US 11,999,049 B2
Tactile feedback of an end effector of a robot manipulator over different orientation ranges
Andreas Spenninger, Karlsfeld (DE)
Assigned to Franka Emika GmbH, Munich (DE)
Appl. No. 17/624,013
Filed by Franka Emika GmbH, Munich (DE)
PCT Filed Jul. 3, 2020, PCT No. PCT/EP2020/068784
§ 371(c)(1), (2) Date Dec. 30, 2021,
PCT Pub. No. WO2021/004920, PCT Pub. Date Jan. 14, 2021.
Claims priority of application No. 10 2019 118 260.3 (DE), filed on Jul. 5, 2019.
Prior Publication US 2022/0347866 A1, Nov. 3, 2022
Int. Cl. B25J 9/16 (2006.01); B25J 13/02 (2006.01)
CPC B25J 13/025 (2013.01) [B25J 9/1638 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method of controlling a robot manipulator during manual guidance of the robot manipulator by a user, wherein the robot manipulator comprises a plurality of members interconnected by joints and an end effector connected to a distal member by a further joint, and wherein actuators are arranged at all joints, the method comprising:
controlling the actuators to compensate for a gravitational force acting on the robot manipulator by a control unit, so that the robot manipulator, starting from a stationary pose, remains in the stationary pose without acceleration without application of external force, but that the robot manipulator is guidable manually;
during the manual guidance of the robot manipulator by the user:
detecting an orientation of the end effector with respect to the distal member or with respect to an earth-fixed coordinate system by an angle detecting unit; and
controlling at least part of the actuators of the robot manipulator by the control unit based on the orientation of the end effector detected by the angle detection unit in such a way that, during the manual guidance of the end effector, the end effector:
within a first range of a first rotation of the end effector, experiences damping by a speed-dependent resistance to the manual guidance, and outside the first range, experiences springing by a rotation angle-dependent resistance to the manual guidance, wherein the first rotation is a rotation angle of the end effector about a longitudinal axis of the end effector, and
within a second range of a second rotation of the end effector, experiences damping by the speed-dependent resistance to the manual guidance, and outside the second range, experiences springing by a deflection-dependent resistance to the manual guidance, wherein the second rotation is a rotational deflection of the end effector from its originally aligned longitudinal axis or a vertical axis of the earth-fixed coordinate system.