| 摘要 |
A speed detection device and a servomotor are provided to perform periodical samplings of coordinates indicating a position of a moving body performing a rotating motion or a reciprocating motion and detect speed of the moving body on the basis of the coordinates. A speed detection device includes a memory(52), first and second registers(R11,R21), and an operation unit. The memory memorizes values of a plurality of preset temporal angles and values of trigonometrical functions for the plurality of preset temporal angles. The first register stores first coordinates of a moving body obtained from a first sampling. The second register stores real second coordinates of the moving body obtained from a second sampling. The operation unit calculates the second coordinates, indicated by multiplication, addition, or subtraction of the first coordinate with the values of the trigonometrical functions, to approximate the real second coordinates. The operation unit calculates speed of the moving body on the basis of the temporal angle corresponding to the value of the trigonometrical function used in the calculated second coordinates. |
