JP2729377B2 - Traffic light - Google Patents

Description

The present invention relates to a traffic signal used at intersections and crossings,
In particular, it relates to the setting of the auditory signal generated by this device.

[Conventional technology]

Conventionally, this type of traffic signal is connected to a traffic signal controller installed at an intersection and emits music from a speaker when a pedestrian traffic signal turns blue. And, by playing this music, it became possible to know that the signal turned green. Further, the noise level around the intersection is measured by a microphone installed at a position that is not affected by the music emitted from the speaker, and the music emitted from the speaker is set to a level that is not canceled by the ambient noise.

[Problems to be solved by the invention]

As described above, in the conventional apparatus, in order to measure the noise level around the intersection, it is necessary to adjust the installation position so as to eliminate mutual interference by providing a certain distance between the speaker and the microphone. For this reason, due to the restrictions on the installation position, it is not possible to install a microphone for noise level measurement depending on the form of the intersection,
Alternatively, there has been a problem that the installation work is significantly restricted and the freedom of the installation work is lost.

Further, in order to solve this problem, it is sufficient to measure the noise level immediately before the emission sound is generated from the speaker without providing a microphone, and determine the output level of the speaker based on the noise level. However, the noise level around the intersection, even while pedestrians are crossing the road,
Since the audio signal dynamically changes even while the auditory signal is being generated from the speaker, the music generated by the speaker may not be heard in a certain time zone.
For this reason, there is a problem that it is not possible to cross the car even though the car can cross the car, or that the music cannot be heard during the crossing and the car crosses in a hurry.

[Means for solving the problem]

The present invention provides a noise measurement circuit that measures an ambient noise level in a predetermined noise frequency band, outputs an audio signal in a frequency band different from the noise frequency band, and outputs an audio signal in accordance with a measurement result of the noise measurement circuit. And a signal generating circuit for changing the level.

[Action]

Even if the noise around the intersection and the auditory signal are mixed, the noise level is always reliably measured.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a main roadside lamp which is installed at an intersection and informs a vehicle whether or not to cross the intersection, 2 denotes a pedestrian lamp which is installed at an intersection and informs pedestrians whether or not to cross the intersection, 3 Is a traffic signal controller for controlling the flashing of the signals of the main roadside light 1 and the pedestrian light 2 to control the traffic control of vehicles and pedestrians at intersections. A music (speech) generating device that receives a control signal to be output and emits music or sound or the like, 5 is a push button box pressed when a pedestrian crosses a road, and 6 is music as an auditory signal (for example, , Etc.), and 7 is a microphone for measuring the surrounding noise level at the intersection.

The music generator 4 includes a noise measurement circuit (not shown) that measures a noise level around the intersection based on a signal input from the microphone 7, and sets a frequency band of music emitted from the speaker 6 to a frequency band different from the noise around the intersection. And a signal generating circuit (not shown) for determining the output level of the music.

The graph of FIG. 2 shows the noise frequency-noise level characteristics (curve 11) of the noise collected by the microphone 7 and the speaker 6
Represents the frequency of the auditory signal versus the level of the auditory signal (curve 12) of the music that is released from FIG. 5, in which the horizontal axis represents frequency and the vertical axis represents level. A is a frequency band of noise measured by the noise measurement circuit based on an input signal from the microphone 7, and B is a frequency band of an auditory signal emitted from the speaker 6 based on an output signal from the signal generation circuit.

As shown in the figure, the frequency band B of the music emitted from the speaker 6 is set higher than the frequency band A of the noise in view of the characteristics of human hearing. This is because the source of the noise (70 dB or more) at the intersection is mainly the engine sound of an automobile having a low frequency band indicated by the frequency band A or the mechanical sound of a train or the like. For this reason, even if music and noise are mixed, the noise measurement circuit can distinguish between noise and music from the signal collected from the microphone 7 and only the surrounding noise without being affected by the music emitted from the speaker 6. It is configured to be able to measure.

The curve 11 can also be used by compressing the noise collection level at each frequency value in consideration of the frequency response in human hearing.

The graph of FIG. 3 shows the output level (vertical axis) of the auditory signal emitted from the speaker 6 according to the signal from the signal generation circuit,
The relationship with the noise level around the intersection (horizontal axis) is shown.

Generally, the noise level around the intersection is about 20 to
There is a 50dB level difference. For this reason, the signal generation circuit is configured to vary the output level of the music emitted from the speaker 6 according to the measurement result of the ambient noise from the noise measurement circuit. In other words, the signal generation circuit has three output level-noise level characteristic straight lines shown in FIG. 3 according to the noise level.
A characteristic line most suitable for the state of the intersection at that time is selected from 21, 22, and 23, and a signal according to the characteristic line is generated and output to the speaker 6. Then, the speaker 6 emits music of an output level based on this signal. Reference numeral 24 denotes the lowest level of the music output from the speaker 6, which drops to a level at which the output music cannot be put to practical use when there is almost no noise, for example, during a quiet time (40 dB or less) at night. Is prevented.

In such a configuration, the traffic signal controller 3 normally controls the main roadside lamp 1 and the pedestrian lamp 2. However, when the pedestrian operates the push button of the push button box 5 at the intersection where the present device is installed, this operation is detected by the music generator 4. Then, the music generator 4 is connected to the pedestrian light 2 by the traffic signal controller 3.
Waiting for the green signal to be transmitted, the music signal is output from the signal generation circuit in synchronization with the transmission of the green signal, which gives the pedestrian the right to cross the road. The output of this signal is continued while the green signal is transmitted from the traffic controller 3 to the pedestrian lamp 2, and the speaker 6 emits predetermined music while the music signal is being input. As described above, an optimum output level of this music is selected according to the level of the ambient noise from the microphone 7, and its frequency band is set to be different from the frequency band of the noise. Therefore, the music output from the speaker 6 can always be music having a necessary and sufficient volume.

As described above, in the present embodiment, the noise measurement circuit can measure noise while distinguishing between noise and music, so that the installation position of the microphone 7 is not restricted as in the related art. For this reason, the microphone 7 can be installed at a position where the sound that enters the ears of the pedestrian is detected, and the pedestrian can listen to music having an optimum volume. In addition, there is a degree of freedom in the work of installing the signal device, and the signal device can be installed even at an intersection in a limited space.

In addition, the signal generation circuit selects and outputs the music output level according to the noise measurement result of the noise measurement circuit, so that the intersection is near the railroad under the guard or near the intersection. Even if a vehicle with a loud engine sound stops or the noise level around the intersection fluctuates while music is being emitted, the music generator 4 is always canceled out by the optimal level, that is, the noise. Unequal level music can be emitted from the speaker 6. Further, the same applies even if a noise level difference occurs due to a difference between day and night.

〔The invention's effect〕

As described above, the present invention includes a noise measurement circuit that measures the surrounding noise level, and a signal generation circuit that sets the frequency band of the auditory signal and varies the output level, thereby reducing noise around the intersection. Even if the auditory signal is mixed, the noise level is always reliably measured.

For this reason, the hearing signal generated by this device can always be set to the optimum level according to the measurement result of the noise level, and is not canceled out by the surrounding noise, so that the pedestrian always outputs a clear hearing signal. This has the effect of being able to detect and safely cross the road.

In addition, there are no restrictions on the installation positions of the speaker and the microphone, and the installation work is free, so that the device can be installed at any type of intersection, and the audible signal is best for pedestrians. Has the effect that these speakers and microphone can be installed at the optimal positions where the information can be transmitted.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 3 is a graph showing the noise measured from the microphone 7 and the frequency-level characteristics of the music output from the speaker 6. FIG. 3 shows the relationship between the output level of the music output from the speaker 6 and the ambient noise level at the intersection. FIG. DESCRIPTION OF SYMBOLS 1 ... Main roadside light device 2 ... Pedestrian light device 3 ... Traffic signal control device 4 ... Music (voice) generation device 5 ... Push button box 6 ... Speaker 7 ... a microphone.

Claims (1)

(57) [Claims] 1. A traffic signal device that notifies a pedestrian crossing a pedestrian crossing that a pedestrian signal has turned blue by means of an auditory signal such as music or voice, and measures a surrounding noise level in a predetermined noise frequency band. And a signal generation circuit that outputs the auditory signal in a frequency band different from the noise frequency band, and that varies an output level of the auditory signal in accordance with a measurement result of the noise measurement circuit. A traffic signal that features.