JP2904844B2 - Screw adjusting device and screw adjusting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to, for example, a video tape recorder (hereinafter referred to as a VTR).
The present invention relates to a screw adjustment device and a screw adjustment method for adjusting the position with high speed and high accuracy by tilting the head with the tip of a screw like a magnetic head such as a magnetic head.

[Prior Art] Conventionally, tilt adjustment using a screw mechanism largely depends on human sensation and sight, and there is an increasing demand for a screw adjustment device that is automated at high speed and with high precision.

Hereinafter, as an example, a description will be given of a conventional example of automation of position adjustment by tilting of a head fastened on a cylinder of a VTR.

FIG. 6 is a sectional view of a main part of a head adjusting unit for fastening a head of a VTR cylinder and performing a tilt adjustment.

In FIG. 6, 1 is a rotary cylinder, 2 is a head base fastened to the rotary cylinder 1, 3 is a head chip on the head base 2, and 4 is a head cylinder on the rotary cylinder 1.
Screw 5 is pushed down the head base 2,
6 is a bit that transmits rotation to the screw.

In the head adjustment unit configured as described above, the initial position of the head chip 3 in the rotation axis direction of the rotary cylinder 1 is detected by visual recognition, and if there is a difference from a predetermined position, the screw 5 is fixed by an electric motor or the like. And the position moved by visual recognition is detected, and the above operation is repeated until the position is within an allowable range for a predetermined position.

Before removing the bit 6, it is necessary to reversely rotate the bit 6 by an amount equal to or less than the backlash so as not to squeeze the screw 5. At this time, the position of the head chip 3 is changed by releasing the screw 5 from the pressing from the bit 6 (hereinafter, this change is referred to as springback). If they were out of range, they had to re-adjust.

[Problems to be Solved by the Invention] However, in the method of the related art, since the adjustment amount is very small, the rotation amount per one step is also small. However, there is a problem that a large number of steps are required, and a very long time is required.

Furthermore, since the spring back has a large variation,
As a result, the ability to follow the target is degraded, and in severe cases, the robot may enter an infinite loop.

SUMMARY OF THE INVENTION An object of the present invention is to provide a screw adjusting device with visual recognition provided with a screw feed amount calculating means capable of performing high-speed and high-accuracy tilt adjustment in order to solve the above-mentioned problems of the prior art.

[Means for Solving the Problems] In order to achieve the above object, a screw adjusting device of the present invention comprises:
A screw adjustment device for adjusting the position of the target member by lifting the target member that contacts the screw,
The screw adjustment device is a positioning control unit that outputs a rotation command to a position instructed based on a rotation detection signal, an imaging unit, and processes a video signal from the imaging unit to measure a position of the target member. A visual recognition unit, a screw feed amount calculating unit that determines a feed amount to be a predetermined position based on position information from the visual recognition unit, and the positioning control unit based on the determined feed amount. The screw feed amount calculating means includes a screw feed amount until the target member enters the coarse adjustment completion range, and a screw feed amount until the target member enters the fine adjustment completion range. Determine the amount, after entering the fine adjustment completion range, reverse rotation of the bit by less than the backlash between the screw and the bit that transmits rotation to the screw, based on the position information of the target member, Previous And determining whether to further adjust the screws.

Further, the screw adjustment method of the present invention is a screw adjustment method for adjusting the position of the target member by lifting a target member that comes into contact with the screw. A coarse adjustment step of rotating the screw until it enters a completion range; a fine adjustment step of rotating the screw until it enters the coarse adjustment completion range after the target member enters the coarse adjustment completion range; and After entering the fine adjustment completion range, the bit is reversely rotated by less than the backlash between the screw and the bit transmitting rotation to the screw, and it is determined whether the target member is within the target allowable range. And a reverse rotation step.

[Operation] According to the present invention, the screw is rotated by the electric motor and the position of the head chip is changed by the screw lifting the head base, and the position information of the head chip detected by visual recognition and the influence of springback are provided. The position control can be performed at high speed and with high accuracy by using an efficient screw feed amount calculating means based on the above.

Embodiment A screw adjusting device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a screw adjusting device according to one embodiment of the present invention.

In FIG. 1, 7 is a main body, 8 is a head base fastened to the main body 7, 9 is a head chip on the head base 8, 10
Is a screw that fastens the head base 8 to the main body 7, 11 is a screw that pushes down the head base 8 and creates a tilt, 12 is a bit that is inserted into the screw 11 and transmits rotation to this, and 13 is a screw that is inserted through the bit 12. The electric motor to rotate, 14 is the electric motor 13
A rotation detector 15 for detecting the rotation state of the motor; 15 is a positioning control means for accumulating the signal of the rotation detector 14 and a command signal; 16 is a motor driving means for driving the electric motor 13 according to an instruction of the positioning control means 15; An image section for imaging the chip 9, a visual recognition section 18 for processing a video signal from the imaging section 17 and measuring the position of the head chip 9, and a position 19 and a springback amount of the head chip 9 from the visual recognition section 18. The screw feed calculating means 20 for determining the amount of tilt of the screw 11 with respect to the target value, based on the amount of tilt determined by the screw feed amount calculating means 19, gives a command to the positioning control means 15 to Command control means for controlling the

The operation of the screw adjusting device configured as described above and the details of the screw feed amount calculating means 19 will be described below with reference to FIGS. 2, 3, 4, and 5.

First, the visual recognition unit 18 measures the initial position of the head chip 9, determines the amount of tilt with respect to the target value, and performs the coarse adjustment by rotating the motor 13 by the amount of pulse corresponding to the amount of tilt. Repeat until the adjustment is completed. Next, the process proceeds to fine adjustment. Here, rotation is performed by a predetermined pulse amount, and the process is repeated until the fine adjustment is completed.

If it enters the fine adjustment completion range, reversely rotate the bit 12 by the amount equal to or less than the backlash with the screw 11.If it is within the target allowable range, the adjustment is completed.If not, predict the effect of springback, The temporary target value is set, the amount of tilt is determined, and the process returns to the coarse adjustment or the fine adjustment to continue the adjustment. This flowchart is shown in FIG. 2, and the operation chart is shown in FIG.

Next, an algorithm for setting a temporary target value will be described. Here, the position when the head chip 9 enters the fine adjustment completion range with respect to the primary provisional target is set to H1, the height after springback is set to H1 ', the springback amount is set to SP1, the original target values are Mo, The i-th temporary target value is set to M1.

 SP1 is represented by the following equation.

SP1 = H1'-H1 The basic method of determining the tentative target is to shift the previous springback amount by a predetermined amount. However, since it is easy to make the same turn, in this embodiment, the past two springback amounts SPn- 2. Set in consideration of SPn-1.

Also, at the height after the last two springbacks, if one is above the upper limit of the target range and the other is below the lower limit of the target range, the tentative target position will be between the positions before applying each springback. Since it is expected that there is a position Hn-2, Hn before applying the past two springbacks
The positions Hn-2 'and Hn-1' after being multiplied by -1 were set in consideration of the positions.

When the above contents are expressed by a mathematical expression with the upper and lower limits of the target range as U and L, respectively, when Hn2 ′, Hn−1 ′ ≦ L or Hn−2 ′, Hn−1 ′ ≧ U, Mn = f ( SPn-2, SPn-1) ... In the case of Hn-2 '> L, Hn-1'<U or Hn-2 '<L, Hn-1'> U, Mn = g (Hn-2, Hn-1) , Hn'-2, Hn'-1) In this example, the formula was embodied as follows.

FIGS. 4 and 5 show the operation charts described above.

As described above, according to one embodiment of the present invention, the screw 11 that is screwed to the main body, the tool (bit 12) that transmits rotation to the screw 11, and the screw 11 that is attached to the main body,
A target member (head chip 9) whose position is adjusted by contacting with a motor, an electric motor 13 that rotationally drives the tool (bit 12), and a driving unit 16 that drives the electric motor 13.
The rotation detecting means 14 attached to the electric motor 13, the positioning control means 15 which receives a signal from the rotation detecting means 14 and outputs a rotation command to a designated position, and images the target member (head chip 9). An imaging unit 17 for processing a video signal from the imaging unit 17;
Visual recognition unit 18 for measuring the position of the screw, position information from the visual recognition unit 18, the screw 11 and the tool (bit 12)
Screw feed amount calculating means 19 for determining a feed amount so as to be at a predetermined position based on behavior information based on contact with
And the positioning control means based on the determined feed amount.
15 and command control means 20 for giving a command to
By switching from the coarse adjustment to the fine adjustment, and further performing the adjustment by predicting the influence of the springback, high-speed and high-accuracy position adjustment can be performed.

[Effects of the Invention] As described above, the present invention predicts the influence of the switching from coarse adjustment to fine adjustment and the effect of springback on the positioning control based on the information from the recognition device using the screw feed amount calculating means. Thus, an excellent effect that high-precision positioning by screw tilt can be performed at high speed can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a screw adjusting device according to one embodiment of the present invention, FIG. 2 is a flowchart of an adjusting operation in this embodiment, FIGS. 3 to 5 are operation charts thereof, and FIG. It is principal part sectional drawing of the head adjustment part of a prior art. 7 ... body, 8 ... head base, 9 ... head chip, 10 ... screw, 11 ... screw, 12 ... bit, 13 ... electric motor, 14 ... rotation detector, 15 ... positioning control means , 16
... Electric motor drive means, 17 ... Imaging unit, 18 ... Visual recognition unit, 19 ... Screw feed amount calculation means, 20 ... Command control means.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/53

Claims (4)

(57) [Claims] 1. A screw adjusting device for adjusting the position of a target member by lifting a target member that comes into contact with a screw, wherein the screw adjusting device is configured to move to a position designated based on a rotation detection signal. Positioning control means for outputting a rotation command, an imaging unit, a video recognition unit that processes a video signal from the imaging unit and measures the position of the target member, and based on position information from the visual recognition unit. A screw feed amount calculating means for determining a feed amount so as to be at a predetermined position; and a command control means for giving a command to the positioning control means based on the determined feed amount. Determines the screw feed amount until the target member enters the coarse adjustment completion range, and the screw feed amount until the target member enters the fine adjustment completion range. Screw and front A screw adjusting device that reversely rotates the bit by an amount equal to or less than a backlash with a bit that transmits rotation to the screw, and determines whether to further adjust the screw based on positional information of the target member. . 2. A screw adjustment method for adjusting the position of the target member by lifting the target member that contacts the screw, wherein the screw adjustment method is performed until the target member enters a coarse adjustment completion range. A coarse adjustment step of rotating the screw; a fine adjustment step of rotating the screw until the target member enters the coarse adjustment completion range after entering the coarse adjustment completion range; and After entering, a reverse rotation step of reversely rotating the bit by less than the backlash between the screw and the bit transmitting rotation to the screw, and determining whether the target member is within a target allowable range. A screw adjustment method comprising: 3. When the target member does not fall within the target allowable range, the amount of springback of the target member caused by the release of the screw from the pressing of the bit is predicted to set a tentative target value. 3. The screw adjusting method according to claim 2, wherein the setting is performed and the coarse adjustment step or the fine adjustment step is performed again. 4. The screw adjusting method according to claim 3, wherein the provisional target value is set in consideration of the past two springback amounts.