VEHICLE NOISE SUPPRESSION METHOD

Abstract

Aspects of the present invention relate to noise modification systems of motor vehicles, and controllers and methods of use thereof.

Claims

1. A controller arranged to control a noise modification system of a vehicle provided with an exhaust system, wherein the controller is adapted to receive a noise signal from a noise sensor providing a measurement of noise in the exhaust system, and adapted to select a noise modification action of the noise modification system in dependence upon determination of a driving style of a driver of the vehicle and in dependence upon said measurement of noise, and operable to transmit a control signal to cause one or more speakers to modify noise emitted by the exhaust system in dependence on said noise modification action.

2. A controller arranged to control a noise modification system of a vehicle provided with an exhaust system, the controller arranged to select a noise modification action of the noise modification system in dependence upon a selected driving mode of the vehicle, wherein the controller is further arranged to select an alternative noise modification action of the noise modification system in dependence upon determination of a driving style of a driver of the vehicle, and operable to transmit a control signal to cause one or more speakers to modify noise emitted by the exhaust system in dependence on said noise modification action.

3. A controller as claimed in claim 1, wherein the controller is operable to transmit the control signal to cause said one or more speakers to modify said measured noise in the exhaust system.

4. A controller as claimed in claim 1, wherein the noise signal from the noise sensor provides a measurement of noise in the exhaust system modified by said noise modification action.

5. A controller as claimed in claim 2 wherein the alternative noise modification action is selected while the driving mode of the vehicle remains unchanged.

6. A controller as claimed in claim 1, wherein the noise modification action comprises at least one of: a noise enhancement action; a noise suppression action; a noise cancelling action; and no modification action.

7. A controller as claimed in claim 1, wherein the determination of driving style is made based on a determination of momentary driving style.

8. A controller as claimed in claim 1, wherein the determination of driving style is made based on a determination of driving style over a period of time.

9. A controller as claimed in claim 1, wherein the determination of driving style is made based on a combination of a determination of momentary driving style and a determination of driving style over a period of time.

10. A controller as claimed in claim 7, wherein the determination of momentary driving style is based on any one or more of the following; i/ a throttle position or rate of change of throttle position, ii/ an engine speed, iii/ a rate of change of engine speed, iv/ a steering angle, v/ a rate of change of steering angle, vi/ a gear change or selection, vii/ a rate of gear change or selection, viii/ a vehicle speed, ix/ a rate of change of vehicle speed, x/ a brake pedal position, xi/ a brake application, xii/ a rate of brake application, xiii/ an engine load, xiv/ a rate of change of engine load, and xv/ a determination of driving style by a further system of the vehicle.

11. A controller as claimed in claim 8, wherein the determination of driving style over a period of time is based on any one or more of the following: i/ a number of changes of a driver control input over the period of time, ii/ the period of time since a driver control input, iii/ a number of changes of any two or more driver control inputs over the period of time, iv/ variance in vehicle speed over the period of time, and v/ variance in vehicle direction over the period of time.

12. A controller as claimed in claim 11 wherein a driver control input is any one or more of the following: i/ a throttle input, ii/ a steering input, iii/ a rate of change of steering input, iv/ a gear change or selection, v/ a braking input, and vi/ a rate of braking input.

13. A controller as claimed in claim 1, wherein the noise modification system comprises one or more of an Active Noise system and an Active Exhaust system.

14. A method of control of a noise modification system adapted for use with an exhaust system of a vehicle, comprising: determining a driving style of a driver of said vehicle; selecting a noise modification action of the noise modification system in dependence on the driving style; and causing, at least in part, modification of noise emitted by the exhaust system in dependence on said noise modification action.

15. A method as claimed in claim 14, comprising: selecting a vehicle driving mode.

16. A method of control of a noise modification system adapted for use with an exhaust system of a vehicle, comprising: selecting a vehicle driving mode; selecting a noise modification action of the noise modification system associated with said driving mode; determining a driving style of a driver of the vehicle; changing the noise modification action of the noise modification system in dependence on the driving style; and causing, at least in part, modification of noise emitted by the exhaust system in dependence on said noise modification action.

17. A method as claimed in claim 14, comprising causing, at least in part, modification of said measured noise in the exhaust system.

18. A method as claimed in claim 14, comprising receiving a noise signal providing a measurement of noise in the exhaust system modified by said noise modification action.

19. A method as claimed in claim 14, wherein the noise modification action comprises at least one of the following: a noise enhancement action; a noise suppression action; a noise cancelling action; and no modification action.

20. A method as claimed in claim 14, wherein the determination of driving style is made based on a determination of momentary driving style.

21. A method as claimed in claim 14, wherein the determination of driving style is made based on a determination of driving style over a period of time.

22. A method as claimed in claim 14, wherein the determination of driving style is made based on a combination of a determination of momentary driving style and a determination of driving style over a period of time.

23. A method as claimed in claim 20, wherein the determination of momentary driving style is based on any one or more of the following: i/ a throttle position or rate of change of throttle position, ii/ an engine speed, iii/ a rate of change of engine speed, iv/ a steering angle, v/ a rate of change of steering angle, vi/ a gear change or selection, vii/ a rate of gear change or selection, viii/ a vehicle speed, ix/ a rate of change of vehicle speed, x/ a brake pedal position, xi/ a brake application, xii/ a rate of brake application, xiii/ an engine load, xiv/ a rate of change of engine load, and xv/ a determination of driving style by a further system of the vehicle.

24. A method as claimed in claim 21, wherein the determination of driving style over a period of time is based on any one or more of the following: i/ a number of changes of a driver control input over the period of time, ii/ the period of time since a driver control input, iii/ a number of changes of any two or more driver control inputs over the period of time, iv/ variance in vehicle speed over the period of time, and v/ variance in vehicle direction over the period of time.

25. A method as claimed in claim 24 wherein a driver control input is any one or more of the following: i/ a throttle input, ii/ a steering input, iii/ a rate of change of steering input, iv/ a gear change or selection, v/ a braking input, and vi/ a rate of braking input.

26. A method as claimed in claim 14, wherein the noise modification system comprises one or more of an active noise system and an active exhaust system.

27. A controller adapted to perform the method of claim 14.

28. A noise modification system provided with a controller as claimed in claim 1.

29. A noise modification system as claimed in claim 28 comprising one or more speakers, and a noise sensor configured to pick up noise generated by the exhaust system and transmit a noise signal to the controller, wherein the controller is arranged to transmit a control signal to cause said one or more speakers to modify exhaust noise in dependence on the noise signal.

30. An exhaust system provided with a noise modification system as claimed in claim 28.

31. An exhaust system as claimed in claim 30 wherein a noise sensor and one or more speakers are acoustically connected to said exhaust system.

32. An exhaust system as claimed in claim 31 comprising a center section, wherein the noise sensor and the one or more speakers are acoustically connected to said center section.

33. A vehicle provided with an exhaust system as claimed in claim 30.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0071] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0072] FIG. 1 shows a schematic representation of a vehicle provided with a noise modification system, comprising Active Noise and Active Exhaust systems, in accordance with embodiments of the invention, in combination with an exhaust system as may typically be found on a vehicle;

[0073] FIG. 2 shows a table indicating an activity mode of a noise modification system in response to a particular driver input, in this case Throttle Pedal Movement, whilst the vehicle is in various Vehicle Driving Modes.

[0074] FIG. 3 shows a schematic representation of an alternative Active Exhaust system to that shown in FIG. 1.

DETAILED DESCRIPTION

[0075] An embodiment of the present invention is described herein with reference to the accompanying FIGS. 1, 2 and 3.

[0076] With reference to FIG. 1, there is a vehicle 100 which is provided with an engine 200, wheels 310, 320, 330, 340, an exhaust system 400 comprising manifolds 410, centre section 420 comprising muffler/box 430, and a rear section 440 comprising rear muffler/box 450. The exhaust system is provided with a noise modification system 500 which comprises both an Active Noise system 510 and an Active Exhaust system 520.

[0077] The Active Noise system 510 comprises control unit 501, speakers 511 and a noise sensor 512. Noise sensor 512 is arranged to ‘pick up’ engine/exhaust noise from centre section 420 and supply a noise signal to controller 501. The controller 501 is adapted to provide a control signal to speakers 511. In one modification action, controller 501 inverts the noise signal from sensor 512 and controls speakers 511 such that they provide a noise cancellation effect which reduces the overall engine/exhaust noise emitted by the exhaust system 400. This is the ‘Suppression’ noise modification action as referenced in FIG. 2. In an alternative modification action, controller 501 provides an amplification to the noise signal from sensor 512 and controls speakers 511 such that they add to/increase the overall engine/exhaust noise emitted by the exhaust system 400. This is the ‘Enhance 1’ noise modification action as further referenced in FIG. 2. In a third modification action, the speakers are not active—this is noted as ‘Off’ in reference to FIG. 2.

[0078] The Active Exhaust system 520 comprises control unit 501, exhaust box 450, and valve 521. Control unit 501 is adapted to control the valve 521. The valve 521 is arranged such that when it is closed, exhaust gasses from the engine 200 run straight through exit pipe 451. When valve 521 is open, a proportion of the exhaust gases are able to enter echo box 452 and then exit through opening 453 back into the exit pipe 451. The remainder of exhaust box 450, as illustrated in section of exhaust box 454, is provided with noise deadening material 455. When there are gasses passing through echo box 452, exhaust box 450 produces a louder sound and with different characteristics than when gasses are passing through exit pipe 451 alone, and so opening the valve 521 acts to enhance exhaust noise. This is the ‘Enhance 2’ noise modification action of the noise modification system 500 as further referenced in FIG. 2.

[0079] Accordingly, the noise modification system 500 of the vehicle 100 is able to perform four different noise modification actions—namely, Suppress, Off, Enhance 1 and Enhance 2, by the various actions of the Active Noise 510 and Active Exhaust 520 sub-systems of the noise modification system 500.

[0080] The skilled person will realise that this embodiment is just by way of example, and that alternative arrangements of Active Noise and/or Active Exhaust systems are possible and may be used whilst still remaining within the ambit of the invention. Further Active Noise sensors and speakers may be provided at other points within a vehicle, such as in an occupant cabin, for example, as well as at other points on an exhaust system. The overall noise of the engine/exhaust system may be controlled specifically via multiple speakers or sets of speakers so as to provide differing noise levels and sensations to those within a vehicle as compared to those outside of the vehicle. Differing noise levels/sensations may even be provided to multiple occupants of the occupant cabin of a vehicle, for example, a driver of the vehicle may be provided with differing sensations to those of passengers. An Active Exhaust system may include an arrangement comprising an exhaust box 450a such as the alternative noted in FIG. 3, wherein when valve 521a is closed, exhaust gases pass through exhaust pipe 456 which is surrounded by noise deadening material 455a, but when valve 521a is open, all or most of the exhaust gasses pass via ‘straight through’ exit pipe 451a, which thus provides a concomitantly louder exhaust noise. The skilled person will recognise that the FIG. 3 arrangement may provide a further advantage in that when acting as a ‘straight through’ pipe, the exhaust box 450a is likely to provide lesser exhaust backpressure and thus potentially allow the engine to generate more power—this may be particularly advantageous when in a ‘Track’ or similar mode, when rules, laws or regulations on noise may be less stringent than in a public road environment.

[0081] The vehicle 100 is further provided with a driving mode selector 600, which is operable by a driver to select one of four driving modes. Various characteristics of the vehicle are altered by the selection of the various driving modes, affecting such things as transmission shift maps and suspension response. However, associated with each of these modes is also an expectation of the noise that the vehicle is going to make whilst in that mode. Accordingly, there are four modes available, ‘Track’, where the vehicle is set up for racing; ‘Sport’, where the vehicle is set up for enthusiastic driving on public roads; ‘Normal’, where the vehicle is set up for normal, everyday driving, and ‘Hush’, where the vehicle is specifically set up to be as quiet as possible, for example for late-night driving in residential areas. This latter setting may be particularly apposite for use with Hybrid vehicles, and it will be recognised that elements of the invention are equally applicable to a hybrid-electric (HEV) or even electric (EV) vehicle, where noise from electric machines may also be affected by a noise management system, in particular by an Active Noise system.

[0082] Referring now to FIG. 2, which comprises the Table below:

TABLE-US-00001 Hush Normal Sport Track Throttle Rapid Off Enhance 1 Enhance 2 Enhance 2 Slow Suppress Off Enhance 1 Enhance 2 Pedal Static instant (upper part Suppress Off Off Enhance 1 of pedal travel) Static instant (lower half Off Off Enhance 1 Enhance 2 of pedal travel) Movement Static >30 seconds Suppress Suppress Off Enhance 1 Static >60 seconds Suppress Suppress Suppress Off

[0083] In the present embodiment, it can be seen that in ‘Hush’ mode, the noise modification system is largely set to either suppress noise (by use of the Active Noise sub-system) or to be ‘Off’.

[0084] In ‘Normal’ mode, the noise modification system is largely inactive. One departure is when the throttle pedal (700) is moved rapidly, whereupon the Active Noise system is set to enhance the engine/exhaust noise, and thus ‘Enhance 1’ appears on the table. Another departure is when the pedal has been static for 30 seconds or more, possibly indicating steady-state driving, when the noise modification system is set to ‘Suppress’ by activation of the Active Noise system, to provide a comfortable driving experience for an extended period. In ‘Sport’ mode, it can be seen that the default action of the noise modification system is for the Active Noise system to provide enhancement, and so ‘Enhance 1’ appears in the table twice. However, if the accelerator pedal is static and in the upper part of pedal travel, or if the pedal is static for over 30 seconds, it is assumed that the driver is at least momentarily not driving enthusiastically or at speed, and so the Active Noise sub-system is turned off and so the noise modification action is set to ‘Off’. If there is rapid accelerator/throttle pedal movement, however, the bypass valve 521 is opened and the ‘Enhance 2’ noise modification action is active, wherein both noise modification systems, Active Noise and Active Exhaust, are enhancing the noise. If the driver makes no change in input to the throttle (ie it is static) for more than 60 seconds, however, steady-state driving is assumed and as for ‘Normal’ mode, the Active Noise sub-system of the noise modification system is activated, thus providing a noise modification action of ‘Suppress’.

[0085] Finally, in ‘Track’ mode, the noise modification system is nominally acting to use both the Active Noise and Active Exhaust systems to enhance the engine noise, and so ‘Enhance 2’ is the default. If the pedal is instantly static or static for over 30 seconds, ‘Enhance 1’ is active, and it is only in the situation where the pedal is static for over 60 seconds that the noise modification system is in the ‘Off’ arrangement. It can be seen that in ‘Track’ mode, the noise modification system is never in the ‘Suppress’ configuration.

[0086] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application. Further aspects of the present invention will now be set out in the accompanying numbered paragraphs: [0087] 1. A controller arranged to control a noise modification system of a vehicle provided with an exhaust system, wherein the controller is adapted to select a noise modification action of the noise modification system in dependence upon determination of a driving style of a driver of the vehicle. [0088] 2. A controller arranged to control a noise modification system of a vehicle provided with an exhaust system, the controller arranged to select a noise modification action of the noise modification system in dependence upon a selected driving mode of the vehicle, wherein the controller is further arranged to select an alternative noise modification action of the noise modification system in dependence upon determination of a driving style of a driver of the vehicle. [0089] 3. A controller as described in paragraph 2 wherein the alternative noise modification action is selected whilst the driving mode of the vehicle remains unchanged. [0090] 4. A controller as described in either of paragraphs 1 or 2 wherein the noise modification action comprises, non-exclusively, one of: [0091] 1/ a noise enhancement action; [0092] 2/ a noise suppression action; [0093] 3/ a noise cancelling action; [0094] 4/ no modification action. [0095] 5. A controller as described in paragraph 1 or 2 wherein the determination of driving style is made based on a determination of momentary driving style. [0096] 6. A controller as described in paragraph 1 or 2 wherein the determination of driving style is made based on a determination of driving style over a period of time. [0097] 7. A controller as described in paragraph 1 or 2 wherein the determination of driving style is made based on a combination of a determination of momentary driving style and a determination of driving style over a period of time. [0098] 8. A controller as described in paragraph 5 or 7 wherein the determination of momentary driving style is based on any one or more of the following; [0099] i/ a throttle position or rate of change of throttle position [0100] ii/ an engine speed [0101] iii/ a rate of change of engine speed [0102] iv/ a steering angle [0103] v/ a rate of change of steering angle [0104] vi/ a gear change or selection [0105] vii/ a rate of gear change or selection [0106] viii/ a vehicle speed [0107] ix/ a rate of change of vehicle speed [0108] x/ a brake pedal position [0109] xi/ a brake application [0110] xii/ a rate of brake application [0111] xiii/ an engine load [0112] xiv/ a rate of change of engine load [0113] xv/ a determination of driving style by a further system of the vehicle, optionally a transmission control system. [0114] 9. A controller as described in paragraph 6 or 7 wherein the determination of driving style over a period of time is based on any one or more of the following: [0115] i/ a number of changes of a driver control input over the period of time [0116] ii/ the period of time since a driver control input [0117] iii/ a number of changes of any two or more driver control inputs over the period of time [0118] iv/ variance in vehicle speed over the period of time [0119] v/ variance in vehicle direction over the period of time [0120] 10. A controller as described in paragraph 9 wherein a driver control input is any one or more of the following: [0121] i/ a throttle input [0122] ii/ a steering input [0123] iii/ a rate of change of steering input [0124] iv/ a gear change or selection [0125] v/ a braking input [0126] iv/ a rate of braking input [0127] 11. A controller as described in paragraph 1 or 2 wherein the noise modification system comprises one or more of an Active Noise system and an Active Exhaust system. [0128] 12. A method of control of a noise modification system adapted for use with an exhaust system of a vehicle, comprising the steps; [0129] Selecting a vehicle Driving Mode; [0130] Selecting a noise modification action of the noise modification system associated with said Driving Mode; [0131] Determining a driving style of a driver of the vehicle, and; [0132] Changing the noise modification action of the noise modification system in dependence on the said driving style. [0133] 13. A method as described in paragraph 12 claimed in any of claims 12 to 14 wherein the noise modification action comprises, non-exclusively, one of the following: [0134] 1/ a noise enhancement action; [0135] 2/ a noise suppression action; [0136] 3/ a noise cancelling action; [0137] 4/ no modification action. [0138] 14. A method as described in paragraph 12 wherein the determination of driving style is made based on a determination of momentary driving style. [0139] 15. A method as described in paragraph 12 wherein the determination of driving style is made based on a determination of driving style over a period of time. [0140] 16. A method as described in paragraph 12 wherein the determination of driving style is made based on a combination of a determination of momentary driving style and a determination of driving style over a period of time. [0141] 17. A method as described in paragraph 14 or 16 wherein the determination of momentary driving style is based on any one or more of the following; [0142] i/ a throttle position or rate of change of throttle position [0143] ii/ an engine speed [0144] iii/ a rate of change of engine speed [0145] iv/ a steering angle [0146] v/ a rate of change of steering angle [0147] vi/ a gear change or selection [0148] vii/ a rate of gear change or selection [0149] viii/ a vehicle speed [0150] ix/ a rate of change of vehicle speed [0151] x/ a brake pedal position [0152] xi/ a brake application [0153] xii/ a rate of brake application [0154] xiii/ an engine load [0155] xiv/ a rate of change of engine load [0156] xv/ a determination of driving style by a further system of the vehicle, optionally a transmission control system. [0157] 18. A method as described in paragraph 15 or 16 wherein the determination of driving style over a period of time is based on any one or more of the following: [0158] i/ a number of changes of a driver control input over the period of time [0159] ii/ the period of time since a driver control input [0160] iii/ a number of changes of any two or more driver control inputs over the period of time [0161] iv/ variance in vehicle speed over the period of time [0162] v/ variance in vehicle direction over the period of time [0163] 19. A method as described in paragraph 18 wherein a driver control input is any one or more of the following: [0164] i/ a throttle input [0165] ii/ a steering input [0166] iii/ a rate of change of steering input [0167] iv/ a gear change or selection [0168] v/ a braking input [0169] vi/ a rate of braking input [0170] 20. A method as described in paragraph 12 wherein the noise modification system comprises one or more of an Active Noise system and an Active Exhaust system. [0171] 21. A controller adapted to perform the method described in paragraph 12. [0172] 22. A noise modification system provided with a controller as described in paragraph 1 or 2 or as described in paragraph 21. [0173] 23. An exhaust system provided with a noise modification system as described in paragraph 22 or a controller as described in paragraph 21. [0174] 24. A vehicle provided with a controller as described in paragraph 21, a noise modification system as described in paragraph 22, or an exhaust system as described in paragraph 23.