| 摘要 |
PURPOSE:To suppress variant components in DFG signals and stably rotate a motor with accuracy by simple digital processing by providing a filtering means to extract motor rotation cycle components and the like contained in DFG signals. CONSTITUTION:The control device is a motor speed control device using frequency signals (DFG signals) in proportion to the drum rotation speed. The filter in the speed control signal generation system is a feedback type comb filter; the feedback system is provided with the following two characteristics: one wherein the transmittance G1 (Z) satisfies Formula I, and the other wherein the transmittance G2 (Z) satisfies Formula II. In Formulae I and II, K1 and K2 are real numbers with K1<1 and K2<1, and N and M are integers with N>2 and N>M. A DFG sensor 4 detects DFG signals through the rotation of the drum 2. A cycle comparison circuit 10 compares DFG cycle data with data from a target cycle generation circuit 9, and produces speed error signals. Variant components are extracted and removed from DFG signals by a variant component extracting removing filter 11. |
