CN1501351A - Servo compensation process for disk drive track and servosystem thereof - Google Patents
Servo compensation process for disk drive track and servosystem thereof Download PDFInfo
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- CN1501351A CN1501351A CNA021520143A CN02152014A CN1501351A CN 1501351 A CN1501351 A CN 1501351A CN A021520143 A CNA021520143 A CN A021520143A CN 02152014 A CN02152014 A CN 02152014A CN 1501351 A CN1501351 A CN 1501351A
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Abstract
The invention relates to a disk drive magnetic track servo compensation method and servo system thereof, wherein the servo system comprises an activator, a harmonic wave surface analyzer for determining magnetic track position radial change, a plurality of compensation generator, each of which can produce periodic signal having different frequencies, and a gain adjustment unit which mixes the periodic signal for forming an actuation position signal. The invention also discloses the magnetic track compensation method.
Description
[technical field]
The present invention relates to a kind of disc drive servo system and method thereof, particularly compensation has been twisted and/or has been offset the servo-drive system and the method thereof of the magnetic track of disk turning axle.
[technical background]
Traditional hard disk generally comprises one or more disks that are used for data storage, and data head can be read and write the data on each magnetic disk surface.In practical operation, when disk rotated, data head suspended on the surface of corresponding disk, when responding the signal that is provided with from the disk drive electronics, read or write on the magnetic medium of corresponding magnetic disk surface.Fig. 1 is a typical disk structure, in the middle of, data head 120 carries out read-write operation on concentric magnetic track 110.
Usually, each magnetic track is divided into a plurality of servo tapered region, and this servo tapered region includes the Frame as Frame 106 and 107, and wherein, each Frame comprises the sector of all or part.Each servo tapered region comprises servo sector of every magnetic track, and wherein, servo sector comprises and is used to differentiate associated magnetic track and Frame for information about.Data head reads relevant information from servo sector, make the disk electronic installation can determine radially and the data head position of circumference.
When settling data head, servo-drive system is used the information of servo tapered region.For example, in seek operation, servo-drive system moves radially the magnetic track that contain this data sector of data head to want addressing.In case find this magnetic track, servo-drive system keep the data head radial position and allow magnetic head with the disk circular motion up to finding the data sector that will seek.
In typical disc driver, anchor clamps often are used to install disk on turning axle.This anchor clamps make disk remain on the appropriate location for disk provides folder power.Folder power can prevent to make disk break away from turning axle owing to activating torque or operability bump, and still, folder power can be twisted disk too greatly.
As shown in Figure 1, magnetic track be to be positioned at position of rotation 110 at first, on the position of central shaft 101, after disk 100 slided, position 130 of track skew moved on to position of rotation 111, on the position of central shaft 102.When disk 100 rotations, in order to follow magnetic track, servo-drive system must radially pass in and out the skew when being positioned at position 111 with compensation track by moving head 120.This is as United States Patent (USP) the 5th, 539, No. 714 disclosed technology contents.A disc drive servo system comprises one first servo compensator and one second servo compensator, and the magnetic head that this second servo compensator is a magnetic track produces a position signal.Second servo compensator is after analyzing from previous spinning disk positional fault signal, produce a sinusoidal position signal, the frequency of this sine signal and disk gyro frequency are complementary, and angular frequency equals the rotation angle frequency of disk, and phase place and magnitude are determined by the analysis of positional fault signal.The sinusoidal position signal partly compensates because the caused radial variations of skew.
If magnetic track is twisted, makes track radius repeat to change the sinusoidal signal that does not have with gyro frequency and adapt.Servo-drive system will produce the difficulty that magnetic track is followed so.In this case, the compensation of an incomplete repetition is provided at the second above-mentioned servo compensator, at this moment, servo compensator must provide the unit of a bigger energized position signalling device, does not have enough dynamic ranges to handle the distortion of magnetic track with the compensation servo compensator.
[summary of the invention]
The object of the present invention is to provide a kind ofly to be twisted or the magnetic track of offset rotation axle when disk compensates when turning axle rotates, thus the method that data head and magnetic track are kept mutually.
Another object of the present invention is to provide a kind of servo-drive system of disc driver magnetic track.
Purpose of the present invention can be achieved through the following technical solutions: the multi resonant compensator of a servo-drive system is analyzed owing to the caused magnetic track radial variations of positional fault signal, determines the spectral range of radial variations.Options transformation of variable coefficient is used to produce at least two period signals in the Fourier transform of radial variations.Described period signal comprises a sinusoidal signal and a sinusoidal signal that is the harmonic frequency twice that equates with rotation harmonic wave fundamental frequency.Described period signal is mixed into a position and corrects signal, in order to correct the magnetic track distortion of radial variations.
Described magnetic track compensation method comprises: analyze the spectral range of magnetic track radial variations, to determine the assembly in the radial variations expansion; By fourier transform analysis positional fault note signal, come from the selected harmonic wave signal of positional fault signal with elimination, determine the magnetic track radial position.Produce at least one period signal, the magnitude of each period signal equates with the magnitude of relevant assembly; Produce a position signal that is used to control driver from the period signal of the above, described position signal makes the path movement that harmonic wave produced of magnetic head along above-mentioned selected radial variations.
The servo-drive system that the present invention further discloses comprises: a driver; One analyzer is used for determining the harmonic wave scope of track location radial variations; A plurality of offset generators, each generator can produce a period signal with different frequency; And a gain adjusting unit, this unit is used for the mixing cycle signal, to form an energized position signal.Analyzer and offset generator can change the magnitude of period signal fully to be eliminated until the harmonic wave signal of the selection that comes from the positional fault signal.
Compared with prior art: magnetic track compensation method of the present invention can provide real-time compensation, and can predict the cycle variation of radius, thereby correct to a greater extent compensation track is twisted or is offset caused magnetic track radial variations.
[description of drawings]
Fig. 1 is the disk deflection graph that the magnetic track of the center of disk and disk departs from turning axle.
Fig. 2 is the servo compensation system of disc driver of the present invention.
Fig. 3 A and Fig. 4 A be magnetic track when being twisted into ellipse magnetic track be not offset and the legend of offset rotation axle.
Fig. 3 B and Fig. 4 B are the partial graphs corresponding to the magnetic track radial variations of Fig. 3 A and Fig. 4 A.
Fig. 3 C and Fig. 4 C are the magnitude partial graphs corresponding to the discrete Fourier transform (DFT) spectrum assembly of Fig. 3 B and Fig. 4 B.
Fig. 5 is the block scheme of servo compensation of the present invention system.
Fig. 6 analyzes and the block scheme of the assembly compensator that the single spectrum assembly of magnetic track radial variations compensates.
[embodiment]
Please refer to Fig. 2, disc driver 200 employings servo compensation of the present invention system is used to compensate because the cycle radial variations that skew and magnetic track distortion cause.Disc driver 200 comprises one or more circular concentric planar disks 240, and each disk 240 is coated with the last layer magnetic medium at least on one side.Data head 220 is at the concentric magnetic track identifying recording layer, as on magnetic track TRKi and TRK (i+1).The magnetic track of corresponding other magnetic disk surface (not icon) roughly with magnetic disk surface on the magnetic track cylindrical shape arrange.Embedded servo tapered region SW1 to SWn with magnetic disk surface each track split become a plurality of Frames of FRM1 to FRMn, wherein, each Frame comprises all or part data sector.For constant density record, the data sector at the Frame place of particular track quantity depend on the radius of magnetic track.Usually, similar magnetic track is classified as the magnetic track with same form.Each servo tapered region SWj (j=1-n) comprises m servo sector, and wherein, m is the number of disk circular concentric data track, so each magnetic disk surface comprises total n*m servo sector.
Disk 200 is connected to computer system by interface 215, the data transmission that Magnetic Disk Controller 207 control computer systems and data buffer are 208, and control data impact damper 208 and disk 240 are through the data transmission of 220 of read/write circuits 206, prime amplifier 205, data read head.Magnetic Disk Controller 207 is also handled the read-write requests of the servo-drive system of link position data head 220.In disc driver 200, servo-drive system comprises a microprocessor 210, servo logic 211, excitation A/D and D/A circuit 212, excitation driving circuit 213, when radially or circumference when placing data read head 220, read the information of servo wedge SW1 to SWn with prime amplifier 205 and read/write circuit 206.
Microprocessor 210 comes Control Servo System by solid, and this solid is stored in non-volatility memorizer 255, and this storer 255 stores PID servo compensation, harmonic compensation program, tracking control, program variable and instruction.In the present embodiment, non-volatility memorizer 255 is ROM, also can be PROM, EPROM, EEPROM and Flash storer etc.Microprocessor 210 can be microcontroller or microprocessor.Microprocessor 210 also can be visited volatile storage 250.
Microprocessor 210 is just controlled servo compensator and is begun to carry out compensation, with the position of correction of data magnetic head 220 when servo sector receives position error signal.When data head 220 passed through the pairing servo sector of analog value, the positional fault signal provided a series of signal value, in the middle of, each signal value has been described the radial deflection between data head 220 and track centreline.Servo compensator produces the servo sector that a servo compensation signal acts on above-mentioned correspondence, and a digit position signal that will come from servo compensator is delivered in the D/A converter of exciting circuit 212, after exciting circuit 212 and excitation driver 213 receive and are somebody's turn to do and handle the digit position signal, provide an analog signal to driver 225, driving data magnetic head 220 moves to the disk center line.This treatment scheme is carried out re-treatment at each servo sector.
Anchor clamps 235 are used to clamp disk 240, guarantee that disk 240 rotates with CD-ROM drive motor.In the present embodiment, disk 240 is that diameter is 2.5 inches glass disks, anchor clamps 235 and spacer assembly (not icon) are fixed on the turning axle 230, wherein, anchor clamps 235 are made of the spool that the series of thin stainless steel is made, the metal spool has a particle, for disk 240 provides anisotropic stress.At assembly process, initial chucking pressure is selected such that vertical distortion is minimum, but makes disk 240 be twisted into saddle.After adding anchor clamps, disk 240 servo sectors be written to servo tapered region SW1 to SWn with definition circular track TRK1 to TRKm.Bump and the thermal cycle suffered of disk 240 later on can cause that disk 240 slides, and offset rotation axle 230 has changed the shape of disk 240 and the TRK1 magnetic track to TRKm.
What Fig. 3 A and Fig. 4 A described is two kinds of distortion of circular track 310, and in Fig. 3 A, circular track 310 is twisted, and is deformed into the oval magnetic track 320 that semi-major axis is Unit 1.2, and rotation center does not have change, and magnetic track 310 and magnetic track 320 remain around turning axle 330 rotations.For magnetic track 320, at every turn around turning axle 330 rotations the time, data head is in first four/one-period rotation, radius must outwards move Unit 0.2 from 1 unit, to reach 1.2 unit, in second four/one-period rotation, radius must inwardly move Unit 0.2 again, to be returned to 1 unit, in the 3rd four/one-period rotation, radius must outwards move Unit 0.2 again, to reach 1.2 unit, in last four/one-period rotation, radius must inwardly move Unit 0.2 again, to be returned to 1 unit.What Fig. 3 B described is in the rotation of whole magnetic track 320, and magnetic track 320 is the situation that δ R changes with the radial variations, and radial variations δ R is equal to the difference between the radius R c of the radius R e that twists magnetic track 320 and circular track 310.
A constant energized position signal remains on the fixing radius data head 220, can correctly not follow magnetic track 320.A servo compensator changes position signal according to the positional fault that detects at last between data head 220 and track center, carry out correct servo sector compensation, but can not further predict the positional fault between servo sector, and should mistake can cause magnetic track off-center position or be twisted.Therefore, be that correctly magnetic track is followed with traditional servo compensator.
Please refer to Fig. 3 C, because first coefficient 381 of second coefficient, 382 dominations of the Fourier transform of the radial variations of Fig. 3 B, so correctly the cycle of compensation track radius changes the sinusoidal signal of the gyro frequency of disk.
What Fig. 4 A described is that major semi-axis is that 1.2 unit semi-minor axis are the oval magnetic track 420 of Unit 0.9, and this ellipse magnetic track 420 departs from Unit 0.1 and departs from Unit 0.15 along semi-major axis from turning axle 330 along semi-minor axis.When magnetic track 420 during around turning axle 330 rotation, data head must outwards move Unit 0.35, to reach Unit 1.35, claims in Unit 0.55 to return Unit 1.05 again to Unit 0.8 again, returns 1 cell radius at last.Fig. 4 B describes is that radial variations is the situation of complete rotation of the oval magnetic track 420 of δ R.Fig. 4 C describes is that radial variations at Fig. 4 B is the magnitude of relevant harmonic wave during the discrete Fourier of δ R expands.For magnetic track 420, first coefficient 481 and the second English coefficient 482 of Fourier transform are more important, and the 3rd coefficient 483 and the 4th coefficient 484 are more much smaller than first coefficient 481 and second coefficient 482, can ignore.
The actual distortion of disk and disk or magnetic track slide the type that depends on added folder power and folded anchor clamps.In Fig. 2, the folder power of a 67lbs can provide the radial force of the maximum of an about 51lbs for disk 240.In interior diameter, very narrow and installation that quilt is strict can cause the local or irregular distortion of magnetic track, and this distortion will produce more harmonic wave than circular or oval-shaped magnetic track.The elastic force of disk makes the distortion of overall diameter become smoothly, makes that more magnetic track forms ellipse, so the magnetic track distortion can make magnetic track span to other magnetic track.In the present embodiment, have at per inch on the disk of 6000 magnetic tracks, clamping expects to cause that 7% to 14% magnetic track is out of shape, and the inner tracks distortion is more remarkable, after being the distortion magnetic track harmonic compensation first time, with the track error that remains with 6.5%.
Please refer to Fig. 5, microprocessor 210 control compensation devices produce an energized position signal, and this signal has cycle assembly 525, and this assembly 525 includes a plurality of harmonic waves of gyro frequency, with further reduction track error.Compensator 500 comprises independently multi resonant compensator 520 of a servo compensator 510 and function.Servo compensator 510 compensation are from the positional fault that reads servo sector for the last time.Significantly, behind the servo compensator 510 receiving position mistake signals (PES) 505, produce energized position and adjust signal 515, to correct by positional fault signal 505 caused radial variations.The magnetic track radial variations is followed in 520 monitoring of multi resonant compensator, and produces the period signal 525 that a predetermined period changes.Multi resonant compensator 520 receiving position mistake signals 505, the spectral range of analysis position mistake signal 505 produces the period signal based on aforementioned spectral scope and data head 220 simultaneously.The multi resonant compensator provides real-time compensation, and predetermined period change in radius, makes servo compensator 510 correct the stochastic source of change in radius to a greater extent.
Multi resonant compensator 520 comprises first harmonic compensator 521, second harmonic compensator 522, third harmonic compensator 523, and its angular frequency is respectively a times, two times and three times of disk gyro frequency.Multi resonant compensator 520 also can comprise four, five or more harmonic compensation device, to improve the performance of multi resonant compensator 520.The signal that multi resonant compensator 520 produces and the cycle of track radius are complementary.In the present embodiment, select first harmonic compensator 521, second harmonic compensator 522 just enough to deal with the distortion and the skew of general disk.
In Fig. 5, first harmonic compensator 521, second harmonic compensator 522, third harmonic compensator 523 correspond respectively to look-up table 551, look-up table 552, the look-up table 553 that is stored in storer ROM 525.Look-up table 551, look-up table 552, look-up table 553 include sine value and the cosine value that generation component is corrected signal.As selection, microprocessor 210 also can produce sine value and cosine value, and the result is stored in the table of storer 250.In the present embodiment, each look-up table includes sine lookup table and cosine look-up table, and these look-up tables can number be searched according to servo sector.Particularly, arrive (1-n) for the value of searching i=0, wherein, n is the number of servo tapered region, look-up table includes sinusoidal function sin (2 π hi/n) and cosine function cos (2 π hi/n), wherein, h represents the numbering 1,2,3 of first harmonic compensator 521, second harmonic compensator 522, third harmonic compensator 523.
The storage unit that is used for store look-up tables 551, look-up table 552, look-up table 553 can have several different methods to reduce.For example, single table of a sine value can be used to substitute sine and the cosine table of separating.One sinusoidal and cosine value can be stored in the table, with index i separately with { (i+n/4) MOD n} is if the total n of servo tapered region is 4 multiple.In addition, if it is lower to include the harmonic wave tabulation of needed information, look-up table can be left in the basket so.For example, if servo tapered region add up to even number, second harmonic compensator 522 can replace searching number i differentiate that current servo sector is stored in table 551 with searching number (2i MOD n), table 552 can be left in the basket.
First harmonic compensator 521, second harmonic compensator 522, third harmonic compensator 523 receive servo sector numbers 541 respectively, rotation numbers 542 and positional fault signal 505 come analysis position mistake signal 505 and produce a sinusoidal position correction signal with the value of look-up table 551, look-up table 552, look-up table 553.Servo sector processor 540 is provided for illustrating the servo sector numbers 541 of data head 220, and is used to calculate the rotation numbers 542 that magnetic track is searched pulse.Servo sector numbers 541 is used in reference to look-up table 551, look-up table 552, look-up table 553 at ROM 255.
First harmonic compensator 521, second harmonic compensator 522, third harmonic compensator 523 are analyzed the radial variations δ R of track centreline, as interrogating 35 magnetic tracks that determined from positional fault signal 505 and/or position, determine the magnitude and the phase place of positional fault signal 505 Fourier transform item numbers, and produce sinusoidal signal according to harmonic wave magnitude, phase place and the frequency of above-mentioned correspondence.The sinusoidal signal that gain adjusting unit 524 is mixed from first harmonic compensator 521, second harmonic compensator 522, third harmonic compensator 523 is adjusted total gain.This is better than single sinusoidal signal or single component signal.
For each servo sector i, excitation signal generator 530 mixed excitations are adjusted signal 515 and period signal 525, wherein, excitation is adjusted signal 515 and is produced according to servo sector i positional fault signal 505 by servo compensator 510, period signal 525 is to be produced by multi resonant compensator 520, be used for next servo sector i+1, to act on the excitation signal 535 of Frame FRMi.Therefore, when microprocessor 210 provided migration to adjust signal 535 to servo-drive system, the cycle compensation will be carried out.As selection, before next servo sector, for signal 515, excitation signal 530 every Frames are corrected position signal 535 twice.Servo-drive system is used from the information of servo compensator 510 and multi resonant compensator 520 and is kept on the center line of the magnetic track that data head 220 expected.
The magnetic head that positional fault signal 505 is pointed out and follow distance between track centreline, this positional fault signal include as track skew or twist that the caused cycle changes and as non-interference that repeats to change such as deviation, bearing noises.Ignoring the non-situation that repeats to change interference, the magnetic head of supposing servo-drive system is positioned on the track centreline of servo sector i-1 of radius R (i-1), positional fault signal PESi has pointed out the track radius Ri of current sector and the difference between last sector track radius R (i-1), if magnetic track distortion and track skew have same magnitude, this Fourier transform that can demonstrate Ri-R (i-1) is proportional with the Fourier transform of Ri, so at second and higher harmonic wave how significant harmonic wave scope is arranged.First harmonic compensator 521, second harmonic compensator 522, third harmonic compensator 523 these three harmonic compensation devices have determined in the Fourier transform of positional fault signal PES 505 each magnitude and phase place, and produce a signal, to cancel this harmonic wave.So, be less from the correction of servo compensator 510, be dominant by non-repetition effect.
Please refer to Fig. 6, in harmonic compensation device 600 first harmonic compensators 521, second harmonic compensator 522, the third harmonic compensator 523 any one.Harmonic compensation device 600 comprises an analyzer 610 and an offset generator 620.Analyzer 610 orders receive the value of each magnetic track servo sector positional fault signal 505, carry out filtration treatment, measure a single harmonic in the conversion of PES 505.For example, first harmonic compensator 521, second harmonic compensator 522, third harmonic compensator 523 are measured first, second, third harmonic wave respectively among Fig. 5, and its frequency is respectively one times of gyro frequency, two times, three times.
Powering up of disc driver 200, in use with zero clearing, when disk arrived normal rotational speed, harmonic compensation device 600 began to activate harmonic compensation device 600 at the access site of storer 250.At this moment, during the first pre-decision track number X that analyzes rotation, analyzer 610 is analyzed PES 505, and the signal that offset generator 620 has produced is as correcting signal 625.As the following stated, signal 625 is corrected to produce in the sector 653 and 654 that offset generator 620 adopts storer 250.Because sector 653,654 is zero when initial, corrects signal 625 and be similarly zero.
During analyzing rotation, analyzer 610 begins filtration treatment when searching pulse, analyzes PES 505.In the present embodiment, the filtration treatment of analyzer 610 is discrete Fourier transforms.For each harmonic wave, Fourier analysis needs two summing value AccSine and AccCosine, and this is with approximately proportional with needed complete Fourier transform.Summation AccSine and AccCosine be respectively sinusoidal product and and the cosine product with.Sinusoidal sum of products cosine product respectively can be in order to equation 1 (Equation1) and equation 2 (Equation 2) calculate down.
Sine
i＝PESi·sin(2π·h·i/h) Equation?1
Cosine
i=PESicos (2 π hi/h) Equation 2 wherein, h is 1,2,3 of corresponding harmonic wave, i is the servo sector that will analyze, PESi is the value of servo sector i PES 505.The product of Sine and Cosine is each servo sector i of evaluated magnetic track, and wherein, magnetic track includes 0 to n-1 servo sector, and in the present embodiment, n is 72.
Equation 3 (Equation 3) and equation 4 (Equation 4) are the values that is stored in summation 651 with the summation 652 of storer 250 after treatment.
Wherein, i is the servo sector that will analyze number, and n is total servoing sector number, the rotation number of F for analyzing, scope from 0,1 ..., (X-1), X be the analysis pre-decision of rotating number.
After handling all servo sectors, analyzer 610 forms sinusoidal sector 653 and cosine sector 654, and they are respectively the mean value of summation 651 and summation 652.The equation of sinusoidal sector (SineFactor) 653 and cosine sector (CosineFactor) 654 is respectively:
Wherein, GF is a gain factor, and X analyzes rotation number, and n is the servo region sum of every disk rotation.
During analysis rotation subsequently, compensator 620 is beginning to produce correction signal 625 based on Factor 653 and Factor 654.By the specified servo sector of servo sector numbers 541, compensation generator 620 is that servo sector is replied suitable sine value and cosine value from ROM 255 for each, and Factor 653 multiply by sine value and cosine value respectively with Factor 654 then.
Sine?Compensation
i＝SineFactor·(Sine?Value)
i Equation?7
Cosine Compensation
i=CosineFactor (Cosine Value)
iEquation 8 wherein, (Sine Value)
iWith (Cosine Value)
iBe to come from the look-up table relevant, Sine Compensation with servo sector i
iWith Cosine Compensation
iThese two products are produced signal 625 mutually.Compensation generator 620 usefulness Factor 653 produce compensation continuously with Factor 654 1 frames one frame ground.
Please refer to Fig. 5, gain adjusting unit 524 a plurality of results and additions from correction signal 625 with the additional gain factor of a plurality of harmonic compensation devices are to produce compensating signature 515.In servo-drive system, in order to keep the stable of servo-drive system, gain adjusting unit 524 usefulness one are less than the gain factor of servo compensator 510.
After rotation, during servo-drive system was allowed to settle, summation 651 was re-set as zero with summation 652, and analyzer 610 is piled up the product of sinusoidal and cosine again.After the pxrd analysis rotation, summation 651 and the calculated value of summation 652 less than aforementioned analysis rotation, this is because compensation generator 620 is just producing a compensating signature now, this compensating signature cancellation all or part is from the corresponding harmonic wave of PES 505.If compensating signature over-compensation cycle magnetic track distortion, sue for peace so 651 with summation 652 be passive.Based on new summation 651 and summation 652, be adjusted according to mean value at the Factor 653 of storer 250 and Factor 654.Because by analysis after second of the rotation rotation that is provided with, rotation beginning, analyzer 610 stop to pile up summation 651 and summation 652 once more, and the permission system stops, compensation generator 620 produces one and corrects signal simultaneously, in order to upgrade Factor 653 and Factor 654.
Therefore, Factor 653 is to upgrade in the cycle with Factor 654, and is converged to a value, and the variation of these value cancellation track radius makes following and is zero.The speed of assembling depends on full gain factor GF, and gain factor GF is used to gain adjusting unit 530.Little full gain factor can need to upgrade several times Factor 653 and Factor 654, changes correcting signal 625 complete compensation track, in the frequency relevant with harmonic compensation device 600.But the harmonic compensation device reduces other system requirement compensation of necessity immediately after analyzing rotation for the first time, as servo compensator 510.If the full gain factor is too big, Factor 653 and Factor 654 will show the behavior of swing, can not converge at ideal value.To a new magnetic track tracking time, the value of the last magnetic track of compensation generator 620 usefulness continues to produce corrects signal, during the initial analysis rotation of new magnetic track.Because in same magnetic track on a drum or a disk distortion is similar, Factor 653 and Factor 654 converge to ideal value very soon, with the cyclic swing of cancellation track radius.
But, in the present embodiment, during rotation be can not use analyzer 610, waited for that before further adjusting Factor 653 and Factor 654 it is important that servo-drive system stops.After stopping the rotation, analyzer 610 is piled up summation 651 and summation 652.Order subsequently: (i) produce a compensating signature, analyze the track radius of predetermined rotation number simultaneously; (ii) upgrade needed sector; (iii) when not analyzing the magnetic track radius of turn, produce a compensating signature, repeat continuously to stop allowing servo-drive system.Therefore, Factor 653 is that summation is overtime with Factor 654.This summation trends towards eliminating system of response and improves associated problem in short-term.And the overtime accumulation of sector stops discontinuous and guarantees that magnetic head 220 maintains on the track center.
Under stability state, compensating signature 625 can be eliminated the communication harmonic wave of PES 505 in a large number, so that the subsequent analysis of PES 505 carries out little correction to preceding Factor 653 with Factor 654.Correspondingly, under stability state, the energized position signal causes that data head follows the cycle radial variations δ R of magnetic track and have the multiple-harmonic of harmonic wave corresponding to the Fourier transform of radial variations δ R.If in the operating period of disk drive, disk is shaken or is in the thermal cycle, causes disk distortion or skew, and steady state (SS) is destroyed, analyzer 610 provides bigger correction upgrading Factor 653 and Factor 654, and corrects new magnetic track distortion or skew.Therefore harmonic compensation device 500 provides a suitable real-Time Compensation signal, so that data can not be capped during operation.
Claims (17)
1. a disc driver magnetic track servo compensation method comprises following content: analyze the spectral range of magnetic track radial variations, to determine the magnitude of a plurality of assemblies in the expansion of radial variations; Produce the period signal that a plurality of different frequencies are the several times of disk gyro frequency, the magnitude of described each regular signal equates with the magnitude of above-mentioned definite a plurality of assemblies; In above-mentioned period signal, produce the position signal of a driver, the radial position of the data head that described position signal control is relevant with turning axle.
2. disc driver magnetic track servo compensation method as claimed in claim 1, it is characterized in that: described analysis spectral range comprises the harmonic wave scope of analysis position mistake signal, to determine the assembly in the expansion of radial variations.
3. disc driver magnetic track servo compensation method as claimed in claim 2, it is characterized in that: described analysis spectral range further comprises:
The harmonic wave scope of analysis position mistake signal is to determine the assembly of the expansion of first value of the setting Location mistake signal during be provided with the first time of analysis of magnetic disc spins;
The harmonic wave scope of analysis position mistake signal, to determine the assembly of the expansion of second value of the setting Location mistake signal during be provided with the second time of analysis of magnetic disc spins, during this time, use with period signal and produce a position signal and a plurality of period signal with first value of setting of magnitude.
4. disc driver magnetic track servo compensation method as claimed in claim 3 is characterized in that: described first is provided with pivot analysis and second, and that pivot analysis is set is invalid and use and separated by one or more rotation during period signal produces a plurality of period signals with first value of setting of magnitude at analysis position mistake signal.
5. disc driver magnetic track servo compensation method as claimed in claim 3, it is characterized in that: the spectral range of described analysis magnetic track radial variations further comprises:
Each first value of setting produces one with second value of setting addition and mixes the value of setting;
The harmonic wave scope of analysis position mistake signal, to determine the assembly of the expansion of the 3rd value of setting Location mistake signal during the analysis of magnetic disc spins is provided with for the third time, the described disc spins of analysis of magnetic for the third time is to follow after being provided with for the second time;
With producing position signal and a plurality of period signal during the mixing value of setting analysis the 3rd value of setting.
6. disc driver magnetic track servo compensation method as claimed in claim 5 is characterized in that: described first is provided with pivot analysis and second is provided with pivot analysis and was separated by one or more rotation during analysis position mistake signal loses efficacy and produces a plurality of period signals with first value of setting; Described second is provided with pivot analysis and the 3rd is provided with pivot analysis and was separated by one or more rotation during analysis position mistake signal loses efficacy and produces a plurality of period signals with the mixing value of setting.
7. disc driver magnetic track servo compensation method as claimed in claim 5, it is characterized in that: the spectral range of the radial variations of described analysis magnetic track further comprises:
During aforementioned pivot analysis with the components values addition together of previous Location mistake signal, to produce a mixed number;
During the next one was provided with the spinning disk analysis, the harmonic wave scope of analysis position mistake signal was to determine next one value of setting of next Location mistake signal assembly;
During analyzing each rotation is set, analyze rotation and be worth and produce position signal and a plurality of period signal from aforesaid the setting with mixed number.
8. disc driver magnetic track servo compensation method as claimed in claim 7 is characterized in that: the step that further constantly repeats claim 7 when following magnetic track.
9. disc driver magnetic track servo compensation method as claimed in claim 1 is characterized in that: described a plurality of assemblies in the radial variations expansion are to be made of first assembly and second assembly.
10. disc driver magnetic track servo compensation method as claimed in claim 1 is characterized in that: described a plurality of assemblies in radial variations expansion are to be made of first assembly and second assembly and the 3rd assembly.
11. a disc driver magnetic track servo-drive system comprises:
One driver, it is used for the response position signal, radially places the data head relevant with the disk turning axle;
One device, described device are used to analyze along the harmonic wave scope of the magnetic track radial variations of turning axle and produce one first signal, and described first signal is described the spectrum assembly of first magnitude and second magnitude of the different first spectrum assemblies;
First generation device is used to produce the period 1 signal, and described period signal frequency response is in the first spectrum assembly, and magnitude equates with the first amount group;
Second generation device is used to produce signal second round, and described period signal frequency response is in the second spectrum assembly, and magnitude equates with the second amount group;
One device is used to mix first and second period signals, for driver produces a position signal.
12. disc driver magnetic track servo-drive system as claimed in claim 11, it is characterized in that: further comprise a servo compensation device, described compensation system is used to correct the signal that the positional fault signal of the data head relevant with magnetic track is described in response, wherein, blending ratio and summation are corrected signal, the period 1 signal and second round signal device, be used to produce the position signal of driver.
13. disc driver magnetic track servo-drive system as claimed in claim 12 is characterized in that: the described device analysis positional fault signal that is used to analyze, to determine the spectral range of radial variations.
14. disc driver magnetic track servo-drive system as claimed in claim 11 is characterized in that: the frequency of the described first spectrum assembly equates with the gyro frequency of disk.
15. disc driver magnetic track servo-drive system as claimed in claim 14 is characterized in that: the frequency of the described second spectrum assembly is the twice of disk gyro frequency.
16. disc driver magnetic track servo-drive system as claimed in claim 11 is characterized in that: analyze the harmonic wave range of devices of disk different light rays, be used to produce the 3rd signal of magnitude of describing the 3rd spectrum assembly of radial variations; Described system comprises that further one the 3rd produces the device that is used to produce the period 3 signal, frequency response the 3rd spectrum assembly of described device, and its magnitude is consistent with the magnitude of the 3rd spectrum assembly; Mix the device of first and second and period 3 signal, described device is used to produce the position signal of driver.
17. a disc driver magnetic track servo-drive system comprises:
One driver, it is used for the response position signal, radially places the data head relevant with the disk turning axle;
One analyzer, be used for analysis position mistake signal, to determine along the harmonic wave scope of the radial variations of the magnetic track of turning axle, the positional fault signal is described the position of the data head relevant with disk track, wherein, analyzer produces one first signal and second signal, and described first signal is described the first spectrum assembly of positional fault signal, and described second signal is described the second spectrum assembly of positional fault signal;
One first compensation generating means, the described first compensation generating means is used to respond first signal, the described first compensation generating means is used to produce a period 1 signal, and the frequency of described period 1 signal and the first spectrum assembly adapt, and are described by the order of magnitude of first signal;
One second compensation generating means, the described second compensation generating means is used to respond second signal, the described second compensation generating means be used to produce one second round signal, described second round, the frequency and the second spectrum assembly of signal adapted, and were described by the order of magnitude of second signal;
One gain adjusting unit, described adjustment unit mixes first and second period signals, and described adjustment unit is used to produce an assembly that constitutes the position signal of driver.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA021520143A CN1501351A (en) | 2002-11-18 | 2002-11-18 | Servo compensation process for disk drive track and servosystem thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA021520143A CN1501351A (en) | 2002-11-18 | 2002-11-18 | Servo compensation process for disk drive track and servosystem thereof |
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| Publication Number | Publication Date |
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| CN1501351A true CN1501351A (en) | 2004-06-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA021520143A Pending CN1501351A (en) | 2002-11-18 | 2002-11-18 | Servo compensation process for disk drive track and servosystem thereof |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108074621A (en) * | 2016-11-10 | 2018-05-25 | 希捷科技有限公司 | Detection to Z axis nonoperational shock |
| CN115775567A (en) * | 2021-09-08 | 2023-03-10 | 株式会社东芝 | Magnetic disk device and method for compensating for harmonic wave corresponding to harmonic wave interference |
-
2002
- 2002-11-18 CN CNA021520143A patent/CN1501351A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108074621A (en) * | 2016-11-10 | 2018-05-25 | 希捷科技有限公司 | Detection to Z axis nonoperational shock |
| CN108074621B (en) * | 2016-11-10 | 2021-07-09 | 希捷科技有限公司 | Detection of non-operational Z-axis impacts |
| CN115775567A (en) * | 2021-09-08 | 2023-03-10 | 株式会社东芝 | Magnetic disk device and method for compensating for harmonic wave corresponding to harmonic wave interference |
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