EP3259163A1

EP3259163A1 - Method and device for controlling the use of prime movers of a hybrid vehicle in addition to the heat engine, according to the efficiency thereof

Info

Publication number: EP3259163A1
Application number: EP16703575.7A
Authority: EP
Inventors: Alexandre BLANCHET; Yohan MILHAU; Cedric Launay
Original assignee: PSA Automobiles SA
Current assignee: Stellantis Auto SAS
Priority date: 2015-02-16
Filing date: 2016-01-15
Publication date: 2017-12-27
Also published as: FR3032670A1; FR3032670B1; CN107531234A; WO2016132030A1; CN107531234B

Abstract

The invention relates to a device (DC) for controlling the use of torque produced by a heat engine (MT), coupled to a gearbox (BV), and at least two prime movers (MM1-MM2) of a power train of a hybrid vehicle (V), according to a torque required depending on the driver's willingness to act. Said device (DC) is arranged, when the torque supplied at the output of the gearbox (BV) and resulting from a maximum torque produced by the heat engine (MT) is less than the torque required at a given moment, so as to determine the efficiency generated by the prime movers (MM1-MM2) at said given moment, then to command the use of at least part of the torque produced by the prime mover generating the highest determined efficiency in addition to the maximum torque produced by the heat engine (MT) in order to obtain the required torque.

Description

METHOD AND DEVICE FOR CONTROLLING THE USE OF ENGINE MACHINES OF A HYBRID VEHICLE IN COMPLEMENT TO THE THERMAL MOTOR, ACCORDING TO THEIR EFFICIENCY

The invention relates to hybrid vehicles having a power train comprising a heat engine and at least two engines, and more specifically the control of the use of engines in addition to the engine in such hybrid vehicles.

Here, the term "driving machine" means a non-thermal machine arranged to provide torque to move a vehicle, either alone or in addition to a heat engine. It may for example be an electric machine (or motor), a hydraulic machine, a pneumatic machine (or compressed air), or a flywheel.

The aforementioned hybrid vehicles, and in particular those of the automotive type, generally offer at least three different modes of running. In a first mode called "thermal" only the engine is used to move the vehicle. In a second mode called "Zero Emission Vehicle" (or ZEV)) only at least one non-thermal engine is used to move the vehicle. In a third mode called "hybrid" at least one of the engines is used in addition to the engine to move the vehicle. This third mode is generally intended to minimize fuel consumption or increase power ("boost" mode) or to increase the number of driving wheels to improve handling.

When the vehicle is traveling in the third mode, the prime mover that is used generally depends on the desired objective (minimizing fuel consumption or increasing power or improving road handling or driving pleasure (depending on the mode of operation). coupling of the engines: clutch / clutch compared to a direct catch on the engine involving the rotation of the engine even off, which is a generator of acoustic and vibratory disturbances). This is the result of programming decided by the vehicle manufacturer following studies, tests and simulations. However, this mode of operation by programming must take into account the operating points imposed by the driver (speed and load) and adapt accordingly to be continuously optimal.

The invention is therefore particularly intended to improve the situation.

It proposes in particular a method for controlling the use of the couples produced by a heat engine, coupled to a gearbox, and at least two engines of a powertrain of a hybrid vehicle, depending on a required torque. function of a willingness to act of a driver of the vehicle.

This method is characterized in that it comprises a step in which:

it is determined, when the torque delivered at the output of the gearbox and resulting from a maximum torque produced by the heat engine is less than the torque required at a given instant, the yields offered by the engines at this time, and then

- At least a portion of the torque produced by the prime mover providing the best performance determined in addition to the maximum torque produced by the engine is used to obtain the required torque.

By using the hybrid in the hybrid mode, the engine that offers the best performance, optimizes the performance of the vehicle while controlling its fuel consumption.

The method according to the invention may comprise other characteristics that can be taken separately or in combination, and in particular:

each efficiency can be determined as a function of known technical characteristics of the driving machine in question and of an energy that can be used by this prime mover at the given moment to produce torque;

when the sum of the maximum torque produced by the heat engine and a maximum torque produced by the prime mover providing the best of the determined yields is less than the required torque, it is possible to use in addition at least a portion of the torque produced by the prime mover which does not offer the best of the determined yields (at the moment considered);

when the determined efficiency of the prime mover used in addition to the heat engine becomes smaller than the determined efficiency of another prime mover, at least a portion of the torque produced by this other prime mover can be used to replace that produced by the machine motor used until now and in addition to the maximum torque produced by the engine;

the driver's will to act can be defined by a depression level of a vehicle accelerator pedal and / or a level of depression of a vehicle brake pedal, or by the activation of a system for automatic regulation or servocontrol of the speed of the vehicle. This willingness to act of the driver can be interpreted in torque-meter on the primary shaft of the torque producing member concerned or torque-meter wheel.

The invention also proposes a device for controlling the use of the torques produced by a heat engine, coupled to a gearbox, and at least two engines of a powertrain of a hybrid vehicle, according to a torque required according to a willingness to act of a driver of the vehicle.

This device is characterized in that it is arranged when the torque delivered at the output of the gearbox and resulting from a maximum torque produced by the heat engine is less than the torque required at a given moment:

- to determine the yields offered by the engines at this moment, and then

- To order the use of at least a portion of the torque produced by the prime mover providing the best performance determined in addition to the maximum torque produced by the engine, to obtain the required torque.

The invention also proposes a hybrid vehicle, possibly of automobile type, and comprising, on the one hand, a power train comprising a heat engine, coupled to a gearbox, and at least two engines, and, on the other hand, a control device of the type of that presented. above.

For example, each driving machine can be selected from (at least) an electric motor, a hydraulic machine, a pneumatic machine and a flywheel.

Other features and advantages of the invention will appear on examining the detailed description below, and the attached drawings, in which:

FIG. 1 diagrammatically and functionally illustrates a hybrid vehicle comprising a transmission chain and a supervision computer equipped with a control device according to the invention, and

FIG. 2 schematically illustrates from top to bottom a first example of a time evolution diagram of the required torque (c1) within a hybrid vehicle, a second example of a time evolution diagram of the speed (c2) of the hybrid vehicle, a third example of a thermal engine torque (c3) torque setpoint evolution time diagram and an additional torque setpoint (c4) within the hybrid vehicle, a fourth example of a time evolution diagram of the yields (η) ) of the first (c5) and second (c6) engines of the hybrid vehicle, and a fifth example of time evolution diagram of the pairs produced by the first (c7) and second (c8) engines of the hybrid vehicle to ensure the torque additional (c4).

The object of the invention is in particular to propose a control method, and the associated DC control device, intended to allow the control of the use of the torques produced by a heat engine MT and at least two MMJ engines of a group. powertrain of a hybrid vehicle V.

In the following, it is considered, by way of non-limiting example, that the hybrid vehicle V is automotive type. This is for example a car. But the invention is not limited to this type of hybrid vehicle. It relates to indeed any type of hybrid terrestrial or maritime (or fluvial) or aeronautical, comprising a powertrain comprising a thermal engine MT and at least two engines MMJ engines.

It is recalled here that the term "driving machine" means a non-thermal machine arranged to provide torque to move a vehicle, either alone or in addition to a heat engine.

Moreover, the term "heat engine" is understood to mean an engine that consumes fuel or chemicals. Therefore, in the aeronautical field it may in particular be a reactor, a turbojet engine or a chemical engine.

In the following, by way of nonlimiting example, the motor machines MMj are of the electric type. But the invention is not limited to this type of driving machine. Thus, it also relates to hydraulic machines (or motors), machines (or engines) pneumatic (or compressed air), and flywheels. Moreover, it will be noted that the motor machines MMj may be of different types.

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

The power train comprises a heat engine MT, an engine shaft AM, an EM clutch, a gearbox BV, a first transmission shaft AT1, at least two engines MMJ (here electric motors), a coupling / decoupling means MC for one of the motors MMj, a second transmission shaft AT2, and first energy storage means (here electric) MS1.

In the following, by way of illustrative example, the powertrain comprises only first MM1 (j = 1) and second MM2 (j = 2) engines (here electrical) coupled to first storage means. low voltage type MS1 (electrical) (for example about 220 V). But the powertrain could include more than two engines.

It will be noted that the first MM1 and second MM2 engines are preferably coupled to the first energy storage means MS1 via a DC / DC type UPS, as illustrated in FIG.

For example, the first transmission shaft AT1 is responsible for rotating the wheels of the vehicle V TV front axle (preferably via a front differential DV), while the second transmission shaft AT2 is responsible for driving in rotation. the wheels of the rear axle TR of the vehicle V (preferably via a rear differential DR). But the opposite is also possible.

The thermal engine MT comprises a crankshaft (not shown) which is fixedly attached to the motor shaft AM to drive the latter (AM) in rotation.

The gearbox BV comprises at least one input shaft (or primary) intended to receive the first torque produced by the heat engine MT via the clutch EM, and an output shaft intended to receive this first torque via the shaft AE input to communicate it to the first transmission shaft AT1 to which it is coupled and which is (here) indirectly coupled to the front wheels of the vehicle V via the front differential DV. For example, the clutch EM comprises a flywheel fixedly secured to the drive shaft AM and a clutch disc fixedly secured to the input shaft of the gearbox BV.

It will be noted that the gearbox BV can be automated or not. Therefore, it may for example be an automatic transmission, a manual gearbox controlled or not, or a double clutch gearbox (or DCT).

The thermal engine MT can produce a first torque which is between a minimum torque and a maximum torque C3M ₃ and which can be determined by the DC control device according to the invention.

The coupling / decoupling means MC here is responsible for coupling / decoupling the first driving machine MM1 to / from the second transmission shaft AT2, on the order of the supervision computer CS, in order to communicate the second pair c7 that it produces, thanks to stored energy in the first storage means MS1, to the second transmission shaft AT2 which is indirectly coupled to the rear wheels (here) of the vehicle V via the rear differential DR. This coupling / decoupling means MC is for example a jaw mechanism or a clutch.

The second motor machine MM2 is coupled to the heat engine MT. This is, for example, an alternator-starter responsible for starting the engine MT to allow it to start, including in the presence of a control system stop and automatic restart (or "stop and start "), and to produce a third pair c8 intended to be transmitted to the first transmission shaft AT1 via the clutch EM and the gearbox BV. This production of the third pair c8 is done thanks to the energy stored in the first storage means MS1.

Note also that in the non-limiting example illustrated in Figure 1, the transmission chain also comprises a DS backup starter responsible for launching the engine MT to enable it to start when the second engine MM2 is in the inability to do so, for example because the MS1 power storage means do not have enough electrical energy. This emergency starter DS, which is not mandatory, is here coupled to second storage means MS2 of very low voltage type (for example 12 V or 24 V), via a DC converter type DC / DC. The latter (CV) can also be coupled, as illustrated, to the ON inverter and the first electrical energy storage means MS1. For example, the second storage means MS2 are arranged in the form of a battery.

The operations of the thermal engine MT, the first MM1 and second MM2 engines, and MC coupling / decoupling means can be controlled by the supervision computer CS. The latter (CS) is particularly capable of operating the hybrid vehicle V in at least three different modes of running. In a first mode called "thermal" only the thermal engine MT is used to move the vehicle (hybrid) V. In a second mode called "Zero Emission Vehicle" (or ZEV)) at least one of the engines MMJ is used to move the vehicle V. In a third mode called "hybrid" at least one MMj is used in addition to the MT heat engine to move the vehicle V.

As indicated above, the invention proposes to implement in the vehicle V a method for controlling the use of couples c3, c7 and c8 respectively produced by the thermal engine MT and at least the first MM1 and second MM2 engines of the hybrid vehicle V.

Such a method can be implemented by the DC control device. In the nonlimiting example illustrated in FIG. 1, the control device DC forms part of the supervision computer CS. But this is not obligatory. This (control) device DC could indeed be an equipment that is coupled to the supervision computer CS, directly or indirectly. Therefore, the DC control device can be realized in the form of software modules (or computer or "software"), or a combination of electronic circuits (or "hardware") and software modules.

The control method, according to the invention, comprises a step which is initiated when the torque which is delivered at the output of the gearbox BV, and which results from the maximum torque c3 _my x produced by the heat engine MT, is lower than torque d which is required by the supervision computer CS at a given moment. In other words, this step starts when, on the one hand, the vehicle V is in its thermal rolling mode, and, on the other hand, the first torque produced by its heat engine MT is maximum (c3 _my x) and is not enough to get the required torque d.

This required torque d is determined by the supervision computer CS based on at least the will of the driver of the vehicle V acting. This will to act is for example defined at least by the level of depression of the pedal. accelerator of the vehicle V and / or the depression level of the brake pedal of the vehicle V, or by the activation of an automatic regulation system or servo-control of the speed of the vehicle V. This will to act of the driver may be interpreted in torque-meter on the primary shaft of the torque-producing member concerned or torque-meter to the wheel. Note that this required pair d can be also determined according to at least one other information relating to the vehicle V (and its state), such as the current speed of the vehicle V, the current inclination of the vehicle V (due to the slope of the track on which it moves), or a constraint of use of a prime mover MMj (such as for example a limit temperature of use) and / or of the thermal engine MT.

As soon as the step is initiated at a given moment for the aforementioned reasons, (the (control) device DC) begins by determining the yields nj offered by the engines MMJ at this given moment. Then, at least a portion of the torque that is produced by the prime mover MMj providing the best determined efficiencies nj, in addition to the maximum torque c3 _max produced by the thermal engine MT, is used to obtain the required torque d. This use is ordered by the DC device and controlled by the supervision computer CS. The torque that is produced by at least one engine MMJ is an additional torque c4, and such that c4 = c1 - c3 _max .

It will be understood that when the step is initiated, the vehicle V moves from its thermal taxiing mode to its hybrid taxiing mode in which it uses its heat engine MT and its engine MMj which, at the moment considered, offers the best of yields nj. This optimizes the performance of the vehicle V while controlling its fuel consumption.

For example, each yield nj can be determined according to known technical characteristics of the motive machine MMj considered and the energy that can be used at the given moment this power machine MMj to produce torque. The efficiency of an engine is represented (by simulation or tests) mainly by its operating point in the rpm / torque field. This performance depends on the physical characteristic of the torque producing member (the technology used and its manufacture). Performance represents the performance level of any energy transformation. During an energy transformation, irreversible thermodynamic exchanges take place. These irreversibilities are called "losses". In order to characterize the performance of an organ, in the field regime / torque, we can consider as criteria friction losses, losses by joule effect (thermal losses), but also the temperature of the rotor and / or the stator and the load level of the dedicated storeroom in the case of a machine motor type, or the temperature of the fluid or gas, the pressure of the gas and the state of the dedicated storeroom in the case of a hydraulic or pneumatic type of engine, or the temperature of the oil in the case of a driving machine of the flywheel type, or the temperatures of the air and the combustion chamber and the oxygen content in the air in the case of a heat engine.

Note that when the sum of the maximum torque c3 _max produced by the thermal engine MT and a maximum torque produced by the prime mover MMj offering the best of the determined efficiencies nj is less than the required torque d, it is particularly advantageous to use in addition to at least a part of the torque produced by the prime mover MMj '(j' ≠ j) which does not offer the best of the determined efficiencies nj. This use is ordered by the DC device and controlled by the supervision computer CS. In other words, if the thermal engine MT and the prime mover MMj with the best efficiency are not enough to produce together the required torque d, then is used in addition to at least one other engine MMj 'to produce a complementary torque.

It will also be noted that when the determined efficiency nj, of the prime mover MMj used initially in addition to the heat engine MT, becomes smaller than the determined efficiency of another engine MMJ '(j' ≠ j), it is particularly advantageous to use at least a portion of the torque that is produced by the other engine MMj 'to replace that produced by the MMJ engine previously used and in addition to the maximum torque c3 _max produced by the heat engine MT. This use is ordered by the DC device and controlled by the supervision computer CS.

FIG. 2 diagrammatically illustrates, on the five diagrams, an example of time evolution of various parameters of the vehicle V during a rolling phase.

The first diagram at the top illustrates a curve of evolution time of the required torque d within the vehicle V. The second diagram, placed just after the first diagram, illustrates a time evolution curve of the speed c2 of the vehicle V, resulting from the control of the torques of the thermal engine MT (c3) and MMJ motor machines (c7 and c8) made by means of the DC device. The third diagram, placed just after the second diagram, illustrates a time evolution curve of the torque setpoint c3 of the thermal engine MT and a time evolution curve of the additional torque setpoint c4 to complete c3 (c4 = d - c3 _max ) within the vehicle V. The fourth diagram, placed just after the third diagram, illustrates curves c5 and c6 of time evolution of the efficiencies η1 and η2 respectively of the first MM1 and second MM2 engines of the vehicle V. The fifth and last diagram, placed just after the fourth diagram, illustrates time evolution curves of the pairs c7 and c8 respectively produced by the first MM1 and second MM2 engines of the vehicle V.

Between times t0 (inclusive) and t1 (excluded), the torque c3 produced by the heat engine MT is sufficient to obtain the required torque d which is increasing. The vehicle V is in its mode of thermal rolling.

At time t1, the required torque d continues to grow, the torque c3 produced by the thermal engine MT reaches its maximum value c3 _my x, and thus the process step is initiated.

Between instants t1 (inclusive) and t2 (excluded), the torque c3 produced by the thermal engine MT is insufficient to obtain the required torque d, and therefore we need an additional torque (defined by an additional torque setpoint c4 ). For example, between t1 and t2, it is determined that the first prime mover MM1 is the one with the best efficiency η1 (see curve c5 which is temporarily above curve c6). The additional c4 torque setpoint then defines the c7 torque to be produced by the first prime mover MM1 with the energy stored in the first storage means MS1, to complete the maximum torque c3 _max produced by the heat engine MT and allow the obtaining the required torque d. The vehicle V is now in its hybrid driving mode.

Between times t2 (inclusive) and t3 (excluded), the required torque of becomes lower than the maximum torque c3 _max produced by the heat engine MT. Therefore, the additional torque setpoint c4 is zero and there is no longer need to ask the first motor machine MM1 to produce torque (the values of the curves c7 and c8 are therefore zero). The vehicle V is therefore again in its thermal rolling mode.

Between instants t3 (inclusive) and t4 (excluded), the torque c3 produced by the thermal engine MT is again insufficient to obtain the required torque d, and therefore additional torque (defined by a setpoint) is needed again. additional torque c4). For example, between t3 and t4, it is determined that the second prime mover MM2 is the one with the best efficiency η2 (see curve c6 which is temporarily above curve c5). The additional torque setpoint c4 then defines the torque c8 that the second motor machine MM2 must produce with the energy stored in the first storage means MS1, to complete the maximum torque c3 _my x produced by the heat engine MT and thus enable the obtaining the required torque d. The vehicle V is then again in its hybrid taxi mode.

At time t4, the required torque d continues to grow, the thermal engine MT and the second motor machine MM2 can not produce enough torque together to obtain it. This results from the fact that the torque produced by the second prime mover MM2 has reached its maximum value c8 _my x- The device DC then orders the production of additional torque by the first prime mover MM1. The additional torque setpoint c4 then defines the sum of the pairs c7 and c8 respectively produced by the first MM1 and second MM2 engines. The vehicle V is still in its hybrid driving mode.

The invention offers several advantages, among which:

it makes it possible to limit the power bypass function (recharging of energy by a prime mover intended for the supply of power by another prime mover), which makes it possible to avoid unnecessary electrical losses,

- it allows the hybrid vehicle to offer optimum performance in prioritizing hybrid energy expenditure in order to control fuel consumption, it makes it possible to refine the typing in performance of the hybrid vehicle between each driving mode since at least one driving machine can be requested depending on the selected driving mode. .

Claims

1. Method for controlling the use of couples produced by a heat engine (MT), coupled to a gearbox (BV), and at least two engines (MMj) of a power train of a hybrid vehicle (V) according to a torque required according to a will to act of a driver of said vehicle (V), characterized in that it comprises a step in which it is determined, when the torque delivered at the output of said gearbox (BV) and resulting from a maximum torque produced by said heat engine (MT) is less than the torque required at a given instant, the yields offered by said engines (MMj) at said given instant, then using at least a part of the torque produced by the prime mover (MMj) providing the best of said determined efficiencies in addition to said maximum torque produced by the heat engine (MT), to obtain said required torque.

2. Method according to claim 1, characterized in that each yield is determined based on known technical characteristics of the engine (MMj) and an energy that can be used at said given instant engine (MMj) for produce torque.

3. Method according to one of claims 1 and 2, characterized in that when the sum of said maximum torque produced by the heat engine (MT) and a maximum torque produced by the prime mover (MMj) offering the best of said yields determined is less than said required torque, it uses in addition at least a portion of the torque produced by the prime mover (MMj ') does not offer the best of said determined yields.

4. Method according to one of claims 1 to 3, characterized in that when the determined efficiency of the prime mover (MMj) used in addition to said engine (MT) becomes lower than the determined efficiency of another engine (MMj '), at least a part of the torque produced by this other driving machine (MMj') is used to replace that produced by the prime mover (MMj) previously used and complement of the maximum torque produced by said engine (MT).

5. Method according to one of claims 1 to 4, characterized in that said will to act of the driver is defined by a depression level of an accelerator pedal of said vehicle (V) and / or a level of depressing a brake pedal of said vehicle (V) or by activating an automatic regulation system or servocontrol of the speed of said vehicle (V).

6. Device (DC) for controlling the use of the torques produced by a heat engine (MT), coupled to a gearbox (BV), and at least two engines (MMj) of a power train of a hybrid vehicle (V) according to a torque required according to a will to act of a driver of said vehicle (V), characterized in that it is arranged, when the torque delivered at the output of said gearbox (BV) and resulting from a maximum torque produced by said heat engine (MT) is less than the torque required at a given instant, to determine the yields offered by said engines (MMj) at said instant, and then to order the use at least a portion of the torque produced by the prime mover (MMj) providing the best of said efficiencies determined in addition to said maximum torque produced by the heat engine (MT), to obtain said required torque.

7. Hybrid vehicle (V) comprising a power train comprising a heat engine (MT), coupled to a gearbox (BV), and at least two engines (MMj), characterized in that it further comprises a device control device (DC) according to claim 6.

8. Vehicle according to claim 7, characterized in that each driving machine (MMj) is selected from a group comprising an electric motor, a hydraulic machine, a pneumatic machine and a flywheel.

9. Hybrid vehicle according to one of claims 7 and 8, characterized in that it is automotive type.