JP2603654B2 - Ultrasonic array sensor - Google Patents
Ultrasonic array sensorInfo
- Publication number
- JP2603654B2 JP2603654B2 JP26003587A JP26003587A JP2603654B2 JP 2603654 B2 JP2603654 B2 JP 2603654B2 JP 26003587 A JP26003587 A JP 26003587A JP 26003587 A JP26003587 A JP 26003587A JP 2603654 B2 JP2603654 B2 JP 2603654B2
- Authority
- JP
- Japan
- Prior art keywords
- ultrasonic
- openings
- array sensor
- ultrasonic transducers
- ultrasonic transducer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
Description
【発明の詳細な説明】 ［技術分野］ 本発明は、複数個の超音波振動子を配列した超音波ア
レイセンサに関するものである。Description: TECHNICAL FIELD The present invention relates to an ultrasonic array sensor in which a plurality of ultrasonic transducers are arranged.
［背景技術］ 超音波センサは、超音波を利用してセンシングを行う
ものであり、パルス波を送信し検知物体からの反射波を
受信するまでの伝搬時間を検出することで物体までの距
離を検出する存在検知型のパルス方式のものや、連続波
を送信し移動物体からの反射波を受信し反射波の周波数
シフトにより移動物体を検出するドップラ方式のものな
どの種々の検知方式のものがある。この種の超音波セン
サでは、超音波が可聴域の音波に比べて波長が短いため
指向性を有し、従って監視したい範囲を限定することが
できる利点を有する。[Background Art] An ultrasonic sensor performs sensing using ultrasonic waves, and detects the propagation time from the transmission of a pulse wave to the reception of a reflected wave from a detection object to thereby determine the distance to the object. There are various types of detection methods such as the presence detection type of pulse system that detects, the Doppler system that transmits a continuous wave, receives the reflected wave from a moving object, and detects the moving object by frequency shift of the reflected wave. is there. This type of ultrasonic sensor has an advantage that the ultrasonic wave has directivity since the wavelength is shorter than the sound wave in the audible range, and therefore, the range to be monitored can be limited.
ところで、従来の超音波振動子を複数個配列した超音
波アレイセンサ（第５図に示す）では、素子としての超
音波振動子１の配列ピッチｄ、素子数などを変えて所望
の指向性を得ていた。さらに詳しくは、上記超音波アレ
イセンサの指向特性は、各々の素子単体の指向性Ｄ
（θ）と、超音波アレイセンサの配列ピッチｄと素子数
などによって決定されるアレイファクタＦ（θ）との積
で求められる。上記超音波振動子１には、その変換方式
により圧電型振動子、磁歪型振動子、静電型振動子など
の各種のものがある。ところが、送受信感度、周波数特
製などや生産性などにより、超音波振動子の形状の小型
化にも限界があり、現在開発され市販されているもので
は直径が1.2λ（λ：波長）程度のものしか製造できな
い。Meanwhile, in a conventional ultrasonic array sensor (shown in FIG. 5) in which a plurality of ultrasonic transducers are arranged, a desired directivity is obtained by changing the arrangement pitch d of the ultrasonic transducers 1 as elements, the number of elements, and the like. I was getting it. More specifically, the directional characteristic of the ultrasonic array sensor is the directivity D of each element alone.
(Θ) and an array factor F (θ) determined by the array pitch d of the ultrasonic array sensor and the number of elements. The ultrasonic vibrator 1 includes various types such as a piezoelectric vibrator, a magnetostrictive vibrator, and an electrostatic vibrator according to the conversion method. However, there is a limit to the miniaturization of the shape of the ultrasonic vibrator due to transmission / reception sensitivity, frequency specialty, productivity, etc. Currently developed and marketed ultrasonic transducers have a diameter of about 1.2λ (λ: wavelength). Can only be manufactured.
このような超音波振動子１を用いた超音波アレイセン
サの指向特性を第６図に示す。なお、この第６図は素子
単体の指向性Ｄ（θ）は同一のものとしたアレイファク
タＦ（θ）を示してある。この超音波アレイセンサで
は、正面方向のビーム（メインローブ）の他に、左右約
60゜degの方向に別のビーム（グレーティングローブ）
が生じ、任意の指向特性で検知範囲を限定するという意
味で問題があった。上述のような超音波アレイセンサの
指向特性において、グレーティングローブが生じる方向
は、主に配列ピッチにより決まり、配列ピッチすなわち
素子の径ｄが一波長より大きくなると、±90゜deg以内
に生じ、ｄ＝1.2λの場合には約±60゜degの方向にグレ
ーティングローブが生じるのである。FIG. 6 shows the directional characteristics of an ultrasonic array sensor using such an ultrasonic transducer 1. FIG. 6 shows an array factor F (θ) in which the directivities D (θ) of the single elements are the same. In this ultrasonic array sensor, in addition to the beam in the front direction (main lobe),
Another beam (grating lobe) in the direction of 60 ° deg
This causes a problem in that the detection range is limited by an arbitrary directional characteristic. In the directional characteristics of the ultrasonic array sensor as described above, the direction in which the grating lobe occurs is mainly determined by the arrangement pitch. When the arrangement pitch, that is, the element diameter d is larger than one wavelength, it occurs within ± 90 ° deg. In the case of = 1.2λ, grating lobes are generated in a direction of about ± 60 °.
［発明の目的］ 本発明は上述の点に鑑みて為されたものであり、その
目的とするところは、超音波振動子の形状が大きくて
も、グレーティングローブのない指向特性を得ることが
できる超音波アレイセンサを提供することにある。[Object of the Invention] The present invention has been made in view of the above points, and an object of the present invention is to be able to obtain a directional characteristic without grating lobes even if the shape of the ultrasonic transducer is large. An object of the present invention is to provide an ultrasonic array sensor.
［発明の開示］ （構成） 本発明は、複数個の超音波振動子を配列して形成され
た超音波アレイセンサにおいて、各超音波振動子に対応
する位置に複数個の開口が穿孔されたマスクを超音波振
動子の送受波面側に設け、上記各超音波振動子の開口を
超音波振動子の中心に対して対称位置に形成すると共
に、各超音波振動子の開口の間隔と、互いに隣接する超
音波振動子の隣接側の開口の間隔とを同一間隔に形成し
たものであり、超音波振動子の形状が大きくても、マス
クの各超音波振動子毎に穿孔された複数個の開口によ
り、配列ピッチを狭くして超音波振動子を配列したもの
と同等にでき、これによりグレーティングローブのない
指向性を得ることができるようにしたものである。[Disclosure of the Invention] (Configuration) In the present invention, in an ultrasonic array sensor formed by arranging a plurality of ultrasonic transducers, a plurality of openings are perforated at positions corresponding to the respective ultrasonic transducers. A mask is provided on the transmission / reception surface side of the ultrasonic transducer, and the openings of the respective ultrasonic transducers are formed at symmetrical positions with respect to the center of the ultrasonic transducer. The interval between the openings on the adjacent side of the adjacent ultrasonic transducer is formed at the same interval, and even if the shape of the ultrasonic transducer is large, a plurality of holes perforated for each ultrasonic transducer of the mask are provided. The aperture makes it possible to narrow the arrangement pitch and make it equal to the arrangement of the ultrasonic transducers, thereby obtaining directivity without grating lobes.
（実施例１） 第１図及び第２図に本発明の一実施例を示す。本実施
例においては、複数個の圧電型の超音波振動子１を一列
に配列して形成された超音波アレイセンサであり、各超
音波振動子１の送受波面である上面の上方に複数個の開
口３が穿孔されたマスク２を被設してある。本実施例で
は各超音波振動子１について夫々２個の開口３が穿孔し
てあり、各超音波振動子１に対応する２個の開口３は超
音波振動子１の中心に対して対称位置に形成してある。
なお、本実施例では第１図（ｂ）に示す各超音波振動子
１の中心を結ぶ線上に夫々の開口３を形成してある。こ
のように各超音波振動子１に２個の開口３を設けると、
各超音波振動子１で得られる出力は夫々の開口３により
得られる出力の合成となり、夫々独立した２個の開口３
により形成される音源の合成として考えられる。また、
各超音波振動子１上に形成された開口３の間隔d1と、互
いに隣接する超音波振動子１上の互いに隣接する開口３
との間隔d2とは同一間隔としてある。つまりはマスク２
のすべての開口３を等間隔で穿孔してある。各超音波振
動子１出力は合成器４で合成され、結果的には夫々の開
口３に応じた音源の合成となる。Embodiment 1 FIGS. 1 and 2 show an embodiment of the present invention. In the present embodiment, an ultrasonic array sensor is formed by arranging a plurality of piezoelectric ultrasonic transducers 1 in a line, and a plurality of piezoelectric ultrasonic transducers 1 are provided above an upper surface that is a wave transmitting / receiving surface of each ultrasonic transducer 1. Is provided with a perforated mask 2. In this embodiment, two openings 3 are perforated for each ultrasonic vibrator 1, and two openings 3 corresponding to each ultrasonic vibrator 1 are symmetrically positioned with respect to the center of the ultrasonic vibrator 1. It is formed in.
In this embodiment, each opening 3 is formed on a line connecting the centers of the respective ultrasonic transducers 1 shown in FIG. 1 (b). When two openings 3 are provided in each ultrasonic transducer 1 in this manner,
The output obtained by each ultrasonic transducer 1 is a composite of the outputs obtained by the respective apertures 3, and the two independent apertures 3
Can be considered as a synthesis of the sound source formed by Also,
The distance d 1 of the opening 3 formed on each of the ultrasonic transducers 1, adjacent to each other on the ultrasonic vibrator 1 adjacent the aperture 3
There as the same interval as the distance d 2 between. That is, mask 2
Are all perforated at equal intervals. The output of each ultrasonic transducer 1 is synthesized by the synthesizer 4, resulting in synthesis of a sound source corresponding to each aperture 3.
第２図に本実施例の超音波アレイセンサの指向特性
（アレイファクタ）を示す。上述のような開口３が穿孔
されたマスク２を設けることにより、従来例の第５図に
示すように単に超音波振動子１を配列したものより、少
なくとも配列ピッチを半分にした場合と同等にでき（例
えば配列ピッチ1.2λの超音波振動子１を用いた場合に
は0.6λとなる）、第２図に示すようにグレーティング
ローブのないメインローブのみの指向特性を得ることが
できる。FIG. 2 shows the directional characteristics (array factor) of the ultrasonic array sensor of this embodiment. By providing the mask 2 in which the openings 3 are perforated as described above, at least the arrangement pitch is reduced to half that of the conventional example in which the ultrasonic transducers 1 are simply arranged as shown in FIG. (For example, 0.6λ when the ultrasonic transducer 1 having an arrangement pitch of 1.2λ is used), it is possible to obtain the directivity characteristic of only the main lobe without the grating lobe as shown in FIG.
（実施例２） 本実施例では、第３図に示すように、各超音波振動子
１を縦横に配列してあり、夫々の超音波振動子１につい
て４個の開口３を設けてある。なお、本実施例において
も、各超音波振動子１の開口３は超音波振動子１の中心
に対して対称位置に形成してあり、縦横に配列された各
超音波振動子１上に形成された開口３の間隔と、互いに
隣接する超音波振動子１同士の互いに隣接する開口３と
の間隔とは同一間隔としてある。本実施例の場合にも上
述の従来例と同様に配列ピッチを一波長以下にすること
ができ、グレーティングローブのない指向特性を得るこ
とができ、しかも開口３の数が増加することにより、第
１の実施例に比べて各超音波振動子１毎の音圧レベルや
感度が良くなる。Embodiment 2 In this embodiment, as shown in FIG. 3, the ultrasonic transducers 1 are arranged vertically and horizontally, and four openings 3 are provided for each ultrasonic transducer 1. Also in this embodiment, the openings 3 of the respective ultrasonic transducers 1 are formed at symmetrical positions with respect to the center of the ultrasonic transducer 1, and are formed on the respective ultrasonic transducers 1 arranged vertically and horizontally. The interval between the openings 3 and the interval between the adjacent ultrasonic transducers 1 and the adjacent openings 3 are the same. Also in the case of this embodiment, the arrangement pitch can be made equal to or less than one wavelength as in the above-described conventional example, a directional characteristic without grating lobes can be obtained, and the number of apertures 3 can be increased. As compared with the first embodiment, the sound pressure level and sensitivity of each ultrasonic transducer 1 are improved.
（実施例３） 第４図は本発明のさらに他の実施例を示す図であり、
本実施例においては第１の実施例と超音波振動子１の配
列や開口３の数及び形成位置などが同様に形成したもの
であり、マスク２に形成された開口３の径を可変して音
圧レベルや感度を可変した点に特徴がある。つまり、本
実施例においては、中央の超音波振動子１の開口３の径
を大きく、両側に行く程に徐々に開口３の径を小さくし
てある。本実施例によれば、開口３の径を変えることに
より、各開口３で得られる音圧レベルや感度を変えるこ
とができ、このため超音波振動子１の感度に重み付けを
行うことができ、さらにグレーティングローブを低減さ
せることができる。(Embodiment 3) FIG. 4 is a view showing still another embodiment of the present invention.
In this embodiment, the arrangement of the ultrasonic transducers 1 and the number and positions of the openings 3 are formed in the same manner as in the first embodiment, and the diameter of the openings 3 formed in the mask 2 is changed. It is characterized by varying the sound pressure level and sensitivity. That is, in this embodiment, the diameter of the opening 3 of the center ultrasonic transducer 1 is increased, and the diameter of the opening 3 is gradually reduced toward both sides. According to the present embodiment, by changing the diameter of the openings 3, the sound pressure level and the sensitivity obtained at each opening 3 can be changed, so that the sensitivity of the ultrasonic transducer 1 can be weighted, Further, grating lobes can be reduced.
［発明の効果］ 本発明は上述のように、各超音波振動子に対応する位
置に複数個の開口が穿孔されたマスクを超音波振動子の
送受波面側に設け、上記各超音波振動子の開口を超音波
振動子の中心に対して対称位置に形成すると共に、各超
音波振動子の開口の間隔と、互いに隣接する超音波振動
子の隣接側の開口の間隔とを同一間隔に形成してあるの
で、超音波振動子の形状が大きくても、マスクの各超音
波振動子毎に穿孔された複数個の開口により、配列ピッ
チを狭くして超音波振動子を配列したものと同等にで
き、このためグレーティングローブのない指向性を得る
ことができる効果がある。[Effects of the Invention] As described above, the present invention provides a mask in which a plurality of openings are perforated at positions corresponding to the respective ultrasonic vibrators on the transmitting / receiving surface side of the ultrasonic vibrator. Are formed symmetrically with respect to the center of the ultrasonic transducer, and the interval between the openings of each ultrasonic transducer and the interval between the openings on the adjacent side of the ultrasonic transducer adjacent to each other are formed at the same interval. Even if the shape of the ultrasonic vibrator is large, it is equivalent to an ultrasonic vibrator arranged by narrowing the arrangement pitch with a plurality of openings perforated for each ultrasonic vibrator of the mask Therefore, there is an effect that directivity without grating lobe can be obtained.
第１図（ａ）は本発明の一実施例の概略構成図、同図
（ｂ）は同上の平面図、第２図は同上の指向特性図、第
３図は本発明の他の実施例の平面図、第４図は本発明の
さらに他の実施例の平面図、第５図は従来例の概略構成
図、第６図は同上の指向特性図である。 １は超音波振動子、２はマスク、３は開口、d1,d2は間
隔である。1 (a) is a schematic configuration diagram of an embodiment of the present invention, FIG. 1 (b) is a plan view of the same, FIG. 2 is a directional characteristic diagram of the same, and FIG. 3 is another embodiment of the present invention. FIG. 4 is a plan view of still another embodiment of the present invention, FIG. 5 is a schematic configuration diagram of a conventional example, and FIG. 6 is a directional characteristic diagram of the same. 1 is an ultrasonic transducer, 2 is a mask, 3 is an opening, and d 1 and d 2 are intervals.
Claims (2)
た超音波アレイセンサにおいて、各超音波振動子に対応
する位置に複数個の開口が穿孔されたマスクを超音波振
動子の送受波面側に設け、上記各超音波振動子の開口を
超音波振動子の中心に対して対称位置に形成すると共
に、各超音波振動子の開口の間隔と、互いに隣接する超
音波振動子の隣接側の開口の間隔とを同一間隔に形成し
て成ることを特徴とする超音波アレイセンサ。In an ultrasonic array sensor formed by arranging a plurality of ultrasonic transducers, a mask having a plurality of openings perforated at positions corresponding to the respective ultrasonic transducers is provided. Provided on the transmitting and receiving surface side, the openings of the respective ultrasonic transducers are formed at symmetrical positions with respect to the center of the ultrasonic transducer, and the intervals between the openings of the respective ultrasonic transducers and the ultrasonic transducers adjacent to each other are formed. An ultrasonic array sensor wherein the intervals between adjacent openings are formed at the same interval.
感度を可変して成る特許請求の範囲第１項記載の超音波
アレイセンサ。2. The ultrasonic array sensor according to claim 1, wherein the sound pressure level and the sensitivity are varied by changing the diameter of each of the openings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26003587A JP2603654B2 (en) | 1987-10-15 | 1987-10-15 | Ultrasonic array sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26003587A JP2603654B2 (en) | 1987-10-15 | 1987-10-15 | Ultrasonic array sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01101483A JPH01101483A (en) | 1989-04-19 |
| JP2603654B2 true JP2603654B2 (en) | 1997-04-23 |
Family
ID=17342396
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26003587A Expired - Fee Related JP2603654B2 (en) | 1987-10-15 | 1987-10-15 | Ultrasonic array sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2603654B2 (en) |
-
1987
- 1987-10-15 JP JP26003587A patent/JP2603654B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01101483A (en) | 1989-04-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |