The purpose of the present invention is to eliminate the need, when a robot has been replaced with a new robot that is different in size, for an operator to directly re-input as operation program to make the robot operative. This robot control device comprises: a storage unit that stores an operation program; and a control unit that operates a robot is a robot coordinate system with three orthogonal axes. The control unit is provided with: a mobility range determination unit that determines whether there is, in the operation program, an axis, among the three orthogonal axes, that exceeds a mobility range of the robot; and a correction unit that, if it has been determined by the mobility range determination unit that there is an axis that exceeds the mobility range of the robot, rewrites the operation program so the axis is kept within the mobility range of the robot.

A robot controller including a control unit configured to cause a control point to move from a first position to a second position by basic joints and wrist joints, and a recording unit configured to record position information including the second position and rotation angles to which the wrist joints are rotated when the control point is positioned at the second position. In a case where posture of the wrist unit at the second position is not a singular point, the control unit causes the basic joints and the wrist joints to perform straight-line motion so as to move the control point along a straight line, and in a case where the posture of the wrist unit at the second position is a singular point, the control unit causes the wrist joints to perform each-joint controlling motion.

A method for avoiding singularities of a robotic arm includes: calculating a virtual environment external force required by the robotic arm to avoid singularities based on current joint positions of joints on the robotic arm when it is determined that the robotic arm needs to avoid singularities; obtaining a current end force of the robotic arm and a desired end trajectory of the robotic arm; performing admittance control calculation based on the virtual environment external force, the current end force and the desired end trajectory to obtain a corrected end trajectory of the robotic arm; and controlling the robotic arm to move based on the corrected end trajectory.