IP Library › Granted Patent US 8,948,915

Granted Patent B2

US 8,948,915 · App. 13/602,202 · Granted Feb 3, 2015

Parallel link robot, parallel link robot system, and method of controlling parallel link robot

Inventor: Mitsuaki Nakanishi (Fukuoka, JP)

Assignee: Kabushiki Kaisha Yaskawa Denki

B25J9/1623 B25J17/0266 B25J9/0051 B25J17/0283 B25J17/0275 B25J9/108 B25J9/1674 G05B2219/37214 G05B2219/42311

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Quick Facts

Patent No.: US 8,948,915
App. No.: 13/602,202
Granted: Feb 3, 2015
Kind: B2

External Links

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Abstract

A parallel link robot includes a base, three servo motors disposed in the base, three arms, and a robot controller. Each of the three arms includes a first link and a second link that respectively include a first joint and a second joint. Each of the three arms is driven by a corresponding one of the three servo motors. The robot controller determines whether or not any of the first and second joints of the arms is dislocated on the basis of the torques of the three servo motors.

Claims (43)

1. A parallel link robot comprising:

a base;

a plurality of drive sources disposed in the base;

a plurality of arms that each includes a link including a joint, each of the plurality of arms being driven by a corresponding one of the plurality of drive sources; and

a dislocation detector that determines whether or not any of the joints of the arms is dislocated on the basis of a driving force of at least one of the plurality of drive sources,

wherein the dislocation detector estimates a driving force of a predetermined one of the drive sources corresponding to a predetermined one of the arms in at least one of a dislocated state and a normal state, the dislocated state being a state in which the joint of the predetermined arm is dislocated, the normal state being a state in which the joint of the predetermined arm is normal, and the dislocation detector determines whether or not the joint of the predetermined arm is dislocated on the basis of the estimated driving force of the predetermined drive source and an actual driving force of the predetermined drive source.

2. The parallel link robot according to claim 1 ,

wherein the dislocation detector estimates a dislocated-state driving force that is a driving force of the predetermined drive source when the joint of the predetermined arm is in the dislocated state, and the dislocation detector determines that the joint of the predetermined arm is dislocated if a difference between the dislocated-state driving force of the predetermined drive source and the actual driving force of the predetermined drive source is equal to or smaller than a first threshold.

3. The parallel link robot according to claim 2 ,

wherein the dislocation detector estimates a predetermined driving force including a driving force component for driving parts other than the predetermined arm, the predetermined driving force being included in the driving force of the predetermined drive source when the predetermined arm is in the normal state, and the dislocation detector determines that the joint of the predetermined arm is dislocated if the predetermined driving force is equal to or larger than a second threshold and the difference between the dislocated-state driving force of the predetermined drive source and the actual driving force of the predetermined drive source is equal to or smaller than the first threshold.

4. The parallel link robot according to claim 2 ,

wherein the dislocation detector determines that the joint of the predetermined arm is dislocated if a state in which the difference between the dislocated-state driving force of the predetermined drive source and the actual driving force of the predetermined drive source is equal to or smaller than the first threshold has continued for a predetermined time.

5. The parallel link robot according to claim 1 ,

wherein the dislocation detector estimates a normal-state driving force that is a driving force of the predetermined drive source when the joint of the predetermined arm is in the normal state, and the dislocation detector determines that the joint of the predetermined arm is dislocated if the difference between the normal-state driving force of the predetermined drive source and the actual driving force of the predetermined drive source is equal to or larger than a third threshold.

6. The parallel link robot according to claim 5 ,

wherein the dislocation detector determines that the joint of the predetermined arm is dislocated if a state in which the difference between the normal-state driving force of the predetermined drive source and the actual driving force of the predetermined drive source is equal to or larger than the third threshold has continued for a predetermined time.

7. The parallel link robot according to claim 1 ,

wherein the dislocation detector estimates a dislocated-state driving force that is a driving force of the predetermined drive source in the dislocated state in which the joint of the predetermined arm is in the dislocated state, the dislocation detector estimates a normal-state driving force that is a driving force of the predetermined drive source when the predetermined arm is in the normal state, and the dislocation detector determines that the joint of the predetermined arm is dislocated if at least one of the following conditions is satisfied, one condition being that the difference between the dislocated-state driving force of the predetermined drive source and the actual driving force of the predetermined drive source is equal to or smaller than a first threshold, and the other condition being that the difference between the normal-state driving force of the predetermined drive source and the actual driving force of the predetermined drive source is equal to or larger than a third threshold.

8. The parallel link robot according to claim 1 ,

wherein the dislocation detector performs control so as to stop the plurality of drive sources when the dislocation detector determines that the joint of the predetermined arm is dislocated on the basis of the estimated driving force of the predetermined drive source and the actual driving force of the predetermined drive source.

9. The parallel link robot according to claim 1 ,

wherein the drive source is a motor, and

wherein the driving force of the drive source is a torque of the motor.

10. A parallel link robot system comprising:

a parallel link robot including

a base,

a plurality of drive sources disposed in the base,

a plurality of arms that each includes a link including a joint, each of the plurality of arms being driven by a corresponding one of the plurality of drive sources; and

a robot controller that controls motion of the parallel link robot,

wherein the robot controller determines whether or not any of the joints of the arms is dislocated on the basis of a driving force of at least one of the plurality of drive sources, and

11. A method of controlling a parallel link robot including a base, a plurality of drive sources disposed in the base, and a plurality of arms that each includes a link including a joint, each of the plurality of arms being driven by a corresponding one of the plurality of drive sources, the method comprising:

determining, using a robot controller that controls motion of the parallel link robot, whether or not any of the joints the arms is dislocated on the basis of a driving force of at least one of the plurality of drive sources,

wherein the determining whether or not the joint is dislocated includes

estimating a driving force of a predetermined one of the drive sources corresponding to a predetermined one of the arms in at least one of a dislocated state and a normal state, the dislocated state being a state in which the joint of the predetermined arm is dislocated, the normal state being a state in which the joint of the predetermined arm is normal, and

determining whether or not the joint of the predetermined arm is dislocated on the basis of the estimated driving force of the predetermined drive source and an actual driving force of the predetermined drive source.

12. The method of controlling the parallel link robot according to claim 11 ,

wherein the estimating the driving force of the predetermined drive source includes estimating a dislocated-state driving force that is a driving force of the predetermined drive source when the joint of the predetermined arm is in the dislocated state, and

wherein the determining whether or not the joint of the predetermined arm is dislocated includes determining that the joint of the predetermined arm is dislocated if a difference between the dislocated-state driving force of the predetermined drive source and the actual driving force of the predetermined drive source is equal to or smaller than a first threshold.

13. The method of controlling the parallel link robot according to claim 11 ,

wherein the estimating the predetermined drive source includes estimating a normal-state driving force that is a driving force of the predetermined drive source when the joint of the predetermined arm is in the normal state, and

wherein the determining whether the joint of the predetermined arm is dislocated includes determining that the joint of the predetermined arm is dislocated if the difference between the normal-state driving force of the predetermined drive source and the actual driving force of the predetermined drive source is equal to or larger than a third threshold.

14. The parallel link robot according to claim 1 , wherein the dislocation detector is a robot controller.

Assignments (1)

ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 3, 2012

From: NAKANISHI, MITSUAKI

To: KABUSHIKI KAISHA YASKAWA DENKI

Reel/Frame 028889/0934 →

Priority Claims (1)

JP P. 2011-194351 · Sep 6, 2011 · national

Continuity (1)

Related Publication 20130060381A1 · Mar 7, 2013