US-12626685-B2 - Electric road vehicle provided with a reproduction device for the realization of a sound associable with a gear shift and related method

US12626685B2US 12626685 B2US12626685 B2US 12626685B2US-12626685-B2

Abstract

A road vehicle includes four wheels, of which at least two are drive wheels; a passenger compartment configured to accommodate at least one driver; at least one electric motor configured to deliver drive torque to the at least two drive wheels; a gear shift system, which is configured to allow the driver to select one of a plurality of virtual gears and to switch from one virtual gear to another while driving; an acoustic system, which comprises at least one reproduction device configured to generate a sound associable with a switch from one virtual gear to another; and a control unit configured to detect a gear shift request from the driver to the gear shift system and control the acoustic system to reproduce the sound.

Inventors

Antonio Palermo
Maddalena CIRILLO
Roberto Betro′
Ugo Sitta

Assignees

FERRARI S.P.A.

Dates

Publication Date: 20260512
Application Date: 20240911
Priority Date: 20230911

Claims (15)

1 . A road vehicle ( 1 ) comprising: four wheels ( 2 , 3 ), of which at least two are drive wheels ( 3 ); a passenger compartment ( 5 ) configured to accommodate at least one driver (DR); at least one electric motor ( 4 ) configured to provide drive torque to the at least two drive wheels ( 3 ); a gear shifting system ( 19 ) which is configured to allow the driver (DR) to select one among a plurality of virtual gears and to shift from one virtual gear to another while driving; an acoustic system ( 6 ) comprising at least one reproducing device ( 7 ) configured to generate a sound(S) associable with a shift from one virtual gear to another; and a control unit configured to detect a gear shift request from the driver (DR) via the gear shift system ( 19 ) and control the acoustic system ( 6 ) to reproduce the sound(S); wherein the acoustic system ( 6 ) itself comprises the electric motor ( 4 ), which is mechanically connected to the reproducing device ( 7 ) so as to be able to excite a resonant frequency thereof; wherein the control unit ( 8 ) is further configured to control the electric motor ( 4 ) so as to inject at least one acoustical current (I qS , I dS ) or voltage (V qS , V dS ) as an input of the electric motor ( 4 ) itself; wherein the at least one acoustical current (I qS , I dS ) or voltage (V qS , V dS ) excites a frequency which causes a vibration of the at least one reproduction device ( 7 ), which emits, due to the vibration, in the form of acoustic waves, a sound(S) as a function of the injected acoustical current (I qS , I dS ) or voltage (V qS , V dS ); wherein the sound(S) associable with a shift from one virtual gear to another is an impulsive sound having a sound wave compressed in an interval (TS) of time of less than one second and having a peak (A) in amplitude equal to or greater than 20 dB.
2 . The road vehicle ( 1 ) according to claim 1 , wherein the reproduction device ( 7 ) is a resonant mechanical element ( 9 ) made of metal.
3 . The road vehicle ( 1 ) according to claim 1 , wherein the control unit ( 8 ) injects, simultaneously with the acoustical current (IqS, IdS) or voltage (VqS, VdS), a movement current (IqT, IdT), which determines the rotation of a rotor ( 10 ) of the electric motor ( 4 ) and thus of the one or two drive wheels ( 3 ) connected thereto.
4 . The road vehicle ( 1 ) according to claim 3 , wherein the acoustical current (IqS, IdS) or voltage (VqS, VdS) has a frequency such that it does not engage with a magnetic flux of the electric motor ( 4 ), thereby avoiding generating movements of the rotor ( 10 ).
5 . The road vehicle ( 1 ) according to claim 1 , wherein the acoustical current (IqS, IdS) or voltage (VqS, VdS) generates the sound(S) via a damped signal.
6 . The road vehicle ( 1 ) according to claim 1 , wherein the sound(S) has a duration from 10 ms to 200 ms.
7 . The road vehicle ( 1 ) according to claim 1 , wherein the sound(S) has an amplitude ranging from 20 dB to 150 dB.
8 . The road vehicle ( 1 ) according to claim 1 , wherein the acoustical current (IqS, IdS) or voltage (VqS, VdS) comprises a plurality of harmonics of different order and/or amplitude and/or frequency, so as to generate a polyphonic sound(S) by causing the vibration of a plurality of reproduction devices ( 7 ).
9 . The road vehicle ( 1 ) according to claim 1 , wherein the control unit ( 8 ) is configured to vary the acoustical current (IqS, IdS) or voltage (VqS, VdS) according to vehicular conditions comprising road roughness and/or open or closed roof.
10 . The road vehicle ( 1 ) according to claim 1 , wherein the control unit ( 8 ) is configured to vary the acoustical current (IqS, IdS) or voltage (VqS, VdS) as a function of driving parameters.
11 . The road vehicle ( 1 ) according to claim 1 , wherein the control unit ( 8 ) is configured to vary the acoustical current (IqS, IdS) or voltage (VqS, VdS) according to the driving style of the driver.
12 . A method for realizing a sound associable with a gear shift in a road vehicle ( 1 ) comprising at least one electric motor ( 4 ) configured to deliver drive torque to at least two wheels ( 3 ) of the road vehicle ( 1 ); the road vehicle ( 1 ) comprising a gear shifting system ( 19 ), which allows a driver (DR) to select one among a plurality of virtual gears and to shift from one virtual gear to another while driving; the method comprising the steps of: detecting a gear shift request provided by the driver (DR) to an interface device ( 17 ) of the gear shifting system ( 19 ); and reproducing, at least within a vehicular cockpit ( 5 ), a sound(S) associable with a shift from one virtual gear to another; wherein the step of reproducing comprises injecting, following the detection of a gear shift request, an acoustical current (IqS, IdS) or voltage (VqS, VdS) as input of the electric motor ( 4 ); wherein the at least one acoustical current (IqS, IdS) or voltage (VqS, VdS) excites a frequency that causes a vibration of at least one resonant element ( 9 ) of the road vehicle ( 1 ); wherein the resonant element ( 9 ) emits, due to the vibration, in the form of acoustic waves, the sound(S) associable with the shift from one virtual gear to another; wherein the sound(S) associable with a shift from one virtual gear to another is an impulsive sound having a sound wave compressed in an interval (TS) of time of less than one second and having a peak (A) in amplitude equal to or greater than 20 dB.
13 . The method according to claim 12 further comprising: preliminarily defining proper orders of harmonics for the resonance of the components of an electrical transmission system; and experimentally carrying out a tuning of the acoustical current (I qS , I dS ) or voltage (V qS , V dS ) resonance bands as a function of the electrical transmission system.
14 . The road vehicle ( 1 ) according to claim 9 , wherein the function of driving parameters comprises a position of a button and/or a driving mode and/or a position or change of position of a pedal and/or selections by the driver (DR) via a further interface system ( 27 ).
15 . A road vehicle ( 1 ) comprising: four wheels ( 2 , 3 ), of which at least two are drive wheels ( 3 ); a passenger compartment ( 5 ) configured to accommodate at least one driver (DR); at least one electric motor ( 4 ) configured to provide drive torque to the at least two drive wheels ( 3 ); a gear shifting system ( 19 ) which is configured to allow the driver (DR) to select one among a plurality of virtual gears and to shift from one virtual gear to another while driving; an acoustic system ( 6 ) comprising at least one reproducing device ( 7 ) configured to generate a sound(S) associable with a shift from one virtual gear to another; and a control unit configured to detect a gear shift request from the driver (DR) via the gear shift system ( 19 ) and control the acoustic system ( 6 ) to reproduce the sound(S); wherein the acoustic system ( 6 ) itself comprises the electric motor ( 4 ), which is mechanically connected to the reproducing device ( 7 ) so as to be able to excite a resonant frequency thereof; wherein the control unit ( 8 ) is further configured to control the electric motor ( 4 ) so as to inject at least one acoustical current (I qS , I dS ) or voltage (V qS , V dS ) as an input of the electric motor ( 4 ) itself; wherein the at least one acoustical current (I qS , I dS ) or voltage (V qS , V dS ) excites a frequency which causes a vibration of the at least one reproduction device ( 7 ), which emits, due to the vibration, in the form of acoustic waves, a sound(S) as a function of the injected acoustical current (I qS , I dS ) or voltage (V qS , V dS ); wherein the sound(S) has a duration from 10 ms to 200 ms.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims priority from Italian patent application no. 102023000018567 filed on Sep. 11, 2023, the entire disclosure of which is incorporated herein by reference. FIELD OF THE ART The present invention relates to a road vehicle provided with a reproduction device for the realization of a sound associable with an electric motor and a related method. In particular, the present invention finds advantageous, but not exclusive application in the control of a high-performance road vehicle, configured to perform track laps, to which the following description will make explicit reference without thereby losing in generality. PRIOR ART Historically, in the technological evolution with the motor vehicle as the protagonist, it became necessary to introduce a gear (or speed) shifting system to overcome the mechanical limits imposed by the internal combustion (endothermic) engine, which, in the absence of the gear shifting system, could not cover an adequate speed range. In particular, therefore, a gear shifting device is used which allows the transmission ratio to be varied to generally allow the multiplication of the torque delivered by the endothermic engine and to adapt the rotation speed of the latter to that of the wheels (so that high power can be available even at rather low forward speeds and high speeds can be reached). This device in the vast majority of the cars is still the mechanically operated gearbox, which allows the pilot to be able to choose depending on the conditions of use of the vehicle between different ratios, i.e. between different gears (the number of gears varies based on the model of the vehicle). Over the decades, starting from the need for the presence of a gear shifting system dictated by the limits of the endothermic engine, the opportunity arose to create numerous types of gear shifting systems, in particular increasingly high-performance ones (e.g. the well-known dual-clutch gearbox). In this way, the gear shifting system has become a distinguishing feature among motor vehicle manufacturers and, as previously mentioned, a tool for involving the pilot while driving the road vehicle. In recent times, with the spread of the electric power train systems, we are moving away from the endothermic engine and at least one electric motor is thus being introduced, which solves the need for a gear shift as it is perfectly capable of quickly providing the necessary torque and of going from zero speed to maximum speed without any transmission problem. Although the electric power train systems tendentially allow to improve performance, as they are always able to take advantage of the maximum acceleration available for a given speed, the pilot's involvement in making certain choices is reduced, such as which gear to use when entering a curve, or the feeling of detachment given by the torque pick-up when upshifting during acceleration or downshifting during deceleration, thereby reducing driving pleasure, especially in the case of high-performance sports vehicles. As is known, therefore, during its operation, the electric motor emits very slight sounds mostly associated with vibration of the mechanical components of the electric motor. This introduces a problem of awareness of the driver with respect to the operating conditions of the electric motor and more generally with respect to the performance of the motor vehicle comprising the electric motor. In practice, from the driver's point of view, the performance of the above-mentioned motor vehicles is not satisfactorily emphasized. Therefore, the need is felt to emphasize more the performance of the motor vehicles or to increase the awareness of the driver with regard to such performance. In addition, some drivers are notoriously interested in perceiving sounds associated with the operation of the motor vehicle for reasons of driving pleasure. Consequently, in high-performance sports cars the sound that is produced by an electric motor is not perceived within the passenger compartment or in any case it may be at least partially unsatisfactory. Therefore, the need to increase the driver's driving pleasure is also felt. The patent document US2023249703 describes a control method to generate a perception of virtual gear shift. Aim of the present invention is to realize an electric road vehicle provided with a reproduction device for the realization of a sound associable with an electric motor and a related method, which are at least partially free from the drawbacks described above and, at the same time, are simple and inexpensive to realize. SUMMARY In accordance with the present invention, there are provided an electric road vehicle provided with a reproduction device for the realization of a sound associable with an electric motor and a related method as claimed in the following independent claims and, preferably, in any one of the claims directly or indirectly dependent on the independent cl