FR3089162A1 - Method and system for continuously monitoring the acceleration of a hybrid motor vehicle - Google Patents

Abstract

Method for continuous control of the acceleration of a motor vehicle with hybrid propulsion comprising a plurality of rotating parts capable of being connected or disconnected. Said method being configured to maintain the same level of acceleration of the vehicle during the connection and disconnection of said rotating parts. Figure for abstract: Fig 1

Description

Description

Title of the invention: Method and system for continuous control of the acceleration of a hybrid motor vehicle The present invention relates to the field of motor vehicles, and more particularly, motor vehicles comprising one or more traction machines.

The increasing complexity of the traction chain of motor vehicles, in particular with the arrival of hybrid propulsion vehicles, requires taking into account the state of the traction machines connected to the wheels in order to calculate the level of torque at the wheel leading to untimely acceleration of the vehicle.

Hybrid vehicles include on the one hand an internal combustion engine and one or more electric machines for driving the vehicle. The torque required for driving the wheels can be provided either by the heat engine, or by the electric machine, or by a combination of the heat engine and the electric machine.

We know, for example, from the document LR 3 022 495 -Al two examples of configurations of a hybrid transmission on which it would be interesting to adapt the torque setpoint to the wheel according to the state of the chain traction.

A first example of a hybrid transmission comprises a heat engine and an electric drive machine, two concentric primary shafts connected to the crankshaft of the heat engine and to the electric machine without cut-off clutch, a secondary shaft connected to the wheels of the vehicle by a differential and a shaft for transferring movement from a primary shaft to the secondary shaft and coupling the primary shafts. In this example, the electric machine is arranged at the opposite end of the primary line relative to the heat engine.

A second example of hybrid transmission differs from the first example in that it further comprises a second electric machine coupled to the transfer shaft.

Thanks to different coupling devices, such a hybrid transmission can operate in pure thermal mode, in which all of the torque required for driving the wheels is provided by the heat engine, a mixed mode with the addition of at least one electric machine, or an electric mode for, in which the entire torque required for driving the wheels is supplied by at least one electric machine.

In motor vehicles which only have a heat engine for driving the wheels, it is known to determine a torque setting at the wheel from a depressing value of the accelerator pedal and the current engine speed, thus corresponding to the “driver's will” to obtain a given acceleration of the motor vehicle.

The engine computer includes, for example, in memory a map in the form of a table whose inputs are said engine speed and said depression, and whose output corresponds to the torque setpoint at the wheel.

During a step, the engine computer translates this torque setpoint to the wheel into an engine torque setpoint, as a function of the torque at the wheel, the reduction ratio between the engine and the wheel, and possibly the efficiency the kinematic chain, unless we consider that it is equal to one.

The engine control unit controls different actuators of the engine in order to adjust at least an amount of air and an amount of fuel, the combustion of which produces torque at the wheel. This torque at the wheel thus represents the driver's desire to obtain a certain acceleration of the vehicle. Indeed, according to the fundamental principle of dynamics, the product of the mass of the vehicle by its acceleration is equal to the driving force of the vehicle, reduced by the sum of the resistant forces applied to the vehicle. However, the driving force or motive force, applied to the wheels, comes from the engine torque which is transmitted to the wheels via the vehicle's transmission chain, in particular by the gearbox and the vehicle differential.

Resistant forces are made up of all the forces that oppose the rolling of the vehicle, such as in particular, aerodynamic forces, such as drag force, resistance forces, internal friction, linked forces gravity when the vehicle is traveling on an uphill slope. Other resistant forces are linked to the inertia of all the rotating parts in the engine and the transmission chain.

The driver adjusts the value of the torque to the wheel by a given depression of the accelerator pedal in order to modify the driving force and therefore the acceleration.

In general, it is known to calibrate the vehicle's accelerator pedal under vehicle mass reference conditions and on flat roads.

Thus, the depressing of the accelerator pedal does not produce the same acceleration when the vehicle is traveling on an uphill or downhill slope, or when the vehicle is more or less loaded than the load corresponding to the reference mass. .

However, the driver of the vehicle expects a certain behavior of the vehicle in terms of speed and acceleration, given his depressing of the accelerator pedal and the external environment. However, any untimely acceleration, that is to say, which the driver does not expect, should be avoided for safety reasons.

However, in hybrid transmissions, the torque to the wheel necessary for driving the vehicle, and whose set value is also a function of the depressing of the accelerator pedal and the engine speed, can come either entirely from the engine, either entirely from an electric machine, or a combination of the two.

In general, the vehicle computer constantly monitors the operation of the engine and of the electric machine (s) so as to distribute it, for example as a function of optimum efficiency or of the state of charge of a battery of the electric machine, the production of the torque between the motor and the electric machine.

For this, the computer permanently decomposes the torque setpoint at the wheel into a first torque setpoint value at the wheel to be supplied by the heat engine and a second torque setpoint value at the wheel to be supplied by the electric machine. Then, each of these two wheel torque setpoint values is translated into torque setpoint for the corresponding drive source, via the reduction ratio and the efficiency of the corresponding transmission chain.

In all known cases of the state of the art, the sum of these two torque settings at the wheel is constantly equal to the torque setting at the total wheel resulting from the will of the driver.

However, the successive connections and disconnections of the electric machine (s), which take place in particular during the transitions between the “pure thermal” operating mode, the “pure electric” mode and the “mixed” mode, entail risks of untimely acceleration.

It is therefore necessary to reduce these untimely accelerations of the vehicle.

Methods are known which make it possible to compensate for the variations in acceleration of the vehicle linked to a mass difference or to a slope difference, compared with an expected acceleration on a flat road and with a load, or mass, of reference.

We can refer in this regard to document EP 1 045 121 - A1 which describes a method comprising the steps of detecting an opening of the accelerator pedal, of determining a target driving force in response at said opening and at vehicle speed, determining a preliminary drive force correction in response to an increase in rolling resistance, and determining a target drive force correction based on said correction preliminary drive force.

[0025] Such a method makes it possible to reduce the feeling of lessening of the performances coming from a rolling uphill slope and / or with a large load, by avoiding the differences in acceleration compared to an acceleration expected under reference conditions. (zero slope, standard load). However, such a method does not make it possible to compensate for untimely accelerations, that is to say which cannot be controlled by the driver, such as for example the accelerations due to modifications of the vehicle's traction chain, controlled by the vehicle computer independently of any direct action from the driver.

We can also refer to document FR 2 875 200 - A1 which proposes a method of developing an order for controlling a transmission device of a motor vehicle powertrain, in which the set point is adapted. of torque to be applied to the vehicle wheels in order to improve the behavior of the vehicle in a slope and / or load situation. The method described provides for increasing the torque setpoint resulting from the will of the driver corresponding to the depressing of the accelerator pedal, relative to a torque setpoint, to avoid differences in accelerations related to the slope or to load.

However, such a method does not further solve the problem of untimely acceleration.

Finally, reference may be made to document US 2018 0126936 - A1 which describes a method for calibrating an inertial sensor mounted on a vehicle and capable of determining a signal such as the acceleration of the vehicle. Said signal can be used to trigger in particular a vehicle safety device, such as an airbag or a braking system of the electronic stability program type, with the acronym "ESP" in English terms.

Such a method allows certain curative measures to be taken in the event of untimely acceleration, but does not prevent its occurrence.

The objective of the invention is therefore to overcome these drawbacks and to improve the safety of passengers in a motor vehicle by avoiding untimely acceleration of the vehicle which can occur independently of the driver’s wishes.

More specifically, the invention aims to limit the accelerations associated with the connection and disconnection of elements of the transmission chain caused by the vehicle computer.

By "untimely accelerations" means accelerations which are not controllable by the driver, such as for example accelerations due to modifications of the vehicle's traction chain, controlled by the vehicle computer independently of any action direct from the driver.

The present invention relates to a method of continuous control of the acceleration of a motor vehicle comprising at least two sources of driving energy comprising a plurality of rotating parts capable of being connected or disconnected, in which it is determined a setpoint for total torque at the reference wheel as a function of the depressing of the vehicle accelerator pedal by the driver and of the engine speed. The determination of such an instruction is known from the state of the art and will not be described further.

By “total” torque is meant the torque at the wheel supplied by, or from, all of the sources of driving energy depending on the depressing of the accelerator pedal and of the engine speed, by through the respective transmission chains between each source and the drive wheels.

According to the method, an acceleration of the motor vehicle is determined, for example using a vehicle acceleration sensor.

Then, using the sensors present on the vehicle, the states of the rotating parts of the energy sources which can be connected or disconnected are determined, and a corrective torque value is calculated as a function of the acceleration, the total torque setpoint at the wheel and the inertia of the connected rotating parts. Said corrective torque value is configured to overcome the inertia of the second motive power source when it is connected or disconnected.

Thus, the method makes it possible to maintain the same level of acceleration of the vehicle when connecting and disconnecting the rotating parts linked to the second source of motive energy, for example an electric machine.

Thus, one can calculate the permissible torque level at any time as a function of the inertia of the components connected to the wheels of the motor vehicle.

Advantageously, a total torque setpoint at the wheel is calculated corresponding to the sum of the corrective torque value and the reference torque setpoint.

For example, the total torque setpoint is distributed to the wheel between a first torque setpoint for the first energy source and a second torque setpoint for the second energy source, the sum of the first and second setpoints of torques being permanently equal to the sum of the reference torque setpoint with the corrective torque value.

According to one embodiment, the setpoint for total torque at the wheel is used to trigger a vehicle safety device, such as an airbag or a braking system of the electronic stability program type, with the acronym "ESP" in Anglo-Saxon terms.

Thus, the inertia of the traction machines is taken into account, which makes it possible to increase the margin of torque authorized by the safety device before the computer is reset to zero.

Advantageously, an expected acceleration of the vehicle is determined as a function of the setpoint for total torque on the road and resistant forces, a template is established as a function of said expected acceleration of the vehicle, by applying a margin or a tolerance of acceptable acceleration for the behavior of the vehicle, the value of the actual acceleration of the vehicle is continuously compared with said gauge and the safety device is triggered if the value of the actual acceleration of the vehicle leaves the gauge.

According to a second aspect, the invention relates to a continuous control system for the acceleration of a motor vehicle comprising at least two sources of driving energy comprising a plurality of rotating parts capable of being connected or disconnected, comprising a module for determining a setpoint for total torque at the reference wheel as a function of the depressing of the accelerator pedal of the vehicle by the driver and of the engine speed.

The determination of such a set point is known from the state of the art and will not be described further.

By "total" torque is meant the torque at the wheel to be supplied by all the sources of driving energy depending on the depressing of the accelerator pedal and the engine speed.

The system further comprises a module for determining an acceleration of the motor vehicle, for example using a vehicle acceleration sensor. The system includes a module for determining, using sensors present on the vehicle, the states of the rotating parts of the energy sources which can be connected or disconnected and a module for calculating a corrective torque value as a function of acceleration, the total torque setpoint at the wheel and the inertia of the connected rotating parts. Said corrective torque value is configured to overcome the inertia of the second motive power source when it is connected or disconnected.

Thus, the system makes it possible to maintain the same level of acceleration of the vehicle when connecting and disconnecting the rotating parts linked to the second source of motive energy, for example an electric machine.

Thus, one can calculate at any time the level of permissible torque as a function of the inertia of the components connected to the wheels of the motor vehicle.

Advantageously, the system includes a module for calculating a setpoint for total torque at the wheel corresponding to the sum of the sum of the corrective torque value and the reference torque setpoint.

The system may include a module for distributing the setpoint of total torque to the wheel between a first setpoint of torque for the first energy source and a second setpoint of torque for the second energy source, the sum of first and second torque setpoints being permanently equal to the sum of the reference torque setpoint with the corrective torque value.

According to one embodiment, the system comprises a module for triggering the safety device, such as an airbag or a braking system of the electronic stability program type, acronym "ESP" in English terms of the vehicle . Said module comprises a module for determining an expected acceleration of the vehicle as a function of the setpoint for total torque on the road and resistive forces, a module for determining a gauge as a function of said expected acceleration of the vehicle, by applying a margin or an acceptable acceleration tolerance for the behavior of the vehicle, and a module for constantly comparing the value of the actual acceleration of the vehicle with said gauge. Said safety device triggering module is configured to trigger the safety device when the value of the actual acceleration of the vehicle leaves the gauge.

Thus, the inertia of the traction machines is taken into account, which makes it possible to increase the margin of torque authorized by the safety device before the computer is reset to zero.

According to a third aspect, the invention relates to a motor vehicle comprising a traction chain comprising at least two sources of driving energy comprising a plurality of rotating parts capable of being connected or disconnected, and a continuous control system of the acceleration of said motor vehicle as described above.

The first source of energy can be a thermal machine and the second source of energy can be an electric machine.

Other objects, characteristics and advantages of the invention will appear on reading the following description, given only by way of nonlimiting example, and made with reference to the appended drawings in which:

[Fig-1] is an embodiment of a process for continuous control of the acceleration of a motor vehicle; and [FIG. 2] schematically illustrates a system for continuously controlling the acceleration of a motor vehicle implementing the method of FIG. 1.

For driving a motor vehicle at γ acceleration, the powertrain must transmit to the drive wheel a torque leading to a drive force F _word , such that, according to the fundamental principle of dynamics, have the following equation:

[Math.l] hi. y - F _mo - Σ F _{rt? s} With:

M, the mass of the vehicle, expressed in kg; and EF _res , the sum of the forces resistive to advancement applied to the vehicle, expressed in N.

The driving force F _mot follows the law according to the following equation:

[Math.2]

C = F r wheel ¹ wheel · 'With:

C _molt , the torque at the wheel, expressed in Nm; and r, the radius of the wheel, expressed in m.

Furthermore, in the case of a torque coming from a single engine, for example from a heat engine, one can write the equation for the transfer of couples from the conservation of power by taking the assumption of a return of 1 according to the following equation:

[Math.3]

P = P * word ¹ wheel [0071] implies:

[Math.4]

C _moÎ .bJ _mo i - C _{r oue} .L ·) _wheel [0073] implies:

[Math.5]

C word ~~ C roueroue! word with:

P _word and P _wheel , respectively the engine power and the power transmitted to the wheel; and C _word , C _wheel , ω _wheel and ω _word , respectively the motor torque, the wheel torque, the speed of rotation of the wheel and the speed of rotation of the motor.

We can therefore write the driving force according to the following equation:

[Math.6] p _ U m or mot m o t 1 '' (A γ o u g [0080] With:

Ω _word on ω _{mu e} , the reverse of the reduction ratio, or reduction ratio, between the engine and the wheels. The report corresponding in particular to the gearbox report engaged.

In the decomposition of the resisting forces EF _res , one can find in particular:

The aerodynamic forces:

[Math.7]

F _a = O.5.pSC _x .V ² With:

Ρ, the density of the air;

S, the front surface of the vehicle;

C _x , the drag coefficient; and V, the speed of the vehicle.

[0090] [0091] We also find the strength of rolling resistance: [Math. 8] F _ro = mgC _rr [0092] [0093] [0094] [0095] [0096] With: g, the acceleration of gravity; and C _rr , the tire resistance coefficient. One finds in addition the force to overcome in slope, in particular in rising slope: [Math.9] F _p = mgsin (a) [0097] [0098] [0099] With: a, the slope of the road. Finally, it is necessary to add to these resistant forces, inertial forces linked to any specific element of the traction chain in rotation about an axis, thereby comprising a rotational inertia such as: [0100] [Math. 10] C p _ ^c merl .x ^r inert.x ~ Y [0101] The inertial torque C _inerLx of a mass element in rotary acceleration in the traction chain can be expressed as a function of the derivative of its rotational speed ώ _χ and its moment of inertia I _x according to the following equation: [0102] [Math. 11] C = Iv.üj V mert _{x! Q} [0103] We can then express the torque C _{inertX / o} at the corresponding wheel in accordance with the torque transfer equation above, ω _{rou e} being the wheel rotation speed according to the following equation: [0104] [Math. 12] c = c ( ^χ ) ^inert X1 wheel wheel J [0105] [0106] Or: [Math. 13] c - t ( ^ωx Ί ² inerr _xlroue ~~ ^1χ · ^ω impeller \ bJ _roile ) [0107] However, the acceleration of the wheel ώ _{rou e} and the longitudinal acceleration γ of the vehicle are related by the following relationship: [0108] [Math. 14] Y rou e F

We can therefore write:

[0110] [Math. 15] rr Y { ^ω χ Ί ² inert _νι % ' ^- \ W _wheel ) ^{, ι} ' ^ι λ / wheel [YES] With:

Ω χ _on a> _wheel , the inverse of the reduction ratio, or reduction ratio, between the part X and the wheel.

The fundamental principle of dynamics, taking into account these inertial forces F _inert of the rotating mass elements of the traction chain, is written as follows:

[0114] [Math. 16] rn-Y = - Fa - F _ro - F _p - F _inert [0115] The term F _inert containing the sum of the inertias of all the parts xl, x2, ... xi,

... xn of the traction chain, each brought back to the wheel, is written according to the following equation:

[0116] [Math. 17] f = y [ ^{2 r} inertia.wheel ί [wheel I [0117] and:

[0118] [Math. 18] c = y ά I ² ^ inertie.roue f [Γ ^Λ x ^ rouel [0119] With:

_{Wheel inertia>} the _wheel force of the rotating components, expressed in N;

Cinertireroue, the torque at the wheel of the rotating components, expressed in N.m;

R, the radius of the wheel, expressed in m;

Π_xi , the angular speed of rotation of a part X of the traction chain, expressed in rad / s;

Co _wheel , the angular speed of rotation of the wheels, expressed in rad / s;

M, the mass of the vehicle, expressed in kg;

Γ, the level of longitudinal acceleration of the vehicle, determined for example by sensor, expressed in m / s ² ; and [0127] I _x , the inertia in rotation of the part X of the traction chain which is measured during its mechanical design, expressed in kg / m ² .

In the case of a vehicle comprising only a heat engine, no other element of the powertrain linked to an electric motor can be connected or disconnected. Equation 18 above then corresponds to the sum of the inertias Ix always present (engine, gearbox primary, clutch, etc.) when the engine is engaged, and the torque setting at the wheel can then be determined to overcome the sum of the inertias and all the other resistive forces as a function of pedal depressing and of an engine speed, so as to obtain a given acceleration γ of the vehicle.

However, when the motor vehicle is a hybrid drive, that is to say that it comprises a heat engine and at least one electric machine, all the rotating parts linked to the electric machine are added. instantly to the rotating masses linked to the heat engine.

Thus, if the torque setpoint at the wheel C _word is not modified, as is the case in the prior art cited, the sudden connection of the rotating parts linked to the electric machine generates a drop sudden acceleration γ of the vehicle linked to the sudden addition of an additional inertial force. Conversely, the sudden disconnection of the rotating parts linked to the electric machine generates a sudden acceleration of the linked vehicle.

The flow diagram represented in FIG. 3 illustrates an example of a method 10 for continuous control of the acceleration of a motor vehicle with at least two motive power sources. The method is configured to maintain the same acceleration level of the vehicle when connecting and disconnecting the rotating parts linked to the second source of motive power, for example an electric machine.

The method 10 comprises a step 11 of determining a setpoint C _word of total torque at the reference wheel as a function of the depressing of the accelerator pedal by the driver and of the engine speed. The determination of such an instruction is known from the state of the art and will not be described further.

By “total” torque is meant the torque to be supplied by all of the driving energy sources depending on the depressing of the acceleration pedal and the engine speed.

The method 10 further comprises a step 12 of determining an acceleration γ of the motor vehicle, for example using an acceleration sensor (not shown) of the vehicle.

In step 13, the method determines, using sensors present on the vehicle, the E states of the rotating mass elements of the traction chain which can be connected or disconnected.

In step 14, a corrective torque value ôC is calculated to overcome the inertia of the second motive power source when it is connected or disconnected.

This corrective torque value ôC is calculated by applying the fundamental principle of dynamics according to the following equation:

[0138] [Math. 19] v, ,, é _mo f + <5 C (d word pppp I ^ mach elec _v I mach elec ,, ^m -Y = r - F _a - r _ro - r _f) - r _jnert - [ _r x ( ω) // [0139] Knowing that the old equation of the fundamental principle of dynamics was written:

[0140] [Math.20]

my = ^C ; J ''. ff _F »i (Λ / fOUi? '* G» T? lllt.fl [0141] With:

F _inert , designating the inertia forces of the rotating components always connected [0143] We deduce by difference that the torque compensation to the wheel to avoid any untimely acceleration linked to the simple connection of the component "electric machine" is such as :

[0144] [Math.21] [0145] With:

I, a rotating component of the second energy source;

Hi, a boolean equal to 1 when the component i is connected to the traction chain;

R, the radius of the wheel, expressed in m;

Co _xi , the angular speed of rotation of component i of the traction chain, expressed in rad / s;

Co _wheel , the angular speed of rotation of the wheels, expressed in rad / s;

M, the mass of the vehicle, expressed in kg;

Γ, the level of longitudinal acceleration of the vehicle, determined for example by sensor, expressed in m / s ² ; and [0153] I _xi , the inertia in rotation of the component i of the traction chain which is measured during its mechanical design, expressed in kg / m ² .

This compensation works in the case where the entire torque setpoint at the wheel continues to come from only one energy source, such as the heat engine, the second energy source, such as the machine. electric supplying no engine torque.

To avoid the untimely acceleration linked to the connection of the second power source, the compensation or corrective torque value ôC must be superimposed on the reference torque reference C _word to obtain a total torque reference at wheel C _total in step 15.

This torque compensation must also be applied during propulsion mode transitions, for example during a transition from a pure thermal mode to a mixed mode, during which the distribution of the total torque setpoint at the early route C is distributed, in step 16, between a first torque setpoint at the wheel C1 for the heat engine, or more generally the first power source and a second torque setpoint at the wheel C2 for the machine electric, or more generally the second source of energy. The sum of the first and second torque setpoints at the wheel C1 and C2 is permanently equal to the sum of the reference torque setpoint C _word with the corrective torque value <5C.

[0157] As illustrated in Figure 1, the total torque setpoint to the _total C route calculated in step 15 may be used to trigger a safety device (not shown) of the vehicle, such as an airbag or an electronic stability program type braking system, with the acronym "ESP" in Anglo-Saxon terms.

The method 10 comprises for this purpose a step 17 of determining an expected acceleration y _att of the vehicle as a function of the setpoint of total torque at the road C _tota i and of the resisting forces F _res .

From this expected acceleration y _att of the vehicle, a step SI is established in step 18 by applying a margin or an acceptable acceleration tolerance (more or less) for the behavior of the vehicle.

In step 19, the value of the actual acceleration γ of the vehicle, determined in step 12, is continuously compared with said gauge SI around the expected acceleration y _att of the vehicle. If the value of the actual acceleration γ of the vehicle leaves the gauge SI, that is to say, if the acceleration tolerance is exceeded, the safety device is triggered. The safety device can implement countermeasures, such as for example, operation of the vehicle in degraded mode, zeroing of the vehicle computer, ESP type braking, etc.

If the value of the actual acceleration γ of the vehicle is less than the gauge SI, we return to step 17.

FIG. 2 schematically illustrates a system 30 for continuous control of the acceleration of a motor vehicle implementing the method 10 of FIG. 1.

The system 30 comprises a module 31 for determining a setpoint C _word of total torque at the reference wheel as a function of the depressing of the accelerator pedal by the driver and of the engine speed. The determination of such an instruction is known from the state of the art and will not be described further.

By “total” torque is meant the torque to be supplied by all of the driving energy sources depending on the depressing of the acceleration pedal and the engine speed.

The system 30 further comprises a module 32 for determining an acceleration γ of the motor vehicle, for example using an acceleration sensor (not shown) of the vehicle.

The system 30 further comprises a module 33 for determining, using sensors present on the vehicle, the E states of the rotating mass elements of the traction chain which can be connected or disconnected.

The system 30 further comprises a module 34 for calculating a corrective torque value ôC to overcome the inertia of the second motive power source when it is connected or disconnected.

This corrective torque value C is calculated by applying the fundamental principle of dynamics according to equations 19 to 21 above.

This compensation works in the case where the entire torque setpoint at the wheel continues to come from only one energy source, such as the heat engine, the second energy source, such as the machine. electric supplying no engine torque.

To avoid untimely acceleration linked to the connection of the second motive power source, the system 30 comprises a module 35 for calculating a total torque setpoint at the wheel C _tota i corresponding to the sum of the corrective torque value <5 C and the reference torque setpoint C _word .

This torque compensation must also be applied during propulsion mode transitions, for example during a transition from a pure thermal mode to a mixed mode, during which the distribution of the total torque setpoint at the Ctotai road is divided.

The system 30 for this purpose comprises a module 36 for distributing the setpoint of total torque at the road C _tota i between a first setpoint of torque at the wheel Cl for the heat engine, or more generally the first source of energy and a second torque setting at the wheel C2 for the electric machine, or more generally the second energy source. The sum of the first and second torque setpoints at the wheel C1 and C2 is permanently equal to the sum of the reference torque setpoint C _word with the corrective torque value <5C.

As illustrated in FIG. 2, the total torque setpoint at road C _tota can be used to trigger a vehicle safety device (not shown), such as an airbag or a type braking system. electronic stability program, acronym "ESP" in Anglo-Saxon terms.

The system 30 for this purpose comprises a module 40 for triggering the vehicle safety device.

Said module 40 comprises a module 41 for determining an expected acceleration y _att of the vehicle as a function of the total torque setpoint at the road C _tota i and of the resistant forces F _res .

The module 40 further comprises a module 42 for determining a template SI as a function of said expected acceleration y _att of the vehicle and of an acceptable acceleration margin or tolerance for the behavior of the vehicle.

The module 40 further comprises a module 43 for permanently comparing the value of the actual acceleration γ of the vehicle with said gauge SI around the expected acceleration y _att of the vehicle. If the value of the actual acceleration γ of the vehicle leaves the gauge SI, the safety device is triggered. The safety device can implement countermeasures, such as for example, operation of the vehicle in degraded mode known as “limp home” in which the speed of the vehicle is limited and the driver is invited to have the vehicle diagnosed, the zeroing of the vehicle computer, ESP type braking, etc.

Thus, thanks to the invention, the inertia of the traction machines is taken into account, which makes it possible to increase the margin of torque authorized by the safety device before the computer is reset to zero.

The invention makes it possible to calculate the permissible torque level at any time as a function of the inertia of the components connected to the wheels of the motor vehicle.

Claims (1)

Claims [Claim 1] Method for continuously controlling the acceleration of a hybrid propulsion motor vehicle comprising at least two sources of driving energy comprising a plurality of rotating parts capable of being connected or disconnected, in which: a setpoint (C _word ) is determined total torque to the reference wheel as a function of the depressing of the accelerator pedal of the vehicle by the driver and of the engine speed; and an acceleration (γ) of the motor vehicle is determined; characterized in that: the states (E) of the rotating parts of the energy sources which can be connected or disconnected are determined; and a corrective torque value (ôC) is calculated as a function of the acceleration (γ), the setpoint (C _word ) of total torque at the wheel and the inertia of the connected rotating parts, said corrective torque value ( ôC) being configured to overcome the inertia of the second source of motive energy during its connection or disconnection. [Claim 2] Method according to claim 1, in which a total torque setting at the wheel (C _tota i) is calculated corresponding to the sum of the corrective torque value (ôC) and the reference torque setting (C _word ). [Claim 3] Method according to claim 2, in which the total torque setpoint at the wheel (C _tota i) is distributed between a first torque setpoint at the wheel (Cl) for the first energy source and a second torque setpoint at the wheel (C2) for the second energy source, the sum of the first and second torque setpoints at the wheel (Cl; C2) being permanently equal to the sum of the reference torque setpoint (C _word ) with the value corrective torque (ôC). [Claim 4] Method according to claim 2 or 3, in which the setpoint for total wheel torque (C _tota i) is used to trigger a vehicle safety device. [Claim 5] Method according to claim 4, in which an expected acceleration (y _att ) of the vehicle is determined as a function of the setpoint for total road torque (C _tota i) and resistant forces (F _res ), a template is established (SI ) as a function of said expected acceleration (y _att ) of the vehicle, the value of the actual acceleration (γ) of the vehicle is continuously compared with said gauge (SI) and the safety device is triggered if the value of l real acceleration (γ) of the vehicle leaves the gauge (SI). [Claim 6] System (30) for continuously controlling the acceleration of a motor vehicle with hybrid propulsion comprising at least two sources of driving energy comprising a plurality of rotating parts capable of being connected or disconnected, comprising a module (31) for determining a setpoint (C _word ) of total torque to the reference wheel as a function of depressing the accelerator pedal of the vehicle by the driver and of the engine speed, a module (32) for determining an acceleration ( γ) of the motor vehicle, characterized in that it comprises: a module (33) for determining the states (E) of the rotating parts of the energy sources which can be connected or disconnected; and a module (34) for calculating a corrective torque value (<5C) as a function of the acceleration (γ), the setpoint (C _word ) of total torque at the wheel and the inertia of the rotating parts connected, said corrective torque value (<5C) being configured to overcome the inertia of the second motive power source when it is connected or disconnected. [Claim 7] System (30) according to claim 6, comprising a module (35) for calculating a setpoint for total torque at the wheel (C _tota i) corresponding to the sum of the sum of the corrective torque value (<5C) and of the reference torque setpoint (C _word ). [Claim 8] System (30) according to claim 7, comprising a module (36) for distributing the setpoint for total wheel torque (C _tota i) between a first setpoint for wheel torque (Cl) for the first energy source and a second wheel torque setpoint (C2) for the second energy source, the sum of the first and second wheel torque setpoints (C1; C2) being permanently equal to the sum of the torque setpoint of reference (C _word ) with the corrective torque value (<5C) [Claim 9] System (30) according to claim 7 or 8, comprising a module (40) for triggering the vehicle safety device, said module (40) comprising a module (41) for determining an expected acceleration (y _att ) of the vehicle as a function of the setpoint of total torque on the road (Ctotai) and of the resistant forces (F _res ), a module (42) for determining a gauge (SI) as a function of said expected acceleration (γ _att ) of the vehicle and a module (43) for continuously comparing the value of the actual acceleration (γ) of the vehicle with said gauge (SI), said module (40) being configured to trigger the device safety when the value of the actual acceleration (γ) of the vehicle leaves the gauge (SI). [Claim 10] Motor vehicle with hybrid propulsion comprising a traction chain comprising at least two sources of driving energy comprising a plurality of rotating parts capable of being connected or disconnected, and a system (30) for continuous acceleration control said motor vehicle according to any one of claims 6 to 9.