FR2816892A1 - Method of adaptive regulation of motor vehicle speed during overtaking involves determining driver characteristics to control overtaking acceleration - Google Patents

Abstract

The method of adaptive regulation of motor vehicle speed during overtaking involves using a vehicle mounted regulation circuit for speed and distance using an electronic control for acceleration. The control circuit has an interface with the user operated acceleration control so that the acceleration of the vehicle is a function of time, taking into account driver characteristics.

Description

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 The invention relates to a method for adaptively regulating the speed of a vehicle, equipped with a system for regulating speed and distance, when it is overtaking a target vehicle traveling in the same direction, in order to improve driver safety and comfort.

 Currently, the automatic traction control systems of a vehicle operate in two modes: a first mode of speed regulation according to a set point requested by the driver, and a second mode of distance regulation according to a set point relative to the target vehicle tracked. When this target vehicle is exceeded by the regulated vehicle, the target is gradually lost, causing the system A. C. C. - "Adaptive Cruise Control" to switch from a distance regulation mode to a speed regulation mode. With current systems, this mode change is poorly felt by drivers due to the fact that switching to cruise control alone induces an uncomfortable acceleration "hole" with the feeling that the vehicle is "collapsing", especially when overtaking in heavy traffic situations.

 The European patent application published in the name of FORD, under the number EP 0897824, relates more specifically to the control of the motor during a transition between speed regulation and distance regulation, in the case of overtaking. The proposed solution is a device of anticipation aiming at displaying on the dashboard a light informing the driver of the entry in regulation in distance while this mode is not really engaged. The time during which this warning light is on, although the system is not actually in distance control, corresponds to a reasonable time during which the driver can assess the appropriateness of overtaking and carry it out. In the event that it exceeds this limit during this period of time, it remains in speed reference during the entire excess without ever having gone through a distance regulation mode. This solution is only a device and not a specific law applied when a target is exceeded.

 The European patent application published in the name of VOLKSWAGEN, under the number EP 0989012, addresses the adaptation of the laws regulating

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 distance and speed to driving situation and recognition of driving style. Detection modules make it possible to recognize different categories of environment and / or conductors in order to choose the control law of the A. C. C. best suited to the recognized situation. The situation of overtaking a target vehicle is mentioned as a particular situation to be detected, but this patent application does not in any way specify how this detection is carried out, nor how the law for controlling the acceleration of the vehicle is then adapted. to the recognition of this situation.

 To overcome these drawbacks, the invention proposes to generate laws for controlling the acceleration of the vehicle regulated in distance and in speed, which are adapted to the disengagement situation and different according to the ACC regulation mode engaged depending on the calm character, dynamic or sporty driver.

)-cc-+/o la valeur de l'accélération à l'origine yo ainsi que la pente PACC de la courbe dépendant du caractère de conduite du conducteur, et en ce que cette accélération est annulée quand la vitesse du véhicule vA (t) atteint la consigne de vitesse VACC fixée par le conducteur en régulation de vitesse. For this, the object of the invention is a method of adaptive regulation of the speed of a vehicle when overtaking another target vehicle traveling in the same direction, equipped with an on-board speed regulation system and distance by electronic acceleration control including in particular a control interface with the driver, characterized in that, from the detection of said overshoot, the acceleration of the regulated vehicle is a linear function of time, of your ton:

) -cc - + / o the value of the acceleration at the origin yo as well as the slope PACC of the curve depending on the driving behavior of the driver, and in that this acceleration is canceled when the vehicle speed vA (t ) reaches the VACC speed setpoint set by the driver in speed control.

 Other characteristics and advantages of the invention will appear on reading the description, illustrated by the following figures which are: FIG. 1: the diagram of a situation of monitoring of a target vehicle by a vehicle under regulation of distance;

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 - Figures 2 to 4: diagrams of three situations when a target vehicle is exceeded by a speed-regulated vehicle, according to the invention; - Figure 5: the block diagram of the adaptive speed control method of a vehicle in overtaking situation; FIG. 6: three examples of speed profiles generated for a regulated vehicle according to the method of the invention.

 The elements bearing the same references in the different figures fulfill the same functions for the same results.

 The object of the invention consisting in managing the acceleration of the regulated vehicle in the particular situations of overtaking of a target vehicle, it is above all necessary to recognize such overtaking. This recognition can be done by switching on the left turn signal - for driving normally on the right - by the driver wishing to disengage according to the basic rules of the highway code. As the regulation by A. C. C. is intended for use on motorways, this first condition is always true outside urban areas. In addition, as the acceleration control law according to the invention, in the overtaking phase, is always under the control of the distance regulation of the A. C. C., a hesitation of the driver or a abandonment of the overtaking maneuver will not cause a collision with the target vehicle.

 This recognition can also be done using other criteria based on the mobility of the driver on the highway, from the angle of his steering wheel, the set speed, navigation information locating the driver and his vehicle on a road map or on-track positioning systems. The combination of all these criteria makes it possible to discriminate between the desire to exceed a moving target and an indication of change of direction around an agglomeration - peri-urban motorways for example -, or even to extend the use of ACC. off the highways.

 Recognition of the desire to overtake must be carried out before the maneuver itself has actually started, so that the driver is not surprised by a change in the behavior of his vehicle and that his driving remains fluid. All of the information

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 previously cited to recognize a dislocation can be used in methods using discriminant analysis, fuzzy logic or a neural network for example.

 According to the diagram in FIG. 1, a vehicle A equipped with a distance and speed regulation system, of the ACC type, follows a vehicle C called a target which is traveling on the same traffic lane, in the same direction, at the speed goes. The regulated vehicle A travels at the speed vA (t), which becomes equal to va when it is in distance regulation to follow the target vehicle traveling at the speed va at a constant distance. In the speed regulation phase, the driver of the regulated vehicle can choose a speed setpoint vACC which, when it is higher than the speed Va of the target C, encourages him to disengage to exceed it.

 Overtaking begins at time To, after the driver of vehicle A has mentioned his intention to overtake target vehicle C, for example by switching on the flashing light. Vehicle A is then in position to follow the target at speed va 1 while its speed regulation setpoint is equal to vACC, greater than va so that the overrun is justified.

 The overtaking situation can be divided into three consecutive phases: - a first phase, called acceleration or setting up of the target vehicle to be overtaken, during which the regulated vehicle will accelerate until it is positioned at the height of its target, - a second so-called speed maintenance phase, during which the regulated vehicle no longer accelerates but exceeds the target vehicle at a constant speed equal to the VACC speed setpoint, - a third so-called drawdown phase, corresponding to the change of lane of the regulated vehicle which joins the queue of the target by positioning itself in front of it, while keeping its set speed vacs when the road traffic allows it. Otherwise, this phase corresponds to a deceleration of the vehicle.

 According to an essential characteristic of the invention, from the instant To of detection of an overrun, the method of adaptive regulation of the

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(i) YA (t) = dVA (t) = PACC't + IVO du

Cette linéarité de l'accélération donne au conducteur la sensation d'accélérer de façon continue. speed of the follower vehicle controls the acceleration of this vehicle so that it is a linear function of time, of the form:

(i) YA (t) = dVA (t) = PACC't + IVO du

This linearity of acceleration gives the driver the sensation of accelerating continuously.

 In addition, the PACC slope of the acceleration curve depends on the driving style, varying depending on whether the driver's character is calm, dynamic or sporty.

 Similarly, to mark the entry into this overtaking phase, the initial acceleration yo, to To, also depends on the sportiness of the driver. Thus, it is zero, for example, for a driver considered to be calm, who wishes to drive smoothly, but it is important on the contrary for a sports driver.

sa cible et va poursuivre son dépassement avec cette vitesse, l'accélération est

nulle : dl (2) yA (Ti) = dt = 0

Cela dans le but de satisfaire le critère de souplesse de conduite pour un maximum de confort lors de la transition entre la phase d'accélération et la phase de maintien de la vitesse au cours du dépassement. According to another essential characteristic, at the instant T1 when the regulated vehicle has reached the speed setpoint ACC after having accelerated to exceed

its target and will continue to overtake with this speed, the acceleration is

null: dl (2) yA (Ti) = dt = 0

This is in order to satisfy the criterion of driving flexibility for maximum comfort during the transition between the acceleration phase and the speed maintenance phase during overtaking.

From the instant To of the start of the acceleration phase, the method calculates the instant Ta of the end of this phase, when the speed vA (t) of the vehicle has reached the setpoint VACC-
Starting from equation (1) of linear acceleration, the speed of the regulated vehicle is written:

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(3) VA (t) = 1 PA *t 2+yo t+v,, 1 2

A l'instant Ti de fin d'accélération :

(4) VA (TI) = 1 PAC (-"T1'Yo'Tl +Vo (4) (VA (Tl) = 2 PACO T2+ YO TI+vo .) -7=0

Ainsi, l'accélération Y0 à l'origine et la pente PACC de la courbe s'écrivent :

, 2 [ (TI)-] rut PACC =-Ti2

Considérant que la première phase d'accélération se termine lorsque le véhicule régulé A se trouve à la hauteur de la cible à dépasser, soit plus précisément quand l'arrière du véhicule A se situe à la hauteur de l'avant de la cible C, la distance dA parcourue par le véhicule A à la vitesse VA (t) jusqu'à l'instant Ti est obtenue en intégrant la vitesse selon l'équation (6) :

2 2Av (6) =j\). (--. (6) dA = 1 VA t. dt= 1 (-2. t ±. t+vo) dt TI TI

en posant Av = VA (Ti)-vo Cette distance parcourue par le véhicule régulé est égale à la distance parcourue par la cible C à la vitesse Vo constante et uniforme jusqu'à T1, à laquelle on ajoute la distance de suivi ds et la longueur du véhicule cible de, d'environ 4 mètres.

(3) VA (t) = 1 PA * t 2 + yo t + v ,, 1 2

At the instant Ti at the end of acceleration:

(4) VA (TI) = 1 PAC (- "T1'Yo'Tl + Vo (4) (VA (Tl) = 2 PACO T2 + YO TI + vo.) -7 = 0

Thus, the acceleration Y0 at the origin and the slope PACC of the curve are written:

, 2 [(TI) -] rut PACC = -Ti2

Considering that the first acceleration phase ends when the regulated vehicle A is at the height of the target to be exceeded, more precisely when the rear of the vehicle A is at the height of the front of the target C, the distance dA traveled by the vehicle A at the speed VA (t) to the instant Ti is obtained by integrating the speed according to equation (6):

2 2Av (6) = j \). (-. (6) dA = 1 VA t. Dt = 1 (-2. T ±. T + vo) dt TI TI

by setting Av = VA (Ti) -vo This distance traveled by the regulated vehicle is equal to the distance traveled by the target C at constant and uniform speed Vo up to T1, to which we add the tracking distance ds and the target vehicle length of, about 4 meters.

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The tracking distance is equal to the product of the tracking speed, equal to the target speed vo, by the tracking time ts which is a function of driving style. This tracking time is equal, for example, to 1 second, 1, 4 seconds or 2 seconds for decreasing sportiness.

D'après les équations (6) et (7), on obtient l'instant Ti de fin de phase d'accélération :

(8) ( < /. +) 2Av

et de cette équation (8) reportée dans l'équation (5), on obtient la pente PACC de la courbe d'accélération yA (t)

(9) P = 9 (d+dc)

Selon une caractéristique de l'invention, le coefficient de pente PACC dépend des limitations physiques du groupe moto-propulseur et est calculé à partir de l'accélération maximale permise par le moteur et déterminée lors des mises au point en fonction des couples aux roues, de l'angle papillon, du couple et du régime moteur. De cette valeur de pente ainsi fixée, permettant d'obtenir le maximum de puissance pour un conducteur qualifié de sportif, il est possible de calculer la vitesse maximale VAmax, que le véhicule régulé va pouvoir atteindre, puis de définir la valeur de la vitesse obtenue pour un conducteur dynamique, respectivement pour un conducteur calme, en multipliant cette vitesse par un premier coefficient de validation ad, respectivement ac, inférieurs à 1 pour obtenir des valeurs inférieures à la vitesse maximale. ad peut être choisi égal à 70 % et ac à 50% par exemple. Thus: (7) dA = Vo-, + +, dA = v- + 0 '+ 4

According to equations (6) and (7), we obtain the instant Ti at the end of the acceleration phase:

(8) (</. +) 2Av

and from this equation (8) reported in equation (5), we obtain the slope PACC of the acceleration curve yA (t)

(9) P = 9 (d + dc)

According to a characteristic of the invention, the slope coefficient PACC depends on the physical limitations of the powertrain and is calculated from the maximum acceleration allowed by the engine and determined during the adjustments as a function of the wheel torques, throttle angle, torque and engine speed. From this slope value thus fixed, making it possible to obtain the maximum power for a driver qualified as a sportsman, it is possible to calculate the maximum speed VAmax, which the regulated vehicle will be able to reach, then to define the value of the speed obtained. for a dynamic driver, respectively for a calm driver, by multiplying this speed by a first validation coefficient ad, respectively ac, less than 1 to obtain values lower than the maximum speed. ad can be chosen equal to 70% and ac to 50% for example.

Thus, these two calibration parameters define the maximum speed that the regulated vehicle can reach while passing the target C traveling at speed vo:

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(10) vAmax (calme) = Oc. VAmax VAmax (dynamique) = ac. VAmax en fonction du caractère de conduite, puis le temps de ce dépassement ainsi que l'accélération au cours de ladite manoeuvre.

(10) vAmax (calm) = Oc. VAmax VAmax (dynamic) = ac. VAmax as a function of the driving character, then the time of this overshoot as well as the acceleration during said maneuver.

Three cases can arise depending on the speed that the regulated vehicle can have at the instant T1 calculated when it is at the height of the front of the target vehicle C.

=r- (-)

Elle est aussi égale à la distance parcourue, dans ce même laps de temps, par la cible roulant à la vitesse Va, à laquelle on doit ajouter une distance de dépassement ddep, qui est un paramètre de calibration fixe, pouvant être égal par exemple à quatre fois la longueur du véhicule cible, soit environ 20 m.

(11) dA =VA - (T2-) =o- (T2-) +

De cette expression (11), on obtient une information de temps de fin de dépassement :

T deP 74 *2"'') 2 + 1

A partir de cet instant T 2, l'accélération du véhicule régulé n'est plus une fonction linéaire du temps selon le procédé de l'invention. Le véhicule régulé à nouveau en distance et en vitesse selon les lois classiques ACC, peut se rabattre devant la cible, soit à vitesse constante soit en décélérant selon le trafic routier. In the first case where the speed VA (tri) is precisely equal to the speed setpoint Vacs, the method calculates the duration of the second phase of maintaining this speed by considering that the distance traveled by the regulated vehicle is sufficient to allow it to fall back in front of the target (Figure 3). If T2 is the instant of end of second phase, the distance traveled dA by the regulated vehicle is equal to:

= r- (-)

It is also equal to the distance traveled, in this same period of time, by the target traveling at speed Va, to which we must add an overshoot distance ddep, which is a fixed calibration parameter, which can for example be equal to four times the length of the target vehicle, or about 20 m.

(11) dA = VA - (T2-) = o- (T2-) +

From this expression (11), we obtain information about the end of overshoot time:

T deP 74 * 2 "'') 2 + 1

From this instant T 2, the acceleration of the regulated vehicle is no longer a linear function of time according to the method of the invention. The vehicle again regulated in distance and speed according to the classic ACC laws, can fall back in front of the target, either at constant speed or by decelerating according to road traffic.

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1 e 2 2

Entre les instants To et T'i, le véhicule accélère avec une accélération linéaire jusqu'à atteindre la vitesse de consigne, puis il va maintenir cette vitesse de T'1 jusqu'à l'instant T2 de fin de dépassement calculé comme précédemment, au-delà duquel il se rabattra devant la cible (figure 2). In the case where the regulated vehicle reaches the speed setpoint VACC before being at the height of the target, the method calculates the instant T ', for which VA (T'1) is equal to vacc. This instant T ', is the solution of the following equation:

1 e 2 2

Between the instants To and T'i, the vehicle accelerates with a linear acceleration until reaching the set speed, then it will maintain this speed of T'1 until the instant T2 of end of overshoot calculated as above, beyond which he will fall back in front of the target (Figure 2).

 In the third case where the regulated vehicle does not reach the speed setpoint at T1 but beyond this instant, the vehicle continues to accelerate even after having exceeded the target (Figure 4).

est la solution de l'équation suivante :

1 (T") 1 T,, 2 T"

Puis, le procédé calcule la distance à parcourir dA par le véhicule régulé entre le début du dépassement à l'instant To et l'instant T"i où sa vitesse atteindra la consigne VACC. Si cette distance à parcourir est supérieure à la distance totale dT admissible pour le dépassement, soit la distance parcourue par la cible augmentée de la distance de dépassement précédemment définie, l'accélération du véhicule est contrôlée par le système de régulation ACC selon une commande classique, à partir de l'instant Tri, où il est à la hauteur de la cible. De To à Tri, le véhicule accélère selon la loi linéaire yA (t) de l'invention, puis la régulation ACC prend la main pour la fin du dépassement. The method calculates the instant T "1 for which VA (T" 1) is equal to vACC, which

is the solution of the following equation:

1 (T ") 1 T ,, 2 T"

Then, the method calculates the distance to be traveled dA by the regulated vehicle between the start of the overshoot at time To and time T "i where its speed will reach the VACC setpoint. If this distance to be traveled is greater than the total distance dT admissible for overtaking, that is to say the distance traveled by the target increased by the overtaking distance previously defined, the acceleration of the vehicle is controlled by the ACC regulation system according to a conventional command, from instant Tri, where it is at the height of the target. From To to Tri, the vehicle accelerates according to the linear law yA (t) of the invention, then the ACC regulation takes control for the end of the overshoot.

la loi linéaire de l'invention de To à T"i, puis maintient sa vitesse à la valeur constante de la consigne VACC jusqu'à l'instant T2 de fin de phase de maintien de la vitesse, au-delà duquel il se rabat devant la cible. But if the distance to be traveled until the instant T "1 calculated is less than the admissible distance for overtaking, the regulated vehicle accelerates according to

the linear law of the invention from To to T "i, then maintains its speed at the constant value of the VACC setpoint until the instant T2 at the end of the speed maintenance phase, beyond which it folds back in front of the target.

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 FIG. 5 is the block diagram of the method for adaptively regulating the speed of a vehicle, according to the invention, comprising the various steps detailed above.

Either a vehicle A regulated in speed and distance by an ACC acceleration system, in step eo,
After step e1 of detecting a desire to exceed a target by the regulated vehicle, the method generates a linear acceleration yA (t) to be supplied to the regulation system ACC during this overshoot (step e2). In step e3, it calculates the instant Ti at the end of the acceleration phase, as well as the speed VA (tri) theoretically acquired by the regulated vehicle at this instant.

In step e4, it compares this speed vA (tri) with the set speed VACC chosen by the driver in speed regulation. If vA (T1) is equal to the vacs-retape setpoint e5-, the process calculates the instant T2 at the end of overshoot - step es-and keeps the speed VA (t) constant, equal to the setpoint vACC, between the instants T1 and T2-step e7-. From the instant T2, the acceleration of the vehicle ceases to be a linear function of time again according to the invention - step 17-then it is again conventionally controlled by the ACC regulation system in step eis .

 If the speed vA (T1) is greater than the setpoint vACC, the method calculates the instant 1'1 when these two speeds are equal-step e8-, and calculates the instant T2 at the end of the overshoot phase-step eg- , so that it maintains the speed VA (t) at the set value between the instants T ', and T2-step ego-. From T2, ACC regulation takes over.

 On the other hand, in the case where vA (tel) is less than the setpoint vACC, the method calculates the instant T ", where the speed reaches the value of the setpoint-step in, then calculates the distance to be traveled up to T "1 - step ex2-, before comparing it to the total distance dr admissible for passing-step ex3-.

 If this distance dA is greater than or equal to said total distance dT, the conventional ACC regulation takes over the main step 14-. Otherwise, the method calculates the instant T2 of end of overshoot-step 015-and maintains the speed VA (t) at the setpoint VACC between the instants T'1 and T2-step 16-.

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 The instant T2 marks the end of the overstepping law-step e17-, and the ACC regulation takes over then-step e, 8-.

ddep = 20 m de = 4 m On constate sur ces courbes que, pour un conducteur sportif, le procédé adopte une loi d'accélération telle que la vitesse de consigne est atteinte à la hauteur du véhicule à dépasser. Pour un conducteur dynamique, la consigne de vitesse VACC est atteinte avant la fin de dépassement, mais après avoir dépassé cependant la cible. Enfin, le style de conduite d'un conducteur calme ne permet pas d'atteindre la consigne de vitesse VACC après la fin du dépassement, soit avant de parcourir la distance totale autorisée dT. La croix sur chacune des trois courbes correspond à l'instant où le véhicule arrive à la hauteur de la cible. FIG. 6 represents three speed profiles, generated for three types of driver, qualified as calm, dynamic and sporty, according to the method of the invention. The curve Ci in solid line corresponds to a sporty driver, the curve C2 in dotted lines corresponds to a dynamic driver and the curve C3 in broken lines to a calm driver. For the numerical example chosen, the values are as follows: vo = 70 km / h and VACC = 88 km / h
Maximum PACC = 0.4 ac = 0.5 ad = 0.7 ts = [2; 1.4; 1] seconds

ddep = 20 m de = 4 m It can be seen on these curves that, for a sporty driver, the process adopts an acceleration law such that the target speed is reached at the height of the vehicle to be exceeded. For a dynamic driver, the VACC speed setpoint is reached before the end of overtaking, but after having exceeded the target. Finally, the driving style of a calm driver does not allow the VACC speed setpoint to be reached after the end of overtaking, that is, before covering the total authorized distance dT. The cross on each of the three curves corresponds to the instant when the vehicle reaches the target.

 Thus, the method according to the invention has the advantage of improving the management of the acceleration of a vehicle, equipped with ACC type regulation, during the overtaking phases of a target vehicle, with the aim of better comfort for the driver. This comfort is obtained in particular thanks to the linearity of the acceleration, which is canceled as soon as the vehicle is up to its target to ensure greater flexibility. In addition, the process takes into account the driving style to provide better responsiveness of the vehicle to the driver. Such a process allows a gain in comfort and safety performance perceptible by the driver

Claims (7)

 CLAIMS 1. Method for adaptive speed regulation of a vehicle when overtaking another target vehicle traveling in the same direction, equipped with an on-board speed and distance regulation system by electronic control of the acceleration, comprising in particular a control interface with the driver, characterized in that, from the detection of the overshoot of said target vehicle (C), the acceleration of the regulated vehicle (A) is a linear function of time, of the form :) = cc'o the value of the acceleration at the origin (yo) as well as the slope (pACC) of the curve depending on the driving style of the driver, and in that this acceleration is canceled when the vehicle speed (VA) reaches the speed setpoint (VACC) set by the driver in speed control.  2. A control method according to claim 1, characterized in that, in the event that, when the target vehicle is exceeded (C), the vehicle speed (VA) is equal to the speed setpoint (vACC) at the latest at the instant (such) when the rear of the regulated vehicle (A) is at the height of the front of the target vehicle, the acceleration (&gamma; A) is canceled from this instant (T1) and the speed (VA) is kept constant at the set value until the instant (T2) corresponding to a distance traveled equal to that traveled by the target vehicle traveling at speed (va) between the instants (fi) and (T2) , increased by a calibration parameter depending on the length of the target.  3. A method of regulation according to claim 1, characterized in that, in the case where, at the time (sorting) when the rear of the regulated vehicle (A) is at the height of the front of the target vehicle (C ), the vehicle speed (VA) is lower than the speed setpoint (v Acd set by the driver and the distance traveled by the regulated vehicle from (T1) is less than the calibration parameter depending on the length of the target vehicle, l Linear acceleration (YA) of the regulated vehicle is maintained until the instant (T ",) when the speed (VA) is equal to the speed setpoint (VACC).  4. Method of regulation according to claim 3, characterized in that it comprises the following steps, after the calculation of the instant (T ",) when the speed (VA) of the regulated vehicle (A) is equal to the setpoint speed (vACC): <Desc / Clms Page number 13>  - calculation of the distance (dA) to be covered by the regulated vehicle between the start of the overtaking and the instant (T ",); - comparison of this distance (dA) to be covered with a total distance (dT) admissible for overtaking , depending on the length of the target vehicle (C); - if the distance (dA) to be covered is greater than the admissible distance (dT), control of the vehicle acceleration by a law of the distance and speed control system from the moment it is at the height of the target vehicle; - if the distance (dA) to be covered is less than the admissible distance (dT), maintenance of the linear acceleration law (YA) of the regulated vehicle until 'at time (1'1)' then maintain its speed (VA) at the constant value of the speed setpoint until time (T,) corresponding to a distance traveled equal to that traveled by the target (C) between times (T ",) and (T2), increased by a dependence calibration parameter nt the length of the target.

 5. A method of regulation according to claim 1, characterized in that the slope (PACC) of the acceleration curve yA (t) as a function of time is determined as a function of the physical limitations of the powertrain of the regulated vehicle (A) and the driving style of the driver so that, for a character qualified as sporty, the slope is calculated from the maximum acceleration allowed by the engine and for characters qualified as less sporty, the slope is degraded by a coefficient calibratable multiplicative, less than 1.  6. Method of regulation according to claim 5, characterized in that, for a character of conduct qualified as calm, the multiplicative coefficient is equal to 50% and for a character of conduct qualified as dynamic, the multiplicative coefficient is equal to 70% .  7. A method of regulation according to claim 1, characterized in that the initial acceleration (y0), which causes the target vehicle to be exceeded (C), depends on the driving style of the driver of the vehicle, being zero for a driver considered calm and of high value for a driver considered sporty.