Detector for determining a position of at least one object

Patent metadata

Field	Value
Publication number	US-11908156-B2
Application number	US-202017421544-A
Country	US
Kind code	B2
Filing date	Jan 8, 2020
Priority date	Jan 9, 2019
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

Described herein is a detector for determining a position of at least one object. The detector includes at least one sensor element having a matrix of optical sensors, the optical sensors each having a light-sensitive area, wherein the sensor element is configured to determine a reflection image of the object. The detector also includes an evaluation device configured to select a reflection feature of the reflection image, and determine a distance estimate of the selected reflection feature of the reflection image by optimizing at least one blurring function f a , wherein the distance estimate is given by a longitudinal coordinate z and an error interval ±ε. The evaluation device is adapted to determine at least one displacement region in at least one reference image corresponding to the distance estimate, and to match the selected reflection feature with at least one reference feature within the displacement region.

First claim

The invention claimed is:

1. A detector ( 110 ) for determining a position of at least one object ( 112 ), wherein the position is at least one item of information regarding a location and/or orientation of the object ( 112 ) and/or at least one part of the object ( 112 ) in space, the detector ( 110 ) comprising:
at least one sensor element ( 116 ) having a matrix ( 118 ) of optical sensors ( 120 ), the optical sensors ( 120 ) each having a light-sensitive area ( 122 ), wherein the sensor element ( 116 ) is configured to determine at least one reflection image ( 126 ) of the object ( 112 ); and
at least one evaluation device ( 128 ), wherein the evaluation device ( 128 ) is configured to select at least one reflection feature of the at least one reflection image ( 126 ), wherein the evaluation device ( 128 ) is configured for determining at least one distance estimate ( 130 ) of the selected at least one reflection feature of the at least one reflection image ( 126 ) by optimizing at least one blurring function f a , wherein the at least one distance estimate ( 130 ) is given by a longitudinal coordinate z and an error interval ±ε,
wherein the evaluation device ( 128 ) is adapted to determine at least one displacement region ( 132 ) in at least one reference image ( 134 ) corresponding to the at least one distance estimate ( 130 ), wherein the at least one displacement region ( 132 ) is a region in the at least one reference image ( 134 ) in which at least one reference feature corresponding to the selected at least one reflection feature is expected to be located in the at least one reference image ( 134 ), wherein the evaluation device ( 128 ) is adapted to match the selected at least one reflection feature with at least one reference feature within the at least one displacement region ( 132 ).

2. The detector ( 110 ) according to claim 1 , wherein the at least one distance estimate ( 130 ) is determined using at least one convolution-based algorithm including a depth-from-defocus algorithm.

3. The detector ( 110 ) according to claim 1 , wherein the at least one blurring function is optimized by varying the parameters of the at least one blurring function.

4. The detector ( 110 ) according to claim 3 , wherein the at least one reflection image ( 126 ) is a blurred image i b , wherein the evaluation device ( 128 ) is configured to reconstruct the longitudinal coordinate z from the blurred image i b and the at least one blurring function f a .

5. The detector ( 110 ) according to claim 4 , wherein the longitudinal coordinate z is determined by minimizing a difference between the blurred image i b and the convolution of the at least one blurring function f a with at least one further image i′ b ,
min∥( i′ b *f a (σ( z ))− i b )∥,

by varying the parameters σ of the at least one blurring function.

6. The detector ( 110 ) according to claim 1 , wherein the at least one blurring function f a is a function or composite function composed from at least one function from the group consisting of: a Gaussian, a sinc function, a pillbox function, a square function, a Lorentzian function, a radial function, a polynomial, a Hermite polynomial, a Zernike polynomial, and a Legendre polynomial.

7. The detector ( 110 ) according to claim 1 , wherein the evaluation device ( 128 ) is adapted to determine a displacement of the matched at least one reference feature and the selected at least one reflection feature, wherein the evaluation device ( 128 ) is adapted to determine a longitudinal information of the matched features using a predetermined relationship between a longitudinal coordinate and the displacement.

8. The detector ( 110 ) according to claim 1 , wherein the at least one reference image ( 134 ) and the at least one reflection image ( 126 ) are images of the object ( 112 ) determined at different spatial positions having a fixed distance, wherein the evaluation device ( 128 ) is adapted to determine an epipolar line in the at least one reference image ( 134 ), wherein the at least one displacement region ( 132 ) extends along the epipolar line, wherein the evaluation device ( 128 ) is adapted to determine the at least one reference feature along the epipolar line corresponding to the longitudinal coordinate z and to determine an extent of the at least one displacement region along the epipolar line corresponding to the error interval ±ε.

9. The detector ( 110 ) according to claim 8 , wherein the evaluation device ( 128 ) is configured to perform the following steps:
Determining the at least one displacement region ( 132 ) for the image position of each reflection feature;
Assigning an epipolar line to the at least one displacement region ( 132 ) of each reflection feature by assigning the epipolar line closest to the at least one displacement region ( 132 ) and/or within the at least one displacement region ( 132 ) and/or closest to the at least one displacement region ( 132 ) along a direction orthogonal to the epipolar line; and
Assigning and/or determining at least one reference feature to each reflection feature such as by assigning the at least one reference feature closest to the assigned at least one displacement region ( 132 ) and/or within the assigned at least one displacement region ( 132 ) and/or closest to the assigned at least one displacement region ( 132 ) along the assigned epipolar line and/or within the assigned at least one displacement region along the assigned epipolar line.

10. The detector ( 110 ) according to claim 1 , wherein the detector ( 110 ) further comprises at least one illumination source ( 124 ), wherein the at least one illumination source ( 124 ) is adapted to generate at least one illumination pattern for illumination of the object, wherein the at least one illumination pattern comprises at least one pattern selected from the group consisting of: at least one point pattern, in particular a pseudo-random point pattern; a random point pattern or a quasi random pattern; at least one Sobol pattern; at least one quasiperiodic pattern; at least one pattern comprising at least one pre-known feature; at least one regular pattern; at least one triangular pattern; at least one hexagonal pattern; at least one rectangular pattern at least one pattern comprising convex uniform tilings; at least one line pattern comprising at least one line; and at least one line pattern comprising at least two lines such as parallel or crossing lines.

11. The detector ( 110 ) according to claim 10 , wherein the at least one illumination pattern comprises at least one hexagonal pattern, wherein the pattern is rotated relative to the baseline and/or wherein the hexagonal pattern is at least one displaced hexagonal pattern, wherein individual points of the hexagonal pattern are displaced by a random distance from the regular position.

12. The detector ( 110 ) according to claim 10 , wherein the sensor element ( 116 ) is adapted to determine at least one reflection pattern, wherein the evaluation device ( 128 ) is adapted to select at least one feature of the at least one reflection pattern and to determine the at least one distance estimate of the selected feature of the at least one reflection pattern by optimizing the at least one blurring function f a .

13. The detector ( 110 ) according to claim 12 , wherein the at least one reference image ( 134 ) is an image of the at least one illumination pattern at an image plane at a position of the at least one illumination source ( 124 ), wherein the evaluation device ( 128 ) is adapted to determine the at least one displacement region ( 132 ) in the at least one reference image ( 134 ) corresponding to t

Assignees

• Trinamix Gmbh

Inventors

• Eberspach Michael
• Lennartz Christian
• Send Robert
• Schindler Patrick
• Schillen Peter
• Bruder Ingmar

Classifications

• G06T7/70 Primary

  Determining position or orientation of objects or cameras (camera calibration G06T7/80) · CPC title

• G06T5/002

  Physics · mapped topic

• G06T5/50

  using two or more images, e.g. averaging or subtraction · CPC title

• G06V10/14

  Optical characteristics of the device performing the acquisition or on the illumination arrangements · CPC title

• G06V10/25

  Determination of region of interest [ROI] or a volume of interest [VOI] · CPC title