JPS62169069A - Sound source direction finder - Google Patents

Abstract

PURPOSE:To surely detect the direction of the presence of another ship even when hydrographic conditions or weather becomes adverse by obtaining a sound source direction based on the output signals of a rotating microphone and a fixed microphone. CONSTITUTION:The output signals S1 and S2 of rotating and fixed microphones 2 and 3 are inputted to an arithmetic sequence unit 7 via filter circuits 4 and 8, amplifying circuits 5 and 9 and A/D converters 6 and 10, respectively. The unit 7 obtains the signals S1a corresponding to a sound source level from the output signals S1 and S2 of the rotating and fixed microphones 2 and 3, respectively, and obtains the time (ta) when the maximum level of the signals S1a is generated in an interval T1 based on a trigger pulse generating period to obtain the direction wherein a sound source is present. Thus, even when hydrographic conditions or weather becomes adverse, the navigating position of another ship can be surely detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sound source direction finding method (1) which is applied to detecting the direction of another ship by its sound source, for example, while the ship is sailing.

[Conventional technology]

When a ship is underway, if the location of other ships is clear, navigational scandals can be avoided.

In this case, the navigational position of the other vessel can be confirmed by listening to the sound emitted from the other vessel on the bridge of the vessel, and the direction in which the other vessel is present can be determined from the radar display. .

[Problem that the invention seeks to solve]

However, with the above-mentioned method of knowing the direction of other navigating vessels, it is difficult to reliably determine the direction, especially when visibility is poor due to bad weather conditions. It becomes difficult.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a sound source direction detection device that can reliably detect the direction of existence of other ships even under adverse sea and weather conditions.

[Means for solving problems]

The present invention includes a highly directional rotating microphone that rotates at a constant angular velocity, an omnidirectional fixed microphone, a pulse generation circuit that generates a trigger pulse in synchronization with the rotational speed of the rotating microphone, and a rotating microphone. and a sound source direction calculating means which receives the output signal of the fixed microphone and the output signal of the fixed microphone to obtain a signal corresponding to the sound source level and calculates the direction of the sound source from the time of occurrence in the trigger pulse generation cycle of the maximum level of this signal. This is a sound source direction finding device that attempts to achieve the following.

(Function) By providing the above-mentioned means, the present invention can obtain a signal corresponding to one sound source novel by the output signal of the rotating microphone and the output signal of the fixed microphone, and the generation time of the maximum level of this signal is set as the trigger pulse. The direction of the sound source can be determined by determining the generation period.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 are block diagrams showing one embodiment of a sound source direction detection device, and FIG. 3 is a diagram showing a navigation state of a ship equipped with this sound source direction detection device.

The ship 1 is provided with a highly directional rotating microphone 2 that rotates at a constant angular velocity ω and an omnidirectional fixed microphone 3. Note that it is desirable that these microphones 2.3 be installed on the ship 1 in a position where there is nothing to block the propagating sound waves. Therefore, a filter circuit 4 is connected to the output end of the rotating microphone 2 to remove noise components and improve the S/N ratio, and an A/D converter 6 is connected to this filter circuit 4 through an amplifier circuit 5. A digital signal corresponding to the output signal level of the microphone 2 is sent to the control calculation section 7. On the other hand, a filter circuit 8, an amplifier circuit 9, and an A/D converter 10 are connected to the output end of the fixed microphone 3 in the same way as the rotary microphone 2, and a digital signal corresponding to the output signal level of the fixed microphone 3 is sent to the control calculation section. 7. Further, a trigger pulse generation circuit 11 is provided, and this trigger pulse generation circuit 11 generates a co-trigger pulse in synchronization with the rotational speed of the rotating microphone 2, that is, when the wave receiving part of the rotating microphone 2 faces toward the leading direction A of the ship 1. is generated. Therefore, trigger pulses are generated periodically in synchronization with the rotational speed of the rotating microphone 2. Note that this trigger pulse is A
The signal is converted into a digital signal by the /D converter 12 and sent to the control calculation section 7.

The library control sieve unit 7 includes a rotating microphone 2 and a fixed microphone 3.
As a sound source direction calculation means that receives the digital signals of each output signal and the digital signal of the trigger pulse, calculates and determines the direction θ in which the sound source Q exists, and determines this sound source Q as the position where another ship is navigating. It has the function of Specifically, it has various functions as shown in FIG. That is, the maximum level detection section 7-1 detects the maximum level of the output signal of the rotary microphone 2 in this period, with the period from when a trigger pulse is generated until the next trigger pulse is generated as one period, and detects the maximum level of the output signal of the rotary microphone 2 in this period. This function has the function of determining the average maximum level of , and also determining the time of occurrence in that section. Further, the maximum level detection section 7-1 receives the output signal of the rotary microphone 2 corrected by the correction level calculation section 7-2, and inputs the maximum level of the output signal of the rotary microphone 2 in each section as described above. It has the function of detecting the level, finding the average maximum level, and finding the time of occurrence. The correction level calculating section 7-2 has a function of correcting the output signal of the rotary microphone 2 with the output signal of the fixed microphone 3, especially when the sound pressure level emitted from the sound source Q changes. Direction calculation section 7-3
has a function of calculating and determining the direction θ in which the sound aQ exists from the time determined by the maximum level detection section 7-1. Note that 13 is a display circuit, and 14 is a rotation drive control section for the rotary microphone 2.

Next, the operation of the apparatus configured as described above will be explained. When the ship 1 is sailing, the rotary microphone 2 is rotated in one direction shown in FIG. 3 at a constant angular velocity ω by the rotational drive control unit 14. Further, at the same time, the trigger pulse generation circuit 11 generates one trigger pulse r when the wave receiving part of the rotating microphone 2 faces in the leading direction A, thereby generating a period T1.
A co-trigger pulse is generated every time. Here, if another ship is navigating and that ship is detected as a ¥i source,
The sound waves propagate and are received by each rotating microphone 2 and fixed microphone 3. By the way, since the rotating microphone 2 is rotating, its output signal S1 reaches its maximum level when facing in the direction where the sound source Q exists, as shown in FIG. This output signal @sl passes through the filter circuit 4, the amplifier circuit 5, and the A/D converter 6, and is sent to the control calculation section 7 as a digital signal. In addition, the sound wave from the sound source Q is also transmitted from the fixed microphone 3, and its output signal S2
is sent to the control calculation unit 7 through the filter circuit 8, the amplifier circuit 9, and the Δ/D converter 10. Note that each digitized output signal S1, S2 and trigger pulse r
A schematic diagram of this is shown in FIG.

Now, in the υj sin calculation unit 7, the following calculation operation is executed. That is, the maximum level detection section 7-1 detects the maximum level of the output signal S1 in the section T1 by each trigger pulse r, and each trigger pulse r at this maximum level
The time ta from the time of occurrence is determined. Then, this time ta is determined over a predetermined interval T1, and the average maximum level is calculated and determined. That is, Σta i/Tx i
=(l)i=1 is calculated by @. Then, this determined value is sent to the direction calculating section 7-3, and the direction θ of the sound source Q is determined. That is, the following is calculated to determine the direction of existence θ of the sound source Q.

Note that the direction θ in which the sound source Q exists is displayed on the display circuit 13.

By the way, the direction of existence θ of the sound source Q can be determined from the above explanation, but this can be applied when the sound pressure generated by the sound source Q is approximately constant. Therefore, when the sound pressure changes, the output signal S1 of the rotating microphone 2 is corrected by the level calculating section 7-
2 and perform the correction. That is, this correction level calculation unit 7-2 takes in each output signal S1, S2, and calculates sla - s1/ s2 (s2≠0) sla -0
(s2-0) - (3) is executed and corrected to obtain a signal S1a corresponding to the sound pressure level of sound #iQ (FIG. 6). Then, this signal s1a is sent to the maximum level detection section 7-1, the maximum level in each section Tr is detected, and the time ta of its occurrence is calculated and determined.

Then, when this generation time (a) is determined, it is sent to the direction calculation section 7-3, and the direction θ of the sound source Q is determined from the above equation (2) and displayed. The direction θ of the ship's existence can be determined.

In this way, in the above embodiment, the signal s1a corresponding to the sound source level is generated by the output signal S1 of the rotating microphone 2 and the output signal S2 of the fixed microphone 3, and this signal se
The generation time ta of the maximum level of a is defined as the interval T! according to the trigger pulse generation cycle. Since the direction of existence θ of the sound source Q is determined by determining the direction of existence θ of the sound source Q, the direction of existence θ of the sound source Q can be reliably determined, and thereby the navigation position of other ships can be easily determined. In particular, reliable judgment can be made even when the sea and weather conditions are adverse. In addition, since the sound pressure level of the sound source Q is detected using the output signal S2 of the fixed microphone 3, and the output signal @S1 of the rotating microphone 2 is corrected using this, the sound r
Even if the sound pressure of AQ changes, its direction θ can be determined without being affected by the change.

Note that the present invention is not limited to the above-mentioned embodiment, and may be modified without departing from the spirit thereof. For example, the present invention can be applied not only to ships but also to systems that determine the position of objects related to a sound source by detecting the position of the sound source.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a sound source direction detection device that can reliably detect the direction of existence of another ship even if the sea and weather conditions are bad.

[Brief explanation of drawings]

1 and 2 are block diagrams showing one embodiment of the sound source direction detection device according to the present invention, FIG. 3 is a diagram showing the navigation state of a ship to which the device of the present invention is applied, and FIGS. 4 to 6 FIG. 2 is a diagram for explaining the action of determining the direction of existence in the device of the present invention. DESCRIPTION OF SYMBOLS 1... Ship, 2... Rotating microphone, 3... Fixed microphone, 7... Control calculation section, 7-1... Maximum level detection section, 7-2... Correction level calculation section, 7-3... Direction calculation section, 11... Trigger pulse generation circuit. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 2g3$ Figure 4 Figure 5, ta. Figure 6

Claims (1)

[Claims] a highly directional rotating microphone that rotates at a constant angular velocity, an omnidirectional fixed microphone, a trigger pulse generation circuit that generates a trigger pulse in synchronization with the rotational speed of the rotating microphone, and an output signal of the rotating microphone and the and sound source direction calculation means which receives the output signal of a fixed microphone, obtains a signal corresponding to the sound source level, and calculates the sound source direction from the generation time in the trigger pulse generation cycle of the maximum level of this signal. Sound source direction finding device.