Electric or hybrid vehicle propulsion system

Abstract

The invention relates to a hybrid or electric vehicle propulsion system, comprising: - an axle (1) connected to wheels of the vehicle; - a rotary electric machine (8) for propelling the wheels of the vehicle; - a reduction gear (7) arranged in the path of the torque between the rotary electric machine and the wheels of the vehicle; - a member for selectively interrupting the transmission of torque in the torque path, this member having an open position and a closed position; and - a control unit configured, upon receiving an instruction to interrupt the torque transmission in the torque path while the member for selectively interrupting the torque transmission is in the closed position: - to control the rotary electric machine so as to cancel or greatly reduce the torque transmitted by the member for selectively interrupting the transmission of torque, and then - to control the passage into the open position of the member for selectively interrupting the transmission of torque (6).

Description

[0001] Electric or hybrid vehicle propulsion system

[0002] The present invention relates to an electric or hybrid vehicle propulsion system.

[0003] As is known, such a propulsion system comprises:

[0004] - an axle connected to the vehicle's wheels,

[0005] - a rotating electric machine for propelling the vehicle's wheels, and

[0006] - a reducer placed in the torque path between the rotating electrical machine and the vehicle wheels.

[0007] For reasons of saving electrical energy and also for safety, it is necessary to be able to interrupt the transmission of torque within such a propulsion system. For this purpose, it is known to interpose a member for selective interruption of the torque transmission in the torque path such as a clutch or a dog clutch. This interruption of torque transmission must not, as far as possible, generate any jolts to preserve the comfort of the vehicle user. It is known, to reduce these jolts, to control the electric machine so that it provides zero torque, then once this zero torque is provided by the electric machine, to open the clutch or the dog clutch. However, given the numerous parameters involved when the vehicle is moving, such as its weight for example, such a situation does not guarantee an absence of jolts when opening the clutch or the dog clutch.

[0008] There is a need to remedy the drawback just mentioned.

[0009] The invention aims to meet this need and achieves this, according to one of its aspects, using a hybrid or electric vehicle propulsion system, comprising:

[0010] - an axle connected to the vehicle's wheels,

[0011] - a rotating electric machine for propelling the vehicle's wheels,

[0012] - a reducer placed in the torque path between the rotating electrical machine and the vehicle wheels,

[0013] - a member for selectively interrupting the transmission of torque in the torque path, this member having an open position and a closed position, and

[0014] - a control unit configured to, upon receiving an instruction to interrupt the torque transmission in the torque path while the selective torque transmission interruption member is in the closed position:

[0015] - control the rotating electrical machine so that the torque transmitted by the selective torque transmission interruption member is within a predefined range of values ​​containing the value 0, then - control the transition to the open position of the selective torque transmission interruption member.

[0016] According to the invention, it is thus ensured that the torque transmitted by the selective torque transmission interruption member is zero or very low before moving it to the open position. This solves the aforementioned jolt problem. This opening of the selective torque transmission interruption member at zero or very low transmitted torque can occur regardless of the operating mode of the vehicle, whether it is in the acceleration, deceleration, freewheeling phase, etc.

[0017] This predefined range of values ​​allows, for example, that the acceleration jerk gradient exerted on the vehicle is between 0.1 g / s and 0.5 g / s.

[0018] In the case where the selective torque transmission interruption member is functionally arranged upstream of the reducer, i.e. between the rotating electrical machine and the reducer, this predefined range of values ​​is for example between -2 Nm and 2 Nm.

[0019] The aforementioned reducer may or may not constitute a gearbox, which may allow several ratios to be obtained. In this case, the instruction to interrupt the torque transmission in the torque path while the selective torque transmission interruption member is in the closed position may correspond to a gear change request.

[0020] As will be seen in more detail later, the control of the rotating electrical machine so that the torque transmitted by the selective torque transmission interruption member is included in the predefined range of values ​​containing the value 0 can be done on the basis of a torque setpoint signal for the torque transmitted by the selective torque transmission interruption member which is in particular a periodic signal passing through 0, such as a ramp or a sinusoidal signal. The application of such a setpoint can lead to the value of the torque transmitted by the selective torque transmission interruption member oscillating around 0.

[0021] The control unit may include:

[0022] - a setpoint unit, generating a setpoint signal for the torque transmitted by the selective torque transmission interruption member,

[0023] - an observer, generating: a signal estimating the torque transmitted by the selective torque transmission interruption member, and a signal estimating the load torque on the axle and

[0024] - a controller configured to generate, on the basis of said setpoint signal, said signal estimating the torque transmitted by the selective torque transmission interruption member and said signal estimating the load torque on the axle, a torque setpoint for the rotating electrical machine.

[0025] Such a control unit can make it possible to estimate in real time the torque transmitted by the selective torque transmission interruption member, and to adapt the torque setpoint for the electric machine so that this setpoint corresponds to a torque transmitted by this selective torque transmission interruption member which is zero or very reduced when the selective torque transmission interruption member moves to the open position.

[0026] The transition to the open position of the selective torque transmission interruption member is made for example when the signal estimating the torque transmitted by this selective torque transmission interruption member has a value included in the predefined range of values ​​containing the value 0, for example the value 0.

[0027] Upon receipt of a torque transmission interruption instruction in the torque path while the selective torque transmission interruption member is in the closed position, the torque transmission instruction signal transmitted by the selective torque transmission interruption member, a instruction signal generated by the instruction unit, may take the form of a periodic signal passing through zero. It may be a signal whose amplitude is centered on zero, for example. This instruction signal may be a sinusoidal periodic signal or a ramp periodic signal. Such a change in the torque transmission instruction transmitted by the selective torque transmission interruption member may result in a change in the torque instruction for the rotating electrical machine.As a result, the signal estimating the torque transmitted by this selective torque transmission interruption member has a value included in the predefined range of values ​​containing the value 0, oscillating in particular in this range of values ​​around the value 0. When the setpoint signal for the torque transmitted by the selective torque transmission interruption member is a ramp, a modified slope ramp can be generated when the signal estimating the torque transmitted by this selective torque transmission interruption member has, for the first time during the control change resulting from the torque interruption setpoint, a value included in the predefined range of values.

[0028] When the signal estimating the torque transmitted by this selective torque transmission interruption member has a value within the aforementioned range of values, an instruction to move this selective torque transmission interruption member to the open position can be sent to the actuator of this selective torque transmission interruption member, this instruction on the actuator being able to cause the desired move to the open position, for example at the next cancellation of the torque transmitted by this selective interruption member. The value of the signal estimating the torque transmitted by this selective torque transmission interruption member is then not necessarily equal to 0 during this move to the open position.

[0029] The amplitude of this setpoint signal for the torque transmitted by the selective torque transmission interruption member can be chosen to cover the various uncertainties linked to the estimation of the torque transmitted by the selective torque transmission interruption member, these uncertainties coming in particular from the friction exerted on this selective torque transmission interruption member.

[0030] The observer can receive as inputs:

[0031] - a signal being a measurement of the rotation speed of the electrical machine,

[0032] - a signal being a measurement of the rotational speed of the inertia modeling the downstream of the selective interruption member of the torque transmission, and the observer can be configured to generate as outputs:

[0033] - the signal estimating the torque transmitted by the selective torque transmission interruption device,

[0034] - the signal estimating the load torque on the axle,

[0035] - a signal estimating the rotation speed of the electric machine, and

[0036] - a signal estimating the rotation speed of the inertia modeling the downstream of the selective torque transmission interruption member.

[0037] The observer can implement a closed control loop in which:

[0038] - the signal corresponding to the measurement of the rotation speed of the electrical machine is compared to the signal estimating this speed and,

[0039] - the signal corresponding to the measurement of the rotation speed of the inertia modeling the downstream of the selective interruption member of the torque transmission is compared to the signal estimating this speed.

[0040] This closed loop can be such that the above comparisons remain of zero value, so that the acceleration value estimated for the electric machine, respectively for the inertia modeling the downstream of the selective interruption member of the torque transmission, is equal to the acceleration value measured for this electric machine, respectively for this inertia modeling the downstream of the selective interruption member of the torque transmission. By this equality between estimated acceleration and measured acceleration, it can be guaranteed that the difference between the estimated torque and the measured torque for the electric machine is equal to the difference between the estimated torque and the measured torque for the inertia modeling the downstream of the selective interruption member of the torque transmission. The measurement of a torque then makes it possible to know the other torques and allows estimations of torques that are not measured.

[0041] The inertia modeling the downstream of the selective torque transmission interruption member may include all inertias such as the axle, the mass of the vehicle and the inertias of the other axle of the vehicle. Alternatively, some of these inertias are not included in the inertia modeling the downstream of the selective torque transmission interruption member, for example the mass of the vehicle. And this or these inertias not included may be taken into account in the signal estimating the load torque on the axle generated by the observer.

[0042] The observer can receive as additional input a signal estimating the torque applied to the inertia modeling the upstream of the selective torque transmission interruption member, between the rotating electrical machine and this selective torque transmission interruption member.

[0043] The inertia modeling the upstream of the selective torque transmission interruption member may include the inertia of the rotor of the rotating electrical machine and the inertia of any element arranged upstream of this selective torque transmission interruption member.

[0044] The observer can understand at least one of:

[0045] - a block for estimating the rotational speed of the electrical machine, this block receiving in particular as input: the signal estimating the torque applied to the inertia modeling the upstream of the selective torque transmission interruption member, the value of the moment of inertia of the inertia modeling the upstream of the selective torque transmission interruption member, the signal estimating the torque transmitted by the selective torque transmission interruption member, and a viscous friction coefficient on the inertia modeling the upstream of the selective torque transmission interruption member,

[0046] - a block for estimating the torque transmitted by the selective torque transmission interruption device, this block receiving in particular as inputs: the signal estimating the rotation speed of the rotating electrical machine and the signal estimating the rotation speed of the inertia modeling the downstream of the selective torque transmission interruption device,

[0047] - a block for estimating the speed of the inertia modeling the downstream of the selective torque transmission interruption member, this block receiving in particular as inputs: the signal estimating the torque transmitted by the selective torque transmission interruption member, the signal estimating the load torque on the axle, the signal estimating the rotation speed of the inertia modeling the downstream of the selective torque transmission interruption member, a viscous friction coefficient on the inertia modeling the downstream of the selective torque transmission interruption member, and the value of the moment of inertia of the inertia modeling the downstream of the selective torque transmission interruption member, and

[0048] - an axle load torque estimation block.

[0049] The controller can implement a feedforward corrector (or anticipation corrector in French) receiving as inputs: the setpoint signal for the torque transmitted by the selective interruption device of the torque transmission, and the signal estimating the load torque on the axle, this corrector providing as output a first torque setpoint for the rotating electrical machine. Such a corrector can allow the rejection of disturbances. When this feedforward corrector is used in combination with the two correctors mentioned below, this rejection of disturbances can simplify the calculation of the parameters of these two other correctors by rejecting the effects due to unmeasured quantities. The use of this feedforward corrector can also allow the system to be positioned around its theoretical equilibrium point by prejudging the dynamics of the system.The two other correctors below can then act on the regulation around this balance point, thus gaining in robustness and speed.

[0050] The controller may also or alternatively implement an error corrector receiving as inputs: the setpoint signal for the torque transmitted by the selective torque transmission interruption member, and the signal estimating the torque transmitted by this selective torque transmission interruption member, this corrector providing as output a second torque setpoint for the rotating electrical machine. This error corrector can ensure that this error will tend towards zero, thus ensuring the static precision of the regulation.

[0051] The controller may also or alternatively implement a feedback corrector receiving as input the signal estimating the torque transmitted by the selective torque transmission interruption member, this corrector providing as output a third torque setpoint for the rotating electrical machine. This feedback corrector, when combined with the error corrector, may supplement the action of this error corrector and contributes to the stability of the regulation, thus improving the reaction time of the controller.

[0052] The combined presence of the three correctors above may correspond to a preferred embodiment of the controller, the latter then providing an optimal response. The invention also covers the following cases explained below as well as other combinations with one or two correctors among the three correctors mentioned above:

[0053] - the controller only implements the error corrector and the feedback corrector,

[0054] - the controller only implements the error corrector and the feedforward corrector, - the controller only implements the feedback corrector and the feedforward corrector,

[0055] - the controller only implements the feedforward corrector.

[0056] In the case where the three aforementioned correctors are present, the torque setpoint for the rotating electrical machine can be generated on the basis of the sum of the first, second and third torque setpoints.

[0057] In all of the above, the control unit may comprise a control module for an inverter / rectifier electrically supplying the rotating electrical machine, this control module generating, on the basis of the torque setpoint generated by the controller, a setpoint for the inverter / rectifier to bring the value of the torque transmitted by the selective torque transmission interruption member into the predefined range of values, when such cancellation is necessary.

[0058] In all of the above, the control unit is for example integrated into the vehicle transmission control unit ("TCU" in English) or the engine control unit ("ECU" in English) or another separate control unit, for example a vehicle control unit, called (Vehicle Control Unit, VCU in English). The control unit can also alternatively be integrated into the inverter / rectifier electrically supplying the rotating electrical machine. This control unit can alternatively be integrated into the actuator of the selective torque transmission interruption member, this actuator acting on the position of this selective torque transmission interruption member. The actuator allows in particular the transition to the open position of the selective torque transmission interruption member.

[0059] Alternatively, this control unit can be distributed between all or part of the different host structures which have just been mentioned for the integration of the control unit.

[0060] The control unit, for example, implements one or more digital processing devices, such as microcontrollers. The control unit is, for example, an ASIC (Application-specific integrated circuit). The aforementioned control module provides, for example, instructions to a driver unit of the inverter / rectifier.

[0061] The selective torque transmission interruption device is, for example, a dog clutch. Alternatively, it can be a clutch.

[0062] In all of the above, the selective torque transmission interruption member may be arranged upstream of the reducer, or downstream of the reducer, or in the reducer, then selectively connecting two shafts of this reducer. "Upstream" and "downstream" must be understood in relation to the torque path generated by the rotating electrical machine.

[0063] The axle can be the front axle or the rear axle of the vehicle.

[0064] The electric machine may have a nominal electric power greater than or equal to 5 kW, 15 kW, 25 kW, 50 kW, 100 kW or 300 kW.

[0065] The electrical machine can be a synchronous machine or an asynchronous machine. The electrical machine has, for example, a nominal supply voltage of 48V, or a nominal supply voltage greater than 200V, especially 300V, especially 400V, especially 800V.

[0066] The rotor can be made of permanent magnets. For example, the rotor is devoid of an electrical excitation winding. The rotor can be formed by a stack of sheets inside which the permanent magnets are arranged.

[0067] Alternatively, the rotor may have an electrical excitation winding.

[0068] The axle is for example a secondary axle, the system further comprising a primary axle and a source of propulsion for the wheels of this primary axle, this source of propulsion being another rotating electric machine and / or a thermal machine.

[0069] The invention also relates, according to another of its aspects, to a method for controlling an electric or hybrid vehicle propulsion system, this propulsion system comprising:

[0070] - an axle connected to the vehicle's wheels,

[0071] - a rotating electric machine for propelling the vehicle's wheels,

[0072] - a reducer arranged in the torque path between the rotating electrical machine and the vehicle wheels, and

[0073] - a member for selectively interrupting the transmission of torque in the torque path, this member having an open position and a closed position, a method in which, upon receiving an instruction to interrupt the transmission of torque in the torque path while the member for selectively interrupting the transmission of torque is in the closed position:

[0074] - the rotating electrical machine is controlled so that the torque transmitted by the selective torque transmission interruption member is within a predefined range of values ​​containing the value 0, then

[0075] - the selective torque transmission interruption device is controlled to move to the open position.

[0076] All of the above still applies to this other aspect of the invention.

[0077] The invention may be better understood by reading the following description of non-limiting examples and by examining the attached drawing in which:

[0078] [Fig 1] schematically represents a hybrid vehicle propulsion system in which the invention can be implemented,

[0079] [Fig 2] represents a model of part of the propulsion system of Figure 1,

[0080] [Fig 3] is a block diagram of a control unit according to an exemplary implementation of the invention,

[0081] [Fig 4] is a block diagram of the controller in Figure 3

[0082] [Fig 5] is a block diagram of the observer of Figure 3, and

[0083] [Fig 6] represents curves highlighting the effect of the invention in a given example.

[0084] Figure 1 shows a propulsion system into which the invention can be integrated. This system can belong to an electric or hybrid vehicle. In the example considered, but in a non-limiting manner, the propulsion system is hybrid, as will be seen later.

[0085] This system here has a primary axle 2, which is for example the front axle. This primary axle 2 is here associated via a part 1 IR with a right wheel 10R and via a part 1 IL with a left wheel 10L.

[0086] This primary axle 2 is here associated with a differential 12 and a reducer 13. This reducer 13 can constitute a gearbox, defining several ratios.

[0087] In the example considered, this primary axle 2 is hybrid in that it receives torque from a rotating electrical machine 14, the latter being able to be powered through an inverter / rectifier 15 by a battery 16 which in the example considered has a nominal voltage greater than 300V, for example 400V or 800V, but which could alternatively have a lower nominal voltage, for example 48V. This battery 16 is for example supervised by a BMS type system 17 (“battery management system” in English). An angular displacement sensor 27 for the rotor of the rotating electrical machine 14 is provided here.

[0088] This primary axle 2 is also hybrid in that it receives torque from a thermal machine 22, if necessary via a torsional oscillation damper 21 using springs and / or a pendulum damping device, for example. A speed sensor 23 is for example associated with the thermal machine 22. Speed ​​sensors 28R and 28L can also be associated with the wheels 10R and 10L.

[0089] In examples not shown, the primary axle 2 is purely electric or purely thermal. The secondary axle 1 is here the rear axle of the vehicle, and it is associated via a part 4R with a right wheel 3R and via a part 4L with a left wheel 3L. This secondary axle 1 is here associated with a differential 5 and a reduction gear 7. This reduction gear 7 receives torque from a rotating electrical machine 8 powered via an inverter / rectifier 9 from the battery 16 already mentioned. In a variant, two different batteries may be present, one being dedicated to the electrical power supply of the rotating electrical machine 8 via the inverter / rectifier 9, the other being dedicated to the electrical power supply of the rotating electrical machine 14 via the inverter / rectifier 15.

[0090] It can be seen in Figure 1 that the on-board network of the vehicle comprises a high voltage part 20, by which the battery 16 is in the example considered connected to each inverter / rectifier 15, 9 and a low voltage part 19 connected to the high voltage part 20 by means of a DC / DC converter 18. This low voltage part 19 here comprises a battery 44 which has for example a nominal voltage of 12V.

[0091] Similar to the position sensor 27 and the speed sensors 28R, 28L and 23, the secondary axle 1 is associated with an angular displacement sensor 26 for the rotor of the rotating electrical machine 8 and with speed sensors for the wheels 3R ​​and 3L. A speed sensor 27 is also provided on the output of the reducer 7 on the differential 5 side.

[0092] In a known manner, the vehicle also comprises all or part of the various components 42 below, such as a user interface for starting the vehicle 33, such as a button, a handbrake 34, an accelerator pedal 35 and its associated sensor 36, a steering wheel 37, a brake pedal 39 and its associated sensor 38, and a gear lever 4L

[0093] The vehicle also includes several control units 29, 30, 31 and 32, namely:

[0094] - the vehicle control unit 32, also called VCU (“vehicle control unit” in English). This control unit manages the torque demand from the driver and distributes it between the front and rear propulsion sources 8, 14 and 22. It can also manage the use of the energy available in the propulsion system due to the recuperation operation or when charging the battery 16 by the heat engine 22.

[0095] - the engine control unit 29, for controlling the thermal machine 22,

[0096] - the brake control unit 30,

[0097] - the transmission control unit 31, controlling in particular the reducer 13 of the primary axle 2.

[0098] According to the invention, a member for selectively interrupting the torque transmission 6 is present. This member for selectively interrupting the torque transmission 6 is here arranged at the output of the reducer 7, but the invention is not limited to such a location. This member for selectively interrupting the torque transmission 6 may alternatively be arranged at the input of the reducer 7, or inside the reducer 7, then selectively connecting two shafts of this reducer 7.

[0099] This selective torque transmission interruption member 6 has an open position in which it interrupts the torque transmission to the wheels 3R ​​and 3L, and a closed position in which this torque transmission to the wheels 3R ​​and 3L is effective. The modification of the position of this selective torque transmission interruption member 6 is caused at least in one direction by an actuator. This selective torque transmission interruption member 6 is for example bistable, monostable normally open, or monostable normally closed. The transition from the closed position to the open position is carried out for example via the actuator.

[0100] The selective torque transmission interruption member 6 is for example a clutch or a dog clutch. Preferably, it is a selective torque transmission interruption member implementing an obstacle transmission, for example via a spline or a toothing, such as a dog clutch.

[0101] The invention makes it possible to ensure that the transition of the selective torque transmission interruption member 6 to the open position occurs when the torque it transmits is zero or very reduced.

[0102] For this purpose, the invention uses a control unit which will now be described.

[0103] The propulsion system described with reference to Figure 1 can be modeled as shown in Figure 2.

[0104] It can be seen in this figure 2 that the selective interruption member of the torque transmission 6 can be modeled as being a connection 53 between an inertia 46 modeling the upstream of this connection 53 and an inertia 48 modeling the downstream of this connection 53.

[0105] The inertia 46 modeling the upstream of the connection 53 includes for example the inertia of the rotor of the rotating electrical machine 8 and the inertia of any element arranged upstream of this connection 53.

[0106] The inertia 48 modeling the downstream of the connection 53 the selective interruption member of the torque transmission can include all the inertias such as the secondary axle 1, optionally the mass of the vehicle, and the inertias of the primary axle 2 of the vehicle.

[0107] According to the model of Figure 2, the torque transmitted by connection 53 can be approximated according to the equation below Where Torque45 corresponds to the estimate of the torque applied by the rotating electrical machine 8 to the inertia 46 modeling the upstream of the selective interruption member of the torque transmission and Torque49 corresponds to the estimate of the torque on the secondary axle 1.

[0108] This model of Figure 2 is in the example considered used by the observer 54 which will be described later. When the positioning of the selective interruption member of the torque transmission 6 is one of those mentioned previously which differs from that of the connection 53 in Figure 2, the values ​​of moment of inertia of the inertias 46 and 48, as well as the reductions applied to the speeds can be adapted by calibration by the observer 54 to take into account the real architecture of the propulsion system.

[0109] The control unit is as shown in Figure 3, for example.

[0110] This control unit comprises a setpoint unit 55, generating a setpoint signal 61 for the torque transmitted by the selective torque transmission interruption member 6.

[0111] This control unit also includes an observer 54, which will be described with reference to FIG. 5. This observer 54 generates in the example considered:

[0112] - a signal 60 estimating the torque transmitted by the selective torque transmission interruption member 6, and

[0113] - signal 49 estimating the load torque on axle 1, providing the aforementioned Torque49 value

[0114] The control unit also comprises a controller 56, which will be described with reference to FIG. 4. This controller 56 is in the example considered configured to generate, on the basis of the setpoint signal 61, the signal 60 estimating the torque transmitted by the selective interruption member of the torque transmission 6 and the signal 49 estimating the load torque on the axle 1, a torque setpoint 59 for the rotating electrical machine 8.

[0115] The 55 deposit unit uses, for example, as inputs:

[0116] - a signal 62 defining an initial setpoint for the torque transmitted by the selective torque transmission interruption member 6, namely the value of the torque setpoint when the opening of the selective torque transmission interruption member 6 is received, for example during a gear change request, and

[0117] - a signal 63 defining a final setpoint for the torque transmitted by the selective torque transmission interruption member 6, namely the final value to be reached for this opening of the selective torque transmission interruption member 6, which is in the example described 0, - a signal 64 corresponding to the rotation speed of the rotating electrical machine 8 measured, coming for example from the sensor 26,

[0118] - a signal 65 corresponding to the rotation speed at the output of the reducer 7 measured by the sensor 25.

[0119] The setpoint signal 61 generated by the setpoint unit 55 is, in the example considered, a periodic signal in the form of ramps, centered on 0. If necessary, the setpoint unit 55 can generate a torque setpoint for the rotating electrical machine in advance, this anticipated torque setpoint being taken into account by the controller 56 when generating the torque setpoint for the rotating electrical machine 59.

[0120] As can be seen in Figure 5, the observer 54 receives for example as inputs the signal 64 already mentioned, and the signal 65 already mentioned. This observer 54 provides as outputs the aforementioned signals 49 and 60, the latter being respectively the signal estimating the torque transmitted by the selective interruption member of the torque transmission 6 and the signal estimating the load torque on the secondary axle 1.

[0121] Figure 5 shows that other additional outputs are possible for observer 54, namely:

[0122] - a signal 47 estimating the rotation speed of the rotating electrical machine 8, and

[0123] - a signal 50 estimating the speed of inertia 48.

[0124] We can also see in Figure 5 that the observer 54 can implement a closed loop in which an error vector is generated at 93 by comparing:

[0125] - signal 64 corresponding to the measurement of the rotation speed of the rotating electrical machine 8 to signal 47 estimating this speed and,

[0126] - signal 65 corresponding to the measurement of the rotation speed at the output of reducer 7 to signal 50 estimating this speed.

[0127] This closed loop aims to keep the result of each of these comparisons zero.

[0128] This closed loop implements a corrector 87 characterized by a set of parameters 98. At the output of this corrector 87, there are several correction signals 94 to 97, namely:

[0129] - a correction signal 94 on the estimation of the rotation speed of the electric machine 8,

[0130] - a correction signal 95 on the estimation of the torque transmitted by the selective torque transmission interruption member 6,

[0131] - a correction signal 96 on the estimation of the rotation speed at the output of the reducer 7, and

[0132] - a correction signal 97 on the estimation of the load torque on the secondary axle 1. The parameter set 98 is for example in the form of a matrix and the correction signals 94 to 97 are for example obtained by multiplying the error vector at 93 by this matrix. These correction signals are received at the input of several blocks 88 to 91 which will now be described. The values ​​of the parameter set 98 are for example chosen so as to ensure convergence of the estimates provided by the observer 54 in a rapid time, for example in a duration of between 50 ms and 300 ms.

[0133] Block 88 is an estimation block which generates signal 47 which is an estimation of the rotation speed of the electrical machine 8. This block 88 receives here as inputs:

[0134] - the signal 45 estimating the torque applied to the inertia 46 modeling the upstream of the selective interruption member of the torque transmission 6 according to the model of figure 2,

[0135] - signal 46 being the value of the moment of inertia of this inertia 46, still according to the model of figure 2,

[0136] - the signal 60 estimating the torque transmitted by the selective torque transmission interruption member 6, and

[0137] - a signal 51 being a coefficient of viscous friction on the inertia 46.

[0138] As shown in Figure 5, this block 88 can also receive as input the value of the signal 47 estimated by the block 88 during the previous calculation iteration.

[0139] Within this block 88, the difference between signals 45 and 60 to which is added a friction torque determined using signals 47 and 51 is then multiplied by the value of the moment of inertia according to 46, then modified taking into account the correction signal 94. The result is then integrated with respect to time to obtain an estimate of the rotation speed of the electrical machine 8 according to signal 47.

[0140] Block 89 is an estimation block that generates signal 60 which is an estimation of the torque transmitted by the selective torque transmission interruption member 6. This block 89 receives here as inputs: signal 47 estimating the rotational speed of the electrical machine 8, signal 50 estimating the speed of the inertia 48 modeling the downstream of the selective torque transmission interruption member 6, and the parameters of the model 53 used for the selective torque transmission interruption member 6, such as the stiffness of this connection and / or an internal damping torque. Within this block 89, the difference between signals 47 and 50 to which is added the correction signal 95 is integrated with respect to time to estimate the voltage applied to the selective torque transmission interruption member 6.To estimate the torque transmitted by this selective torque transmission interruption member 6, this voltage is then multiplied by the stiffness of the model 53 used for the selective torque transmission interruption member 6 according to FIG. 2. In a variant, the signal 60 can be additionally obtained via an internal damping torque obtained on the basis of the difference between the signals 47 and 50, this difference being multiplied by a damping factor of the model 53.

[0141] Block 90 is an estimation block which generates signal 50 which is an estimation of the speed of inertia 48 modeling the downstream of the selective interruption member of the torque transmission 6. This block 90 receives here as inputs:

[0142] - the signal 60 estimating the torque transmitted by the selective torque transmission interruption member 6,

[0143] - signal 49 estimating the load torque on secondary axle 1,

[0144] - the value determined for signal 50 by block 90 during the previous calculation iteration,

[0145] - the signal 52 being a viscous friction coefficient on the inertia 48 modeling the downstream of the selective interruption member of the torque transmission 6, and

[0146] - signal 48 being the value of the moment of inertia of this inertia 48, still according to the model of figure 2.

[0147] Within this block 90, the difference between signals 60 and 49 to which is added the friction torque obtained using signals 50 and 52 is divided by the moment of inertia value according to signal 48 and then corrected taking into account correction signal 96. The result is integrated with respect to time to obtain signal 50.

[0148] Block 91 is an estimation block which generates signal 49 which is an estimate of the load torque on secondary axle 1. This block 91 receives as input the correction signal 97. This block is based for example on the fact that the time derivative at order n of signal 49 is imposed to be zero.

[0149] Block 92 is a selector for sending signals 47 and 50 to comparator 86.

[0150] We will now describe with reference to figure 4 the controller 56 of figure 3. As can be seen in this figure 3, the controller 56 for example implements three separate correctors 73, 74 and 75 which will now be described.

[0151] A first controller 73 implements a feedforward corrector receiving as inputs:

[0152] - the setpoint signal 61 for the torque transmitted by the selective torque transmission interruption member 6, and

[0153] - signal 49 estimating the load torque on secondary axle 1.

[0154] This corrector uses for example a set of parameters 77 being for example two gains K1 and K2, each of these gains being for example respectively multiplied with one of the input signals 61, 49.

[0155] The invention is however not limited to gains of constant value. The values ​​of these gains can vary via non-linear formulas or data storage tables, the chosen value being able to depend on the rotation speed of the electrical machine 8 and / or the rotation speed of the output of the reducer, and / or being able to depend on the temperature of this electrical machine 8 or of the reducer 7, for example, and / or on the reduction ratio applied by the reducer 7 if the latter makes it possible to obtain different ratios. Alternatively, the corrector is not a proportional corrector, being of the proportional-derivative type for example.

[0156] The first controller 73 provides an output signal 70 being a first torque setpoint for the rotating electrical machine.

[0157] The second controller 74 can implement an error corrector receiving as inputs:

[0158] - the setpoint signal 61 for the torque transmitted by the selective torque transmission interruption member 6, and

[0159] - signal 60 estimating the torque transmitted by the selective torque transmission interruption member 6.

[0160] These two inputs are compared at 80 and this difference is used by the corrector to generate at output a signal 71 being a second torque setpoint for the rotating electrical machine. This corrector 74 can implement at least one integration. It can also implement an anti-drift system of the integrator based on the limit values ​​for the torque of the electrical machine 8. This anti-drift system can make it possible to suspend the integration carried out by the corrector when these torque limit values ​​are reached. This corrector uses a set of parameters 78 being for example gains. As already mentioned with reference to the controller 73, these gains are not necessarily of constant value.The values ​​of these gains can vary via non-linear formulas or data storage tables, the chosen value being able to depend on the rotation speed of the electrical machine 8 and / or the rotation speed of the output of the reducer, and / or being able to depend on the temperature of this electrical machine 8 or of the reducer 7 and / or the reduction ratio applied by the reducer 7 if the latter makes it possible to obtain different ratios, for example.

[0161] The third controller 75 can implement a feedback corrector. This controller receives here as input the signal 60 estimating the torque transmitted by the selective torque transmission interruption member 6. This corrector provides as output a signal 72 being a third torque setpoint 72 for the rotating electrical machine. This third torque setpoint can make it possible to stabilize the closed-loop system including the rotating electrical machine 8, the reducer 7 and the observer 54 here assimilated to a sensor. The corrector uses a set of parameters 79 being for example gains. As already mentioned with reference to the controller 73 and the controller 74, these gains are not necessarily of constant value.The values ​​of these gains can vary via non-linear formulas or data storage tables, the chosen value being able to depend on the rotation speed of the electrical machine 8 and / or the rotation speed of the output of the reducer, and / or being able to depend on the temperature of this electrical machine 8 or of the reducer 7 or of the oil in the reducer, for example, and / or on the reduction ratio applied by the reducer 7 if the latter makes it possible to obtain different ratios, for example. In a variant, this corrector is not a proportional corrector but can be of the proportional-derivative type.

[0162] In the case where the three aforementioned correctors 73, 74 and 75 are present, the signal 59 corresponding to the torque setpoint for the rotating electrical machine can be generated on the basis of the sum of the first, second and third torque setpoints via a summer 81. The output signal of this summer 81 can optionally drive a limiting block 85. The latter limits the values ​​of the torque setpoint signal 59 for the electrical machine 8 within a range defined by terminals 82 and 83, these terminals being able to be defined dynamically according to the speed of the electrical machine 8. The output signal of this limiting block 85 can then be received by a control module 57 of the electrical machine 8, this control module generating a control signal 58 of the inverter / rectifier 9 through which the electrical machine 8 is powered from the battery 16.

[0163] The control unit which has just been described can allow, upon receipt of an instruction to interrupt the torque transmission in the torque path while the selective torque transmission interruption member 6 is in the closed position:

[0164] - control the rotating electrical machine 8 so as to cancel or significantly reduce the torque transmitted by the selective torque transmission interruption member 6, then

[0165] - control the selective torque transmission interruption member 6 so that it moves to the open position.

[0166] Figure 6 represents as a function of time:

[0167] -on the upper part, the evolution of signals 47 and 50 which respectively represent the estimation of the speed of the rotating electrical machine 8 and the estimation of the speed of the inertia 48,

[0168] - on the middle part, the evolution of the signals 59, 60 and 61 which respectively represent the torque setpoint for the rotating electrical machine, the estimation of the torque transmitted by the selective interruption member of the torque transmission 6, and the setpoint 61 for the torque transmitted by the selective interruption member of the torque transmission 6, - on the lower part, the evolution of the state of the selective interruption member of the torque transmission 6, the “open / closed” command for this state of the selective interruption member of the torque transmission 6 according to a signal 130, and the “open / close” command for the actuator of the selective interruption member of the torque transmission 6 according to a signal 140.

[0169] It can be seen that between times t0 and t1, the selective torque transmission interruption member 6 is in the closed position and a ratio of the reducer 7 is engaged. As shown in Figure 6, in this configuration, a difference may exist between the estimation of the torque transmitted by the selective torque transmission interruption member 6 according to the signal 60 and the torque setpoint for the rotating electrical machine 8 according to the signal 59.

[0170] At a time t1, an instruction to interrupt the torque transmission in the torque path is received. From this time t1, the instruction 61 for the torque transmitted by the selective torque transmission interruption member 6 is modified so as to oscillate around the value 0. This instruction 61 changes values ​​in order to be maintained within a predefined range of values, defined between an upper value which is here a constant according to a level 110, and a lower value which is here a constant according to a level 120. The invention is however not limited to constant values ​​for the upper and lower values.

[0171] The values ​​according to levels 110 and 120 are for example chosen so that the acceleration jerk gradient (“jerk” in English) exerted on the vehicle is between 0.1 g / s and 0.5 g / s. In the case where the selective interruption member of the torque transmission 6 is functionally arranged between the rotating electrical machine and the reducer, this predefined range of values ​​is for example between -2 Nm and 2 Nm. In other cases, these values ​​for levels 110 and 120 are adapted taking into account the reduction ratio(s) in the reducer 7.

[0172] This modification of the setpoint is accompanied by a shift in the torque setpoint for the rotating electrical machine 8 according to the signal 59 so that the signal 60, namely respectively the estimation of the torque transmitted by the selective interruption member of the torque transmission 6, follows the signal 61 which is the setpoint for this torque transmitted by the selective interruption member of the torque transmission 6.

[0173] It can be seen in Figure 6 that, when the signal 60 estimating the torque transmitted by the selective torque transmission interruption member 6 reaches the predefined range of values, the actuator can receive an instruction allowing the selective torque transmission interruption member 6 to move to the open position. If necessary, simultaneously or almost simultaneously, with this reception of the instruction by the actuator, a different slope ramp can be generated for the instruction 61 for the torque transmitted by the selective torque transmission interruption member 6.

[0174] At time t2, the selective torque transmission interruption member 6 moves to the open position, and no gear is then engaged. This time t2 occurs while the setpoint signal 61 for the torque transmitted by the selective torque transmission interruption member 6 is in the oscillation phase mentioned above and while the torque estimation signal 60 transmitted by the selective torque transmission interruption member 6 has a value within the predefined range of values. Once the selective torque transmission interruption member 6 has effectively moved to the open position, the oscillation of the setpoint signal 61 around 0 is interrupted, and the rotating electrical machine 8 is no longer controlled by the control unit.

Claims

Claims 1. Hybrid or electric vehicle propulsion system, comprising: - an axle (1) connected to wheels (3R, 3L) of the vehicle, - a rotating electric machine (8) for propelling the vehicle wheels, - a reducer (7) arranged in the torque path between the rotating electrical machine (8) and the wheels (3R, 3L) of the vehicle, - a member for selectively interrupting the torque transmission (6) in the torque path, this member having an open position and a closed position, and - a control unit configured to, upon receiving an instruction to interrupt the torque transmission in the torque path while the selective torque transmission interruption member (6) is in the closed position: - control the rotating electrical machine (8) so that the torque transmitted by the selective torque transmission interruption member (6) is within a predefined range of values containing the value 0, then - controlling the transition to the open position of the selective torque transmission interruption member (6). characterized in that the control of the rotating electrical machine so that the torque transmitted by the selective torque transmission interruption member (6) is included in the predefined range of values containing the value 0 is done on the basis of a setpoint signal (61) for the torque transmitted by the selective torque transmission interruption member (6) which is a periodic signal passing through 0, in particular a ramp or a sinusoidal signal.

2. System according to the preceding claim, in which the control unit comprises: - a setpoint unit (55), generating the setpoint signal (61) for the torque transmitted by the selective torque transmission interruption member (6), - an observer (54), generating a signal (60) estimating the torque transmitted by the selective torque transmission interruption member (6), and a signal (49) estimating the load torque on the axle (1), and - a controller (56) configured to generate, on the basis of said setpoint signal (61), said signal (60) estimating the torque transmitted by the selective torque transmission interruption member (6) and said signal (49) estimating the load torque on the axle, a torque setpoint (59) for the rotating electrical machine.

3. System according to claim 1 or 2, wherein, upon receipt of an instruction to interrupt the transmission of torque in the torque path while the member selective torque transmission interruption member (6) is in the closed position, the setpoint signal (61) for the torque transmitted by the selective torque transmission interruption member (6) takes the form of a periodic signal passing through zero.

4. System according to claim 3, in which the setpoint signal (61) takes the form of a periodic sinusoidal or ramp signal.

5. System according to claim 3, in which the observer (54) receives as inputs: - a signal (64) being a measurement of the rotation speed of the electrical machine (8), - a signal (65) being a measurement of the rotation speed of the inertia (48) modeling the downstream of the selective torque transmission interruption member (6), and the observer being configured to generate as outputs: - the signal (60) estimating the torque transmitted by the selective torque transmission interruption member, - the signal (49) estimating the load torque on the axle, - a signal (47) estimating the rotation speed of the electric machine, and - a signal (50) estimating the rotation speed of the inertia (48) modeling the downstream of the selective torque transmission interruption member.

6. System according to claim 5, the observer (54) implementing a closed control loop in which: - the signal (64) being a measurement of the rotation speed of the electrical machine is compared to the signal (47) estimating this speed and, - the signal (65) being a measurement of the speed of the inertia (48) modeling the downstream of the selective interruption member of the torque transmission (6) is compared to the signal (50) estimating this speed.

7. System according to claim 6, in which the observer (54) comprises at least one: - a block (88) for estimating the rotational speed of the electric machine, this block receiving in particular as input: the signal estimating the torque applied to the inertia (46) modeling the upstream of the selective torque transmission interruption member (6), the value of the moment of inertia of the inertia (46) modeling the upstream of the selective torque transmission interruption member, the signal estimating the torque transmitted by the selective torque transmission interruption member, and a viscous friction coefficient on the inertia modeling the upstream of the selective torque transmission interruption member, - a block (89) for estimating the torque transmitted by the selective torque transmission interruption member (6), this block receiving in particular as inputs: the signal (47) estimating the rotation speed of the electric machine and the signal (50) estimating the rotation speed of the inertia (48) modeling the downstream of the selective interruption member of the torque transmission, - a block (90) for estimating the speed of the inertia (48) modeling the downstream of the selective torque transmission interruption member (6), this block (90) receiving in particular as inputs: the signal (60) estimating the torque transmitted by the selective torque transmission interruption member (6), the signal (49) estimating the load torque on the axle, the signal (50) estimating the rotation speed of the inertia (48) modeling the downstream of the selective torque transmission interruption member (6), a viscous friction coefficient on the inertia modeling the downstream of the selective torque transmission interruption member, and the value of the moment of inertia of the inertia modeling the downstream of the selective torque transmission interruption member, and - a block (91) for estimating the load torque on the axle (1).

8. System according to any one of claims 2 to 7, the controller (56) implementing a feedforward corrector (73) receiving as inputs: the setpoint signal (61) for the torque transmitted by the selective torque transmission interruption member, and the signal (49) estimating the load torque on the axle (1), this corrector providing as output a first torque setpoint (70) for the rotating electrical machine (8).

9. System according to any one of claims 2 to 8, the controller (56) implementing an error corrector receiving as inputs: the setpoint signal (61) for the torque transmitted by the selective torque transmission interruption member (6), and the signal (60) estimating the torque transmitted by this selective torque transmission interruption member, this corrector providing as output a second torque setpoint (71) for the rotating electrical machine (8).

10. System according to any one of claims 2 to 9, the controller (56) implementing a feedback corrector receiving as input the signal (60) estimating the torque transmitted by the selective torque transmission interruption member (6), this corrector providing as output a third torque setpoint (72) for the rotating electrical machine (8).

11. System according to claims 8, 9 and 10, wherein the torque setpoint (59) for the rotating electrical machine is generated on the basis of the sum of the first (70), second (71) and third (72) torque setpoints.

12. System according to any one of claims 2 to 11, in which the control unit comprises a control module (57) of an inverter / rectifier (9) electrically supplying the rotating electrical machine (8), this control module (57) generating on based on the torque setpoint (59) generated by the controller (56) a setpoint (58) for the inverter / rectifier (9) to bring the value of the torque transmitted by the selective torque transmission interruption member (6) into the predefined range of values.

13. System according to any one of the preceding claims, the member for selectively interrupting the torque transmission (6) being a dog clutch.

14. System according to any one of the preceding claims, the selective torque transmission interruption member (6) being arranged upstream of the reducer (7), or downstream of the reducer (7), or in the reducer (7), then selectively connecting two shafts of this reducer.

15. System according to any one of the preceding claims, the axle (1) being the front axle or the rear axle of the vehicle.

16. Propulsion system according to any one of the preceding claims, said axle (1) being a secondary axle, the system further comprising a primary axle (2) and a propulsion source (14, 22) of the wheels (10R, 10L) of this primary axle (2), this propulsion source being another rotating electrical machine or a thermal machine.

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