Method for controlling the actuators of a motor vehicle implementing an advanced bicycle model

Abstract

The invention relates to a method for controlling actuators of a motor vehicle comprising: a first step (401) of determining a reference yaw rate for the motor vehicle, using a reference model taking as inputs a steering wheel angle of the vehicle and a longitudinal speed setpoint of the vehicle; a second step (402) of implementing the vehicle's actuators so as to control the effective yaw rate of the vehicle based on the reference yaw rate, the method being characterized in that the reference model used is a modified bicycle model to account for: variations in the longitudinal speed of the motor vehicle, and non-linearities in the operating range of the motor vehicle's tires. The invention also relates to a vehicle configured to implement the method. Figure for the abstract: Fig. 4

Description

Title of the invention: Method for controlling the actuators of a motor vehicle implementing an advanced bicycle model. Technical field

[0001] The invention relates to the field of motor vehicles, and more particularly to a method for controlling the actuators of a vehicle implementing a bicycle-type reference model. The invention also relates to a vehicle implementing the method for controlling its actuators. Prior art

[0002] An actuator is a device that can be installed in a motor vehicle, and whose role is to convert an electrical command signal into an action. A motor vehicle includes, among other things, braking actuators, engine torque actuators, steering wheel actuators, etc. The invention relates to the control of such actuators in a vehicle.

[0003] Typically, driving instructions given by the driver and / or by computers, for example driving assistance computers (in English AD AS for Advanced Drive r Assistance System) or driving computers for an autonomous vehicle, are converted into instructions for the various actuators of the vehicle.

[0004] The principle is summarized in Figure 1 for the lateral control of a vehicle. Driving instructions, in particular a steering angle instruction ôf (which can be obtained, for example, from the steering wheel angle) and a longitudinal speed instruction vx, possibly supplemented by other inputs such as an estimate of the road friction coefficient / 7, are provided to a reference model 101. The reference model is a mathematical model that models the behavior of the motor vehicle, and therefore the trajectory to be followed. In the case of lateral control, it provides a reference trajectory, modeled by a reference yaw rate Wref. The yaw rate corresponds to the speed at which the vehicle rotates around its center of gravity. The drift corresponds to the angle of the vehicle's velocity vector with respect to its axis.

[0005] A command allocation and calculation unit 102 implements the vehicle's actuators so that the vehicle follows the defined reference trajectory. This is typically a closed loop controlled by a PID (Proportional, Integral, Derivative) controller or equivalent, for example an Hx controller configured to translate the reference commands into movements 103 of the actuators 104, observe the vehicle's actual response, and adjust the commands. actuators so as to control the effective yaw rate y / of the vehicle based on the reference yaw rate ÿref

[0006] Advantageously, the reference model 101 can also provide a reference drift B of the vehicle to the calculation and command allocation unit ^ref 102, which can be taken into account to control the vehicle's actuators. The calculation of the reference drift Pre^ is part of the calculations required to establish the reference yaw rate Vref by the reference model 101.

[0007] Typically, the reference model used for the lateral control of a vehicle is the bicycle model, whose parameters are shown in [Fig. 2]. This model uses a simplified representation of a four-wheeled vehicle, in which the wheels of the same wheel set are modeled as a single wheel located on the axis of the vehicle's center of gravity, hence its name. This model implements: - 1 an index to designate each wheel of the vehicle, with per example i = 1 for the front left wheel, i = 2 for the front right wheel, i = 3 for the rear left wheel, and i = 4 for the rear right wheel; - and ar: the drift angles of the front and rear wheels respectively, expressed in radians. Subsequently, in the spirit of the bicycle model where the two wheels of the same train are represented by a single wheel, we will consider that the drift angles of the wheels of the same train are the same, that is to say for the front train: i= ^2 = &f, and for the rear train: a3=a4=(ir; - Cat: the cornering stiffness of the tire of the wheel with index J, expressed in N / rad. Subsequently, in the spirit of the bicycle model where the two wheels of the same set are represented by a single wheel, we will consider that the cornering stiffness of the tires of the same set of wheels is the same, that is to say for the front set: Ca{ = Ca2 = Car and for the rear set: Ca. = C«4 = CQr; - 6f: the angle of the front wheels, expressed in radians; - F y : the lateral force applied to the index wheel \ expressed in Newtons; - vx: the longitudinal velocity vector, expressed in m / s; - I z: the moment of inertia of the vehicle, expressed in kg / m2; - M; the mass of the vehicle, expressed in kg; - [3: the vehicle's drift, which is also the angle of the velocity vector relative to to the axis of the vehicle, expressed in radians and whose derivative is 0, the drift speed of the vehicle, also expressed in radians; - V7: the heading or yaw angle of the vehicle, V7 the yaw rate, expressed in rad / s and ÿ7 the yaw acceleration, expressed in rad / s2; - If, lr: the distance between the center of gravity and the front axle respectively and rear of the vehicle, expressed in meters; - • 'c yaw moment, expressed in Nm / s.

[0008] In accordance with standard mathematical representations, when a symbol is surmounted by a dot, it represents the first derivative of that symbol, and when it is surmounted by two dots, it represents the second derivative of that symbol. It is possible to move from one representation to the other by integrating or differentiating.

[0009] The matrix representation in state space of the bicycle model can be defined as : P _ " Mvx , lfCgrIrCar i F

[0010] where: The state variables are the vehicle drift p and yaw rate ty, the control input is the yaw moment Mz.

[0011] However, as it stands, the bicycle model has two defects: - it assumes that the longitudinal speed of the vehicle is fixed or varies very slowly, - it assumes that the operating range of the tires remains in the linear zone.

[0012] These two assumptions are very limiting. Figure 3 represents the slip K of the tire / road contact as a function of the longitudinal or lateral force F exerted on the tire. It illustrates the different operating zones of a tire: - Zone 301 is the linear operating zone of the tire, where the forces exerted and the slippage of the tire vary linearly; - Zone 302 is the non-linear operating zone of the tire. This is the zone of high tire grip mobilization, in which the vehicle nevertheless remains controllable; - Zone 303 is the tire instability zone, i.e. the total slip zone.

[0013] Typically, the linear operating zone 301 of the tire is only valid up to lateral accelerations of approximately 4 m / s² on a surface with good grip. If grip is reduced, for example due to weather or the road surface, the

[0014]

[0015]

[0016]

[0017]

[0018] The linear area is restricted, which also restricts the scope of validity of the bicycle model. One object of the invention is therefore to propose an "advanced" bicycle model that more closely reflects the actual behavior of the vehicle, specifically one that takes into account variations in the vehicle's longitudinal speed and the non-linear operating zones of the tires. In this way, the yaw and drift commands calculated by block 101 of [Fig. 1] are more representative and allow for optimal use of the vehicle's actuators. Summary of the invention To this end, the present invention describes a method for controlling actuators in a motor vehicle. The method comprises: - a first step of determining a reference yaw rate ^ref For 'c motor vehicle, using a reference model taking as inputs a steering wheel angle of the vehicle and a longitudinal speed setpoint of the vehicle, - a second step of implementing the vehicle's actuators in such a way as to control the vehicle's effective yaw rate based on the reference yaw rate Wref In the control method according to the invention, the reference model used is a modified bicycle model to take into account: - variations in the longitudinal speed of the motor vehicle, - non-linearities in the operating area of ​​the vehicle's tires. More precisely : - The determination of the reference yaw rate Wref of the first step is made from a steering wheel angle 6f of the vehicle and a longitudinal speed setpoint of the vehicle, and - The second step involves implementing the vehicle's actuators in such a way as to control the effective yaw rate ÿ / of the vehicle based on the reference yaw rate Vref According to a particular embodiment of the process according to the invention: - the determination of the reference yaw rate Vref of the first stage also includes the determination of a reference drift Pref; - the second step further includes the implementation of the vehicle actuators in such a way as to control the effective drift B of the vehicle on the reference drift B„. lref

[0019] Advantageously, the equations of the reference model take into account the specific rear drift of the understeer gradient Vsv and the acceleration longitudinal axis of the vehicle.

[0020] According to one embodiment of the invention, the calculation of the yaw acceleration I / / and the drift velocity p are equivalent to: ô _ R _ û / _l. ,...¾¾... _i_ fk ) JL m ( fp _p P- Mvx P\ Mv,v^d^LJ + Mv2 [Fr d2s} with : - Caf: the rigidity of the front wheels' drift, - Because: the rigidity of the rear wheel drift, - ôf: the angle of the front wheels, - vx; the longitudinal velocity vector, - Iz: the moment of inertia of the vehicle, - M; the mass of the vehicle, - If : the distance between the center of gravity and the axle, respectively front and rear, of the vehicle, - L; the vehicle's wheelbase, - d2g: the vehicle's specific rear drift - sv: the vehicle's understeer gradient, - ; the longitudinal acceleration of the vehicle, And :

[0021] F _ [JW , W 1 FF [ 1+O v, l+o'x2 /

[0022] p _ ( 1 FR [ 1+Ox3 "F 1+Ox4 /

[0023] with: - 1: an index to designate each wheel of the vehicle, with ÏG[1; 4] ; - f(Aj): a function given by the Dugoff model for the wheel with index iy - : a longitudinal drift for the wheel with index J.

[0024] Advantageously, at least one of the vehicle's actuators is an actuator acting on the vehicle's lateral dynamics, such as a braking actuator or a steering actuator for the vehicle's steering wheels.

[0025] According to a particular embodiment of the invention, at least one parameter of the vehicle used to calculate the reference model is defined by the characteristics of the vehicle, then adapted to modify the vehicle's behavior. Advantageously, one or more of these parameters are chosen from a vehicle wheelbase L, a vehicle understeer gradient Vsv, and a vehicle specific rear drift d2s.

[0026] According to a particular embodiment of the invention, the second stage of implementing the vehicle actuators takes as input an estimate of a coefficient of friction of the road surface.

[0027] The invention also relates to a motor vehicle comprising computing means and actuators, the computing means being configured to determine instructions transmitted to the actuators which implement them. In this vehicle, the computing means are configured to implement a method for controlling the actuators of a vehicle according to the invention. Brief description of the drawings

[0028] The invention will be better understood and other features, details and advantages will become clearer from the following description, given by way of non-limiting reason, and from the accompanying figures, given by way of example.

[0029] [Fig-1] Fig. 1 schematically represents the steps required for the control side of a motor vehicle.

[0030] [Fig.2] Fig.2 represents the parameters used for the bicycle model to characterize the lateral dynamics of a motor vehicle.

[0031] [Fig.3] Figure 3 represents the coefficient of slip K of the tire / road contact as a function of the force F, longitudinal or lateral, exerted on a tire.

[0032] [Fig.4] Fig.4 schematically represents the steps of a method for controlling actuators of a motor vehicle according to the invention.

[0033] [Fig.5] Fig.5 illustrates the performance of the method for controlling actuators of a motor vehicle according to the invention.

[0034] [Fig.6] Fig.6 illustrates the performance of the method of controlling actuators of a motor vehicle according to the invention, also taking into account the coefficient of friction of the road.

[0035] Identical references may be used in different figures when they refer to identical or comparable elements. Description of the implementation methods

[0036] The present invention relates to a method for controlling actuators of a motor vehicle. Figure 4 schematically represents the steps of the method according to the invention, namely: - a first step 401 of determining a reference trajectory for the vehicle using a reference model, and - a second step 402 of implementation of the vehicle actuators, so as to follow the reference trajectory defined during step 401.

[0037] These first and second steps conform to the prior art. As described in Figure 1, a known embodiment consists of determining, in step 401, a reference yaw rate Ÿref of the motor vehicle from the reference model, based on a steering wheel angle and a longitudinal speed setpoint, and controlling the effective yaw rate < / 7 du véhicule sur la vitesse de lacet de référence Wref lors de l’étape 402 dans une boucle fermée. L’étape 402 correspond aux traitements mis en œuvre par les blocs 102, 103 et 104 de la [Fig. 1].

[0038] Advantageously, step 401 may also include the determination of a reference drift, which can also be used to determine the actuator setpoints.

[0039] The invention differs from the prior art in that the reference model used is a modified bicycle model to take into account: - variations in the longitudinal speed of the motor vehicle, - non-linearities in the operating area of ​​the motor vehicle's tires.

[0040] Subsequently, the following notations will also be used: - vy: the lateral velocity vector, expressed in m / s; - kv; the understeer rate; - L; the wheelbase of the vehicle, in meters; - ax and 3y; the acceleration of the vehicle, respectively longitudinal and lateral, expressed in m / s2; - F: the coefficient of friction of the road surface; - -^eff: the effective radius of the tires, expressed in meters; - : the rotation speed of the index 2 wheel, expressed in rad / sec; - Fxi: the longitudinal force applied to the wheel of index 2, expressed in Newtons; - Ox, : the longitudinal drift for the wheel with index i; - Cat: the longitudinal stiffness of the tire of the index 2 wheel, expressed in N / rad; - ai: the lateral slip angle (in English "slide slip angle") for the index 2 wheel, expressed in radians.

[0041] The bicycle model assumes that the longitudinal acceleration ax of the vehicle is zero (3X = 0). The invention proposes to modify the classic bicycle model to to remove this assumption and take into account the fact that the vehicle's speed is not constant.

[0042] To do this, the drift angle fi of the vehicle at its center of gravity is expressed by the equation: fi = ^

[0043] We can calculate its derivative fi, considering that vx is not constant, and that consequently vx 0: / ?=« <2)

[0044] We thus obtain the derivative Vy of the lateral velocity: Vy=Vx(fi + fi^) (3)

[0045] The "standard" bicycle model assumes that the lateral forces applied to the vehicle are proportional to the lateral drift angles of the wheels. However, as mentioned in the introduction, this assumption is only valid up to transverse lateral accelerations of approximately 4 m / s² on a high-adhesion surface, and much less so as soon as adhesion decreases.

[0046] To account for the fact that vehicle tires are not always in a linear operating range, the invention proposes using the Dugoff model, well known to those skilled in the art, to simulate tire dynamics. Other models for modeling the operation of vehicle tires can be used, for example, the Pacejka model. However, the Dugoff model has the advantage of not requiring additional parameters compared to the bicycle model.

[0047] According to the Dugoff model, the longitudinal force FX1 applied to the tire-ground contact is given by: p — p (4) with C'Xj the longitudinal slip at each wheel, defined by: (5) ^xi max(vÀ, ref wj

[0048] Still according to Dugoff's model, the lateral force Fy. exerted at the tire-ground contact is given by: ü _ z- a 1 (6) where the variable is calculated as follows: / (^) = (2-2,¾ if 2^1 (7) f(2,) = 1 otherwise with : p. Fz^I+Oï ) (8) li=..... 2^(0^) +(Ca.tan(a)) with : - Pj the grip for the wheel with index i, which is generally approximated by P, - Fz the force along the vertical axis applied to the wheel with index 2, which can be obtained for example by shock absorber stroke sensors of the vehicle, or calculated from information related to the lateral and longitudinal accelerations of the vehicle.

[0049] We apply the fundamental principle of dynamics in rotation about the vertical axis, which allows us to express the evolution of the yaw rate by: IZV = (Py^FyJlf- (Fy^ + Fy^lr (9)

[0050] To take into account the linearity zones of the tires, equation (6) is used to express the forces in equation (9) as follows: / Cs, C«2a^\ (Ctt3af^ C^af^X (10) (.......uk;.......+........ïÆ.......pf [...............+........ri,;;.......pr

[0051] It is now a matter of using equations (3) and (10) in the calculations of the "evolved" reference model which is the subject of the invention.

[0052] To simplify the notation, the following is used:

[0053] P " F ( 1+CTx j ' 1+(7¾ /

[0054] p _ ( . W \ r R \ 1+ctï3 1+ox ;

[0055] This allows equation (10) to be rewritten in the form: IzV = ^R^-'ar ip (11)

[0056] The understeer gradient Vsv, which allows the understeering, oversteering or neutral behavior of a vehicle to be characterized, is defined as follows: k Cafe either _ M sv- L Ca[Ca,

[0057] We therefore have: LCafCa,^ sv — h'Car~ lfCaf

[0058] The specific rear drift d2s of a vehicle (in English "specific rear slip

[0059]

[0060] is defined by: = JiLh. U2s Car L This allows us to write: _ 1 P "Mf ” d^L We then have: LC Vsv Calr- Caflf = which can be rewritten in the form: (12) LC Calr= C aflf+ --^-

[0061] The lateral drift of the front wheel can be expressed as: „ _ f. o àï d3) Pf-Of-p- v*

[0062] The lateral drift of the rear wheel can be expressed as: «r= -^ + 4?

[0063] Using (13) and (14), equation (11) can be rewritten in the form: I Z V = F P C a ,L t (6 r P-&)- F R C a J r (-P+ i £) either : W = FpCa, IfBf+Pt-FPC«, It + FRCar C) +

[0064] Taking into account equation (13), we obtain: / f ]fCX T \ FrCarïf+FR1 Izÿ=FFCa( If6f+13[ -FPCaf lt+FR[ca[lf+-^-]) + w[---------

[0065] By introducing into the previous equation the expression (13) of the specific drift The rear of the vehicle and the understeer gradient result in: • / / = à^^ + £((FR-FF)Cadf + ^i^^ (16)

[0066] Equivalently, the behavior of the drift fi can be calculated by taking into account the fact that the longitudinal acceleration is not zero, and that the operating zone of the tires is not necessarily the linear zone, via the equation of the fundamental principle of dynamics: M(vy + t / / Vx) = (Fy^ + Fy2)+ (Fy3 + F y J

[0067] Using equation (3), we obtain: + + W^x) = (^1 + ^2) +(-^73 + ^4)

[0068] By introducing equation (12) expressing the specific rear drift of the vehicle and the understeer gradient in a manner comparable to that done for equation (16), we then obtain: Mvx Mvx (LC I • I ' af + uj —— 1 \ Mvx Fr-Ff +

[0069] Equations (16) and (17) therefore correspond to the state-space representation of the advanced bicycle model as defined by an embodiment of the invention. It takes into account that the longitudinal acceleration of the vehicle may be non-zero, and that the tires may not be in their linear operating zone. This representation allows the calculation of the reference instructions used by the unit. of calculations and command allocation 102 to implement the vehicle actuators, namely the reference yaw rate ^ref and possibly the drift by integrating Wref

[0070] It will be noted in particular that, unlike the "classic" bicycle model, the "evolved" bicycle model proposed by the invention takes into account the specific rear drift d2s of the vehicle, the understeer gradient V sv of the vehicle and its longitudinal acceleration ax.

[0071] Advantageously, the "evolved" bicycle-type reference model according to the invention can be used to modify the vehicle's behavior by defining a reference trajectory that would be that of a vehicle with a different size than the vehicle in question. For example, it is possible to modify, via software in the reference model, the vehicle's wheelbase L, its understeer gradient Vsv, and / or its specific rear drift d2s, so that its behavior is similar to that of a vehicle that, for example, has a shorter wheelbase (to provide agility in the city, for example) or a longer one (to improve the perception of stability during maneuvers such as lane changes), or a different oversteer / understeer behavior.

[0072] This adaptation of the vehicle's behavior can be implemented through tuning tables. By way of illustration, the use of three tuning tables is then described, allowing the vehicle's wheelbase L, understeer gradient Vsv, and rear specific drift d2s to be varied simultaneously, but the invention applies identically by varying only one or two of these parameters.

[0073] A first table allows obtaining a coefficient R^ which is applied to the understeer gradient V sv of the vehicle so that it behaves as if its understeer gradient were Vsv ^es = R^ sv. This coefficient can depend, among other things, on the vehicle speed, the engine torque requested or the type (comfort, sport...) chosen by the customer for their vehicle.

[0074] A second table allows for obtaining a coefficient jR2 which is applied to the wheelbase L of the vehicle, to simulate a shorter or longer vehicle, for example. This coefficient can depend, among other things, on the lateral acceleration ay of the vehicle and its longitudinal speed vy. Using a coefficient R2 less than 1 allows for the simulation of a wheelbase shorter than the vehicle's actual wheelbase, thus improving its agility. The vehicle's steering feel is then more "direct," meaning that for the same turn, the required steering angle is reduced. Conversely, if R2 is greater than 1, the steering has a less "direct" behavior: the vehicle behaves as if it were longer, and a larger steering angle is required for the same turn.

[0075] We then have:

[0076] l[:des=R2lf

[0077] lr,des=R2lr

[0078] with lf ^es and lr ^es the distance between the center of gravity and the front and rear axles of the vehicle respectively, simulated by this embodiment of the invention.

[0079] A third table provides a coefficient R^ which is applied to the rear drift of the vehicle: d2s des = ^3-^2s- The rear drift of the vehicle allows adjustment of the phasing between the front and rear axles. Advancing or retarding the setpoint makes it possible to obtain a completely transparent rear axle, that is to say, a rear axle that turns without this being perceptible to the passengers.

[0080] By using Vsv r]es instead of Vsv, lf des and lr jes instead of lf and lr, and / or d2s des instead of d2s in equations (16) and (17), it is possible to modify the dynamic behavior of the vehicle and obtain the corresponding reference behavior values ​​¢ / and the yaw rate setpoint values ​​• / / and of derivatives can then be obtained by integration of and fi. in order to be transmitted to the calculation and order allocation unit 102.

[0081] Figure 5 shows results obtained during experimentation. Curves 501 represent the yaw rate and drift setpoints obtained using the standard bicycle model. Curves 502 represent the same setpoints, this time using the bicycle model according to the invention, which takes into account that the tires may be outside their linear operating range. The measurements are taken on a scenario including a turn at 0.7 m / s² lateral acceleration, which is beyond the linear operating range of the tires.

[0082] It can be seen that the command obtained by the bicycle model according to the invention is well-suited to the non-linear operating range (between 4.5 and 5.5 seconds, and between 7.5 and 8.5 seconds), since the yaw command used as a reference is lower than the command delivered by a "standard" bicycle model. Thus, the command allocation unit will not attempt to force the car to follow a command higher than what the physics of the tires allows. This results in smoother and more comfortable vehicle handling, without the jerky acceleration and braking that would have occurred when using the "standard" bicycle model to try to reach a command that is beyond the car's physical limits. The vehicle then handles particularly well, while consuming less fuel.

[0083] Figure 6 shows curve 502 from Figure 5, and a new curve 602 constructed using an estimate of the road's coefficient of friction as input to the calculation and command allocation unit 102. In this example, p = 0.4, which corresponds to a slippery / snowy road scenario. It can be seen that using the bicycle model according to the invention, which takes into account the road's coefficient of friction in the equations modeling tire behavior, also allows the yaw rate command to be adapted to the road surface friction. Thus, on a slippery road, the calculation and command allocation unit 102 causes the car to adopt a behavior with lower lateral dynamics, therefore better suited to driving on a slippery / snowy road.

[0084] The invention relates to a method for controlling actuators of a motor vehicle as defined above, but also to a motor vehicle comprising computing means (for example, a computer, a microprocessor, or any other electronic device enabling calculations) and actuators, for example, steering and braking actuators. The computing means are configured to implement the control method. actuators according to the invention in order to determine a reference setpoint according to an "advanced" bicycle model to control the vehicle's actuators in order to follow the trajectory defined by the reference setpoint.

Claims

Demands

1. A method for controlling actuators of a motor vehicle comprising: - a first step (401) of determining a reference yaw rate Wref for the motor vehicle, using a reference model taking as inputs an angle Ôf of the vehicle's steering wheel and a longitudinal speed setpoint vx of the vehicle, - a second step (402) of implementing the vehicle's actuators so as to control the effective yaw rate ty of the vehicle on the reference yaw rate tyref, the method being characterized in that the reference model used is a bicycle model modified to take into account: - variations in the longitudinal speed vx of the motor vehicle, - non-linearities of the operating area of ​​the motor vehicle's tires.

2. A method for controlling the actuators of a vehicle according to the preceding claim, wherein: - the determination of the reference yaw rate ^ref of the first step (401) further comprises the determination of a reference drift B; ^ref - the second step (402) further comprises implementing the vehicle actuators so as to control the effective drift / 3 of the vehicle on the reference drift ^ref

3. A method for controlling the actuators of a vehicle according to any one of the preceding claims, wherein the equations of the reference model take into account a specific rear drift d2S' of an understeer gradient Vsv and a longitudinal acceleration ax of the vehicle.

4. A method for controlling the actuators of a vehicle according to any one of the preceding claims, wherein the expression for the calculation of

5. The yaw rate and the vehicle's drift velocity (0) are: K ni FPCa, , FRlf ar 1, . / +Caf / FRVsv) m7~ Sf-Pl'MÿT' + T^L + v? + ) - ! with : - Caf: the rigidity of the front wheels' drift, - This: the rigidity of the rear wheel drift - 6f: the angle of the front wheels, - vx: the longitudinal velocity vector, - I z: the moment of inertia of the vehicle, - M; the mass of the vehicle, - lr: the distance between the center of gravity and the axle, respectively front and rear of the vehicle, - L; the vehicle's wheelbase, - d2s: the vehicle's specific rear drift, - Vsv: the vehicle's understeer gradient, - : the longitudinal acceleration of the vehicle, And F \ 1+Oxj + 1+0¾ / with : - 1: an index to designate each wheel of the vehicle, with j G [1; 4]; - f(Àj): a function given by the Dugoff model for the wheel with index J, - : a longitudinal drift for the index wheel < Method of controlling actuators of a vehicle according to any one of the preceding claims, wherein at least one of the vehicle actuators is an actuator acting on the lateral dynamics of the vehicle, such as a braking actuator or a steering actuator for the vehicle's steering wheels.

6. A method for controlling vehicle actuators according to any one of the preceding claims, wherein at least one vehicle parameter used to calculate the reference model is defined by the vehicle characteristics and then adapted to modify the vehicle behavior.

7. A method for controlling actuators of a vehicle according to claim 6, wherein said at least one parameter of the vehicle adapted to modify the behavior of the vehicle comprises one or more parameters from a wheelbase L of the vehicle, an understeer gradient V of the vehicle and a specific rear drift d^ of the vehicle.

8. A method for controlling vehicle actuators according to any one of the preceding claims, wherein the second step (402) of implementing the vehicle actuators takes as input an estimate of a coefficient P of road surface friction.

9. Motor vehicle comprising computing means and actuators, said computing means being configured to determine instructions transmitted to the actuators which implement them, characterized in that the computing means are configured to implement a method of controlling actuators of a vehicle according to any one of claims 1 to 8.

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