WO2017140968A1

WO2017140968A1 - Device for determining parameters for a system for adaptively controlling the speed of a vehicle

Info

Publication number: WO2017140968A1
Application number: PCT/FR2017/050267
Authority: WO
Inventors: Vincent DESCHAMPS
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2016-02-18
Filing date: 2017-02-06
Publication date: 2017-08-24
Also published as: FR3047956B1; FR3047956A1

Abstract

A device (DD) determines parameters for a system (SR) for adaptively controlling the speed of a vehicle (V), and comprises computing means (MC) able: to determine maximum and minimum, nominal acceleration setpoints depending on the speed of a vehicle (V) at a current time t0, a speed setpoint and environmental data at t0; to estimate future speeds and future environmental data at times tj subsequent to t0; then to estimate future maximum and minimum accelerations that the vehicle (V) would have if it were in a particular acceleration mode at the times tj depending on the speed setpoint, the environmental data at t0, and the aforementioned estimates; and then to estimate the maximum time for which the vehicle (V) can freewheel depending on the estimates of the future maximum and minimum accelerations and on the acceleration at t0 in this particular acceleration mode.

Description

DEVICE FOR DETERMINING PARAMETERS FOR AN ADAPTIVE REGULATION SYSTEM FOR THE SPEED OF A VEHICLE

The invention relates to vehicles, possibly of the automotive type, and more specifically the adaptive speed regulation within such vehicles.

Some vehicles include a regulation system (or ACC ("Adaptive Cruise Control")) to adjust their speed adaptively adaptive to their environment at the moment considered. To do this, after having been activated, these regulation systems determine, according to a speed reference and information relating to the environment of their vehicle at the current moment, a "final" acceleration instruction ( positive or negative) which is adapted to regulate the speed adaptively, that is to say taking into account the environment of their vehicle at this moment in progress.

This environment information may be representative of the distance separating the vehicle concerned from an upstream vehicle, or the speed (possibly relative) of an upstream vehicle, or the acceleration (possibly relative) of an upstream vehicle, or a prescribed speed, or the presence of a turn or a roundabout.

Thus, these control systems make it possible to regulate the speed of their vehicle and the distance separating their vehicle from an upstream vehicle according to the current environment of their vehicle.

Sometimes, as described in the patent document WO 2014009108, the control system can also be arranged to add to the acceleration setpoint that it has determined a request to establish a freewheeling phase or with the engine brake (possibly with energy recovery when the vehicle comprises a hybrid powertrain (or GMP)). This request is then intended to optimize the energy consumption of the vehicle. It is recalled that the phases of coasting or engine braking are two examples of particular modes of acceleration in which the chain of transmission of a vehicle can be placed.

A disadvantage of these latter control systems lies in the fact that the request to establish freewheeling phase or engine brake is performed without knowing how long the vehicle will actually be able to remain in this phase of taxiing requested because of his environment. As a result, freewheeling or engine braking phases can be introduced and then almost immediately stopped, and this sometimes repetitive in the course of time, which is detrimental to driving pleasure.

The invention is therefore particularly intended to improve the situation.

It proposes for this purpose a device, intended to determine parameters for an adaptive speed control system of a vehicle having a transmission chain that can be placed in at least one particular acceleration mode, and comprising means for calculation calculated to determine for this vehicle nominal acceleration, minimum and maximum acceleration as a function of the speed of the vehicle at a current time tO, a speed reference and information relating to a vehicle environment at tO .

This device is characterized by the fact that its calculation means are also clean:

to estimate future speeds and future environmental information of the vehicle at times tj after t0, then

to estimate minimum and maximum future accelerations that the vehicle would have if it were in each particular acceleration mode at times tj as a function of the speed reference, environmental information at t0, estimates of future speeds, estimates of future environmental information, and accelerations that the vehicle would have if it were in each particular acceleration mode at tO, then

to estimate maximum driving times of the vehicle in each particular acceleration mode according to these estimates of the minimum and maximum future accelerations and accelerations what would the vehicle have if it were in each particular acceleration mode to.

This provides all the parameters that are really useful for a control system to adaptively adjust the speed of the vehicle according to the evolution of its environment, regardless of the acceleration concerned (freewheel or brake engine (or brake energy recovery)) and regardless of the type of control concerned.

The device according to the invention may comprise other characteristics that can be taken separately or in combination, and in particular:

its calculation means may also be suitable for comparing each estimate of the acceleration that the vehicle would have if it were in a particular acceleration mode at t 0 to the corresponding minimum and maximum future acceleration estimates in order to determine an instant t for which the estimated acceleration the vehicle would have if it were in a particular acceleration mode at t0 is greater than the estimated maximum future acceleration corresponding to that instant tj or less than the estimated the corresponding minimum future acceleration at this instant tj, the difference between t0 and this determined instant tj then constituting the estimated maximum running time of the vehicle in this particular acceleration mode;

its calculation means may be arranged to produce for each particular acceleration mode a flag having a value representative of the fact that if the vehicle were in this particular mode, and at the instant t0 the acceleration in this particular mode was less than the maximum acceleration at time t0, whether or not there is an instant t'j for which the acceleration in that particular mode would become greater than the estimate of the maximum future acceleration corresponding to that particular mode, and if at the instant t0 the acceleration in this particular mode was greater than the minimum acceleration at the instant t0, there exists or not an instant t'j for which the acceleration in this particular mode would become lower than the estimate the minimum future acceleration corresponding to that particular mode;

- the particular modes of acceleration can be chosen from (at least) freewheel acceleration, engine brake acceleration and recuperative brake acceleration;

its calculation means may also be able to estimate each minimum future acceleration and each maximum future acceleration at an instant tj as a function of the estimated acceleration at t0 corresponding to a slope of a portion of a taxiway borrowed by said vehicle (V) at t0 and an estimate of the slope that will have a portion of said traffic lane taken by said vehicle (V) at this time tj;

its calculating means may also be suitable for carrying out the estimations as a function, moreover, of a speed imposed explicitly or implicitly on a portion of the taxiway that the vehicle will take at each of the instants tj;

its calculating means may also be clean, in the presence of another vehicle placed at a relative distance upstream of their vehicle and having at a relative speed relative to the latter vehicle, to make the estimates in accordance with a speed imposed explicitly or implicitly on a portion of the taxiway that will be used by the other vehicle at each moment tj;

its calculation means can also be clean, in the presence of another vehicle placed at a relative distance upstream of their vehicle and having a relative speed relative to the latter vehicle, at estimating relative future speeds and relative future distance for each instant tj, these future relative speeds and future relative distances constituting at least some future environmental information.

The invention also proposes a vehicle, possibly of automobile type, and comprising a regulation system comprising a device for determining the type of that presented above.

For example, the vehicle comprises a supervision computer able to supervise the operation of its powertrain and comprising a part of the calculation means of the determination device, and an auxiliary calculator able to determine environmental information from data acquired by acquisition means embedded and / or transmitted by waves by neighboring vehicles and / or neighboring information stations and comprising a complementary part of the calculating means of the determination device.

Other features and advantages of the invention will appear on examining the detailed description below, and the attached drawing, in which the single figure schematically and functionally illustrates an example of a vehicle with a thermal powertrain and comprising an example. control system comprising an exemplary embodiment of a determination device according to the invention.

The object of the invention is in particular to propose a parameter determination device DD intended to determine parameters for a system SR charged with adaptively regulating the speed of a vehicle V comprising a transmission chain that can be placed in at least one particular acceleration mode.

In the following, by way of non-limiting example, the vehicle V is of automobile type. This is for example a car. But the invention is not limited to this type of vehicle. It concerns any vehicle having a transmission chain comprising a powertrain (or GMP), possibly coupled to a gearbox BV, and intended to produce torque, for example to rotate wheels, and acquisition means to provide information about their environment (especially in a front part). Therefore, the invention relates at least to land vehicles (cars, motorcycles, commercial vehicles, coaches (or buses), and trucks, for example).

It is important to note that the invention relates both to powertrain vehicles of exclusively thermal type (and therefore comprising at least one heat engine), that vehicles with a hybrid-type powertrain (and therefore comprising at least a heat engine and at least one non-thermal drive machine), and powertrain vehicles with a non-thermal drive machine (s).

FIG. 1 shows schematically in the sole figure, for example, a vehicle V comprising a transmission chain comprising a power unit (or GMP) of thermal type, a supervision computer CS capable of supervising (or managing) the operation of the GMP, an EM clutch, a gearbox BV, and a regulation system SR comprising a parameter determination device DD according to the invention.

The thermal GMP includes in particular a thermal engine MT, that is to say consuming fuel or chemicals.

This thermal engine MT comprises a crankshaft (not shown) which is fixedly secured to a motor shaft in order to drive the latter in rotation.

The BV gearbox can be of any type. Thus, it may be a manual gearbox (not controlled), an automatic gearbox (or BVA), or a manual gearbox (BVMP or DCT (double clutch gearbox) ). It comprises at least one input shaft (or primary) intended to receive the torque produced by the heat engine MT via the clutch EM, and an output shaft intended to receive this torque via the input shaft in order to communicating with a transmission shaft to which it is coupled and which is coupled indirectly to the wheels (here of the TV front train of the vehicle V), preferably via a differential before DV. For example, the clutch EM comprises a flywheel fixedly secured to the drive shaft and a clutch disc fixedly secured to the input shaft of the gearbox BV.

The transmission chain also comprises an electric machine AD (starter or alternator-starter) which is coupled to the heat engine MT, possibly via a freewheel, in particular to launch it during a start. This electric machine AD is also coupled to energy storage means MS, which are, for example, arranged in the form of a battery, for example of the very low voltage type (for example 12 V, 24 V or 48 V). .

The operations of the thermal engine MT, the clutch EM and the electric machine AD are here controlled by the supervision computer CS.

It will be noted that when the vehicle comprises a hybrid powertrain transmission chain (or GMP), the latter also comprises a driving machine coupled to means for energy storage, possibly via a DC / DC type inverter. Here "motor machine" means a non-thermal machine or motor intended to provide torque to move a vehicle, either alone or in addition to a heat engine. Therefore, it may for example be an electric motor, a hydraulic machine, a pneumatic machine or a flywheel. It will be noted that this driving machine may not be coupled to the heat engine MT or may be continuously coupled to the heat engine MT (and in this case it forms with the latter (MT) an indecouplable block).

In addition, the hybrid transmission chain must also include a coupling / decoupling means adapted to couple / uncouple the prime mover to a / of a transmission shaft in order to communicate the torque that it produces thanks to the energy stored in the associated storage means. This transmission shaft is responsible for rotating the wheels (for example the rear axle TR of the vehicle V), preferably via a rear differential. This coupling / decoupling means is for example a jaw mechanism or a clutch or a hydraulic torque converter.

Note that the non-thermal driving machine can be reversible operation to allow recovery of the braking energy during a driving phase type brake motor. The braking energy (recovered by the torque of the non-thermal driving machine) is stored in energy storage means.

It is important to note that the particular modes of acceleration in which a transmission chain may be placed vary according to the type of transmission. Generally, these particular acceleration modes can be chosen from at least freewheel acceleration, engine brake acceleration and recuperative brake acceleration.

The regulation system SR (or ACC (Adaptive Cruise Control)) is in charge of adaptively regulating the speed of the vehicle V. It will be noted that such a regulation system SR can also and possibly make it possible to regulate the inter-vehicle time ( or TIV).

Such a regulation system SR performs its regulation by providing at the supervision computer CS at each instant t a final acceleration setpoint cif (t) which is a function of parameters which are determined or estimated by a determination device (of parameters) DD according to the invention. This final acceleration setpoint c1 (t) (positive or negative) is converted by the supervision computer CS into a request for a torque GMP and / or a request for pressure of the braking system intended (s) to be imposed so that the actual acceleration of the vehicle V actually follows this final acceleration target cif (t).

As illustrated, a determination device DD, according to the invention, mainly comprises calculation means MC.

The calculation means MC are firstly arranged so as to determine for their vehicle V, in a conventional manner and well known to those skilled in the art, nominal acceleration instructions ca _n0 m (t), minimum a _m in (t) and maximum to _my x (t) as a function (at least) of the speed v (t0) of this vehicle V at a current instant t0, a speed setpoint cv and information which are relating to an environment of their vehicle V to t0.

The information relating to the environment of the vehicle V to t0 is provided by an auxiliary computer CA which is responsible, at least, for analyzing the environment of the vehicle V. This auxiliary computer CA determines this environment information from data. which are acquired by the acquisition means MA on board the vehicle V and / or transmitted by way of waves to the vehicle V by neighboring vehicles (Car2X function) and / or neighboring information stations.

The acquisition means MA may, for example, comprise at least one camera and / or at least one scanning laser and / or at least one radar or lidar. They are at least responsible for analyzing the environment in front of (or upstream of) the vehicle V.

For example, this environment information may be representative of the current distance separating the vehicle V from a vehicle in front of it (or upstream) or behind it (or downstream), or the current speed of a vehicle. a vehicle situated upstream or downstream of the vehicle V, or the acceleration of a vehicle upstream or downstream of the vehicle V, or the activation status of a signaling function provided by blocks a vehicle upstream or downstream of vehicle V (and in particular a change of direction (or flashing)), or a prescribed speed, or the presence of a turn or a roundabout or of a vehicle upstream.

The speed setpoint cv used by the calculating means MC is supplied by the driver of the vehicle V or by the supervision computer CS (and in this case it is determined as a function, in particular, of the environmental information available to it).

It will be noted that when the regulation system SR performs a pure regulation of the vehicle speed V, the calculation means MC determine the nominal acceleration setpoint ca _n0 m (t) as a function of (at least) the speed v (t0 ) of the vehicle V at t0, the speed setpoint cv, a possible speed imposed explicitly or implicitly, and a law (or mapping) of evolution of the acceleration setpoint as a function of the speed difference between vc and v (t0).

Here is meant by "speed imposed explicitly" a speed regulation (speed limitation, obligation to stop (or stop)), and "speed imposed implicitly" speed resulting from the environment (presence of a bend or a roundabout or vehicle upstream or obstacle upstream or cross road or an obligation to give way, for example).

It will also be noted that when the regulation system SR performs a regulation of the inter-vehicle time, the calculation means MC determine the nominal acceleration setpoint ca _n0 m (t) as a function of (at least) the speed v (t0). from this vehicle V to t0, the relative distance dr (tO) between their vehicle V and a vehicle located tO upstream of their vehicle V, the relative speed vr (tO) between their vehicle V and the upstream vehicle at t0 , an inter-vehicle time setpoint selected by the driver (typically between one second and three seconds), and laws, of variation of speed as a function of time, which must be used respectively to calculate the nominal, minimum accelerations and maximum intended to allow the vehicle V to reach the speed of the upstream vehicle respecting the inter-vehicle time instruction selected TIV.

The nominal acceleration set point AC _n0 m (t) is, for example, between the minimum acceleration a _m in (t) and the maximum acceleration

3max (t) -

These nominal acceleration set point AC _n0 m (t) and minimum acceleration setpoints a _m in (t) and maximum a _ma x (t) can be determined by a first submodule SM1 of the calculation means MC. They constitute three of the parameters determined by the determination device DD.

To calculate the minimum acceleration a _m in (t), the first submodule SM1 uses the same parameters as those used to determine the nominal acceleration set point ca _n0 m (t), with the exception of the speed setpoint cv. which is replaced by a minimum speed instruction cv _min function of cv (for example cv _min = 0.97 ^* cv), and of the selected vehicle interval time TIV which is replaced by a minimum inter-vehicle time TIV _min function of TIV (for example (TIV _min = TIV + 0.5 s) It is also possible to use a law of variation of speed as a function of time which is different from that used to calculate the nominal acceleration setpoint ca _n0 m (t) allowing the vehicle V to reach the set speed cv.

To calculate the maximum acceleration a _max (t), the first sub-module SM1 uses the same parameters as those used to determine the nominal acceleration set point _{n o} m (t), with the exception of the internal time setpoint. selected vehicle TIV which is replaced by a maximum inter-vehicle time TIV _max function of TIV (for example (TIV _max = TIV - 0,5 s) The speed setpoint cv is retained, because if it were increased this would be tantamount to accepting that the vehicle V rolls at a speed greater than the speed set selected by the driver, which is a priori not acceptable.It can also be used a law of variation of speed as a function of time which is different from that used to calculate the speed. nominal acceleration set point ca _n0 m (t) allowing the vehicle V to reach the set speed cv, and also different from that used to calculate the minimum acceleration setpoint a _min (t).

The calculation means MC are also arranged in such a way as to make predictions of the future. More specifically, they are arranged so as (at least):

estimating future speeds evf (tj) and future environmental information of the vehicle at times tj subsequent to t0, and then

estimating minimum future accelerations eafi _min (tj) and maximum eafimax (tj) that would have their vehicle V if it were in each particular acceleration mode of its transmission chain at times tj, as a function of the speed reference cv, environmental information at t0, estimates of future speeds, estimates of future environmental information, eai accelerations (tO) that would have their vehicle V if it were in each particular acceleration mode at tO then

- estimate maximum running times EDRI _max their vehicle V in each mode acceleration particular from tO, depending on the estimated minimum future EAFI acceleration in _m (t) and maximum EAFI _ma x (tj) that would have their vehicle V if it were in each particular acceleration mode at times tj.

The number of instants tj is at least two. For example, it can be three or four or more. It will be noted that this number may depend on the time interval separating successive instants tj. The shorter this time interval, the higher the number mentioned above. For example, this time interval may be equal to one second (in this case, t1 = t0 + 1 s (j = 1), t2 = t1 + 1 s (j = 2), t3 = t2 + 1 s (j = 3), and more generally tn = tn-1 + 1 s (j = n)).

The index i of the accelerations denotes a particular mode of acceleration. For example, in the case of a GMP having only a heat engine and a mechanical gearbox, the index i can take only one value equal to one for the engine brake acceleration mode. In the case of a GMP having only one engine and an automated gearbox, the index i can take two values, a first equal to one for the coasting acceleration mode, and an equal second two for the engine brake acceleration mode. In the case of a hybrid GMP with an electric motor permanently coupled to the engine (the all being detachable from the road), the index i can take two values, a first equal to one for the coasting acceleration mode, and a second equal to two for the maximum regenerative brake acceleration mode. In the case of a GMP all electric or hybrid with an electric motor uncouplable from the engine and the road, the index i can take a single value equal to one for the acceleration mode coasting.

It will be understood that it is estimated that the maximum freewheeling time is _max because, if it is too low, it is not advantageous to introduce this running from the point of view of consumption. Moreover, if at the instant t0 the first ea1 (tO) or second ea2 (t0) acceleration is greater than the maximum acceleration a _max (t0) or less than the minimum acceleration a _m in (t0), the means calculation MC consider that the maximum running time edr1 _max corresponding is zero.

If on the other hand, the maximum duration of freewheeling is important, and that a possible flag (to which we will return later) associated with the mode of engine brake indicates that in this mode of engine brake the acceleration with engine brake does not will become no greater than the estimated future acceleration in this mode of engine braking, so it is interesting to introduce this rolling freewheel from the point of view of consumption.

The maximum running duration estimates edri _max in each particular acceleration mode (i) are other parameters determined by the determination device DD.

The estimates of ea1 (t0) and ea2 (t0) may, for example, be determined by a second submodule SM2 which may be part of the calculation means MC. This determination can, for example, be made using the current torque supplied by the GMP, the speed of rotation of the vehicle wheels V, the pressure of the master cylinder (or PMC) of the braking system, an estimated the slope p (t0) of the portion of the traffic lane used by the vehicle V at the instant t0, the gearbox ratio engaged, an estimate of the mass of the vehicle V, and the vehicle architecture parameters V . By way of example, each estimate of the future speed evf (tj) can be determined by a formula of the type:

ef (tj) = v (t0) + (t1-t0) ^* ea1 (t0) freewheeling, or

evf (tj) = v (t0) + (tj - t0) ^* ea2 (t0) in engine braking.

Similarly, assuming that the speed of the upstream vehicle is constant, the estimated vr (tj) of the relative velocity of the vehicle V with respect to the upstream vehicle at a time tj may, for example, be determined by a formula of the type:

vr (tj) = vr (t0) + (tj-t0) ^* ea1 (t0) freewheeling, or

vr (tj) = vr (t0) + (tj - t0) ^* ea2 (t0) in engine braking.

Also likewise, assuming that the speed of the upstream vehicle is constant, the estimate dr (tj) of the relative distance between the vehicle V and the upstream vehicle at a time tj may, for example, be determined by a formula of the type :

dr (t) = r (tO) + vr (tO) ^* (t - tO) + [(t - t0) ^2/2] ^* ea1 (tO) coasting, or

dr (t) = r (tO) + vr (tO) ^* (t - tO) + [(t - t0) ^2/2] ^* ea2 (t0) in engine braking.

Estimates evf (tj), future environment information at times tj and edri _max estimates may, for example, be determined by a third submodule SM3 which is part of computing means MC.

The calculation means MC can estimate the minimum future accelerations eafi _m in (tj) and maximum eafi _ma x (tj) by means of the third submodule SM3. To do this, the third sub-module SM3 may, for example, use the first sub-module SM1 which is responsible for determining the minimum accelerations _min (t) and maximum a _max (t), as explained above. In this case, the third sub-module SM3 supplies the first submodule SM1 with the estimates of the future speeds evf (tj) and the estimates of the future environment information at the times tj in addition to the speed setpoint cv and the information of environment to tO he already knows, that he believes in every EAFI _m (t) and each EAFI _my x (t). It is assumed here that the estimate of each acceleration eai (tO) will remain constant.

In the example illustrated nonlimitingly in the single figure, the first SM1 and third SM3 sub-modules of the calculation means MC are located in the auxiliary computer CA. This is advantageous because the environment information at t0 is determined in this auxiliary computer CA, and therefore it makes it possible to limit the data exchanges via a possible communication network of the vehicle V, possibly of the multiplexed type. But this is not obligatory. Indeed, they could be implemented in another computer embedded in the vehicle V, and possibly dedicated. Therefore, the first SM1 and third SM3 sub-modules of the calculation means MC can be implemented in the form of software modules (or computer or "software"), or a combination of electronic circuits (or "hardware" ) and software modules.

Also in the example illustrated nonlimitingly in the single figure, the second submodule SM2 is implanted in the supervision computer CS. But this is not obligatory. Indeed, it could be implanted in another computer embedded in the vehicle V, such as for example the computer of the braking system or the auxiliary computer CA, or could itself be a calculator. Therefore, the second sub-module SM2 can be realized in the form of software modules (or computer or "software"), or a combination of electronic circuits (or "hardware") and software modules.

For example, the estimate of the maximum running time of the vehicle V freewheel edr1 _max or engine brake edr2 _max from t0 can be done as indicated below.

In the case of freewheeling, the calculation means MC may, for example, compare the estimated acceleration at t0 ea1 (t0) with the estimates of the minimum future accelerations eaf1 _min (tj) and maximum eafl max (tj) tj to determine a time at which the estimated acceleration a to ea1 (t0) is (or becomes) greater than the estimate of the maximum future acceleration EAF1 _ma x (t) at this time tj or less than the estimate of the minimum future acceleration eaf1 _min (tj) at this instant tj. In this case, the difference between t0 and this determined instant tj constitutes the estimate of the maximum running time of the vehicle V in freewheel edr1 _max .

In the case of engine braking, the calculation means MC may, for example, compare the estimated acceleration at t0 ea2 (t0) with the minimum future acceleration estimates eaf2 _min (tj) and maximums eaf2 _max ( tj) in order to determine an instant tj for which this estimate of the acceleration at t0 ea2 (t0) is (or becomes) greater than the estimate of the maximum future acceleration eaf2 _max (tj) at this instant tj. In this case, the difference between t0 and this instant tj determined is the estimated maximum running time of the vehicle in engine brake _max edr2.

Preferably, in parallel with the determination of each of the estimated maximum vehicle driving EDR1 _max, MC calculation means produces for each specific shuttle mode (i) a flag (or "flag") whose value is representative of the fact that if the vehicle V was in a particular mode, and that at the instant t0 the acceleration in this particular mode was less than the maximum acceleration at t0 a _max (t0), there is or is not a moment for which the acceleration in this particular mode would become greater than the estimate of the maximum future acceleration eafi _max (t'j) corresponding to this particular mode, and if at the instant t0 the acceleration in this mode particular was higher than the minimum acceleration has tO _min (t0), or not there is a T'j time at which the acceleration in this particular embodiment would become less than the estimated minimum future acceleration EAFI _min (t 'j) corresponding to this particular mode.

For example, the flag value may be equal to one (1) if the acceleration estimate eai (t0) has become greater than the estimate of the maximum future acceleration eafi _ma x (t'j), and may be equal to minus one (-1) or zero (0) if the acceleration estimate eai (tO) has become less than the estimate of the minimum future acceleration eafimin (t'j).

Note that if at time t0, the acceleration in the particular mode considered is between the minimum acceleration a _min (t0) and the maximum acceleration a _ma x (t0) at time t0, then the instant t'j is equal to instant tj. If, on the other hand, the acceleration in the engine brake is at the instant t0 less than the minimum acceleration a _m in (t0) or greater than the maximum acceleration at _my x (t0) at time t0, then the time tj is zero whereas the time t'j can be nonzero. By for example, if the acceleration in the particular mode under consideration is less than the minimum acceleration a _m in (t0), then there may be a time t d for which the acceleration in this particular mode considered may become greater than estimated maximum acceleration eafi _ma x (t'j) for this particular mode considered.

In what precedes, it is considered that one predicts the future by making the hypothesis:

- Free-wheel acceleration and engine brake acceleration remain constant in the future. In other words, we neglect the reduction of the aerodynamic effects with the speed, because the speed will vary slowly if we make the free wheel (because we do not predict the future at thirty seconds), and we consider that the slope of the taxiway used by vehicle V will not vary in the short term,

- that there is no effect induced by a downshift or an increase of report following a speed variation in the future. In other words, it is considered, for example, that the excess deceleration in engine braking does not vary in the presence of a downshift in the future, and

- that the dynamics of a vehicle located upstream of the vehicle V does not change in the future.

This results from the fact that the maximum driving times edri _max are generally less than ten seconds, and that the slopes of the taxiway portions vary globally slowly.

But more refined estimates can be made.

Thus, the computing means MC, and more specifically their third sub-module SM3, may be able to estimate each first or second acceleration (nominal, minimum or maximum) at a time tj as a function of the estimate of the first ea1 (t0) or second ea2 (t0) acceleration at t0, of a slope p (Xv (tO)) of a portion of the traffic lane taken by their vehicle V at t0 and an estimate of the slope ep (X _v (tj)) that will have a portion of this lane used by their vehicle V at this moment tj. The variable X _v here denotes the absolute position of the vehicle V, which can be provided, for example, by a navigation aid device on board the vehicle. vehicle V, which possibly uses information provided by a constellation of positioning satellites. The variable X _v (tj) is obtained by integrating, from Xv (tO), the estimate of the future velocity ev (tj).

It should be noted that the slopes can be determined by at least one sensor embedded in the vehicle V or defined by topographical information provided by the navigation aid device. This topographic information can be contained in a database of the navigation aid device or can be transmitted to the latter, for example by a satellite communication network. For example, this navigation aid device can provide the slope of the portion of the taxiway via what is known to those skilled in the art as the electronic horizon.

In this option, it is therefore possible, for example, to replace the estimates ea1 (t0) and ea2 (t0) used in the formulas indicated above by:

ea1 (tj) = ea1 (t0) + g ^* (p (X _v (t0)) - ep (X _v (tj))) freewheeling, and

ea2 (tj) = ea2 (t0) + g ^* (p (X _v (t0)) - ep (X _v (tj))) with engine braking.

As a variant or in addition, the calculation means MC, and more specifically their third sub-module SM3, may be clean, in the presence of another vehicle placed at t0 at a relative distance dr (tO) upstream. of their vehicle V and having t0 a relative speed vr (tO) relative to their vehicle V, to estimate future relative speed vr (tj) and future relative distance dr (tj) for each instant tj. It will be understood that in this case these future relative speeds vr (tj) and future relative distances dr (tj) constitute at least some of the future environment information of the instants tj.

In this option, the calculation means MC, and more specifically their third submodule SM3, can be used, for example, to estimate the speed of the vehicle V at the instant tj ev (tj) (deductible by integration of ea1). (tj) or ea2 (tj)), the speed of the vehicle upstream at time tj ev _am0 nt (tj) (function of the last known values of the speed of the upstream vehicle), the position X _v (tj) of the vehicle V at the instant tj (deductible by integration of ev (tj)), and the position Xamont (tj) of the upstream vehicle at time tj (deductible by integration of e upstream (tj). Then, the calculation means MC can consider that each future relative speed vr (tj) is equal to ev (tj) _{-ev am0} nt (tj), and that each future relative distance dr (tj) is equal to dr (tO). + Xamont (tj) - Xv (tj).

As a variant or in addition, the calculation means MC may be able to perform their estimations as a function also of a speed imposed explicitly or implicitly on a portion of the taxiway that will borrow their vehicle V at each time tj.

This option can be implemented by a fourth submodule SM4 of the computing means MC. To do this, instead of using the speed command cv (supplied by the driver), this fourth sub-module SM4 uses the speed imposed at time tj (which then constitutes a kind of predictive speed command), when it is lower than the imposed speed in progress (at t0). When the speed imposed at time tj is greater than the imposed speed in progress (at t0), sub-modules SM1 and SM3 are used by replacing the set speed vc with this imposed speed in progress (at t0) when the Vehicle V moves to the position where it begins to be imposed (not to anticipate).

In order to implement its function, this fourth sub-module SM4 uses other parameters for calculating nominal, minimum and maximum accelerations than those which are normally used, that is to say when the speed reference cv is used. . In fact, these other calculation parameters define three laws, of speed variation as a function of the distance to the event defining the imposed speed, which must be used respectively to calculate the nominal, minimum and maximum accelerations intended to allow the vehicle V to reach this imposed speed. By comparison, when using the speed setpoint cv, the calculation parameters define three laws, of speed variation as a function of time, which must be used respectively to calculate the nominal, minimum and maximum accelerations intended to allow the vehicle V to reach the set speed cv.

In the case of the last option, the calculation means MC, and more specifically their fourth submodule SM4, may be, for example, clean to make their estimates in addition to a speed imposed explicitly or implicitly on a portion of the taxiway that will be used by the other upstream vehicle at each of the instants tj.

As illustrated, the regulation system SR comprises a decision module MD arranged to determine a final acceleration target cif (t) which is adapted to adaptively adjust the speed of the vehicle V according to the parameters determined by the device for determining DD, and more precisely at least the nominal acceleration setpoint ca _nO m (t0), the minimum acceleration a _min (t0), the maximum acceleration amax (t0), each acceleration estimate eai (tO), of each estimated maximum freewheeling time edri _max and of each possible flag signaling whether the estimate of the acceleration eai (tO) has become greater than the estimate of the maximum future acceleration eafi _max (tj) or lower than the estimate of the minimum future acceleration eafi _m in (tj).

For example, the decision module MD can compare the estimate of the maximum freewheeling time edr1 _max to a chosen threshold. Then, if edr1 _max is greater than this chosen threshold, and the engine brake flag is not at 1, then the decision means MD decide to choose as final acceleration setpoint cif (t) the estimate of the freewheeling acceleration ea1 (t0).

In the example shown non-limitatively in the single figure, the decision means MD are located in the supervision computer CS. This is advantageous because the latter (CS) is the one with the most important knowledge of the transmission chain and therefore has useful data on energy consumption, in particular, which limits data exchanges via the possible communication network of the vehicle V. But this is not mandatory. Indeed, they could be implanted in another on-board computer in the vehicle V, such as for example the braking system, which generally has, for its own needs, a relative knowledge of the transmission chain, or could themselves. constitute a calculator. Therefore, the decision means MD can be realized in the form of software modules, or a combination of electronic circuits and software modules.

Claims

1. Parameter determination device (DD) for an adaptive velocity control system (SR) of a vehicle (V) having a transmission chain adapted to be placed in at least one particular acceleration mode, said device (DD) ) comprising calculation means (MC) capable of determining nominal, minimum and maximum acceleration setpoints, as a function of a speed of said vehicle (V) at a current instant t0, of a speed setpoint and of information relating to an environment of said vehicle (V) at t0, characterized in that said calculation means (MC) are further adapted to estimate future speeds and future environmental information of said vehicle (V) at later times tj at tO, then to estimate the minimum and maximum future accelerations that said vehicle (V) would have if it were in each particular acceleration mode at said instants tj as a function of said speed setpoint, said ormations of environment at t0, said estimated future speeds, said estimates of future environment information, and accelerations that would have said vehicle (V) if it were in each particular acceleration mode at tO, then at estimating maximum running times of said vehicle (V) in each particular acceleration mode according to said estimates of the minimum and maximum future acceleration and said acceleration of said vehicle (V) if it were in each particular acceleration mode at tO.

2. Device according to claim 1, characterized in that said calculating means (MC) are adapted to compare each estimate of the acceleration that said vehicle (V) would have if it were in a particular acceleration mode at tO to said estimates of the corresponding minimum and maximum future accelerations to determine an instant tj for which said estimate of the acceleration the vehicle would have if it were in a particular acceleration mode at t0 is greater than the estimate of the corresponding maximum future acceleration at this instant tj or less than the estimate of the corresponding minimum future acceleration at this instant tj, the difference between t0 and this instant tj determined then constituting said estimate of the maximum duration of driving of said vehicle (V) in this particular acceleration mode.

3. Device according to one of claims 1 and 2, characterized in that said calculating means (MC) are arranged to produce for each particular mode of acceleration a flag having a value representative of the fact that if said vehicle (V) was in this particular mode, and that at the instant t0 the acceleration in this particular mode was less than said maximum acceleration at t0, there is or is not an instant t'j for which the acceleration in this particular mode would become greater to said estimate of the maximum future acceleration corresponding to this particular mode, and if at the instant t0 the acceleration in this particular mode was greater than said minimum acceleration at t0, there exists or not an instant t'j for which l acceleration in this particular mode would become less than said estimate of the minimum future acceleration corresponding to that particular mode.

4. Device according to one of claims 1 to 3, characterized in that said particular acceleration modes are selected from a group comprising freewheel acceleration, engine brake acceleration and recuperative brake acceleration.

5. Device according to one of claims 1 to 4, characterized in that said calculation means (MC) are adapted to estimate each minimum future acceleration and each maximum future acceleration at a time tj according to said estimated acceleration at a corresponding t0, from a slope of a portion of a traffic lane taken by said vehicle (V) to t0 and from an estimate of the slope that a portion of said traffic lane taken by said vehicle (V) will have at this moment tj.

6. Device according to one of claims 1 to 5, characterized in that said calculating means (MC) are adapted to perform said estimates in addition to a speed imposed explicitly or implicitly on a portion of said lane said vehicle (V) will borrow at each of said instants tj.

7. Device according to claim 6, characterized in that said calculating means (MC) are clean, in the presence of another vehicle placed at tO at a relative distance upstream of said vehicle (V) and having at a relative speed relative to said vehicle (V), to perform said estimates as a function also of a speed imposed explicitly or implicitly on a portion of said route of circulation that will borrow said other vehicle at each of said instants tj.

8. Device according to one of claims 1 to 7, characterized in that said calculating means (MC) are clean, in the presence of another vehicle placed at tO at a relative distance upstream of said vehicle (V) and having at t0 a relative speed with respect to said vehicle (V), estimating future relative speed and future relative distance for each instant tj, these future relative speeds and future relative distances constituting at least some of said future environment information.

9. Vehicle (V) comprising a powertrain and a control system (SR), characterized in that said control system (SR) comprises a determination device (DD) according to one of the preceding claims.

10. Vehicle according to claim 8, characterized in that it comprises a supervision computer (CS) able to supervise the operation of said powertrain and comprising a part of said calculation means (MC) of the determination device (DD), and an auxiliary calculator (CA) capable of determining environmental information from data acquired by on-board acquisition means and / or transmitted by waves by neighboring vehicles and / or neighboring information stations and comprising a complementary part of said calculation means (MC) of the determination device (DD).