FR3144796A1 - CHECK OF EACH TORQUE REFERENCE REQUESTED FOR A GMP OF A LAND VEHICLE IN THE PRESENCE OF A RISK OF COLLISION - Google Patents

Abstract

A control method is implemented in a land vehicle comprising a powertrain supplying or recovering from at least one train a torque depending on a torque setpoint requested to move or brake the vehicle, a braking device, and a control function. emergency specific to imposing automatic emergency braking chosen by the braking device in the presence of a detected risk of collision involving the vehicle. This method comprises a step (10-20) in which, in the presence of the detected risk and a torque setpoint requested for a train, this requested torque setpoint is authorized when it is less than or equal to zero, or else we replaces this requested torque setpoint with a torque setpoint equal to zero when it is greater than zero. Figure 3

Description

CHECK OF EACH TORQUE REFERENCE REQUESTED FOR A GMP OF A LAND VEHICLE IN THE PRESENCE OF A RISK OF COLLISION Technical field of the invention

The invention relates to land vehicles comprising an emergency function capable of imposing automatic emergency braking, and more precisely the control within such vehicles of each torque setpoint requested for their powertrain (or GMP) in the presence of 'a risk of collision detected.

State of the art

Some land vehicles, possibly of the automobile type, include:

- a GMP capable of supplying or recovering on at least one train a torque which is a function of a torque setpoint requested to move or brake them;

- a braking device, and

- an emergency function which is capable of imposing automatic emergency braking chosen by this braking device in the presence of a detected risk of collision involving them.

It will be understood that the torque setpoint requested is either positive when you want to move the vehicle with its GMP or negative when you want to brake the vehicle with its GMP.

The emergency function, which is sometimes referred to by the English acronym AEB (“Automatic Emergency Braking”) or AEBS (“Automatic Emergency Braking System”), allows, when a risk of collision is detected in a vehicle, to brake automatically the latter to prevent him from being involved in this collision or to at least reduce his impact speed during this collision. This automatic emergency braking, carried out by means of the braking device and therefore mechanical, is accompanied by an action on the GMP required by the emergency function. More precisely, when a risk of collision is detected, the emergency function alerts the GMP supervision computer which is then responsible for imposing on the GMP a torque setpoint equal to zero, so that it no longer provides torque. .

When the GMP is purely thermal, receiving the zero torque reference causes the fuel injection to be cut off. When the GMP is purely electric, receiving the zero torque reference causes the torque production by each electric motor of the GMP to stop.

The imposition of a zero torque reference prevents the GMP from opposing the action (mechanical braking) exerted by the braking device. However, when the GMP is in the process of providing a negative torque (for example during a regenerative braking phase), and therefore participates in braking the vehicle, this imposition of a zero torque setting immediately interrupts the participation of the GMP when braking the vehicle. This reduces, possibly significantly, the vehicle's ability to slow down and therefore may prevent collision avoidance or cause an insufficient reduction in impact speed. In addition, this may prevent respecting a torque distribution between front and rear trains or between driving machines of different types of the same train, and therefore this may prevent the realization or optimization of certain specific phases. Thus, in the case of a GMP that is at least partially thermal, this can cause a reduction in the depollution capacity of the exhaust line depollution devices (prevention of heating of the catalyst and/or heating of the particle filter and /or purging the particle filter) and/or preventing the protection of the turbocharger. Furthermore, the systematic imposition of a zero value on the torque setpoint supplied to the GMP, upstream of a torque distribution between the front and rear axles, can make the connection with the requested torque setpoint slow when the alert automatic emergency braking of the supervision computer by the emergency function is completed.

The invention therefore aims in particular to improve the situation.

Presentation of the invention

To this end, it proposes in particular a control method intended to be implemented in a land vehicle comprising:

- a powertrain capable of supplying or recovering from at least one train a torque based on a torque setpoint requested to move or brake the vehicle,

- a braking device, and

- an emergency function capable of imposing automatic emergency braking chosen by the braking device in the presence of a detected risk of collision involving the vehicle.

This control method is characterized by the fact that it comprises a step in which, in the presence of the detected risk and a torque setpoint requested for a train, this requested torque setpoint is authorized when it is less than or equal to zero, or this requested torque reference is replaced by a torque reference equal to zero when it is greater than zero.

Thus, the GMP no longer opposes an action (mechanical braking) exerted at the instant considered by the braking device when the requested torque setpoint is less than or equal to zero, and therefore there is no longer any risk reduction in the vehicle's slowing down capacity, and certain specific phases can be achieved or optimized when the requested torque setpoint is greater than zero.

The control method according to the invention may include other characteristics which can be taken separately or in combination, and in particular:

- in its stage, in the presence of a powertrain comprising a thermal engine and a reversible electric engine associated with a train, and in the presence of the detected risk and a torque setpoint requested for this train, we can authorize this torque setpoint requested when it is less than or equal to zero and it is possible to determine for the thermal motor machine and the reversible electric motor machine respectively first and second torque setpoints of which a sum is equal to this requested torque setpoint, or else we can replace this requested torque setpoint with a torque setpoint equal to zero when it is greater than zero and it is possible to determine for the thermal motor machine and the reversible electric motor machine respectively first and second torque setpoints, a sum of which is equal to zero ;

- in its stage, in the presence of a powertrain capable of supplying or recovering a front torque on a front axle, depending on a front torque setpoint requested to move or brake the vehicle, and on a rear axle a rear torque, depending on a rear torque setpoint requested to move or brake the vehicle, and in the presence of the detected risk and a requested front torque setpoint and/or a requested rear torque setpoint, the torque setpoint can be authorized requested when it is less than or equal to zero or the requested front torque setpoint can be replaced by a front torque setpoint equal to zero when it is greater than zero, and/or the requested rear torque setpoint can be authorized when it is less than or equal to zero or the requested rear torque setpoint can be replaced by a rear torque setpoint equal to zero when it is greater than zero.

The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a control method of the type of that presented above, in a land vehicle comprising, firstly, a powertrain capable of supplying or recovering from at least one train a torque depending on a torque setpoint requested to move or brake the vehicle, secondly, a device for braking, and, thirdly, an emergency function capable of imposing automatic emergency braking chosen by the braking device in the presence of a detected risk of collision involving the vehicle, to control the (each) instruction of torque requested in the presence of such a detected risk.

The invention also proposes a control device intended to equip a land vehicle comprising:

- a powertrain capable of supplying or recovering from at least one train a torque based on a torque setpoint requested to move or brake the vehicle,

- a braking device, and

- an emergency function capable of imposing automatic emergency braking chosen by the braking device in the presence of a detected risk of collision involving the vehicle.

This control device is characterized by the fact that it comprises at least one processor and at least one memory arranged to carry out the operations consisting, in the presence of this detected risk and a torque setpoint requested for a train, in authorizing this requested torque setpoint when it is less than or equal to zero, or to replace this requested torque setpoint with a torque setpoint equal to zero when it is greater than zero.

The invention also proposes a land vehicle, possibly of the automobile type, and comprising:

- a powertrain capable of supplying or recovering from at least one train a torque based on a torque setpoint requested to move or brake the vehicle,

- a braking device,

- an emergency function capable of imposing automatic emergency braking chosen by the braking device in the presence of a detected risk of collision involving the vehicle, and

- a control device of the type presented above.

Brief description of the figures

Other characteristics and advantages of the invention will appear on examination of the detailed description below, and the appended drawings, in which:

schematically and functionally illustrates an exemplary embodiment of a land vehicle comprising a GMP transmission chain with front and rear electric drive machines and associated with a supervision computer, a braking device, an emergency braking function, a device trajectory control, and a control device according to the invention,

schematically and functionally illustrates an exemplary embodiment of a supervision computer comprising an exemplary embodiment of a control device according to the invention, and

schematically illustrates an example of an algorithm implementing a control method according to the invention.

Detailed description of the invention

The invention aims in particular to propose a control method, and an associated DC control device, intended to allow control of the (each) torque setpoint requested for the powertrain (or GMP) of a land vehicle V comprising an automatic emergency braking function (or emergency function) FF, in the presence of a detected risk of collision involving this land vehicle V.

In what follows, we consider, by way of non-limiting example, that the land vehicle V is of the automobile type. This is for example a car, as illustrated in the . But the invention is not limited to this type of land vehicle. It concerns any type of land vehicle comprising a GMP transmission chain, a braking device and an automatic emergency braking function. Thus, it concerns in particular utility vehicles, motorhomes, minibuses, coaches, trucks, motorcycles, road machinery, construction machinery, agricultural machinery, leisure machinery (snowmobile, kart), and tracked machinery.

Furthermore, we consider in what follows, by way of non-limiting example, that the (land) vehicle V comprises an all-electric GMP transmission chain (and therefore whose traction is ensured exclusively by at least one machine electric motor MMEj). But the GMP could be of hybrid type (thermal and electric).

We have schematically represented on the a vehicle V comprising a transmission chain with electric GMP (and therefore with electric driving machine(s) MMEj), a supervision computer CS, an on-board network RB, a service battery BS, a source electrical energy BP, a CV converter, a brake pedal PF associated with a braking device DF, an accelerator pedal PA, an emergency (automatic braking) function FF, and a DC control device according to the 'invention.

The RB on-board network is an electrical supply network to which electrical (or electronic) equipment (or components) are coupled which consume electrical energy.

The utility battery BS is responsible for supplying electrical energy to the on-board network RB, in addition, here, to that supplied by the CV converter powered by the electrical energy source BP, and sometimes instead, here, of this CV converter. For example, this BS utility battery can be arranged in the form of a very low voltage type battery (typically 12 V, 24 V or 48 V). It is rechargeable at least via the CV (current) converter. We consider in the following, by way of non-limiting example, that the BS utility battery is of the 12 V Lithium-ion type.

The transmission chain has a GMP which is, here, purely electric. In the example illustrated non-limitingly on the the GMP comprises in particular, on the one hand, a front electric driving machine MME1 (j = 1), a front motor shaft AM1, and a front transmission shaft AT1, associated with the front axle T1, and, on the other hand, a rear electric drive machine MME2 (j = 2), a rear motor shaft AM2, and a rear transmission shaft AT2, associated with the rear axle T2. Here we mean “electric driving machine” an electric machine arranged so as to provide a motor torque, defined by a torque setpoint (front or rear), to move the vehicle V when it is supplied with electrical energy by the source of electrical energy BP, and, when it is reversible, to recover the regenerative braking torque, defined by a regenerative torque setpoint (front or rear), to decelerate (or brake) the vehicle V in a regenerative braking phase . Note that the front MME1 and rear MME2 electric motive machines can both be reversible. But this is not obligatory, because it is enough that at least one electric driving machine of the GMP (possibly unique) is reversible. It should also be noted that when the GMP is hybrid it can include at least one electric machine associated with a train Tj and only dedicated to the recovery of regenerative braking torque in the regenerative braking phases.

The operation of the transmission chain (and therefore of the GMP) is supervised by the CS supervision computer.

The (each) electric motor machine MMEj (here an electric motor) is coupled to the electrical energy source BP, in order to be supplied with electrical energy, and possibly to supply this electrical energy source BP with current (electric ) recharge (or recuperative) during a regenerative braking phase when it is reversible.

Furthermore, this (each) electric motor machine MMEj is coupled to the associated motor shaft AMj, to provide it with motor torque by rotational drive. This motor shaft AMj is here coupled to a reduction gear RDj which is also coupled to the associated transmission shaft ATj, itself coupled to the train Tj (here of wheels), preferably via a differential Dj. Note that train T1 (j = 1) is a front train located in the front part PVV of vehicle V, and train T2 (j = 2) is a rear train located in the rear part PRV of vehicle V. Note also that in the presence of a single electric driving machine MMEj, this can be associated with the front axle T1 or the rear axle T2.

The operation of the (each) electric motor machine MMEj is controlled by an associated machine computer CMj, and supervised by the supervision computer CS. This (each) machine computer CM receives in particular from the supervision computer CS each torque instruction that the latter (CS) determines for the GMP according to a torque requested by the driver of the vehicle V (here by means of the pedal d PA accelerator).

The CV converter is also responsible, here, during the driving phases of the vehicle V, of converting part of the electrical current supplied by the electrical energy source BP to supply the on-board network RB and the utility battery BS with converted electrical current. (to recharge it).

Note, as illustrated non-limitatively in the , that the CV converter can be part of a CH charger also comprising a charging calculator (not illustrated) responsible, at least, for controlling the charging of the electrical energy source BP.

We consider in what follows, by way of non-limiting example, that the source of electrical energy BP is a rechargeable main (or traction) battery. But in a variant embodiment the BP electrical energy source could be a fuel cell.

When the BP electrical energy source is a main (or traction) battery, it can, for example, comprise electrical energy storage cells, possibly electrochemical (for example of the lithium-ion (or Li-ion) type). or Ni-Mh or Ni-Cd). Also for example, the electrical energy source BP can be of the low voltage type (typically 450 V for illustration purposes). But it could be medium voltage or high voltage.

It will also be noted that in the example illustrated non-limitingly on the the vehicle V also includes a distribution box BD to which the utility battery BS, the CV converter and the on-board network RB are coupled. This distribution box BD is responsible for distributing in the on-board network RB the electrical energy stored in the utility battery BS or produced by the converter CV, for powering the electrical components (or equipment) coupled to the on-board network RB depending on power requests received (in particular from the GMP CS supervision computer).

The DF braking device is here coupled to the wheels of the front T1 and rear T2 trains. It is responsible for braking the vehicle V when the regenerative braking function is not activated, or in addition to this last function (when it alone is not sufficient to ensure all braking). The operation of this DF braking device is controlled by a CF braking computer.

The emergency (automatic braking) function FF is capable, in the presence of a detected risk of collision involving the vehicle V, of imposing automatic emergency braking chosen by the braking device DF and of alerting the supervision computer of the GMP.

As indicated above, this emergency function FF can be the one designated by the English acronym AEB (Automatic Emergency Braking) or AEBS (Automatic Emergency Braking System), which makes it possible to automatically brake the vehicle V when there is a risk of collision has been detected, to prevent it from being involved in a collision or to at least reduce its impact speed during a collision.

In the example illustrated non-limitingly on the The FF emergency function is part of the CF braking computer. But this is not obligatory. Indeed, the emergency function FF could be provided by a dedicated computer, or could be part of another computer on board the vehicle V and ensuring at least one other function, for example.

As mentioned above, the invention proposes in particular a control method intended to allow the control of each torque setpoint for the GMP of the vehicle V in the presence of a detected risk of collision involving the latter (V).

This (control) method can be implemented at least partially by the DC control device (illustrated at least partially in Figures 1 and 2) which comprises for this purpose at least one processor PR1, for example a digital signal (or DCP (“Digital Signal Processor”)), and at least one MD memory. This DC control device can therefore be produced in the form of a combination of electrical or electronic circuits or components (or “hardware”) and software modules (or “software”). For example, it can be a microcontroller.

The memory MD is live in order to store instructions for the implementation by the processor PR1 of at least part of the control process. The processor PR1 may include integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or non-wired connections. By integrated (or printed) circuit we mean any type of device capable of performing at least one electrical or electronic operation.

In the example illustrated non-limitingly in Figures 1 and 2, the DC control device is part of the CS supervision computer. But this is not obligatory. Indeed, the DC control device could include its own dedicated computer, which is then coupled to the supervision computer CS, or could be part of another computer on board the vehicle V and ensuring at least one other function, for example .

As illustrated without limitation on the , the (control) method, according to the invention, comprises a step 10-20 which is implemented when a risk of collision involving the vehicle V has just been detected, for example by an on-board device responsible for analyzing data acquired in the environment of the vehicle V.

Step 10-20 of the method comprises a sub-step 20 in which, when a risk of collision involving the vehicle V has just been detected and at least one torque reference has been requested for a train Tj, we (the DC control device) authorizes this requested torque setpoint when it is less than or equal to zero, or replaces this requested torque setpoint with a torque setpoint which is equal to zero when it is greater than zero.

It is recalled that the (each) requested torque setpoint is defined as a function of the percentage of depression of the accelerator pedal by the driver of vehicle V and/or a regenerative torque setpoint requested, for example by a computer. CC control of a DCT trajectory control device. For example, this DCT trajectory control device can be of the ESP/ABS type (ESP: “Electronic Stability Program”), ABS: “Anti-Blocking System”). Note that this CC control computer can also be arranged to control the DF braking device if necessary.

Thanks to the invention, when the supervision computer CS is alerted by the emergency function FF of automatic emergency braking, it informs the control device DC, which authorizes the transmission of the requested torque setpoint to the machine computer CMj concerned when it is less than or equal to zero, or replaces this requested torque reference with a zero torque reference when it is greater than zero with a view to transmitting this zero torque reference to the machine computer CMj concerned. This authorization or replacement therefore takes place very advantageously downstream of a possible distribution of torque between the front axle T1 and the rear axle T2, and without necessarily imposing a torque setpoint on each driving machine or electrical machine (non-driving) of the GMP.

This makes it possible, when the requested torque reference is less than or equal to zero (and therefore regenerative braking is required), to prevent the GMP from opposing the action (mechanical braking) exerted, at at the instant considered, by the braking device DF. There is therefore no longer any risk of reducing the slowing capacity of the vehicle V and therefore preventing collision avoidance or causing an insufficient reduction in the impact speed.

Furthermore, when the requested torque setpoint is greater than zero, the invention makes it possible to respect a possible distribution of torque between the front trains T1 and rear trains T2 or between (driving) machines of different types of the same train Tj, and therefore to carry out or optimize certain specific phases. Thus, in the case of a GMP that is at least partially thermal, there is no longer any risk of reducing the depollution capacity of the exhaust line depollution devices and/or preventing the protection of the turbocharger. .

It will be noted that when the requested torque reference is less than or equal to zero, the invention also makes it possible to respect a torque distribution between the front trains T1 and rear trains T2 or between (driving) machines of different types of the same train. Tj, because we impose a torque setpoint or a limitation of the torque setpoint per train and not per component (electrical or thermal).

In addition, the invention makes it possible to have a very rapid connection with the requested torque reference when the automatic emergency braking alert of the supervision computer CS by the emergency function FF is completed.

For example, and as illustrated without limitation on the , step 10-20 may include a sub-step 10 in which, once the automatic emergency braking alert has been received, (the DC control device) can compare the (each) requested torque setpoint to the zero value. In this case, if the requested torque setpoint is less than or equal to zero, we (the DC control device) authorizes the transmission of this requested torque setpoint in substep 20, while if the requested torque setpoint is greater than zero, we (the DC control device) replace it with a zero torque reference in substep 20.

Note that when the GMP is hybrid (which is not the case here), it can include a thermal engine and a reversible electric engine associated with the same train Tj. In this case, in the presence of the detected risk and a torque setpoint requested for this train Tj, we (the DC control device) can:

- either authorize the requested torque setpoint when it is less than or equal to zero, and determine first and second torque setpoints respectively for these thermal motors and reversible electric motors, with the condition that the sum of these first and second torque setpoints must be equal to this requested torque setpoint,

- either replace the requested torque setpoint with a torque setpoint equal to zero when it is greater than zero, and determine first and second torque setpoints respectively for these thermal motors and reversible electric motors, with the condition of doing so that the sum of these first and second torque instructions must be equal to zero.

In these two cases this is particularly advantageous because it can make it possible to carry out a chosen distribution of the requested torque setpoint between the first and second torque setpoints for the same train Tj, for example to reinforce regenerative braking (via the second torque ) by increasing the quantity of fuel injected via the first couple. As an illustrative example, in the first case if the requested torque setpoint is equal to -20 Nm, we can use first and second torque setpoints equal respectively to +10 Nm and -30 Nm (or +20 Nm and -40 Nm) in order to obtain a sum equal to -20 Nm while recharging the BP electrical energy source (here a BP main (or traction) battery) and carrying out a specific phase. As an illustrative example, in the second case if the requested torque setpoint is equal to +20 Nm, we can use first and second torque setpoints equal respectively to +20 Nm and -20 Nm in order to obtain a sum equal to 0 Nm while recharging the BP electrical energy source (here a BP main (or traction) battery) and carrying out a specific phase.

Note also, as illustrated non-limitatively in the , that the GMP can be capable of providing or recovering on the front axle T1 a front torque which is a function of a front torque setpoint requested to move or brake the vehicle V, and on the rear axle T2 a rear torque which is a function of a rear torque setpoint requested to move or brake the vehicle V. In this case, in the presence of the detected risk and a requested front torque setpoint and/or a requested rear torque setpoint, we (the device DC control) can:

- authorize the requested front torque setpoint when it is less than or equal to zero, or replace the requested front torque setpoint with a front torque setpoint equal to zero when it is greater than zero, and/or

- authorize the requested rear torque setpoint when it is less than or equal to zero, or replace the requested rear torque setpoint with a rear torque setpoint equal to zero when it is greater than zero.

It will be understood that in this way we can advantageously control independently the front and rear parts of the GMP which are respectively associated with the front axles T1 and the rear axles T2. Indeed, for each of the front and rear parts of the GMP the authorization or replacement is decided after the first distribution of torque between the front axle T1 and the rear axle T2 (via the front and rear torque instructions requested) , and without necessarily first imposing a torque setting on each driving machine of each part of the GMP. Consequently, when at least one of the front and rear parts of the GMP comprises a thermal engine and a reversible electric engine, it is then possible (after the authorization or replacement which concerns it) to carry out a second chosen distribution of the front or rear torque setpoint requested between first and second torque setpoints dedicated respectively to the thermal motor and reversible electric motor of the front or rear part concerned (since this second distribution induces a sum of the first and second torque setpoints which satisfies the aforementioned condition relating to this authorization or replacement).

As an illustrative example, if the requested torque setpoint is equal to -200 Nm (and therefore less than zero), we can, for example, use first and second torque setpoints equal to -50 Nm and -150 respectively. Nm (or -100 Nm and -100 Nm), respectively for the first MME1 and second MME2 electric motor machines, in order to obtain a sum equal to -200 Nm while recharging the electrical energy source BP (here a main battery (or traction) BP) and performing a specific phase. Then, it is also possible, possibly, to carry out a torque distribution between the first electric driving machine MME1 and the thermal engine associated with the front axle T1.

Also as an illustrative example, if the requested torque setpoint is equal to +20 Nm (and therefore greater than zero), we can, for example, use first and second torque setpoints equal to +20 Nm and - respectively. 20 Nm), respectively for the thermal engine and the first electric engine MME1 associated with the front axle T1, in order to obtain a sum equal to 0 Nm on the latter (T1), and a third torque setpoint equal to zero for the second electric driving machine MME2 associated with the rear axle T2, in order to obtain a sum equal to 0 Nm on the latter (T2).

Note also, as illustrated non-limitatively in the , that the supervision computer CS (or the computer of the DC control device) can also include a mass memory MM1, in particular to store each requested torque setpoint, as well as any intermediate data involved in all its calculations and processing. Furthermore, this CS supervision computer (or the DC control device computer) can also include an IE input interface for receiving at least each requested torque reference and each message representative of an automatic braking alert. urgently to use them in calculations or processing, possibly after having formatted and/or demodulated and/or amplified them, in a manner known per se, by means of a digital signal processor PR2. In addition, this CS supervision computer (or the computer of the DC control device) can also include an IS output interface, in particular to deliver a message (or request) containing each authorized requested torque setpoint or each resulting zero torque setpoint. a replacement of the requested torque setpoint concerned.

It will also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when executed by processing means of the electronic circuit (or hardware) type, such as for example the processor PR1, is capable of implementing the control method described above to control in the vehicle V the (each) torque setpoint requested for the GMP in the presence of a detected risk of collision involving this vehicle V.

Claims (6)

Control method for a land vehicle (V) comprising i) a powertrain capable of supplying or recovering from at least one train (Tj) a torque depending on a torque setpoint requested to move or brake said vehicle (V), ii ) a braking device (DF), and iii) an emergency function capable of imposing automatic emergency braking chosen by said braking device (DF) in the presence of a detected risk of collision involving said vehicle (V) , characterized in that it comprises a step (10-20) in which, in the presence of said detected risk and a torque setpoint requested for a train (Tj), this requested torque setpoint is authorized when it is lower or equal to zero, or this requested torque reference is replaced by a torque reference equal to zero when it is greater than zero. Method according to claim 1, characterized in that in said step (10-20), in the presence of a powertrain comprising a thermal engine and a reversible electric engine associated with a train (Tj), and in the presence of said risk detected and a torque setpoint requested for this train (Tj), we authorize this requested torque setpoint when it is less than or equal to zero and we determine for said thermal motor machine and reversible electric motor machine respectively first and second torque setpoints, a sum of which is equal to this requested torque setpoint, or else this requested torque setpoint is replaced by a torque setpoint equal to zero when it is greater than zero and we determine for said thermal motor machine and motor machine reversible electric respectively of the first and second torque instructions, a sum of which is equal to zero. Method according to claim 1 or 2, characterized in that in said step (10-20), in the presence of a powertrain capable of supplying or recovering on a front axle (T1) a front torque, depending on a setpoint of front torque requested to move or brake said vehicle (V), and on a rear axle (T2) a rear torque, function of a rear torque setpoint requested to move or brake said vehicle (V), and in the presence of said risk detected and a requested front torque setpoint and/or a requested rear torque setpoint, said requested front torque setpoint is authorized when it is less than or equal to zero or said requested front torque setpoint is replaced by a setpoint of front torque equal to zero when it is greater than zero, and/or we authorize said requested rear torque setpoint when it is less than or equal to zero or we replace said requested rear torque setpoint by a rear torque setpoint equal to to zero when it is greater than zero. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the control method according to one of claims 1 to 3, in a land vehicle (V ) comprising i) a powertrain capable of supplying or recovering on at least one train (Tj), a torque depending on a torque setpoint requested to move or brake said vehicle (V), ii) a braking device (DF) , and iii) an emergency function capable of imposing automatic emergency braking chosen by said braking device (DF) in the presence of a detected risk of collision involving said vehicle (V), to control said requested torque setpoint in the presence of such a detected risk. Control device (DC) for a land vehicle (V) comprising i) a powertrain capable of supplying or recovering on at least one train (Tj) a torque depending on a torque setpoint requested to move or brake said vehicle (V ), ii) a braking device (DF), and iii) an emergency function capable of imposing automatic emergency braking chosen by said braking device (DF) in the presence of a detected risk of collision involving said vehicle (V), characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting, in the presence of said detected risk and a torque setpoint requested for a train ( Tj), to authorize this requested torque setpoint when it is less than or equal to zero, or to replace this requested torque setpoint with a torque setpoint equal to zero when it is greater than zero. Land vehicle (V) comprising i) a powertrain capable of supplying or recovering from at least one train (Tj) a torque depending on a torque setpoint requested to move or brake said vehicle (V), ii) a braking device (DF), and iii) an emergency function capable of imposing automatic emergency braking chosen by said braking device (DF) in the presence of a detected risk of collision involving said vehicle (V), characterized in that it further comprises a control device (DC) according to claim 5.