JPH0230908B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a signal system for indirectly controlling the movement of trains, automobiles, etc. when one of a plurality of signal lights goes out due to a failure. The present invention also relates to a method for immediately detecting when a signal light that should not be displayed is accidentally turned on due to a malfunction and controlling it to turn off the light or to display a safer signal.

[Conventional technology and its problems]

The conventional signal light lighting circuit is as shown in Figure 1.
It consisted of several signal relays and a signal bulb disconnection detector provided as necessary. in this case,
Signal relays are designed to prevent welding due to signal lamp lighting current and to have a fail-safe structure, so they are large in size and expensive. Furthermore, if an important traffic light continues to be turned off due to a break in the signal light, safety will be reduced, so it is necessary to add a signal light bulb break detector to the traffic light lighting control circuit. In addition, even if the signal bulb breakage detector is added, it is not possible to determine which bulb is broken in multiple red, blue, and yellow signal lights, for example.
There were problems such as the inability to perform safe indication control to automatically respond to failures. The present invention was made to improve the above-mentioned drawbacks, and the present invention has a lighting circuit that has a semiconductor switch that can be controlled by a microcomputer for each light bulb, a fuse that is connected in series to the lighting power supply circuit, and the fuse is intentionally blown when a failure is detected. A light bulb lighting circuit that gives priority to turning off the light, a circuit that shorts out a part of the circuit to blow the fuse,
Consists of a current sensor that converts the current in the light bulb lighting circuit into voltage and allows a microcomputer to test the current in the light bulb lighting circuit.The microcomputer checks each bulb lighting circuit for failures, and when a failure is detected, the signal light of the traffic light is turned on. Triax is a general-purpose electronic component that is characterized by controlling the lights to turn on or off so as to provide a safe indication.
The present invention provides a method for lighting signal lights that is small, lightweight, inexpensive, and highly safe, using small transformers, diodes, resistors, fuses, microcomputers, etc.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.
Figure 2 is a configuration diagram of this circuit, where BX and CX are AC power supplies that supply signal lights, G, Y, and R are signal lights that indicate green (go), sideways (caution), and red (stop), and TC.
1 to TC4 are triacs, S1 and S2 are current sensors with a signal light circuit as the primary coil and a resistor connected to the secondary side, F is a fuse, and the CPU is a microcomputer, and the control line from its output port to the trigger terminal of the triac is A signal line from the current sensor is connected to the input port. FLR is
This is the B contact of the CPU failure detection relay that forms the B contact when the CPU fails. Also, r is the current limiting resistance.
This is a resistor that adjusts the short circuit current of the G and Y lighting circuits including F to a constant value when TC4 is turned on. The method of fault diagnosis and fail-safe control in the event of a fault using this circuit will be explained below with reference to FIGS. 2 and 4.

First, when the signal light is turned on, the state of the signal light is inspected. In FIG. 2, when turning on the signal light G, the triaxes TC1 to TC4 are controlled to turn off to turn off all the signal lights. In this state t1, it is checked that the signal S2 is 0, that is, the current is 0 and the signal light is not lit. Next, the microcomputer outputs an on signal (high level signal) to C1 to control TC1 into a conductive state, causing current to flow through the G lamp and controlling its lighting. At the same time, input the S2 signal at t2 and confirm that the G light is lit. When lighting other signal lights, check the lighting in the same way. Next, when the G light continues to be lit, the voltage of the circuit S2 is read at regular intervals to confirm that the G light is lit, and a 0 signal is output to C1 for a short time to turn TC1 on.
OFF control and turn off the G light (t3). and S2
It is checked that the G light can be turned off at time t3 by the signal , that is, that the G light can be turned off normally at any time. In addition, for signal lights that are off, first turn off all lights, then control the lighting of the lights you want to inspect for a moment (about half a cycle of AC power) (t
4) Inspect the light-off circuit by checking the current at this time. The same applies to inspections of other signal lights. In these inspections, turning on an unlit signal light for inspection or turning off a lit signal light only takes a short time of a few milliseconds or less, and for a short period of time, it is almost impossible for a human to look at the traffic light. Changes in the traffic light display due to the inspection are not visible to the naked eye.

Next, a fail-safe control method when a failure of the signal light lighting circuit is detected will be explained. When a traffic signal is simply controlled by an electronic circuit, if a tri-ac fault occurs in the conduction side of the electronic circuit, G
Even when you want to turn off the light and turn on the Y and R lights on the more restrictive side, the G light remains lit, making it unsafe. Therefore, when TC1 and TC2 have a continuity failure, fuse F connected in series with them is blown,
Cut off the current flowing through Y. The F is fused by controlling the conduction of the triac TC4 by a microcomputer to short-circuit A and B of the circuit and temporarily increasing the current flowing through F. In the case of a failure in which the G and Y lights go out, it is possible to make it safer by controlling the display to a lower level, such as the Y for G and the R light for Y. In this way, the signal light circuit is inspected for short circuits and open circuits at fixed time intervals T.
By doing this sequentially, failures can be detected early, and the display of traffic lights can be safely controlled from the time a failure is detected, and a warning can be issued to maintenance personnel using a microcomputer. As for the microcomputer, it is assumed that the attached failure detection relay FLR can be restored (configuring the B contact of the FLR) when a failure is detected by the microcomputer's own self-check.

〔Effect of the invention〕

In power on/off circuits using semiconductors, especially in signal light lighting circuits that require fail-safe performance, if the semiconductor has a conduction failure, the power is turned off using the method described above, and if the semiconductor has an open failure, it will turn off the power to other signal lights on the safe side. By controlling the lighting so that it appears, fail-safe use of semiconductor switches has become possible. In other words, it becomes possible to fail-safely light a traffic light using an electronic circuit, and the traffic light lighting circuit can be constructed using general-purpose, inexpensive, and highly reliable electronic components, which can be expected to improve economic efficiency.
Furthermore, since failures can be detected in a short time and the failure duration time can be shortened, it is also expected to improve maintainability. In addition, if the signal light in Figure 2 is multi-filament lighting, the third
If a current sensor is provided for each filament as shown in the figure, it is possible to detect a half-broken core in a signal light (one-sided broken core in a multi-filament). In addition, railway signals can be precisely controlled by linking them to the track circuit and automatically turning them off at night when there are no trains, or reducing the brightness of the lights to save power, further improving economic efficiency. can be expected.

[Brief explanation of drawings]

Fig. 1 is a circuit configuration diagram showing a signal light lighting circuit using a conventional relay, Figs. 2 and 4 are circuit configuration diagrams for implementing the method of the present invention, and Fig. 3 is an operation in the circuit configuration of Fig. 2. This is a time chart to explain. In addition, BX and CX are AC power supplies, HR and DR are signal light control relays, AiR is a signal light bulb disconnection detector, and TC.
1 to TC4 are triaxes, S1 and S2 are current sensors, F is a fuse, CPU is a microcomputer, and FLR is a failure detection relay for the microcomputer.

Claims (1)

[Claims] 1. In a traffic light consisting of multiple light bulbs (signal lights) that are lit by an AC power source, a semiconductor switch that can control on/off the lighting power source for each signal light using the AC power source for the traffic light and a microcomputer, a current sensor for the signal light lighting circuit, It consists of a fuse connected in series with some signal lights, a short-circuit switch that can be turned on and off by a microcomputer, a microcomputer, and a signal light. Multiple signal lights are turned on and off in sequence for a short period of time that does not interfere with the display of the lights, and the lighting status of the signal lights is inspected based on the presence or absence of current at that time.
When a failure is determined, the signal lights are turned on by forcibly turning them off using a fuse or by controlling the lighting of normal signal lights to turn on or off multiple signal lights depending on the nature of the failure so as to provide a safer indication than the failure state. A fail-safe electronic control method for a signal light, characterized in that it ensures fail-safe performance.