SPEED LIMIT CONTROL IN A DRIVING MODE OF A LAND VEHICLE WITH COORDINATED SPEED CONTROL FUNCTIONS

Abstract

A control method is implemented in a land vehicle and includes a powertrain providing torque as a function of a torque setpoint, at least two speed control functions capable of generating torque setpoints enabling the vehicle to comply with associated speed setpoints, one of these speed control functions being a speed limiting function, and at least two selectable driving modes. This method includes a step (10-90) in which, if a driving mode is selected while at least one speed control function is activated with an associated speed setpoint higher than a speed limit associated with the selected driving mode, the speed limiting function is required to operate primarily using a speed setpoint equal to this speed limit, in order to comply with the imposed speed setpoint. Figure 3

Description

Title of the invention: SPEED LIMIT CONTROL IN A DRIVING MODE OF A LAND VEHICLE WITH COORDINATED SPEED CONTROL FUNCTIONS Technical field of the invention

[0001] The invention relates to land vehicles comprising at least two speed control functions, one of which is a speed limiter, and offering at least two driving modes, and more specifically, the control of the speed limit of such vehicles. Prior art

[0002] Some land vehicles, possibly of the automobile type, include a powertrain (or PWM) designed to provide their drive wheels with torque that is a function of a torque setpoint, and offer at least two driving modes.

[0003] It should be noted that in some of these vehicles, the driver can select one of several driving modes (such as, for example, an economy mode, a comfort mode, and a sport mode). In this case, when the vehicle is started, one of the driving modes is always selected, at least by default, and then the driver can decide to select another driving mode.

[0004] Each driving mode differs from the others at least by a gear shift law for the gearbox dedicated to it, as well as possibly by a convergence speed of the aerothermal system in the passenger compartment dedicated to it.

[0005] This differentiation can be directly felt by vehicle users with regard to the vehicle's longitudinal dynamics, as it depends on the gear shift pattern. However, it does not allow vehicle users to perceive the differences between driving modes in terms of driving range, unless the driver frequently pays attention to average energy consumption and / or driving range. It should be noted that at least one of these two pieces of information is not always systematically displayed on a vehicle screen, and therefore its accessibility may require at least one action by the driver on a human-machine interface, which may lead some drivers not to consult it.

[0006] Furthermore, the higher the speed of a vehicle, the lower its driving range. However, there is currently no limit on the maximum speed of a vehicle based on the driving mode selected by the driver, which would be an additional differentiating element easily understood by vehicle users, particularly in the case of economy driving mode.

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

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

[0009] - a powertrain designed to supply drive wheels with a functional torque from a couple's instruction,

[0010] - at least two independent speed control functions, when activated, to generate torque commands allowing the vehicle to comply with associated speed commands, one of these speed control functions being a speed limiting function, and

[0011] - at least two driving modes that can be selected.

[0012] This control method is characterized by the fact that it includes a step in which, if a driving mode is selected while at least one speed control function is activated with an associated speed setpoint greater than a selected limit speed associated with the selected driving mode, the speed limitation function is required to operate primarily using a speed setpoint equal to this limit speed, so that the imposed speed setpoint is respected.

[0013] Thanks to the invention, when a driving mode associated with a speed limit has been selected and at least one speed control function is activated, the speed limitation function is now used to enforce this speed limit, which makes it possible to significantly increase the vehicle's mileage range while allowing better demarcation of the selected driving mode, and without this requiring an adaptation of the speed limitation function or the design, development and implementation of a function dedicated to respecting the speed limit associated with a selected driving mode.

[0014] The control method according to the invention may include other features which may be taken separately or in combination, and in particular:

[0015] - in its stage, in the presence of N different driving modes, with N > 2, one can associate N chosen limit speeds respectively with these N driving modes, and we can impose on the speed limitation function to operate primarily using a speed setpoint equal to the chosen limit speed and associated with the driving mode selected from among the N driving modes;

[0016] - in its step, when the activated speed control function is selected from a speed control function, an adaptive speed control function and a speed limiting function, it is possible to allow an overshoot of the imposed speed setpoint up to the speed setpoint associated with the activated speed control function when a torque setpoint representing a driver's intention becomes greater than a chosen threshold;

[0017] - in the presence of the last option, in its step, in a first mode of implementation, when the vehicle has a current speed that has exceeded the imposed speed limit due to the driver's will, the imposed speed limit may cease to be imposed as long as the current speed has not become less than or equal to the speed limit imposed by the driver's will;

[0018] - also in the presence of the last option, in its stage, in a second In this embodiment, when the vehicle has a current speed that has exceeded the imposed speed setpoint due to the driver's will, and this current speed begins to decrease due to the driver's will, the speed limiting function can be required to use successive speed setpoints equal to the reduced current speed, and the imposed speed setpoint can be reimposed when the current speed has become less than or equal to the speed setpoint imposed by the driver's will;

[0019] - also in the presence of the last option, in its stage, in a third In this embodiment, when the vehicle has a current speed that has exceeded the imposed speed setpoint due to the driver's will, and then the driver's will corresponds to a zero torque setpoint for a chosen duration, the speed limitation function can be forced to use the imposed speed setpoint again;

[0020] - in its step, each speed limit associated with the selected driving mode can be predefined. Alternatively, in its step, each speed limit associated with the selected driving mode can be chosen (or selected) by a vehicle user;

[0021] - in its step, in the event of selection of a driving mode when only the The speed limitation function is activated with an associated speed setting. When the vehicle's current speed exceeds the lower of the imposed speed setting and the associated speed setting due to driver input, the lower speed setting can be discontinued, and the higher of the imposed and associated speed settings can be used. If the vehicle's current speed exceeds this higher speed setting due to driver input, the higher speed setting can be discontinued until the current speed is reduced to or below this higher speed setting by the driver input. When the current speed is reduced to or below this higher speed setting, the function will discontinue its use. or equal to the lowest speed setting by the driver's will, the use of this lowest speed setting can be imposed again;

[0022] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is suitable for implementing a control method of the type presented above, in a land vehicle and comprising, firstly, a powertrain suitable for supplying drive wheels with torque as a function of a torque setpoint, secondly, at least two speed control functions which, when activated, generate torque setpoints enabling the vehicle to respect associated speed setpoints respectively, one of these speed control functions being a speed limiting function, and, thirdly, at least two driving modes which can be selected, to control a speed limit to be respected in the vehicle.

[0023] The invention also proposes a control device for equipping a land vehicle and comprising:

[0024] - a powertrain designed to supply drive wheels with a functional torque from a couple's instruction,

[0025] - at least two independent speed control functions, when activated, to generate torque commands allowing the vehicle to comply with associated speed commands, one of these speed control functions being a speed limiting function, and

[0026] - at least two driving modes that can be selected.

[0027] This control device is characterized in that it includes at least one processor and at least one memory arranged to perform the operations consisting, in the event of selection of a driving mode while at least one speed control function is activated with an associated speed setpoint greater than a selected limit speed and associated with the selected driving mode, of triggering an imposition on the speed limitation function to operate primarily using a speed setpoint equal to this limit speed, so that the imposed speed setpoint is respected.

[0028] The invention also proposes a land vehicle, possibly of the automobile type, comprising:

[0029] - a powertrain designed to supply drive wheels with a functional torque from a couple's instruction,

[0030] - at least two independent speed control functions, when activated, to generate torque commands allowing the vehicle to comply with associated speed commands, one of these speed control functions being a speed limiting function,

[0031] - at least two selectable driving modes, and

[0032] - a control device of the type presented above.

[0033] For example, the powertrain may include at least one internal combustion engine capable of providing torque and / or at least one electric engine capable of providing torque. Brief description of the figures

[0034] Other features and advantages of the invention will become apparent from an examination of the detailed description below, and the accompanying drawings, in which:

[0035] [Fig. 1] schematically and functionally illustrates an example of an embodiment of a land vehicle comprising a hybrid powertrain, a supervisory computer, two speed control computers, and a control device according to the invention,

[0036] [Fig.2] schematically and functionally illustrates an example of an embodiment of a supervisory computer comprising an example of an embodiment of a control device according to the invention, and

[0037] [Fig.3] schematically illustrates an example of an algorithm implementing a control method according to the invention. Detailed description of the invention

[0038] The invention aims in particular to propose a control method, and an associated DC3 control device, intended to allow control of the speed limit vin to be respected in a land vehicle V comprising at least two speed control functions FCV1 and FCV2, one of which (FCV1) is a speed limitation function, and offering at least two driving modes mcn.

[0039] In what follows, the land vehicle V is considered, by way of non-limiting example, to be of the automobile type. This is, for example, a car, as illustrated in [Fig. 1]. However, the invention is not limited to this type of land vehicle. It relates in fact to any type of land vehicle comprising a powertrain (or powertrain) and at least two speed control functions, one of which is a speed limiter, and offering at least two driving modes.

[0040] A (land) vehicle V comprising a hybrid GMP transmission chain (and therefore in particular a thermal drive machine MMT and an electric drive machine MME), a CS supervision computer, a rechargeable battery BR, an accelerator pedal PA, first CCI and second CC2 speed control computers, and a DC3 control device according to the invention, is schematically represented in [Fig.1].

[0041] It should be noted that the powertrain could also be all-electric or purely thermal. Furthermore, the transmission system could also allow for four-wheel drive (or 4x4) or 4x2 operation.

[0042] As illustrated, the transmission chain also includes, here, a drive shaft AM, a first coupling device DC1, a second coupling device DC2, a gearbox BV, and a transmission shaft AT.

[0043] The operation of the transmission chain (and therefore of the GMP) is supervised by a CS supervision computer.

[0044] The MMT internal combustion engine comprises a crankshaft (not shown) which is fixedly attached to the drive shaft AM in order to rotate the latter (AM). This MMT internal combustion engine is suitable for coupling to the gearbox BV via the first coupling device DC1, as well as here via the second coupling device DC2 (optional). Furthermore, it (MMT) is suitable for coupling to the input shaft AP of the gearbox BV via the first coupling device DC1, as well as here via the second coupling device DC2 (optional). This coupling device DC1 is suitable for delivering a second torque c2 from the first torque c1 produced by the MMT internal combustion engine, for the gearbox BV. Finally, this gearbox BV is suitable for delivering a third torque c3 from the second torque c2 delivered by the coupling device DC1, for at least one set T1 of drive wheels.This third torque c3 is defined by a torque setpoint ccg which is transmitted by the CS supervisory computer.

[0045] For example, the Tl train can be located in the front PVV section of the vehicle V. It is preferably, and as illustrated, coupled to the AT driveshaft via a differential (here, the front one) DV. But in a variant, this Tl train could be the one referenced as T2, which is located in the rear PRV section of the vehicle V.

[0046] Also, for example, the first coupling device DC1 can be a clutch (single or double). But it could also be a torque converter or a dog clutch.

[0047] By way of non-limiting example, the gearbox may be of the so-called "dual-clutch (or DCT)" type. However, the invention is not limited to this type of gearbox. It should be noted that it is preferable for the gearbox to be automated.

[0048] In the illustrated example, which is not exhaustive, the crankshaft of the MMT internal combustion engine is also coupled to a belt CR, which is itself coupled to an alternator-starter AD that is electrically powered by the rechargeable battery BR (and which can also recharge the latter (BR)). Thus, the alternator-starter AD can supply torque to the belt CR, which can then supply this torque to the crankshaft.

[0049] It should be noted that this rechargeable BR battery can, for example, be of the 48 V type. But this is not mandatory. Indeed, it could alternatively be of the 12 V, 24 V, or 400 V type, for example.

[0050] The electric drive unit MME is (here) installed between the internal combustion drive unit MMT and the first coupling device DC1, and is designed to provide torque on command from the supervisory computer CS when it is supplied with electrical energy by the rechargeable battery BR. It (MME) can also be designed to recover regenerative braking torque, defined by a (negative) regenerative braking torque setpoint, to brake the vehicle V, and to convert this recovered regenerative braking torque into electrical energy to recharge the rechargeable battery BR.

[0051] When the first coupling device DC1 has been placed in its fully coupled (or completely closed) state and the thermal drive machine MMT supplies (positive) torque and / or the electric drive machine MME supplies (positive) torque, the first coupling device DC1 delivers torque for the primary shaft AP of the gearbox BV.

[0052] It should also be noted that in the example illustrated, but not limited to, in [Fig. 1], the transmission chain includes a second coupling device DC2 installed between the thermal engine MMT and the first coupling device DC1, in order to allow coupling of the electric engine MME between the first DC1 and second DC2 coupling devices. Thus, when the second coupling device DC2 is in its fully decoupled (or completely open) state, only the electric engine MME can supply torque upstream of the first coupling device DC1.

[0053] For example, this second DC2 coupling device can be a clutch.

[0054] It should also be noted that in the example illustrated, but not limited to, in [Fig. 1], the first coupling device DC1, the possible second coupling device DC2, the electric drive machine MME and the gearbox BV are part of a gearbox assembly EBV. However, this is not mandatory.

[0055] The accelerator pedal PA is operated (here) by the driver's foot in vehicle V. It has a depress percentage at which the torque setpoint ccg is defined, which then represents the driver's intent. It should be noted that the vehicle can offer an operating mode in which its powertrain delivers maximum torque when the torque setpoint ccg, representing the driver's intent, exceeds a chosen threshold. For example, this chosen threshold may correspond to a chosen (very significant) depress percentage of the accelerator pedal PA, sometimes called the "kickdown point." Generally, this kickdown point corresponds to a depress percentage (or threshold) of at least 90%.

[0056] As indicated above, the vehicle V performs at least two speed control functions, FCV1 (j = 1) and FCV2 (j = 2), one of which (FCV1) is a Speed ​​limitation function. These FCVj speed control functions can be controlled by a single speed control unit, or by at least two speed control units. Note that in the example shown in [Fig. 1], vehicle V includes first CCI (j = 1) and second CC2 (j = 2) speed control units, respectively controlling the first FCV1 (j = 1) and second FCV2 (j = 2) speed control functions. However, a single speed control unit could control both of these FCVj speed control functions. Note also that in the example shown in [Fig. 1], vehicle V performs only two different FCVj speed control functions, but it could perform more than two (for example, three or four).

[0057] The first speed control computer CCI here controls a speed limitation function FCV1, which is responsible for generating, during assisted speed control phases (and therefore when activated), torque commands ccg (possibly negative) enabling the vehicle V not to exceed a speed command cv, for example, selected by the driver. This generated torque command ccg is then transmitted to the supervisory computer CS. In fact, the torque command ccg is determined by the speed limitation function FCV1 (once activated, for example by the driver) based on an acceleration that it has determined according to the difference between the maximum speed command cvl (or cvi) and the current speed vv of the vehicle V, and minimum and maximum accelerations that are a function of this difference.

[0058] The second speed control unit CC2 here controls a second speed control function FCV2, which can be selected from a speed regulation function, an adaptive cruise control (or ACC – a function for regulating speed and distance between vehicles) function, and a speed limiting function. This second speed control function FCV2 is responsible for generating, during assisted speed control phases (and therefore when it has been activated), torque commands ccg (possibly negative) enabling the vehicle V to maintain a speed command cv2, for example, selected by the driver.

[0059] It is recalled that a speed limiting function is associated with a speed setpoint corresponding to a predefined (and therefore fixed) speed limit. This speed limiting function is designed, when it detects that the vehicle V reaches this speed limit or that a component is operating at its limit, to determine for the powertrain (and more precisely for at least one of its components) at least one operating setpoint capable of preventing the speed from exceeding this speed limit. It should be noted that this speed limit is fixed and that it is either imposed by the manufacturer of vehicle V, or chosen (or selected) by the driver or owner of vehicle V.

[0060] It is also recalled that a speed control function is associated with a speed setpoint corresponding to a predefined (and therefore fixed) speed limit. This speed control function is designed to generate torque setpoints for the powertrain intended to maintain the current speed vv of vehicle V at the associated speed setpoint. It should be noted that this speed limit is chosen (or selected) by the driver of vehicle V.

[0061] It is also important to note that the FCVj speed control functions are coordinated, and therefore when two of them are activated only one ccg torque setpoint, generated by one of them, is provided to the CS supervisory computer for the GMP.

[0062] It should also be noted that the first CCI and second CC2 speed control computers and the CS supervisory computer can, for example, communicate via an internal RC communication network of the vehicle V, possibly multiplexed, as illustrated non-limitingly in [Fig.1].

[0063] The vehicle V also offers at least two driving modes mcn that can be selected by the driver, and for example chosen from an economy mode mcl (n = 1), a comfort mode mc2 (n = 2) and a sport mode mc3 (n = 3). Each driving mode mcn offered is associated with a gear shift law for the gearbox BV, as well as possibly with a convergence speed of the air conditioning in the passenger compartment.

[0064] It should be noted that the vehicle V can offer N different driving modes mcn, n = 1 to N with N > 2, and chosen, for example, from the three mentioned above (economy mode mcl, comfort mode mc2, and sport mode mc3). In this case, at least one of the N driving modes mcn, and possibly all of them, is associated with a selected speed limit vin. It will be understood that this speed limit vin must not be exceeded by the vehicle V when its driving mode mcn has been selected by the driver, except in specific circumstances which will be discussed later.

[0065] As mentioned above, the invention proposes in particular a control method intended to allow control of the speed limit vin to be respected in the vehicle V.

[0066] This (control) method can be implemented at least partially by the DC3 control device (illustrated at least partially in Figures 1 and 2), which for this purpose comprises at least one PR1 processor, for example a digital signal processor (or DSP), and at least one MD memory. This DC3 control device can therefore be implemented as a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software"). For example, it could be a microcontroller.

[0067] The MD memory is random access memory (RAM) to store instructions for the implementation by the PR1 processor of at least part of the control process. The PR1 processor may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. An integrated (or printed) circuit is defined as any type of device capable of performing at least one electrical or electronic operation.

[0068] In the example illustrated, but not limited to, Figures 1 and 2, the DC3 control device is part of the CS supervisory computer. However, this is not mandatory. Indeed, the DC3 control device could comprise its own dedicated computer, or it could be part of another computer embedded in the vehicle V and performing at least one other function.

[0069] As illustrated non-limitingly in [Fig.3], the (control) method according to the invention comprises a step 10-90 which is implemented whenever two conditions are met, namely a (the) driving mode mcn associated with a chosen speed limit vin has been selected (for example by the driver) and at least one speed control function FCVj (here j = 1 or 2) is activated with an associated speed setpoint cvj.

[0070] Step 10-90 of the method includes a substep 40 in which, when the two aforementioned conditions are satisfied and in addition the speed setpoint cvj associated with the selected speed control function FCVj is greater than the speed limit vin associated with the selected driving mode mcn, the speed limiting function FCV1 is forced (for example the control device DC3 triggers an imposition) to operate primarily using a speed setpoint cvi which is equal to this speed limit vin, so that the imposed speed setpoint cvi is respected.

[0071] It will be understood that in order to enforce the imposed speed setpoint cvi, the speed limitation function FCV1 generates torque setpoints ccg which are possibly negative.

[0072] Thus, when a driving mode mcn associated with a speed limit vin has been selected and at least one speed control function FCVj is activated by the driver, the speed limitation function FCV 1 is used very advantageously to enforce this speed limit vin (and therefore prevent it from being exceeded), after having possibly activated it (if it was not already so) and having imposed a speed command cvi equal to this speed limit vin. The behavior of the vehicle V is therefore similar to that which it exhibits when the speed limitation function FCV1 is activated by the driver, as long as the current speed vv of the vehicle V remains slightly lower than the imposed speed command cvi (and of course, provided that cvj > vin (= cvi)). Then, if the speed vv continues to increase, the speed of vehicle V is regulated by the speed limitation function FCV1.

[0073] This is particularly advantageous because it requires neither an adaptation of the speed limitation function FCV1 (particularly due to the coordination between the speed control functions FCVj), nor the design, development, and implementation of a function dedicated to enforcing the speed limit vin associated with a selected driving mode mcn. Admittedly, this requires designing the control device DC3, but this design is particularly simple and very inexpensive because the latter (DC3) primarily needs to trigger the enforcement of the speed limit vin associated with the selected driving mode mcn, possibly after having first activated the speed limitation function FCV1 (if it was not already activated).

[0074] In addition, this speed limitation associated with the selected mcn driving mode makes it possible to significantly increase the mileage range of the vehicle V, and constitutes an additional differentiating element easily understood by users of the vehicle V, in particular in the case of the economy driving mode because it is generally associated with lower speeds to reduce energy consumption.

[0075] It will be noted that in the presence of N different driving modes mcn, with N > 2, one (for example the control device DC3) can associate N limit speeds vin chosen respectively to these N driving modes mcn, and in substep 40 one imposes (for example the control device DC3 triggers an imposition) on the speed limitation function FCV1 to operate primarily using a speed setpoint cvi which is equal to the limit speed vin chosen and associated with the driving mode mcn selected from among the N driving modes mcn.

[0076] It should also be noted that in step 10-90 each speed limit vin associated with the selected driving mode mcn can be predefined (and therefore not modifiable by a user of the vehicle V). However, in an alternative embodiment, in step 10-90 each speed limit vin associated with the selected driving mode mcn can be chosen (or selected) by a user of the vehicle V, for example by means of a human-machine interface of the latter (V).

[0077] By way of illustrative examples, the speed limit vil associated with the economy driving mode mcl can be between 90 km / h and 110 km / h, the speed limit vl2 associated with the comfort driving mode mc2 can be between 110 km / h and 130 km / h, and the speed limit vl3 associated with the sport driving mode mc3 can be between 140 km / h and 160 km / h. However, other values ​​or ranges of values ​​may be used.

[0078] For example, and as illustrated, but not limited to, in [Fig. 3], step 10-90 of the process may also include a substep 10 in which one (for example, the control device DC3) may begin by comparing the speed setpoint cvj associated with the activated speed control function FCVj to the speed limit vin associated with the selected driving mode mcn. If the speed setpoint cvj associated with the activated speed control function FCVj is lower than the speed limit vin associated with the selected driving mode mcn, then one (for example, the control device DC3) may repeat substep 10, or the process may terminate.Conversely, if the speed setpoint cvj associated with the activated speed control function FCVj is higher than the speed limit vin associated with the selected driving mode mcn, one (for example the control device DC3) can perform substep 40, possibly after performing a substep 20 described below.

[0079] Also, for example, and as illustrated but not limited to [Fig. 3], the step Step 10-90 of the process may also include a substep 20 in which it is determined (for example, by the control device DC3) whether the speed limiting function FCV1 is already activated. If so, it (for example, by the control device DC3) performs substep 40. Conversely, if it is not, the speed limiting function FCV1 is activated (for example, by the control device DC3 triggers the activation of) in a substep 30 of step 10-90, and then it (for example, by the control device DC3) performs substep 40.

[0080] Also, for example, and as illustrated but not limited to [Fig. 3], the step 10-90 of the process may also include a substep 60 in which, when the activated speed control function FCV2 is selected from a speed regulation function, an adaptive speed regulation function and a speed limiting function, one (for example the control device DC3) may allow an overshoot of the imposed speed setpoint cvi up to the speed setpoint cvj associated with that activated speed control function FCV2 when the torque setpoint ccg representing the driver's intent becomes greater than the selected threshold (and thus the hard point).

[0081] It will be understood that this last option is intended to allow, in the event of reaching (and exceeding) the hard point, the driver of vehicle V to regain control of the vehicle (V) and for the CS supervisory computer to resume taking into account the depressment of the accelerator pedal PA of vehicle V, even though the speed limitation function FCV1 was generating torque commands ccg enabling vehicle V to comply with the imposed speed command cvi. In other words, if the driver wants his vehicle V to go faster than the imposed speed command cvi, he must pass the hard point of the accelerator pedal. PA. This effectively amounts to disabling the enforcement of the cvi imposed speed setting.

[0082] In the presence of the last option, as illustrated non-limitingly in [Fig. 3], step 10-90 of the process may also include a substep 50 in which it is possible (for example, the control device DC3) to determine whether the hard point has been reached (and exceeded). If not, it is possible (for example, the control device DC3) to repeat substep 50. Conversely, if it is possible, it is possible (for example, the control device DC3) to perform substep 60.

[0083] At least three embodiments can be envisaged so that the authorization to exceed the imposed speed setpoint cvi ceases.

[0084] In a first embodiment, when in substep 50 of step 10-90 the vehicle V has a current speed vv which has exceeded the imposed speed setpoint cvi due to the driver's will (by exceeding the hard point), then in substep 60 the imposing (for example the control device DC3 can trigger the cessation of the imposing) of the imposed speed setpoint cvi can cease as long as the current speed vv has not become less than or equal to the imposed speed setpoint cvi by the driver's will (end of exceeding the hard point, possibly by cessation of the depressment of the accelerator pedal PA).

[0085] In other words, in this first embodiment, when the driver no longer wants to exceed the imposed speed setpoint cvi, he causes a reduction in the speed vv of the vehicle V below or at the level of the imposed speed setpoint cvi, for example by reducing or ceasing the depressor of the accelerator pedal PA or by acting on the brake pedal.

[0086] In a second embodiment, when in substep 50 of step 10-90 the vehicle V has a current speed vv that has exceeded the imposed speed setpoint cvi due to the driver's intention (by exceeding the hard point), it is possible (for example, the control device DC3) to determine in a substep 70 of step 10-90 whether this current speed vv begins to decrease due to the driver's intention. If not, it is possible (for example, the control device DC3) to repeat substep 60 (in order to maintain the authorization to exceed the imposed speed setpoint cvi). Conversely, if it does, in a substep 80 of step 10-90 it is possible (for example, the control device DC3) to determine whether the reduced current speed vv remains above the imposed speed setpoint cvi.If so, in a substep 90 of step 10-90, it is possible to impose (for example, the control device DC3 can trigger the imposition) on the speed limiting function FCV1 to use successive speed setpoints cvi that are equal to the reduced current speed vv as long as the latter (vv) remains greater than the imposed speed setpoint cvi. On the other hand, in . the negative, when the current reduced speed vv becomes less than or equal to the speed setpoint imposed by the driver's will (for example by reducing or ceasing the depressor of the accelerator pedal PA or by acting on the brake pedal), the imposed speed setpoint cvi can be reimposed (for example the control device DC3 can trigger a new imposition of), for example by performing substep 40 again.

[0087] In other words, in this second embodiment, when the driver no longer wishes to exceed the imposed speed setpoint cvi, they cause a reduction in the vehicle's speed vv below or at the level of the imposed speed setpoint cvi, for example by reducing or ceasing the depressor of the accelerator pedal PA or by acting on the brake pedal. However, here, the speed limiting function FCV1 receives speed setpoints cvj that decrease until they reach the imposed speed setpoint cvi, so that it functions again as soon as a reduction in the current speed vv is detected in substep 70.

[0088] In a third embodiment, when in substep 50 of step 10-90 the vehicle V has a running speed vv which has exceeded the imposed speed setpoint cvi due to the driver's will (by exceeding the hard point), and then the driver's will corresponds to a zero torque setpoint ccg for a chosen duration, it is possible to impose (for example the control device DC3 can trigger the imposition) the speed limiting function FCV1 to use the imposed speed setpoint cvi again.

[0089] In this third embodiment, it is considered that a driver's intention corresponding to a zero torque setpoint ccg for at least the chosen duration indicates that the driver again wants the imposed speed setpoint cvi to be respected. If, during the chosen duration, the torque setpoint ccg corresponding to the driver's intention is again non-zero, then the authorization to exceed the imposed speed setpoint cvi can continue (for example, by the control device DC3).

[0090] For example, the chosen duration can be between 500 ms and 2 s.

[0091] It should be noted that in step 10-90, a driving mode mcn may be selected and only the speed limitation function FCV1 may be activated with an associated speed setpoint cvi. In this case, there may be a different imposed speed setpoint cvi and an associated speed setpoint cvi (one being lower than the other), and therefore initially the lower of the two speed setpoints cvi and cvi is used by the speed limitation function FCV1. In this case, when the vehicle V has a current speed vv that has exceeded the lower speed setpoint due to driver intent (by exceeding the speed limit), the imposing function may cease (for example, the device of DC3 control can trigger a cessation of the enforcement of the lower speed setpoint (cvi and cvl), and the use of the higher speed setpoint (cvi and cvl) can be enforced (for example, DC3 control can trigger the enforcement). Then, if the vehicle (V) has a current speed that exceeds the higher speed setpoint due to driver intent (by a new, or continued, overtaking of the speed limit), the enforcement of the higher speed setpoint (cvi and cvl) can cease (for example, DC3 control can trigger a cessation of the enforcement) as long as the current speed (vv) has not returned to less than or equal to this higher speed setpoint by driver intent.Then, when the current speed vv becomes less than or equal to the lowest speed setpoint between cvi and cvl by the driver's will, the use of this lowest speed setpoint can again be imposed (for example, the DC3 control device can again trigger the imposition of).

[0092] It should also be noted that each activation of the speed limitation function FCV1 not initiated by the driver is triggered by the control device DC3. Consequently, the human-machine interface normally used by the speed limitation function FCV1 to signal its action to the driver is preferably not used. In this case, a specific human-machine interface can be used (by the control device DC3) to explain to the driver why the vehicle's speed vv may be temporarily limited to the imposed speed setpoint cvi.

[0093] It will also be noted, as illustrated non-limitingly in [Fig.2], that the CS supervisory computer (or the DC3 control device computer) may also include a mass memory MM1, in particular to store the selected driving mode mcn (and possibly the associated speed limit vin), each speed control function FCVj activated by the driver and the associated speed setpoint cvj, and 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 DC3 control unit computer) may also include an IE input interface for receiving at least the message indicating the selection of a driving mode mcn (and possibly the associated speed limit vin), the message indicating the speed control function FCVj activated by the driver (and possibly the associated speed setpoint cvj), the current vehicle speed vv V, and each message indicating an overshoot of the hard point, possibly after having them shaped and / or demodulated and / or amplified, in a manner known per se, by means of a PR2 digital signal processor. In addition, this CS supervisory computer (or the DC3 control unit computer) may also include an IE input interface for receiving at least the message indicating the selection of a driving mode mcn (and possibly the associated speed limit vin), the message indicating the speed control function FCVj activated by the driver (and possibly the associated speed setpoint cvj), the current vehicle speed vv V, and each message indicating an overshoot of the hard point, possibly after having them shaped and / or demodulated and / or amplified, in a manner known per se, by means of a PR2 digital signal processor. DC3) may also include an IS output interface, in particular to deliver each cvi imposed speed setpoint imposition message, each possible FCV1 speed limitation function activation message, and each cvi imposed speed setpoint overrun authorization message.

[0094] 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 type of electronic circuits (or hardware), such as for example the PR1 processor, is suitable for implementing the control method described above to control a speed limit vin to be respected in the vehicle V.

Claims

Demands

1. A control method for a land vehicle (V) comprising i) a powertrain adapted to supply drive wheels with torque as a function of a torque setpoint, ii) at least two speed control functions which, when activated, generate torque setpoints enabling said vehicle (V) to comply with associated speed setpoints, one of these speed control functions being a speed limiting function, and iii) at least two selectable driving modes, characterized in that it comprises a step (10-90) in which, - When a driving mode is selected while at least one speed control function is activated with an associated speed setpoint greater than a selected speed limit associated with said selected driving mode,The speed limitation function is required to operate primarily using a speed setpoint equal to the speed limit, so that the imposed speed setpoint is respected; - When the activated speed control function is selected from a speed regulation function, an adaptive speed regulation function, and a speed limiting function, an overspeed of the imposed speed setpoint is permitted up to the speed setpoint associated with the activated speed control function when a torque setpoint representing the intent of a driver of the vehicle (V) exceeds a chosen threshold.

2. Method according to claim 1, characterized in that in said step (10-90), in the presence of N different driving modes, with N > 2, N speed limits are associated respectively with said N driving modes, and said speed limitation function is required to operate primarily using a speed setpoint equal to said speed limit chosen and associated with said driving mode selected from said N driving modes.

3. The method according to claim 1, characterized in that in said step (10-90), when said vehicle (V) has a current speed that has exceeded the said imposed speed limit due to the said will of the driver, the said imposed speed limit ceases to be imposed until the said current speed has become less than or equal to the said imposed speed limit due to the said will of the driver.

4. The method according to claim 1, characterized in that in said step (10-90), when said vehicle (V) has a running speed which has exceeded said imposed speed setpoint due to said driver's will and this running speed begins to decrease due to said driver's will, said speed limiting function is required to use successive speed setpoints equal to said reduced running speed, and said imposed speed setpoint is again required when said running speed has become less than or equal to said imposed speed setpoint due to said driver's will.

5. Method according to claim 1, characterized in that in said step (10-90), when said vehicle (V) has a running speed which has exceeded said imposed speed setpoint due to said driver's will, and then said driver's will corresponds to a zero torque setpoint for a chosen duration, said speed limiting function is again required to use said imposed speed setpoint.

6. A method according to claim 1 or 2, characterized in that in said step (10-90), when a driving mode is selected while only said speed limitation function is activated with an associated speed setting, when said vehicle (V) has a current speed that has exceeded the lower of said imposed speed setting and said associated speed setting due to said driver's intent, this lower speed setting is no longer imposed and the higher of said imposed speed setting and said associated speed setting is used, then if said vehicle (V) has a current speed that exceeds said higher speed setting due to said driver's intent,The use of the highest speed setting ceases until the current speed has been reduced to or below that highest speed setting by the driver's will, and when the current speed has returned to or below the lowest speed setting, by the said will of the driver, the use of this lower speed instruction is again imposed.

7. Product computer program comprising a set of instructions which, when executed by processing means, is suitable for implementing the control method according to any one of claims 1 to 6, in a land vehicle (V) and comprising i) a powertrain suitable for supplying drive wheels with torque as a function of a torque setpoint, ii) at least two speed control functions suitable, when activated, for generating torque setpoints enabling said vehicle (V) to comply respectively with associated speed setpoints, one of these speed control functions being a speed limiting function, and iii) at least two driving modes that can be selected, to control a speed limit to be observed in said vehicle (V).

8. Control device (DC3) for a land vehicle (V) comprising i) a powertrain capable of supplying drive wheels with torque as a function of a torque setpoint, ii) at least two speed control functions capable, when activated, of generating torque setpoints enabling said vehicle (V) to comply with associated speed setpoints, one of these speed control functions being a speed limiting function, and iii) at least two selectable driving modes, characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to perform the operations consisting, when a driving mode is selected while at least one speed control function is activated with an associated speed setpoint greater than a selected speed limit associated with said selected driving mode,to trigger a requirement for said speed limiting function to operate primarily using a speed setpoint equal to that speed limit, so that said imposed speed setpoint is respected.

9. A land vehicle (V) comprising i) a powertrain capable of supplying drive wheels with torque as a function of a torque setpoint, ii) at least two speed control functions capable, when activated, of generating torque setpoints enabling said vehicle (V) to comply respectively with associated speed instructions, one of these speed control functions being a speed limiting function, and iii) at least two driving modes that can be selected, characterized in that it further comprises a control device (DC3) according to claim 8.

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