Method for controlling an extended-range electric vehicle including an electronic sound enhancement system

Abstract

A method for controlling an extended-range electric vehicle including an internal combustion engine and an electronic sound enhancement system includes selecting a preferred engine order equalization, said preferred engine order equalization achieving a desired engine sound in a passenger compartment of the vehicle responsive to an operator input to an accelerator pedal and decoupled from actual engine operation responsive to a state of charge (SOC) of a propulsion battery. Sound is generated in the passenger compartment by the electronic sound enhancement system responsive to the preferred engine order equalization.

The invention claimed is: 
     
       1. A method for controlling an extended-range electric vehicle including an internal combustion engine and an electronic sound enhancement system, comprising:
 selecting a preferred engine order equalization, said preferred engine order equalization achieving a desired engine sound in a passenger compartment of the vehicle responsive to an operator input to an accelerator pedal and decoupled from actual engine operation responsive to a state of charge (SOC) of a propulsion battery; and 
 generating, by the electronic sound enhancement system, sound in the passenger compartment responsive to the preferred engine order equalization. 
 
     
     
       2. The method of  claim 1 , wherein selecting the preferred engine order equalization comprises selecting one of a plurality of engine order equalizations to generate the desired engine sound in the passenger compartment that accounts for presently occurring engine sound associated with the actual engine operation. 
     
     
       3. The method of  claim 2 , wherein selecting one of a plurality of engine order equalizations to generate the desired engine sound in the passenger compartment that accounts for presently occurring engine sound associated with the actual engine operation comprises:
 determining a first sound spectrum corresponding to the desired engine sound in the passenger compartment; 
 determining a second sound spectrum corresponding to the presently occurring engine sound; and 
 selecting the preferred engine order equalization comprising a differential sound spectrum based upon differences between the first and corresponding second magnitudes for each frequency of the first and second sound spectrums. 
 
     
     
       4. The method of  claim 1 , further comprising discontinuing employing the electronic sound enhancement system to generate any sound in the passenger compartment of the vehicle when the extended-range electric vehicle is operating in an electric vehicle mode/operating with the engine in an OFF state. 
     
     
       5. The method of  claim 1 , wherein selecting a preferred engine order equalization comprises selecting a preferred engine order equalization associated with a purring sound responsive to a non-aggressive operator input to the accelerator pedal. 
     
     
       6. The method of  claim 1 , wherein selecting a preferred engine order equalization comprises selecting a preferred engine order equalization associated with a sporty engine base order sound responsive to a non-aggressive operator input to the accelerator pedal. 
     
     
       7. The method of  claim 1 , wherein selecting a preferred engine order equalization comprises selecting a preferred engine order equalization associated with a sporty engine base order sound responsive to an aggressive operator input to the accelerator pedal. 
     
     
       8. The method of  claim 1 , wherein selecting a preferred engine order equalization comprises selecting a preferred engine order equalization associated with a performance engine base order sound responsive to an aggressive operator input to the accelerator pedal. 
     
     
       9. The method of  claim 1 , wherein selecting a preferred engine order equalization comprises selecting a preferred engine order equalization associated with a purring engine base order sound responsive to an aggressive operator input to the accelerator pedal. 
     
     
       10. The method of  claim 1 , further comprising employing the electronic sound enhancement system to generate enhancement sound in the passenger compartment of the vehicle when the extended-range electric vehicle is transitioning between an engine ON state and an engine OFF state. 
     
     
       11. The method of  claim 1 , further comprising generating, by the electronic sound enhancement system, sound in the passenger compartment at higher magnitude levels and character when in one of a performance mode or a sporty mode in the passenger compartment of the vehicle to mask system sounds. 
     
     
       12. The method of  claim 1 , further comprising generating, by the electronic sound enhancement system, sound in the passenger compartment responsive to a preferred engine order equalization when the engine is in the ON state responsive to a low ambient temperature. 
     
     
       13. The method of  claim 1 , further comprising generating, by the electronic sound enhancement system, sound in the passenger compartment responsive to the preferred engine order equalization when the engine is in the ON state responsive to a disengaged hood latch. 
     
     
       14. A method for controlling an extended-range electric vehicle including an internal combustion engine and an electronic sound enhancement system, comprising:
 monitoring, by a controller, a state of charge (SOC) of a propulsion battery and an operator input to an accelerator pedal; 
 selecting a preferred engine order equalization that achieves a desired engine sound in a passenger compartment of the vehicle responsive to the operator input to the accelerator pedal, said desired sound associated with the preferred engine order equalization decoupled from actual engine sound; and 
 generating sound in the passenger compartment responsive to the preferred engine order equalization employing the electronic sound enhancement system. 
 
     
     
       15. The method of  claim 14 , wherein selecting a preferred engine order equalization that achieves a desired engine sound in a passenger compartment of the vehicle responsive to the operator input to the accelerator pedal, said desired sound associated with the preferred engine order equalization decoupled from actual engine sound comprises selecting one of a plurality of engine order equalizations to generate the desired engine sound in the passenger compartment accounting for the actual engine sound. 
     
     
       16. The method of  claim 14 , wherein selecting one of a plurality of engine order equalizations to generate the desired engine sound in the passenger compartment accounting for the actual engine sound comprises:
 determining a first sound spectrum corresponding to the desired engine sound; 
 determining a second sound spectrum corresponding to the actual engine sound; and 
 selecting the preferred engine order equalization comprising a differential sound spectrum based upon differences between the corresponding first and second magnitudes for each frequency of the first and second sound spectrums.