A robot controller for keeping the posture of a tool in a task coordinate system
by a simple processing and allowing a robot to perform flexible translational motion.
A robot controller for controlling a motor for driving a joint by a control circuit
having a position/speed state feedback loop, has a mechanism for measuring the
angle of a joint of a robot, a mechanism for storing the initial posture of a tool
attached to the end of a hand of the robot, a mechanism for setting the position
or speed gain of a specific joint axis smaller than the position or speed gains
of the other joint axes, and a mechanism for calculating the correction of a position
or speed command to keep the tool posture with respect to the robot base on the
basis of the angle of the joint and the initial posture of the tool.
