System for determining the spatial position and orientation of a body

• US 6,061,644 A
• Filed: 12/05/1997
• Issued: 05/09/2000
• Est. Priority Date: 12/05/1997
• Status: Expired due to Term

• Current Assignee: Northern Digital Inc. (Roper Technologies, Inc.)
• Original Assignee: Northern Digital Inc. (Roper Technologies, Inc.)
• Inventors: Leis, Stephen Eldon
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): Bui, Bryan
• Application Number:
  US08/985,462
• Time in Patent Office: 886 Days
• Field of Search: 702/152-154, 382/103-104, 382/154, 345/156-158
• US Class Current: 702/153
• CPC Class Codes: G01S 17/74 Systems using reradiation of electromagnetic waves other than radio waves, e.g. IFF, i.e. identification of friend or foe
• CPC Class Codes: G01S 17/875 for determining attitude
• CPC Class Codes: G01S 5/163 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49

Abstract

A system for determining the spatial position and orientation of each of a plurality of bodies. Each one of the bodies has at least three markers in a predetermined, relative geometric relationship. The markers are adapted to emit energy in response to an activation signal and/or to reflect energy impinging upon such passive marker from an activatable energy source. A common energy detector is provided for detecting the energy emitted by the active marker and the energy reflected by the passive marker. A common processor is provided. The processor has a memory. The memory has stored therein the predetermined, relative geometric relation of the markers for each one of the bodies. The processor compares the stored predetermined geometric relation of the markers for each of the bodies with the energy detected by the energy detector to identify the bodies emitting/or reflecting the detected energy. With such an arrangement, a body can be tracked using a very simple sequence of operation in real-time with robust positive marker identification by taking advantage of a simple marker placement methodology. Multiple bodies can scan thereby be tracked simultaneously.

Claims

1. A system for determining the spatial position and orientation of each of a plurality of bodies, comprising:

at least three markers affixed to each one of the bodies in a predetermined, relative geometric relationship, such markers being adapted to emit energy in response to an activation signal and/or to reflect energy impinging thereon from an activatable energy source;

an energy detector for detecting the energy emitted by one of the markers and/or the energy reflected by one of the markers;

a processor having;

a memory, such memory having stored therein the predetermined, relative geometric relation of the markers for each one of the bodies; and

wherein the processor compares the stored predetermined geometric relation of the markers for each of the bodies with the energy detected by the energy detector to identify the bodies emitting and/or reflecting the detected energy.

2. The system recited in claim 1 wherein each body has the markers thereon disposed in a known and fixed relative geometry with unique segment lengths amongst all pairs of all the markers on such body.

3. The system recited in claim 1 wherein each body has the markers thereon with pairs of like segments amongst all bodies having unique relative angles.

4. The system recited in claim 3 wherein the detector comprises a stereometric arrangement of sensors.

5. A method for determining the spatial position and orientation of each of a plurality of bodies, comprising:

detecting energy emitted by an active marker and/or energy reflected by a passive marker, at least three such markers being disposed on each one of the bodies in a predetermined, relative geometric relationship, the markers being adapted to emit energy in response to an activation signal and/or to reflect energy impinging thereon from an activatable energy source;

providing a memory having stored therein the predetermined, relative geometric relation of the markers for each one of the bodies;

comparing the stored predetermined geometric relation of the markers for each of the bodies with the energy detected by the energy detector to identify the bodies emitting and/or reflecting the detected energy.

6. The method recited in claim 5 including tracking the body in real-time.

7. The method recited in claim 5 including tracking a plurality of such bodies simultaneously.

8. The method recited in claim 5 including disposing on each of the bodies the markers in a known and fixed relative geometry with unique segment lengths amongst all pairs of all the markers on such body.

9. The system recited in claim 8 including disposing on each one of the bodies the markers thereon with pairs of like segments amongst all bodies having unique relative angles.

10. The system recited in claim 5 including disposing on each one of the bodies the markers thereon with pairs of like segments amongst all bodies having unique relative angles.

11. The method recited in claim 5 including determining a pose of one or more bodies in real-time in a closed form solution using a single sensor cycle.

12. The method recited in claim 5 including automatically recognizing and tracking the bodies.