FRICTION COMPENSATING METHOD AND DEVICE THEREFOR

摘要

PROBLEM TO BE SOLVED: To execute always proper friction compensation without generating vibration at the time of starting even at the time of the occurrence of the change of the position of a still state and a contacting state by using and secular change. SOLUTION: A feed forward compensation part 2 obtains speed information based on a position command r1 and executes feed forward control through a switch control part 3 with respect to compensation corresponding to this speed. A still friction compensating part 1 judges the start of control rotating a motor M by the change of the command r1, outputs a primary still friction compensating amount as an offset amount remarkably smaller than still fiction force at the time point to the part 3 and increases the still friction compensating amount with the lapse of time thereafter. After the time point of judging the start of the operation of the motor M by the change of a position detecting signal S as a feedback signal, the still friction compensating amount at the time point is maintained and outputted to the part 3. The part 3 compares the still friction compensating amount to be inputted from the part 1 and a compensating amount inputted from the part 2 with each other and outputs a larger compensating amount to an adder 8 to be added to a feedback control amount.