FEEDBACK CONTROLLER AND TRACKING CONTROLLER FOR OPTICAL DISK USING IT

摘要

PURPOSE:To apply no adverse influence to a control by an aperiodic component by excluding the aperiodic component from an addition object for every cycle when the aperiodic component in which a periodicity is not recognized is included in a control deviation signal. CONSTITUTION:A control operation signal including the control deviation signal outputted from a sensor 25 is inputted to a control part 26. The control quantity signal of an object 27 to be controlled by this control part 26 is inputted to a comparison part 200 as a main feed back signal. A subtracter 28 compares information for every one cycle in a repetitive cycle of the output of a memory 17 with current information to discriminate the level of the information of the subtracter 28 by a level decision part 29 and decide the presence and the absence of the aperiodic component. The decision part decides that the aperiodic component is included, an instantaneous switch 32 is switched to an opposite direction to a solid line, the information before one cycle outputted from the memory 17 passes through a repetitive compensating part 33 and is inputted to the memory 17 again. Accordingly, the aperiodic component is not stored in the memory and the adverse influence to the control by the aperiodic component can be cut off.