METHOD AND SYSTEM FOR OPERATING A ROBOT

Abstract

A method for operating at least one robot includes determining the minimum distance of the robot from an obstacle, in particular the closest obstacle to the robot, in particular excluding at least one previously known, in particular temporary, obstacle; reducing the maximum speed of the robot if this minimum distance is below a first minimum distance; and reducing this maximum speed of the robot more if the minimum distance is below a second minimum distance which is smaller than the first minimum distance.

Claims

1-10. (canceled)

11. A method for operating at least one robot, the robot including a manipulator arm comprising a plurality of joints and corresponding drives for actuating the joints controlled by a robot controller, the method comprising: determining with a computer a minimum distance between the robot and an obstacle; issuing a command by the robot controller to at least one drive of the robot for reducing a maximum velocity of the robot in response to the determined minimum distance falling below a first minimum distance value; and issuing a command by the robot controller to at least one drive of the robot for further reducing the maximum velocity of the robot in response to the minimum distance falling below a second minimum distance value that is less than the first minimum distance value.

12. The method of claim 11, wherein the minimum distance is at least one of: determined for an obstacle that is closest to the robot; determined while excluding at least one previously known obstacle; or determined while excluding at least one previously known temporary obstacle.

13. The method according to claim 11, further comprising: at least one of: determining a pose of the obstacle, or determining a pose of the robot; wherein the minimum distance is determined on the basis of at least one of the pose of the obstacle or the pose of the robot.

14. The method of claim 13, wherein at least one of: determining a pose of the obstacle comprises determining the pose relative to a reference fixed in the environment; or determining a pose of the robot comprises at least one of: determining the pose relative to a reference fixed in the environment, determining the pose relative to the same reference used for determining the pose of the obstacle, determining the pose based on an end effector of the robot, determining the pose based on a detected joint position of the robot, or determining the pose based on a payload carried by the robot.

15. The method of claim 11, wherein the determining the minimum distance includes determined the minimum distance with at least one sensor.

16. The method of claim 15, wherein at least one of: determining the minimum distance with the sensor comprises determining the minimum distance on the basis of at least one of the pose of the obstacle or the pose of the robot; the at least one sensor is on of environment-based or robot-based; determining the minimum distance with the sensor comprises determining the minimum distance by at least one of: image processing, laser light, ultrasound, radar emission, a light grid, a projection, or in a capacitive manner.

17. The method of claim 11, wherein the minimum distance is determined by at least one data processing device which is external to the robot.

18. The method of claim 11, wherein determining the minimum distance comprises determining the minimum distance to a spatial area of a group that comprises a plurality of discrete spatial areas.

19. The method of claim 18, wherein at least one of: determining the minimum distance to a spatial area comprises determining the minimum distance between a first discrete spatial area of the group, and a second discrete spatial area of the group or of a different group of discrete spatial areas; or the discrete spatial areas are prespecified, environment-based spatial areas.

20. The method of claim 11, wherein reducing the maximum velocity comprises at least one of: reducing the maximum velocity in steps between at least two minimum distances; or reducing the maximum velocity continuously between at least two minimum distances.

21. The method of claim 11, wherein reducing the maximum velocity comprises at least one of: reducing the maximum velocity on the basis of a relative velocity between the obstacle and the robot; reducing the maximum velocity on the basis of a planned movement of the robot; or reducing the maximum velocity as a function of at least one of: a working reach, a current velocity, or a payload.

22. The method of claim 11, wherein at least one of: reduction of the maximum velocity is parameterized by a user; reduction of the maximum velocity is based on a configuration of a signal transmission of at least one of the robot or of a sensor for determining the minimum distance.

23. A system for operating at least one robot, the system comprising: means for determining a minimum distance between the robot and an obstacle means for reducing a maximum velocity of the robot in response to the determined minimum distance falling below a first minimum distance value; and means for further reducing the maximum velocity of the robot in response to the minimum distance falling below a second minimum distance value that is less than the first minimum distance value.

24. The system of claim 23, wherein the minimum distance is at least one of: determined for an obstacle that is closest to the robot; determined while excluding at least one previously known obstacle; or determined while excluding at least one previously known temporary obstacle.

25. A computer program product for operating at least one robot, the robot including manipulator arm and drives for moving the manipulator arm, the computer program product including program code stored on a non-transient, computer-readable storage medium, the program code, when executed by a computer, causing the computer to: determine a minimum distance between the robot and an obstacle; reduce a maximum velocity of the robot in response to the determined minimum distance falling below a first minimum distance value; and further reduce the maximum velocity of the robot in response to the minimum distance falling below a second minimum distance value that is less than the first minimum distance value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention.

[0073] FIG. 1 schematically depicts two robots and a system for operating the robots according to an embodiment of the present invention;

[0074] FIG. 2 illustrates a method of operating the robots according to an embodiment of the present invention; and

[0075] FIG. 3 illustrates a reduction in a maximum velocity according to an embodiment of the present invention.

DETAILED DESCRIPTION

[0076] FIG. 1 shows an example of a stationary robot 2 and a mobile robot 30 with a robot arm 32 with an end effector in the form of a gripper 33 with a payload 34, and a system for operating these robots according to an embodiment of the present invention.

[0077] The system has a sensor 1 fixed in the environment, for example a camera with image processing, and sensors 31 fixed to the robot 30, for example laser scanners.

[0078] A common monitoring space of the sensors 1, 31 is divided into prespecified spatial areas that are fixed in the environment, as indicated by dashed lines in FIG. 1.

[0079] A data processing device 5 which is external to the robot receives joint positions of the robots 2, 30, and also signals from the sensors 1, 31.

[0080] From the joint position of the robot 2, the data processing device 5 determines in a step S10 (cf. FIG. 2) a current pose of this robot relative to an environment-based reference system, which is indicated in FIG. 1 as (x, y, z). Analogously, the data processing device 5 determines a current pose of the robot 30 from the joint position of the robot 30, in particular an odometrically detected pose of its mobile base.

[0081] Likewise, the data processing device 5 can also determine the current pose of the robot 1 and/or 30 on the basis of the sensor 1 in step S10, which can be particularly advantageous in the case of the mobile robot.

[0082] Then, in a step S20, the data processing device 5 determines from these detected poses each of the monitored spatial areas that are penetrated by the given robot(s)—that is, in which the given robot(s) is at least partially present. These monitored spatial areas are each indicated by cross-hatching in FIG. 1 (these are different for the two robots 1, 30).

[0083] On the basis of the sensor signals from the sensors 1, 31, the data processing device 5 also determines in step S20 a pose of unforeseen obstacles, and which of the monitored spatial areas are penetrated by the given obstacle—that is, in which the given obstacle is at least partially present.

[0084] For this purpose, a person 4 is shown by way of example in FIG. 1. In addition, the monitored spatial area F.sub.6.1 which this person has penetrated is indicated by cross-hatching.

[0085] Then, in a step S30, the data processing device 5 determines for each of the robots 2, 30 the minimum distances between all monitored spatial areas penetrated by an unforeseen obstacle (in the embodiment, the single monitored spatial area F.sub.6.1) and the monitored spatial area penetrated by the robot—of which FIG. 1 shows by way of example the spatial areas F.sub.4.2, F.sub.5.3 and F.sub.8.3, with indices (the indices each identify the row and column of the corresponding monitored spatial area).

[0086] Then, in step S30, the data processing device 5 selects the least of these minimum distances for each of the robots 2, 30,—that is, the least minimum distance between a monitored spatial area penetrated by the robot and a monitored spatial area penetrated by the obstacle—as the minimum distance between each given robot and the obstacle.

[0087] For this purpose, the minimum distances .sub.6.1a.sub.4.2 between the monitored spatial areas F.sub.6.1 and F.sub.4.2, 6.1a.sub.5.3 between F.sub.6.1 and F.sub.5.3 and .sub.6.1a.sub.8.3 between F.sub.6.1 and F.sub.8.3. are indicated by way of example in FIG. 1. On the basis of the environment-based, prespecified monitored spatial areas, these distances can advantageously be determined in advance and saved in tabular form.

[0088] It can be seen that the minimum distance between the obstacle 4 and the robot 2 and/or the monitored spatial areas that are penetrated by them and that are closest to each other is the distance .sub.6.1a.sub.5.3, since none of the other spatial areas currently penetrated by the robot 2 has a lesser distance from the spatial area penetrated by the obstacle 4, and it can also be seen that the minimum distance between the obstacle 4 and the robot 30 or the monitored spatial areas that are penetrated by them and that are closest to each other is the distance .sub.6.1a.sub.4.2.

[0089] Then, in a step S40, the data processing device 5 determines an amount for each of the robots 2, 30 by which the maximum velocity permitted for this robot with a free working area is reduced, this amount increasing with the determined minimum distance, and transmits this amount to the robot(s) or its controller, which then reduces the maximum velocity accordingly in a step S50.

[0090] FIG. 3 shows an example of such a reduction of the maximum velocity of the robot 2 as a solid line. It can be seen that its maximum velocity is reduced if the minimum distance to the obstacle 4 falls below a first minimum distance A.sub.1, is reduced even more if the minimum distance (also) falls below a second minimum distance A.sub.2 which is less than the first minimum distance, is reduced even more if the minimum distance (also) falls below a third minimum distance A.sub.3, which is less than the second minimum distance, and is reduced even more if the minimum distance falls below (even) a fourth minimum distance A.sub.4 which is less than the third minimum distance.

[0091] Although embodiments have been explained in the preceding description, it is noted that a large number of modifications are possible.

[0092] In particular, instead of the monitored spatial areas penetrated by a robot, the minimum distance between the monitored spatial area (closest to the robot) and one or more robot-based references, in particular its elbow, end flange and/or tool, can be determined directly.

[0093] Instead of the step-by-step reduction explained with reference to FIG. 3, the maximum velocity can also be reduced, at least partially, continuously as the distance decreases.

[0094] As an example, FIG. 3 shows such a reduction in the maximum velocity for the robot 30 as a dashed line. In addition, FIG. 3 also shows that the maximum velocity can be reduced differently for different robots.

[0095] It is also noted that the embodiments are merely examples that are not intended to restrict the scope of protection, the applications and the structure in any way. Rather, the preceding description provides a person skilled in the art with guidelines for implementing at least one embodiment, with various changes, in particular with regard to the function and arrangement of the described components, being able to be made without departing from the scope of protection as it arises from the claims and from these equivalent combinations of features.

[0096] While the present invention has been illustrated by a description of various embodiments, and while these embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit and scope of the general inventive concept.

REFERENCE NUMERALS

[0097] 1 camera (sensor) [0098] 2 stationary robot [0099] 30 mobile robot [0100] 31 laser scanner (sensor) [0101] 32 robot arm [0102] 33 gripper [0103] 34 payload [0104] 4 person (obstacle) [0105] 5 external data processing device [0106] F.sub.4.2, F.sub.5.3, F.sub.6.1, F.sub.8.3 monitored spatial area [0107] .sub.6.1a.sub.4.2, 6.1a.sub.5.3, 6.1a.sub.8.3 distance [0108] (x, y, z) environment-based reference [0109] A1, A2, A3, A4 minimum distance