US 12,384,019 B2
Safe activation of free-drive mode of robot arm
Jacob Gregers Hansen, Kolding (DK)
Assigned to Universal Robots A/S, Odense S (DK)
Appl. No. 17/770,715
Filed by Universal Robots A/S, Odense S. (DK)
PCT Filed Oct. 9, 2020, PCT No. PCT/DK2020/050283
§ 371(c)(1), (2) Date Apr. 21, 2022,
PCT Pub. No. WO2021/078344, PCT Pub. Date Apr. 29, 2021.
Claims priority of application No. 2019 01237 (DK), filed on Oct. 22, 2019.
Prior Publication US 2022/0379463 A1, Dec. 1, 2022
Int. Cl. B25J 13/08 (2006.01); B25J 9/00 (2006.01); B25J 9/16 (2006.01); G05B 19/423 (2006.01)
CPC B25J 9/0081 (2013.01) [B25J 9/1674 (2013.01); B25J 13/085 (2013.01); G05B 19/423 (2013.01); G05B 2219/36418 (2013.01); G05B 2219/36429 (2013.01); G05B 2219/39194 (2013.01); G05B 2219/39529 (2013.01); G05B 2219/40586 (2013.01)] 32 Claims
OG exemplary drawing
 
1. A robot controller for controlling a robotic arm, the robot controller for switching the robotic arm between a first mode of operation and a free-drive mode of operation, where the robot controller is configured to perform operations comprising:
keeping the robotic arm in a posture that is static when only gravity acts on the robotic arm; and
allowing a change in the posture of the robot arm when an external force different from gravity is applied to the robotic arm;
wherein the free-drive mode of operation is activatable in response to a free-drive activation signal at the robot controller;
wherein, in response to the free-drive activation signal, the robotic controller is configured to perform operations comprising:
monitoring a value of at least one parameter of at least one sensor associated with a joint of the robotic arm, the monitoring being performed in an activation sequence period of time, and
comparing the value to at least one threshold value; and
wherein the robot controller is configured to switch the robotic arm to the free-drive mode of operation when the value of the at least one parameter does not exceed the at least one threshold value within the activation sequence period of time.