A method of controlling a system for modulating a flow of cooling air of a vehicle in high-speed conditions of the vehicle

Abstract

A method (30) of controlling a system (100) for modulating a flow of cooling air of a vehicle (V) in high-speed conditions of the vehicle (V) is described. A travel speed (Speed, Speed_Pred) of the vehicle (V) is determined and compared (504, 506) with at least one threshold value (Speed Antistk_Lo , Speed Antistk _ Hi ). In response to the travel speed of the vehicle being higher than the threshold value, an opening signal (AG Opening_Antistk ) of the system for modulating the flow of cooling air is asserted (502, 508, 510). In response to the travel speed of the vehicle being lower than the threshold value, the opening signal (AGS O pening_Antistk ) of the system for modulating the flow of cooling air is de-asserted (502, 508, 510). In response to the opening signal being asserted, the system for modulating the flow of cooling air is set to a condition of at least partial opening. In response to the opening signal being de-asserted, the system for modulating the flow of cooling air is controlled according to a logic that allows partial or complete closure.

Description

[0001] “A method of controlling a system for modulating a flow of cooling air of a vehicle in high-speed conditions of the vehicle”

[0002] ****

[0003] TEXT OF THE DESCRIPTION

[0004] Field of the invention

[0005] The instant invention relates to vehicles provided with systems for modulating a flow of cooling air entering the vehicle, for example of the type conventionally called “Active Grill Shutter”, AGS.

[0006] Solutions as described herein can be applied to vehicles with (even partially) electric propulsion, for example BEV (Battery Electric Vehicle) or HEV (Hybrid Electric Vehicle) type vehicles, provided with such a system for modulating a flow of cooling air.

[0007] Prior art

[0008] Figure 1 schematically illustrates the operation of a system for modulating a flow of cooling air entering a vehicle V, of which the anterior or front portion is represented in a top view.

[0009] As is known, when the vehicle is in motion, an air flow can be let into the vehicle V (and in particular, into the engine compartment) through an air intake located in the front part of the vehicle V (not illustrated in Figure 1 for simplicity), and directed to a vehicle cooling system that comprises a group of heat exchangers located inside the vehicle. Such heat exchangers may comprise, for example, a condenser 102 and / or a radiator 104. The cooling system may further comprise a compressor (not illustrated in Figure 1 for simplicity), driven by a respective electric motor, which is operated using the rotational speed of the compressor itself as a control variable. Although useful for cooling some components of the vehicle V, the entering of an air flow to the vehicle exchangers 102, 104 may negatively affect the aerodynamic properties of the vehicle and, consequently, its performance. In some vehicles, a system 100 for modulating an air flow is therefore provided at the air intake, for example a system of the type conventionally known as “Active Grill Shutter” (AGS) 100, configured to modulate the flow rate of air entering the vehicle V and passing through the group of heat exchangers 102, 104.

[0010] As illustrated in Figures 2A, 2B and 2C, an AGS system 100 comprises baffle plates 201 (or deflectors) whose orientation with respect to the direction of the air flow can be varied (e.g., by means of one or more electric actuators), so as to vary the surface area of the baffle plates 201 that counteracts the passage of the air flow to the exchangers 102, 104 or, in other words, to vary the area of the actual section of the air intake. In this regard, Figures 2A, 2B and 2C illustrate such an AGS system 100 in different configurations. Specifically, Figure 2A illustrates an AGS system 100 in a “closed” configuration, where the surface of each baffle plate 201 is oriented perpendicular to the direction of the incoming air flow FIN SO as to counteract (possibly completely blocking) the passage of the incoming air flow to the vehicle V. Figure 2B illustrates the AGS system 100 in a partially closed configuration, where the surface of each baffle plate 201 is oriented in an oblique direction with respect to the direction of the incoming air flow FIN SO as to only partially counteract the passage of the incoming air flow to the vehicle V and allow an exit flow Four of lower flow rate than the incoming flow FIN. Figure 2C illustrates the AGS system 100 in an “open” configuration, where the surface of each baffle plate 201 is oriented parallel to the direction of the air flow so as to minimize the surface area of the baffle plates 201 that opposes the incoming air flow FIN and to oppose as little as possible the passage of the air flow entering the vehicle V (or, in other words, to maximize the outlet air flow Four, which takes a flow rate almost equal to that of the incoming flow FIN). Obviously, it will be understood that intermediate configurations between those represented as an example in Figures 2A, 2B and 2C are also possible and that, in general, the orientation of the baffle plates 201 can be varied continuously between the “fully closed” configuration and the “fully open” configuration depending on the cooling needs.

[0011] An electronic control unit (not illustrated in the figures for simplicity) can be installed on board the vehicle and configured to control the system 100 for modulating a flow of cooling air according to management modes that allow the cooling air flow Four to be modulated (by varying the configuration of the modulation system 100 between the configurations exemplified in Figures 2A, 2B and 2C or other intermediate configurations) as a function of the quantity of cooling air that one wishes to send to the group of exchangers 102 and 104 (for example, as a function of the desired conditioning power). This electronic control unit can be, for example, a control unit of the conditioning and refrigeration system (or HVAC, “Heating, Ventilation and Air Conditioning”, system) or a vehicle control unit. It is known in the art that the greater the degree of closure of the AGS system 100, the better the aerodynamic properties of the vehicle, since the reduction of the air flow passing through the AGS system 100 determines a reduction in the aerodynamic drag of the vehicle. On the other hand, a greater closure of the AGS system 100 determines a lower cooling capacity of the vehicle components. Therefore, the electronic control unit can be configured to manage the AGS system 100 in such a way as to obtain a good balance between aerodynamic and cooling performance.

[0012] An AGS system 100 as just described is otherwise known in the art, which makes it superfluous to provide a more detailed description here. Furthermore, the particular system described is purely exemplary since solutions according to embodiments of this disclosure can be applied to systems for modulating air flows entering the vehicle other than the one described above.

[0013] When the vehicle is moving at high speed, the torque produced by the electric motor (or electric motors, if there is more than one) that controls the movement of the baffle plates 201 of the AGS system 100 may not be sufficient to overcome the resistance given by the inlet air flow FIN when trying to bring the AGS system 100 from a closed condition to an (even partially) open condition. Therefore, it may happen that at high speed the AGS system, initially in a closed state, is not able to open (locked state). As a result, there may be a condition where the AGS system is not able to guarantee the correct passage of the air flow Four in the engine compartment and in particular on the group of heat exchangers 102, 104, with a consequent reduction of the cooling capacity of the cooling system of the vehicle V, which can be recovered only by reducing the vehicle speed, so that the resistance given by the air flow FIN to the movement of the baffle plates 201 is reduced and the actuators of the AGS system are again able to move the baffle plates 201 to a more open position.

[0014] Therefore, the need is felt in the art to develop an algorithm to control the system for modulating a flow of cooling air (or AGS system) of a vehicle that allows to avoid the blocking of the AGS system in the closed condition (“stuck-close condition”) when the vehicle moves at high speed.

[0015] Object of the invention

[0016] The object of the invention is to solve the above-mentioned technical problem. In particular, the object of the invention is to provide a method of controlling an AGS system that allows to avoid the blocking of the AGS system in the closed condition when the vehicle is moving at high speed.

[0017] Summary of the invention

[0018] The object of the invention is achieved by a method having the features forming the subject of the following claims, which form an integral part of the technical teaching provided here in relation to the invention.

[0019] The method can be implemented by one or more electronic control units of a vehicle, for example a control unit of the HVAC system and / or a unit for the thermal control of the vehicle.

[0020] Brief description of the figures

[0021] The invention will now be described with reference to the attached figures, provided purely by way of non-limiting example, in which:

[0022] Figure 1 and Figures 2A to 2C, already described previously, schematically illustrate the operation of a system for modulating the flow of cooling air entering the vehicle, such as an “Active Grill Shutter” (AGS) system;

[0023] Figure 3 is a block diagram illustrating the steps of a method of controlling an AGS system in high-speed conditions, according to one or more embodiments of the present disclosure;

[0024] Figure 4 is a block diagram illustrating some steps of a first phase of the method of controlling the AGS system, in particular a phase that allows the vehicle speed to be predicted at a later time, based on the current speed, according to one or more embodiments of the present disclosure;

[0025] Figure 5 is a block diagram illustrating some steps of a second phase of the method of controlling the AGS system, in particular a phase that allows to produce an anti-blocking signal as a function of the vehicle speed predicted in the previous phase, according to one or more embodiments of the present disclosure;

[0026] Figure 6 is a diagram that exemplifies the time course of the input and output signals of a delay generator block (or debouncer);

[0027] Figure 7 is a time diagram illustrating the course of an antiblocking signal of the AGS system as a function of the predicted speed of the vehicle, according to one or more embodiments of the present disclosure; and

[0028] Figure 8 is a block diagram summarizing the steps of a method of controlling an AGS system in high-speed conditions of the vehicle, according to one or more embodiments of the present disclosure.

[0029] Detailed description

[0030] As mentioned, the invention is applicable to conditioning and / or refrigeration systems comprising one or more heat exchangers which, when the vehicle is in motion, are hit by a flow of cooling air whose flow rate is adjustable by means of an AGS system.

[0031] In particular, the method according to the present invention has the purpose of controlling the AGS system in such a way as to prevent the blocking condition in the closed position, due to the excessive aerodynamic drag produced by the air flow that hits the front part of the vehicle when it moves at high speed. In fact, the baffle plates or deflectors 201 of the AGS system are moved, in the opening and closing phases, by one or more electric motors. The air flow FIN that hits the front part of the vehicle V during driving generates a torque that is applied to the rotation axes of the baffle plates 201 . This torque increases (e.g., approximately proportionally) as the travel speed of the vehicle V increases, due to the geometry of the AGS system and the increase in friction due to the dynamic pressure exerted by the air flow on the baffle plates themselves. It is possible to determine a maximum value of the vehicle speed (which can be indicated by the AGS system supplier) below which the torque developed by the AGS system drive motor is sufficient to correctly actuate (e.g., rotate) the baffle plates 201 so that they are positioned as requested (e.g., in order to adjust the air flow rate Four to a certain target value). The problem of the AGS system blocking in the closed position is more felt during the acceleration phases of the vehicle when the AGS system is already initially in the closed position, because in such a case when the vehicle reaches a high travel speed it may become impossible to correctly actuate the baffle plates 201 to bring the AGS system 100 into an open condition, in order to allow the passage of the air flow necessary to ensure that the cooling requirements of the cooling system of the vehicle (e.g., of the exchangers 102 and 104) are met. In this condition, the only way to allow the AGS system to open is to reduce the vehicle speed below the speed limit indicated by the AGS supplier. Otherwise, if the vehicle speed is not reduced and the AGS system is kept closed, the reduced cooling capacity of the cooling system of the vehicle causes (particularly in the case of electric or hybrid vehicles) a thermal derating which results in a reduction in vehicle performance (in order to preserve the safety of the battery-powertrain). Both scenarios (slowing down the vehicle to allow the AGS system to open, or thermal derating with a reduction in performance) are undesirable, particularly in the case of high- performance sports vehicles. At the same time, opening the AGS system during an acceleration phase, and particularly during a driving mission involving maximum acceleration over a short distance (“drag race” mode), causes a reduction in vehicle performance due to the increase in aerodynamic drag. Therefore, an objective of the method according to the present invention is to control the AGS system so as to avoid the blocking condition in the closed position, without however degrading the acceleration performance in “drag race” type driving missions.

[0032] As illustrated in the block diagram of Figure 3, the method 30 can substantially comprise two steps indicated by the references 302 and 304. In step 302, further described below, a value of the predicted speed Speed_Pred (in the immediate future) of the vehicle V is determined instant by instant, as a function of the current speed Speed of the vehicle (which can be sensed by appropriate vehicle sensors). In step 304, further described below, an anti-blocking signal of the AGS system AGSopening_Antistk is produced as a function of the predicted speed Speed_Pred computed in step 302.

[0033] The AGS system may be characterized, in some cases, by a certain actuation delay (e.g., during the opening phase), due to the transmission and processing of signals by the control units of the vehicle V, and / or due to the actuation delay of the electric motor that controls the baffle plates 201 . This actuation delay can be quantified in a certain time interval which can be indicated by the supplier of the AGS system and / or can be determined on the basis of analyses and experimental data. In order to take into account (e.g., correct) the actuation delay of the AGS system, it is useful, in one or more embodiments, to slightly anticipate the request for opening of the AGS system in an appropriate manner, since an opening request that is too late could lead to the blocking condition in closing (since, in the “drag race” acceleration phase, the vehicle speed increases very rapidly and the limit speed indicated by the AGS system supplier can be quickly exceeded), but on the other hand, an opening request that is too early would determine a non-negligible reduction in the acceleration performance of the vehicle (i.e. , an increase in travel time in a “drag race” driving mode).

[0034] For these reasons, the first phase 302 of the method 30 allows to predict, in the immediate future, a speed value Speed_Pred of the vehicle V as a function of the current speed Speed. The functioning of the operation block 302 for the speed prediction Speed_Pred will now be described with reference to Figure 4.

[0035] In particular, as illustrated in Figure 4, in a block 402 the current speed Speed of the vehicle expressed in km / h is divided by the constant factor 3.6 in order to determine the current speed of the vehicle expressed in m / s. In a block 404, the gradient of the current speed expressed in m / s is computed, which from a physical point of view corresponds to an expression of the current acceleration of the vehicle, for example according to the following equation:

[0036] _ Speedto- Speedto-dt

[0037] ACC — dt

[0038] Therefore, substantially, the gradient computed in step 404 (i.e., the acceleration of the vehicle) is equal to the difference between the vehicle speed (in m / s) sensed at the instant to and the vehicle speed (in m / s) sensed at the previous instant to-dt, where dt is the duration of the iterative step of the control algorithm and may correspond, for example, to the refresh interval of the signal Speed.

[0039] In blocks 406 and 408, the acceleration Acc computed by block 404 is limited to zero at the low end and to a constant value Acc_Max at the high end, to produce a Taw” acceleration signal Acc_Raw. In particular, the acceleration Acc_Raw is limited to zero at the low end in block 406 because, for the vehicle speed prediction algorithm, only the vehicle acceleration phases (in which the travel speed increases) must be considered and not the vehicle deceleration phases (in which the travel speed decreases). In block 408, the acceleration Acc_Raw is limited at the high end to the maximum value Acc_Max, which represents a theoretical maximum value, to exclude any unlikely values of the parameter Acc due to possible computation errors. The maximum acceleration value Acc_Max can be stored in a vehicle control unit, and thus represents an input constant for the control algorithm 302.

[0040] In block 410, the Taw” acceleration signal Acc_Raw is filtered to remove any punctual peak values and produce a filtered acceleration signal Acc_Flt. In block 412, the filtered acceleration Acc_Flt is multiplied by the constant factor 3.6 and by a prediction time interval Atpred to determine a predicted increase in vehicle speed (in km / h) ASpeed_Pred in the next time interval of duration equal to Atpred. So substantially the quantity ASpeed_Pred indicates the predicted increase in vehicle speed between the current time t and a future time t+Atpred. By adding up the predicted increase ASpeed_Pred and the current speed Speed in block 414, the Taw” predicted speed Speed_Pred_Raw is determined. Finally, in block 416 the raw predicted speed Speed_Pred_Raw computed by block 414 is limited to a constant value Speed_Max at the high end to determine the actual predicted speed Speed_Pred. The maximum speed value Speed_Max is dictated by the fact that a speed limiter may be implemented in the vehicle. The maximum speed value Speed_Max may be stored in a vehicle control unit, and therefore represents an input constant for the control algorithm 302.

[0041] The functioning of the operation block 304 for determining the AGS system anti-blocking signal AGSoPening_Antistk will now be described with reference to Figures 5, 6, and 7.

[0042] In particular, Figure 5 is a block diagram illustrating the steps of the control algorithm 304 for determining the signal AGSoPening_Antistk as a function of the predicted speed Speed_Pred. Essentially, a set-reset (SR) flip-flop 502 is set (by asserting the signal at the set input S of the flip-flop, produced by a comparator 504) when the predicted speed Speed_Pred is higher than or equal to a certain upper threshold SpeedAntistk_Hi, and is reset (by asserting the signal at the reset input R of the flip-flop, produced by a comparator 506) when the predicted speed Speed_Pred is lower than or equal to a certain lower threshold SpeedAntistk_Lo, producing an output signal Hystout. So, substantially, comparators 504 and 506 together with set-reset flip-flop 502 behave overall as a hysteretic comparator, which asserts the signal Hystout when the predicted speed Speed_Pred rises above the upper threshold Speed Anti Stk_Hi and de-asserts the signal Hystout when the predicted speed Speed_Pred falls below the lower threshold SpeedAntistk_Lo. The upper threshold SpeedAntistkj-n and the lower threshold SpeedAntistk_Lo may be stored in a vehicle control unit, and thus represent two input constants for control algorithm 304. In particular, the upper threshold SpeedAntistk_Hi may be chosen equal to the maximum speed defined by the AGS system supplier (beyond which the AGS system could block in the closed configuration) reduced by an amount equal to a safety margin that may be defined by the vehicle manufacturer. The lower threshold SpeedAntistk_Lo can be chosen, in turn, equal to the upper threshold SpeedAntistk_Hi reduced by an amount equal to a hysteresis margin that can be defined by the vehicle manufacturer.

[0043] The signal Hystout is passed to a delay block 508. The delay block 508 works as exemplified in the diagram of Figure 6, which illustrates the time courses of a generic input signal IHDL and a generic output signal OutDL of a generic delay block DL, and a generic delay having duration Atoeiay. Substantially, the delay block DL delays the propagation of only the falling edges of the respective input signal IHDL by an amount equal to the time interval Atoeiay, while the rising edges of the input signal / not are propagated substantially without delay. As a consequence, any de-assertions of the input signal IHDL whose overall duration is shorter than the duration of the interval Atoeiay are completely filtered out by the delay block DL (see for example times to, ti and t2 in Figure 6), while de-assertions of the input signal InDL whose overall duration is longer than the duration of the interval Atoeiay are initially filtered out (i.e., the output signal OutDL remains asserted for a period equal to Atoeiay) and then propagated (see for example times ts, t4 and ts in Figure 6). In other words, the delay block DL performs a sort of “debouncing” of the input signal IHDL with a filter time equal to Atoeiay. So, returning to Figure 5, the signal Hystout is processed in delay block 508 which acts as discussed in relation to Figure 6 using a filter time equal to AtrumoffDeiay to produce a respective output signal AntiStkActivation.

[0044] Still referring to Figure 5, a selector 510 receives an asserted value (one, ‘T, which indicates the need to open the AGS system) at a first input, a de-asserted value (zero, ‘O’, which indicates the possibility of closing the AGS system) at a second input, and the signal AntiStkActivation as a control signal, such that if the control signal AntiStkActivation is asserted (equal to one) the signal AGSoPening_Antistk is also asserted to request the opening of the AGS system and prevent it from subsequently blocking in the closed position (in anticipation of an increase of the vehicle speed above the critical threshold), while if the control signal AntiStkActivation is de-asserted (equal to zero) the signal AGSoPening_Antistk is also de-asserted to allow the complete or partial closing of the AGS system (in anticipation of the fact that, in the near future, the vehicle speed will remain below the critical threshold that would lead to blocking in the closed position).

[0045] Therefore, the set of operations illustrated in Figure 5 substantially has the effect of setting the AGS system to an at least partially open condition (with AGSoPening_Antistk signal asserted) when the predicted speed of the vehicle in the immediate future Speed_Pred rises above the upper threshold SpeedAntistkj-n, and instead allowing the AGS system to close (with AGSoPening_Antistk signal de-asserted) with some delay AtrumoffDeiay after the speed Speed_Pred drops below the lower threshold SpeedAntistk_Lo. It will be noted that the use of two distinct speed thresholds SpeedAntistkj-n and SpeedAntistk_Lo is useful for the stability of the control algorithm 304 (as it allows to obtain a hysteretic behavior) but, in principle, is not necessary. Advantageously, the hysteretic behavior of the comparator consisting of blocks 502, 504 and 506 reduces the number of actuations of the AGS system and thus helps preventing premature aging of its mechanical and electrical components. It will be noted that the introduction of the delay AtTumoffDeiay in the de-assertion of the signal AGSoPening_Antistk with respect to the signal Hystout is also useful as it allows the anti-blocking strategy of the AGS system to be kept active for a certain period of time even if the vehicle speed has dropped below the critical value (thus avoiding continuous activations and deactivations of the AGS system in the event that the vehicle is subjected to continuous accelerations and decelerations around the critical speed value), but in principle it is not necessary.

[0046] So, substantially, when the predicted speed of the vehicle is higher than a certain threshold, the AGS system is operated to an at least partial or total opening position to avoid blocking in the closed condition (signal AGSoPening_Antistk in asserted condition). On the contrary, when the predicted speed of the vehicle is lower than the threshold, the AGS system is free to close completely or partially (signal AGSopening_Antistk in de-asserted condition). In particular, when the signal AGSopening_AntiAging is in de-asserted condition, the closure percentage of the AGS system is determined based on a conventional algorithm as a function of the requested cooling power and / or as a function of other operating parameters of the conditioning system, in a way known in itself that will not be further explored here.

[0047] Figure 7 is a time diagram that qualitatively illustrates an example of the trend of the signal AGSopening_Antistk as a function of the predicted speed of the vehicle Speed_Pred. At time to the predicted speed of the vehicle Speed_Pred drops below the lower threshold SpeedAntistk_Lo, the signal Hystout is immediately de-asserted but the anti-blocking signal AGSoPening_Antistk remains asserted for a further time interval AtrumoffDeiay, until time ti when the signal AGSopening_Antistk is also de-asserted. In this way, it is ensured that the AGS system remains forcedly in a condition that is at least partially open during the time interval between times to and ti, so that, if in this interval the predicted speed were to rise again above the upper threshold SpeedAntistkj-n, the AGS system would already be in the “forced” opening condition and therefore a closing and reopening cycle of the AGS system would be saved, to the advantage of a reduction in wear of the AGS system components. In the time interval following instant ti the AGS system is managed by a conventional control algorithm (which imposes a certain percentage of opening or closing of the AGS system to adjust the air flow to a certain level, e.g., depending on the requested cooling power). At instant t2 the predicted speed of the vehicle Speed_Pred rises above the upper threshold SpeedAntistk_Hi, and consequently the signal AGSoPening_Antistk is immediately asserted, so that the AGS system is forced to open at least partially.

[0048] Therefore, as can be seen from the preceding description, the method 30 described herein of controlling a system for modulating a flow of cooling air of a vehicle in high-speed conditions of the vehicle is substantially divided into two phases, as also exemplified in the block diagram of Figure 8: in phase 302 the predicted speed (in the immediate future) of the vehicle is determined instant by instant, as a function of the current speed of the vehicle; and in phase 304 the anti-blocking signal of the AGS system is produced as a function of the predicted speed computed in phase 302.

[0049] Thanks to the present invention, it is possible to control the AGS system in such a way as to bring it into an open condition (totally or at least partially) when it is predicted that the vehicle will reach a certain threshold speed in the short term, close to or equal to the critical speed indicated by the supplier of the AGS system beyond which the blocking in the closed position could occur. In this way, the blocking problem is prevented. Furthermore, by keeping the AGS system at least partially open even in a certain subsequent time interval, when the predicted speed of the vehicle has returned below the critical threshold, the number of unnecessary actuations of the AGS system is reduced, increasing the operational life of the AGS system (i.e. , reducing its wear).

[0050] In the present disclosure, specific reference has been made to one or more embodiments of the method 30 in which the parameter that is monitored to evaluate the activation of the anti-blocking functionality of the AGS system is the vehicle speed predicted at a future time Speed_Pred. It will be understood, however, that in one or more alternative embodiments the parameter that determines whether or not the anti-blocking functionality is activated (i.e., the parameter that is compared with the threshold or thresholds by comparators 504, 506) could instead be the current speed Speed of the vehicle, if the threshold SpeedAntistk_Hi is chosen with a sufficiently large margin compared to the critical speed indicated by the AGS system supplier. Therefore, in one or more embodiments, step 302 of method 30 may be omitted.

[0051] Of course, the details of the construction and the embodiments may be widely varied with respect to what is described and illustrated without departing from the scope of the invention as defined by the attached claims.

Claims

CLAIMS1. A method (30) of controlling a system (100) for modulating a flow of cooling air of a vehicle (V) in high-speed conditions of the vehicle (V), the method comprising: determining a travel speed (Speed, Speed_Pred) of the vehicle (V) and comparing (504, 506) said travel speed (Speed, Speed_Pred) with at least one threshold speed value (SpeedAntistk_Lo, Speed Antistk_Hi) ; in response to said travel speed (Speed, Speed_Pred) of the vehicle (V) being higher than said at least one threshold speed value, asserting (502, 508, 510) an opening signal (AGSoPening_Antistk) of the system (100) for modulating the flow of cooling air; in response to said travel speed (Speed, Speed_Pred) of the vehicle (V) being lower than said at least one threshold speed value, deasserting (502, 508, 510) said opening signal (AGSoPening_Antistk) of the system (100) for modulating the flow of cooling air; in response to said opening signal (AGSoPening_Antistk) being asserted, setting the system (100) for modulating the flow of cooling air in a condition of at least partial opening; and in response to said opening signal (AGSoPening_Antistk) being deasserted, controlling the system (100) for modulating the flow of cooling air according to a logic that allows partial or full closure thereof.

2. A method (30) according to claim 1 , wherein: the step of comparing (504, 506) said travel speed (Speed, Speed_Pred) with at least one threshold speed value (SpeedAntistk_Lo, SpeedAntistk_Hi) comprises comparing said travel speed (Speed, Speed_Pred) with a lower threshold speed value (SpeedAntistk_Lo) and with an upper threshold speed value (SpeedAntistk_Hi) said opening signal (AGSoPening_Antistk) is asserted (502, 508, 510) in response to said travel speed (Speed, Speed_Pred) rising above said upper threshold speed value (SpeedAntistk_Hi) and said opening signal (AGSoPening_Antistk) is de-asserted (502, 508, 510) in response to said travel speed (Speed, Speed_Pred) falling below said lower threshold speed value (SpeedAntistk_Lo).

3. A method (30) according to claim 1 or claim 2, comprising: in response to said opening signal (AGSoPening_Antistk) being deasserted, adjusting the closure percentage of said system (100) for modulating the flow of cooling air as a function of a current cooling power requested by said conditioning system of the vehicle (V).

4. A method (30) according to any of the previous claims, wherein: said opening signal (AGSoPening_Antistk) is asserted (502, 508, 510) immediately in response to said travel speed (Speed, Speed_Pred) rising above said at least one threshold speed value; and said opening signal (AGSoPening_Antistk) is de-asserted (502, 508, 510) after a certain delay (AtrumoffDeiay) in response to said travel speed (Speed, Speed_Pred) falling below said at least one threshold speed value.

5. A method (30) according to any of the previous claims, wherein said determined travel speed is a current travel speed (Speed) of the vehicle (V).

6. A method (30) according to any of claims 1 to 4, wherein said determined travel speed is a predicted travel speed (Speed_Pred) of the vehicle (V).

7. A method (30) according to claim 6, comprising determining (302) said predicted travel speed (Speed_Pred) of the vehicle (V) by applying the following steps: sensing a speed signal indicative of the current travel speed (Speed) of the vehicle (V); computing a gradient (404) of said speed signal to determine (406, 408, 410) an acceleration signal indicative of the current acceleration (Acc, Acc_Raw, Acc_Flt) of the vehicle (V); computing a predicted speed increase (ASpeed_Pred) by multiplying (412) said current acceleration of the vehicle (V) by a prediction time interval (Atpr d) and adding up said predicted speed increase (ASpeed_Pred) and said current travel speed (Speed) to determine said predicted travel speed (Speed_Pred_Raw, Speed_Pred).

8. A method (30) according to claim 7, comprising limiting (406, 408) said acceleration signal indicative of the current acceleration (Acc,Acc_Raw, Acc_Flt) of the vehicle (V) between a lower limit equal to zero and a constant upper limit (Acc_Max).

9. A method (30) according to claim 7 or claim 8, comprising filtering (410) said acceleration signal indicative of the current acceleration (Acc, Acc_Raw, Acc_Flt) of the vehicle (V) to remove punctual peak values.

10. A method (30) according to any of claims 7 to 9, comprising limiting (416) said predicted travel speed with a constant upper limit (Speed_Max).

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