| 摘要 |
<P>PROBLEM TO BE SOLVED: To operate a member to be operated by securing a prescribed operation range without making the member deviate from a lower limit and an upper limit of a preset operation range irrespective of the state of a load. <P>SOLUTION: In a PID control part 50, a wiper motor 26 is constituted so as to be inverted in rotation when an operation result of a duty shows a negative value. In the case that the wiper motor 26 is inverted in rotation when the duty shows the minus value, there arises a similar situation that a so-called brake is applied. Accordingly, by setting inversion timing by using a pulse count value on the basis of a direction in which the wiper unit is frequently used (that is, [Lo]) as the operation of the wiper unit 12, the moving range of the wiper unit (that is, a wiping area) can be increased. Furthermore, since the re-release of the brake (re-inversion of the energization direction of the wiper motor 26) is prohibited even if the wiper unit does not reach a target inversion position based on the pulse count value, the awkward operation of the wiper unit 12 can be prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT |
