Device for optically scanning and measuring an environment

• US 8,384,914 B2
• Filed: 07/20/2010
• Issued: 02/26/2013
• Est. Priority Date: 07/22/2009
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Technologies Incorporated
• Inventors: Becker, Reinhard, Ossig, Martin
• Primary Examiner(s): PHAM, HOA Q
• Application Number:
  US13/384,806
• Publication Number:
  US 20120188559A1
• Time in Patent Office: 952 Days
• Field of Search: 356601-622, 356/4.01, 356/5.01, 356/141.5, 358/505, 358/511, 358474-475
• US Class Current: 356/614
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/50 Systems of measurement based on relative movement of target
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver

Abstract

In a laser scanner for optically scanning and measuring an environment, the scanner having a center which defines for a scan the stationary reference system of the scanner and the center of the scan, a light emitter which emits an emission light beam, a light receiver which receives a reception light beam reflected by an object in the environment of the scanner, a control and evaluation unit which determines, for a multitude of measuring points of the scan, at least the distance between the center of the scan and the object, the scanner, for registering a scene with several scans having different centers, being movable between the centers of the scans, and a scanner mouse for registering the path followed by the scanner between the different centers of the scans, the scanner mouse optically registering the movement of the laser scanner relative to a reference surface.

Claims

1. Device for optically scanning and measuring an environment, which device is designed as a laser scanner, having a center, which defines for a scan the stationary reference system of the laser scanner and the center of this scan, a base, a measuring head which is rotatable relative to the base, a light emitter which is comprised by the measuring head and which emits an emission light beam, a light receiver, which is comprised by the measuring head and which receives a reception light beam being reflected by an object in the environment of the laser scanner or scattered otherwise, a control and evaluation unit which, for a multitude of measuring points of the scan, determines at least the distance between the center and the object, wherein the laser scanner for registering a scene with scans having several, different centers, is movable as a whole between the different centers, characterized in that an optical measuring device is provided for registering the path followed by the laser scanner as a whole between the different centers, the optical measuring device registering its movement, as a whole, relative to a reference surface by means of determination of the optical flow, wherein the optical measuring device is mounted on the base or on the measuring head or on a carriage, by means of which the laser scanner being mounted on the carriage is movable, as a whole, between the different centers, relative to the reference surface.

2. Device according to claim 1, characterized in that the optical measuring device is provided with at least one optical element being orientated to the reference surface.

3. Device according to claim 1, characterized in that the optical measuring device bears against the reference surface.

4. Device according to claim 1, characterized in that the optical measuring device, during or after the scan, is connected, by means of a cable and an interface or via radio, to the control and evaluation unit or to an external evaluation unit.

5. Device according to claim 1, characterized in that the optical measuring device or a data memory of the optical measuring device, after registering the whole scene, is connected to the control and evaluation unit or to an external evaluation unit.

6. Device according to claim 1, characterized in that the optical measuring device comprises a sensor, which registers, at regular intervals, data from the reference surface, and a computing unit, which compares the registered data with each other and which, by virtue of the differences, particularly by determining the optical flow, computes the movement of a scanner mouse relative to the reference surface.

7. Device according to claim 6, characterized in that the optical measuring device comprises a light source, for example an LED or a laser, which emits light onto the reference surface, wherein the sensor takes pictures of the irradiated reference surface.

8. Device according to claim 7, characterized in that the light source, the sensor and the computing unit are mounted on a common printed board or are integrated in a common module/chip.

9. Device according to claim 1, characterized in that further measuring devices are assigned to the laser scanner, the data of which measuring devices are to be joined together with the data of the laser scanner and, if necessary, in advance with the data of the optical measuring device, and be evaluated.

10. Method for optically scanning and measuring a scene, using a device according to claim 1, wherein the scene is registered by means of different scans which are partially overlapping within a range of measuring points and wherein the laser scanner, for every scan having a certain center, is moved to a certain position, while the optical measuring device registers the path followed by the laser scanner between the different centers.