Position and orientation tracking system

Patent metadata

Field	Value
Publication number	US-2021379775-A1
Application number	US-201917293216-A
Country	US
Kind code	A1
Filing date	Nov 14, 2019
Priority date	Nov 14, 2018
Publication date	Dec 9, 2021
Grant date	—

Abstract

The present disclosure relates to a tracking system for tracking a position and orientation of an object, the tracking system including: a tracking base provided in an environment, the tracking base including: a tracking head support; and, at least three tracking heads mounted to the tracking head support, a target system including at least three targets mounted to the object, each target including a reflector that reflects a radiation beam to the base sensor of a respective tracking head; and, a control system that: causes each tracking head to track a respective target as it moves throughout the environment; determines a position of each target with respect to a respective tracking head; determines an orientation of the target system using at least in part the determined position of each target; and, determines the position and orientation of the object using at least in part the position and orientation of the target system.

First claim

1 ) A tracking system for tracking a position and orientation of an object, the tracking system including:
a) a tracking base provided in an environment, the tracking base including:
i) a tracking head support; and,
ii) at least three tracking heads mounted to the tracking head support, each tracking head having:
(1) a radiation source arranged to send a radiation beam to a respective target;
(2) a base sensor that senses reflected radiation;
(3) at least one tracking head actuator that controls an orientation of the tracking head; and,
(4) at least one tracking head angle sensor that monitors an orientation of the tracking head;

b) a target system including at least three targets mounted to the object, each target including a reflector that reflects the radiation beam to the base sensor of a respective tracking head; and, c) a control system that:
i) causes each tracking head to track a respective target as it moves throughout the environment;
ii) determines a position of each target with respect to a respective tracking head at least in part using signals from:
(1) each base sensor; and,
(2) the at least one tracking head angle sensor;
iii) determines an orientation of the target system using at least in part the determined position of each target; and,
iv) determines the position and orientation of the object using at least in part the position and orientation of the target system.

2 ) The tracking system according to claim 1 , wherein the position of each target is determined using a distance measurement obtained from the base sensor and elevation and azimuth angles obtained from the at least one tracking head angle sensor.

3 ) The tracking system according to claim 1 or claim 2 , wherein signals from a base sensor of a respective tracking head are used to control the at least one tracking head actuator to ensure that the tracking head tracks the target as it moves throughout the environment.

4 ) The tracking system according to claim 2 , wherein the position of each target is relative to a local coordinate system of the respective tracking head.

5 ) The tracking system according to claim 3 , wherein a first tracking head defines a tracking base coordinate system and the position measurements of at least second and third tracking heads are transformed into the tracking base coordinate system using tracker calibration data.

6 ) The tracking system according to claim 4 , wherein the tracker calibration data defines the geometric relationship between the local coordinate systems of each respective tracking head.

7 ) The tracking system according to claim 4 , wherein the control system determines the position of each target in an environment coordinate system using environment calibration data.

8 ) The tracking system according to claim 6 , wherein the environment calibration data defines the geometric relationship between the tracking base coordinate system and the environment coordinate system.

9 ) The tracking system according to claim 7 , wherein the position of each target in the environment coordinate system is used to define position vectors and a vector cross product is calculated to define a normal vector to a plane of the target system which defines the orientation of the target system in the environment coordinate system.

10 ) The tracking system according to claim 8 , wherein the position and orientation of the target system is transformed into the position and orientation of the object using target system calibration data which defines the geometric relationship between the target system and the object.

11 ) The tracking system according to any one of claims 1 to 3 , wherein each tracking head is calibrated relative to the environment coordinate system such that the control system transforms positional data from each tracking head directly into the environment coordinate system.

12 ) The tracking system according to any one of the preceding claims, wherein the control system compares the determined position and orientation of the object with a desired position and orientation of the object and calculates a compensation vector in accordance with results of the comparison.

13 ) The tracking system according to any one of the preceding claims, wherein each target is mounted to a pan and/or tilt controlled mount operable to assist the targets in maintaining line of sight with the tracking heads.

14 ) The tracking system according to any one of the preceding claims, wherein:
a) the at least three tracking heads are spaced apart by at least one of:
i) 100 mm to 1000 mm;
ii) 250 mm to 750 mm; and,
iii) about 500 mm; and,
b) the at least three targets are spaced apart by at least one of:
i) 100 mm to 1000 mm;
ii) 250 mm to 750 mm; and,
iii) about 500 mm.

15 ) The tracking system according to any one of the preceding claims, wherein the at least three targets are mounted on at least one of:
a) a target support; and, b) directly on the object.

16 ) The tracking system according to claim 15 , wherein the target support is at least one of:
a) rotatably mounted to the object; and, b) fixed relative to the object.

17 ) The tracking system according to any one of the preceding claims, wherein the at least three targets are mounted in a plane and spaced apart in two dimensions to thereby form a triangular target array.

18 ) The tracking system according to any one of the claims 15 to 17 , wherein the target support includes a triangular frame, with a target mounted proximate each apex.

19 ) The tracking system according to any one of claims 1 to 15 , wherein the position of the multiple targets relative to the object is fixed.

20 ) The tracking system according to claim 1 , wherein the targets are rigidly mounted to the object and wherein the control system selectively switches tracking of targets to maintain line of sight between the tracking heads and targets.

21 ) The tracking system according to claim 20 , wherein the selective switching of targets ensures that at least three targets are continuously tracked by the tracking heads.

22 ) The tracking system according to any one of the preceding claims, wherein each target is a spherically mounted retroreflector (SMR).

23 ) The tracking system according to any one of the preceding claims, wherein the tracking head support includes a platform and wherein the multiple tracking heads are rigidly mounted to the platform.

24 ) The tracking system according to any one of the claim 23 , wherein the multiple tracking heads are mounted in a co-linear arrangement on the platform.

25 ) The tracking system according to claim 23 or claim 24 , wherein the tracking base includes a number of legs that support the platform in an elevated position relative to the environment.

26 ) The tracking system according to claim 25 , wherein the platform is elevated to a height that is at least one of:
a) 2 m to 4 m; b) 2 m to 3 m; and, c) at least 2.5 m.

27 ) The tracking system according to any one of claims 23 to 26 , wherein the platform has an elongate tubular structure and three elongate tubular legs downwardly depend therefrom in a tripod configuration.

28 ) The tracking system according to claim 27 , wherein a pair of outer legs are bonded to the platform and a third inner leg is rotatably mounted to the platform permitting the tracking

Assignees

• Fastbrick Ip Pty Ltd

Inventors

• Pivac Mark Joseph

Classifications

• G01S17/88

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• G01S17/66

  Tracking systems using electromagnetic waves other than radio waves · CPC title

• G05B2219/45086

  Brick laying, masonry robot · CPC title

• E04G21/22

  for setting building elements with mortar, e.g. bricklaying machines · CPC title

• B25J19/022 Primary

  using lasers · CPC title