Device And Method For Safeguarding A Machine-Controlled Handling Device

• US 20080021597A1
• Filed: 08/23/2005
• Published: 01/24/2008
• Est. Priority Date: 08/27/2004
• Status: Active Grant

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: ABB Research Ltd. (ABB Limited)
• Inventors: Kock, Sonke, Matthias, Bjorn, Merte, Rolf
• Granted Patent: US 7,783,386 B2
• Time in Patent Office: Days
• US Class Current: 700/255
• CPC Class Codes: B25J 9/1676 Avoiding collision or forbidden zones
• CPC Class Codes: F16P 3/141 using sound propagation, e.g. sonar
• CPC Class Codes: F16P 3/144 using light grids
• CPC Class Codes: F16P 3/147 using electro-magnetic technology, e.g. tags or radar

Abstract

An apparatus and method is disclosed for protection of a machine-controlled handling appliance having moving parts, having a safety sensor system for detection of objects in the working area of the handling appliance, having a safety controller which interacts with the handling appliance controller and in the process controls safety-relevant handling appliance functions as a function of signals from the safety sensor system. The safety sensor system has non-contacting proximity sensors so that a safety-relevant part of the working area of the handling appliance is covered by the detection areas of the proximity sensors.

Claims

1. An apparatus for protection of a machine-controlled handling appliance having moving parts, having a safety sensor system for detection of objects in the working area of the handling appliance, having a safety controller which interacts with the handling appliance controller and in the process controls safety-relevant handling appliance functions as a function of signals from the safety sensor system, wherein the safety sensor system has non-contacting proximity sensors so that a safety-relevant part of the working area of the handling appliance is covered by the detection areas of the proximity sensors.

2. The apparatus as claimed in claim 1, wherein the safety sensor system has a combination of position-resolving and time-resolving sensors and non-contacting proximity sensors.

3. The apparatus as claimed in claim 2, wherein the safety sensor system has a combination of position-resolving and time-resolving sensors, non-contacting proximity sensors and mechanical limit switches or contact mats.

4. The apparatus as claimed in claim 1, wherein the proximity sensors have a combination of sensors with different physical principles of operation, in particular imaging sensors, microwave sensors and/or radar.

5. The apparatus as claimed in claim 1, wherein the proximity sensors transmit information about the presence of an object in their respective detection area and about the distance of the object from the respective sensor to the safety controller.

6. The apparatus as claimed in claim 5, wherein the proximity sensors suppress information about the presence of an object which is located in their detection area during the transmission to the safety controller if the object is located in a specific permissible distance range from the proximity sensor.

7. The apparatus as claimed in claim 1, wherein the proximity sensors are proximity switches with variably adjustable switching distances, so that they transmit information about the presence of an object in their respective monitoring area and within a range which corresponds to the respectively selected switching distance, from the proximity sensor to the safety controller.

8. The apparatus as claimed in claim 1, wherein the safety-relevant part of the working area is subdivided into sectors, with each sector having an associated non-contacting proximity sensor or a position-resolving and time-resolving sensor as the sector monitoring sensor, whose detection area corresponds to the sector associated with it.

9. The apparatus as claimed in claim 8, wherein each sector which is associated with one proximity sensor is subdivided into at least two zones of different safety relevance, with the safety relevance corresponding to the distance from the moving parts of the handling appliance.

10. The apparatus as claimed in claim 9, wherein each sector which is associated with one proximity sensor is subdivided into a working zone, a safety zone and a danger zone, in such a manner that the handling appliance is switched off if someone is present in the danger zone and the handling appliance is switched to a slower safety mode if someone is present in the safety zone.

11. The apparatus as claimed in claim 1, wherein the proximity sensors have ultrasound sensors.

12. The apparatus as claimed in claim 1, wherein the proximity sensors have microwave sensors.

13. The apparatus as claimed in claim 1, wherein the handling appliance is a freely programmable industrial robot.

14. The apparatus as claimed in claim 13, wherein the safety sensors are fitted to the robot base in such a manner that the working area of the robot is monitored from the base, starting from the inside, outwards.

15. The apparatus as claimed in claim 13, wherein information about the position of the robot arm is recorded by position-finding sensors on the robot, in particular on the robot axes, and is transmitted to the safety controller.

23. An apparatus as claimed in claim 11, wherein the ultrasound sensors have a beam angle of between 10°

and 40°

, particularly advantageously of between 12° and

30°

, so that that part of the working area of the handling machine which is monitored by the ultrasound sensors is subdivided into sectors with beam angles of between 10° and

40°

, in a particularly advantageous manner between 12° and

30°

.

24. The apparatus as claimed in claim 12, wherein the microwave sensors operate using the FMCW (Frequency-Modulated Continuous Wave) method.

25. The apparatus as claimed in claim 24, wherein the microwave sensors are fitted such that they can be scanned mechanically, and the scanning angle can be recorded by an angle sensor, in such a manner that, in addition to the information about the distance to the object, information is also obtained about the direction in which the object is located.

26. The apparatus as claimed in claim 24, wherein individual elements of an antenna array of the microwave sensors can be driven via a variable phase-shifting network, in such a manner that the main emission direction (main lobe) of the microwave antennas can be scanned by variation of the phases thus, in addition to the information about the distance to the object, also obtaining information about the direction in which the object is located.

16. A method for protection of a machine-controlled handling appliance having moving parts, with a safety sensor system being used for detection of objects in the working area of the handling appliance, in such a manner that a safety controller interacts with the handling appliance controller, and the safety controller controls safety-relevant handling appliance functions as a function of signals from the safety sensor system, wherein information about the presence of people and/or objects in the working area of the handling appliance is determined zone-by-zone by the safety sensor system and is transmitted to the safety controller, wherein information about the position of the moving part or parts of the handling appliance is transmitted zone-by-zone from the handling appliance to the safety controller, and wherein safety-relevant handling appliance functions are controlled zone-by-zone by the safety controller by interaction with the handling appliance controller and as a function of both types of information.

17. The method as claimed in claim 16, wherein the handling appliance is a freely programmable industrial robot whose working area is partially subdivided into sectors, and each sector is further subdivided into at least two zones of different safety relevance, corresponding to the distance from the moving robot arm, and wherein information about the position of the robot arm is detected by position sensors on the robot axes, and is transmitted to the safety controller.

18. The method as claimed in claim 17, wherein each sector is subdivided into a working zone, a safety zone and a danger zone, and wherein the robot is switched off if the safety sensor system identities the presence of someone in the danger zone, and the robot controller switches the robot to a slower safety mode if someone is present in the safety zone.

19. The method as claimed in claim 18, wherein if the safety sensor system identifies the presence of someone in a safety zone and, at the same time, the position sensors detect that the robot arm is positioned in the same safety zone or in an adjacent safety zone, the robot controller switches the robot to a slower safety mode.

20. The method as claimed in claim 17, wherein information which is transmitted from the safety sensor system to the safety controller about objects from a safety zone or danger zone in which the robot arm is located is masked out by the safety controller.

21. The method as claimed in claim 17, wherein information which is transmitted from the safety sensor system to the safety controller about objects from a safety or danger zone in which parts or supply apparatuses for such parts which are to be handled by the robot are located are masked out by the safety controller.

22. The method as claimed in claim 16, wherein the safety sensor system has non-contacting Proximity sensors so that a safety-relevant part of the working area of the handling appliance is covered by the detection areas of the proximity sensors.