Linear ultrasound transducer array for an automotive occupancy sensor system

• US 6,431,592 B2
• Filed: 04/15/1999
• Issued: 08/13/2002
• 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
• Primary Examiner(s): LERNER, AVRAHAM H
• Application Number:
  US09/292,170
• Publication Number:
  US 20010048217A1
• Time in Patent Office: 1,216 Days
• Field of Search: 280/735, 280/730.2
• 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 Automotive Occupancy Sensor system unit mountable within the headliner of a vehicle passenger compartment for determination of the presence of an occupant in a zone above at least one seat within said vehicle, said headliner defining the top of the interior space of said vehicle passenger compartment, said unit outputting a signal indicative of presence of an object in a Head-zone defined between said headliner down to about the seat back vertical mid-point to determine occupancy state of said seat for use in cooperation with an airbag deployment system, said unit comprising in operative combination:

a) at least one housing in which is mounted a spaced array of selectively directed sensors, said array including a plurality of ultrasound transducers, said housing providing for mounting in the headliner of the vehicle generally above said seat so that said ultrasound transducers are directed generally downward into said Head-zone adjacent and above said seat, and said ultrasound transducers do not substantially project into said vehicle interior space below said headliner, and wherein each individual transducer is both the emitter of pulses and receiver of the echoes of the respective pulses emitted by said individual transducer, said array excludes a separate receiver-only device, and an array in which transducers are paired and the transducers of each pair are aimed to have intersecting center axes is disclaimed;

b) Automotive Occupancy Sensor electronics mounted in said housing connected to said array for selective emission by individual ones of said ultrasound transducers of ultrasound pulses downwardly into a selected portion of said vehicle interior space and for receipt by each respective individual transducer of the return echo of its pulse and analysis of said echoes from said defined Head-zone; and

c) said Automotive Occupancy Sensor electronics including a processor and at least one classification algorithm using range data derived from said echoes to produce and to output a unique signal, indicative of the determination of the presence or absence of an object in said defined Head-zone without determination of acceleration of said object relative to deceleration of said vehicle.

2. An improved Automotive Occupancy Sensor system as in claim 1, wherein at least one of said ultrasound transducers is a piezoelectric transducer sensor.

3. An improved Automotive Occupancy Sensor 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 Automotive Occupancy Sensor system as in claim 3, wherein

a) said seat has a central, fore-aft axis;

and

b) said transducer array line is offset and generally parallel to said seat axis.

5. An improved Automotive Occupancy Sensor system as in claim 4, wherein said array line is offset outboard of said seat axis.

6. An improved Automotive Occupancy Sensor system as in claim 4, wherein said array line is offset inboard of said seat axis.

7. An improved Automotive Occupancy Sensor 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 Automotive Occupancy Sensor 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 Automotive Occupancy Sensor 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 being directed downwardly into the defined Head-zone with respect to the occupancy of each of said seats.

10. An improved Automotive Occupancy Sensor system as in claim 1, wherein said Automotive Occupancy Sensor system electrically outputs said presence or absence determination signal to an airbag deployment system for use in regulating the deployment of at least one of a front airbag system and a side airbag system.

11. An improved Automotive Occupancy Sensor system as in claim 1, wherein

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

b) said Automotive Occupancy Sensor 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 Automotive Occupancy Sensor processors use range data limited to said Keep-Out zone subset of said transducers of said array to determine motion of an occupant into said Keep-Out zone, to initiate a faster update rate of said output signal during the existence of a crash-imminent state.

12. An improved Automotive Occupancy Sensor system as in claim 1, wherein said array does not include a Faraday cage for at least one of said transducers.

13. An improved Automotive Occupancy Sensor system as in claim 1, wherein

a) said Automotive Occupancy Sensor electronics includes a processor and at least one algorithm to determine from said range data an intrusion of a person into a parked vehicle;

and

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

14. An improved Automotive Occupancy Sensor system unit mountable within the headliner of a vehicle passenger compartment for determination of the intrusion of an occupant into a side Keep-Out zone, said Keep-Out zone being defined above at least one seat within said vehicle and adjacent the vehicle seat side as extending downwardly from the headliner of said vehicle interior to about the vertical mid-point of said seat back and from a vehicle interior side to an adjacent side of a vehicle seat, said unit outputting a signal indicative of presence of a object in said Keep-Out zone for use in cooperation with an airbag deployment system for side-impact protection, said unit comprising in operative combination:

a) at least one housing in which is mounted a spaced array of selectively directed sensors, said array including a plurality of ultrasound transducers, said housing providing for mounting in the headliner of the vehicle generally above said seat so that at least one ultrasound transducer is directed generally downward into said Keep-Out zone above said seat and adjacent the vehicle side, and said ultrasound transducers do not substantially project into said vehicle interior space below said headliner, and wherein each individual transducer is both the emitter of pulses and receiver of the echoes of the respective pulses emitted by said individual transducer, said array excludes a separate receiver-only device, and an array in which transducers are paired and the transducers of each pair are aimed to have intersecting center axes is disclaimed;

b) Automotive Occupancy Sensor electronics mounted in said housing connected to said array for selective emission by individual ones of said ultrasound transducers of ultrasound pulses into a selected portion of said vehicle interior space and receipt by each respective individual transducer of the return echo of its pulse and analysis of said echoes from said Keep-Out zone; and

c) said Automotive Occupancy Sensor electronics including a processor and at least one classification algorithm using range data derived from said echoes to produce and to output a unique signal, indicative of the determination of the presence or absence of an object in said defined Keep-Out zone without determination of acceleration of said object relative to deceleration of said vehicle.

15. An improved Automotive Occupancy Sensor system as in claim 14, wherein at least one of said ultrasound transducers is a piezoelectric transducer sensor.

16. 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 the steps of:

a) defining a preselected occupancy Head-zone adjacent and above said seat defined between the headliner of said vehicle interior down to about the seat back vertical mid-point;

b) transmitting a plurality of spaced ultrasound transducer pulses in a spaced array from a plurality of spaced transducers downward from above towards said seat into said occupancy Head-zone, and wherein each individual transducer is both the emitter of pulses and receiver of the echoes of the respective pulses emitted by said individual transducer, said array excludes a separate receiver-only device, and an array in which transducers are paired and the transducers of each pair are aimed to have intersecting center axes is disclaimed;

c) evaluating for at least one transducer the return ultrasound echo signals corresponding to its pulses to derive echo range values from said return echo signals;

d) determining object presence within said defined Head-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 object in said Head-zone.

17. A method of determining the intrusion of an object in a Keep-Out zone at least one seat within a vehicle for an airbag deployment system, comprising the steps of:

a) defining a preselected occupancy Keep-Out zone in said vehicle interior space extending downwardly from the headliner of said vehicle interior to about the vertical mid-point of said seat back and from a vehicle interior side to an adjacent side of a vehicle seat;

b) transmitting a plurality of spaced ultrasound transducer pulses in a spaced array from a plurality of spaced transducers downward from above into said occupancy Keep-Out zone above said seat and adjacent the vehicle seat side, and wherein each individual transducer is both the emitter of pulses and receiver of the echoes of the respective pulses emitted by said individual transducer, said array excludes a separate receiver-only device, and an array in which transducers are paired and the transducers of each pair are aimed to have intersecting center axes is disclaimed;

c) evaluating for at least one transducer the return ultrasound echo signals corresponding to its pulses to derive echo range values from said return echo signals;

d) determining object intrusion into said defined Keep-Out zone from said echo range values; and

e) sending a least one signal to said airbag deployment system indicative of one of the intrusion and the non-intrusion of an occupant in said Keep-Out zone.

18. An improved sensor system for a vehicle interior Automotive Occupancy Sensor, comprising in operative combination:

a) a mounting board means for mounting sensors in the top headliner of a vehicle to not substantially project into said vehicle interior;

b) a plurality of ultrasound 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 selected from;

i) an occupancy Head-zone extending downwardly from said headliner to about the vertical mid-point of the back of a seat in said vehicle;

ii) a Keep-Out zone forwardly of said Head-zone above a seat in said vehicle and adjacent a front dashboard in said vehicle; and

iii) a side Keep-Out zone above a seat in said vehicle and extending from a side of said vehicle interior to an adjacent side of a vehicle seat; and

d) wherein each individual transducer is both the emitter of pulses and receiver of the echoes of the respective pulses emitted by said individual transducer, said array excludes a separate receiver-only device, and an array in which transducers are paired and the transducers of each pair are aimed to have intersecting center axes is disclaimed.

19. An improved sensor system as in claim 18, wherein at least one of said ultrasound transducers is a piezoelectric transducer sensor.

20. An improved sensor system as in claim 18, wherein said the transducers of said spaced array are mounted in a generally straight line on said board.

21. An improved sensor system as in claim 18, wherein said defined zone is said occupancy Head-zone.

22. An improved sensor system as in claim 18, wherein said defined zone is one of said Keep-Out zones.

23. An improved sensor system as in claim 18, wherein said transducers are mounted on said board in a spaced array angled to provide coverage in at least two of said defined zones in said vehicle.