Control device, robot system, and robot

Patent metadata

Field	Value
Publication number	US-11318609-B2
Application number	US-201916545114-A
Country	US
Kind code	B2
Filing date	Aug 20, 2019
Priority date	Aug 21, 2018
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

A control device includes a control unit which executes a control force to a movable unit according to an output of a force detection unit. The control unit executes a stop control of the movable unit when a predetermined stop condition is satisfied. The stop control includes a second control which continues the force control to control the movable unit when the stop condition is satisfied during the execution of a first control including a force control.

First claim

What is claimed is:

1. A control device that controls a robot provided with a movable unit and a force detection unit which detects a force applied to the movable unit from an object in contact with the movable unit, the control device comprising:
a control unit which executes a force control to the movable unit according to an output of the force detection unit, wherein
the control unit executes a stop control of the movable unit when a predetermined stop condition is satisfied, and
the stop control includes a second control which controls the movable unit by continuing the force control when the stop condition is satisfied during the execution of a first control including the force control,
wherein the predetermined stop condition is at least one of:
an opened safety door;
an activated emergency stop button;
a received stop instruction;
an object detected within a redetermined threshold distance; and
a worker contacted the robot, and

wherein the movable unit has a contact portion coming into contact with the object, and
when a moving amount of the contact portion in the second control is equal to or larger than a predetermined threshold value, the control unit ends the second control and maintains a position of the movable unit.

2. The control device according to claim 1 , wherein
the force control is an impedance control using a virtual inertia coefficient and a virtual viscosity coefficient, and
the virtual inertia coefficient of the second control is larger than the virtual inertia coefficient of the first control, and the virtual viscosity coefficient of the second control is larger than the virtual viscosity coefficient of the first control.

3. A control device that controls a robot provided with a movable unit and a force detection unit which detects a force applied to the movable unit from an object in contact with the movable unit, the control device comprising;
a control unit which executes a force control to the movable unit according to an output of the force detection unit, wherein
the control unit executes a stop control of the movable unit when a predetermined stop condition is satisfied, and
the stop control includes a second control which controls the movable unit by continuing the force control when the stop condition is satisfied during the execution of a first control including the force control,
wherein the predetermined stop condition is at least one of:
an opened safety door;
an activated emergency stop button;
a received stop instruction;
an object detected within a predetermined threshold distance; and
a worker contacted the robot, and

wherein a work sequence of the robot includes a plurality of processes using the force control,
the control unit is configured to select a stop control mode including a first mode including the second control and a second mode for controlling the movable unit according to a control setting different from the second control, and
the movable unit is controlled according to a combination of the stop control mode and a timing to start the stop control predetermined for each of the plurality of processes when the stop condition is satisfied.

4. The control device according to claim 3 , wherein
the stop control mode includes a third mode for executing a third control to retract the movable unit from the object.

5. The control device according to claim 4 , wherein
the control unit retracts the movable unit from the object according to a copying control in which a target force in a direction perpendicular to a retraction direction of the movable unit is smaller than the target force of the retraction direction in the third control.

6. The control device according to claim 3 , wherein
the timing to start the stop control includes an end time of the process.

7. The control device according to claim 3 , wherein
the timing to start the stop control includes a start timing of a stop control set for a subsequent process of the process in which the stop condition is satisfied.

8. The control device according to claim 3 , wherein
the combination includes a restart control mode for restarting a process interrupted by the stop control.

9. The control device according to claim 8 , wherein
the restart control mode includes a mode restarting from a process different from the process interrupted by the stop control.

10. A robot system comprising:
a robot provided with a movable unit and a force detection unit which detects a force applied to the movable unit from an object in contact with the movable unit; and
the robot control device according to claim 1 .

11. A robot comprising:
a force detection unit detecting a force applied to the robot from an object; and
a movable unit in which a force control is applied according to an output of the force detection unit, wherein
the movable unit is controlled in a state in which an operation is stopped when a predetermined stop condition is satisfied during an execution of the force control and the force control is continued when the stop condition is satisfied after the stop,
wherein the movable unit has a contact portion coming into contact with the object, and
when a moving amount of the contact portion in the second control is equal to or larger than a predetermined threshold value, the control unit ends the second control and maintains a position of the movable unit.

Assignees

• Seiko Epson Corp

Inventors

• Takeuchi Kaoru
• Karito Nobuhiro
• Sejimo Isamu

Classifications

• B25J13/085

  Force or torque sensors (B25J13/082, B25J13/084 take precedence) · CPC title

• B25J9/1633 Primary

  compliant, force, torque control, e.g. combined with position control · CPC title

• B25J19/02

  Sensing devices · CPC title

• B25J9/161

  Hardware, e.g. neural networks, fuzzy logic, interfaces, processor · CPC title