| 摘要 |
PROBLEM TO BE SOLVED: To provide an impedance matching device capable of predicting maintenance timing. SOLUTION: The impedance matching device includes: variable impedance elements 3a and 3b; an operating mechanism operating operation shafts of the variable impedance elements using motors 7a and 7b as driving sources; a target position setting portion 9 setting target positions of the operation shafts; a motor controlling portion 13 controlling the motors to conform the detected positions of the operation shafts to the set target positions; and an abnormality determining portion 12 performing abnormality determination when an offset existing between a target position of an operation shaft and a present position is over an allowed value. While the number of times abnormality determination by the abnormality determining portion is under a set determination value, an allowed value of the offset is defined as an initial allowed value, and after the number of times abnormality determination reaches to the determination value, the allowed value of the offset is changed to an allowed value after abnormality detection, which is larger than the initial allowed value. In this way, the number of times abnormality determination reaches to the determination value, or the allowed value of the offset is changed to the allowed value after the abnormality detection, so that the maintenance timing can be predicted. COPYRIGHT: (C)2011,JPO&INPIT |
