JPS6193730A - Signal transmission system of mobile track - Google Patents

Abstract

PURPOSE:To always obtain an excellent transmission/reception state by using the radio system at a mobile track at a district where a radio wave propagation state is excellent, mounting a radio equipment to bring it into a district with excellent radio wave propagation state at a district where the radio wave propagation is wrong state and receiving a signal through a wired system. CONSTITUTION:When a mobile car is in a district with an excellent radio wave propagation state, a control signal from a controller CT to the said mobile car is received by an antenna 4a of a mobile car 9 in the radio system. The signal is amplified 3a, demodulated 1 and fed to each driver. A signal from each sensor in the mobile car 9 is modulated 2, amplified 3c and fed to the CT from the antenna 4a. The transmission/reception to the antenna is switched by a transmission/reception dividing filter 8 and a changeover switch 5. When the mobile car is about to enter a district with bad radio wave state such as rear part of a building, a mobile radio station 10 mounted on the mobile car is installed at the place, the control signal from the CT is received by an antenna 4b, amplified 3b and fed to a demodulator 1 through a coaxial cable 7. A modulation signal from the mobile car 9 is amplified 3d through a cable 7 and transmitted from the antenna 4b via the dividing filter 8.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a vehicle-mounted signal transmission system.

[Technical background of the invention and its problems]

Conventionally, a wired system has been used to transmit signals necessary for controlling a traveling vehicle equipped with a moving mechanism. This simply connects the controller and the control section mounted on the vehicle with copper wire or the like.

Therefore, vehicles must always drag the copper wire while moving, which greatly limits their movement and range of action. Additionally, as the amount of transmitted signals increases, the thickness of the steel wires also increases, making these cables a heavy burden on vehicles.

On the other hand, wireless signal transmission devices are being considered to compensate for the drawbacks of the wired method. FIG. 2 shows an example of this. This method freed the vehicle from having to draw copper wires and dramatically expanded its range of action.

However, the biggest drawback of wireless systems is that they are unreliable and that radio waves are easily affected by the environment.

If the vehicle is behind a building, the radio waves may not reach you.
It becomes impossible to control the vehicle. In particular, many traveling vehicles, such as cranes and cargo handling vehicles, perform some type of work, and it is extremely undesirable for their control functions to be affected by the state of the radio waves.

[Purpose of the invention]

This invention improves the drawbacks of the conventional method mentioned above.
In areas where the radio wave conditions are good, the vehicle can move freely using the wireless system, and in areas where the radio wave conditions are poor, the on-board wireless station is installed in a place where the radio wave conditions are good and the wired connection is carried out from there. The purpose of the present invention is to provide a signal transmission method that can always obtain good transmission and reception conditions by receiving signals at the same time.

[Summary of the invention]

The outline of this invention is as follows. First, when a moving vehicle is in an area with good radio wave conditions, a control signal from a controller is received wirelessly through an antenna installed in the moving vehicle.

This signal is amplified by an amplifier and then passed through a demodulator.
-cs*, *no**it<゜66・-"・Signals from various sensors in 911 pass through a modulator to AM or FMK
Modulated. This signal is then amplified through an amplifier and then transmitted to the controller through the above antenna. Switching between transmission and reception is performed through a transmission and reception duplexer.

When the vehicle continues to travel in the above conditions and attempts to enter an area where radio wave conditions are poor, such as behind a building, the mobile radio station installed in the vehicle is installed at that location. This radio station has a built-in antenna for transmitting and receiving, a transmitting and receiving branching filter, and an amplifier for amplifying the transmitted and received signals, and signals are transmitted and received from the controller via this mobile radio station. That is, control signals from the controller are received through an antenna built into the mobile radio station. This signal is amplified by an amplifier within the mobile radio station and then sent to a demodulator within the mobile vehicle. The signal demodulated by the demodulator is sent to each drive device in the moving vehicle.

On the other hand, signals from various sensors inside the moving vehicle are modulated into AM or FM through a modulator built into the moving vehicle.

This signal is then sent to the mobile radio station, amplified by the radio station's amplifier, and then sent to the antenna through the transmitter/receiver splitter. Here, the mobile vehicle and the mobile radio station are connected by a coaxial cable, and signals are transmitted through this cable.

When the vehicle again emerges from the shadow of the building and into an area with good radio reception, signal transmission takes place through the device built into the vehicle.

The mobile vehicle then retrieves the mobile radio station using the cable and continues its journey.

〔Effect of the invention〕

This invention has the following effects.

(11) In the conventional wired system, the movement of the vehicle is restricted by cables, and in the wireless system, the reliability of signal transmission is lacking, but with the present invention, when the radio wave condition is good and you want to move over a wide By using the wireless method alone, or in combination with the wired method in places where radio wave conditions are poor, signals can be reliably sent and received even if the range of movement is somewhat limited.

(2) In conventional wireless systems, it was necessary to run coaxial cables along the route of the moving vehicle and install antennas at several locations in order to improve the radio wave condition, but in the present invention, coaxial cables, etc. need to be installed. This is not necessary and the number of antennas to be installed can be significantly reduced.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to illustrated examples. 1st
The figure shows an embodiment of the invention in a block diagram.

When the moving vehicle is in an area with good radio wave conditions, various control signals from the controller to the moving vehicle are received wirelessly through an antenna 4a installed in the moving vehicle. This signal is amplified by an amplifier 3a, demodulated by a demodulator 1, and sent to each drive device. On the other hand, the signals from each glaze sensor moving eastward pass through the modulator 2 AM-? It is modulated into FM waves. After this signal is amplified through an amplifier 3C, it is transmitted from an antenna 4a to a controller. Transmission/reception switching for the antenna is performed using the transmission/reception duplexer 8.
It is done through.

Next (When a moving vehicle attempts to enter an area where the radio wave condition is poor, such as behind a building, the mobile radio station installed in the moving vehicle is installed at that location.Then, the transmission and reception of signals with the controller is This is carried out by the mobile radio station. That is, the control signal from the controller is received through the antenna 4b built in the mobile radio station. This signal is amplified by the amplifier 3b in the mobile radio station, and then sent to the coaxial cable 7. The entire signal is sent to a demodulator l inside the moving vehicle.

The signal demodulated by the demodulator 1 is sent to each drive device.

On the other hand, signals from various sensors inside the moving vehicle are modulated into AM-tFM waves through a modulator 2 built into the moving vehicle. This signal is then amplified by an amplifier 3d built into the mobile radio station through a coaxial cable 7, and then sent through a transmission/reception duplexer 8 to an antenna 4b.

When the vehicle moves out of the shadow of the building and into an area with good radio reception, signal transmission is performed through the vehicle's built-in device. The mobile vehicle then retrieves the mobile radio station using cable 7 and continues moving! Ru. Note that the switching between the mobile vehicle and the mobile radio station is performed in steps 1 and 5.

[Other embodiments of the invention]

Although FIG. 1 shows an example in which a wireless system using radio waves is used, it can also be easily applied to cases where ultrasonic waves or laser light are used. Furthermore, the present invention can be easily applied to transmission between one controller and a plurality of moving vehicles.

In addition, in FIG. 1, both the devices on the moving vehicle side and the mobile radio station side have transmitting and receiving functions, but the present invention can be easily applied even if the moving vehicle side is limited to the function of checking the radio wave state only. applied to.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional wireless-only transmission system. 1--Demodulator, 2--Modulator, 3a, 3bt3c,
3d...Amplifier, 4a+4b...Antenna, 5...
Selector switch, 6...power supply, 7...coaxial cable,
8... Transmission/reception duplexer, 9... Mobile vehicle, 1o... Mobile radio station, 11... Controller.

Claims (1)

[Claims] In the signal transmission system of mobile vehicles, a mobile radio station that has an amplifier for amplifying the transmitted and received signals, an antenna for transmitting and receiving, and a transmitting and receiving duplexer, and that can be stored in or separated from the body of the mobile vehicle, and transmits and receives signals In addition to an amplifier, an antenna, and a transmitting/receiving splitter, the mobile vehicle itself consists of a demodulator for the received signal, a modulator for the transmitted signal, a switch and a power supply for switching the use of devices on the mobile station side and the main body side. A signal transmission system for mobile vehicles characterized by comprising a built-in transceiver and a coaxial cable connecting the transceiver and a mobile radio station.