Device And Method For Secure Control Of A Manipulator

Abstract

A method for controlling a robotic manipulator includes manually controlling the robotic manipulator with an operating device connected to a control device of the manipulator and having a first safety level, and monitoring an admissible state of operation with a protective device connected to the control device and having a second, higher safety level, The manipulator performs an operation commanded by the operating device only if the protective device is communicating an admissible state to the control device.

Claims

1. A method for safe control of a robotic manipulator, comprising: manually controlling the robotic manipulator with an operating device connected to a control apparatus of the robotic manipulator; monitoring an admissible state of operation of the robotic manipulator with a protective device connected to the control apparatus; wherein the operating device has a first, low safety level and an enabling device that does not serve for personal protection and is not subject to increased safety requirements; wherein the protective device has a second safety level that is higher than the first safety level; and transferring the control apparatus to a defined operation mode in which the manipulator only performs an operation commanded by the operating device if the protective device transmits an admissible state to the control apparatus; wherein the control apparatus is transferred to the defined operation mode by at least one of: activating the operating device, manually connecting the control apparatus and the operating device, or entering a control command into the operating device; wherein the protective device does not transmit an admissible state to the control apparatus if a user is within an inadmissible protection area.

2. The method of claim 1, wherein the operation commanded by the operating device comprises a motion of the robotic manipulator.

3. The method of claim 1, wherein manually controlling the robotic manipulator with an operating device comprises controlling the robotic manipulator with a selected one of a plurality of operating devices.

4. An arrangement for controlling a robotic manipulator, comprising: a control apparatus configured to control movement of the robotic manipulator; an operating device having a first, low safety level and configured to facilitate manual control of the robotic manipulator by a user, the operating device connected to the control apparatus and including an enabling device; and a protective device connected to the control apparatus and having a second safety level that is higher than the first safety level, the protective device monitoring an admissible state of operation of the robotic manipulator; wherein the control apparatus is transferred to a defined operation mode in which the manipulator only performs an operation commanded by the operating device if the protective device transmits an admissible state to the control apparatus; wherein the control apparatus is transferred to the defined operation mode by at least one of: activation of the operating device, manual connection of the control apparatus and the operating device, or entry of a control command into the operating device; and wherein the protective device does not transmit an admissible state to the control apparatus if the user is within an inadmissible protection area.

5. The arrangement of claim 4, further comprising an emergency stop operating device having a second safety level that is higher than the first safety level and which is connected to the control apparatus of the robotic manipulator.

6. The arrangement of dam 4, further comprising at least one additional operating device having a first, low safety level.

7. The arrangement of claim 4, further comprising at least one additional operating device having a second safety level that is higher than the first safety level. The arrangement of dam 4, wherein the protective device includes at least one of a safety fence, a safety door, a closing contact, or an area monitoring device.

9. The arrangement of claim 8, wherein the area monitoring device comprises an optical device.

10. A computer program stored on a non-transitory, computer-readable storage medium, the computer program, when run by a control apparatus of a robotic manipulator, causing the control apparatus to: facilitate manual control of a robotic manipulator with an operating device connected to the control apparatus; monitor an admissible state of operation of the robotic manipulator with a protective device connected to the control apparatus; the operating device having a first, low safety level and an enabling device that does not serve for personal protection and is not subject to increased safety requirements; the protective device having a second safety level that is higher than the first safety level; and transfer the control apparatus to a defined operation mode in which the manipulator only performs an operation commanded by the operating device if the protective device transmits an admissible state to the control apparatus; wherein the control apparatus is transferred to the defined operation mode in response to at least one of: activation of the operating device, manual connection of the control apparatus and the operating device, or entry of a control command into the operating device; wherein the protective device does not transmit an admissible state to the control apparatus if a user is within an inadmissible protection area.

11. A computer program product with programming code stored on a non-transitory, computer-readable storage medium and comprises a computer program according to claim 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate 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.

[0028] Additional advantages and features result from the subordinate claims and the exemplary embodiments. To this end the sole figure shows the following, partially in schematic form.

[0029] FIG. 1: a control system for a robot according to an embodiment of the present invention.

DETAILED DESCRIPTION

[0030] FIG. 1 shows in cross section a six-axis industrial robot 1 having a control cabinet 2. Robot 1 is only allowed to move within a working area bounded by a protective fence 3 in which no persons are allowed to be present during automatic operation, and which thus defines a prohibited protected zone.

[0031] To this end it has a protective door 3.1, which is monitored through a closing contact 3.2. To guarantee safety of personnel, the protective device with protective fence 3, protective door 3.1 and closing contact 3.2 uses secure technology. In particular, closing contact 3.2 is connected to control cabinet 2 using secure technology through the multi-channel redundant conductor L.sub.2-3 indicated in FIG. 1, and accordingly has a second, high safety level, for example category 3.

[0032] For controlling robot 1, in particular for inputting travel commands in joint or world coordinates, a standard PC 4 is provided. The latter is connected via a simple network, indicated in FIG. 1 in single-channel form by conductor L.sub.2-4, to control cabinet 2, which interprets and processes the control commands entered via the keyboard of PC 4 and actuates the drives of robot 1 accordingly. The input data are visualized on the screen of PC4, for example by depicting the robot in the virtual working space and/or its joint angles. The standard PC 4, connected by a single channel to control cabinet 2, is thus an operating device using non-secure technology, of a first, low safety level, for example category 1 or lower.

[0033] In order to ensure safety of personnel from problems not detected by the protective device, within reach next to the PC 4 a standard emergency off switch 5 (indicated in multi-channel form in FIG. 1 by conductor L.sub.2-4) is connected to control cabinet 2, and thus forms an emergency off input device of an equally high or higher safety level than protective device 3-3.2.

[0034] In order to be able to also control the robot reliably within the protected zone, a conventional manual programming device 6 with an emergency off switch 6.1 and an enabling pushbutton 6.2 can be connected in addition through multi-channel conductor L.sub.2-6 to control cabinet 2 using secure technology.

[0035] Control over the manipulator can be turned over either to the PC 4 or to the manual programming device 6, if present, by a user action. If control is turned over to the manual programming device 6, the control system 2 of the robot ignores inputs from the PC 4.

[0036] Conversely, in an operating mode for controlling the manipulator by means of operating device 4, in which control device 2 is placed by switching the control system over, the control system executes only motions specified by the PC 4 as long as closing contact 3.2 reports a closed protective door 3.1 or does not report an open protective door 3.1 to control device 2, thereby guaranteeing that no person is entering the protected zone defined by protective fence 3. If other problems arise, for example intrusion into the protected zone through a hole in protective fence 3, the operator can shut down the robot reliably by operating the emergency off button 5 situated in quickly accessible proximity.

[0037] Thus the robot can be controlled inexpensively and yet reliably through a standard PC 4, which uses non-secure technology and is connected to control cabinet 2, as a result of using the protective device 3, 3.1, 3.2 provided for automatic operation.

[0038] 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 discussed 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 LABELS

[0039] 1 robot

[0040] 2 control cabinet

[0041] 3 protective fence

[0042] 3.1 protective door

[0043] 3.2 closing contact

[0044] 4 standard PC (operating device)

[0045] 5 emergency off switch

[0046] 6 manual programming device

[0047] 6.1 emergency off switch

[0048] 6.2 enabling pushbutton

[0049] L.sub.2-x conductor (one- or two-channel)