JPS6374762A - Position transducer for unmanned cart - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an automatic guided vehicle position detection device for detecting the position of an automatic guided vehicle on a traveling path.

[Prior Art] Conventionally, a travel control system for an automatic guided vehicle has been proposed in which a guide line is arranged along a required travel route and the automatic guided vehicle is caused to travel along the guide line.

In such a system, marks indicating branching points, stopping points, etc. of the traveling route are provided on the traveling route. The structure of this mark differs depending on whether it is used in the count method or the absolute value method.

First, an example of mark arrangement in the counting method is shown in FIG. Here, the counting method is a method of knowing the position by sequentially counting from a certain starting point on the running road, but in this Figure 8, 1 is a guide line arranged along the running route, 2 is a guide An automatic guided vehicle runs along the route while detecting line 1, 3a is a sensor that detects a mark, Ml
, M2°M3 are the positions STI, ST2 . ST3
It is a mark made of iron plate placed on each. In this counting method, when the automatic guided vehicle 2 detects the mark M1 at the starting point [ST1], information on this position STI is entered into the keyboard on the automatic guided vehicle 2 by key operation. Automatic guided vehicle 2 has map data of the driving route (mark placement and location name)
, and then mark M2. When M3... is detected, by sequentially counting, it detects the position from the starting point STI, and
It detects the current location.

Next, an example of mark arrangement in the case of the absolute value method is shown in Fig. 9.
Here, the absolute value method is a method in which multiple high-frequency currents are passed on the road and the combination of different frequencies is used to create an absolute value code for that position to determine the position.
1 is a guide line arranged along the running route, 2 is an automatic guided vehicle that runs along the running route while detecting the guide line 1, 3A, 3
B is the first one that detects the mark. second sensor, Ml';
M2'.

M3' is the position STI, ST2. These marks are placed on each ST3, and these marks indicate the electric wires 4 through which high-frequency currents with frequencies fl and f2 are flowing, respectively.
, 5.

That is, at position ST1, the first sensor 3A detects a current with frequency f1, the second sensor 3B detects a current with frequency f2, and at position ST1, the first sensor 3A detects a current with frequency f2, and the second sensor 3B detects a current with frequency f2. detects a current with frequency f1, and at position ST3, the second sensor 3B detects current with frequencies fl and f2.

In this example, the first. The types of frequency detection by the second sensors 3A and 3B are fl, f2. Since there are three types, fl and f2, a total of six absolute value codes can be created. In this absolute value method, each automatic guided vehicle 2 [ST1
~When reaching ST3 and detecting marks Ml'~M3',
Since the information obtained from these marks M1' to M3' has information specific to the position, the current position can be detected from the mark information.

[Problems to be solved by the invention] However, in the conventional position detection device for an automatic guided vehicle,
There are the following problems.

First, when using the counting method shown in FIG. 8, construction on the ground side is simple, but control on the automatic guided vehicle side becomes complicated.

Furthermore, in the case of using the absolute value method shown in FIG. 9, control on the automatic guided vehicle side can be simplified, but construction on the ground side is complicated and construction costs are high.

This invention aims to solve the problems caused by both of the above methods at once, and provides a position detection device for an automatic guided vehicle that can realize the absolute value code method with simple ground-side construction. With the goal.

[Means for Solving the Problems] The position detection device for an automatic guided vehicle according to the present invention has a storage battery-driven code that can output positional information of the traveling route for the automatic guided vehicle as an absolute value code. The present invention is characterized in that a transmitter is provided, and the automatic guided vehicle is also provided with a code receiver capable of receiving the code output from the code transmitter.

[Function] In the above-mentioned automatic guided vehicle position detection device of the present invention, the storage battery-driven code transmitter disposed on the travel path outputs the required position information on the travel path in the form of an absolute value code. When the automatic guided vehicle comes to the code transmitter installation position, the above absolute value code is received by the code receiver attached to the automatic guided vehicle,
The position is detected.

[Embodiments of the Invention] The present invention will be specifically described below with reference to illustrated embodiments. FIG. 1 is a schematic diagram showing an example of the arrangement of a code transmitter and a code receiver in a position detection device for an automatic guided vehicle as an embodiment of the present invention. 2 is an automated guided vehicle that travels along the route while detecting the guide line 1, 3 is a code receiver provided on the automated guided vehicle 2, and 6 is an STI at each position on the route. , ST2. ST3. This is a code transmitter located in ... that outputs each position information as an absolute value code.

FIG. 2 is an electrical circuit diagram of the code oscillator 6 placed on the ground side. In this FIG. The N frequency divider 9 is a shift register, and this shift register 9 receives the clock from the lock oscillator 7 at the C terminal as shown in FIG. 4(a), and receives the clock from the lock oscillator 7 at the A terminal as shown in FIG. 4(b). When the output from the 1/N frequency divider 8 rises, setting data is input in parallel from the data bit input terminal 9c and latched, and the data is output every clock. The data is shifted and serially outputted from the Q output terminal as shown in FIG. 4(C).

Incidentally, among the bit input terminals of the shift register 9, a stop bit is inputted to one bit (see the one indicated by the symbol 9a), and a start bit is inputted to two bits (see the one indicated by the symbol 9b).

Reference numeral 10 denotes a switch group for inputting absolute value code data, and by appropriately closing the switches constituting this switch group 10, desired absolute value code data consisting of a binary pattern can be set. Reference numeral 11 denotes a transmitting antenna, which transmits serial data information (absolute value code information) from the shift register 9 modulated at frequency fA.

Figure 3 shows a code receiver 3 attached to an automatic guided vehicle 2.
In this figure, 12 is a receiving antenna, 13 is a bandpass filter whose center frequency is fA, 14 is a shift register that converts serial data into parallel data and outputs it, and 15 is a signal from shift register 14. a bit pattern comparator receiving a bit pattern, 16
1 is a clock oscillator for driving the shift register, and 17 is a CPU for reading the absolute value code. Therefore, in this code receiver 3, the signal received by the receiving antenna 12 is demodulated by the bandpass filter 13 and then input to the shift register 14. The input serial data is converted into parallel data at the clock timing from the clock oscillator 16 in the shift register 14 and output, but the bit pattern (pattern including start, data, and stop bits) is output from the shift register 14. It is compared by the bit pattern comparator 15, and if the input bit pattern is the required pattern, C
PtJ178 outputs an interrupt signal. This allows CPU17
reads the parallel output of the shift register 14 and detects its absolute value code.

Figure 4 is a timing chart for code transmission @6, Figure 4(a) is the clock timing, Figure 4(b) is the timing chart.
4(Q) is the output timing of the shift register 9. The shift register output shown in FIG. 4(c) has 2 bits for start and 10 bits for data. (1024 types of absolute value codes can be created if there is one), and one code is expressed by using one bit for parity check and one bit for stop.

Note that, as can be seen from FIG. 4(c), codes are separated by an 8-bit "0".

Also, the time t for transmitting one code. sets the baud rate to 4
Assuming 800 BPS, t=about 3.75 m5.

Furthermore, the maximum speed of the automatic guided vehicle 2 is set to 7.2 km/h (2
mm/ms), the distance that the automatic guided vehicle 2 moves while reading the code three times in succession is 11.25 mm. Therefore, the sizes of the code transmitter 6 and the code receiver 3 are set in consideration of this point.

FIG. 5 is a perspective view of the code transmitter 6. As can be seen from FIG. Clock oscillator 7°17N frequency divider 8. Shift register9. A printed circuit board 19 on which the switch group 10 and the like are mounted is inserted and attached. Further, since the code transmitter 6 is driven by a storage battery, a battery 20 is provided within the cylindrical body 17. The size of the cylindrical body 17 is, for example, 50 mm in diameter and 75 m in height.
About m is used.

The code transmitter 6 can be inserted into a hole 22 with a lid 21 formed in the running road surface 23 as shown in FIG. 7(a), or installed on the floor of a clean room as shown in FIG. 7(b). The grating 24 may be disposed in a portion of the grating 24 where the grating 24 is exposed.

Furthermore, since the lid 21 and grating 24 are removed once or twice a month for cleaning, etc., it is difficult to make fixed marks on the floor surface.
This code transmitter 6 as shown in the figure can be said to be useful.6 Figure 6 is a perspective view of the code receiver 3. As can be seen from this figure, the code receiver 3 is equipped with a bandpass filter. 13. Shift register 14° bit pattern comparator 15. A coil 26 for the receiving antenna 12 is installed around the printed circuit board 25 on which the clock oscillator 16 and the like are mounted.
It is wound. Note that the printed circuit board 26 has a square shape of, for example, 100 mm x 100a+a.

With the above-described configuration, the automatic guided vehicle 2 travels along the travel path and reaches the required positions STI, ST2, . When attempting to pass through ST3..., the absolute value code output from the battery-powered code transmitter 6 disposed at these positions is detected by the code received by the automatic guided vehicle 2 with 3 concave diameters while passing. Based on the received signal, the CPU 17 detects the absolute value code at that position. Thereby, the automatic guided vehicle 2 detects which position on the travel route it is about to pass, and uses this detection information as stop information or branch information.

As described above, according to the position detection device for an automatic guided vehicle of this embodiment, the following effects and advantages can be obtained.

(1) The absolute value code representing the position information can be easily set or changed by turning the switch group 10 on and off.

(2) One code transmitter 6 only needs to be provided at one location, and the code transmitter 6 can also be provided on curved sections regardless of the traveling trajectory of the automatic guided vehicle 2.

Note that with the conventional method, it was not possible to place marks on curved sections.

(3) Since the code transmitter 6 is driven by a storage battery, there is no need for an external power supply line, and the construction is simple.

(4) It can sufficiently handle complex operation control such as increasing the number of stations or varying the speed of an automatic guided vehicle.

[Effects of the Invention] As detailed above, according to the automatic guided vehicle position detection device of the present invention, a storage battery that can output positional information of the traveling route for the automatic guided vehicle in the form of an absolute value code is provided. In addition to the drive-type code transmitter, the automatic guided vehicle is also equipped with a code receiver that can receive the code output from the code transmitter. This has the advantage of being able to implement an absolute value code method.

[Brief explanation of the drawing]

1 to 7 show a position detection device for an automatic guided vehicle as an embodiment of the present invention, FIG. 1 is a schematic diagram showing an example of the arrangement of a code transmitter and a code receiver, and FIG. is the electrical circuit diagram of the code transmitter. 3 is an electric circuit diagram of the code receiver, FIG. 4 is a timing chart of the clock, divider output and shift register output in the code transmitter, and FIG. 5 is a perspective view of the code transmitter. Figure 6 is a perspective view of the code receiver.
FIGS. 7(a) and 7(b) are a sectional view and a perspective view, respectively, for explaining the installation location of the code transmitter, and FIG. FIG. 9 is a schematic diagram showing an example of mark arrangement. FIG. 9 is a schematic diagram showing an example of mark arrangement in a conventional absolute value system position detection device for an automatic guided vehicle. In the figure, 2 - automatic guided vehicle, 3 - code receiver, 6 -
Code receiver, 20-battery. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A storage battery-driven code transmitter capable of outputting position information of the travel route in an absolute value code is disposed on the travel route for the automatic guided vehicle, and a code output from the code transmitter is provided to the automatic guided vehicle. A position detection device for an automatic guided vehicle, characterized in that it is provided with a code receiver capable of receiving a code.