CONTROLLED DELIVERY OF INCREASED ENGINE TORQUE IN A TWO-ENGINE LAND VEHICLE

Abstract

A control method is implemented in a land vehicle comprising a first drive unit capable of providing a first driving torque for a first set of wheels, and a second electric drive unit capable of providing a second driving torque for a second set of wheels, and offering at least one selectable driving mode. This method includes a step (10-50) in which, if an assistance driving mode is selected while the driving mode has been selected and the first drive unit is providing a chosen first driving torque, the second drive unit is required to temporarily provide, for a chosen duration, a chosen second driving torque. Figure 3

Description

Title of the invention: CONTROLLED PROVISION OF INCREASED ENGINE TORQUE IN A TWO-POWER LAND VEHICLE Technical field of the invention

[0001] The invention relates to land vehicles comprising two drive machines, at least one of which is electric, and offering at least one driving mode, and more precisely the control of the engine torque provided by these drive machines in such vehicles. State of the art

[0002] Certain land vehicles (and for example of the automobile type), comprise a powertrain (or GMP) comprising two motor machines, at least one of which is electric, and capable of respectively providing first and second engine torques for first and second trains, and offer at least one driving mode (and generally several (for example economic, comfort and sport)).

[0003] In the land vehicles presented above, it is the driver who selects the driving mode (possibly from among several). In the presence of several driving modes, the latter are generally associated respectively with tables establishing different correspondences between percentages of depression of the accelerator pedal and first engine torques to be provided.

[0004] In certain life situations, the driver may temporarily need increased engine torque (or "boost") in order to increase the acceleration and speed of the vehicle. This may be the case, in particular, when the driver of a first vehicle following a second vehicle wishes to overtake the latter, or when the driver of a vehicle must suddenly increase speed to avoid an obstacle.

[0005] Currently, regardless of the driving mode selected, when the driver suddenly wants to increase the speed of his (land) vehicle, he can only do so by increasing the percentage of depression of the vehicle's accelerator pedal, and the intensity of the increase in acceleration depends on the correspondence table currently in use (and associated with the driving mode selected). However, such an increase cannot be obtained when the percentage of depression is already maximum, or may prove insufficient due to the correspondence table currently in use (in particular in the economical driving mode), and therefore forces the driver to make several successive increases in the percentage of depression. It will be understood that in the two aforementioned life situations the driver may find himself unable to manage the life situation in question, which can be dangerous.

[0006] Certainly, when the vehicle offers several driving modes the driver can select a new driving mode likely to offer more engine torque, but this new selection can take up part of the driver's attention (in particular when the selection is made at the level of the digital screen of the central instrument panel of the vehicle), which can prove dangerous, or can be impossible when the driving mode selected is the one which offers the most engine torque.

[0007] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0008] For this purpose, it proposes in particular a control method intended to be implemented in a land vehicle:

[0009] - comprising a first driving machine capable of providing a first torque motor for a first train, and a second electric motor suitable for providing a second motor torque for a second train, and

[0010] - providing at least one selectable driving mode.

[0011] This control method is characterized by the fact that it comprises a step in which, in the event of selection of an assistance driving mode while the driving mode has been selected and the first driving machine provides a first chosen engine torque, the second driving machine is required to temporarily provide, for a chosen duration, a second chosen engine torque.

[0012] Thanks to the invention, the GMP suddenly and temporarily provides an overall engine torque which is increased compared to that which would be provided in the case of using the selected driving mode, which makes it possible to increase the acceleration of the vehicle and therefore the speed of the latter.

[0013] The control method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0014] - in its step, when the duration is finished, we can use again only the first prime mover to provide the first chosen engine torque;

[0015] - in its step, when the land vehicle offers N selectable driving modes- tionable, with N > 2, the second engine torque chosen can be a function of the driving mode selected;

[0016] - in its step, the second chosen engine torque can be a chosen percentage of the first engine torque chosen;

[0017] - in the presence of the last option, in its step, the chosen percentage can be between 1% and 5%;

[0018] - in its step, the chosen duration can be between 5 seconds and 30 seconds;

[0019] - in its step, in case of selection of the assistance driving mode, one can authorize the second prime mover to temporarily provide, for the chosen duration, the second chosen engine torque, when an electrical power source of the vehicle, supplying current to the second electric prime mover, has a value representative of a state of charge greater than a chosen threshold;

[0020] - in the presence of the last option, in its step, the chosen threshold can be understood between 10% and 20% of a maximum state of charge of the power source.

[0021] The invention also provides 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 presented above, in a land vehicle, on the one hand, comprising a first prime mover capable of providing a first engine torque for a first train, and a second electric prime mover capable of providing a second engine torque for a second train, and, on the other hand, offering at least one selectable driving mode, to temporarily offer a driver of the land vehicle an increased (overall) engine torque.

[0022] The invention also proposes a control device intended to equip a land vehicle:

[0023] - comprising a first driving machine capable of providing a first torque motor for a first train, and a second electric motor suitable for providing a second motor torque for a second train, and

[0024] - providing at least one selectable driving mode.

[0025] 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 event of selection of an assistance driving mode while the driving mode has been selected and the first driving machine provides a first chosen engine torque, in triggering an imposition of a temporary supply, for a chosen duration, of a second chosen engine torque by the second driving machine.

[0026] The invention also provides a land vehicle, possibly of the automobile type, and:

[0027] - comprising a first driving machine capable of providing a first torque motor for a first train, a second electric motor suitable for providing a second motor torque for a second train, and a control device of the type presented above, and

[0028] - providing at least one selectable driving mode. Brief description of the figures

[0029] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0030] [Fig.l] schematically and functionally illustrates an exemplary embodiment of a land vehicle comprising an all-electric GMP, a supervision computer, and a control device according to the invention,

[0031] [Fig.2] schematically and functionally illustrates an exemplary embodiment of a supervision computer comprising an exemplary embodiment of a control device according to the invention, and

[0032] [Fig.3] schematically illustrates an example of an algorithm implementing a control method according to the invention. Detailed description of the invention

[0033] The invention aims in particular to propose a control method, and an associated control device DC2, intended to allow control of the supply of first cml and second cm2 engine torques respectively by first MM1 and second MM2 drive machines, at least one of which (MM2) is electric, in a land vehicle V offering at least one driving mode mcn, so as to temporarily offer the driver an increased overall engine torque.

[0034] In the following, it is considered, by way of non-limiting example, that the land vehicle V is of the automobile type. It is for example a car, as illustrated in [Fig.l]. But the invention is not limited to this type of land vehicle. It in fact relates to any type of land vehicle comprising a powertrain (or GMP) comprising first and second motor machines, at least one of which is electric, and offering at least one driving mode.

[0035] Furthermore, it is considered in the following, by way of non-limiting example, that the GMP is purely electric (and therefore comprises first and second electric motors). But the GMP could be hybrid (thermal and electric).

[0036] Furthermore, it is considered in the following, by way of non-limiting example, that the first MM1 and second MM2 electric motors are supplied with electrical energy by an electrical power source constituting a main battery (or traction or even power) BP, rechargeable (at least during recharging phases). But the first MM1 and second MM2 electric motors could be supplied with electrical energy by a fuel cell.

[0037] [Fig.l] schematically shows a (land) vehicle V comprising a purely electric GMP transmission chain (and therefore comprising first MM1 and second MM2 electric motors), an on-board network RB, a service battery BS, a main battery (or traction or power) BP, a converter CV, a supervision computer CS, a coupling device DC1, and a control device DC2 according to the invention.

[0038] The CV converter is of the DC / DC type (“Direct Current / Direct Current”). direct current). It is therefore responsible for converting a direct current from a first voltage to a second voltage.

[0039] The on-board network RB is an electrical power supply network to which electrical (or electronic) equipment (or components) that consume electrical energy are coupled.

[0040] The service 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 main battery BP, and sometimes instead, here, of this CV converter. For example, this service battery BS 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 by the (current) converter CV. It is considered in the following, by way of non-limiting example, that the service battery BS is of the 12 V Lithium-ion type.

[0041] The transmission chain has a GMP which is, here, purely electric and therefore which comprises, in particular, first MM1 and second MM2 electric motors, first AMI and second AM2 motor shafts, and first ATI and second AT2 transmission shafts. Here, the term "electric motor" means an electric machine arranged so as to provide a motor torque cmj (j = 1 or 2), defined by a torque setpoint, to move the vehicle V when it is supplied with electrical energy (here) by the main battery BP (we then speak of providing a positive output torque), as well as possibly to recover torque, for example in a regenerative braking phase (we then speak of providing a negative output torque).

[0042] The operation of the GMP is supervised by a CS supervision computer.

[0043] The first drive machine MM1 is coupled to the first motor shaft AMI, to provide it with a first motor torque cml (j = 1) by rotational drive when it is (here) supplied with electrical energy by the main battery BP. This first motor shaft AMI is here coupled to a reducer RD which is also coupled to the first transmission shaft ATI, itself coupled to a first train Tl of driving wheels, preferably via a first differential DV.

[0044] It will be noted that the first train T1 is here located in the front part PVV of the vehicle V. But in a variant this first train T1 could be the second train T2 which is located in the rear part PRV of the vehicle V.

[0045] The second driving machine MM2 is coupled to the second motor shaft AM2, to provide it with a second motor torque cm2 (j = 2) by rotational drive when it is supplied with electrical energy (here) by the main battery BP. This second motor shaft AM2 is here coupled to a coupling device DC1 which is also coupled to the second transmission shaft AT2, itself coupled to the second train T2 of driving wheels, preferably via a second differential DR.

[0046] It will be noted that when the first train T1 is located in the rear part PRV of the vehicle V, the second train T2 is located in the front part PVV of the vehicle V.

[0047] The coupling device DC1 is arranged so as to couple or decouple the second driving machine MM2 from the second transmission shaft AT2, according to the needs defined by the supervision computer CS. For example, this coupling device DC1 can be a clutch (possibly hydraulic). But it could also be a dog clutch, for example.

[0048] The CV converter is also responsible, here, during the driving phases of the vehicle V for converting part of the electric current stored in the main battery BP to supply the on-board network RB and the service battery BS with converted electric current (to recharge it).

[0049] It will be noted, as illustrated non-limitingly in [Fig.l], that the CV converter can be part of a CH charger also comprising a recharge calculator (not illustrated) responsible, at least, for controlling the recharges of the main battery BP.

[0050] The main battery (or traction or even power) BP may, for example, comprise electrical energy storage cells, possibly electrochemical (for example of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type). Also for example, the main battery BP may be of the low voltage type (typically 450 V for illustration purposes). But it could be of the medium voltage or high voltage type.

[0051] It will also be noted that in the example illustrated non-limitingly in [Fig.l] the vehicle V also comprises a distribution box BD to which the service battery BS, the converter CV 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 service battery BS or produced by the converter CV, for the supply of the electrical components (or equipment) coupled to the on-board network RB according to power supply requests received (in particular from the supervision computer CS of the GMP).

[0052] It will also be noted, as illustrated in [Fig.l], that the vehicle V also comprises an accelerator pedal PA actuable (here) by a foot of the driver of the vehicle V. It has a depression percentage pe from which an overall torque setpoint ccg can be defined from which the first and second torque setpoints are defined respectively defining the first cml and second cm2 engine torques to be supplied at the instant in question respectively by the first MM1 and second MM2 prime movers. It is recalled that the overall torque setpoint ccg is representative of the driver's wishes.

[0053] The vehicle V also offers at least one driving mode mcn which can be selected by the driver, and for example chosen from an economical mode mcl (n = 1), a comfort mode mc2 (n = 2) and a sport mode me3 (n = 3). Each driving mode mcn induces, when selected by the driver, the use of an associated tcn correspondence table to determine the overall torque setpoint ccg. The (each) tcn correspondence table establishes a first correspondence between percentages of depression of the accelerator pedal PA pe and the first overall engine torques cmgln to be provided. It will be understood that for the same percentage of depression (of the accelerator pedal PA) pe the first overall engine torque cmgi 1 to be provided in the economy mode mcl is lower than the first overall engine torque cmgl2 to be provided in the comfort mode mc2, which is lower than the first overall engine torque cmgi3 to be provided in the sport mode mc3.

[0054] Each correspondence table tcn can be determined during the development phase of a vehicle similar to the vehicle V, then can be stored, for example, in the control device DC2 (or in the supervision computer CS).

[0055] Preferably, the vehicle V can offer three different driving modes mcn, n = 1 to 3, chosen from the three aforementioned (economy mode mcl, comfort mode mc2 and sport mode mc3).

[0056] Each driving mode mcn can, for example, be selected by the driver in a menu which is accessible on the digital screen of an equipment EA fitted to the vehicle V. For example, this equipment EA can be the central instrument panel installed in the dashboard of the vehicle V, which is accessible to the driver and the front passenger. This makes it possible to avoid having to provide a control member dedicated (at least in part) to the selection of a driving mode mcn in the driver's environment (for example in the dashboard or on the steering wheel VV), which would locally increase the size and / or complexity of the equipment concerned. But in an alternative embodiment not illustrated, each driving mode mcn could be selected by the driver by means of such a dedicated control member (at least in part).

[0057] As mentioned above, the invention notably proposes a control method intended to enable the control of the supply of the first cml and second cm2 engine torques so as to temporarily offer the driver an increased overall engine torque cmga when the driver requires it.

[0058] This (control) method can be implemented at least partially by the control device DC2 (illustrated at least partially in FIGS. 1 and 2) which comprises for this purpose at least one processor PR1, for example a digital signal processor (or DSP ("Digital Signal Processor")), and at least one memory MD. This control device DC2 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.

[0059] The memory MD is live in order to store instructions for the implementation by the processor PR1 of at least part of the control method. The processor PR1 may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. An integrated (or printed) circuit is understood to mean any type of device capable of carrying out at least one electrical or electronic operation.

[0060] In the example illustrated non-limitingly in Figures 1 and 2, the control device DC2 is part of the supervision computer CS. But this is not obligatory. Indeed, the control device DC2 could comprise its own dedicated computer, or could be part of another computer on board the vehicle V and providing at least one other function.

[0061] As illustrated non-limitingly in [Fig. 3], the (control) method, according to the invention, comprises a step 10-50 which is implemented each time three conditions are satisfied, namely a (the) driving mode mcn has been selected (by the driver), the first driving machine MM1 is supplying a first engine torque cml, and an assistance driving mode mca has just been selected by this driver.

[0062] Step 10-50 of the method comprises a sub-step 40 in which, when the three aforementioned conditions are satisfied, the second driving machine MM2 is imposed (for example the control device DC2 triggers the imposition) to temporarily supply, for a chosen duration dt, a second chosen motor torque cm2.

[0063] Thus, the GMP suddenly and temporarily (for the chosen duration dt) provides an overall engine torque cmga which is increased by the contribution of the second engine torque cm2 chosen from the second prime mover MM2, which makes it possible to temporarily increase the acceleration of the vehicle V and therefore the speed of the latter (V).

[0064] It will be noted that when the second driving machine MM2 is not operating at the time when the user selects the assistance driving mode mca, the coupling device DC1 is placed in its coupled (or closed) state and the second driving machine MM2 is operated. However, if the second driving machine MM2 already provides a first second motor torque cm2i at the time when the user selects the assistance driving mode mca, the second driving machine MM2 is only provided with a second total motor torque equal to the sum of this first second motor torque cm2i and a second second motor torque cm22 equal to the second motor torque cm2 chosen for the assistance driving mode mca, of course provided that the second driving machine MM2 can provide such a second total motor torque at the time considered.

[0065] For example, and as illustrated non-limitingly in [Fig.l], the vehicle V may comprise an OCD control member which is dedicated to the selection of the driving mode. mca assistance driving in the driver's immediate environment. It will be noted that in the example illustrated non-limitingly in [Fig.l] the dedicated OCD control member equips the steering wheel VV (or the top of the steering column to which the steering wheel VV is coupled). But in an alternative embodiment not illustrated, the dedicated OCD control member could equip the dashboard, for example.

[0066] Also for example, the chosen duration dt can be between 5 seconds and 30 seconds. As an illustrative example this chosen duration dt can be equal to 15 seconds. But other values ​​of chosen duration dt can be used. For example, this chosen duration dt can be chosen during the development phase of a vehicle similar to vehicle V.

[0067] Also for example, and as illustrated non-limitingly in [Fig.3], step 10-50 of the method can also comprise a sub-step 10 in which one (for example the control device DC2) is informed of the selection of the assistance driving mode mca by the driver (here by the actuation of the dedicated control member OCD).

[0068] Also for example, and as illustrated non-limitingly in [Fig.3], step 10-50 of the method can also comprise a sub-step 50 in which, when the chosen duration dt is over, the first prime mover MM1 is used again (for example the control device DC2 triggers the use of again) to provide the first chosen engine torque cml. Of course, if the second prime mover MM2 was already providing a first second engine torque cm2i at the time when the user selected the assistance driving mode mca, it (MM2) again provides this first second engine torque cm2i after the chosen duration dt has elapsed. In other words, as soon as the assistance driving mode mca is no longer active, it is the initially selected driving mode mcn which is automatically active again.This is advantageous because it saves the driver from having to reselect a mcn driving mode (and possibly the one he had initially selected).

[0069] Of course, if the driver wishes to benefit again from an increased overall engine torque cmga after the end of the chosen duration dt, he can select the assistance driving mode mca again.

[0070] Also for example, in sub-step 40 of step 10-50, in case of selection of the assistance driving mode mca, the driver can control the increased overall engine torque cmga provided by varying the depression percentage pe. In other words, if during the chosen duration dt of effective selection of the assistance driving mode mca the driver decides to modify the depression percentage pe to modify the current acceleration, at least one new first chosen engine torque cml is determined in the associated correspondence table tcn to the selected driving mode mcn, which causes the provision of a new increased overall engine torque cmga. It will be understood that this new increased overall engine torque cmga can be either higher than the previous one when the new percentage of depression pe is higher than the previous one, or lower than the previous one when the new percentage of depression pe is lower than the previous one.

[0071] It will be noted that in sub-step 40 of step 10-50, when the vehicle V offers N selectable driving modes mcn, with n = 1 to N and N > 2, the second engine torque cm2 (or cm22) chosen may be a function of the driving mode mcn selected. For example, the less economical the driving mode mcn selected is (in terms of driving energy consumption), the greater the second engine torque cm2 may be.

[0072] But in a first variant (possibly combinable with the option mentioned in the previous paragraph), the value of the second engine torque cm2 chosen could vary depending on the current speed of the vehicle V.

[0073] In a second variant, the value of the second engine torque cm2 could be fixed and therefore the same regardless of the driving mode mcn selected.

[0074] In a third variant (possibly combinable with the option mentioned three paragraphs above), the second engine torque cm2 chosen could be a chosen percentage pcc of the first engine torque cml chosen and supplied. We then have cmga = cml + cm2 = cml*(l + (pcc (in %) / 100).

[0075] For example, the chosen percentage pcc can be between 1% and 5%. As an illustrative example, this chosen percentage pcc can be equal to 3%. But other values ​​of chosen percentage pcc can be used. For example, this chosen percentage pcc can be chosen during the development phase of a vehicle similar to vehicle V.

[0076] It will be noted that the chosen percentage pcc can be fixed and therefore the same regardless of the driving mode mcn selected. But in a variant it can vary depending on the driving mode mcn selected. For example, the less economical the driving mode mcn selected is (in terms of driving energy consumption), the greater the chosen percentage pcc can be.

[0077] Also for example, and as illustrated non-limitingly in [Fig.3], step 10-50 of the method can also comprise a sub-step 20 in which, in the event of selection of the assistance driving mode mca, one (for example the control device DC2) can authorize the second prime mover MM2 to temporarily supply, for the chosen duration dt, the second chosen engine torque cm2, when the electrical power source of the vehicle V which supplies current (or electrical energy) to the second electric prime mover MM2 (here the main battery BP) has a value representative of a state of charge which is greater than a chosen threshold si. Such an option is intended to avoid excessive discharge of the electrical power source supplying current to at least the second driving machine MM2 (here the main battery BP) by using the mca assistance driving mode, as this could then penalize the driver.

[0078] In the presence of this last option, if the value representing the state of charge (or SOC (“State Of Charge”)) is greater than the chosen threshold si, sub-step 40 is carried out. On the other hand, if the value representing the state of charge (or SOC (“State Of Charge”)) is less than or equal to the chosen threshold si, step 10-50 of the method can also comprise, as illustrated non-limitingly in [Fig. 3], a sub-step 30 in which one (for example the control device DC2) decides to prohibit the use of the assistance driving mode mca required by the driver. For example, this prohibition can be signaled to the driver by broadcasting a dedicated audible (or audio) warning message via at least one loudspeaker present in the vehicle V and / or displaying a dedicated text warning message on a screen of the vehicle V, such as for example that of the dashboard or that of the central instrument panel.

[0079] Also for example, the chosen threshold si can be between 10% and 20% of the maximum state of charge of the electrical power source (here the main battery BP). As an illustrative example this chosen threshold si can be equal to 15%. But other values ​​of chosen threshold si can be used. For example, this chosen threshold si can be chosen during the development phase of a vehicle similar to vehicle V.

[0080] It will also be noted, as illustrated non-limitingly in [Fig.2], that the supervision computer CS (or the computer of the control device DC2) can also comprise a mass memory MME, in particular for storing the selected driving mode mcn and possibly the value representative of the current state of charge of the main battery BP, the current speed of the vehicle V and the first chosen engine torque cml supplied by the first prime mover MM1, as well as possible intermediate data involved in all its calculations and processing.Furthermore, this supervision computer CS (or the computer of the control device DC2) can also comprise an input interface IE for receiving at least the selected driving mode mcn and possibly the value representing the current state of charge of the main battery BP, the current speed of the vehicle V and the first chosen engine torque cml supplied by the first prime mover MM1, possibly after having shaped and / or demodulated and / or amplified them, in a manner known per se, by means of a digital signal processor PR2. In addition, this supervision computer CS (or the computer of the control device DC2) can also comprise an output interface IS, in particular for delivering each message imposing the temporary supply of a second engine torque cm2 chosen by the . second MM2 driving machine, and any message prohibiting use of the mca assistance driving mode.

[0081] 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 temporarily offer the driver of the vehicle V an increased overall engine torque cmga when required.

Claims

Claims

1. Control method for a land vehicle (V) i) comprising a first prime mover (MM1) capable of providing a first engine torque for a first train (T1), and a second electric prime mover (MM2) capable of providing a second engine torque for a second train (T2), and ii) offering at least one selectable driving mode, characterized in that it comprises a step (10-50) in which, in the event of selection of an assistance driving mode while said driving mode has been selected and said first prime mover (MM1) provides a first chosen engine torque, said second prime mover (MM2) is forced to temporarily provide, for a chosen duration, a second chosen engine torque.

2. Method according to claim 1, characterized in that in said step (10-50) when said duration is over, only said first prime mover (MM1) is used again to provide said first chosen engine torque.

3. Method according to claim 1 or 2, characterized in that in said step (10-50), when said land vehicle (V) offers N selectable driving modes, with N > 2, said second chosen engine torque is a function of the selected driving mode.

4. Method according to one of claims 1 to 3, characterized in that in said step (10-50) said second chosen engine torque is a chosen percentage of said first chosen engine torque.

5. Method according to claim 4, characterized in that in said step (10-50) said chosen percentage is between 1% and 5%.

6. Method according to one of claims 1 to 5, characterized in that in said step (10-50) said duration is between 5 seconds and 30 seconds.

7. Method according to one of claims 1 to 6, characterized in that in said step (10-50), in the event of selection of said assistance driving mode, said second prime mover (MM2) is authorized to temporarily supply, for said chosen duration, said second chosen engine torque, when an electrical power source (BP) of said vehicle (V), supplying current to said second electric prime mover (MM2), has a value representative of a state of charge greater than a chosen threshold.

8. Computer program product comprising a set of instructions which, when executed by processing means, is suitable for implementing the control method according to one of claims 1 to 7, in a land vehicle (V) i) comprising a first prime mover (MM1) suitable for providing a first engine torque for a first train (T1), and a second electric prime mover (MM2) suitable for providing a second engine torque for a second train (T2), and ii) offering at least one selectable driving mode, to temporarily offer a driver of said land vehicle (V) an increased engine torque.

9. Control device (DC2) for a land vehicle (V) i) comprising a first prime mover (MM1) capable of providing a first engine torque for a first train (T1), and a second electric prime mover (MM2) capable of providing a second engine torque for a second train (T2), and ii) offering at least one selectable driving mode, 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 event of selection of an assistance driving mode while said driving mode has been selected and said first prime mover (MM1) provides a first chosen engine torque, in triggering an imposition of a temporary supply, for a chosen duration, of a second chosen engine torque by said second prime mover (MM2).

10. Land vehicle (V) i) comprising a first prime mover (MM1) capable of providing a first engine torque for a first train (T1), and a second electric prime mover (MM2) capable of providing a second engine torque for a second train (T2), and ii) offering at least one selectable driving mode, characterized in that it further comprises a control device (DC2) according to claim 8.

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