LASER SCANNER

Abstract

A laser scanner device adapted to be mounted to a vehicle, the device comprising a LIDAR module, the LIDAR module comprising at least one laser source, characterized by a horizontal field of view of at least 60°, an instantaneous vertical field of view of at least ±2°, a scan resolution of at least one point per 0.8° in horizontal and vertical direction, and a frame rate of at least 10 Hz for scanning at least the entire horizontal and instantaneous vertical field of view with said scan resolution.

Claims

1. A laser scanner device adapted to be mounted to a vehicle, the laser scanner device comprising: a LIDAR module comprising at least one laser source, wherein the LIDAR module has: a horizontal field of view of at least 60°, an instantaneous vertical field of view of at least ±2°, a scan resolution of at least one point per 0.8° in a horizontal and a vertical direction, and a frame rate of at least 10 Hz for scanning at least the entire horizontal and an instantaneous vertical field of view with said scan resolution.

2. The laser scanner device according to claim 1, further comprising: a rotating mirror which steers a scanning beam horizontally in a uniform manner.

3. The laser scanner device according to claim 1, further comprising: a galvano which steers a scanning beam horizontally in a non-uniform manner.

4. The laser scanner device according to claim 2, further comprising: a polygon, a mirror and/or a MEMS for steering the scanning beam vertically in the instantaneous vertical field of view.

5. The laser scanner device according claim 1, further comprising: a tilt mechanism for tilting the device to achieve an overall vertical field of view of at least ±25°.

6. The laser scanner device according to claim 1, further comprising: a fixed receiver having at least 32 detectors, in particular at least 64 detectors.

7. The laser scanner device according to claim 1, wherein the LIDAR module has: a uniform scan resolution of at least 0.15°.

8. The laser scanner device according to claim 1, wherein the LIDAR module has: a non-uniform scan resolution of between 0.15° and 0.3°, and wherein a point density of the non-uniform scan increases towards the edges of the field of view.

9. The laser scanner device according to claim 1, further comprising: a housing which encompasses the at least one laser module.

10. The laser scanner device according to claim 1, further comprising: a rectangular receiver optics aperture.

11. The laser scanner device according to claim 1, further comprising: at least two laser sources.

12. The laser scanner device according to claim 1, wherein the LIDAR module has: a horizontal field of view of at least 70°.

13. The laser scanner device according to claim 1, wherein the LIDAR module has: an instantaneous vertical field of view of at least ±3°.

14. The laser scanner device according to claim 1, wherein the LIDAR module has: a scan resolution of at least one point per 0.5° in horizontal and vertical direction.

15. The laser scanner device according to claim 1, wherein the LIDAR module has: a frame rate of at least 20 Hz for scanning at least the entire horizontal and instantaneous vertical field of view with said scan resolution.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The invention in the following will be described in detail by referring to exemplary embodiments that are accompanied by figures, in which:

[0026] FIG. 1 shows a custom mechanical mount for horizontal laser scanner operation as a first exemplary embodiment of the scanner device according to the invention;

[0027] FIGS. 2a-c show a second exemplary embodiment of the scanner device according to the invention with its inside components;

[0028] FIGS. 3a-b show the mechanical dimensions of the second embodiment;

[0029] FIG. 4 shows a non-uniform point distribution in horizontal direction for the second embodiment having an oscillating galvano mirror;

[0030] FIG. 5 shows a first exemplary solution path for the second embodiment;

[0031] FIG. 6 shows a second exemplary solution path for the second embodiment; and

[0032] FIG. 7 shows parameter values for an exemplary embodiment of the scanner according to the invention.

DETAILED DESCRIPTION

[0033] FIG. 1 shows a custom laser scanner (e. g. a Leica Geosystems ScanStation P40) mounted horizontally at a suitable height at the front of a car. This setup allows a qualitative analysis of range performance, accuracy, dynamic range (road-sign scans) and tarmac scans (low reflectivity at high ranges and low incident angles).

[0034] A full VFOV and HFOV scan for post-processing can be achieved with an angular resolution of 0.15° (vertical and horizontal). A customized mechanical mount for horizontal scanner applications could provide an evaluation platform to assess the LIDAR performance within a dynamic application. A fixed configuration for single trace scans and a rotatable configuration for full FOV scans with single traces are possible.

[0035] FIGS. 2a, 2b and 2c show a second exemplary embodiment of the laser scanner device according to the invention. In contrast to the solution shown in FIG. 1, this embodiment comprises a common and compact housing to house all beam steering elements. Conceptually, the shown embodiment is based on a fast rotating polygon wheel projecting the instantaneous Field of View (iVFOV), and either a fixed rotating mirror or a dynamically rotating galvano projecting the horizontal field of view (HFOV). FIGS. 3a and 3b show achievable advantageous dimensions of the device in mm.

[0036] FIG. 4 shows a non-uniform point distribution along the horizontal direction (HFOV) due to the galvano scan mechanism. The iVFOV and VFOV scan patterns remain uniform. From an application point of view the non-uniform point density towards the edge of the window provides following advantages:

[0037] 1. Increased projected point pattern for objects seen under a low angle of incidence, e. g. buildings along the road; and

[0038] 2. Increased information density, e. g. detection of objects accidentally crossing a street.

[0039] FIGS. 5 and 6 each show a morphological analysis of technologies that can be used to constitute a device according to the second embodiment. Advantageous examples are indicated by bold type.

[0040] FIG. 7 shows parameter values for an exemplary embodiment of the scanner according to the invention.

[0041] Although the invention is illustrated above, partly with reference to some preferred embodiments, it must be understood that numerous modifications and combinations of different features of the embodiments can be made. All of these modifications lie within the scope of the appended claims.