CONTROL OF DECEASE OF A LAND VEHICLE WITH A SPEED CONTROL FUNCTION, FOR OBTAINING CONTINUOUS VARIATIONS

Abstract

A process is implemented in a vehicle comprising a powertrain providing torque as a function of a torque setpoint, a speed control function controlling a deceleration phase of the vehicle by determining torque setpoints that converge the current speed towards a speed setpoint, and an accelerator pedal having a percentage of depressment representative of an acceleration desired by the driver.This process includes a step (10-30) in which, when the percentage of penetration corresponds to a desired negative or zero acceleration on a horizontal surface with the current speed, a factor is determined as a function of the desired acceleration and a zero acceleration maintaining the current speed on a horizontal surface, and this factor is provided to the speed control function so that it determines a torque setpoint varying between the torque setpoint corresponding to the desired acceleration and the minimum torque as a function of the factor. Figure 3.

Description

Title of the invention: CONTROL OF DECELERATIONS OF A LAND VEHICLE WITH A SPEED CONTROL FUNCTION, FOR OBTAINING CONTINUOUS VARIATIONS Technical field of the invention

[0001] The invention relates to land vehicles comprising a powertrain (or PWM) and at least one speed control function to control their speed, and more specifically the control of the determination of the torque setpoint intended for the PWM during a deceleration phase. State of the art

[0002] Certain land vehicles, possibly of the motor vehicle type, comprise:

[0003] - a powertrain (or powertrain) designed to provide drive wheels with torque that is a function of a torque setting, and

[0004] - a specific speed control function, when activated, to determine the torque setpoint as a function of a speed setpoint.

[0005] As those skilled in the art know, current speed control functions do not intervene in the braking strategies of a vehicle, and therefore the only means that these functions have at their disposal to decelerate the vehicle when necessary is to generate negative torque commands to recover regenerative braking torque to bring the current speed of the vehicle towards a chosen speed command.

[0006] The maximum regenerative braking torque that a speed control function can recover is generally equal to a minimum torque corresponding to a zero (0%) accelerator pedal depressment, which is strictly greater than another minimum torque that the powertrain can supply to the drive wheels, for reasons of driving comfort and safety. Consequently, the level of deceleration that can be achieved is relatively low, and therefore the time required to maintain the set speed is relatively long. This is particularly detrimental when the vehicle is on a downhill slope, during a change in the set speed, or in a so-called "coasting" mode when the driver suddenly releases the accelerator pedal and the speed control function takes over control of the vehicle.

[0007] In certain vehicles, the regenerative braking torque, defined by a (negative) torque setpoint, is recovered by an electric drive unit of the powertrain, associated to a rechargeable battery, and transformed into electrical energy by this electric motor to recharge the rechargeable battery. It is understood that such recharging can only occur if the current state of charge of the rechargeable battery allows it.

[0008] It has been proposed to use, in certain vehicle operating situations occurring during a deceleration phase, a first threshold for the percentage of accelerator pedal depressment above which the torque command determined by the speed control function corresponds to the maximum deceleration command (or the minimum regenerative braking torque), and a second threshold for the percentage of accelerator pedal depressment above which the torque command determined by the speed control function no longer corresponds to regenerative braking torque. However, such operation induces a threshold effect that does not necessarily reflect the driver's intention to accelerate, and above all, there is neither continuity (or progressiveness) nor linearity in the deceleration variations corresponding to a continuity or linearity in the variations of the percentage of accelerator pedal depressment.

[0009] By way of illustration, during a phase of gradual release of the accelerator pedal between 100% and 1.5% depressed, there is no deceleration caused by the speed control function, and when the pedal falls below the first threshold (here equal to 1.5%), the speed control function suddenly imposes maximum deceleration. However, such behavior does not reflect the driver's intention to accelerate when they want a continuous (or progressive) and linear acceleration corresponding to the gradual release of the accelerator pedal.

[0010] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0011] In particular, it proposes for this purpose a control method intended to be implemented in a land vehicle and comprising:

[0012] - a powertrain designed to supply drive wheels with a functional torque from a couple's instruction,

[0013] - a speed control function of its own, when activated, to control a vehicle deceleration phase by determining torque commands specific to converge the vehicle's current speed towards a chosen speed command, and

[0014] - an accelerator pedal having a percentage of depressment representative of a acceleration of the vehicle as desired by its driver.

[0015] This control method is characterized by the fact that it includes a step in which, when the speed control function controls the deceleration phase and the percentage of compression corresponds to a desired acceleration less than or equal to zero on a horizontal surface with the current speed, a transition factor is determined as a function of this desired acceleration and a zero acceleration suitable for maintaining constant the current speed on a horizontal surface, and this determined transition factor is provided to the speed control function so that it determines a torque setpoint, suitable for making the current speed converge towards the chosen speed setpoint, varying between a torque setpoint corresponding to the desired acceleration and the minimum (regenerative braking) torque as a function of the determined transition factor.

[0016] Thanks to the invention, it is now possible to obtain during each deceleration phase continuous (or progressive) variations of deceleration and therefore corresponding to the successive percentages of depressurization and consequently to the driver's desire for acceleration.

[0017] The control method according to the invention may include other features which may be taken separately or in combination, and in particular:

[0018] - in its step, the transition factor can be determined as a function further of a desired minimum acceleration corresponding to a zero percentage of sinking;

[0019] - in the presence of the first option, in its step, a factor can be determined of transition which is equal to a difference between the number one and a ratio between a first difference, between the desired acceleration and the minimum desired acceleration, and a second difference, between the zero acceleration necessary to maintain constant the speed in progress on a horizontal surface and the minimum desired acceleration.

[0020] 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, a speed control function suitable, when activated, for controlling a deceleration phase of the vehicle by determining torque setpoints suitable for bringing a current vehicle speed towards a chosen speed setpoint, and, thirdly, an accelerator pedal having a percentage of depressment representative of an acceleration of the vehicle desired by a driver of the latter, for controlling the determination of the torque setpoint during a deceleration phase of the vehicle.

[0021] The invention also proposes a control device for equipping a land vehicle and comprising:

[0022] - a powertrain designed to supply drive wheels with a functional torque from a couple's instruction,

[0023] - a specific speed control function, when activated, to control a vehicle deceleration phase by determining torque commands specific to converge the vehicle's current speed towards a chosen speed command, and

[0024] - an accelerator pedal having a percentage of depressment representative of a acceleration of the vehicle as desired by its driver.

[0025] This control device is characterized in that it comprises at least one processor and at least one memory arranged to perform the operations consisting, when the speed control function controls the deceleration phase and the percentage of compression corresponds to a desired acceleration less than or equal to zero on a horizontal surface with the current speed, of determining a transition factor as a function of this desired acceleration and a zero acceleration suitable for maintaining constant the current speed on a horizontal surface, and of providing this determined transition factor to the speed control function so that it determines a torque setpoint, suitable for making the current speed converge towards the chosen speed setpoint, varying between a torque setpoint corresponding to the desired acceleration and the minimum (regenerative braking) torque as a function of the determined transition factor.

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

[0027] - a powertrain designed to supply drive wheels with a functional torque from a couple's instruction,

[0028] - a speed control function of its own, when activated, to control a vehicle deceleration phase by determining torque commands to converge the vehicle's current speed towards a chosen speed command,

[0029] - an accelerator pedal having a percentage of depressment representative of a acceleration of the vehicle as desired by its driver, and

[0030] - a control device of the type presented above.

[0031] For example, the speed control function can be specific, in the presence of the determined transition factor, to determining a torque setpoint varying between a torque setpoint corresponding to the desired acceleration and the minimum (regenerative braking) torque as a function of the determined transition factor.

[0032] Also, for example, this vehicle may include a rechargeable battery for storing electrical energy, and the powertrain may include at least one electric drive machine capable of recovering regenerative braking torque, defined by the torque setpoint, to brake the vehicle, and of transforming this recovered regenerative braking torque into electrical energy to recharge the rechargeable battery. Brief description of the figures

[0033] Other features and advantages of the invention will become apparent from an examination of the detailed description below, and the accompanying drawings, in which:

[0034] [Fig. 1] schematically and functionally illustrates an example of an embodiment of a land vehicle comprising a control device according to the invention, a speed control computer, and a hybrid powertrain and supervisory computer,

[0035] [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

[0036] [Fig.3] schematically illustrates an example of an algorithm implementing a control method according to the invention. Detailed description of the invention

[0037] The invention aims in particular to propose a control method, and an associated DC3 control device, intended to allow control of the determination of the torque setpoint ccg which is intended for the powertrain (or GMP) of a land vehicle V comprising at least one speed control function FCV, during a deceleration phase of the latter (V), in order to allow obtaining a continuity (or progressiveness) of the variations of the deceleration.

[0038] In what follows, the land vehicle V is considered, by way of non-limiting example, to be of the automobile type. For example, it is a car, as illustrated in [Fig. 1]. However, the invention is not limited to this type of land vehicle. It relates to any type of land vehicle comprising a speed control function and a powertrain (or powertrain) capable of recovering regenerative braking torque to induce deceleration.

[0039] 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 supervisory computer, a rechargeable battery BR, an accelerator pedal PA, a speed control computer CA comprising a speed control function FCV, and a DC3 control device according to the invention, is schematically represented in [Fig.1].

[0040] It should be noted that the powertrain could also be all-electric. Furthermore, the transmission chain could also allow for a four-wheel drive (or 4x4) mode.

[0041] 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.

[0042] The operation of the transmission chain (and therefore of the powertrain) is supervised by a CS supervisory computer.

[0043] The MMT internal combustion engine comprises a crankshaft (not shown) which is fixedly attached to the engine shaft AM in order to drive the latter (AM) in rotation. This MMT is designed to be coupled 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 designed to provide engine torque to move the vehicle V, as instructed by the CS supervisory control unit.

[0044] This first coupling device DC1 is coupled to the primary shaft AP of the gearbox BV and is responsible for delivering motor torque for at least one set Tl of drive wheels of the vehicle V (coupled to this gearbox BV) when it receives torque from the thermal drive machine MMT and / or the electric drive machine MME.

[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 may include a cascade of gears connecting the electric drive machine MME to the input of the gearbox BV (downstream of a second coupling device DC2).

[0047] In the illustrated example, which is not exhaustive, the crankshaft of the MMT internal combustion engine is also coupled to a belt CC, which is itself coupled to a starter-alternator AD that is electrically powered (here) by the rechargeable battery BR (and which can also recharge the latter (BR)). Thus, the starter-alternator AD can supply torque to the belt CC, which can then supply this torque to the crankshaft.

[0048] 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, 400 V, or 800 V type, for example.

[0049] The electric drive unit MME is (here) installed between the internal combustion engine unit MMT and the gearbox BV, being coupled to the first coupling device DC1, and is capable of supplying torque on command from the supervisory computer CS when it is powered by the rechargeable battery BR. It (MME) is also capable of recovering regenerative braking torque, defined by a regenerative braking torque setpoint (negative), to brake (or decelerate) the vehicle V, and to transform this recovered regenerative braking torque into electrical energy to recharge the rechargeable battery BR.

[0050] When the thermal drive machine MMT is coupled to the first coupling device DC1 and provides (positive) torque and / or the electric drive machine MME provides (positive) torque, the first coupling device DC1 delivers torque for the primary shaft AP of the gearbox BV.

[0051] This gearbox BV delivers a torque to the drive wheels that is a function of a torque setpoint ccg. Preferably, this delivered torque is greater than or equal to a first minimum torque clmin that the powertrain can supply to the drive wheels.

[0052] By way of non-limiting example, the gearbox can be of the so-called "dual-clutch (or DCT)" type. But the gearbox could be of another type.

[0053] 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 power unit MMT and the first coupling device DC1, in order to allow coupling (on command) of the electric power unit MME to the first coupling device DC1. Thus, when the second coupling device DC2 has been placed in its fully decoupled (or completely open) state, only the electric power unit MME can supply torque to the gearbox BV.

[0054] For example, this second DC2 coupling device can be a clutch.

[0055] 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.

[0056] The accelerator pedal PA is actuable (here) by a foot of the driver of the vehicle V. It has a percentage of depressment pepa which is representative of the acceleration ave of the vehicle V desired by the driver, and from which is defined the torque setpoint ccg, which is preferably greater than or equal to a second minimum torque c2min which is then strictly greater than the possible first minimum torque clmin.

[0057] It should be noted that the accelerator pedal PA may optionally have a dual function so as to allow the implementation of a so-called "one-pedal" function. This function allows, when selected by the driver of vehicle V, the accelerator pedal PA to be used not only to accelerate vehicle V, but also to decelerate (or brake) vehicle V. When this one-pedal function has been selected, part of the travel of the accelerator pedal PA is reserved for accelerating vehicle V while the other Part of the travel of this accelerator pedal PA is reserved for the deceleration of vehicle V. The distribution of the two parts of the travel of the accelerator pedal PA is configurable during the development of vehicle V. For example, the first 20 percent of the depressment (or travel) of the accelerator pedal PA can be used to manage the braking of vehicle V and the remaining 80 percent of the depressment (or travel) of the accelerator pedal PA to manage the acceleration of vehicle V.

[0058] The speed control unit CA provides at least one speed control function FCV within the vehicle V. In the following, by way of non-limiting example, the speed control function FCV is considered a speed limiting function which, when activated, generates a torque setpoint ccg enabling the vehicle V not to exceed a chosen speed setpoint cv (for example, one selected by the driver of the vehicle V). This generated torque setpoint ccg is then transmitted to the supervisory control unit CS. During a deceleration phase, the purpose of the speed control function FCV is therefore to bring the current speed vv of the vehicle V towards the speed setpoint cv by determining negative torque setpoints ccg.The maximum regenerative braking torque that the FCV speed control function can recover is equal to a minimum (regenerative braking) torque crmin which corresponds to a percentage of zero (0%) brake deposition pepa and which is a function of the current speed vv.

[0059] Since deceleration is an acceleration of negative magnitude, the minimum deceleration value is the greatest possible deceleration that vehicle V is permitted to have, and therefore the one with the highest absolute value. Conversely, the maximum deceleration value is the least possible deceleration that vehicle V is permitted to have, and therefore the one with the smallest absolute value (possibly zero).

[0060] But the invention is not limited to this type of speed control function (speed limitation). It relates in fact to any type of speed control function capable of generating a torque setpoint based on a speed setpoint. Thus, the speed control function could also be a speed regulation function or a speed limiting function, for example.

[0061] It should be noted that the speed control computer CA and the supervision computer CS can, for example, communicate via an internal communication network RC of the vehicle V, possibly multiplexed, as illustrated non-limitingly in [Fig.1].

[0062] As mentioned above, the invention proposes in particular a control method intended to allow control of the determination of the torque setpoint ccg during a deceleration phase of the vehicle V, so that the variations in deceleration are continuous (or progressive).

[0063] 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.

[0064] 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.

[0065] In the example illustrated, but not limited to, in 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 installed in the vehicle V and performing at least one other function, such as the CA speed control computer.

[0066] As illustrated non-limitingly in [Fig.3], the (control) method, according to the invention, includes a step 10-30 which is implemented each time the vehicle V is in a deceleration phase controlled by the FCV speed control function (previously activated).

[0067] Step 10-30 of the process includes a substep 20 in which, when the speed control function FCV controls the deceleration phase and the percentage of penetration pepa corresponds to a desired acceleration ave less than or equal to zero on a horizontal surface with the current speed vv, one (for example the control device DC3) determines a transition factor ft which is a function of at least this desired acceleration ave and a zero acceleration an suitable for maintaining constant the current speed vv on a horizontal surface.

[0068] It is recalled that the desired acceleration ave is a function of the percentage of depressment pepa of the accelerator pedal PA. Furthermore, the zero acceleration an (= 0 m / s²) is the acceleration that the engine must provide to the vehicle V for its current speed vv to remain constant on a horizontal (and therefore without incline) road. Each current speed vv therefore corresponds to a specific zero acceleration an, which constitutes what is frequently called a "comfort point." By way of illustrative examples, when the current speed vv is equal to 30 km / h, the zero acceleration an can correspond to a percentage of depressment pepa If the current speed vv is equal to 10%, then the zero acceleration an can correspond to a percentage of penetration pepa equal to 20%, and when the current speed vv is equal to 130 km / h, the zero acceleration an can correspond to a percentage of penetration pepa equal to 30%. The aforementioned values ​​(and many others) can, for example, be contained in a lookup table establishing a correspondence between current speeds and pairs of percentage of penetration and zero acceleration. For example, this lookup table can be stored in the memory of the DC3 control device. In one embodiment, at least one mathematical formula could be used to determine the percentage of penetration pepa corresponding to the zero acceleration an in the presence of the current speed vv.

[0069] Step 10-30 of the process also includes a substep 30 in which the transition factor ft (determined by the DC3 control device) is provided to the speed control function FCV. This allows the speed control function FCV to determine a torque setpoint ccg (suitable for bringing the current speed vv towards the speed setpoint cv) that varies between the torque setpoint corresponding to the desired acceleration ave (at the current comfort point) and the minimum (regenerative braking) torque crmin, depending on the previously determined transition factor ft. This torque setpoint ccg therefore varies between the torque setpoint corresponding to the desired acceleration ave (at the current comfort point) and the minimum torque crmin, depending on the current value of the transition factor ft.

[0070] Thus, thanks to the determination and use of the transition factor ft (a function of the current speed vv and the percentage of penetration pepa), it is now possible to obtain, during each deceleration phase, continuous (or progressive) variations in the deceleration (via the torque setpoint ccg), corresponding to successive percentages of penetration pepa and consequently to the driver's desired acceleration. It will be understood that this continuity (or progressiveness) results from the continuity (or progressiveness) of the values ​​that the transition factor ft can successively take when the percentage of penetration pepa varies.

[0071] This results from the fact that the tipping point from which the transition between the desired acceleration ave (a function of the penetration percentage pepa) and the minimum torque crmin is permitted is the penetration percentage pepa that corresponds to an acceleration of 0 m / s² on a horizontal surface (the comfort point for the current speed vv). Consequently, for penetration percentages pepa lower than that of the relevant comfort point and decreasing progressively (or continuously), the speed control function FCV determines torque setpoints ccg that will gradually (or continuously) change from a setpoint corresponding to the desired acceleration (at the comfort point) at the minimum torque (crmin). The driver can then gradually exit this deceleration and request positive acceleration by pressing the accelerator pedal (PA) to reach a depressment percentage (pepa) corresponding to an acceleration greater than 0 m / s².

[0072] For example, and as illustrated non-limitingly in [Fig.3], step 10-30 of the process may also include a substep 10 in which one (for example the control device DC3) can analyze the percentage of penetration pepa in progress in order to determine whether it corresponds to a desired acceleration ave less than or equal to zero on a horizontal surface with the current velocity vv.

[0073] In the negative (percentage of penetration pepa in progress corresponding to a desired acceleration ave greater than zero on a horizontal surface with the current velocity vv), one (for example the control device DC3) can perform substep 10 again with the next percentage of penetration pepa.

[0074] On the other hand, in the affirmative, we (for example the control device DC3) perform substep 20 to determine a transition function ft.

[0075] Also, for example, in substep 20 of step 10-30, one (for example, the control device DC3) can determine the transition factor ft as a further function of a minimum desired acceleration avmin which corresponds to a zero (0%) percentage of penetration pepa. With this option, the transition factor ft is therefore a function of the desired acceleration ave, the zero acceleration an, and the minimum desired acceleration avmin.

[0076] Also, for example, in substep 20 of step 10-30, in the presence of the preceding option, one (for example, the control device DC3) can determine a transition factor ft which is equal to the difference between the number one (1) and a ratio between the first dl and second d2 differences (i.e., ft = 1 - (dl / d2)). The first difference dl is equal to the subtraction between the desired acceleration ave and the minimum desired acceleration avmin (i.e., dl = ave - avmin). The second difference d2 is equal to the subtraction between the zero acceleration an (suitable for maintaining a constant speed vv on a horizontal surface) and the minimum desired acceleration avmin (i.e., d2 = an - avmin). It will be understood that in this case, the transition factor ft varies between zero and one.The value zero (zero) is obtained when 100% of the driver's acceleration intent is taken into account (and therefore when avmin is zero) and the value 1 (one) is obtained when 100% of avmin and 0% of the driver's acceleration intent are taken into account.

[0077] This latter method of determining (or calculating) the transition factor ft advantageously allows obtaining both continuity (or gradualness) and linearity variations in deceleration which correspond to a continuity and linearity of variations in the percentage of pepa penetration.

[0078] But other methods of determining (or calculating) the transition factor ft, allowing both continuity (or progressiveness) and linearity of the variations of the deceleration from the desired acceleration ave, from zero acceleration an and from the desired minimum acceleration avmin, can be used.

[0079] It should be noted that the speed control function FCV can, for example, determine the torque setpoint ccg by calculating a centroid between the torque setpoint corresponding to the desired acceleration ave (at the current comfort point) and the minimum torque crmin, taking into account the transition factor ft. The result of this centroid between the two aforementioned torque values ​​can therefore be equal to the torque corresponding to the desired acceleration ave (at the current comfort point) if the transition factor ft is equal to 0, or to the minimum torque crmin if the transition factor ft is equal to 1, and can take all intermediate values ​​between the two aforementioned torque values ​​when the transition factor ft is between 0 and 1.

[0080] The invention offers several advantages, including:

[0081] - a behavior of the vehicle V completely transparent to the driver and to the image of his will (pressing the accelerator pedal PA),

[0082] - an evolution of the regenerative braking torque (and therefore of the deceleration) continuous and linear, mirroring the profile of the PA accelerator pedal,

[0083] - actual use during the deceleration phases of successive positions of the accelerator pedal PA corresponding to zero acceleration (or comfort points) to initiate smooth transitions towards maximum deceleration,

[0084] - the possibility of obtaining regenerative braking torque in the event of resumption by the driver in the event of activation of the speed limitation function,

[0085] - an improvement in the modulation of the PA accelerator pedal because it is necessary to go find the position of the latter (PA) which corresponds to a zero acceleration an to completely cancel the regenerative braking torque.

[0086] It should also be noted, as illustrated but not limited to [Fig. 2], that the CS supervisory computer (or the DC3 control device computer) may also include a mass memory MM1, in particular for storing the current pepa penetration percentage, the current speed vv and the desired acceleration ave, as well as any intermediate data involved in all its calculations and processing. Furthermore, this CS supervisory computer (or the DC3 control device computer) may also include an IE input interface for receiving at least the current pepa penetration percentage, the current speed vv and the desired acceleration ave, optionally after having shaped and / or demodulated and / or amplified them, in a manner known per se, by means of a processor. digital signal PR2. In addition, this CS supervisory computer (or the DC3 control device computer) can also include an IS output interface, in particular to deliver each message containing a determined transition factor ft.

[0087] 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 the determination of the torque setpoint ccg during a deceleration phase of 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) a speed control function adapted, when activated, to control a deceleration phase of said vehicle (V) by determining torque setpoints adapted to bring a current speed of said vehicle (V) towards a chosen speed setpoint, and iii) an accelerator pedal (AP) having a percentage of depressment representative of an acceleration of said vehicle (V) desired by a driver thereof, characterized in that it comprises a step (10-30) in which, when said speed control function controls said deceleration phase and said percentage of depressment corresponds to a desired acceleration less than or equal to zero on a horizontal surface with said current speed,A transition factor is determined as a function of the desired acceleration and a zero acceleration suitable for maintaining a constant speed on a horizontal surface. This determined transition factor is then provided to the speed control function so that it can determine a torque setpoint, designed to bring the current speed towards the chosen speed setpoint, varying between a torque setpoint corresponding to the desired acceleration and the minimum torque, depending on the determined transition factor.

2. Method according to claim 1, characterized in that in said step (10-30) said transition factor is determined as a function further of a desired minimum acceleration corresponding to a percentage of zero penetration.

3. Method according to claim 2, characterized in that in said step (10-30) a transition factor is determined equal to a difference between the number one and a ratio between a first difference, between said desired acceleration and said minimum desired acceleration, and a second difference, between said zero acceleration suitable for maintaining constant said speed during a horizontal surface and said minimum desired acceleration.

4. Product computer program comprising a set of instructions which, when executed by processing means, is

5. suitable for implementing the control method according to any one of claims 1 to 3, 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) a speed control function suitable, when activated, for controlling a deceleration phase of said vehicle (V) by determining torque setpoints suitable for making a speed during said vehicle (V) converge towards a chosen speed setpoint, and iii) an accelerator pedal (PA) having a percentage of depressment representative of an acceleration of said vehicle (V) desired by a driver of the latter (V), for controlling the determination of said torque setpoint during a deceleration phase of said vehicle (V). 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) a speed control function capable, when activated, of controlling a deceleration phase of said vehicle (V) by determining torque setpoints capable of bringing the current speed of said vehicle (V) towards a chosen speed setpoint, and iii) an accelerator pedal (PA) having a percentage of depressment representative of an acceleration of said vehicle (V) desired by its driver, characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to perform the operations consisting,when said speed control function controls said deceleration phase and said percentage of compression corresponds to a desired acceleration less than or equal to zero on a horizontal surface with said current speed, to determine a transition factor as a function of this desired acceleration and a zero acceleration suitable for maintaining said current speed constant on a horizontal surface, and to provide this determined transition factor to said speed control function so that it determines a torque setpoint, suitable for making said current speed converge towards said chosen speed setpoint, varying between a torque setpoint corresponding to said desired acceleration and said minimum torque as a function of said determined transition factor.

6. Land vehicle (V) comprising i) a powertrain suitable for supplying drive wheels with torque as a function of a torque setpoint, ii) a speed control function suitable, when activated, for controlling a deceleration phase of said vehicle (V) by determining torque setpoints suitable for bringing a current speed of said vehicle (V) towards a chosen speed setpoint, and iii) an accelerator pedal (PA) having a percentage of depressment representative of an acceleration of said vehicle (V) desired by a driver of the latter (V), characterized in that it further comprises a control device (DC3) according to claim 5.

7. Vehicle according to claim 6, characterized in that said speed control function is capable, in the presence of said determined transition factor, of determining a torque setpoint varying between a torque setpoint corresponding to said desired acceleration and said minimum torque as a function of said determined transition factor.

8. Vehicle according to claim 6 or 7, characterized in that it comprises a rechargeable battery (BR) suitable for storing electrical energy, and in that said powertrain comprises at least one electric drive machine (EDM) suitable for recovering regenerative braking torque, defined by said torque setpoint for braking said vehicle (V), and for converting said recovered regenerative braking torque into electrical energy to recharge said rechargeable battery (BR).

9. Vehicle according to any one of claims 6 to 8, characterized in that it is of the automobile type.

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