POWER ASSIST DEVICE AND METHOD OF CONTROLLING THE POWER ASSIST DEVICE

• US 20110010012A1
• Filed: 02/26/2009
• Published: 01/13/2011
• Est. Priority Date: 02/27/2008
• Status: Active Grant

• Current Assignee: Araki Manufacturing Co., Ltd., Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Araki Manufacturing Co., Ltd., Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Murayama, Hideyuki, Yamamoto, Hitoshi, Akiyama, Shinji, Shibata, Atsushi, Fujino, Ken-ichi
• Granted Patent: US 8,392,024 B2
• Time in Patent Office: Days
• US Class Current: 700/260
• CPC Class Codes: B23P 2700/50 Other automobile vehicle parts, i.e. manufactured in assembly lines
• CPC Class Codes: B25J 19/06 Safety devices
• CPC Class Codes: G05B 19/4182 manipulators and conveyor only
• CPC Class Codes: G05B 19/423 Teaching successive positions by walk-through, i.e. the tool head or end effector being grasped and guided directly, with or without servo-assistance, to follow a path
• CPC Class Codes: G05B 2219/36429 Power assisted positioning
• CPC Class Codes: G05B 2219/37357 Force, pressure, weight or deflection
• CPC Class Codes: G05B 2219/40272 Manipulator on slide, track
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y10T 29/53039 with control means energized in response to activator stimulated by condition sensor
• CPC Class Codes: Y10T 29/53057 Responsive to timer

Abstract

A method of controlling a power assist device that includes an operating handle, a force sensor, a robot arm, an actuator that drives the robot arm, and a conveying portion for conveying the robot arm. When a body in motion, the conveying portion is controlled to move in synchronization with the body, and when the motion of the body is stopped or has resumed, the drive of the robot arm is stopped for a predetermined time, and does not resume until after a predetermined time has elapsed.

Claims

1. A method of controlling a power assist device that includes an operating part operated by an operator, an operating force detecting portion that detects an operating force that is applied to the operating part, a robot arm that supports the operating part and holds a workpiece, a driving portion that drives the robot arm based on the operating force detected by the operating force detecting portion, a conveying portion that conveys the robot arm in a predetermined direction, and a counter workpiece conveying portion that conveys a counter workpiece, wherein the conveying portion is moved in synchronization with the counter workpiece conveying portion, the control method comprising:

controlling the conveying portion so that the conveying portion moves synchronously with the counter workpiece when a conveyance path is in motion; and

stopping control over the driving portion for a predetermined time period to stop drive of the robot arm when the motion of the counter workpiece on the conveyance path has stopped or when the motion of the conveyance path resumes.

2. The method of controlling a power assist device according to claim 1, wherein the drive of the robot arm by the driving portion resumes after the predetermined time has elapsed.

3. The method of controlling the power assist device according to claim 1, wherein:

the operating part includes a deadman switch with which the drive of the driving portion is switched ON/OFF by the operator; and

after the predetermined time has elapsed, the drive of the driving portion is resumed after the drive of the driving portion is switched ON with the deadman switch.

4. The method of controlling the power assist device according to claim 3, wherein even if the predetermined time has not elapsed, the drive of the driving portion resumes when the deadman switch is switched ON.

5. The method of controlling the power assist device according to claim 1, wherein:

the operating part includes a deadman switch with which the drive of the driving portion is switched ON/OFF by the operator; and

even if the predetermined time has not elapsed, the drive of the driving portion resumes when the deadman switch is switched ON.

6. The method of controlling the power assist device according to claim 1, wherein the drive of the robot arm by the driving portion is not stopped when a distance between the counter workpiece and one of the robot arm and the workpiece is equal to or greater than a predetermined distance.

7. The method of controlling a power assist device according to claim 1, wherein the predetermined time, over which the driving of the robot arm by the driving portion is stopped, is determined based on the distance between the counter workpiece and one of either the robot arm and the workpiece.

8. The method of controlling the power assist device according to claim 1, wherein:

the robot arm includes a detecting portion that detects vibrations of the workpiece; and

the predetermined time, over which the driving of the robot arm by the driving portion is stopped, is determined based on the vibration state of the workpiece detected by the detecting portion.

9. A method of controlling a power assist device that includes a holding portion that holds a workpiece;

a driving portion that drives the holding portion, a conveying portion that conveys the holding portion in a predetermined direction, and a counter workpiece conveying portion that conveys a counter workpiece, wherein the conveying portion is moved synchronously with the counter workpiece conveying portion, the control method comprising;

controlling the conveying portion so that the conveying portion moves synchronously with the counter workpiece when a conveyance path is in motion; and

stopping control over the driving portion for a predetermined time period to stop drive of drive of the holding portion when the motion of the counter workpiece on the conveyance path has stopped or when the motion of the conveyance path resumes.

10. (canceled)

18. (canceled)

19. A power assist device comprising:

an operating part that is operated by an operator;

an operating force detecting portion that detects an operating force applied to the operating part;

a robot arm that supports the operating part and holds a workpiece;

a driving portion that drives the robot arm based on the operating force detected by the operating force detecting portion;

a conveying portion that conveys the robot arm in a predetermined direction;

a controller that controls motions of the driving portion and the conveying portion, wherein the controller controls the conveying portion to moved synchronously with the counter workpiece conveying portion; and

a counter workpiece conveying portion that conveys a counter workpiece,

wherein the controller controls the conveying portion synchronously with the counter workpiece conveying portion when a conveyance path is in motion, and

wherein the controller controls the driving portion to stop control over the drive of the robot arm, for a predetermined time period when the motion of the counter workpiece on the conveyance path has stopped or when the motion of the conveyance path resumes.

11. The power assist device according to claim 19, wherein the controller controls the drive of the robot arm by the driving portion to resume after the predetermined time has elapsed.

12. The power assist device according to claim 19, wherein:

the operating part includes a deadman switch by which the operator switches the drive of the driving portion ON/OFF; and

when the predetermined time has elapsed, the controller resumes the drive of the driving portion when the drive of the driving portion is switched ON with the deadman switch.

13. The power assist device according to claim 12, wherein even if the predetermined time has not elapsed, the controller resumes the drive of the driving portion by switching the deadman switch from OFF to ON.

14. The power assist device according to claim 19, wherein:

the operating part includes a deadman switch by which the operator switches the drive of the driving portion ON/OFF; and

even if the predetermined time has not elapsed, the controller resumes the drive of the driving portion by switching the deadman switch from OFF to ON.

15. The power assist device according to claim 19, wherein the controller does not stop the drive of the robot arm by the driving portion, if a distance between the counter workpiece and one of the robot arm and the workpiece is equal to or greater than a predetermined distance.

16. The power assist device according to claim 19, wherein the controller stops the drive of the robot arm by the driving portion for the predetermined time, in accordance with a distance between the counter workpiece and one of the robot arm and the workpiece.

17. The power assist device according to claim 19, wherein:

the robot arm includes detecting portion that detects vibrations of the workpiece; and

the controller stops the drive of the robot arm by the driving portion for the predetermined time, in accordance with the vibration state of the workpiece detected by the detecting portion.

20. A power assist device comprising:

a holding portion that holds a workpiece;

a driving portion that drives the holding portion;

a conveying portion that conveys the holding portion in a predetermined direction;

a controller that controls motions of the driving portion and the conveying portion, wherein the controller controls the conveying portion to move synchronously with the counter workpiece conveying portion; and

a counter workpiece conveying portion for conveying a counter workpiece,

wherein the controller controls the conveying portion synchronously with the counter workpiece conveying portion when a conveyance path is in motion, and

wherein the controller controls the driving portion to stop control over the drive of the holding portion, for a predetermined time period when the motion of the counter workpiece on the conveyance path has stopped or when the motion of the conveyance path resumes.