Method and handheld distance measuring device for creating a spatial model

Patent metadata

Field	Value
Publication number	US-9470792-B2
Application number	US-201514645557-A
Country	US
Kind code	B2
Filing date	Mar 12, 2015
Priority date	Mar 14, 2014
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

Some embodiment include a handheld distance measuring device having a laser distance meter for measuring distances to target points in an environment and an image acquisition unit for acquiring images of the environment, characterized by a control unit having program code for controlling a spatial modeling functionality having a measurement sequence, in the scope of which images of a region of the environment are acquired from different positions of the distance measuring device, these images having a shared image region, wherein the image acquisition unit assumes different, which represent the respective position and alignment of the distance measuring device, during the acquisition of the first image and the second image.

First claim

What is claimed is:

1. A handheld distance measuring device comprising:
a laser distance meter for measuring distances to target points in an environment;
an analysis component for deriving and providing the measured distances; and
an image acquisition unit having at least one camera for acquiring images of the environment;
wherein a control unit having program code for controlling a spatial modeling functionality of the distance measuring device, which is implemented for use with a measurement sequence, in the scope of which a first image and a second image of a region of the environment are acquired from different positions of the distance measuring device, these images having a shared image region,
wherein the image acquisition unit assumes different poses, which represent a respective position and alignment of the distance measuring device, during the acquisition of the first image and the second image,
wherein in the scope of the spatial modeling functionality and in reaction to a first user command, from a first position of the distance measuring device the first image of a first region of the environment is acquired by the image acquisition unit and a first distance to a first target point in the first region is measured by the laser distance meter in chronological correlation and simultaneously, with the acquisition of the first image,
wherein in reaction to a second user command, from a second position of the distance measuring device the second image of the first region of the environment is acquired by the image acquisition unit and a second distance to the first target point or to a second target point in the immediate environment of the first target point is measured by the laser distance meter in chronological correlation and simultaneously, with the acquisition of the second image,
wherein the control unit is embodied for the purpose, in the scope of the spatial modeling functionality, of identifying features of the environment in the images, which are imaged in the shared image region, based on the identified features, the first distance, and the second distance, ascertaining a spatial relationship between the poses, and based on the first image, the second image and the spatial relationship, preparing a spatial model of the environment using stereo photogrammetry, wherein distances between spatial points in the environment can be ascertained on the basis of the spatial model,
wherein, in the scope of the spatial modeling functionality, the control unit is embodied for the purpose of joining together a first partial spatial model and a second partial spatial model, which have a shared overlap, to form an overall spatial model, wherein distances between spatial points of both regions of the environment can be ascertained on the basis of the spatial model.

2. The handheld distance measuring device according to claim 1 , wherein:
the image acquisition unit has a plurality of cameras; and
the first image and the second image are each wide-angle images assembled from individual images of the plurality of cameras, wherein the angle range acquired by the images comprises at least 120°,
wherein the cameras are at least one of:
arranged in the form of a hemisphere,
equipped with monochromatic image sensors,
embodied as wafer-level cameras, and
embodied with backside illumination.

3. The handheld distance measuring device according to claim 1 , further comprising:
a display device for displaying the spatial model and spatial points, and
an input device for selecting spatial points in the spatial model by way of a user,
wherein the control unit is embodied for the purpose of ascertaining a distance between the selected spatial points and the display device is embodied for the purpose of displaying this distance,
wherein the display device and the input device are embodied as a touchscreen.

4. The handheld distance measuring device according to claim 1 , wherein:
the spatial model has a plurality of spatial coordinates obtained using feature extraction and also image data of the images recorded by the image acquisition unit.

5. The handheld distance measuring device according to claim 1 , wherein:
the at least one camera of the image acquisition unit is embodied for recording high-contrast images, and
the control unit is embodied for the purpose of identifying features in the high-contrast images in the scope of the spatial modeling functionality.

6. The handheld distance measuring device according to claim 1 , further comprising means for wireless data transmission,
wherein the spatial model is transmittable using the wireless data transmission from the distance measuring device to at least one external device, and/or using the wireless data transmission, data are transmittable from the distance measuring device to at least one external device, wherein the data include at least coordinates of spatial points and/or image and distance data, and the spatial model can be prepared by a computing unit of the external device based on the data.

7. The handheld distance measuring device according to claim 1 , further comprising:
a plurality of laser distance meters for measuring distances to a plurality of points in the first region, wherein the control unit is embodied for the purpose of using the distances to the plurality of points for ascertaining the spatial relationship.

8. The handheld distance measuring device according to claim 1 , further comprising:
an acceleration and/or location sensor including a gyroscope, an inclination sensor, or a compass, for providing acceleration or location data of the distance measuring device, wherein the control unit is embodied for the purpose of using the acceleration or location data for ascertaining the spatial relationship.

9. A method for creating a spatial model of an environment with a handheld distance measuring device, which has a laser distance meter and an image acquisition unit, the method comprising:
acquiring a first image of a first region of the environment by the image acquisition unit from a first position of the distance measuring device, in chronological correlation with the acquisition of the first image, a measurement of a first distance to a first target point in the first region of the environment by the laser distance meter;
acquiring a second image of the first region of the environment by the image acquisition unit from a second position, which deviates from the first position of the distance measuring device, and in chronological correlation with the acquisition of the second image, a measurement of a second distance to the first target point or to another target point in the immediate environment of the first target point, wherein the first image and the second image have a shared image region, wherein the image acquisition unit assumes different poses, which represent the respective position and alignment of the distance measuring device, during the acquisition of the first image and the second image,
identifying features of the environment in the images, which are imaged in the shared image region,
ascertaining, based on the identified features, the first distance, and the second distance, a spatial relationship between the poses; and
preparing a spatial model based on the first image, the second image, and the spatial relationship, using stereo photogrammetry, wherein distances between spatial points of the environment can be ascertained on the basis of the spatial model,
wherein the prepared spatial model is a first partial spatial model, the method further comprising:
acquiring a third image of a second region of the environment by the image acquisition unit from a third position of the distance measuring device, in chronologic

Assignees

• Leica Geosystems Ag

Inventors

• Giger Kurt

Classifications

• H04N23/57

  Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices · CPC title

• G06T2207/10012

  Stereo images · CPC title

• G01S17/86

  Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders · CPC title

• G06T7/74

  involving reference images or patches · CPC title

• G06T2207/10028

  Range image; Depth image; 3D point clouds · CPC title