Tactile feedback of an end effector of a robot manipulator over different orientation ranges

A robot manipulator controllable during manual guidance 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 robot manipulator further comprising:

• an angle detection unit configured to detect an orientation of the end effector with respect to the distal member or with respect to an earth-fixed coordinate system during the manual guidance of the robot manipulator by the user, and
• a control unit configured to control the actuators to compensate for a gravitational force acting on the robot manipulator such that the robot manipulator, starting from a stationary pose, remains in the stationary pose without acceleration without the application of external force, but that the robot manipulator is guidable manually, the control unit further configured to control at least part of the actuators of the robot manipulator, during the manual guidance of the robot manipulator by the user, 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.