OPTOELECTRONIC SENSOR

• US 20110153139A1
• Filed: 12/16/2010
• Published: 06/23/2011
• Est. Priority Date: 12/17/2009
• Status: Active Grant

• Current Assignee: Sick AG (Sick)
• Original Assignee: Sick AG (Sick)
• Inventors: ERB, Frank, Feser, Matthias
• Granted Patent: US 8,406,950 B2
• Time in Patent Office: Days
• US Class Current: 701/28
• CPC Class Codes: B66F 9/063 Automatically guided
• CPC Class Codes: B66F 9/0755 Position control; Position detectors
• CPC Class Codes: G01S 17/06 Systems determining position data of a target
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4812 transmitted and received beams following a coaxial path
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 2201/0216 Vehicle for transporting goods in a warehouse, factory or similar

Abstract

An optoelectronic sensor (10), in particular a laser scanner, for a vehicle (100) which moves on a path (104) bordered at both sides, said optoelectronic sensor having a light receiver (24) for the conversion of received light (20) into electric signals as well as an evaluation unit (30, 34) which is configured to determine the position of objects in a monitored zone of the sensor (10) from the electric signals and to recognize whether an unauthorized object is located within a protected field (102) dynamically changing in position and/or extent, wherein a safety output (32) is provided via which a stop signal or a brake signal can be output to the vehicle (100) by the evaluation unit (30, 34) on the recognition of a protected field intrusion. The evaluation unit (30, 34) is furthermore configured to recognize borders (110) of the path (104) from the electric signals and to fit the protected field (102) dynamically into the borders (110).

Claims

11. A vehicle (100) having an optoelectronic sensor (10), wherein the vehicle (100) is a driverless transport system which moves on a path (104) having borders on both sides, said optoelectronic sensor having a light receiver (24) for the conversion of received light (20) into electric signals as well as an evaluation unit (30, 34) which is configured to determine the position of objects in a monitored zone of the sensor (10) from the electric signals and to recognize whether an unauthorized object is located within a protected field (102) dynamically changing in at least one of position and extent, wherein a safety output (32) is provided via which a stop signal or a brake signal can be output to the vehicle (100) by the evaluation unit (30, 34) on the recognition of a protected field intrusion, wherein the evaluation unit (30, 34) is furthermore configured to recognize said borders (110) from the electric signals and to fit the protected field (102) dynamically into the borders (110) and wherein the path (104) is a straight aisle in a storage facility.

12. A vehicle (100) in accordance with claim 11, wherein spacer elements (114) are provided to border the path.

13. A vehicle (100) in accordance with claim 12, wherein said spacer elements are provided only at the start of the path

16. A vehicle (100) in accordance with claim 11 in the form of a high rack service truck for use in a high rack storage facility,

14. A vehicle (100) having an optoelectronic sensor (10), wherein the vehicle (100) is a driverless transport system which moves on a path (104) having borders on both sides, said optoelectronic sensor having a light receiver (24) for the conversion of received light (20) into electric signals as well as an evaluation unit (30, 34) which is configured to determine the position of objects in a monitored zone of the sensor (10) from the electric signals and to recognize whether an unauthorized object is located within a protected field (102) dynamically changing in at least one of position and extent, wherein a safety output (32) is provided via which a stop signal or a brake signal can be output to the vehicle (100) by the evaluation unit (30, 34) on the recognition of a protected field intrusion, wherein the evaluation unit (30, 34) is furthermore configured to recognize said borders (110) from the electric signals and to fit the protected field (102) dynamically into the borders (110) and wherein spacer elements (114) are provided to border the path.

1. An optoelectronic sensor (10), for a vehicle (100) which moves on a path (104) bordered at both sides, said optoelectronic sensor having a light receiver (24) for the conversion of received light (20) into electric signals as well as an evaluation unit (30, 34) which is configured to determine the position of objects in a monitored zone of the sensor (10) from the electric signals and to recognize whether an unauthorized object is located within a protected field (102) dynamically changing in at least one of position and extent, wherein a safety output (32) is provided via which a stop signal or a brake signal can be output to the vehicle (100) by the evaluation unit (30, 34) on the recognition of a protected field intrusion, characterized in that

the evaluation unit (30, 34) is furthermore configured to recognize borders (110) of the path (104) from the electric signals and to fit the protected field (102) dynamically into the borders (110).

2. A sensor (10) in accordance with claim 1, the sensor being a laser scanner.

3. A sensor (10) in accordance with claim 1,

wherein the protected field (102) has a longitudinal extent dependent on the speed of the vehicle (100) approximately in the direction of travel and a preset transverse extent matched to at least one of the vehicle (100) and the path (104).

4. A sensor (10) in accordance with claim 3 wherein said protected field (102) is substantially rectangular.

5. A sensor (10) in accordance with claim 1,

wherein the evaluation unit (30, 34) is configured to vary the two parameters angle of rotation (φ

) and offset (Δ

_x) of the protected field (102) with respect to a center axis of the vehicle (100) for the dynamic matching.

6. A sensor (10) in accordance with claim 1,

wherein the evaluation unit (30, 34) is configured first to fix a main angle of rotation (φ

_H) and a main offset (Δ

x_H) of the protected field (102) while running on a path section (104) and to determine a differential readjustment angle of rotation (φ

_N) during the continued travel on the path section (104).

7. A sensor (10) in accordance with claim 6,

wherein the evaluation unit (30, 34) is configured to determine at least one of the main angle of rotation (φ

_H) and the readjustment angle of rotation (φ

_N) as that angle at which the sum (x_L+x_R) of the two distances of a longitudinal axis of the protected field (102) is maximized with respect to the borders (110) at both sides of the path (104).

8. A sensor (10) in accordance with claim 6,

wherein the evaluation unit (30, 34) is configured to determine the main offset (Δ

x_H) and/or a readjustment offset (Δ

x_H) so that the central longitudinal axis of the protected field (102) has the same distance from the borders (110) at both sides of the path (104).

9. A sensor (10) in accordance with claim 6,

wherein the evaluation unit (30, 34) is configured to seek the main angle of rotation (φ

_H) in an environment of the angle given by the direction of travel with a first precision and the readjustment angle (φ

_N) in an environment of the main angle of rotation (φ

_H) with a second precision.

10. A sensor (10) in accordance with claim 1,

wherein the evaluation unit (30, 34) is configured to output the stop signal or brake signal when no protected field (102) of the required dimensions can be fitted into the borders (110).

15. A vehicle (100) in accordance with claim 14, wherein said spacer elements are provided only at the start of the path.

17. A vehicle (100) in accordance with claim 14 in the form of a high rack service truck for use in a high rack storage facility,

18. A vehicle (100) in accordance with claim 11,

wherein a first sensor (10) is provided for protected field monitoring in the direction of travel and a second sensor (10) is provided for protected field monitoring against the direction of travel.

18-1. A vehicle (100) in accordance with claim 14,

wherein a first sensor (10) is provided for protected field monitoring in the direction of travel and a second sensor (10) is provided for protected field monitoring against the direction of travel.

20. A method for monitoring the environment of a vehicle (100) which moves on a path (104) bordered at both sides, wherein the monitoring takes place using an optoelectronic sensor (10), wherein the position of objects in the monitored zone is determined from electric signals acquired by conversion of received light and wherein it is recognized whether an unauthorized object is located within a protected field (102) dynamically changeable in position and extent, with a stop signal or brake signal being output to the vehicle (100) on recognition of a protected field intrusion, characterized in that

borders (110) of the path (104) are recognized from the electric signals and the protected field (102) is dynamically fitted into the borders (110).

21. A method in accordance with claim 20 wherein a laser scanner is used as said optoelectronic sensor.

22. A method in accordance with claim 20, wherein the vehicle is used in one of a driverless transport system and a positively driven transport system.

23. A method in accordance with claim 20 wherein said vehicle is used in a high rack storage facility

24. A method in accordance with claim 20,

wherein the two parameters angle of rotation (φ

) and offset (Δ

_x) of the protected field (102) are varied with respect to a center axis of the vehicle (100) on the dynamic fitting.

25. A method in accordance with claim 20,

wherein a main angle of rotation (φ

_H) and a main offset (Δ

x_H) of the protected field (120) is first fixed on the running on a path section (104) and a differential readjustment angle (φ

_N) is determined during the continued travel on the path section (104).

26. A method in accordance with claim 20,

wherein at least one of the main angle of rotation (φ

_H) and the readjustment angle of rotation (φ

_N) is determined as that angle at which the sum of the two distances (x_L+x_R) of a longitudinal axis of the protected field (102) is maximized with respect to the borders (110) at both sides of the path (104).

27. A method in accordance with claim 26, wherein at least one of the main offset (Δ

x_H) and a readjustment offset (Δ

x_N) is determined so that the central longitudinal axis of the protected field (102) has the same distance from the borders (110) at both sides of the path (104).

28. A method in accordance with claim 20,

wherein at least one of the main offset (Δ

x_H) and/or a readjustment offset (Δ

x_N) is determined so that the central longitudinal axis of the protected field (102) has the same distance from the borders (110) at both sides of the path (104).

29. A method in accordance with claim 20,

wherein one of a stop signal and a brake signal is output when no protected field (102) of the demanded dimensions can be fitted into the borders (110).