OBJECT POSITION AND ORIENTATION DETECTION SYSTEM

• US 20100091112A1
• Filed: 11/12/2007
• Published: 04/15/2010
• Est. Priority Date: 11/10/2006
• Status: Active Grant

• Current Assignee: Carl Zeiss Industrielle Messtechnik GmbH (Carl-Zeiss-Stiftung)
• Original Assignee: OXFORD AI LTD
• Inventors: Cumming, David, Veeser, Stefan
• Granted Patent: US 9,536,163 B2
• Time in Patent Office: Days
• US Class Current: 348/207.1
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06F 3/0325 using a plurality of light emitters or reflectors or a plurality of detectors forming a reference frame from which to derive the orientation of the object, e.g. by triangulation or on the basis of reference deformation in the picked up image
• 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: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 10/245 by locating a pattern; Special marks for positioning

Abstract

An object position and orientation detection system and in particular one which is capable of describing observed movement in 3 dimensions. In one example, a spherical patterned marker with concentric rings is imaged using one or more digital cameras, and the resulting images are processed to determine the position and orientation of an object to which the patterned marker is attached. The method of optical tracking employed by the system allows motion to be determined in six degrees of freedom. In conjunction with a suitable display, such as a projector, an interactive white board or similar application can be realised.

Claims

1-95. -95. (canceled)

96. An object position and orientation detection system comprising:

an object, at least part of which comprises a patterned marker having a detectable pattern arranged thereon;

imaging means adapted to create one or more two dimensional images of the object; and

image processing means adapted to calculate the position and orientation of the object in three dimensions by matching the pattern in at least one image with an artificially generated two dimensional pattern corresponding to a known position and orientation of the object in three dimensions.

97. A system as claimed in claim 96, wherein the pattern as viewed by the imaging means changes from one geometric entity to another dependent on the orientation of the patterned marker relative to the imaging means.

98. A system as claimed in claim 96, wherein the patterned marker is substantially spherical.

99. A system as claimed in claim 96, wherein the patterned marker comprises a single sphere.

100. A system as claimed in claim 96, wherein the pattern is periodic.

101. A system as claimed in claim 98, wherein the pattern on the substantially spherical patterned marker comprises a set of rings around the substantially spherical marker which create a variety of patterns depending on the orientation of the substantially spherical marker with respect to the imaging means.

102. A system as claimed in claim 96, wherein the position and orientation of the object are calculated in real time.

103. A system as claimed in claim 96, wherein the artificially generated pattern is derived from a model simulating the appearance of the patterned marker, the model having parameters corresponding to the position and orientation of the patterned marker in three dimensions.

104. A system as claimed in claim 96, wherein matching the pattern with an artificially generated pattern comprises using a similarity measure between the pattern and the artificially generated pattern, and using a gradient based method to fine tune the match.

105. A system as claimed in claim 104, wherein the gradient of the similarity measure is evaluated with respect to the parameters of the model to find the best match.

106. A system as claimed in claim 96, wherein the patterned marker is hollow with a surface adapted to diffuse light.

107. A system as claimed in claim 106, wherein the surface comprises celluloid.

108. A system as claimed in claim 106, wherein the surface of the patterned marker and the material from which the marker is made have the same reflective properties but different transmission properties.

109. A system as claimed in claim 96, wherein the pattern is enhanced by illuminating it with a point light source which is positioned behind the patterned marker.

110. A system as claimed in claim 109, wherein the light source provides infra red illumination.

111. A system as claimed in claim 96, wherein the imaging means comprises a single camera.

112. A system as claimed in claim 111, wherein the imaging means comprises a web camera.

113. A system as claimed in claim 109, wherein the imaging means is provided with an optical filter selected to prevent the imaging means from receiving electromagnetic radiation at frequencies other than those provided by the light source.

114. A system as claimed in claim 109, wherein the pattern is not detectable when the light source is switched off, the switching being used to communicate information to a computer system.

115. A system as claimed in claim 103, wherein the two dimensional artificially generated pattern is derived from a three dimensional model.