JP3444953B2 - Drive control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for moving a moving body to a target position at a predetermined speed.

In recent years, for example, in a drive control device for moving a head to a predetermined position in a magnetic disk device or a magneto-optical disk device, a circuit board has been downsized with the downsizing of the device, and a control circuit The component mounting area that is allowed by the company is decreasing.

For this reason, it is necessary to reduce the memory capacity that can be built in the constituted microcontroller (MCU) and perform highly accurate control.

[0004]

2. Description of the Related Art Conventionally, a drive control device has been used for controlling a head drive of a magnetic disk device, for example.

FIG. 8 shows a plan view of an example of a conventional magnetic disk device. Magnetic disk device 1 shown in FIG.
In FIG. 1, the actuator 12 has a magnetic head 14 mounted on the tip of the actuator 12 via a support spring mechanism 13a from an arm 13, and the base of the arm 13 is rotatably supported by a pivot 15.

A rotation support portion 16 is formed on the side of the arm 13 opposite to the pivot 15, and a coil 17 wound around the rotation support portion 16 is provided. And the coil 17
Two magnets 18a and 18b are fixedly arranged below the. This coil 17 and magnets 18a, 18b
A VCM (voice coil motor) is constituted by

In such an actuator 11, a magnetic disk 20 fixed to a spindle 19 of a sensorless type spindle motor (not shown) is rotated, and a coil 17 is provided with a flexible printed board 22 rather than a wiring board 21. The magnetic head 14
The arm 13 is rotated so as to move the magnetic disk 20 in the radial direction of the magnetic disk 20. In this case, the magnetic head 14 is levitated by the air flow generated by the rotation of the magnetic disk 14.

Then, although not shown in the drawing, a control board is attached. The control board is roughly divided into a CPU (central processing unit), an MCU (microcontroller), a read / write controller, a head positioning controller, and a spindle motor controller.

The magnetic disk 20 is formed by coating or sputtering a magnetic medium on the surface of a disk made of glass or aluminum, and has information for positioning on a concentric cylinder (or track) in advance. Will be recorded. Then, the magnetic head 14 is set to the target cylinder, and the head positioning control unit performs V
The CM is controlled to move at a predetermined speed.

Therefore, FIG. 9 shows a block diagram of the speed control of FIG. The speed control in FIG. 9 determines the target speed of the magnetic head 14 according to the current position or the time from the start of seek, and performs feedback control so that the moving speed of the magnetic head matches the target speed.

That is, the position information recorded on the magnetic disk 20 is read out, and the target velocity generator 23 calculates the remaining distance from the target position where the magnetic head 14 is to be moved. To generate the target speed. Further, the past position information is held, and the speed generator 24 compares the current position with the current position to estimate the current speed. Then, the difference between the estimated speed and the target speed is calculated, and the instruction current is supplied to the VCM by the compensator 25, for example, by PI (proportional and integral of speed error) control so as to reduce the speed error.

If the current supplied to the VCM is simply proportional to the acceleration of the magnetic head 14,
The relationship of X∝∬Idt is established with the current I given to the VCM and the moving amount of the magnetic head as X, and the relationship of position, speed and current can be derived with this as a reference.

Generally, as an example of speed control, B has been conventionally used.
There are an ang bang control system, a accelerating acceleration / deceleration curve having a square wave shape, a triangular wave shape only when decelerating, and an acceleration curve having a minimum acceleration differential value.

For example, when a control is performed which has a target velocity generation section such that the P-th power of the position (P is a fixed value) satisfies the relational expression V∝X ^P proportional to the velocity, for example, the acceleration is constant with respect to time. In the case of, P = 1/2, and in the case of being proportional to the linear function, P = 2/3.

As described above, the optimum speed at the time of reading the current position is obtained by the power calculation with V∝X ^P , but since the processing time is long in the MCU, the relationship between the position and the speed is obtained. ROM (Read Only Mem
ory) as a fixed table, and each time the position is obtained, the table value is referred to obtain the position.

Here, FIG. 10 shows a diagram of a reference table in the control of FIG. As shown in FIG. 10, the generated value Y
A predetermined number of reference values X are set at equal intervals on the curve of Y = X ^P in the reference value X for. That is, the higher the accuracy of the target speed of the table, the better. Therefore, it is necessary to create a table for each cylinder, for example. For example, when the number of cylinders is 1200, the moving distance that gives the average access time is about 1/3, and if the distance required for acceleration / deceleration is 1/2, then 1200 × (1/3) × (1 / 2) A lookup table having data of = 200 is required. In order to ensure accuracy, it is necessary to have a value of 2 bytes, for example, and a ROM size of 400 bytes is required.

In the reference table of FIG. 10, the table values of the two points near the reference value of the magnetic head 14 are calculated,
The value is obtained by linear interpolation.

[0018]

However, in storing the above-mentioned table in the ROM, an MCU having a small ROM capacity (for example, 16 to 64 Kbytes) is several percent of the total memory amount and cannot be ignored. That is, if a table is stored in a small memory capacity, the number of table divisions decreases, resulting in a decrease in accuracy. On the other hand, if the number of table divisions is increased, a large memory capacity is required and the device cannot be downsized. There's a problem.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a drive control device for reducing the memory capacity and performing highly accurate control.

[0020]

In order to solve the above problems, the present invention obtains a target speed Y of a driving body based on a driving means for driving the driving body and a moving distance X of the driving body. in the driving control device and a processing means based on the target speed Y controlling the speed of該駆body by controlling the driving means, pre-Symbol processing means, the range of 0.0 to 1.0
Then, the reference value X is set to 1/2 ^ N [N is a preset positive integer
Number], the normal corresponding to the reference value X
Target value Y1 = X∧P = (1/2 ^ N) ^ P [P is preset
[Determined coefficient] is stored in the first table, and
Within the range of ~ 1.0, divide the reference value X evenly into 2 ^ N.
, The normalized target value Y2 = X corresponding to the reference value X
The second table in which ^ P = (2 ^ N · X / X0) ^ P is stored
Storage means for Le and is built, 0.5 <2∧N · X / X0
Find N that satisfies ≦ 1.0, and from the first table,
The normalized target value Y1 is read out and the second target value is read.
Read the normalized target value Y2 from the bull and drive X0
From the position to start to the target position, Y0 is the distance X
The maximum speed corresponding to 0, and P is a preset coefficient
Then, Y = Y0, Y1, Y2 = Y0, (1/2 ∧N) ∧P
・ (2∧N ・ X / X0) ∧P based on the target speed Y
And target speed generating means for generating.

Further, the present invention is set interval in accordance with the moving distance of the movable body, the engagement in accordance with the section
The first table and the second table in which the number P is set.
Is equipped with a cable .

Further, according to the present invention, a step is formed at the boundary of the section.
Of each section so thatSet the maximum speed Y0 to the maximum of the previous section
Y10 for large speed, normalization target of the first table in the previous section
Speed is Y11, normalized target speed of the second table in the previous section
Degree Y12, target from the position to start drive control in the previous section
When the distance to the position is X10, Y0 = Y10 ・ Y11 ・ Y12 = Y11 ・ (1 / 2∧N) ∧P ・
(2∧N ・ X / X10) ∧P

[0023]

[0024]

According to the present invention, 0.5 <2∧N · X / X0 ≦
N that satisfies 1.0 is obtained, and in the range of 0.0 to 1.0,
The reference value X is 1/2 ^ N [N is a preset positive integer]
Normalized target value corresponding to the reference value X when divided by
Y1 = X∧P = (1/2 ^ N) ^ P [P is preset
Coefficient] is stored from the first table
Read 1 and refer to within the range of 1/2 to 1.0
When the value X is evenly divided by 2 ^ N, it corresponds to the reference value X.
Normalized target value Y2 = X ^ P = (2 ^ N · X / X0) ^ P
The normalized target value Y2 is read from the stored second table.
Then, drive X0 from the position to start the drive control to the target position.
The distance, Y0 is the maximum speed corresponding to the distance X0, and P is preset.
Assuming a fixed coefficient, Y = Y0.Y1.Y2 = Y0. (1 / 2∧N) ∧P ・
By generating the target speed Y based on (2∧NX / X0) ∧P , it is possible to reduce the memory capacity and perform highly accurate speed control.

[0025]

[0026]

[0027]

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block diagram of an embodiment of the present invention.
FIG. 1 (A) is a schematic block diagram of the drive control device 31 of the present invention, and FIG. 1 (B) is a diagram showing a normalized reference table used for this.

In the drive control device 31 shown in FIG. 1A, a drive unit 33, which is a drive unit, moves a drive body 34 to a target position in accordance with a drive amount instructed by a processing unit 32, which is a processing unit. Is. The processing unit 32 has a control target value creating means for calculating a control target value, and is provided with a memory unit 35 which is a storage unit such as a ROM, and the memory unit 35 uses a predetermined number of conversion values K for Y ₀ = K ^P. The value of (position proportional to the converted speed) and the normalized reference table at the divided positions are stored in advance.

That is, the reference table is shown in FIG.
As shown, the normalized target value Y and the normalized reference value X^PSeki
Equation Y = X^PThe first to normalize (X is 0.0 to 1.0)
And the reference value X is 1/2, 1/4,
1/2 of the areas divided by 1/8, 1/16, ...
~ 1.0 area X_A(Hatched area), evenly 2 ^N
It has a divided second table. In this case, normalization
Area X where the illuminance X is 1/4 to 1/2_BCalculation of target value Y in
Changes the value of the conversion value K, and the area X in the memory unit 35 is changed._A
The table is repeatedly used. Converted value K
Indicates that the table reference value X is the area X_AWithin (1 / 2-1.0)
It is set in advance as a value that fits in.

In the first and second tables,
Although the case of 2 is explained as a sequence of positive integers, 4,
The same applies to the case of positive integers such as 8, ...

Therefore, when the power of Y = X ^P is calculated by referring to the table, the table value (target value) Y ₀ (0.5 ^P <Y ₀ ≦ 1.0) corresponding to the reference value X is obtained. Can be obtained by referring to a table and Y ₀ · X can be calculated to obtain the target value Y.

On the other hand, when the reference value X is smaller than 0.5 or larger than 1.0, the converted value K may be changed appropriately. That is, when the speed of the driving body 34 is controlled, the target speed may be generated by sequentially changing the value of the conversion value K according to the remaining distance. For example, the reference value X is 1/3 ((1/4) <
To obtain the value Y of (1/3) <(1/2)), 1/3
Is multiplied by 2 to be included in the region X _A of ½ to 1.0, an approximate value is obtained by referring to a table, and the value is (1
/ 2) It can be obtained by multiplying by ^P. That is, the table does not need to have all the reference values X from 0.0 to 1.0, and the conversion value K is changed to 1/2 to
A table in the range of 1.0 is sufficient.

In this way, the reference table normalized by the value of K ^P in the plurality of set conversion values K and the reference value X in the range of 1/2 to 1.0 is stored in the memory unit 35 in advance. Thus, the memory capacity can be reduced (for example, 1/5 to 1/10 of the conventional memory capacity). Specifically, for example, when the table is divided into 2 ¹⁰ (N = 10), (16/32) ^P , (17/32) in the normalized reference table (range of 0.5 to 1.0) ^P ...
(32/32) is composed of 34 bytes (17 words) as ^P, (1/2 ⁰⁾ for holding the value of K ^{P P,} (1 /
^{2 1) P ··· (1/2 10} ) P of as 22 bytes (1
1 word).

By the way, it is verified that the above-mentioned reference table matches the original curve (hatched line and part other than the hatched line). Now, when the P-th power of the reference value X satisfies the relational expression Y = X ^P for making the target value Y match, the reference value X is divided by the position X ₀ at which the drive control is started as a predetermined reference position. Normalize (take a value of 0.0 to _1.0 in X / X ₀ ). Then, if the target value when X = X ₀ is Y ₀ , then Y = Y ₀ (X / X ₀ ) ^P (1) When this is converted, Y = Y ₀ (X / X ₀ ) ^P = Y ₀ (1/2 ^N ) ^P (2 ^N · X / X ₀ ) ^P (2)

Here, when 0.0 <(X / X ₀ ) ≦ 1.0, (1/2 ^{N + 1} ) <(X / X ₀ ) ≦ (1 /
From 2 ^N ), if r = 2 ^N (X / X ₀ ) ... (3), then 1/2 <r ≦ 1.0.

Therefore, X₀Y when₀Is preset
In memory 35 (1/2 ^N)^PThe value of
And the r in the range of 0.5 to 1.0 is normalized.
Reference table (2^NDivided area X_A) As a case
Since it has been paid, the target value Y in the equation (1) is calculated.
Can be

Then, when the remaining distance is smaller than the predetermined amount X ₁ , X ₁ is Y = X ^P , and Y = Y ₀ (X ₁ / X ₀ ) ^P = Y ₁ (4) Must be satisfied, and when X <X ₁ , the normalization standard is changed from X ₀ to X ₁ so that the relational expression of Y = Y ₁ (X / X ₁ ) ^P (5) is obtained. To do. In this _{case, Y = Y 1 (X /} X 1) P = {Y 0 (X 1 / X 0) P} (X / X 1) P = Y 0 (X / X 0) P ··· (6) It can be transformed into

That is, since it is the same as when the original X ₀ is used, the curves match even if the normalization standard is changed. This is the first criterion (X
₍₀ , Y ₀ ), the normalization table (reference table) is used to compress and decompress the table according to the (X, Y) value and repeatedly use it to obtain an arbitrary length. It means that the generated value (target value) corresponding to the reference value of can be calculated. Thus, those that can be calculated without be repeatedly used while changing the converted value curve of X ^P deviates from the original curve generated values.

Further, in comparison with the case of simply referring to the conventional table (FIG. 10), when the operation of Y = X ^P is performed by using the reference value having a value of X = 0 to 256, the reference table is referred to as X. On the other hand, when the calculation is performed by assuming that the value is equally divided and X increases by 1, the calculation must be performed using the value of Y corresponding to X stored for each 1 at the time of referring to the table.

On the other hand, in the present invention, the standard for converting the normalized reference table is changed one after another. For example, the normalized reference table X is 32 in the range of 0 to 1.
When divided, the value of X (2 ^N ) is 1, 2, 4, 8, 1
There is a conversion value for every 6, 32, 64, 128, 256, and 1 (= 1/2 ⁰ ) at the maximum and 1 / at the minimum when referring to the table.
This is the same as when performing the calculation using the Y value stored for each size of 32 (= 1/2 ⁵ ). As a result, the error caused by using the normalized look-up table can be made smaller than that of the conventional method described above, and the accuracy can be improved.

Next, FIG. 2 shows a block diagram of an application example of the present invention. FIG. 2 is a block diagram when applied to the magnetic disk device 41 to control the speed in the positioning control of the magnetic head on the magnetic disk. The mechanical configuration is shown in FIG.
Is the same as. The speed control loop is similar to that shown in FIG.

In FIG. 2, the magnetic disk device 41 is
To the host computer via the interface circuit IF
Hard disk controller (HDC) 42 connected
Has a RAM 43, and the MCU 4 as a processing unit
4. Send and receive information for recording and playback on magnetic disks
Read / write (R / W) circuit 45, magnetic disk
Drives a spindle motor (SPM) that rotates at a constant pressure
SPM drive circuit 46, moving magnetic head as a drive
VCM drive circuit as drive unit for driving VCM
Control 47. In addition, the MCU 44 is
K by conversion value K ^PValue and normalized lookup table
ROM44a and RAM4 as a memory unit for storing
4b. In addition, the target maximum speed VobjMax and
Even at the velocity dv, a value proportional to the power of the seek distance
Then a normalized lookup table with similar curves
Paid.

That is, the magnetic disk device 41 takes in position information of the magnetic head (servo marks read from the magnetic disk by the magnetic head) into the MCU 44 to generate a target speed, and the VCM drive circuit 47 seeks the VCM as desired. It is what makes me.

FIG. 3 is a graph showing the speed control of FIG. FIG. 3 shows a current waveform supplied to the VCM, in which current is supplied in the acceleration section T1, the constant acceleration section (constant deceleration section) T3, and the deceleration section T2 between the accelerations ± a. In this case, the target velocity curve when the target maximum velocity VobjMax is set is designed to be proportional to the power of the position, as in FIG. As described above, the speed is proportional to the integral of the current, and the movement amount (position) calculates the target speed based on the relationship proportional to the double integral of the current.

Therefore, FIG. 4 shows a processing flowchart in the speed control of FIG. Now, when a servo mark interrupt is input (step (ST) 1), it is determined whether or not a seek command has been received (ST 2). When the seek command is received, the target position Pobj is obtained (ST3), and the target maximum speed VobjMax, the acceleration dv in the acceleration section, the mode switching position from acceleration to constant speed, and the mode switching position from constant speed to deceleration are calculated. Done (ST
4).

Therefore, when Vobj = 0, that is, when the magnetic head is stopped (ST5), control is started as an acceleration section (ST6), and the current position Y of the magnetic head is set.
Obtain [i] (ST7). When the seek command is not received in ST2, the magnetic head is on the magnetic disk rotating at a constant speed, and the current position Y [i] is acquired by reading the servo information (ST7).

Next, the relative position X with respect to the target position Poobj
Calculate [i] (X [i] = Y [i] -Poobj)
(ST18) The distance to be moved is calculated and the current speed is calculated (V [i] = Y [i] −Y).
[I-1]) (ST9).

Therefore, it is determined which mode is selected (ST1
0), an acceleration mode process (ST11, described in FIG. 5), a constant speed mode process (ST12, described in FIG. 6), and a deceleration mode process (ST13, described in FIG. 7). When each mode processing is completed, the relative velocity VErr is calculated (VErr = V [i] -Vobj) (ST1
4) Obtain the deviation amount between the current speed and the target speed, give the relative speed to the compensator (see FIG. 9), and calculate the output current U [i] (ST15).

Then, the bias current Bias (Y [i]) corresponding to the current position Y [i] is added (U '[i] =
U [i] + Bias (Y [i])) (ST16), VC
The current U ′ [i] is output to M (ST17), and the interrupt processing is ended (ST18). In the servo mark interrupt process, there are SPM rotation control, control system measurement (calibration), etc. in addition to the VCM interrupt process.
After the CM interrupt processing ends, the processing shifts to these processing.

FIG. 5 shows a flowchart of the acceleration mode process of FIG. In the acceleration mode process of ST11 of FIG. 4 (T1 period of FIG. 3), it is further determined whether or not it is the switching position to the deceleration mode (ST111), and if it is the switching position, the deceleration mode (Mode = DEC) is set (ST).
112) and shifts to the deceleration mode (ST113).

When it is not the switching position, it is judged whether or not it is the switching position to the constant speed mode (ST114), and if it is the switching position, the constant speed mode (Mode = CONST) is set (ST115) and the constant speed mode is entered ( ST11
6).

At the switching position, the current speed V [i]
Determines whether or not the target maximum speed VobjMax has been reached (ST117).
(T115), and shifts to the constant speed mode (ST115). If not yet reached, the target velocity Vob is generated from the equation of Vobj ₀ = Vobj + dv (7) (ST118).

Next, FIG. 6 shows a flowchart of the constant speed mode process of FIG. In the constant speed mode process in ST12 of FIG. 4 or the constant speed mode transition in ST116 of FIG. 5 (T3 period of FIG. 3), it is first determined whether or not the switch position is to the deceleration mode (ST121). As a mode (Mode = DEC) (ST12
2) Shift to deceleration mode (ST123).

When it is not in the switching position, the target speed V
obj is the target maximum speed (Vobj = VobjMax) (ST124).

Next, FIG. 7 shows a flowchart of the deceleration mode process of FIG. As a premise, ROM4 of MCU44
4a has (1/2 ^N ) ^P (hereinafter, (1
/ 2 ^ N) ^ P) and the velocity V = X ^ P
The normalized reference table of (0.5 ≦ X ≦ 1.0) is stored. In the deceleration mode process of ST13 in FIG. 4 (T2 period in FIG. 3), first, it is determined whether the position is the switching position to the FINE mode (ST131). The FINE mode is position control near the target track.

If it is not the switching position, the current relative position is divided by the relative position (X ₀ ) at which deceleration is started, and the absolute value is taken (m = abs (X [i] / X ₀ )) (ST13).
3). Then, N satisfying 1/2 ^ (N + 1) ≤m≤1 / 2 ^ N is obtained (ST134), and the memory (ROM
(1/2 ^ N) ^ P stored in 44a) is read (ST135). As a result, the remaining distance r is obtained (r =
m · 2 ^ N) (ST136), the normalized reference table is referenced by r, and linear interpolation is performed to obtain the value NormTable.
(R) is obtained (ST137).

Then, the target speed Vobj is Vobj = VobjMax × NormTable (r) × (1/2 ^ N) ^ P                                                           ... (8) (ST138).

That is, VobjMax is preset as described above, and the value of (1/2 ^ N) ^P and Nor
Since the reference table of mTable (r) is stored in the ROM 44a, the target speed V can be easily calculated from the equation (8).
obj can be obtained.

Note that P is a value depending on the deceleration curve, and P = 1/2 for constant acceleration (see FIG. 3) and P = 2/3 for triangular wave-shaped acceleration. For example, in the case of triangular-wave acceleration, the relationship between the remaining speed X from the deceleration start position at acceleration -a to the point where the speed becomes zero and the target speed Vobj is: Vobj = (9a / 2) ^ (1/3) X ^ (2/3) ... (9), and Vojb is proportional to X to the 2/3 power. Therefore, the target speed can be obtained by calculating the 2/3 power of the remaining distance to the target.

By the way, in ST9 in FIG. 4, the present speed is calculated by the position difference. However, the low speed filter may be passed after the position difference is obtained, and the observer ( It may be calculated by a state observer). This can prevent the influence of noise in the high frequency range. For example, in Observer,

[0062]

[Equation 1]

It becomes In addition, T is a sampling period, B
_L is the magnetic flux density generated in the current Ui supplied to the coil of the VCM, m is the mass of the actuator, L ₁ and L ₂ are the observation positions of the magnetic head and are the source of velocity calculation (output of the observer). .

By the way, the VCM control described above is
When calculating the target speed of, the target speed proportional to the power of the remaining distance is calculated. However, the relationship between the remaining distance X and the target speed V is approximated by the power of the distance. Can be divided and calculated.

For example, of the remaining distance, as shown by the alternate long and short dash line in FIG. 3, the distance is proportional to the 1/2 power of the distance (P1 or P3) in the first section, and the 2/3 power (P2) in the next section. The target curve is defined for each section of the remaining distance so as to be proportional to Specifically, the target speed of the section 1, Vobj = VobjMax1 · NormTable ( X / X1) · (1/2 N1) P1 ··· (11) 1/2 ^ (N1 + 1) <X / X1 ≦ 1 / 2 ^ and N1, the target speed of the section 2, Vobj = VobjMax2 · NormTable ( X / X2) · (1/2 N2) P2 ··· (12) 1/2 ^ (N2 + 1) <X / X2 ≦ and 1/2 ^ N2, the target speed of the section 3, Vobj = VobjMax3 · NormTable ( X / X3) · (1/2 N3) P3 ··· (13) 1/2 ^ (N3 + 1) <X / X2 The target speed is calculated for each of the divided sections as ≦ 1/2 ^ N3.

In this case, the respective target maximum velocities are set as follows: VobjMax2 = VobjMax1.NormTable (X2 / X1). (1/2 ^N1 ) ^P1 ... (14) · NormTable (X3 / X2) · (1/2 N2) as ^P2 · · · (15), by similarly calculating the following, it is possible to match the velocity at the boundary of each section.

Next, another application example will be described. The control target is the rotation speed of the DC motor, and the DC motor is used, for example, in an SPM that rotates a magnetic disk, a drive system of a robot, or the like. In this case, the transfer function is K
/ (S + a). Therefore, when a = 0, the target rotation speed can be given by assuming that the transfer function is K / s, that is, the transfer function is proportional to the integral value.

Since the VCM speed control described above makes the control target of the target speed proportional to K / s, DC
If the position of the motor is detected, basically speed control can be performed in the same manner.

[0069]

As described above, according to the present invention, 0.5 <
Find N that satisfies 2∧N · X / X0 ≦ 1.0, and
In the range of 1.0, set the reference value X to 1/2 ^ N [N is preset
Corresponding to the reference value X when divided by
Normalized target value Y1 = X∧P = (1/2 ^ N) ^ P [P
Is a first table in which a preset coefficient] is stored.
The normalized target value Y1 is read out from ½ to 1.
When the reference value X is equally divided into 2 ^ N in the range of 0,
Normalized target value Y2 = X ^ P = (2 ^ N
X / X0) ^ P is stored in the second table
Is the position where the standard value Y2 is read and X0 is the drive control start position?
From the target position, Y0 is the maximum corresponding to the distance X0
When the speed and P are preset coefficients, Y = Y0, Y1, Y2 = Y0, (1 / 2∧N) ∧P ・
By generating the target speed Y based on (2∧NX / X0) ∧P , it is possible to reduce the memory capacity and perform highly accurate speed control.

[0070]

[0071]

[0072]

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of an application example of the present invention.

FIG. 3 is a graph showing the speed control of FIG.

FIG. 4 is a processing flowchart in the speed control of FIG.

5 is a flowchart of the deceleration mode process of FIG.

6 is a flowchart of an acceleration mode process of FIG.

7 is a flowchart of the constant speed mode process of FIG.

FIG. 8 is a plan view of an example of a conventional magnetic disk device.

9 is a block diagram of the speed control of FIG.

10 is a diagram showing a reference table in the control of FIG.

[Explanation of symbols]

31 Drive control device 32 processing unit 33 Drive 34 driver 35 memory 41 Magnetic disk unit 42 HDC 43 RAM 44 MCU 45 R / W circuit 46 SPM drive circuit 47 VCM drive circuit

Continuation of front page (56) Reference JP 61-160113 (JP, A) JP 3-233609 (JP, A) JP 4-32078 (JP, A) JP 7-21707 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G05D 3/12 G11B 21/08

Claims (3)

(57) [Claims] 1. Driving means for driving a driving body, and the driving
Obtain the target speed Y of the driving body based on the moving distance X of the body
Then, the drive means is controlled based on the target speed Y to drive the drive.
Drive control device having processing means for controlling speed of moving body
In thePrevious The processing means isIn the range of 0.0 to 1.0, the reference value X is 1/2 ^ N [N is
When dividing by [preset positive integer],
Normalized target value Y1 = X∧P = (1/2
^ N) ^ P [P is a preset coefficient] stored in the first
Table and the reference value X in the range of 1/2 to 1.0.
Is evenly divided into 2 ^ N, which corresponds to the reference value X.
Normalized target value Y2 = X ^ P = (2 ^ N · X / X0) ^ P
Second table remembered Storage means with andFind N that satisfies 0.5 <2∧N · X / X0 ≦ 1.0,
When the normalized target value Y1 is read from the first table,
Both read the normalized target value Y2 from the second table.
Protruding X0 from the position to start drive control to the target position
Distance, Y0 is the maximum speed corresponding to the distance X0, and P is
When the coefficient is set to Y = Y0 ・ Y1 ・ Y2 = Y0 ・ (1/2 ∧N) ∧P ・
(2∧N ・ X / X0) ∧P On the basis of Target speed generating means for generating the target speed Y
And a drive control device. 2. The first table in which a section is set according to a moving distance of the moving body, and the coefficient P is set according to the section.
Table and the second table are provided . 3. A step is not generated at the boundary of the section.
Of each sectionMaximum speed Y0 is the maximum speed of the previous section Y10, previous
The normalized target speed of the first table in the section of
The normalized target speed of the second table of the section is Y12, the previous section
The distance from the position to start the drive control to the target position
X10, Y0 = Y10 ・ Y11 ・ Y12 = Y11 ・ (1 / 2∧N) ∧P ・
(2∧N ・ X / X10) ∧P Set to 3. The drive control device according to claim 2, wherein
Place