System for influencing exhaust noise in a multi-flow exhaust system

Abstract

An anti-noise system for influencing exhaust noises propagating through a multi-flow exhaust system includes a controller 80 and at least one actuator. The at least one actuator is disposed in a sound generator 20; 21; 23; 25; 27, connected to the controller 80 for receiving control signals, and adapted to generate sound inside the sound generator 20; 21; 23; 25; 27. The sound generator 20; 21; 23; 25; 27 is connectable to at least two exhaust tracts 60, 61 of the multi-flow exhaust system of the vehicle simultaneously. The controller 80 is configured to generate a control signal that prompts the at least one actuator disposed in the sound generator 20; 21; 23; 25; 27 to cancel sound inside the at least two exhaust tracts 60, 61 of the vehicle's multi-flow exhaust system at least in part and preferably completely.

Claims

1. An anti-noise system for influencing exhaust noises propagating through a multi-flow exhaust system of a vehicle comprising at least two exhaust tracts, the anti-noise system comprising: a controller; a sound generator; at least one actuator disposed in the sound generator, the at least one actuator being in communication with the controller for receiving control signals, and the at least one actuator being configured for generating sound inside the sound generator; an error microphone that is in communication with the controller, wherein: the sound generator is connectable to at least two exhaust tracts of the multi-flow exhaust system of the vehicle simultaneously; the controller is configured to generate a control signal that prompts the at least one actuator disposed in the sound generator to cancel sound inside the at least two exhaust tracts of the vehicle's multi-flow exhaust system in amplitude at least in part or completely; the error microphone is adapted to measure sound inside the exhaust system and to output a corresponding measurement signal to the controller; the controller is configured to cancel measurement signals received from the error microphone by outputting the control signal to the at least one actuator at least in part or completely; the error microphone is connectable by an additional pipe to the at least two exhaust tracts of the vehicle's multi-flow exhaust system simultaneously at a position of the exhaust system located in a section of a fluid connection between the sound generator and the exhaust system.

2. The anti-noise system according to claim 1, wherein: the controller is connectable to an engine control unit of an internal combustion engine of the vehicle; and the controller is configured to generate the digital control signal subject to signals received from the engine control unit.

3. The anti-noise system according to claim 1, wherein at least one of: the system comprises exactly one actuator; the system comprises exactly one error microphone; the system comprises exactly one controller.

4. The anti-noise system according to claim 1, wherein the sound generator comprises a twin D-pipe, wherein both D-pipes of the twin D-pipe are in fluid communication with the interior volume of the sound generator and each one of the D-pipes of the twin D-pipe is connectable to just one exhaust tract of the multi-flow exhaust system of the vehicle.

5. The anti-noise system according to claim 1, wherein the sound generator comprises a Y-pipe, with one leg of the Y-pipe being in fluid communication with the interior volume of the sound generator, and one of the remaining legs of the Y-pipe being each connectable to just one exhaust tract of the multi-flow exhaust system of the vehicle.

6. The anti-noise system according to claim 1, wherein the sound generator comprises an antechamber volume into which several connection pipes enter, whereby each connection pipe is connectable to exactly one exhaust tract of the multi-flow exhaust system of the vehicle.

7. The anti-noise system according to claim 1, wherein one end of the additional pipe engages one of the at least two exhaust tracts and another end of the additional pipe engages another one of the at least two exhaust tracts.

8. The anti-noise system according to claim 1, wherein the additional pipe and the error microphone are located downstream of the sound generator with respect to a flow of exhaust fluid in at least one of the at least two exhaust tracks.

9. The anti-noise system according to claim 1, wherein one of the at least two exhaust tracts comprises a first exhaust track end portion, wherein a first flow of exhaust fluid exits the one of the at least two exhaust tracts via the first exhaust track end portion, another one of the at least two exhaust tracts comprising a second exhaust track end portion, wherein a second exhaust track fluid exits the another one of the at least two exhaust tracts via the second exhaust track end portion, the additional pipe and the error microphone being located between the sound generator, the first exhaust track end portion and the second exhaust track end portion.

10. A multi-flow exhaust system for a vehicle, comprising: a first exhaust tract for connecting to an internal combustion engine of the vehicle and adapted to have at least a portion of exhaust gas discharged from the internal combustion engine pass through the first exhaust tract; a second exhaust tract for connecting to the internal combustion engine of the vehicle and adapted to have at least a portion of exhaust gas discharged from the internal combustion engine pass through the second exhaust tract, wherein each of the exhaust tracts comprise a tailpipe through which exhaust gas passing through the respective exhaust tract is discharged to the outside of the exhaust system; and an anti-noise system comprising: a controller; a sound generator; an actuator disposed in the sound generator, the actuator being operatively connected with the controller for receiving control signals, the actuator being configured for generating sound inside the sound, generator; an additional pipe connected to each of the first exhaust tract and the second exhaust tract; an error microphone operatively connected with the controller, wherein: the sound generator is connected to each of the first exhaust tract and the second exhaust tract; the controller is configured to generate a control signal that prompts the actuator to cancel sound inside the first exhaust tract and the second exhaust tract, in amplitude, at least in part or completely simultaneously; the error microphone measures sound inside the exhaust system and provides an output of a corresponding measurement signal to the controller; the controller is configured to cancel measurement signals received from the error microphone by outputting the control signal to the actuator at least in part or completely; the error microphone is connected by the additional pipe to the first exhaust tract and the second exhaust tract simultaneously at a position of the exhaust system located in a section of a fluid connection between the sound generator and the exhaust system.

11. The multi-flow exhaust system for a vehicle according to claim 10, wherein the lengths of the first exhaust tract and the second exhaust tract, of the multi-flow exhaust system between the internal combustion engine and the position along the respective exhaust tract at which the sound generator is connected to the respective exhaust tract are identical, and the lengths of all connection pipes between the respective exhaust tract and the sound generator are identical.

12. The multi-flow exhaust system for a vehicle according to claim 10, wherein the first exhaust tract and the second exhaust tract comprise a shared volume that is located with respect to the flow direction of the exhaust gas passing through the exhaust tracts upstream of the section of the fluid connection between the sound generator and the exhaust system and downstream of the internal combustion engine.

13. The multi-flow exhaust system for a vehicle according to claim 10, wherein: the first exhaust tract and the second exhaust tract comprise a shared volume that is located upstream of the tailpipes and downstream of the internal combustion engine with respect to the flow direction of exhaust gas passing through the exhaust tracts; and the sound generator is disposed in the region of the shared volume and thus simultaneously connected to both of the first exhaust tract and the second exhaust tract of the multi-flow exhaust system of the vehicle.

14. The multi-flow exhaust system for a vehicle according to claim 10, wherein the first exhaust tract and the second exhaust tract comprise a shared volume that is located upstream of the tailpipes and downstream of the internal combustion engine with respect to the flow direction of exhaust gas passing through the exhaust tracts; and the sound generator is disposed in the region of the shared volume and thus simultaneously connected to both of the at least two exhaust tracts of the multi-flow exhaust system of the vehicle.

15. The multi-flow exhaust system for a vehicle according to claim 10, in combination with internal combustion engine to provide a vehicle wherein: the internal combustion engine has an engine control unit; the multi-flow exhaust system is in fluid communication with the internal combustion engine; and the controller of the anti-noise system is in communication with the engine control unit of the internal combustion engine of the vehicle.

16. The anti-noise system according to claim 10, wherein the additional pipe and the error microphone are located downstream of the sound generator with respect to a flow of exhaust fluid in at least one of the first exhaust tract and the second exhaust track.

17. The anti-noise system according to claim 10, wherein the first exhaust track comprises a first exhaust track end portion, wherein first exhaust track fluid exits the first exhaust track via the first exhaust track end portion, the second exhaust track comprising a second exhaust track, wherein second exhaust track fluid exits the second exhaust track via the second exhaust track end portion, the additional pipe and the error microphone being located between the sound generator, the first exhaust track end portion and the second exhaust track end portion.

18. A method for controlling an anti-noise system for influencing exhaust noises propagating through a multi-flow exhaust system of the vehicle, the method comprising the steps of: providing an anti-noise system comprising a controller, a sound generator and an actuator disposed in the sound generator, the actuator being operatively connected with the controller for receiving control signals, the actuator being configured for generating sound inside the sound generator, wherein the sound generator is connected to each of a first exhaust tract and a second exhaust tract and the controller is configured to generate a control signal that prompts the actuator to cancel sound inside the first exhaust tract and the second exhaust tract, in amplitude, at least in part or completely; at least one of receiving an operating parameter from an engine control unit of the vehicle and measuring sound inside the exhaust system; calculating a control signal subject to at least one of operating parameters and the sound measured, the control signal being adapted to cancel the airborne sound passing through the first exhaust tract and the second exhaust tract of the multi-flow exhaust system at least in part or completely; generating airborne anti-noise by operating at least one actuator with the control signal; providing an additional pipe connected to each of the first exhaust tract and the second exhaust tract; providing an error microphone operatively connected with the controller; and supplying the generated airborne anti-noise to the first exhaust tract and the second exhaust tract of the multi-flow exhaust system simultaneously, wherein: the error microphone measures sound inside the exhaust system and provides an output of a corresponding measurement signal to the controller; the controller is configured to cancel measurement signals received from the error microphone by outputting the control signal to the actuator at least in part or completely; the error microphone is connected by the additional pipe to the first exhaust tract and the second exhaust tract simultaneously at a position of the exhaust system located in a section of a fluid connection between the sound generator and the exhaust system; and connecting the sound generator to the first exhaust tract and the second exhaust tract.

19. The method according to claim 18, wherein the additional pipe and the error microphone are located downstream of the sound generator with respect to a flow of exhaust fluid in at least one of the first exhaust tract and the second exhaust track.

20. The method according to claim 19, wherein the first exhaust track comprises a first exhaust track end portion, wherein first exhaust track fluid exits the first exhaust track via the first exhaust track end portion, the second exhaust track comprising a second exhaust track end portion, wherein second exhaust track fluid exits the second exhaust track via the second exhaust track end portion, the additional pipe and the error microphone being located between the sound generator, the first exhaust track end portion and the second exhaust track end portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The forgoing as well as other advantageous features of the disclosure will be more apparent from the following detailed description of exemplary embodiments together with the claims and the Figures. In the Figures, like or similar elements are indicated by like or similar reference signs. It is noted that the invention is not limited to the embodiments of the exemplary embodiments described, but is defined by the scope of the enclosed claims, and that not all possible embodiments necessarily exhibit each and every, or any, of the advantages identified herein. In particular, embodiments according to the invention may implement individual features in a different number and combination than the examples instanced below. In the following explanation of exemplary embodiments of the invention, it is referred to the enclosed Figures, of which:

(2) FIG. 1 is a schematic illustration showing a perspective view of a part of an exhaust system that comprises a sound generator of an anti-noise system;

(3) FIG. 2 is a schematic illustration showing a block diagram of an anti-noise system cooperating with an exhaust system of an internal combustion engine according to the prior art, wherein the sound generator of FIG. 1 may be used;

(4) FIG. 3A is a schematic illustration showing an anti-noise system cooperating with an exhaust system of an internal combustion engine according to one of three embodiments of the invention;

(5) FIG. 3B is a schematic illustration showing an anti-noise system cooperating with an exhaust system of an internal combustion engine according to another of three embodiments of the invention;

(6) FIG. 3C is a schematic illustration showing an anti-noise system cooperating with an exhaust system of an internal combustion engine according to another of three embodiments of the invention;

(7) FIG. 4A is a schematic illustration showing the connection of the sound generator of the anti-noise system of FIGS. 3A, 3B, 3C to the exhaust system of an internal combustion engine according to one of four embodiments of the invention;

(8) FIG. 4B is a schematic illustration showing the connection of the sound generator of the anti-noise system of FIGS. 3A, 3B, 3C to the exhaust system of an internal combustion engine according to another of four embodiments of the invention;

(9) FIG. 4C is a schematic illustration showing the connection of the sound generator of the anti-noise system of FIGS. 3A, 3B, 3C to the exhaust system of an internal combustion engine according to another of four embodiments of the invention;

(10) FIG. 4D is a schematic illustration showing the connection of the sound generator of the anti-noise system of FIGS. 3A, 3B, 3C to the exhaust system of an internal combustion engine according to another of four embodiments of the invention;

(11) FIG. 4E is a schematic illustration showing the connection of the sound generator of the anti-noise system of FIGS. 3A, 3B, 3C to the exhaust system of an internal combustion engine according to still another embodiment of the invention; and

(12) FIG. 5 is a schematic illustration showing a motor vehicle comprising an exhaust system with an anti-noise system according to the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

(13) Hereinafter, several embodiments of the present invention are explained with respect to the Figures.

(14) Referencing FIGS. 3A, 3B, 3C, the exhaust gas streams generated by an internal combustion engine 100 are first combined and then supplied to a turbocharger 110. Afterwards, the exhaust gas is separately passed along two exhaust tracts 60, 61 through two catalytic converters 62, 63 and two premufflers 64, 65, and finally discharged to the surroundings through discharge openings 50, 51 of tail pipes 40, 41. The direction of flow of the exhaust gas is indicated by arrows.

(15) It is noted that the turbocharger 110, the catalytic converters 62, 63, and the premufflers 64, 65 are only optional. Alternatively or additionally, other elements may also be provided for emission control and sound absorption. It is further noted that there may be more than one pair of exhaust tracts.

(16) According to the embodiments of all FIGS. 3A, 3B, and 3C, the anti-noise system comprises a sound generator 20 with a loudspeaker disposed therein. Close to the tailpipes 50, 51, the sound generator 20 is in fluid communication with the two exhaust tracts 60, 61 via conduits 21.

(17) The lengths of the two exhaust tracts 60, 61 between the internal combustion engine 100 and the position on the respective exhaust tract 60, 61, where the sound generator 20 is connected to the respective exhaust tract 60, 61, are identical. This is, however, not mandatory.

(18) According to the embodiments of all FIGS. 3A, 3B, 3C, at least one error microphone 70, 71, 72 formed by a pressure sensor is disposed between the region, where the sound generator is fluidly connected, and the tailpipes 50, 51.

(19) According to the embodiment of FIG. 3A, only one error microphone 70 is provided for measuring the pressure fluctuations and thus sound inside the exhaust tract 60.

(20) According to the embodiment of FIG. 3B, each exhaust tract 60, 61 comprises an error microphone 70, 71 for measuring pressure fluctuations and thus sound inside the associated exhaust tract 60, 61.

(21) According to the embodiment of FIG. 3, only one error microphone 72 is provided which simultaneously is in fluid communication with the two exhaust tracts 60, 61 via a T-shaped hose connection 73, and which simultaneously measures pressure fluctuations and thus sound inside the two exhaust tracts 60, 61.

(22) The loudspeakers of the sound generators 20 and the error microphones 70, 71, 72 are connected to an anti-noise controller 80 by control lines.

(23) The anti-noise controller 80 is further connected to an engine control unit 90 of the internal combustion engine 100 via a CAN data bus, and receives from the engine control unit 90 up-to-date operating parameters of the internal combustion engine 100, in particular engine speed and torque. It is noted that a different vehicle data bus may be used instead of the CAN data bus, in particular a LIN data bus, a MOST data bus, or a FlexRay data bus.

(24) The anti-noise controller 80, which is in the present case a microprocessor configured by software, is adapted to generate a control signal based on the operating parameters of the internal combustion engine received by the engine control unit 90 and on error signals (measurement signals) received from the error microphones 70, 71, 72 by using a Filtered-X, Least Mean Squares (FxLMS) algorithm, whereby the control signal is adapted to operate the loudspeaker of the sound generator 20 such that the noise passing through the exhaust tracts 60, 61 is canceled in amplitude at least in part. The result in view of noise cancellation can be verified by the error microphones 70, 71, 72.

(25) As is evident from FIGS. 4A, 4B, 4C, 4D and 4E, the connection of the sound generator 20 to the two exhaust tracts 60, 61 can be implemented differently in each of the embodiments described above.

(26) According to the embodiments of all FIGS. 4A, 4B, and 4C, the tailpipes 50, 51 are connected to respective corresponding exhaust tracts 60, 61 by Y-shaped manifolds 66, 67. The base or root, respectively, of each Y-shaped manifold 66, 67 is connected to a corresponding tailpipe 50, 51, and a leg of the Y-shaped manifold is connected to a conduit of the respective exhaust tract 60, 61. The other leg of the Y-shaped manifold 66, 67 is in fluid communication with the respective sound generator 21, 23, 25. The acute angle between the legs of the Y-shaped manifold 66, 67 prevents the loudspeaker of the corresponding sound generator 21, 23, 25 from being affected by the pressure of the exhaust gas passing through the exhaust tracts 60, 61.

(27) According to the embodiment of FIG. 4A, the fluid connection of the sound generator 21 is achieved with a T-shaped adapter 22 which both legs are connected to the legs of the Y-shaped manifolds 66, 67, and which base is connected to the sound generator 21.

(28) According to the embodiment of FIG. 4B, the fluid connection of the sound generator 23 is achieved with a Y-shaped adapter 24 which both legs are connected to the legs of the Y-shaped manifold 66, 67, and which base is connected to the sound generator 23.

(29) According to the embodiment of FIG. 4C, the sound generator 25 comprises an antechamber volume into which the two legs of the Y-shaped manifolds 66, 67 enter.

(30) Also in the embodiment of FIG. 4D, the two tailpipes 50, 51 are connected to the respective corresponding exhaust tracts 60, 61 by Y-shaped manifolds 68, 69 with the base or root, respectively, of each Y-shaped manifold 68, 69 being connected to a corresponding tailpipe 50, 51, and a leg of the Y-shaped manifold 68, 69 being connected to a conduit of the respective exhaust tract 60, 61. The other legs of the Y-shaped manifold 68, 69 are configured as a twin D-pipe near the connection to the sound generator 27. Near the connection to the sound generator 27, each of the other legs of the Y-shaped manifolds 68, 69 have thus a semicircular cross section, with the flat sides put together and joined by a welding seam.

(31) According to the embodiments of all FIGS. 4A, 4B, 4C, and 4D, the lengths of the respective conduits between the respective exhaust tracts 60, 61 and the sound generator 21, 23, 25, 27 are identical.

(32) The error microphone(s) used are not shown in FIGS. 4A to 4D. As shown in FIGS. 3A to 3C, there are the options: to provide one error microphone that is disposed along the exhaust gas flow downstream of the region, where the fluid connection of the respective sound generator 21, 23, 25, 27 to the exhaust tracts 60, 61 is effected, and which is associated with one of the two exhaust tracts 60, 61; or to provide two error microphones, each being associated to one of the two exhaust tracts 60, 61 and disposed along the exhaust gas flow downstream of the region, where the fluid connection of the respective sound generator 21, 23, 25, 27 to the exhaust tracts 60, 61 is effected; or to provide one error microphone associated to both exhaust tracts 60, 61 simultaneously and being connected to these by a fluid connection disposed along the exhaust gas flow downstream of the region, where the fluid connection of the respective sound generator 21, 23, 25, 27 to the exhaust tracts 60, 61 is effected.

(33) According to the embodiment of FIG. 4E, the sound generator 29 is in fluid communication with a volume 110 through a conduit 28, with the volume 110 being shared by the two exhaust tracts 60, 61. This volume 110 is located along the exhaust gas passing through the exhaust tracts 60, 61 downstream of the internal combustion engine 100 and upstream of the tailpipes 50, 51. In the embodiment shown, the volume 110 is located downstream of a turbocharger (not shown). Further, an error microphone 74 is provided which is in fluid communication with the volume 110 downstream (with respect to the exhaust gas flow) of the region of the fluid connection of the sound generator 29 to the volume 110. Furthermore, the error microphone 74 is connected to the controller 80.

(34) Referencing FIG. 5, a motor vehicle is shown that houses an internal combustion engine 100 and in addition the above anti-noise system with the multi-flow exhaust system (of which only the exhaust tract 60 is shown in FIG. 5) and the anti-noise controller 80. The sound generator with the loudspeaker is not shown in FIG. 5.

(35) While the disclosure has been described with respect to certain exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the disclosure set forth herein are intended to be illustrative and not limiting in any way. Various changes may be made without departing from the spirit and scope of the present disclosure as defined in the following claims.