Monitoring the torque setpoint of a vehicle in the event of activation of the speed-limiting function

Abstract

The invention relates to a monitoring method implemented in a vehicle comprising a powertrain able to provide an engine torque according to a torque setpoint, and offering a speed-limiting function that imposes a limited torque setpoint when it is activated. This method comprises a step (10-20) in which, if a failure causing a deactivation of this function is detected, a progressive increase in the torque setpoint is imposed from the limited torque setpoint up to a chosen torque setpoint representing a torque request from the driver.

Description

DESCRIPTION TITLE: MONITORING A VEHICLE'S TORQUE SETPOINT WHEN THE SPEED LIMITER FUNCTION IS ACTIVATED The present invention claims priority from French application No. 2312186 filed on 09.11.2023, the content of which (text, drawings and claims) is incorporated herein by reference. Technical field of the invention

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

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

[0003] In the vehicles described above, a fault may be incorrectly detected while the speed limiter function is activated. For example, the fault may be indicated by the accelerator pedal being fully depressed (or "kick down") when the driver has not actually done so, or by the gear selector being placed in neutral when the driver has not (the vehicle is actually in drive position).

[0004] In some of the aforementioned vehicles, when a fault is detected, the speed limitation function is automatically deactivated and set to a fault in order to satisfy what is believed to be the driver's intent. However, once deactivated, the torque setting used by the engine control unit suddenly becomes that which represents the driver's intent (generally defined by the percentage of accelerator pedal depressed). Consequently, the vehicle may accelerate abruptly (for example, up to 1.5 m / s²). 2 ), 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 in its environment.

[0005] The invention is therefore intended, in particular, to improve the situation. Presentation of the invention

[0006] In particular, it proposes a monitoring method designed to be implemented in a vehicle for this purpose:

[0007] - comprising a powertrain (or powertrain) designed to provide engine torque according to a torque setpoint, and

[0008] - offering a speed limiting function that imposes a limited torque setting when activated.

[0009] This monitoring method is characterized by the fact that it includes a step in which, in the event of detection of a fault causing a 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 demand 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, in order 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 features which may be taken separately or in combination, and in particular:

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

[0013] - in the presence of the first option, in its stage, the chosen duration may be a function of the vehicle's current speed;

[0014] - in its stage, we can impose a progressive increase in steps or a substantially linear increase in the torque setpoint;

[0015] - Alternatively, in its step we can impose a progressive increase in the torque setpoint 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 between 0.2 m.s' 2 and 0.5 m.s' 2 .

[0017] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is suitable for implementing a monitoring method of the type described above, in a vehicle comprising a powertrain (or PWM) suitable for providing engine torque as a function of a torque setpoint, and offering a speed limiting function imposing a limited torque setpoint when activated, to monitor the torque setpoint when the speed limiting function is activated.

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

[0019] - comprising a powertrain (or powertrain) designed to provide engine torque according to a torque setpoint, and

[0020] - offering a speed limiting function that imposes a limited torque setting when activated.

[0021] This monitoring device is characterized by the fact that it includes at least one processor and at least one memory arranged to perform the operations consisting, in the event of detection of a fault causing a deactivation of the speed limiting function, of triggering a progressive increase in the torque setpoint from the torque setpoint limited up to a chosen torque setpoint, which is representative of a torque demand from a vehicle driver.

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

[0023] - comprising a powertrain (or powertrain) capable of providing engine torque according to a torque setpoint, and a monitoring device of the type described above, and

[0024] - offering a speed limiting function that imposes a limited torque setting when activated. Brief description of the figures

[0025] Other features and advantages of the invention will become apparent upon examination of the detailed description below, and the accompanying drawings, in which:

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

[0027] [Fig. 2] schematically and functionally illustrates an example of an embodiment of a supervisory computer comprising an example of an 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 DS monitoring device, 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 what follows, we consider, by way of non-limiting example, that vehicle V is a land vehicle of the automobile type. For example, it could be a car, as illustrated in Figure 1. However, the invention is not limited to this type of vehicle. It relates to any type of vehicle (land, sea (or river), or air) comprising a powertrain and offering a speed-limiting function.

[0031] Furthermore, in what follows, we consider, by way of non-limiting example, that the powertrain (or PWM) is purely electric (and therefore includes at least one electric motor). However, the invention relates to all types of PWMs, and in particular purely thermal PWMs and hybrid PWMs (thermal and non-thermal).

[0032] Furthermore, in the following, we consider, as a non-limiting example, that the electric motor unit (EMU) is powered by a main (or traction or power) battery (BM), which is rechargeable at least during charging phases. However, each electric motor unit (EMU) could also be powered by a fuel cell.

[0033] Figure 1 schematically represents a vehicle V comprising an electric GMP transmission chain (and therefore at least one electric motive machine MME), an on-board network RB, a service battery BS, a main (or traction) battery BP, a CV converter, a CS supervisory computer, a CA assistance computer controlling a speed limitation function FLV, and a DS monitoring device 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 one voltage to a second voltage.

[0035] The RB on-board network is an electrical power supply network to which electrical (or electronic) equipment (or components) that consume electrical energy are coupled.

[0036] The BS service battery is responsible for supplying electrical power to the RB onboard network, supplementing, in this case, that supplied by the The CV converter is powered by the main battery BP, and sometimes, in this case, by the CV converter itself. For example, this service battery BS can be configured as a very low voltage type battery (typically 12 V, 24 V, or 48 V). It is rechargeable at least by the CV (current) converter. In the following, we will assume, as a non-limiting example, that the service battery BS is a 12 V lithium-ion type.

[0037] The transmission chain has a powertrain which is, here, purely electric and therefore includes, in particular, an electric drive machine MME, a drive shaft, and a transmission shaft AT. Here, "electric drive machine" means an electric machine arranged 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 (this is referred to as providing a positive output torque), as well as possibly to recover torque, for example in a regenerative braking phase (this is referred to as providing a negative output torque).

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

[0039] The drive machine MME is coupled to the drive shaft AM to supply it with motor torque cm by rotational drive. This drive shaft AM is coupled to a gearbox RD, which is also coupled to the transmission shaft AT, itself coupled to a set of drive wheels T1, preferably via a differential DV.

[0040] Note that the T1 train is located here in the front PW section of the vehicle V. However, in a variant, this T1 train could be the one referenced as T2, which is located in the rear PRV section of the vehicle V.

[0041] It should also be noted that the RD reduction gear is associated with the LV gear lever 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 vehicle's driving phases, for converting a portion of the stored electrical current. in the main battery BP to supply converted electrical current to the on-board network RB and the auxiliary battery BS (to recharge it).

[0043] It should be noted, as illustrated non-exhaustively in Figure 1, that the CV converter can be part of a CH charger also including a charging computer (not shown) responsible, at least, for controlling the charging of the main battery BP.

[0044] The main battery (or traction or power battery) BP can, for example, include electrical energy storage cells, possibly electrochemical (e.g., lithium-ion (Li-ion), Ni-MH, or Ni-Cd). Also, for example, the main battery BP can be a low-voltage type (typically 450 V, for example). But it could also be a medium-voltage or high-voltage type.

[0045] It should also be noted that in the example illustrated (non-exhaustively) in Figure 1, vehicle V also includes a distribution box BD to which the auxiliary battery BS, the converter CV, and the on-board network RB are coupled. This distribution box BD is responsible for distributing the electrical energy stored in the auxiliary battery BS or produced by the converter CV into the on-board network RB to power the electrical components (or equipment) connected to the on-board network RB, according to power demands received (in particular from the powertrain control unit CS).

[0046] It should also be noted, as illustrated in Figure 1, that the vehicle V also includes an accelerator pedal PA which can be operated (here) by a foot of the driver of the vehicle V. It has a percentage of depressment pe from which the torque setpoint cc can be defined, which is then representative of the driver's intention.

[0047] The FLV speed limitation function is designed to require, for example from the CS supervisory control unit, the imposition of a limited torque setpoint ccl when activated with a speed limit selected by the driver. It should be understood that this limited torque setpoint ccl depends, in particular, on the selected speed limit.

[0048] When a fault related to a vehicle parameter (V) linked to the driver's torque input is detected, the FLV speed limiter function is automatically deactivated and rendered faulty, for example, by the CS control unit. For example, this type of fault could be the accelerator pedal (PA) being fully depressed (or kick down) when the driver has not done so, or the gear selector (LV) being placed in neutral when the driver has not (the gear is actually engaged).

[0049] It should be noted that the driver is preferably informed of the deactivation by broadcasting a dedicated audible (or audio) warning message via at least one speaker present in the vehicle V and / or displaying a dedicated textual warning message on a screen of the vehicle V, such as for example that of the dashboard or that of the central instrument cluster.

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

[0051] This monitoring method can be implemented at least partially by the DS monitoring device (illustrated at least partially in Figures 1 and 2), which comprises at least one PR1 processor, for example, a digital signal processor (DSP), and at least one MD memory. This DS monitoring device can therefore be implemented as a combination of electrical or electronic circuits or components (or "hardware") and software modules. For example, it could be a microcontroller.

[0052] The MD memory is random access memory (RAM) to store instructions for the PR1 processor to implement at least part of the monitoring process. The PR1 processor may include integrated circuits (or printed circuit boards), or several integrated circuits (or printed circuit boards) connected by wired or wireless connections. An integrated circuit (or printed circuit board) is defined as... any type of device capable of performing at least one electrical or electronic operation.

[0053] In the example illustrated (but not limited to) in Figures 1 and 2, the DS monitoring device is part of the CS supervisory control unit. However, this is not mandatory. The DS monitoring device could have its own dedicated control unit, or it could be part of another control unit installed in the vehicle (V) that performs at least one other function, such as the CA assistance control unit.

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

[0055] Step 10-20 of the process includes a substep 20 in which, when the two aforementioned conditions are met and in addition a failure causing a deactivation of the speed limiting function FLV has been detected, a progressive increase in the torque setpoint cc is imposed (for example, the DS monitoring device 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 setting cc is gradually increased from ccl to ccc in order to limit the acceleration level of vehicle V, and therefore its speed, to reduce the risk of collision with a third party or an object in its immediate vicinity (V). It is clear that by proceeding in this way, the safety requirements of vehicle V are met while allowing the driver to become aware of the situation (via the warning message and the initial increase in vehicle V's speed) and to act accordingly, for example by modifying their torque demand (here by changing the percentage of accelerator pedal depressment pe PA).

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

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

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

[0060] Note that in substep 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. However, other values ​​for the chosen duration dt can be used. For example, this chosen duration dt can be selected during the development phase of a vehicle similar to vehicle V.

[0061] It should 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 one 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, substep 20 of step 10-20 can impose a gradual increase in the torque setpoint cc (for example, the DS monitoring device can trigger the imposition of a gradual increase in the torque setpoint cc). This increase follows a stepwise progression of the torque setpoint cc. For example, the height of the steps can be constant. However, this is not mandatory. Indeed, one could, for example, have a step height that increases as the torque setpoint cc approaches the chosen torque setpoint ccc.

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

[0065] In a fourth embodiment, in substep 20 of step 10-20, a gradual increase in the torque setpoint cc can be imposed (for example, the DS monitoring device can trigger the imposition of a) which respects an increase in vehicle acceleration V below a chosen threshold s1. In this case, in substep 20 of step 10-20, the chosen threshold s1 can, for example, be between 0.2 ms -2 and 0.5 m.s' 2 As an illustrative example, this chosen threshold s1 can be equal to 0.3 ms -2 However, other values ​​for the chosen threshold s1 can be used. For example, this chosen threshold s1 can be selected during the development phase of a vehicle similar to vehicle V.

[0066] It should also be noted, as illustrated (but not limited to) in Figure 2, that the CS supervisory computer (or the DS monitoring device computer) may also include a mass storage unit MM1, notably for storing the limited torque setpoint ccl, the selected 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 CS supervisory computer (or the DS monitoring device computer) may also include an input interface IE for receiving at least the limited torque setpoint ccl, the selected torque setpoint ccc, and possibly the current speed vv of the vehicle V, possibly after having been shaped and / or demodulated and / or amplified, in a manner known per se, by means of a digital signal processor PR2.In addition, this CS supervisory computer (or the DS monitoring device computer) may also include an IS output interface, notably to deliver each imposition message of a progressive increase in the DC torque setpoint.

[0067] It should also be noted that the invention also offers a computer program product (or computer program) comprising a game instructions which, when executed by processing means of electronic circuit type (or hardware), such as the PR1 processor, is suitable for implementing the monitoring process described above to monitor the torque setpoint cc when the speed limiting function FLV 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 in 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.s' 2 and 0.5 ms- 2

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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