JPH01138666A - Positioning device - Google Patents

Abstract

PURPOSE:To stabilize a positioning action by charging a correcting value to minimize a transient response immediately after a position mode is switched to a capacitor for integration during the seek action and using for the initial value of an integrator immediately after the position mode is switched. CONSTITUTION:For an integrating circuit 16, a target track signal 1, a mode switching signal 6 and a position signal 11 are inputted and a correcting value signal 15 is outputted. The correcting value to minimize a transient response immediately after the position mode is switched at respective tracks is written to a ROM 2 beforehand, an analog correcting value 5 is charged to a capacitor 10 for integration by switches 7-9 connected to a terminal (a) side with the mode switching signal 6 during the seek action and the position signal 11 is outputted through an inversion amplifier composed of resistances 12 and 13 and an operational amplifying circuit 14. Immediately, after the position mode is switched, the switches 7-9 are connected to a terminal (b) side, and the analog correcting value 5 charged at the capacitor 10 is used as the initial value of an integrator 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a positioning system, and more particularly to a positioning system suitable for positioning a magnetic head of a magnetic disk device at a target position using a closed loop control method.

[Conventional technology]

Conventionally, the positioning method of the magnetic head of this type of magnetic disk drive is performed by feedback control, and the speed loop is type 1, so the actual speed is It does not follow completely and causes a speed error. In particular, if the speed error is large near the target track, there is a drawback that the transient response after switching to the 5-position mode becomes large. In addition, external forces in a certain direction are applied to the positioner due to the effects of deflection of the FPC (Flexible Printed Circuit) head lead wire, wind due to disk rotation, gravity, unbalance of the positioner's moment of inertia, etc. However, this external force has the disadvantage of increasing the transient response during positioning operations.

[Problems to be Solved by the Invention] The problems to be solved by the present invention are to eliminate the drawbacks of the conventional positioning system as described above, reduce the transient response during positioning of the magnetic head, and An object of the present invention is to provide a positioning system that produces stable positioning operation sounds.

[Failure to solve the problem]

The positioning device of the present invention moves a moving object between a plurality of target positions (for example, tracks of a magnetic disk) in a speed control mode using a position signal representing all changes in the position of the moving object as a feedback signal, and then performs position control. In the positioning device, the positioning device is configured to follow the target position according to the speed control mode, the correction value means outputting a correction value signal corresponding to the target position among the target positions, and the correction value signal when in the speed control mode. an operational amplifier constituting an inverting amplifier that inputs the position signal in the speed control mode; and in the position control mode, the capacitor and the operational amplifier input the position signal and output a corrected position signal. and a switch for configuring an integrator.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 2 is a block diagram of a positioning device using a closed loop control method for positioning a magnetic head according to an embodiment of the present invention. FIG. 1 is a detailed circuit diagram of an integrator circuit 16 which is the main part of this embodiment.

As shown in FIG. 2, in this embodiment, a magnetic disk device 17
The positioning of the magnetic head 19 with respect to the information recording concentric tracks of the magnetic disk 18 in the magnetic disk 18 is completely controlled, and the magnetic head 19 is normally moved by a voice coil motor type driving device [20]. Positioning operation has two modes: speed control mode and position control mode. During seek (movement) operation, it is controlled by a control loop using speed control mode, and during track follow (following the target track) operation, Controlled by a control loop with position control mode.

During a seek operation, a magnetic head output signal 21 indicating position information read by the magnetic head 19 is demodulated into a position signal 11 by a position signal demodulation circuit 22. The position signal 11 is differentiated by an electronic tachometer 25 and output as a measured speed signal 26 indicating the actual speed of the magnetic head 19. Further, a predetermined target speed according to the number of tracks from the current track position of the magnetic head 19 to the target track position is written in the 0M28, and a remaining p track number signal 27 is input. Accordingly, the target speed is output as a digital speed reference signal 29.

The digital speed reference signal 29 is input to a DA converter 30 and output as a speed reference signal 31.

The measured speed signal 26 and the speed reference signal 31 are input to a speed error signal generation circuit 32, which takes the difference between the measured speed signal 26 and the speed reference signal 31 and amplifies it, thereby outputting a speed mode drive signal 33.

Thereafter, the speed mode drive signal 33 is input to the mode switching circuit 34. During the seek operation, the mode switching circuit 34 passes only the speed mode drive signal 33, and the speed mode drive signal 33 is input as the drive signal 35 to the power amplifier 36, and after current amplification, as the drive current 37.
The signal is input to the drive device 20, and by driving the drive device 20, the magnetic head 19 is moved to the target track.

During the track follow operation, PIL) compensation closed loop control is performed, and the magnetic head output signal 21, which is the output of the magnetic head 19, is demodulated into the position signal 11 by the position signal demodulation circuit 22, and the signal is output to the integrator circuit 16. input. The integrator circuit 16 performs both integral element compensation and proportional element compensation of FID compensation. The integrator circuit 16 receives the target track signal 1, the mode switching signal 6, and the position signal 11, and charges the integrating capacitor during the seek operation to obtain a correction value that reduces the transient response immediately after switching the position mode. In order to reduce the transient response immediately after mode switching, a correction position signal 15 is output. (The integrator circuit 16 will be explained in detail later using FIG. 1.) Thereafter, the corrected position signal 15 is transmitted to the position signal summing amplifier 2.
3 is input. In the position signal summing amplifier 23, the corrected position signal 15 is added to the actually measured speed signal, and the PID
Perform differential element compensation of compensation, and position mode drive signal 24
Output. The position mode drive signal 24 is input to the mode switching circuit 34. Here, during the track follow operation, the mode switching circuit 34 passes only the position mode drive signal 24, and the position mode drive signal 24 is inputted to the power amplifier 36 as a drive signal 35, and after current amplification, is driven as a drive current 37. The magnetic head 19fc is inputted to the device 20 and is held on the target track by driving the drive device 20.

Next, the integrator circuit 16, which is the main wall portion of this embodiment, will be explained.

As shown in FIG. 1, the integrator circuit 16 receives a target track signal 1, a mode switching signal 6, and a position signal 11.
A corrected position signal 15 is output. ROM2 has a correction value written in advance to reduce the transient response that occurs immediately after switching the position mode for each track.
When the target track signal 1 is input to OM2, a digital correction value 3 is output. Digital correction value 3 is
Thereafter, it is input to the DA converter 4, and after DA conversion, it is output as an analog correction value 5.

During the seek operation, the switch 7.8.9 is connected to the terminal a side by the mode switching signal 6, and the analog correction value 5 is charged to the integration capacitor 10 as a transient response correction value, and the analog correction value 5 is charged as a transient response correction value to the position The signal 11 is output through an inverting amplifier composed of resistors 12, 13 and an operational amplifier circuit 14.

Immediately after the position mode is changed from the seek operation to the track follow operation, the switch 7, 8, 9 is connected to the terminal side by the mode change signal 6, and the analog correction value 5 charged in the capacitor 10 is connected to the resistor 12, 13, It is used as the initial value of the integrator composed of the capacitor 10 and the operational amplifier circuit 14, and serves to reduce the transient response immediately after switching the position mode, thereby achieving stable positioning operation.

During track follow operation, resistors 12, 13. An integrator constituted by a capacitor 10 and an operational amplifier circuit 14 performs integral element compensation and proportional element compensation of PID compensation, and outputs a corrected position signal of 15 ft.

〔Effect of the invention〕

As explained above, the present invention uses the integrator circuit 16 to reduce the transient response immediately after switching the position mode.
The transient response correction value of each trunk is written in the correction value means in advance, and during the seek operation, the integration capacitor is charged by the correction value signal, and the integrator is charged immediately after the position mode is switched from the seek operation to the track follow operation. By using it as an initial value, it works to reduce the transient response immediately after switching the position mode, and has the effect of performing stable positioning operation.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an integrator circuit which is the main part of an embodiment of the present invention, and FIG. 2 is a proximal diagram of a positioning and determining device of an embodiment of the present invention having the integrator circuit shown in FIG. be. 2.28-ROM, 4, 30-D Ai exchange! ,7゜8
．． 9... Switch, 14... Operational amplifier, 16...
- Integrator circuit, 18... Magnetic disk, 19... Magnetic head, 20... Drive device, 22... Position signal demodulation circuit, 23... Position signal summing amplifier, 25...
・Electronic tachometer, 32...speed error signal generation circuit,
34...Mode switching circuit, 36...Power amplifier. Agent Patent Attorney Shincha Uchihara 1.

Claims (1)

[Claims] A positioning device that moves a moving object between a plurality of target positions in a speed control mode using a position signal representing a change in the position of the moving object as a feedback signal, and then follows the target position in a position control mode. a correction value means for outputting a correction value signal corresponding to a desired one of the target positions; a capacitor charged by the correction value signal in the speed control mode; and a capacitor charged with the correction value signal in the speed control mode; an operational amplifier that configures an inverting amplifier that inputs the position signal; and a switch that allows the capacitor and the operational amplifier to configure an integrator that inputs the position signal and outputs a corrected position signal when in the position control mode. Characteristic positioning device.