JP2009142941A - Control device and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a robot, by which a burden of an operator in teaching operation is reduced to secure the safety of the operator. <P>SOLUTION: The control device 1 related to an embodiment of the present invention includes: an operation pendant 10 for inputting a command to a robot arm 30; and an acceleration sensor 11 incorporated in the operation pendant 10 for detecting the acceleration of the operation pendant 10. When there is an input of acceleration exceeding a prescribed value from the acceleration sensor 11, the operation of the robot arm 30 is stopped. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device and a control method, and more particularly, to a control device and a control method for making an emergency stop during teaching work of a robot.

  The teaching operation of the operation of the industrial robot is performed by operating a portable operation pendant. At the time of teaching work, the operator must operate the operation pendant while approaching the robot. At this time, the robot may behave differently from the one intended by the operator due to a failure of the robot, an operation mistake of the operation pendant, or the like. In such a case, it is necessary to avoid danger to workers around the robot and ensure safety.

  For this reason, the conventional operation pendant is provided with a switch called a deadman switch. This deadman switch enables teaching work and robot operation only when the operator holds the operation pendant in a normal posture. For example, the 3-position type deadman switch enables the operation of the operation pendant only when the operator half-presses the deadman switch. On the other hand, when the press is released or completely pressed, the operation by the operation pendant, that is, the operation of the robot is prohibited.

  This is based on the experience that an operator feels a change in the operation of the robot for some reason and suddenly releases or claws the operation pendant. By turning off the deadman switch, safety is ensured by performing teaching operation and stopping the robot.

Further, means for ensuring safety when a robot operation is determined to be abnormal has been developed (see Patent Documents 1 and 2). In Patent Document 1, the acceleration of the robot itself is detected by an acceleration sensor attached to the robot. When the acceleration detected by the acceleration sensor is larger than a predetermined value, the robot operation is stopped urgently. In Patent Document 2, an external force is estimated by an acceleration sensor attached to the robot, and the robot is automatically moved in a direction in which the estimated external force is reduced.
JP 2005-293098 A JP-A-6-91587

  Conventionally, during a teaching operation, it is necessary to perform a teaching operation with the deadman switch of the operation pendant being half-pressed. For this reason, there is a problem that the operator is burdened with the work burden of pressing the button halfway.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to reduce the burden on the worker during teaching work and to ensure the safety of the worker. And providing a control method.

  In the control device according to the first aspect of the present invention, an operation pendant that inputs a command to the controlled body, an acceleration sensor that detects acceleration of the operation pendant, and an acceleration that is greater than or equal to a predetermined value is input from the acceleration sensor. And an operation control unit for stopping the operation of the controlled body. As a result, the work burden on the worker can be reduced and the safety of the worker can be ensured.

  The control device according to a second aspect of the present invention further includes a deadman switch provided in the operation pendant in the control device, wherein the operation control unit is a pressing state of the deadman switch or the acceleration sensor. The operation of the controlled body is stopped based on the acceleration detected in step. Thereby, the safety of the operator can be further ensured.

  In the control device according to a third aspect of the present invention, in the control device described above, the acceleration sensor detects an inclination of the operation pendant as an acceleration. Thereby, the safety of the operator can be further ensured.

  In the control device according to a fourth aspect of the present invention, in the control device described above, the operation of the controlled body is controlled based on a change in acceleration of the operation pendant detected by the acceleration sensor. Thereby, the work burden of teaching operation can be reduced.

  In the control device according to a fifth aspect of the present invention, in the control device described above, the acceleration sensor recognizes a position of the operation pendant, and the controlled body of the operation pendant is recognized by the acceleration sensor. The operating range is controlled based on the position. Thereby, it becomes possible to further ensure the safety of the operator.

  A control method according to a sixth aspect of the present invention is a control method for controlling a controlled body by a command input from an operation pendant, wherein the acceleration of the operation pendant is detected, and the acceleration of the operation pendant is a predetermined value. When it is above, the operation of the controlled body is stopped. As a result, the work burden on the worker can be reduced and the safety of the worker can be ensured.

  A control method according to a seventh aspect of the present invention is the control method described above, wherein the operation of the controlled object is performed based on a pressed state of a deadman switch provided on the operation pendant or an acceleration of the operation pendant. Stop. Thereby, the safety of the operator can be further ensured.

  In the control method according to an eighth aspect of the present invention, in the control method described above, the acceleration sensor detects an inclination of the operation pendant as an acceleration. Thereby, the safety of the operator can be further ensured.

  A control method according to a ninth aspect of the present invention controls the operation range of the controlled body based on a change in acceleration of the operation pendant in the control method described above. Thereby, the work burden of teaching operation can be reduced.

  A control method according to a tenth aspect of the present invention is the control method described above, wherein the position of the operation pendant is recognized, and the operation range of the controlled body is controlled based on the position of the operation pendant. Thereby, it becomes possible to further ensure the safety of the operator.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus and control method of a robot which can reduce a worker's burden at the time of teaching work and can ensure a worker's safety can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description is omitted as necessary for the sake of clarity.

Embodiment 1 FIG.
A control apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing an overall configuration of an industrial robot using a control device 1 according to the present embodiment. FIG. 2 is a block diagram for explaining the configuration of the control device 1 according to the present embodiment. Here, the control apparatus 1 for teaching the operation of the robot arm 30 as an example of the controlled body will be described.

  As shown in FIG. 1, the control device 1 according to the present embodiment includes an operation pendant 10 and a control panel 20. The operation pendant 10 inputs a command for the robot arm 30 that is a controlled body. The operation pendant 10 is portable and can be held by an operator who performs teaching work. When the operator operates the operation pendant 10, the robot arm 30 can be instructed to operate. Therefore, the operator performs teaching work with the operation pendant 10 while being close to the robot arm 30. The control panel 20 receives a command for the robot arm 30 from the operation pendant 10 and drives the robot arm 30 based on the command.

  As shown in FIG. 2, the operation pendant 10 includes an acceleration sensor 11 and an abnormality determination unit 12. The acceleration sensor 11 is built in the operation pendant 10. The acceleration sensor 11 detects the magnitude of the acceleration of the operation pendant 10. As the acceleration sensor 11, for example, a triaxial acceleration sensor capable of measuring triaxial acceleration in the XYZ directions can be used. The abnormality determination unit 12 determines whether the acceleration of the operation pendant 10 measured by the acceleration sensor 11 is equal to or less than a predetermined value (allowable acceleration value).

  The control panel 20 is provided with a robot safety circuit 21 and a robot power circuit 22. The robot safety circuit 21 is called a safety unit. The robot safety circuit 21 confirms that the robot arm 30 is in a safe state in which a signal is supplied from the abnormality determination unit 12 as a safety measure for the robot arm 30 having a high risk of contact with an operator. This is a safety interlock for operating 30. The robot power circuit 22 is a circuit that supplies power for driving the robot arm 30.

  When acceleration equal to or greater than the allowable acceleration value is input from the acceleration sensor 11 to the abnormality determination unit 12, the abnormality determination unit 12 stops supplying signals to the robot safety circuit 21. The robot safety circuit 21 stops the supply of power from the robot power circuit 22 to the robot arm 30 in response to the stop of the signal from the abnormality determination unit 12. When the supply of power to the robot arm 30 is cut off, the robot arm 30 stops.

  Here, with reference to FIG. 3, the control method of the robot arm 30 is demonstrated. FIG. 3 is a flowchart for explaining a control method of robot arm 30 according to the present embodiment. As shown in FIG. 3, first, the safety state is confirmed, and the teaching operation of the robot arm 30 is started (step S11). The safety state is a state in which a signal from the abnormality determination unit 12 is supplied to the robot safety circuit 21. At this time, the teaching operation from the operation pendant 10 is effective, and the robot arm 30 can be taught the operation. The robot arm 30 is driven by the power from the robot power circuit 22 in accordance with a command input from the operation pendant 10.

  Then, the acceleration sensor 11 measures the acceleration of the operation pendant 10 (step S12). Thereafter, gravity correction of the acceleration measured by the acceleration sensor 11 is performed (step S13). When the acceleration sensor 11 is tilted, the same result as that in which acceleration is applied due to gravity is obtained, so the influence of gravity is removed. Thereafter, the abnormality determination unit 12 determines whether or not the acceleration after gravity correction is equal to or less than an allowable acceleration value (step S14). When the measured acceleration is equal to or less than the allowable acceleration value, the abnormality determination unit 12 supplies a signal to the robot safety circuit 21 and the safety state is confirmed (step S14, YES).

  On the other hand, for example, in a state where the worker is exposed to danger such as when the robot arm 30 performs an unintended operation, the worker often performs an operation of moving the operation pendant 10 suddenly from the defense instinct. At this time, a sudden acceleration is measured by the acceleration sensor 11 provided in the operation pendant 10. Therefore, when the measured acceleration is larger than the allowable acceleration value, the abnormality determination unit 12 stops supplying the signal to the robot safety circuit 21. Thereby, it will be in a dangerous state (step S14, NO). If a dangerous state occurs, the robot safety circuit 21 cuts off the power supply from the robot power circuit 22 and stops the operation of the robot arm 30 (step S15).

  As described above, by measuring the acceleration of the operation pendant 10 held by the worker during the teaching work, the operation of the worker can be estimated. When a sudden change in acceleration occurs, the safety of the operator can be ensured by shutting off the power supply to the robot arm 30 and stopping the operation. Further, as in the prior art, it is possible to eliminate the burden on the operator that the deadman switch must be pressed halfway.

  It should be noted that not only the acceleration change of the operation pendant 10 in a state where the operator grips but also the operation pendant 10 itself has fallen or the operation pendant 10 is dropped, an acceleration greater than the allowable acceleration value is detected. In this case, the operation of the robot arm 30 can be stopped.

Embodiment 2. FIG.
A control apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 4 is a schematic diagram showing an overall configuration of an industrial robot using the control device 1 ′ according to the present embodiment. FIG. 5 is a block diagram for explaining the configuration of the control device 1 ′ according to the present embodiment. The present embodiment is different from the first embodiment in that a deadman switch 13 is provided on the operation pendant 10. 4 and 5, the same components as those in FIGS.

  As shown in FIG. 4, the control device 1 according to the present embodiment includes an operation pendant 10 and a control panel 20. The operation pendant 10 according to the present embodiment is provided with a deadman switch 13 that has been widely used in the past. In the present embodiment, for example, a three-position type deadman switch 13 is provided. The 3-position type deadman switch 13 makes the operator's teaching operation valid and permits the operation of the robot arm 30 only when the button is half-pressed and continuously held at a predetermined position.

  As shown in FIG. 5, the operation pendant 10 includes an acceleration sensor 11, an abnormality determination unit 12, and a deadman switch 13. In the control device 1 ′ according to the present embodiment, the control device 1 ′ enables the operator's teaching operation and permits the operation of the robot arm 30 based on the pressed state of the deadman switch 13. Further, as described in the first embodiment, the acceleration of the operation pendant 10 held by the operator is measured, and the operation of the robot arm 30 is stopped when a sudden change in acceleration occurs.

  Here, a method for controlling the robot arm 30 will be described. First, the pressed state of the deadman switch 13 is determined. When the deadman switch 13 is half-pressed, the operator's teaching operation is validated and the robot arm 30 is driven. On the other hand, when the pressing of the deadman switch 13 is released or when it is completely pressed, the operation by the operation pendant, that is, the operation of the robot is prohibited.

  Then, when the deadman switch 13 is in a half-pressed state, it is determined whether or not it is in a safe state in which a signal from the abnormality determination unit 12 is supplied to the robot safety circuit 21. After confirming the safe state, teaching work of the robot arm 30 is started. Therefore, the operation of the operation pendant 10 is valid only when the deadman switch 13 is half-pressed and the signal from the abnormality determination unit 12 is supplied to the robot safety circuit 21. Thereafter, as in the first embodiment, the acceleration of the operation pendant 10 is measured by the acceleration sensor 11, and it is determined whether or not the acceleration after gravity correction is equal to or less than the allowable acceleration value. When the measured acceleration is larger than the allowable acceleration value, the operation of the robot arm 30 is stopped.

  As described above, in the present embodiment, by using the acceleration sensor 11 and the deadman switch 13 together, it is possible to further ensure the safety of the worker.

Other embodiments.
The acceleration sensor 11 described above can detect not only the acceleration of the operation pendant 10 but also the gravity caused by tilting the operation pendant 10, and the inclination of the operation pendant 10. Therefore, when the tilt of the operation pendant 10 is detected (the posture of the operation pendant 10 is detected) and the tilt is larger than a predetermined value (allowable tilt angle), the operation of the operation pendant 10 is invalidated and the operation of the robot arm 30 is performed. You may make it stop. For example, when the operation pendant 10 is rolled to the floor or the like, the operation of the robot arm 30 is stopped when the inclination of the operation pendant 10 exceeds the allowable inclination angle. If no change in acceleration is detected, it may be determined that the operation pendant 10 is fixed and the operation of the robot arm 30 may be stopped.

  Further, by using the built-in acceleration sensor 11, the robot arm 30 can be operated in accordance with the slow movement of the operation pendant 10 so that the acceleration does not exceed the allowable acceleration. As a result, the operator can easily perform an operation for teaching the operation of the robot arm 30.

  Further, the position of the operation pendant 10 can be estimated using the acceleration sensor 11. That is, the measured acceleration can be integrated twice to calculate the displacement, and the position of the operation pendant 10 can be recognized. The initial position can be the storage position of the operation pendant 10. It is estimated that the operator is approaching the robot arm 30 based on the position of the operation pendant 10. When it is determined that the operation pendant 10 is located within a predetermined distance from the robot arm 30, the operation of the robot arm 30 can be stopped.

  Further, when a safety fence is provided around the robot arm 30, even if the safety fence is closed, if the operation pendant 10 is not in a specified position, the robot arm 30 cannot be operated at high speed. Also good. For example, when the operation pendant 10 is stored in the storage position, the robot arm 30 can be operated at high speed. That is, it is also possible to use the control device according to the present invention to confirm the closing process of the operation pendant 10. Further, the operation of the robot arm 30 can be similarly restricted by detecting the storage posture.

  As described above, according to the control device of the present invention, the acceleration sensor 11 of the operation pendant 10 is provided, and it is determined that there is an abnormality in the robot operation when the acceleration of the operation pendant 10 exceeds a predetermined value. Make a stop. As a result, it is possible to ensure safety against the dangerous state of the worker during teaching work and to reduce the work burden on the worker.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

FIG. 3 is a schematic diagram illustrating a configuration of an industrial robot using the control device according to the first embodiment. 2 is a block diagram illustrating a configuration of a control device according to Embodiment 1. FIG. FIG. 3 is a flowchart for explaining a robot control method according to the first embodiment. It is a schematic diagram which shows the structure of the industrial robot using the control apparatus which concerns on Embodiment 2. FIG. 6 is a block diagram illustrating a configuration of a control device according to Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus 10 Operation pendant 11 Acceleration sensor 12 Abnormality determination part 13 Deadman switch 20 Control panel 21 Robot safety circuit 22 Robot power circuit 30 Robot arm

Claims (10)

An operation pendant for inputting commands to the controlled object;
An acceleration sensor for detecting the acceleration of the operation pendant;
An operation control unit for stopping the operation of the controlled body when an acceleration of a predetermined value or more is input from the acceleration sensor;
A control device comprising: Further comprising a deadman switch provided on the operation pendant,
The control device according to claim 1, wherein the operation control unit stops the operation of the controlled body based on a pressed state of the deadman switch or an acceleration detected by the acceleration sensor.   The control device according to claim 1, wherein the acceleration sensor detects an inclination of the operation pendant as an acceleration.   The control device according to claim 1, wherein the operation of the controlled body is controlled based on a change in acceleration of the operation pendant detected by the acceleration sensor. The acceleration sensor recognizes the position of the operation pendant,
The control device according to claim 1, wherein an operation range of the controlled body is controlled based on a position of the operation pendant recognized by the acceleration sensor. A control method for controlling a controlled body by a command input from an operation pendant,
Detecting the acceleration of the operation pendant;
A control method for stopping the operation of the controlled body when an acceleration of the operation pendant is equal to or greater than a predetermined value.   The control method according to claim 6, wherein the operation of the controlled body is stopped based on a pressed state of a deadman switch provided on the operation pendant or an acceleration of the operation pendant.   The control method according to claim 6 or 7, wherein the acceleration sensor detects an inclination of the operation pendant as an acceleration.   The control method according to claim 6, 7 or 8, wherein an operation range of the controlled body is controlled based on a change in acceleration of the operation pendant. Recognizing the position of the operation pendant,
The control method according to any one of claims 6 to 9, wherein an operation range of the controlled body is controlled based on a position of the operation pendant.

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