JPH076523A - Positioning device - Google Patents

Abstract

PURPOSE:To avert the inadequacy of positioning control in consequence of use of an erroneously detected speed (or position) at the time of executing positioning control. CONSTITUTION:This positioning device has a control section 105 which controls a control object 101 (reading head driving motor) by calculating a controlled variable in accordance with the difference between the target speed determined by the detection position detected by a speed detecting section 103 and a target position and the detection speed of a reading head detected by a speed detecting section 102. The positioning device described above has an estimation section 106 which is inputted with the controlled variable and the detection position or detection speed, estimates the present position of the reading head or the present speed of the reading head and outputs the estimated value and a judgment section 107 which compares the detection position or detection speed and the estimated value and judges the detection position or detection speed as an abnormal value if the difference is larger than the prescribed value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device for performing high-speed and highly accurate positioning control of a read head in an ODD (optical disk device), an HDD (hard disk device), or a drive unit in a robot. The present invention relates to a feedback control type positioning device that detects speed and position and performs control calculation.

[0002]

2. Description of the Related Art In ODD (optical disk device) and HDD (hard disk device), when accessing a target track of a disk, it is necessary to move an optical head (reading head) to the target track at high speed and accurately. Generally, as a method of controlling the movement of the read head,
The target speed profile is set in advance, the current position and moving speed of the optical head are detected, the difference (residual distance) between the current position and the target position is input, and the target speed is set according to the target speed profile. The calculated target speed and the detected moving speed are input, predetermined control calculations are performed, the control amount is calculated, and follow-up control is performed so that the moving speed becomes equal to the target speed. In the vicinity of the target track,
Switch from the speed control by the target speed profile until then to the position control to the target track position, or
By changing the target speed profile, high-speed and highly accurate positioning control is performed.

[0003]

However, according to the conventional positioning device, although the current position and the moving speed of the optical head are detected and the control amount is calculated using the detection result, noise and detection system False detection may occur due to accuracy. Therefore, when the control amount is calculated using the erroneously detected data, an abnormal control amount is given, so that not only high-speed and highly-accurate positioning control cannot be performed but also a runaway is caused. There was a point.

It is desirable that the above-mentioned erroneous detection can be removed at the detected stage. However, in order to remove the erroneous detection at the detected stage, the inconvenience of increasing the cost of the apparatus and the tentative detected stage will occur. Even if it is configured to be removed, there is still a possibility that erroneous detection may occur depending on the use environment or changes over time.

The present invention has been made in view of the above, and the positioning control becomes inaccurate due to the use of an erroneously detected speed (or position) when performing the positioning control. The purpose is to avoid.

Further, the present invention has been made in view of the above, and is to enable high-speed and highly-accurate positioning control even when erroneous detection occurs in the detection of the current position and the moving speed of the read head. With the goal.

[0007]

In order to achieve the above object, the present invention provides a target speed determined based on a detection position detected by a predetermined speed detecting means and a target position, and a predetermined speed detecting means. In a positioning device having a control means for calculating a control amount based on a difference between the detected detection speed of the read head and controlling the read head drive motor, the control amount and the detected position or the detected speed are input to read the read head. Of the present position or the current speed of the read head and outputs an estimated value, and compares the detected position or the detected speed with the estimated value. If the difference is larger than a predetermined value, the detected position or (EN) A positioning device provided with a judging means for judging a detected speed as an abnormal value.

In order to achieve the above object, the present invention also provides a target speed determined based on a detection position detected by a predetermined speed detecting means and a target position, and a reading head detected by the predetermined speed detecting means. In the positioning device having the control means for controlling the read head drive motor, the control amount is calculated based on the difference between the detected speed and the detected speed, and the previously detected value storage means stores the previously detected position or the detected speed as the previously detected value. And the detected position or detected speed and the previously detected value stored in the previously detected value storage means are compared, and if the difference is larger than a predetermined value, it is determined that the detected position or detected speed is an abnormal value. And a positioning device provided with the means.

If the judgment means judges that the value is an abnormal value, the control means calculates the control amount using the estimated value or the previously detected value.

Further, the judging means stores the occurrence position and the number of occurrences of the abnormal value at that time when judging the abnormal value,
If it is determined that the abnormal value has occurred a predetermined number of times or more at the same occurrence position, a warning is given through a predetermined warning means.

[0011]

The positioning device of the present invention obtains an estimated value based on the control amount and the detected position or the detected speed, and when the difference between the detected position or the detected speed and the estimated value is larger than a predetermined value, the detected position is detected. Alternatively, the detected speed is determined to be an abnormal value. In the case of an abnormal value, the estimated value is used to calculate the control amount of the read head drive motor.

Further, the positioning device of the present invention determines that the difference is the abnormal value when the difference between the detected position or detected speed and the previously detected value (previous detected position or detected speed) is larger than a predetermined value. In the case of an abnormal value, the control value of the read head drive motor is calculated using the previously detected value.

Further, the positioning device of the present invention issues a warning when an abnormal value occurs at the same position a predetermined number of times or more.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The positioning device of the present invention will be described below in detail in the order of [Embodiment 1] and [Embodiment 2] with reference to the drawings.

[Embodiment 1] Generally, in the positioning control, since the control is performed by using the detection position and the detection speed, the detection position and the detection speed must be accurate.
Therefore, in the first embodiment, the control is performed in consideration of the error in the detection position and the detection speed.

FIG. 1 is a block diagram showing the configuration of a positioning device according to the first embodiment. A control object 101 showing a read head and a drive motor for driving the read head, and a moving speed of the control object 101 (drive motor). , A position detection unit 103 for detecting the current position of the controlled object 101, a target speed v _ref, and an actual speed v described later.
A comparator 104 that compares (the detected speed v _K or the estimated speed v ₀ ) to obtain the difference, and a controller that controls the controlled object 101 by obtaining the control amount u based on the comparison result of the comparator 104. 105, the control amount u obtained by the control unit 105, and the detection speed v detected by the speed detection unit 102.
Type and _K, the estimating unit 106 estimates and outputs the estimated velocity v _0, enter the the detected speed v _K and estimated velocity v _0, whether the detected velocity v _K is whether abnormal value is a normal value Of the detection speed v _K or the estimated speed v ₀ as the actual speed v and the detection position s detected by the position detection unit 103 are referred to, and at the same position a predetermined number of times or more. The determination unit 107 includes a warning unit 108 that issues a warning when the detected speed v _K is determined to be an abnormal value. Any method may be used as the warning method of the warning unit 108, for example, a warning may be given by lighting an LED (light emitting diode).

The operation of the above arrangement will be described.
First, a general control operation will be described. Comparator 10
4, the target speed v _ref and the actual speed v described later are compared to obtain a speed difference, and the obtained speed difference is input to the control unit 105. The control unit 105 receives the input speed difference (target speed v
Based on (difference between _ref and actual speed v), a controlled variable u is calculated by a predetermined calculation, and the controlled variable 1 is calculated using the calculated controlled variable u.
01 (drive motor) is controlled. The target speed v
_{The ref} is calculated by a known technique, and the calculation method is not particularly limited. For example, the _ref is referred to a predetermined target velocity profile based on the difference between the current position of the controlled object 101 and the moving target position. The target speed v _ref should be calculated.

Next, the estimation unit 10 which is a feature of the present invention.
6, the operation of the determination unit 107 and the warning unit 108,
This will be described in detail with reference to the flowchart of FIG. Figure 2
3 is a flowchart showing a control operation of the first embodiment.
First, the estimation unit 106 determines the control amount u obtained by the control unit 105 and the detected speed v _K detected by the speed detection unit 102.
, And the estimated speed v ₀ is estimated and output. In addition,
As an estimation method by the estimation unit 106, for example, a Kalman filter or the like may be used to remove noise from the control amount u and the detected velocity v _K to estimate the velocity. continue,
The determination unit 107 first obtains a difference (hereinafter referred to as C) between the detected speed v _K and the estimated speed v ₀ (S201), and compares the obtained difference C with a predetermined value (hereinafter referred to as S). (S2
02), when C is smaller than S, the detected speed v _K is determined to be a normal value (S203), the actual speed v = the detected speed v _K (S204), and the actual speed v is output to the comparator 104 (S204). S205). Therefore, when the difference (C) between the detected speed v _K and the estimated speed v ₀ is smaller than the predetermined value (S), the detected speed v _K is output to the comparator 104.

On the other hand, if C is larger than S in S202, the judgment unit 107 judges that the detected speed v _K is an abnormal value (S206). At this time, the judgment unit 107 refers to the detection position s detected by the position detection unit 103, and judges the judgment unit 1
The location and the number of occurrences of abnormal values are stored in a storage unit (not shown) in 07 (S207). Subsequently, the determination unit 107 refers to the stored place and the number of occurrences of the abnormal value, determines whether or not the abnormal value has occurred a predetermined number of times or more at the same position (S208), and generates the abnormal value. If so, a warning of a disk error is issued via the warning unit 108 (S209).

If the abnormal value has not occurred a predetermined number of times or more in S208, or the judgment unit 107 determines in S209.
After the end of the warning, the actual speed v = the estimated speed v ₀ (S2
10), output the actual speed v to the comparator 104 (S20)
5). Therefore, when the difference (C) between the detected speed v _K and the estimated speed v ₀ is larger than the predetermined value (S), the estimated speed v ₀ is output to the comparator 104.

As described above, according to the first embodiment, the function of estimating the speed is provided, and when the difference between the estimated speed and the detected speed is a predetermined value or more, the detected speed is determined as an abnormal value. Therefore, it can be recognized that the speed detection is an erroneous detection. Therefore, it is possible to prevent the positioning control from being inaccurate due to the use of the erroneously detected speed when performing the positioning control.

Further, when the detected speed is judged to be an abnormal value, the estimated speed is used instead of the detected speed to perform the positioning control, so that the erroneously detected speed is not used. High-speed and accurate positioning control can be performed by obtaining the control amount.

Further, the position where the abnormal value is detected is stored, and when the abnormal value is detected at the same position a predetermined number of times or more,
Since the warning function is provided, the disk abnormality can be detected without providing a special function for detecting the disk abnormality.

In the first embodiment, the speed of the controlled object 101 is estimated and the control is performed in consideration of the error of the detected speed v _K using the estimated speed v _0. However, instead of estimating the speed, the position The estimation may be performed, and the control may be performed in consideration of the error of the detection position s using the estimated position, and the same effect as that of the first embodiment can be obtained.

In general, in positioning control,
In the vicinity of the target position, the speed control may be switched to the position control from the target position.
Function for estimating the position of 01 (estimating unit for obtaining the estimated position)
By providing, it is possible to perform control in consideration of the error of the detection position s.

[Second Embodiment] A positioning device according to the second embodiment is
Instead of the estimated speed v ₀ used for the control of the first embodiment, the detection speed v _K (previous detection speed v _K−1 ) detected by the speed detection unit 102 in the previous positioning control is used for positioning. It controls.

FIG. 3 is a block diagram showing the configuration of a positioning device according to the second embodiment, and the same reference numerals as those in FIG. 1 denote the first embodiment.
The same as above, and the description is omitted. Note that 301 represents a storage unit for storing the detected speed v _K detected by the speed detecting unit 102, the detected speed v _K (prior to detection speed detected by the speed detecting unit 102 during their last positioning control v
_K-1 ) is output to the determination unit 107, and after the previous detection speed v _K-1 is output, the detection speed v _K detected by the speed detection unit 102 during the current positioning control is stored. Further, the storage unit 301 outputs the detected speed v _K stored in the current positioning control to the determination unit 107 in the next positioning control.

The operation of the above configuration will be described.
The operation of the positioning device of the second embodiment is basically the same as that of the first embodiment.
The operations of the different parts will be described in the same manner as the operations of the positioning device of FIG.

The operations of the judgment unit 107 and the warning unit 108 will be described with reference to the flowchart of FIG. In the figure, steps S202 to S209 perform the same operation as that of the first embodiment (the flowchart of FIG. 2).

The judging section 107 first determines the speed detecting section 102.
Obtains a difference between the detected velocity v _K-1 before output from the detection speed v _K a storage unit 301 which is detected (hereinafter referred to as C) by (S401), if C is less than S, the judgment unit 107 performs the processing of S202 to S205 similarly to the first embodiment. That is, the determination unit 107 determines that the detection speed v
_When the difference (C) between _K and the previous detection speed v _K−1 is smaller than the predetermined value (S), the detection speed v _K is output to the comparator 104.

On the other hand, if C is larger than S in S202, the judgment unit 107 performs S206 as in the first embodiment.
The process from S209 to S209 is performed, and if the abnormal value has not occurred a predetermined number of times or more in S208, or after the warning in S209 ends, the determination unit 107 determines the actual speed v = the previous detected speed v _K-1.
(S402), the actual speed v is output to the comparator 104 (S205). That is, the determination unit 107 determines that the difference (C) between the detected speed v _K and the previous detected speed v _{K- 1} is a predetermined value (S).
If it is larger, the previous detection speed v _K-1 is compared with the comparator 104.
Output to.

As in the first embodiment, in the second embodiment,
If a function for storing the detected position s of the controlled object 101 is provided, it is possible to easily perform control in consideration of the error of the detected position s. Further, in the vicinity of the target position, the position from the speed control to the target position can be easily controlled. Even when the control is switched to the control, the control can be performed in consideration of the error of the detection position s.

As described above, according to the second embodiment, the same effect as that of the first embodiment is obtained, and further, the detected speed v _K is compared with the previous detected speed v _K−1, and the detected speed v _K is a normal value. Since it is determined whether it is an abnormal value or not, even if an erroneous detection occurs in the detection of the current position and the moving speed of the read head, the configuration is relatively simple (simpler than that in the first embodiment) and high speed and high accuracy. It is possible to perform various positioning controls.

[0034]

As is apparent from the above, according to the positioning device of the present invention, the target speed determined based on the detection position detected by the predetermined speed detecting means and the target position and the predetermined speed detecting means detect the target speed. In a positioning device having control means for calculating a control amount based on the difference between the detected speed of the read head and the read head drive motor, the control amount and the detected position or the detected speed are input to read the read head. An estimation unit that estimates the current position or the current speed of the read head and outputs an estimated value is compared with the detected position or the detected speed and the estimated value. If the difference is larger than a predetermined value, the detected position or the detected value is detected. Since it has a judgment means for judging the speed as an abnormal value,
It is possible to prevent the positioning control from becoming inaccurate due to the use of the erroneously detected speed (or position).

According to the positioning device of the present invention, the target speed determined based on the detection position and the target position detected by the predetermined speed detecting means, and the detection speed of the read head detected by the predetermined speed detecting means. In a positioning device having a control means for controlling the read head drive motor by calculating the control amount based on the difference between The position or the detected speed is compared with the previously detected value stored in the previously detected value storage means, and when the difference is larger than a predetermined value, a judgment means for judging the detected position or the detected speed as an abnormal value is provided. Since it is equipped, the speed (or position) erroneously detected when performing positioning control
It can be avoided that the positioning control becomes inaccurate due to the use of.

Further, according to the positioning device of the present invention, when the judgment means judges that the value is an abnormal value, the control means is
Since the control amount is calculated using the estimated value or the previously detected value, it is possible to perform high-speed and highly-accurate positioning control even if erroneous detection occurs in the detection of the current position and movement speed of the read head. .

Further, according to the positioning device of the present invention, the judging means stores the occurrence position and the number of times of occurrence of the abnormal value at that time when judging the abnormal value, and determines that the abnormal value is equal to or more than the predetermined number at the same occurrence position. If determined, the warning is given through a predetermined warning means, so that the disk abnormality can be detected without providing a special function for detecting the disk abnormality.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of a positioning device according to a first embodiment.

FIG. 2 is a flowchart showing a control operation of the first embodiment.

FIG. 3 is a block diagram showing a configuration of a positioning device according to a second embodiment.

FIG. 4 is a flowchart showing a control operation of the second embodiment.

[Explanation of symbols]

101 Control Target 102 Speed Detection Unit 103 Position Detection Unit 105 Control Unit 106 Estimating Unit 107 Judgment Unit 108 Warning Unit 301 Storage Unit

Claims (4)

[Claims] 1. A control amount based on a difference between a target speed determined based on a detection position and a target position detected by a predetermined speed detection unit and a detection speed of a read head detected by a predetermined speed detection unit. In a positioning device having a control means for calculating and controlling the read head drive motor, the control amount and the detected position or the detected speed are input and the current position of the read head or the current speed of the read head is estimated and estimated. An estimation unit that outputs a value and a determination unit that compares the detected position or the detected velocity with the estimated value and, if the difference is larger than a predetermined value, determines the detected position or the detected velocity as an abnormal value. A positioning device comprising: 2. The control amount is based on the difference between the target speed determined based on the detection position and the target position detected by the predetermined speed detection means and the detection speed of the read head detected by the predetermined speed detection means. In a positioning device having control means for calculating and controlling a read head drive motor, a previously detected value storage means for storing a previously detected position or detected speed as a previously detected value, the detected position or detected speed and the previously detected value. It is characterized by further comprising: determination means for comparing the previously detected value stored in the value storage means and, if the difference is larger than a predetermined value, determining the detected position or the detected speed as an abnormal value. Positioning device. 3. The control means calculates a control amount by using the estimated value or the previously detected value when the determination means determines that the value is an abnormal value.
Or the positioning device according to 2. 4. The judgment means stores the occurrence position and the number of times of occurrence of the abnormal value at the time of judging the abnormal value, and when it is judged to be the abnormal value for a predetermined number of times or more at the same occurrence position, The positioning device according to claim 1, 2 or 3, wherein a warning is given through a predetermined warning means.