Method and apparatus for improved position, velocity, orientation or angular rate sensor

• US 7,268,727 B2
• Filed: 04/30/2004
• Issued: 09/11/2007
• Est. Priority Date: 04/30/2004
• Status: Expired due to Fees

• Current Assignee: Novariant Incorporated (Kubota Corporation)
• Original Assignee: Novariant Incorporated (Kubota Corporation)
• Inventors: Montgomery, Paul Yalden, Lawrence, David Gary
• Primary Examiner(s): Phan; Dao L.
• Application Number:
  US10/835,699
• Publication Number:
  US 20050242991A1
• Time in Patent Office: 1,229 Days
• Field of Search: 342/357.01, 342/357.06, 342/357.12, 342/357.14, 701/213, 701/215
• US Class Current: 342/357.36
• CPC Class Codes: G01S 19/15 Aircraft landing systems
• CPC Class Codes: G01S 19/35 Constructional details or hardware or software details of the signal processing chain
• CPC Class Codes: G01S 19/36 relating to the receiver frond end
• CPC Class Codes: G01S 19/39 the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
• CPC Class Codes: G01S 19/396 Determining accuracy or reliability of position or pseudorange measurements
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial

Abstract

A global navigation satellite system (GNSS) receiver system includes a processing unit; and one or more antenna units for receiving GNSS signals, each of the antenna units having a phase center; one or more inertial sensor units each positioned substantially adjacent the phase centers; and at least one communication channel between each antenna unit and the processing unit.

Claims

1. A global navigation satellite system (GNSS) receiver system associated with an object, comprising:

a processing unit; and

a plurality of antenna units for receiving GNSS signals, each of the antenna units including an antenna element, each of said antenna elements having a phase center;

one or more inertial sensor units each positioned substantially adjacent said phase centers; and

at least one communication channel between each antenna unit and said processing unit.

2. A GNSS receiver system in accordance with claim 1, wherein said processing unit determines at least one of a position, velocity, orientation, or angular rate of said object.

3. A GNSS receiver system in accordance with claim 1, wherein said processing unit uses data from said plurality of antenna units and data from said one or more inertial sensor units to determine at least one of a position, velocity, orientation, or angular rate of said object.

4. A GNSS receiver system in accordance with claim 3, wherein said plurality of antenna units includes GNSS signal tracking unit and a means for receiving an external reference signal.

5. A GNSS receiver system in accordance with claim 4, further comprising an external reference oscillator, wherein said external reference oscillator delivers a common reference signal to one or more of said antenna units.

6. A GNSS receiver system in accordance with claim 1, further comprising one or more RF coaxial cables coupling said processing unit and said plurality of antenna units, said processing unit further comprising a power supply, said one or more RF coaxial cables providing power to said plurality of antenna units.

7. A GNSS receiver system in accordance with claim 1, wherein inertial measurement data are transmitted via said at least one communications channel in at least one of analog or digital form.

8. A GNSS receiver system in accordance with claim 7, wherein an RF coaxial cable is used as said at least one communications channel.

9. A GNSS receiver system in accordance with claim 8, wherein GNSS data and inertial measurement data are transmitted from said plurality of antenna units using at least one of EDMA, TDMA or COMA modulation.

10. A GNSS receiver system in accordance with claim 7, wherein said at least one communications channel is bidirectional.

11. A GNSS receiver system in accordance with claim 3, wherein said object is substantially rigid.

12. A GNSS receiver system in accordance with claim 3, wherein said output of said plurality of antenna units and said output of said one or more inertial units are used for component level failure detection and isolation.

13. A GNSS receiver system in accordance with claim 3, wherein said output of said plurality of antenna units and said output of said one or more inertial units are used for GNSS carrier phase cycle slip detection and isolation.

14. A GNSS receiver system in accordance with claim 3, wherein said object comprises a plurality of substantially rigid bodies, articulated with respect to each other.

15. A GNSS receiver system in accordance with claim 3, wherein said object is substantially flexible.

16. A GNSS receiver system in accordance with claim 15, wherein said plurality of antenna units are used to determine flexibility of said oblect.

17. A GNSS receiver system in accordance with claim 3, wherein said object comprises a plurality of substantially rigid bodies.

18. A GNSS receiver system in accordance with claim 17, wherein said plurality of antenna units are attached to each of said substantially rigid bodies.

79. A GNSS receiver system in accordance with claim 1, each of the antenna units including a downconverter for receiving GNSS measurements from antenna elements.

19. An antenna unit for use in a global navigation satellite system (GNSS) receiver, comprising:

a GNSS antenna element having a phase center and a downconverter for receiving GNSS signals from the GNSS antenna element;

an integrated inertial sensor unit positioned substantially adjacent said phase center.

20. An antenna unit in accordance with claim 19, further comprising a communication channel interface for interfacing inertial measurements from said integrated inertial sensor unit to an external processing unit.

21. An antenna unit in accordance with claim 20, wherein said inertial measurements are provided in at least one of an analog or digital format.

22. An antenna unit in accordance with claim 20, wherein said communication channel interface comprises an RF coaxial cable interface, said RF coaxial cable interface configured to receive GNSS signals from said GNSS antenna element.

23. An antenna unit in accordance with claim 22, wherein said RF coaxial cable interface further comprises a power supply interface for powering said antenna unit.

24. An antenna unit in accordance with claim 22, further including a modulation unit for modulating said GNSS measurements and said inertial measurements to said RF coaxial cable interface using at least one of TDMA, CDMA, or FDMA modulation.

25. An antenna unit in accordance with claim 19, further including a GNSS signal tracking unit.

26. An antenna unit in accordance with claim 25, further including a reference oscillator interface for receiving an external reference oscillator signal.

27. A sensing method for use in a vehicle, comprising:

transmitting inertial sensor signals and global network satellite system (GNSS) signals from a plurality of integrated inertial-GNSS sensing units to a processing unit, the plurality of integrated-inertial GNSS sensing units comprising an antenna element having a phase center and an inertial measurement unit positioned substantially adjacent said phase center; and

using said inertial sensor signals and said GNSS signals at said processing unit to determine one or more of a position, velocity, orientation or angular rate of said vehicle.

28. A sensing method in accordance with claim 27, wherein said transmitting inertial sensor signals comprises transmitting via a communications channel in an analog or digital form.

29. A position, velocity, orientation or angular rate-sensing method in accordance with claim 28, wherein said communications channel comprises an RF coaxial cable and further comprising providing power from said processing unit to said at least one inertial measurement units via said RF coaxial cable.

30. A sensing method in accordance with claim 29, wherein said transmitting comprises transmitting said inertial sensor signals and global network satellite system (GNSS) signals via said RF coaxial cable using at least one of TDMA, FDMA, or CDMA techniques.

31. A sensing method in accordance with claim 27, further comprising executing GNSS signal tracking processing at said plurality of integrated inertial-GNSS sensing units and providing an external reference oscillator signal to at least one of said integrated inertial-GNSS sensing units.

32. A sensing method in accordance with claim 27, further comprising executing GNSS signal tracking processing at said plurality of integrated inertial-GNSS sensing units and providing a common external reference oscillator signal to a plurality of said integrated inertial-GNSS sensing units.

33. A method in accordance with claim 27, further comprising using said processing unit to determine flexibility of a body to which said plurality of integrated inertial-GNSS sensing units are attached.

34. A method in accordance with claim 27, further comprising said processing unit using inertial sensor signals from said inertial measurement unit and global network satellite system (GNSS) signals from said antenna element to detect failure of all other of said antenna elements and said inertial measurement units, respectively.

35. A method in accordance with claim 34, further comprising the step of isolating any said antenna element or said inertial measurement unit for which failure was detected.

36. A method in accordance with claim 34, further comprising the steps of GNSS carrier phase cycle slip detection and isolation.

80. A method in accordance with claim 27, further including using a downconverter at said plurality of integrated inertial-GNSS sensing units to receive GNSS measurements.

37. A global navigation satellite system (GNSS) receiver system associated with an object, comprising:

a processing unit; and

one or more antenna units for receiving GNSS signals, each of the antenna units having a phase center;

one or more inertial sensor units each positioned substantially adjacent said phase centers; and

at least one communication channel between each antenna unit and said processing unit;

wherein an antenna unit comprises a plurality of antenna elements mounted on a rigid substrate.

38. A GNSS receiver system in accordance with claim 37, wherein an antenna unit phase center comprises a phase center of a single antenna element.

39. A GNSS receiver system in accordance with claim 37, wherein said processing unit determines at least one of a position, velocity, orientation, or angular rate of said object.

40. A GNSS receiver system in accordance with claim 37, wherein said processing unit uses data from said one or more antenna units and data from said one or more inertial sensor units to determine at least one of a position, velocity, orientation, or angular rate of said object.

41. A GNSS receiver system in accordance with claim 40, wherein each of said one or more antenna units includes GNSS signal tracking unit and a means for receiving an external reference signal.

42. A GNSS receiver system in accordance with claim 41, further comprising an external reference oscillator, wherein said external reference oscillator delivers a common reference signal to each of said one or more antenna units.

43. A GNSS receiver system in accordance with claim 37, further comprising an RF coaxial cable coupling said processing unit and said one or more antenna units, said processing unit further comprising a power supply, said RF coaxial cable providing power to said one or more antenna units.

44. A GNSS receiver system in accordance with claim 37, wherein inertial measurement data are transmitted via said at least one communications channel in at least one of analog or digital form.

45. A GNSS receiver system in accordance with claim 44, wherein said RF coaxial cable is used as said at least one communications channel.

46. A GNSS receiver system in accordance with claim 45, wherein GNSS data and inertial measurement data are transmitted from said one or more antennas units using at least one of FDMA, TDMA or CDMA modulation.

47. A GNSS receiver system in accordance with claim 46, wherein said at least one communications channel is bidirectional.

48. A GNSS receiver system in accordance with claim 37, wherein said object is substantially rigid.

49. A GNSS receiver system in accordance with claim 39, wherein said output of said one or more antenna units and said output of said one or more inertial units are used for component level failure detection and isolation.

50. A GNSS receiver system in accordance with claim 39, wherein said output of said one or more antenna units and said output of said one or more inertial units are used for GNSS carrier phase cycle slip detection and isolation.

51. A GNSS receiver system in accordance with claim 39, wherein said object comprises a plurality of substantially rigid bodies, articulated with respect to each other.

52. A GNSS receiver system in accordance with claim 39, wherein said object is substantially flexible.

53. A GNSS receiver system in accordance with claim 52, wherein said one or more antenna units are used to determine the flexibility of said object.

54. A GNSS receiver system in accordance with claim 39, wherein said object comprises a plurality of substantially rigid bodies.

55. A GNSS receiver system in accordance with claim 54, wherein said one or more antenna units is attached to each of said substantially rigid bodies.

81. A GNSS receiver system in accordance with claim 37, each of the antenna units including a downconverter for receiving GNSS measurements from antenna elements.

56. An antenna unit for use in a global navigation satellite system (GNSS) receiver, comprising an integrated inertial sensor unit positioned substantially adjacent a phase center of said antenna unit, wherein said phase center comprises a geometric mean of phase centers of a plurality of antenna elements.

57. An antenna unit in accordance with claim 56, further comprising a communication channel interface for interfacing inertial measurements from said integrated inertial sensor unit to an external processing unit.

58. An antenna unit in accordance with claim 57, wherein said inertial measurements are provided in at least one of an analog or digital format.

59. An antenna unit in accordance with claim 57, wherein said communication channel interface comprises an RF coaxial cable interface, said RF coaxial cable interface configured to receive GNSS measurements from said GNSS antenna element.

60. An antenna unit in accordance with claim 59, wherein said RF coaxial cable interface further comprises a power supply interface for powering said antenna unit.

61. An antenna unit in accordance with claim 59, further including a modulation unit for modulating said GNSS measurements and said inertial measurements to said RF coaxial cable interface using at least one of TDMA, CDMA, or FDMA modulation.

62. An antenna unit in accordance with claim 56, further including a GNSS signal tracking unit.

63. An antenna unit in accordance with claim 62, further including a reference oscillator interface for receiving an external reference oscillator signal.

64. A sensing method for use in a vehicle, comprising:

transmitting inertial sensor signals and global network satellite system (GNSS) signals from at least one integrated inertial-GNSS sensing unit to a processing unit, the at least one integrated-inertial GNSS sensing unit having a phase center and an inertial measurement unit positioned substantially adjacent said phase center;

using said inertial sensor signals and said GNSS signals at said processing unit to determine one or more of a position, velocity, orientation or angular rate of said vehicle; and

wherein said phase center comprises a geometric mean of a phase center of a plurality of antenna elements.

65. A sensing method in accordance with claim 64, wherein said transmitting inertial sensor signals comprises transmitting via a communications channel in an analog or digital form.

66. A position, velocity, orientation or angular rate-sensing method in accordance with claim 64, wherein said communications channel comprises an RF coaxial cable and further comprising providing power from said processing unit to said at least one inertial measurement units via said RF coaxial cable.

67. A sensing method in accordance with claim 65, wherein said transmitting comprises transmitting said inertial sensor signals and global network satellite system (GNSS) signals via said RF coaxial cable using at least one of TDMA, FDMA, or CDMA techniques.

68. A sensing method in accordance with claim 64, further comprising executing GNSS signal tracking processing at said at least one integrated inertial-GNSS sensing unit and providing an extemal reference oscillator signal to said at least one integrated inertial-GNSS sensing unit.

69. A sensing method in accordance with claim 64, further comprising executing GNSS signal tracking processing at said at least one integrated inertial-GNSS sensing unit and providing a common external reference oscillator signal to a plurality of said at least one integrated inertial-GNSS sensing units.

70. A method in accordance with claim 64, further comprising using said processing unit to determine flexibility of a body to which said at least one integrated inertial-GNSS sensing unit is attached.

71. A method in accordance with claim 64, further comprising said processing unit using inertial sensor signals from said inertial measurement unit and global network satellite system (GNSS) signals from said antenna element to detect failure of all other of said antenna units and said inertial measurement units, respectively.

72. A method in accordance with claim 71, further comprising the step of isolating any said antenna unit or said inertial measurement unit for which failure was detected.

73. A method in accordance with claim 71, further comprising the step of detection and isolation of GNSS carrier phase cycle slip detection and isolation.

82. A method in accordance with claim 64, further including using a downconverter at said plurality of integrated inertial-GNSS sensing units to receive GNSS measurements.

74. A global navigation satellite system (GNSS) receiver system comprising:

a processing unit; and

a rulurality of antenna units for receiving GNSS signals, each of the antenna units including an antenna element, each of said antenna elements having a phase center;

a reference oscillator shared among all antenna units;

a plurality of inertial sensor units each associated with at least one of the antenna units and each substantially adjacent a corresponding phase center; and

at least one communication channel between each antenna unit and said processing unit;

at least one communication channel between each inertial sensor unit and said processing unit.

75. A GNSS receiver system in accordance with claim 74, wherein said inertial sensor units are substantially collocated with said GNSS antenna units.

76. A GNSS receiver system in accordance with claim 74, wherein said inertial units are mounted on several locations on a flexible body.

77. A GNSS receiver system in accordance with claim 74, wherein said inertial units are mounted on independently moving rigid bodies.

78. A GNSS receiver system in accordance with claim 74, wherein said inertial units are mounted on rigid bodies articulated with respect to each other.

83. A GNSS receiver system in accordance with claim 74, each of the antenna units including a downconverter for receiving GNSS measurements from antenna elements.