Patent US6176837B1 successfully refreshed from Google Patents.
US6176837B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motion tracking system
Assignee: Massachusetts Institute of Technology
•
Filing: 1998-04-17
•
Granted: 2001-01-23
•
Expires: 2018-04-17
Abstract
Abstract Tracking a motion of a body by obtaining two types of measurements associated with the motion of the body, one of the types including acoustic measurement. An estimate of either an orientation or a position of the body is updated based on one of the two types of measurement, for example based on inertial measurement. The estimate is then updated based on the other of the two types of measurements, for example based on acoustic ranging. The invention also features determining range measurement to selected reference devices that are fixed in the environment of the body.
Inventors
- 👤 Eric M. Foxlin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:06
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/87; G01C; G01C21/00; G01C21/10; G01C21/12; G01C21/16; G01C21/165; G01C21/1652; G01S11/00; G01S11/16; G01S15/86; G01S5/00; G01S5/18; G01S5/186; A; A61; A61B; A61B5/00; A61B5/103; A61B5/1036; A61B5/1038
Claims Analysis
Total Claims: 61
Claim 1
Independent Claim
87 words
A method for tracking a motion of a body comprising: obtaining three types of measurements associated with the motion of the body, a first type comprising acoustic measurement, a second type comprising linear inertial measurement, and a third type comprising angular inertial measurement; updating an estimate of a position of the body based on the second type of measurement; updating the position estimate based on the first type of measurement; and updating an estimate of an orientation of the body based on the third type of measurement.
Claim 2
Independent Claim
87 words
A method for tracking a motion of a body comprising: obtaining three types of measurements associated with the motion of the body, a first type comprising acoustic measurement, a second type comprising linear inertial measurement, and a third type comprising angular inertial measurement; updating an estimate of a position of the body based on the second type of measurement; updating the position estimate based on the first type of measurement; and updating an estimate of an orientation of the body based on the third type of measurement.
Claim 3
Dependent Claim
15 words
The method of claim 1 in which the first type of measurement comprises acoustic ranging.
Claim 4
Dependent Claim
20 words
The method of claim 1 in which the estimate of orientation is undated based on the first type of measurement.
Claim 5
Independent Claim
106 words
An apparatus for tracking motion of a body comprising: three sensor systems configured respectively to obtain three types of measurements associated with motion of the body, a first type comprising acoustic measurement, a second type comprising linear inertial measurement and a third type comprising angular inertial measurement; and a processor coupled to the three sensor systems and configured to update an estimate of a position of the body based on the second type of measurement, to update the position estimate based on the the first type of measurement, and to update an estimate of an orientation of the body based on the third type of measurement.
Claim 6
Independent Claim
106 words
An apparatus for tracking motion of a body comprising: three sensor systems configured respectively to obtain three types of measurements associated with motion of the body, a first type comprising acoustic measurement, a second type comprising linear inertial measurement and a third type comprising angular inertial measurement; and a processor coupled to the three sensor systems and configured to update an estimate of a position of the body based on the second type of measurement, to update the position estimate based on the the first type of measurement, and to update an estimate of an orientation of the body based on the third type of measurement.
Claim 7
Dependent Claim
100 words
A tracking device comprising: a sensor system including an inertial sensor; and a set of one or more acoustic sensors rigidly coupled to the inertial sensor; and a processor programmed to perform the functions of accepting inertial measurements from the inertial sensor; updating a location estimate and an orientation estimate of the sensor system using the accepted inertial measurements; selecting one of a plurality of acoustic reference devices; accepting an acoustic range measurement related to the distance between the sensor system and the selected acoustic reference device; updating the location estimate and the orientation estimate using the accepted range measurement.
Claim 8
Dependent Claim
100 words
A tracking device comprising: a sensor system including an inertial sensor; and a set of one or more acoustic sensors rigidly coupled to the inertial sensor; and a processor programmed to perform the functions of accepting inertial measurements from the inertial sensor; updating a location estimate and an orientation estimate of the sensor system using the accepted inertial measurements; selecting one of a plurality of acoustic reference devices; accepting an acoustic range measurement related to the distance between the sensor system and the selected acoustic reference device; updating the location estimate and the orientation estimate using the accepted range measurement.
Claim 9
Dependent Claim
44 words
The tracking device of claim 5 wherein the sensor system includes a transmitter for transmitting a control signal encoding an identifier of the selected acoustic reference device, and each acoustic sensor includes a microphone for receiving an acoustic signal from the acoustic reference device.
Claim 10
Dependent Claim
22 words
The tracking device of claim 5 , wherein the set of one or more acoustic sensors includes two or more acoustic sensors.
Claim 11
Dependent Claim
77 words
The tracking device of claim 5 , wherein the processor is configured to update a location estimate and an orientation estimate using the accepted inertial measurements by updating an uncertainty in the location and the orientation estimates; and update the location estimate and the orientation estimate using the accepted range measurement by determining an uncertainty in the range measurement and updating the uncertainty in the location and the orientation estimates using the uncertainty in the range measurement.
Claim 12
Independent Claim
66 words
A method for tracking the motion of a body including: selecting one of a plurality of reference devices; transmitting a control signal to the selected reference device; receiving a range measurement signal from the reference device; accepting a range measurement related to a distance to the selected reference device; and updating a location estimate or an orientation estimate of the body using the accepted range measurement.
Claim 13
Independent Claim
66 words
A method for tracking the motion of a body including: selecting one of a plurality of reference devices; transmitting a control signal to the selected reference device; receiving a range measurement signal from the reference device; accepting a range measurement related to a distance to the selected reference device; and updating a location estimate or an orientation estimate of the body using the accepted range measurement.
Claim 14
Dependent Claim
23 words
The method of claim 9 , further comprising: determining a range measurement based on a time of flight of the range measurement signal.
Claim 15
Dependent Claim
22 words
The method of claim 10 further comprising: determining a range measurement based on a time of flight of the range measurement signal.
Claim 16
Dependent Claim
16 words
The method of claim 10 wherein transmitting the control signal includes transmitting a wireless control signal.
Claim 17
Dependent Claim
74 words
Software stored on a computer readable medium comprising instructions for causing a computer to perform the functions of: selecting one of a plurality of reference devices; transmitting a control signal to the selected reference device; receiving a range measurement signal from the reference device; accepting a range measurement related to a distance to the selected reference device; and updating a location estimate or an orientation estimate of the body using the accepted range measurement.
Claim 18
Dependent Claim
74 words
Software stored on a computer readable medium comprising instructions for causing a computer to perform the functions of: selecting one of a plurality of reference devices; transmitting a control signal to the selected reference device; receiving a range measurement signal from the reference device; accepting a range measurement related to a distance to the selected reference device; and updating a location estimate or an orientation estimate of the body using the accepted range measurement.
Claim 19
Dependent Claim
117 words
A tracking system comprising: an acoustic reference system including a plurality of acoustic reference devices; and a tracking device including a sensor system including an inertial sensor and a set of one or more acoustic sensors rigidly coupled to the inertial sensor, and a processor programmed to perform the functions of accepting inertial measurements from the inertial sensor, updating a location estimate and an orientation estimate of the sensor system using the accepted inertial measurements, selecting one of a plurality of acoustic reference devices, accepting an acoustic range measurement related to the distance between the sensor system and the selected acoustic reference device, and updating the location estimate and the orientation estimate using the accepted range measurement.
Claim 20
Dependent Claim
117 words
A tracking system comprising: an acoustic reference system including a plurality of acoustic reference devices; and a tracking device including a sensor system including an inertial sensor and a set of one or more acoustic sensors rigidly coupled to the inertial sensor, and a processor programmed to perform the functions of accepting inertial measurements from the inertial sensor, updating a location estimate and an orientation estimate of the sensor system using the accepted inertial measurements, selecting one of a plurality of acoustic reference devices, accepting an acoustic range measurement related to the distance between the sensor system and the selected acoustic reference device, and updating the location estimate and the orientation estimate using the accepted range measurement.
Claim 21
Dependent Claim
70 words
The system of claim 14 wherein the sensor system includes a transmitter for transmitting a control signal encoding an identifier of the selected acoustic reference device, and each acoustic sensor includes a microphone for receiving an acoustic signal from the acoustic reference device, and wherein each acoustic reference device includes a receiver for receiving the control signal from the sensor system, and an acoustic transducer for sending the acoustic signal.
Claim 22
Dependent Claim
13 words
The system of claim 14 , further comprising more than three acoustic receivers.
Claim 23
Independent Claim
96 words
An apparatus for tracking motion of a body comprising: two sensor systems configured respectively to obtain two types of measurements associated with motion of the body, one of the types comprising acoustic measurement, wherein the sensor system for obtaining acoustic measurement comprises greater than three acoustic receivers; and a processor coupled to the two sensor systems and configured to update an estimate of either an orientation or a position of the body based on one of the two types of measurement, and to update the estimate based on the other of the two types of measurement.
Claim 24
Independent Claim
96 words
An apparatus for tracking motion of a body comprising: two sensor systems configured respectively to obtain two types of measurements associated with motion of the body, one of the types comprising acoustic measurement, wherein the sensor system for obtaining acoustic measurement comprises greater than three acoustic receivers; and a processor coupled to the two sensor systems and configured to update an estimate of either an orientation or a position of the body based on one of the two types of measurement, and to update the estimate based on the other of the two types of measurement.
Claim 25
Dependent Claim
16 words
The apparatus of claim 17 , wherein one of the types of measurement comprises acoustic ranging.
Claim 26
Dependent Claim
18 words
The apparatus of claim 17 , in which the other of the types of measurement comprises inertial measurement.
Claim 27
Dependent Claim
24 words
The apparatus of claim 17 in which the processor is configured to update an estimate of orientation based on the first type of measurement.
Claim 28
Dependent Claim
24 words
The apparatus of claim 20 in which the processor is configured to update an estimate of position based on the first type of measurement.
Claim 29
Independent Claim
57 words
A method for tracking the motion of a body including: selecting one of a plurality of reference devices; transmitting a control signal to the selected reference device; accepting a range measurement related to a distance to the selected reference device; and updating a location estimate or an orientation estimate of the body using the accepted range measurement.
Claim 30
Independent Claim
57 words
A method for tracking the motion of a body including: selecting one of a plurality of reference devices; transmitting a control signal to the selected reference device; accepting a range measurement related to a distance to the selected reference device; and updating a location estimate or an orientation estimate of the body using the accepted range measurement.
Claim 31
Dependent Claim
34 words
The method of claim 22 , further comprising: receiving a range measurement signal from the selected reference device; and determining a range measurement based on a time of flight of the range measurement signal.
Claim 32
Dependent Claim
17 words
The method of claim 22 , wherein transmitting the control signal includes transmitting a wireless control signal.
Claim 33
Dependent Claim
65 words
Software stored on a computer readable medium comprising instructions for causing a computer to perform the functions of: selecting one of a plurality of reference devices; transmitting a control signal to the selected reference device; accepting a range measurement related to a distance to the selected reference device; and updating a location estimate or an orientation estimate of the body using the accepted range measurement.
Claim 34
Dependent Claim
65 words
Software stored on a computer readable medium comprising instructions for causing a computer to perform the functions of: selecting one of a plurality of reference devices; transmitting a control signal to the selected reference device; accepting a range measurement related to a distance to the selected reference device; and updating a location estimate or an orientation estimate of the body using the accepted range measurement.
Claim 35
Dependent Claim
93 words
A tracking device comprising: a sensor system including an inertial sensor; and a set of one or more acoustic sensors rigidly coupled to the inertial sensor; and a processor programmed to perform the functions of accepting inertial measurements from the inertial sensor; updating a location or orientation estimate of the sensor system using the accepted inertial measurements; selecting one of a plurality of acoustic reference devices; accepting an acoustic range measurement related to the distance between the sensor system and the selected acoustic reference device; updating the estimate using the accepted range measurement.
Claim 36
Dependent Claim
93 words
A tracking device comprising: a sensor system including an inertial sensor; and a set of one or more acoustic sensors rigidly coupled to the inertial sensor; and a processor programmed to perform the functions of accepting inertial measurements from the inertial sensor; updating a location or orientation estimate of the sensor system using the accepted inertial measurements; selecting one of a plurality of acoustic reference devices; accepting an acoustic range measurement related to the distance between the sensor system and the selected acoustic reference device; updating the estimate using the accepted range measurement.
Claim 37
Dependent Claim
46 words
The tracking device of claim 26 , wherein the sensor system includes a transmitter for transmitting a control signal encoding an identifier of the selected acoustic reference device, and each acoustic sensor includes a microphone for receiving an acoustic signal from the selected acoustic reference device.
Claim 38
Dependent Claim
22 words
The tracking device of claim 26 , wherein the set of one or more acoustic sensors includes two or more acoustic sensors.
Claim 39
Dependent Claim
22 words
The tracking device of claim 26 , wherein the set of one or more acoustic sensors includes more than three acoustic sensors.
Claim 40
Dependent Claim
59 words
The tracking device of claim 26 , wherein the processor is configured to update the estimate using the accepted inertial measurements by updating an uncertainty in the estimate; and update the estimate using the accepted range measurement by determining an uncertainty in the range measurement and updating the uncertainty in the estimate using the uncertainty in the range measurement.
Claim 41
Dependent Claim
82 words
A tracking system for tracking the position of a body comprising: a sensor system comprising a plurality of acoustic receivers rigidly coupled to a portable assembly; and a plurality of acoustic reference devices arrayed at a distance from the portable assembly, wherein the acoustic receivers are arrayed on the portable assembly so that at least one of the acoustic receivers is positioned to receive signals from at least three of the acoustic reference devices regardless of the orientation of the portable assembly.
Claim 42
Dependent Claim
82 words
A tracking system for tracking the position of a body comprising: a sensor system comprising a plurality of acoustic receivers rigidly coupled to a portable assembly; and a plurality of acoustic reference devices arrayed at a distance from the portable assembly, wherein the acoustic receivers are arrayed on the portable assembly so that at least one of the acoustic receivers is positioned to receive signals from at least three of the acoustic reference devices regardless of the orientation of the portable assembly.
Claim 43
Dependent Claim
18 words
The tracking system of claim 31 , wherein the plurality of acoustic receivers comprises greater than 3 receivers.
Claim 44
Dependent Claim
40 words
The system of claim 32 , further comprising a processor programmed to select, based on the current orientation of the portable assembly, a subset of the acoustic receivers according to their ability to receive signals from the acoustic reference devices.
Claim 45
Dependent Claim
39 words
The tracking system of claim 31 , wherein for a majority of the orientations of the portable assembly, at least two of the acoustic receivers are positioned to receive signals from at least three of the acoustic reference devices.
Claim 46
Independent Claim
95 words
A method for tracking motion of a rigid body comprising: disposing a plurality of transducers in the environment; mounting a plurality of transducers on the body; measuring the range between a selected one of the transducers disposed in the environment and a selected one of the transducers mounted on the body; predicting a range measurement between the selected transducer in the environment and the selected transducers mounted on the body; updating an estimate of the orientation or position of the body based on the difference between the actual range measurement and the predicted range measurement.
Claim 47
Independent Claim
95 words
A method for tracking motion of a rigid body comprising: disposing a plurality of transducers in the environment; mounting a plurality of transducers on the body; measuring the range between a selected one of the transducers disposed in the environment and a selected one of the transducers mounted on the body; predicting a range measurement between the selected transducer in the environment and the selected transducers mounted on the body; updating an estimate of the orientation or position of the body based on the difference between the actual range measurement and the predicted range measurement.
Claim 48
Dependent Claim
26 words
The method of claim 35 , wherein the transducers disposed in the environment are acoustic emitters and the transducers mounted on the body are acoustic receivers.
Claim 49
Dependent Claim
26 words
The method of claim 35 , wherein the transducers disposed in the environment are acoustic receivers and the transducers mounted on the body are acoustic emitters.
Claim 50
Dependent Claim
26 words
The method of claim 35 , wherein the transducers disposed in the environment are optical emitters and the transducers mounted on the body are optical receivers.
Claim 51
Dependent Claim
26 words
The method of claim 35 , wherein the transducers disposed in the environment are optical receivers and the transducers mounted on the body are optical emitters.
Claim 52
Dependent Claim
28 words
The method of claim 35 , wherein the transducers disposed in the environment are radio frequency emitters and the transducers mounted on the body are radio frequency receivers.
Claim 53
Dependent Claim
28 words
The method of claim 35 , wherein the transducers disposed in the environment are radio frequency receivers and the transducers mounted on the body are radio frequency emitters.
Claim 54
Dependent Claim
57 words
The method of claim 35 , wherein at the transducers mounted on the body are disposed so that, in substantially all orientations of the rigid body, at least one of the transducers mounted on the body is positioned to be able to complete a range measurement with at least three of the transducers disposed in the environment.
Claim 55
Dependent Claim
33 words
The method of claim 42 , further comprising: selecting one of the transducers mounted on the body and obtaining a range measurement between it and one of the transducers disposed in the environment.
Claim 56
Independent Claim
84 words
A method for tracking a motion of a body comprising: obtaining two types of measurements associated with the motion of the body, a first type comprising range measurement, and a second type comprising inertial measurement; updating estimates of an orientation and a position of the body based on the second type of measurement; and updating the estimate of the position of the body based on the first type of measurement, without first calculating a position estimate based only on the first type of measurement.
Claim 57
Independent Claim
84 words
A method for tracking a motion of a body comprising: obtaining two types of measurements associated with the motion of the body, a first type comprising range measurement, and a second type comprising inertial measurement; updating estimates of an orientation and a position of the body based on the second type of measurement; and updating the estimate of the position of the body based on the first type of measurement, without first calculating a position estimate based only on the first type of measurement.
Claim 58
Dependent Claim
16 words
The method of claim 44 , in which the first type of measurement comprises acoustic ranging.
Claim 59
Dependent Claim
24 words
The method of claim 44 , further comprising updating the estimate of an orientation of the body based on the first type of measurement.
Claim 60
Independent Claim
73 words
A method for tracking a motion of a body comprising: obtaining two types of measurements associated with the motion of the body, a first type comprising range measurement, and a second type comprising angular inertial measurement; updating an estimate of an orientation of the body based on the second type of measurement; and updating the orientation estimate and an estimate of the position of the body based on the first type of measurement.
Claim 61
Independent Claim
73 words
A method for tracking a motion of a body comprising: obtaining two types of measurements associated with the motion of the body, a first type comprising range measurement, and a second type comprising angular inertial measurement; updating an estimate of an orientation of the body based on the second type of measurement; and updating the orientation estimate and an estimate of the position of the body based on the first type of measurement.
References Cited (Backward Citations)
US3630079A
Cited
US4315326A
Cited
US4408488A
Cited
US4928263A
Cited
US5412619A
Cited
US5645077A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-01-23 | 2004-07-24 | 2005-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-01-23 | 2008-07-24 | 2009-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-01-23 | 2012-07-24 | 2013-01-23 | $7700.00 | Window Closed / Lapsed |