EP0620448A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Position and orientation measurement
Assignee: Polhemus Inc
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Filing: 1994-04-08
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Granted: —
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Expires: 2014-04-08
Abstract
Abstract A remote object position and orientation determining system employs electromagnetic coupling to sense the position and orientation of a remote object. A plurality of electromagnetic fields are generated having steady state components by applying time-division multiplexed pulsed DC signals to a plurality of field generating elements having spatially independent components defining a source reference coordinate frame. In this manner, the fields are distinguishable from one another. The generated electromagnetic fields are sensed with a remote sensor having a plurality of passive field-sensing elements having spatially independent elements in order to detect the rate-of-change of each of the generated electromagnetic fields. The output of the remote sensors are integrated in order to establish the steady state components of the generated electromagnetic fields. The steady state components are resolved into remote object position and orientation relative to the source reference coordinate frame.
Inventors
- 👤 Peter Traneus Anderson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-10 01:16
CPC Classifications
G; G01; G01S; G01S5/00; G01S5/02; G01S5/0247
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
156 words
An apparatus for determining the position and orientation of a remote object relative to a reference coordinate frame comprising: a source having a plurality of field generating elements that are adapted to generate electromagnetic fields, the field generating elements having spatially independent components defining a source reference coordinate frame; a driver that is adapted to apply to the plurality offield generating elements, signals which generate a plurality of electromagnetic fields, the electromagnetic fields being distinguishable from one another; a remote sensor having a plurality of field sensing elements that are adapted to sense each of the generated electromagnetic fields, the sensing elements having spatially independent components; and a processor, including an integrator arranged to integrate the sensed electromagnetic fields in order to establish the steady state components of the generated electromagnetic field, the processor being adapted to process the output of the sensor into remote object position and orientation relative to the source reference coordinate frame.
Claim 2
Independent Claim
156 words
An apparatus for determining the position and orientation of a remote object relative to a reference coordinate frame comprising: a source having a plurality of field generating elements that are adapted to generate electromagnetic fields, the field generating elements having spatially independent components defining a source reference coordinate frame; a driver that is adapted to apply to the plurality offield generating elements, signals which generate a plurality of electromagnetic fields, the electromagnetic fields being distinguishable from one another; a remote sensor having a plurality of field sensing elements that are adapted to sense each of the generated electromagnetic fields, the sensing elements having spatially independent components; and a processor, including an integrator arranged to integrate the sensed electromagnetic fields in order to establish the steady state components of the generated electromagnetic field, the processor being adapted to process the output of the sensor into remote object position and orientation relative to the source reference coordinate frame.
Claim 3
Dependent Claim
55 words
Apparatus as claimed in claim 1 in which the processor includes the integrator which is adapted to integrate the output of at least one of the sensing elements in order to produce an integral of the or each output and a calculator that is adapted to calculate remote object position and orientation from the integral(s).
Claim 4
Dependent Claim
38 words
Apparatus in claim 1 or 2, wherein the driver generates pulsed-DC signals that are applied sequentially to the field generating elements, defining a field generation cycle, whereby the electromagnetic fields have steady state components and are time-division multiplexed.
Claim 5
Dependent Claim
16 words
Apparatus as claimed in claim 3, wherein the integration is performed over one field generation cycle.
Claim 6
Dependent Claim
24 words
Apparatus as claimed in claim 3 or 4, wherein the processor samples the integral approximately at the end of each of the pulsed-DC signals.
Claim 7
Dependent Claim
25 words
Apparatus as claimed in claim 3, 4 or 5, wherein the processor samples the integral a plurality of times during each of the pulsed-DC signals.
Claim 8
Dependent Claim
28 words
Apparatus as claimed in claim 3,4,5 or 6, wherein the processor resets the integrator after a given period and samples the integral before and after resetting the integrator.
Claim 9
Dependent Claim
24 words
Apparatus as claimed in claim 3,4,5,6 or 7, wherein the signal integrator is adapted to integrate the outputs of all of the sensing elements.
Claim 10
Dependent Claim
27 words
Apparatus as claimed in any preceding claim, wherein each of the field sensing elements is a passive sensor that responds to the rate-of-change of the electromagnetic fields.
Claim 11
Dependent Claim
176 words
Apparatus as claimed in claim 7 wherein the processor calculates remote position and orientation from a matrix S where where XsrcXsen = AD(XSRC,Xinteg) - .75 AD(RESET,Xinteg) - .25 AD(NOSRC,Xinteg) XsrcYsen = AD(XSRC,Yinteg) - .75 AD(RESET,Yinteg) - .25 AD(NOSRC,Yinteg) XsrcZsen = AD(XSRC,Zinteg) - .75 AD(RESET,Zinteg) - .25 AD(NOSRC,Zinteg) YsrcXsen = AD(YSRC,Xinteg) - .50 AD(RESET,Xinteg) - .50 AD(NOSRC,Xinteg) YsrcYsen = AD(YSRC,Yinteg) - .50 AD(RESET,Yinteg) - .50 AD(NOSRC,Yinteg) YsrcZsen = AD(YSRC,Zinteg) - .50 AD(RESET,Zinteg) - .50 AD(NOSRC,Zinteg) ZsrcXsen = AD(ZSRC,Xinteg) - .25 AD(RESET,Xinteg) - .75 AD(NOSRC,Xinteg) ZsrcYsen = AD(ZSRC,Yinteg) - .25 AD(RESET,Yinteg) - .75 AD(NOSRC,Yinteg) ZsrcZsen = AD(ZSRC,Zinteg) - .25 AD(RESET,Zinteg) - .75 AD(NOSRC,Zinteg) and where, for X, Y and Z sources and X, Y and Z sensor integrators, AD (iSRC, jinteg) is the sampled integrator value for the jth sensor integrator; while the ith source is transmitting, AD (RESET, jinteg) is the sampled integrator value for the jth sensor integrator during an integrator reset interval, and AD (NOSRC, jinteg) is the sampled integrator value for the jth sensor integrator during an interval when no transmission source is transmitting.
Claim 12
Dependent Claim
21 words
Apparatus as claimed in any of claims 1 to 10 wherein each of the field sensing elements is a dipole antenna.
Claim 13
Independent Claim
102 words
A method of determining the position and orientation of a remote object relative to a reference coordinate frame comprising: generating a plurality of electromagnetic fields in a source reference coordinate frame, the fields having spatially independent components and being distinguishable from one another; sensing the generated electromagnetic fields with a remote sensor having a plurality of field sensing elements, the sensing elements having spatially independent components in order to detect each of the generated electromagnetic fields; integrating the sensed electromagnetic fields; and processing the output of the remote sensor into remote object position and orientation relative to the source reference coordinate frame.
Claim 14
Independent Claim
102 words
A method of determining the position and orientation of a remote object relative to a reference coordinate frame comprising: generating a plurality of electromagnetic fields in a source reference coordinate frame, the fields having spatially independent components and being distinguishable from one another; sensing the generated electromagnetic fields with a remote sensor having a plurality of field sensing elements, the sensing elements having spatially independent components in order to detect each of the generated electromagnetic fields; integrating the sensed electromagnetic fields; and processing the output of the remote sensor into remote object position and orientation relative to the source reference coordinate frame.
Claim 15
Dependent Claim
37 words
A method as claimed in claim 12, including integrating the output of the field sensor over a given period of time in order to produce the integral and resolving the integral into remote object position and orientation.
Claim 16
Dependent Claim
45 words
A method as claimed in claim 12 or 13, wherein the generating includes applying pulsed-DC signals sequentially to a plurality of field generator elements having spatially independent components, defining a field generation cycle, whereby the electromagnetic fields have steady state components and are time-division multiplexed.
Claim 17
Dependent Claim
28 words
A method of claim 14 wherein the processing includes integrating the output of the field sensor over a given period of time that is one field generation cycle.
Claim 18
Dependent Claim
24 words
A method of claim 14 or 15, wherein the processing includes sampling the integral approximately at the end of each of the pulsed-DC signals.
Claim 19
Dependent Claim
26 words
A method as claimed in claim 14,15 or 16, wherein the processing includes sampling the integral a plurality of times during each of the pulsed-DC signals.
Claim 20
Dependent Claim
22 words
A method as claimed in claim 14, 15, 16 or 17, wherein the processing includes resetting the integral after the given period.
Claim 21
Dependent Claim
16 words
A method as claimed in claim 18, including sampling the integral before and after the resetting.
Claim 22
Independent Claim
29 words
A method as claimed in any of claims 12 to 19, wherein the sensing includes use of passive sensing elements that respond to the rate-of-change of the electromagnetic fields.
Claim 23
Dependent Claim
175 words
A method as claimed in claim 19, wherein the resolving includes calculating remote position and orientation from a matrix S where where XsrcXcen = AD(XSRC,Xinteg) - .75 AD(RESET,Xinteg) - .25 AD(NOSRC,Xinteg) XsrcYsen = AD(XSRC,Yinteg) - .75 AD(RESET,Yinteg) - .25 AD(NOSRC,Yinteg) XsrcZsen = AD(XSRC,Zinteg) - .75 AD(RESET,Zinteg) - .25 AD(NOSRC,Zinteg) YsrcXsen = AD(YSRC,Xinteg) - .50 AD(RESET,Xinteg) - .50 AD(NOSRC,Xinteg) YsrcYsen = AD(YSRC,Yinteg) - .50 AD(RESET,Yinteg) - .50 AD(NOSRC,Yinteg) YsrcZsen = AD(YSRC,Zinteg) - .50 AD(RESET,Zinteg) - .50 AD(NOSRC,Zinteg) ZsrcXsen = AD(ZSRC,Xinteg) - .25 AD(RESET,Xinteg) - .75 AD(NOSRC,Xinteg) ZsrcYsen = AD(ZSRC,Yinteg) - .25 AD(RESET,Yinteg) - .75 AD(NOSRC,Yinteg) ZsrcZsen = AD(ZSRC,Zinteg) - .25 AD(RESET,Zinteg) - .75 AD(NOSRC,Zinteg) and where, for X, Y and Z sources and X, Y and Z sensor integrators, AD(iSRC, jinteg) is the sampled integrator value for the jth sensor integrator; while the ith source is transmitting, AD(RESET, jinteg) is the sampled integrator value for the jth sensor integrator during an integrator reset interval, and AD(NOSRC, jinteg) is the sampled integrator value for the jth sensor integrator during an interval when no transmission source is transmitting.
References Cited (Backward Citations)
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