FR2985708A1 - Torque transmission system for car, has electronic control unit connected to estimator to simultaneously calculate torque set points, where one of set points is calculated for same position of accelerator pedal by substituting target speed - Google Patents

Abstract

The system has an electronic control unit connected to an estimator to simultaneously calculate a torque set point (etacorr1) based on an engine rotation speed (omega) and another torque set point (etacorr2) greater than the former set point at successive moments during a change of gear ratio. The latter set point is calculated for a same position of an accelerator pedal by substituting target speed (omegafin) with the engine speed. The target speed is obtained by dividing a wheel rotation speed of the vehicle by a coefficient proportional to a final gear ratio of the box following the change. Independent claims are also included for the following: (1) a vehicle (2) a method for managing a transmission system with a robotized gear box during change of gear ratio.

Description

The invention relates to a method for controlling a robotized gearbox with a single clutch. Such a gearbox typically comprises a clutch for coupling or rotational decoupling an input shaft of the box with a primary shaft, and a series of gearboxes that can be engaged or disengaged, and for imposing different gear ratios. reduction between the speed of rotation of a secondary shaft driving the wheels of the vehicle, and the speed of rotation of the primary shaft. A robotic actuator is used to engage or disengage the actuators at specific times. The transmissible torque of the clutch is managed by an electronic control unit of the robotized box. The variations in the transmissible torque of the clutch can therefore be adapted both with respect to the variations in engine torque and with respect to the moment of disengagement of a gearbox and the reengagement of a different gearbox. The variations of the torque transmissible by the clutch, and the positioning of the corresponding curve with respect to the torque curve developed by the engine, will determine the evolution of the engine speed curve, as well as the torque curve transmitted to the engine. drive wheels of the vehicle. This torque curve has a hollow with a zero crossing, due to the opening of the clutch when disengaging a gear to engage a different gear. The manner in which the torque to the wheels then rises to reach a "cruising" value corresponding to a clutch closed configuration after the end of the engine speed synchronization, strongly influences the feeling of the passengers of the vehicle, and more on the feel of the driver, who may be tempted to force unnecessarily the support exerted on the accelerator pedal. The object of the invention is to limit the amplitude of the torque depression persisting temporarily after the engagement of the new gear. Solutions are proposed to reduce the torque dip, which however require the presence of a second motor adapted to drive the primary shaft or the secondary shaft, as for example in the patent application FR 288 7496 which uses an electric motor in a "parallel hybrid" engine configuration, or in the patent application FR 2784058 where the gearbox comprises a dedicated electric motor. The invention aims to reduce the amplitude of the torque depression without using an additional motor, which would temporarily replace the motor driving the input shaft of the box.

To this end, a transmission system for a motor vehicle comprises a robotized gearbox comprising an input drive shaft. The system is able to be connected to a counter of the rotational speed of the motor shaft, a speed sensor of a vehicle wheel and an accelerator pedal. The system comprising a torque setpoint estimator adapted to determine a motor torque setpoint to be applied to the motor shaft, according to a rotation speed of the motor shaft and an accelerator pedal position. The system comprises an electronic control unit connected to the estimator, which is configured for calculating, in parallel with successive instants, by means of the estimator, a first set of instructions during a shift of the gearbox ratio. of torque as a function of the engine speed estimated by the counter, and a second torque setpoint higher than the first torque setpoint, calculated for the same position of the accelerator pedal, by replacing the engine speed with a target speed obtained by dividing a speed of rotation of the wheel (s) of the vehicle by a coefficient, proportional to the final gear ratio of the gearbox following the gear change. In relation to the reduction ratio of a gearbox of the gearbox, it is meant the quotient of the speed of rotation of the secondary shaft by the speed of the primary rotation shaft associated with the gearbox. In practice, the estimator is connected to a counter able to evaluate the rotational speed of a flywheel of a motor connected to the input shaft of the gearbox, and is connected to a pedal position sensor. acceleration. The accelerator pedal could also be a joystick or other manual control. According to a preferred embodiment, the electronic control unit is furthermore configured to: simultaneously decrease a transmissible torque setpoint sent to a gearbox clutch, and a motor torque setpoint sent to a motor connected to a gearbox. the motor shaft, to cancel the transmissible torque setpoint of the clutch, maintaining the torque setpoint lower than or equal to the torque setpoint transmittable by the clutch, and then disengage a first reducer corresponding to the ratio initially engaged, and engage a second reducer corresponding to the final report, then simultaneously grow the transmissible torque setpoint sent to the clutch, and the engine torque setpoint, maintaining the engine torque setpoint less than or equal to the torque setpoint transferable from the clutch, until the transmissible torque setpoint of the clutch becomes strictly superior at the first torque setpoint, then decrease the transmissible torque setpoint of the clutch by following the second torque setpoint, until the transmissible torque setpoint of the clutch rejoins the first torque setpoint . By approaching the second torque setpoint, it is intended to become greater than the second torque setpoint, minus a first threshold pre-recorded in the electronic control unit. By following the second torque setpoint, it is meant that the absolute value of the difference of the value "following" and the second torque setpoint remains less than or equal to a second threshold pre-recorded in the electronic control unit. Preferably, the electronic control unit is configured to impose a torque setpoint transmittable to the clutch according to the diagram above during a change of the amount ratio under load, ie during a change of gear ratio. a first gear ratio to a higher gear ratio ("gear shift"), the torque transmitted to the wheels from the engine being positive, ie the motor that drives the vehicle forward ("gear change under load"). Other steering strategies of the two clutches can be provided for other types of gear changes, for example for "retro" or "on the move" gear changes. Advantageously, the electronic control unit is further configured to maintain the transmissible torque setpoint of the clutch substantially equal to the engine torque setpoint, during the first decay phase, and to maintain the engine torque setpoint strictly lower than the transmissible torque setpoint of the clutch while this transmissible torque setpoint increases from zero to the first torque setpoint. According to an advantageous embodiment, the torque setpoint estimator is configured to read a map according to the position of the acceleration pedal and according to the engine speed, respectively according to the target speed, to deduce therefrom a gross torque setpoint, and is configured to subtract from the gross torque setpoint, an inertial term which is proportional to the derivative of the engine speed, respectively which converges to a term proportional to the derivative of the engine speed, and to deliver the difference obtained as the value of the first torque setpoint, respectively as the value of the second torque setpoint. Preferably, the electronic control unit is further configured to converge the motor torque setpoint, to the gross torque setpoint calculated by the torque setpoint estimator, and to converge the rotation speed of the engine. motor shaft to the target mode substantially at the same time. According to another aspect, there is provided a vehicle equipped with a transmission system according to one of the preceding claims, comprising a motor connected to the drive shaft of the box, a counter of the rotational speed of the engine, a sensor of rotation speed of at least one wheel of the vehicle and an accelerator pedal. A method of managing a transmission system with a robotic gearbox with a clutch is also provided. During a gear change, after having disengaged a first transmission ratio and having engaged a second transmission ratio, a first torque setpoint is calculated in parallel over time using the same mapping. a rotational speed of the engine and an accelerator pedal position, and a second torque setpoint greater than the first torque setpoint, calculated using the same mapping, from a rotational speed at least one wheel of the vehicle, of the same accelerator pedal position, and of the gear ratio, after gear ratio, between the speed of rotation of the vehicle wheels and the speed of rotation of the primary shaft, and in that a transmissible torque setpoint of the clutch is brought above the first torque setpoint, then it is lowered by following the second torque setpoint until it reaches the first setpoint. nsigne of couple. According to a preferred embodiment, the transfer torque setpoint of the second clutch is linearly increased from the moment when it exceeds the first torque setpoint, until it reaches the second torque setpoint, and then decrease it by following the second torque instruction. Advantageously, the transmissible torque setpoint of the second clutch is increased linearly after it has exceeded the first torque setpoint, until it reaches a threshold or the second torque setpoint, and then it is imposed on it. the first case a constant value equal to the threshold until it reaches the second torque setpoint, then it is decreased by following the second torque setpoint. The threshold may be a function of the initial and final ratio values, and of at least one parameter of a temperature outside the vehicle, an atmospheric pressure outside the vehicle, a temperature of the engine cooling water, a temperature of the engine, oil from the gearbox. The invention will be better understood on reading the detailed description of an embodiment taken by way of non-limiting example, and illustrated by the appended drawings in which: FIG. 1 is a schematic representation of an equipped powertrain system of a gearbox according to the invention, FIG. 2 illustrates different modes of use of a torque setpoint estimator in the gearbox according to the invention, and FIG. 3 illustrates the chronology of different torque instructions. issued by an electronic control unit of the transmission of the power system of Figure 1. As shown in Figure 1, a power system 1 comprises a motor 2 whose torque is calculated from a pedal 8 and which allows to drive by means of a differential 14 two driving wheels 16 of a vehicle.

The motor 2 drives a flywheel 3 of inertia J which is integral with an input drive shaft 4. A counter 9 rotational speed w is placed so as to scroll marks made on the circumference of the steering wheel motor 3. The counter 9 may comprise a sensor, for example of the magnetic type or an optical type sensor. A speed sensor 26 of the vehicle's wheels is placed at one of the wheels of the vehicle. The purpose of the rotational speed sensor is to estimate the linear speed of travel of the vehicle. It can be placed on a driving wheel or on a non-driving wheel, or group several sensors and a calculator able to recalculate the speed of advance of the vehicle from different measurements made on several wheels of the vehicle, and therefore a wheel speed "average" horn Between the drive shaft 4 and the differential 14 is interposed an automatic gearbox comprising in particular a clutch 10 for securing or detaching the drive shaft 4 from a primary shaft 13, several reducers including a first reducer 11 allowing applying a first transmission ratio R, between a secondary shaft 12 and the primary shaft 13, and one or more second reducers 21 for imposing other transmission ratios Rf between the secondary shaft 12 and the primary shaft 13. By transmission ratio means here the ratio of the rotational speeds between the secondary shaft 12 and the primary shaft 13. The gearbox comprises an electronic control unit 5 adapted to send transmissible torque instructions to the drive shaft. The electronic control unit 5 comprises a torque setpoint estimator 6 which is connected to the acceleration pedal 8 and to the rotational speed counter 9, and which is st able, using a map 7, to determine different setpoint torque, in particular a setpoint torque C which is used to be sent as torque setpoint to the motor 2. FIG. 2 schematically illustrates the operation of the torque setpoint estimator 6 in two separate uses of this torque setpoint estimator. In the upper part of FIG. 2, the torque set point estimator 6 is represented as a calculation unit receiving as input a rotational speed w coming from the rotation speed counter 9 and a pedal angle to it coming from a sensor of the acceleration pedal 8. In this configuration, the torque setpoint estimator 6 delivers a first torque setpoint reference value C corresponding to the torque setpoint which is sent to the engine 2 during the driving phases where the clutch 10 is closed at its locking value. By lock value of the clutch is meant a value of closing force to obtain a torque transmission without sliding of the clutch. In this configuration, the torque setpoint estimator 6 also delivers a corrected setpoint COrn e, - of torque, which is the torque value that one wishes to have at the input of the gearbox, for example at the of the input shaft 4. or first setpoint This corrected value P _corri setpoint takes into account the inertia of the elements arranged between the motor and the input shaft 4. This inertia is noted J in the illustrated example and corresponds substantially to the inertia of the flywheel 3.

We thus have the relation: C corrl = C Jw 'Where C is the gross value of the torque setpoint, w' is the derivative of the rotation speed w with respect to time and J corresponds to the inertia of the elements between the motor and the input shaft 4.

Typically, the torque setpoint estimator 6 receives the pedal angle and rotational speed values a respectively on a first input 27 and on a second input 28. The values a of pedal angle and of rotational speed w are used to read in a map 7 of the torque reference estimator 6.

The torque estimator 6 thus obtains, after a thresholding by a clipping device 22, the setpoint torque C intended for the motor 2. In parallel with the reading of the cartography 7, the torque setpoint estimator 6 performs a bypass relative to the time of the regime (0 (t) which it receives on a third input 29, to obtain a derivative w 'which is multiplied at the level of a multiplier 18 by the constant J. The value obtained is subtracted from the level a subtractor 19 of the torque C to obtain the corrected torque setpoint Ccorri In the lower part of FIG. 2, the same torque setpoint estimator 6 is represented when it is used to calculate a second corrected setpoint of torque ecorrz, or second torque setpoint This second use is implemented when the gearbox is in gearshift, from an initial ratio R, before the gearshift, to a final transmission ratio Rfax. s the change ratio. The same pedal angle value a as before is sent to the first input 27 of the torque setpoint estimator. The same rotational speed value is sent to the third input 29. On the second input 28, the estimator this time receives a target speed corresponding to the rotational speed of the motor that one would like to have for the same pedal control, if the gear change was already done. The target speed is equal to CO end = R1 .R bridge where horn is the speed of rotation of the vehicle wheels, Rf is the transmission ratio of a second gearbox, which becomes active after the gear change, and Rpont is a bridge ratio, corresponding to the quotient of the speed of rotation of the drive wheels 16 by the speed of rotation of the secondary shaft 12. The product Rf.Rpon, therefore corresponds to the quotient of the speed of rotation of the wheels of the vehicle by the speed of rotation of the primary shaft 13, which is then also the rotational speed of the drive shaft 4, when the final report is engaged and the clutch 10 is completely closed. As before, the mapping 7 and the clipping device 22 are used to calculate a torque setpoint C to which is subtracted a calculated inertia term using the differentiator 17 and the multiplier 18. The torque value ecorr2 as well obtained corresponds substantially to the torque setpoint that would be required at the input of the box-that is to say at the level of the motor shaft 4-, for the same position a of the pedal and depending on the current speed of rotation of the wheels of the vehicle, if the change of ratio was already completed. It is not departing from the scope of the invention if the computation of Ccorr2 is performed by entering on the third input 29 the cofin value, or a combination of cofin and w, for example a linear combination of cofin and w. However, the inertial term delivered at the output of the multiplier 18 must converge towards the inertial term calculated from w. cofin converges itself to w, thanks to the step of synchronization of the engine speed which is described below, in the explanation of FIG. 3. The second corrected setpoint of torque Ccorr2 converges by higher value towards the first corrected setpoint of torque Ccorri, in the case of a change of ratio amount under load. Figure 3 illustrates, on three graphs 23, 24, 25 having for the abscissa the same time scale, the changes in various characteristic quantities during a gear change made in accordance with the invention. The gear changes concerned here are changes in the ratio of amounts under load, that is to say gear changes where the final gear ratio is greater than the initial gear ratio, and for which the gear change takes place in a gear configuration. where the torque applied to the wheels from the engine is positive, that is to say in a configuration where the motor drives the wheels of the vehicle. The first graph 23 is a graph representing the changes in the rotational speed of the engine. The graph of the medium 24 is a graph representing the evolutions of different setpoint torque, in particular of the transmissible torque setpoint of the clutch 10 and of the setpoint torque transmitted to the engine 2. The bottom graph 25 represents the changes in the transmitted torque. to the driving wheels 16 of the vehicle. The first graph 23 illustrates the evolution of the rotation speed w of the motor 2. Successive time intervals A, B, C, D1, D2, E, F are indicated on the time scale. Each of these intervals corresponds to a particular step during the gear change. For a constant support of the pedal, the initial gear RI being engaged on a first gear 11, the rotational speed w of the motor follows a substantially linear increasing curve wedge.

For the same foot pedal support, ie the same pedal angle a, to roll at the same linear forward speed, the rotational speed of the motor should follow a cofin linear upward curve which can be deduced from the speed of rotation of the wheels of the vehicle according to the formula: CO end - R1 .R bridge where is the speed of rotation of the wheels of the vehicle, Rf is the transmission ratio of the second gear 21, which becomes active after cor gear change, and Rpont is the bridge ratio, as explained above. One of the purposes of controlling the gearbox and the engine during gearshift is to bring the speed curve w to coincide with the curve wfin at the end of the shift. It is thus necessary to provoke a temporary decay of the regime w as indicated during the phases B, C, D1 and D2, then a progressive "docking" on the curve wfin. Another aim of the control is that the torque transmitted to the wheels during the shift is subject to variations that generate the least possible discomfort for the driver and for the passengers of the vehicle. The second graph 24 illustrates the variations of different setpoint couples, which are calculated by the electronic control unit 5 during the gear change. During the first two time intervals A and B, if the pedal support remains constant, the torque setpoint C sent to the engine 2 remains substantially constant and the engine speed w follows the ascending curve wini. The torque setpoint C is the torque setpoint produced by the torque setpoint estimator 6, according to the diagram indicated in the upper part of FIG. 2. During these phases A and B, the clutch 10 is gradually opened and reduced. in parallel with the torque setpoint C sent to the motor 2. In graph 24, there is shown both the curve C representing the torque setpoint sent to the motor, and a curve C4 representing the torque setpoint calculated by the estimator of torque setpoint 6. The torque setpoint sent to the motor coincides with the curve C4 during the time interval A, then again from the time intervals E and F. On the other hand, the torque setpoint sent to the motor follows a C3 curve lower than the C4 curve during phases B and C of opening of the clutch as well as during phases D1 and D2 of synchronization of the engine speed.

Preferably, during the opening phase B of the clutch, the difference between the transmissible torque setpoint of the clutch Cembr and the torque setpoint C sent to the engine, is kept close to zero. In this way, the rotational speed of the engine remains substantially constant. In this way, the transmissible torque setpoint of the clutch is brought to zero, and the motor torque setpoint is brought to its (negative) friction torque. When the torque setpoint of the motor corresponds to the friction torque of the motor, the combustion phases of the motor are interrupted and the motor brakes the input shaft with a torque corresponding to the resistive torque of the friction forces of the motor (typically between 10 Nm and 3 Nm). When the clutch is open at the end of the phase B, the torque to the wheels Cr is zero, as indicated on the third graph 25. The disengagement of the first reducer, the selection and the engagement of the second reducer are carried out during the phase C, during which the transmissible torque setpoint of the clutch remains zero. One of the aims of the invention is to improve the torque recovery to the wheels after the cancellation of this torque during phase C. The electronic control unit 5 controls for this particular way the reference torque C transmitted to the engine 2 and the setpoint torque Cembr transmitted to the clutch during a synchronization phase of the motor which extends over the graph over two time intervals D1 and D2.

The purpose of this synchronization phase is to finish bringing the engine rotation speed w to the target speed curve w end at the end of the shift. During the steps B, C and D1 opening the clutch, the phases during which the engine torque is less than the torque transmittable by the clutch, already contribute to a decrease of the engine speed w, according to the equation: dco C - Cembr dt J Where C is the motor torque setpoint, and Cembr is the transmissible torque setpoint of the clutch. The driving mode on the time intervals D1 and D2 is chosen so as to raise, during this time interval, the curve Cr of torque to the wheels above an eroid curve obtained using control strategies carried out according to the methods known in the prior art. The phase D1 is carried out in a manner known in the prior art, that is to say that the Cembr setpoint of transmissible torque of the clutch increases linearly from zero to the first torque set CCOrri that it reaches. at a point P. The torque setpoint C of the motor also increases in a linear manner, so as to maintain a substantially constant distance between the two curves, and therefore a negative slope w 'substantially constant of the engine speed curve. Once the transmissible torque setpoint of - COrn, the clutch has reached the first torque setpoint e, it continues to grow during at least part of the time interval D2, until reaching the second torque setpoint ecorr2, for example at a point R or a point R '. The manner in which the electronic control unit imposes this transition between P _corri and ecorr2 may vary according to the chosen embodiment. The first torque setpoint ecorrl is calculated using the torque setpoint estimator as described in the first part of FIG. 2. This ecorri value corresponds to a fictitious torque setpoint at the input of the gearbox. , calculated as if the setpoint torque sent to the engine was the torque C of the torque estimator 6, taking into account an inertial term corresponding to the effective variations of the engine speed curve w. The second torque setpoint ecorr2 is also a fictitious torque setpoint at the input of the box which assumes that the motor setpoint torque is calculated from the target engine speed as if it had already been reached. This second torque setpoint is calculated for the same accelerator pedal position.

Over the time interval D2, the curve portion e, is determined according to known strategies, from the engine speed values w and the Cembr transmissible torque target values of the clutch, so as to ensure that the time a "docking" of the curve w on the cofin target speed curve, as well as a "docking" of the curve C on the "usual" setpoint curve of engine torque e4 at the end of the time interval D2 . Typically, the curve C3 may comprise a convex curve portion tangent to the curve C4 over the time interval D2.

Times in milliseconds are given as an indication to give a possible order of duration for each of the phases A, B, C, D1, D2, E, F. Typically, the time interval A has a duration of the order of 200 milliseconds, the time interval B a duration of the order of 100 milliseconds, the interval C, the interval D1 a duration of 100 milliseconds, the interval D2 a duration of 200 to 400 milliseconds, and the interval time E also has a duration of the order of 100 milliseconds. Graph 24 shows dotted two Ceerri and Ccorr2 torque reference curves. Both are calculated using the torque setpoint estimator 6 by modifying the inputs of the estimator as indicated in FIG. 2. The second torque setpoint Ccorr2 calculated by substituting the effective speed w of the motor, a lower target speed is greater than the first Ceerri torque set point until the engine speed has reached the target speed curve Wfin. The two curves eeorr1 and Ccorr2 join at a point Q at the boundary between the time intervals D2 and E, corresponding to the moment when the effective speed w of the engine has reached the target speed curve Wfin.

The invention proposes, once the Cembr torque setpoint of the clutch has arrived at the point P, having for ordinate the first - COrn, torque setpoint e, to continue to increase the torque setpoint of the second clutch Cembr2 plus quickly that grows the first torque set COrn e, -, in order to accelerate the recovery of torque to the wheels. In a way, the second torque setpoint P -corr2 corresponds to the torque that would be requested at the input of the gearbox if the gearshift had already been made. In order to avoid a return of torque Cr to the wheels which would be too fast, to the point of generating instabilities of torque or discomfort sensations, however, the transmissible torque setpoint of the clutch is maintained below the second setpoint of couple Ccorr2. According to some embodiments, the transmissible torque setpoint could be brought temporarily above Ccon-2, but then Ccou2 is chosen as the steering curve to converge again to Ccorr1. It is thus possible to increase the Cembr transmissible torque setpoint between point P and a point R 'lying on the curve of the second torque set P -corr2, in the extension of the linear curve of growth Cembr before P. According to another embodiment, R' could be found at a predefined distance by a lower value of this second torque setpoint.

It is also possible to increase the transmissible torque setpoint of the clutch between the point P and a point R, also located on the curve of second torque setpoint P -corr2, between P and R taking place at a slope lower than that of the Cembr curve before P.

Once reached the point R or the point R ', it decreases the transmissible torque setpoint of the clutch Cembr to point Q - where the curves P -corrl and ecorr2- meet, for example by following the curve corr2 or e converging by lower value to this curve. - We can also consider lowering the transmissible torque setpoint of the clutch following a curve which is a barycentre, prerecorded coefficients, curves Ccorrl and Ccorr2 By distance to the curve ecorr2, we mean the distance along the vertical, that is to say along the axis of the couples. the growth The torque setpoint of the second clutch therefore decreases between the point R or the point R'- and the point Q, and reaches the first torque set COrn e, -, substantially at the same moment when the speed w of the engine reaches the cofin curve, which is also the moment when the setpoint torque of the motor "docked" the torque curve e4 calculated by the torque set point estimator 6. After the point Q, the transmissible torque setpoint clutch so as to pass above the first torque set COrn e, -, and thus move the clutch in a first locked state where the clutch no longer slips, given the torque applied thereto. Then, from the time interval F, a complete locking of the clutch is made by bringing the transmissible torque setpoint to a value significantly greater than the torque that is likely to be applied thereto. It will be noted that in the prior art, the control of the clutch over the time interval D2 is often done by directly joining the point P and the point Q along a linear curve. Graph 25 of FIG. 3 illustrates the gain obtained on the curve Cr of torque to the wheels, by applying the clutch control strategy according to the invention, with respect to the Croid curve obtained according to the strategy of the prior art. Following the strategy of the prior art, the torque torque Croid torque curve to the wheels increases very gradually over the time intervals D1 and D2, with a smaller slope on D2 than on D1. Using the control of the clutches according to the invention, the torque to the wheels Cr continues to grow with a slope identical to that of the time interval D1 during part of the time interval D2, before stabilizing at the new "cruise" value corresponding to the new gear engaged. The lack of torque to the wheels is therefore practically perceptible only over the time interval D1. The "extra torque" gained over the time interval D2 may have a maximum amplitude A of up to 15% of the torque to the final wheels. In practice, the slope of the interval PR of the transmissible reference curve is limited to the graph 24, so that the amplitude A remains of the order of 5% of the torque to the final wheels. This limitation can be done for example by reducing the slope of the curve Cembr as indicated on the portion PR, with respect to the slope of the curve on the rise between zero and P-corri The invention is not limited to the examples described, and can be declined in many variants. The shape of the curve portion e, corresponding to the synchronization phase of the motor may be different from that illustrated. The curve Cembr on the time intervals D and D2 can be defined other than by portions of straight lines, while remaining preferably between the curves P _corri and ecorr2- One can for example impose on Cembr not to exceed a given maximum compared to environmental conditions, and to impose a plateau after reaching this maximum value, before rejoining the curve P -corri- The conditions taken into account in the calculation of the Cembr2 maximum can for example include all or part of the following parameters: the initial and final ratio values, the temperature and the outside air pressure, the engine cooling water temperature, the gearbox oil temperature, the driving mode setting (sporty or comfort). It is possible to use the same torque set point estimator 6 to calculate the first torque set COrn e, -, the second torque setpoint P -corr2, and the motor torque setpoint C. It is also possible to use a torque setpoint estimator 6 dedicated to each of the three values mentioned C, P -corrl and ecorr2, and of similar or identical structure. The torque setpoint estimator 6 may be a subassembly of the electronic control unit, or may be a remote subassembly with respect to this control unit and connected thereto. The gearbox control mode according to the invention makes it possible to reduce the torque defect that still exists at the moment when the torque setpoint of the clutch, during its ascent, reaches the first torque setpoint. At this time, the synchronization of the engine speed is partly performed, and the kinetic energy reserve of the flywheel related to this synchronization is limited. However, the reserve of available kinetic energy (+ 15% of torque to the wheels possible with the invention) is largely sufficient compared to the extra torque that it is desired to provide by means of the invention.

Claims (10)

REVENDICATIONS1. Transmission system for a motor vehicle comprising a robotized gearbox, comprising an input drive shaft (4), able to be connected to a counter (9) of the rotational speed (w) of the motor shaft (4), a speed sensor (26) of a vehicle wheel (16) and an acceleration pedal (8), the system comprising a torque setpoint estimator (6) suitable for determining a motor torque setpoint (C) to be applied to the motor shaft (4), as a function of a rotation speed (w) of the motor shaft (4) and a pedal position (a) of acceleration (8), characterized in that the system comprises an electronic control unit (5) connected to the estimator (6), which is configured to calculate, in parallel with a transmission ratio change, in parallel at successive instants, by means of the estimator, a first torque setpoint (C corri) as a function of the engine speed (w) estimated by the counter, and a e second torque setpoint (C corr2) greater than the first torque setpoint, calculated for the same position (a) of the acceleration pedal, by replacing the engine speed (w) with a target speed (cofin) obtained by dividing a speed (cor) of rotation of the wheel (s) of the vehicle by a coefficient (Rpont Rf), proportional to the final gear ratio (Rf) of the box following the gear change. 2. A transmission system according to claim 1, wherein the electronic control unit (5) is further configured to: - simultaneously decrease a transmissible torque setpoint (Cembr) sent to a clutch (10) of the transmission box. speeds, and a motor torque setpoint (C) sent to a motor (2) connected to the motor shaft (4), to cancel the transmissible torque setpoint of the clutch, while maintaining the motor torque setpoint ( C) less than or equal to the torque command transmitted by the clutch (Cembr), - then disengage a first gear (11) corresponding to the ratio initially engaged, and engage a second reducer (21) corresponding to the final report, then make simultaneously increasing the transmissible torque setpoint (Cembr) sent to the clutch (10), and the motor torque setpoint (C), while keeping the motor torque setpoint lower than or equal to the transmissible torque setpoint of the clutch, up that the transmissible torque setpoint of the clutch (Cembr) becomes strictly greater than the first - COrn ,, torque setpoint (e,) - then decrease the transmissible torque setpoint of the clutch by following the second setpoint of torque (Ceerr2), until the transmissible torque setpoint of the clutch (Cembr2) rejoins the first torque setpoint (e, orr1) - 3. Transmission system according to claim 2, wherein the electronic control unit (10) is further configured to maintain the transmissible torque setpoint (Cembr) of the clutch substantially equal to the engine torque setpoint (C) during the first decay phase, and to maintain the motor torque setpoint (C) strictly lower than the transmissible torque setpoint (Cembr) of the clutch while this transmissible torque setpoint increases from zero to the first torque setpoint (e, orr1) - 4. Transmission system according to one of the preceding claims, wherein the estimator (6) torque setpoint is configured to read a map (7) according to the position (a) of the accelerator pedal (8). ) and as a function of the engine speed (w), respectively as a function of the target speed (wfin), to deduce a gross torque setpoint (C), and is configured to subtract from the raw torque setpoint (C), a term inertial (Jw ') which is proportional to the derivative of the engine speed, respectively which converges to a proportional term (Jw') to the derivative of the engine speed, and to deliver the difference obtained as the value of COrn ,, first torque setpoint (e) respectively as value of second torque setpoint (e.corr2) - 5. Transmission system according to the preceding claim, wherein the electronic control unit (10) is further configured to converge the motor torque setpoint (e3) to the gross torque setpoint (C) calculated by the torque setpoint estimator (6), and to converge the rotational speed (w) of the motor shaft to the target speed (cofin) substantially at the same time. 6. Vehicle equipped with a transmission system according to one of the preceding claims, comprising a motor (2) connected to the drive shaft (4) of the box, a counter (9) of the rotation speed (w) of the motor, a speed sensor (26) (c) r) of at least one wheel (16) of the vehicle and an accelerator pedal (8). 7. A method of managing, during a gearshift, a transmission system with a robotized gearbox with a clutch, in which, after disengaging a first transmission ratio and having engaged a second transmission ratio, it calculates in parallel over time, using a same map (7), a first torque setpoint (Ccorri) from a rotation speed (w) of the motor (2) and a position ( a) accelerator pedal (8), and a second torque setpoint (e.corr2) greater than the first torque setpoint (Ccorri), calculated using the same mapping, from a speed of rotation (cor) of at least one wheel of the vehicle, of the same position (a) of the accelerator pedal, and of the gear ratio (RpontRf), after gearshift, between the speed of rotation of the wheels of the vehicle and the speed of rotation (w) of the primary shaft, and in that a set of e transmittable torque (Cembr) of the clutch above the first torque setpoint (ecorri), then it is down again following the second torque setpoint (e.corr2) until it reaches the first setpoint of couple. 8. The method as claimed in claim 7, in which the transmissible torque setpoint (Cembr) of the second clutch (20) is linearly increased from the moment when it exceeds the first torque setpoint (Ccorri), until reaches the second torque setpoint (ecorr2), then decreases it by following the second torque setpoint (P_corr2) - 9. The method as claimed in claim 7, in which the transmissible torque setpoint (Cembr) of the second clutch is linearly increased after it has exceeded the first torque set point (ecorri) until it reaches a threshold or the second torque setpoint, then it is imposed in the first case a constant value equal to the threshold until it reaches the second torque setpoint (ecorr2), then it is decreased by following the second setpoint torque (P, orr2) - The method of claim 9, wherein the threshold is a function of the initial and final ratio values, and at least one of a temperature outside the vehicle, an atmospheric pressure outside the vehicle, a temperature of engine cooling water, an oil temperature of the gearbox.