FR3100512A1 - CHECKING THE OPERATING POINT OF A HYBRID MOTORPOWER UNIT OF A VEHICLE DURING A PRIORITY ENERGY RECHARGE - Google Patents

Abstract

A control method is implemented in a vehicle comprising a powertrain comprising a first driving machine, thermal and coupled to a gearbox, and a second machine, non-thermal and recovering energy during a displacement to recharge in energy an energy storage device. This method comprises a step (10-30) in which each operating point of the powertrain is determined as a function of the current speed of the vehicle, and of the sum of a first torque, representative of a request from the driver to move the vehicle, and a second torque representative of the power that must be recovered by the second motor to recharge the energy storage device as a priority. Figure to be published with the abstract: Fig. 2

Description

CHECKING THE OPERATING POINT OF A VEHICLE'S HYBRID POWERTRAIN DURING PRIORITY ENERGY CHARGING

Technical field of the invention

The invention relates to vehicles comprising a hybrid powertrain, and more specifically the control of the operating point of the powertrain when priority recharging of the energy storage device must be carried out.

Here, the term "hybrid powertrain" means a powertrain (or GMP) comprising a first driving machine, thermal and coupled to a gearbox offering at least two ratios, and a second machine, non-thermal, possibly driving, and recovering energy during travel to re-energize an energy storage device. Furthermore, here the term "driving machine" means a machine arranged to provide or recover torque to move a vehicle, either alone or in addition to at least one other thermal or non-thermal driving 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 motive machine may, 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 that allows their energy storage device to be recharged by means of their second (non-thermal) machine during a travel phase provided by the torque produced by the power delivered by their first (thermal) motor machine. ). In this case, the second machine recovers torque to transform it into energy which powers the energy storage device.

There are currently two types of charging respectively called priority and non-priority (or shedding).

Priority charging is triggered when the charge level of the energy storage device is below a minimum threshold and therefore the energy storage device must be recharged to a so-called priority charge level. Currently, this priority recharging corresponds to a priority power which depends on the difference between the current charge level and the priority charge level, and is triggered as a priority in relation to the need for engine torque (travel) requested by the driver of the vehicle. The priority charge level is the minimum charge level to be reached, unlike the non-priority (or load shedding) charge level which is the target level necessarily higher than the priority one. This priority power is defined by a torque setpoint in the frame of reference of the crankshaft of the first prime mover, and therefore is delivered by this crankshaft so that the second machine can recover the corresponding torque.

A non-priority recharge is triggered when the charge level of the energy storage device is notably higher than the minimum threshold but lower than a target charge level, and therefore when it is desired to recharge the energy storage device at a load level said to be non-priority in advance. Currently, this non-priority recharge corresponds to a non-priority power which depends on the difference between the current charge level and the non-priority charge level, and is triggered in a non-priority manner with respect to the need for engine torque (displacement ) requested by the driver of the vehicle. This non-priority power is defined by a torque setpoint in the frame of reference of the crankshaft of the first driving machine, and therefore is delivered by this crankshaft so that the second machine can recover the corresponding torque.

So that a priority or non-priority power can be produced, it is necessary to determine for the powertrain (or GMP) an optimal operating point defining the ratio to be engaged in the gearbox (coupled to the crankshaft (via the clutch) and for example to at least one set of wheels), in particular. Such an optimum operating point is determined as a function of a gearshift law having as main variables the torque to be provided at the level, for example, of the driving wheels (and as a function of the torque requested by the driver of the vehicle), the performance level of the prime mover, the vehicle load deviation from a nominal external load, and the current vehicle speed. The load difference represents the difference between the external forces applying to the vehicle under so-called "nominal" conditions (flat road, nominal empty mass) and the forces actually applying taking into account the real mass, actual slope, actual wind, etc.

A disadvantage of this mode of determining the optimal operating points lies in the fact that the first prime mover may be unable to supply the power necessary to satisfy the need for recharging.

The aim of the invention is therefore in particular to improve the situation.

Presentation of the invention

In particular, it proposes for this purpose a control method intended to be implemented in a vehicle comprising a powertrain comprising a first driving machine, thermal and coupled to a gearbox offering at least two ratios, and a second machine, not thermal and recovering energy during travel to recharge an energy storage device.

This control method is characterized in that it includes a step in which each operating point of the powertrain is determined according to a current speed of the vehicle, and a sum of a first torque, representative of a request from a driver of the vehicle to move the vehicle, and a second torque representative of a power that the second machine must recover to recharge the energy storage device as a priority.

Thanks to the invention, the first driving machine is always able to provide the power necessary to satisfy the need for recharging.

The control method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

- in its step, the second torque can be determined as a function of the current speed of the vehicle and of at least one external parameter chosen from among a current slope of a portion of traffic lane on which the vehicle is traveling and a speed vector wind outside the vehicle;

- in its step, each operating point can be determined by means of a gearshift law defining, for at least vehicle speeds and sums of first and second torques, gear ratios to be set in the gearbox;

- in its stage, the gearshift law can define the gears to be introduced as a function of vehicle load deviations in relation to nominal external loads and a performance index of the first driving machine;

- in its step, each load difference can be a function of at least one external parameter, chosen from a current slope of a portion of traffic lane on which the vehicle is traveling and a speed vector of a wind outside of the vehicle, and/or of a mass of the vehicle.

The invention also proposes a computer program product comprising a set of instructions which, when it is executed by processing means, is capable of implementing a control method of the type of that presented above for controlling an operating point of a vehicle powertrain comprising a first driving machine, thermal and coupled to a gearbox, offering at least two ratios, and a second machine, non-thermal and recovering energy during movement for recharging an energy storage device with energy.

The invention also proposes a control device intended to equip a vehicle comprising a powertrain comprising a first driving machine, thermal and coupled to a gearbox offering at least two ratios, and a second machine, non-thermal and recovering energy during travel to recharge an energy storage device with energy.

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 determining each operating point of the powertrain as a function of a current speed of the vehicle, and a sum of a first torque, representative of a request from a driver of the vehicle to move the vehicle, and of a second torque representative of the power that the second machine must recover to recharge the energy storage device on a priority basis.

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 coupled to a gearbox offering at least two ratios, and a second machine, not -thermal and recovering energy during movement to recharge an energy storage device with energy, and, on the other hand, a control device of the type presented above.

For example, the second machine can be an electric machine and the energy storage device can be a rechargeable battery.

Brief description of figures

Other characteristics and advantages of the invention will appear on examination of the detailed description below, and of the accompanying drawings, in which:

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

schematically illustrates an example of an algorithm implementing a control method according to the invention, and

schematically and functionally illustrates an embodiment of a control device according to the invention.

Detailed description of the invention

The aim of the invention is in particular to propose a control method, and an associated DC control device, intended to allow the control of an operating point of a hybrid powertrain of a vehicle V.

It is recalled that the term "hybrid powertrain" is understood here to mean a powertrain (or GMP) comprising a first driving machine, thermal and coupled to a gearbox offering at least two ratios, and a second machine, non-thermal and recovering energy during travel to re-energize an energy storage device.

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

Schematically shown in Figure 1 is a vehicle V comprising a hybrid GMP transmission chain, a supervision computer CS suitable for supervising (or managing) the operation of the transmission chain, and a DC control device according to the invention .

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

The first prime mover 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 supply a torque, here for at least a first train T1 (here of driving wheels), via the clutch EM, the second machine MM2 and the gearbox BV.

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

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

The second machine MM2 is coupled to the energy storage device DS in order to supply the latter (DS) with energy. It will be noted that in the example illustrated without limitation this second machine MM2 is driving and therefore can produce torque from the energy supplied by the energy storage device DS. To this end, it (MM2) 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 gearbox gears, to provide it with torque.

It will be noted that this second machine MM2 could be installed in other places of the vehicle, and in particular it could be coupled, via appropriate coupling means, to the second train T2 (here of driving wheels) of the vehicle V, in order to provide it with of the torque produced from the energy stored in the energy storage device DS. In the example illustrated without limitation in Figure 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 non-limiting example, that the second machine MM2 is an electric machine (or motor). But the invention is not limited to this type of second non-thermal machine. Indeed, the second machine can also be a hydraulic machine, a pneumatic (or compressed air) machine, or a flywheel, for example.

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

The primary shaft AP of the gearbox BV is intended, here, to receive the sum of the torque transmitted by the clutch EM and the torque supplied by the second machine MM2.

The BV gearbox offers at least two gears. It 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 drive 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 comprise a starter or an alternator-starter AD coupled to the first driving machine MM1 and responsible for launching 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 service battery BS. The latter (BS) can be arranged in the form of a battery of the very low voltage type (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 machine MM2 via a converter DC/DC type CV, so that it can be recharged when the second MM2 machine is an electric machine.

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

As mentioned above, the invention proposes a control method intended to allow the control of the operating points of the hybrid powertrain of the vehicle V. This control method can be implemented at least partially by the DC control device of the vehicle V which for this purpose comprises at least one processor PR, for example of digital signal (or DSP ("Digital Signal Processor")), and at least one memory MD, and therefore which can be produced in the form of a combination of electrical or electronic circuits or components (or “hardware”) and software modules (or “software”). The memory MD is live in order to store instructions for the implementation by the processor PR of at least part of the control method. The processor PR can comprise integrated (or printed) circuits, or else several integrated (or printed) circuits connected by wired or wireless connections. By integrated (or printed) circuit is meant 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 is part of the supervision computer CS. But this is not mandatory. This control device DC could indeed be an item of equipment comprising its own computer and coupled to the supervision computer CS, directly or indirectly.

As illustrated without limitation in FIG. 2, the control method, according to the invention, comprises a step 10-30 which begins in a sub-step 10 when the vehicle V is in a displacement phase ensured by the torque produced by the power delivered by its first prime mover MM1.

In this sub-step 10 one (the control device DC) begins by determining whether the energy storage device DS must be the subject of a priority recharge. To do this, it can, for example, compare the current charge level of the energy storage device DS with a minimum threshold.

If not ("no" - and therefore if a non-priority recharge can be carried out), the first prime mover MM1 will produce the quantity of torque allowing as far as possible to ensure at least the will of the driver plus the recharge . If the sum of the two is not achievable by the first driving machine MM1, the recharge will be reduced in favor of compliance with the driver's wishes. In all cases, the will of the driver takes precedence.

Non-priority charging is therefore opportunistic depending on the capacity of the first driving machine MM1 to provide it in addition to the driver's request.

On the other hand, in the affirmative ("yes" - and therefore if one needs to carry out a priority recharge), one (the control device DC) carries out sub-steps 20 and 30 in which it determines the point operation of the powertrain as a function of the current speed vv of the vehicle V, and of the sum of a first torque c1, representative of the request of the driver of the vehicle V to move the latter (V), and of a second torque c2 representative of the power that the second machine MM2 must recover to recharge the energy storage device DS as a priority. More precisely, in sub-step 20 the DC control device determines the second torque c2, and in sub-step 30 the DC control device determines the operating point of the GMP. The first torque c1 is for example supplied to the control device DC by the supervision computer CS.

Thus, thanks to the optimum operating point determined, the first driving machine MM1 is able to produce, and produces, a total torque equal to c1 + c2 which satisfies the priority recharge and the driver's request, and the second machine MM2 recovers the second couple c2 in this total couple. Consequently, the first driving machine MM1 is always able to supply the power necessary to satisfy the need for recharging.

It will be noted that in sub-step 20 of step 10-30 one (the control device DC) can determine the second torque c2 as a function of the current speed vv of the vehicle V (or what is equivalent the speed of the wheels) and at least one external parameter which is chosen from among the current slope of the portion of the taxiway on which the vehicle V is traveling and the wind speed vector outside the vehicle V.

The current slope can be provided by map data accessible in the vehicle V or by a tilt sensor fitted to the vehicle V, for example.

The wind speed vector defines the direction, direction and speed of the wind outside the vehicle V. It is, for example, defined by meteorological information accessible in the vehicle V.

For example, the DC control device can convert the priority recharging need (expressed in power) into a second torque c2, for example at the wheels. Then, the DC control device can convert the power (for priority charging) into the second torque c2 depending on the current speed vv (or wheel speed) and at least one external parameter. It will be noted that this conversion may optionally include a delinearization phase intended to limit, for example, the second torque c2 at low speed. The purpose of delinearization is to possibly not take into account the need for priority recharging in the calculation of the operating point in order to make the behavior of the vehicle V repeatable, because we are then solely dependent on the driver's will.

It will also be noted that in sub-step 30 of step 10-30 one (the control device DC) can determine each operating point by means of a gearshift law which defines, for at least speeds vv of the vehicle V and of the sums of first c1 and second c2 pairs, ratios to be established in the gearbox BV. For example, the ratio change law can be fed with at least the current speed vv of the vehicle V and the sum of the first c1 and second c2 pairs in order to determine the ratio to be set.

Since the will (or request) of the driver takes priority over non-priority recharging, the gearshift law is not modified when one wishes to trigger non-priority recharging, which makes it possible to offer the driver an optimal acoustic level via an adapted regime of the first prime mover MM1.

This transition law is predetermined in the laboratory or in the factory and stored in the DC control device.

In the presence of the last option, in sub-step 30 of step 10-30, one (the DC control device) can use a gear change law which defines the gears to be established as a function also of load differences of the vehicle V with respect to nominal external loads and a performance index of the first prime mover MM1.

The performance index represents, for example, a ratio between the maximum achievable torque under current conditions and the maximum achievable torque under nominal conditions (altitude/temperature). It is generally known by the CS supervision computer.

For example, each load difference can be a function of at least one external parameter, chosen from the current slope of the traffic lane portion on which the vehicle V is traveling and the wind speed vector outside the vehicle V , and/or the mass of the vehicle V.

The mass of the vehicle V can be supplied by a mass sensor fitted to the vehicle V, for example.

It will be noted, as illustrated without limitation in FIG. 3, 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 current values of the variables and parameters (internal and external), any meteorological or cartographic information, and intermediate data involved in all its calculations and processing. Furthermore, this DC control device can also comprise an IE input interface for receiving at least the current values of the variables and parameters (internal and external), and any meteorological or cartographic information for use in calculations or processing, possibly after having formatted and/or demodulated and/or amplified them, in a manner known per se, by means of a digital signal processor PR′. Moreover, this control device DC can also comprise an output interface IS, in particular for delivering orders, commands and messages (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 able to implement the control method described above to control an operating point of the powertrain of the vehicle V.

It will also be noted that one or more sub-steps of the control process step 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 a homogenization of the behavior of the vehicle V with respect to the level of recharging because this behavior remains mainly dependent on the will of the driver. Only the cases of priority charging lead to a change in the behavior of the vehicle V, at iso will of its driver.

Claims (10)

Control method for a vehicle (V) comprising a powertrain comprising a first driving machine (MM1), thermal and coupled to a gearbox (BV) offering at least two ratios, and a second machine (MM2), non-thermal and recovering energy during travel to recharge an energy storage device (DS) with energy, characterized in that it comprises a step (10-30) in which each operating point of said powertrain is determined by function of a current speed of said vehicle (V), and of a sum of a first torque, representative of a request from a driver of said vehicle to move said vehicle (V), and of a second representative torque of a power that said second machine (MM2) must recover to recharge said energy storage device (DS) as a priority. Method according to claim 1, characterized in that in said step (10-30) said second torque is determined as a function of said current speed of the vehicle (V) and of at least one external parameter chosen from among a current slope d a portion of traffic lane on which said vehicle (V) travels and a speed vector of a wind outside said vehicle (V). Method according to claim 1 or 2, characterized in that in said step (10-30) each operating point is determined by means of a gearshift law defining, for at least speeds of said vehicle (V) and sums of first and second pairs, ratios to be introduced in said gearbox (BV). Method according to claim 3, characterized in that in said step (10-30) said ratio change law defines the ratios to be introduced as a function, moreover, of differences in the load of said vehicle (V) with respect to nominal external loads and a performance index of said first prime mover (MM1). Method according to claim 4, characterized in that in said step (10-30) each load difference is a function of at least one external parameter, chosen from among a current slope of a portion of traffic lane on which said vehicle (V) and a speed vector of a wind outside said vehicle (V), and/or of a mass of said vehicle (V). Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the control method according to one of the preceding claims for controlling an operating point of a vehicle powertrain (V) comprising a first driving machine (MM1), thermal and coupled to a gearbox (BV) offering at least two ratios, and a second machine (MM2), non-thermal and recovering energy during a trip to recharge an energy storage device (DS) with energy. Control device (DC) for a vehicle (V) comprising a powertrain comprising a first motor machine (MM1), thermal and coupled to a gearbox (BV) offering at least two gears, and a second motor (MM2), non-thermal and recovering energy during movement to recharge an energy storage device (DS) with energy, characterized in that it comprises at least one processor (PR) and at least one memory (MD) arranged to carry out the operations consisting in determining each operating point of said powertrain as a function of a current speed of said vehicle (V), and of a sum of a first torque, representative of a request from a driver of said vehicle to move said vehicle (V) with said first prime mover (MM1), and of a second torque representative of the power that said second machine (MM2) must recover to recharge said energy storage device (DS) on a priority basis . Vehicle (V) comprising a powertrain comprising a first driving machine (MM1), thermal and coupled to a gearbox (BV) offering at least two ratios, and a second machine (MM2), non-thermal and recovering energy during movement to recharge an energy storage device (DS) with energy, characterized in that it further comprises a control device (DC) according to claim 7. Vehicle according to claim 8, characterized in that said second machine (MM2) is an electric machine and said energy storage device (DS) is a rechargeable battery. Vehicle according to Claim 8 or 9, characterized in that it is of the automobile type.