LINEAR ULTRASOUND TRANSDUCER ARRAY FOR AN AUTOMOTIVE OCCUPANCY SENSOR SYSTEM

• US 20010048217A1
• Filed: 04/15/1999
• Published: 12/06/2001
• Est. Priority Date: 04/15/1999
• Status: Active Grant

• Current Assignee: Robert Bosch Corporation (Robert Bosch GmbH)
• Original Assignee: Robert Bosch Corporation (Robert Bosch GmbH)
• Inventors: SEIP, RALF
• Granted Patent: US 6,431,592 B2
• Time in Patent Office: Days
• US Class Current: 280/735
• CPC Class Codes: B60R 21/01526 using piezoelectric elements
• CPC Class Codes: B60R 21/01536 using ultrasonic waves
• CPC Class Codes: B60R 21/01542 detecting passenger motion
• CPC Class Codes: G01S 15/04 Systems determining presence of a target

Abstract

An improved automotive occupancy sensor (AOS) system comprising a linear or spaced array of ultrasound (US) transducers mounted adjacent the headliner of a vehicle to direct an array of US beams to define a preselected occupancy zone adjacent a seat of the vehicle. The AOS electronics may be integrally packaged with the transducer array and flush mounted within the headliner. The array permits occupancy state to be determined by a AOS classification algorithm and method using only or US echo range data, thereby reducing the cost and complexity of the system, improving speed and simplifying calibration.

Claims

1. An improved AOS system for determination of the presence of an occupant in a zone above at least one seat within a vehicle for use in cooperation with an airbag deployment system, comprising in operative combination:

a) at least one spaced array of sensors including a plurality of US transducers mounted adjacent the headliner of the vehicle generally above said seat and directed generally downward to define a pre-selected occupancy H-zone adjacent and above said seat covered by US beams transmitted from said transducers;

b) AOS electronics mounted within said vehicle and connected to said array to cause said array to emit US pulses into said defined H-zone and to receive US echoes of objects in said H-zone as AOS input signals; and

c) said AOS electronics including a processor and classification algorithm using range data derived from said AOS US input signals to output a signal indicative of the determination of the presence or absence in said H-zone of an object.

2. An improved AOS system as in

claim 1

, wherein at least one of said US transducers is a PZT sensor.

3. An improved AOS system as in

claim 1

, wherein:

a) said vehicle has a centerline; and

b) said transducer array is disposed in a line generally parallel to said vehicle centerline.

4. An improved AOS system as in

claim 3

, wherein

a) said seat has a central axis;

and

b) said transducer array line is offset with respect to said seat axis.

5. An improved AOS system as in

claim 4

, wherein said array line is offset outboard of said seat axis.

6. An improved AOS system as in

claim 4

, wherein said array line is offset inboard of said seat axis.

7. An improved AOS system as in

claim 3

, including at least one of said transducer arrays disposed generally above each of a driver seat and a front passenger seat.

8. An improved AOS system as in

claim 7

, further including at least one of said transducer arrays disposed generally above at least one rear passenger seat.

9. An improved AOS system as in

claim 7

, further including at least one of said transducer arrays disposed generally above both a rear passenger seat and one of a front passenger seat and a driver seat, said array transducers defining a distinct H-zone with respect to the occupancy of each of said seats.

10. An improved AOS system as in

claim 1

, wherein said AOS system outputs said presence or absence determination signal to an airbag deployment system for regulating the deployment of at least one of a front airbag system and a side airbag system.

11. An improved AOS system as in

claim 1

, wherein at least one of said US transducers is directed so as to produce at least one of said US echos by reflection from the head of said occupant in the event that said seat is occupied.

12. An improved AOS system as in

claim 11

, wherein

a) said seat includes a headrest;

b) at least one of said US transducers is directed so as to produce at least one of said US echos by reflection from the head of said seat occupant in the event that said seat is occupied.

13. An improved AOS system as in

claim 1

, wherein

a) a subset of at least one of said US transducers but less than the full array of said US transducers is directed to define a keep-out zone located forward of said H-zone;

b) said AOS includes sensors to determine whether a crash-imminent state exists; and

c) in response to a determination of the existence of said crash-imminent state, said AOS processors use range data limited to a subset of said transducers of said array to determine motion of an occupant into said keep-out zone, to permit a faster update rate in said output signal during the existence of a crash-imminent state.

14. An improved AOS system as in

claim 1

, wherein said array does not include a Faraday cage for at least one of said transducers.

15. An improved AOS system as in

claim 1

, wherein

a) said AOS electronics includes a processor and algorithm to determine from said range data an intrusion of a person into a parked vehicle;

and

b) said AOS electronics outputs an intrusion signal to at least one anti-theft device.

16. An improved AOS system for determination of the intrusion of an occupant into a keep-out zone above at least one seat within a vehicle and adjacent the vehicle side for use in cooperation with an airbag deployment system for side-impact protection, comprising in operative combination:

a) at least one spaced array of sensors including a plurality of US transducers mounted adjacent the headliner of the vehicle generally above said seat and directed generally downward to define a pre-selected keep-out zone above a seat and adjacent the vehicle side covered by US beams transmitted from said transducers;

b) AOS electronics mounted within said vehicle and connected to said array to cause said array to emit US pulses into said defined keep-out zone and to receive US echoes of objects in said keep-out zone as AOS input signals; and

c) said AOS electronics including a processor and classification algorithm using range data derived from said AOS US input signals to output a signal indicative of the determination of the presence or absence in said keep-out zone of an object.

17. An improved AOS system as in

claim 16

, wherein at least one of said US transducers is a PZT sensor.

18. A method of determining the presence of an occupant in a zone above at least one seat within a vehicle for an airbag deployment system, comprising in any operative order the steps of:

a) transmitting a plurality of spaced US transducer beams in a space array downward from above towards said seat to define an occupancy H-zone adjacent and above said seat;

b) receiving return US echo signals for at least one of said transducers;

c) deriving echo range values from said return echo signals;

d) determining occupant presence within said H-zone from said echo range values; and

e) sending a least one signal to said airbag deployment system indicative of one of the presence and the absence of an occupant in said H-zone.

19. A method as in

claim 18

, including:

a) determining the time history of said echo range values; and

b) determining the velocity of the motion of an occupant relative to said vehicle from said time history; and

c) predicting the presence of said occupant in said H-zone at a future time by extrapolating from said velocity.

20. A method as in

claim 18

, wherein said transmitting step includes transmitting said beams directed and spaced so that at least one of said beams is reflected by the head of said seat occupant in the event that said seat is occupied.

21. A method as in

claim 20

, wherein:

a) said seat includes a headrest;

b) said transmitting step includes transmitting at least one of said beams substantially towards said headrest so as to produce at least one return echo signal from said headrest; and

c) said determining step includes determining the location of said headrest from at least one of said echo range values.

22. A method as in

claim 18

, wherein

a) said transmitting step includes transmitting a subset of at least one of said US transducer beams but less than the full array of said US transducer beams to define a keep-out zone located forward of said H-zone;

b) determining whether a crash-imminent state exists; and

c) in response to a determination that a crash-imminent state exists, determining motion of an occupant into said keep-out zone using said echo range values corresponding to said subset of transducer beams, to permit a faster update rate in said occupant presence determination during the duration of the crash-imminent state.

23. A method of determining the intrusion of an occupant in a keep-out zone above at least one seat within a vehicle for an airbag deployment system, comprising in any operative order the steps of:

a) transmitting a plurality of spaced US transducer beams in a space array downward from above towards said seat to define an occupancy keep-out zone above said seat and adjacent the vehicle side;

b) receiving return US echo signals for at least one of said transducers;

c) determining occupant intrusion into said keep-out zone from echo range values derived from said return echo signals; and

d) sending a least one signal to said airbag deployment system indicative of one of the intrusion and non-intrusion of an occupant in said keep-out zone.

24. An improved sensor system for a vehicle interior AOS, comprising in operative combination:

a) a mounting board means for mounting sensors in the headliner of a vehicle;

b) a plurality of US transducers mounted on said mounting board; and

c) said transducers are mounted on said board in a spaced array angled to provide coverage in at least one defined zone in said vehicle.

25. An improved sensor system as in

claim 24

, wherein at least one of said US transducers is a PZT sensor.

26. An improved sensor system as in

claim 24

, wherein said the transducers of said spaced array are mounted in a generally straight line on said board.

27. An improved sensor system as in

claim 24

, wherein said defined zone is an occupancy H-zone adjacent and above a seat in said vehicle.

28. An improved sensor system as in

claim 24

, wherein said defined zone is a keep-out zone above a seat in said vehicle and adjacent a side of said vehicle.

29. An improved sensor system as in

claim 24

, wherein:

a) said transducers are mounted on said board in a spaced array angled to provide coverage in at least two defined zones in said vehicle; and

b) said defined zones are selected from;

i) an occupancy H-zone adjacent and above a seat in said vehicle;

ii) a keep-out zone above a seat in said vehicle and adjacent a front dashboard in said vehicle.

iii) a keep-out zone above a seat in said vehicle and adjacent a side of said vehicle.