WO2003062010A1

WO2003062010A1 - Device and method for control of a motor prolusion group for a vehicle

Info

Publication number: WO2003062010A1
Application number: PCT/FR2003/000147
Authority: WO
Inventors: Ahmed Ketfi-Cherif; Yves Pichon; Frédéric Roudeau; Laurent Royer; Dirk Von Wissel
Original assignee: Renault S.A.S.
Priority date: 2002-01-22
Filing date: 2003-01-17
Publication date: 2003-07-31
Also published as: FR2834940B1; EP1467889A1; FR2834940A1

Abstract

The invention relates to a device and method for control of a motor propulsion group for a vehicle. The control device comprises: a module (1) for interpretation of the drivers demands, a module (3), for detection of the vehicle environment, a module (12), for determining a command for the transmission ratio and a module (13), for determining a command for the engine torque. The modules (12) for determining a transmission ratio command and (13) for determining an engine torque command, work independently of each other. According to the invention, particularly to meet the demands of an infinitely variable transmission (17) at the input to which an engine (16) is arranged, the module (12) for calculating a command from the transmission ratio comprises a first module (10) for calculating a base engine speed (16) and a second module (11) to infer therefrom a value for the command of the transmission ratio.

Description

l

"Device and method for controlling a powertrain for a vehicle"

The present invention relates to a device and a method for controlling a powertrain for a vehicle. In the prior art, there is known a type of powertrain for a vehicle which essentially comprises an engine, for example a heat engine, which is connected to the drive wheels of a vehicle via a transmission chain. . In another state of the art, a type of transmission called "infinitely variable transmission" has been developed which constitutes an improvement in continuously variable transmissions. An infinitely variable transmission allows the creation of an infinite transmission ratio. In such a type of transmission, when the vehicle is stopped, the transmission chain can remain engaged. This feature eliminates the converter which must usually be used on a continuously variable transmission and allows the vehicle to take off and stop. Because the power transmitted to the drive wheels depends on the one hand on the engine torque delivered by the engine, like a heat engine, and on the other hand on the transmission ratio established on the infinitely variable transmission, the choice of a value of said transmission ratio influences the choice of torque produced by the engine.

In patent EP-A1 -0.838.613, it has already been proposed to produce a module for calculating the two set parameters of the powertrain that are the engine torque and the transmission ratio for an infinitely variable transmission. In this document, the problem of stopping the vehicle and taking it off are resolved by applying simultaneous simultaneous corrections to the engine torque setpoint and to a coefficient determining the transmission ratio over the infinitely variable transmission. In order to allow such a cross control, the document EP-A1 -0.838.613 describes a particular infinitely variable transmission structure.

This results in great complexity, on the one hand, in the ^' cross control structure between engine torque and transmission ratio and, on the other hand, in the design, of the mechanical elements of the infinitely variable transmission which is associated with it. adapted.

In a patent application of the same applicant, filed the same day and which is entitled "Method for controlling the transmission device of a vehicle powertrain and control device implementing such a method", a method has been described. control of a transmission which does not depend on the type of transmission. However, the solution indicated does not make it possible to treat, in a way that is pleasant for the driver and the passengers, the take-off situation and the stop situation of the vehicle when the latter comprises an infinitely variable transmission system.

However, the present invention makes it possible to use the advantages of a command managing the different driving situations under predetermined constraints so as to ensure safe and pleasant driving for all types of vehicles. It makes it possible to adapt this command, especially when starting and stopping a vehicle whose powertrain has an infinitely variable transmission. In fact, the present invention relates to a device for controlling a powertrain of a vehicle of the type comprising:

- A motor controllable by an engine torque setpoint, said engine being connected to the drive wheels by an infinitely variable transmission, controllable by a transmission ratio setpoint;

- a module to interpret the driver's wishes;

- a module to determine the environment of the vehicle. The device of the invention is characterized in that it also includes:

a module for determining a transmission ratio setpoint, said module being connected to a control input of said infinitely variable transmission;

- a module for determining a motor torque setpoint connected to a control input of said motor; and in that said modules are independently connected to the outputs of the modules to interpret the intention of the driver and ^'for detecting the vehicle surroundings. According to other aspects:

- the device ^'of the invention comprises a module calculating a base engine speed to determine a base desired value of transmission ratio, an output value is transmitted to a setpoint correction module transmission report base for producing said transmission report setpoint;

the module for correcting the basic transmission ratio setpoint of the device of the invention comprises a correction module for determining a transverse dynamic correction using a predetermined transverse dynamic correction function, recorded in the form of a program recorded in a memory of the control device and executed by a calculation unit thereof; - the correction module of the transmission ratio of base reference ^'of the device of the invention includes a correction module for determining a dynamic correction characteristic of the infinitely variable transmission with a dynamic correction function caractéristiq ue of infinitely variable predetermined transmissions, recorded in the form of a program recorded in a memory of the control device and executed by a calculation unit thereof.

The invention also relates to a method for controlling a drive train of a vehicle of the type comprising a motor controllable by an engine torque setpoint, said engine being connected to the drive wheels by an infinitely variable transmission, controllable by a transmission ratio setpoint. The method consists, at each instant of operation of the powerplant: determining a vector of parameters of the environment of the vehicle and a vector of parameters of the interpretation of the driver's wishes;

- to determine independently and / or concurrently an engine speed setpoint and a transmission ratio setpoint, each setpoint being determined using said vectors of vehicle environment parameters and the interpretation of the driver's wishes applying an engine speed setpoint function and a transmission ratio setpoint function; so as to allow smooth powertrain operation, independent of the infinitely variable type of transmission, when the vehicle is stopped and starting. According to other characteristics of the process of the invention:

- The method consists in successively determining a basic transmission ratio set value then a corrected transmission ratio set value.

Other characteristics and advantages of the present invention will be better understood with the aid of the description and the appended drawings in which:

- Figure 1 is a block diagram of a control device according to a preferred embodiment of the invention;

- Figure 2 is a block diagram of part of the device of Figure 1;

- Figure 3 is a block diagram of part of the device of Fig ure 2;

- Figure 4 is a block diagram of part of the device of Figure 3; - Figure 5 is a block diagram of part of the device of Figure 3;

- Figure 6 is a block diagram of part of the device of Figure 5; - Figure 7 is a block diagram of part of the device of Figure 5.

In Figure 1, there is shown the block diagram of a preferred embodiment of a device implementing the control method of the invention. The device of the invention comprises:

• a module 1 for interpreting the driver's wishes;

• a module 3 ^′ ^for detecting the environment of the vehicle;

• a module 12 for determining a transmission report setpoint; • a module 1 3 for determining a motor torque setpoint.

Each of the modules 12 and 13 is connected to the output terminals of the module 1 for interpreting the driver's wishes and of the module 3 for detecting the environment of the vehicle. According to an essential characteristic of the invention, these two modules 12 and 13 work independently of one another. This avoids having to resolve a possible conflict between the choice of an engine torque control and the choice of a transmission ratio on an infinitely variable transmission. This separation of the two chains for choosing the powertrain control parameters makes it possible to envisage the same control processor (or control device) for vehicles comprising different powertrains (groups) or for the same vehicle, groups powertrains not all having the same infinitely variable transmission.

To this end, the module 13 includes an output terminal which transmits an engine torque setpoint signal which is connected to an input 14 of the actuators of the drive motor 16 of the vehicle. Similarly, the module 12 for determining the transmission setpoint has an output terminal 12c which is connected to a command or setpoint input device 15 of the infinitely variable transmission 17 connected to the drive motor 16 which equips the g drive train of the vehicle of the invention and which is itself mechanically connected to the wheels 18 driving the vehicle.

The mod ule 12 for determining the transmission setpoint receives, on a first input terminal 12a, a vector / representative of the interpretation of the driver's wishes. It receives, on a second first input terminal 12b, a vector D representative of ra detection of the environment of the vehicle. The vectors / and D produced respectively by the modules 1 for interpreting the driver's wishes and 3 for detecting the environment of the vehicle are also transmitted to input terminals 13a and 13b of the module 1 3 to determine a setpoint of engine couple.

A vector / interpretation of the driver's wishes or wishes may have several independent components in the form of numerical values or Boolean values so as to describe the driver's wishes or wishes with a view to adopting a driving attitude or a vehicle behavior.

A vehicle environment detection vector D can comprise several independent components in the form of digital values or Boolean values so as to describe the parameters to be taken into account at the level of a computer making it possible to resolve the driver's request. , represented by the vector /, and the constraints specific to the vehicle at the date of decision-making, constraints represented by the vector D.

The control method according to the invention therefore consists, during the period of operation, of executing a loop repeating the following operations: - detect the vectors representative of the interpretation of the driver's wishes and of the detection of the vehicle environment;

- on the basis of these two vectors, establish separately:> a torque setpoint by executing a function for determining a motor torque setpoint; > a transmission report setpoint by executing a function for determining a transmission report setpoint; - simultaneously execute the two setpoints produced: torque 'by applying it as ^' control of the vehicle engine and ^' transmission ratio as control of the infinitely variable transmission of the vehicle.

From the separation of modules 12 and 13 and the writing of the control process, it is clear that the operations for establishing the two aforementioned setpoints separately can be carried out according to concurrent processes, that is to say at the same time on independent processors, or interleaved with the same processor. In the preferred embodiment of the invention detailed in FIG. 1, the module 12 for determining a transmission ratio setpoint for an infinitely variable transmission comprises:

• a first module 1 0 for choosing the infinitely variable transmission input regime;

• a second module 1 1 for calculating a transmission report setpoint.

The first module 10 and the second module 1 1 are respectively connected by suitable inputs to the aforementioned inputs 1 2a and 12b of the module 12 which contains them and which make it possible to provide the first and second modules 1 0 and 1 1 with the vectors respectively. vector / interpretation of ^'the driver's intention by the input terminal 12a and the vector D vehicle environment detector via input terminal 12b.

The first module 10 applies a function f () for processing the input vectors / and D so that it produces at its output 10c an infinitely variable transmission input value called déninbas according to the relation: ωinbas = f (/, D).

The function f () for choosing the infinitely variable transmission input mode is, in one embodiment, executed by the first module 10 using a map memory which is recorded during tests on a typical vehicle, and which is addressed by a mapping address generator which produces a reading address value on the basis of the list of digital values contained in the vectors I and D presented at its inputs. This results in an output speed input value of the infinitely variable transmission ωinbas.

The second module 1 1 applies a function g () of calculation on the value produced at the output 10c of the first module 10 for choosing the input regime of the infinitely variable transmission.

Furthermore, the module 1 1 for dynamic correction receives on inputs 1 1 a and 1 1 b the vectors / of interpretation of the driver's will and D of detection of the environment of the vehicle so that the second module 1 1 presents at its output, which is also the output of module 12 to determine a torque setpoint, a value of the torque setpoint Kconsigne which is determined by the relation:

Kconsigne = g (/, D, ωinbas).

The function g () for calculating a transmission ratio setpoint is, in one embodiment, executed by the second module 11 with the aid of a mapping memory which is recorded during tests on a vehicle. type, and which is addressed by a map address generator which is produced reading address value on the basis of the list of numerical values contained in the vectors / and D and the numerical value of the input speed of the infinitely variable transmission ω inbas calculated by the first module 10, list of values presented at its inputs, there results an output of the torque setpoint Kconsigne.

In a preferred embodiment, the first module 10 and the second module 1 1 are produced using a microcontroller which receives the input arguments /, D and / or ω inbas of the functions f () and g ( ), a program memory for performing the calculation of each function f () or g () and if necessary, storing intermediate calculation results, and finally a memory for assigning the calculated result. The calculated result is then available to the rest of the means of the device of the invention. In FIG. 2, a block diagram of the second module 11 has been represented for calculating a transmission ratio setpoint value on the value ωinbas produced at the output 10c of the regime of the first mod ule 10 for choosing the input regime of infinitely variable transmission. In fig ure 2, the second modu 1 1 for calculating a transmission ratio setpoint comprises a first module 20 for performing a transverse dynamic correction g 1 () which receives, at input 20a, the speed parameter ωinbas produced by the module 10, and the vectors / and D. ^• The first module 20 performs the transverse dynamic correction so that it produces on an output register 20b a value KcorO which is defined by the relation: KcorO = g1 (/, D, ωinbas). The function g 1 () of dynamic transverse correction of a first transmission ratio set value is, in one embodiment, executed by the first module 20 using a mapping memory which is recorded during test on a representative vehicle, and which is addressed by ^a mapping address generator which produces a reading address value on the basis of the list of numerical values contained in the vectors / and D and of the numerical value of the regime parameter ωinbas produced by module 10 to perform a transverse dynamic correction, list of values presented at its entries. The result is a first corrected transmission ratio setpoint KcorO at output.

The transverse dynamic correction is essentially carried out during the detection of the bend state. A turning state detection module makes it possible to produce a Boolean turning variable which is equal to “1” when the vehicle is in a turning situation and “0”. Otherwise. The turning state is detected for example on the basis of the teaching of the publication EP-A-0,965,777. The Boolean variable Virage is a ^'component of the vector D for detecting the vehicle surroundings.

The first module - 20 for transverse dynamic correction then includes a module for estimating the vehicle load which can be produced according to the teaching of the French patent application filed on March 29, 2001 under number 01 .04229 in the name of the present applicant and entitled "Vehicle load estimation device and automatic transmission vehicle using such a device".

The module for estimating the load comprises such a device for estimating the load of a vehicle which comprises a first means for calculating a static component of the load, a second means for calculating a dynamic component of the load and a third means for r produce a signal representative of the vehicle load. The first means for calculating a static component of the load comprises a circuit executing a transfer function to bring back the value of the torque measured at the wheels of the vehicle, an input of which is connected to the output of a measurement sensor of the engine torque or at the output of a software estimator of the instantaneous motor torque and one output of which is connected to an input of the third means. -

The second means for calculating a dynamic component of the load comprises a time derivation operator (d / dt) which receives a quantity representative of the instantaneous transmission ratio, calculated using an operator like a divider which receives as input signals representative of the speed of rotation of the engine of a first speed sensor and of the speed of rotation of the wheels of a second speed sensor of the wheels of the vehicle. The first and second sensors may be realized as software estimators based on numerical parameters already available in ^'the control device and q is u'il conn u.

The third means for producing a signal representative of the vehicle load comprises an addition operator receiving on a first input the signal representative of a static component and on a second input a signal representative of a dynamic component so that the signal representative of the load is expressed in the form: Vehicle_load = C_static - C_dyπamic.

In a particular embodiment, the first, second and third means are arranged so that the generator

31 which incorporates this load estimation device produces a signal at the output representative of the vehicle load expressed by:

Load_vehicle = oc 1. Torque_motor - β l. Couples_resistants - _γ 1. .. (d / dt) (Vitesse_roue) - 1. δ (d / dt) (Rapport_de_trans) relationship wherein Charge_véhicule, Couple_moteur, Couples_résistants, Vitesse_roue and Rapport_de_trans are respectively: the ^charging of the vehicle, the estimated engine torque or measured by a sensor, the couples resistant to the advancement of the vehicle estimated using an estimator of the resistant couples, the rotational speed of the driving wheels estimated or of the transmission ratio, αl, β l, γl and δl are four predetermined coefficients and relationship in which (d / dt) indicates a time derivation operator.

The skilled artisan will recognize in light of the teaching of the previous patent application FR-01 .04229 as ^'that of the present patent application, perform load estimation module of the vehicle ^for' place a component Vehicle_load in the vehicle environment detection vector D. Using the Turn parameter indicating a turn state and

Charge_véhicule indicating the load of the vehicle, the first module 20 for ^dynamic correction further uses an estimate of the tangential acceleration γ_tan which is another component of the vehicle environmental sense vector D and a parameter characterization of the type of driver which is a component of the vector / interpretation of the driver's wishes or wishes.

In a particular embodiment, the first transverse dynamic correction module 20 comprises a fuzzy logic calculator to make a choice of pre-positioning of the engine speed.

A set of rules from Rulel to RuIeN, executes Faij assertions on the input parameters of the Fuzzy Logic calculator which are respectively: - a numerical value T_! Oad representative of the vehicle load,

- a numerical value α_pedale representative of the deg re of depressing the accelerator pedal,

- a numerical value γ_t representative of the. instantaneous lateral acceleration value, a numerical value Acc_br representative of the estimated deceleration term under braking, and - a Driver_State numerical value representative of the characterization of the driver.

To execute the rule l to RuIeN inference rules stored in a computer rules memory, the fuzzy logic computer selects according to the input parameters the usable rule Rulei and determines by inference a pre-positioning value of the engine speed cornering he registers in a register. This value can be a single value or a range of values as is known in calculation techniques in Fuzzy Logic.

The rules are freely programmable by the skilled person according to the behavior requested from the vehicle. In one embodiment, they are determined by tests and are parameterized by fuzzification coefficients ^' recorded in a suitable memory of the computer. During the execution of the calculation, a rule is selected according to a - rule selection mechanism and the pre-positioning component N_rep_turning of engine speed in a cornering situation or in a cornering and braking situation is recorded in the output register .

Once the determined speed value ^{'N_rep_virage} engine in case of bend, the first module _20. transverse dynamic correction can address using the components of the aforementioned vectors I and D and of the engine speed value N_rep_virage in the event of a shift in the mapping memory determining a first corrected value KcorO of transmission ratio.

The output register 20b of the first module 20 of

^' transverse dynamic correction which provides a first corrected value ^• KcorO is connected to an input 21 a of a second mod ule 21 dynamic correction specific to the infinitely variable character of the transmission.

The second module 21 for dynamic correction, specific to the infinitely variable character, of the transmission also receives on its inputs 21 c and 21 d the aforementioned vectors / and D. The second module 21 applies a function g2 () so that a setpoint K setpoint of transmission ratio is produced at its output which is defined by the relation: Kconsigne = g2 (/, D, KcorO),

The output 12c is also the output of the module 1 1 for calculating a transmission ratio setpoint value and of the module 12 for determining the transmission ratio setpoint.

The g2 () function for calculating a transmission ratio setpoint is, in one embodiment, executed by the second module 21 using a map memory which is recorded during tests on a typical vehicle. , and which is addressed by a mapping address generator which produces a reading address value on the basis of the list of digital values contained in the vectors / and D and of the corrected setpoint digital value transmission ratio KcorO calculated by the first module 20 to carry out a transverse dynamic correction, list of values represented by its inputs. This results in an output of the transmission ratio setpoint Kconsigne.

In a particular embodiment, advantage is taken of the fact that the function g () executed by the second module 1 1 for calculating a ratio, transmission setpoint is substantially performed by the composition of the functions g 1 () and g2 () described in the embodiment of FIG. 2.

In Figure 3, there is shown a block diagram to represent a particular embodiment of the second mod ule 21 dynamic setpoint correction of the transmission ratio, shown in Figure 2 in the module 1 1. The second modu le 21 for dynamic correction specific to the infinitely variable nature of the transmission of the powertrain group concerned by the invention comprises: - a first modu 30 for calculating the transmission ratio in a take-off situation of the vehicle; and - A second module 31 for calculating the transmission ratio in a situation of switching to a stationary vehicle.

From the point of view of the infinitely variable transmission, all driving situations lie between its two states or situations. In the preferred embodiment represented in FIG. 3, the vectors have been particularized! and D describing, on the one hand, the interpretation of the driver's will, and on the other hand, the detection of the vehicle environment for a set of scalar values present on the input 1 1 b of the module 1 1 to which the module 31 belongs. The vector D representative of the environment of the vehicle can comprise a plurality of independent parameters among which are found respectively:

- the general idling speed produced by a specific sensor - for detecting the idling engine speed in the vector D for detecting the environment of the vehicle;

- the engine speed or instantaneous speed of rotation of the engine, ω inmes, measured by a specific sensor at the output of the engine of the power train in the vector D for detecting the environment of the vehicle;

the instantaneous speed of rotation of the vehicle wheels, ω wheels, measured by a sensor of the speed of rotation of the vehicle wheels measured in the vector D for detecting the environment of the vehicle. The vector / representative of the interpretation of the driver's will present on the input 1 1 b of the mod ule 1 1 to which the module 21 belongs can include a plurality of independent parameters among which is the degree of depression of the accelerator pedal α_pedal produced by the module 1 for detecting the intention or the will of the driver.

The dynamic correction module 21 for the infinitely variable transmission includes it: a first module 30 for calculating the take-off report setpoint; and

- A second module 31 for calculating a report setpoint in a vehicle stop situation. The first module 30 for calculating the report setpoint in the take-off situation of the vehicle performs two functions -RD () and DR () which make it possible to calculate respectively a second corrected setpoint value Kcori of the transmission ratio and an offset value ΔK transmission report setpoint.

The input parameters are respectively ωwheels, _pedal as well as the first value KcorO produced by the output 20b of the transverse dynamic correction module.

At the output 30a of the first module 30, the second corrected reference value Kcori of transmission ratio is produced which is defined by the relation: Kcori = RD (ωwheels, α_pedal, KcorO).

The RD () function for calculating a second corrected setpoint value Kcori of transmission ratio is, in one embodiment, executed by the first module 30 using a mapping memory which is recorded during of tests on a typical vehicle, and which is addressed by a mapping ad address generator which produces a reading address value on the basis of the list of numerical values comprising the rotation regime of the vehicle wheels ω wheels, the degree of depressing of the accelerator pedal α_pedal and the numerical value of setpoint corrected for transmission ratio KcorO calculated by the first mod ule 20 to perform the calculation of the second corrected setpoint for ratio of transmission, list of values presented to its inputs. This results in a second corrected setpoint value Kcori of transmission ratio. At the output 30b of the first module 30 for calculating the take-off report setpoint is available the offset value ΔK which is defined by the relation:

ΔK = DR (ω wheels, α_pedal, KcorO).

5 The DR () function for calculating an offset value ΔK of transmission ratio is, in one embodiment, executed by the first module 30 using a mapping memory which is recorded during tests on a typical vehicle, and which is addressed by an address generator of

, ιo mapping which produces a reading address value on the basis of the list of numerical values comprising the rotation speed of the wheels of the vehicle, the degree of depressing of the accelerator pedal α_pedal and the. normal value of corrected transmission ratio setpoint KcorO

15 calculated by the first module 20 to perform the calculation of the second corrected transmission ratio setpoint, list of values presented to its inputs. This results in an output value ΔK of transmission ratio.

The second corrected report setpoint Kcori

20 transmission is transmitted to a first input of the second

^' module 31 for calculating the transmission ratio setpoint in the event of a vehicle stop. Three other input terminals of secon.d module 31 are respectively connected to three input terminals 1 1 b to respectively receive a speed value

25 of idle speed of the internal combustion engine, a speed measurement value at the input of the transmission device ω inmes and a speed measurement value on the driving wheels ω wheels.

The second module 31 executes a correction function RA () so that at its output 31 a it produces a third corrected setpoint value Kcor2 of transmission ratio which is defined by the relation:

Kcor2 = RA (ω ral, ω inmes, ω wheels, Kcori). The function RA () of correction of the second corrected set value Kcori of transmission ratio is, in one embodiment, executed by the second module 31 using a mapping memory which is recorded during tests on a typical vehicle, and which is addressed by a mapping address generator which produces a reading address value on the basis of the list of numerical values comprising the value of the idle speed, the measured value of the engine speed , the rotation speed of the vehicle wheels es wheels and the numerical value of the second corrected transmission ratio set value Kcori calculated by the first module 30 to calculate the second corrected transmission ratio set value, list of values presented at its inputs. This results in output a third corrected setpoint Kcor2 of transmission ratio.

The module 21 for determining the transmission ratio setpoint then comprises an adder 32, a first input of which receives the third corrected transmission ratio setpoint Kcor2 and a second input which receives the offset value ΔK from the input 30b of the first module 30 and produces a gross reference value Kbrute of transmission ratio which is determined by the relation: Kbrute = Kcor2 + ΔK

The gross setpoint value Kbrute of the output 32a of the adder 32 is transmitted to an input of a low-pass filter 33, the output of which generates the setpoint value K set on a storage register 15 which is used to control the infinitely variable transmission independently of the torque control carried out using the module 13. The cut-off characteristic of the low-pass filter 33 is determined during configuration as a function of the response of the device of the invention so as to minimize the noise on the signal representative of. the gross setpoint Kbrute. The part of the process of the invention which makes it possible to carry out this part of the control of the powertrain can be described as follows.

The step of determining a raw value Kbrute of transmission ratio setpoint consists of:

- calculating a second corrected value Kcori of transmission ratio setpoint taking essentially into account a first value KcorO of transmission ratio setpoint, of the intention of the driver represented by the degree of depressing of the pedal α_pedal, and the environment of the vehicle represented by the instantaneous speed of rotation of the wheels of the vehicle, by applying these three values to a function RD () of correction at the start of the transmission ratio, the said function being predetermined ^' , recorded and executed in a suitable processor, then to make a correction in the situation where the vehicle is stopped by applying a correction function when the vehicle is stopped RA (), as a function of said second corrected value Kcori, and of the environment of the vehicle, said RA () function being predetermined, recorded and executed in a suitable processor; then and / or at the same time - to calculate a shift ratio value ΔK of transmission ratio setpoint taking essentially into account a first transmission ratio setpoint value KcorO, of the driver's intention represented by the deg re d depressing of the pedal α_pedal, and of the environment of the vehicle represented by the instantaneous speed of rotation of the wheels of the vehicle, by applying these three values to a function DR () of correction in an intermediate state of the vehicle between a situation of stop and a full speed situation for the transmission ratio, said DRQ function being predetermined, registered and. executed in a suitable processor; then adding the third corrected transmission ratio setpoint value with the transmission ratio setpoint offset value; then - to filter by means of a low-pass filter the addition value.

In Figure 4, there is shown a preferred embodiment of the first module 30 for calculating the transmission ratio setpoint in take-off situation of the vehicle of the previous figure.

The module 30 comprises a first circuit 41 for executing a switching function which makes it possible to decompose the value ωwheels presented at its input 41 a into two values U 1 and U2 called switching values respectively at its outputs 41 b and 41 c.

In one embodiment, the switching function U () produces two output values, respectively U 1 and U2, chosen so that, for each value ω wheels presented at input 41 a, the sum of the values taken U 1 and U2 at outputs 41 b and 41 c is constant.

In a particular mode, we choose a constant equal to 1 according to the relation: ^' U 1 + U2 = 1

In another embodiment, the switching function U () also responds to the characteristic defined in the following table:

in which the sign - denotes an arbitrary choice of negative values, in particular satisfying the aforementioned conditions, the sign + denotes an arbitrary choice of positive values, in particular checking the aforementioned conditions, and the values 0 and 1, these specific scalar values.

In another embodiment, the switching function U () also responds to the constraint expressed by the relation:

U2 / U 1 = ωC / ωwheels where ωC is a constant value predetermined by setting which depends in particular on the type of the infinitely variable transmission

17- The switching values U 1 and U2 are respectively transmitted to the first inputs 44b and 43a respectively of a multiplier 44 and a multiplier 43.

The multipiieur 44 receives on a second input ^'44a the first corrected value KcorO transmission ratio setpoint. The output 30a of the multiplier 44, which serves as the first output to the mod ule 30, produces the first corrected value Kcori of setpoint of the transmission ratio, value q ui is determined by the relation:

Kcori = KcorO XU 1. The multiplier 43 comprises a second input 43b connected to the output 42b of an amplifier 42 whose gain G is predetermined by construction and whose first input 42a receives the parameter α_pedal by an ^' input 1 1 a

The output 30b connected to the output of the multiplier 43 produces the transmission ratio setpoint offset value according to the relationship: ΔK = G x α_pedal x U2

In this way, the module 30 for calculating the transmission ratio setpoint in a situation where the vehicle is disconnected generates a setpoint value Kcori between a zero value and a corrected value KcorO. Furthermore, the module 30 also generates an offset value ΔK q ui which makes it possible to manage the case where the control device is no longer in a situation. take-off of the vehicle.

The part of the process of the invention which makes it possible to carry out this part of the control of the powertrain can be described as follows.

The step of determining a second corrected setpoint value Kcori is carried out by executing:

a switching function U () which makes it possible to decompose the value ωwheels of the instantaneous speed of rotation of the wheels of the vehicle into two predetermined values U 1 and U2; then

- a multiplication of one of the switching values, ie U 1, which is worth zero value 0 when the wheels are stationary or ωwheels = 0, by the first corrected setpoint value KcorO. The determination of an offset ΔK of the transmission ratio setpoint is carried out by executing:

- an amplification by a predetermined gain G of. the value representing the intention of the driver represented by the parameter α_péda! e of degree of depressing of the accelerator pedal; then

- a multiplication of one of the switching values, or U2, which is ^the maximum value is 1 when the wheels are in the regim of maximum rotation, the amplified G x α_pédale parameter value of a degree of depression accelerator pedal.

In FIG. 5, there is shown a preferred embodiment of the second module 31 for calculating the setpoint of the transmission ratio when the vehicle of the module 21 is stopped, shown in FIG. 3. The second module 31 has three main inputs which are respectively ωinmes, ωral, ω wheels and an input reserved for receiving the first corrected value of transmission ratio setpoint Kcori. • The second module 31 includes a subtractor circuit 50 to execute the difference between a speed measurement value at the input of the transmission device ω inmes presented at its "+" input 50a and a value of idle speed ωral presented to its input “-” 50b so that its output is connected to an input 51 a of a circuit 51 for maximum calculation. The circuit 51 for determining the maximum receives on a first input 51 a difference signal ^" coinmes - ω ral and on a second input 51 b a constant value which preferably is 0.-

The output 51 c of circuit 51 determines the larger of the two values 0 and ωinmes - ωral. and supplies it to a switching circuit 52 similar to that which performs the switching function described with the aid of the preceding figure.

The switching function recorded in circuit 52 has two switching values at its outputs, respectively the value U 1 at output 52b and the value U2 at output 52a.

The digital values U 1 and U2 determined by the switching function recorded in the circuit 52 are dependent on the difference between the idling speed and the actual engine speed at the input of the transmission device. Thus U 1 tends towards the value "-1" and U2 towards the value "2" when the two control values move away from each other. Instead U 1 tends to ^"0" and U2 goes to "1" when the value of reg ime engine approaches the value of idle. To determine the switching function recorded in circuit 52, the value U 1 is derived from a function associated with the transmission ratio Kcori as estimated by modu le 53 and which corresponds to a remote engine speed idle speed. The value U2 is derived from a function associated with the transmission ratio Kral making it possible to ensure, in the case of an infinitely variable transmission, the idling speed on the heat engine, particularly when the heat engine remains in gear.

The circuit 31 of the embodiment of FIG. 5 then comprises a multiplier 53, a first input 53a of which receives the first corrected value Kcori of transmission ratio setpoint and including a second. input 53b receives the first value of the switching product U1 so that the output 53c produces the value Kcori X U 1 in the form of a signal transmitted to the input “- +” of an adder 54.

The circuit 31 of the embodiment of FIG. 5 then comprises a module 55 of which a first input 55a is connected to the aforementioned input 50b which receives the representative signal and of which a second input 55b is connected to an input T1 of the parameter ωwheels. The output 55c of circuit 55 produces a Kral value determined by the ratio:

Kral = ωroues / ωral which expresses the distance between the current speed at the vehicle wheels relative to the idle speed.

It is noted that, even for a speed measurement value at the input of the constant constantinmes transmission device, the Kral ratio can be modified if the transmission ratio has changed by the action of module 1 3 on register 14.

The circuit 31 of the embodiment of fig u re 5 then comprises a multiplier 56, a first input of which receives the second switching value U2 from the output terminal 52c and a second input of which receives the parameter Kral produced on the terminal 55c of so that the output 56a produces a signal representative of the product Kral x U2. The output 56a is connected to a second input marked “+” of the adder 54 p recited. The circuit 31 of the embodiment of FIG. 5 then comprises a test circuit T for executing a test defined by the condition: ωwheels <S 1, S1 being a predetermined rotation speed which depends on the constitution and the setting of the infinitely variable transmission 17. The test circuit T includes a memory of at least one test threshold value S1 and includes a test input T1 which receives at all times the measured value of speed or speed of rotation at the wheel ω wheels. The test circuit T also includes a first output T2 as well as a second output T3 complementary to the output T-2 so that the output T2 is 1 if the test T is not verified and 0 if the test T is verified . The output T2 is connected to an input 57a of a multiplier 57, another input 57b of which is connected to the output of the aforementioned adder 54. The circuit 31 of the embodiment of FIG. 5 then comprises a controller 58 of the neutral in engagement which makes it possible to detect the situation of the vehicle in which the infinitely variable transmission 16 is in a state of neutral is in engagement. The controller circuit 58 of the neutral engagement comprises a first 58a input that receives the instantaneous value ω wheel rotational wheel speed and a second input 58b q ui is _^ connected to the main output 31 to the second module 31, so as to forming a feedback path in the circuit of the second modu on 31 for calculating the transmission when the vehicle is stopped.

The controller circuit 58 of the neutral in engagement comprises means for recording and executing a predetermined CNEP () function so that, at the output 58c of the controller 58, the instantaneous value of one is presented. transmission ratio parameter in neutral situation in Knep socket, which is defined by the relation:

Knep = CN EP (ω wheels, Kcor2). The CNEP function being determined by the operation described above of the circuit 31 of FIG. 5.

The parameter Knep from the output 58c of the controller 58 is transmitted to a first input 59a of a multiplier 59, a second input 59b of which is connected to the output T3 of the aforementioned test circuit T.

The controller circuit 31 of the neutral in engagement, in the embodiment of FIG. 5, comprises an adder S of which a first input is connected to the output 57c of the multiplier 57 and of which a second input is connected to the output 59c of the multiplier 59 so that the adder S produces at its output a signal representative of a third corrected value Kcor2 of transmission ratio setpoint, value determined by the relation: Kcor2 = (T1 <S 1) x (Kcori x U 1 + Kral x U2) x (T1> S 1) x Knep; in which the expression (T1 <S 1) is equal to “1” if it is verified and “0” otherwise, or exclusively the expression (T1> S1) is equal to “1” if it is verified and “0” otherwise.

In this way, as a function of the result of the test T, the second module for calculating the transmission ratio when the vehicle is stopped determines a transmission ratio setpoint either when the vehicle is idling or else when the vehicle is in neutral gear.

The output of the adder S is therefore supplied both as output 31a of the module 31 and at the input 58b of the controller 58 of the neutral in engagement.

The part of the process of the invention which makes it possible to carry out this part of the control of the powertrain can be described as follows. The step of determining a third corrected value

Kcor2 of consig does not consist:

- to execute a driving test to determine whether the vehicle is in running state, in particular by detecting whether the speed of rotation of the wheels is less than a predetermined speed S 1;

- ^' in the event that the rolling test is positive, determining a setpoint characteristic of a neutral situation in engagement and specifying it as the third corrected transmission ratio setpoint;

- in the event that the driving test is negative, to be determined if the vehicle is in idle speed, in particular by detecting if the engine speed is below a predetermined idle speed, so that:

- in the case where the idling test is negative, to be determined by a predetermined switching function a first component of transmission setpoint characteristic of the idling speed and a second component of transmission setpoint characteristic of a driving speed, the second value being all the more important as the driving state moves away from the idling speed;

- in the case where the idling test is positive, essentially determining a transmission setpoint characteristic of the idling speed, the other component value being zero;

- executing a composition of the two component values of transmission ratio setpoint, as an addition of the two component values so as to produce a composition result value in order to specify it as the third corrected value of transmission ratio setpoint.

Specifying a value calculated according to the present method as the third corrected value of transmission ratio setpoint means that said value can be used by the method of the invention, in particular because this value has been saved in a suitable memory. and that it can be presented at the input or at the input of a calculation process as the input device of a controller or other processing circuit.

In FIG. 6, a preferred embodiment of the neutral controller circuit 58 has been shown in engagement with the circuit of FIG. 5.

In FIG. 6, the neutral controller 58 in engagement comprises a first amplifier 60 programmed by a predetermined gain G3 during the adjustments of the control method as a function of the infinitely variable transmission 17. A first input 60a of the controller 58 in neutral in engagement receives from the vector D representative of the environment of the vehicle the input parameter ω wheels. ^' - ^'

The output of the first gain amplifier G3 60 is expressed by the relation: S (60) = G3 x ωholes and it is transmitted to a first input of an adder 61 of which a second input is connected to the output of a second amplifier 63 of predetermined G4 gain when setting the control method of the invention for a predetermined infinitely variable transmission. The output of the adder 61 therefore produces a value S (61) determined by the relation: S (61) = S (60) + S (63).

The neutral controller 58 in engagement then comprises an integrator 64 which is. set with a predetermined integration constant and presents at its output an integration value defined by the relation:

S (64) = l nteg (S (61), T) in which lnteg () designates the integration operation and T the predetermined integration period, S (61) designating the value transmitted at the input of the integrator r 64.

The output 64a of the integrator 64 is connected to a first input of a circuit 65 for determining the maximum of the second input is connected to a constant value, preferably chosen to be zero. The output 65a of the circuit 65 for determining the maximum is worth the integration value S (64) if this is positive or 0 otherwise, and this value is specified as the output Knep value of the neutral controller 58 in engagement. To ensure an adaptation of the neutral coefficient in Knep socket, in the embodiment of the invention shown in FIG. 6, a feedback loop has been made in which the value S (65) taken at the output 65a of the maximum detection circuit is transmitted to a negative input, referenced -, of a subtractor 62 whose other positive input, referenced +, is connected to the output of circuit 31 (Figure 3) so that output 62a of the adder 62 produces a value S (62) which is valid at all times: S (62) = Kcor2 - Knep. An input of the second gain amplifier 63 G4 is connected to the output 62a of the subtractor 62 so that the output of the adder 61 therefore has a value S (61) which is equal to:

S (61) = G3 x ωroues + G4 x (Kcor2 - Knep) and this value is then integrated and maximized by circuits 64 and 65 to be produced at the output of controller 65 as value of neutral coefficient in Knep socket, value prod followed by the circuit for implementing the CnepQ function described above in this preferred embodiment. The part of the process of the invention which makes it possible to carry out this part of the control of the powertrain can be described as follows.

The step of determining a Knep value of a transmission ratio setpoint in neutral position in engagement can be described as follows.

a value of the vector D representative of the environment of the vehicle is determined, in particular by measuring the speed of rotation of the wheels; ^• then the vector D representative of the environment of the vehicle is formatted by a predetermined formatting operation, in particular that of combining the vector D representative of the environment of the vehicle with the third value Kcor2 of transmission ratio setpoint available at the time formatting according to a predetermined combination law; then

- to integrate the value formatted with a predetermined time constant T and to specify as value Knep of a transmission ratio setpoint in ^" neutral in engagement ^" situation, only if this value is positive and maintaining it at a zero value otherwise .

The adaptation of the determination of the setpoint Knep value consists in: - taking the instantaneous value calculated from the positive value resulting from the integration; then

- subtract this calculated instantaneous value from the third transmission ratio setpoint Kcor2 available at the time of formatting. Preferably, the formatting operation consists in applying a linear combination with predetermined coefficients:

- on the measurement of the instantaneous speed of the vehicle wheels affected by a first coefficient G3; and - the difference between said calculated instantaneous value and the third transmission ratio setpoint value Kcor2 available at the time of formatting assigned a second coefficient G4.

The format operation is described by the relation: S (61) = ω x G3 + G4 wheels x (Kcor2 - Knep ^inst) in relation laq ual Knep ^mst designates the current adaptation value of the desired component transmission ratio for the neutral situation in gear. In FIG. 7, a particular embodiment is shown of a circuit 41 executing a switching function according to the diagram described in FIG. 4.

The circuit 41 for calculating the switching function in the exemplary embodiment of FIG. 7 comprises two operators

70 and 71. The first operator 70 is programmed to produce a switching value U 1 determined by:

. _M _ ωroues ωC - ωroues and the second operator _. 71 is programmed to produce a switching value U2 determined by:

1 1 _ rones

CÙC - ωrous relations in which the value ωroués indicates the instantaneous speed of rotation of the wheels of the vehicle available in the vector D representative of the environment of the vehicle, and ωC indicates a predetermined value of speed ^• of instantaneous rotation of the wheels of the vehicle, characteristic , of the type of the infinitely variable transmission 17 which equips its powertrain.

The outputs U 1 and U2 are present at the output of the generator circuit of the switching function 41.

It is noted that the functions U1 and U2 of the operators 70 and 71 verify the equations-- and the conditions cited during the description of the switching function of the module 41.

Claims

REVEN DICATIONS 1 - Device for controlling a powertrain of a vehicle of the type comprising:

- a motor (16) controllable (14) by an engine coupling setpoint, said motor (16) being connected to the drive wheels (18) by an infinitely variable transmission (17), controllable (1 5) by a setpoint ratio setpoint transmission;

- a module (1) for interpreting the driver's wishes;

- a module (3) for determining the environment of the vehicle, characterized in that it also comprises:

- a module (12) for determining a transmission ratio setpoint, said module (12) being connected to a control input (15) of said infinitely variable transmission (17);

- a module (13) for determining a motor torque setpoint connected to a control input (14) of said motor

(1 6); and in that the modulated its (12) for determining a transmission ratio setpoint and (13) for determining an engine torque setpoint are independently connected to the outputs of the modules (1) to interpret the will of the driver and (3) for detect the vehicle environment.

2 - Control device according to claim 1, characterized in that the module (12) for determining a transmission ratio setpoint for an ^' infinitely variable transmission comprises:

• a first module (10) for choosing the infinitely variable transmission input regime;

• a second module (1 1) for calculating a transmission report setpoint; the first module (10) and the second module (1 1) being respectively connected by suitable inputs to inputs (12a, 12b) of the module (12) to supply the first and second modules (1 0) and (1 1) two vectors respectively the vector (/) of interpretation of the driver's will by the

. input terminal (12a) and the vehicle environment detection vector (D) by the input terminal 12b.

3 - Control device according to claim 2, characterized in that the first module (10) applies a function f () for processing the input vectors (/; D) so that it produces at its output (10c) an infinitely variable transmission input value (d'entréeinbas) (17) according to the relation: ωinbas = f (/, D). 4 - Control device according to claim 3, characterized in that the second module (1 1) applies a function g () of calculation on the value produced at the output (10c) of the first module ^' (10) of choice of the infinitely variable transmission input regime, as well as on vectors (/) of interpretation of the driver's will and (D) of detection of the environment of the vehicle so that the second module (1 1) presents at its output a value of the torque setpoint Kconsigne determined by the relation: Kconsigne = g (/, D, ω inbas). 5 - A control device according to claim 3, characterized in that the first module (10) and the second module (1 1) are produced using a microcontroller which receives the input arg uments /, D functions f () and g (), a program memory for performing the calculation of each function f () or g () and if necessary, storing intermediate calculation results, and finally a memory for assigning the calculated result.

6 - Control device according to one of claims 2 to 5, characterized in that the second module (1 1) comprises a first module (20) for performing a transverse dynamic correction g 1 () which q receives, at input ( 20a), the speed parameter ω inbas produced by the module (1 0), and the vectors for interpreting the driver's will and for detecting the environment of the vehicle (/ and D), said dynamic correction transverse being carried out so that the first module (20) produces at its output (20b) a first value KcorO of transmission ratio setpoint defined by the relation: KcorO = g 1 (/, D, ωinbas). 7 - control device according to one of claims

2 to 6, characterized in that the second module (1 1) comprises a second dynamic correction module (21) specific to the infinitely variable nature of the transmission, an input (21a) of which is connected to an output (20b) of the module (20) which supplies a first value KcorO of transmission ratio setpoint is connected to a second module 21 of dynamic correction specific to the infinitely variable nature of the transmission and whose inputs (21 c, 21 d) receive vectors (/ and D), so that the second module (21) applies a function g2 () to produce a set value K transmission ratio setpoint q ui is defined by the relation: Kconsigne = g2 (/, D, KcorO ).

8 - A control device according to claim 7, characterized in that q ue the function g () executed by the module (1 1) is substantially achieved by the composition of the functions g 1 () and g2 ().

9 - Control device according to claim 7 or 8, characterized in that the second mod ule (21) of dynamic correction specific to the infinitely variable nature of the transmission of the powertrain comprises:

- a first module (30) for calculating the transmission ratio in a take-off situation of the vehicle; and

- A second module (31) for calculating the transmission ratio in a situation of switching to a stationary vehicle. 10 - Control device according to claim 9, characterized in that the first module (30) for calculating the report setpoint in the take-off situation of the vehicle performs two functions RD () and DR () which allow respectively to calculate a second corrected setpoint Kcori of the transmission ratio and a shift value ΔK of the transmission ratio setpoint and in that the input parameters are respectively the instantaneous speed of rotation of the vehicle wheels (ω wheels), the degree of depressing of the pedal d accelerator (α_pedal) as well as the first value (KcorO) produced by the output (20b) of the module (20) of transverse dynamic correction so that at a first output (30a) of the first module (30) is produced a second set value (Kcori) corrected for transmission ratio which is defined by the relation:

Kcori = RD (ωwheels, _pedal, KcorO). and in that at a second output (30b) of the first module (30) for calculating the setpoint of the takeoff report of the vehicle is available an offset value (ΔK) which is defined by the relation:

ΔK = DR (ωroues, α_péda! E, KcorO).

1 1 - Control device according to claim 1.0, characterized in that ιa second corrected setpoint value Kcori of transmission ratio is transmitted to a first input of the second module (31) for calculating the transmission ratio setpoint in situation d '' a vehicle stop and in that three other inputs of the second module (31) are respectively connected to three input terminals (1 1 b) respectively receiving a value of engine speed in idle speed (ω ral) , an instantaneous value of rotation of the infinitely variable transmission input shaft (ωinmes) and an instantaneous value of rotation of the vehicle wheels (ω wheels), and in that the second module (31) performs a function of correction RA () so that at its output (31 a) it produces a third corrected reference value (Kcor2) of transmission ratio which is defined by the relation:

Kcor2 = RA (ωral, ω inmes, ω wheels, Kcori). 12 - Control device according to claim 1 1, characterized in that the module (21) for determining the transmission ratio setpoint then comprises an adder (32), a first input of which receives the third corrected setpoint value Kcor2 from transmission ratio and a second input of which receives the offset value ΔK originating from the input (30b) of the first module (30) and produces a gross recorded value Kbrute of transmission ratio which is determined by the relation: Kbrute = Kcor2 + ΔK and in that the raw setpoint value Kbrute of the output (32a) of the adder (32) is transmitted to an input of a low-pass filter (33) whose output generates the setpoint value K set on a storage register (15) which is used to control the infinitely variable transmission independently of the torque control carried out using the module (1 3).

13 - Control device according to claim 9 or 10, characterized in that the first module (30) for calculating the transmission ratio setpoint in take-off situation comprises a first circuit (41) for executing a switching function which allows to decompose the value ω wheels presented at its input (41 a) into two values (U 1, U2) of switching values respectively at its outputs (41 b, 41 c).

14 - Control device according to claim 12, characterized in that the switching function U () produces two output values, respectively U 1 and U2, chosen so that, for each value ω wheels presented at the input (41 a), the sum of the values taken U 1 and U2 at the outputs (41 b and 41 c) is constant. 15 - Control device according to claim 14, characterized in that a constant equal to 1 is chosen according to the relation:

U 1 + U2 = 1 16 - Control device according to resell ication 14 or 15, characterized in that the switching function U () also responds to the characteristic defined in the following table:

in which the sign - designates an arbitrary choice of negative values, in particular verifying the aforementioned conditions, the sign + designates an arbitrary choice of positive values, in particular verifying the aforementioned conditions, and the values 0 and 1, these specific scalar values.

17 - Control device according to claim 14, 15 or 16, characterized in that the switching function U () also responds to the constraint expressed by the relation:

U2 / U 1 = ωC / ωwheels where ωC is a ^" constant value predetermined by adjustment which depends in particular on the type of variable variable infinite transmission (17).

1 8 - control device according to one from claims 13 to 16, characterized in that the first module (30) for calculating the transmission ratio setpoint in takeoff situation comprises two multipliers (43, 44), so that the switching values (U 1, U2) are respectively transmitted to the first inputs (44a, 43a) of the multiplier (44) and of the multiplier (43) respectively, in that the multiplier (44) receives on a second input ( 44b) the first corrected value KcorO of transmission ratio setpoint, in that the output (30a) of the multiplier (44), connected to the. output of the module (30), produces the first corrected value (Kcori) of setpoint of the transmission ratio, value which is determined by the relation:

Kcori = KcorO XU 1; in that the multiplier m (43) has a second input (43b) connected to the output (42b) of an amplifier (42) whose gain G is predetermined by construction and whose first input 42a receives the parameter for measuring the degree of depressing of the accelerator pedal (α_pedal) by an input 1 1 a, in that the output (30b) of the connected module (30) at the output of the multiplier (43) produces the transmission ratio setpoint offset value according to the relationship: ΔK = G x _pedal x U2 so that the module (30) for calculating the transmission ratio setpoint in a situation of take-off of the vehicle generates a setpoint value Kcori between a zero value and a corrected value KcorO, the offset ΔK making it possible to manage the case where the control device is no longer in a situation of take-off of the vehicle. .

19 - Device. _. control according to claim 9, characterized in that the second module (31) for calculating the setpoint of the transmission ratio in the vehicle stationary situation of the module (21) receives by three main inputs respectively an instantaneous value of rotation of the input shaft of the infinitely variable transmission (ωinmes), a. value of engine speed in idle speed (ωral), and an instantaneous value of rotation of the vehicle wheels (ω wheels) and in that it receives by a reserved input the first corrected value of transmission ratio setpoint ( Kcori), in. that the second module (31) includes a subtractor circuit (50) for executing the difference between a speed measurement value at the input of the transmission device ωinmes presented at its “+” input (50a) and a value r ω ral presented at its input "-" (50b) so that its output is connected to an input (51 a) of a circuit (51) for calculating the maximum of the difference ω inmes - ω ral which receives on a second input (51 b) a constant va leu r which preferably has the value 0, and whose output (51 c) of the circuit (51) determines the greater of the two values 0 and ωinmes - ωral and supplies it to a switching circuit (52); in that the second module (31) comprises a multiplier

(53) of which a first input (53a) receives the first corrected value Kcori of transmission ratio setpoint and a second input (53b) receives a first switching value

(U 1) so that the output (53c) produces a value of the product Kcori X U 1 in the form of a signal transmitted to the input "+" of an adder (54); in that the second module (31) comprises a module (55), a first input (55a) of which is connected to the input (50a) of the second module and of which a second input (55b) is connected to the input of the parameter (ωwheels), the output (55c) of the circuit (55) producing a Kral value determined by. The report ; Kral = ω wheels / ω ral in that the second module (31) comprises a multiplier (56), a first input of which receives the second switching value (U2) of the output terminal (52a) and of which a second input receives the Kral parameter produced on the terminal (55c) so that the output (56a) produces a signal representative of the Kral product x (U2), the output (56a) being connected to a second input marked "+" of the adder ( 54), in that the second module (31) comprises a test circuit (T) for executing a test defined by the condition: ω wheels <S 1.

S1 being a predetermined rotation speed which depends on the constitution and the setting of the infinitely variable transmission (17), the test circuit (T) comprising a memory of at least one test threshold value S 1 and an input of test (T1) which receives at each instant the measured value of speed or rotation speed at the wheel ω wheels, the test circuit (T) comprising a first output (T2) as well as a second output (T3) supplemented of the output (T2), the output (T2) is connected to a input (57a) of a multiplier (57) of which another input (57b) is connected to the output of the adder (54); in that the second module (31) then comprises a controller (58) of the neutral in engagement which makes it possible to detect the situation of the vehicle in which the neutral is in engagement.

20 - Control device according to claim 1 9, characterized in that the controller circuit (58) of the neutral in engagement has a first input (58a) which receives the instantaneous value of rotation of the vehicle wheels ωwheels and a second input (58b ) which is connected to the general output (31 a) of the second module (31), means for recording and executing a CNEPQ function so that at the output (58c) of the controller (58) the instantaneous value of a parameter of transmission ratio in neutral situation in Knep socket, which is defined by the relation:

Knep = CNEP (ω wheels, Kcor2).

21 - control device according to claim 20, characterized in that the parameter Knep from the output (58c) of the controller (58) is transmitted to a first input (59a) of the multiplier (59) including a second input (59b ) is connected to the complementary output (T3) of the test circuit (T), in that the output (59c) of the multiplier (59) is connected to a first input of an adder (S) of which a second input is connected at the output (57c) of the multiplier (57) so that the add iterator (S) presents at its output a signal representative of a third corrected value Kcor2 of transmission ratio setpoint determined by the relation:

Kcor2 = (TKS 1) x (Kcori x U 1 + Kral x U2) x (T1> S 1) x Knep; in which the expression (T1 <S 1) is worth "1" if it is verified and "0" otherwise, or exclusively the expression (T1> S1) is worth "1" if it is verified and "0" otherwise, so that, according to the result of the test (T), the second module for calculating the transmission ratio when the vehicle is stopped determines a report ratio set value transmission or when the vehicle is idling or when the vehicle is in neutral gear.

22 - control device according to claim 20, characterized in that the neutral controller (58) in engagement comprises a first amplifier (60) programmed by a gain G3 predetermined during adjustments as a function of the infinitely variable transmission (17), in that a first input (60a) of the neutral controller (58) in neutral receives from the vector D representative of the environment of the vehicle the input parameter (ωwheels) whose output of the first gain amplifier (60) ( G3) is expressed by the relation:

S (60) = G3 xtoroues and it is transmitted to a first input of an adder (61) of which a second input is connected to the output of a second amplifier (63) with G4 gain predetermined during the setting for an infinitely transmitted transmission predetermined variable, whose ^' output from add iterator 61 produces a value S (61) determined by the relation:

S (61) = S (60) + S (63). in that the prized neutral controller (58) includes an integrator (64) which is adjusted with a predetermined integration constant and presents at its output an integration value defined by the relation:

S (64) = lnfeg (S (61), T) of which an output (64a) of the integrator (64) is connected to a first input of a circuit (65) for determining the maximum of which the second input is connected at a constant value, preferably chosen to be zero whose one output (65a) of the circuit (65) for determining the maximum is worth the integration value S (64) if the latter is positive or 0 otherwise, and this value is specified as value Knep output of the neutral controller (58) in gear.

23 - Control device according to claim 22, characterized in that q ue, to ensure an adaptation of the coefficient from neutral to Knep socket, a feedback loop has been produced in which the value S (65) taken at the output (65a) of the maximum detection circuit is transmitted to a negative input, of a subtractor (62) _. whose other positive input,, is connected to the output of the circuit (31) (Figure 3) so that the output (62a) of the adder (62) produces a value S (62) which is valid at all times :

S (62) = Kcor2 - Knep. in that an input of the second gain amplifier G4 is connected to the output (62a) of the subtractor (62) so that the output of the adder (61) has a value S (61) which is determined to ^' : -

S (61) = G3 x ωwheels + G4 x (Kcor2 - Knep) said value (S (61)) then being transmitted to an integration circuit (64) according to a determined time constant, the part of which is connected to the input of a circuit (65) -whose ^'output is the output value of the integrator if it is greater than a predetermined constant value as the n ulle stored in a register connected to a further input of the circuit (65) or this constant otherwise, to be produced at the output of the controller (65) as a value of neutral coefficient in Knep socket.

24 - control device according to one of claims

13 to 1 8, characterized in that the circuit (41) for calculating the switching function comprises two operators (70 and 71), the first operator (70) being programmed to produce a switching value U 1 determined by:

. . . ωwheels U 1 = ωC - (Ωwheels and the - second operator (71) being programmed to produce a 'switching value U2 determined by: ωwheels

U2 = 1 - ωC - ωwheels relationships in which, the value ωwheels denotes the instantaneous speed of rotation of the vehicle wheels available in the vector D representative of the environment of the vehicle, and ωC denotes a predetermined value of instantaneous speed of rotation of the vehicle wheels, characteristic of the type of infinitely variable transmission (17) which equips its powertrain.

25 - Method of controlling a powertrain of a vehicle of the type comprising a motor controllable by 10 a setpoint of engine torque, said engine being connected to the drive wheels by an infinitely variable transmission, controllable by ^" A setpoint ratio of transmission, characterized in that it consists in each instant of operation of the powertrain: 15 - in determining a vector of parameters of the environment of the vehicle and a vector of parameters of the interpretation of the will of the driver;

- to determine independently and / or concurrently an engine speed setpoint and a gear ratio setpoint

20 transmission, each instruction being determined with the aid of said vectors of parameters of the environment of the vehicle and the interpretation of the driver's will by applying a

. Engine control setpoint function and transmission ratio setpoint function;

^'25 so as to allow ^a' power plant operation smoothly, independent of the infinitely variable transmission type, the stopping and starting of the vehicle.

26 - control method according to claim 25,

30 characterized in that the two torque and transmission ratio setpoints are determined according to concurrent processes, at the same time on independent processors, or in an interlaced manner with the same processor. 27 - Control method according to claim 26, characterized in that to determine a raw value Kbrute of transmission ratio setpoint, it consists:

- calculating a second corrected value Kcori transmission ratio set in consideration essentially of a first KcorO value of transmission ratio setpoint, intent ^'of the conductor represented by the degree of depression of the pedal _pédale, and the environment of the vehicle represented by the instantaneous speed of rotation of the wheels of the vehicle, by applying these three values to a function RD () of correction at the start of the transmission ratio, said function being predetermined, recorded and executed in a suitable processor, then to make a correction in the situation where the vehicle is stopped by applying a correction function when the vehicle is stopped RA (), as a function of said second corrected value Kcori, and of the environment of the vehicle, said RA () function being predetermined, recorded and executed in a suitable processor; then and / or at the same time

- calculating an offset value ΔK of transmission ratio setpoint taking essentially into account a first value KcorO of transmission ratio setpoint, the intention of the driver represented by the deg d of depressing of the pedal α_pedal, and the environment of the vehicle represented by the instantaneous speed of rotation of the wheels of the vehicle, by applying these three values to a function DR () of correction in an intermediate state of the vehicle between a standstill situation and a full situation speed for the transmission ratio, said DR () function being predetermined, recorded and executed in a suitable processor; then adding the third corrected transmission ratio setpoint value with the transmission ratio setpoint offset value; then

- to filter by means of a low-pass filter the addition value. 28 - Control method according to claim 27, characterized in that to determine a second corrected setpoint value Kcori, it consists in executing:

a switching function U () which makes it possible to decompose the value ω wheels of the instantaneous speed of rotation of the wheels of the vehicle into two predetermined values U 1 and U2; then

- a multiplication of one of the switching values, ie U 1, which is equal to the zero value 0 when the wheels are stationary or ωwheels = 0, by the first corrected setpoint value KcorO. 29 - Control method according to claim 28, characterized in that to determine an offset ΔK of the transmission ratio setpoint, it consists in executing:

an amplification by a predetermined gain G of the value representative of the intention of the driver represented by the parameter α_pedal of degree of depressing of the accelerator pedal; then

- a multiplication of one of the switching values, namely U2, which is equal to the maximum value 1 when the wheels are at maximum rotation speed, by the amplified value G x α_pedal of the parameter for depressing the pedal accelerator.

30 - Control method according to claim 29, characterized in that q ue to determine a third corrected setpoint value Kcor2, it consists: - to execute a running test to determine if the vehicle is in running state, in particular by detecting whether the speed of rotation of the wheels is greater than a predetermined speed S 1; - in the event that the rolling test is positive, to determine a setpoint characteristic of a neutral situation in engagement and to specify it as the third corrected value of transmission ratio setpoint;

- in the case where the running test is negative, determining whether the vehicle is in idling speed, in particular by detecting whether the engine speed is below a predetermined idling regim, ^{^'de'} so q ue:

- in the case where the idle test is negative, to be determined by a predetermined switching function a first transmission component value characteristic of the idle speed and a second transmission component value characteristic of the speed lage, the second value being all the more important as the driving state moves away from the idling speed; .

- in the case where the idling test is positive, essentially determining a setpoint value of _, characteristic transmission of the idling speed, the other component value being n ulle; - to execute a compos ition of the two component values of transmission ratio setpoint, as an addition of the two component values so as to produce a composition result value in order to specify it as the third corrected value of transmission ratio setpoint. 31 - Control method according to claim 30, characterized in that to determine a Knep value of a transmission ratio setpoint in neutral situation in engagement is executed: - by determining the vector D representative of the environment of the vehicle, in particular by measuring the speed of rotation of the wheels; then

- by formatting the vector D representative of the environment of the vehicle, by a predetermined formatting operation, particularly consisting in combining the vector D representative of the environment of the vehicle with the third value Kcor2 of transmission ratio setpoint available at the time of formatting; then - by integrating the value formatted with a predetermined time constant T and specifying it as the Knep value of a transmission report setpoint in neutral situation, in engagement, only if this value is positive and maintaining it at a otherwise null. 32 - Control method according to resell 31, characterized in that the adaptation of the determination of the set Knep value consists in:

- take the instantaneous value calculated from the positive value resulting from the integration; then - to subtract this calculated instantaneous value from the third transmission ratio setpoint Kcor2 available at the time of the fo _. rmatage.

33 - control method according to claim 32, characterized in that the formatting operation consists in applying a linear combination. with predetermined coefficients:

- on the measurement of the instantaneous speed of the vehicle wheels affected by a first coefficient G3; and

- On the difference between said calculated instantaneous value and the third transmission ratio setpoint value Kcor2 available at the time of formatting affected by a second coefficient G4; the formatting operation being defined by the relation: S (61) = G3 x ω wheels + G4 x (Kcor2 - Knep ^{i πst} ) relationship ^'wherein Knep ^mst denotes the value being adapted to the component of the transmission ratio set for the neutral position of engagement.