Remote attitude and position indicating system

• US 6,456,567 B1
• Filed: 04/09/2001
• Issued: 09/24/2002
• Est. Priority Date: 04/10/2000
• Status: Expired due to Term

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Rakes, Lonny, Judkins, Eric, Schoess, Jeffrey Norman, Blevins, William Mark
• Primary Examiner(s): Pihulic, Daniel T.
• Application Number:
  US09/829,319
• Publication Number:
  US 20020031050A1
• Time in Patent Office: 533 Days
• Field of Search: 367/907, 367/96, 367/127, 342/67, 89/411.7, 235/404, 345/679, 356/147
• US Class Current: 367/127
• CPC Class Codes: F41G 3/02 using an independent line of sight
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: Y10S 367/907 Coordinate determination

Abstract

A method and apparatus using ultrasonic sensors for determination of the pointing vector described by two points separated in space in the coordinate frame of the measuring system. For measurement, acoustic signals are transmitted from two emitters whose spatially separated coordinates form the desired pointing vector. Three detectors, associated receiver electronics and software are required to compute six distinct spheres from the time of flight measurements. The intersection of the three spheres, associated with each emitter, describe the desired location in the detector coordinate system of that emitter. With the coordinates of each emitter, the pointing vector is computed using standard geometry. A reference is required to determine the time of flight of the signals to each detector. Another embodiment uses an active reflective technique, where the timing is obtained through round trip transmission and reception of the signal with a known fixed delay at the vector points.

Claims

1. A method for determining a position and orientation of an object, the method comprising the steps of:

providing two linearly aligned emitters on the object;

providing at least three non co-linear detectors in line of sight from the at least two linearly aligned emitters;

providing a system frame of reference;

transmitting a distinct signal from each of the at least two linearly aligned emitters;

receiving the distinct signals by each of the at least three non co-linear detectors;

deriving at least six time of flight measurements from the distinct signals to the at least three non co-linear detectors; and

computing the position and orientation of the object relative to the system frame of reference from the derived at least six time of flight measurements.

2. The method of claim 1 wherein the step of deriving at least six time of flight measurements comprises deriving a round trip time interval of each of the transmitted distinct signals.

3. The method of claim 2 further comprising factoring a known delay time for active electronics for re-transmitting the distinct signals back to each of the at least two linearly aligned emitters.

4. The method of claim 1 wherein the step of deriving at least six time of flight measurements comprises triggering a precision timer upon receipt of a timing signal transmitted simultaneously with each transmitted distinct signal.

5. The method of claim 1 further comprising the step of converting the time of flight measurements to distances.

6. A system for determining position and orientation of an object, the system comprising:

at least five acoustic transducers wherein at least three of said at least five acoustic transducers comprise non co-linear detectors and at least two of said at least five acoustic transducers comprise linear emitters affixed on the object;

a means for providing said system with a frame of reference;

a means for sending a distinct signal from each of said at least two linearly aligned emitters to said at least three detectors;

a means for receiving each said distinct signal by said non co-linear detectors;

a means for determining at least six time of flight measurements from said received distinct signals; and

a means for computing the position and orientation of the object from said at least six time of flight measurements relative to said frame of reference.

7. The invention of claim 6 wherein said frame of reference comprises a geodetic frame of reference.

8. The invention of claim 6 wherein said frame of reference comprises a known orientation of said at least three non co-linear detectors.

9. The invention of claim 6 wherein said frame of reference comprises a member from the group consisting of a global positioning system (GPS), an inertial navigation system (INS) and pitch/roll/heading sensors.

10. The invention of claim 6 wherein said at least five transducers comprise a range of frequency from 25 KHz to 200 KHz.

11. The invention of claim 6 wherein each of said at least six time of flight measurements comprise a time from transmission of said distinct signal by each of said at least two linearly aligned emitters to receipt of each of said distinct signals by each of said at least three non co-linear detectors.

12. The invention of claim 6 wherein each of said at least six time of flight measurements further comprise a timing circuit to measure a time between transmission of each of said distinct signals to receipt of said distinct signals by each of said non co-linear detectors.

13. The invention of claim 12 further comprising a timing reference on each transmitted distinct signal.

14. The invention of claim 6 wherein each of said at least six time of flight measurements comprise a round trip time interval for each distinct signal from said at least two linearly aligned emitters to each non co-linear detector minus electronic delays.

15. A system for determining a position and orientation of a mortar tube, the system comprising:

five acoustic transducers wherein two of said five acoustic transducers comprise linear emitters affixed to the mortar tube and three of said five transducers comprise non co-linear detectors positioned in a field of view of said emitters;

a means for providing said system a geodetic frame of reference;

a means for sending a distinct signal from each of said two linear emitters to said three non co-linear detectors;

a means for determining six time of flight measurements from said received distinct signals; and

a means for computing the position and orientation of the mortar tube from said six time of flight measurements relative to said frame of reference.

16. The invention of claim 15 wherein said frame of reference comprises a member from the group consisting of a global positioning system (GPS), an inertial navigation system (INS) and pitch/roll/heading sensors.

17. The invention of claim 15 wherein each of said six time of flight measurement comprise a time from transmission of said distinct signal by each of said two linear emitters to receipt of each of said distinct signals by each of said three non co-linear detectors.

18. The invention of claim 15 wherein each of said six time of flight measurements further comprise a timing circuit to measure a time between transmission of each of said distinct signals to receipt of said distinct signals by each of said non co-linear detectors.

19. The invention of claim 18 further comprising a timing reference on each transmitted distinct signal.

20. The invention of claim 15 wherein each of said six time of flight measurements comprise a round trip time interval for each distinct signal from said linear emitters to each said non co-linear detector minus electronic delays.