Control device for robot

Patent metadata

Field	Value
Publication number	US-10350754-B2
Application number	US-201715662724-A
Country	US
Kind code	B2
Filing date	Jul 28, 2017
Priority date	Sep 27, 2016
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A control device controlling a robot including a driving unit, a moving unit that is slidable along a predetermined track and a predetermined shaft that is slidably supported by the moving unit includes an instruction value calculating unit calculating an instruction value that drives the driving unit such that the moving unit is moved to a target position, an accelerating-speed calculating unit calculating an angular accelerating speed of when the instruction value changes, a gravity-center distance calculating unit calculating a gravity center distance, a correction instruction-value calculating unit calculating a correction instruction value by correcting the instruction value such that a position of the gravity center which is projected on the predetermined track approaches the target position, and a driving control unit controlling the driving unit based on the correction instruction value.

First claim

What is claimed is:

1. A control device for a robot including a driving unit, a moving unit that is driven by the driving unit and is slidable along a predetermined track in a horizontal surface, and a predetermined shaft that is slidably supported by the moving unit in a vertical direction, the predetermined shaft to which a subject is assembled, comprising:
an instruction value calculating unit calculating an instruction value that drives the driving unit such that the moving unit is moved to a target position that is a latest target position of the moving unit;
an accelerating-speed calculating unit calculating an accelerating speed of when the instruction value calculated by the instruction value calculating unit changes;
a gravity-center distance calculating unit calculating a gravity center distance that is a distance from a support portion of the moving unit supporting the predetermined shaft to a gravity center of a total load that is equivalent to the predetermined shaft and the subject, based on the gravity center and a position of the predetermined shaft in the vertical direction;
a correction instruction-value calculating unit calculating a correction instruction value by correcting the instruction value calculated by the instruction value calculating unit, based on the instruction value, a spring constant of the support portion relative to a twisting of the predetermined shaft, a mass of the total load, the accelerating speed calculated by the accelerating-speed calculating unit and the gravity center distance calculated by the gravity-center distance calculating unit, such that a position of the gravity center which is projected on the predetermined track approaches the target position; and
a driving control unit controlling the driving unit based on the correction instruction value calculated by the correction-instruction valve calculating unit.

2. The control device for the robot according to claim 1 , wherein
when the moving unit is in an accelerating state, the correction instruction-value calculating unit calculates the correction instruction value such that the moving unit is in advance of the target position.

3. The control device for the robot according to claim 1 , wherein
when the moving unit is in a decelerating state, the correction instruction-value calculating unit calculates the correction instruction value such that the moving unit is in delay of the target position.

4. The control device for the robot according to claim 1 , wherein
the correction instruction-value calculating unit calculates the correction instruction value such that the position of the gravity center matches the target position.

5. The control device for the robot according to claim 1 , wherein
the correction instruction-value calculating unit calculates the correction instruction value such that the position of the gravity center matches an intermediate position between the position of the gravity center and the target position.

6. The control device for the robot according to claim 1 , wherein
the correction instruction-value calculating unit changes the correction instruction value that is calculated to an instruction value obtained by filtering the correction instruction value.

7. The control device for the robot according to claim 1 , wherein
the moving unit is slidable along an arc track that is predetermined around a center axis that is predetermined as a center, in a horizontal surface,
the spring constant is expressed as K, the mass of the total load is expressed as M, a target angular position of the moving unit relative to the center axis as a center, which corresponds to the target position, is expressed as θ, an angular accelerating speed of when the target angular position θ changes is expressed to as aω, the gravity center distance is expressed as L, and a correction quantity of the target angular position θ is expressed as Δθ,
the instruction value calculating unit calculates the target angular position θ as the instruction value, and
the correction instruction-value calculating unit calculates the correction instruction value by adding the correction quantity Δθ calculated by using a formula that Δθ=M×aω×L 2 /K to the target angular position θ.

8. The control device for the robot according to claim 7 , wherein
the robot includes the moving unit including a first moving unit that is slidable relative to a first arc track that is predetermined around a center axis that is predetermined as a center in a horizontal surface and a second moving unit,
the second moving unit is movably supported by the first moving unit, the second moving unit is slidable relative to a second arc track that is predetermined and is included in the arc track around the first moving unit as a center in a horizontal surface, the arc track is equivalent to the predetermined track, and
the instruction value calculating unit, the accelerating-speed calculating unit, the gravity-center distance calculating unit, the correction instruction-value calculating unit and the driving control unit execute processings relative to the first moving unit and the second moving unit.

9. A control device for a robot including a driving unit, a moving unit that is driven by the driving unit and is slidable along a predetermined track in a horizontal surface, and a predetermined shaft that is slidably supported by the moving unit in a vertical direction, the predetermined shaft to which a subject is assembled, comprising:
a target position calculating unit calculating a target position that is a latest target position of the moving unit;
an accelerating-speed calculating unit calculating an accelerating speed of when the target position calculated by the target position calculating unit changes;
a gravity-center distance calculating unit calculating a gravity center distance that is a distance from a support portion of the moving unit supporting the predetermined shaft to a gravity center of a total load that is equivalent to the predetermined shaft and the subject, based on the gravity center and a position of the predetermined shaft in the vertical direction;
a correction target-position calculating unit calculating a correction target position that is obtained by correcting the target position, based on the target position calculated by the target position calculating unit, a spring constant relative to a twisting of the predetermined shaft, a mass of the total load, the accelerating speed calculated by the accelerating-speed calculating unit, and the gravity center distance calculated by the gravity-center distance calculating unit, such that a position of the gravity center which is projected on the predetermined track approaches the target position;
a correction instruction-value calculating unit calculating a correction instruction value that drives the driving unit to control the driving unit to move to the correction target position calculated by the correction target-position calculating unit; and
a driving control unit controlling the driving unit based on the correction instruction value calculated by the correction-instruction valve calculating unit.

10. The control device for the robot according to claim 9 , wherein
when the moving unit is in an accelerating state, the correction target-position calculating unit calculates the correction target position such that the moving unit is in advance of the target position.

11. The control device for the robot according to claim 9 , wherein
when the moving unit is in a decelerating state, the correction target-position calculating unit calculates the correction target position such that the moving unit is in delay of the target position.

Assignees

• Denso Wave Inc

Inventors

• Nagamatsu Kenji

Classifications

• B25J9/1679

  characterised by the tasks executed · CPC title

• B25J9/1641

  compensation for backlash, friction, compliance, elasticity in the joints · 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

• B25J9/161

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

• G05B2219/40582

  Force sensor in robot fixture, base · CPC title