JPS58175082A - Mark reader - Google Patents

Abstract

PURPOSE:To detect the end of reading of marks easily, by providing the 3rd detector between the 1st detector and the 2nd detector, and generating a mark reading signal when any of the 1st-3rd detectors does not detect the presence of bars. CONSTITUTION:A series of bar codes 3 are stuck on a floor 1 at an interval (b) to detect the position information of a traveling object 2 in traveling, the 1st - 3rd detectors 8-10 provided on the traveling object 2 read said bar and detect the position. The 2nd and the 3rd detectors 9, 10 are provided at interval (d), (e)[e<a1<d<a1+b, b<d<a2] from the detecting position of the 1st detector 8 in the end of bar, and when the detector 8 detects the beginning of the bar, the type of the bar is discriminated in response to the output of the 2nd detector 9, and when any of the 1st - the 3rd detectors 8-10 does not detect the bars, a mark reading signal (h) is generated. Thus, the end of reading of the mark is detected easily with a simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mark or barcode reading device.

In general, in unmanned vehicles that can automatically travel on predetermined tracks, barcodes consisting of a series of par signs are affixed on the floor so that the unmanned vehicles can detect location information while traveling. , unmanned vehicles have this mark (barcode)
A method is adopted that reads the information and detects its location information.

Conventional mark reading methods include parallel reading method,
There were serial reading methods and timing bit serial reading methods. Among these, the parallel reading method uses multiple detectors to detect the presence or absence of bars at once by arranging the bars in a direction perpendicular to the direction of movement of the unmanned vehicle, and reading the bar presence/absence information. This method requires the same number of detectors as the number of bits in the barcode, making it expensive.

In addition, the serial reading method arranges bars in the direction of movement of the unmanned vehicle, detects the bars in series with one detector, counts the number of detected pulses, and reads information from the count value. However, this method requires many circuits such as a scan circuit, a pulse generation circuit, and a counting circuit, making the device complex and expensive. Furthermore, in the serial reading method 1 of the timing bit method, for example, an unmanned vehicle is equipped with two detectors in a direction perpendicular to the direction of movement of the vehicle, and at the timing when one detector detects a bar, the other detector detects the bar. This method reads information by detecting the presence or absence of the object, but this method has the drawback that errors in the direction of movement can sensitively affect reading accuracy.

Therefore, the inventor of the present invention proposed a mark reading system that eliminates the above-mentioned drawbacks by arranging the first and second bars of different widths in the direction of movement of the moving body. Second detectors are arranged and mounted on the moving body in the direction of movement thereof, and the type of bar is determined according to the output of the second detector when the first detector detects the starting end of the bar. have already developed something.

By the way, in the conventional mark reading method, when trying to detect whether reading of a mark has been completed, a mark is separately provided to indicate the completion of reading, and a logic circuit is used to distinguish between this mark and an information mark. The conventional method is to detect the completion of reading, or to provide a dedicated detector to detect the completion mark of reading. However, this method requires a mark other than the information mark, and also requires a complicated logic circuit and a new detector.

This invention was made in view of such conventional problems, and in the above mark reading method developed by the inventor of the present invention, during mark reading between the 1.4s2 detectors, one of the detections is always detected. A simple configuration can be achieved by arranging and mounting a third detector so that the device detects the bar, and generating a mark reading completion signal when none of the three detectors detects the presence of a bar. It is an object of the present invention to provide a mark reading device that can easily detect whether reading of a mark is completed or not.

An embodiment of the present invention will be described below with reference to the drawings.

1 to 4 show a mark reading device according to an embodiment of the present invention. In the figure, 1 is a road surface which is an object to be detected, and a bar code (mark) 3 formed by encoding positional information is pasted on the road surface 1. Reference numeral 2 denotes an unmanned carrier (moving body) that travels on the road surface 1 in the direction indicated by the arrow. When the carrier 2 passes over the mark 3, the mark 3 is read to determine its position. Mark 3 above is the first bar with a width of 12 inches (meaning binary "0°") and
The second bar of (!2>J) (meaning binary °1')
, and are arranged arbitrarily at intervals, and in the examples shown in FIGS. 3 and 4, 4 and 5 are the first bars, and 6 is the second bar. Note that each of these bars is formed using a reflecting plate.

On the other hand, a detection device 7 is disposed on the bottom surface of the transport vehicle 2, and the detection device 7 includes a first light receiving sensor (a first
Detector) 8 and detects the presence or absence of the bar @2. It is composed of a third light receiving sensor (@2. third detector) 9.10. The detection position 9λ of the second light receiving sensor 9 on the road surface 1 is set at a distance d from the detection position 8a of the first light receiving sensor 8 in the direction of the arrow, that is, toward the end of the bar. The detection position 10m of the light receiving sensor 10 is set at a distance e from the detection position 8 of the first light receiving sensor 8 toward the end of the bar. However, here, e(al(d(aI +b, b(d(112).The carrier 2 is also provided with a light emitting element (not shown) that emits light downward, The bar detected by the first light receiving sensor 8 is determined according to the output of the second light receiving sensor 9 when the first light receiving sensor 8 detects the starting end of the bar. 1st.
A discrimination circuit (not shown) is mounted to discriminate which bar is the second bar. Furthermore, the transport vehicle 2 has a first one. Second. Third
A reading completion signal generating circuit receives the outputs of the light receiving sensors 8, 9.10 and generates a mark reading completion signal when none of the three sensors 8, 9.10 detects the presence of a bar (Fig. 135). ) is installed.

FIG. 5 shows the circuit configuration of the read completion signal generation circuit 16, and in the figure, 11 is the first . 26 The output of the third light receiving sensor 8,9. A first pulse generation circuit consisting of a stable multivibrator, 13
receives the inverted signal of the output of the OR circuit 11, and
a second pulse generation circuit consisting of a monostable multivibrator that generates a pulse signal in synchronization with the falling edge of the output;
14 is an OR circuit which uses the output of the first pulse generating circuit 12 and the reset signal 1 from the outside, and 15 is its S.
The output of the second pulse generation circuit 13 is connected to the terminal, and K
This is a flip-flop circuit whose terminal is connected to the output of the OR circuit 14.

Next, the operation will be explained.

When the transport vehicle 2 is traveling on the road surface 1, its light emitting elements always emit light downward, and when the transport vehicle 2 passes over the mark 3, the first. The second light receiving sensor 8.9 sequentially receives the reflected light from the bars 4 to 6 of the mark 3. When the first light receiving sensor 8 detects the starting end 4m of the first bar 4, that is, when its detection output rises, the second light receiving sensor 9 The detection position 9 has already passed the terminal end 4b of the bar 4,
Since no bar is detected, the discrimination circuit determines that the bar 4 is the first bar. Similarly for bar 5,
Since the light receiving sensor 9 of jI2 does not detect a bar when the output of the first light receiving sensor 8 rises, the bar 5 is determined to be the first bar.

Furthermore, since the width 12 of the bar 6 is a2)d, when the first light receiving sensor 8 detects the starting end 6a of the bar 6, the detector 119a of the second light receiving sensor 9 is on the bar 6. The sensor 9 detects the bar, thereby determining that the bar 6 is the second bar, and thus the binary position information of the mark 3 consisting of a plurality of bars can be read.

When the third mark position information is being read in this way, the first mark position information is being read. The distance d between the second light receiving sensors 8 and 9 is d)b,
1st. Since the interval e between the third light receiving sensors 8110 is set to C<31>, the first, second... At least one of the third light receiving sensors 8, 9, 10 always detects the presence of a bar.

Then, in the reading completion signal generation circuit 16, the output of the Ok circuit 11 becomes °1'' when the second light receiving sensor 9 starts to detect the presence of the first bar 4, and the first pulse generation circuit 12 outputs an OR signal. Since a pulse signal is generated in synchronization with the rise of the output of the circuit 11 and is applied to the terminal of the flip-flop circuit 15 via the OR circuit 14, the output of the circuit 15 is reset to °d. When all the readings of 3 are completed, the 1st, 2nd, and 3rd light receiving sensors 8
゜9.10 output possible Since f and c are all 0 and the output of the OR circuit 11 is also 0, the second pulse generation circuit 13 generates a pulse signal in synchronization with the fall of the output of the OR circuit 11. Since the signal is generated and applied to the S terminal of the flip-flop circuit 15, the output of the circuit 15 becomes 11', thereby making it possible to obtain a mark reading completion signal.

Further, this reading completion signal generation circuit 16 is activated when reading a new mark 3 or when receiving a reset signal 2 from outside.
When the mark reading completion signal is received, the generation of the mark reading completion signal is stopped.

In the apparatus of this embodiment as described above, the first. Since reading of the mark is detected to be completed when none of the 2nd and 3rd light receiving sensors detect the presence of the bar, it is necessary to separately provide a mark to indicate the start and completion of reading. Moreover, the mark reading completion signal can be generated simply by providing a third detector and an extremely simple circuit.

Although the above embodiment describes a mark reading device that reads position information of an unmanned carrier, the present invention can be similarly applied to a device that reads information such as type 9 number of an article transported by a conveyor, vehicle, etc. In this case, a mark is affixed to the article being transported and is read by a detector on the stationary side. Also, the width of the bar is a1. a2. The distance between the two and the distance d and e between the light receiving sensors are based on the above-mentioned condition e(al(d(a
I +b, b(d) There may be variations within the range satisfying d<12.Furthermore, the detector and bar used for mark reading may be other than the light receiving sensor and reflector as described above. Alternatively, a metal detector and a metal plate, or a magnetic sensor and a magnet may be used.

As described above, according to the mark reading device according to the present invention, the first mark reading device has different widths. The second bars are arranged in the moving direction of the moving body, and the first... Second detectors are arranged and mounted on the moving object in the moving direction thereof, and the type of buni is determined according to the output of the second detector when the first detector detects the starting end of the bar. , and the first. A third detector is provided between the second detector; Second. Since the mark reading completion signal is generated when none of the third detectors detects the presence of a bar, the completion of mark reading can be easily detected with a simple configuration.

[Brief explanation of drawings]

1 and 2 are a plan view and a side view of a mark reading device according to an embodiment of the present invention, FIGS. 3 and 4 are an enlarged side view of the main part of the device and a plan view of the mark, and FIG. 2 is a circuit configuration diagram of a read completion signal generation circuit of the above device. FIG. 1... Road surface (detected object), 2... Unmanned carrier (moving object), 3... Mark, 4, 5... First bar, 41
゜51...Starting end, 4b...Terminal end, 6...Second bar, 6a...Starting end, 8,9.10...First end. Second.
Third light receiving sensor (first, second, third detector), 8
m, 9λ. 10m...detection position, 16...reading completion signal generation circuit. Patent applicant Mazda Kosan Co., Ltd. Agent Patent attorney Ken Hayase - Figure 1 Figure 3 Figure 5

Claims (1)

[Claims] (1) Width a1. The 1st of the amount 2 (λ1〈龜2). a test object to which a mark consisting of a plurality of second bars arranged at mutually spaced intervals is affixed; a movable body that moves relative to the test object in the width direction of the bar; a first detector mounted on the body for detecting the starting end of the bar, and each detection position on the detected object having a distance d from the detection position of the first detector to the terminal end side of the bar. e(e(tortoise 1<d<11+b, b(a(λ2)) 2nd. When detects the starting end of a bar, it is determined whether the bar detected by the first detector is either a first bar or a second bar according to a detection signal of the presence or absence of a bar from the second detector. The discrimination circuit receives the outputs of the first, second, and third detectors and generates a reading completion signal for generating a mark reading completion signal when none of the three detectors detects the presence of a bar. A mark reading device characterized by comprising a circuit.