Robot controller for robot which sets two objects in combined state

Patent metadata

Field	Value
Publication number	US-9724825-B2
Application number	US-201615203848-A
Country	US
Kind code	B2
Filing date	Jul 7, 2016
Priority date	Jul 9, 2015
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A robot controller which uses a robot to more stably, more rapidly move a given object and a different object relative to each other to set the given object and the different object in a combined state in which portions of the two objects are in contact and combined with each other. The robot controller includes an unit which measures a force acting between two objects, an unit which sets a direction of translational force control, an unit which sets a translational force control target force, an unit which sets an axis of rotational force control, an unit which calculates a target amount of translational force control direction movement, an unit which calculates a target amount of rotational force control axis rotational movement, an unit which calculates a target amount of rotational movement, and an unit which generates an operation command for the robot.

First claim

The invention claimed is:

1. A robot controller which controls a force acting between a given object located on an end effector of a robot and a different object to move the given object relative to the different object to obtain a state in which a predetermined portion of the given object and a predetermined portion of the different object are in contact and combined with each other, the robot controller comprising:
a force measuring unit which measures the force acting between the given object and the different object;
a translational force control direction setting unit which sets at least one direction of translational force control in which the given object is translated relative to the different object based on the force acting between the given object and the different object;
a translational force control target force setting unit which sets, for each of the at least one direction of translational force control, a translational force control target force representing a target value for the force acting between the given object and the different object in the direction of translational force control;
a rotational force control axis setting unit which sets at least one axis of rotational force control representing an axis of rotation about which the given object is rotated relative to the different object based on the force acting between the given object and the different object, and sets an axis that is not parallel to the direction of translational force control as at least one of the at least one axis of rotational force control;
a translational force control direction target movement amount calculation unit which calculates a target amount of translational force control direction movement representing a target value for an amount of translational movement of the given object relative to the different object in the direction of translational force control, based on the force acting between the given object and the different object;
a rotational force control axis target rotational movement amount calculation unit which calculates a target amount of rotational force control axis rotational movement representing a target value for an amount of rotational movement of the given object relative to the different object about the axis of rotational force control, based on the force acting between the given object and the different object;
a target direction target movement amount calculation unit which calculates a target amount of translational movement representing a target value for an amount of translational movement of the given object, and a target amount of rotational movement representing a target value for an amount of rotational movement of the given object, based on
the force acting between the given object and the different object,
the direction of translational force control set by the translational force control direction setting unit,
the axis of rotational force control set by the rotational force control axis setting unit,
the target amount of translational force control direction movement calculated by the translational force control direction target movement amount calculation unit, and
the target amount of rotational force control axis rotational movement calculated by the rotational force control axis target rotational movement amount calculation unit; and
an operation command generation unit which generates an operation command for the robot, based on the target amount of translational movement and the target amount of rotational movement calculated by the target direction target movement amount calculation unit,
wherein the translational force control direction target movement amount calculation unit
calculates the target amount of translational force control direction movement, based on one of a first predetermined amount of translational force control direction movement, and the first predetermined amount of translational force control direction movement and the translational force control target force in the direction of translational force control, when the force acting between the given object and the different object in the direction of translational force control is smaller than a first predetermined threshold for a force in the direction of translational force control, and
calculates the target amount of translational force control direction movement, based on one of
the force acting between the given object and the different object in the direction of translational force control and the translational force control target force in the direction of translational force control, and the force acting between the given object and the different object in the direction of translational force control, the translational force control target force in the direction of translational force control, and a second predetermined amount of translational force control direction movement, when the force acting between the given object and the different object in the direction of translational force control is not less than the first predetermined threshold for the force in the direction of translational force control.

2. The robot controller as set forth in claim 1 , wherein the translational force control direction target movement amount calculation unit calculates an amount of correction movement for the target amount of translational force control direction movement, based on the target amount of rotational force control axis rotational movement, to, in turn, calculate the target amount of translational force control direction movement by correction using the amount of correction movement, in accordance with a relationship between an amount of rotational movement about the axis of rotational force control of the given object and an amount of translational movement of a portion where the given object and the different object come into contact with each other upon rotation about the axis of rotational force control of the given object.

3. The robot controller as set forth in claim 1 , further comprising:
a contact position setting unit which sets a contact position at which the given object and the different object come into contact with each other, or calculates and sets a contact position at which the given object and the different object come into contact with each other based on the force acting between the given object and the different object,
wherein the rotational force control axis setting unit sets at least one predetermined axis of rotational force control, and sets as at least one contact position reference axis of rotational force control, at least one axis which passes through the contact position in one of the given object and the different object and is parallel to the predetermined axis of rotational force control, and
the rotational force control axis target rotational movement amount calculation unit calculates a target amount of rotational movement about the contact position reference axis of rotational force control to set the calculated target amount of movement as the target amount of rotational force control axis rotational movement, based on one of a force about the predetermined axis of rotational force control, and a target amount of rotational movement about the axis of rotational force control calculated for the predetermined axis of rotational force control.

4. The robot controller as set forth in claim 1 , further comprising:
a contact portion orientation calculation unit which calculates one of an orientation of a contact portion in the given object, where the state in which the predetermined portion of the given object and the predetermined portion of the different object are in contact and combined with each other is set, an orientation of the contact portion in the different object, and orientations of the contact portion in the given object and the contact portion in the different

Assignees

• Fanuc Corp

Inventors

• Iwatake Takahiro

Classifications

• B25J9/1633 Primary

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

• G05B2219/39505

  Control of gripping, grasping, contacting force, force distribution · CPC title

• B25J9/1612

  characterised by the hand, wrist, grip control · CPC title

• B25J13/085

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

• B25J9/1687

  Assembly, peg and hole, palletising, straight line, weaving pattern movement · CPC title