System and method for pedestrian alert

1. A method for pedestrian alert comprising:

deriving a pedestrian path representing a projected path for a pedestrian;

deriving a vehicle path representing a projected path for a vehicle;

determining an intersection of the pedestrian path and the vehicle path;

determining an environmental noise level detected by an external microphone;

determining an alert characteristic responsive to the determined intersection; and

emitting an alert signal from the vehicle responsive to the determined alert characteristic,

wherein the determined alert characteristic is adjusted responsive to the environmental noise level; and

wherein the emitted alert signal draws the attention of the pedestrian to the presence of the motor vehicle to mitigate a likelihood of a collision between the vehicle and the pedestrian.

2. The method of claim 1 , wherein the determined alert characteristic includes a direction characteristic and the alert signal is emitted in a direction responsive to the direction characteristic.

3. The method of claim 2 , wherein one or more of the acts are repeated on a continuous or periodic basis over time and wherein the direction of the emitted alert signal changes over time responsive to changes to the direction characteristic.

4. The method of claim 2 , wherein the direction of the emitted signal is controlled using any of: phase and amplitude modulation of an array of loudspeakers, selecting one or more audio transducers from an array of transducers and steering of one or more steerable audio transducers.

5. The method of claim 1 , wherein the determined alert characteristic includes any one or more of loudness, pitch and signal content.

6. The method of claim 5 , wherein the loudness characteristic is adjusted up or down responsive to the environmental noise level.

7. The method of claim 5 , wherein the signal content characteristic includes an impulsive sound containing transient broadband information to enable the source of the alert signal to be more easily localized by the pedestrian.

8. The method of claim 5 , wherein the signal content characteristic is adapted to be more easily audible by a human with a common form of hearing loss.

9. The method of claim 1 , wherein the acts of deriving a pedestrian path, determining an intersection, determining alert characteristics and emitting an alert signal occur concurrently for respective ones of two or more pedestrians.

10. The method of claim 1 , wherein the determined intersection is one of: intersection will occur and intersection will not occur.

11. A system for pedestrian alert comprising:

a processor;

an external microphone coupled to the processor;

memory storing processor-executable instructions that, when executed by the processor, cause the processor to:

derive a pedestrian path representing a projected path for a pedestrian,

derive a vehicle path representing a projected path for a vehicle,

determine an intersection of the pedestrian path and the vehicle path,

determine an environmental noise level detected by the external microphone, and

determine an alert characteristic responsive to the determined intersection; and

an emitter to emit an alert signal from the vehicle responsive to the determined alert characteristic,

wherein the determined alert characteristic is adjusted responsive to the environmental noise level, and wherein the emitted alert signal draws the attention of the pedestrian to the presence of the vehicle to mitigate a likelihood of a collision between the vehicle and the pedestrian.

12. The system of claim 11 , wherein the determined alert characteristics include a direction characteristic and the alert signal is emitted in a direction responsive to the direction characteristic.

13. The system of claim 12 , wherein one or more of the components of the system operate on a continuous or periodic basis over time and wherein the direction of the emitted alert signal changes over time responsive to changes to the direction characteristic.

14. The system of claim 12 , wherein the direction of the emitted signal is controlled using any of: phase and amplitude modulation of an array of loudspeakers, selecting one or more audio transducers from an array of transducers and steering of one or more steerable audio transducers.

15. The system of claim 11 , wherein the determined alert characteristic includes one or more of loudness, pitch and signal content.

16. The system of claim 15 , wherein the loudness characteristic is adjusted up or down responsive to the environmental noise level.

17. The system of claim 15 , wherein the signal content characteristic includes an impulsive sound containing transient broadband information to enable the source of the alert signal to be more easily localized by the pedestrian.

18. The system of claim 15 , wherein the signal content characteristic is adapted to be more easily audible by a human with a common form of hearing loss.

19. The system of claim 11 , wherein the system operates for two or more pedestrians concurrently.

20. The system of claim 11 , wherein the determined intersection is one of: intersection will occur and intersection will not occur.

21. A non-transitory machine-readable medium encoded with machine-executable instructions, wherein execution of the machine-executable instructions is to cause a machine to:

derive a pedestrian path representing a projected path for a pedestrian;

derive a vehicle path representing a projected path for a vehicle;

determine an intersection of the pedestrian path and the vehicle path;

determine an environmental noise level detected by an external microphone;

determine an alert characteristic responsive to the determined intersection; and

emit an alert signal from the vehicle responsive to the determined alert characteristic,

wherein the determined alert characteristic is adjusted responsive to the environmental noise level;

and wherein the emitted alert signal draws the attention of the pedestrian to the presence of the motor vehicle to mitigate a likelihood of a collision between the vehicle and the pedestrian.

22. The non-transitory machine-readable medium of claim 21 , wherein the determined alert characteristics include a direction characteristic and the alert signal is emitted in a direction responsive to the direction characteristic.

23. The non-transitory machine-readable medium of claim 22 , wherein the instructions are to cause the machine to operate on a continuous or periodic basis over time and wherein the direction of the emitted alert signal changes over time responsive to changes to the direction characteristic.

24. The non-transitory machine-readable medium of claim 22 , wherein the direction of the emitted signal is controlled using any of: phase and amplitude modulation of an array of loudspeakers, selecting one or more audio transducers from an array of transducers and steering of one or more steerable audio transducers.

25. The non-transitory machine-readable medium of claim 21 , wherein the determined alert characteristic includes one or more of loudness, pitch and signal content.

26. The non-transitory machine-readable medium of claim 25 , wherein the loudness characteristic is adjusted up or down responsive to the environmental noise level.

27. The non-transitory machine-readable medium of claim 25 , wherein the signal content characteristic includes an impulsive sound containing transient broadband information to enable the source of the alert signal to be more easily localized by the pedestrian.

28. The non-transitory machine-readable medium of claim 25 , wherein the signal content characteristic is adapted to be more easily audible by a human with a common form of hearing loss.

29. The non-transitory machine-readable medium of claim 21 , wherein the machine is to operate for two or more pedestrians concurrently.

30. The non-transitory machine-readable medium of claim 21 , wherein the determined intersection is one of: intersection will occur and intersection will not occur.