MONITORING OF A VEHICLE'S TORQUE SETPOINT WHEN THE SPEED LIMIT FUNCTION IS ACTIVATED

Abstract

A monitoring method is implemented in a vehicle comprising a powertrain capable of providing an engine torque as a function of a torque setpoint, and offering a speed limitation function imposing a limited torque setpoint when it is activated. This method comprises a step (10-20) in which, in the event of detection of a fault causing a deactivation of this function, a progressive increase in the torque setpoint is imposed from the limited torque setpoint to a chosen torque setpoint, representative of a torque request from the driver. Figure 3

Description

Title of the invention: MONITORING THE TORQUE SETPOINT OF A VEHICLE IN THE EVENT OF ACTIVATION OF THE SPEED LIMIT FUNCTION Technical field of the invention

[0001] The invention relates to vehicles comprising a powertrain (or GMP) capable of providing an engine torque as a function of a torque setpoint, and offering a speed limitation function, and more precisely the monitoring of this torque setpoint when the speed limitation function is activated. State of the art

[0002] Certain vehicles, possibly land-based (and for example of the automobile type), comprise a powertrain (or GMP) comprising at least one driving machine capable of providing an engine torque as a function of a torque setpoint, and offer a speed limitation function imposing a limited torque setpoint when it is activated with a limit speed selected by the driver.

[0003] In the vehicles presented above, it may happen that a fault is detected erroneously while the speed limitation function is activated. For example, the fault may be a full press of the accelerator pedal (or in English "kick down") when the driver has not made such a press, or a placing of the gearbox lever in neutral when the driver has not made such a placement (the driving position being in reality engaged).

[0004] In some of the aforementioned vehicles, when the fault situation is detected, the speed limitation function is automatically deactivated and put into default in order to satisfy what is believed to be the driver's wishes. However, once deactivation has been carried out, the torque setpoint which is taken into account by the GMP supervision computer is suddenly that which is representative of the driver's wishes (generally defined by the percentage of depression of the accelerator pedal). Consequently, the vehicle risks accelerating suddenly (for example up to 1.5 m.s2), and therefore risks hitting a pedestrian or a fixed or moving object, which can greatly surprise the driver and therefore prove dangerous for the vehicle as well as for everything located in the latter's environment.

[0005] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0006] For this purpose, it proposes in particular a monitoring method intended to be implemented in a vehicle:

[0007] - comprising a powertrain (or GMP) capable of providing torque motor depending on a torque setpoint, and

[0008] - providing a speed limitation function imposing a torque setpoint limited when activated.

[0009] This monitoring method is characterized by the fact that it comprises a step in which, in the event of detection of a fault causing deactivation of the speed limitation function, a progressive increase in the torque setpoint is imposed from the limited torque setpoint to a chosen torque setpoint, which is representative of a torque request from a driver of the vehicle.

[0010] Thanks to the invention, the level of acceleration of the vehicle, and therefore the speed of the vehicle, is limited to limit the risk of collision with a third party or an object located in the immediate environment of the latter.

[0011] The monitoring method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0012] - in its step, we can impose a progressive increase in the setpoint of couple in a time interval of a chosen duration;

[0013] - in the presence of the first option, in its step, the chosen duration can be function of a current vehicle speed;

[0014] - in its stage, one can impose a progressive increase in stages or substantially linear torque setpoint;

[0015] - alternatively, in its step one can impose a progressive increase in the torque instruction which respects an increase in vehicle acceleration below a chosen threshold;

[0016] - in the presence of the last option, in its step, the chosen threshold can be understood between 0.2 m.s2 and 0.5 m.s2.

[0017] 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 vehicle comprising a powertrain (or GMP) capable of providing an engine torque as a function of a torque setpoint, and offering a speed limitation function imposing a limited torque setpoint when it is activated, to monitor the torque setpoint when the speed limitation function is activated.

[0018] The invention also proposes a monitoring device intended to equip a vehicle:

[0019] - comprising a powertrain (or GMP) capable of providing torque motor depending on a torque setpoint, and

[0020] - providing a speed limitation function imposing a torque setpoint limited when activated.

[0021] 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, in the event of detection of a fault causing deactivation of the speed limitation function, in triggering an imposition of a progressive increase in the torque setpoint from the limited torque setpoint to a chosen torque setpoint, which is representative of a torque request from a driver of the vehicle.

[0022] The invention also provides a vehicle, possibly of the automobile type, and:

[0023] - comprising a powertrain (or GMP) capable of providing a torque motor depending on a torque setpoint, and a monitoring device of the type presented above, and

[0024] - providing a speed limitation function imposing a torque setpoint limited when activated. Brief description of the figures

[0025] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0026] [Fig-1] schematically and functionally illustrates an example of the embodiment of a land vehicle comprising an all-electric GMP, a supervision computer, and a monitoring device according to the invention,

[0027] [Fig.2] schematically and functionally illustrates an exemplary embodiment of a supervision computer comprising an exemplary embodiment of a monitoring device according to the invention, and

[0028] [Fig.3] schematically illustrates an example of an algorithm implementing a monitoring method according to the invention. Detailed description of the invention

[0029] The invention aims in particular to propose a monitoring method, and an associated monitoring device DS, intended to enable the monitoring of the torque setpoint cc defining the engine torque cm to be supplied by the powertrain (or GMP) of a vehicle V, when the speed limitation function FLV of the latter (V) is activated.

[0030] In the following, it is considered, by way of non-limiting example, that the vehicle V is terrestrial and 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 vehicle. It in fact concerns any type of vehicle (terrestrial, maritime (or river), or aerial) comprising a powertrain (or GMP) and offering a speed limitation function.

[0031] Furthermore, it is considered in the following, by way of non-limiting example, that the powertrain (or GMP) is purely electric (and therefore comprises at least an electric MME motor machine). But the invention concerns any type of GMP, and in particular purely thermal GMPs and hybrid GMPs (thermal and non-thermal).

[0032] Furthermore, it is considered in the following, by way of non-limiting example, that the electric motor MME is supplied with electrical energy by a main battery (or traction or even power) BP, rechargeable at least during recharging phases. But the (each) electric motor MME could be supplied with electrical energy by a fuel cell.

[0033] [Fig.l] schematically shows a vehicle V comprising a transmission chain with electric GMP (and therefore at least one electric motor MME), an on-board network RB, a service battery BS, a main (or traction) battery BP, a converter CV, a supervision computer CS, an assistance computer CA controlling a speed limitation function FLV, and a monitoring device DS according to the invention.

[0034] The CV converter is of the DC / DC type (“Direct Current / Direct Current”). It is therefore responsible for converting a direct current from a first voltage to a second voltage.

[0035] 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.

[0036] The service battery BS is responsible for supplying electrical energy to the on-board network RB, in addition, here, to that supplied by the converter CV powered by the main battery BP, and sometimes instead, here, of this converter CV. 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.

[0037] The transmission chain has a GMP which is, here, purely electric and therefore which comprises, in particular, an electric motor MME, a motor shaft, and a transmission shaft AT. Here, the term “electric motor” means an electric machine arranged so as to provide a motor torque cm, defined by a torque setpoint cc, 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).

[0038] The operation of the GMP is supervised by a CS supervision computer.

[0039] The driving machine MME is coupled to the motor shaft AM, to provide it with engine torque cm by rotational drive. This motor shaft AM is here coupled to a reducer RD which is also coupled to the transmission shaft AT, itself coupled to a drive wheel set Tl, preferably via a differential DV.

[0040] It will be noted that the train T1 is here located in the front part PVV of the vehicle V. But in a variant this train T1 could be that referenced T2 which is located in the rear part PRV of the vehicle V.

[0041] It will also be noted that the reducer RD is associated with the gear lever LV which can be placed in a parking position (“P”), a neutral position (“N”), a driving position (“D”), and a reverse position (“R”).

[0042] 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 (to recharge it) with converted electric current.

[0043] 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.

[0044] 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.

[0045] 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).

[0046] 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 the torque setpoint cc can be defined, which is then representative of the driver's wishes.

[0047] The speed limitation function FLV is arranged so as to require, for example from the supervision computer CS, the imposition of a limited torque setpoint ccl when it is activated with a limit speed selected by the driver. It will be understood that this limited torque setpoint ccl depends in particular the selected speed limit.

[0048] When a fault, relating to a parameter of the vehicle V in connection with the driver's desire in terms of torque, is detected, the speed limitation function FLV is automatically deactivated and put into fault, for example by the supervision computer CS. For example, this type of fault may be a full press of the accelerator pedal PA (or kick down) when the driver has not made such a press, or a placement of the gear lever LV in the neutral position when the driver has not made such a placement (the driving position being in reality engaged).

[0049] It will be noted that the driver is preferably informed of the deactivation 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.

[0050] As mentioned above, the invention proposes in particular a monitoring method intended to enable monitoring of the torque setpoint cc (defining the engine torque cm to be supplied by the GMP) when the FLV speed limitation function is activated.

[0051] 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.

[0052] The memory MD is RAM 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.

[0053] 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, or could be part of another computer on board the vehicle V and providing at least one other function, such as for example the assistance computer CA.

[0054] As illustrated non-limitingly in [Fig.3], the (monitoring) method, according to the invention, comprises a step 10-20 which is implemented each time two conditions are satisfied, namely the vehicle V is moving forward and the speed limitation function FLV has been activated (for example by the driver), and therefore it imposes a limited torque setpoint ccl.

[0055] Step 10-20 of the method comprises a sub-step 20 in which, when the two aforementioned conditions are satisfied and in addition a fault causing a deactivation of the speed limitation function FLV has been detected, a progressive increase in the torque setpoint cc is imposed (for example the monitoring device DS triggers the imposition of a) from the limited torque setpoint ccl to a chosen torque setpoint ccc which is representative of the current torque demand of the driver.

[0056] In other words, the torque setpoint cc is gradually increased from ccl to ccc, in order to limit the acceleration level of the vehicle V, and therefore the speed of the vehicle V, to limit the risk of collision with a third party or an object located in the immediate environment of the latter (V). It will be understood that by proceeding in this way, the safety requirements of the vehicle V are respected while allowing the driver to become aware of the situation (via the warning message and the start of the increase in the speed of the vehicle V), and to act accordingly, for example by modifying his torque request (here by modifying the percentage of depression pe of the accelerator pedal PA).

[0057] For example, and as illustrated non-limitingly in [Fig. 3], step 10-20 of the method may also comprise a sub-step 10 in which one (for example the monitoring device DS) is informed of the deactivation of the speed limitation function FLV due to the detection of a fault.

[0058] Several embodiments can be envisaged for the implementation of the progressive increase in the cc torque setpoint.

[0059] Thus, in a first embodiment, in sub-step 20 of step 10-20 it is possible to impose a (for example the monitoring device DS can trigger the imposition of a) progressive increase in the torque setpoint cc in a time interval having a chosen duration dt.

[0060] It will be noted that in sub-step 20 of step 10-20 the chosen duration dt can be fixed. In this case, the chosen duration dt can, for example, be between 2 s and 5 s. As an illustrative example, this chosen duration dt can be equal to 3 s. 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.

[0061] It will also be noted that the fixed value of the chosen duration dt can possibly be chosen by the driver of the vehicle V.

[0062] But in a variant the chosen duration dt could be a function of the current speed vv of the vehicle V.

[0063] In a second embodiment, compatible with the first embodiment, in sub-step 20 of step 10-20 it is possible to impose a (for example the monitoring device DS can trigger the imposition of a) progressive increase in the torque setpoint cc which respects a progressive increase in stages of the torque setpoint cc. For example, the height of the stages can be constant. But this is not an obligation. Indeed, it could, for example, be possible to have a height of stages which increases as the torque setpoint cc approaches the chosen torque setpoint ccc.

[0064] In a third embodiment, compatible with the first embodiment, in sub-step 20 of step 10-20 it is possible to impose a (for example the monitoring device DS can trigger the imposition of a) substantially linear progressive increase in the torque setpoint cc.

[0065] In a fourth embodiment, in sub-step 20 of step 10-20 it is possible to impose a (for example the monitoring device DS can trigger the imposition of a) progressive increase in the torque setpoint cc which respects an increase in the acceleration of the vehicle V lower than a chosen threshold si. In this case, in sub-step 20 of step 10-20 the chosen threshold si can, for example, be between 0.2 m.s2 and 0.5 m.s2. As an illustrative example this chosen threshold si can be equal to 0.3 m.s2. But other values ​​of the chosen threshold si can be used. For example, this chosen threshold si can be chosen during the development phase of a vehicle similar to the vehicle V.

[0066] 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 MM1, in particular for storing the limited torque setpoint ccl, the chosen torque setpoint ccc and possibly the current speed vv of the vehicle V, 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 the limited torque setpoint ccl, the chosen torque setpoint ccc and possibly the current speed vv of the vehicle V, 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 CS supervision calculator (or the DS monitoring device calculator) can also include an IS output interface, in particular to deliver each message imposing a progressive increase in the cc torque setpoint.

[0067] It will also be noted that the invention also provides a program product computer (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 PR1 processor, is capable of implementing the monitoring method described above to monitor the DC torque setpoint when the FLV speed limitation function is activated.

Claims

Claims

1. Monitoring method for a vehicle (V) comprising a powertrain capable of providing an engine torque as a function of a torque setpoint, and offering a speed limitation function imposing a limited torque setpoint when it is activated, characterized in that it comprises a step (10-20) in which, in the event of detection of a fault causing deactivation of said function, a progressive increase in said torque setpoint is imposed from said limited torque setpoint to a chosen torque setpoint, representative of a torque demand from a driver of said vehicle (V).

2. Method according to claim 1, characterized in that in said step (10-20) a progressive increase of said torque setpoint is imposed in a time interval of a chosen duration.

3. Method according to claim 2, characterized in that in said step (10-20) said chosen duration is a function of a current speed of said vehicle (V).

4. Method according to one of claims 1 to 3, characterized in that in said step (10-20) a progressive increase in stages of said torque setpoint is imposed.

5. Method according to one of claims 1 to 3, characterized in that in said step (10-20) a substantially linear progressive increase in said torque setpoint is imposed.

6. Method according to claim 1, characterized in that in said step (10-20) a progressive increase in said torque setpoint is imposed respecting an increase in an acceleration of said vehicle (V) lower than a chosen threshold.

7. Method according to claim 6, characterized in that in said step (10-20) said chosen threshold is between 0.2 m.s2 and 0.5 m.s2.

8. 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 7, in a vehicle (V) comprising a powertrain capable of providing an engine torque as a function of a torque setpoint, and offering a speed limitation function imposing a limited torque setpoint when it is activated, to monitor said torque setpoint when said speed limitation function is activated.

9. Monitoring device (DS) for a vehicle (V) comprising a powertrain capable of providing an engine torque as a function of a torque setpoint, and offering a speed limitation function imposing a limited torque setpoint when it is activated, 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 detection of a fault causing a deactivation of said function, in triggering an imposition of a progressive increase in said torque setpoint from said limited torque setpoint to a chosen torque setpoint, representative of a torque request from a driver of said vehicle (V).

10. Vehicle (V) comprising a powertrain capable of providing an engine torque as a function of a torque setpoint, and offering a speed limitation function imposing a limited torque setpoint when it is activated, characterized in that it further comprises a monitoring device (DS) according to claim 9.

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