Device and method for safeguarding a machine-controlled handling device

• US 7,783,386 B2
• Filed: 08/23/2005
• Issued: 08/24/2010
• Est. Priority Date: 08/27/2004
• Status: Active Grant

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: ABB Research Ltd. (ABB Ltd.)
• Inventors: Merte, Rolf, Matthias, Bjorn, Kock, Sonke
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Figueroa; Jaime
• Application Number:
  US11/661,290
• Publication Number:
  US 20080021597A1
• Time in Patent Office: 1,827 Days
• Field of Search: 700/255, 700/123, 340/500, 340/540, 340/541, 340/556, 340/679, 250/221, 307/117, 348/143, 348/152, 345/420, 901/46, 901/47
• 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, comprising:

a safety sensor system for detection of objects in a working area of the handling appliance;

a safety controller which interacts with a controller of the handling appliance and, in the process of interacting, controls safety-relevant functions of the handling appliance as a function of signals transmitted from the safety sensor system,

wherein the safety sensor system includes non-contacting proximity sensors each having respective detection areas so that a safety-relevant part of the working area of the handling appliance is covered by the detection areas of the proximity sensors,

wherein the proximity sensors respectively comprise at least one sensor with different physical principles of operation with respect to the principles of operation of other proximity sensors among the proximity sensors included in the safety sensor system,

wherein each proximity sensor determines distance information about the distance of a detected object from the respective proximity sensor,

wherein the safety controller controls the safety-relevant functions of the handling appliance by outputting the signals, which are based on the distance information respectively determined by the proximity sensors to the controller of the handling device.

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

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

4. The apparatus as claimed in claim 1, wherein the proximity sensors include at least two sensors selected from the group of an imaging sensor, a microwave sensor, and a radar sensor.

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.

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 transmission of the signals 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 comprise proximity switches with variably adjustable switching distances, so that the proximity switches 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 comprise at least one ultrasound sensor.

12. The apparatus as claimed in claim 1, wherein the proximity sensors comprise at least one microwave sensor.

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 proximity sensors are fitted to a base of the robot 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, and is transmitted to the safety controller.

22. An apparatus as claimed in claim 11, wherein the at least one ultrasound sensor has a beam angle of between 10°

and 40°

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

40°

.

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

24. The apparatus as claimed in claim 23, wherein the at least one microwave sensor is configured for mechanical scanning, 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.

25. The apparatus as claimed in claim 23, wherein individual elements of an antenna array of the at least one microwave sensor is configured to 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.

26. The apparatus as claimed in claim 15, wherein the position-finding sensors are on the robot axes.

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 a working area of the handling appliance, the safety sensor system including non-contacting proximity sensors, each having respective detection areas so that a safety-relevant part of a working area of the handling appliance is covered by the detection areas of the proximity sensors, the proximity sensors comprising at least one sensor with different physical principles of operation with respect to the principles of operation of other proximity sensors among the proximity sensors included in the safety sensor system, the method comprising:

controlling safety-relevant handling appliance functions as a function of signals from the safety sensor system;

determining presence information about the presence of people and/or objects in the working area of the handling appliance zone-by-zone by the safety sensor system;

determining position information about the position of the moving part or parts of the handling appliance zone-by-zone;

determining distance information about the distance of a detected object from the respective proximity sensor, and

wherein the step of controlling of the safety-relevant handling appliance functions includes controlling the safety-relevant handling appliance functions as a function of the determined presence information, the determined position information, and the distance information.

17. The method as claimed in claim 16, wherein the handling appliance is a freely programmable industrial robot with an arm 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 the determined position information comprises information about the position of the robot arm detected by position sensors on the robot axes.

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 the method further comprises switching off the robot if the safety sensor system identifies the presence of someone in the danger zone, and switching the robot to a slower safety mode if someone is present in the safety zone.

19. The method as claimed in claim 18, comprising 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, switching the robot to a slower safety mode.

20. The method as claimed in claim 17, comprising masking out information about objects from a safety zone or danger zone in which the robot arm is located.

21. The method as claimed in claim 17, comprising masking out information 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.

27. The method as claimed in claim 16, wherein the proximity sensors include at least two sensors selected from the group of an imaging sensor, a microwave sensor, and a radar sensor.