CN1162847C - Cyclic track servo system and method for VCD drive - Google Patents
Cyclic track servo system and method for VCD drive Download PDFInfo
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- CN1162847C CN1162847C CNB011104902A CN01110490A CN1162847C CN 1162847 C CN1162847 C CN 1162847C CN B011104902 A CNB011104902 A CN B011104902A CN 01110490 A CN01110490 A CN 01110490A CN 1162847 C CN1162847 C CN 1162847C
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- position deviation
- write head
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Abstract
The present invention relates to a cyclic track servo system for an optical drive, which is used for controlling an optical read and write head to carry out the cyclic track motion on a data track, and comprises a sensor, a control device, a decision device and a power device, wherein the sensor senses and outputs the position deviation value of the optical read and write head and the center of the data track. The control device receives the position deviation value to generate the control quantity which forms the linear relation with the position deviation value. The decision device receives the position deviation value and outputs the correction quantity forming the non-linear relationship with the position deviation value when the position deviation value is not zero. The power device receives the control quantity and the correction quantity and generates driving force to drive the optical read and write head, and the produced driving force forms the linear relation with the sum of the control quantity and the correction quantity.
Description
Technical field
The invention relates to a kind of CD-ROM drive rail servo (Tracking Servo) system and method, be particularly to cyclic track servo system and method that a kind of improvement follows the rail performance.
Background technology
Because the arriving in digitized information epoch, also grow with each passing day the deposited demand of the storage volume that the floppy disk (floppy disk) that generally is used in early days can provide for the demand of portable digital Storage Media with high power capacity.Therefore, just have high storage capacity, the optical storage media and the storage device of characteristic such as be easy to carry promptly be widely used, as CD-ROM drive (CD-ROM drive), CD writer (CD-Rdrive) and LD (Laser Disc) player or the like.
In above-mentioned optical storage media, numerical data all is to be recorded on the discoid discs (Optical Disk), the data rail (InformationTrack) that has into the form concentric spirals shape on this kind CD, numerical data are promptly by form the section record in addition with different optical contrast (Optical Contrast) character on the data rail.On the data rail, read or when writing data, CD-ROM drive or CD writer can be rotated discs, and on the data rail, throw and absorb light beam (light beam) and carry out reading or writing of data by the lens (lens) of optical read/write head (pick up head).At this moment, screw out by the center one side direction outside by discs owing to data rail curl, no matter therefore when reading or write data, CD-ROM drive or CD writer all must make read/write head move laterally at the center from discs along with the rotation of discs, so that read/write head can correctly be aimed at the center of data rail, the motion of this kind read/write head is commonly referred to as and follows rail motion (Track-following), and its direction of motion is called as and follows rail direction (Tracking direction), and the system of this kind of control action then is called as cyclic track servo system (Tracking Servo System) in CD-ROM drive or the CD writer simultaneously.
Fig. 1 has shown the diagrammatic cross-section of a CD-ROM drive or CD writer read/write head and discs rotating mechanism.Discs 11 has a spiral helicine data rail 111, is placed on to use on the spinner 12 to be rotated.13 of read/write heads have lens 131 and make lens carry out the trickle fine setting actuator (actuator) 132 that follows the rail motion.In addition, 14 auxiliary read/write heads 13 of coarse adjustment actuator carry out the deficiency that rail moves and finely tunes actuator 132 with auxiliary of following of longer distance.
Fig. 2 has shown in tradition, the calcspar of the cyclic track servo system that above-mentioned CD-ROM drive or CD writer are used.Assembly identical with Fig. 1 among Fig. 2 uses identical symbol.Cyclic track servo system 2 is a loop (closed loop), comprises a fine setting controller 211, a fine setting driver 212, fine setting actuator 132, a coarse adjustment controller 221, a coarse adjustment driver 222, coarse adjustment actuator 14, an optical sensor 23 and an amplifier 24.
After fine setting controller 211 receives the TES signal that is exaggerated, produce one with the fine setting controlled quentity controlled variable of position deviation amount linear dependence (relation of two variablees can on coordinate in line), and export fine setting driver 212 to by a fine setting control signal FCS.Output one fine setting drive signal FDS was to finely tuning actuator 132 after fine setting driver 212 received fine setting control signal FCS, make fine setting actuator 132 produce a fine setting expulsive force and promote read/write head 13 displacements, the size of wherein finely tuning expulsive force is also linear relevant with the fine setting controlled quentity controlled variable of fine setting control signal FCS output.
221 of coarse adjustment controllers receive the fine setting control signal FCS of fine setting controller 211 outputs, because its sampling frequency is lower than the sampling frequency of fine setting controller 211, therefore fine setting control signal FCS are had the effect of low-pass filter (low-pass filtering).So, produce the coarse adjustment control signal CCS of an exportable coarse adjustment controlled quentity controlled variable.Output one coarse adjustment drive signal CDS was to coarse adjustment actuator 14 after coarse adjustment driver 222 received coarse adjustment control signal CCS, make coarse adjustment actuator 14 produce a coarse adjustment expulsive force and promote read/write head 13 displacements, the size of wherein coarse adjustment expulsive force is also linear relevant with the coarse adjustment controlled quentity controlled variable of coarse adjustment control signal CCS output.
Above-mentioned traditional cyclic track servo system have read/write head can't with the problem of data rail centrally aligned.Because when the coarse adjustment actuator follows the rail motion at the promotion read/write head, mechanical actuation is inter-agency to have stiction, the coarse adjustment expulsive force that the coarse adjustment actuator is produced just might promote the read/write head motion after must overcoming this stiction earlier, and this one overcome the quiet power of rubbing the coarse adjustment expulsive force must optical sensor sense that read/write head and data rail center have deviation and after exporting tracking error signal the beginning can produce, cause read/write head can't aim at data rail center all the time, this situation is concerning CD writer, the shake (jitter) that can cause writing data in the discs is excessive, reduces the quality of imprinting.
Above-mentioned problem can reduce the position deviation at read/write head and data rail center by the gain (gain) that improves the coarse adjustment controller strengthens the coarse adjustment expulsive force, but because total system is a linear system, excessively the gain of raising coarse adjustment controller will make total system restrain fast and present unsure state, so its effect is limited.
The influence that above-mentioned problem can also recently reduce stiction and caused by the driven gear that reduces the coarse adjustment actuator becomes very tediously long but reduce driven gear than the time of jumping onto the tracks of reading that can make CD-ROM drive or CD writer.
Summary of the invention
Therefore, the invention provides a kind of CD-ROM drive circulation orbital servo (Tracking Servo) system and method, can under the condition of reasonable gear ratio, keep lens alignment data rail center, reduce the generation of shake.
A purpose of the present invention is to provide a kind of CD-ROM drive cyclic track servo system, in order to the control optical read/write head data rail is followed the rail motion, comprising: sensing apparatus, control device, decision making device and propulsion system.Wherein, sensing device senses and export optical read/write head and the position deviation amount at data rail center.Control device receiving position departure and producing and the linear controlled quentity controlled variable of position deviation amount.Decision making device receiving position departure, output becomes the correction of nonlinear relationship with the position deviation amount when the position deviation amount is non-vanishing.Propulsion system then receive controlled quentity controlled variable and correction and produce expulsive force and promote this optical read/write head, expulsive force that it produced and controlled quentity controlled variable and correction with linear.
Another object of the present invention is to provide a kind of CD-ROM drive cyclic track servo system, the data rail is followed the rail motion, comprising: sensing apparatus, first and second control device, decision making device and first and second propulsion system in order to the control optical read/write head.Wherein, sensing device senses and export optical read/write head and the position deviation at data rail center and exporting by an error signal.First control device receives error signal and produces first control signal linear with error signal.Second control device receives and low-pass filter second control signal and produce one second control signal.Decision making device receives error signal, and output becomes the corrected signal of nonlinear relationship with error signal when optical read/write head has position deviation with data rail center.First propulsion system receive first control signal and produce the major drive promotion optical read/write head linear with first control signal.Second propulsion system receive first control signal and corrected signal and produce second expulsive force and promote optical read/write head, wherein second expulsive force and first control signal and corrected signal with linear.
The present invention's another purpose again is to provide a kind of CD-ROM drive to follow the rail method, in order to the control optical read/write head data rail is followed the rail motion, may further comprise the steps.At first, sensing and produce optical read/write head and the position deviation amount at data rail center.Then, produce and the linear control expulsive force of position deviation amount.Come again, when the position deviation amount is non-vanishing, produce the correction expulsive force that becomes nonlinear relationship with the position deviation amount.At last, with control and revise expulsive force with promote optical read/write head.
The present invention reaches by following technical measures:
A kind of CD-ROM drive cyclic track servo system follows the rail motion in order to control an optical read/write head to a data rail, comprising:
One sensing apparatus, sensing is also exported this optical read/write head and a position deviation amount at this data rail center;
One control device, receive this position deviation amount and produce one with the linear controlled quentity controlled variable of this position deviation amount;
One decision making device receives this position deviation amount, and output one becomes the correction of nonlinear relationship with this position deviation amount when this position deviation amount is non-vanishing;
One propulsion system receive this controlled quentity controlled variable and correction and produce an expulsive force and promote this optical read/write head, wherein this expulsive force and this controlled quentity controlled variable and correction with linear.
A kind of CD-ROM drive cyclic track servo system follows the rail motion in order to control an optical read/write head to a data rail, comprising:
One sensing apparatus, sensing is also exported this optical read/write head and the position deviation at this data rail center and exporting by an error signal;
One first control device, receive this error signal and produce one with the first linear control signal of this error signal;
One second control device receives and this first control signal of low-pass filter and produce one second control signal;
One decision making device receives this error signal, and output one becomes the corrected signal of nonlinear relationship with this error signal when this optical read/write head has position deviation with this data rail center;
One first propulsion system receive this first control signal and produce one and promote this optical read/write head with the linear major drive of this first control signal;
One second propulsion system receive this first control signal and this corrected signal and produce one second expulsive force and promote this optical read/write head, wherein this second expulsive force and this first control signal and corrected signal with linear.
A kind of CD-ROM drive follows the rail method, in order to control an optical read/write head one data rail is followed the rail motion, may further comprise the steps:
Sensing also produces this optical read/write head and a position deviation amount at this data rail center;
Generation one and the linear control expulsive force of this position deviation amount;
When this position deviation amount is non-vanishing, produce a correction expulsive force that becomes nonlinear relationship with this position deviation amount;
With this control and revise expulsive force with promote this optical read/write head.
The invention relates to a kind of CD-ROM drive rail servo (Tracking Servo) system and method, be particularly to cyclic track servo system and method that a kind of improvement follows the rail performance, under the situation that does not reduce the driven gear ratio, lower the shake (jitter) that CD writer is produced when the record material in the mode that changes Circuits System.
The present invention is by a decision making device is provided in traditional cyclic track servo system, this decision making device utilizes fuzzy control or logical condition to calculate the auxiliary coarse adjustment actuator of a correction and exerts oneself, and this auxiliary size of exerting oneself becomes nonlinear dependence with the position deviation amount, and the expulsive force that has not only increased the coarse adjustment actuator also can not cause the instability of system.
Description of drawings
Below, with regard to the embodiment of graphic explanation a kind of CD-ROM drive cyclic track servo system of the present invention and method.
Fig. 1 is the diagrammatic cross-section of a CD ROM reading-writing head and discs rotating mechanism;
Fig. 2 is the calcspar of a traditional cyclic track servo system;
Fig. 3 is the calcspar of an embodiment of cyclic track servo system of the present invention;
Fig. 4 is the determination methods that shows decision making device in the cyclic track servo system of the present invention;
Fig. 5 is the process flow diagram that CD-ROM drive of the present invention follows an embodiment of rail method.
Symbol description
11～discs; 111～data rail;
12～spinner; 13～read/write head;
131～lens; 132～fine setting actuator;
14～coarse adjustment actuator; 211～fine setting controller;
212～fine setting driver; 221～coarse adjustment controller;
222,223～coarse adjustment driver; 23～optical sensor;
24～amplifier; 25～decision making device.
Embodiment
Fig. 3 has shown the calcspar of present embodiment.Among Fig. 3 with Fig. 2 in identical assembly use identical symbol.
Cyclic track servo system 3 is a loop (closed loop), comprises a fine setting controller 211, a fine setting driver 212, fine setting actuator 132, a coarse adjustment controller 221, a coarse adjustment driver 223, coarse adjustment actuator 14, an optical sensor 23, an amplifier 24 and a decision making device 31.
After fine setting controller 211 receives the TES signal that is exaggerated, produce one with the fine setting controller of position deviation amount linear dependence (relation of two variablees can on coordinate in line), and export fine setting driver 212 to by a fine setting control signal FCS.Output one fine setting drive signal FDS was to finely tuning actuator 132 after fine setting driver 212 received fine setting control signal FCS, make fine setting actuator 132 produce a fine setting expulsive force and promote read/write head 13 displacements, the size of wherein finely tuning expulsive force is also linear relevant with the fine setting controlled quentity controlled variable of fine setting control signal FCS output.
221 of coarse adjustment controllers receive the fine setting control signal FCS of fine setting controller 211 outputs, because its sampling frequency is lower than the sampling frequency of fine setting controller 211, therefore fine setting control signal FCS are had the effect of low-pass filter (low-pass filtering).So, produce the coarse adjustment control signal CCS of an exportable coarse adjustment controlled quentity controlled variable.
Decision making device 25 receives the TES signal that is exaggerated from amplifier 24, via a determination methods (repeating after the appearance), uses logical condition formula or fuzzy control method to determine a correction, exports coarse adjustment driver 223 to by a corrected signal CRS again.
The determination methods of decision making device 25 in the cyclic track servo system 3 of Fig. 4 displayed map 3.At first in step 14, decision making device 25 prestores a reference voltage level V
REFReference voltage level V
REFBe when read/write head and data rail centrally aligned, the magnitude of voltage that the TES signal is produced.Decision making device 25 judges whether TES voltage of signals value equals reference voltage level V
REF(meaning is whether read/write head is aimed at data rail center) is when TES voltage of signals value equals reference voltage level V
REFShi Ze does not export correction (meaning is that correction is zero) in step 42, then re-executes step 41 at next sampling spot; Equal reference voltage level V and work as TES voltage of signals value
REFShi Ze judges that in step 43 whether TES voltage of signals value is greater than reference voltage level V
REFWhen TES voltage of signals value greater than reference voltage level V
REFThe time (position of meaning read/write head is not as good as data rail center, position deviation amount for just), then determine the expulsive force of a correction to step 44 with increase coarse adjustment actuator 14; And work as TES voltage of signals value less than reference voltage level V
REFThe time (position of meaning read/write head surmounts data rail center, position deviation amount for negative), then determine a correction to reduce the expulsive force of coarse adjustment actuator 14 to step 44.Then, repeat this flow process in next sampling spot again.
Fig. 5 is the process flow diagram that CD-ROM drive of the present invention follows an embodiment of rail method.At first, at step 51 sensing and produce optical read/write head and the position deviation amount at a discs data rail center.Then, produce and the linear control expulsive force of position deviation amount in step 52.Come again, when the position deviation amount is non-vanishing, use logical condition formula or fuzzy control method to produce the correction expulsive force that becomes nonlinear relationship with the position deviation amount in step 53.At last, in step 54, utilize control and revise expulsive force with promote optical read/write head.
In sum, the present invention propose one improve follow the rail performance follow the rail system and method, increase by a decision making device in the rail system and method in traditional following, obtain the tracking error signal of representing read/write head position deviation amount, use fuzzy control or logical condition formula to come computing, be aided with the coarse adjustment motor in good time and exert oneself, revisal read/write head off normal can often keep to the rail state read/write head in the read-write process.How second the time value that the present invention confirms to improve shake through experimental result reaches number.
Though the present invention discloses as above with a preferred embodiment; right its is not in order to limit the present invention; anyly have the knack of this skill person; without departing from the spirit and scope of the present invention; when can doing a little change and retouching, so protection scope of the present invention is when looking claim and being as the criterion in conjunction with instructions and accompanying drawing.
Claims (31)
1. a CD-ROM drive cyclic track servo system follows the rail motion in order to control an optical read/write head to a data rail, and it is characterized in that: described system comprises:
One sensing apparatus, sensing is also exported this optical read/write head and a position deviation amount at this data rail center;
One control device, receive this position deviation amount and produce one with the linear controlled quentity controlled variable of this position deviation amount;
One decision making device receives this position deviation amount, and output one becomes the correction of nonlinear relationship with this position deviation amount when this position deviation amount is non-vanishing;
One propulsion system receive this controlled quentity controlled variable and correction and produce an expulsive force and promote this optical read/write head, wherein this expulsive force and this controlled quentity controlled variable and correction with linear.
2. the system as claimed in claim 1, it is characterized in that: described data rail is positioned on the discs.
3. the system as claimed in claim 1, it is characterized in that: described sensing apparatus is an optical sensor.
4. the system as claimed in claim 1, it is characterized in that: described optical read/write head comprises lens.
5. the system as claimed in claim 1 is characterized in that: described sensing apparatus by a tracking error signal with this position deviation amount output.
6. the system as claimed in claim 1 is characterized in that: described control device by a control signal with this controlled quentity controlled variable output.
7. the system as claimed in claim 1, it is characterized in that: described decision making device is exported this correction by a corrected signal.
8. the system as claimed in claim 1, it is characterized in that: the position deviation amount is timing, this correction increases this propulsion system expulsive force, when described position deviation amount when negative, this correction reduces this propulsion system expulsive force.
9. the system as claimed in claim 1, it is characterized in that: described decision making device calculates this correction by the fuzzy control method.
10. the system as claimed in claim 1, it is characterized in that: described decision making device calculates this correction by the logical condition formula.
11. the system as claimed in claim 1 is characterized in that: described propulsion system comprise an one drive circuit and an actuator, and this driving circuit receives this controlled quentity controlled variable and correction and exports a drive signal to this actuator, makes this actuator produce this expulsive force.
12. CD-ROM drive cyclic track servo system as claimed in claim 1 follows the rail motion in order to control an optical read/write head to a data rail, it is characterized in that:
Described sensing apparatus, sensing is also exported this optical read/write head and the position deviation at this data rail center and exporting by an error signal;
Described control device comprises a first control device, receive this error signal and produce one with the first linear control signal of this error signal; With
One second control device receives and this first control signal of low-pass filter and produce one second control signal;
Described decision making device receives this error signal, and output one becomes the corrected signal of nonlinear relationship with this error signal when this optical read/write head has position deviation with this data rail center;
Described propulsion system comprise one first propulsion system, receive this first control signal and produce one and promote this optical read/write head with the linear major drive of this first control signal; With
Second propulsion system receive this second control signal and this corrected signal and produce one second expulsive force and promote this optical read/write head, wherein this second expulsive force and this first control signal and corrected signal with linear.
13. system as claimed in claim 12 is characterized in that: described data rail is positioned on the discs.
14. system as claimed in claim 12 is characterized in that: described sensing apparatus is an optical sensor.
15. system as claimed in claim 12 is characterized in that: described optical read/write head comprises lens.
16. system as claimed in claim 12 is characterized in that: described error signal is a tracking error signal.
17. system as claimed in claim 12 is characterized in that: described first control device is a fine setting controller.
18. system as claimed in claim 12 is characterized in that: described second control device is a coarse adjustment controller.
19. system as claimed in claim 12 is characterized in that: this error signal has a reference voltage when described optical read/write head and this data rail centrally aligned.
20. system as claimed in claim 19, it is characterized in that: when the voltage of described error signal during greater than this reference voltage, this corrected signal increases by second expulsive force of these second propulsion system, when the voltage of this error signal during less than this reference voltage, this corrected signal reduces second expulsive force of these second propulsion system.
21. system as claimed in claim 12 is characterized in that: described decision making device produces this corrected signal by the fuzzy control method.
22. system as claimed in claim 12 is characterized in that: described decision making device produces this corrected signal by the logical condition formula.
23. system as claimed in claim 12, it is characterized in that: described first propulsion system comprise one first driving circuit and one first actuator, this first driving circuit receives this first control signal and exports one first drive signal to this first actuator, makes this first actuator produce this major drive.
24. system as claimed in claim 12, it is characterized in that: described second propulsion system comprise one second driving circuit and one second actuator, this second driving circuit receives this second control signal and this corrected signal and exports one second drive signal to this second actuator, makes this second actuator produce this second expulsive force.
25. system as claimed in claim 24 is characterized in that: described first actuator is a fine setting actuator.
26. system as claimed in claim 24 is characterized in that: described second actuator is a coarse adjustment actuator.
27. a CD-ROM drive follows the rail method, in order to control an optical read/write head one data rail is followed the rail motion, may further comprise the steps:
Sensing also produces this optical read/write head and a position deviation amount at this data rail center;
Generation one and the linear control expulsive force of this position deviation amount;
When this position deviation amount is non-vanishing, produce a correction expulsive force that becomes nonlinear relationship with this position deviation amount;
With this control and revise expulsive force with promote this optical read/write head.
28. method as claimed in claim 27 is characterized in that: described data rail is positioned on the discs.
29. method as claimed in claim 27 is characterized in that: described optical read/write head comprises an optical lens.
30. method as claimed in claim 27 is characterized in that: the value of described correction expulsive force obtains by the fuzzy control method.
31. method as claimed in claim 27 is characterized in that: the value of described correction expulsive force obtains by the logical condition formula.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011104902A CN1162847C (en) | 2001-04-16 | 2001-04-16 | Cyclic track servo system and method for VCD drive |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011104902A CN1162847C (en) | 2001-04-16 | 2001-04-16 | Cyclic track servo system and method for VCD drive |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1381840A CN1381840A (en) | 2002-11-27 |
| CN1162847C true CN1162847C (en) | 2004-08-18 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB011104902A Expired - Lifetime CN1162847C (en) | 2001-04-16 | 2001-04-16 | Cyclic track servo system and method for VCD drive |
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| CN (1) | CN1162847C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101521029B (en) * | 2008-02-28 | 2011-10-26 | 凌阳科技股份有限公司 | Best record power-correcting method for improving track-seeking stability of power-correcting region |
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2001
- 2001-04-16 CN CNB011104902A patent/CN1162847C/en not_active Expired - Lifetime
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| Publication number | Publication date |
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| CN1381840A (en) | 2002-11-27 |
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