MONITORING OF RECOVERY BRAKING PHASES IN A LAND VEHICLE

The monitoring method in land vehicles addresses the issue of inadequate driver alerts during regenerative braking by using intermediate and tolerance torques to ensure safe and informed driving, preventing unexpected under-deceleration and battery heating.

FR3152461B1Active Publication Date: 2025-07-18STELLANTIS AUTO SAS
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Patent Information

Application Number
FR2023009104
Authority / Receiving Office
FR · FR
Patent Type
Patents
Current Assignee / Owner
Filing Date
2023-08-30
Publication Date
2025-07-18
Estimated Expiration
2043-08-30

AI Technical Summary

Technical Problem

Existing systems in land vehicles with regenerative braking capabilities fail to adequately alert drivers when they cannot fully satisfy regenerative braking demands due to battery limitations, potentially leading to unnecessary and potentially dangerous internal heating.

Method used

A monitoring method that determines an intermediate torque based on the vehicle's current speed and a tolerance torque, alerting the driver only when the recoverable regenerative braking torque is less than this intermediate torque, thereby avoiding unnecessary alerts and ensuring safe driving conditions.

Benefits of technology

The method enhances driving safety by accurately informing drivers of temporary regenerative braking limitations, preventing unexpected under-deceleration and potential battery heating issues.

✦ Generated by Eureka AI based on patent content.

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Abstract

A monitoring method is implemented in a land vehicle comprising a powertrain comprising an electric motor associated with a rechargeable battery and capable of recovering a regenerative braking torque to recharge the rechargeable battery. This method comprises a step (10-50) in which an intermediate torque is determined equal to a difference between a maximum regenerative braking torque that can be requested by a driver of the vehicle, depending on the current speed of the vehicle, and a so-called tolerance torque, negative and depending on this current speed, and, when a regenerative braking torque that can potentially be recovered is less than the determined intermediate torque, the driver is alerted of a temporary impossibility of fully satisfying a regenerative braking request. Figure 3
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Description

Title of the invention: MONITORING OF RECOVERY BRAKING PHASES IN A LAND VEHICLE Technical field of the invention

[0001] The invention relates to land vehicles comprising a powertrain comprising at least one electric motor capable of recovering a regenerative braking torque to recharge a rechargeable battery, and more precisely the monitoring within such vehicles of the regenerative braking phases. State of the art

[0002] Certain land vehicles, possibly of the automobile type, comprise a powertrain (or GMP) comprising at least one electric motor associated with a rechargeable battery and capable of recovering a regenerative (or regenerative) braking torque and transforming the latter into a recharging current intended to recharge the rechargeable battery.

[0003] Here, the term "electric motor machine" means an electric machine arranged to provide torque to move the vehicle when it is supplied with electrical energy and to recover torque in the transmission chain.

[0004] In a regenerative braking phase requested by the driver of the vehicle, possibly after selecting a regenerative braking level (or mode), the electric motor must ensure (or participate in) the braking of its land vehicle by acting as a generator which recharges the rechargeable battery.

[0005] However, in certain situations, such as for example when the state of charge of the rechargeable battery is very high or when the latter has too low a temperature, the recharging capacity of the rechargeable battery may be low, or even very low, and therefore it may be impossible to fully satisfy the driver's regenerative braking demand. It will be understood that fully satisfying this demand would cause the production of a recharging current higher, or even much higher, than what the rechargeable battery can withstand, and consequently potentially significant and therefore potentially dangerous internal heating.

[0006] In order to prevent such internal heating from occurring, a computer of the vehicle determines the regenerative braking torque that can potentially be recovered taking into account the capacity currently being recharged of the rechargeable battery. Then, another computer of the vehicle (or the same one) determines whether the regenerative braking torque that can potentially be recovered is less than the regenerative braking torque requested by the driver, and if so, this computer triggers alerting the driver of a temporary inability to fully satisfy a regenerative braking request. It will be understood that this mechanism is intended to warn the driver that the intensity of regenerative braking will be lower, or even much lower, than expected.

[0007] The disadvantage of this mechanism is that it is too restrictive, and therefore in certain situations regenerative braking could be maintained at least partially without the driver being alerted.

[0008] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0009] For this purpose, it proposes in particular a monitoring method intended to be implemented in a land vehicle comprising a powertrain (or GMP) comprising at least one electric motor associated with a rechargeable battery and capable of recovering a regenerative braking torque to recharge the rechargeable battery.

[0010] This monitoring method is characterized by the fact that it comprises a step in which an intermediate torque is determined equal to a difference between a maximum regenerative braking torque that can be requested by a driver of the vehicle, depending on a current speed of the vehicle, and a so-called tolerance torque, negative and depending on this current speed, and, when a regenerative braking torque that can potentially be recovered is less than the determined intermediate torque, the driver is alerted of a temporary impossibility of fully satisfying a regenerative braking request.

[0011] By taking into account a tolerance torque, it is possible to avoid unnecessarily alerting the driver when it is considered that he will not really feel (or at least not significantly) the under-deceleration by regenerative braking caused by the fact that his regenerative braking request cannot be temporarily fully satisfied.

[0012] The monitoring method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0013] - in its step, the driver can be alerted when the braking torque re The potential recoverable torque is less than the determined intermediate torque for at least a chosen duration;

[0014] - in the presence of the first option, in its step, the chosen duration can be between 0.2 s and 1 s;

[0015] - in its step one can determine the intermediate torque as a function in addition of a regenerative braking level previously chosen by the driver,

[0016] - in the presence of the last option, in its step, the level of regenerative braking can be chosen from three predefined and different regenerative braking levels;

[0017] - in its step the tolerance torque can increase when the current speed increases.

[0018] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a monitoring method of the type presented above, in a land vehicle comprising a powertrain (or GMP) comprising at least one electric motor associated with a rechargeable battery and capable of recovering a regenerative braking torque to recharge the rechargeable battery, to monitor the regenerative braking phases.

[0019] The invention also proposes a monitoring device intended to equip a land vehicle comprising a powertrain (or GMP) comprising at least one electric motor associated with a rechargeable battery and capable of recovering a regenerative braking torque to recharge the rechargeable battery.

[0020] This monitoring 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 of determining an intermediate torque equal to a difference between a maximum regenerative braking torque that can be requested by a driver of the vehicle, depending on a current speed of the vehicle, and a so-called tolerance torque, negative and depending on this current speed, and, when a regenerative braking torque that can potentially be recovered is less than this determined intermediate torque, to trigger an alert to the driver of a temporary impossibility of fully satisfying a regenerative braking request.

[0021] The invention also proposes a land vehicle, possibly of the automobile type, and comprising, on the one hand, a powertrain (or GMP) comprising at least one electric motor associated with a rechargeable battery and capable of recovering a regenerative braking torque to recharge the rechargeable battery, and, on the other hand, a monitoring device of the type presented above. Brief description of the figures

[0022] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0023] [Fig.l] schematically and functionally illustrates an exemplary embodiment of a land vehicle comprising a monitoring device according to the invention and a hybrid GMP transmission chain and supervised by a supervision computer,

[0024] [Fig.2] schematically and functionally illustrates an exemplary embodiment of a supervision calculator comprising an exemplary embodiment of a monitoring device according to the invention, and

[0025] [Fig.3] schematically illustrates an example of an algorithm implementing a monitoring method according to the invention. Detailed description of the invention

[0026] The invention aims in particular to propose a monitoring method, and an associated monitoring device DS, intended to enable monitoring of the regenerative braking phases carried out by at least one electric motor machine MM2 of a powertrain (or GMP) of a land vehicle V.

[0027] 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 concerns any type of land vehicle comprising a GMP transmission chain comprising at least one electric motor associated with a rechargeable battery and capable of recovering regenerative braking torque. Thus, it concerns utility vehicles, camper vans, minibuses, coaches, trucks, motorcycles, road machinery, construction machinery, agricultural machinery, and leisure machinery (karts), for example.

[0028] Furthermore, it is considered in the following, by way of non-limiting example, that the (land) vehicle V comprises a transmission chain with a powertrain (or GMP) of the hybrid type (and therefore comprising at least a first thermal motor MM1 and a second electric motor MM2). But the GMP could be of the all-electric type (and in this case the drive of the vehicle V is provided exclusively by at least one electric motor MM2).

[0029] [Fig.l] schematically shows a vehicle V comprising a hybrid GMP transmission chain (and therefore comprising the first thermal motor MM1 and second electric motor MM2), a supervision computer CS, a service battery BS, a rechargeable battery BR, a converter CV, and a monitoring device DS according to the invention.

[0030] The service battery BS is responsible for supplying electrical energy to the on-board network of the vehicle V, in addition to that supplied by the CV converter powered by the rechargeable battery BR via a main electrical circuit, and sometimes instead 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 CV converter. 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.

[0031] The on-board network is an electrical power supply network to which electrical (or electronic) equipment (or components) that consume electrical energy are coupled.

[0032] The main electrical circuit (or "high voltage" or "power") is connected, on the one hand, to the rechargeable battery BR via an interface device, and, on the other hand, to electronic equipment, such as for example the CV converter and the second driving machine MM2. It also allows the rechargeable battery BR to be recharged by an external power source and temporarily coupled to a charging connector of the vehicle V.

[0033] The transmission chain has a GMP which is, here, hybrid and therefore which comprises, here, in addition to its first MM1 and second MM2 driving machines, in particular, a motor shaft AM, a transmission shaft AT, first DC1 and second DC2 coupling devices, and a gearbox BV.

[0034] It is recalled that the term “drive machine” here means a machine arranged so as to provide engine torque to move the vehicle V, and to recover regenerative braking torque when it is electric.

[0035] The operation of the transmission chain (and therefore of the GMP) is supervised by a CS supervision computer.

[0036] The first driving machine MM1 is, here, thermal and responsible, when it is supplied with fuel, for producing a first torque and supplying the latter to the motor shaft AM.

[0037] Furthermore, this first driving machine MM1 (and more precisely the motor shaft AM) is capable of being coupled by the first coupling device DC1 to the primary shaft AP of the gearbox BV to provide it with the first engine torque produced.

[0038] The output shaft of the gearbox BV is coupled to the transmission shaft AT which is itself coupled to a first train T1 (here of wheels), preferably via a differential DI.

[0039] This 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 one which is here referenced T2 and which is located in the rear part PRV of the vehicle V.

[0040] For example, the first coupling device DC1 may be a hydraulic circuit clutch. But it could be of another type.

[0041] Also for example, the gearbox BV can be automated. Thus, it can, for example, be double clutch (or DCT (“Dual Clutch Transmission”)). But this is not obligatory.

[0042] It will be noted that in the example illustrated non-limitingly in [Fig.l] the crankshaft of the first prime mover MM1 is also coupled to a belt, itself coupled to an alternator-starter AD which is supplied with electrical energy by the service battery BS (and which can also recharge the latter (BS)). Thus, the alternator-starter AD can supply torque to the belt, which can supply this crankshaft torque.

[0043] The second prime mover MM2 is electric and is responsible, when supplied with electrical energy by the rechargeable battery BR, for producing a second torque. It is also responsible, in a regenerative braking phase, requested by the driver of the vehicle V, possibly after selecting a regenerative braking level nfr, for ensuring (or participating in) the braking of the vehicle V by acting as a generator. In this case, it recovers in the transmission chain (here at the level of the first train T1) the regenerative braking torque cfr and transforms the latter (cfr) into a recharging current intended to recharge the rechargeable battery BR.

[0044] Furthermore, this second driving machine MM2 is, here, suitable for being coupled, downstream of the first coupling device DC1, by the second coupling device DC2, to the gearbox BV to provide it with the second engine torque produced.

[0045] The operation of the second electric motor MM2 is controlled by a machine computer CM, and supervised by the supervision computer CS.

[0046] The second coupling device DC2 can be placed in coupled and decoupled states, depending on a state instruction generated by the GMP supervision computer CS.

[0047] Furthermore, this second coupling device DC2 may, for example, comprise a cascade of pinions connecting the second driving machine MM2 to the input of the gearbox BV (downstream of the first coupling device DC1).

[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 rechargeable battery BR to supply the on-board network and the service battery BS with converted electric current (to recharge it).

[0049] The rechargeable battery BR 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 rechargeable battery BR 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.

[0050] The operation of the rechargeable battery BR is controlled by a battery calculator CB which is in particular responsible for determining the current charge state, the internal temperature and the recharge capacity crb of the rechargeable battery BR.

[0051] The vehicle V also comprises a brake pedal PF having a depression percentage variable by action of the driver, and an accelerator pedal PA having a depression percentage variable by action of the driver.

[0052] It will also be noted that the vehicle V has a (current) speed vev which is estimated, preferably periodically. For example, this period may be between 10 milliseconds and 100 milliseconds. As an illustrative example, the period can be equal to 50 milliseconds.

[0053] For example, this (current) speed vev can be estimated by a possible trajectory control device equipping the vehicle V and which can be of the ESP / ABS type (ESP: “Electronic Stability Program”), ABS: “Anti-Blocking System”)), from information provided by a sensor associated here with one of the drive wheels. For example, this sensor can be coupled to a wheel hub and can constitute an angular encoder determining a number of teeth passing in front of it per second, and the computer of the trajectory control device can determine the distance traveled as a function of the number of teeth indicated by the sensor and the wheel development, then estimate the speed vev by integrating this distance traveled over time.

[0054] But the speed estimates (or measurements) vev could have an origin other than the trajectory control device calculator.

[0055] As mentioned above, the invention proposes in particular a monitoring method intended to enable the monitoring of the regenerative braking phases carried out by the second driving machine MM2 of the vehicle V.

[0056] This (monitoring) method can be implemented at least partially by the monitoring device DS (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 monitoring device DS 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.

[0057] The memory MD is live in order to store instructions for the implementation by the processor PR1 of at least part of the monitoring 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.

[0058] In the example illustrated non-limitingly in Figures 1 and 2, the monitoring device DS is part of the supervision computer CS. But this is not obligatory. Indeed, the monitoring device DS could comprise its own dedicated computer, which is then coupled to the supervision computer CS, for example.

[0059] As illustrated non-limitingly in [Fig. 3], the (monitoring) method, according to the invention, comprises a step 10-50 which is implemented each time the vehicle V must be subject to a regenerative braking phase, for example on the order of the supervision computer CS and due to a request for regenerative braking. emanating from the driver, for example following release of the accelerator pedal PA.

[0060] Step 10-50 of the method comprises a sub-step 20 in which one (for example the monitoring device DS) determines an intermediate torque ci which is equal to the difference between a maximum regenerative braking torque cfrmax which can be requested by the driver, depending on the current speed vev of the vehicle V, and a so-called tolerance torque et, negative and depending on this current speed vev (i.e. ci = cfrmax - et).

[0061] Note that cfrmax is negative since it is a braking torque, and therefore leil < Icfrmaxl (but ci > cfrmax).

[0062] It will also be noted that the maximum regenerative braking torque cfrmax can, for example, be determined by the monitoring device DS as a function of the current speed vev and the maximum amplitude of variation in the depression of the accelerator pedal PA that the driver could potentially achieve when releasing the accelerator pedal PA and taking into account the current percentage of depression of the accelerator pedal PA.

[0063] It will also be noted that in sub-step 20 one (for example the monitoring device DS) can determine the intermediate torque ci also as a function of the regenerative braking level nfr which has been previously chosen by the driver.

[0064] For example, this regenerative braking level (or electric motor braking mode) nfr can be chosen from three predefined and different regenerative braking levels. As an illustrative example, the driver can choose from a so-called “normal” regenerative braking level, associated with a regenerative braking torque of approximately -0.6 m / s2, an increased regenerative braking level (or “brake level”), associated with a regenerative braking torque of approximately -1 m / s2, and a so-called reinforced regenerative braking level (or “brake+ level”), associated with a regenerative braking torque of approximately -1.5 m / s2.

[0065] Also for example, and as illustrated non-limitingly in [Fig.3], step 10-50 can comprise a sub-step 10 in which one (for example the monitoring device DS) can begin by determining the maximum regenerative braking torque cfrmax.

[0066] It will also be noted that the tolerance torque and is a torque which corresponds to an under-deceleration by regenerative braking which is considered acceptable for the driver compared to the deceleration by regenerative braking which he expects, without it being necessary to alert him.

[0067] For example, in sub-step 20 of step 10-50 the tolerance torque and can increase when the current speed vev increases. This growth can be done in a substantially continuous manner (for example due to the use of a mathematical formula) or by jumps associated respectively with predefined speeds vev (we then have a same tolerance torque value and for all values of a predefined speed interval).

[0068] Step 10-50 of the method comprises a sub-step 50 in which when a potentially recoverable regenerative braking torque cfrpr is less than the determined intermediate torque ci, the driver is alerted (for example the monitoring device DS triggers an alert of the) of a temporary impossibility of fully satisfying a regenerative braking request.

[0069] It will be understood that the regenerative braking torque that can potentially be recovered cfrpr depends on the recharge capacity erb of the rechargeable battery BR at the time considered, which depends at least on the current state of charge and the internal temperature of the rechargeable battery BR. As indicated above, the recharge capacity erb is determined (or estimated) by the battery calculator CB.

[0070] It is therefore considered here that it is only when the regenerative braking torque that can potentially be recovered cfrpr is less than the maximum regenerative braking torque cfrmax minus the tolerance torque that the driver will really feel (or at least significantly) the under-deceleration by regenerative braking caused, and therefore that he must be alerted to avoid being surprised. This makes it possible to reinforce driving safety, and therefore the safety of the vehicle V and its passengers.

[0071] It will be noted that when the regenerative braking torque that can potentially be recovered cfrpr is greater than or equal to the intermediate torque ci determined, it is considered that the driver will not really feel (or at least not significantly) the under-deceleration by regenerative braking caused, and therefore that there is no need to alert him unnecessarily. In this case, as illustrated non-limitingly in [Fig. 3], if we are still in the regenerative braking phase, we will carry out sub-step 10 again to determine a new maximum regenerative braking torque cfrmax.

[0072] For example, and as illustrated non-limitingly in [Fig.3], step 10-50 may comprise a sub-step 30 in which one (for example the monitoring device DS) can determine the regenerative braking torque that can potentially be recovered cfrpr. But the regenerative braking torque that can potentially be recovered cfrpr may be determined by another computer of the vehicle V, such as for example the machine computer CM.

[0073] Also for example, and as illustrated non-limitingly in [Fig.3], step 10-50 may comprise a sub-step 40 in which one (for example the monitoring device DS) can compare the regenerative braking torque that can potentially be recovered cfrpr and the determined intermediate torque ci. If the result of this comparison indicates that the regenerative braking torque that can potentially be recovered cfrpr is less than or equal to the determined intermediate torque ci (i.e. cfrpr < ci (but Icfrprl > Icil)), substep 10 will be carried out again. On the other hand, if the result of the comparison indicates that the regenerative braking torque that can potentially be recovered cfrpr is greater than the determined intermediate torque ci (i.e. cfrpr > ci (but Icfrprl < Icil)), substep 50 will be carried out.

[0074] Also for example, in sub-step 50 of step 10-50, the driver can be alerted (for example the monitoring device DS can trigger the generation of an alert of the) by means of a warning light of the vehicle V and / or a text message and / or an audible message.

[0075] Also for example, the indicator light may be part of the dashboard or be displayed on a display screen of the vehicle V (possibly that of the central instrument panel installed on or in the dashboard). It may be an indicator light dedicated to the recovery of regenerative braking torque or a service indicator light (not dedicated).

[0076] Also for example, the text alert message can be displayed on at least one screen of the vehicle V (for example the dashboard or the central instrument panel) or on the screen of a smartphone of the driver.

[0077] Also for example, the audible alert message can be broadcast by at least one loudspeaker of the vehicle V or of the aforementioned smartphone.

[0078] It will be noted that preferably in sub-step 50 of step 10-50 the driver can be alerted (for example the monitoring device DS can trigger an alert of the) when the regenerative braking torque that can potentially be recovered cfrpr is less than the determined intermediate torque ci for at least a chosen duration of. This in fact makes it possible to avoid unnecessarily alerting the driver when the regenerative braking torque that can potentially be recovered cfrpr is less than the determined intermediate torque ci for a very short time, for example due to an estimation error.

[0079] For example, in sub-step 50 of step 10-50 the chosen duration of can be between 0.2 s and 1 s. As an illustrative example, the chosen duration of can be equal to 0.5 s. But other values of chosen duration of can be used. For example, the value of the chosen duration of can be chosen during the vehicle tuning phase V.

[0080] It will also be noted, as illustrated non-limitingly in [Fig.2], that the supervision computer CS (or the computer of the monitoring device DS) can also comprise a mass memory MEM, in particular for storing each recharge capacity erb, each maximum amplitude of variation in depression of the accelerator pedal PA, each level of regenerative braking chosen nfr and each current speed vev, as well as any intermediate data involved in all its calculations and processing. Furthermore, this supervision computer CS (or the computer of the monitoring device DS) can also comprise an input interface IE for receiving at least each recharge capacity crb, each maximum amplitude of variation in the depression of the accelerator pedal PA, each level of regenerative braking chosen nfr and each possible current speed vev, 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 supervision computer CS (or the computer of the monitoring device DS) may also include an output interface IS, in particular to deliver a message (or order) to trigger an alert intended for the driver.

[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 monitoring method described above for monitoring the regenerative braking phases in the land vehicle V.

Claims

Claims

1. Monitoring method for a land vehicle (V) comprising a powertrain comprising at least one electric motor (MM2) associated with a rechargeable battery (BR) and capable of recovering a regenerative braking torque to recharge said rechargeable battery (BR), characterized in that it comprises a step (10-50) in which an intermediate torque is determined equal to a difference between a maximum regenerative braking torque that can be requested by a driver of said vehicle (V), depending on a current speed of said vehicle, and a so-called tolerance torque, negative and depending on said current speed, and, when a regenerative braking torque that can potentially be recovered is less than said determined intermediate torque, said driver is alerted of a temporary impossibility of fully satisfying a regenerative braking request.

2. Method according to claim 1, characterized in that in said step (10-50) said driver is alerted when said regenerative braking torque which can potentially be recovered is lower than said determined intermediate torque for at least a chosen duration.

3. Method according to claim 2, characterized in that in said step (10-50) said chosen duration is between 0.2 s and 1 s.

4. Method according to one of claims 1 to 3, characterized in that in said step (10-50) said intermediate torque is determined as a function, in addition, of a level of regenerative braking previously chosen by said driver.

5. Method according to claim 4, characterized in that in said step (10-50) said regenerative braking level is chosen from three predefined and different regenerative braking levels.

6. Method according to one of claims 1 to 5, characterized in that in said step (10-50) said tolerance torque increases when said current speed increases.

7. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the monitoring method according to one of claims 1 to 6, in a land vehicle (V) comprising a powertrain comprising at least one electric motor machine (MM2) associated with a rechargeable battery (BR) and capable of recovering a regenerative braking torque to recharge said rechargeable battery (BR), to monitor regenerative braking phases.

8. Monitoring device (DS) for a land vehicle (V) comprising a powertrain comprising at least one electric motor (MM2) associated with a rechargeable battery (BR) and capable of recovering a regenerative braking torque to recharge said rechargeable battery (BR), characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting in determining an intermediate torque equal to a difference between a maximum regenerative braking torque that can be requested by a driver of said vehicle (V), as a function of a current speed of said vehicle, and a so-called tolerance torque, negative and as a function of said current speed, and, when a regenerative braking torque that can potentially be recovered is less than said determined intermediate torque,to trigger an alert to said driver of a temporary inability to fully satisfy a regenerative braking request.,

9. Land vehicle (V) comprising a powertrain comprising at least one electric motor (MM2) associated with a rechargeable battery (BR) and capable of recovering a regenerative braking torque to recharge said rechargeable battery (BR), characterized in that it further comprises a monitoring device (DS) according to claim 8.

10. Land vehicle according to claim 9, characterized in that it is of the automobile type.