JPS6070310A - position detection device - Google Patents

Abstract

PURPOSE:To correct a counted value, by reading the marks, which are attached on one track at an equal interval and the address values attachsd on the other track at a coarse pitch by a reader, and reading the pulse and the address, which are generated at every mark. CONSTITUTION:A counted value is made to be zero. With the movement of a carrier, marks 14 are counted. Then the counted value indicates the address from the original point. When the erase of the counted value occurs due to power OFF, the address does not agree with the counted value of the counter. The codes on a second track TRb are provided to cope with this problem. The code indicates the absolute address. When the carrier comes to this cope position, the code is detected by light emitting and receiving devices, and the address is read. The counted value of the counter, which counts the maks on the first track TRa, is corrected to the read address value. Even though reading errors occur due to the attachment of dust, the errors can be corrected by the reading of the code 16. Thus the miniaturization and enlargement of the address, which is imparted along a conveying path can be simply changed by the pitch of the marks 14.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a position detection device in a ta transport system for articles such as magnetic cartridges.

PRIOR ART AND PROBLEMS There is a magnetic storage device in which short cylindrical magnetic cartridges are inserted into individual cells of a honeycomb storage, and then taken out for use, i.e. read/write. In an article loading and unloading system, the carrier moves on a fixed trajectory to transport the article from one location to another, so the current location must always be recognizable. As a position recognition means, there is a method of attaching a strip with a binary pattern marked along the trajectory and reading it optically to know the position address. FIG. 1 shows an example of this, and 10 is a honeycomb-shaped storage, with holes 10a and 1.
0b, . . . magnetic cartridges are stored one by one and taken out from there.

Although not shown, a carrier called a picker or the like carries in and out, moves along a rail, stops in front of a designated hole, and takes the magnetic cartridge in and out of the chain hole. 12 is a band-shaped body attached along the rail;
It has a plurality of tracks TR1, TR2, . . . , and each trunk is marked with a black and white pattern as shown. The black part blocks light, and the white part allows white to pass through.
A light emitter and a light receiver are arranged on the front and back sides of the strip 12, and position information is obtained by reading the black and white state of each track in a direction perpendicular to the strip 12. The black and white patterns along the vertical chain lines in the figure are addresses Nl, N2, etc.
. , and within each address there are many more positions PI, P2 . It is classified into... For example, between P3 and P4 is the center of the address.P3゜P4 is the L on the left, L on the right
(low) address, P2. P5 is the same M (mid) address, and PI and P6 are the same H (high) or edge address. Each of these positions corresponds to the storage 10 as shown.

The address information marked on this strip is an absolute address, and by reading it, the address can be immediately determined, and the edges within the address are PL, P2, .・・・・・・
You can understand by reading... However, as is clear from the drawings, the pattern is quite complex, so it is not easy to manufacture, and if dust or the like adheres, it becomes difficult to read the address.

Purpose of the Invention The present invention improves the above points, is simple to manufacture, and is less susceptible to dust adhesion, etc. For one address =
! 41! 'The aim is to provide a device that can detect position using a soft body.

Structure of the Invention The present invention includes a strip attached along a conveyance path and marked with a pattern indicating an address, and a reading device that prints out the numbered turns and records the address (in an upright detection device, The strip is marked on its 11th rack at equal intervals, and on the 2nd track is marked with a code indicating the address value of the position by a combination of bar widths with a pinch coarser than the marks. , a counter that counts the pulses generated for each mark of the first trunk, reads the code of the second trunk to obtain an address value, and corrects the count value of the counter with the address. This will be described below with reference to embodiments.

Embodiment of the Invention FIG. 2 shows an address strip used in the present invention, +a
) shows a part of the strip, and (b) shows the part further enlarged. As shown in the figure, this belt-shaped body 12 includes a first trunk TRa having marks or scales 14 marked at equal intervals, and a second trunk TRb having code patterns 16 marked at a coarser pitch than the marks.

This band-shaped body 12 is also attached along the carrier guide rail, and the mark is read by a projector and a light receiver. If the cartridge loading/unloading surface of the above-mentioned magnetic cartridge storage is a two-dimensional plane, the carrier must also move two-dimensionally.
directional rails, extending laterally and directionally across these rails;
Since mechanisms such as an X-direction rail that moves up and down and a carrier that moves along the X-direction rail are employed, the addressing strip 12 is attached along these X- and Y-direction rails.

In the present invention, the address is detected by counting the equally spaced marks 14 on the first trunk TRa to one. If the counter is cleared at the starting end, that is, the coordinate origin, to make the count value 0, and the mark 14 is counted according to the movement of the carrier, the contents of the counter count indicate the address from the origin. However, if this is the case, the actual address and counter count value will not match if there is noise intrusion, malfunction, or count contents are erased due to power off. is no longer possible (because the counter has been cleared). The code on the second trunk TRb addresses this problem; this code indicates an absolute address, which can be read to find out the address at that location. The code 16 is made up of a plurality of black patterns and the color of the own pattern between them, and like a barcode, the combination of widths Wb, W2, etc. of each pattern indicates a numerical value (address). The code 16 on the two-track TRb may be fairly coarse, and when the carrier comes to this code position, the emitted and receiver detects the code, reads the address, and counts the marks on the first trunk TRa. Correct the count value of the counter to the read address value.

Figure 4 shows the hardware that performs such processing.
For example, the sensor (emitter, receiver) for the first track TRa.
, 24 is a sensor for the second trunk TRb, 26 is a counter, and 3o is a reader. The output of the first sensor 22 is a pulse generated every time the mark 14 is detected, and the counter 26 counts this and outputs the ``1'' value as an address ADD. If you fail, PI in Figure 1, P2゜...
...The address becomes quite fine, and if the pinch is made coarser than that, Nl, N2, etc. in Fig. 1 are obtained. . . . The pitch of the marks 14 can be changed as appropriate. When the code 1G is detected, the output of the second sensor 24 is a black bar [Wl, W2. W3
When the code is not detected, the pulse becomes, for example, an H level signal, and in this example, there is no pulse, and in this example, the width of the white bar is W4. The portion corresponding to W5 becomes an L level signal. The reading device 3o includes a control unit 28 and a counter 32 that counts the clock.
, ROM (including a read-only memory 34 and a comparator 36,
The counter 32 counts the widths W1 to W3 of the black bars and the width W4 of the white bars. Read W5, access the ROM 34 using these values as addresses, read the addresses (numeric values) represented by the widths W1 to W5, and input the address value and counter 2.
Compare the count values of 6 with the comparator 36, and if they do not match, the ROM 3
The counter 26 is reset with the address value read from 4, and the contents of the counter 26 are corrected.

Note that the comparator 26 is omitted, and the code 16 is detected and the ROM
Each time an address is read from 34, the counter 26 may be unconditionally reset to that value.

In this way, the counter 26 always outputs the correct address (between codes 16 and after the next code is detected).

FIG. 3 schematically shows the X or Yl axis of the carrier drive mechanism. 40 is a carrier or X-axis wheel drive moke, 4
2 is a power amplifier that drives the motor, 44 is a processor, 46 is a sense register, 1 is a command signal, I2 is sense information, I3 is a control signal for the sensor 22.24, I4
is sensor output information, and I5 is a pulse signal indicating motor speed.

The reader 30 of FIG. 4 is implemented by a processor 44 in this example. When a signal ``l'' indicating the carrier movement destination by address is input, the processor 44 gives a start instruction to the motor 40, and detects the carrier current from the output 14 of the sensor 2' 2.24 generated in conjunction with the rotation of the motor 4o and the movement of the carrier. Knowing the address, the motor 40 is rotated until it reaches the address indicated by the signal 11.

FIG. 5 shows a more detailed circuit than that in FIG. The drive circuit for the motor 40 is configured to rotate in forward and reverse directions.

That is, transistors Ql-Q4 are connected to a bridge, and a motor 4o is connected to the detection end of the bridge, so that Ql.

Q2 on, forward rotation, Q3. The situation reverses with Q4 on. The armature current is detected by a resistor inserted in the armature circuit, and this
I7 is input to the power amplifier 42 to perform current limiting and the like. Since the output of the processor 44 is a digital signal, it is converted into an analog signal by the DA converter 48 and input to the power amplifier 42 through the preamplifier 50.5'2. Amplifier 52 performs speed control. That is, the speed pulse I5 taken out from the motor 40 or the speed generator connected thereto is converted into a voltage by the frequency-voltage converter 54, and is negatively fed back to the amplifier 52. This suppresses abnormal increases in carrier speed. Signal ■8 is for emergency stop. Carrier position control using the command signal 11 is the same as that explained in FIG.

Note that the code (address) of the second track TRb may be a bar code indicating the address value of the position, and the number of bars, length, combination thereof, etc. can be changed as appropriate. Also, the mark on the first trunk (edge of address: EOA)
) may be processed by software.

As is clear from the detailed description of the invention, the address detection strip of the present invention has a simple mark pattern, is easy to manufacture, and is less likely to be adversely affected by dust adhesion. Further, even if a counting error occurs in the mark 14 due to dust adhesion, it can be corrected by reading the code 16, and even if dust adheres to the code 16 and a reading error occurs, it can be corrected immediately with the next code 16. Further, the finer or coarser address given along the conveyance path can be easily changed or dealt with by pinching the mark 14.

Only two mark sensors are required, and the signal processing circuit is also simple.

[Brief explanation of drawings]

Figure 1 is a diagram explaining the main parts of a conventional position detection device, Figure 2
The figure is an explanatory diagram of the address strip used in the present invention, FIG. 3 is a block diagram showing an overview of the motor drive device, and FIG. 4 is a block diagram showing an example of a circuit for processing the mark detection signal of the strip in FIG. 2. 5 are block diagrams showing a more detailed configuration of FIG. 3. In the drawing, 12 is a band-shaped body, 22, 24, 26, 30 are reading devices, TRa, T'Rb are first... In the second trunk, 14 is a mark, 16 is a code, 26 is a counter, and 30 is means for correcting the δ1 value of the counter 26.

Claims (1)

[Claims] A position detection device comprising: a strip attached along a conveyance path and marked with a pattern indicating an address; and a reading device that detects the pattern and records the address; Marks are placed on the first trunk at equal intervals, and a code is placed on the second trunk that indicates the address value of the position by a combination of bar widths with a coarser pinch than the marks, and the reader reads each mark on the first trunk. A position detecting device comprising: a counter for counting pulses generated every time; and means for reading the code of the second track to obtain an address value and correcting the count value of the counter using the address.