Providing audible signals to a driver
A method for providing audible signals (such as speech) to a driver of a vehicle which appear to originate from a virtual sound source in front of the driver, so that it will feel normal for the driver to respond interactively by speaking without turning the head to the source of the audible signal. The driver's head position is estimated according to data provided by sensors in the driver's seat, and this position data, together with acoustical characteristics of the vehicle interior, is used to derive a transfer function for filtering electrical audible signals to the loudspeakers to simulate a virtual sound source in front of the driver.
1. A method for creating a virtual audible source for an audible signal at a virtual source location relative to a driver seated in a seat of a vehicle interior, the vehicle interior having interior acoustical characteristics and at least one loudspeaker having a predetermined loudspeaker location, the method comprising:
obtaining seat data from one or more sensors located in the seat;
computing an estimated head position of the driver based on the seat data;
computing an acoustical transfer function for the at least one loudspeaker according to the estimated head position, the virtual source location, the predetermined loudspeaker location, and the interior acoustical characteristics, wherein the virtual source location is in front of the driver;
applying the acoustical transfer function to the audible signal to obtain a filtered audible signal; and
sending the filtered audible signal to the at least one loudspeaker.
2. The method of claim 1 , further comprising: obtaining anthropometric data related to the driver; and computing the estimated head position based on the anthropometric data.
3. The method of claim 1 , wherein the sensors located in the seat include seat adjustment position sensors.
4. The method of claim 1 , wherein the sensors located in the seat include driver contact pressure sensors.
5. The method of claim 1 , further comprising: computing the estimated head position of the driver based on visual data obtained from at least one camera.
6. The method of claim 1 , wherein computing the acoustical transfer function comprises selecting a filter from a predetermined plurality of filters associated with a geometrical grid in the vehicle interior.
7. The method of claim 1 , wherein the acoustical transfer function is computed using at least a generic Head Related Transfer Function (HRTF) and a vehicle-dependent transfer function specific to the vehicle interior.
8. The method of claim 1 , wherein the virtual audible source location corresponds to a head up display (HUD) image location.
9. A computer product for creating a virtual audible source for an audible signal at a virtual source location relative to a driver seated in a seat of a vehicle interior, the vehicle interior having interior acoustical characteristics and at least one loudspeaker having a predetermined loudspeaker location, the computer product comprising a set of executable commands for performing the method on an on-board computer of the vehicle, wherein the executable commands are contained within a tangible computer-readable non-transient data storage medium, such that when the executable commands of the computer product are executed, the computer product causes the on-board computer to perform: obtaining seat data from one or more sensors located in the seat; computing an estimated head position of the driver based on the seat data; computing an acoustical transfer function for the at least one loudspeaker according to the estimated head position, the virtual source location, wherein the virtual source location is in front of the driver, the predetermined loudspeaker location, and the interior acoustical characteristics; applying the acoustical transfer function to the audible signal to obtain a filtered audible signal; and sending the filtered audible signal to the at least one loudspeaker.
10. The computer product of claim 9 , further comprising executable instructions, which, when executed, cause the on-board computer to perform: obtaining anthropometric data related to the driver; and computing the estimated head position based on the anthropometric data.
11. The computer product of claim 9 , further comprising executable instructions, which, when executed, cause the on-board computer to perform: selecting a filter from a predetermined plurality of filters associated with a geometrical grid in the vehicle interior.
12. The computer product of claim 9 , wherein the acoustical transfer function is computed using at least a generic Head Related Transfer Function (HRTF) and a vehicle-dependent transfer function specific to the vehicle interior.
13. A method for creating a virtual audible source for an audible signal at a virtual source location relative to a driver seated in a seat of a vehicle interior, the vehicle interior having interior acoustical characteristics and at least one loudspeaker having a predetermined loudspeaker location, the method comprising: computing an estimated head position of the driver based on visual data obtained from a camera; computing an acoustical transfer function for the at least one loudspeaker according to the estimated head position, the virtual source location, wherein the virtual source location is in front of the driver, the predetermined loudspeaker location, and the interior acoustical characteristics, wherein the computing the acoustical transfer function uses at least: a Head Related Transfer Function (HRTF) decomposed into a generic HRTF and a vehicle dependent transfer function specific to the vehicle interior; applying the acoustical transfer function to the audible signal to obtain a filtered audible signal; and sending the filtered audible signal to the at least one loudspeaker.