Detection And Ranging”, or “Detection and estimation of the distance by light” in French), a LIDAR sensor corresponding to an optoelectronic system composed of a laser emitting device, a receiving device comprising a light collector (to collect the part of the light radiation emitted by the emitter and reflected by any object located in the path of the light rays emitted by the emitter) and a photodetector which transforms the collected light into an electrical signal; a LIDAR sensor thus makes it possible to detect the presence of objects (for example the second vehicle 11) located in the emitted light beam and to measure the distance between the sensor and each detected object;and / or one or more cameras (associated or not with a depth sensor) for acquiring one or more images of the environment around the first vehicle 10 located in the field of vision of the camera(s).;

[0041] The data obtained from this or these sensors vary depending on the type of sensor. When it is a radar or a LIDAR, the data correspond for example to distance data between points of the detected object and the sensor. Each detected object is thus represented by a point cloud (each point corresponding to a point of the object receiving the radiation emitted by the sensor and reflecting at least part of this radiation), the point cloud representing the envelope (or part of the envelope) of the detected object as seen by the sensor and ultimately by the vehicle 10 carrying the sensor. When it is a video camera, the data correspond to data associated with each pixel of the acquired image(s), for example gray level values ​​coded on for example 8, 10, 12 or more bits for each color channel, for example RGB (from the English “Red, Green, Blue” or in French “Rouge, vert, bleu”).These data make it possible, for example, to determine the successive positions taken by an object moving in the environment 1, for example the second vehicle 11, and to deduce therefrom one or more dynamic parameters of the moving object such as the lateral speed, the longitudinal speed and / or the lateral and longitudinal accelerations. These data also make it possible to determine the lines on the ground in order, for example, to participate in determining whether the second vehicle 11 and the first vehicle 10 belong to the same traffic lane, for example.

[0042] The data acquired by the on-board sensor(s) feeds, for example, one or more driving assistance systems, known as ADAS (Advanced Driver-Assistance System) on board the first vehicle 10. Such an ADAS system is configured to assist, or even replace, the driver of the first vehicle 10 in controlling the first vehicle 10 on its route.

[0043] According to an example, the first vehicle 10 has an ADAS system corresponding to an automatic speed regulation system, called ACC system. When the ACC system is activated, the ACC system aims to achieve a setpoint acceleration, called A setpoint (t), which varies over time 't' and which makes it possible to maintain or reach a regulation speed and / or to maintain a determined safety distance from the second vehicle 11 upstream of the first vehicle 10, that is to say a target vehicle traveling in front of the first vehicle 10 in the same direction of travel on the same traffic lane. The data obtained from the sensor(s) embedded in the first vehicle 10 allow the ACC system of the first vehicle 10 to establish a target acceleration value A target (t) over time 't'. The target acceleration A target (t) becomes a longitudinal acceleration setpoint A setpoint (t).The ACC system or a computer of this system transmits for example the acceleration instructions A setpoint (t) that it has determined to the computer(s) supervising the operation of a powertrain of the first vehicle 10, in particular so that the latter determine(s) the torque instructions to be generated by the powertrain to comply with the acceleration instructions A setpoint (t) and regulate the longitudinal speed of the first vehicle 10.

[0044] A target acceleration value is for example determined at a current time t 0 from a set of data obtained from one or more object detection sensors on board the first vehicle 10 and / or from setpoint parameters entered for example by the driver or determined from data on the environment of the first vehicle 10. The target acceleration value (expressed in ms -2< ) is for example calculated from: data representative of the dynamic behavior of the second vehicle 11 (for example speed and / or acceleration), these data being for example obtained from a set of positions taken by the second vehicle 11 over a time interval preceding the current instant t 0 for which the target acceleration is determined. The data on the positions taken by the second vehicle 11 are advantageously determined from the data received from the object detection sensor(s) embedded in the first vehicle 10; data representative of the dynamic behavior of the first vehicle 10 (for example speed, acceleration, distance from the second vehicle 11), these data being obtained from sensors embedded in the first vehicle 10, the distance being for example obtained from the data received from the object detection sensor(s);and / or setpoint parameters provided to the ACC system, such as for example a target speed, a distance or a target inter-vehicle time (IVT or IVT), these parameters being stored in memory, determined by analysis of the environment (for example the target speed is determined by reading speed limit signs or from data received from a navigation system) or entered by a user via a Human-Machine Interface, known as HMI.;

[0045] A process for controlling the ACC system of the first vehicle 10 having the second vehicle 11 as the target vehicle is advantageously implemented by the first vehicle 10, that is to say by a computer or a combination of computers of the on-board system of the first vehicle 10, for example by the computer(s) responsible for controlling the ACC system.

[0046] In a first operation, a first piece of information representative of a longitudinal speed Vx of the second vehicle 11 and a second piece of information representative of a lateral speed Vy of the second vehicle 11 are determined.

[0047] The longitudinal speed Vx and the lateral speed Vy are for example obtained from data representative of a set of temporally successive positions of said second vehicles obtained from sensors embedded in the first vehicle 10 and configured to detect objects, for example moving objects, in the environment of the first vehicle 10. These data are for example expressed in a reference frame (X,Y) associated with the first vehicle 10, the X axis corresponding to the longitudinal axis and the Y axis to the transverse or lateral axis. The lateral speed Vy is representative of the speed of movement of the second vehicle 11 along the Y axis and the longitudinal speed Vx is representative of the speed of movement of the second vehicle 11 along the X axis.

[0048] According to a variant, the first information and the second information are transmitted by the second vehicle 11 and received by the first vehicle 10 via a wireless connection, for example according to a vehicle-to-everything (V2X) type communication mode or according to a vehicle-to-vehicle (V2V) type communication mode.

[0049] In a second operation, a probability indicator that the second vehicle 11 makes a turn having a determined radius of curvature is determined according to a determined function of a ratio of the first information to the second information.

[0050] The dynamic parameters or attributes of the second vehicle 11 are used to determine whether this second vehicle 11 is making a turn having a determined radius of curvature, for example a radius of curvature equal to 10 meters is representative of a 90° turn.

[0051] The probability that the second vehicle 11 makes a turn having a determined radius of curvature (for example equal to 80, 90 or 100°) is determined according to a determined function of a coefficient equal to the ratio of the longitudinal speed Vx to the lateral speed Vy (or to the absolute value of each of these quantities so that the coefficient is positive).

[0052] Indeed, it is observed that the ratio of Vx to Vy (Vx / Vy) is representative of the curvature of a bend.

[0053] In fact, the equation of an arc of a circle with radius of curvature r in the (X,Y) frame of reference of the first vehicle 10, with x the abscissa and y the ordinate is: x 2< + (y - r) 2< = r 2< (equation 1).

[0054] By temporally deriving this equation, we obtain: 2*x*Vx + 2*(yr)*Vy = 0, which gives: Vx / Vy = r − y / x

[0055] By setting k as the coefficient equal to (ry) / x, we obtain: k = Vx / Vy

[0056] Assuming y = 2 m (corresponding to a typical width of a car type vehicle) and for a radius of curvature equal to 20 m (corresponding to a radius of curvature of a portion of road corresponding to a roundabout), x is equal to 9 (obtained according to equation 1) and k is equal to 2.

[0057] For a radius of curvature equal to 10 m for example (corresponding to a radius of curvature of a 90° turn), x is equal to 6 m and k is equal to 1.33.

[0058] According to a variant, and to secure the very low speeds of the second vehicle 11, an equation (noted equation 4) of k is equal to: k = V x + eps V y with eps a constant, for example eps equal to 2 m / s or in other examples eps is equal to 1.5 or 2.5 m / s. InIn fact, when the longitudinal speed is zero or very low, the lateral speed means nothing. The data transmitted by the sensors of the first vehicle 10 being variable or oscillating, it is possible to have a non-zero lateral speed with a zero longitudinal speed, and also to have a negative lateral speed. For these reasons, an offset value eps (from the English "offset") makes it possible to secure the information on the longitudinal speed Vx to avoid having a coefficient 'k' that is too low as soon as the longitudinal speed is low. For example, the second vehicle is traveling at a longitudinal speed of between 10 and 30 km / h in a 90° bend.

[0059] There figure 2illustrates an example of such a function 20 between a probability indicator of the presence of the second vehicle in a bend having a determined radius of curvature (the probability indicator being noted Ip on the ordinate of diagram 2) and the coefficient k determined for example from equation 4 (on the abscissa of diagram 2).

[0060] The probability indicator corresponds, for example, to a value between 0 and 1 or to a value between a minimum value and a maximum value, the minimum value being, for example, equal to 0 and the maximum value being, for example, equal to 0.2 or, for example, equal to 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9.

[0061] According to the example of the figure 2 , the probability indicator takes a maximum value Ip max equal to 0.2 and a minimum value Ip min equal to 0.

[0062] The function between the probability indicator Ip and the coefficient k according to the example of the figure 2understand : a first part according to which Ip is constant with a maximum value Ipmax, for example equal to 0.2, for a coefficient k between 0 and a minimum value k 1 , for example equal to 1.33 which corresponds to a bend having a radius of curvature equal to 10 m, that is to say a 90 bend; Ip thus takes the maximum value Ip max for any bend having a radius of curvature at the radius of curvature corresponding to a coefficient k equal to k 1 (for example for any bend having a radius of curvature less than 10 m when k 1 equals 1.33)°; a second part according to which Ip decreases as k increases, Ip decreasing according to a linear function to go from the maximum equal to 0.2 at least equal to 0 between k 1 and k 2 (k 2 > k 1 ), with k2 for example equal to 2 which corresponds to a bend having a radius of curvature equal to 20 m (corresponding for example to a traffic lane on a roundabout); and a third part according to which Ip is constant and is worth the minimum value equal to 0 for any value of the coefficient k greater than or equal to k 2 , that is to say for any bend having a radius of curvature greater than 20 m for example when k 2 equals 2. .

[0063] Thus, the value of the probability indicator is smaller the larger the radius of curvature of the bend is in an interval of radii of curvature between a minimum (for example 10 m) and a maximum (for example 20 m). The probability indicator Ip is between a minimum Ip min for the radius of curvature of maximum value and a maximum Ip max for the radius of curvature of minimum value. For any bend with a radius of curvature less than the minimum radius of curvature, Ip is equal to Ip max . For any bend with a radius of curvature greater than the maximum radius of curvature, Ip is equal to Ip min

[0064] In a third operation, a relevance indicator associated with the second vehicle 11, i.e. the current target vehicle of the ACC system of the first vehicle 10, is determined based on the probability indicator Ip determined in the second operation.

[0065] The relevance indicator is for example determined by further taking into consideration a basic relevance of the target vehicle determined when the ACC system of the first vehicle 10 determines or selects the second vehicle 11 as the target vehicle.

[0066] For example, the basic relevance takes the value 1 by default when the ACC system selects a vehicle as a target vehicle, the basic relevance associated with this vehicle being equal to 0 until this vehicle has been selected as a target vehicle.

[0067] According to a variant, the value of the basic relevance depends for example on a reliability indicator associated with the detection of the vehicle selected as being the target vehicle, the basic relevance then varying between a minimum value (for example equal to 0.5, 0.6 or 0.7) and a maximum value for example equal to 1.

[0068] According to this other example, the final relevance indicator used in the rest of the process is determined or calculated according to the following equation: I = I base − Ip

[0069] With I the final relevance indicator, I base the basic relevance indicator and p the probability indicator determined in the second operation. The value of I is for example saturated or bounded between 0 and 1.

[0070] In a third operation, the ACC system of the first vehicle 10 is controlled based on the relevance indicator I.

[0071] The control of the ACC system advantageously comprises an adjustment of a value or a setpoint parameter of the system according to the relevance indicator. For example, the inter-vehicle time provided as a setpoint (TIV setpoint) or as a target (TIV target) is adjusted according to the relevance indicator.

[0072] For example, the target or setpoint value of the TIV is chosen by the driver from a set of values, for example from a set comprising a high value (for example equal to 2 s), an intermediate value (for example equal to 1.5 s) and a low value (for example equal to 1 s).

[0073] The target or setpoint value is for example adjusted so as to be: maintained when the relevance indicator reaches its maximum value; and reduced as the relevance indicator decreases, the reduction in the set or target inter-vehicle time (TIV) being, for example, limited to a minimum value.

[0074] The adjustment of the target or setpoint value of the TIV is for example obtained by adjusting the current longitudinal speed of the second vehicle 11 (for example determined by the first vehicle 10 from the data obtained from the on-board object detection sensor(s)). The adjusted longitudinal speed V ajust of the second vehicle is for example determined as a function of the current speed V target of the second vehicle 11 and of a difference between a setpoint speed V setpoint of the ACC system and the current speed V target, the difference being weighted by a weighting coefficient, denoted C p , which is a function of the relevance indicator I.

[0075] The adjusted speed V ajust of the second vehicle 11 is for example obtained by the following equation: V ajust = V cible + C p * V consigne − V cible

[0076] According to this example, the relevance indicator makes it possible to modulate or adjust the speed of the target vehicle used as input to the longitudinal controller of the ACC system to ensure that the first vehicle 10 brakes less when the second vehicle 11 takes a turn having a determined radius of curvature less than a threshold (for example less than 10, 11 or 12 m), which indicates that the second vehicle 11 changes trajectory while the first vehicle 10 maintains its own. Adjusting the relevance indicator as a function of the probability indicator makes it possible to deselect the second vehicle 11 more quickly so that it is no longer the target vehicle while it is leaving the traffic lane 1001 on which the first vehicle 10 is located and which the first vehicle 10 maintains as a traffic lane.

[0077] When the radius of curvature increases (for example when the second vehicle 11 is on a roundabout), the relevance indicator of the second vehicle is adjusted little or not at all by the probability indicator Ip which takes a value close to 0 or equal to 0. This makes it possible to keep the second vehicle 11 as the target vehicle in trajectories including gentler turns, such as roundabouts for example. This thus avoids deselecting the second vehicle 11 too quickly, which could generate too sudden and unwanted acceleration of the first vehicle 10.

[0078] There figure 3 illustrates an example of the relationship between the weighting coefficient C p (corresponding to the y-axis of diagram 3) and the relevance indicator I (corresponding to the x-axis of diagram 3), a function 30 linking these two quantities.

[0079] According to the example of the figure 3, the weighting coefficient C p is for example between 0 and a maximum value (for example equal to 0.5 or 0.6), the weighting coefficient C p being equal to its maximum value when the relevance indicator I is between 0 and a determined value (noted I d ) less than 1, the weighting coefficient being according to a decreasing function of the relevance indicator I when the relevance indicator is between the determined value I d and 1

[0080] Such a process thus makes it possible to avoid excessive braking of the first vehicle 10 triggered by the ACC system when the second vehicle 11 takes a bend whose radius of curvature is less than a threshold, indicating a change in trajectory of the second vehicle 11.

[0081] The regulation of the ACC system is modified all the more (with respect to a normal operating mode when the second vehicle remains on its trajectory without taking a bend whose radius of curvature is less than a threshold) the further the first vehicle 10 is from the second vehicle 11. In other words, the regulation of the ACC system is modified all the more (with respect to a normal operating mode) the higher the current TIV, with a lower limit and an upper limit to limit the adjustment.

[0082] There figure 4 schematically illustrates a device 4 configured to control the ACC system of a vehicle, for example of the first vehicle 10, according to a particular and non-limiting exemplary embodiment of the present invention. The device 4 corresponds for example to a device on board the first vehicle 10, for example a computer.

[0083] The device 4 is for example configured for the implementation of the operations described with regard to the figures 1 to 3 and / or steps of the method described with regard to the Figure 5 . Examples of such a device 4 include, but are not limited to, on-board electronic equipment such as a vehicle on-board computer, an electronic calculator such as an ECU (“Electronic Control Unit”), a smartphone, a tablet, a laptop. The elements of the device 4, individually or in combination, may be integrated into a single integrated circuit, into several integrated circuits, and / or into discrete components. The device 4 may be implemented in the form of electronic circuits or software (or computer) modules or even a combination of electronic circuits and software modules.

[0084] The device 4 comprises one (or more) processor(s) 40 configured to execute instructions for carrying out the steps of the method and / or for executing the instructions of the software(s) embedded in the device 4. The processor 40 may include integrated memory, an input / output interface, and various circuits known to those skilled in the art. The device 4 further comprises at least one memory 41 corresponding for example to a volatile and / or non-volatile memory and / or comprises a memory storage device which may comprise volatile and / or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic or optical disk.

[0085] The computer code of the embedded software(s) including the instructions to be loaded and executed by the processor is for example stored in memory 41.

[0086] According to various particular and non-limiting embodiments, the device 4 is coupled in communication with other similar devices or systems (for example other computers) and / or with communication devices, for example a TCU (from the English “Telematic Control Unit” or in French “Telematic Control Unit”), for example via a communication bus or through dedicated input / output ports.

[0087] According to a particular and non-limiting exemplary embodiment, the device 4 comprises a block 42 of interface elements for communicating with external devices. The interface elements of the block 42 comprise one or more of the following interfaces: RF radio frequency interface, for example Wi-Fi ®< type (according to IEEE 802.11), for example in the 2.4 or 5 GHz frequency bands, or Bluetooth ®< type (according to IEEE 802.15.1), in the 2.4 GHz frequency band, or Sigfox type using UBN (Ultra Narrow Band) radio technology, or LoRa in the 868 MHz frequency band, LTE (Long-Term Evolution), LTE-Advanced; USB interface (Universal Serial Bus); HDMI interface (High Definition Multimedia Interface); LIN interface (Local Interconnect Network).

[0088] Data is for example loaded to the device 4 via the interface of the block 42 using a Wi-Fi ®< network such as according to IEEE 802.11, an ITS G5 network based on IEEE 802.11p or a mobile network such as a 4G (or 5G) network based on the LTE (Long Term Evolution) standard defined by the 3GPP consortium, in particular an LTE-V2X network.

[0089] According to another particular and non-limiting exemplary embodiment, the device 4 comprises a communication interface 43 which makes it possible to establish communication with other devices (such as other computers of the on-board system) via a communication channel 430. The communication interface 43 corresponds for example to a transmitter configured to transmit and receive information and / or data via the communication channel 430. The communication interface 43 corresponds for example to a wired network of the CAN (Controller Area Network), CAN FD (Controller Area Network Flexible Data-Rate), FlexRay (standardized by the ISO 17458 standard) or Ethernet (standardized by the ISO / IEC 802-3 standard).

[0090] According to a particular and non-limiting exemplary embodiment, the device 4 can provide output signals to one or more external devices, such as a display screen, touch-sensitive or not, one or more speakers and / or other peripherals (projection system) via respective output interfaces. According to a variant, one or other of the external devices is integrated into the device 4.

[0091] There Figure 5 illustrates a flowchart of the different steps of a method for controlling an ACC system of a vehicle, for example of the first vehicle 10, according to a particular and non-limiting exemplary embodiment of the present invention. The method is for example implemented by a device on board the first vehicle 10 or by the device 4 of the figure 4 .

[0092] In a first step 51, a first piece of information representative of a longitudinal speed and a second piece of information representative of a lateral speed of a second vehicle corresponding to a target vehicle of said ACC system are determined.

[0093] In a second step 52, a probability indicator that the second vehicle will make a turn having a determined radius of curvature is determined based on a ratio of the first information to the second information.

[0094] In a third step 53, a relevance indicator associated with the second vehicle is determined based on the probability indicator

[0095] In a fourth step 54, the ACC system is controlled based on the relevance indicator.

[0096] According to a variant, the variants and examples of the operations described in relation to the Figure 1, 2 and / or 3 apply to the process steps of the Figure 5 .

[0097] Of course, the present invention is not limited to the exemplary embodiments described above but extends to a method for controlling a vehicle, for example an autonomous vehicle, which would include secondary steps without thereby departing from the scope of the present invention. The same would apply to a device configured for implementing such a method.

[0098] The present invention also relates to an adaptive cruise control system for a vehicle comprising the device 4 of the figure 4 .

[0099] The present invention also relates to a vehicle, for example an automobile or more generally an autonomous land-based motor vehicle, comprising the device 4 of the figure 4 or the adaptive vehicle cruise control system above.

Claims

1. A method for controlling an adaptive speed control system, referred to as an ACC system, of a first vehicle (10), said method comprising the following steps: - determination (51) of a first piece of information representative of a longitudinal speed and of a second piece of information representative of a lateral speed of a second vehicle (11) corresponding to a target vehicle of said ACC system; characterised in that the method comprises the steps of: - determination (52) of an indicator of the probability that said second vehicle (11) is making a turn having a radius of curvature determined as a function of a report of said first information on said second information; - determination (53) of a relevance indicator associated with said second vehicle (11) as a function of said probability indicator; - control (54) of said ACC system as a function of said relevance indicator.

2. Method according to claim 1, wherein said probability indicator is a function of a coefficient corresponding to the report of the sum of said lateral speed and a constant over the absolute value of said longitudinal speed.

3. Method according to claim 2, for which said constant is equal to 2 m / s.

4. Method according to claim 2 or 3, wherein said probability indicator takes a minimum value determined for any value greater than a maximum value determined for said coefficient and said probability indicator takes a maximum value determined for any value less than a minimum value determined for said coefficient.

5. Method according to claim 4, for which said determined minimum value of said coefficient is equal to 1.33 and said determined maximum value of said coefficient is equal to 2.

6. Method according to one of claims 1 to 5, for which the said control of the said ACC system comprises an adjustment of a setpoint inter-vehicle time value as a function of the said relevance indicator.

7. Method according to claim 6, for which the said adjustment of the setpoint inter-vehicle time value is obtained by determining an adjusted speed of the said second vehicle (11), the said adjusted speed being determined as a function of a current speed of the said second vehicle (11) and of a difference between a setpoint speed of the said ACC system and the said current speed, the said difference being weighted by a balance coefficient as a function of the said relevance indicator.

8. Method according to claim 7, wherein said relevance indicator is between 0 and 1, said balance coefficient being between 0 and a maximum value, said balance coefficient being equal to its maximum value when said relevance indicator is between 0 and a determined value less than 1, said balance coefficient being according to a decreasing function of said relevance indicator when said relevance indicator is between said determined value and 1.

9. Device (4) for controlling an adaptive speed regulation system of a vehicle, said device (4) comprising a memory (41) associated with at least one processor (40) configured for implementing the steps of the method according to any one of claims 1 to 8.

10. Vehicle (10) comprising the device (4) according to claim 9.