JP2627177B2 - Load transfer equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load transporting facility provided with a self-propelled truck guided by a traveling rail and self-propelled.

2. Description of the Related Art Transmission and reception of a signal from a ground-side controller to a self-propelled carriage in the above-described load transfer facility is disclosed, for example, in Japanese Patent Laid-Open No.
As shown in the publication, the control signal transmission / reception rail provided on the traveling rail is contacted with the current collecting means provided on the self-propelled bogie, and the self-propelled bogie is remote from a controller on the ground side,
Was controlled automatically.

SUMMARY OF THE INVENTION However, in the conventional configuration for transmitting and receiving signals, since the signal rail and the current collecting means are used, the current collecting means and the rails are severely worn, and are not regularly replaced. There is a problem that transmission and reception of signals are not performed well, and a problem that a large cost is required for the periodic replacement. In order to solve such a problem, signal transmission / reception means can be considered by radio waves. However, there is a problem of noise given to equipment other than the self-propelled trolley, and a dead zone (a zone where the electric field becomes zero) occurs due to the effect of standing waves. There was a problem that communication became impossible.

An object of the present invention is to solve the above-mentioned problems, and to provide a load transporting unit that transmits and receives signals by radio waves, makes repairs almost unnecessary, and avoids communication failure. .

Means for Solving the Problems In order to solve the above problems, the present invention relates to a plurality of self-propelled trolleys, which are guided by a traveling rail and convey a load by self-propelling, and have means for transmitting and receiving signals by radio waves, A transmission / reception unit for transmitting / receiving a signal by radio waves to / from the self-propelled vehicle using a guide line laid along the rail as an antenna, a control unit on the ground for controlling a plurality of self-propelled vehicles, and a terminal at the end of the guide line. Switching means for temporally switching the resistance value of the connected terminating resistor.

Operation With the above-described configuration, signals are transmitted and received between the self-propelled carriage and the ground control means using radio waves by using an induction wire laid along the traveling rail as an antenna. Therefore, unlike the conventional collecting means and signal rail, regular maintenance for wear is not required. Further, the dead zone generated by the standing wave in the dielectric wire moves temporally by switching the resistance value of the terminating resistor by the switching means every time. Therefore, even if the self-propelled vehicle stops, the vehicle does not continuously enter the dead zone, thereby preventing the communication between the self-propelled vehicle and the control means on the ground from being disabled.

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

FIG. 1 illustrates a control block of a self-propelled carriage of the load transport equipment of the present invention. In FIG. 1, reference numeral 1 denotes a ground controller which is a micro computer, and is a ground control means for controlling a plurality of self-propelled vehicles 2 collectively. The ground controllers are scattered along traveling rails on which the self-propelled vehicles 2 travel. A load transfer signal from a station for transferring loads or a host computer (not shown), and a feedback signal for each self-propelled vehicle 2 from a ground modem 3 to be described later, for example, an address signal of the current position, A signal such as the presence or absence of a load is input to make a determination, and a control signal such as a destination to travel for each self-propelled vehicle 2 and whether or not to perform transfer is provided by an interface unit (not shown) installed in the ground controller 1. To the terrestrial modem 3. The transmission method of the ground controller 1 and the ground modem 3 uses RS-232C,
Full duplex with asynchronous serial transmission.

As shown in FIG. 2, the terrestrial modem 3 includes an interface unit 4 with the terrestrial controller 1, a transmission unit 5 and a reception unit 6 corresponding to a wireless transceiver, and a transmission operation performed by the reception unit 6.
The transmitting unit 5 and the receiving unit 6 are connected to a traveling rail 8 connected by rail connecting members 9 as shown in FIG. UH is a guide line laid along the running direction over the entire length.
The feeder line 10 for F-TV is used as an antenna. The transmitting unit 5 corresponds to a weak radio station defined by the Radio Law, and uses a frequency modulation system as a modulation system, and the receiving unit 6 uses a superheterodyne system as a reception system. The digital control signal for each self-propelled vehicle 2 from the ground controller 1 input to the interface unit 4 of the ground modem 3 is converted into a digital analog signal by the interface unit.
The signal is transmitted from the feeder line 10 via the duplexer 7 and the impedance matching box 11 FM-modulated using 0 MHz as the main carrier. 200 at the end of feeder wire 10
The terminating resistor 12 of Ω is connected.

As shown in FIGS. 1 and 3, the self-propelled trolley 2 is provided with two antennas 13 and 14 in the traveling direction of the self-propelled trolley 2 so as to approach and face the feeder line 10. First antenna 13
Is formed by a loop antenna conforming to 170 MHz, the second antenna 14 is formed by a loop antenna conforming to 138 MHz, and the installation interval between the two antennas 13 and 14 is λ / of the transmission frequency from the feeder line 10. 4, (λ; wavelength), that is,
Λ / 4 of 170MHz, about 44cm.

The control signal from the ground controller 1 transmitted from the feeder line 10 is received by the two antennas 13 and 14, averaged by the distributor 15 and input to the main body modem 16. The main body modem 16 has the same configuration except that the local oscillation frequencies of the terrestrial modem 3, the transmitter 5, and the receiver 6 are changed.
The signal input from the distributor 15 is demodulated by the receiving unit 6A via the duplexer 7A, converted into a digital signal by the interface unit 4A, and transmitted to the main unit controller 17 which is a control unit of the main unit by the RS-232C transmission method. You. The main body controller 17 includes, as sensors, a transfer section detector 18 comprising a photoelectric switch for detecting the presence / absence of a load and a fixed position of the load, an origin serving as a base point of an address of a current position provided along the traveling rail 8, and a station. Control switch 19 comprising a photoelectric switch for detecting the zone and curve of the vehicle, a photodetector 20 for detecting approach to a preceding self-propelled vehicle, a bumper switch 21 for detecting a rear-end collision, and a rotation speed of a travel motor 22 for determining the travel distance. An encoder 23 for detecting the signal is connected, and a signal from each sensor and a control signal from the ground controller 1 inputted from the main body modem 16 or a manual operation from a control box (not shown) connected to the operation surface 24 are connected. The traveling motor 22 or the switching switch 26 is switched by the inverter 25 and the switching switch 26 to control the transfer motor 27. Self-propelled trolley 2 and self-propelled trolley 2
Transfer of goods from the factory. Also the main controller
Reference numeral 17 denotes a projector 28 that emits light to detect the approach of a following self-propelled vehicle. The feedback signal from the main body controller 17 to the ground controller 1 is serially transmitted as a digital signal to the main body modem 16, digital-to-analog converted by the main body modem 16 interface section 4A, and 138 MHz main carrier is transmitted by the transmission section 5A. FM modulation as
The signal is transmitted by the two analogs 13 and 14 via the distributor 15.
Main unit controller 1 sent from two analog 13 and 14
The feedback signal from 7 is received by a feeder line 10, demodulated by a receiving section 6 of a terrestrial modem 3 through an impedance matching box 11, converted into an analog-to-digital signal by an interface section 4, and serialized to a terrestrial controller 1. Transmitted. The ground controller 1 grasps the situation of the self-propelled vehicle 2 based on a feedback signal from the main body controller 17 input from the ground modem 3.

In FIG. 3, 29 is a drive wheel driven by the traveling motor 22, 30 is an idle wheel, and 31 is the self-propelled truck 2 on the traveling rail 8.
Is a guide roller for guiding the roller.

As described above, by using the terrestrial modem 3 and the main body modem 16 as transceivers, and using the feeder line 10 and the first and second antennas 13 and 14 as antennas, the terrestrial controller 1 can be used.
Can exchange signals with the main unit controller 17,
Further, since the conventional signal rail and current collecting means can be eliminated, and abraded portions can be eliminated, the need for periodic maintenance can be eliminated. Also, 2
By providing the antennas 13 and 14 at an interval of λ / 4, communication can be stabilized.

As shown in FIG. 4, there is actually a reflected wave a which should not exist theoretically, and a dead zone A (a zone where the electric field becomes zero) exists due to the effect of the standing wave due to the reflected wave a. I do. In FIG. 4, b indicates a traveling wave. The resistance value of the terminating resistor 12 is temporally switched in order to avoid communication failure due to the dead zone A.

FIG. 5 shows a circuit diagram of the terminating resistor 12. In FIG. 5, reference numerals 42 and 43 denote connection terminals to the feeder wire 10, and a 200Ω resistor R1 is connected to the connection terminal 42 via a capacitor C1, and this resistor R1 is connected in series in the forward direction. The anode of the diode D1 is connected, and the cathode of the other diode D2 is connected to the connection terminal 43 via the capacitor C2. 44 and 45 are power terminals, and a positive power terminal 44
Is connected to the input terminal 46A of the timer 46, the negative power supply terminal 45 is connected to the common connection 46B of the timer 46, and is connected to the cathode of the diode D2 via the induction coil L2. The output terminal 46C of the timer 46 is connected to the anode of the diode D1 via the 1KΩ resistor R2 and the induction coil L1. The timer 46 is turned on and off every three seconds when, for example, 5 V DC power is supplied through the power terminals 44 and 45, and the diodes D1 and D2 are turned on by about 2 mA every three seconds.
The diodes D1 and D2 are turned on by flowing the forward bias current I of FIG. 1 and the resistance value between the connection terminals 42 and 43, that is, the resistance value of the terminating resistor 12, is changed every three seconds as shown in FIG.
It is switched to 200Ω when 2 is on and several 100KΩ when off.

In this manner, the resistance value of the terminating resistor 41 is switched over by the timer 46 every time, so that the reflected wave a shown in FIG.
And the position of the dead zone A changes as a result. Therefore, even when the self-propelled trolley 2 is stopped, the self-propelled trolley 2 does not enter the dead zone continuously.
It is possible to prevent the communication between the controller and the ground controller 1 from being disabled. Further, the number of antennas 13 and 14 provided on the self-propelled carriage 2 can be reduced to one because the communication failure due to the dead zone is avoided.

The switching time of the timer 46 is determined by the transmission timing from the ground controller 1 to the self-propelled trolley 2, the number of the self-propelled trolleys 2 running on the loop rail 8, and the self-propelled trolley 2 having an error due to a standing wave. This is set according to the probability of communication failure and the time at which the ground controller 1 determines that an error has occurred in the self-propelled trolley 2 and starts transmission to another self-propelled trolley 2.

Advantageous Effects of the Invention As described above, according to the present invention, it is possible to transmit and receive signals between the self-propelled carriage and the control means on the ground using radio waves as antennas, using guide wires laid along the traveling rails as antennas. In addition, since there is no place to be worn like conventional signal rails and current collecting means, there is no need to perform regular maintenance, and maintenance costs can be reduced. Further, since the resistance value of the terminating resistor connected to the induction line is switched every time by the switching means, the dead zone generated by the standing wave on the induction line moves temporally on the induction line. Even if the self-propelled bogie is stopped, it will not enter the dead zone continuously, and it will be possible to avoid a loss of communication between the self-propelled bogie and the ground control means, providing highly reliable load transport equipment can do.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a self-propelled trolley of a load transport facility showing one embodiment of the present invention, FIG. 2 is a configuration diagram of a ground (main body) modem of the load transport facility, and FIG. 3 is a load transport facility. FIG. 4 is a waveform diagram of a traveling wave and a reflected wave on a feeder line of the same load transport equipment, FIG. 5 is a circuit diagram of a terminating resistor of the same load transport equipment, and FIG. It is a characteristic diagram of the resistance value of the terminating resistor of the figure. 1 ground controller (ground control means), 2 self-propelled trolley, 10 feeder line (induction line), 12 terminal resistor, 46 timer (switching means).

Claims (1)

(57) [Claims] 1. A plurality of self-propelled trolleys having a means for transmitting and receiving a load by being guided by a traveling rail and carrying a signal by radio waves, and an induction wire laid along the traveling rail as an antenna. Transmitting and receiving means for transmitting and receiving signals to and from the self-propelled bogie, ground control means for controlling a plurality of self-propelled bogies, and a resistance value of a terminating resistor connected to the end of the guide wire. And a switching means for switching between the two.