KR100288839B1 - How to control feed motor position and speed of DVD ROM driver - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed motor position and speed control method of a DVD-ROM driver. In particular, the present invention monitors the current position of a feed motor using an up-down counter, and It calculates the actual speed of the feed motor using the timer as a signal from the hole sensor, calculates the direction of movement and the distance to be moved from the current position to the target position where the next regeneration data is located. The present invention relates to a feed motor position and speed control method that improves system performance by calculating a position and speed of a feed motor quickly and efficiently controlling the speed by commanding a speed control command by applying a control command calculation differently.

Description

How to control feed motor position and speed of DVD ROM driver

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed motor position and speed control method of a digital video disk ROM driver. In particular, the central processing unit uses an up-down counter to observe the position of the feed motor and provides a hall sensor. The present invention relates to a feed motor position and speed control method for shortening the seek time by measuring the actual speed of a feed motor using a timer as a signal coming from and controlling software corresponding positions and speeds. .

In general, information indicative of the reproduction time or the position of data related to the reproduction of a disc is stored in a disc information area (TOC area) of a compact disc or a read in area of a digital video disc. Thus, when the disc is played back after the disc starts playing or the disc data is searched, the TOC area or the lead-in area is read to obtain information, and then the corresponding operation is performed.

If you want to replay the data by changing the location where the data is read from such a disc, seek the desired location, move to that location, and play it back. In a compact disc player or DVD ROM driver, the search time is Performance will depend. In particular, since the access time of the feed motor occupies the most time, the system performance can be improved when the access time of the feed motor is accelerated and precise control is achieved.

1 is a block diagram of a conventional DVD ROM driver.

As shown therein, a feed motor 1 for transferring the pick-up module; A magnetic part 2 for generating a corresponding voltage by magnetism that changes according to the rotational operation of the feed motor 1; A position and speed detector (3) for detecting a signal from the magnetic unit (2) with a hall sensor and outputting two sinusoidal signals corresponding to the position and speed of the feed motor; A comparator (4) for outputting two square wave signals output from the position and speed detector (3) as respective square wave signals; A differentiator (5) for obtaining speed information by differentiating a square wave signal output from the position and speed detector (3); A phase shifter (6) for shifting phases so that two Hall sensor signals output from the comparator (4) are synchronized with each other; An adder (7) which adds a signal output from the differentiator (5) and a phase shifted signal so that the phase coincides with the phase shifter (6) to obtain a high precision speed; A deflip-flop (8) for transmitting two square waves output from the comparator (4) as clock signals and input signals, respectively, for use as a forward rotation signal and a reverse rotation signal; A negative AND product 9 for negatively ANDing two square waves output from the comparator 4 to obtain position information; Obtaining the rotation direction information of the feed motor 1 by the signal transmitted from the flip-flop (8) and obtaining the position information by the signal output from the negative logical element 9 to output the desired speed to the adder (11) A central processing unit (10); An adder (11) for selectively outputting a current speed signal output from the adder (7), a speed command signal output from the central processing unit (10) and a feed motor signal for fine adjustment of the feed motor; And a motor driving amplifier 12 for amplifying the output signal of the adder 11 to drive the feed motor 1.

The operation of the general DVD ROM driver configured as described above is as follows.

First, the position and speed detector 3 outputs two Hall sensor signals having a phase difference of 90 ° from the rotated feed motor 1 through the Hall sensor. The comparator 4 then transforms the two sinusoidal signals into a square wave and outputs them, and the phase shifter 6 shifts the phase so that the two sinusoidal signals having a phase difference of 90 ° are phase aligned. The differentiator 5 obtains the speed by differentiating the sinusoidal signal output from the position and speed detector 3, and the adder 7 outputs the signal output from the phase shifter 6 and the signal output from the differentiator 5. Add. This adds up the phase-matched signal, which results in a non-zero speed signal with high accuracy.

The flip-flop 8 receives two square wave signals from the comparator 4 as clock signals and input data, respectively, and transfers them to the central processing unit 10. It is determined whether the rotation direction of 1) is forward rotation or reverse rotation. In addition, the CPU 10 obtains position information of the feed motor 1 by performing negative AND on two square wave signals through the negative logic element 9. Thus, by obtaining the position information, the rotation direction and the speed of the feed motor 1 in hardware, the system configuration becomes complicated, and the system volume becomes large.

Afterwards, the central processing unit 10 moves speed according to the position to which the feed motor 1 is to be moved, so that the control operation of the central processing unit 10 allows the feed motor 1 to approach the corresponding position in the disk. Outputs a signal instructing.

Thus, the adder 11 adds the speed command command signal output from the central processing unit 10 and the current speed signal of the feed motor 1 output from the adder 7 to transmit the motor drive signal to the motor driving amplifier 12. Output Accordingly, the motor driving amplifier 12 drives the feed motor 1 by amplifying the signal output from the adder 11 to a level set so that the feed motor 1 can be driven. Thus, the feed motor 1 is driven at a speed by the speed command command signal of the central processing unit 10.

Such a conventional DVD ROM driver determines the rotation direction of the feed motor through a comparator, a flip-flop, and a negative logic element, and determines the speed of the feed motor through a differentiator, thereby accessing the feed motor to the corresponding position in the disk. It takes a lot of time to reduce the system performance.

In addition, by obtaining the position and speed information of the feed motor in hardware, the system configuration is complicated and the system volume becomes large.

Therefore, the present invention has been proposed to solve the conventional problems as described above, an object of the present invention is to monitor the position of the feed motor using the up-down counter in the central processing unit and to measure the actual speed of the feed motor through the timer Accordingly, the present invention provides a feed motor position and speed control method that improves system performance by shortening a seek time by controlling a position and a speed to be controlled correspondingly.

In order to achieve the above object, the feed motor position and speed control method of the DVD ROM driver according to the present invention reads the position of the feed motor, and calculates the direction difference value to be moved from the current position to the target position. Calculating a position difference value for calculating; A gain value determining step of determining a gain value set to apply a speed control command calculation differently according to the position shift value; When the gain value is determined, the feed motor is moved until the feed motor moves at a high speed to the target position by using a difference between the control speed command value according to the distance to be moved from the speed command conversion table and the actual speed of the feed motor. The method is characterized in that the method consists of a speed command step for commanding a speed control command.

The present invention uses the signal generated by the Hall sensor in the central processing unit to observe the position of the feed motor using the up-down counter, and also measures the actual speed of the feed motor through the timer (duty) duty ratio of the Hall sensor Correspondingly, by controlling the position and the speed to be controlled, the seek time is improved, thereby improving the system performance.

1 is a block diagram of a general DVD ROM driver.

2 is a block diagram of a feed motor position and speed control device of a DVD ROM driver to which the present invention is applied.

3 is a flowchart illustrating a feed motor position and speed control method of a DVD ROM driver according to the present invention.

4 is a flowchart showing a method of controlling the lead-in area movement of the feed motor of FIG.

FIG. 5 is a flow chart for the speed control command command method of FIG.

6 is a timing diagram for calculating a speed of a feed motor using a timer.

7 is a speed command relationship diagram over time for generating a speed command conversion table.

* Explanation of symbols for main parts of the drawings

20: position and speed detection unit 30: comparator

40: central processing unit 50: adder

60: motor drive amplifier 70: feed motor

80: magnetic part

Hereinafter, an embodiment according to the technical concept of the feed motor position and speed control method of the present invention, the DVD ROM driver configured as described above will be described in detail.

First, the configuration of the feed motor position and speed control device of the DVD ROM driver to which the present invention is applied is shown in FIG.

As shown, the comparator 30 for transforming the sinusoidal signal output from the position and speed sensor 20 into a square wave according to the rotation operation of the feed motor 70 and outputs; Counting the signal output from the comparator 30 to the up-down counter to calculate the position information of the feed motor 70, and process the signal output from the comparator 30 with a timer to obtain the speed information of the feed motor 70 After calculating, the central processing unit 40 for controlling the position and the speed of the feed motor 70 with the position information and the speed information; An adder / low pass filter that adds a speed command signal for a high speed movement of the feed motor 70 output from the central processing unit 40 and a feed motor signal for fine adjustment of the feed motor 70 output from the servo chip. 50; The motor output amplifier 60 amplifies a signal output from the adder / low pass filter 50 into a signal capable of driving the feed motor 70.

In addition, the configuration of the feed motor position and speed control method of the DVD ROM driver according to the present invention is shown in FIG.

As shown, the position difference value calculating step (ST11-ST17) which reads the position of the feed motor 70, and calculates the direction difference value which should be moved and the direction from a read current position to a target position; A gain value determining step (ST18-ST22) for determining a gain value set to apply a speed control command calculation differently according to the position shift value; When the gain value is determined, the feed motor 70 is rapidly moved to the target position by using the difference between the control speed command value according to the distance to be moved from the speed command conversion table and the actual speed of the feed motor 70. It consists of speed command steps ST23-ST29 which command the speed control command of the feed motor 70 until it moves.

The position difference value calculating steps ST11 to ST17 may include an initialization step of driving an up-down counter for position control and a timer for speed control and turning on a D / A converter for a speed control command of the feed motor 70 ( ST11-ST13, the position detecting step (ST14) of reading the position of the feed motor 70 using the up-down counter, and comparing the present position with the target position to which the feed motor 70 should be moved. If the forward rotation operation of the feed motor 70 is required to the position, the current position is subtracted from the target position to calculate a position difference value, and if the reverse rotation operation of the feed motor 70 is required to the target position as a result of the comparison, And a difference value calculating step (ST15-ST17) for calculating the position difference value by subtracting the target position from the position.

In the gain value determining step (ST18-ST22), the speed control of the feed motor 70 is optimally set according to the distance to move the gain value required in the control speed calculation process, and the range of the position shift value is included. Determine and determine the set gain value.

The speed command step (ST23-ST29) includes a speed command value reading step (ST23) of reading a control speed command value from a speed command conversion table in which a speed command value corresponding to a moving distance of the feed motor 70 is recorded, A speed command command step (ST24) for calculating a current actual speed of the feed motor 70 by using a timer to command the speed control command of the feed motor 70 with a difference from the speed command value, and the speed control command Read the new current position of the feed motor 70 moved according to the command, calculate the moving direction from the new current position to the target position and the new position difference value to be moved, and if the position difference value is not 0, the speed command value Determining whether or not to perform the speed command to end the speed control command by determining that the movement operation to the target position is completed when the position difference value is 0 and the position difference value is 0 (ST25-ST29). It is composed of

The speed command command step ST24 reads the current position of the feed motor 70, calculates a difference value by subtracting this current position from the position of the feed motor 70 immediately read, and feeds the feed motor. Feed motor force movement test step (ST31-ST32) for checking the forced movement by the external operation of the 70 and the actual speed to obtain the actual speed of the feed motor 70 currently being rotated using the driven timer A command speed calculation step (ST34-) for commanding a speed control command by calculating a command speed for controlling the feed motor 70 according to the measuring step ST33 and the calculated difference value and the rotation direction to be rotated to the target position. ST39).

In addition, the method of moving to the lead-in area of the feed motor 70 includes an initialization step (ST41-ST42) for setting a timer for speed control and turning on the D / A converter for command of speed control command, and the outermost circumference of the pickup section. The innermost movement step (ST43-ST45) which moves to the innermost region and jumps to the lead-in area while delaying the time for moving from the region to the innermost region, and the timer and D / A converter being driven are It consists of a clear step (ST46-ST47) to turn off.

Referring to the operation of the feed motor position and speed control method of the present invention DVD ROM driver as described above is as follows.

First, when power is turned on to a digital video disc player and a play key is input by an external operation, a play operation is performed. At the same time, an up-down counter for determining the current position of the feed motor 70 and a timer for measuring the current speed are driven, and a digital / analog converter (D / A converter) for commanding the speed control command of the feed motor 70 is provided. ) ON (ST11-ST13).

Then, when a key for requesting a data seek (seek time) for the feed motor 70 is input, the central processing unit 40 transmits the feed motor with two Hall sensor signals from the Hall sensor transmitted through the comparator 30. Find out the current position of 70). That is, if the first square wave transmitted through the comparator 30 is detected as a high signal when the rising edge of the clock signal is generated and is detected as a high signal when the falling edge of the clock signal is generated, the up counter increases the counting signal and outputs the centralized signal. The device 40 knows the position of the feed motor 70 and the forward rotation operation. When the square wave transmitted through the comparator 30 is detected as a low signal when the rising edge of the clock signal is generated and is detected as a high signal when the falling edge is generated, the central processing unit 40 reduces the counting signal and outputs the counted signal. The position of 70 and the reverse rotation operation are grasped (ST14).

When the current position of the feed motor 70 is known in this way, the central processing unit 40 determines the desired next data recording position in the disk, that is, the direction of movement to the target position. If the target position is larger than the current position and the forward rotation operation is required, the position difference value is calculated by subtracting the current position from the target position, and the reverse rotation operation of the feed motor 70 is required to the target position because the target position is smaller than the current position. If the target position is subtracted from the current position, a position difference value is calculated (ST15-ST17).

Then, the central processing unit 40 checks the position difference value so that it is not zero (where the position difference value is 0, it means that the current position and the target position of the feed motor 70 are the same). Determine the range that is included. At this time, if the magnitude of the position difference value is greater than 98, the gain value is set to 4 and the gain value is set to 4 so that the speed control is efficiently performed when the distance to be moved is 98 or more. And if the position difference value is in the range of 98 or less and 30 or more, take a gain value set to 3 so that the speed control is performed efficiently when the distance to the target position for the next playback data is 98 or more and 30 or less, and the position difference value In the case of 30 or less, the gain value set to 2 is taken to effectively control the speed in this range (ST18-ST22). (At this time, divided into the range of 98 or more, 98 or less, 30 or more, and 30 or less makes speed control more efficient. By the division of gains set to

When the gain value required in the control speed calculation process is determined according to the range in which the position difference value is included, the speed command conversion table in which the speed command value according to the movement distance of the feed motor 70 is recorded is applied to the current position difference value. The corresponding control speed command value is read (ST23).

Here, the speed command conversion table records the speed command value of Y according to the movement control time of X, as shown in FIG. In this way, X is the speed control time according to the movement to the target position, Y is the 8-bit command value of 0 to 255 speed, x is the current of the feed motor 70 moving to the target position. Represents the control time and y represents the control speed according to the moving distance. The remaining distance, that is, the remaining area S, of the distances to be moved from the current position to the target position is expressed by the following Equation 1.

Since the relationship between the remaining distance of the moving feed motor 70 and the moving distance to the target position is X: x = Y: y, it becomes x = (Xy) / Y. Becomes

Thus, the control speed for the remaining distance to move is Eq.

In this way, the control speed for each of the distances to be moved, that is, the control time, of the feed motor 70 is determined to generate the speed command conversion table.

When the gain value and the speed command value to be controlled are obtained according to the range to which the position shift value belongs, the speed to the target position is calculated and the speed control command is commanded (ST24).

Thus, when a method of commanding the speed control command is explained, the current position of the feed motor 70 is read and the difference is calculated by subtracting the current position of the feed motor 70, which is the position movement under the control of the central processing unit 40. This is to check whether the position of the feed motor 70 is moved due to an external malfunction or a user mistake (ST31-ST32).

And the central processing unit 40 uses the timer to determine the current position of the feed motor 70. That is, as shown in FIG. 6, the square wave transmitted from the comparator 30 is counted as a clock signal having a period of 2.37 ms to read the counting value in every state of the square wave in the timer. Thus, the counting value is only read in every state, thus saving the time consumed by reading, clearing, and restarting the counting value. The current speed of the feed motor 70 can be obtained by calculating the count value and the 2.37 ms period thus read (ST33).

When the result of the position movement inspection result by the operation of the feed motor 70 and the actual speed of the feed motor 70 are obtained, the command speed of the feed motor is obtained accordingly. That is, the difference between the speed command of the feed motor 70 to be controlled read from the speed command conversion table and the actual speed of the feed motor 70 is calculated, and the speed change command corresponding to the difference is commanded to determine the speed of the feed motor 70. The speed is the speed command value recorded in the speed command conversion table. At this time, if there is no position movement of the feed motor 70 by the external operation, and the forward rotation operation to the target position is requested, the command speed is as follows.

Command Speed = Stop Voltage + (Speed Command-Actual Speed) * Gain.

(Stop voltage: voltage controlling the feed motor 70 to stop, speed command: speed corresponding from the speed command conversion table, actual speed: actual speed, gain: position of the feed motor 70 obtained using the timer. Gain set so that the speed control is performed efficiently according to the range of the moving value.) (ST34-ST35).

In addition, if there is no position movement of the feed motor 70 by external operation, and the reverse rotation operation to the target position is required, the command speed is a stop voltage-(speed command-actual speed) * gain (ST37). When the position of the feed motor 70 is moved by an external operation and forward rotation operation is required, the command speed becomes a stop voltage + (speed command + actual speed) * gain (ST36), When the position of the feed motor 70 is moved and the reverse rotation operation is required, the command speed is a stop voltage-(speed command + actual speed) * gain (ST38).

When the command speed of the feed motor 70 is obtained in this way, the central processing unit 40 commands a speed control command to the D / A converter to generate a speed difference change by this command speed, which is recorded in the speed command conversion table. The feed motor 70 is rotated in the same manner as the speed command value (ST39).

Then, when the feed motor 70 is changed in position and speed by the control of the central processing unit 40, the central processing unit 40 uses the up-down counter to grasp the new current position of the changed feed motor 70. (ST25). Then, the moving direction from the new current position to the target position and the new position difference value to be moved are calculated (ST26-ST28). Thus, since this position difference value check result is not 0, the speed command value corresponding to the new position difference value is read again from the speed command conversion table (ST23). And the actual speed of the feed motor 70 of the new current position is determined using a timer. Thus, the moving speed to the target position is calculated using the determined gain value, the speed command value to be controlled and the actual speed information to command the speed control command (ST24).

In this way, the position difference value according to the movement of the feed motor 70 is continuously calculated, and the speed command value and the feed in the speed conversion table until the position difference value becomes 0, that is, until the movement operation to the target position is completed. The speed control command is commanded according to the difference value from the actual speed of the motor 70. Thus, when the position difference value is 0, it is determined that the movement operation to the target position is completed, and the speed control command is terminated.

Meanwhile, when the disc reproducing operation is performed, the feed motor 70 is moved to the lead-in area of the disc to read information on data reproduction. A method of controlling the movement to the lead-in area of the feed motor will be described. After setting the timer for speed control and turning on the D / A converter, the feed motor 70 is driven to move the pickup to the innermost region (ST41-ST43). Then, the time required for moving from the outermost region to the innermost region of the feed motor is delayed and controlled to jump to the lead-in region (ST44-ST45). When the feed motor 70 is moved to the lead-in area in this manner, the driven timer and the D / A converter are turned off (ST46-ST47).

Since the target position approach operation of the feed motor 70 is made in software, the present invention improves system performance by making the search operation quickly.

The present invention can be applied to feed motor position and speed control of a compact disc player, a digital video disc player, and a compact disc ROM driver.

It is also applicable to the case where the friction coefficient is generated in the load in DC motor control.

As described above, the feed motor position and speed control method of the DVD ROM driver according to the present invention, by using the up-down counter in the central processing unit to observe the position of the feed motor and to measure the actual speed of the feed motor through the timer Correspondingly, by controlling the position and the speed to be controlled, the seek time is improved, thereby improving the system performance.

In addition, by measuring the position and speed of the feed motor in software in the central processing unit, there is no need for a hardware device for calculating the position and speed of the existing feed motor, thereby simplifying the system configuration.

In addition, the speed control command calculation is applied differently according to the position shift value from the search start position of the feed motor to the target position for the next reproduction data.

Claims (5)

A position difference value calculating step (ST11-ST17) of reading the position of the feed motor 70 and calculating a direction difference value to be moved and a direction from the read current position to the target position; A gain value determining step (ST18-ST22) for determining a gain value set to apply a speed control command calculation differently according to the position difference value; When the gain value is determined, the feed motor 70 is rapidly moved to the target position by using the difference between the control speed command value according to the distance to be moved from the speed command conversion table and the actual speed of the feed motor 70. And a speed command step (ST23-ST29) for commanding a speed control command of the feed motor 70 until it is moved. The D / A converter according to claim 1, wherein the position difference value calculation steps ST11 to ST17 drive an up-down counter for position control and a timer for speed control, and a D / A converter for a speed control command of the feed motor 70. Initialization step (ST11-ST13) to turn on, the position detection step (ST14) for reading the position of the feed motor 70 by using the up-down counter, and the obtained current position and the feed motor 70 to be moved When the forward rotation operation of the feed motor 70 is required to compare the target positions to the target position, the position difference value is calculated by subtracting the current position from the target position, and the reverse rotation of the feed motor 70 to the target position is performed as a result of the comparison. When the operation is required, the feed motor position and speed control method of the DVD ROM driver, characterized in that it comprises a difference value calculating step (ST15-ST17) to calculate the position difference value by subtracting the target position from the current position. 2. The speed command value reading according to claim 1, wherein the speed command steps (ST23-ST29) read a control speed command value from a speed command conversion table in which a speed command value corresponding to a movement distance of the feed motor 70 is recorded. Step command ST23 and a speed command command step ST24 for calculating a current actual speed of the feed motor 70 using a timer to command a speed control command of the feed motor 70 with a difference from the speed command value. And reading the new current position of the feed motor 70 moved according to the speed control command command, calculating the direction of movement from the new current position to the target position and the new position difference value to be moved, so that the position difference value is If it is not 0, the speed command value reading step ST23 is performed. If the position difference value is 0, it is determined that the movement operation to the target position is completed and the speed command for terminating the speed control command is performed. The feed motor position and speed control method of the DVD ROM driver, characterized in that the decision step (ST25-ST29). 4. The speed command command step (ST24) according to claim 3, wherein the speed command command step (ST24) reads the current position of the feed motor 70, and makes a difference by subtracting the current position from the position of the feed motor 70 immediately read. A value of the feed motor forced movement test step ST31-ST32 which calculates a value and checks whether the feed motor 70 is forcibly moved by an external manipulation of the feed motor 70, and the feed motor 70 currently being rotated using a driven timer. An actual speed measurement step (ST33) for obtaining an actual speed, a command speed for controlling the feed motor 70 according to the calculated difference value and the rotation direction to be rotated to the target position, and a command for commanding a speed control command; Feed motor position and speed control method of the DVD ROM driver, characterized in that the speed calculation step (ST34-ST39). The method of claim 1, wherein the method of moving to the lead-in area of the feed motor 70 comprises: an initialization step of setting a timer for speed control and turning on a D / A converter for speed control command command (ST41-ST42). And an innermost movement step (ST43-ST45) for moving to the innermost region and jumping to the lead-in area while delaying the time for moving from the outermost region to the innermost region of the pickup section, and a timer being driven. And a clear step of turning off the D / A converter (ST46-ST47).