| 摘要 |
PURPOSE:To make a high-speed stable positioning possible even if a position signal including uncertainty is used by moving a magnetic head along a prescribed curve until the magnetic head is decelerated to the same degree as the error of a speed signal and selecting and using position information thereafter. CONSTITUTION:The differential signal between the position signal, which is obtained in an adder 12 and a set value is supplied to a discriminating circuit 10, and it is supplied to a function generator 7 if it does not reach a determined limit position Xp, but it is supplied to a selecting circuit 11 if it reaches this position Xp. The function generator 7 generates a function of the curve, and the difference between a speed signal value generated by a difference function circuit 5 and a command speed value from the function generator 7 is obtained in an adder 13 to attain a speed error signal (A), and this signal drives a magnetic head 3 through the selecting circuit 11. When the length corresponding to the output of the adder 12 is shorter than the limit position Xp, the output of the adder 12 is applied as a position error signal (B) to a phase correction circuit 8, and the magnetic head 3 is driven to the position of a target track. Thus, the high-speed stable magnetic head positioning control is possible. |
