JPH0894741A - Ultrasonic sensor - Google Patents
Ultrasonic sensorInfo
- Publication number
- JPH0894741A JPH0894741A JP23183794A JP23183794A JPH0894741A JP H0894741 A JPH0894741 A JP H0894741A JP 23183794 A JP23183794 A JP 23183794A JP 23183794 A JP23183794 A JP 23183794A JP H0894741 A JPH0894741 A JP H0894741A
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- JP
- Japan
- Prior art keywords
- wave
- time
- transmitting
- receiving
- sensor circuit
- 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.)
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- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、超音波を利用して距離
測定を行う超音波センサに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic sensor for measuring distance using ultrasonic waves.
【０００２】[0002]
【従来の技術】この種の超音波センサの第１従来例とし
て図５及び図６に示す構成のものが存在する。このもの
は、発振した超音波U を送波として物体M に向けて送受
波部A1から送出するとともに物体M からの反射波U1を受
波として送受波部A1により検知する送受波センサ回路A
と、送受波センサ回路A の出力を受けて計測した超音波
U の送出時から送受波部A1の検知時までの遅延時間t1で
もって送受波部A1から物体M までの距離Ｌを演算して処
理する演算処理部B と、を備えてなっている。2. Description of the Related Art As a first conventional example of this type of ultrasonic sensor, there is a structure shown in FIGS. This compound, transducing sensor that detects the wave transceiver section A 1 of the reflected wave U 1 from the object M as reception with towards the object M to the ultrasonic wave U oscillated as transmitting transmits the wave transceiver unit A 1 Circuit A
And the ultrasonic wave measured by receiving the output of the transmission / reception sensor circuit A
It is provided with an arithmetic processing unit B for processing by calculating the distance L to the object M with the delay time t 1 until time of detection wave transceiver section A 1 from wave transceiver section A 1 from the time of delivery of the U There is.
【０００３】詳しくは、送受波センサ回路A は、送受波
部 (詳しくは超音振動子)A1 及び送受波回路A2からな
り、演算処理部B から図６(a) に示すパルスP を受け
て、発振部A21 で発振した発振信号を昇圧部A22 で昇圧
し、逆並列接続ダイオードA23 を経て、同図(b) に示す
送受波回路A2の出力波形である送波信号W0により送受波
部A1が振動し、その振動によって超音波U が送受波部A1
から物体M に向けて送出される。そして、物体M に到達
して反射して来た反射波U1により振動する送受波部A1で
その反射波U1を受け、それを増幅部A24 で増幅して同図
(c) に示す反射波信号W1が超音波U 送出時から遅延時間
t1後に検知される。このとき、送波信号W0による送受波
部A1の機械的振動が送波信号W0の終了後も残響として残
り、それが同図(c) に示すように超音波U 送出時から時
間t4の間だけ電気的な残響波信号W4として残る。次い
で、その信号は検波部A25 により検波された後、送受波
回路A2から演算処理部B に送られる。More specifically, the wave transmission / reception sensor circuit A is composed of a wave transmission / reception section (specifically, an ultrasonic transducer) A 1 and a wave transmission / reception circuit A 2 , and a pulse P shown in FIG. The oscillating signal received and oscillated by the oscillating unit A 21 is boosted by the boosting unit A 22 and passed through the anti-parallel connection diode A 23, and then the transmitting signal which is the output waveform of the transmitting / receiving circuit A 2 shown in FIG. W 0 vibrates the transmitting / receiving section A 1 , and the vibration causes the ultrasonic wave U to transmit / receive section A 1
From the object toward the object M. Then, receiving the reflected wave U 1 at the wave transceiver section A 1 which vibrates by the reflected wave U 1 came reflected to reach the object M, the figure is amplified by the amplifying unit A 24 it
The reflected wave signal W 1 shown in (c) is the delay time from the ultrasonic wave U transmission.
Detected after t 1 . In this case, transmit signal W 0 rest, it as shown in FIG. (C) from the time the ultrasonic wave U transmission time as well reverberation after the end of the mechanical vibration transmitting signal W 0 of the wave transceiver section A 1 by It remains as an electric reverberation signal W 4 only for t 4 . Then, the signal is detected by the detection unit A 25 , and then sent from the transmission / reception circuit A 2 to the arithmetic processing unit B 2 .
【０００４】そして演算処理部B では、Ｌ＝Ｖ・t1／２
の関係式(A) により送受波部A1から物体M までの距離Ｌ
を演算する。ここで、Ｖは音速である。[0006] The arithmetic processing unit B, L = V · t 1 /2
The distance L from the transmitting and receiving wave unit A 1 by equation (A) to the object M
Is calculated. Here, V is the speed of sound.
【０００５】また、第２従来例として図７及び図８に示
す構成のものが存在する。第１従来例と相違するところ
は、第１従来例では送波及び受波の両機能を有する送受
波センサ回路A を使用しているのに対し、このものは、
送波機能を有する送波センサ回路C 及び受波機能を有す
る受波センサ回路D を使用していることである。As a second conventional example, there is a configuration shown in FIGS. 7 and 8. The difference from the first conventional example is that in the first conventional example, a wave transmission / reception sensor circuit A having both functions of transmitting and receiving waves is used.
That is, a wave transmission sensor circuit C 1 having a wave transmission function and a wave reception sensor circuit D 1 having a wave reception function are used.
【０００６】詳しくは、送波センサ回路C は、送波部C1
及びその送波部C1へ送波信号W0を送る送波回路C2からな
り、受波センサ回路D は、送波部C1と同一指向方向で物
体Mまでの距離Ｌを一致して配置した受波部D1及びその
受波部D1からの受波信号を受ける受波回路D2からなる。More specifically, the wave transmission sensor circuit C includes a wave transmission section C 1
And the transmitting section C 1 sends a transmit signal W 0 consists transmitting circuit C 2, wave receiving sensor circuit D, consistent distance L to the object M by the transmitting unit C 1 and the same orientation consisting reception circuit D 2 for receiving a received signal from the placed reception unit D 1 and the reception section D 1.
【０００７】そして、送波センサ回路C は、送波回路C2
が、第１従来例と同様にして、演算処理部B から図８
(a) に示すパルスP を受けて、同図(b) に示す送波信号
W0により送波部C1から超音波U を物体M に向けて送出す
ると、受波センサ回路D は、物体M からの反射波U2を受
波部D1で受け、受波回路D2で増幅して同図(c) に示す反
射波信号W2が超音波U 送出時から遅延時間t2後に検知さ
れる。このとき、物体Mで反射せずに送波部C1から直接
受波部D1に到達する直接波U3による直接波信号W3も同図
(c) に示すように超音波U 送出時から遅延時間t3後に検
知される。The transmission sensor circuit C is composed of the transmission circuit C 2
However, in the same way as the first conventional example, the calculation processing unit B to FIG.
Receiving the pulse P shown in (a), the transmitted signal shown in (b) in the same figure
When the ultrasonic wave U is transmitted from the wave-transmitting unit C 1 to the object M by W 0 , the receiving sensor circuit D receives the reflected wave U 2 from the object M at the receiving unit D 1 and receives the receiving circuit D 2 The reflected wave signal W 2 shown in FIG. 7C after being amplified by is detected after a delay time t 2 from the time of transmitting the ultrasonic wave U. At this time, the direct wave signal W 3 due to the direct wave U 3 directly reaching the wave receiving portion D 1 from the wave transmitting portion C 1 without being reflected by the object M is also shown in FIG.
As shown in (c), it is detected after a delay time t 3 from the time of transmitting the ultrasonic wave U.
【０００８】そして演算処理部B では、Ｌ＝Ｖ・t2／２
の関係式(B) により送波部C1及び受波部D1から物体M ま
での距離Ｌを演算する。[0008] Then the arithmetic processing section B, L = V · t 2 /2
The distance L from the wave transmission unit C 1 and the wave reception unit D 1 to the object M is calculated by the relational expression (B).
【０００９】また、第３従来例として図９及び図10に示
す構成のものが存在する。第２従来例と相違するところ
は、第２従来例の送波センサ回路C に代えて第１従来例
で使用した送受波センサ回路A を用い、かつ受波センサ
回路D は、その受波部D1を送受波センサ回路A の送受波
部A1よりも物体M から離れる方向へ所定距離ｄだけずら
して設置されている。As a third conventional example, there is a structure shown in FIGS. 9 and 10. The difference from the second conventional example is that the wave transmitting / receiving sensor circuit A used in the first conventional example is used in place of the wave transmitting sensor circuit C of the second conventional example, and the wave receiving sensor circuit D is its wave receiving portion. D 1 is installed so as to be displaced from the wave transmission / reception section A 1 of the wave transmission / reception sensor circuit A by a predetermined distance d in the direction away from the object M.
【００１０】そして、送受波センサ回路A は、第１従来
例と同様にして、演算処理部B から図10(a) に示すパル
スP を受けて、同図(b) に示す送波信号W0により送受波
部A1から超音波U を物体M に向けて送出すると、反射波
U1を送受波部A1で受け、同図(c) に示す反射波信号W1が
遅延時間t1後に検知されるとともに、残響波信号W4が時
間t4の間だけ残る。一方、受波センサ回路D は、第２従
来例と同様にして、反射波U2を受波部D1で受け同図(d)
に示す反射波信号W2が遅延時間t2後に検知されるととも
に、直接波信号W3も遅延時間t3後に検知される。The transmission / reception sensor circuit A receives the pulse P shown in FIG. 10 (a) from the arithmetic processing section B in the same manner as the first conventional example, and transmits the transmission signal W shown in FIG. 10 (b). When the ultrasonic wave U is sent from the wave transmitter / receiver A 1 toward the object M by 0 , the reflected wave
U 1 is received by the transmission / reception unit A 1 , the reflected wave signal W 1 shown in FIG. 7C is detected after the delay time t 1 , and the reverberation wave signal W 4 remains for the time t 4 . On the other hand, the wave receiving sensor circuit D receives the reflected wave U 2 at the wave receiving portion D 1 in the same manner as in the second conventional example (d).
The reflected wave signal W 2 shown in is detected after the delay time t 2 , and the direct wave signal W 3 is also detected after the delay time t 3 .
【００１１】そして演算処理部B では、Ｌ＝t1・ｄ／２
（t2−t1）の関係式(C) により送受波部A1から物体M ま
での距離Ｌを演算する。上記の関係式(C) は、反射波U1
に関する２Ｌ＝Ｖ・t1の関係式及び反射波U2に関するｄ
＋２Ｌ＝Ｖ・t2の関係式の２つの音速Ｖを含む関係式か
らその音速Ｖを消去して求めることができ、つまり、距
離Ｌは関係式(C) により音速Ｖに関係なく計算できるこ
とになる。Then, in the arithmetic processing unit B, L = t 1 · d / 2
The distance L from the transmitting / receiving section A 1 to the object M is calculated by the relational expression (C) of (t 2 −t 1 ). The relation (C) above is the reflected wave U 1
With respect to 2L = V · t 1 and d with respect to reflected wave U 2.
+ 2L = V · t 2 It is possible to obtain by deleting the sound velocity V from the relational expression including the two sound velocity V of the relational expression, that is, the distance L can be calculated by the relational expression (C) regardless of the sound velocity V. Become.
【００１２】[0012]
【発明が解決しようとする課題】上記した第１従来例及
び第２従来例にあっては、物体M までの距離Ｌは、関係
式(A) のＬ＝Ｖ・t1／２及び関係式(B) のＬ＝Ｖ・t2／
２で求めることができるが、両関係式ともに音速Ｖが関
係しており、この音速Ｖは周囲温度によって変化するの
で、距離Ｌも周囲温度が変わると正確に求めることがで
きなくなる。In the above-mentioned first conventional example and second conventional example, the distance L to the object M is L = V · t 1/2 of the relational expression (A) and the relational expression. (B) L = V · t 2 /
Although the sound velocity V is related to both relational expressions, and this sound velocity V changes depending on the ambient temperature, the distance L cannot be accurately calculated when the ambient temperature changes.
【００１３】例えば、実際の距離Ｌが摂氏２５度にて１
ｍのとき、周囲温度が摂氏−２０度〜６０度に変化する
と、計測距離は０．９４ｍ〜１．０８ｍとなる。For example, when the actual distance L is 25 degrees Celsius, 1
At m, if the ambient temperature changes from -20 degrees Celsius to 60 degrees Celsius, the measurement distance becomes 0.94 m to 1.08 m.
【００１４】この周囲温度の影響を無くするようにした
のが第３従来例であり、関係式(C)のＬ＝t1・ｄ／２（t
2−t1）は、周囲温度により変化する音速Ｖに関係なく
計算できるようになっている。In the third conventional example, the influence of the ambient temperature is eliminated, and L = t 1 · d / 2 (t in the relational expression (C).
2- t 1 ) can be calculated regardless of the sound velocity V that changes depending on the ambient temperature.
【００１５】しかしながら、第３従来例のものは、送波
及び受波の両機能を有するために残響波信号W4が残る送
受波センサ回路A と、受波機能のみを有して直接波信号
W3を受ける受波センサ回路D とを用いているために、図
10(c) 及び(d) に示すように、第１従来例における残響
波信号W4及び第２従来例における直接波信号W3がそのま
ま存在する。However, the third conventional example has a wave transmitting / receiving sensor circuit A in which the reverberation wave signal W 4 remains because it has both wave transmitting and wave receiving functions, and a direct wave signal having only a wave receiving function.
Since the receiving sensor circuit D that receives W 3 is used,
As shown in 10 (c) and 10 (d), the reverberation wave signal W 4 in the first conventional example and the direct wave signal W 3 in the second conventional example exist as they are.
【００１６】ところで、距離Ｌが小さい、つまり物体M
が近距離の位置にある場合、反射波信号W1及びW2の超音
波U 送出時からの遅延時間t1及びt2は小さいために、超
音波U 送出スタート時点から発生する上記の残響波信号
W4及び超音波U 送出スタート時点近くに発生する上記の
直接波信号W3と重なってしまって、反射波信号W1及びW2
を検出できず、従って、近距離の場合には使用できない
ことになる。By the way, the distance L is small, that is, the object M
, The delay times t 1 and t 2 of the reflected wave signals W 1 and W 2 from the time of sending the ultrasonic wave U are small, the above-mentioned reverberant wave generated from the time point of starting the ultrasonic wave U is started. signal
W 4 and ultrasonic wave U Overlapped with the above-mentioned direct wave signal W 3 generated near the start time of transmission, reflected wave signals W 1 and W 2
Cannot be detected and therefore cannot be used for short distances.
【００１７】本発明は、上記事由に鑑みてなしたもの
で、その目的とするところは、周囲温度に影響されず
に、近距離測定もできる超音波センサを提供することに
ある。The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ultrasonic sensor capable of measuring short distances without being affected by ambient temperature.
【００１８】[0018]
【課題を解決するための手段】上記した課題を解決する
ために、請求項１記載のものは、発振した超音波を送波
として物体に向けて送受波部から送出するとともに物体
からの反射波を受波として送受波部により検知する送受
波センサ回路と、前記送受波部と同一指向方向に設置さ
れた受波部により前記送受波部からの直接波及び前記反
射波を受波として検知する受波センサ回路と、前記送受
波センサ回路及び前記受波センサ回路の出力を受けて計
測した前記超音波の送出時から前記送受波部又は前記受
波部の検知時までの第１又は第２の時間と前記超音波の
送出時から前記直接波の検知時までの第３の時間とでも
って前記送受波部から前記物体までの距離を演算して処
理する演算処理部と、を備え、前記第２の時間は、前記
第１の時間よりも大きく、かつ前記第１の時間が前記超
音波の送出時から前記送受波センサ回路に残る残響波終
了時までの第４の時間よりも小さい場合に前記第３の時
間よりも小さくなるよう、前記送受波部及び前記受波部
を配置してなる構成にしてある。In order to solve the above-mentioned problems, according to a first aspect of the present invention, the oscillated ultrasonic wave is transmitted as a transmitted wave toward the object from the wave transmitting / receiving section and the reflected wave from the object is transmitted. A wave transmission / reception sensor circuit that detects as a wave reception by the wave transmission / reception unit, and a direct wave and the reflected wave from the wave transmission / reception unit are detected as a wave reception by the wave reception unit installed in the same direction as the wave transmission / reception unit. Receiving sensor circuit and first or second from the time of transmitting the ultrasonic wave measured by receiving the outputs of the wave transmitting / receiving sensor circuit and the wave receiving sensor circuit to the time of detecting the wave transmitting / receiving unit or the wave receiving unit. And an arithmetic processing unit that calculates and processes a distance from the wave transmitting / receiving unit to the object with a third time from the time of transmitting the ultrasonic wave to the time of detecting the direct wave. The second time is more than the first time If the first time is shorter than the fourth time from the time of transmitting the ultrasonic wave to the end of the reverberant wave remaining in the wave transmission / reception sensor circuit, it is set to be shorter than the third time. The wave transmitting / receiving section and the wave receiving section are arranged.
【００１９】また、請求項２記載のものは、請求項１記
載のものにおいて、前記送受波センサ回路を前記受波セ
ンサ回路よりも高い検知感度にするとともに、前記演算
処理部は、前記送受波センサ回路及び前記受波センサ回
路のそれぞれの出力の有無により距離の演算を選択的に
実行する構成にしてある。According to a second aspect of the present invention, in the first aspect, the wave transmission / reception sensor circuit has a higher detection sensitivity than that of the wave reception sensor circuit, and the arithmetic processing unit causes the wave transmission / reception to be performed. The distance calculation is selectively executed depending on the presence / absence of outputs from the sensor circuit and the wave receiving sensor circuit.
【００２０】また、請求項３記載のものは、請求項１又
は２記載のものにおいて、前記演算処理部の処理結果に
より動作する動作部を設けた構成にしてある。A third aspect of the present invention is the structure according to the first or second aspect, further including an operation section that operates according to the processing result of the arithmetic processing section.
【００２１】[0021]
【作用】請求項１記載のものによれば、物体が送受波部
から近距離にある場合、つまり超音波の送出時から送受
波部で受ける反射波の検知時までの第１の時間が、超音
波の送出時から送受波センサ回路に残る残響波終了時ま
での第４の時間よりも小さいために反射波が残響波に重
なっているような場合でも、超音波の送出時から受波部
で受ける反射波の検知時までの第２の時間が超音波の送
出時から受波部で受ける送受波部からの直接波の検知時
までの第３の時間よりも小さいから、受波部で受ける反
射波及び直接波の２つの受波に関して周囲温度に影響さ
れる音速を含んでそれぞれ成立する２つ関係式からその
音速を消去した関係式により距離を周囲温度に影響され
ずに演算処理部で求めることができる。According to the first aspect of the present invention, when the object is in a short distance from the wave transmitting / receiving unit, that is, the first time from the time of transmitting the ultrasonic wave to the time of detecting the reflected wave received by the wave transmitting / receiving unit, Even when the reflected wave overlaps the reverberation wave because it is shorter than the fourth time from the time of transmitting the ultrasonic wave to the end of the reverberation wave remaining in the wave transmission / reception sensor circuit, even when the reflected wave overlaps the reverberation wave The second time until the detection of the reflected wave received at is smaller than the third time from the time of transmitting the ultrasonic wave to the time of detecting the direct wave from the wave receiving / receiving unit at the wave receiving unit. An arithmetic processing unit that does not affect the distance by the ambient temperature by a relational expression that eliminates the sound velocity from the two relational expressions that respectively include the sound velocity affected by the ambient temperature for the two received waves of the reflected wave and the direct wave Can be found at.
【００２２】請求項２記載のものによれば、例えば、送
受波センサ回路の方だけがノイズを検知できるよう受波
センサ回路よりも高感度にしてあると、演算処理部は、
両回路共に出力が有る場合は低感度の受波センサ回路で
さえ検知しているためその出力にはノイズや異常はない
として距離演算を実行し、また両回路共に出力が無い場
合は高感度の送受波センサ回路でさえ検知していないた
め物体が存在しないとして距離演算を実行せず、また送
受波センサ回路の出力が有って受波センサ回路の出力が
無い場合には唯一の送受波センサ回路の出力にもノイズ
があるとして距離演算を実行せず、また送受波センサ回
路の出力が無くて受波センサ回路の出力が有る場合には
送受波センサ回路が異常又は故障であるとして出力の有
る受波センサ回路により距離演算を実行する。According to the second aspect of the present invention, for example, if the wave transmission / reception sensor circuit has higher sensitivity than the wave reception sensor circuit so that noise can be detected, the arithmetic processing unit
If both circuits have an output, even the low-sensitivity wave sensor circuit detects it, so the distance calculation is performed assuming that there is no noise or abnormality in the output, and if both circuits have no output, the high-sensitivity sensor is used. Since even the wave transmission / reception sensor circuit does not detect, the distance calculation is not executed because there is no object, and if there is an output of the wave transmission / reception sensor circuit but no output of the wave reception / reception sensor circuit, the only wave transmission / reception sensor If the circuit output also has noise, the distance calculation is not executed, and if there is no output from the wave transmission / reception sensor circuit and there is output from the wave reception / reception sensor circuit, it is determined that the wave transmission / reception sensor circuit is abnormal or malfunctioning. The distance calculation is executed by the existing receiving sensor circuit.
【００２３】請求項３記載のものによれば、演算処理部
で演算された距離や送受波センサ回路の異常等の情報が
動作部に送られることによって、情報自体を表示した
り、情報により負荷等を動作したりする。According to the third aspect of the present invention, information such as the distance calculated by the arithmetic processing unit and the abnormality of the wave transmission / reception sensor circuit is sent to the operating unit to display the information itself or load the information. And so on.
【００２４】[0024]
【実施例】本発明の一実施例を図１乃至図３に基づいて
以下に説明する。なお、図２(a)乃至同図(h) に示す各
波形信号の伝送位置が、符号(a) 乃至(h) でもって図１
の各対応位置に記してある。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. It should be noted that the transmission positions of the respective waveform signals shown in FIGS. 2 (a) to 2 (h) are indicated by reference numerals (a) to (h) in FIG.
In each corresponding position.
【００２５】このものは、送受波センサ回路1 、受波セ
ンサ回路2 、演算処理部3 、動作部4 で構成され、その
送受波センサ回路1 は送受波部11及び送受波回路12から
なり、また受波センサ回路2 は受波部21及び受波回路22
からなる。This device is composed of a wave transmission / reception sensor circuit 1, a wave reception sensor circuit 2, an arithmetic processing section 3 and an operation section 4, and the wave transmission / reception sensor circuit 1 is composed of a wave transmission / reception section 11 and a wave transmission / reception circuit 12. The wave receiving sensor circuit 2 includes a wave receiving unit 21 and a wave receiving circuit 22.
Consists of.
【００２６】送受波部11は、超音波振動子であって、超
音波U を送波として物体M に向けて送出するとともに、
その物体M に到達して反射して来た反射波U1を受波とし
て受ける。The wave transmitting / receiving unit 11 is an ultrasonic transducer, and transmits the ultrasonic wave U as a wave to the object M, and
The reflected wave U 1 that reaches the object M and is reflected is received as a received wave.
【００２７】送受波回路12は、後述する演算処理部3 か
ら図２(a) に示すパルスP を受けて、発振部12a で発振
した発振信号を昇圧部12b で昇圧し、逆並列接続ダイオ
ード12c を経て、同図(b) に示す送波信号W0を出力し、
送受波部11を振動させる。また送受波部11で受けた物体
M からの反射波U1による信号は、逆並列接続ダイオード
12c を通過することができない極弱いものであって、増
幅部12d により増幅して同図(c) に示す反射波信号W1が
超音波U 送出時から第１の時間t1後に検知される。この
とき、送波信号W0による送受波部11の機械的振動が送波
信号W0の終了後も残響として残り、それが同図(c) に示
すように超音波U 送出時から第４の時間t4の間だけ電気
的な残響波信号W4として残る。次いで、反射波信号W1及
び残響波信号W4は検波部12e でしきい値Y0によりカット
して同図(d) に示す反射波検波信号W10 及び残響波検波
信号W40 のように検波された後、残響波除去部12f で同
図(e) に示すように残響波検波信号W40 を除去して反射
波検波信号W10 だけを残し、後述する演算処理部3 に送
られる。The transmission / reception circuit 12 receives the pulse P shown in FIG. 2 (a) from the arithmetic processing unit 3 described later, boosts the oscillation signal oscillated by the oscillating unit 12a by the boosting unit 12b, and the anti-parallel connection diode 12c. After that, the transmitted signal W 0 shown in (b) of the figure is output,
The transmitting / receiving unit 11 is vibrated. In addition, the object received by the wave transceiver 11
The signal due to the reflected wave U 1 from M is an antiparallel diode.
It is an extremely weak signal that cannot pass through 12c, and the reflected wave signal W 1 shown in FIG. 6 (c) after being amplified by the amplification unit 12d is detected after the first time t 1 from the time when the ultrasonic wave U is transmitted. . At this time, the the remaining time, it ultrasonic U dispatched as shown in the diagram (c) as a mechanical vibration is also reverberation after the end of the transmitting signal W 0 of the wave transceiver unit 11 by transmitting signals W 0 4 The electric reverberation wave signal W 4 remains only during the time t 4 . Next, the reflected wave signal W 1 and the reverberant wave signal W 4 are cut by the threshold value Y 0 in the detection unit 12e to obtain the reflected wave signal W 10 and the reverberant wave signal W 40 shown in FIG. After being detected, the reverberation wave removing unit 12f removes the reverberation wave detection signal W 40 as shown in FIG. 6 (e), leaving only the reflected wave detection signal W 10 and sending it to the arithmetic processing unit 3 described later.
【００２８】受波部21は、送受波部11と同様に超音波振
動子であって、送受波部11から送出された超音波U が物
体M に到達して反射して来た反射波U2及び物体M に反射
せずに送受波部11から直接到達する直接波U3の２つの受
波を受けるよう、図３に示すように、送受波部11と同一
指向方向で、しかも物体M から距離Ｌに位置する送受波
部11よりもさらに所定距離ｄだけずらし、かつ送受波部
11との空間距離Ｓを大きくするための張出部12a を有す
るハウジング12に送受波部11と一体的に配設されてい
る。The wave receiving unit 21 is an ultrasonic transducer similarly to the wave transmitting / receiving unit 11, and the ultrasonic wave U transmitted from the wave transmitting / receiving unit 11 reaches the object M and is reflected by the reflected wave U. 2 and the object M, as shown in FIG. 3, in order to receive the two waves of the direct wave U 3 which arrives directly from the wave transmitter / receiver 11 without being reflected by the object M. From the wave transmission / reception section 11 located at a distance L from the wave transmission / reception section
It is provided integrally with the wave transmitting / receiving unit 11 in a housing 12 having an overhanging portion 12a for increasing the spatial distance S from the wave transmitting / receiving unit 11.
【００２９】受波回路22は、受波部21で受けた反射波U2
及び直接波U3を増幅部22a で増幅して図２(f) に示す反
射波信号W2及び直接波信号W3が超音波U 送出時からそれ
ぞれ第２の時間t2後及び第３の時間t3後に検知される。
次いで、この２つの信号は検波部22b でしきい値Y0によ
りカットして同図(g) に示す反射波検波信号W20 及び直
接波検波信号W30 のように検波された後、直接波除去部
22c で同図(h) に示すように直接波検波信号W30 を除去
して反射波検波信号W20 だけを残し、後述する演算処理
部3 に送られる。The wave receiving circuit 22 receives the reflected wave U 2 received by the wave receiving unit 21.
And direct wave U 3 is amplified by the amplifying unit 22a to Figure 2 the reflected wave signal W 2 and the direct wave signal W 3 shown in (f) ultrasonic wave U delivery time from the second time t 2 and after 3, respectively Detected after time t 3 .
Next, these two signals are cut by the threshold value Y 0 in the detection section 22b and detected as a reflected wave detection signal W 20 and a direct wave detection signal W 30 shown in FIG. Removal section
At 22c, the direct wave detection signal W 30 is removed and only the reflected wave detection signal W 20 is left, as shown in FIG.
【００３０】ここで、直接波信号W3の第３の時間t3は、
ハウジング12に一体的に配設された送受波部11と受波部
21との空間距離Ｓで決まり、図４に示すように送受波部
11及び受波部21のずらし距離ｄに伴う反射波U2の反射波
U1からの遅延時間t2−t1だけ残響波信号W4終了時までの
第４の時間t4よりも遅れるよう空間距離Ｓを設定してあ
り、この一定の第３の時間t3は後述する演算処理部3 に
記憶させてある。[0030] In this case, the third time t 3 of the direct wave signal W 3 is,
A wave transmitting / receiving unit 11 and a wave receiving unit integrally provided in the housing 12.
Determined by the spatial distance S from 21 and as shown in FIG.
11 and the reflected wave of the reflected wave U 2 accompanying the shift distance d of the wave receiving unit 21
Have set the spatial distance S so later than the fourth time t 4 until the delay time t 2 -t 1 only reverberation wave signal W 4 at the end of the U 1, the third time t 3 of the constant It is stored in the arithmetic processing unit 3 described later.
【００３１】演算処理部3 は、図２(a) に示すパルスP
を送受波回路12の発振部12a に送った時つまり超音波U
送出時からの遅延時間である図２(e) の第１の時間t1及
び同図(h) の第２の時間t2を計測するとともに、記憶し
てある第３の時間t3も使用して送受波部11から物体M ま
での距離Ｌを以下のように演算処理する。The arithmetic processing unit 3 uses the pulse P shown in FIG.
Is transmitted to the oscillator 12a of the transmission / reception circuit 12, that is, the ultrasonic wave U
The first time t 1 in FIG. 2 (e) and the second time t 2 in FIG. 2 (e), which are the delay time from the sending time, are measured, and the stored third time t 3 is also used. Then, the distance L from the transmitting / receiving unit 11 to the object M is calculated as follows.
【００３２】まず、物体M が送受波部11から近距離のた
めに、送受波部11で受ける反射波U1の検知時までの第１
の時間t1が、残響波終了時までの第４の時間t4よりも小
さくて反射波信号W1が残響波信号W4に重なっているよう
な場合について述べる。この場合、図４に示すように、
受波部21で受ける反射波U2の検知時までの第２の時間t2
が送受波部11からの直接波U3の検知時までの第３の時間
t3よりも小さくなっており、これは図３に示すように送
受波部11と受波部21との空間距離Ｓをハウジング12の張
出部12a により大きくすることによって、反射波U2より
も直接波U3の伝播距離を大きくしているためである。First, since the object M is located at a short distance from the wave transmitting / receiving unit 11, the first wave until the reflected wave U 1 received by the wave transmitting / receiving unit 11 is detected.
The time t 1 of is smaller than the fourth time t 4 until the end of the reverberation wave and the reflected wave signal W 1 overlaps the reverberation wave signal W 4 will be described. In this case, as shown in FIG.
The second time t 2 until the detection of the reflected wave U 2 received by the wave receiver 21
Is the third time until the detection of the direct wave U 3 from the wave transmitter / receiver 11.
It is smaller than t 3 , and this is larger than the reflected wave U 2 by increasing the spatial distance S between the wave transmitting / receiving section 11 and the wave receiving section 21 by the overhang 12a of the housing 12 as shown in FIG. This is because the propagation distance of the direct wave U 3 is increased.
【００３３】そこで、直接波U3及び受波部21で受けるこ
とができる反射波U2の２つの受波に関して周囲温度に影
響される音速Ｖを含んでそれぞれ成立する２つ関係式つ
まり直接波U3に関するＳ＝Ｖ・t3及び反射波U2に関する
ｄ＋２Ｌ＝Ｖ・t2からその音速Ｖを消去したＬ＝（t2・
Ｓ−t3・ｄ）／２・t3の関係式(1) により距離Ｌを周囲
温度に影響されずに演算処理部3 で求められる。Therefore, regarding the two received waves of the direct wave U 3 and the reflected wave U 2 that can be received by the wave receiving section 21, two relational expressions, that is, the direct wave, which include the sound velocity V affected by the ambient temperature, that is, the direct wave L which erase the sound speed V from d + 2L = V · t 2 regarding S = V · t 3, and the reflected wave U 2 relates U 3 = (t 2 ·
The distance L is calculated by the arithmetic processing unit 3 by the relational expression (1) of S−t 3 · d) / 2 · t 3 without being influenced by the ambient temperature.
【００３４】次に、物体M が送受波部11から比較的遠距
離のために、送受波部11で受ける反射波U1の検知時まで
の第１の時間t1が、残響波終了時までの第４の時間t4よ
りも大きくて反射波信号W1が残響波信号W4に重なってい
ない場合について述べる。Next, since the object M is relatively far from the transmitting / receiving unit 11, the first time t 1 until the detection of the reflected wave U 1 received by the transmitting / receiving unit 11 is until the end of the reverberation wave. The case where the reflected wave signal W 1 does not overlap with the reverberation wave signal W 4 because it is longer than the fourth time t 4 of FIG.
【００３５】この場合、反射波U2の第２の時間t2は反射
波U1の第１の時間t1よりも遅延時間t2−t1だけ遅らせて
設定してある直接波U3の第３の時間t3よりも大きくな
る。[0035] In this case, the reflected wave U 2 of the second time t 2 is the direct wave U 3 which is set delayed by a delay time t 2 -t 1 than the first time t 1 of the reflected wave U 1 It becomes larger than the third time t 3 .
【００３６】そして、反射波U2の反射波信号W2が直接波
U3の直接波信号W3に重なっているために反射波U2の第２
の時間t2が検知できないような比較的近い遠距離の場合
には、直接波U3及び送受波部11で受けることができる反
射波U1の２つの受波に関して周囲温度に影響される音速
Ｖを含んでそれぞれ成立する２つ関係式つまり直接波U3
に関するＳ＝Ｖ・t3及び反射波U1に関する２Ｌ＝Ｖ・t1
からその音速Ｖを消去したＬ＝t1・Ｓ／２・t3の関係式
(2) により距離Ｌを周囲温度に影響されずに演算処理部
3 で求められる。[0036] Then, the direct wave reflected wave signal W 2 of the reflected wave U 2
The second wave of the reflected wave U 2 because it overlaps with the direct wave signal W 3 of U 3
In the case of a relatively short distance such that the time t 2 of is undetectable, the sound velocity affected by the ambient temperature with respect to the two received waves of the direct wave U 3 and the reflected wave U 1 that can be received by the transmitting / receiving unit 11. Two relational expressions that hold each including V, that is, direct wave U 3
With respect to S = V · t 3 and with respect to reflected wave U 1 2L = V · t 1
The relational expression of L = t 1 · S / 2 · t 3 from which the sound velocity V is deleted from
By (2), the distance L is not affected by ambient temperature
Required by 3.
【００３７】さらに、反射波U2の反射波信号W2が直接波
U3の直接波信号W3よりも遅れて重なっていないような相
当に遠距離の場合には、関係式(2) に加えて、反射波U2
の第２の時間t2が検知できるため、前述した関係式(1)
でも距離Ｌを周囲温度に影響されずに演算処理部3 で求
められる。Furthermore, the direct wave reflected wave signal W 2 of the reflected wave U 2
When fairly distant as not overlapping later than the direct wave signal W 3 of U 3, in addition to the relational expression (2), the reflected wave U 2
Since the second time t 2 of can be detected, the above relational expression (1)
However, the distance L can be obtained by the arithmetic processing unit 3 without being influenced by the ambient temperature.
【００３８】次に、送受波センサ回路1 及び受波センサ
回路2 の検知感度において述べる。すなわち、送受波セ
ンサ回路1 の方だけがノイズを検知できるよう受波セン
サ回路2 よりも高感度にしてある。そして、演算処理部
3 は、両回路共に出力が有る場合は低感度の受波センサ
回路2 でさえ検知しているためその出力にはノイズや異
常はないとして距離演算を実行し、また両回路共に出力
が無い場合は高感度の送受波センサ回路1 でさえ検知し
ていないため物体が存在しないとして距離演算を実行せ
ず、また送受波センサ回路1 の出力が有って受波センサ
回路2 の出力が無い場合には唯一の送受波センサ回路1
の出力にもノイズがあるとして距離演算を実行せず、ま
た送受波センサ回路1 の出力が無くて受波センサ回路2
の出力が有る場合には送受波センサ回路1 が異常又は故
障であるとして出力の有る受波センサ回路2 により距離
演算を実行する。Next, the detection sensitivity of the wave transmission / reception sensor circuit 1 and the wave reception sensor circuit 2 will be described. That is, the wave transmission / reception sensor circuit 1 has higher sensitivity than the wave reception sensor circuit 2 so that noise can be detected. And the arithmetic processing unit
3 indicates that even if both circuits have outputs, even the low-sensitivity wave sensor circuit 2 detects it, so if there is no noise or abnormality in the output, distance calculation is executed, and if both circuits have no output. Is not detected even by the high-sensitivity transmitting / receiving sensor circuit 1, so distance calculation is not executed because there is no object, and the output of the transmitting / receiving sensor circuit 1 is present and the output of the receiving sensor circuit 2 is not present. Is the only transmitting and receiving sensor circuit 1
There is noise in the output of the receiving sensor circuit 2 because the distance calculation is not executed.
If there is an output of, the wave receiving / transmitting sensor circuit 1 determines that the wave receiving / transmitting sensor circuit 1 is abnormal or malfunctions, and the wave receiving sensor circuit 2 having an output executes the distance calculation.
【００３９】動作部4 は、演算処理部3 からの情報を受
け、演算された距離Ｌや送受波センサ回路1 の異常等の
情報自体を表示したり、情報により負荷等を動作させた
りする。The operation unit 4 receives information from the arithmetic processing unit 3 and displays the information such as the calculated distance L and the abnormality of the wave transmission / reception sensor circuit 1 itself, or operates the load or the like according to the information.
【００４０】かかる超音波センサにあっては、上述した
ように、物体M が送受波部11から近距離の場合は関係式
(1) により、また遠距離の場合は関係式(1) 又は関係式
(2)により、距離Ｌを周囲温度に影響されずにそれぞれ
演算処理部3 で求めることができる。In the ultrasonic sensor, as described above, when the object M is close to the wave transmitting / receiving unit 11, the relational expression
Depending on (1), and for long distances, relational expression (1) or relational expression
According to (2), the distance L can be calculated by the arithmetic processing unit 3 without being affected by the ambient temperature.
【００４１】また、演算処理部3 では、送受波センサ回
路1 及び受波センサ回路2 のそれぞれの出力の有無によ
り演算を選択的に実行することによって、距離Ｌをより
正確に求めることができる。Further, in the arithmetic processing unit 3, the distance L can be obtained more accurately by selectively executing the arithmetic operation depending on the presence or absence of the outputs of the wave transmitting / receiving sensor circuit 1 and the wave receiving sensor circuit 2.
【００４２】また、動作部4 では、演算処理部3 で演算
された距離Ｌや送受波センサ回路1の異常等の情報自体
を表示することによって、情報を目視確認可能となり、
或いは情報により負荷等を動作させて、その負荷等の制
御にも応用できる。Further, in the operation section 4, the information itself such as the distance L calculated by the calculation processing section 3 and the abnormality of the wave transmission / reception sensor circuit 1 is displayed so that the information can be visually confirmed.
Alternatively, it can be applied to control the load or the like by operating the load or the like according to the information.
【００４３】なお、本実施例では、物体M が送受波部11
から近距離の場合に、反射波U2よりも直接波U3の伝播距
離を大きくするために、ハウジング12の張出部12a によ
り送受波部11と受波部21との空間距離Ｓを大きくしてい
るが、ハウジング12に空間距離Ｓを大きくするトンネル
状の迂回経路を設け、その迂回経路を介して送受波部11
から受波部21へ直接波U3が伝播するようにしてもよい。In this embodiment, the object M is the wave transmitter / receiver 11
In order to make the propagation distance of the direct wave U 3 larger than the reflected wave U 2 at a short distance from, the spatial distance S between the wave transmitting / receiving section 11 and the wave receiving section 21 is increased by the overhang 12a of the housing 12. However, the housing 12 is provided with a tunnel-like detour path for increasing the spatial distance S, and the transmitting / receiving unit 11 is provided through the detour path.
The wave U 3 may be directly propagated from the wave receiving unit 21 to the wave receiving unit 21.
【００４４】また、本実施例では、送受波センサ回路1
の方がノイズを検知できるよう受波センサ回路2 よりも
高感度にしてあるが、距離Ｌの演算を選択的に実行する
ための条件として、ノイズではなく例えば故障のみ等の
他の条件で選択できるよう検知感度を適宜設定してもよ
い。Further, in this embodiment, the transmission / reception sensor circuit 1
Has a higher sensitivity than the wave-receiving sensor circuit 2 so that noise can be detected, but as a condition for selectively executing the calculation of the distance L, not noise but other conditions such as only failure are selected. The detection sensitivity may be appropriately set so that it can be achieved.
【００４５】[0045]
【発明の効果】請求項１記載のものは、物体が送受波部
から近距離にある場合、つまり超音波の送出時から送受
波部で受ける反射波の検知時までの第１の時間が、超音
波の送出時から送受波センサ回路に残る残響波終了時ま
での第４の時間よりも小さいために反射波が残響波に重
なっているような場合でも、超音波の送出時から受波部
で受ける反射波の検知時までの第２の時間が超音波の送
出時から受波部で受ける送受波部からの直接波の検知時
までの第３の時間よりも小さいから、受波部で受ける反
射波及び直接波の２つの受波に関して周囲温度に影響さ
れる音速を含んでそれぞれ成立する２つ関係式からその
音速を消去した関係式により距離を周囲温度に影響され
ずに演算処理部で求めることができる。According to the first aspect of the present invention, when the object is in a short distance from the wave transmitting / receiving unit, that is, the first time from the time of transmitting the ultrasonic wave to the time of detecting the reflected wave received by the wave transmitting / receiving unit, Even when the reflected wave overlaps the reverberation wave because it is shorter than the fourth time from the time of transmitting the ultrasonic wave to the end of the reverberation wave remaining in the wave transmission / reception sensor circuit, even when the reflected wave overlaps the reverberation wave The second time until the detection of the reflected wave received at is smaller than the third time from the time of transmitting the ultrasonic wave to the time of detecting the direct wave from the wave receiving / receiving unit at the wave receiving unit. An arithmetic processing unit that does not affect the distance by the ambient temperature by a relational expression that eliminates the sound velocity from the two relational expressions that respectively include the sound velocity affected by the ambient temperature for the two received waves of the reflected wave and the direct wave Can be found at.
【００４６】請求項２記載のものは、請求項１記載のも
のの効果に加えて、送受波センサ回路及び受波センサ回
路のそれぞれの出力の有無により演算処理部での演算を
選択的に実行することによって、距離をより正確に求め
ることができる。According to a second aspect of the present invention, in addition to the effect of the first aspect, the arithmetic processing unit selectively executes the arithmetic operation depending on the presence / absence of outputs of the wave transmitting / receiving sensor circuit and the wave receiving sensor circuit. By doing so, the distance can be obtained more accurately.
【００４７】請求項３記載のものによれば、請求項１又
は２記載のものの効果に加えて、動作部にて、演算処理
部で演算された距離や送受波センサ回路の異常等の情報
自体を表示することによって、情報を目視確認可能とな
り、或いは情報により負荷等を動作させて、その負荷等
の制御にも応用できる。According to the third aspect, in addition to the effect of the first or second aspect, the information itself such as the distance calculated by the arithmetic processing section in the operation section, the abnormality of the transmission / reception sensor circuit, etc. By displaying, the information can be visually confirmed, or the load or the like can be operated by the information and applied to the control of the load or the like.
【図１】本発明の一実施例を示すブロック回路構成図で
ある。FIG. 1 is a block circuit configuration diagram showing an embodiment of the present invention.
【図２】同上の信号波形を示す図である。FIG. 2 is a diagram showing signal waveforms of the same.
【図３】同上の近距離の場合の部分断面図である。FIG. 3 is a partial cross-sectional view in the case of the above short distance.
【図４】同上の近距離の場合の信号波形を示す図であ
る。FIG. 4 is a diagram showing a signal waveform in the case of the above short distance.
【図５】第１従来例を示すブロック回路構成図である。FIG. 5 is a block circuit configuration diagram showing a first conventional example.
【図６】同上の信号波形を示す図である。FIG. 6 is a diagram showing a signal waveform of the same.
【図７】第２従来例を示すブロック回路構成図である。FIG. 7 is a block circuit configuration diagram showing a second conventional example.
【図８】同上の信号波形を示す図である。FIG. 8 is a diagram showing a signal waveform of the same.
【図９】第３従来例を示すブロック回路構成図である。FIG. 9 is a block circuit configuration diagram showing a third conventional example.
【図10】同上の信号波形を示す図である。FIG. 10 is a diagram showing a signal waveform of the same.
【符号の説明】 1 送受波センサ回路 11 送受波部 2 受波センサ回路 21 受波部 3 演算処理部 4 動作部 M 物体 Ｌ 距離 U 超音波 U1 送受波部で受ける反射波 U2 受波部で受ける反射波 U3 直接波 t1 第１の時間 t2 第２の時間 t3 第３の時間 t4 第４の時間[Explanation of reference symbols] 1 wave sensor circuit 11 wave transmitter / receiver section 2 wave sensor sensor circuit 21 wave receiver section 3 arithmetic processing section 4 operation section M object L distance U ultrasonic wave U 1 reflected wave received by the wave transmitter / receiver section U 2 wave received Reflected wave received at the section U 3 Direct wave t 1 1st time t 2 2nd time t 3 3rd time t 4 4th time
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成７年９月７日[Submission date] September 7, 1995
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１３[Correction target item name] 0013
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１３】例えば、実際の距離Ｌが摂氏２５度にて１
ｍのとき、周囲温度が摂氏−２０度〜６０度に変化する
と、計測距離は約０．９２ｍ〜１．０６ｍとなる。For example, when the actual distance L is 25 degrees Celsius, 1
At m, when the ambient temperature changes from -20 degrees Celsius to 60 degrees Celsius, the measurement distance becomes about 0.92 m to 1.06 m .
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２１[Correction target item name] 0021
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２１】[0021]
【作用】請求項１記載のものによれば、物体が送受波部
から近距離にある場合、つまり超音波の送出時から送受
波部で受ける反射波の検知時までの第１の時間が、超音
波の送出時から送受波センサ回路に残る残響波終了時ま
での第４の時間よりも小さいために反射波が残響波に重
なっているような場合でも、超音波の送出時から受波部
で受ける反射波の検知時までの第２の時間が超音波の送
出時から受波部で受ける送受波部からの直接波の検知時
までの第３の時間よりも小さいから、受波部で受ける反
射波及び直接波の２つの受波に関して周囲温度に影響さ
れる音速を含んでそれぞれ成立する２つ関係式からその
音速を消去した関係式により近距離不感帯を除去でき距
離を周囲温度に影響されずに演算処理部で求めることが
できる。According to the first aspect of the present invention, when the object is in a short distance from the wave transmitting / receiving unit, that is, the first time from the time of transmitting the ultrasonic wave to the time of detecting the reflected wave received by the wave transmitting / receiving unit, Even when the reflected wave overlaps the reverberation wave because it is shorter than the fourth time from the time of transmitting the ultrasonic wave to the end of the reverberation wave remaining in the wave transmission / reception sensor circuit, even when the reflected wave overlaps the reverberation wave The second time until the detection of the reflected wave received at is smaller than the third time from the time of transmitting the ultrasonic wave to the time of detecting the direct wave from the wave receiving / receiving unit at the wave receiving unit. Short distance dead zones can be removed by a relational expression that eliminates the sound velocity from the two relational expressions that are established for each of the two received waves, the reflected wave and the direct wave, that are affected by the ambient temperature. Can be calculated by the arithmetic processing unit without being affected by the ambient temperature.
【手続補正３】[Procedure 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００４０[Correction target item name] 0040
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００４０】かかる超音波センサにあっては、上述した
ように、物体M が送受波部11から近距離の場合は関係式
(1) により、また遠距離の場合は関係式(1) 又は関係式
(2)により、近距離不感帯を除去でき、かつ距離Ｌを周
囲温度に影響されずにそれぞれ演算処理部3 で求めるこ
とができる。In the ultrasonic sensor, as described above, when the object M is close to the wave transmitting / receiving unit 11, the relational expression
Depending on (1), and for long distances, relational expression (1) or relational expression
Due to (2), the short-range dead zone can be removed, and the distance L can be calculated by the arithmetic processing unit 3 without being affected by the ambient temperature.
【手続補正４】[Procedure amendment 4]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００４５[Name of item to be corrected] 0045
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００４５】[0045]
【発明の効果】請求項１記載のものは、物体が送受波部
から近距離にある場合、つまり超音波の送出時から送受
波部で受ける反射波の検知時までの第１の時間が、超音
波の送出時から送受波センサ回路に残る残響波終了時ま
での第４の時間よりも小さいために反射波が残響波に重
なっているような場合でも、超音波の送出時から受波部
で受ける反射波の検知時までの第２の時間が超音波の送
出時から受波部で受ける送受波部からの直接波の検知時
までの第３の時間よりも小さいから、受波部で受ける反
射波及び直接波の２つの受波に関して周囲温度に影響さ
れる音速を含んでそれぞれ成立する２つ関係式からその
音速を消去した関係式により近距離不感帯を除去でき距
離を周囲温度に影響されずに演算処理部で求めることが
できる。According to the first aspect of the present invention, when the object is in a short distance from the wave transmitting / receiving unit, that is, the first time from the time of transmitting the ultrasonic wave to the time of detecting the reflected wave received by the wave transmitting / receiving unit, Even when the reflected wave overlaps the reverberation wave because it is shorter than the fourth time from the time of transmitting the ultrasonic wave to the end of the reverberation wave remaining in the wave transmission / reception sensor circuit, even when the reflected wave overlaps the reverberation wave The second time until the detection of the reflected wave received at is smaller than the third time from the time of transmitting the ultrasonic wave to the time of detecting the direct wave from the wave receiving / receiving unit at the wave receiving unit. Short distance dead zones can be removed by a relational expression that eliminates the sound velocity from the two relational expressions that are established for each of the two received waves, the reflected wave and the direct wave, that are affected by the ambient temperature. Can be calculated by the arithmetic processing unit without being affected by the ambient temperature.
Claims (3)
て送受波部から送出するとともに物体からの反射波を受
波として送受波部により検知する送受波センサ回路と、
前記送受波部と同一指向方向に設置された受波部により
前記送受波部からの直接波及び前記反射波を受波として
検知する受波センサ回路と、前記送受波センサ回路及び
前記受波センサ回路の出力を受けて計測した前記超音波
の送出時から前記送受波部又は前記受波部の検知時まで
の第１又は第２の時間と前記超音波の送出時から前記直
接波の検知時までの第３の時間とでもって前記送受波部
から前記物体までの距離を演算して処理する演算処理部
と、を備え、前記第２の時間は、前記第１の時間よりも
大きく、かつ前記第１の時間が前記超音波の送出時から
前記送受波センサ回路に残る残響波終了時までの第４の
時間よりも小さい場合に前記第３の時間よりも小さくな
るよう、前記送受波部及び前記受波部を配置してなるこ
とを特徴とする超音波センサ。1. A transmission / reception sensor circuit for transmitting an oscillated ultrasonic wave as a transmission wave from a transmission / reception unit toward an object and detecting a reflected wave from the object as a reception wave by the transmission / reception unit,
A wave reception sensor circuit that detects the direct wave and the reflected wave from the wave transmission / reception unit as a wave reception by a wave reception unit installed in the same direction as the wave transmission / reception unit, the wave transmission / reception sensor circuit, and the wave reception sensor. A first or second time from the time of transmitting the ultrasonic wave measured by receiving the output of the circuit to the time of detecting the wave transmitting / receiving unit or the wave receiving unit and the time of detecting the direct wave from the time of transmitting the ultrasonic wave. And a calculation processing unit that calculates and processes the distance from the wave transmitting / receiving unit to the object with a third time up to, and the second time is greater than the first time, and When the first time is shorter than the fourth time from the time of transmitting the ultrasonic wave to the end of the reverberant wave remaining in the wave transmitting / receiving sensor circuit, the wave transmitting / receiving unit is set to be shorter than the third time. And the wave-receiving portion is arranged. Wave sensor.
回路よりも高い検知感度にするとともに、前記演算処理
部は、前記送受波センサ回路及び前記受波センサ回路の
それぞれの出力の有無により距離の演算を選択的に実行
することを特徴とする請求項１記載の超音波センサ。2. The wave transmission / reception sensor circuit has higher detection sensitivity than that of the wave reception sensor circuit, and the arithmetic processing unit determines a distance depending on whether or not each of the wave transmission / reception sensor circuit and the wave reception sensor circuit outputs. The ultrasonic sensor according to claim 1, wherein the calculation of is performed selectively.
る動作部を設けたことを特徴とする請求項１又は２記載
の超音波センサ。3. The ultrasonic sensor according to claim 1, further comprising an operation unit that operates according to a processing result of the arithmetic processing unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23183794A JPH0894741A (en) | 1994-09-27 | 1994-09-27 | Ultrasonic sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23183794A JPH0894741A (en) | 1994-09-27 | 1994-09-27 | Ultrasonic sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0894741A true JPH0894741A (en) | 1996-04-12 |
Family
ID=16929794
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23183794A Pending JPH0894741A (en) | 1994-09-27 | 1994-09-27 | Ultrasonic sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0894741A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10339672A (en) * | 1997-06-06 | 1998-12-22 | Babcock Hitachi Kk | Acoustic gas temperature measuring apparatus |
| JP2007500348A (en) * | 2003-07-29 | 2007-01-11 | ドン ハル リ | Distance measuring method and apparatus using ultrasonic waves |
-
1994
- 1994-09-27 JP JP23183794A patent/JPH0894741A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10339672A (en) * | 1997-06-06 | 1998-12-22 | Babcock Hitachi Kk | Acoustic gas temperature measuring apparatus |
| JP2007500348A (en) * | 2003-07-29 | 2007-01-11 | ドン ハル リ | Distance measuring method and apparatus using ultrasonic waves |
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