Optoelectronic sensor and method for detecting objects

1. An optoelectronic sensor ( 10 ) for detecting objects in a monitoring region ( 20 ), the sensor ( 10 ) having a scanning unit ( 12 , 58 ) movable about an axis of rotation ( 18 ), a plurality of scanning modules ( 22 ) for periodically scanning the monitoring region ( 20 ) and for generating corresponding received signals, and an evaluation unit ( 48 ) for obtaining information about the objects from the received signals, the scanning modules ( 22 ) comprising at least one light transmitter ( 24 ) for transmitting several light beams ( 28 ) separated from one another and at least one light receiver ( 36 ) for generating the received signals from the light beams ( 32 ) remitted by the objects,

wherein at least two of the scanning modules ( 22 ) are rotated with respect to one another by a rotation angle (γ), the rotation angle (γ) being measured about an axis corresponding to the main viewing direction.

2. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein the optoelectronic sensor ( 10 ) is a laser scanner.

3. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein the scanning modules are accommodated in the scanning unit ( 12 ).

4. The optoelectronic sensor ( 10 ) according to claim 1 ,

having two to ten scanning modules ( 22 ).

5. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein a scanning module ( 22 ) generates two to ten light beams ( 28 , 32 ).

6. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein light beams ( 28 , 32 ) of a scanning module ( 22 ) have a mutual angular offset (α).

7. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein the scanning unit ( 12 ) comprises a plurality of mounting locations ( 56 ) for scanning modules ( 22 ), wherein not all of the mounting locations ( 56 ) are occupied by a scanning module ( 22 ).

8. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein the scanning modules ( 22 ) are of identical construction to one another.

9. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein at least some scanning modules ( 22 ) are at least one of arranged one above the other and offset with respect to one another in the direction of rotation.

10. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein in at least one scanning module ( 22 ) a plurality of light beams ( 28 , 32 ) are arranged in a two-dimensional pattern in cross-section.

11. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein at least two scanning modules ( 22 ) have a common circuit board ( 54 ).

12. The optoelectronic sensor ( 10 ) according to claim 1 ,

wherein the evaluation unit ( 48 ) is adapted to determine a distance of the object by means of a light time of flight between transmitting the light beams ( 28 ) and receiving the remitted light beams ( 32 ).

13. The optoelectronic sensor ( 10 ) according to claim 1 , wherein the at least two scanning module ( 22 ) are further tilted by a tilt angle (β) relative to the main viewing direction, the tilt angle (β) being measured with respect to a central scanning plane perpendicular to the axis of rotation ( 18 ).

14. The optoelectronic sensor ( 10 ) according to claim 13 , wherein at least one of the tilt angle (β) and the rotation angle (γ) is fixed.

15. The optoelectronic sensor ( 10 ) according to claim 13 , wherein the tilt angle (β) is in an interval including 0°.

16. The optoelectronic sensor ( 10 ) according to claim 13 , wherein the tilt angle (β) is in the range of ±60°.

17. The optoelectronic sensor ( 10 ) according to claim 13 , wherein the scanning modules ( 22 ) are at least one of tilted (β) and rotated (γ) in such a way that scanning planes with uniform angular spacing are generated.

18. The optoelectronic sensor ( 10 ) according to claim 13 , wherein the scanning modules ( 22 ) are at least one of tilted (β) and rotated (γ) in such a way that scanning planes with a denser angular spacing are generated in at least one angular range.

19. The optoelectronic sensor ( 10 ) according to claim 13 , wherein the scanning modules ( 22 ) are at least one of tilted (β) and rotated (γ) in such a way that at least some scanning planes are generated which are redundantly scanned.

20. The optoelectronic sensor ( 10 ) according to claim 13 , wherein the scanning modules ( 22 ) are at least one of tilted (β) and rotated (γ) in such a way that at least one angular range without scanning planes is generated.

21. The optoelectronic sensor ( 10 ) according to claim 13 , wherein the scanning modules ( 22 ) are at least one of tilted (β) and rotated (γ) in such a way that scanning planes of a scanning module ( 22 ) are arranged be-tween scanning planes of another scanning module ( 22 ).

22. A method for detecting objects in a monitoring region ( 20 ) which is periodically scanned by means of a scanning unit ( 12 , 58 ) movable about an axis of rotation ( 18 ) and having a plurality of scanning modules ( 22 ), the method comprising:

rotating at least two of the plurality of scanning modules ( 22 ) with respect to one another;

the scanning modules ( 22 ) each transmitting a plurality of light beams ( 28 ) which are separated from one another;

the scanning modules ( 22 ) receiving the plurality of light beams as remitted light beams ( 32 ) after remission at the objects and generating corresponding received signals; and

evaluating the received signals to obtain information about the objects,

wherein an arrangement of scanning planes is defined by combining scanning modules ( 22 ) which are rotated by a rotation angle (γ), the rotation angle (γ) being measured about an axis corresponding to the main viewing direction.

23. The method according to claim 22 , further comprising the step of tilting the at least two scanning module ( 22 ) by a tilt angle (β) relative to the main viewing direction, the tilt angle (β) being measured with respect to a central scanning plane perpendicular to the axis of rotation ( 18 ).