Robot control device controlling robot based on external force applied to robot and robot system

Patent metadata

Field	Value
Publication number	US-9737991-B2
Application number	US-201615000714-A
Country	US
Kind code	B2
Filing date	Jan 19, 2016
Priority date	Jan 21, 2015
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

A robot control device includes a contact judging part which judges if the robot has contacted an object based on external force which is detected by the sensor, a stop command part which makes the robot stop when it is judged that the robot has contacted the object, a continuous contact judging part which judges if the robot continues to contact the object after making the robot stop, and a retraction command part which makes the robot retract in a direction away from the object when it is judged that the robot continues to contact the object.

First claim

The invention claimed is:

1. A robot control device which controls an operation of a robot based on an output from a sensor which detects an external force applied to the robot, the robot control device comprising:
a processor configured to
judge whether the robot has contacted an object based on the external force detected by the sensor;
stop the robot when the processor judges that the robot has contacted the object;
judge whether the robot continues to contact the object after stopping the robot; and
retract the robot in a direction away from the object when the processor judges that the robot continues to contact the object after said stopping the robot.

2. The robot control device according to claim 1 , wherein the processor is configured to judge that the robot has contacted the object when the external force detected by the sensor is equal to or larger than a predetermined threshold value.

3. The robot control device according to claim 1 , wherein the processor is configured to judge that, after said stopping the robot, the robot continues to contact the object when the external force over a predetermined threshold value is detected by the sensor until a predetermined time has elapsed from a time point when the robot stops.

4. The robot control device according to claim 1 ,
wherein the processor is further configured to calculate an integrated value of the external force from a time point when the robot stops, and
wherein the processor is configured to judge that, after said stopping the robot, the robot continues to contact the object when the integrated value exceeds a predetermined threshold value until a predetermined time has elapsed from the time point.

5. A robot system, comprising:
a robot; and
the robot control device according to claim 1 which controls the robot.

6. The robot system according to claim 5 , wherein the sensor is a force sensor built in a swivel drum, robot arm or wrist of the robot.

7. The robot system according to claim 6 , wherein the processor is configured to acquire information of the external force applied to the robot from the force sensor at a predetermined period.

8. The robot control device according to claim 3 , further comprising:
a storage configured to store
the external force applied to the robot, and
the predetermined threshold value; and

a clock configured to clock the predetermined time.

9. The robot control device according to claim 8 , wherein the storage and the clock are built in an external device.

Assignees

• Fanuc Corp

Inventors

• Takahashi Hiromitsu
• Takaki Kazuhisa

Classifications

• B25J9/1676 Primary

  Avoiding collision or forbidden zones · CPC title

• B25J9/1694

  characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion · CPC title

• B25J9/1674 Primary

  characterised by safety, monitoring, diagnostic · CPC title

• B25J9/1664

  characterised by motion, path, trajectory planning · CPC title

• Y10S901/09

  Closed loop, sensor feedback controls arm movement · CPC title