Method for limiting the force action of a robot part

• US 20030233171A1
• Filed: 06/12/2003
• Published: 12/18/2003
• Est. Priority Date: 06/15/2002
• Status: Active Grant

• Current Assignee: KUKA Laboratories GmbH (Midea Group Co., Ltd)
• Original Assignee: KUKA Roboter GmbH (Midea Group Co., Ltd)
• Inventors: Heiligensetzer, Peter
• Granted Patent: US 6,748,298 B2
• Time in Patent Office: Days
• US Class Current: 700/260
• CPC Class Codes: B25J 9/1633 compliant, force, torque control, e.g. combined with position control
• CPC Class Codes: B25J 9/1674 characterised by safety, monitoring, diagnostic
• CPC Class Codes: G05B 2219/40199 Soft material covers links, arms for shock and pain attenuation
• CPC Class Codes: G05B 2219/40215 Limit link kinetic energy to amount another element can dissipate upon impact

Abstract

In order to reduce the risk of damage on external objects, material articles or persons during the operation of a robot, particularly a miniature robot, the invention provides a method for limiting the force action of a robot part, such as a robot arm, on such an external object during a collision in such a way that as a result of a maximum permitted force, maximum force F_max, acting on the object in the case of a collision, a corresponding, maximum permitted kinetic energy, maximum energy E_kin,max of the robot part is determined, continuously and at adequately short time intervals the actual kinetic energy, actual energy E_kin, of the robot part is determined and on exceeding the maximum permitted energy E_kin,max, the actual operating speed V of the robot is reduced.

Claims

1. Method for limiting the force action of a robot part, such as a robot arm, on an external object during a collision, wherein:

as a result of a maximum permitted force, maximum force F_max, acting on the object in the case of a collision, a corresponding maximum permitted kinetic energy, maximum energy E_kin,max, of the robot part is determined,

continuously and at adequately short time intervals, the actual kinetic energy, actual energy E_kin, of the robot part is determined and

on exceeding the maximum permitting energy E_kin,max, the actual operating speed v of the robot is reduced.

2. Method according to claim 1, wherein the operating speed v is reduced by a predetermined value.

3. Method according to claim 1, wherein the operating speed is reduced by a predetermined, absolute value.

4. Method according to claim 1, wherein the predetermined operating speed is reduced by a predetermined, relative value.

5. Method according to claim 4, wherein the operating speed is reduced by a relative value, which is related to the actual speed.

6. Method according to claim 4, wherein the operating speed is reduced by a relative value, based on the maximum speed given by the maximum energy E_kin,max.

7. Method according to claim 4, wherein the actual speed is reduced by a value between 3 and 10%.

8. Method according to claim 4, wherein the actual speed is reduced by a value of 5%.

9. Method according to claim 4, wherein on dropping below the actual kinetic energy E_kin compared with the maximum permitted kinetic energy E_kin,max, a check is made as to whether the actual, instantaneous operating speed drops below the speed value in accordance with the operating process performed by the robot.

10. Method according to claim 9, wherein if the actual operating speed drops below the speed in accordance with the operating process performed by the robot, the actual operating speed is increased by a predetermined value, absolute or relative.

11. Method according to claim 9, wherein in the. case of a predetermined, maximum permitted force F_max, the permitted maximum kinetic energy E_kin,max is increased by a cushioning covering on robot parts.

12. Method according to claim 11, wherein the maximum permitted kinetic energy is increased by elastic coverings.

13. Method according to claim 11, wherein the maximum permitted kinetic energy is increased by viscoelastic coverings.

14. Method according to claim 11, wherein the permitted maximum kinetic energy is increased by elasticities in the drive line.