Detector for determining a position of at least one object

Patent metadata

Field	Value
Publication number	US-11922657-B2
Application number	US-202017421767-A
Country	US
Kind code	B2
Filing date	Jan 8, 2020
Priority date	Jan 9, 2019
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

Described herein is a detector for determining a position of an object. The detector includes a sensor element having a matrix of optical sensors, wherein the sensor element is configured to determine a reflection image. The detector also includes an evaluation device configured to select a reflection feature of the reflection image at a first image position in the reflection image, determine a longitudinal coordinate z of the selected reflection feature by optimizing a blurring function f a , and determine a reference feature in a reference image at a second image position in the reference image corresponding to the reflection feature. The reference image and the reflection image are determined at two different spatial configurations, wherein the spatial configurations differ by a relative spatial constellation, wherein the evaluation device is configured to determine the relative spatial constellation from the longitudinal coordinate z and the first and the second image positions.

First claim

The invention claimed is:

1. A detector ( 110 ) for determining a position of at least one object ( 112 ), the detector ( 110 ) comprising:
at least one sensor element ( 130 ) having a matrix ( 132 ) of optical sensors ( 134 ), the optical sensors ( 134 ) each having a light-sensitive area ( 136 ), wherein the sensor element ( 130 ) is configured to determine at least one reflection image ( 142 ); and
at least one evaluation device ( 146 ), wherein the evaluation device ( 146 ) is configured to select at least one reflection feature of the reflection image ( 142 ) at at least one first image position ( 148 ) in the reflection image ( 142 ), wherein the evaluation device ( 146 ) is configured for determining at least one longitudinal coordinate z of the selected reflection feature by optimizing at least one blurring function f a , wherein the evaluation device ( 146 ) is configured to determine at least one reference feature in at least one reference image ( 168 ) at at least one second image position ( 154 ) in the reference image ( 168 ) corresponding to the at least one reflection feature, wherein the reference image ( 168 ) and the reflection image ( 142 ) are determined at two different spatial configurations, wherein the spatial configurations differ by a relative spatial constellation, wherein the evaluation device ( 146 ) is configured to determine the relative spatial constellation from the longitudinal coordinate z and the first image position ( 148 ) and the second image position ( 154 ).

2. The detector ( 110 ) according to claim 1 , wherein the longitudinal coordinate z is determined by using at least one convolution-based algorithm such as a depth from defocus algorithm.

3. The detector ( 110 ) according to claim 1 , wherein the 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 reflection image ( 142 ) is a blurred image i b , wherein evaluation device ( 146 ) is configured to reconstruct the longitudinal coordinate z from the blurred image i b and the 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 blurring function f a with a further image i′ b ,
min∥( i′ b *f a (σ( z ))− i b )∥,

by varying the parameters σ of the blurring function.

6. The detector ( 110 ) according to claim 1 , wherein the at least one blurring function f a is a function, or a 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 relative spatial constellation is at least one constellation selected from the group consisting of: a relative spatial orientation; a relative angle position; a relative distance; a relative displacement; and relative movement.

8. The detector ( 110 ) according to claim 1 , wherein the detector ( 110 ) comprises at least two sensor elements ( 130 ) separated by a relative spatial constellation, wherein at least one first sensor element ( 150 ) is adapted to record the reference image ( 168 ) and at least one second sensor element ( 152 ) is adapted to record the reflection image ( 142 ).

9. The detector ( 110 ) according to claim 1 , wherein the detector ( 110 ) is configured to record the reflection image ( 142 ) and the reference image ( 168 ) using the same matrix ( 132 ) of optical sensors ( 134 ) at different times.

10. The detector ( 110 ) according to claim 9 , wherein the evaluation device ( 146 ) is configured to determine at least one scaling factor for the relative spatial constellation.

11. The detector ( 110 ) according to claim 1 , wherein the evaluation device ( 146 ) is configured to determine a displacement of the reference feature and the reflection feature, wherein the evaluation device ( 146 ) is configured to determine at least one triangulation longitudinal coordinate z triang of the object using a pre-defined relationship between the triangulation longitudinal coordinate z triang of the object and the displacement, wherein the evaluation device ( 146 ) is configured to determine an actual relationship between the longitudinal coordinate z and the displacement considering the determined relative spatial constellation, wherein the evaluation device ( 146 ) is configured to adjust the pre-defined relationship depending on the actual relationship.

12. The detector ( 110 ) according to claim 11 , wherein the evaluation device ( 146 ) is configured to replace the pre-defined relationship by the actual relationship and/or the evaluation is configured to determine a moving average and to replace the pre-defined relationship by the moving average.

13. The detector ( 110 ) according to claim 11 , wherein the evaluation device ( 146 ) is configured to determine a difference between the longitudinal coordinate z and the triangulation coordinate z triang , wherein the evaluation device ( 146 ) is configured to compare the determined difference to at least one threshold and to adjust the pre-defined relationship in case the determined difference is above or equal to the threshold.

14. The detector ( 110 ) according to claim 11 , wherein the evaluation device ( 146 ) is configured to determine an estimate of a corrected relative spatial relationship using a mathematical model including parameters including various sensor signals and/or positions and/or the image positions and/or the system properties and/or longitudinal coordinates, a displacement on the sensor d, a focal length of a transfer device f, temperature, z triang , the baseline b, an angle between the illumination source and the baseline ( 3 , or the longitudinal coordinate z, wherein the mathematical model is at least one mathematical model selected from the group consisting of: a Kalman filter, a linear quadratic estimate, a Kalman-Bucy-Filter, a Stratonovich-Kalman-Bucy-Filter, a Kalman-Bucy-Stratonovich-Filter, a minimum variance estimator, a Bayesian estimator, a Best linear unbiased estimator, an invariant estimator, and a Wiener filter.

15. The detector ( 110 ) according to claim 1 , wherein the evaluation device ( 146 ) is configured to determine at least one longitudinal region, wherein the longitudinal region is given by the longitudinal coordinate z and an error interval ±c, wherein the evaluation device is configured to determine at least one displacement region in the reference image ( 168 ) corresponding to the longitudinal region, wherein the evaluation device ( 146 ) is configured to determine an epipolar line in the reference image ( 168 ), wherein the displacement region extends along the epipolar line, wherein the evaluation device ( 146 ) is configured to determine the reference feature along the epipolar line corresponding to the longitudinal coordinate z and to determine an extent of the displacement region along the epipolar line corresponding to the error interval ±ε.

16. The detector ( 110 ) according to claim 15 , wherein the evaluation device ( 146 ) is configured to perform the following steps:
Determining a displacement region for the second image position ( 154 ) of each reflection feature;
Assigning an epipolar line to the displacement region of each reflection feature such as by assigning the epipolar line closest to a displacement region and/or with

Assignees

• Trinamix Gmbh

Inventors

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

Classifications

• G06T7/74 Primary

  involving reference images or patches · CPC title

• G01S7/4816

  of receivers alone · CPC title

• G01S17/48

  Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves · CPC title

• G06T5/002

  Physics · mapped topic

• G06T5/20

  using local operators · CPC title