Method of avoiding interference of industrial robot

• US 6,212,444 B1
• Filed: 02/18/1998
• Issued: 04/03/2001
• Est. Priority Date: 06/18/1996
• Status: Expired due to Fees

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Nagayama, Atsuo, Kato, Tetsuaki
• Primary Examiner(s): Grant, William
• Assistant Examiner(s): Rapp, Chad
• Application Number:
  US09/011,740
• Time in Patent Office: 1,140 Days
• Field of Search: 700/255, 700/245, 700/247, 700/253
• US Class Current: 700/255
• CPC Class Codes: B25J 9/1666 Avoiding collision or forbidden zones
• CPC Class Codes: B25J 9/1674 characterised by safety, monitoring, diagnostic
• CPC Class Codes: G05B 19/4061 Avoiding collision or forbidden zones
• CPC Class Codes: G05B 19/425 Teaching successive positions by numerical control, i.e. commands being entered to control the positioning servo of the tool head or end effector
• CPC Class Codes: G05B 2219/39082 Collision, real time collision avoidance
• CPC Class Codes: G05B 2219/39083 Robot interference, between two robot arms
• CPC Class Codes: G05B 2219/39085 Use of two dimensional maps and feedback of external and joint sensors
• CPC Class Codes: G05B 2219/39105 Manipulator cooperates with moving machine, like press brake
• CPC Class Codes: G05B 2219/45143 Press-brake, bending machine
• CPC Class Codes: G05B 2219/49137 Store working envelop, limit, allowed zone
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A method of preventing interference of an industrial robot in which teaching of an operation program to the robot is easy and interference of the robot with an external cooperative apparatus can be easily avoided. If a current position of a reference point on the robot for detecting interference is outside a common area (S12) and a target position of the reference point is outside the common area (S18), a motion command is outputted to drive the robot. If the target position of the reference point is within the common area, it is determined that whether or not a movable part of the cooperative apparatus is within the common area, and if the movable part is outside the common area, an operation forbidding signal for the cooperative apparatus is turned on and the motion command is outputted to make the robot move. If the movable part of the cooperative apparatus is within the common area, the motion command is withheld till the movable part of the cooperative device moves out of the common area (S4, S5). If the current position of the reference point is within the common area (S12), the operation of the cooperative apparatus is forbidden (S15, S17).

Claims

1. A method of avoiding an interference of an industrial robot with a cooperative apparatus for performing an operation cooperatively with said industrial robot, said method comprising:

setting a common area in which an operating area of said industrial robot and an operating area of said cooperative apparatus overlap and interfere with each other, to said industrial robot and said cooperative apparatus;

outputting a first entrance forbidding signal to said cooperative apparatus for forbidding a movable part of said cooperative apparatus to enter said common area when a predetermined reference point on said industrial robot is within said common area; and

outputting a second entrance forbidding signal to said industrial robot for forbidding the reference point of said industrial robot to enter said common area when the movable part of said cooperative apparatus is within said common area.

2. A method of avoiding an interference of an industrial robot according to claim 1, further comprising decelerating said industrial robot to stop and keeping said industrial robot to wait at a stopped position, when the reference point of said industrial robot is outside said common area and said second entrance forbidding signal is outputted from said cooperative apparatus.

3. A method of avoiding an interference of an industrial robot according to claim 2, further comprising automatically allowing said industrial robot to resume an operation thereof, when the output of said second entrance forbidding signal from said cooperative apparatus stops.

4. A method of avoiding an interference of an industrial robot according to claim 1, further comprising decelerating said industrial robot to stop and keeping said industrial robot to wait at a stopped position, when said second entrance forbidding signal is outputted from said cooperative apparatus and a command for moving the reference point of said industrial robot into said common area is read.

5. A method of avoiding interference of an industrial robot according to claim 4, wherein said decelerating includes determining whether or not the reference point is to enter said common area based on a motion command in each distribution period;

and withholding an output of said motion command and decelerating said robot to stop when said motion command is for moving said reference point to enter said common area.

6. A method of avoiding interference of an industrial robot according to claim 4, wherein said decelerating further comprises:

determining whether or not said reference point is to enter said common area based on a motion command in each block of a taught program;

dividing said motion command into a first block for moving said reference point to a boundary position of said common area and a second block for moving said reference point from said boundary position to a position designated by said motion command, when said motion command is for moving said reference point to enter said common area; and

executing the first block of said motion command and decelerating the robot to stop at an end position of said first block.

7. A method of avoiding an interference of an industrial robot according to claim 4 further comprising automatically allowing said industrial robot to resume an operation thereof, when the output of said second entrance forbidding signal from said cooperative apparatus stops.

8. A method of avoiding an interference of an industrial robot with a cooperative apparatus for performing an operation cooperatively with said industrial robot, said method comprising:

setting a common area in which an operation area of said industrial robot and an operation area of said cooperative apparatus overlap and interfere with each other, to a controller of said industrial robot and said cooperative apparatus;

outputting an operation forbidding signal for stopping an operation of a movable part of said cooperative apparatus, when a predetermined reference point on said industrial robot is within said common area;

outputting an entrance forbidding signal for forbidding the reference point in said industrial robot to enter said common area, when the movable part of said cooperative apparatus is within said common area; and

decelerating said industrial robot to stop and keeping said industrial robot to wait at a stopped position, when said entrance forbidding signal is outputted from said cooperative apparatus in said outputting and a command for moving said reference point of said industrial robot to enter said common area is read.

9. A method of avoiding interference of an industrial robot according to claim 8, wherein said decelerating further comprises determining whether or not said reference point is to enter said common area based on a motion command in each distribution period;

and withholding an output of said motion command and decelerating said robot to stop when said motion command is for moving said reference point to enter said common area.

10. A method of avoiding interference of an industrial robot according to claim 8, wherein said decelerating further comprises:

determining whether or not said reference point is to enter said common area based on a motion command in each block of a taught program;

dividing said motion command into a first block for moving said reference point to a boundary position of said common area and a second block for moving said reference point from said boundary position to a position designated by said motion command, when said motion command is for moving said reference point to enter said common area; and

executing said first block of said motion command and decelerating said robot to stop at an end position of said first block.

11. A method of avoiding an interference of an industrial robot according to claim 8 further comprising automatically allowing said industrial robot to resume an operation thereof, when the output of said entrance forbidding signal from said cooperative apparatus stops.

12. An apparatus avoiding an interference of an industrial robot with a cooperative apparatus performing an operation cooperatively with said industrial robot, comprising:

a setting device setting a common area in which an operating area of said industrial robot and an operating area of said cooperative apparatus overlap and interfere with each other, to said industrial robot and said cooperative apparatus;

a first outputting device outputting a first entrance forbidding signal for forbidding a movable part of said cooperative apparatus to enter said common area when a predetermined reference point on said industrial robot is within said common area;

a second outputting device outputting a second entrance forbidding signal for forbidding the reference point of said industrial robot to enter said common area when the movable part of said cooperative apparatus is within said common area; and

a decelerating device decelerating said industrial robot to stop and keeping said industrial robot to wait at a stopped position, when the reference point of said industrial robot is outside said common area and said second entrance forbidding signal is outputted from said cooperative apparatus.

13. The apparatus recited in claim 12, further comprising a resuming device automatically allowing said industrial robot to resume an operation thereof, when the output of said second entrance forbidding signal from said cooperative apparatus stops.

14. The apparatus recited in claim 12, further comprising:

a determining device determining whether or not said reference point is to enter said common area based on a motion command in each block of a taught program;

a dividing device dividing said motion command into a first block for moving said reference point to a boundary position of said common area and a second block for moving said reference point from said boundary position to a position designated by said motion command, when said motion command is for moving said reference point to enter said common area; and

an executing device executing the first block of said motion command and decelerating the robot to stop at an end position of said first block.