Vibration suprresion positioning controller

A vibration-damping positioning controller which produces a position command when given a differential value of a target position command that changes in a predetermined pattern, and which causes load to follow the position command by inputting the position command to the feed back control system, the controller comprising:

• an integrator for integrating the differential value of the target position command;
• a subtracter which subtracts the position command from an output of the integrator, to thereby output a position command error;
• a stable prefilter which receives the differential value of the target position command and eliminates a frequency component identical with a vibration pole ω0 of the feedback control system;
• command fixing means which receives an output from the stable prefilter and the position command error, judges that the command is started when a differential value of the target position command has changed from zero to a non-zero value, judges that the command is ended when the differential value of the target position command has changed from a non-zero value to zero, outputs zero from the time the position command error has assumed zero after the command is ended until the next command is started, and in other cases produces an output of the stable prefilter in an unmodified form;
• and
• a second integrator which integrates an output from the command fixing means, to thereby output the position command.