DE102010007025A1 - Method for monitoring manipulator area, particularly for robot, involves presetting geometric limit of area to be monitored and monitoring object within predetermined limit by environment sensing unit - Google Patents

Abstract

The method involves presetting a geometric limit (WS) of the area to be monitored and monitoring an object within the predetermined limit by an environment sensing unit. The limit is predetermined on the basis of a detected environment or a kinematics of the manipulator in a partially automatic manner. Independent claims are also included for the following: (1) a device for monitoring a manipulator area, particularly for a robot; and (2) a computer program product with a program code for executing a monitoring method.

Description

The present invention relates to a method and a device for monitoring objects within a manipulator space, the geometric limit of which is preset in a partially automated manner.

In order to prevent damage to objects not intended for rail planning and, in particular, to prevent human injury by manipulators, in particular industrial robots, it has hitherto been customary to physically close off the working space of the manipulator, for example by protective fences, light barriers or the like, which prevent access to an automation cell. However, such a solution is complicated and inflexible and thus unfavorable, especially for mobile or interacting manipulators.

Therefore, the beats DE 10 2007 007 576 B4 to compare three-dimensional images of the working space in an undisturbed target state and a current, to be monitored actual state. If both images deviate from one another, it is possible to conclude an invalid object which causes a difference between the two images. The limits of the working space shown here are defined manually by the user via a man-machine interface.

This system is complex due to image processing. In addition, a change of an object within the working space, for example, the replacement of a feeder by a feeder with other optical contours, can be classified unnecessarily as a workspace infringement.

Alternatively, from the DE 10 2004 041 821 A1 a method according to the preamble of claim 1 is known. Thereafter, laser scanners monitor a workspace for objects. The limit of the monitored workspace is also defined manually. In the working space permissible objects such as feeders and the like, and in particular the manipulator itself, the sensor electronics does not respond by hiding corresponding detection zones.

Unfortunately, both methods for specifying the boundaries of the monitored space require manual definition by the user, which is usually done by means of a graphical user interface on which the user must position geometric primitives such as points and lines. This is especially time-consuming and error-prone when teaching several different new workspaces, as is the case with mobile manipulators or at trade fair stands with a rapidly changing environment.

The object of the present invention is to improve the monitoring of a manipulator space.

This object is achieved by a method having the features of claim 1. Claim 8 provides a device, claim 10, a computer program product, in particular a storage medium or a data carrier, for performing a method according to claim 1 under protection. The subclaims relate to advantageous developments.

An environment detection device monitors whether one or more unavailable or permissible objects are present within a manipulator space. If this is the case, a corresponding, possibly graduated, reaction can take place. For example, a working space of the manipulator for all or selected parts of the manipulator, such as his tool and / or his arm, be allowed. If an unintentional object is detected in this working space, the manipulator can for example be safely shut down in order to prevent a collision. For example, in the direction of penetration in front of the workspace, a warning room can be defined. If an unidentified object is detected in this warning space, for example, a warning can be output and / or the speed of the manipulator can be reduced. Equally, it is also possible to monitor a protective room which is permissible, for example, for operators, in which case parts of the manipulator, in particular, are detected as objects not intended and trigger a corresponding reaction, such as warning, speed reduction or shutdown. In the monitored room permissible objects, ie in particular those whose existence was considered in the planning of a manipulator work program, such as parts of the manipulator itself, supply and discharge devices, tool cabinets and the like, may preferably be provided within the working space, so that their detection none of the above triggered reactions triggers.

According to the invention, a geometrical boundary of the space to be monitored or monitored is no longer specified purely manually but partially or completely automatically on the basis of a previously recorded environment and / or kinematics of the manipulator.

In this case, the boundary can be defined partially or completely automatically by, in particular, along a (r), preferably extended (n), two- or three-dimensional detected environmental contour. In this way, the user does not have to manually define the boundary according to the surrounding contour by inputting geometric primitives or the like and to approximate the surrounding contour with difficulty and error prone. Instead, the limit is automatically set, for example along a detected environmental contour.

In a first step, the limit may be specified as a function of the environmental detection device, for example its range and the like. Then, in a second step, in areas in which extended environmental contours have been detected within the boundary defined in the first step, the boundary can be defined on the basis of these environmental contours.

The limit can be adjusted automatically and / or by the user. Thus, for example, such a predetermined limit can be shortened automatically or partially automatically based on corresponding user inputs in total or in sections to the manipulator in order to provide tolerances or to take into account a braking distance of the manipulator. Similarly, the predetermined limit can also be extended in whole or in sections, for example as a protective space boundary or to allow penetration of a working tool into an environment to be processed.

Additionally or alternatively, a previously detected environment can also be used for hybrid, i. e. combined manual and semi-automated specification of the boundary, in particular in a graphical user interface, to be provided. In particular, not extended environmental contours, which in the present case especially understood objects or contours are understood with lesser extent in one or more spatial directions such as corners, edges, columns, beams and the like, can serve as anchoring elements that are fully automatic or semi-automatic with the user, For example, geometry primitives such as lines, in particular lines or curves, surfaces, in particular planes or spheres, bodies, in particular cuboids or spheres, and the like can be connected, for example, adjacent anchoring elements or along extended environmental contours. Similarly, such detected objects or contours can serve to define unmonitored subspaces, for example access corridors, supply and discharge passages and the like.

In a preferred embodiment, the environment of the manipulator is detected in advance by the environment detection device, which is subsequently also used to monitor the room. This not only saves equipment expenditure, but also reduces transfer errors between the detection of the environment for setting the limit on the one hand and the monitoring of the so limited space on the other. The environment detection device can, for example, have one or more, preferably non-contact, distance sensors, for example laser scanners for one-dimensional distance detection, which can detect two- or three-dimensional distances by corresponding pivoting and / or method. Similarly, however, ultrasonic, infrared, microwave, radar, imaging and -auswertende or other sensors are used.

A monitored room has a boundary. In this case, the space may be composed of partial spaces, for example rooms monitored by different sensors and / or unmonitored partial spaces such as access corridors and the like. Accordingly, its boundary may also have several sections or areas which are not necessarily all related. In particular, a manipulator-remote, outer boundary of the monitored space can represent a limit in the sense of the present invention.

Further advantages and features emerge from the subclaims and the exemplary embodiments. This shows, partially schematized:

1 in plan view from above, a mobile robot with a room monitoring device according to an embodiment of the present invention; and

2 . 3 an inventive specification of the working space limit for the mobile robot of 1 ,

1 shows in plan view from above a mobile six-axis articulated robot 1 , Its base frame 1.1 is on a mobile platform 2 arranged over caterpillars 2.1 in the room is movable. Rotatable about a vertical axis on the base frame 1.1 is a carousel 1.2 with a rocker rotatable about a horizontal axis 1.3 hinged, at this one about an axis parallel to this rotation rotatable arm 1.4 which carries a central hand with three axes of rotation intersecting in one point, at whose flange a tool 1.5 is attached.

On the mobile platform 2 are four laser scanners 3A to 3D arranged, for example, by pivoting or a two-dimensional detection each one in 1 scan shaded area A, B, C and D and can capture objects therein. In a modification, not shown, alternatively, for example, a sensor with the arm 1.4 swing and thus always check the area in which the robot acts. Similarly, sensors can also be arranged inertially or stationary and communicate, for example, via radio with a mobile robot.

In the environment are exemplarily an extended environmental contour 4.1 as well as two pillars 4.2 drawn, which will be discussed in more detail below.

When the robot is maximally extended in a horizontal plane, the tool moves 1.5 when turning around the vertical axis of the carousel 1.2 the in 2 solid circle in this plane.

One recognizes in 1 in that the boundary is one of the environment detection means 3 with the four laser scanners 3A to 3D on the one hand, does not correspond to the maximum working space of the robot 1 corresponds to, so even with objects that are outside the maximum range of the robot (solid line in 2 ), but within the detection range A ∩ B ∩ C ∩ D (dashed in 2 ) would address a monitoring. On the other hand, the surrounding contour would also 4.1 , which projects into the working area of the robot and is taken into account in its path planning, classified as an unscheduled object.

According to the invention, therefore, the outer boundary WS 'of the working space to be monitored in a first, in 2 indicated step based on the kinematics of the robot 1 automatically predetermined such that only his maximum achievable working space is monitored, which is defined in the embodiment by circular discs, which drive his arm with tool at maximum in the circular disc plane robot when turning about the vertical axis of the carousel. Objects, however, from the laser scanners 3A to 3D in areas A, B, C and D are ignored or the range of the laser scanners changed accordingly.

In a second, in 3 indicated step, the boundary WS of the working space to be monitored is additionally defined automatically by detected extended environmental contours, as far as they are within the predetermined according to the kinematics of the robot limit WS '(see. 2 ) lie. The laser scanners capture this 3A to 3D in a new position of the platform 2 of the mobile robot 1 in advance the environment, so that the position of such environmental contours relative to the robot is known, in the embodiment, the corner projecting into the boundary WS ' 4.1 , Then the boundary WS 'in this area is defined by the detected contour, ie it follows this.

In a further step, the boundary WS in this area is automatically shortened by a factor specified by the operator or dependent on the robot or its work program, so that it no longer stops on the contour 4.1 runs, but parallel to this closer to the robot 1 out. This prevents the contours of small movements of the platform of the mobile robot during its operation 4.1 is undesirably detected as an unscheduled object in the workspace.

In a further step, the operator wants to define a non-object monitored access corridor to the stand of the mobile robot, for example marked on the hall floor and through the two pillars 4.2 is limited.

To do this, the pre-recorded environment including the one being scanned by the scanner 3A covered pillars 4.2 provided in a graphical user interface, for example, essentially the 3 accordingly. Then, for example, by selecting a corresponding command, the user can partially automatically specify a cuboid as a protected space S not monitored for objects in such a way that the latter is in its robotic edges with the pillars 4.2 concludes and to the mobile platform 2 enough. For this purpose, it is sufficient, for example, on the graphical user interface, the two pillars shown 4.2 as well as a geometry primitive "cuboid" to mark and, for example, the robot-remote outside by jointly marking the pillar 4.2 assign, so that the boundary WS in this area by the on the basis of the detected pillars 4.2 predetermined, unsupervised shelter S is defined.

By the automated specification of the boundary WS on the basis of the kinematics of the robot, in particular its respective maximum extension, and by the scanner 3A to 3D captured environment 4.1 . 4.2 , this partially automated by specifying the geometry primitive S and the shortening factor of the boundary in the contour 4.1 can still be adjusted manually, it is possible, even for the mobile robot with changing locations and concomitant changing environment quickly and failsafe to specify appropriate working space limits.

Another advantage is shown by a tolerance-related incorrect positioning of the moving base of a mobile manipulator with respect to a taught starting base position. While the monitoring of the space specified for the home base position may result in a response of the monitor when the manipulator is positioned too close to an environmental contour due to navigation errors, for example, the at least semi-automated specification of the boundary will be based on the current actual time. Basic environment to a monitored space that has been properly adjusted to the changed position.

During operation, the laser scanners check 3A to 3D constantly the working space defined by its boundary WS. In this permissible objects may be provided, for example, the parts 1.2 to 1.5 of the robot 1 whose current position is known from its joint coordinates and whose contour is known, for example, from CAD data. Is such a proposed permissible object, for example, a part 1.2 to 1.5 at the position defined by the current joint coordinates of the robot, detected by the laser scanners, this is ignored without the monitoring responding.

Captures one of the laser scanners 3A to 3D an unauthorized, inadmissible object within the boundary WS, for example an operator who has entered the working area of the robot without authorization and has left the protection area S, becomes the robot 1 safely shut down. Similarly, for example, depending on the distance of the detected impermissible object to the arm of the robot, a gradual response by issuing a warning at sufficiently large distance and the speed of the robot is reduced, on the other hand, at too short distance, the robot is shut down safely.

LIST OF REFERENCE NUMBERS

1

robot

1.1

base frame

1.2

carousel

1.3

wing

1.4

poor

1.5

wrist

2

mobile platform

2.1

caterpillar track

3A

3D

Laser scanner (environment detection device)

4.1

extensive environment contour

4.2

pier

A-D

detection range

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007007576 B4 [0003]
• DE 102004041821 A1 [0005]

Claims (10)

Method for monitoring a manipulator room, in particular for a robot ( 1 ), with the steps: specifying a geometric boundary (WS) of the space to be monitored; and monitoring for non-intended objects within the predetermined boundary (WS) by an environment detection device ( 3A - 3D ); characterized in that the boundary (WS) is at least partially automated based on a detected environment ( 4.1 . 4.2 ) and / or a kinematics of the manipulator is specified. Method according to claim 1, characterized in that the environment ( 4.1 . 4.2 ) of the manipulator in advance by the environment detection device ( 3A - 3D ) is detected. Method according to one of the preceding claims, characterized in that the space to be monitored comprises a working space which is permissible for parts of the manipulator, a shelter (S), which is not permissible for parts of the manipulator, and / or at least one warning space, wherein a, preferably stepped reaction takes place when the environment detection device detects an unidentified object in a work or warning room. Method according to one of the preceding claims, characterized in that the boundary (WS) at least partially automated by a, preferably extended, environmental contour ( 4.1 ) is defined. A method according to claim 4, characterized in that a pre-recorded environment ( 4.2 ) is provided for partial manual specification of the boundary (WS), in particular in a graphical user interface. Method according to one of the preceding claims, characterized in that a predetermined limit (WS) is shortened at least partially automated towards the manipulator or extended away from the manipulator. Method according to one of the preceding claims, characterized in that a specification of unmonitored subspaces (S) is provided. Device for monitoring a manipulator room, in particular for a robot, comprising: an environment detection device ( 3A - 3D ) for monitoring for non-intended objects within a predetermined geometric boundary (WS) of the space to be monitored; characterized by a presetting device for at least partially automated presetting of the boundary (WS) on the basis of a detected environment ( 4.1 . 4.2 ) and / or a kinematics of the manipulator, which is set up for carrying out a method according to one of the preceding claims. Apparatus according to claim 8, characterized in that the environment detection device at least one, preferably non-contact, distance sensor ( 3A - 3D ) for one-, two- or three-dimensional distance detection. Computer program product with program code, which is stored on a machine-readable carrier and carries out a method according to one of the preceding claims 1 to 7, when executed in a device according to claim 8 or 9.

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