Abstract:
A device for controlling an automated transmission of a motor vehicle engine-transmission unit capable of delivering a torque setpoint signal to be applied to the motor vehicle wheels, including two static and dynamic components, produced based on input data delivered by an input unit including a recorded list of parameters representing the driver&#39;s wishes, the motor vehicle state, and the motor vehicle surroundings. The device includes a first unit capable of calculating a dynamic torque component not adapted to a cornering situation; a second unit capable of calculating a static torque component, connected to the input of the first unit; and a unit for adaptation to the come in situation delivering a static torque component adapted to the cornering situation in accordance with a list of predetermined input parameters.

Description:
BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present invention relates to a method of formulating a setpoint for a transmission of a motor vehicle power train in a situation termed cornering. It also relates to a device implementing such a method of formulating a setpoint. 
     This method applies advantageously to automated transmission devices in particular impulse Control Boxes termed BCI, Automatic Control Boxes termed BVA and Robotized Wear Boxes termed BVR, but also continuous-ratio transmissions, such as CVT (“Continuous Variable Transmission”), IVT (“Infinitely Variable Transmission”) and hybrid transmissions. 
     II. Description of the Related Art 
     A motor vehicle automated transmission conventionally comprises a control block receiving one or more input parameters interpreting inter alia, the desire of the driver. Then, as a function of the value of these parameters, the control block delivers a control setpoint with a view to an application to the wheels of the motor vehicle. 
     An upgrade of such a control block has already been described in document FR-A-2827339, in the name of the Applicant. This document details a device for controlling the operating point of a power train. The control carried out by this device is a torque control to be applied to the wheels of the motor vehicle. As defined in document FR-A-2827339, the value of the torque to be applied to the wheels of the motor vehicle is calculated directly at the wheels of the motor vehicle. 
     The device of document FR-A-2827339 possesses a module for interpreting the desire of the driver called an IVC module. 
     The IVC module generates a torque setpoint to be applied to the wheels destined for a block for optimization of the operating point OPF. The latter transmits said torque with a view to a torque control to be applied to the wheels of the motor vehicle. The OPF block simultaneously generates an engine revs setpoint on the basis of said torque to be applied to the wheels of the motor vehicle. This torque setpoint to be applied to the wheels of the motor vehicle is determined as a function of the desire of the driver, of the characteristics of the motor vehicle and of its environment, so as to best adapt the behavior of the motor vehicle, according to the driving situations. 
     In the cornering phase, a driver, at the steering wheel of a motor vehicle equipped with a conventional automatic transmission, has to cope with awkward driving situations. 
     For example, on approaching a corner, the driver generally eases off the accelerator pedal. The automatic gearbox which was previously in a given gear, then shifts directly to the gear above on account of the conventional shifting laws of an automatic gearbox. It thus deprives the motor vehicle of engine brake. The shift to the gear above then causes an unpleasant sensation of boarding of the motor vehicle. 
     In a driving situation, when the driver approaches a corner in a high gear, (fourth gear for example), and slows down through this corner, he is in general in the same high gear coming out of the corner. He must therefore depress the accelerator pedal to the maximum to cause the motor vehicle to pick up again. This action is often experienced badly by the driver and the passengers of the motor vehicle. 
     Methods and associated devices which make it possible to perform adaptations so as to attempt to improve passenger comfort in the cornering phase are already known in the prior art. 
     Document U.S. Pat. No. 5,514,051 filed by Porsche, proposes a method consisting in adjusting driving parameters of the motor vehicle as a function of predefined adjustment suites. When the motor vehicle is in a particular state, a cornering state for example a computer then refers to these predetermined profiles to adjust the driving parameters. 
     The solution proposed by document U.S. Pat. No. 5,514,051 makes it necessary to define, during the construction of each motor vehicle, a series of reference driving profiles. 
     A correction procedure based on laws for shifting gear ratios in a cornering situation according to various predetermined parameters such as for example the speed of movement or the lateral acceleration of the motor vehicle are also known through the documents FR-2 779 793 filed by the Applicant and FR-2 827 026 filed by the Applicant and PSA. These shifting laws make it possible to retain a gear ratio or to downshift in a cornering situation. This solution, adapted to automatic transmissions with discrete ratios is not at all so in the case of automatic transmissions with continuous ratios. 
     Document FR-2 834 939 in the name of the Applicant proposes to effect an adaptation of the control setpoint of the power train for particular driving phases especially during the cornering phases. The adaptation of the setpoint is done at the engine revs level. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is aimed at remedying the aforesaid drawbacks. The principle of the invention consists in envisaging an adaptation of the torque setpoint to be applied to the wheels of the motor vehicle so as to improve the behavior of the motor vehicle in a cornering situation. The invention furthermore envisages a torque reserve applicable to the wheels of the motor vehicle to help it pick up again after each cornering. This adaptation in the cornering phase is applied directly to the torque calculated at the wheel, as defined previously thereby allowing greater accuracy as regards the corrections made. 
     Furthermore, the adaptation proposed by the invention is capable of operating with any type of transmission. 
     For this purposes the invention proposes a method of controlling an automated transmission of a power train for a motor vehicle. This method comprises a step of formulating a torque setpoint to be applied to the wheel, composed of two components, static and dynamic, formulated as a function of input data representative of the characteristics of the motor vehicle, of the desire of the driver and of the environment of the motor vehicle. The static component of torque forms the subject of an adaptation in the cornering phase and beyond said cornering phases as a function of a list of predetermined parameters, said adaptation in the cornering phase comprising the following steps: 
     a) produce a dynamic component of raw torque representative of the desire of the driver as a function of predetermined input parameters, then correct it to obtain a dynamic torque component, 
     b) determine a static component of raw torque on the basis of said dynamic torque component, 
     c) calculate a static torque component adapted to a cornering situation, as a function of said static component of raw torque. 
     This method makes it possible to generate a torque setpoint to be applied to the wheels, adapted to a cornering situation. It will make it possible to obtain engine revs adapted to the situation. The proposed solution allows the motor vehicle to have available a sufficient torque reserve so that the passengers of the motor vehicle do not experience the unpleasant sensations related to a change of operating point of the power train necessary for the resumption of acceleration coming out of the corner. 
     Preferably, said static torque component adapted to a cornering situation is integrated with additional corrections, dependent on the driving phase considered, so as to deliver a static component of optimal torque. 
     According to one mode of implementation, it is possible to adapt the setpoint in the cornering phase and beyond the cornering phase as a function of a signal representative of the position of the accelerator pedal of the motor vehicle. 
     According to another mode of implementation, it is possible to adapt the setpoint in the cornering phase and beyond the cornering phase as a function of the engine revs of the motor vehicle. 
     According to another mode of implementation, it is possible to adapt the setpoint in the cornering phase and beyond the cornering phase as a function of the transverse acceleration of the motor vehicle. 
     According to another mode of implementation, it is possible to adapt the setpoint in the cornering phase and beyond the cornering phase as a function of the speed of the motor vehicle. 
     According to another mode of implementation, it is possible to adapt the setpoint in the cornering phase and beyond the cornering phase as a function of the instantaneous maximum torque applicable to the wheels of the motor vehicle. 
     According to a preferred mode of implementation, the step of calculating the static torque component adapted to a cornering situation comprises the following sub-steps: 
     d) calculate a raw cornering setpoint signal as a function of the speed of the motor vehicle, of the transverse acceleration of the motor vehicle and of the engine revs of the motor vehicle, 
     e) construct a first step signal corresponding to said raw cornering setpoint signal but delayed and a second signal corresponding to said raw cornering setpoint signal but filtered, and 
     f) compare and integrate said signal corresponding to said raw cornering setpoint signal but filtered, with a list of predetermined input parameters comprising the static component of raw torque, the instantaneous maximum torque applicable to the wheels of the motor vehicle, the speed of the motor vehicle, the transverse acceleration of the motor vehicle. 
     Preferably, said raw cornering setpoint signal is constructed by comparing the transverse acceleration of the motor vehicle with dynamic thresholds mapped as a function of the speed of the motor vehicle and of the engine revs of the motor vehicle. 
     The invention is also aimed at a device for an automated transmission of a power train for a motor vehicle able to deliver a torque setpoint signal to be applied to the wheels of the motor vehicle, comprising two components, static and dynamic, formulated as a function of input data delivered by an input block which comprises a recorded list of parameters representative of the desire of the driver, of the state of the motor vehicle and of the environment of the motor vehicle. The control device advantageously comprises:
         a first block able to calculate a dynamic torque component without adaptation to the cornering situation,   a second block able to calculate a static component of raw torque, connected to the output of said first block able to calculate the dynamic torque component without adaptation to the cornering situation,   a block for adaptation to the cornering situation delivering a static torque component adapted to the cornering situation as a function of a list of predetermined input parameters.       

     According to one embodiment, the device advantageously comprises means for integrating the static torque component adapted to a cornering situation with additional corrections dependent on the driving phase considered. 
     The list of predetermined parameters of the block for adaptation to the cornering situation advantageously comprises the static component of raw torque, the instantaneous maximum torque applicable to the wheels of the motor vehicle, the speed of the motor vehicle, the transverse acceleration of the motor vehicle and the current setpoint of engine revs. 
     According to one embodiment, the block for adaptation to the cornering situation of the static component of raw torque can comprise:
         a first block for constructing a raw cornering setpoint signal,   a second block for constructing a step signal corresponding to said raw cornering setpoint signal but delayed and a signal corresponding to said raw cornering setpoint signal but filtered,   a block for filtering the transverse acceleration of the motor vehicle,   a means able to store a first mapping delivering a weighting setpoint as a function of the speed of the motor vehicle,   a means able to store a second mapping so as to determine, as a function of the motor vehicle&#39;s transverse acceleration filtered by said filtering block, a percentage of the deviation between the instantaneous maximum torque component applicable to the wheels of the motor vehicle and the static component of raw torque,   means for comparing and for integrating said raw cornering setpoint signal but filtered, with the raw static torque component, of the instantaneous maximum torque applicable to the wheels of the motor vehicle, the speed of the motor vehicle, the engine revs of the motor vehicle and the transverse acceleration of the motor vehicle.       

     Preferably, the first construction block comprises means able to store two mappings relating respectively to positive and negative thresholds of the transverse acceleration of the motor vehicle and comparison means able to generate the raw signal representative of the cornering as a function of a list of predetermined input parameters. 
     According to an embodiment, the list of predetermined parameters can comprise the engine revs of the motor vehicle, the transverse acceleration of the motor vehicle and the speed of the motor vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other advantages and characteristics of the invention will appear on examining the detailed description of a wholly nonlimiting embodiment of the invention, and the appended drawings, in which: 
         FIG. 1  is a schematic diagram of an exemplary embodiment of an IVC module integrating the adaptation of the setpoint in the cornering phase, 
         FIG. 2  represents more precisely an exemplary embodiment of a detail of the diagram of  FIG. 1 , 
         FIG. 3  illustrates an example of the signals delivered by a block of the diagram represented in  FIG. 2 , 
         FIG. 4  represents in greater detail an exemplary embodiment of a part of the diagram of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     We refer to  FIG. 1 . Represented in this figure is the integration of the device for adaptation of the torque setpoint to be applied to the wheels of the motor vehicle in the cornering phase, into the automated transmission box of the motor vehicle (not represented). 
     This device comprises two blocks  1  and  2 , respectively an inputs block  1  and an IVC module  2 . 
     The function of the input block  1  is to deliver the input parameters to the module  2  for the adjustment of the torque setpoint to be applied to the wheels of the motor vehicle, in the cornering phase. The block  1  receives as input signals delivered by sensors (not represented) integrated with the motor vehicle. 
     These input data, transmitted to the module  2  by the block  1 , can be delivered respectively to each functional block included in this module  2 . 
     The input block  1  comprises three modules  3 ,  4  and  5 . Each of these three modules delivers a predetermined type of input data to the module  2 . 
     A first module  3  denoted CarV is capable of formulating the data relating to the characteristics of the motor vehicle. These are programmed and stored in a memory common to the device (not represented) by the constructor so as to characterize the behavior of the vehicle delivered to a customer. 
     A second module  4  denoted MMI (man/machine interface) is capable of formulating data relating to the desire of the driver. These data interpret the wishes of the driver. They can for example comprise signals representative of the brake or accelerator pedal of the motor vehicle or else a signal interpreting the sportiness of the driver. In one embodiment, it is noted that the monitoring of the automated transmission box can evaluate the sportiness of the driver from 0 to 100%. 
     A third module denoted  5  ENV is capable of formulating signals relating to the environment of the motor vehicle. These make it possible to take account of the state of the motor vehicle and of its situation in the environment. They comprise for example signals corresponding to the engine revs, to the speed or else to the lateral acceleration of the motor vehicle, particularly in a cornering situation. 
     The signals delivered by the three modules  3 ,  4  and  5  are formulated on the basis of signals originating from sensors (not represented) integrated with the motor vehicle. 
     These three modules  3 ,  4  and  5  are respectively connected to the IVC module  2  by way of the connections  6 ,  7  and  8 . 
     The IVC module  2 , described in document FR-A-2 827 339, in the name of the Applicant, represents a block able to generate a torque setpoint to be applied to the wheels of the motor vehicle by interpreting the desire of the driver. 
     The module  2  receives as input the input parameters formulated by the block  1  and delivers as output the dynamic Cd (or dynamic torque setpoint) and static Cs (or static torque setpoint) components of the torque setpoint to be applied to the wheels of the motor vehicle. The two setpoints are respectively transmitted by way of the connections  9  and  10 . The setpoints Cd and Cs are targets intended to be optimized so as to formulate an optimal engine revs setpoint. 
     The dynamic torque setpoint Cd is the value of the torque that the driver wishes to see achieved instantaneously. The static torque setpoint Cs is defined as the future torque setpoint that the driver could demand and that the power train must render immediately available at the wheels of the motor vehicle. The setpoint Cs evolves slowly. Specifically, it is not aimed at meeting an immediate demand of the driver. It has to be the reflection of a tendency imposed by the behavior of the driver over a predetermined period. Stated otherwise, the torque Cs corresponds to the torque value applicable to the wheels of the motor vehicle that the driver would wish to obtain by reloading the accelerator pedal of the motor vehicle. 
     According to the invention, the module  2  comprises three functional blocks  11 ,  15  and  17 . 
     The first functional block is a block  11  (Calculation of Cd without adaptation) able to calculate a dynamic torque setpoint without adaptation denoted Cd_raw. This Cd_raw setpoint is calculated on the basis of the signals representative of the position of the accelerator pedal of the motor vehicle, of the revs of the engine of the motor vehicle and of the speed of the motor vehicle, these signals being delivered by the input block  1 . 
     The Cd_raw setpoint can undergo additional corrections, for example an adaptation of the setpoint in a slope situation. For this purpose, the Cd_raw setpoint is transmitted by way of the connection  12  to a corrective block  13  denoted Corr 1 , which delivers the setpoint Cd as output. 
     The second functional block is a block  15  (Calculation of Cs without adaptation) which is capable of calculating a Cs_raw static torque setpoint without particular adaptation. The Cs_raw setpoint is constructed on the basis of the dynamic torque Cd, arising from the block  13  Corr 1  and transmitted via the connection  14 . Furthermore, the Cs_raw setpoint is calculated as a function of parameters such as the sportiness of the driver for example; this parameter can be, for example, calculated on the basis of the signal representative of the position of the accelerator pedal of the motor vehicle, delivered by the input block  1 . 
     The Cs_raw setpoint is delivered, by way of a connection  16 , to the third functional block  17  integrated with the module  2 . The function of the block  17  (Cornering adaptation) is to formulate, on the basis of the Cs_raw setpoint, a torque setpoint applicable to the wheels of the motor vehicle, adapted to the cornering situation Cs_cor. The setpoint Cs_cor delivered by the block  17  affords the possibility of improving the operating point of the motor vehicle. Specifically, the operating point will make it possible to preset the value of the engine revs, to a value anticipating the desire of the driver. The block  17  will be described in greater detail hereafter. 
     In parallel with the adaptation to the cornering situation, the Cs_raw setpoint can undergo other corrections, for example in a braking or slope situation. These additional corrections are performed respectively by the two corrective blocks  18  Corr 2  and  19  Corr 3 . The Cs_raw setpoint is transmitted to the blocks  18  and  19  by the respective connections  20  and  21 . 
     The three blocks  17 ,  18  and  19  deliver their output setpoints to the block  22  denoted max. The block  18  delivers its setpoint to the block  22  via a connection  23 , the block  17  via a connection  24  and the block  19  via a connection  25 . 
     The block  22 , placed at the output of the blocks  17 ,  18  and  19 , arbitrates the various corrections effected by these three blocks. Specifically, the setpoint Cs can comprise at one and the same time an adaptation for cornering and an adaptation for braking for example. The block  22  then delivers as output an output setpoint Cs integrating the various corrections made. 
       FIG. 2  is now referred to. This figure details the block  17  carrying out the adaptation of the Cs_raw setpoint in the cornering phase. 
     The block  17  receives various input parameters such as the speed of the motor vehicle denoted Vveh, the engine revs setpoint denoted N and the transverse acceleration denoted Gammat. The transverse acceleration can be measured by an accelerometer integrated with the motor vehicle, but also calculated on the basis of the speed of the motor vehicle. All these input parameters originate from the input block  1 , represented in  FIG. 1 , and delivered to the various blocks included in the module  2 . 
     The block  17  also receives Cs_raw arising from the block  15  (Calculation of Cs without adaptation), as well as the component Cmax which is the maximum torque applicable to the wheels of the motor vehicle, that the power train can provide instantaneously to the wheels of the motor vehicle. This component Cmax is produced with the aid of a recorded table (not represented) which is addressed, in a preferred embodiment, as a function of the rotation speed measured at the wheel of the motor vehicle. The value Cmax therefore evolves dynamically as a function of the speed of the motor vehicle. 
     The block  17  comprises several functional blocks allowing the construction of the setpoint Cs_cor. 
     Firstly the block  17  comprises a subtracter  31  SUB, whose role is to effect the difference between the component Cmax, delivered by way of the connection  32 , and the Cs_raw setpoint delivered via the connection  33 . The difference, denoted DeltaC, is delivered as output of the subtracter  31  by way of a connection  34 . 
     A mapping  35  (Mapp ActionVeh) is placed parallel to the subtracter  31 , and receives as input the speed of the motor vehicle Vveh via a connection  36 . The mapping  35  formulates a weighting denoted ActionVeh, taking values between “0” and “1” and delivered via the connection  37 . The signal ActionVeh, delivered by the mapping  35 , makes it possible to cancel the correction in the cornering phase below an adapted motor vehicle speed threshold, determined by the mapping  35 . The signal ActionVeh then ensures progressive disappearance of the filtering as a function of the variation of the speed of the motor vehicle. 
     A second mapping  38  (Mapp PercDelta) situated in parallel with the block  31  receives as input, via a connection  39 , a transverse acceleration value denoted Gammat_fil. This value Gammat_fil originates from a filter  40  (Gammat Filtering) included in the block  17 . The block  40  is able to filter, according to a predetermined specific filtering law, the variable Gammat, transmitted to the block  40  via a connection  41 . The mapping  38  delivers as output, via the connection  39 , a variable denoted PercDeltaraw. This variable is a raw percentage of the deviation between the Cs_raw setpoint and the component C_max. This deviation between the Cs_raw setpoint and the component C_max is the variable DeltaC, which has been calculated by the block  31 . 
     A fourth block  42  (Cornering Signal Construction) is situated in parallel with the block  41 . The role of the block  42  is to construct a first cornering recognition setpoint Cor_raw. The block  42  receives as input the transverse acceleration of the motor vehicle Gammat via the connection  43 , the engine revs N via the connection  44  and the speed of the motor vehicle Vveh via the connection  45 . On the basis of these input parameters the block  42  is able to construct a variable denoted Cor_raw delivered via a connection  46 . The formulation of this setpoint will be described in greater detail hereafter. 
     A block  47  (delayed cornering and filtered cornering construction) is placed at the output of the block  42  for constructing the signal in a cornering situation. The block  47  receives as input the Cor_raw variable, transmitted via the connection  46 . In addition to the Cor_raw variable, the speed of the motor vehicle Vveh is also applied to the input of the block  47 , via a connection  48 . On the basis of the input data, the block  47  constructs two signals Cor_fil transmitted as output via a connection  49  and Cor_del transmitted as output via a connection  50 . 
     The variation of the two signals Cor_fil and Cor_del is represented in  FIG. 3  as a function of time. It is considered that the signal Cor_raw is a step taking the value “1” between t 0  and t 1  and “0” otherwise. The signal Cor_del makes it possible to keep the correction between t 1  and t 3 , i.e. for a total duration equal to Duration_freeze+Duration_decrem, after the disappearance of the signal Cor_raw at t 1 . The signal Cor_fil makes it possible for its part, to progressively weaken the effect of the correction. Thus, the signal Cor_fil takes the value “1” at t 0  until t 2  then decreases progressively, for example in the form of a linear ramp, between t 2  and t 3 , i.e. for a duration Duration_decrem. The two variables Duration_freeze and Duration_decrem are two variables calibratable by the constructor. They can represent a duration, as in the example of  FIG. 3 , or a distance traversed by the motor vehicle (by integrating the speed of the motor vehicle). 
       FIG. 2  is referred to again. The signal Cor_fil is transmitted to a first multiplier  51  MUL 1  via the connection  49 . The multiplier  51  is situated at the output of the blocks  31 ,  35 ,  38  and  47  and also receives the signals ActionVeh and PercDeltaraw respectively via the connections  37  and  39 . The signal PercDelta resulting from the multiplication of the three input signals, Cor_fil, ActionVeh and PercDeltaraw, represents the percentage of the variation in torque to be applied to the wheels of the motor vehicle that one actually wishes to apply. 
     A second multiplier  53  MUL 2  is placed at the output of the first multiplier  51 . The multiplier  53  receives the variable PercDelta calculated previously and transmitted via a connection  52 . The multiplier  53  receives, via the connection  34 , the variable DeltaC delivered by the subtracter  31 . By multiplying the two variables PercDelta and DeltaC, the multiplier  53  delivers as output, via a connection  54 , the signal DeltaC_cor which represents the variation of the static torque applicable to the wheels of the motor vehicle, that one wants to apply. 
     An adder  55  ADD situated at the output of the multiplier  53  receives as input the aforesaid variable DeltaC_cor, via the connection  54 , as well as the torque Cs_raw, via a connection  56 . The sum of the two signals DeltaC_cor and Cs_raw results in the setpoint Cs_cor_calculated, which is the static torque potentially applicable to the wheels of the motor vehicle in the cornering phase and beyond. 
     A selector  57  is placed at the output of the adder  55 . The selector  57  receives as input the setpoint Cs_cor_calculated, transmitted via a connection  59 , and the torque setpoint Cs_raw transmitted via a connection  58 . The selector  57  also receives a control signal which is the signal Cor_del formulated by the block  47 . As a function of the control signal Cor_del, the selector  57  is able to deliver an output signal corresponding to one or the other of these input signals. 
     As a function of the value of Cor_del, one of the configurations represented in  FIG. 2  holds. If “Cor_del=0”, the correction in the cornering phase is not applied. The multiplexer  57  establishes a connection  60  between the input where the Cs_raw signal is transmitted and its output terminal so as to deliver the Cs_raw setpoint as output. If “Cor_del=1”, the motor vehicle is in a second configuration where it is considered in a cornering situation or coming out of a corner. The calculated correction is therefore applied. The selector  57  establishes a connection  61  between the input where the signal Cs_cor_calculated is transmitted and its output so as to deliver the setpoint Cs_cor_calculated as output. The latter is applied so long as the control signal Cor_del is equal to “1”. 
       FIG. 4  is now referred to. This figure details the block  42 . The block  42  formulates the signal Cor_raw, which is a binary signal indicating whether or not the motor vehicle is in a cornering situation. The signal Cor_raw thus takes the value “1” if the motor vehicle is in a cornering situation and “0” otherwise. 
     The block  42  receives various input parameters, delivered to the blocks included in the module  2  by the input block  1 , represented in  FIG. 1 . The block  42  receives in particular signals representative of the engine revs N, of the speed of the motor vehicle Vveh and of the transverse acceleration of the motor vehicle, Gammat. 
     Inside the block  42  are stored two mappings  71  and  72  denoted respectively Mapp Gammat_pos and Mapp Gammat_neg. These two mappings can formulate positive and negative dynamic threshold values, corresponding respectively to a cornering to the right or to the left. In a variant of the embodiment of the invention, it would be possible to use a single mapping and to formulate a threshold as a function of the absolute value of Gammat. 
     The thresholds are mapped as a function of the engine revs N transmitted via connections  73  and  74 , and of the speed of the motor vehicle Vveh transmitted via connections  75  and  76 . 
     The two mappings  71  and  72  can each deliver a threshold value transmitted respectively to two comparators COMPP  77  and COMPN  78 . The two threshold values are transmitted by way of the respective connections  79  and  80 . 
     The function of the two comparators  77  and  78  is to compare the value of the transverse acceleration Gammat with the two threshold values formulated by the mappings  71  and  72 . The transverse acceleration Gammat is transmitted via connections  81  and  82 . If the motor vehicle approaches a right-hand corner, the comparator  77  delivers a signal having the value “1” via the connection  84 , while the other comparator  78  delivers a signal having the value “0”. If the motor vehicle approaches a left-hand corner, the comparator  78  delivers a signal having the value “1” via the connection  85 , while the other comparator  77  delivers a signal having the value “0”. If the motor vehicle is not in a cornering situation the two comparators each deliver a signal having the value “0”. 
     A block  83  OR is placed at the output of the two comparators  77  and  78 . The block  83  receives as input the signals transmitted via the connections  84  and  85  by the comparators  77  and  78  and delivers as output, via the connection  46 , the signal Cor_raw. If one of the input signals, delivered by the comparators  77  and  78 , is set to “1”, the signal Cor_raw then takes the value “1”; it takes the value “0” otherwise. 
       FIG. 2  is referred to again. The static component of torque Cs thus increased, by the component DeltaC_cor, in a cornering situation affords several advantages. It makes it possible to preset the power train on an operating point, thus offering a greater torque reserve applicable to the motor vehicle wheel, thereby allowing the motor vehicle to accelerate more rapidly on coming out of a corner, in response to a request of the driver. Specifically, to obtain the torque reserve applicable to the motor vehicle wheel, the power train is positioned on an engine revs operating point formulated as a function of the torque to be applied to the motor vehicle wheel) that is greater than it would have been without this increased demand. This results in an acoustic effect known to the driver during a downshift at the start of cornering and above all, this prevents the engine revs from descending rapidly to low values in a cornering situation, to which the driver is not accustomed.