| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect a rotary angle from the output of an angular velocity sensor. SOLUTION: A low-pass filter 22 takes out the necessary component of a band from the output of the angular velocity sensor 10. The output signal Do of the filter 22 is supplied to a low-pass filter 31, which detects a low-frequency component and supplies its output to a rotary deciding unit 32, which decides whether an element 1 to be detected is rotated or not. When the element 1 is stopped, the low-frequency component of the output of the filter 31 is written as an offset value in a ring buffer 34. When the element 1 is rotated, the writing of the low-frequency component of the output of the filter 31 in the buffer 34 is stopped, and the offset values of a plurality of samples written in the buffer 34 are read. The mean value of the offset values of the plurality of the samples is calculated, its calculated result Ds is subtracted from the signal Do, and the subtracted result Dv is integrated by an integrating circuit 51. |
