| 摘要 |
PURPOSE:To contrive the shortening of the settling time by providing a control means increasing the control gain of a position control system in response to the position deviation so as to decrease the increase in the settling time due to the difference from the initial speed in the transient state where the mode is switched from the speed control mode into the position control mode. CONSTITUTION:When a position signal A corresponding to a position deviation Xe is large, a multiplier 11 multiplies a position signal A with an output signal C of a phase compensation device 9 to increase it further, thereby increasing the correction signal. As a result, a signal B applied from an adder 12 to a position control contact (b) is larger than an output signal C and the head is going to go to an object quickly. In this case, the loop gain is increased, as the present position X0 of the head approaches object position Xo=0, the correction signal outputted from the multiplier 11 approaches zero, then the signal B applied to the position control contact (b) approaches the output signal C. Thus, since the head approaches the object position, the loop gain approaches a normal gain, then the positioning of high speed access is attained with high accuracy. |
