FR2855101A1 - Vehicle drive train controlling method, involves separating intermediate control signals in drive control torque signals and thermal engine control torque signal by adjusting drive load level, wheel torque, and thermal engine speed - Google Patents

Abstract

The method involves determining a load level (Ucapa) of a drive of an infinitely variable transmission in a hauling mode, wheel torque (To), and thermal engine speed (wice), by a determination unit (36). Intermediate control signals (V1-V3) in the drive control torque signals and a thermal engine control torque signal are obtained by adjusting the determined values. The intermediate control signals are divided into drive control and thermal engine control signal by a decoupling unit (35). An independent claim is also included for a device for controlling a drive train with an infinitely variable transmission for implementing a method of controlling the drive train.

Description

i

  "Method and device for controlling a powertrain with an infinitely variable transmission in draw mode" The present invention relates to a method and a device 5 for controlling a powertrain with an infinitely variable transmission in draw mode. The system concerned is a vehicle equipped with an internal combustion engine and an infinitely variable transmission operating in "draft" mode.

  In "draft" mode, the heat engine provides propelling torque to the vehicle wheels. The particularity of the system concerned is that it does not include a coupler, that is to say that mechanical power is always exchanged between the wheels of the vehicle and the powertrain. In particular, such a system does not include a clutch or converter, between the heat engine and the infinitely variable transmission.

  The infinitely variable transmission used in the system of the invention consists of: * two electric machines electrically connected by an energy buffer element and operating as an electric variator; a kinematic chain with four input / output shafts respectively connected to the heat engine, the wheels and the electric machines.

  Actuators make it possible to control the operating state essentially of the heat engine and of the two electric machines. These actuators must receive control signals produced by a supervisor, for example implemented on an on-board computer.

  In previous patent applications, the applicant has already defined architectures making it possible to take advantage of this kind of infinitely variable transmission. The applicant cites in particular the patent application FR-A-2,818,346 filed on December 18, 2000 which relates to an infinitely variable transmission with power bypass comprising two electric machines mounted in series on a first track and access to the motor shaft thermal on a second channel and with two reduction stages and the patent application FR-A-2,823,156 filed on April 6, 2001 which relates to an infinitely variable power derivation transmission with two operating modes, the transmission having two channels for deriving mechanical power, one of the channels of which has two reduction stages mounted in parallel and activated according to the operating mode chosen.

  In a French patent application FR-A-2,824,377, filed on May 4, 2001 in the name of the present applicant, a method of synthesizing a control law for the aforementioned actuators has been proposed which ensures its robustness to disturbances of the controls, measurement noises, modeling errors, saturation of actuators and switching of regulators which are integrated in the on-board electrical network. The envisaged control law also aims to ensure compliance with the limitations of the organs to ensure the control of the control instructions on these limitations. 20 This command makes it possible to comply with performance specifications, to present robustness properties to disturbances and measurement noises, while ensuring correct regulation of the energy buffer element.

  In the method for synthesizing a control law for the 25 organs of an infinitely variable transmission defined in this patent application, the synthesis law is implemented in a central electronic unit of supervisor type with three control levels. The synthesis law is delivered to the control computer which controls the heat engine and the electrical machines of the transmission.

  The process defined in this previous patent application FR-A-2,824,377 consists in: - modeling the dynamic behavior of the powertrain of the vehicle according to a linear dynamic model invariant over time, receiving input signals from the actuators of the group powertrain which provides a torque setpoint on each of the electric machines and of the heat engine, and vehicle status signals 5 comprising the torque and the speed of the heat engine, as well as the speed of the wheels of the vehicle, for delivering the torque of transmission to the wheels, as well as the torque and speed of the heat engine; - correct the linear dynamic model of the powertrain by introducing the uncertainties in the dynamics of the engine and electrical machines and the parametric uncertainties on the resistance to travel and on the mass of the vehicle; - calculate by the minimization method of an infinite H norm, of a robust performance regulator which stabilizes all the systems described by said model with uncertainties.

  In a French patent application No. 01.16915 filed on December 27, 2001 in the name of the present applicant, a three-layer architecture for a powertrain supervisor was defined, which makes it possible to make the supervisor little dependent on the type of thermal engine, characteristics of the infinitely variable transmission and characteristics, both of the road behavior of the vehicle and the driving style of the driver.

  In a first IVC layer, the supervisor has a first means for interpreting the driver's wishes while taking into account the driving environment of the vehicle.

  In a second OPF layer, the supervisor comprises a second means which cooperates with the first means to determine, independently of the type of thermal engine, the optimum operating point of the powertrain to apply a setpoint determined according to the interpretation of the driver's will.

  In a third COS layer, the supervisor comprises a third means which cooperates with the second means for determining the control signals of the actuators of a powertrain with an infinitely variable transmission of the type described above.

  It is an object of the present invention to make it possible, at the level of the third COS layer of the supervisor, to calculate the control of the three actuators available - heat engine and electric machines making it possible to achieve the operating point required by the upper layers of supervision, particularly in the draw mode, and using a Torque Tracking method.

  The control method of the invention relates to a powertrain whose thermal engine of the group is directly coupled to the wheels of the vehicle through an infinitely variable transmission including two electric machines electrically connected by an electric energy buffer element. The control method is such that the vehicle can be driven by the powertrain, braked by it, decoupled from it, or kept stationary.

  The method of the invention is characterized in that it consists, in a specific drive mode of the vehicle by the powertrain, of controlling the torque at the wheel and the speed of the heat engine by using only a level measurement. charging of the electrical energy buffer element and of the speed and torque measurements provided by the electric machines.

  The solution proposed by the invention makes it possible to control the GMP powertrain to simultaneously achieve all of the required objectives, namely to produce a determined value of torque at the wheels, of engine speed and of energy level. the energy buffer element.

  The proposed solution has the particularity of applying to a GMP powertrain without couplers between the heat engine and the transmission, such as a clutch or a converter.

  The invention also relates to a device for controlling a powertrain with an infinitely variable transmission in draw mode of the kind comprising: - a first controller for interpreting the driver's wishes, - a second controller for determining an optimal operating point of the engine thermal, and - a third controller for producing control signals for the actuators of the powertrain.

  Other characteristics and advantages of the present invention will be better understood with the aid of the description and the appended figures in which: - Figure 1 is a schematic view showing the main elements of a vehicle in which the method is implemented and the device of the invention; - Figures 2 and 3 are flow charts for explaining the various aspects of the method of the invention; Figure 4 is a schematic view showing the main parts of the device of the invention; FIG. 5 is a schematic view showing a particular embodiment of a third block in FIG. 4.

  In the following text, the following notations have the following meaning: * The term â or ^ a denotes an estimate of the variable a; * The term a * or the term a * designates an optimized setpoint of the variable a; The term a # or the term a # denotes a calculated setpoint of the variable a; * The term a or the term a 'designates the temporal variation of the variable a; The variable Ts designates the sampling time of the command; In Figure 1, there is shown a block diagram of a vehicle equipped with a powertrain (GMP). The GMP powertrain 5 consists of a torque-controlled thermal engine (ICE) 4 and an infinitely variable transmission (IVT) 5. This transmission consists of a kinematic chain 13 comprising four mechanical power exchange channels and an electric variator 21. The electric variator 10 21 is itself made up of two electric machines Mei, 11 and Me2, 12 controlled in torque and electrically linked by an energy buffer element 10. Although the element of energy storage 10 of the embodiment described, ie a capacitor, the control method is also applicable in the case of an infinitely variable transmission with energy storage of different technology such as a battery or a super capacitor.

  Each electric machine Mel, 11 or Me2, 12 can work in the four characteristic quadrants (oe, Te), or in other words: - as a motor, mode in which the electric machine draws electric energy from the buffer element of energy 10 and delivers mechanical power through a shaft 17 or 18 on the four-way kinematic chain, or - as a generator, a mode in which the electric machine takes mechanical power from the kinematic chain 13 and recycles electrical energy to the energy buffer element 10.

  The kinematic chain 13 comprises four mechanical power exchange shafts 30 which are: a shaft 15 for exchanging mechanical power with the crankshaft of the heat engine 4 which can work as an engine or as an engine brake; - a shaft 16 for exchanging mechanical power with the wheels 6 of the vehicle; - shafts 17 and 18 for exchanging mechanical power with the rotors of the two electric machines s 11 and 12.

  The heat engine 4 is torque controlled by a controller 3 and the electrical machines 11 and 12 are respectively controlled by a controller 19 and by a controller 20. The kinematic chain 13 of the IVT transmission 5 10 includes, as is known from couplers such as clutches and brakes which are controlled by a transmission mode controller which is neither described nor represented in the present application but which is defined in the aforementioned previous patent applications of the applicant.

  The operating mode of the GMP powertrain concerned by the present invention is an operating mode called Torque Tracking (TT), during which the heat engine provides positive torque to the transmission (draft). During this mode, the mechanical objectives pursued by the method of the invention are the regulation of the engine speed and the torque supplied to the wheels. The energy objective pursued by the process of the invention is the regulation of the voltage of the capacitor.

  In the following description, we will use the quantities designated by the notations: 25.This speed of the first electric machine 11, * oe2: speed of the second electric machine 12, Tde1: disturbance torque applied to the torque supplied by the first electric machine Me 1 1, Tde2: disturbance torque applied to the torque supplied by the second electric machine Me2 12, Te1 # torque setpoint for the first electric machine Mel 11, Te2 # torque setpoint for the first electric machine Me2 12, ice speed of the ice thermal engine 4, Tice: torque of the ice thermal engine applied to the crankshaft Tdice: disturbance torque applied to the torque of the thermal engine 4, Tjce #: torque setpoint for the thermal engine 4, To: torque applied to the wheels by the GMP powertrain, * Tdwh: disturbance torque applied to the torque at the wheels, 10. W: energy level of the capacitor, (p (Tel, Te2, Wel,) e2): this function scalar is defined by the power exchanged by the capacitor 10 with the electric machines, as well as all the losses of the electric variator comprising the two electric machines Mei and Me2 and their storage capacitor, PdW: disturbance power applied to the dynamics of the capacitor.

  The variables describing the state of the system are divided into two one-dimensional lists or vectors X1 and X2, here represented in their transposed vector form: X1 = [coel, toe1, Tice, Tdwh, Tdice, Tdel, Tde2] (8) X2 = [W, PdW] (9) The state vector X1 includes * values of the speed of the electric drive 25 * values of the engine torque; has disturbance values of the torque signals.

  The state vector X2 comprises: at least one value describing the energy state of the energy buffer element in the variable speed drive; e at least one disturbance value of this energy state.

  The control device 2 of the invention receives an input a vector V of three groups of state parameters of the electric variator 21 which are: - the state of electric power (Tei, toe1) of the electric machine Me 1 1 by a line 22 from the controller 19; - the state of electrical power (Te2, cte2) of the electrical machine Me2 12 by a line 23 coming from the controller 20; - the electric charge state (Ucapa) of the energy buffer element 10.

  In response, and by applying the method of the invention, the control device 2 returns control signals for the actuators of the powertrain 1, namely: - a control signal emitted by a line 7 intended for the controller 3 of the engine 4 which achieves a regulation objective on the engine speed; - a control signal emitted by lines 8 and 9 intended for the controllers of the electric variator 21 which makes it possible to reach 15 simultaneously with the objective of regulation on the engine speed and a goal of torque regulation at the wheel To .

  In a preferred embodiment, the control signal emitted by a line 7 is a torque control signal Tice # of the heat engine.

  In a preferred embodiment, the control signal emitted by lines 8 and 9 is a pair of torque control signals Tel # and Te2 # respectively transmitted to suitable inputs of the controllers 19 and 20 of the electrical machines Mei 1 1 and Me2 12.

  In Figure 2, there is shown the sequence of main operations performed by the control method of the invention.

  After a command start operation during a step S1 during which the control device of the invention is configured then initialized, and subsequently only initialized except during maintenance operations, the control passes to a step S2 during which the commands Tice #, Tel #, Te2 # of the three actuators are calculated on the basis of a measurement vector Z which will be described below. To this end, the method of the invention has been represented by a predetermined function f (), it being understood that its expression is determined analytically or algorithmically on the basis of the information in the description as a function of the objectives of the command which are to calculate the control of the three 5 actuators available - thermal engine and electric machines - making it possible to achieve the operating point required by the upper layers of supervision, particularly in the pulling mode and using a torque tracking method (Torque Tracking).

  Once the values have been calculated during step S2, these values are passed to the three powertrain controllers, namely Tice for the engine controller, Tel for the controller of the first electric machine and Te2 for the controller of the second machine 15 electric. Then, the control passes to a step S3 of testing the end of the specific training mode. Indeed, the process of the invention can be stopped and then another selected training mode. If the test S3 is negative, the control goes to a step S4 for measuring the instantaneous values of the variables 20 then passed as arguments to the function f () during its evaluation during the abovementioned step S2. The various measurements are collated in a vector Z, which in a preferred embodiment of the invention comprises: - the level of energy stored in the energy buffer element 25 of the infinitely variable transmission variator, preferably measured by the voltage across its terminals; - for each of the two electric machines of the variator the torque Tel or Te2 and the speed of rotation (0e1 or% e2.

  If the test S3 is negative, the control goes to an end step during which the control device of the invention is deactivated.

  In a particular embodiment, the method of the invention comprises the following steps: - determination of the load level Ucapa of the variator 21, of the torque at the wheel To and of the speed of the flective heat engine, - obtaining of intermediate values by regulation the load level, the wheel torque and the engine speed determined as a function of setpoint values, and - decoupling of the intermediate values in control signals Tei #, Te2 # of drive 21 and in control signal Tice # of the motor thermal 4.

  In a particular embodiment, the method of the invention consists in decoupling the intermediate signals by exploiting determined values of: - regimes (0el,, Oe2) of the electric machines (Mei, 11; Me2, 12), - engine speed (cOice) (4), - torque applied (Tice) to the crankshaft of the engine (4), electromagnetic torques (Tel, Te2) of electric machines (Mei 11, Me2 12), - load level (Ucapa) of the electric variator, - correction factors for electrical power exchanges in the variator, correction factors for the torques applied on the crankshaft and on the wheels.

  In FIG. 3, an embodiment of a step S2 has been shown for evaluating a setpoint of the powertrain by a function f () described with the aid of FIG. 2.

  During a step S8, the method of the invention consists in carrying out an estimation of the thermal engine speed Acoice, of the energy level AW, of the torque at the wheel ATo and of a vector AXf 30 gathering the simulation magnitudes of the electromechanical chain representing the electric variator of the infinitely variable transmission of the given powertrain.

  The vector AXf will be described and defined using FIG. 4.

  Once the determination step S8 has been carried out, a regulation step S9 is performed on the basis of the data estimated in step S8 and on the data of two reference values which correspond to a request for an operating point of the powertrain. . In a particular embodiment, adapted in particular to the three-layer architecture defined in the process described in the previous French patent application No. 01.16915 of the present applicant, these setpoints are respectively the engine speed setpoint cOice * and the 10 wheel torque setpoint To *. The regulation step S9 produces a vector V * of intermediate values by applying a regulation algorithm which will be defined below.

  Once the regulation step S9 has been carried out, a decoupling step S10 is performed on the basis of the intermediate variables produced in step S9. The decoupling step S10 produces the setpoint torque intended for the powertrain controllers, namely - an engine torque setpoint Tice #; a torque setpoint for each of the electric machines 20 respectively Tel # and Te2 #; so that the regulated operating point of the powertrain (eOme, To) is reached. The decoupling algorithm will be defined below.

  In Figure 4, there is shown a particular embodiment of the main units of the control device 2 of the invention. In a particular embodiment, these units constitute the essential part of the third level controller COS which is described in the previous patent application No. 01.16915 of the present applicant and which receives an optimal point 30 of operation of the powertrain in the form of '' a set of setpoint signals (cỉce, *, To *). The optimal operating point is determined by an optimal operating point controller, whatever the type of powertrain according to the interpretation of the driver's wishes, taking into account parameters such as the degree of depressing of the pedal d accelerator, and / or of a driving regulator and of the detection of the parameters of the environment of the vehicle, such as its driving speed or the slope in which it is located, interpretation and detection entrusted to a controller of the command of the vehicle.

  The control structure implemented in the control device 2 according to the invention is based on the structure of 1o multivariable control with three instructions presented in French patent application No. 01. 16915 filed in the name of the present applicant. The object of the present invention is to construct the intermediate control layer (COS) in the "pull" mode during which the heat engine is controlled by the two upper layers without being decoupled from the infinitely variable transmission.

  The supervisor or controller OPF, which performs the optimization of the operating point of the heat engine, supplies the input of the third layer controller COS with a speed set point 20 of the heat engine. The IVC supervisor or controller also provides a setpoint for the wheel torque. There is also a capacitor voltage setpoint which most often serves as an energy buffer element for the electric drive.

  From these three setpoints and the available measurements 25 describing the environment of the vehicle, such as the speed of the vehicle or the slope in which it is engaged, the controller COS generates the torque setpoints for the three main actuators of the GMP, namely the two electric machines (Me1 and Me2) and the heat engine in the "draw" mode concerned by the invention.

  In a first layer, a module performs an interpretation of the driver's wishes as a function of the detection of the environment of the vehicle, in particular the speed of movement of the vehicle. In particular, it is detected that the degree of depressing of the accelerator pedal or that of the brake pedal is zero to determine that it is in "draw" mode.

  FIG. 4 shows a particular embodiment of the main units of the control device 2 of the invention which are: * a unit 36 for determining the variables describing the state of the system, * a control unit 34 and 10 * a decoupling unit 35.

  The configuration of these units is based on a vehicle behavior model, in the form of a representation model in the sense of the Automatic, of a design that is simple enough to be directly usable, and complex enough to translate all of the phenomena. relevant physical. Its choice was made on the basis of numerous theoretical determinations on the one hand and practical tests enabling the above-mentioned objectives to be achieved. The above design model is a non-linear multivariate model. The determination unit 36 has five entry doors, one entry door a receiving the torque setpoint signal from the first electric machine Tel #; an entry door b receiving the torque setpoint signal from the second electric machine Te2 #; an entry door c receiving the torque setpoint signal from the heat engine Tice #; an entry door d receiving a vector characterizing the electrical state of the electrical machines 0coel, fe2, Tel, Te2; an entry door e receiving a signal for measuring the voltage across the terminals of the Ucapa super capacity.

  The determination unit 36 has four output gates which are: an output gate S1 which produces an estimation signal in the form of a vector AXf transmitted to the input gate e of the decoupling unit 35; an output gate S2 which produces a pair of values 5 for estimating the engine speed Acce, and its time derivative Aoe'ce, pair of values which is transmitted respectively to the input gate f of the regulating unit 34 and the entry door d of the decoupling unit 35; an output door S3 which produces a pair of values 10 for estimating the energy level of the energy buffer element AW and its temporal variation AW 'which is transmitted to the input door e of the unit regulation; an output door S4 which produces a signal for estimating the motor torque ATO which is transmitted to door d of the regulation unit 34.

  The determination unit 36 comprises an AXf construction circuit whose role is to construct the estimation signal AXf which is represented by the following vector which comprises nine vector components Xf = [W Bel r2 Tice Te, Te2 Tdh Tdice PdW] (16) The estimation of these signals is calculated by a linear observer constructed from the chosen design model, by implementing known techniques of Automatic Linear Systems. Reference may be made to the works 25 concerning the state reconstructions of such systems and in particular to the work of Philippe de Larminat, "Automatic control of linear systems", 2 editions, Hermès, Science Publication 2000.

  The gains from this observer constitute parameters for adjusting the determination unit.

  The regulation unit 34 has six entry doors, an entry door a receiving a signal for setting the voltage across the energy buffer 10; an entry door b receiving engine speed (oice *; an entry door c receiving engine torque To *; an entry door d receiving engine torque ATo; an entry door e receiving energy level AW or its variation an input gate f receiving 10 engine speed ^ Qice and of its variation a setpoint signal of a setpoint signal of an unsignal signal AW '; an estimate signal of the estimate of the estimate of the (j ) ice- The regulating unit 34 has three doors respectively: an output door SI of an output control signal which intermediate vI; an output door S2 of an intermediate control signal v2; an output door S3 of signal intermediate command v3.

  From the three setpoints: - energy level of the buffer element W *; - of the engine speed, cje *; and of torque to the wheels To *, the regulation unit 34 constructs three intermediate control signals (vI, v2, v3) corresponding respectively to each setpoint, on the basis of the information provided by the determination unit: - the signal vI is calculated by a circuit incorporating a proportional type regulator derived from the charge setpoint of the energy buffer element as the voltage across a capacitor 10; - signal v2 is calculated by a circuit incorporating a proportional type regulator derived from the thermal speed setpoint and the thermal speed estimate; - the signal v3 is calculated by a proportional type regulator from the torque setpoint at the wheels and the estimated torque at the wheels.

  The decoupling unit 35 has five entry doors, an entry door a receiving the intermediate control signal v1 from the output S1 of the regulation unit 34; an input door b receiving the intermediate control signal v2 from the output S2 of the regulation unit 34; an input door c receiving the intermediate control signal v3 coming from the output S3 of the regulation unit 34; an entry door d receiving a signal for estimating the energy level AWice or its variation A'Wice; an entry gate e receiving an estimation signal from a control vector Xf.

  The decoupling unit 35 has three output doors which are respectively: a torque reference output output S1 of the first electric machine Te, #; an output gate S2 of torque setpoint of the second electric machine Te2 #; an output door S3 of torque engine setpoint Tice #.

  From the intermediate control signals (vl, v2, v3) produced by the regulation unit 34 and from the estimates of the vector AXf on the state of the system supplied by the determination unit 36, the decoupling unit 35 constructs the thermal engine torque control signals Tice #, and of the two electromagnetic couples Tel # and Te2 # of the electrical machines of the variator 21. The step concerned of the method of the invention comprises the following sub-steps: - a step of decoupling of intermediate control signals (vl, v2, v3) based on the inversion of the design model by successive derivations of outputs such as this method is exposed in particular in the work of A. Isidori, "Non Linear Control Systems" , 2d Edition, Springer-Verlag, 1989, to produce a triplet of intermediate commands (ul, u2, u3); - a step of integrating the first two intermediate signals (ul, u2) to produce the torque control signal at the wheel in the form of the electromagnetic torque control doublet (TeI #, Te2 #); a step of saturation of the signal u3 with the maximum thermal torque depending on the thermal regime, the control signal Tjce # is deduced from the signal u3 by a discrete delay operator.

  FIG. 5 shows a particular embodiment of the decoupling unit 35.

  The three regulation signals V1, V2, V3 are transmitted to a vector assembler 140 whose output transmits in sequence three signals to a first input terminal of a circuit 141 which performs the inversion of the design model by branches 20 successive exits.

  The model inversion circuit 141 also includes a second input terminal connected to the input e (35) which receives the estimation vector AXf. As a result, the inversion works both on the regulatory components V1, V2 and V3 and on the 25 components of the estimation vector AXf.

  The three output signals which correspond to the inversion of the model are designated respectively by U1, U2 and U3 and are transmitted to a vector separator 142 whose first output terminal selects the first pair of values U1 and U2, which are supplied at the input of an integration circuit 143 - 147, to obtain the two control signals (Tei #, Te2 #) intended for the control circuits of the variator's electrical machines.

  In this particular embodiment, the integration circuit includes a gain 143 adjusted with a time constant Ts. The output signal of the gain 143 which also processed the components U1 and U2, is transmitted to an input terminal of an adder 144. The output terminal of the adder 144 is connected to a first input terminal d 'a saturation circuit 146. The estimation vector AXf is also supplied to an input terminal of a selection block of components 2 and 3, referenced 145 whose output terminal is connected directly to a second terminal d input of the saturation circuit 146. It appears from this diagram that the saturation circuit 146 works on the one hand 10 from the value of the inversion components U1 and U2, and on the other hand from the components of estimation of the rotational speeds of the two electric machines Acoee and A ^ 0e2.

  The decoupling unit 35 also comprises a block 149 for selecting component 1, the input terminal of which receives the pair of values representative of the estimate of the engine speed ACoice of the estimate of its temporal variation * 'ice.

  The output terminal of the component selection block 149 thus transmits the engine speed estimation signal A * oeie to a first input terminal of a saturation circuit 148. A second input terminal of the saturation circuit 148 is connected to the vector splitter 142 to receive the third signal of the U3 model. The saturation circuit 148 includes means for achieving the saturation control signal Tice which determines the control of the engine torque.

  To make it possible to respect the sequence of the method of the invention, a circuit 150 is connected to the output terminal of circuit 148 which adds a discrete delay for the elaboration of the command Tice # of the motor torque at the output terminal S3 ( 35) of the decoupling unit 35.

  In general, the decoupling unit 35 of the device of the invention comprises: - a vectorial assembler 140 gathering intermediate values resulting from the regulation of the load level, the torque at the wheels and the engine speed determined; - a non-linear decoupling module 141 receiving the output of the assembler 140 and all of the determined variables; a module 143 applying to the first two outputs of the module 141 a gain equal to the sampling period Ts of the system; an addition operator 144 adding to the output signal of the module 143 the first output signal of said unit; a circuit 145 applying saturation to the output of the operator 144 as a function of the maximum electromagnetic torque which depends on the speeds determined for each electric machine 15 a circuit 147 applying a delay to the output signal of the saturation circuit 146 so as to producing torque control signals Te1 #, Te2 # of the two electric machines, a circuit 148 applying to the third output of the module 141 a saturation as a function of the maximum torque of the heat engine which depends on the determined speed of the heat engine, and a circuit 150 applying a delay to the output signal of the saturation circuit 148 so as to produce a control signal Tice # of the torque of the thermal engine.

  In a particular embodiment, the specific drive mode executed by the method of the invention ensures the idling regulation of the heat engine while controlling the torque (To) supplied by the powertrain.

Claims (4)

  1. A method of controlling a vehicle powertrain comprising a heat engine directly coupled to the wheels of the vehicle and an infinitely variable transmission with an electric variator including two electric machines, according to which the vehicle can be driven by the powertrain, braked by the latter, decoupled from it or kept stationary, characterized in that it consists, in a specific drive mode of the vehicle by the powertrain, of controlling the torque at the wheel (To) and the engine speed (0ie) using only a measurement of the charge level of the electrical energy buffer element (Ucapa) and speed (Tel, Te2) and torque ("e., 0e2) measurements provided by electrical machines (Me. 11, Me2 12).   2. Method according to claim 1, characterized in that the specific drive mode makes it possible to regulate the idling of the heat engine while controlling the torque (To) supplied by the powertrain.   3. Method according to claim 1 or 2, characterized in that it comprises the following steps: - determination of the load level (Ucapa) of the variator (21), of the torque at the wheel (To) and of the engine speed thermal (coice), - obtaining intermediate values by regulating the load level, the wheel torque and the engine speed determined as a function of setpoint values, and - decoupling the intermediate values into control signals (Tel #, Te2 #) of the variator (21) and as a control signal (Tice #) of the heat engine (4).   4. Control method according to claim 3, characterized in that the step of decoupling the intermediate signals uses determined values of: - regimes (COe1, (e2) of the electrical machines (Me., 11; Me2, 12), - engine speed (oice) (4), - torque applied (Tice) to the crankshaft of the heat engine (4), - electromagnetic torques (Tei, Te2) of electric machines (Me, 11, Me2 12), level of load (Ucapa) of the electric variator, - correction factors for electrical power exchanges in the variator, - correction factors for the torques applied on the crankshaft and on the wheels.   - Device for controlling a powertrain with an infinitely variable transmission in "creep speed 15" and / or "neutral in gear" mode to implement the method according to one of the preceding claims, the device being of the type comprising three controllers (20, 22, 25) characterized in that the third controller (25) comprises a regulation unit (34); - a coupling unit (35); and - a determination unit (36) and in that the coupling unit (35) comprises - a vector collector (140) gathering intermediate variables (vl, v3) resulting from the regulation (34) of the charge level and of the determined wheel torque executed by the regulating unit (34); - a module (141) for non-linear decoupling receiving the output of the assembler (140) and the set of determined variables (^ Xf) executed by the determination unit (36); - a module (143) applying to the first two outputs of the module (141) a gain equal to the sampling period (Ts) of the system; - an addition operator (144) adding to the output signal of the module (143) the first output signal of said unit; - a circuit (146) applying saturation at the operator's output (144) as a function of the maximum electromagnetic torque which depends on the speeds determined for each electric machine - a circuit (147) applying a delay to the output signal of the saturation (146) so as to produce torque control signals (Tei #, Te2 #) of the two electric machines, - a circuit (148) applying saturation as a function of the maximum torque to the third output of module 10 (141) of the heat engine which depends on the determined speed of the heat engine, and - a circuit (150) applying a delay to the output signal of the saturation circuit (148) so as to produce a control signal (Tice #) of the engine torque thermal.