JPH0560863A - Ultrasonic distance measuring device - Google Patents

Ultrasonic distance measuring device

Info

Publication number
JPH0560863A
JPH0560863A JP3220648A JP22064891A JPH0560863A JP H0560863 A JPH0560863 A JP H0560863A JP 3220648 A JP3220648 A JP 3220648A JP 22064891 A JP22064891 A JP 22064891A JP H0560863 A JPH0560863 A JP H0560863A
Authority
JP
Japan
Prior art keywords
vehicle
gate
time
setting
signal
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.)
Granted
Application number
JP3220648A
Other languages
Japanese (ja)
Other versions
JP2778300B2 (en
Inventor
Toshiya Kimura
敏也 木村
Original Assignee
Nissan Motor Co Ltd
日産自動車株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nissan Motor Co Ltd, 日産自動車株式会社 filed Critical Nissan Motor Co Ltd
Priority to JP3220648A priority Critical patent/JP2778300B2/en
Publication of JPH0560863A publication Critical patent/JPH0560863A/en
Application granted granted Critical
Publication of JP2778300B2 publication Critical patent/JP2778300B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Abstract

PURPOSE:To always accurately measure the distance up to a preceding vehicle by setting a second gate time-for detecting the presence of an intruding vehicle other than a first gate time and newly setting the first gate time when the intruding vehicle is detected. CONSTITUTION:An ultrasonic distance measuring device measures the distance up to a preceding vehicle on the basis of the propagation delay time from the forward transmission of an ultrasonic signal from a vehicle to the reception of the reflection signal from the preceding vehicle. A first gate setting means 1 sets a first gate time with predetermined time width making the reflection signal receivable corresponding to the reception timing of the once received reflection signal due to the preceding vehicle and a second gate setting means 3 sets a second gate time making the reflection signal receivable during the period from the elapse of a definite time after the transmission of the ultrasonic signal to the rising of the first gate time. A first gate correcting and setting means 5 receives the reflection signal due to a separate vehicle different from the preceding vehicle within the second gate time to newly set the first gate time corresponding to the reception timing of said signal.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、車両前方への超音波信
号の送波から先行車両による反射信号の受波までの伝搬
遅延時間に基づいて先行車両までの距離を測定する超音
波距離測定装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ultrasonic distance measurement for measuring a distance to a preceding vehicle based on a propagation delay time from transmission of an ultrasonic signal forward of a vehicle to reception of a reflected signal from the preceding vehicle. Regarding the device.

【0002】[0002]

【従来の技術】図5は超音波距離測定装置の従来例を示
す図、図6はこの従来例の動作タイミングチャートを示
す図である。
2. Description of the Related Art FIG. 5 is a diagram showing a conventional example of an ultrasonic distance measuring apparatus, and FIG. 6 is a diagram showing an operation timing chart of this conventional example.

【0003】この装置は、駆動信号発生器51およびド
ライバ53の制御下で超音波送波器55から車両前方に
一定周期(図6(a)参照)で送波された超音波信号の
先行車両による反射信号(図5(d)参照)を超音波受
波器57で受波し、この反射信号を増幅器59、帯域フ
ィルタ61、検波回路63、ゲート回路65、コンパレ
ータ67で処理後、CPU69において超音波信号の送
波から受波までの伝搬遅延時間に基づいて先行車両まで
の車間距離を測定し、距離表示器71に表示するもので
ある。なお、上記装置において、帯域フィルタ61は受
波された信号のうち特定周波数の反射信号成分のみを抽
出するものであり、検波回路63はこの抽出した信号成
分に対して包絡線検波等の処理を行うものであり、コン
パレータ67は検波処理された信号を閾値設定部73で
設定されている閾値と比較して、閾値を越える場合には
先行車両による反射信号としてCPU69に出力するも
のである。
This device is a preceding vehicle of an ultrasonic signal transmitted from the ultrasonic wave transmitter 55 to the front of the vehicle at a constant period (see FIG. 6A) under the control of the drive signal generator 51 and the driver 53. The reflected signal (see FIG. 5D) is received by the ultrasonic wave receiver 57, and the reflected signal is processed by the amplifier 59, the bandpass filter 61, the detection circuit 63, the gate circuit 65, and the comparator 67, and then in the CPU 69. The inter-vehicle distance to the preceding vehicle is measured based on the propagation delay time from the transmission of the ultrasonic signal to the reception of the ultrasonic signal and displayed on the distance indicator 71. In the above device, the bandpass filter 61 extracts only the reflected signal component of the specific frequency from the received signal, and the detection circuit 63 performs processing such as envelope detection on the extracted signal component. The comparator 67 compares the signal subjected to the detection processing with the threshold value set by the threshold value setting unit 73, and when the signal exceeds the threshold value, outputs it to the CPU 69 as a reflection signal from the preceding vehicle.

【0004】[0004]

【発明が解決しようとする課題】ところで、上述した従
来装置では、ノイズ等の影響を低減して先行車両による
反射信号のみを検出するために、1度先行車両による反
射信号が受波されると、CPU69がその受波タイミン
グに応じて反射信号の受け入れを可能とするゲート時間
(ΔT)を設定し、これに応じてゲート回路65が開閉
するようになっている(図6(d)参照)。したがっ
て、先行車両が存在せず、1度も反射信号が受波されな
い間は、ゲート回路65が開状態を維持することになる
(図6(c)参照)。
By the way, in the above-mentioned conventional apparatus, in order to reduce the influence of noise or the like and detect only the reflected signal from the preceding vehicle, once the reflected signal from the preceding vehicle is received. The CPU 69 sets the gate time (ΔT) that allows the reflected signal to be received in accordance with the reception timing, and the gate circuit 65 is opened and closed accordingly (see FIG. 6D). .. Therefore, the gate circuit 65 remains open while the preceding vehicle does not exist and the reflected signal is not received even once (see FIG. 6C).

【0005】しかしながら、先行車両との間に他の車両
が割り込んで来た場合には、この割り込み車両が新たな
先行車両となるので、この割り込み車両までの距離を測
定しなければならないが、割り込み車両からの反射信号
は前記ゲート時間外に受波されるため、割り込み車両ま
での距離を反射信号が受波されているにも拘らずすぐに
測定できないという改善すべき課題を有していた。
However, when another vehicle interrupts the preceding vehicle, this interrupting vehicle becomes a new preceding vehicle. Therefore, the distance to the interrupting vehicle must be measured. Since the reflected signal from the vehicle is received outside the gate time, there is a problem to be improved that the distance to the interrupting vehicle cannot be immediately measured even though the reflected signal is received.

【0006】本発明は上記に鑑みてなされたもので、そ
の目的としては、常に先行車両までの距離を的確に測定
できるようにした超音波距離測定装置を提供することに
ある。
The present invention has been made in view of the above, and an object thereof is to provide an ultrasonic distance measuring device capable of always accurately measuring a distance to a preceding vehicle.

【0007】[0007]

【課題を解決するための手段】上記目的を達成するた
め、車両前方への超音波信号の送波から先行車両による
反射信号の受波までの伝搬遅延時間に基づいて先行車両
までの距離を測定する装置において、本発明は図1に示
す如く、1度受波した先行車両による反射信号の受波タ
イミングに応じて反射信号を受波可能とする所定時間幅
の第1のゲート時間を設定する第1ゲート設定手段1
と、超音波信号の送波後一定時間の経過から前記第1の
ゲート時間の立ち上がりに至るまで反射信号を受波可能
とする第2のゲート時間を設定する第2ゲート設定手段
3と、第2のゲート時間内に前記先行車両とは異なる別
の車両による反射信号を受波したときには、この受波タ
イミングに応じて第1のゲート時間を新たに設定する第
1ゲート修正設定手段5とを有することを要旨とする。
To achieve the above object, the distance to a preceding vehicle is measured based on the propagation delay time from the transmission of an ultrasonic signal forward of the vehicle to the reception of a reflected signal by the preceding vehicle. In the apparatus according to the present invention, as shown in FIG. 1, the present invention sets a first gate time of a predetermined time width capable of receiving a reflection signal in accordance with the reception timing of the reflection signal from the preceding vehicle that has received once. First gate setting means 1
A second gate setting means 3 for setting a second gate time that allows the reflected signal to be received from the passage of a fixed time after the transmission of the ultrasonic signal to the rise of the first gate time; When a reflected signal from another vehicle different from the preceding vehicle is received within the gate time of 2, the first gate correction setting means 5 for newly setting the first gate time according to the reception timing is provided. Having it is the gist.

【0008】[0008]

【作用】本発明に係る超音波距離測定装置にあっては、
第1のゲート時間の他に割り込み車両の有無を検知する
ための第2のゲート時間を設定し、割り込み車両を検知
したときには、この割り込み車両を新たな先行車両とし
て距離を測定するべくこの割り込み車両からの反射信号
の受波タイミングに応じて第1のゲート時間を新たに設
定するものである。
In the ultrasonic distance measuring device according to the present invention,
In addition to the first gate time, a second gate time for detecting the presence or absence of an interrupting vehicle is set, and when an interrupting vehicle is detected, this interrupting vehicle is used as a new preceding vehicle to measure the distance. The first gate time is newly set in accordance with the reception timing of the reflected signal from.

【0009】[0009]

【実施例】以下、図面を用いて本発明の実施例を説明す
る。
Embodiments of the present invention will be described below with reference to the drawings.

【0010】図2は本発明の一実施例に係る超音波距離
測定装置の構成を示す図である。その構成としては、前
出の図5の構成に対し、ゲート回路(以下「第1のゲー
ト回路」と呼ぶ)65、コンパレータ(以下「第1のコ
ンパレータ」と呼ぶ)67、閾値設定部(以下「第1の
閾値設定部」と呼ぶ)73とそれぞれ同様の機能を有す
る第2のゲート回路15、第2のコンパレータ17、第
2の閾値設定部23が検波回路63に並列接続されてい
る点が異なり、また、これに伴いCPU19の処理機能
が異なる。
FIG. 2 is a diagram showing the configuration of an ultrasonic distance measuring apparatus according to an embodiment of the present invention. As for the configuration, in addition to the configuration of FIG. 5 described above, a gate circuit (hereinafter referred to as “first gate circuit”) 65, a comparator (hereinafter referred to as “first comparator”) 67, a threshold setting unit (hereinafter A second gate circuit 15, a second comparator 17, and a second threshold value setting unit 23, each having the same function as the “first threshold value setting unit” 73, are connected in parallel to the detection circuit 63. And the processing functions of the CPU 19 are different accordingly.

【0011】次に、本実施例の作用を図3のCPU19
のフローチャートおよび図4のタイミングチャートを用
いて説明する。
Next, the operation of this embodiment will be described with reference to the CPU 19 of FIG.
This will be described with reference to the flowchart of FIG.

【0012】まず、CPU19は第1および第2のゲー
ト回路65および15をそれぞれ全開状態および全閉状
態として、一定周期で超音波の送波を始め(図4(a)
参照)、計測を開始する。なお、ここで、全開および全
閉の状態とは、超音波信号送波後の一定の反射波検出不
能時間経過後から次の超音波信号送波までの期間内につ
いて反射信号のコンパレータ17,67への受け入れを
それぞれ可能とするおよび不可能とすることをいう(図
4(a)〜(c)参照)。
First, the CPU 19 sets the first and second gate circuits 65 and 15 to the fully open state and the fully closed state, respectively, and starts transmitting ultrasonic waves at a constant cycle (FIG. 4 (a)).
), Start measurement. Here, the fully open and fully closed states mean that the comparators 17 and 67 of the reflected signals are in the period from the elapse of a fixed reflected wave undetectable time after the ultrasonic signal transmission to the next ultrasonic signal transmission. To enable and disable the reception of each of them (see FIGS. 4 (a) to 4 (c)).

【0013】先行車両が存在しない場合、CPU19と
しては反射信号に応じたゲート時間が設定できないの
で、第1および第2のゲート回路65および15はそれ
ぞれ全開状態および全閉状態を保持する(ステップ10
0,110,150,170)。
When there is no preceding vehicle, the CPU 19 cannot set the gate time according to the reflected signal, so that the first and second gate circuits 65 and 15 hold the fully open state and the fully closed state, respectively (step 10).
0,110,150,170).

【0014】この状態から先行車両が検知されると、図
5の従来例で説明した如く処理が行なわれ、この先行車
両までの距離が測定されると共に引き続きノイズに影響
されない的確な測定を行うべく、図4(d)に示す如く
所定の第1のゲート時間(ΔT)が第1のゲート回路6
5に対して設定される(ステップ100〜130)。そ
して、これに伴い、CPU19は、割り込み車両の検知
のために、前記反射波検出不能時間経過後から第1のゲ
ート時間の立上がりまでの時間を第2のゲート時間(図
4(e)参照)として第2のゲート回路15に対して設
定する(ステップ140,240)。
When the preceding vehicle is detected from this state, the processing is performed as described in the conventional example of FIG. 5, the distance to the preceding vehicle is measured, and accurate measurement that is not influenced by noise is continuously performed. , The predetermined first gate time (ΔT) has the first gate circuit 6 as shown in FIG.
5 is set (steps 100 to 130). Along with this, the CPU 19 uses the second gate time (see FIG. 4E) as the time from the elapse of the reflected wave undetectable time to the rise of the first gate time in order to detect the interrupting vehicle. Is set for the second gate circuit 15 (steps 140 and 240).

【0015】この状態で先行車両までの距離測定中に別
の車両が割り込んで来た場合には、先行車両による反射
信号の有無に拘らず、少なくともこの割り込み車両によ
る反射信号が第2のゲート時間内において受波される
(ステップ140)。CPU19は、この第2のゲート
時間内における受波が1回目か2回目かをレジスタNの
値から判定する(ステップ180,190)。そして、
1回目であれば、図4(f)に示す如くこの受波タイミ
ングに応じて新たな第2のゲート時間を設定する(ステ
ップ250)。2回目であれば、この割り込み車両を新
たな先行車両として以後の距離測定を行うべく、2回目
の反射信号に基づいて距離を測定出力すると共にレジス
タNの値をクリヤ後、図4(g),(h)に示す如く2
回目の反射信号の受波タイミングに応じて新たな第1の
ゲート時間および第2のゲート時間を設定する(ステッ
プ200〜230)。
In this state, when another vehicle interrupts while measuring the distance to the preceding vehicle, at least the reflected signal from the interrupting vehicle is the second gate time regardless of the presence of the reflected signal from the preceding vehicle. It is received inside (step 140). The CPU 19 determines from the value of the register N whether the received wave is the first wave or the second wave within the second gate time (steps 180 and 190). And
If it is the first time, as shown in FIG. 4 (f), a new second gate time is set according to this reception timing (step 250). If it is the second time, the distance is measured and output based on the reflection signal of the second time and the value of the register N is cleared in order to perform the following distance measurement by using this interrupting vehicle as a new preceding vehicle, and then, as shown in FIG. , 2 as shown in (h)
New first gate time and second gate time are set according to the reception timing of the reflected signal for the second time (steps 200 to 230).

【0016】なお、上述した実施例において、ステップ
130は第1のゲート設定手段、ステップ250は第2
ゲート設定手段、ステップ230は第1ゲート修正設定
手段を構成するものである。
In the above embodiment, step 130 is the first gate setting means and step 250 is the second gate setting means.
The gate setting means, step 230 constitutes a first gate correction setting means.

【0017】また、反射信号の受波タイミングに応じて
設定される第1および第2のゲート時間としては、先行
車両の移動速度に応じて変化させるようにしても良い
が、計測1サイクル内での距離変化の最大値がある程度
予想できるような場合には、固定しておいても良い。
Further, the first and second gate times set according to the reception timing of the reflected signal may be changed according to the moving speed of the preceding vehicle, but within one measurement cycle. If the maximum value of the change in the distance can be predicted to some extent, it may be fixed.

【0018】したがって、本実施例によれば、従来装置
に対して割り込み車両を検知するための第2のゲート時
間を第1のゲート時間とは別に設定しているので、急な
割り込み車両があってもこの割り込み車両を新たな先行
車両として測定対象を迅速に変更して的確な距離測定を
継続することができる。
Therefore, according to the present embodiment, since the second gate time for detecting an interrupting vehicle is set separately from the first gate time in the conventional device, there is a sudden interrupting vehicle. However, this interrupting vehicle can be used as a new preceding vehicle to quickly change the measurement target and continue accurate distance measurement.

【0019】[0019]

【発明の効果】以上説明したように本発明によれば、第
1のゲート時間の他に割り込み車両の有無を検知するた
めの第2のゲート時間を設定し、割り込み車両を検知し
たときには、この割り込み車両を新たな先行車両として
距離を測定するべくこの割り込み車両からの反射信号の
受波タイミングに応じて第1のゲート時間を新たに設定
するようにしたので、常に先行車両までの距離を的確に
測定することができる。
As described above, according to the present invention, in addition to the first gate time, the second gate time for detecting the presence / absence of an interrupting vehicle is set. In order to measure the distance by setting the interrupting vehicle as a new preceding vehicle, the first gate time is newly set according to the reception timing of the reflected signal from this interrupting vehicle, so the distance to the preceding vehicle is always accurate. Can be measured.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明のクレーム対応図である。FIG. 1 is a diagram corresponding to a claim of the present invention.

【図2】本発明の一実施例の構成を示す図である。FIG. 2 is a diagram showing a configuration of an exemplary embodiment of the present invention.

【図3】当該一実施例の処理を示すフローチャートであ
る。
FIG. 3 is a flowchart showing a process of the embodiment.

【図4】当該一実施例の作用を説明するためのタイミン
グチャートである。
FIG. 4 is a timing chart for explaining the operation of the embodiment.

【図5】従来例の構成を示す図である。FIG. 5 is a diagram showing a configuration of a conventional example.

【図6】当該従来例の作用を説明するためのタイミング
チャートである。
FIG. 6 is a timing chart for explaining the operation of the conventional example.

【符号の説明】[Explanation of symbols]

1 第1ゲート設定手段 3 第2ゲート設定手段 5 第1ゲート修正設定手段 15 第2のゲート回路 17 第2のコンパレータ 19 CPU 23 第2の閾値設定部 51 駆動信号発生器 53 ドライバ 55 超音波送波器 57 超音波受波器 59 増幅器 61 帯域フィルタ 63 検波回路 65 ゲート回路 67 コンパレータ 69 CPU 71 距離表示器 73 閾値設定部 1 1st gate setting means 3 2nd gate setting means 5 1st gate correction setting means 15 2nd gate circuit 17 2nd comparator 19 CPU 23 2nd threshold value setting part 51 drive signal generator 53 driver 55 ultrasonic wave transmission Wave device 57 Ultrasonic wave receiver 59 Amplifier 61 Band filter 63 Detection circuit 65 Gate circuit 67 Comparator 69 CPU 71 Distance indicator 73 Threshold setting section

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 車両前方への超音波信号の送波から先行
車両による反射信号の受波までの伝搬遅延時間に基づい
て先行車両までの距離を測定する装置において、1度受
波した先行車両による反射信号の受波タイミングに応じ
て反射信号を受波可能とする所定時間幅の第1のゲート
時間を設定する第1ゲート設定手段と、超音波信号の送
波後一定時間の経過から前記第1のゲート時間の立ち上
がりに至るまで反射信号を受波可能とする第2のゲート
時間を設定する第2ゲート設定手段と、第2のゲート時
間内に前記先行車両とは異なる別の車両による反射信号
を受波したときには、この受波タイミングに応じて第1
のゲート時間を新たに設定する第1ゲート修正設定手段
とを有することを特徴とする超音波距離測定装置。
1. An apparatus for measuring a distance to a preceding vehicle based on a propagation delay time from transmission of an ultrasonic signal forward of the vehicle to reception of a reflected signal by the preceding vehicle, the preceding vehicle receiving once The first gate setting means for setting a first gate time of a predetermined time width that allows the reflected signal to be received according to the reception timing of the reflected signal by the By a second gate setting means for setting a second gate time that allows reception of a reflected signal until the rise of the first gate time, and another vehicle different from the preceding vehicle within the second gate time. When the reflected signal is received, the first signal is received according to the reception timing.
And a first gate correction setting means for newly setting the gate time of the ultrasonic distance measuring device.
JP3220648A 1991-08-30 1991-08-30 Ultrasonic distance measuring device Expired - Lifetime JP2778300B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3220648A JP2778300B2 (en) 1991-08-30 1991-08-30 Ultrasonic distance measuring device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3220648A JP2778300B2 (en) 1991-08-30 1991-08-30 Ultrasonic distance measuring device

Publications (2)

Publication Number Publication Date
JPH0560863A true JPH0560863A (en) 1993-03-12
JP2778300B2 JP2778300B2 (en) 1998-07-23

Family

ID=16754263

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3220648A Expired - Lifetime JP2778300B2 (en) 1991-08-30 1991-08-30 Ultrasonic distance measuring device

Country Status (1)

Country Link
JP (1) JP2778300B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5799576A (en) * 1996-01-25 1998-09-01 Koike; Hiroyuki Rotary stamp

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59190948U (en) * 1983-06-07 1984-12-18
JPS63180883A (en) * 1987-01-23 1988-07-25 Toyota Motor Corp Obstacle detector for unmanned truck
JPH0240799A (en) * 1988-07-30 1990-02-09 Mazda Motor Corp Running controller for vehicle

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59190948U (en) * 1983-06-07 1984-12-18
JPS63180883A (en) * 1987-01-23 1988-07-25 Toyota Motor Corp Obstacle detector for unmanned truck
JPH0240799A (en) * 1988-07-30 1990-02-09 Mazda Motor Corp Running controller for vehicle

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5799576A (en) * 1996-01-25 1998-09-01 Koike; Hiroyuki Rotary stamp

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