JPH05675B2 - - Google Patents
Info
- Publication number
- JPH05675B2 JPH05675B2 JP9244587A JP9244587A JPH05675B2 JP H05675 B2 JPH05675 B2 JP H05675B2 JP 9244587 A JP9244587 A JP 9244587A JP 9244587 A JP9244587 A JP 9244587A JP H05675 B2 JPH05675 B2 JP H05675B2
- Authority
- JP
- Japan
- Prior art keywords
- noise
- pulse
- period
- pulses
- detection processing
- 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 - Lifetime
Links
- 238000001514 detection method Methods 0.000 claims description 53
- 238000012545 processing Methods 0.000 claims description 31
- 238000012544 monitoring process Methods 0.000 claims description 23
- 230000008034 disappearance Effects 0.000 claims description 4
- 230000007257 malfunction Effects 0.000 description 8
- 238000005259 measurement Methods 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000008033 biological extinction Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
Landscapes
- Transducers For Ultrasonic Waves (AREA)
- 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、雑音による誤動作防止機能を備えた
超音波検知器に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an ultrasonic detector having a function of preventing malfunction due to noise.
[背景技術]
一般に、超音波検知器において受波される雑音
がエンジンなどの回転機が発する超音波パルスで
ある場合、その周期が超音波検知器の動作周期に
比較的に近いため、雑音による誤動作を生じ易い
という問題があつた。そこで、このような雑音の
周期性を利用して、検出された雑音からその繰り
返し周期と継続時間(パルス幅)とを計測するこ
とにより、次の雑音のない時点を予測し、その時
点に送波パルスを出力して物体などの検知処理を
行う方法が提案されている。[Background Art] Generally, when the noise received by an ultrasonic detector is an ultrasonic pulse emitted by a rotating machine such as an engine, the period is relatively close to the operating cycle of the ultrasonic detector, so There was a problem that malfunctions were likely to occur. Therefore, by taking advantage of the periodicity of such noise and measuring its repetition period and duration (pulse width) from the detected noise, it is possible to predict the next point in time when there will be no noise, and to send data at that point. A method has been proposed for detecting objects by outputting wave pulses.
第3図に従来の周期性を有する雑音による誤動
作の防止方法を示す。第3図aに回転機から発生
されたトーンバースト状の雑音波形を示す。この
雑音Nのパルス幅はτ2で、繰り返し周期τ1で発生
している。第3図bに雑音Nが存在しない場合の
超音波検知器の動作タイミングを示してあり、送
波パルスPを送波した後の所定期間T1(以降、受
波期間と称する)に物体からの反射パルスを受波
し、上記受波期間T1の経過後から次に送波パル
スPが送波される前までの期間T2(雑音監視期間
と称する)に雑音Nを監視する。なお、上記送波
パルスPが送波されてから受波間T2が経過する
までが、超音波検知器が物体の検知処理を行う期
間T3(検知処理期間と称する)である。このよう
に、雑音Nが存在しない場合には、第3図bに示
すように、検知処理期間T3の検知処理と雑音監
視期間T2の雑音監視との動作を繰り返し行う。
なお、上記雑音監視期間T2には、物体からの反
射波が検知領域外にあり、空気中の減衰により物
体からの反射波が超音波検知器に受波される可能
性がない期間であるため、この雑音監視期間T2
に受波される信号は雑音Nであると判定できるの
である。この雑音監視期間T2に2個以上の雑音
Nが検出された場合には、その雑音Nの繰り返し
周期τ1とパルス幅τ2とを計測し、次の雑音Nが到
来する時点を予測し、第3図cの下に示す検知処
理可能な時点Aを決定する。そして、通常は同図
bの動作周期で物体の検知を行つていたものを、
同図cに示すように次の送波パルスPを送波する
時点を時点Aまで遅らせ、つまり雑音監視期間
T2後の最初の雑音Nの直後まで物体の検知処理
を遅らせ、雑音Nによる誤動作を防止するように
していた。 FIG. 3 shows a conventional method for preventing malfunctions caused by periodic noise. FIG. 3a shows a tone burst noise waveform generated from a rotating machine. This noise N has a pulse width of τ 2 and is generated at a repetition period of τ 1 . Figure 3b shows the operation timing of the ultrasonic detector when there is no noise N. , and monitors the noise N during a period T 2 (referred to as a noise monitoring period) from after the reception period T 1 has elapsed until before the next transmission pulse P is transmitted. Note that the period from when the transmission pulse P is transmitted to when the reception interval T 2 has elapsed is a period T 3 (referred to as a detection processing period) during which the ultrasonic detector performs object detection processing. In this way, when the noise N does not exist, as shown in FIG. 3b, the detection processing during the detection processing period T3 and the noise monitoring during the noise monitoring period T2 are repeated.
Note that during the above noise monitoring period T2 , the reflected wave from the object is outside the detection area, and there is no possibility that the reflected wave from the object will be received by the ultrasonic detector due to attenuation in the air. Therefore, this noise monitoring period T 2
Therefore, it can be determined that the signal received by N is noise N. If two or more noises N are detected during this noise monitoring period T2 , the repetition period τ1 and pulse width τ2 of the noise N are measured, and the time when the next noise N will arrive is predicted. , determine a time point A at the bottom of FIG. 3c at which the detection process is possible. Then, the object that was normally detected in the operation cycle shown in figure b,
As shown in figure c, the time to transmit the next transmission pulse P is delayed until time A, that is, the noise monitoring period.
Object detection processing was delayed until immediately after the first noise N after T 2 to prevent malfunctions due to noise N.
ところで、市街地の超音波雑音Nはその殆どが
第3図aに示すような矩形波状のものではなく、
第2図aに示すように複数の矩形波状のトーンバ
ースト波から構成され、さらにこの複数のトーン
バースト波の前後にはグリツチと呼ばれる髭状の
パルスを伴うことが多い。このような雑音Nに対
しては、この雑音Nの繰り返し周期τ1及びパルス
幅τ2を適切に判断することが難しく、上述の従来
の超音波検知器では、例えば繰り返し周期τ1及び
パルス幅τ2を第2図中のa1,a2と判断してしま
う。この場合には、雑音Nの繰り返し周期τ1が小
さくなり、雑音Nが消えるまで物体の検知処理を
行うことができないことになる。このように、従
来の超音波検知器では検知処理可能な時点Aの適
切な時点の決定が困難である不都合があつた。 By the way, most of the ultrasonic noise N in urban areas is not rectangular wave-like as shown in Figure 3a;
As shown in FIG. 2a, it is composed of a plurality of rectangular tone burst waves, and furthermore, whisker-like pulses called glitches are often accompanied before and after the plurality of tone burst waves. For such noise N, it is difficult to appropriately judge the repetition period τ 1 and pulse width τ 2 of this noise N, and in the conventional ultrasonic detector described above, for example, the repetition period τ 1 and pulse width τ 2 are difficult to judge appropriately. We judge τ 2 to be a 1 and a 2 in Figure 2. In this case, the repetition period τ 1 of the noise N becomes small, and object detection processing cannot be performed until the noise N disappears. As described above, the conventional ultrasonic detector has the disadvantage that it is difficult to determine an appropriate time point A at which detection processing is possible.
[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、市街地の雑音のよ
うな複数の雑音パルスで構成された雑音において
も、適切にパルス幅及び繰り返し周期を計測する
ことができるようにし、この雑音の影響のない適
切な次の検知処理期間を決定することができる超
音波検知器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-mentioned points, and its object is to appropriately control the pulse width even in noise composed of a plurality of noise pulses such as urban noise. Another object of the present invention is to provide an ultrasonic detector that can measure the repetition period and determine an appropriate next detection processing period without being affected by this noise.
[発明の開示]
(構成)
本発明は、超音波パルスを間欠的に送波し、物
体からの反射波を受波して、物体の存在や物体ま
での距離を検知する超音波検知器において、超音
波パルスの送波時点から検知領域に存在する物体
による反射波を受波する受波期間の終了時点まで
の物体の検知処理を行う検知処理期間の間に、雑
音を監視する雑音監視期間を設け、この雑音監視
期間に雑音パルスを検出する雑音パルス検出手段
と、この雑音パルス検出手段にて所定の短時間以
内に次の雑音パルスが検出されたときには、先の
雑音パルスと次の雑音パルスとは1雑音パルスで
あると判定し、先の雑音パルスの発生時点から次
の雑音パルスの消滅時点までの時間を上記雑音パ
ルスのパルス幅としてこのパルス幅を計測するパ
ルス幅計測手段と、上記雑音監視期間内に1雑音
パルスと判定される雑音パルスが複数検出された
場合にそれら雑音パルスの繰り返し周期を計測す
る繰り返し周期計測手段と、上記パルス幅及び繰
り返し周期計測手段の計測結果に基づいて次に到
来する雑音パルスの発生時点を予測するととも
に、この予測結果に基づいて次の検知処理期間を
決定する予測決定手段とを備えたものであり、市
街地の雑音のような複数の雑音パルスで構成され
た雑音においても、雑音パルス検出手段にて所定
の短時間以内に次の雑音パルスが検出されたとき
には、パルス幅計測手段にて先の雑音パルスと次
の雑音パルスとは1雑音パルスであると判定し先
の雑音パルスの発生時点から次の雑音パルスの消
滅時点までの時間を上記雑音パルスのパルス幅と
してこのパルス幅を計測して適切にパルス幅を計
測すると共に、繰り返し周期計測手段にてこの雑
音パルスの繰り返し周期を計測することができる
ようにし、上記両計測手段の計測結果に基づいて
予測決定手段にてこの雑音の影響のない適切な次
の検知処理期間を決定することができるようにし
たものである。[Disclosure of the Invention] (Structure) The present invention provides an ultrasonic detector that transmits ultrasonic pulses intermittently and receives reflected waves from an object to detect the presence of an object and the distance to the object. , a noise monitoring period in which noise is monitored during the detection processing period in which object detection processing is performed from the time of transmitting the ultrasonic pulse to the end of the reception period in which the reflected wave from the object existing in the detection area is received. and a noise pulse detection means for detecting a noise pulse during this noise monitoring period, and when the next noise pulse is detected within a predetermined short time by this noise pulse detection means, the previous noise pulse and the next noise are detected. Pulse width measuring means that determines that a pulse is one noise pulse, and measures the pulse width as the time from the generation point of the previous noise pulse to the point of disappearance of the next noise pulse, as the pulse width of the noise pulse; a repetition period measuring means for measuring the repetition period of the noise pulses when a plurality of noise pulses determined to be one noise pulse are detected within the noise monitoring period, and based on the measurement results of the pulse width and repetition period measuring means. The system is equipped with a prediction determining means that predicts the generation point of the next arriving noise pulse and determines the next detection processing period based on the prediction result. Even in the case of noise composed of It is determined that this is the case, and the time from the generation point of the previous noise pulse to the point of disappearance of the next noise pulse is measured as the pulse width of the above noise pulse, and the pulse width is appropriately measured, and the period is repeatedly measured. A means is capable of measuring the repetition period of this noise pulse, and a prediction determining means determines an appropriate next detection processing period free from the influence of this noise based on the measurement results of both of the measuring means. It was made so that it could be done.
(実施例)
第1図及び第2図に本発明の一実施例を示す。
本実施例の超音波検知器は、第1図に示すよう
に、送受波兼用の超音波振動子1を備え、この超
音波振動子1を駆動して超音波パルスを間欠的に
送波する送波回路2と、物体からの反射波パルス
を受波する受波回路3と、受波回路3出力を増幅
検波する増幅検波回路4と、この増幅検波回路4
出力から検知領域に物体が存在するかどうかを検
知する物体検知回路5と、この物体検知回路5に
て物体が検知されたことを表示する表示器6とか
らなる。なお、本実施例においては、第2図bに
示す受波期間T1に受波された反射波より物体の
存在を検知するものであり、つまり受波パルスの
送波パルスPの送波時点からの時間遅れにより物
体までの距離を算出して物体の存在を検知する。(Example) An example of the present invention is shown in FIGS. 1 and 2.
As shown in FIG. 1, the ultrasonic detector of this embodiment includes an ultrasonic transducer 1 for both transmitting and receiving waves, and drives this ultrasonic transducer 1 to intermittently transmit ultrasonic pulses. A wave transmitting circuit 2, a wave receiving circuit 3 that receives reflected wave pulses from an object, an amplifying and detecting circuit 4 that amplifies and detects the output of the wave receiving circuit 3, and this amplifying and detecting circuit 4.
It consists of an object detection circuit 5 that detects whether an object is present in the detection area based on the output, and a display 6 that displays that an object has been detected by the object detection circuit 5. In this embodiment, the presence of an object is detected from the reflected wave received during the reception period T1 shown in FIG. The presence of an object is detected by calculating the distance to the object based on the time delay.
上記構成は物体検知処理に関する回路構成であ
つたが、次に雑音による誤動作を防止する回路構
成について説明する。なお、本実施例において
も、送波パルスPの送波時点から検知領域に存在
する物体による反射波を受波する受波期間T1の
終了時点までの物体の検知処理を行う検知処理期
間T3の間に、雑音を監視する雑音監視期間T2を
設けてあり、この雑音監視期間T2に受波回路3
の出力から雑音パルスを検出する雑音パルス検知
手段としての雑音検知回路7を備えるとともに、
この雑音検知回路7出力に基づいて雑音の影響を
受けない適切な期間に検知処理を行うように信号
処理を行つて送波回路2及び物体検知回路5を制
御する信号処理回路8を備えている。上記雑音検
知回路7は、雑音パルスNが検出されたときに、
この雑音パルスNが消滅した時点から所定の短時
間以内に次の雑音パルスが発生するかどうかを検
出するようになつており、例えば第2図aのよう
な複数の雑音パルスを含む市街地の雑音であるこ
とを検出できるようにしてある。そして、上記信
号処理回路8は、雑音検出回路7にて所定の短時
間以内に次の雑音パルスが検出されたとき、先の
雑音パルスと次の雑音パルスとは1雑音パルスで
あると判定し、先の雑音パルスの発生時点から次
の雑音パルスの消滅時点までの時間を上記雑音パ
ルスのパルス幅としてこのパルス幅を計測するパ
ルス幅計測手段と、上記雑音監視期間T2内に1
雑音パルスと判定される雑音パルスが複数検出さ
れた場合にそれら雑音パルスの繰り返し周期を計
測する繰り返し周期計測手段と、パルス幅及び繰
り返し周期計測手段の計測結果に基づいて次に到
来する雑音パルスの発生時点を予測するととも
に、この予測結果に基づいて次の検知処理期間を
決定する予測決定手段とで構成されている。 The above configuration is a circuit configuration related to object detection processing. Next, a circuit configuration for preventing malfunctions due to noise will be explained. In this embodiment as well, there is a detection processing period T in which object detection processing is performed from the time of transmitting the transmission pulse P to the end of the wave reception period T1 in which the reflected wave from an object existing in the detection area is received. 3 , there is a noise monitoring period T 2 for monitoring noise, and during this noise monitoring period T 2 the receiving circuit 3
A noise detection circuit 7 is provided as a noise pulse detection means for detecting noise pulses from the output of the
A signal processing circuit 8 is provided which performs signal processing based on the output of the noise detection circuit 7 to control the wave transmitting circuit 2 and the object detection circuit 5 so that detection processing is performed in an appropriate period unaffected by noise. . The noise detection circuit 7, when the noise pulse N is detected,
It is designed to detect whether the next noise pulse occurs within a predetermined short time from the time when this noise pulse N disappears. It is designed so that it can be detected that Then, when the next noise pulse is detected by the noise detection circuit 7 within a predetermined short time, the signal processing circuit 8 determines that the previous noise pulse and the next noise pulse are one noise pulse. , a pulse width measuring means for measuring the pulse width of the noise pulse as the time from the generation point of the previous noise pulse to the point of extinction of the next noise pulse;
a repetition period measuring means for measuring the repetition period of the noise pulses when a plurality of noise pulses determined to be noise pulses are detected; and a repetition period measuring means for measuring the repetition period of the noise pulses determined as noise pulses; It is comprised of a prediction determining means that predicts the time of occurrence and determines the next detection processing period based on the prediction result.
以下、本実施例の雑音による誤動作と防止機能
について第2図に従つて説明する。なお、第3図
aに示す矩形波状の雑音パルスNであるときの動
作は従来例にて説明したと同様であるので説明は
省略する。いま、第2図aに示す市街地の雑音の
ような複数の雑音パルスで構成された雑音が発生
しているとする。この雑音パルスは、パルス間に
隙間があり、しかも複数のパルスの前後にグリツ
チが存在しているものである。この雑音パルス
が、雑音監視期間T2に受波回路3にて受波され
ると、雑音検知回路7にて雑音を検知する。そし
て、この雑音が検知されてから所定の短時間以内
は、パルス幅計測手段ではパルス幅を計測せずに
この雑音パルスのパルス幅及び発生時点を記憶し
ておく。そして、次の雑音パルスが所定の短時間
以内に雑音検知回路7にて検知されたときには、
パルス幅計測手段にて先の雑音パルスと次の雑音
パルスとは1雑音パルスであると判定し、先の雑
音パルスの発生時点から次の雑音パルスの消滅時
点までの時間を上記雑音パルスのパルス幅として
パルス幅を計測する。第2図aの雑音の場合に
は、さらに次々と雑音パルスが所定の短時間以内
に発生しているから、上述の複数の雑音パルスを
1雑音パルスとした場合のパルス幅は、次の雑音
パルスが発生する毎に計測されて記憶されて行
く。なお、最初の雑音パルスの発生時点はこのよ
うに次の雑音パルスが所定の短時間以内に雑音検
知回路7にて検知されている間は記憶され、この
最初の雑音パルスの発生時点から上述の説明のよ
うにして上記パルス幅が計測されていく。そし
て、次の雑音パルスが雑音検知回路7にて所定の
短時間以内に検知されなくなつたとき、初めてパ
ルス幅計測手段の出力であるパルス幅が予測決定
手段に出力される。この雑音のパルス幅計測手段
により計測されたパルス幅は、第2図cに示すτ3
となる。そして、雑音監視期間T2内に次の上述
と同様の雑音が受波回路3にて受波された時点
で、繰り返し周期計測手段にてこの雑音パルスの
繰り返し周期τ4が計測される。そして、上記両計
測手段の計測結果に基づいて予測決定手段にてこ
の雑音の影響のない適切な次の検知処理期間を決
定する。このように、市街地の雑音のような複数
の雑音パルスとグリツチとからなる雑音であつて
も、この複数の雑音パルスをまとめて1雑音であ
ると判定するようにしてあるから、従来のように
グリツチと雑音パルスとのパルス幅a1及び繰り返
し周期a2にて検知処理期間を決定するということ
がなく、このため確実に雑音による誤動作を防止
することができ、超音波検知器の信頼性を向上す
ることができる。 The malfunction caused by noise and the prevention function of this embodiment will be explained below with reference to FIG. 2. Note that the operation when the noise pulse N has a rectangular waveform shown in FIG. 3a is the same as that described in the conventional example, and therefore the description thereof will be omitted. Suppose that noise composed of a plurality of noise pulses is generated, such as the urban noise shown in FIG. 2a. This noise pulse has gaps between pulses and glitches before and after a plurality of pulses. When this noise pulse is received by the reception circuit 3 during the noise monitoring period T2 , the noise detection circuit 7 detects the noise. Then, within a predetermined short time after this noise is detected, the pulse width measuring means does not measure the pulse width, but stores the pulse width and generation time of this noise pulse. Then, when the next noise pulse is detected by the noise detection circuit 7 within a predetermined short time,
The pulse width measuring means determines that the previous noise pulse and the next noise pulse are one noise pulse, and the time from the generation point of the previous noise pulse to the point of extinction of the next noise pulse is calculated as the pulse of the above noise pulse. Measure the pulse width as width. In the case of the noise shown in Figure 2a, since noise pulses are generated one after another within a predetermined short time, the pulse width when the above-mentioned plurality of noise pulses are considered as one noise pulse is the same as that of the next noise pulse. Each time a pulse occurs, it is measured and stored. Note that the time point at which the first noise pulse is generated is thus stored as long as the next noise pulse is detected by the noise detection circuit 7 within a predetermined short time, and from the time point at which the first noise pulse is generated, the above-mentioned steps are performed. The pulse width is measured as described above. Then, only when the next noise pulse is no longer detected by the noise detection circuit 7 within a predetermined short time, the pulse width, which is the output of the pulse width measuring means, is output to the prediction determining means. The pulse width measured by the pulse width measuring means of this noise is τ 3 shown in FIG. 2c.
becomes. Then, when the next noise similar to that described above is received by the wave receiving circuit 3 within the noise monitoring period T 2 , the repetition period measuring means measures the repetition period τ 4 of this noise pulse. Then, based on the measurement results of both of the measuring means, the prediction determining means determines an appropriate next detection processing period free from the influence of this noise. In this way, even if the noise is made up of multiple noise pulses and glitches, such as city noise, the multiple noise pulses are collectively determined to be one noise, so unlike the conventional method, The detection processing period is not determined by the pulse width a 1 and repetition period a 2 of the glitch and noise pulse, which makes it possible to reliably prevent malfunctions due to noise and improve the reliability of the ultrasonic detector. can be improved.
[発明の効果]
本発明は上述のように、超音波パルスを間欠的
に送波し、物体からの反射波を受波して、物体の
存在や物体までの距離を検知する超音波検知器に
おいて、超音波パルスの送波時点から検知領域に
存在する物体による反射波を受波する受波期間の
終了時点までの物体の検知処理を行う検知処理期
間の間に、雑音を監視する雑音監視期間を設け、
この雑音監視期間に雑音パルスを検出する雑音パ
ルス検出手段と、この雑音パルス検出手段にて所
定の短時間以内に次の雑音パルスが検出されたと
きには、先の雑音パルスと次の雑音パルスとは1
雑音パルスであると判定し、先の雑音パルスの発
生時点から次の雑音パルスの消滅時点までの時間
を上記雑音パルスのパルス幅としてこのパルス幅
を計測するパルス幅計測手段と、上記雑音監視期
間内に1雑音パルスと判定される雑音パルスが複
数検出された場合にそれら雑音パルスの繰り返し
周期を計測する繰り返し周期計測手段と、上記パ
ルス幅及び繰り返し周期計測手段の計測結果に基
づいて次に到来する雑音パルスの発生時点を予測
するとともに、この予測結果に基づいて次の検知
処理期間を決定する予測決定手段とを備えている
ので、市街地の雑音のような複数の雑音パルスで
構成された雑音においても、雑音パルス検知手段
にて所定の短時間以内に次の雑音パルスが検出さ
れたときには、パルス幅計測手段にて先の雑音パ
ルスと次の雑音パルスとは1雑音パルスであると
判定し、先の雑音パルスの発生時点からの次の雑
音パルスの消滅時点までの時間を上記雑音パルス
のパルス幅としてこのパルス幅を計測して適切に
パルス幅を計測すると共に、繰り返し周期計測手
段にてこの雑音パルスの繰り返し周期を計測する
ことができ、このため上記両計測手段の計測結果
に基づいて予測決定手段にてこの雑音の影響のな
い適切な次の検知処理期間を決定することがで
き、従つて雑音による誤動作を防止効果が高まる
効果がある。[Effects of the Invention] As described above, the present invention provides an ultrasonic detector that transmits ultrasonic pulses intermittently and receives reflected waves from an object to detect the presence of an object and the distance to the object. Noise monitoring that monitors noise during the detection processing period in which object detection processing is performed from the time of transmitting the ultrasonic pulse to the end of the reception period in which the reflected wave from the object existing in the detection area is received. Set a period,
Noise pulse detection means detects a noise pulse during this noise monitoring period, and when the next noise pulse is detected within a predetermined short time by this noise pulse detection means, the previous noise pulse and the next noise pulse are 1
a pulse width measuring means that determines that the pulse is a noise pulse, and measures the pulse width of the noise pulse as the time from the time when the previous noise pulse is generated until the time when the next noise pulse disappears; and the noise monitoring period. a repetition period measuring means for measuring the repetition period of the noise pulses when a plurality of noise pulses determined to be one noise pulse are detected within the same period; The device is equipped with a prediction determining means that predicts the time point at which a noise pulse will occur and determines the next detection processing period based on the prediction result. Also, when the next noise pulse is detected within a predetermined short time by the noise pulse detection means, the pulse width measurement means determines that the previous noise pulse and the next noise pulse are one noise pulse. , the time from the generation point of the previous noise pulse to the point of disappearance of the next noise pulse is measured as the pulse width of the noise pulse, and the pulse width is appropriately measured, and the pulse width is measured appropriately, and the repetition period measuring means is used to measure the pulse width. The repetition period of this noise pulse can be measured, and therefore, based on the measurement results of both of the measurement means, the prediction and determination means can determine an appropriate next detection processing period that is free from the influence of this noise. Therefore, the effect of preventing malfunctions due to noise is enhanced.
第1図は本発明の一実施例の回路構成を示すブ
ロツク図、第2図は同上の要部の動作説明図、第
3図は従来例の動作説明図である。
7は雑音検知回路、8は信号処理回路、Pは送
波パルス、τ1は繰り返し周期、τ2はパルス幅、T1
は受波期間、T2は雑音監視期間、T3は検知処理
期間である。
FIG. 1 is a block diagram showing the circuit configuration of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of the main parts of the same, and FIG. 3 is an explanatory diagram of the operation of a conventional example. 7 is a noise detection circuit, 8 is a signal processing circuit, P is a transmission pulse, τ 1 is a repetition period, τ 2 is a pulse width, T 1
is the wave reception period, T 2 is the noise monitoring period, and T 3 is the detection processing period.
Claims (1)
反射波を受波して、物体の存在や物体までの距離
を検知する超音波検知器において、超音波パルス
の送波時点から検知領域に存在する物体による反
射波を受波する受波期間の終了時点までの物体の
検知処理を行う検知処理期間の間に、雑音を監視
する雑音監視期間を設け、この雑音監視期間に雑
音パルスを検出する雑音パルス検出手段と、この
雑音パルス検出手段にて所定の短時間以内に次の
雑音パルスが検出されたときには、先の雑音パル
スと次の雑音パルスとは1雑音パルスであると判
定し、先の雑音パルスの発生時点から次の雑音パ
ルスの消滅時点までの時間を上記雑音パルスのパ
ルス幅としてこのパルス幅を計測するパルス幅計
測手段と、上記雑音監視期間内に1雑音パルスと
判定される雑音パルスが複数検出された場合にそ
れら雑音パルスの繰り返し周期を計測する繰り返
し周期計測手段と、上記パルス幅及び繰り返し周
期計測手段の計測結果に基づいて次に到来する雑
音パルスの発生時点を予測するとともに、この予
測結果に基づいて次の検知処理期間を決定する予
測決定手段とを備えて成ることを特徴とする超音
波検知器。1 In an ultrasonic detector that transmits ultrasonic pulses intermittently and receives reflected waves from an object to detect the presence of an object and the distance to the object, the detection area starts from the time the ultrasonic pulse is sent. A noise monitoring period for monitoring noise is provided during the detection processing period in which object detection processing is performed up to the end of the reception period in which reflected waves from objects existing in the area are received, and noise pulses are transmitted during this noise monitoring period. When the noise pulse detection means detects the next noise pulse within a predetermined short time, it is determined that the previous noise pulse and the next noise pulse are one noise pulse. , a pulse width measuring means for measuring the pulse width of the noise pulse as the time from the generation point of the previous noise pulse to the point of disappearance of the next noise pulse, and determining that there is one noise pulse within the noise monitoring period. a repetition period measuring means for measuring the repetition period of the noise pulses when a plurality of noise pulses are detected; and a repetition period measuring means for measuring the repetition period of the noise pulses; What is claimed is: 1. An ultrasonic detector comprising prediction determining means for predicting and determining the next detection processing period based on the prediction result.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9244587A JPS63256878A (en) | 1987-04-15 | 1987-04-15 | Ultrasonic detector |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9244587A JPS63256878A (en) | 1987-04-15 | 1987-04-15 | Ultrasonic detector |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS63256878A JPS63256878A (en) | 1988-10-24 |
JPH05675B2 true JPH05675B2 (en) | 1993-01-06 |
Family
ID=14054606
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP9244587A Granted JPS63256878A (en) | 1987-04-15 | 1987-04-15 | Ultrasonic detector |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS63256878A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6257573B2 (en) * | 2015-11-06 | 2018-01-10 | 三菱電機株式会社 | Ultrasonic sensor device |
-
1987
- 1987-04-15 JP JP9244587A patent/JPS63256878A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS63256878A (en) | 1988-10-24 |
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