Control method for a hybrid electric powertrain

Abstract

Control method for managing dog clutch engagement in a vehicle powertrain (1) comprising an internal combustion engine (2), primary (3) and secondary (4) electrical machines, and a dog clutch gearbox having a first primary shaft (5) connected to the engine, a second primary shaft (6) connected to the primary electrical machine, the method comprising: when the target ratio to be engaged is intended to lock the first primary shaft, respectively the second primary shaft, with the secondary shaft in rotation, then a convergence torque is applied by means of the secondary electrical machine, respectively by means of the primary electrical machine, the convergence torque to be applied being determined in subordination to an acceptance of charging and discharging of the battery calculated according to the characteristic(s) of the battery and the power taken or delivered by the electrical machines.Figure from the summary: Fig. 2.

Description

Title of the invention: Control method for a hybrid electric powertrain

[0001] The present invention relates to a control method for a hybrid electric powertrain.

[0002] The invention generally relates to the control of automatic powertrain transmissions (PCTs) of hybrid vehicles, comprising a gearbox that combines the torque from several torque actuators (internal combustion engine and electric machines) to the vehicle wheels, in different gear ratios, via a differential. The invention preferably relates to the control of a non-rechargeable hybrid electric powertrain transmission, also known by the English term "Hybrid Electric Vehicle" or by the corresponding acronym "HEV", but can also be applied to a plug-in hybrid electric vehicle transmission, also known by the English term "Plug-in Hybrid Electric Vehicle" or by the corresponding acronym "PHEV".

[0003] In this document, the term "storage battery," or even simply "battery," refers to an electrical energy storage battery capable of storing an amount of energy at least equal to 1 kWh. In practice, the electrical energy storage capacity is between 1 kWh and 3 kWh, preferably between 1.6 kWh and 2 kWh.

[0004] This storage battery, of particular interest here, is different and distinct from the conventional on-board network battery referred to in this document as the 12V battery. Conversely, the voltage across the terminals of the storage battery is at least 100 volts or even more, for example 400 volts.

[0005] In practice, the aim is to maximize driving in zero-emission mode in dense urban areas.

[0006] The configuration of particular interest here relates to a motor vehicle powertrain comprising an internal combustion engine (three or four cylinders for example), a main electric machine capable of pulling the vehicle, a secondary electric machine, and a piloted dog-clutch gearbox having a first primary shaft mechanically connected with the internal combustion engine and with the secondary electric machine, a second primary shaft mechanically connected with the main electric machine, and a secondary shaft forming an output to the differential and the wheels.

[0007] The system is clutchless and lacks the synchronizer sleeves found in conventional gearboxes. The various mechanical engagements and gear changes are achieved by means of dog clutches, also called dog clutches.

[0008] Note that the configuration may also include an additional tree called a transfer tree, the functions of which will be seen later.

[0009] This configuration allows operation in zero-emission mode with two distinct transmission ratios from the main electric machine. This configuration also allows operation in thermal mode with at least two distinct transmission ratios from the internal combustion engine.

[0010] In addition, there are of course hybrid operating modes, which gives a total of at least a dozen possible combinations, including in particular a series hybrid mode and parallel hybrid modes.

[0011] This configuration generally corresponds to the configuration called "E-tech full hybrid" by the car manufacturer Renault.

[0012] An example of this configuration is known from document FR3072056.

[0013] The internal combustion engine, the main electrical machine and the secondary electrical machine are controlled by a computer called a supervisory computer.

[0014] The supervisory computer manages the gear change sequences.

[0015] In the absence of a synchronizer sleeve, the engagement of a dog clutch must occur at zero or very low relative rotational speed. Consequently, the secondary electrical machine is used to converge the rotational speed of the first primary shaft (or respectively of the second primary shaft) to a target rotational speed conducive to the engagement of the dog clutch to be engaged.

[0016] To do this, the secondary electric machine draws electrical energy from the storage battery or, conversely, returns electrical energy to the storage battery.

[0017] In another scenario, it is the main electrical machine that is called upon to converge the regime of the second primary shaft towards a regime conducive to the engagement of a dog clutch.

[0018] The inventors sought to optimize the convergence time of the rotation regime while respecting the charging (or respectively discharging) acceptance capacities of the storage battery.

[0019] To this end, a control method is proposed for managing dog clutch engagement with respect to a target transmission ratio to be engaged, in a motor vehicle powertrain (1) comprising an internal combustion engine (2), a main electric machine (3) electrically connected with a storage battery (9), a secondary electric machine (4) connected electrically with said storage battery, and at least one dog-clutch gearbox comprising a first primary shaft (5) mechanically connected with the internal combustion engine and with the secondary electrical machine, a second primary shaft (6) mechanically connected with the main electrical machine, and a secondary shaft (7), the method providing that: K1- when the target ratio to be engaged is intended to lock the first primary shaft in rotation with the secondary shaft, then a convergence torque is applied by means of the secondary electric machine on the first primary shaft so as to achieve a target rotational speed on the first primary shaft suitable for a synchronized engagement of the dog clutch, K2- when the target ratio to be engaged is intended to lock the second primary shaft in rotation with the secondary shaft, then a convergence torque is applied by means of the main electric machine on the second primary shaft so as to achieve a target rotational speed on the second primary shaft suitable for a synchronized engagement of the dog clutch.

[0020] The method is characterized in that the convergence torque to be applied by one of the main or secondary electrical machines is determined in real time as a condition of charging acceptance and discharging acceptance of the storage battery, the charging acceptance and discharging acceptance of the storage battery being calculated as a function of the battery's own characteristic(s) and the power taken or returned by the other of the main or secondary electrical machines.

[0021] The convergence torque is intended to make the rotation regime of the shaft concerned converge towards the regime suitable for the engagement of the dog / clatter.

[0022] The term 'acceptance of charge or recharging' must be taken as a 'generalized' acceptance; indeed, acceptance includes, in addition to the acceptance of the battery itself, the acceptance provided by the current delivered or taken from the other electrical machine.

[0023] Thanks to these arrangements, it is possible to exchange the maximum power with the battery, while respecting its characteristics and preserving its lifespan, with at the same time minimizing the time required to converge the rotational speed of the shaft concerned towards the appropriate speed.

[0024] Advantageously, the principle promoted by the present invention makes it possible to optimize battery use to the maximum without damaging it. From another point of view, the present invention makes it possible to precisely size the installed capacity of the storage battery for a given gear ratio functionality.

[0025] The battery's own acceptance of charging or recharging depends in particular on the state of charge and the internal temperature of the battery.

[0026] As will be seen later, the convergence torque can be a convergence torque in braking or a convergence torque in motoring.

[0027] In case K1, the convergence torque, brake or motor, is applied by means of the secondary electrical machine. In case K2, the convergence torque, brake or motor, is applied by means of the main electrical machine.

[0028] It is further noted that the cumulative power of the two electrical machines, main and auxiliary, is much greater than the instantaneous power that can be delivered by the battery or reinjected into the battery, which underlines the relevance of the present invention.

[0029] According to one embodiment, the convergence torque in braking can be limited by accepting the recharging of the storage battery, particularly if the dog clutch engagement occurs during an upshift phase of the transmission ratio, while the convergence torque in motoring can be limited by accepting the discharge of the storage battery if the dog clutch engagement occurs during a downshift phase under vehicle acceleration.

[0030] It should be noted that the limitation discussed above corresponds to specific operating circumstances. In other operating circumstances, the limitation does not apply, and the torque of the main or auxiliary machine is used to the maximum possible extent to bring the primary shaft speed (first or second) as quickly as possible to the target dog engagement speed.

[0031] According to one embodiment, for the case Kl the maximum convergence torque applied by the secondary electrical machine (4) in brake CmaxHSG-F or in motor CmaxHSG-M is defined as follows: CmaxHSG-F = (Pchg_max + Pme) / wHSG, where - wHSG is the operating speed of the HSG, - Pchg_max is the maximum power accepted during charging. - Pme is the power consumed by the main electrical machine, and CmaxHSG-M = (Pdechg_max - Pme) / wHSG, where - Pdechg_max is the maximum power accepted during discharge.

[0032] It is noted that Pme is positive when the main electrical machine consumes current, and that Pme is negative when the main electrical machine operates as a generator and delivers current (i.e. sends current back to the battery).

[0033] It is noted that the term '+Pme' increases the charging acceptance when Pme is positive, that is to say when the main electric machine draws energy from the battery.

[0034] It is noted that the term '-Pme' increases the discharge acceptance when Pme is negative, that is, when the main electrical machine sends energy back to the battery.

[0035] According to one embodiment, the total braking torque Cmax_brake or motor torque Cmax_motor on the first primary shaft is written as follows: Cmax_brake = Cice-F + CmaxHSG-F, Cmax_motor = Cice-M + CmaxHSG-M, where Cice-F is the braking torque delivered by the internal combustion engine on the first primary shaft, and Cice-M is the engine torque delivered by the internal combustion engine on the first primary shaft.

[0036] In practice, the effects of the internal combustion engine and the secondary electrical machine are additive.

[0037] According to one embodiment, a new real-time operating setpoint deviation is calculated and is expressed as follows: w_diff-F = Cmax_frein / Jice_hsg*Te, for the circumstance where a brake torque is delivered, w_diff-M = Cmax_mot / Jice_hsg*Te, for the circumstance where a motor torque is delivered, where Jice_hsg is the rotational moment of inertia, and Te is the recurrence period of the calculation, with w_diff-F being a decrease value and w_diff-M being an increase value (relative to the previous setpoint), and Jice_hsg is the rotational moment of inertia of the rotating parts linked to the first primary shaft, and Te the recurrence period of the calculation.

[0038] According to one embodiment, the new real-time regime setpoint deviation is calculated iteratively with an iteration frequency of at least 50 Hz.

[0039] The decision is thus repeated very regularly. Preferably, the iteration frequency can be 100 Hz.

[0040] According to one embodiment, for the case K2, the maximum convergence torque applied by the main electric machine in brake mode CmaxME-F or in motor mode CmaxME-M is defined as follows: CmaxME-F = (Pchg_max + Phsg) / wME, where - wME is the operating mode of the main electrical machine, - Pchg_max is the maximum power accepted during charging - Phsg is the power consumed by the secondary electrical machine (4), and CmaxME-M = (Pdechg_max - Phsg) / wME, where - Pdechg_max is the maximum power accepted during discharge.

[0041] According to one embodiment, it is further provided that the incoming power Pchg_bat and the outgoing power of the battery Pdechg_bat are measured, and the following is defined: Pchg_marge = Pchg_bat - Pchg_max Pdechg_marge = Pdechg_bat - Pdechg_max and we store the maximum value of Pchg_margel and Pdechg_margel respectively, collected during regime synchronization, and we apply:

[0042] CmaxHSG_F = (Pchg_max + Pme - K*Pchg_margel) / wHSG,

[0043] CmaxHSG_M = (Pdechg_max - Pme - K*Pdechg_margel) / wHSG.

[0044] K being a safety factor.

[0045] The present invention also relates to an electric or hybrid vehicle, comprising an electric motor vehicle powertrain including an internal combustion engine, a main electric machine electrically connected with a storage battery, a secondary electric machine electrically connected with said storage battery, and at least one piloted dog clutch gearbox having a first primary shaft mechanically connected with the internal combustion engine and with the secondary electric machine, a second primary shaft mechanically connected with the main electric machine, a secondary shaft, and at least one control unit, said control unit being configured to implement a control method as described above.

[0046] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig.1] schematically illustrates an example of a powertrain architecture in which the present invention can be implemented; - [Fig.2] shows a chronogram that illustrates a first example of a gear shift sequence; - [Fig.3] shows a timing diagram that illustrates a second example of a gear shift sequence; - [Fig.4] shows a chronogram that illustrates a third example of a gear shift sequence; - [Fig.5] shows a chronogram that illustrates a fourth example of a gear shift sequence; - [Fig.6] represents a functional block diagram of the calculation.

[0047] In the various figures, the same reference numerals designate identical or similar elements. For the sake of clarity, some elements are not necessarily shown to scale. It should be noted, in particular, that time intervals are not shown to scale.

[0048] Fig. 1 is a functional diagram of a hybrid powertrain 1, with three shafts and two electric machines, using three dog clutch coupling systems, the operation of which will be detailed in the following paragraphs. The powertrain 1 comprises three actuators, namely an internal combustion engine 2 (ICE), a main electric machine 3 (ME), and a secondary electric machine 4 (HSG). The powertrain 1 includes an electrical energy storage battery, denoted 9.

[0049] The drive unit 1 comprises a solid primary shaft 5 connected to the motor 2, a second primary shaft 6 (also called a hollow primary shaft) connected to the main electric machine 3, a secondary shaft 7, and a return shaft 8 connected to the secondary electric machine 4. The gears are engaged by three dog clutches C1, C2, C3, which lack mechanical synchronizers. It should therefore be noted that the dog clutch gearbox presented here lacks a synchronizer sleeve and a clutch.

[0050] The gearbox comprises six idler gears PI, P2, P3, P4, P5 and P6. Gear 51 is rotationally fixed to the first primary shaft 5. Gear 81 is rotationally fixed to the idler shaft 8. Gears 61, 62 are rotationally fixed to the second primary shaft 6. Gears 71, 72, 73 are rotationally fixed to the secondary shaft 7. Gears 41, 42 form a cascade of engagement between the secondary electrical machine 4 and the idler shaft 8.

[0051] It is noted that the first primary shaft 5 and the idler shaft 8 are permanently engaged together via the gears 51 and 81. The first primary shaft 5 and the second primary shaft 6 are coaxial. The first primary shaft 5 passes through the entire length of the second primary shaft 6.

[0052] For reasons of clarity in the presentation, the bearings and bushings which support the shafts are not shown in the figures.

[0053] The gearbox transmits the torque from the motor 2, the torque from the main electric machine 3, and the torque from the secondary electric machine 4 via the secondary shaft 7, towards the wheels of the vehicle RG, RD through a differential.

[0054] Gear changes are achieved via the control of three dog clutches C1, C2, C3, located respectively on the solid primary shaft 5, the secondary shaft 7, and the transfer shaft 8. Each dog clutch has a neutral position and two engaged positions on either side of the neutral position. In [Fig. 1], only one control fork is shown; it is labeled 92 and activates the third clutch.

[0055] The first coupler, called primary coupler Cl, placed on the solid primary shaft 5, allows a thermal transmission ratio called ICE2 to be engaged on the left (position CIA, see [Fig.1]), or a thermal transmission ratio called ICE4 to be engaged on the right (position C1B),

[0056] The second coupler, called secondary coupler C2, placed on the secondary shaft, allows to engage a first electrical ratio called EV1 (position C2A (left) or allows to engage a second electrical ratio EV2 (position C2B, right).

[0057] The third coupler, called transfer coupler C3, is placed on the return shaft 8. The position on the right, noted C3B, allows the torque from the motor 2 and the secondary electric machine 4 to be transferred towards the secondary shaft 7, via the idler gear P2, which gives a transmission ratio called ICE3.

[0058] The left-hand position marked C3A allows the torque of the secondary electrical machine 4 to be transferred to the second primary shaft 6.

[0059] When the third coupler is in position C3A and in addition the second coupler is in position C2A, then another thermal transmission ratio called ICE la is obtained, via the idler gear P3.

[0060] When the third coupler is in position C3A and the second coupler is also in position C2B, then another thermal transmission ratio called ICElb is obtained, via the idler gear P4.

[0061] The gearbox has two electric transmission ratios EV 1 and EV2 for the motion from the main electric machine 3, and five thermal transmission ratios ICE1a, ICE1b, ICE2, ICE3 and ICE4 for the motion from the secondary electric machine 4 and the internal combustion engine 2. Each transmission speed ratio has a given gear ratio.

[0062] By adding to this the series and parallel hybrid modes, the set of available combinations allows the gearbox to have at least a dozen speed ratios, preferably 15 speed ratios.

[0063] The main electric machine 3 is electrically connected with the storage battery 9, as illustrated in [Fig.1], via a specific power control unit as known per se.

[0064] The secondary electric machine 4 is electrically connected with the storage battery 9 via a specific power control unit (identical to or associated with the previous one).

[0065] The electrical energy storage battery is capable of storing an amount of energy at least equal to 1 kWh. In practice, the electrical energy storage capacity is between 1 kWh and 3 kWh, preferably between 1.6 kWh and 2 kWh. This sizing allows for a very high proportion of zero-emission driving in urban conditions and also limits the weight and cost of such a battery within the vehicle architecture. The battery sizing therefore results from a careful compromise.

[0066] A battery management computer, referred to in industry jargon as BMS from the Anglo-Saxon term Battery Management System, is planned and identified as 91.

[0067] Although it is not excluded to have a rechargeable battery (Plug-In), the invention is particularly relevant to the case of non-rechargeable hybrid vehicles which do not require any function or infrastructure to recharge the battery from the general electrical network.

[0068] The voltage across the terminals of the battery 9 is a variable voltage depending on its state of charge. The nominal voltage can be between 48 volts and 400 volts depending on the configuration.

[0069] Pdechg_max denotes the maximum discharge power accepted by the battery. This value depends in particular on the internal temperature of the battery and its current state of charge, but may also depend to a lesser extent on other parameters.

[0070] Pchg_max is the maximum charging power accepted for the battery. This value depends in particular on the internal temperature of the battery and its current state of charge, but may also depend secondarily on other parameters.

[0071] At any given time, we note:

[0072] wME the rotational speed of the main electrical machine 3,

[0073] wHSG the rotational speed of the secondary electrical machine 4,

[0074] Cme the torque delivered by the main electrical machine 3,

[0075] Pme the power of the main electrical machine 3,

[0076] CHSG-F the braking torque delivered by the secondary electrical machine 4,

[0077] CmaxHSG-F being the maximum not to be exceeded,

[0078] CHSG-M the motor torque delivered by the secondary electrical machine 4, CmaxHSG-M being the maximum not to be exceeded

[0079] Phsg the power of the secondary electrical machine 4

[0080] Cice denotes the torque delivered by the internal combustion engine 2, and Pice the power of said engine 2

[0081] Cice-F is the braking torque delivered by motor 2

[0082] Cice-M is the motor torque delivered by motor 2

[0083] CmaxME-F the maximum torque applied by the main electric machine in braking, CmaxME-M the corresponding value in motor.

[0084] Pme is positive when the main electrical machine consumes current, and Pme is negative when the main electrical machine operates as a generator and delivers current (i.e. sends current back to the battery).

[0085] The same applies to Phsg, which is positive when the secondary electrical machine consumes current, and Phsg is negative when the secondary electrical machine operates as a generator and delivers current (i.e., sends current back to the battery).

[0086] We now study the case Kl: Engagement of a dog relative to the first primary tree, or possibly relative to the reference tree.

[0087] The target ratio to be engaged is intended to lock the first primary shaft 5 with the secondary shaft 7 in rotation, it is therefore a matter of engaging one of the positions CIA, C1B, or auxiliaryly C3B.

[0088] A convergence torque is applied by means of the secondary electrical machine 4 on the first primary shaft 5 so as to achieve a target rotation regime on the first primary shaft 5 conducive to a synchronized engagement of the dog clutch.

[0089] In practice, there are two scenarios: either it is necessary to reduce the speed of the first primary shaft 5, in which case the convergence torque is a braking torque CHSG-F, or it is necessary to increase the speed of the first primary shaft, in which case the convergence torque is a driving torque CHSG-M.

[0090] Case K1D - decrease in the speed of the first primary shaft (so-called 'upward' passage).

[0091] We can write CmaxHSG-F = (Pchg_max + Pme) / wHSG which expresses the limitation in battery charging acceptance (to which we add the withdrawal from the main electrical machine).

[0092] We also write Cmax_frein = Cice-F + CmaxHSG-F, i.e. the braking torques of the motor and the secondary electrical machine are added together. where Cice-F is the braking torque delivered by the internal combustion engine on the first primary shaft.

[0093] Figures 2 and 3 illustrate two cases of ratio change. The beginning of the following commentary is common to both figures.

[0094] The upper part illustrates the engagement of the dog Cl which passes from position A to position B via the intermediate position N. The disengagement takes place between times a and b, and the re-engagement takes place between times f and g.

[0095] The area of ​​the graph below illustrates the respective torques of the heat engine Cice, the main electric machine Cme, and the secondary electric machine CHSG-F.

[0096] The area of ​​the graph below shows the evolution of the rotation speed of the first primary shaft û)5 which goes from œs1 to œs2.

[0097] The lower area of ​​the graph illustrates the powers: the maximum self-charging power of the battery Pchg_max, the power of the main electric machine Pme and -Phsg the power of the secondary electric machine (here represented inverted in view of the aforementioned convention, to compare it to Pchg_max + Pme).

[0098] On the power balance illustrated in [Fig. 2], it can be seen that the power reinjected into the battery by the auxiliary electric machine 4 is greater than the threshold Pchg_max, because we simultaneously benefit from the power withdrawal Pme carried out by the main electrical machine 3. This non-problematic overshoot takes place between times c and e.

[0099] Conversely, in the case of [Fig.3] where the driver lifts his foot off the accelerator at the beginning of the gear change, the electrical power Pme consumed by the main electrical machine is no longer present and even reverses due to regenerative braking.

[0100] We observe a clipping of the power -Phsg that the secondary electrical machine can deliver between times d and e.

[0101] Thus, it is observed that the circumstance of lifting the foot which coincides with an uphill passage is unfavorable and causes a clipping of the braking power delivered by the secondary electric machine.

[0102] Case K1A - increasing the speed of the first primary shaft (so-called 'downward' passage). In this case, the secondary electrical machine 4 must supply energy to the first primary shaft 5 to increase its rotational speed û)5 and bring it to the correct speed in order to engage the lower gear.

[0103] Fig. 4 illustrates such a case, moreover in a circumstance where the driver demands power, for example in downshifting configuration under kick down.

[0104] We have Cmax_mot = Cice-M + CmaxHSG-M, Cice-M is the engine torque delivered by the internal combustion engine on the first primary shaft.

[0105] CmaxHSG-M = (Pdechg_max - Pme) / wHSG,

[0106] Here, unlike the previous cases, the rotation speed of the first primary shaft û)5 changes from œs2 to œsl.

[0107] In this type of situation, the main electric machine 3 is used to minimize the torque dip during gear changes, and consequently the Cme torque is largely positive. It should then be noted that the term "-Pme" significantly impacts the battery's discharge capacity.

[0108] We then have a fairly significant clipping between times c and e as illustrated in the lower part of the graph in [Fig.4].

[0109] However, the control of the internal combustion engine makes it possible to deliver a substantial engine torque Cice-M despite the limitation which affects the torque CHSG-M delivered by the secondary electrical machine.

[0110] It should be noted that the calculations shown above are carried out recurrently, with a fairly high frequency typically at least equal to 50 Hz. Recurrence period is denoted Te.

[0111] The process calculates a new deviation from the operating setpoint, which is calculated and expressed as follows.

[0112] w_diff-F = Cmax_frein / Jice_hsg*Te, for the circumstance where a brake torque is delivered, and w_diff-M = Cmax_mot / Jice_hsg*Te, for the circumstance where a motor torque is delivered.

[0113] Jice_hsg is the rotational moment of inertia of the rotating parts connected to the first primary shaft.

[0114] w_diff-F is a decrease value and w_diff-Mest is an increase value.

[0115] We now study the case K2 - engagement of a dog relative to the second primary shaft.

[0116] Compared to what has been described above, we have a permutation of roles between the main electric machine 3 and the secondary electric machine 4. Furthermore, the internal combustion engine 2 does not intervene to converge the rotational regime of the second primary shaft 6.

[0117] Not all comments will be included, but a person in the field will be able to find, mutatis mutandis, the equivalent functions and results in points.

[0118] It is the main electrical machine 3 which is used to converge the rotation regime of the second primary shaft.

[0119] Case K2D - decrease in the speed of the second primary shaft (upward passage).

[0120] We write CmaxME-F = (Pchg_max + Phsg) / wME.

[0121] wME is the rotation regime of the main electrical machine 3, and û)6 is the rotation regime of the second primary shaft 6.

[0122] We also write CmaxME-M = (Pdechg_max - Phsg) / wME,

[0123] Figure 5 illustrates, similarly to the previous timing diagrams, the case of an upward transition between two electrical ratios. Here, there is no power clipping except for the first main electrical machine.

[0124] Case K2A - increase in the speed of the second primary shaft (downward flow). This case is not shown in the figures but can be easily deduced from the preceding timing diagrams.

[0125] Finally, it is planned to add a safety margin term in the calculations defined for the different scenarios above, this safety margin term being able to correspond to measurement imperfections.

[0126] To this end, the incoming power Pchg_bat and the outgoing power of the battery Pdechg_bat are measured via the BMS, and deviations called 'margin' are defined between the measured values ​​and the theoretical maximum values ​​as follows:

[0127] Pchg_marge = Pchg_bat - Pchg_max

[0128] Pdechg_marge = Pdechg_bat - Pdechg_max

[0129] according to a particular aspect, the maximum value of Pchg_margel or respectively Pdechg_margel of these deviations is kept in memory during a regime synchronization sequence.

[0130] With knowledge of these maximum margin values, one can write a variant of the maximum torques that the secondary electrical machine is allowed to deliver.

[0131] CmaxHSG_F = (Pchg_max + Pme - K*Pchg_margel) / wHSG,

[0132] CmaxHSG_M = (Pdechg_max - Pme - K*Pdechg_margel) / wHSG.

[0133] K is a parameterizable coefficient; it can be interpreted as a safety factor. It can be initialized to the value 1.

[0134] On [Fig.6], the main control unit 10 receives from the BMS unit which manages the battery the information Pchg_bat, Pdechg_bat, Pchg_max, Pdechg_max.

[0135] Box 21 represents the correction loop. Box 22 represents the correction loop for the Cmax-Brake calculation. Box 23 represents the dynamic engine speed conversion. Box 24 represents the conversion of the accelerator pedal command from the driver (COND).

[0136] It should be noted that the disengagement at the beginning of the sequence which appears on the timing diagrams is optional and is not essential from the point of view of the present invention.

Claims

1.

2. Demands A control method for managing dog clutch engagement with respect to a target transmission ratio to be engaged, in a motor vehicle powertrain (1) comprising an internal combustion engine (2), a main electric machine (3) electrically connected to a storage battery (9), a secondary electric machine (4) electrically connected to said storage battery (9), and at least one pilot-operated dog clutch gearbox having a first primary shaft (5) mechanically connected to the internal combustion engine (2) and to the secondary electric machine (4), a second primary shaft (6) mechanically connected to the main electric machine (3), and a secondary shaft (7), the method comprising that: K1- when the target ratio to be engaged is intended to lock the first primary shaft (5) in rotation with the secondary shaft (7), then a convergence torque is applied by means of the secondary electric machine (4) on the first primary shaft (5) so as to achieve a target rotational speed on the first primary shaft (5) conducive to synchronized engagement of the dog clutch, K2- when the target ratio to be engaged is intended to lock the second primary shaft (6) in rotation with the secondary shaft (7), then a convergence torque is applied by means of the main electric machine (3) on the second primary shaft (6) so as to achieve a target rotational speed on the second primary shaft (6) conducive to synchronized engagement of the dog clutch, characterized in that the convergence torque to be applied by one of the main or secondary electric machines (3,4) is determined in real time subject to a charging acceptance and a discharging acceptance of the storage battery, the charging acceptance and the discharging acceptance of the storage battery being calculated according to the battery's own characteristic(s) and the power drawn or delivered by the other of the main or secondary electrical machines (3,4). A control method according to claim 1, wherein the braking convergence torque can be limited by accepting the recharging of the storage battery, particularly if the dog clutch engagement occurs during an upshift phase of the gear ratio. transmission, while the convergence torque in the motor can be limited by an acceptance of discharge of the storage battery if the dog clutch engagement occurs particularly during a downshifting phase under vehicle acceleration.

3. A control method according to any one of claims 1 to 2, wherein for the case Kl, the maximum convergence torque applied by the secondary electric machine (4) in braking CmaxHSG-F or in motor CmaxHSG-M is defined as follows: CmaxHSG-F = (Pchg_max + Pme) / wHSG, where - wHSG is the HSG operating speed, - Pchg_max is the maximum power accepted in charging, - Pme is the power consumed by the main electric machine (3), and CmaxHSG-M = (Pdechg_max - Pme) / wHSG, where - Pdechg_max is the maximum power accepted in discharging.

4. Control method according to claim 3, wherein the total braking torque Cmax_brake or motor torque Cmax_motor on the first primary shaft is written as follows: Cmax_brake = Cice-F + CmaxHSG-F, Cmax_motor = Cice-M + CmaxHSG-M, where Cice-F is the braking torque delivered by the internal combustion engine on the first primary shaft, Cice-M is the motor torque delivered by the internal combustion engine on the first primary shaft.

5. A control method according to claim 4, wherein a new real-time speed setpoint deviation is calculated and expressed as follows: w_diff-F = Cmax_brake / Jice_hsg*Te, for the circumstance where a brake torque is delivered, w_diff-M = Cmax_motor / Jice_hsg*Te, for the circumstance where a motor torque is delivered, with w_diff-F being a decrease value and w_diff-M being an increase value, and Jice_hsg is the rotational moment of inertia of the rotating parts connected to the first primary shaft, and Te the recurrence period of the calculation.

6. A control method according to claim 5, wherein the new real-time operating setpoint deviation is calculated iteratively with an iteration frequency of at least 50 Hz.

7. A control method according to any one of claims 1 to 6, wherein for the case K2, the maximum convergence torque applied by the main electric machine (3) in braking CmaxME-F or in motor CmaxME-M is defined as follows: CmaxME-F = (Pchg_max + Phsg) / wME, where - wME is the speed of the main electric machine, - Pchg_max is the maximum power accepted in charging - Phsg is the power consumed by the secondary electric machine (4), and CmaxME-M = (Pdechg_max - Phsg) / wME, where - Pdechg_max is the maximum power accepted in discharging.

8. A control method according to any one of claims 3 to 7, wherein it is further provided that the input power Pchg_bat and the output power of the battery Pdechg_bat are measured, and the following are defined: Pchg_marge = Pchg_bat - Pchg_max Pdechg_marge = Pdechg_bat - Pdechg_max and the maximum value of Pchg_margel and Pdechg_margel respectively, collected during regime synchronization, are stored in memory, and the following are applied: CmaxHSG_F = (Pchg_max + Pme - K*Pchg_margel) / wHSG, CmaxHSG_M = (Pdechg_max - Pme - K*Pdechg_margel) / wHSG, K being a safety factor.

9. Hybrid vehicle comprising an electric powertrain (1) of a motor vehicle comprising an internal combustion engine (2), a main electric machine (3) electrically connected with a storage battery (9), a secondary electric machine (4) electrically connected with said storage battery (9), and at least one piloted dog clutch gearbox having a first primary shaft (5) mechanically connected with the internal combustion engine (2) and with the secondary electric machine (4), a second primary shaft (6) mechanically connected with the main electric machine (3), a secondary shaft (7), and at least one control unit (10), said control unit being configured to implement a method of controlling any one of claims 1 to 8.

10. Hybrid vehicle according to claim 9, in which the dog-clutch gearbox is without a synchronizer sleeve and without a clutch.

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