A robot system with a robot manipulator and with a visual output unit, wherein the robot manipulator includes a robot link and the robot link includes an inertial measuring unit, wherein the inertial measuring unit is designed to determine a direction of a gravity vector when the robot link is immobile, and to determine, over a plurality of points in time, a current orientation of the robot link in relation to the gravity vector using attitude gyros, and to transmit, to the visual output unit, the current orientation of the robot link in relation to the gravity vector, and wherein the visual output unit is designed to display the current orientation of the robot link in relation to the gravity vector.

The embodiments relate to a method for operating a medical robotic device with an end effector for performing a diagnostic and/or therapeutic measure, involving predetermining at least one position to be reached by the end effector, evaluating at least two movement sequences of the medical robotic device, by which the end effector reaches the respectively predetermined at least one position, using an optimization criterion to select the movement sequence with the best evaluation result as the optimum movement sequence and implementing the optimum movement sequence, so that the respective predetermined position is reached by the end effector, in order to improve the reaching of the predetermined position.

The invention disclosed an error modeling method for six degree-of-freedom robot end effector space-curve trajectory. More specifically, the invention is focused on end effector continuous space-curve trajectory tasks, and provides an error model taking into account of the influence of interpolation algorithm and joint linkage parameter error. This method selects key trajectory points on the ideal trajectory and by inverse solution converts them to the joint space, and performs interpolation; meanwhile the linkage parameter error taken into account to obtain the actual end effector position. The distance from the planned trajectory point to the ideal trajectory curve is used as the comprehensive error to reflect the deviation from the planned trajectory to the ideal trajectory. A simple and practical error model is obtained, which provides a theoretical basis for controlling the end effector-tracking accuracy.