EP4028296A1

EP4028296A1 - Method for controlling the combustion starting torque threshold of a hybrid power train of a vehicle along a path

Info

Publication number: EP4028296A1
Application number: EP20757629.9A
Authority: EP
Inventors: Cyril BYKOFF; Jerome DECHOZ; Djamaleddine Maamria
Original assignee: PSA Automobiles SA
Current assignee: Stellantis Auto SAS
Priority date: 2019-09-09
Filing date: 2020-07-22
Publication date: 2022-07-20
Also published as: FR3100509B1; WO2021048475A1; CN114364586A; FR3100509A1

Abstract

A control method is implemented in a vehicle comprising a first combustion drive machine and a second non-combustion drive machine and supplied with power by a power storage device. Said method comprises a step (10-60) of determining a subdivision of the vehicle's path into parts associated with different average traffic speeds and percentages within said path, subsequently determining the power required to complete the path using the second drive machine according to said associated parts and percentages and, depending on whether the power required is less than or greater than the available power, subsequently using a first or second starting torque threshold of the first drive machine, promoting movement of the vehicle by means of the second drive machine or by means of the first drive machine.

Description

DESCRIPTION

TITLE: CHECKING THE THERMAL START-UP TORQUE THRESHOLD OF A HYBRID POWERTRAIN UNIT OF A VEHICLE ON A ROUTE

The present invention claims the priority of French application 1909900 filed on 09.09.2019, the content of which (text, drawings and claims) is incorporated here by reference.

Technical field of the invention

The invention relates to vehicles comprising a hybrid powertrain, and more specifically to the control of the starting torque threshold of the thermal motive machine of the powertrain during a journey.

By "hybrid powertrain" is meant here a powertrain (or GMP) comprising a first thermal drive machine and a second non-thermal drive machine and using energy stored in an energy storage device during travel. Furthermore, the term "prime mover" is understood here to mean a machine arranged so as to provide or recover torque to move a vehicle, either alone or in addition to at least one other thermal or non-thermal motor machine. A non-thermal prime mover can, for example, be an electric machine (or motor), a hydraulic machine, a pneumatic (or compressed air) machine, or a flywheel. A heat engine machine can, for example, be a heat engine. When the non-thermal prime mover is an electric machine, the energy storage device is a rechargeable battery.

State of the art Some vehicles include a hybrid powertrain in which the first prime mover (thermal) and / or the second prime mover (non-thermal) can be put into operation in order to move them along a path.

The second driving machine being less polluting than the first driving machine, a strategy intended to use the second driving machine as much as possible is implemented in a hybrid fuel-powered vehicle. To do this, a starting torque threshold for the first prime mover is used which is predefined, and therefore constant. Currently, as long as the torque determined to move the vehicle remains below this threshold, only the second driving machine is operated, and when this determined torque becomes greater than this threshold, the first driving machine and possibly the second are operated. driving machine.

A drawback of this operating mode lies in the fact that it does not guarantee that the vehicle will reach its final destination having consumed as much as possible of the energy stored in its energy storage device (up to a threshold minimum predefined). Indeed, on certain journeys the vehicle can very quickly find itself with a quantity of stored energy equal to the minimum threshold, even though it is still far from its final destination, and on certain other journeys the vehicle can reach its destination. final by having a quantity of stored energy which is still (very) higher than the minimum threshold. In other words, the current operating mode does not allow the amount of stored energy to converge towards the minimum threshold (corresponding to a need for recharging), and therefore does not allow fuel consumption to be optimized). In addition, the current operating mode does not make it possible to maintain a movement phase with the second driving machine at the end of a journey if the situation allows it (for example for urban traffic).

It has certainly been proposed, in particular in patent document FR-A1 3005296, to take into account the determined route of a vehicle at GMP hybrid to predictively optimize the distribution of fuel and electricity consumption according to management laws and the state of charge of its battery. However, this solution requires complete knowledge of the route (or route), namely the succession of route sections with the average speed on each of these sections. But in practice, it is unthinkable to transmit so much information from one computer to another, in a vehicle.

One of the aims of the invention is therefore to improve the situation.

Presentation of the invention

For this purpose, it proposes in particular a control method intended to be implemented in a vehicle comprising a powertrain comprising a first driving machine, thermal, and a second driving machine, non-thermal and supplied with energy by a storage device. 'energy.

This control method is characterized by the fact that it includes a step in which, in the presence of a determined route for the vehicle:

- We determine a subdivision of this path into at least two parts in which the average traffic speeds are different, and the percentages that these parts represent in the distance path, then

- determining an energy required to perform this trip using only the second driving machine as a function of these parts of the trip and these determined associated percentages, then

- If this determined necessary energy is less than an energy available in the energy storage device, a first starting torque threshold of the first driving machine is used, which promotes movement of the vehicle by means of the second driving machine, while if this determined necessary energy is greater than this available energy, a second starting torque threshold of the first prime mover is used which is strictly lower than the first threshold and promoting movement of the vehicle by means of the first prime mover.

Thanks to the invention, as long as the total torque requested is greater than the first (very high) threshold, the second prime mover is requested to be used, and as long as the total torque requested is greater than the second (very low) threshold, it is requested that the first prime mover is started.

The control method according to the invention can include other characteristics which can be taken separately or in combination, and in particular: - in its step, a subdivision of the path can be determined into first, second, third, fourth and fifth parts;

- the first part can be associated with a first average speed of circulation less than 30 km / h, the second part can be associated with a second average speed of circulation higher than the first average speed of circulation and lower than 50 km / h, the third part can be associated with a third average speed of circulation higher than the second average speed of circulation and lower than 70 km / h, the fourth part can be associated with a fourth average speed of circulation higher than the third average speed of circulation and less than 90 km / h, and the fifth part can be associated with a fifth average speed of circulation higher than the fourth average speed of circulation;

- in a first embodiment, in its step, the energy required can be determined by means of a law which is a function of an average speed expected on the path;

- in a second embodiment, in its step, the energy required can be determined by determining each quantity of average partial energy required to travel each part of the path as a function of an adjustable parameter multiplied by the distance associated with this part, then by adding all these determined quantities; - in a third embodiment, in its step it is possible to determine a first necessary energy by means of a law which is a function of an average speed expected on the path, and a second necessary energy by determining each quantity of partial energy necessary average to travel each part of the path according to an adjustable parameter multiplied by the distance associated with this part, then by adding all these determined quantities, then we can take as the necessary energy that which is the greatest of these first and second necessary energies determined;

- in its step, the energy available can be determined by multiplying the maximum energy that can be stored by the energy storage device at the time considered (possibly depending on its wear) by a percentage of energy available in the latter.

The invention also proposes a computer program product comprising a set of instructions which, when it is executed by processing means, is suitable for implementing a control method of the type presented above for controlling start-ups of a first thermal drive machine of a vehicle powertrain also comprising a second non-thermal drive machine supplied with energy by an energy storage device, in the presence of a determined path for this vehicle.

The invention also proposes a control device intended to equip a vehicle comprising a powertrain comprising a first driving machine, thermal, and a second driving machine, non-thermal and supplied with energy by an energy storage device.

This control device is characterized in that it comprises at least one processor and at least one memory arranged to perform the operations consisting, in the presence of a determined route for the vehicle: - determining a subdivision of this journey into at least two parts in which the average traffic speeds are different, and the percentages that these parts represent in the distance journey, then

- determining an energy required to complete the trip using only the second prime mover as a function of these parts of the trip and of these determined associated percentages, then

- if this determined necessary energy is less than an energy available in the energy storage device, to impose the use of a first starting torque threshold of the first prime mover promoting movement of the vehicle by means of the second machine engine, and if this determined necessary energy is greater than this available energy, in imposing the use of a second starting torque threshold of the first motive machine strictly lower than this first threshold and promoting movement of the vehicle by means of the first driving machine.

The invention also proposes a vehicle, optionally of the automobile type, and comprising, on the one hand, a powertrain comprising a first driving machine, thermal, and a second driving machine, non-thermal and supplied with energy by a storage device. energy, and, on the other hand, a control device of the type presented above.

For example, the second prime mover can be an electric machine and the energy storage device can be a rechargeable battery. Brief description of the figures

Other characteristics and advantages of the invention will become apparent on examination of the detailed description below, and of the appended drawings, in which: [Fig. 1] illustrates schematically and functionally a vehicle comprising a hybrid transmission chain and a supervision computer equipped with a control device according to the invention,

[Fig. 2] schematically illustrates an example of an algorithm implementing a control method according to the invention,

[Fig. 3] illustrates schematically within a diagram four examples of the temporal evolution of the state of charge for the first (c1), second (c2) and third (c3) different journeys made by a vehicle of the prior art and for this same third trip (c4) made by a vehicle equipped with a control device according to the invention, and

[Fig. 4] illustrates schematically and functionally an exemplary embodiment of a control device according to the invention.

Detailed description of the invention

The object of the invention is in particular to propose a control method, and an associated DC control device, intended to allow the control of the starting torque threshold of the first thermal motive machine MM1 of a hybrid powertrain (or GMP). of a vehicle V, during a determined journey.

It is recalled that the term “hybrid powertrain” is understood here to mean a powertrain (or GMP) comprising a first thermal drive machine and a second non-thermal drive machine, using energy stored in a storage device. energy during a movement and possibly capable of recovering energy during a movement to recharge its energy storage device with energy.

In what follows, it is considered, by way of nonlimiting example, that the vehicle V is of the automobile type. It is for example a car, as illustrated without limitation in Figure 1. But the invention is not limited to this type of vehicle. It concerns in fact any type of vehicle comprising a transmission chain with hybrid GMP. Therefore, the invention relates not only to land vehicles, but also to ships and airplanes.

FIG. 1 schematically represents a vehicle V comprising a hybrid GMP transmission chain, a CS supervision computer capable of supervising (or managing) the operation of the transmission chain, and a DC control device according to the invention. .

The hybrid GMP comprises here, in particular, a first thermal MM1 driving machine, an AM driving shaft, an EM clutch, a second non-thermal MM2 driving machine, a BV gearbox, a DS energy storage device, and a AT drive shaft.

The first driving machine MM1 is a heat engine comprising a crankshaft (not shown), fixedly secured to the motor shaft AM in order to drive the latter (AM) in rotation. Furthermore, this first driving machine MM1 is intended to provide torque, here for at least a first train T1 (here of driving wheels), via the clutch EM, the second driving machine MM2 and the gearbox BV.

For example, this first train T1 is located at the front of vehicle V, and coupled to the AT driveshaft, preferably, and as illustrated, via a differential (here before) D1. But in a variant this first T1 train could be located at the rear of vehicle V.

Here, the clutch EM is responsible, by way of purely illustrative example, to couple / decouple the motor shaft AM (coupled to the first driving machine MM1) to / from the second driving machine MM2, on the order of the supervision computer CS, in order to communicate a torque from the torque produced by the first drive machine MM1. This EM clutch can be of any type.

The second driving machine MM2 is coupled to the energy storage device DS in order to be supplied with energy and possibly to supply the latter (DS) with energy. It is here also coupled, by way of purely illustrative example, to the output of the clutch EM, to receive the torque that it transmits, and to the primary shaft AP of the gearbox BV, to provide it with torque. It will be noted that this second driving machine MM2 could be installed in other places of the vehicle V, and in particular it could be coupled, via suitable coupling means, to the second train T2 (here of driving wheels) of the vehicle V, in order to supply it with torque produced from the energy stored in the energy storage device DS. In the example illustrated without limitation in FIG. 1, the second train T2 is located at the rear of the vehicle V, but in a variant it could be located at the front of the vehicle V.

In what follows, it is considered, by way of nonlimiting example, that the second drive machine MM2 is an electric machine (or motor). But the invention is not limited to this type of second non-thermal drive machine. Indeed, the second driving machine can also be a hydraulic machine, a pneumatic (or compressed air) machine, or a flywheel, for example.

Due to the latter choice (electric), the DS energy storage device is a rechargeable battery, for example of the low voltage type (typically 220 V for illustration). But this DS rechargeable battery could be medium voltage or high voltage type.

The primary shaft AP of the BV gearbox is intended to receive the torque transmitted, here, by the second drive machine MM2.

The gearbox BV also comprises at least one secondary shaft (not shown) intended to receive torque via the primary shaft AP in order to communicate it to the transmission shaft AT to which it is coupled and which is here indirectly coupled to the wheels. (here before) of the vehicle V via the differential D1.

It will be noted, as illustrated without limitation in FIG. 1, that the transmission chain can also include a starter or an alternator-starter AD coupled to the first driving machine MM1 and responsible for starting the latter (MM1) in order to allow it to start. . This launch is done using electrical energy which is, for example and as illustrated without limitation, stored in a BS service battery. The latter (BS) can be arranged in the form of a very low voltage type battery (for example 12 V, 24 V or 48V), and can also, for example, supply an on-board network to which electrical equipment is connected. of the vehicle V. It will be noted that the service battery BS can, as illustrated without limitation, be coupled to the energy storage device DS, when the latter (DS) is a rechargeable battery, and to the second driving machine MM2 via a DC / DC type CV converter, so that it can be recharged when the second driving machine MM2 is an electric machine.

The operations of the first MM1 and second MM2 driving machines, and possibly of the EM clutch and the BV gearbox, can be controlled by the CS supervision computer.

As mentioned above, the invention provides a control method intended to allow the control of the starting torque threshold of the first driving machine MM1 (thermal) of the hybrid GMP of the vehicle V, during a determined journey. This control method can be implemented at least partially by the DC control device of the vehicle V which comprises for this purpose at least one processor PR, for example a digital signal processor (or DSP (“Digital Signal Processor”)), and at least one memory MD, and therefore which can be produced in the form of a combination of circuits or electrical or electronic components (or “hardware”) and of software modules (or “software”). The MD memory is live in order to store instructions for the implementation by the processor PR of at least part of the control process. The processor PR can comprise integrated circuits (or printed), or else several integrated circuits (or printed) connected by wired or non-wired connections. An integrated (or printed) circuit is understood to mean any type of device capable of performing at least one electrical or electronic operation.

In the example illustrated without limitation in FIG. 1, the control device DC forms part of the supervision computer CS. But it is not compulsory. This DC control device could indeed be a equipment comprising its own computer and coupled to the CS supervision computer, directly or indirectly.

As illustrated without limitation in FIG. 2, the control method, according to the invention, comprises a step 10-60 which begins in a sub-step 10 when a route has been (or has just been) determined for the vehicle. V.

For example, this route may have been determined by a DAN navigation aid device which is on board the vehicle V, as a function of an arrival point (or destination) and possible departure point (or origin ) and intermediate point (s). Such a DAN navigation aid device can be fitted to the vehicle V permanently (as illustrated without limitation in FIG. 1) or temporarily (for example due to the fact that it is a mobile device or that 'it is part of an intelligent communication equipment carried by a passenger of the vehicle V).

In a sub-step 20 of step 10-60, one (the control device DC) determines a subdivision of the determined path into at least two parts pj in which the average traffic speeds are different, and the percentages that these represent. pj parts in the distance journey. It will be understood that we are talking here about percentages of kilometers. Furthermore, it will be understood that a part pj of a path is a set of at least one portion of this path with which a particular average traffic speed is associated. Consequently, these parts pj do not necessarily correspond to successive path portions (generally portions of different parts pj follow each other, and therefore the path portions of a part pj are generally distributed over the entire path).

Then, in a sub-step 30 of step 10-60, we (the control device DC) determine an energy e1 necessary to perform the determined path using only the second driving machine MM2 as a function of the parts pj of this path and the associated percentages which have just been determined. Then, in a sub-step 40 of step 10-60, one (the control device DC) compares the required energy e1 determined with an energy e2 which is available in the energy storage device DS at the instant considered.

If this determined necessary energy e1 is less than an energy e2 available in the energy storage device DS (ie e1 <e2), a first threshold s1 of torque is used in a sub-step 50 of step 10-60 starting of the first driving machine MM1 which promotes the movement of the vehicle V by means of the second driving machine MM2. In other words, a very high first threshold s1 is used to promote the use of the second prime mover MM2. Thus, as long as the total torque requested by the driver and possibly by at least one computer of the vehicle V is greater than this very high value (s1), the first driving machine MM1 is requested to be started.

On the other hand, if the determined necessary energy e1 is greater than this available energy e2 (ie e1> e2), a second threshold s2 of starting torque of the first is used in a sub-step 60 of step 10-60. driving machine MM1 which is strictly lower than the first threshold s1 and promotes movement of the vehicle V by means of the first driving machine MM1. In other words, a very low second threshold s2 is used to promote the use of the first prime mover MM1. Thus, as long as the total torque requested by the driver and possibly by at least one computer of the vehicle V is greater than this very low value (s2), the first driving machine MM1 is requested to be started.

It will be understood that it is the DC control device which determines the first s1 or second s2 threshold and which imposes the use of this first s1 or second s2 threshold by the supervision computer CS.

The advantage provided by the implementation of the invention appears clearly on the diagram of the temporal evolution of the state of charge ec of an energy storage device of a vehicle of the prior art (curves c1 to c3) and of the vehicle V (equipped with a DC control device) of figure 3. In this diagram, the first c1, second c2 and third c3 curves correspond respectively to the first, second and third paths different performed by a vehicle of the prior art, and the fourth curve c4 corresponds to this same third journey performed by the vehicle V. The reference eci designates the initial state of charge of the energy storage device, and the reference ecf designates the final state of charge of this same energy storage device towards which one tends at the end of a determined path.

During the first (c1) and second (c2) trips the final state of charge ecf is not reached, which means that there is energy left in the energy storage device at the end of the trip. We could therefore have used this energy and consumed less fuel, which means that the consumption is not optimal.

During the third trip (c3) of the prior art the final state of charge ecf is reached very early, and therefore the last half of the trip was carried out with the only first drive machine MM1. Vehicle V has therefore probably driven through urban areas without using its second MM2 prime mover, which means that fuel consumption is not optimal.

During the third trip (c4) of the invention, the final state of charge ecf is only reached at the end of the trip, and therefore the vehicle V was probably able to cross at the end an urban area with its only second machine motor MM2. This means that the consumption is optimal.

The greater the number of parts pj resulting from the subdivision of a path, the greater the precision of the energy required e1 will be.

For example, in substep 20 of step 10-60 one (the DC control device) can determine a subdivision of the path into first p1, second p2, third p3, fourth p4 and fifth p5 parts (j = 1 to 5).

In this case, the first part p1 can, for example, be associated with a first average speed of circulation less than 30 km / h, the second part p2 can, for example, be associated with a second average speed of circulation greater than the first average speed of circulation and less than 50 km / h, the third part p3 can, for example, be associated with a third average speed of circulation higher than the second average speed of circulation and lower than 70 km / h, the fourth part p4 can, for example, be associated with a fourth average speed of circulation higher than the third average speed of circulation and less than 90 km / h, and the fifth part p5 can, for example, be associated with a fifth average speed of circulation greater than the fourth average speed of circulation.

All these different average speeds, associated respectively with the different parts pj of the path, are provided here by the supervision computer CS.

Note that in sub-step 20 of step 10-60 we (the DC control device) can determine the required energy e1 in at least three different ways.

In a first way, we (the control device DC) can determine the necessary energy e1 by means of a law which is a function of an average speed expected on the path. This average speed is for example determined as a function of the number of kilometers and the estimated duration of the journey, provided (here) by the DAN navigation aid device. For example, it is possible to use a law of the type e1 = A + B ^* mean speed + C ^* (mean speed) ² , where A, B and C are predefined constants determined in the laboratory, for example by simulation.

In a second way, we (the control device DC) can start by determining each quantity of partial energy required on average to travel each part pj of the path as a function of an adjustable parameter, multiplied by the distance associated with this part pj, Then, we (the control device DC) can determine the necessary energy e1 by adding all these determined quantities. This adjustable parameter is, for example, the consumption per kilometer at the average speed of each part (or subdivision) pj of the journey. In other words, we multiply each quantity of average partial energy necessary to travel each part pj of the path by the distance remaining to be traveled on this part pj, and we add the whole. In a third way, we (the DC control device) can start by determining, on the one hand, a first necessary energy e11 by means of a law which is a function of an average speed predicted on the path (as for the first way ), and, on the other hand, a second necessary energy e12 by determining each quantity of average partial energy necessary to travel each part pj of the path as a function of an adjustable parameter multiplied by the distance associated with this part pj, then by adding all these determined quantities (as for the second way). Then, we (the DC control device) can take as the necessary energy e1 that which is the greatest of the first e11 and second e12 determined necessary energies.

It will also be noted that in sub-step 20 of step 10-60, the control device DC can also determine the available energy e2 by multiplying a maximum energy storable by the energy storage device DS to l instant considered by a percentage of energy available in the latter (DS). This percentage of available energy is information which is determined periodically by a computer associated with the DS energy storage device, and therefore which is easily accessible. For example, the maximum energy that can be stored by the energy storage device DS at the time in question may be a function of its wear and tear (DS).

It will also be noted that in sub-steps 50 and 60 of step 10-60 the control device DC can use first s1 and second s2 thresholds which are predefined (determined in the laboratory or in the factory) or that it calculates in real time, for example as a function of torques usually observed during homologation runs.

It will be noted, as illustrated without limitation in FIG. 4, that the control device DC can also comprise, in addition to its random access memory MD and its processor PR, a mass memory MM, in particular for storing the data defining the path. and its different parts pj and different percentages and different associated average speeds of circulation, possible maximum energy storable by the energy storage device DS and percentage of energy available in the latter (DS), and of intermediate data involved in all its calculations and processing. Furthermore, this DC control device can also include an input interface IE for receiving at least the data defining the path and its various parts pj and various percentages and various associated average traffic speeds, and any maximum energy. storable and percentage of energy available for use in calculations or processing, possibly after having shaped and / or demodulated and / or amplified, in a manner known per se, by means of a digital signal processor PR ′. In addition, this DC control device can also include an output interface IS, in particular for delivering orders, commands and messages, and in particular the first s1 or second s2 threshold to be used, at least for the supervision computer CS.

It will also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when it is executed by processing means of the electronic circuit (or hardware) type, such as for example the processor PR is suitable for implementing the control method described above to control the start-ups of the first driving machine MM1 of the hybrid GMP of the vehicle V.

It will also be noted that one or more sub-steps of the step of the control method can be carried out by different components. Thus, the control method can be implemented by a plurality of digital signal processors, random access memory, mass memory, input interface, output interface.

The invention allows the driver of the vehicle V (or a possible driving assistance device fitted to the latter (V) and responsible for driving it in an automated (or autonomous) manner) to optimize the discharge of the storage device d 'DS energy and fuel consumption in order to finish the trip having consumed all of the cheapest energy (stored in DS) while retaining the possibility of finishing your trip if necessary by means of the only second driving machine MM2 (non-thermal) in the case of an arrival in an urban area.

Claims

1. Control method for a vehicle (V) comprising a powertrain comprising a first driving machine (MM1), thermal, and a second driving machine (MM2), non-thermal and supplied with energy by an energy storage device (DS), characterized in that it comprises a step (10-60) in which, in the presence of a determined path for said vehicle (V), a subdivision of this path into at least two parts is determined in which average traffic speeds are different, and the percentages that these parts represent in said distance journey, then an energy necessary to perform said journey is determined using only said second prime mover (MM2) as a function of said parts of the journey and said associated percentages determined, then if said determined necessary energy is less than an energy available in said energy storage device (DS), a first starting torque threshold is used of said first driving machine (MM1) favoring a movement of said vehicle (V) by means of said second driving machine (MM2), while if said determined necessary energy is greater than said available energy, a second starting torque threshold of said first driving machine (MM1) strictly lower than said first threshold and promoting movement of said vehicle (V) by means of said first driving machine (MM1).

2. Method according to claim 1, characterized in that in said step (10-60) a subdivision of said path is determined into first, second, third, fourth and fifth parts.

3. Method according to claim 2, characterized in that said first part is associated with a first average speed of circulation less than 30 km / h, said second part is associated with a second average speed of circulation greater than said first average speed of circulation and less than 50 km / h, said third part is associated with a third average speed of circulation greater than said second average speed of circulation and less than 70 km / h, said fourth part is associated with a fourth average speed of circulation greater than said third average speed of circulation and less than 90 km / h, and said fifth part is associated with a fifth average speed of circulation greater than said fourth average speed of circulation.

4. Method according to one of claims 1 to 3, characterized in that in said step (10-60) said necessary energy is determined by means of a law based on an average speed expected on said path.

5. Method according to one of claims 1 to 3, characterized in that in said step (10-60) said energy necessary is determined by determining each quantity of partial energy required on average to travel each part of said path as a function of an adjustable parameter multiplied by said distance associated with this part, then by adding all these determined quantities.

6. Method according to one of claims 1 to 3, characterized in that in said step (10-60) a first energy required is determined by means of a law which is a function of an average speed provided on said path, and a second energy necessary by determining each quantity of average partial energy necessary to travel each part of said path as a function of an adjustable parameter multiplied by said distance associated with this part, then by adding all these determined quantities, then taking as necessary energy that which is the greater of said first and second determined necessary energies.

7. Computer program product comprising a set of instructions which, when it is executed by processing means, is suitable for implementing the control method according to one of the preceding claims to control the starts of a. first thermal motive machine (MM1) of a vehicle power train (V) also comprising a second non-thermal motive machine (MM2) supplied with energy by an energy storage device (DS), in the presence of a path determined for said vehicle (V).

8. Control device (DC) for a vehicle (V) comprising a powertrain comprising a first driving machine (MM1), thermal, and a second driving machine (MM2), non-thermal and supplied with energy by a storage device energy (DS), characterized in that it comprises at least one processor (PR) and at least one memory (MD) arranged to perform the operations consisting, in the presence of a determined path for said vehicle (V), determining a subdivision of this path into at least two parts in which average traffic speeds are different, and the percentages that these parts represent in said distance path, then determining an energy required to complete said path using only said second prime mover (MM2) as a function of said parts of the path and of said determined associated percentages, then if said determined necessary energy is less than an energy available in said device itif energy storage (DS), to impose the use of a first starting torque threshold of said first prime mover (MM1) promoting movement of said vehicle (V) by means of said second prime mover (MM2), and if said determined necessary energy is greater than said available energy, in imposing the use of a second starting torque threshold of said first prime mover (MM1) strictly lower than said first threshold and promoting movement of said vehicle (V) by means of of said first driving machine (MM1).

9. Vehicle (V) comprising a powertrain comprising a first driving machine (MM1), thermal, and a second driving machine (MM2), non-thermal and supplied with energy by an energy storage device (DS), characterized in that it further comprises a control device (DC) according to claim 8.

10. Vehicle according to claim 9, characterized in that said second driving machine (MM2) is an electric machine and said energy storage device (DS) is a rechargeable battery.