CN104700848A - Magnetic disc and head control method - Google Patents
Magnetic disc and head control method Download PDFInfo
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- CN104700848A CN104700848A CN201410075140.5A CN201410075140A CN104700848A CN 104700848 A CN104700848 A CN 104700848A CN 201410075140 A CN201410075140 A CN 201410075140A CN 104700848 A CN104700848 A CN 104700848A
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Abstract
The invention provides a magnetic disc and head control method, and the magnetic discs are stable in search work and matched with head replacement of the heads; the method can predict the position of the second head relative to a second magnetic disc before switching the first head into the second head according to switching matching search request of the first head and the second head, wherein the first head is arranged relative to the first magnetic disc, and the second head is arranged relative to the second magnetic disc.
Description
Technical field
Present embodiment relates in general to the control method of disk set and magnetic head.
Background technology
In disk set, in order to increase the data field for user data write, having and from the inner circumferential of disk towards periphery, servo figure being divided into multiple district and the method improving the write frequency of the servo figure in the district of outer circumferential side relative to the district of inner circumferential side.In addition, also having to reduce Gray code region, the upper bit address in Gray code region being divided into method that is multiple and that the upper bit address be partitioned into stored dispersedly.
Summary of the invention
The invention provides and can to make and magnetic head between multiple magnetic head changes the disk set of searching work stabilization together and the control method of magnetic head.
According to embodiment, be provided with the 1st and the 2nd disk, the 1st and the 2nd magnetic head and control part.The servo figure that the write frequency of the 1st and the 2nd disk is different from each other is divided into multiple district and carries out record.1st head relative is arranged in described 1st disk.2nd head relative is arranged in described 2nd disk.Control part, according to accompany from described 1st magnetic head to the switching of described 2nd magnetic head search requirement, from described 1st magnetic head to described 2nd magnetic head switch before, predict that described 2nd head relative is in the position of described 2nd disk.
Accompanying drawing explanation
Fig. 1 is the block diagram of the schematic configuration representing disk set of the first embodiment.
Fig. 2 (a) is the vertical view of the magnetic track configuration represented in the disk of Fig. 1, the figure of Fig. 2 (b) to be the figure of the partition method representing servo region, Fig. 2 (c) be configuration example of the servo region representing Fig. 2 (b).
Fig. 3 (a) is the figure of the change case representing the border, district that the core shift due to disk causes, and Fig. 3 (b) is the figure of the change case on the border, district represented in the card of mutually different disk.
Fig. 4 represents that the magnetic head of Fig. 1 changes the block diagram of the schematic configuration of control part.
Fig. 5 is the figure that the magnetic head of the disk set schematically showing Fig. 1 changes the track searching head position when requiring.
Fig. 6 is the figure that the magnetic head of the disk set schematically showing Fig. 1 changes the VCM output waveform search the term of execution.
Fig. 7 is the process flow diagram of the searching work of the disk set representing Fig. 1.
Fig. 8 is the process flow diagram of the servo interrupt work of the disk set representing Fig. 1.
Fig. 9 is the process flow diagram representing the process that VCM kick (kick) function based on Fig. 7 carries out.
Figure 10 is the process flow diagram of the process carried out based on the VCM kick correction function of Fig. 8.
Embodiment
Explain the control method of disk set that embodiment relates to and magnetic head with reference to the accompanying drawings.In addition, the present invention does not limit by these embodiments.
(the 1st embodiment)
Fig. 1 is the block diagram of the schematic configuration representing disk set of the first embodiment.
In FIG, be provided with multiple disk 2,3 in disk set, be respectively equipped with card M0, M1 on the two sides of disk 2, be respectively equipped with card M2, M3 on the two sides of disk 3.And disk 2,3 is supported integratedly via main shaft 14.
In addition, in disk set, be provided with magnetic head H0 ~ H3 for each card M0 ~ M3, it is not relative with card M0 ~ M3 that magnetic head H0 ~ H3 configures component.Here, magnetic head H0 ~ H3 is maintained on card M0 ~ M3 via arm A0 ~ A3 respectively.Arm A0 ~ A3 can make magnetic head H0 ~ H3 slide in surface level respectively.
Here, as shown in Fig. 2 (a) ~ Fig. 2 (c), such as, on card M0, be provided with magnetic track T along downtrack D2.The data field DA write for user data and the servo region SS being written with servo data is provided with at each magnetic track T.Here, servo region SS is configured to radial, between the servo region SS along downtrack D2, be configured with data field DA.
As shown in Fig. 2 (b), servo region SS is divided into district Z0 ~ Z2, and Bing Ge district Z0 ~ Z2 is along configuring while downtrack D2 departs from.Now, district Z0, Z1 are configured to across spaced apart end portions overlapped, and district Z1, Z2 are configured to across spaced apart end portions overlapped.Near the magnetic track being overlapped in district Z0, Z1, be provided with border, district Z0A, near the magnetic track being overlapped in district Z1, Z2, be provided with border, district Z0B.In addition, in the example of Fig. 2 (b), be just divided into the method for 3 district Z0 ~ Z2 to be described servo region SS, but also servo region SS can be divided into any number being more than or equal to 2.District Z0 ~ Z2 can be configured to the write frequency different (hereinafter referred to district's servo mode) in the SS of servo region.In the example of Fig. 2 (b), in the district Z0 of outer circumferential side, reference frequency and the write frequency of servo figure can be improved compared with the district Z2 of inner circumferential side.Such as, write frequency can be set as 200MHz in district Z0, in district Z1, write frequency be set as 150MHz and in district Z2, write frequency be set as 100MHz.Here, improve write frequency by comparing inner circumferential side at outer circumferential side, compared with the situation certain with making the write frequency of district Z0 ~ Z2, the space of district Z0, Z1 can be reduced, data field DA can be increased.In addition, about card M1 ~ M3, also servo region SS is divided into district Z0 ~ Z2 and goes forward side by side line item in the same manner as card M0.
Here, as shown in Figure 2 (c), be written with above 40 at servo region SS, servo region mark 41, sector/cyclinder information (Gray code) 42 and pulse pattern (burst pattern) 43.In addition, sector/cyclinder information 42 can provide the downtrack D2 of card M0 and cross over the servo numbering of track direction D1, and can be used in making magnetic head H0 to move to goal track position search control.In addition, in order to reduce Gray code region, also the upper bit address in Gray code region can be divided into multiple and store the upper bit address (this being called upper bit address segmentation storage mode below) be partitioned into dispersedly.Pulse pattern 43 can be used in the Tracing Control of the scope inner position magnetic head H0 at goal track.This pulse pattern 43 both can be casement pulse pattern or area-type pulse pattern, also can be phase differential type figure.
In addition, as shown in Figure 1, in disk set, be provided with the voice coil motor 4 of actuating arm A0 ~ A3, and be provided with the Spindle Motor 13 disk 2,3 being rotated via main shaft 14.And, disk 2,3, magnetic head H0 ~ H3, arm A0 ~ A3, voice coil motor 4, Spindle Motor 13 and main shaft 14 retract within the case 1.
Be provided with magnetic recording control part 5 at disk set, be provided with magnetic head control portion 6, power control section 7 at magnetic recording control part 5, read write raceway groove 8 and hard disk controlling portion 9.Reset current control part 6A and reproducing signal test section 6B is provided with in magnetic head control portion 6.Spindle Motor control part 7A and voice coil motor control part 7B is provided with in power control section 7.Be provided with magnetic head in hard disk controlling portion 9 and change control part 9A.In addition, the process of magnetic head replacing control part 9A is realized by the firmware performed by CPU.
Signal during record-playback amplifies by magnetic head control portion 6.Reset current control part 6A controls the reset current flowed at magnetic head H0 ~ H3.Reproducing signal test section 6B is detected the signal read by magnetic head H0 ~ H3.Power control section 7 drives voice coil motor 4 and Spindle Motor 13.The rotation of Spindle Motor control part 7A to Spindle Motor 13 controls.Voice coil motor control part 7B can control the driving of voice coil motor 4.Read write raceway groove 8 and convert the signal reproduced by magnetic head H0 ~ H3 to processed by main frame 12 data mode, and/or the data exported from main frame 12 are converted to the signal form recorded by magnetic head H0 ~ H3.As such formal transformation, DA conversion and/or numberingization can be enumerated.In addition, read the decoding process that write raceway groove 8 carries out the signal reproduced by magnetic head H0 ~ H3, and/or code modulated is carried out to the data exported from main frame 12.Hard disk controlling portion 9 can carry out record-playback control based on the instruction carrying out from host 12, and/or at main frame 12 and read and write between raceway groove 8 and carry out exchanges data.Magnetic head is changed control part 9A and can be controlled the magnetic head replacing of magnetic head H0 ~ H3.
Magnetic recording control part 5 is connected to main frame 12.In addition, both can be undertaken writing instruction and/or reading the personal computer indicated by disk set as main frame 12, also can be external interface.
And, by Spindle Motor 13, disk 2,3 is rotated, on one side respectively via magnetic head H0 ~ H3 from card M0 ~ M3 read output signal, and to be detected by reproducing signal test section 6B.The signal detected by reproducing signal test section 6B, after carrying out data conversion by reading write raceway groove 8, is sent to hard disk controlling portion 9.Then, in hard disk controlling portion 9, the Tracing Control of magnetic head H0 ~ H3 is carried out based on the pulse pattern 43 contained by the signal detected by reproducing signal test section 6B.
In addition, calculate the current location of magnetic head H0 ~ H3 based on the sector/cyclinder information 42 contained by the signal detected by reproducing signal test section 6B, carry out searching control and make magnetic head H0 ~ H3 close to target location.Here, when exist to change with magnetic head together search requirement, change in control part 9A at magnetic head, before magnetic head H0 ~ H3 switching, the position (in addition, so-called target magnetic head refers to the magnetic head being instructed to switch from current magnetic head to it) of target of prediction magnetic head H0 ~ H3.Then, predicting the outcome of the position of based target magnetic head H0 ~ H3, switches the write frequency corresponding to switching that read frequency makes it with magnetic head H0 ~ H3 corresponding.Now, setting is used for the internal clocking of the mode sense data corresponding with the write frequency corresponding to the switching of magnetic head H0 ~ H3.Here, by the position of target of prediction magnetic head H0 ~ H3 before magnetic head H0 ~ H3 switches, even if there is core shift at disk 2,3, also can judge the write frequency of the district Z0 ~ Z2 corresponding with the position of target magnetic head H0 ~ H3, searching work stabilization can be made.
And, change in control part 9A at magnetic head, with search requirement correspondingly, before being switched to target magnetic head H0 ~ H3 from current magnetic head H0 ~ H3, give suitable acceleration output to voice coil motor 4 and target magnetic head H0 ~ H3 accelerated, to make the initial relative velocity after being switched to target magnetic head H0 ~ H3 close to 0.Here, by before magnetic head H0 ~ H3 switches, suitable acceleration can be given to voice coil motor 4 and exports, thus the initial relative velocity of target magnetic head H0 ~ H3 (speed of the leap track direction D1 between magnetic head H0 ~ H3 and card M0 ~ M3) is reduced.Therefore, in district's servo mode, can not continuing for a long time by detected state of servo data can be prevented, can prevent the detection of servo data from expending time in, so searching work stabilization can be made.
In addition, in upper bit address segmentation storage mode, even if when the divided storage of the upper bit address in Gray code region, also the initial relative velocity of target magnetic head H0 ~ H3 can be made to be less than or equal to the compensable speed of decoding, therefore, it is possible to the position relationship of upper bit address when upper bit address when compensating sampling instant in the past and current sample time reproduce suitable original cylinder address.Therefore, even if when bit address on have employed splits storage mode, the mistranslation code of head position also can be prevented, can reduce the time of searching.
To be the figure of the change case that the border, district caused by the core shift of disk is shown, Fig. 3 (b) be Fig. 3 (a) represents the figure of the change case on the border, district in the card of mutually different disk.
In Fig. 3 (a), be provided with border, district Z0A between district Z0, Z1 at card M0.In addition, near the Z0A of border, district, be provided with to be difficult to carry out data record due to MR biased (offsct) etc. give up region N0A.In addition, in the example of Fig. 2 (b), make 2 districts Z0, Z1 and give up region N0A to coexist, (timing (rotation angle) that each district Z0, Z1 occur on a magnetic track of the dish rotated) is by sector configuration each district Z0, Z1 so with staggering phase place.Rotation center when servo data can such as record relative to it concentrically carries out record circularly.But due to departing from of the rotation center that causes because of the installation core shift of disk 2, border, district Z0A is by 1 sinusoidal wave shape change.Therefore, servo track Ye Yugai district border Z0A changes abreast.
On the other hand, in Fig. 3 (b), be provided with border, district Z3A between district Z0, Z1 at card M3.In addition, what near the Z3A of border, district, be provided with the record that is difficult to carry out data gives up region N3A.Departing from due to the rotation center that causes because of the installation core shift of disk 3 on card M3, border, district Z3A is by 1 sinusoidal wave shape change.Here, if install core shift difference between disk 2,3,1 sinusoidal wave amplitude and phase place difference between Ze district border Z0A, Z3A.Therefore, when the current location PZ of magnetic head H0 is positioned at district Z0, at magnetic head H3, the situation that current location PZ is in district Z1 occurs, between magnetic head H0, H3, the frequency of servo reproducing signal is different from each other.
Now, when exist with from magnetic head H0 to the magnetic head of magnetic head H3 changes together search requirement, before switching from magnetic head H0 to magnetic head H3, predict the position of magnetic head H3.Then, the position of the magnetic head H3 that the frequency switching servo reproducing signal makes itself and this dope is corresponding.Thus, though install between disk 2,3 core shift different, also can prevent the servo data when switching from detection from magnetic head H0 to magnetic head H3 failure, searching work stabilization can be made.
Fig. 4 represents that the magnetic head of Fig. 1 changes the block diagram of the schematic configuration of control part 9A.
In the diagram, change control part 9A at magnetic head and be provided with initial relative movement condition estimating portion 21, VCM open loop (open) acceleration portion 22, VCM pulse output adjustment part 23, district's servo switch judgement part 24, servo handoff functionality portion of district 25, driver VCM efferent 26 and HDC multi tate output function portion 27.In addition, these unit can be made up of firmware.
In addition, as optimization parameter PM, the head position runout information on the information relevant to the installation core shift of disk 2,3, the sector runout information of card M0 ~ M3 and the radial direction of being correlated with the location tolerance of magnetic head H0 ~ H3 can be set.As the information relevant to the installation core shift of disk 2,3,1 time can be set and rotate synchronous sinusoidal wave amplitude and phase place.In addition, optimization parameter PM is in the information be stored in adjustment operation in not volatile memory of dispatching from the factory, but about the information relevant to installing core shift, there is no need to adopt optimization parameter, the DFT coefficient value etc. used in the compensation deals of RRO synchronized component also can be utilized to carry out converting and calculating.
Initial relative movement condition estimating portion 21, when such as switching from current magnetic head H0 to target magnetic head H3, based on the core shift track of the card M3 of the core shift track of the card M0 of current magnetic head H0 and the magnetic head H3 of target, calculate from magnetic head change search require the positional offset amount of target magnetic head H3 after the N_HS sampling time.In addition, the N_HS sampling time becomes to perform the hits that magnetic head changes non-control state required for sequence, be also from accept magnetic head change search require utilize target magnetic head to carry out searching the imaginary time of control.22 pairs, VCM open loop acceleration portion voice coil motor 4 carries out opened loop control and makes initial relative velocity when have switched magnetic head close to 0.It is closer to zero that VCM pulse exports adjustment part 23 to the initial relative velocity 0 when have switched magnetic head be changed error fine setting, and is adjusted by the output of final sampling to voice coil motor 4 between noncontrolled area.The predicted value of the positional offset amount of district servo switch judgement part 24 based target magnetic head H3, predicts track address when switching to target magnetic head H3, and judges the write frequency of servo figure based on the track address that this dopes.Servo handoff functionality portion of district 25, based on the result of determination of district's servo switch judgement part 24, switches read frequency to make it corresponding with write frequency when having switched to target magnetic head H3.Driver VCM efferent 26, based on the instruction from VCM open loop acceleration portion 22 or HDC multi tate output function portion 27, drives voice coil motor 4.The driving instruction change that HDC multi tate output function portion 27 carries out voice coil motor 4 makes it carry out 2 output 1 sampling period.
And, if having issued magnetic head replacing to search requirement, then, in initial relative movement condition estimating portion 21, calculate change in location predicted value d_Cyl and velocity variations predicted value d_Vel based on optimization parameter PM.
In addition, the residual quantity of the radial direction position AC bias of the magnetic track caused due to the installation core shift of card M0, M3 according to not shown d_Ecc() and the residual quantity of DC bias due to the radial direction position of the location tolerance gained of magnetic head H0, H3, as formula (1), calculate change in location predicted value d_Cyl.
D_Cyl=d_Ecc+(DC
3-DC
0) formula (1)
Wherein, DC: the radial direction position DC bias caused by the magnetic head location tolerance that the best is parallel
In addition, the residual quantity of the radial direction position AC bias of the magnetic track that the installation core shift due to card M0, M3 causes and d_Ecc, calculate as formula (2).
D_Ecc=dP
0-dP
3formula (2)
DP
0=A
0sin(2 π N
0/ Nsct+B
0) formula (2a)
DP
3=A
3sin(2 π N
3/ Nsct+B
3) formula (2b)
N
3=N
0+ (dS
3-dS
0) formula (2c)
Wherein, dP
0the radial direction AC bias that the installation core shift of the magnetic track due to card M0 of current time (magnetic head change search require the moment) causes, and core shift amplitude A 0, core shift phase place B0, current sector numbering N0 can be utilized, 1 week servoing sector number Nsct obtains as formula (2a).In addition, dP
3the radial direction AC bias because the core shift of the magnetic track of target magnetic head face M3 causes, and the core shift amplitude A 3 on card M3, core shift phase place B3, current time sector number expected value N3 can be utilized, 1 week servoing sector number Nsct obtains as formula (2b).In addition, current time sector number expected value N3, according to the residual quantity of this magnetic head surface information dS of disk face M0 ~ M3 sector runout information, corrects and calculates the sector number N of current magnetic head
0.
Similarly, d_Vel is the residual quantity of the radial direction speed of the magnetic track caused due to the installation core shift of card M0, M3, calculates as formula (3).
D_Vel=dV
0-dV
3formula (3)
DV
0=2 π A
0/ Nsctcos(2 π N
0/ Nsct+B
0) formula (3a)
DV
3=2 π A
3/ Nsctcos(2 π N
3/ Nsct+B
3) formula (3b)
In addition, in formula (2) and formula (3), the phase differential of current time and magnetic head switching instant can be ignored, and calculates and changes the variation prediction value of searching the track location caused due to core shift requiring the moment at magnetic head.But the originally preferably change in location predicted value of magnetic head switching instant, so also can as formula 2d) like that, consider to search from magnetic head replacing the dead time Tdly process requiring that the moment performs to magnetic head switching instant.
N0=N0 '+Tdly/Ts formula (2d)
Wherein, Ts: control cycle
Then, in VCM open loop acceleration portion 22, based on velocity variations predicted value d_Vel, calculate VCM output order value VCMOUT_kick and make velocity variations predicted value d_Vel become 0, and this VCM output order value VCMOUT_kick is outputted to driver VCM efferent 26.Then, by driving voice coil motor 4 via driver VCM efferent 26, magnetic head H0 ~ H3 starts to carry out accelerated motion.
With this accelerated motion, the head position change after the N_HS time, so VCM open loop acceleration portion 22 also considers location variation d_Pos calculate cylinder address expected value ZnSv_cylcode when target magnetic head switches simultaneously.The additive value of the location variation d_Pos changing with magnetic head the cyclinder variable quantity d_Cyl that performs and accompany and produce due to accelerated motion that cylinder address expected value ZnSv_cylcode when target magnetic head switches is calculated cylinder address information on current magnetic head H0, found out in advance by initial relative movement condition estimating portion.The cyclinder numbering predicted value ZnSv_cylcode calculated is output to district's servo switch judgement part 24.
And, in district's servo switch judgement part 24, based on cyclinder numbering predicted value ZnSv_cylcode, judge which district Z0 ~ Z2 target magnetic head H3 is in, and the identifying information ZnSv_ID corresponding with this district Z0 ~ Z2 is outputted to servo handoff functionality portion of district 25.Then, in servo handoff functionality portion of district 25, based on identifying information ZnSv_ID, switch correspondingly with from magnetic head H0 to the servo reproducing signal of magnetic head H3, the read frequency of switching servo figure and/or duration filtering characteristic etc.Now, identifying information ZnSv_ID is set in and reads write raceway groove 8, if identifying information ZnSv_ID changes, then carries out the setting relevant to servosignal check processing and changes.
In addition, each there is the magnetic head signal that servo interrupt all performs HS(magnetic head amplifier and select switch operating) hand-off process sequence, HC occurs in the final step of HC hand-off process sequence when switching final servo interrupt, VCM pulse exports adjustment part 23 and starts.Now, timestamp (timestamp) the information T0 based on the VCM open loop acceleration start time in VCM open loop acceleration portion 22 is transfused to VCM pulse output adjustment part 23.
Then, export in adjustment part 23 in VCM pulse, accelerate the timestamp information T0 of start time and the difference of current timestamp information T1 according to VCM open loop, obtain the minute TR in fact accelerated.Then, obtain this minute TR and the residual quantity dT by the imaginary pulse settings time T_HS in VCM open loop acceleration portion 22, the output of adjustment voice coil motor 4 is to compensate this residual quantity dT.Now, in order to make VCM output order that extreme change not occur, HDC multi tate output function portion 27 can be used.Now, export HDC multi tate output function portion 27,23 pairs, adjustment part from VCM pulse and export VCM output order OUT1, OUT2, Delay.Then, in HDC multi tate output function portion 27, be output to driver VCM efferent 26 based on VCM output order OUT1 the 1st output, after have passed through the time set by Delay, be output to driver VCM efferent 26 based on VCM output order OUT2 the 2nd output.Such as, the retention time exported for the 1st time can be set as the Ts(1 sampling time)/2, but by the adjusted value that voice coil motor 4 exports, also can extend the retention time exported for the 1st time, VCM exports the level being converged in expection.
Fig. 5 is that the magnetic head of the disk set schematically showing Fig. 1 changes the figure searching the track of head position when requiring.In addition, A1 ~ A8 represents the sampling instant of the servo data of current magnetic head H0, and B1 ~ B8 represents the sampling instant of the servo data of target magnetic head H3.In addition, the longitudinal axis represents that current magnetic head H0 and target magnetic head H3 is crossing over the position in track direction.In addition, at sampling instant A1 ~ A8, B1 ~ B8, solid line represents the effective servosignal reproduced by magnetic head amplifier, and dotted line represents by the undetected invalid servosignal of magnetic head amplifier.In addition, the deviation between sampling instant A1 ~ A8 and sampling instant B1 ~ B8 results from the sector deviation between disk 2,3.
In Figure 5, due to the installation core shift of disk 2,3, the magnetic track track K1 of the card M3 that the magnetic track track K2 of the card M0 that current magnetic head H0 locates locates with target magnetic head H3 is separated.Now, change there being magnetic head after searching requirement, until when searching the magnetic head acceleration based on VCM pulse output not carrying out present embodiment before control starts, target magnetic head H3 advances along the track K2 of current magnetic head H0.Therefore, when searching control and starting, between the current location of target magnetic head H3 and target location, opsition dependent variation prediction value d_Cyl produces and departs from.And, when searching control and starting, produce the initial velocity of velocity variations predicted value d_Vel relative to the magnetic track of target magnetic head H3.This searches the initial velocity (velocity variations predicted value d_Vel) controlling start time, can represent by the residual quantity of the magnetic track velocity V1 of the magnetic track velocity V2 of card M0 and card M3.
Here, by using VCM open loop acceleration portion 22 track of target magnetic head H3 can be changed to K4 from K2.Therefore, when searching control and starting, the speed of target magnetic head H3 can be made close to the magnetic track velocity V1 of target magnetic head face M3, initial relative velocity when magnetic head switches can be lowered.Therefore, it is possible to lower the predicated error of cyclinder numbering, and the omission of servo data can be prevented, even if having magnetic head to change near border, district to search when requiring, also can prevent the time of searching from extremely extending.
But, only in VCM open loop acceleration portion 22, because being required the impact etc. that the fluctuation of the timing sent and/or the phase deviation of A1 ~ A8 and B1 ~ B8 cause by HCseek, search the initial relative velocity controlling start time and produce fluctuation.VCM pulse exports adjustment part 23, in order to reduce this prima facies to velocity perturbation, can based on the residual quantity dT of imaginary acceleration time and the actual minute TR accelerated, carry out exporting adjustment by the final sampling of HC sequence to make imaginary force amass (time integral value of acceleration) and actual forces to amass consistent, and the track of target magnetic head H3 is changed to K3 from K4, can to make to search when controlling to start relative to the initial relative velocity of magnetic track closer to 0.
In addition, VCM open loop acceleration portion 22, the time integral that can will speed up tolerance, as velocity variations predicted value d_Vel, utilizes pulse settings time T_HS to calculate open loop acceleration amount, and this open loop acceleration amount is added with biased output valve and exports VCM output order value VCMout_kick.
Fig. 6 is the figure that the magnetic head of the disk set representing Fig. 1 changes the VCM output waveform search the term of execution.
In figure 6, in Tracing Control period P1, it is on duty that VCM output valve is set to bias level LB phase.And, if such as have magnetic head to change as shown in Figure 5 between sampling instant A2 to A3 search requirement, then because of HS hand-off process and/or wait for that servo lock is stable etc. and transfer to non-controlling period P2, transfer to afterwards and search control period P3.Here, if change there being magnetic head the timestamp information searched when requiring to be set to T0, and make only to expend N_HS sampling instant from having magnetic head to change to search and requiring to searching control, be then set to pulse settings time T_HS from the time of moment T0 to N_HS sampling instant.And, in VCM open loop acceleration portion 22, calculate VCM output order value VCMout_kick based on this pulse settings time T_HS, opened loop control is carried out to voice coil motor 4.
In addition, export in adjustment part 23 in VCM pulse, obtain the current time stamp information T1 in the opened loop control of voice coil motor 4, accelerate according to VCM open loop the difference that the timestamp information T0 in moment and current time stab information T1, obtain the minute TR in fact accelerated.And, obtain the residual quantity dT of pulse settings time T_HS and minute TR, and the output adjusting voice coil motor 4 is to compensate this residual quantity dT.
Here, adjustment part 23 is exported by arranging VCM pulse, even if when the process servo region SS started between timing oscillation and/or disk 2,3 that requirement is searched in magnetic head replacing exists phase deviation, also can adjust this error when being close to and searching and control the servo interrupt before starting.
In addition, export in adjustment part 23 in VCM pulse, adopt multi tate to export and make not need to determine the time from searching and controlling to the 1st output, be finally output into biased output, but neither be set to multi tate exports and make finally to be output into biased output.
In addition, in the above-described embodiment, employing exports by 2 times of multi tate that the Ts/2 time changes VCM output order value usually, but the retention time exported for the 1st time may not be Ts/2 but the time slightly short compared with Ts, extends the acceleration time as far as possible longly.
Fig. 7 is the process flow diagram of the searching work of the disk set representing Fig. 1.
In the figure 7, if look-up command is issued, then first will require that the head number of position converts target physical head number (S0) to.Then, judge whether target magnetic head tgtH is current magnetic head nowH(S1).And, when target magnetic head tgtH is current magnetic head nowH (S1 is), after the requirement position of magnetic head converts servo address to and is set to target cyclinder tgtC (S4), perform general searching and prepare process (S5).In this process, carry out known searching and process the setting of necessary tracking pattern and/or various flag settings etc., afterwards, start to carry out searching control in common servo interrupt process.
On the other hand, when target magnetic head tgtH is not current magnetic head nowH (S1's is no), after target magnetic head tgtH being called VCM kick function as independent variable, returning cyclinder numbering variable quantity ZnSv_cylcode as rreturn value (S2), enter S3.The flow process of VCM kick correspondence department as shown in Figure 9, but is also the correspondence department performing the process suitable with VCM open loop acceleration portion 22 with the initial relative movement presumption unit 21 of Fig. 4, and detailed description, by aftermentioned, is omitted at this.
And, in the same manner as when target magnetic head tgtH is current magnetic head nowH, after being set to target cyclinder tgtC (S3), performing and search preparation process (S4).
Next, because be provided with mark f_VCMkick when performing VCM kick function, so determine whether that will perform district's servo is switched and determined (S5) according to this mark f_VCMkick.
When VCM kick performs (S5 is), the call area servo process (S6) as independent variable using the rreturn value of VCM kick function and ZnSv_cylcode.This function process, which district whether ZnSv_cylcode being in servo border, district compares judgement, when there being Zn to change, after following closely and next servo SAM being detected by current magnetic head H0, send the processing requirements that the raceway groove setting that switches HDC setting and SFG and/or filtering characteristic etc. according to ZnSv_ID sets to change SGATE.When not performing VCM kick (S5's is no), skip S6.
Thereby, it is possible to after following next servo interrupt closely, suitably extract the servo-information in the relative medium face of target magnetic head H3.
Fig. 8 is the process flow diagram of the servo interrupt work of the disk set representing Fig. 1.
In fig. 8, if there is servo interrupt, then before having carried out control, after various process (S11), determine whether that HC switches (S12).Before controlling various process be after following servo closely and detecting and start to search/follows the trail of wait control calculate before the general various process (also comprising demodulation process and state updating etc.) carried out, in this process, when there is ZnSv hand-off process and requiring, use district's servo function of raceway groove to perform thesaurus (bank) to switch, make to become the suitable raceway groove conformed to ZnSv_ID and set.
About interruption time usual, when not having HC to switch (S12's is no), carry out usual control treatment (S18).In this usual control treatment, carry out head position control treatment, other various control treatment and next sampling processing etc.After usual control treatment, carry out the rear various process (S19) of control.
On the other hand, when there being HC to switch (S12 is), perform HC series processing S14 in multiple sampling period, to switch to target magnetic head and normally can detect servo.This HC series processing the term of execution, normally cannot obtain servo-information, so skip usual control treatment S18 to become non-control state.
In HC series processing S14, the selection of HS(magnetic head is carried out to the reproducing signal of magnetic head amplifier) switch or be set to servo search modes or change the raceway groove set model detected for servo successively, carry out state transition and realize stable magnetic head more changing jobs.
But, in the present embodiment, because the process of the VCM pulse output adjustment part of Fig. 4 will be carried out by the final step of HC series processing, so judge (S13) the final step being whether HC sequence, and set up when VCMkick performs when marking f_VCMkick (S15 is), call VCM kick correction function (S16).VCM kick correction function, as reference Fig. 5 and Fig. 6 carries out job description, the error of imaginary time and the time in fact to accelerate is utilized to export to export VCM by multi tate and correct, so the timestamp information of the moment T0 and current time T1 that will speed up beginning is as independent variable call function.The details of VCM kick correction function is aftermentioned with reference to Figure 10.
Afterwards, perform the final step process (S17) of the HC sequence of both having deposited and remove HC switch flag, HC series processing terminates.That is, from the servo interrupt of next sampling, it is no that the HC of S12 is switched and determined, and performs search control as usual control treatment (S18).
Fig. 9 is the process flow diagram representing the process that the VCM kick function based on Fig. 7 carries out.
In fig .9, if VCM kick function is called, then mark f_VCMkick is set as 1 and sets up mark f_VCMkick(S21 by initial relative movement condition estimating portion 21).By selecting the N_HS of the hits consumed to be added with as magnetic head current sector number nowSCT, thus setting sector number SCT(S22).Then, calculate the core shift state (S23) of current magnetic head nowH based on optimization parameter PM, obtain the sector runout information (S24) of target magnetic head tgtH according to optimization parameter PM.Then, after being added with sector bias d_SCT by sector number SCT (S25), the core shift state (S26) of target magnetic head tgtH is calculated.Then, the core shift state of based target magnetic head tgtH, calculates cyclinder numbering variable quantity d_cylcode and velocity variations predicted value d_Vel(S27).
Next, VCM open loop acceleration portion 22 calculates d_Vel/T_HS as acceleration figure ACC(S28).Then, will speed up value ACC and be converted into VCM output (S29), after restriction (limit) process carrying out VCM output (S30), perform VCM output (S31).Then, the location variation dPos(S32 of 1/2*ACC*T_HS*T_HS as the magnetic head H0 ~ H3 exported based on this VCM is calculated).Then, this location variation dPos is added (S33) with cyclinder numbering variable quantity d_cylcode, current time is set to timestamp information T0(S34).
In addition, in the present embodiment, be set to and necessarily carry out VCM kick process (setting f_VCMkick) by VCM kick function, but because have same installation core shift, so HCseek between same medium face such as between H0 and H1 and/or, HCseek etc. between H2 and H3, without the need to performing VCM kick of the present invention process.According to the relation of tgtH and nowH, when not needing to carry out the process of VCM kick, also f_VCMkick can be reset, and skipping the process of S21 ~ S34.
Figure 10 is the process flow diagram representing the process that the VCM kick correction function based on Fig. 8 carries out.
In Fig. 10, if VCM kick correction function VCM is called, then VCM pulse exports adjustment part 23 using current time as timestamp information T1(S41) and minute TR(S42 is calculated as T1-T0).Then, the residual quantity dT(S43 of T_HS-TR as pulse settings time T_HS and minute TR is calculated), and calculate ACC*dT as velocity error VELerr(S44).Then, calculate multi tate correct output (S45) and carry out multi tate output processing (S46).In addition, correct in output at multi tate, if be set to Delay=dT2, then can be set to OUT1=VELerr/dT2, OUT2=0.
(the 2nd embodiment)
In the diagram, be illustrated with regard to the structure being provided with initial relative movement condition estimating portion 21, VCM open loop acceleration portion 22, VCM pulse export adjustment part 23 and district's servo switch judgement part 24, but also can omit VCM open loop acceleration portion 22 and VCM pulse exports adjustment part 23.In this situation, district's servo switch judgement part 24 is based on the predicted value of the positional offset amount of the target magnetic head H3 doped by initial relative movement condition estimating portion 21, predict track address when having switched to target magnetic head H3, judge the write frequency of servo figure based on this track address doped.And servo handoff functionality portion of district 25 switches the write frequency of servo figure based on the result of determination of district's servo switch judgement part 24.
(the 3rd embodiment)
In the diagram, be illustrated with regard to the structure being provided with initial relative movement condition estimating portion 21, VCM open loop acceleration portion 22, VCM pulse export adjustment part 23 and district's servo switch judgement part 24, but also can omit VCM pulse exports adjustment part 23.In this situation, driver VCM efferent 26 is based on the order-driven voice coil motor 4 coming from VCM open loop acceleration portion 22.
Several embodiment of the present invention is described, but these embodiments propose as an example, have no intention to limit scope of invention.These new embodiments can be implemented in other various modes, can carry out various omission, displacement and change within a range not departing from the gist of the invention.These embodiments and/or its distortion are included in scope of invention and/or purport, and the invention be also contained in described in technical scheme and equivalency range thereof.
Claims (20)
1. a disk set, wherein, possesses:
1st and the 2nd disk, the servo figure that wherein write frequency is different from each other is divided into multiple district and carries out record;
1st magnetic head, it is arranged relative to described 1st disk;
2nd magnetic head, it is arranged relative to described 2nd disk; With
Control part, it, according to before requiring to switch to described 2nd magnetic head from described 1st magnetic head with searching of accompanying to the switching of described 2nd magnetic head from described 1st magnetic head, predicts that described 2nd head relative is in the position of described 2nd disk.
2. disk set according to claim 1, wherein,
Described control part according to described in search requirement, make before switching to described 2nd magnetic head from described 1st magnetic head described 2nd magnetic head accelerate, make the initial relative velocity after switching to described 2nd magnetic head close to 0.
3. disk set according to claim 1, wherein,
Described control part, based on the predicting the outcome of position of described 2nd magnetic head, switches read frequency, it is corresponded to and the said write frequency corresponding to the switching of described 2nd magnetic head from described 1st magnetic head.
4. disk set according to claim 1, wherein,
Described control part possesses presumption unit, the core shift track of this presumption unit based on described 1st disk and the core shift track of described 2nd disk, calculates from described positional offset amount of searching described 2nd magnetic head after the predetermined sampling requiring.
5. disk set according to claim 4, wherein,
Described presumption unit departs from based on the sector between described 1st disk and described 2nd disk the positional offset amount calculating described 2nd magnetic head.
6. disk set according to claim 4, wherein,
Described control part possesses detection unit, and this detection unit predicts track address when having switched to described 2nd magnetic head from described 1st magnetic head based on the positional offset amount of described 2nd magnetic head, and judges said write frequency based on the described track address doped.
7. disk set according to claim 6, wherein,
Described control part possesses acceleration portion, and this acceleration portion makes voice coil motor acceleration and deceleration with opened loop control, to make initial relative velocity when having switched to described 2nd magnetic head from described 1st magnetic head close to 0.
8. disk set according to claim 7, wherein,
Described control part possesses adjustment part, and this adjustment part is adjusted by the output of final sampling to described voice coil motor between noncontrolled area, is corrected to make the fluctuation of described initial relative velocity when having switched to described 2nd magnetic head from described 1st magnetic head.
9. disk set according to claim 7, wherein,
Described detection unit predicts described track address based on the shift amount of the 2nd magnetic head obtained by described VCM open loop acceleration portion.
10. disk set according to claim 9, wherein,
Described detection unit predicts described track address based on the location tolerance of described 2nd magnetic head.
The control method of 11. 1 kinds of magnetic heads, wherein,
According to accompany from the 1st magnetic head arranged relative to the 1st disk to the switching of the 2nd magnetic head arranged relative to the 2nd disk search requirement, before switching to described 2nd magnetic head from described 1st magnetic head, predict that described 2nd head relative is in the position of described 2nd disk.
The control method of 12. magnetic heads according to claim 11, wherein,
Search requirement according to described, before switching to described 2nd magnetic head from described 1st magnetic head, make described 2nd magnetic head accelerate, to make the initial relative velocity after switching to described 2nd magnetic head close to 0.
The control method of 13. magnetic heads according to claim 11, wherein,
Predicting the outcome of position based on described 2nd magnetic head switches read frequency, and this read frequency is corresponded to and the said write frequency corresponding to the switching of described 2nd magnetic head from described 1st magnetic head.
The control method of 14. magnetic heads according to claim 11, wherein,
Based on the core shift track of described 1st disk and the core shift track of described 2nd disk, calculate from described positional offset amount of searching described 2nd magnetic head after the predetermined sampling instant requiring.
The control method of 15. magnetic heads according to claim 14, wherein,
Depart from based on the sector between described 1st disk and described 2nd disk, calculate the positional offset amount of described 2nd magnetic head.
The control method of 16. magnetic heads according to claim 14, wherein,
Positional offset amount based on described 2nd magnetic head predicts track address when having switched to described 2nd magnetic head from described 1st magnetic head, switches said write frequency based on the described track address doped.
The control method of 17. magnetic heads according to claim 16, wherein,
Make voice coil motor acceleration and deceleration by opened loop control, make initial relative velocity when having switched to described 2nd magnetic head from described 1st magnetic head close to 0.
The control method of 18. magnetic heads according to claim 17, wherein,
Adjusted by the output of final sampling to described voice coil motor between noncontrolled area, the fluctuation of described initial relative velocity when having switched to described 2nd magnetic head from described 1st magnetic head is corrected.
The control method of 19. magnetic heads according to claim 17, wherein,
Shift amount based on described 2nd magnetic head by described opened loop control gained predicts described track address.
The control method of 20. magnetic heads according to claim 19, wherein,
Location tolerance based on described 2nd magnetic head predicts described track address.
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| US201361914291P | 2013-12-10 | 2013-12-10 | |
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| CN201410075140.5A Pending CN104700848A (en) | 2013-12-10 | 2014-03-03 | Magnetic disc and head control method |
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| CN110176253A (en) * | 2018-02-21 | 2019-08-27 | 株式会社东芝 | The control method of disk set and disk set |
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| CN110176253A (en) * | 2018-02-21 | 2019-08-27 | 株式会社东芝 | The control method of disk set and disk set |
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