Methods for controlling a system in a vehicle using a transmitting/receiving transducer and/or while compensating for thermal gradients

• US 20010020777A1
• Filed: 04/06/2001
• Published: 09/13/2001
• Est. Priority Date: 06/09/1998
• Status: Active Grant

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Automotive Technologies International Incorporated
• Inventors: Breed, David S., Johnson, Wendell C., Du Vall, Wilbur E.
• Granted Patent: US 6,517,107 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

Abstract

Methods for controlling a vehicle system in which radiation is directed from a transducer into the passenger compartment and is reflected off or modified by an object in the passenger compartment and received by the same or a different transducer. When ultrasonic waves are used, one or more techniques are used to compensate for thermal gradients in the passenger compartment and/or enable the use of a single transducer to send and receive waves, for example, a tubular mounting structure for the transducers, electronic reduction of ringing of the transducer, mechanical damping of the transducer cone, shaped horns, grills and reflectors for the output of the transducers to precisely control the beam pattern, a logarithmic compression amplifier, a temperature compensation method based on change in transducer properties with temperature and/or a dual level network, one level for categorization and the second for occupant position sensing.

Claims

1. In a motor vehicle having an interior passenger compartment for enclosing at least one occupying item having surfaces, a method for controlling a system in the vehicle based on the at least one occupying item comprising the steps of:

irradiating at least a portion of the passenger compartment in which the at least one occupying item is situated;

receiving reflected radiation from the surfaces of the at least one occupying item within the passenger compartment at a receiver;

processing the received radiation in order to create at least one electronic signal containing information of the distance from at least one of the surfaces of the at least one occupying item to the receiver; and

selectively amplifying the at least one signal by means of an amplifier whereby the magnitude of at least one larger peak in the at least one signal is reduced relative to the magnitude of at least one smaller peak in the at least one signal, the system in the vehicle being controlled based on the amplified at least one signal.

2. The method of

claim 1

wherein the amplifier is a log compression amplifier.

3. The method of

claim 1

, further comprising the step of:

starting the amplifier only after the transducer is driven to emit waves.

4. The method of

claim 1

, wherein the at least a portion of the passenger compartment is irradiated by a first transducer, further comprising the step of:

electronically reducing motion of a vibrating element of the first transducer to reduce ringing of the transducer.

5. The method of

claim 4

, wherein the step of electronically reducing the motion of the vibrating element of the first transducer comprises the steps of arranging a second transducer for measuring output of the first transducer and obtaining information from the second transducer to enable electronic circuitry to reduce the motion of the vibrating element of the first transducer.

6. The method of

claim 5

, further comprising the step of:

directing the first transducer vibrating element to move opposite to its measured motion after a driving phase with a view toward stopping motion of the first transducer.

7. The method of

claim 4

, wherein the step of electronically reducing the motion of the vibrating element of the transducer comprises the steps of:

determining a natural frequency of the first transducer,

tuning drive circuitry of the first transducer to drive the first transducer at the determined natural frequency, and

deriving a sequence of pulses to be fed into the drive circuitry with reversed polarity to counteract the motion of the first transducer and diminish oscillations of the first transducer.

8. The method of

claim 1

, wherein the receiver is a transducer which irradiates the at least a portion of the passenger compartment, further comprising the step of:

arranging the transducer in a tube having an opening.

9. The method of

claim 8

, further comprising the step of:

determining a length of the tube based on the distance required for ringing of the transducer to subside and a predetermined minimum target sensing distance defined as a distance between the opening of the tube and a position closest to the tube in which the at least one occupying item may be sensed.

10. The method of

claim 8

, further comprising the step of:

selecting a size of the opening of the tube and a diameter of the tube to avoid excessive signal loss and ensure reception of the reflected waves by the transducer.

11. The method of

claim 8

, further comprising the step of:

recessing the tube within a surface defining the passenger compartment.

12. The method of

claim 8

, further comprising the step of:

selecting a size of a diameter of the tube to avoid excessive signal loss.

13. The method of

claim 8

, wherein the tube includes a shaped horn adjacent the opening of tube.

14. The method of

claim 13

, wherein the opening of the tube is elliptical.

15. The method of

claim 2

, wherein the log compression amplifier includes diodes, farther comprising the step of:

stabilizing the log compression amplifier by maintaining the diodes at a substantially constant temperature.

16. The method of

claim 2

, wherein the log compression amplifier includes resistors, further comprising the step of:

adjusting the amount of compression provided by the log compression amplifier by controlling the resistance of the resistors.

17. A method for generating a neural network for determining the position of an object in a vehicle, comprising the steps of:

conducting a plurality of data generation steps, each of said data generating steps comprising the steps of

placing an object in the passenger compartment of the vehicle,

irradiating at least a portion of the passenger compartment in which the object is situated,

receiving reflected radiation from the object at a receiver,

forming a data set of a signal representative of the reflected radiation from the object, the distance from the object to the receiver and the temperature of the passenger compartment between the object and the receiver,

changing the temperature of the air between the object and the receiver, and

performing the irradiation step, radiation receiving step and data set forming step for the object at different temperatures between the object and the receiver; and

generating a pattern recognition algorithm from the data sets such that upon operational input of a signal representative of reflected radiation from the object, the algorithm provides an approximation of the distance from the object to the receiver.

18. The method of

claim 17

, wherein the algorithm is a neural network.

19. The method of

claim 17

, wherein the step of conducting a plurality of data generation steps further comprises the step of placing different objects in the passenger compartment and then performing the irradiation step, the radiation receiving step and temperature changing step for different objects, the identity of the object being included in the data set such that upon operational input of a signal representative of reflected radiation from the object, the algorithm provides an approximation of the identity of the object.

20. The method of

claim 19

, wherein the step of conducting a plurality of data generation steps further comprises the step of placing the different objects in different positions in the passenger compartment and then performing the irradiation step, the radiation receiving step and temperature changing step for the different objects in the different positions, the identity and position of the object being included in the data set such that upon operational input of a signal representative of reflected radiation from the object, the algorithm provides an approximation of the identity and position of the object.

21. The method of

claim 17

, wherein the step of conducting a plurality of data generation steps further comprises the step of placing the object in different positions in the passenger compartment and then performing the irradiation step, the radiation receiving step and temperature changing step for the object in the different positions, the position of the object being included in the data set such that upon operational input of a signal representative of reflected radiation from the object, the algorithm provides an approximation of the position of the object.

22. The method of

claim 17

, wherein the step of changing the temperature of the air comprises the step of dynamically changed the temperature of the air by introducing a flow of blowing air at a different temperature than the ambient temperature of the passenger compartment.

23. The method of

claim 22

, further comprising the step of

creating the blowing air flow by operating a vehicle heater or air conditioner of the vehicle.

24. The method of

claim 17

, wherein the step of changing the temperature of the air comprises the step of changing the temperature of the air by creating a temperature gradient between a top and a bottom of the passenger compartment.

25. A method for identifying an object in a passenger compartment of a vehicle, comprising the steps of:

mounting a plurality of wave-emitting and receiving transducers on the vehicle, each transducer being arranged to transmit and receive waves at a different frequency,

controlling the transducers to simultaneously transmit waves at the different frequencies into the passenger compartment, and

identifying the object based on the waves received by at least some of the transducers after being modified by passing through the passenger compartment.

26. The method of

claim 25

, further comprising the step of

determining the spacing between the frequencies of the waves transmitted and received by the transducers to reduce the possibility of each transducer receiving waves transmitted by another transducer.

27. The method of

claim 25

, further comprising the step of

determining the position of the object based on the waves received by at least some of the transducers after being modified by passing through the passenger compartment.

28. The method of

claim 25

, wherein the transducers are ultrasonic transducers.

29. The method of

claim 28

, further comprising the step of:

electronically reducing motion of a respective vibrating element of at least one of the transducers to reduce ringing of the transducer.

30. The method of

claim 28

, further comprising the step of

mounting at least one of the transducers in a respective tube having an opening through which the waves are transmitted and received.

31. The method of

claim 25

, wherein the transducers of different frequency transmit and receive substantially simultaneously.

32. In combination, a vehicle and an arrangement for identifying an object in a passenger compartment of the vehicle, the arrangement comprising:

a plurality of wave-emitting and receiving transducers mounted on the vehicle, each transducer being arranged to transmit and receive waves at a different frequency, and

a processor coupled to said transducers for controlling said transducers to simultaneously transmit waves at the different frequencies into the passenger compartment and receiving signals representative of the waves received by said transducers after being modified by passing through the passenger compartment, said processor being arranged to identify the object based on the signals representative of the waves received by at least some of said transducers.

33. The arrangement of

claim 32

, wherein said processor is arranged to determine the position of the object based on the signals representative of the waves received by at least some of the transducers.

34. The arrangement of

claim 32

, wherein said transducers are ultrasonic transducers.

35. The arrangement of

claim 34

, wherein at least one of said transducers is arranged in a tube having an opening through which the waves are transmitted and received.

36. A method for determining the position of an object in a passenger compartment of a vehicle, comprising the steps of:

mounting a plurality of wave-emitting and receiving transducers on the vehicle, each transducer being arranged to transmit and receive waves at a different frequency,

controlling the transducers to simultaneously transmit waves at the different frequencies into the passenger compartment, and

determining the position of the object based on the waves received by the transducers after being modified by passing through the passenger compartment.

37. The method of

claim 36

, further comprising the step of

determining the spacing between the frequencies of the waves transmitted and received by the transducers to reduce the possibility of each transducer receiving waves transmitted by another transducer.

38. The method of

claim 36

, further comprising the step of

identifying the object based on the waves received by at least some of the transducers after being modified by passing through the passenger compartment.

39. The method of

claim 36

, wherein the transducers are ultrasonic transducers.

40. The method of

claim 39

, further comprising the step of:

electronically reducing motion of a respective vibrating element of at least one of the transducers to reduce ringing of the transducer.

41. The method of

claim 39

, further comprising the step of

mounting at least one of the transducers in a respective tube having an opening through which the waves are transmitted and received.

42. In combination, a vehicle and an arrangement for determining the position of an object in a passenger compartment of the vehicle, the arrangement comprising:

a plurality of wave-emitting and receiving transducers mounted on the vehicle, each transducer being arranged to transmit and receive waves at a different frequency, and

a processor coupled to said transducers for controlling said transducers to simultaneously transmit waves at the different frequencies into the passenger compartment and receiving signals representative of the waves received by said transducers after being modified by passing through the passenger compartment, said processor being arranged to determine the position of the object based on the signals representative of the waves received by at least some of the transducers.

43. The arrangement of

claim 42

, wherein said processor is arranged to identify the object based on the signals representative of the waves received by at least some of said transducers.

44. The arrangement of

claim 42

, wherein said transducers are ultrasonic transducers.

45. A method for controlling deployment of an occupant restraint device based on the position of an object in a passenger compartment of a vehicle, comprising the steps of:

mounting a plurality of wave-emitting and receiving transducers on the vehicle, each transducer being arranged to transmit and receive waves at a different frequency,

controlling the transducers to simultaneously transmit waves at the different frequencies into the passenger compartment,

determining whether the object is of a type requiring deployment of the occupant restraint device in the event of a crash involving the vehicle based on the waves received by at least some of the transducers after being modified by passing through the passenger compartment, and if so,

determining whether the position of the object relative to the occupant restraint device would cause injury to the object upon deployment of the occupant restraint device based on the waves received by at least some of the transducers.

46. The method of

claim 45

, further comprising the step of

identifying the object based on the waves received by at least some of the transducers after being modified by passing through the passenger compartment.

47. The method of

claim 45

, wherein the transducers are ultrasonic transducers.

48. The method of

claim 47

, further comprising the step of:

electronically reducing motion of a respective vibrating element of at least one of the transducers to reduce ringing of the transducer.

49. The method of

claim 47

, further comprising the step of

mounting at least one of the transducers in a respective tube having an opening through which the waves are transmitted and received.

50. The method of

claim 45

, wherein the step of determining whether the object is of a type requiring deployment of the occupant restraint device comprises the step of training a first neural network on signals from at least some of the transducers representative of waves received by the transducers when different objects are situated in the passenger compartment.

51. The method of

claim 50

, wherein the step of determining whether the position of the object relative to the occupant restraint device would cause injury to the object upon deployment of the occupant restraint device comprises the step of training a second neural network on signals from at least some of the transducers when different objects in different positions are situated in the passenger compartment.

52. A method for categorizing and determining the position of an object in a passenger compartment of a vehicle, comprising the steps of:

mounting a plurality of wave-receiving transducers on the vehicle,

training a first neural network on signals from at least some of the transducers representative of waves received by the transducers when different objects in different positions are situated in the passenger compartment such that the first neural network provides an output signal indicative of the categorization of the object, and

training a second neural network on signals from at least some of said transducers representative of waves received by the transducers when different objects in different positions are situated in the passenger compartment such that the second neural network provides an output signal indicative of the position of the object.

53. The method of

claim 52

, further comprising the step of

controlling the transducers to transmit and receive waves each at a different frequency.

54. The method of

claim 52

, further comprising the step of

mounting at least one of the transducers in a respective tube having an opening through which the waves are transmitted and received.