JPH06259877A - Disk device - Google Patents

Abstract

(57) [Abstract] [Purpose] In a disk device having a control device that switches control modes, control mode transition operation is performed at high speed and stably, and the success rate of control mode transition is improved. [Structure] Means 2 for deciding an operation amount of a second control mode based on a state quantity detected by a state quantity detecting means 7 of a controlled object 6 in a first control mode, and operation of a third control mode. The mode switching control device is configured by the means 3 for determining the amount, the operation amount switching command generation means 5 for each control mode, and the operation amount switching means 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device, for example, a disk device having a controller for controlling a control target by switching a plurality of control modes such as a positioning device.

[0002]

2. Description of the Related Art FIG. 18 shows a magazine (SONY Semiconductor I
C Data Book 1988 Compact Disc p.127 Figure 4)
3 is a time chart regarding the pulling-in system of the focusing servo system in the compact disc device shown in FIG. In the figure, the horizontal axis represents time and the vertical axis represents signal voltage. (a) is the focus actuator drive voltage, (b) is the focus error signal, (c) is the sense terminal voltage, and (d) is the signal showing the focus pull-in completion state. The wavy line in the figure is a waveform assuming that no focus is applied. The objective lens is driven in the direction perpendicular to the medium to search for the in-focus position, the in-focus position is found at time t0, and the focusing servo system is operated to cause the light spot to follow the surface wobbling of the medium.

FIG. 19 shows the magazine (SONY Semiconductor
2 is a time chart regarding a one-track jump operation in a compact disc shown in IC Data Book 1988 Compact Disc p.133). The horizontal axis represents time, and the vertical axis represents signal voltage. (a) is a tracking error signal, (b) is a tracking error signal (a) comparator signal, (c) is a tracking error signal (a) zero-cross point detection mask signal, (d) is an acceleration jump pulse,
(e) is a deceleration jump pulse, (f) is a tracking servo ON / OFF command, (g) is a jump direction command, (h) is a head feed (thread) servo system ON / OFF command,
(i) is a CPU busy signal. An acceleration / deceleration pulse is applied to the tracking actuator to swing the objective lens in the direction perpendicular to the track to move the light spot to the adjacent track. After the light spot reaches the adjacent track, the tracking servo system is operated.

FIG. 20 shows a magazine (SONY Semiconductor IC
Data Book 1991 for floppy disk / hard disk
IC CXA11 for hard disk shown in IC p.360)
FIG. 67 is a block diagram of 67AQ. Reference numeral 181 is a bus, 182 is a magnetic disk controller, 183 is a central processing unit and analog / digital converting means, 184 is a servo data magnetic disk, 185 is a read magnetic head, 186.
Is a read signal amplifier, 187 is a servo signal demodulation circuit,
188 is position / speed conversion means, 189 is position control means,
190 and 191 are switches, 192 is digital / analog conversion means, 193 is cross-track pulse detection means,
194 is a signal adding means, 195 is a low-pass filter, 1
Reference numeral 96 is a phase compensator, 197 is a power amplifier, and 198 is a magnetic head actuator represented by a voice coil motor.

When a data search command is sent from the host computer to which the magnetic disk device is connected to the central processing unit 183 via the bus 181 and the magnetic disk controller 182, the switch 19 of the magnetic disk device is switched.
When the switch 1 is turned on and the switch 190 is turned off, the track crossing speed of the magnetic head 185 is changed to the position / speed converting means 18.
8 and the difference from the target speed output from the central processing unit 182 via the DA converter 192 is calculated by the adding means 194 and sent to the power amplifier 197 via the phase compensator 196. When a drive voltage is applied to the actuator 198, the magnetic head 185
The traverse speed of the truck is controlled.

After that, at the moment when the magnetic head 185 reaches the target track, the switch 190 is turned on and the switch 19 is turned on.
When 1 is turned off, the magnetic head 185 is mounted based on the tracking error signal output from the servo signal demodulation circuit 187 and based on the output of the position control means 189 represented by a phase lead compensator or the like. The position of the actuator 198 is controlled so that the magnetic head is positioned at the center of the target track.

FIG. 21 shows the Institute of Electrical Engineers of Japan Vol.110, No.8, p.6.
It is a block diagram of the access control system of the optical disk apparatus published in FIG. Reference numeral 201 is an optical disk, 202 is a disk motor, 203 is a linear motor, 204 is a phase compensation circuit, 205 is a coupling compensation circuit, 206 is a speed control circuit, and SW1 and SW2 are switches. When searching for information on the disc, first turn off SW1 and turn on SW2.
The speed of the linear motor is controlled by turning on SW1 and turning off SW2 at the moment when the light spot reaches the target track.
Then, the two-stage coupling tracking servo system is operated.

[0008]

In the conventional optical disk apparatus, in the pulling operation of the focusing servo system, the objective lens is driven in the direction perpendicular to the optical disk surface to operate the focusing servo system at the in-focus position. Therefore, whether or not the focusing servo system pull-in operation succeeds is determined only by the search speed of the objective lens and the focusing servo system pull-in ability.If the search speed is high, immediately after the focusing servo system is operated. However, there is a problem in that the overshoot amount exceeding the linear range of the focus error signal occurs, and the pulling operation of the focusing servo system to the in-focus position fails.

In the conventional optical disk apparatus, for example, in the one-track jump operation, the tracking servo system is operated at the moment when the light spot reaches the center of the adjacent track by applying an acceleration / deceleration pulse to the tracking actuator. Whether or not the operation succeeds is determined only by the track crossing speed of the light spot and the pull-in ability of the tracking servo system. Therefore, if the track jump speed is high, immediately after the tracking servo system is operated, the tracking error signal However, there is a problem in that the overshooting amount exceeding the linear range of 1 occurs and the operation of positioning the light spot on the adjacent track fails.

In the conventional magnetic disk device, the speed of the voice coil motor equipped with the magnetic head is controlled during the seek operation, and the position control is switched at the moment when the magnetic head reaches the target track. , The seek speed of the magnetic head and the pull-in capability of the position control system are used only.Therefore, if the speed control system is disturbed and the speed of reaching the target track is too fast, the overshoot amount of the position control system is too large. There has been a problem that the operation of positioning the magnetic head on the target track fails.

In the conventional optical disk device, the speed of the linear motor is controlled during the seek operation, and the optical head is switched to the two-stage coupling tracking servo system of the linear motor and the tracking actuator at the moment when it reaches the target track. The success or failure is determined only by the seek speed of the light spot and the pulling-in capability of the two-step coupling tracking servo system. Therefore, if the speed control system is disturbed and the arrival speed to the target track is too fast, the two-step coupling tracking servo There is a problem that the operation of positioning the light spot on the target track fails due to the excessive amount of system overshoot. Further, since the tracking actuator does not operate during the speed control of the linear motor, there is a problem that the seek time cannot be shortened as compared with the positioning time by the maximum acceleration and the maximum deceleration of the linear motor.

In each of the prior arts, the initial value of the manipulated variable in the subsequent control mode is 0. Therefore, in the subsequent control mode, a transient response occurs immediately after the mode is switched, and the overshoot amount with respect to the target value is exceeded. However, there is a problem in that That is, in any of the conventional techniques, the two control modes are operated independently,
When the control operation speed is increased, the control mode transition is apt to fail, which makes it difficult to increase the control operation speed.

The present invention has been made to solve the above problems, and an object thereof is to obtain a disk device having a mode switching control device capable of operating at high speed while improving the success rate of control mode transition. I am trying.

[0014]

DISCLOSURE OF THE INVENTION A disk device according to the present invention detects a state quantity of a control system in a first control mode at the time of transition to a control mode, and a second control based on the detected state quantity. It has a mode switching control device that determines the operation amount of the mode, shifts from the first control mode to the second control mode, and then shifts to the third control mode.

The disk device according to the second aspect of the present invention calculates the state quantity of the stabilization compensator of the control system in the third control mode during execution of the second control mode, and the third
It has a mode switching control device used as an initial value of the stabilization compensator immediately after the control mode is changed.

Further, in the disk device according to the third aspect of the present invention, in the pulling operation of the focusing servo system, the focus position of the light beam is searched by means for driving the focus position of the light beam in the direction perpendicular to the disk surface. Then, the moving speed of the light beam is detected during the search of the focus position of the light beam, the operation amount is added to the means for driving the focus position of the light beam based on the detected speed, and then the operation of the focusing servo system is switched. Is.

Further, in the disk device according to the fourth aspect of the present invention, in the track jump operation, the track crossing speed is detected during the track crossing, and the operation amount is added to the light beam driving means based on the detected speed, After that, the operation is switched to the operation of the tracking servo system. Alternatively,
During the seek operation, the track crossing speed of the magnetic head is detected and controlled so as to match the target speed, and the operation amount is added to the magnetic head drive means based on the speed deviation on the verge of reaching the target track, and then the operation of the tracking servo system is switched. It is a thing. Alternatively, in the macro seek operation, the track crossing speed of the light beam is detected and the optical head drive means is controlled so as to match the target speed, and the operation amount is added to the optical head drive means based on the speed deviation just before reaching the target track. After that, the operation is switched to the tracking servo system operation.

According to a fifth aspect of the present invention, in the disk device according to the fifth aspect of the present invention, while the first actuator having a large movable range is being controlled in speed, the second actuator of the first actuator is controlled according to the speed of the first actuator. It has a two-stage actuator control device for accelerating or decelerating the tip of the second actuator by driving in the same or opposite direction to the moving direction.

In the disk device according to the sixth aspect of the present invention, when the tip of the second actuator reaches the target position, the tip of the second actuator is moved by the second actuator having a small movable range. At the same time as controlling the position to the target position, the first actuator having a large movable range is decelerated. After that, a two-stage actuator control device for switching to the two-stage actuator coupling position control mode by the first and second actuators is provided.

[0020]

In the disk device according to the present invention, the operation amount in the second control mode, which is determined based on the state amount in the first control mode, is input to the controlled object, and thereafter the operation amount in the third control mode is changed. It is input to the controlled object.

[0021]

【Example】

Example 1. An embodiment according to claim 1 of the present invention will be described below with reference to FIG. In FIG. 1, 1 is an operation amount determining means in the first control mode, 2 is an operation amount determining means in the second control mode, 3 is an operation amount determining means in the third control mode, 4 is an operation amount switching means, 5 is an operation amount switching command generating means, 6 is a controlled object, 7 is a state quantity detecting means of the control system, u is an operated amount which is an input to the controlled object, u
1, u2, u3 are manipulated variables determined by 1, 2, and 3, respectively, y is a controlled variable which is the output of the controlled object, and x is a state variable.

Based on the command output from the control mode switching command generating means 5, the control modes 1 to 3 are controlled.
When the control mode is switched to the control mode 1, the state quantity x of the control mode 1 is detected by the state quantity detecting means during the operation of the control mode 1, and the second control is performed based on the value of the state quantity x. The operation amount u2 in the mode is determined by the operation amount determining means 2. After the end of the first control mode, the control mode is once switched to the second control mode, and then u3 is input to the controlled object 6 as the operation amount u as the third control mode.

Example 2. FIG. 2 shows another embodiment based on claim 1 of the present invention, and the same number parts as in FIG. 1 are the same. In FIG. 1, the state amount detecting means 7 detects the state amount x in the first control mode from the control amount y. However, as shown in FIG. 2, the operation amount u1 in the first control mode is also used. The state quantity x may be detected.

Example 3. FIG. 3 shows another embodiment based on claim 1 of the present invention, and the same number parts as in FIG. 1 are the same. 8 and 10 are control modes 1 and 3 respectively
Target value generating means for generating the target values r1 and r3 in
9 and 11 are target values r in control modes 1 and 3, respectively.
It is a signal addition means for calculating the difference between 1, r3 and the controlled variables y1, y3. In FIG. 1, in the control modes 1 and 3, the manipulated variables u1 and u3 are simply output, but as shown in FIG. 3, the controlled variables are fed back and the manipulated variables are calculated based on the difference from the target value. The configuration may be determined. In FIG. 3, while the control mode 2 is operating, the target value generating means 10 in the control mode 3 outputs the target value r3, and if y3 is output from the controlled object 6, based on the output of the signal adding means 11. In the control mode 3, the operation amount determining means 3 calculates the operation amount u3 and uses it as the operation amount u3 immediately after the control mode 3 is entered.

Example 4. FIG. 4 shows another embodiment based on claim 1 of the present invention, and the same reference numerals in FIG. 4 denote the same parts. As shown in FIG. 4, not only the control amount y1 in the control mode 1 but also the operation amount u1 may be used together to detect the state amount x of the control mode 1. Further, the control targets in the control mode 1 and the control mode 2 may be different from each other, and the control amount for controlling the control target in the control mode 2 may be calculated based on the state amount of the control target in the control mode 1.

Example 5. FIG. 3 is also an embodiment based on claim 2 of the present invention. For example, the manipulated variable determining means 3 in the third control mode, which is constituted by a stabilization compensator or the like, is operated during the control mode 2. Based on the deviation signal which is the difference between the target signal r3 and the output signal y3 calculated in the signal adding means 11, the operation amount determining means 3 in the third control mode constantly calculates the operation amount u3 required for the control mode 3. I'll do it. Then, immediately after switching to the control mode 3, u3 calculated immediately before the end of the control mode 2 is output.

Conventionally, the manipulated variable immediately after the control mode is switched is 0, and the controlled variable which is the output of the controlled object is
It gradually approaches the target value by spending the time determined by the response time constant of the feedback control system. In contrast,
By calculating the manipulated variable in the control mode after switching before switching the control mode in advance, the operation in the subsequent control mode can be started from an appropriate initial value that is not 0, so that the transient of the feedback control system A response can be avoided, and the overshoot amount with respect to the target value becomes small.

Example 6. FIG. 5 shows an embodiment according to claim 3 of the present invention. FIG. 5 is a block diagram of the focusing servo pull-in system of the optical disk device according to the present invention. Reference numeral 51 is a focusing actuator, 52 is a focusing error detecting means, and 53 is a focusing actuator drive voltage generating means for searching the in-focus position of the light beam. Reference numeral 54 is a light beam search speed detecting means, 55 is a focusing actuator acceleration / deceleration command generating means, 56 is a focusing servo system stabilization compensator, 57 is a mode switching command generating means, and 58 is a mode switching means. s is the focal position of the light beam, r is the position of the medium surface of the optical disk on which the light beam should be focused, e is a focusing error signal, v is the relative speed between the focal position of the light beam and the medium surface of the optical disk, and u1 is the focusing Actuator search voltage or current, u2
Is a focusing actuator acceleration / deceleration command voltage or current determined by the focusing actuator acceleration / deceleration command generation means 55 on the basis of the speed v, u3 is a focusing actuator drive voltage or current during focusing servo operation, and u is any of u1, u2, and u3. Is the selected focusing actuator drive voltage or current.

FIG. 6 shows an operation waveform diagram of this embodiment. The horizontal axis represents time, and the symbols in the figure are as described above. v is a relative velocity between the focal position of the light beam and the medium surface of the optical disc. First, in order to find the in-focus position of the light beam, the focusing actuator 51 is driven based on the output u1 of the focusing actuator drive voltage generating means 53 shown in FIG. 5, and the focus position s of the light beam is the medium surface r of the disk.
When the value of the focusing error signal e approaches
As shown in, the time t0 to t1 when the focus error becomes larger and approaches the linear focusing error detection range,
For example, the relative velocity v between the focal position of the light beam and the medium surface of the optical disc is detected by the light beam search velocity detecting means 54 as the amount of change in the focusing error signal e per unit time.

Next, the magnitude and time of the brake current u2 are calculated based on the detected speed v, and when the focal position of the light beam coincides with the medium surface at time t2, the mode switching command generation means 57 outputs the mode switching command. Is generated, the mode switching means 58 selects the output u2 of the focusing actuator acceleration / deceleration command generating means 55, and a braking current is applied to the focusing actuator 51. The focal position of the light beam goes too far until time t3, then reverses direction, and the brake current u2 is applied until t4. At time t5, the output u3 of the focusing servo system stabilizing compensator 56 is selected at the moment when the focal position of the light beam again coincides with the medium surface, the focusing servo system operates, and the focal position of the light beam is held on the medium surface. to continue.

FIG. 7 is a diagram for explaining the above operation more easily. The horizontal axis x is the distance between the focal position of the light beam and the medium surface of the disk, the vertical axis is the focusing error signal, and the origin O is the in-focus position. The focal position of the light beam is initially located at the left end of the figure, and gradually moves to the right. Distance x reached the linear range of the focusing error signal at time t0 and moved to time t1
If 0 is detected, the average speed v0 during that time can be calculated as v0 = x0 / (t1-t0) ... (1). The current value i of the brake current u2 and the braking time T required to cancel the v0 to make the speed zero, the thrust constant of the focusing actuator 51 at a high frequency is Kf [N / m], and the moving part mass is M [kg. ],
The generated braking force and acceleration are F [N], α [m / s2],

[0032]

[Equation 1]

It may be determined so as to satisfy the above condition. If the brake current value i is constant, the brake current pulse width can be calculated from the equation (2) as follows: T = Mv0 / (Kfi) (3) actually,
At the moment when the speed of the light beam becomes zero, the in-focus position O goes too far, so T or i may be set larger than the value calculated by the equation (2) or (3).

After that, the focus position O is reached at time t2, but immediately after that, the brake current u2 calculated in advance is fed forward to the focusing actuator 51. The focal position of the light beam still goes too far and exceeds the linear range of the focusing error signal, so that the time t3
At this time, the speed becomes zero, but the braking operation continues until time t4 as shown in FIG. 6, so that the focal position of the light beam starts moving in the opposite direction toward the in-focus position. From time t4 to t5, the driving current of the focusing actuator is zero, so the focus position of the light beam coasts and reaches the focus position again at time t5. At this time, since the moving speed of the light beam is sufficiently decelerated, even if u3 in FIG. 5 is selected at t5 to switch to the feedback control operation, the focus position can be stably maintained on the medium surface. As described above, when the search speed of the light beam is too fast or the wobbling speed of the medium surface is too fast, the light beam goes too far from the in-focus position and even if it exceeds the linear range of the focusing error signal It can shift to servo operation.

Example 7. FIG. 8 is a diagram showing the operation of another embodiment according to claim 3. The horizontal axis represents time, and the vertical axis symbols are the same as those described above. Light beam from time t0 to t1
The average speed v1 during that period is calculated as v1 = x0 / (t1-t0) (4) from the distance x0 moved during the period, and the brake current u2 is determined based on that value, and the mode Switching means 58
As a result, the operation amount u is switched from u1 to u2 at time t1 so that the focusing servo system can reach the speed at which the focusing servo system can be retracted.
Accelerate or decelerate. After that, the manipulated variable u is switched from u2 to u1 again to continue the search for the focus position, and based on the distance x1 that the light beam has moved between times t2 and t3 in the linear range of the focusing error signal, the average speed v2 during that time = X1 / (t3-t2) ... (5) is calculated and the brake current u2 is determined based on the calculated value. At time t3, the operation amount u is switched from u1 to u2 to perform the brake operation. To do. During that time, the stabilization compensator 56 of the focusing servo system calculates the operation amount u3, and when the light beam reaches the in-focus position at time t4, the mode switching means 58 switches the operation amount u from u2 to u3.

As described above, the manipulated variable u may be switched from u1 to u2, then to u1, and then from u2 to u3. That is, the control mode 1 and the control mode 2 for outputting the operation amount according to the state quantity of the control mode 1 are alternately switched several times to control the state quantity, and then the final control mode 3 is entered. Is also good. Further, the timing of switching the operation amount u from u2 to u3 does not necessarily have to be the in-focus position, but may be in the linear range of the focusing error signal near the in-focus position.

Example 8. FIG. 9 shows an embodiment according to claim 4. FIG. 4 is a block diagram of a seek control system of a magnetic disk device having a large number of tracks for storing information. Reference numeral 81 denotes a target speed generating means for a seek (information retrieval) operation, which generates a target seek speed r1. Reference numeral 83 is a speed detecting means, 82 is a speed deviation detecting means, 84 is a stabilization compensator 84 of a speed control system, 85 is a control mode switching command generating means, 86 is a control mode switching means, 87 is a magnetic head driving means, 88 is a brake current generating means, 8
Reference numeral 9 is a magnetic disk, and 90 is a position deviation detecting means.

The moving speed v of the magnetic head driving means 87 is
The speed detecting means 83 detects v1 and the speed deviation detecting means 82 detects the speed deviation e1. Based on the speed deviation e1, the stabilization compensator 84 of the speed control system, which is composed of a gain compensator or the like, calculates the current or voltage as the operation amount as u1. Mode switching means 8
In the seek operation, 6 selects u1 as the manipulated variable u based on the output of the mode switching command generating means 85,
The magnetic head drive means 87 is moved to the target track while controlling the speed. At the same time, the brake current generating means 88 calculates the brake current u2 based on the speed deviation e1, and when the magnetic head reaches the target track position,
Position deviation e3 detected by the position deviation detecting means 90
Is detected and the operation amount u is switched from u1 to u2.

When the braking operation is completed, the position deviation e3 is detected by the means 90 for detecting the deviation between the track center position r3 of the magnetic disk 89 and the magnetic head position y3, and the output u3 of the stabilizing compensator 91 is detected. The tracking servo operation in which the magnetic head follows the center of the target track is selected by the mode switching means 86 as the operation amount u. While the brake current u2 is being output, the stabilization compensator 91 calculates the manipulated variable u3 necessary for the tracking servo operation based on the control deviation e3, and as the initial value of the manipulated variable u3 in the tracking servo mode. Used.

FIG. 10 is a diagram for explaining the operation of this embodiment. The horizontal axis represents time t, and the vertical axis represents the speed deviation e1, the detected speed v1 of the magnetic head during seek, and the operation amount u which is the drive current or drive voltage of the magnetic head. During speed control, the magnetic head is decelerated based on the manipulated variable u1 as it approaches the target track, and is switched to the manipulated variable u2 at time t1. The manipulated variable u2 required for this braking operation is obtained by using Kf, M, v0, and i of the equations (2) and (3) as the thrust constant of the magnetic head driving means represented by the actuator,
The brake pulse current i and its pulse width T may be determined based on the formula (2) or the formula (3) instead of the movable part mass, the speed at the time of reaching the target track, and the drive current.
Since the value of u3 is calculated during that time, u3 is added to the magnetic head drive means 87 with an initial value other than 0 even when the brake current is terminated at time t2.

Example 9. FIG. 11 shows another embodiment according to claim item 4. FIG. 11 is a block diagram of means for realizing the track jump function of the optical disk device according to the present invention. 111 is an optical disk, 112 is a tracking error detecting means, 113 is a track jump pulse generating means,
Reference numeral 114 is a mode switching command generating means, 115 is a mode switching means, 116 is a light beam driving means, 117 is an acceleration or deceleration pulse generating means, and 118 is a stabilizing compensator in the tracking servo system. In the figure, the difference between the track center position r3 of the optical disk 111 and the position y of the light beam output from the light beam driving means in the radial direction of the optical disk is detected by the tracking error detection means 112 as a tracking error signal e3, The light beam driving means 116 is driven by the operation amount u3 which is the output of the stabilization compensator 118 in the tracking servo system, and the light beam is caused to follow the track center.

For example, when the light beam is moved one track, the acceleration / deceleration pulse u1 generated by the track jump pulse generating means 113 is applied to the light beam driving means 116.
In addition, the light beam travels across the tracks to adjacent tracks. During this time, the tracking error signal e3
Based on the above, the acceleration or deceleration pulse generation means 117 detects the track crossing speed of the light beam, and when the light beam approaches the center of the target track, an acceleration or deceleration pulse u2 corresponding to this speed is generated. At the same time, based on the command from the mode switching command generating means 114, the mode switching means 115 switches the manipulated variable u from u1 to u2. After that, when the speed of the light beam reaches an appropriate value for the transition to the tracking servo operation, the tracking servo system is operated again by switching to u3.

FIG. 12 is a diagram for explaining the operation of this embodiment.
In the figure, the horizontal axis represents time, and the vertical axis represents the tracking error signal e3, the track traverse speed v of the light beam, and the operation amount u of the light beam driving means. Initially, the tracking servo system operates and the light beam follows the track center, but when the track jump pulse u1 is applied, the light beam starts moving to the adjacent track. The jump pulse u1 is switched from acceleration to deceleration at a point of time when the track has moved approximately half a track, and during that time, the track crossing speed v0 is changed to, for example, v0 = (e01- e02) / (t1-t2) ... (6) is detected. If this speed is too fast, it is determined that the transition to the tracking servo operation fails when the light beam reaches the adjacent track, and a deceleration pulse is generated by the manipulated variable u2, and this is applied to the light beam driving means 116. . At time t3 when the speed is sufficiently decelerated, the operation amount is switched to u3 to operate the tracking servo system.

While the manipulated variable u2 is selected,
By calculating the operation amount u3 of the tracking servo system in the stabilization compensator 118 and using it as the initial value immediately after switching to the tracking mode, a tracking servo operation with a small overshoot amount can be realized. Further, in the present embodiment, the one-track jump operation of the light beam has been described, but the same method can be applied when jumping not only one track but a plurality of tracks.

Example 10. FIG. 13 shows an embodiment according to claim item 5. FIG. 13 is a block diagram of a speed control system using a two-stage actuator. In FIG. 13, 12
Reference numeral 1 is a first actuator having a large movable range, 122 is a second actuator mounted on the first actuator 121 and having a small movable range, 123 is drive command generating means for the second actuator, and 124 is speed detection. Reference numeral 125 is a target speed generating means, 216 is a speed deviation detecting means, and 127 is a stabilizing compensator.

In the figure, the vector sum of the velocity vact1 of the first actuator 121 having a large movable range and the velocity vact2 of the second actuator 122 having a small movable range mounted on the first actuator 121 is represented by
It is the velocity vact of the tip position of the second actuator.
This is detected as vdet by the speed detecting means 124, the difference from the target speed vref generated by the target speed generating means 125 is detected as verr by the speed deviation detecting means 126, and this is the output of the stabilization compensator 127. The first actuator 121 is driven and controlled by the first actuator drive current or voltage iact1.

Further, during the speed control of the first actuator, the drive command generating means 1 for the second actuator 122 is provided.
By issuing a command iact2 from 23 to accelerate or decelerate the second actuator, the speed of the second actuator is controlled.

FIG. 14 is a diagram for explaining the operation of the embodiment shown in FIG. FIG. 14A shows the drive current waveform iact1 of the first actuator 121, FIG. 14B shows the drive current iact2 of the second actuator 122, FIG. 14C shows the moving speed vact1 of the first actuator 122, and FIG. Speed vact2 of the actuator of the actuator with respect to the first actuator,
(e) is the moving speed vact of the tip of the second actuator.
And the vector sum of vact1 and vact2, (f) is the position xact2 of the second actuator with respect to the first actuator
Is.

First, the first actuator 121 is iac
It is accelerated in the moving direction by t1, the velocity vact1 increases, reaches the maximum velocity vmax1, and then decelerates. Immediately before reaching the target position, the second actuator 122 is accelerated in the direction in which the combined speed of the two-stage actuator is decelerated, that is, in the direction opposite to the moving direction of the first actuator 121. Two
The combined velocity vact of the stage actuator is decelerated more rapidly than when only the velocity vact1 of the first actuator is decelerated. As shown in FIG. 13 (e), if only the first actuator 121 is decelerated, the speed becomes zero at time t2, but the second actuator 122 is also driven to move the tip position of the second actuator. By decelerating the speed vact of, the vact can be made zero at an earlier time t1.

Example 11. Another embodiment according to claim 5 will be described. For example, in an optical disk device, a linear motor is generally used as the first actuator, and a tracking actuator is generally used as the second actuator. During seek operation of the optical disk device, the speed vact at the tip position of the second actuator is increased by accelerating the second actuator in the direction opposite to the moving direction of the first actuator while decelerating the first actuator 121. It is decelerated rapidly and can move quickly to the target position. The moving speed vact of the two-stage actuator is detected as the track crossing speed vdet of the light spot. As the acceleration current iact2 of the second actuator, the current value i
Consider a pulse current of [A] and time width T [s]. The mass of the moving part of the second actuator is M [kg], and the generated acceleration is α [m / s
2], the thrust constant is Kf [N / A], and the generated thrust F [N],

[0051]

[Equation 2]

And is the same as that shown in the sixth embodiment.

Example 12. FIG. 15 shows the operation of another embodiment according to claim 5. 15 (a) (b) (c) (d) (e) (f)
Is the same as in FIG. First, the first actuator 121 is accelerated in the moving direction by iact1, and the velocity vac
When t1 becomes large and reaches the maximum speed, the vehicle is decelerated. First
During speed control of the actuator 121 of No. 2, the second actuator 122 is temporarily accelerated / decelerated between time t0 and t1,
At the time t2 immediately before reaching the target position as in the tenth embodiment, the speed control of the first actuator is continued while the second actuator is swung in the moving direction of the first actuator.
From the time t3 to the time t3, the second actuator 122 is moved in the direction in which the combined speed of the two-stage actuator is reduced,
The actuator 121 is accelerated in the direction opposite to the moving direction of the actuator 121. The combined velocity vact of the two-stage actuator is decelerated more rapidly than when only the velocity vact1 of the first actuator is decelerated.

In FIG. 14 (f), the position xact2 of the second actuator with respect to the first actuator at time t2.
However, the velocity vact is zero while swinging in the direction opposite to the moving direction of the first actuator, but in FIG. 15 (f),
The position xact2 of the second actuator with respect to the first actuator reaches the target position at time t3 when it becomes almost zero.

Example 13 FIG. 16 shows another embodiment according to claim item 5. The same numbers as in FIG. 13 are the same. In FIG. 15, the current iact2 that accelerates the second actuator during speed control of the first actuator is
Ver, which is the difference between the immediately preceding target speed vref and the detected speed vdet
It is generated from the second actuator drive command generating means 123 based on r. For example, in the equation (2), v0 may be replaced with v0 + verr, because verr> 0.
If so, iact2 is larger than the predetermined value i calculated by the equation (2), and if verr <0, it becomes smaller than the predetermined value i. Therefore, the subsequent speed deviation verr can be brought close to 0, and the accuracy can be improved. Good speed control can be realized.

Example 14 FIG. 17 shows an embodiment according to claim item 6. In FIG. 17, 121 and 122 are
Same as FIG. 161 is a target position generating means, 162 and 163 are stabilization compensators of the position control system, 164 is a control mode switching command generating means, and 165 and 166 are control modes based on the output of the control mode switching command generating means 164. Switching means, 167 is a braking force generating means, and 168 is a means for generating a deviation between the target position and the position xact of the tip of the two-stage actuator.

In FIG. 17, the first actuator 1
Vector sum xact of the position xact1 of 21 and the position xact2 of the second actuator with respect to the first actuator
Are controlled so as to match the target position xref. First,
Based on the command output from the mode switching command generating unit 164, the control mode switching unit 165 selects the upper path and the 166 selects the lower path. At this time, the second movable range is small so that xact follows xref.
The actuator 122 alone constitutes a feedback position control system.

The characteristic of this position control system is that the stabilization compensator 1
It is determined by the characteristics of 62 and is composed of a phase lead compensator, a phase delay compensator and the like. At the same time, the position control deviation xerr is
The operation amount i12 of the first actuator and the operation amount i21 of the second actuator, which are also input to the stabilization compensator 163 after the control mode switching and used in the two-stage actuator position control mode, are calculated, and the two-stage actuator coupling is performed. It is used as the initial value of the manipulated variable immediately after switching to the position control mode.

Usually, at the moment of shifting to the position control mode, the first or second actuator has the initial velocity, and the second actuator 122 controls the position, and at the same time, the first actuator 121 The braking force i11 for canceling the initial speed at the moment of shifting to the position control mode is applied from the braking force generation means 167.

Assuming that the initial speed of the first actuator is v0, this braking force is, for example, a current value i [A], a time width as a braking current for canceling this v0 and stopping the first actuator 121. Consider a pulse current of T [s]. Let M be the moving part mass of the second actuator.
[kg], the generated acceleration is α [m / s2], the thrust constant is Kf [N / A], and the generated thrust F [N], i and T are determined by the above equation (2).

From the mode switching command generation means 164, a control mode switching command is generated at the moment when the first actuator 121 almost stops, and the mode switching means 165 is switched to the lower side and the mode switching means 166 is switched to the upper side. . That is, the first actuator 12
Both the first and second actuators 122 are drive-controlled by the manipulated variables i12 and i22 determined by the stabilization compensator 163 based on the position control deviation xerr. For example, the stabilization compensator 163 band-separates the control deviation xerr into a low frequency and a high frequency, and transmits it to the first actuator 121 and the second actuator 122.

Conventionally, only the two-stage actuator position control mode was provided. Therefore, when the initial velocity of the first actuator is large, the first actuator goes too far from the target position immediately after switching the position control mode, and the second position The actuator is also dragged by the first actuator and a large overshoot occurs. When the detection range of the target position xref is narrow, the tip position xac of the second actuator is
Although the positioning of t has failed, as described above, once the position control mode of the second actuator alone is executed, the initial velocity of the first actuator becomes large, and
Even if the actuator of # 2 goes too far, the tip position of the second actuator can be reliably positioned at the target position. The position control operation can be stably continued by switching to the two-stage actuator coupling position control mode after the second actuator is stopped.

Example 15 As another embodiment of claim 6, a case where the invention is applied to a two-stage actuator coupling tracking servo system of an optical disk device will be described with reference to FIG. A linear motor is generally used as the first actuator 121, and a tracking actuator is generally used as the second actuator 122. 16
Reference numeral 1 is an optical disk, and xref is the track center position. xact is the tip position of the light beam, and the off-track amount xerr is detected by the tracking error detection means 168. The stabilization compensator 163 can be realized by, for example, combining the phase compensation circuit and the coupling compensation circuit of FIG. The operation is
Same as Example 14.

The above-described stabilization compensator, mode switching command generating means, mode switching means, etc. described in the embodiments may all be realized by hardware such as an electronic circuit, or mounted on a digital signal processor or the like. It is also possible to realize it with the created software.

[0065]

As described above, according to the present invention, the controlled object which receives the manipulated variable as the input and the controlled variable as the output, three or more control modes for controlling the controlled object, and the respective control modes The operation amount determining unit, the control mode switching command generating unit, the operation amount switching unit that switches the operation amount based on the command from the control mode switching command generating unit, and the state amount of the control system in the first control mode are used. In a disk device provided with a control system having means for determining the operation amount of the second control mode based on the third control mode, after switching from the first control mode to the second control mode.
Since it is configured to switch to the control mode of No. 3, it is possible to quickly and stably shift from the first control mode to the third control mode.

According to the second aspect of the present invention, the operation amount necessary for the control mode 3 is calculated during the operation of the control mode 2 and is used as the initial value of the operation amount immediately after switching to the control mode 3. Therefore, the transition to the control mode 3 is smoothly performed, and the success rate of the transition to the control mode 3 is improved.

According to the third aspect of the present invention, in the pulling-in operation of the focusing servo system of the optical disk device, the search speed of the light beam is detected and detected while searching the in-focus position of the light beam. The focusing actuator is accelerated or decelerated based on the speed, and then the focusing servo system is operated.Therefore, the focusing servo system pulling speed at the in-focus position does not vary, and stable focusing servo system pulling operation is performed. realizable.

According to the fourth aspect of the present invention, in the seek control system of the magnetic disk device, when the speed control mode of the magnetic head is switched to the position control mode, it is calculated based on the speed deviation during the speed control. Since the brake pulse is applied and then switched to the position control mode, the fluctuation of the speed immediately after switching to the position control mode is small, and the shift to the position control mode is performed stably. In addition, the operation amount in the position control mode and the state amount of the stabilization compensator are calculated while the brake pulse is being generated, and are used as the initial values of the operation amount and the state amount immediately after switching to the position control mode. As a result, the transient response of the position control mode becomes small, and stable position control with a small overshoot can be realized. Further, in the track jump operation of the optical disk device, the track crossing speed of the light beam is detected, an acceleration / deceleration command calculated based on the detected speed is applied to the tracking actuator, and then the tracking servo operation is switched to. For example, even if the traverse speed of the light beam fluctuates, the fluctuation of the initial speed at the start of the operation of the tracking servo system becomes small, and the pull-in operation of the tracking servo system is performed stably. Also, if the configuration is such that the state quantity of the stabilization compensator of the tracking servo system is calculated while the acceleration / deceleration command is being generated, the overshoot amount of the transient response waveform immediately after the tracking servo system is pulled in becomes small and stable tracking servo The operation can be realized.

According to the fifth aspect of the present invention, in the two-stage actuator control device for the disk device, the second actuator having a small movable range is set to the first actuator while the speed of the first actuator having a large movable range is controlled. Since it is configured to accelerate in the direction opposite to the moving direction of the actuator of,
The tip of the two-stage actuator can be rapidly decelerated, and quick positioning can be performed. Further, in the two-stage actuator control device, when accelerating the second actuator having a small movable range in the direction opposite to the moving direction of the first actuator during speed control of the first actuator having a large movable range, If the acceleration and the acceleration time of the first actuator are determined based on the speed control deviation of the first actuator immediately before, the speed of the tip of the two-stage actuator can be controlled stably, and
The success rate of transition to the multi-stage actuator tracking mode is improved.

According to the sixth aspect of the present invention, in the two-stage actuator control device for the disk device, the position control is performed only by the second actuator having a small movable range, and at the same time, the initial velocity possessed by the first actuator is adjusted. Since the brake pulse is applied to the first actuator so as to cancel it, and then the mode is changed to the two-stage actuator coupling position control mode, the first actuator has a large initial velocity, and even if it goes too much during position control, 2
Successful transition to the stage actuator coupling position control mode. Further, if the configuration is such that the state quantity of the stabilization compensator in the two-stage actuator coupling position control mode is calculated while the second actuator alone is performing position control,
Immediately after switching to the two-stage actuator coupling position control mode, the transient response waveform has a small excess amount, and the operation in the two-stage actuator coupling position control mode is stably performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a mode switching control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a mode switching control device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a mode switching control device according to third and fifth embodiments of the present invention.

FIG. 4 is a block diagram showing a mode switching control device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a focusing servo pull-in system of an optical disc device according to a sixth embodiment of the present invention.

FIG. 6 is a waveform diagram showing an operation of a focusing servo pull-in system of an optical disc device according to a sixth embodiment of the present invention.

FIG. 7 is a diagram of focusing error waveforms showing a focusing servo pull-in operation of an optical disc device according to a sixth embodiment of the present invention.

FIG. 8 is a waveform diagram showing an operation of a focusing servo pull-in system of an optical disc device according to a seventh embodiment of the present invention.

FIG. 9 is a block diagram showing a seek control system of a magnetic disk device according to an eighth embodiment of the present invention.

FIG. 10 is a waveform diagram showing the operation of the seek control system of the magnetic disk device according to the eighth embodiment of the present invention.

FIG. 11 is a block diagram showing a track jump control system of an optical disc device according to a ninth embodiment of the present invention.

FIG. 12 is a waveform diagram showing a track jump operation of an optical disc device according to a ninth embodiment of the present invention.

FIG. 13 is a block diagram showing a speed control system using a two-stage actuator according to a tenth embodiment of the present invention.

FIG. 14 is a waveform diagram showing a speed control operation by a two-stage actuator based on Embodiment 10 of the present invention.

FIG. 15 is a waveform diagram showing a speed control operation by a two-stage actuator based on Embodiment 12 of the present invention.

FIG. 16 is a block diagram showing a speed control system using a two-stage actuator according to a thirteenth embodiment of the present invention.

FIG. 17 is a block diagram showing a position control system using a two-stage actuator according to a fourteenth embodiment of the present invention.

FIG. 18 is a waveform diagram showing a pull-in operation of a focusing servo system of a conventional optical disc device.

FIG. 19 is a waveform diagram showing a track jump operation of a conventional optical disc device.

FIG. 20 is a waveform diagram showing a seek control operation of the conventional magnetic disk device.

FIG. 21 is a block diagram showing a seek control system and a two-stage actuator coupling tracking servo system of a conventional optical disc device.

[Explanation of symbols]

1 Operation amount determining means in the first control mode 2 Operation amount determining means in the second control mode 3 Operation amount determining means in the third control mode 4 Operation amount switching means 5 Operation amount switching command generating means 6 Control object 7 Control System state quantity detecting means 8 Target value generating means in first control mode 9 Control deviation calculating means in first control mode 10 Target value generating means in third control mode 11 Control deviation calculating means in third control mode 51 Focusing Actuator 52 Focusing Error Detection Means 53 Focusing Actuator Driving Voltage Generating Means for Searching Focused Position of Light Beam 54 Light Beam Search Speed Detection Means 55 Focusing Actuator Acceleration / Deceleration Command Generating Means 56 Focusing Servo System Stabilization Compensation Bowl 5 7 Mode Switching Command Generation Means in Focusing Servo System 58 Mode Switching Means in Focusing Servo System 81 Target Speed Generation Means for Seek Operation 82 Speed Deviation Detection Means 83 Speed Detection Means 84 Stabilization Compensator of Speed Control Systems 85 Seek Control Systems Control mode switching command generating means in 86 Control mode switching means in seek control system 87 Magnetic head driving means 88 Brake current generating means 89 Magnetic disk 90 Position deviation detecting means 91 Stabilizing compensator in tracking servo system 111 Optical disk 112 Tracking error detecting means 113 Track Jump Pulse Generating Means 114 Mode Switching Command Generating Means in Track Jump Control System 115 Mode Switching Means in Track Jump Control System 11 Light beam driving means 117 Acceleration or deceleration pulse generating means 118 Stabilization compensator in tracking servo system 121 First actuator having a large movable range 122 Second actuator 123 having a small movable range 123 Second actuator drive command generating means 124 Speed detection Means 125 Target speed generation means 126 Speed deviation detection means 127 Stabilization compensator in speed control system 161 Target position generation means 162 Stabilization compensator of second actuator independent position control system 163 Stabilization of two-stage actuator coupled position control system Compensator 164 Control mode switching command generating means 165 Control mode switching means in second actuator 166 Control mode switching means in first actuator 167 Brake force generating means 168 Target position and two-step position Position deviation generating means from the tip of the actuator

Claims (6)

[Claims] 1. A controlled object which inputs a manipulated variable and outputs a controlled variable, three or more control modes for controlling the controlled object, means for determining the manipulated variable in each control mode, and control mode switching. The command generation means, the operation quantity switching means for switching the operation quantity based on the command from the control mode switching command generation means, and the operation quantity for the second control mode based on the state quantity of the control system in the first control mode. A disk device provided with a control system having a means for determining, characterized in that after shifting from the first control mode to the second control mode, it shifts to the third control mode. 2. A controlled object which inputs a manipulated variable and outputs a controlled variable, three or more control modes for controlling the controlled object, means for determining the manipulated variable in each control mode, and control mode switching. The command generation means, the operation quantity switching means for switching the operation quantity based on the command from the control mode switching command generation means, and the operation quantity for the second control mode based on the state quantity of the control system in the first control mode. A third control mode is a feedback control mode having a stabilizing compensator, and after the first control mode is switched to the second control mode. When the control mode is shifted to the third control mode, the state quantity of the stabilization compensator of the control system in the third control mode is calculated during execution of the second control mode, and the third control mode is calculated. A disk device characterized by being used as an initial value of a stabilization compensator immediately after switching to a mode. 3. A focusing servo means for controlling the focus position of the light beam on the medium surface, a means for searching the focus position of the light beam prior to the operation of the focusing servo, and a light beam during the search for the focus position of the light beam. And a means for adding a manipulated variable to the means for searching the focal position of the light beam based on the detected speed information, and means for searching the focal position of the light beam, and the detected speed information. A disk device comprising a means for switching between an output of a means for adding an operation amount to a means for searching a focal position of a light beam based on the output and an output of an operation amount determining means of a focusing servo system. 4. A disk having a large number of tracks for storing information, a means for driving the head in a track crossing direction, a means for detecting a track crossing speed of the head, and a means for controlling the track crossing speed of the head. Acceleration / deceleration by the tracking servo means that makes the head follow the track and the means that drives the head in the track crossing direction immediately after the head reaches the target track after controlling the track crossing speed of the head. A disk device characterized by applying current or voltage and then switching to tracking servo means. 5. A two-stage actuator control device in which a first actuator having a large movable range and a second actuator having a small movable range are mounted on the first actuator and which controls a tip position or speed of the second actuator. In the disk device including the above, the tip end portion of the second actuator is accelerated by driving the second actuator in the same direction or in the opposite direction to the moving direction of the first actuator during speed control of the first actuator. Alternatively, a disk device that is decelerated. 6. A first actuator having a large movable range, and a second actuator having a small movable range is mounted on the first actuator. The second actuator is driven by driving the first and second actuators. In a disk device equipped with a two-stage actuator control device for controlling the tip position or speed of the second actuator, immediately after the second actuator tip reaches the target position after the first actuator is moved, the second actuator alone is used as the second actuator. And means for positioning the actuator tip of the
And a means for applying a braking force to the actuator, and after the application of the braking force is switched to a positioning control system by the first and second actuators.