Control device and control method for robot and the robot

• US 9,095,979 B2
• Filed: 07/29/2013
• Issued: 08/04/2015
• Est. Priority Date: 07/31/2012
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Motoyoshi, Masaki
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): Rink, Ryan
• Application Number:
  US13/953,120
• Publication Number:
  US 20140039678A1
• Time in Patent Office: 736 Days
• Field of Search: 700/258, 700/254
• US Class Current: 1/1
• CPC Class Codes: B25J 9/1641 compensation for backlash, friction, compliance, elasticity in the joints
• CPC Class Codes: B25J 9/1694 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 Class Codes: G05B 19/404 characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia G05B19/19, G05B19/41 take precedence
• CPC Class Codes: G05B 2219/39195 Control, avoid oscillation, vibration due to low rigidity
• CPC Class Codes: G05B 2219/40549 Acceleration of end effector

Abstract

A control method for suppressing vibration of a robot arm including a plurality of coupled links and driving units configured to drive the links includes calculating a first arm speed from at least one of acceleration and an angular velocity detected in a damping position for suppressing vibration, calculating a third arm speed according to the detected first arm speed and a second arm speed in the damping position calculated on the basis of a driving amount of the driving units, and subjecting the driving units to correction control on the basis of the calculated third arm speed.

Claims

1. A control device for a robot including:

a robot main body;

an arm coupled to the robot main body and including a plurality of links;

driving units configured to drive the plurality of links; and

an angle sensor configured to detect a driving amount of the driving units,

the control device comprising;

an inertia sensor set in a damping position corresponding to a target location at which vibration of the arm is to be suppressed, and configured to detect at least one of an acceleration and an angular velocity in the damping position;

a first calculating unit configured to calculate a first arm speed in the damping position from at least one of the acceleration and the angular velocity in the damping position detected by the inertia sensor;

a second calculating unit configured to calculate a driving speed from the driving amount of the driving units detected by the angle sensor and calculate a second arm speed in the damping position based on the driving amount and the driving speed;

a third calculating unit configured to calculate a third arm speed based on the first arm speed and the second arm speed;

a fourth calculating unit configured to calculate, based on the third arm speed, a correction speed for each of the driving units that drive the links present between the robot main body and the damping position; and

a control unit configured to control, based on the driving amount, the driving speed, and the correction speed, the driving units that drive the links present between the robot main body and the damping position.

2. The control device for the robot according to claim 1, wherein the third calculating unit further comprises a filter for removing a low frequency component equal to or less than a predetermined frequency included in a waveform of the third arm speed.

3. A control method for a robot including:

an arm including a plurality of coupled links; and

driving units configured to drive the plurality of links,

the control method including;

detecting a first arm speed in a damping position corresponding to a target location at which vibration of the arm is to be suppressed;

calculating a third arm speed based on a difference between the detected first arm speed and a second arm speed calculated based on a driving amount of the driving units, the second arm speed being a speed at which the damping position is driven; and

subjecting the driving units to correction control based on the calculated third arm speed.

4. A control method for a robot including:

a robot main body;

an arm coupled to the robot main body and including a plurality of links;

driving units configured to drive the plurality of links; and

an angle sensor configured to detect a driving amount of the driving units,

the control method comprising;

detecting, with an inertia sensor set in a damping position corresponding to a target location at which vibration of the arm is to be suppressed, at least one of an acceleration and an angular velocity in the damping position;

detecting, with the angle sensor, a driving amount of the driving units that drive the links present between the damping position and the robot main body;

calculating a first arm speed in the damping position from at least one of the acceleration and the angular velocity in the damping position detected by the inertia sensor;

calculating a driving speed from the driving amount of the driving units detected by the angle sensor and calculating a second arm speed in the damping position based on the driving amount and the driving speed;

calculating a third arm speed in the damping position based on the first arm speed and the second arm speed;

calculating, based on the third arm speed, a correction speed for each of the driving units that drive the links present between the robot main body and the damping position; and

controlling, based on the driving amount, the driving speed, and the correction speed, the driving units that drive the links present between the robot main body and the damping position.

5. The control method for the robot according to claim 4, wherein the calculating of the third arm speed further includes removing a low frequency component equal to or less than a predetermined frequency included in a waveform of the calculated third arm speed.

6. The control method for the robot according to claim 4, wherein the calculating of the correction speed for each of the driving units that drive the links present between the robot main body and the damping position based on the third arm speed is applied to the driving unit preselected among the driving units.

7. The control method for the robot according to claim 4, wherein the calculating of the correction speed for each of the driving units that drive the links present between the robot main body and the damping position based on the third arm speed includes pre-weighting each of the driving units.

8. A robot comprising:

a robot main body;

an arm coupled to the robot main body and including a plurality of links;

driving units configured to drive the plurality of links;

an angle sensor configured to detect a driving amount of the driving units;

an inertia sensor set in a damping position corresponding to a target location at which vibration of the arm is to be suppressed, and configured to detect at least one of an acceleration and an angular velocity in the damping position;

a first calculating unit configured to calculate a first arm speed in the damping position from at least one of the acceleration and the angular velocity in the damping position detected by the inertia sensor;

a second calculating unit configured to calculate a driving speed from the driving amount of the driving units detected by the angle sensor and calculate a second arm speed in the damping position based on the driving amount and the driving speed;

a third calculating unit configured to calculate a third arm speed based on the first arm speed and the second arm speed;

a fourth calculating unit configured to calculate, based on the third arm speed, a correction speed for each of the driving units that drive the links present between the robot main body and the damping position; and

a control unit configured to control, based on the driving amount, the driving speed, and the correction speed, the driving units that drive the links present between the robot main body and the damping position.

9. The robot according to claim 8, wherein the third calculating unit further comprises a filter for removing a low frequency component equal to or less than a predetermined frequency included in a waveform of the third arm speed.