CONTROLLER FOR MACHINE EFFECTING END

A controller for controlling a position of a driven element with respect to a machine effecting end so as to be in accord with a command. An acceleration sensor is mounted to a member of the machine effecting end to which a tool is attached. Acceleration detected by the sensor is subjected to second-order integration by a torsion estimator to obtain displacement Δθ of the machine effecting end from the original position. Position feedback P1 of a driven element is subtracted from position command Pc to obtain first position deviation ε1. The displacement Δθ is added to the first position deviation ε1 to obtain second position deviation ε2. The second position deviation ε2 is subjected to learning control of a learning controller to obtain a correction value, which is added to the first position deviation ε1 to obtain velocity command Vc. The second position deviation is the sum of the displacement ε1 of the driven element from the commanded position and the displacement Δθ of the machine effecting end relative to the driven element, and thus signifies a positional displacement of the machine effecting end from the commanded position. The second position deviation is subjected to the learning control so as to converge to “0”, whereby the position of the driven element with respect to the machine effecting end becomes in accord with the command.