JPH07301672A - Inter-vehicle distance radar device - Google Patents
Inter-vehicle distance radar deviceInfo
- Publication number
- JPH07301672A JPH07301672A JP6093324A JP9332494A JPH07301672A JP H07301672 A JPH07301672 A JP H07301672A JP 6093324 A JP6093324 A JP 6093324A JP 9332494 A JP9332494 A JP 9332494A JP H07301672 A JPH07301672 A JP H07301672A
- Authority
- JP
- Japan
- Prior art keywords
- light
- distance
- vehicle
- light emitting
- emitting element
- 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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- Optical Radar Systems And Details Thereof (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、自車両から前方の物標
までの車間距離が安全走行に必要な車間距離を保持して
いない時に、ドライバーに警報音等により注意を促す車
間距離警報装置等に用いられる車間距離レーダ装置に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-vehicle distance warning device for alerting a driver with an alarm sound or the like when the inter-vehicle distance from his vehicle to a target in front does not hold the inter-vehicle distance required for safe driving. The present invention relates to an inter-vehicle distance radar device used for such purposes.
【0002】[0002]
【従来の技術】従来の車間距離レーダ装置としては、図
7に示す装置が知られている。この装置は、自車両の前
方に、例えば、電波、レーダまたは光等のパルス信号を
送出した時から、前方の先行車両(前方の物標)から反
射されるパルス信号を受信するまでの時間の計測結果に
基づいて車間距離を演算するものである。上記装置は、
光を送出する発光源としてレーザダイオード(LD)と
発光ダイオード(LED)とを使用しているものがあ
る。2. Description of the Related Art As a conventional inter-vehicle distance radar device, a device shown in FIG. 7 is known. This device measures the time from when a pulse signal such as a radio wave, radar, or light is transmitted in front of the host vehicle until the pulse signal reflected from the preceding vehicle (target in front) is received. The inter-vehicle distance is calculated based on the measurement result. The above device
Some use a laser diode (LD) and a light emitting diode (LED) as a light emitting source for transmitting light.
【0003】パルス信号送出手段25は、前方の先行車
両へ向けて電波やレーダ等のパルス信号を送出し、反射
パルス信号受信手段27は、前方の先行車両から反射す
る電波、レーザまたは光等のパルス信号を受信して電気
信号に変換する。また、制御手段29は、パルス信号の
送出タイミングを制御し、時間計測手段31は、制御手
段29の指令に基づいてパルス送出時間から反射パルス
信号を受信するまでの時間をカウントして測定する。The pulse signal sending means 25 sends a pulse signal such as a radio wave or a radar toward the preceding vehicle ahead, and the reflected pulse signal receiving means 27 sends a radio wave, a laser or a light reflected from the preceding vehicle ahead. The pulse signal is received and converted into an electric signal. Further, the control means 29 controls the timing of sending the pulse signal, and the time measuring means 31 counts and measures the time from the pulse sending time to the reception of the reflected pulse signal based on the command of the control means 29.
【0004】図8は各種信号のタイミングチャートであ
り、トリガ信号(1)は、所定時間Tr毎に繰り返し出
力される信号である。送出パルス信号(2)は、制御手
段3で制御されるパルス信号送出手段25から出力され
る信号であり、トリガ信号(1)に同期して出力され
る。受信パルス信号(3)は、反射パルス信号受信手段
27において外部の障害物から反射して受信される信号
であり、受信パルス信号(3)の振幅が所定のしきい値
Vthを超えた時、反射パルス信号受信手段27により検
出信号が出力される。一方、クロックパルス(4)は、
時間計測手段31により、パルス信号(2)が送出され
てから検出信号が出力されるまでの時間をカウントする
ための信号であり、一定時間の間、間隔△t毎に出力さ
れるものであった。FIG. 8 is a timing chart of various signals, and the trigger signal (1) is a signal repeatedly output every predetermined time Tr. The sending pulse signal (2) is a signal output from the pulse signal sending means 25 controlled by the control means 3, and is output in synchronization with the trigger signal (1). The reception pulse signal (3) is a signal received by the reflection pulse signal receiving means 27 by being reflected from an external obstacle, and when the amplitude of the reception pulse signal (3) exceeds a predetermined threshold value Vth, The detection signal is output by the reflected pulse signal receiving means 27. On the other hand, the clock pulse (4) is
It is a signal for counting the time from when the pulse signal (2) is sent out to when the detection signal is output by the time measuring means 31, and it is output at intervals Δt for a certain period of time. It was
【0005】[0005]
【発明が解決しようとする課題】しかしながら、このよ
うな従来の車間距離レーダ装置は発光源としてレーザダ
イオード(LD)と発光ダイオード(LED)とを有
し、発光源としてLDを用いた場合は、一般的に長距離
の検出が可能となるものの、検知幅が狭く、また高温時
等の環境下では長時間の動作に不適切な場合があった。
一方、発光源としてLEDを用いた場合は、一般的に検
知幅は拡がるものの、検知距離は短くなる。However, such a conventional inter-vehicle distance radar device has a laser diode (LD) and a light emitting diode (LED) as a light emitting source, and when the LD is used as a light emitting source, Although it is generally possible to detect a long distance, the detection width is narrow, and there are cases where it is inappropriate for long-time operation in an environment such as high temperature.
On the other hand, when an LED is used as the light emitting source, the detection width is generally widened but the detection distance is shortened.
【0006】上記の対策としては、発光源にLDおよび
LEDの双方を同時に用いることも考えられるが、特
に、近距離の検出時において信号強度が強すぎるため、
車間距離レーダ装置で算出した距離の値が実際の距離に
対して誤差を生じてしまう可能性があった。また、発光
強度が高いLDの熱耐久特性の観点からは、LDの総点
灯時間をできるかぎり短くしたいという従来からの要請
もあった。As a countermeasure for the above, it is conceivable to use both an LD and an LED as a light emitting source at the same time, but in particular, since the signal strength is too strong when detecting a short distance,
There is a possibility that the value of the distance calculated by the inter-vehicle distance radar device may cause an error with respect to the actual distance. Further, from the viewpoint of the thermal durability characteristic of the LD having high emission intensity, there has been a conventional demand to shorten the total lighting time of the LD as much as possible.
【0007】本発明は、このような従来の課題に鑑みて
なされたものであり、その目的は、車間距離レーダの測
距範囲内での測定した距離と実際の距離との誤差を少な
くして高精度の距離計測を行うとともに、レーザダイオ
ードの点灯時間を従来に比べて短縮し、発光素子の長寿
命化を図り、レーダ装置の信頼性を向上する車間距離レ
ーダ装置を提供することにある。The present invention has been made in view of such conventional problems, and an object thereof is to reduce an error between a measured distance and an actual distance within a distance measuring range of an inter-vehicle distance radar. An object of the present invention is to provide an inter-vehicle distance radar device which performs highly accurate distance measurement, shortens the lighting time of a laser diode as compared with the conventional one, prolongs the life of a light emitting element, and improves the reliability of a radar device.
【0008】[0008]
【課題を解決するための手段】上記目的を達成するた
め、図1のクレーム対応図を用いて、請求項1記載の第
1の発明は、自車両の車速を検出する車速検出手段10
1と、前方の物標に対して光を送光する第1の発光素子
103および第2の発光素子105から所定時間内に所
定回数の光を前方の物標に送光する送光手段107と、
この送光手段107から送光された光が前方の物標によ
り反射され、当該反射された反射光の受光信号を増幅す
る増幅手段109と、この増幅手段109により増幅さ
れた受光信号をサンプリングして加算する加算手段11
1と、この加算手段111により加算された受光信号か
ら前方の物標と自車両との距離を演算する距離演算手段
113と、この距離演算手段113により演算された距
離と前記車速検出手段103により検出された自車両の
車速とに基づいて前記送光手段107の第1の発光素子
103と第2の発光素子105とを選択して発光させる
発光素子選択手段115とを備えたことを要旨とする。To achieve the above object, the first invention according to claim 1 uses the claim correspondence diagram of FIG. 1 to detect the vehicle speed of the host vehicle.
1 and a light sending means 107 for sending a predetermined number of times of light to a front target from a first light emitting element 103 and a second light emitting element 105 which send light to a front target. When,
The light sent from the light sending means 107 is reflected by a target in front, and an amplifying means 109 for amplifying a received light signal of the reflected light reflected by the target, and a received light signal amplified by the amplifying means 109 are sampled. Adding means 11 for adding
1, the distance calculation means 113 for calculating the distance between the target object in front and the own vehicle from the received light signals added by the addition means 111, the distance calculated by the distance calculation means 113 and the vehicle speed detection means 103. And a light emitting element selecting means 115 for selecting the first light emitting element 103 and the second light emitting element 105 of the light transmitting means 107 to emit light based on the detected vehicle speed of the own vehicle. To do.
【0009】請求項2記載の第2の発明は、前記発光素
子選択手段115は、前記車速検出手段101の検出に
より自車両が停止中の場合に前記送光手段107の第1
の発光素子103を選択することを要旨とする。According to a second aspect of the present invention, the light emitting element selecting means 115 is the first of the light transmitting means 107 when the own vehicle is stopped by the detection of the vehicle speed detecting means 101.
The gist is to select the light emitting element 103.
【0010】請求項3記載の第3の発明は、前記発光素
子選択手段115は、前記車速検出手段101により自
車両が走行中の場合で、且つ、前記距離演算手段113
により前方の物標との距離が検出されない場合に前記送
光手段107の第2の発光素子を選択することを要旨と
する。According to a third aspect of the present invention, the light emitting element selecting means 115 is configured such that the own vehicle is traveling by the vehicle speed detecting means 101 and the distance calculating means 113 is used.
Therefore, when the distance to the target in front is not detected, the second light emitting element of the light transmitting means 107 is selected.
【0011】請求項4記載の第4の発明は、前記発光素
子選択手段115は、前記車速検出手段101により自
車両が走行中の場合で、且つ、前記距離演算手段113
により前方の物標との距離が所定値以上の場合に前記送
光手段107の第1の発光素子103および第2の発光
素子105を選択することを要旨とする。According to a fourth aspect of the present invention, the light emitting element selecting means 115 is configured such that the vehicle speed detecting means 101 allows the vehicle to travel and the distance calculating means 113.
Therefore, the gist is to select the first light emitting element 103 and the second light emitting element 105 of the light transmitting means 107 when the distance to the target in front is a predetermined value or more.
【0012】請求項5記載の第5の発明は、前記発光素
子選択手段115は、前記車速検出手段101により自
車両が走行中の場合で、且つ、前記距離演算手段113
により前方の物標との距離が所定値未満の場合に前記送
光手段107の第1の発光素子103を選択することを
要旨とする。According to a fifth aspect of the present invention, the light emitting element selecting means 115 is configured such that the own vehicle is traveling by the vehicle speed detecting means 101 and the distance calculating means 113 is used.
Therefore, when the distance to the target in front is less than the predetermined value, the first light emitting element 103 of the light transmitting means 107 is selected.
【0013】請求項6記載の第6の発明は、前記加算手
段111により加算される受光信号の加算値に対応して
前記増幅手段109の受光信号を増幅する増幅率を変更
することを要旨とする。A sixth aspect of the present invention is to change the amplification factor for amplifying the light receiving signal of the amplifying means 109 in accordance with the added value of the light receiving signals added by the adding means 111. To do.
【0014】請求項7記載の第7の発明は、前記加算手
段111により加算される受光信号の加算値のピーク値
が所定値以上の場合に前記増幅手段109の受光信号を
増幅する増幅率を所定値未満にすることを要旨とする。According to a seventh aspect of the present invention, when the peak value of the added value of the received light signals added by the adding means 111 is not less than a predetermined value, the amplification factor for amplifying the received light signal of the amplifying means 109 is set. The gist is to make it less than the specified value.
【0015】請求項8記載の第8の発明は、前記加算手
段111により加算された受光信号の加算値のピーク値
が所定値未満の場合に前記増幅手段109の受光信号を
増幅する増幅率を所定値以上にすることを要旨とする。According to an eighth aspect of the present invention, when the peak value of the added value of the received light signals added by the adding means 111 is less than a predetermined value, the amplification factor for amplifying the received light signal of the amplifying means 109 is set. The gist is to make it a predetermined value or more.
【0016】請求項9記載の第8の発明は、前記送光手
段の第1の発光素子に発光ダイオードを、第2の発光素
子にレーザダイオードを用いたことを要旨とする。An eighth aspect of the present invention is summarized in that a light emitting diode is used for the first light emitting element and a laser diode is used for the second light emitting element of the light transmitting means.
【0017】[0017]
【作用】上述の如く構成すれば、第1の発明は、まず、
車速検出手段101から自車両の車速が検出される。ま
た、送光手段107の第1の発光素子および第2の発光
素子から送光された光が前方の物標により反射され、当
該反射された反射光の受光信号を増幅する増幅手段10
9により増幅された受光信信号を加算手段111によ
り、サンプリングされて加算される。加算後、距離演算
手段113により加算された受光信号から前方の物標と
自車両との距離が演算される。演算後、発光素子選択手
段115により、演算された距離と前記車速検出手段1
03により検出された自車両の車速とに基づいて前記送
光手段107の第1の発光素子103と第2の発光素子
105とを選択するので、車間距離レーダの測距範囲内
での測定した距離と実際の距離との誤差を少なくして高
精度の距離計測を行うとともに、レーザダイオードの点
灯時間を従来に比べて短縮し、発光素子の長寿命化を図
り、レーダ装置の信頼性を向上できる。With the above construction, the first aspect of the invention is as follows.
The vehicle speed of the host vehicle is detected by the vehicle speed detecting means 101. Further, the light sent from the first light emitting element and the second light emitting element of the light sending unit 107 is reflected by the target in front, and the amplifying unit 10 that amplifies the received light signal of the reflected light reflected by the target.
The light reception signal amplified by 9 is sampled and added by the adding means 111. After the addition, the distance calculation means 113 calculates the distance between the front target and the vehicle from the received light signals added. After the calculation, the light emitting element selecting unit 115 calculates the calculated distance and the vehicle speed detecting unit 1.
Since the first light emitting element 103 and the second light emitting element 105 of the light transmitting means 107 are selected based on the vehicle speed of the host vehicle detected by 03, the measurement is performed within the range of the inter-vehicle distance radar. The accuracy of distance measurement is reduced by reducing the error between the distance and the actual distance, and the lighting time of the laser diode is shortened compared with the conventional method to extend the life of the light emitting element and improve the reliability of the radar device. it can.
【0018】第2の発明は、前記発光素子選択手段11
5は、前記車速検出手段101の検出により自車両が停
止中の場合に前記送光手段107の第1の発光素子10
3を選択するので、第1の発明と同様に高精度の距離計
測を行うとともに、レーザダイオードの点灯時間を従来
に比べて短縮し、発光素子の長寿命化を図ることができ
る。The second invention is the light emitting element selecting means 11
5 is the first light emitting element 10 of the light transmitting means 107 when the vehicle is stopped by the detection of the vehicle speed detecting means 101.
Since 3 is selected, the distance measurement can be performed with high accuracy as in the first aspect of the invention, and the lighting time of the laser diode can be shortened as compared with the conventional case, and the life of the light emitting element can be extended.
【0019】第3の発明は、前記発光素子選択手段11
5は、前記車速検出手段101により自車両が走行中の
場合で、且つ、前記距離演算手段113により前方の物
標との距離が検出されない場合に前記送光手段107の
第2の発光素子105を選択するので、第1の発明と同
様に高精度の距離計測を行うとともに、レーザダイオー
ドの点灯時間を従来に比べて短縮し、発光素子の長寿命
化を図ることができる。A third invention is the light emitting element selecting means 11
5 is a second light emitting element 105 of the light transmitting means 107 when the own vehicle is traveling by the vehicle speed detecting means 101 and when the distance calculating means 113 does not detect the distance to the target in front. Is selected, the distance measurement can be performed with high accuracy as in the first aspect of the invention, the lighting time of the laser diode can be shortened as compared with the conventional one, and the life of the light emitting element can be extended.
【0020】第4の発明は、前記車速検出手段101に
より自車両が走行中の場合で、且つ、前記距離演算手段
113により前方の物標との距離が所定値以上の場合に
前記送光手段107の第1の発光素子103および第2
の発光素子を選択するので、第1の発明と同様に高精度
の距離計測を行うとともに、レーザダイオードの点灯時
間を従来に比べて短縮し、発光素子の長寿命化を図るこ
とができる。In a fourth aspect of the present invention, the light transmitting means is provided when the vehicle speed is detected by the vehicle speed detecting means 101 and when the distance calculation means 113 is more than a predetermined distance from the target ahead. 107 the first light emitting element 103 and the second
Since the light emitting element is selected, the distance measurement can be performed with high precision as in the first aspect of the invention, and the lighting time of the laser diode can be shortened as compared with the conventional case, and the life of the light emitting element can be extended.
【0021】第5の発明は、前記発光素子選択手段11
5は、前記車速検出手段101により自車両が走行中の
場合で、且つ、前記距離演算手段113により前方の物
標との距離が所定値未満の場合に前記送光手段107の
第1の発光素子103を選択するので、第1の発明と同
様に高精度の距離計測を行うとともに、レーザダイオー
ドの点灯時間を従来に比べて短縮し、発光素子の長寿命
化を図ることができる。A fifth aspect of the present invention is the light emitting element selecting means 11
5 is the first light emission of the light transmitting means 107 when the own vehicle is traveling by the vehicle speed detecting means 101 and when the distance calculating means 113 is less than a predetermined distance from the target in front. Since the element 103 is selected, the distance measurement can be performed with high accuracy as in the first aspect of the invention, and the lighting time of the laser diode can be shortened as compared with the related art, and the life of the light emitting element can be extended.
【0022】第6の発明は、前記加算手段111により
加算される受光信号の加算値に対応して前記増幅手段1
09の受光信号を増幅する増幅率を変更するので、第1
の発明と同様に高精度の距離計測を行うとともに、レー
ザダイオードの点灯時間を従来に比べて短縮し、発光素
子の長寿命化を図ることができる。In a sixth aspect of the invention, the amplifying means 1 corresponds to the added value of the received light signals added by the adding means 111.
Since the amplification factor for amplifying the received light signal of 09 is changed,
As in the invention described above, the distance measurement can be performed with high accuracy, and the lighting time of the laser diode can be shortened as compared with the conventional case, so that the life of the light emitting element can be extended.
【0023】第7の発明は、前記加算手段111により
加算される受光信号の加算値のピーク値が所定値以上の
場合に前記増幅手段109の受光信号を増幅する増幅率
を所定値未満にするので、第1の発明と同様に高精度の
距離計測を行うとともに、レーザダイオードの点灯時間
を従来に比べて短縮し、発光素子の長寿命化を図ること
ができる。In a seventh aspect of the invention, when the peak value of the added value of the received light signals added by the adding means 111 is a predetermined value or more, the amplification factor for amplifying the received light signal of the amplifying means 109 is set to be less than a predetermined value. Therefore, the distance measurement can be performed with high accuracy as in the first aspect of the invention, and the lighting time of the laser diode can be shortened as compared with the conventional case, and the life of the light emitting element can be extended.
【0024】第8の発明は、前記加算手段111により
加算された受光信号の加算値のピーク値が所定値未満の
場合に前記増幅手段109の受光信号を増幅する増幅率
を所定値以上にするので、第1の発明と同様に高精度の
距離計測を行うとともに、レーザダイオードの点灯時間
を従来に比べて短縮し、発光素子の長寿命化を図ること
ができる。In the eighth aspect of the invention, when the peak value of the added value of the light receiving signals added by the adding means 111 is less than a predetermined value, the amplification factor for amplifying the light receiving signal of the amplifying means 109 is set to a predetermined value or more. Therefore, the distance measurement can be performed with high accuracy as in the first aspect of the invention, and the lighting time of the laser diode can be shortened as compared with the conventional case, and the life of the light emitting element can be extended.
【0025】第9の発明は、前記送光手段107の第1
の発光素子に発光ダイオードを、第2の発光素子にレー
ザダイオードを用いたので、前方の物標との距離等に対
応して発光素子を選択可能になる。A ninth aspect of the invention is the first aspect of the light transmitting means 107.
Since the light emitting diode is used as the light emitting element and the laser diode is used as the second light emitting element, the light emitting element can be selected according to the distance to the target in front.
【0026】[0026]
【実施例】以下、本発明の一実施例を図面に基づいて説
明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.
【0027】第2図は、本発明の車間距離レーダ装置に
係る一実施例の構成を示すブロック図である。なお、本
実施例では、物標は自車両の前方を走行する先行車両で
あるとして説明する。FIG. 2 is a block diagram showing the configuration of an embodiment of the inter-vehicle distance radar device of the present invention. In addition, in this embodiment, the target is described as a preceding vehicle traveling in front of the host vehicle.
【0028】上記車間距離レーダ装置は、CPU1、信
号処理部3、距離センサヘッド5および車速センサ7を
備えている。CPU1は、信号処理部3を制御するとと
もに、当該信号処理部3からのデータを受けて車間距離
の演算を行う。本実施例において、CPU1は、車間距
離の演算の他に後述する送受光素子選択制御回路9を制
御するとともに、増幅率制御回路23も適宜制御する。
信号処理部3は、CPU1からの制御信号により駆動回
路11を制御し、信号増幅回路21からのデータ等を出
力する。車速センサ7は自車両の車速を検出する。The inter-vehicle distance radar device includes a CPU 1, a signal processing unit 3, a distance sensor head 5 and a vehicle speed sensor 7. The CPU 1 controls the signal processing unit 3 and receives data from the signal processing unit 3 to calculate an inter-vehicle distance. In the present embodiment, the CPU 1 controls the transmission / reception element selection control circuit 9, which will be described later, as well as the calculation of the inter-vehicle distance, and also controls the amplification factor control circuit 23 as appropriate.
The signal processing unit 3 controls the drive circuit 11 by the control signal from the CPU 1 and outputs the data and the like from the signal amplification circuit 21. The vehicle speed sensor 7 detects the vehicle speed of the host vehicle.
【0029】上記距離センサヘッド5は送受光素子選択
制御回路9、駆動回路11、送光部13、LED15、
LD17、受光部19、信号増幅回路21および増幅率
制御回路23を備えている。送受光素子選択制御回路9
はCPU1からの制御信号により駆動回路11にLED
15およびLD17の選択信号を出力する。駆動回路1
1は、LED15およびLD17等の送光部13を所定
のパルス幅およびパルス間隔に駆動する。また駆動回路
11は、送受光素子選択制御回路9の制御により、LD
を発光源として適宜点灯状態または非点灯状態とする。
送光部13はLED15とLD17とを備えて、前方の
先行車両等に光を送出する。LED15は発光ダイオー
ドからなり、検知幅が広いが検知距離は短い性質を有す
る。LD17はレーザダイオードからなり、検知幅が狭
いが検知距離は長い性質を有する。なお、本実施例で
は、LED15を用いたが、これと同程度の機能を有す
る発光素子で、例えば、エレクトロルミネッセンス(E
L)を用いることも可能である。受光部19は、ホトダ
イオード(PD)等から構成されており光信号を電気信
号に変換する。変換された電気信号は、信号増幅回路2
1において所定レベルまで増幅される。なお、本実施例
における信号増幅回路21の増幅率は外部制御信号によ
り変更されうる可変機能を持ち合わせている。増幅率制
御回路23は、受信信号の強度に応じて信号増幅回路2
1の信号増幅度を変更するものであり、その増幅度段階
数を複数段設定するようにし、信号の検出状態(加算結
果)に応じて、増幅度を変化させる。The distance sensor head 5 includes a light transmitting / receiving element selection control circuit 9, a drive circuit 11, a light transmitting section 13, an LED 15,
The LD 17, the light receiving unit 19, the signal amplification circuit 21, and the amplification factor control circuit 23 are provided. Transmit / receive element selection control circuit 9
LED to the drive circuit 11 by the control signal from the CPU 1.
The selection signal of 15 and LD17 is output. Drive circuit 1
1 drives the light transmitting section 13 such as the LED 15 and the LD 17 with a predetermined pulse width and pulse interval. Further, the drive circuit 11 is controlled by the transmission / reception element selection control circuit 9
Is used as a light emitting source and is appropriately turned on or off.
The light transmitting unit 13 includes an LED 15 and an LD 17, and transmits light to a preceding vehicle or the like ahead. The LED 15 is a light emitting diode and has a wide detection width but a short detection distance. The LD 17 is composed of a laser diode and has a narrow detection width but a long detection distance. Although the LED 15 is used in this embodiment, a light emitting element having a function similar to that of the LED 15 may be used.
It is also possible to use L). The light receiving unit 19 is composed of a photodiode (PD) or the like and converts an optical signal into an electric signal. The converted electric signal is supplied to the signal amplification circuit 2
At 1, the signal is amplified to a predetermined level. The amplification factor of the signal amplification circuit 21 in this embodiment has a variable function that can be changed by an external control signal. The amplification factor control circuit 23 controls the signal amplification circuit 2 according to the strength of the received signal.
The signal amplification degree of 1 is changed, the amplification step number is set to a plurality of stages, and the amplification degree is changed according to the detection state (addition result) of the signal.
【0030】次に本実施例の作用を図3および図4のフ
ロー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 flow charts of FIGS.
【0031】まず、車速センサ7により自車両の車速を
0Km/hと検出した時の信号の送出から受信、信号処
理および距離演算までの動作を図3のフローチャートを
用いて説明する。本実施例では、車両が停止している際
には、長距離を検出する必要がないので、LED15の
みを発光させる。First, the operations from signal transmission to reception, signal processing and distance calculation when the vehicle speed of the host vehicle is detected by the vehicle speed sensor 7 to be 0 Km / h will be described with reference to the flowchart of FIG. In the present embodiment, when the vehicle is stopped, it is not necessary to detect a long distance, so only the LED 15 is made to emit light.
【0032】まず、車速センサ7は車速Vfを検出し
(S1)、車速Vfが0Km/hならばステップS2で
の判定によりステップS3に進む。ここでは、車速が零
であるのでLD17を発光させずに、測距を開始する
(S4)。測距が開始されると駆動回路13は、制御信
号に応答してLED15から前方に向けて光を所定のパ
ルス幅(例えば130nsec)及びパルス間隔(例え
ば、6μsec)にて所定時間内に所定回数(例えば8
192回)送光し(S5)、物標からの反射光をホトダ
イオード(PD)等の受光素子により受光する(S
6)。First, the vehicle speed sensor 7 detects the vehicle speed Vf (S1), and if the vehicle speed Vf is 0 km / h, the process proceeds to step S3 by the determination in step S2. Here, since the vehicle speed is zero, the distance measurement is started without causing the LD 17 to emit light (S4). When the distance measurement is started, the drive circuit 13 responds to the control signal and directs the light from the LED 15 forward in a predetermined number of times within a predetermined time with a predetermined pulse width (for example, 130 nsec) and a pulse interval (for example, 6 μsec). (Eg 8
Light is transmitted 192 times) (S5), and reflected light from the target is received by a light receiving element such as a photodiode (PD) (S).
6).
【0033】上記物標からの反射光の受光から加算処理
を1回の測距中に多数回(例えば8192回)行い、各
動作中に得られた時間的に連続する複数個(例えば81
92回)の予め決められたビット数のデジタルデータb
3群を信号処理部3は、同期加算処理する(S7)。The addition process is performed a number of times (for example, 8192 times) during one distance measurement from the reception of the reflected light from the target, and a plurality of temporally consecutive (for example, 81
(92 times) a predetermined number of bits of digital data b
The signal processing unit 3 performs a synchronous addition process on the third group (S7).
【0034】本実施例においては、この加算処理を81
92回実施する(S8)が、これにより、距離に対する
加算値レベルの特性b4を得ることができる(1回の測
距終了:S9)。ここで加算値レベルのピークを示して
いる箇所の加算値(Pk)を検査し(S10)、ステッ
プS11での判定によりPkが7900以上であるか否
かを判定する。Pkが7900以上である場合は、加算
値飽和もしくはそれに限りなく近い状態であり、4つの
サンプリング点における加算値を利用した距離演算方法
では、それを正確に演算することができないため、ステ
ップS12に進む。In the present embodiment, this addition processing is performed at 81
This is performed 92 times (S8), but this makes it possible to obtain the characteristic b4 of the added value level with respect to the distance (end of one distance measurement: S9). Here, the added value (Pk) at the portion showing the peak of the added value level is inspected (S10), and it is determined whether Pk is 7900 or more by the determination in step S11. When Pk is 7900 or more, it is in a state where the added value is saturated or is infinitely close to it, and the distance calculation method using the added values at the four sampling points cannot accurately calculate it. move on.
【0035】ここで、図5は、増幅率制御回路23にお
いて複数段設定されている増幅度の様子の一例を示した
ものであるが、信号検出状態に応じて、互いに隣り合う
増幅段階へ切り替え可能である。ステップS12に進む
と図5における増幅度を1段低下させ、ステップS4に
戻り測距を再び最初からやり直す。Here, FIG. 5 shows an example of the states of the amplification degrees set in a plurality of stages in the amplification factor control circuit 23. Switching to the amplification stages adjacent to each other according to the signal detection state. It is possible. When the process proceeds to step S12, the amplification degree in FIG. 5 is decreased by one step, and the process returns to step S4 to restart the distance measurement from the beginning.
【0036】一方、Pkが7900未満である場合は、
ステップS13に進み、そのPkが5000未満である
かどうかを判定する。ここで、図6はピーク加算値(P
k)と距離演算精度との関係を図示したものであるが、
例えば、要求される距離演算精度を±1m以下とした場
合は、Pkは5000以上である必要がある。Pkが5
000未満である場合は、精度良く距離を演算すること
ができないので、ステップS14にて図5に示す増幅度
を1段向上させた後、ステップS4に戻り、測距を再び
やり直す。On the other hand, when Pk is less than 7900,
In step S13, it is determined whether the Pk is less than 5000. Here, FIG. 6 shows the peak addition value (P
Although the relationship between k) and the distance calculation accuracy is illustrated,
For example, when the required distance calculation accuracy is ± 1 m or less, Pk needs to be 5000 or more. Pk is 5
If it is less than 000, the distance cannot be calculated accurately, so the amplification degree shown in FIG. 5 is increased by one step in step S14, and then the process returns to step S4 and the distance measurement is performed again.
【0037】一方、Pkが5000以上である場合は、
距離演算に十分な加算結果であるので、加算ピークとな
る点を含む4つのサンプリング点における加算値を利用
して下式にしたがって、距離演算を行う(S15)。On the other hand, when Pk is 5000 or more,
Since the addition result is sufficient for the distance calculation, the distance calculation is performed according to the following equation using the addition values at the four sampling points including the point that becomes the addition peak (S15).
【0038】 D=(vlx2-v2xl-v3x4+v4x3 )/(v1-v2-v3+V4 ) ここで、Dは演算距離、x1〜x4はサンプリング点におけ
る距離(例えば20,30,40,50m)、v1〜v4は
x1〜x4のサンプリング点における加算値である。距離演
算を終了した後は、直ちにステップS1に戻る。D = (vlx2-v2xl-v3x4 + v4x3) / (v1-v2-v3 + V4) where D is a calculation distance and x1 to x4 are distances at sampling points (for example, 20, 30, 40, 50 m) , V1 to v4 are
It is the added value at the sampling points of x1 to x4. After completing the distance calculation, the process immediately returns to step S1.
【0039】次に、自車両が走行していて(S2)、か
つ、前方に車両等が存在しない場合(S16)の動作に
ついて説明する。この場合、レーダの検知領域内に車両
が進入してきたことを即座に検出する必要があるため、
送光部13は、LED15とLD17とを同時に発光さ
せ、かつ受光回路の増幅度も最大に設定しておく(図5
の第9段階:S17)。測距が開始されると(S18)
送光部13は、LED15およびLD17により前方に
向けて光を所定のパルス幅(例えば130nsec)及
びパルス間隔(例えば、6μsec)にて所定時間内に
所定回数送光し(S19)、前方の先行車両からの反射
光をホトダイオード(PD)等の受光素子により受信す
る(S20)。反射光の受信から加算処理に至る流れは
(S21,22)、既に説明したフロー(S7〜9)と
同様である。前方に車両が存在しない間は、加算結果に
ピークが現われず、ステップS24にて検知車両なしと
判定し、直ちにステップS1に戻る。ステップS1,2
およびS16からS23の動作を繰り返しているうちに
検知領域内に車両等が進入してくるとCPU1は、加算
結果にピークが現われ始めるので、その結果に基づいて
前記同様、加算ピークとなる点を含む4つのサンプリン
グ点における加算値を利用して下式に従い、距離演算を
行う(S24)。Next, the operation when the host vehicle is traveling (S2) and there is no vehicle in front (S16) will be described. In this case, because it is necessary to immediately detect that the vehicle has entered the detection area of the radar,
The light transmitting unit 13 causes the LED 15 and the LD 17 to emit light at the same time and sets the amplification degree of the light receiving circuit to the maximum (FIG. 5).
Step 9: S17). When ranging starts (S18)
The light sending unit 13 sends the light forward by the LED 15 and the LD 17 at a predetermined pulse width (for example, 130 nsec) and a pulse interval (for example, 6 μsec) for a predetermined number of times within a predetermined time (S19), and the front ahead. Reflected light from the vehicle is received by a light receiving element such as a photodiode (PD) (S20). The flow from reception of reflected light to addition processing (S21, 22) is the same as the flow (S7-9) already described. While there is no vehicle ahead, no peak appears in the addition result, it is determined in step S24 that there is no detected vehicle, and the process immediately returns to step S1. Steps S1,2
When a vehicle or the like enters the detection area while repeating the operations from S16 to S23, the CPU 1 begins to show a peak in the addition result. Distance calculation is performed according to the following equation using the added values at the four sampling points including (S24).
【0040】 D=(vlx2-v2xl-v3x4+v4x3 )/(v1-v2-v3+V4 ) 距離演算を終了した後は、直ちにステップS1へ戻る。
一旦前方の先行車両が検知された後の動作については、
以下に説明するようなフローを辿る。D = (vlx2-v2xl-v3x4 + v4x3) / (v1-v2-v3 + V4) After the distance calculation is completed, the process immediately returns to step S1.
Regarding the operation after the preceding vehicle ahead is detected once,
The flow as described below is followed.
【0041】本実施例においては、前方に先行車両が存
在する場合、当該先行車両までの距離が例えば15m以
下であるか否か(S25)によって、発光の方法を変更
する。まず、前方の先行車両までの距離が15m以下で
ある場合について説明する。距離が15m以内である場
合には、遠距離を検知する必要がないため、LD17を
発光させることはしない(S26)。これにより、LD
17の総発光時間を短縮することができる。測距が開始
されると(S27)、LED15により前方に向けて光
を所定のパルス幅(例えば130nsec)及びパルス
間隔(例えば、6μsec)にて所定時間内に所定回数
送光し(S28)、先行車両からの反射光をホトダイオ
ード(PD)等の受光素子により受光する(S29)。
反射光の受光から加算処理に至る流れは(S30,3
1)既に説明したフロー(S7〜9)と同様である。加
算処理が終了する(S32)。In the present embodiment, when the preceding vehicle is present in front, the light emission method is changed depending on whether or not the distance to the preceding vehicle is, for example, 15 m or less (S25). First, the case where the distance to the preceding vehicle ahead is 15 m or less will be described. When the distance is within 15 m, it is not necessary to detect the long distance, and therefore the LD 17 is not caused to emit light (S26). This makes the LD
The total light emission time of 17 can be shortened. When the distance measurement is started (S27), the LED 15 transmits light forward with a predetermined pulse width (for example, 130 nsec) and a pulse interval (for example, 6 μsec) a predetermined number of times within a predetermined time (S28). Reflected light from the preceding vehicle is received by a light receiving element such as a photodiode (PD) (S29).
The flow from the reception of the reflected light to the addition processing is (S30, 3
1) The same as the flow (S7 to 9) described above. The addition process ends (S32).
【0042】ここで、加算値レベルのピークを示してい
る箇所の加算値(Pk)を検査し(S33)、ステップ
S34での判定によりPKが7900以上であるか否か
を判定する。Pkが7900以上である場合は、加算値
飽和もしくはそれに限りなく近い状態であり、4つのサ
ンプリング点における加算値を用いた距離演算方法で
は、それを正確に演算することができないため、ステッ
プS35に進み、増幅度を図5において1段低下させ
る。そして、ステップS27に戻り、測距を再び最初か
らやり直す。Pkが7900未満である場合は、ステッ
プS36に進み、そのPkが5000未満であるかどう
かを判定する。Pkが5000未満である場合は、精度
良く距離を演算することができないので、ステップS3
7にて増幅度を図5において1段向上させた後、ステッ
プS27に戻り、測距を再びやり直す。なお、本実施例
において増幅度が第9段階(最大増幅度)にまで上げら
れた後は、加算ピークが5000未満であったとして
も、これ以上向上させる動作は行わない。一方、Pkが
5000以上である場合は、距離演算に十分な加算結果
であるので、加算ピークとなる点を含む4つのサンプリ
ング点における加算値を利用して下式に従って、距離演
算を行う(S38)。Here, the added value (Pk) at the portion showing the peak of the added value level is inspected (S33), and it is determined by the determination in step S34 whether PK is 7900 or more. When Pk is 7900 or more, it is in a state where the added value is saturated or is infinitely close to it, and the distance calculation method using the added value at the four sampling points cannot accurately calculate it. Then, the amplification degree is lowered by one step in FIG. Then, the process returns to step S27, and the distance measurement is performed again from the beginning. If Pk is less than 7900, the process proceeds to step S36, and it is determined whether the Pk is less than 5000. If Pk is less than 5000, it is not possible to calculate the distance accurately, so step S3
After the amplification degree is increased by one step in FIG. 5 at 7, the process returns to step S27 and the distance measurement is performed again. In the present embodiment, after the amplification level is raised to the ninth level (maximum amplification level), even if the added peak is less than 5000, no further improvement operation is performed. On the other hand, when Pk is 5000 or more, the addition result is sufficient for the distance calculation, so the distance calculation is performed according to the following equation using the addition values at the four sampling points including the point that becomes the addition peak (S38). ).
【0043】 D=(vlx2-v2xl-v3x4+v4x3 )/(v1-v2-v3+V4 ) 距離演算を終了した後には、直ちにステップS1に戻
る。D = (vlx2-v2xl-v3x4 + v4x3) / (v1-v2-v3 + V4) After the distance calculation is completed, the process immediately returns to step S1.
【0044】次に、ステップS25において、前方の車
両までの距離が15mを上回る時の動作について説明す
る。距離が15mを上回る場合は、LED15のみでは
前方の車両を検知しきれない可能性もあるため、LED
15とともにLD17も発光させる(S39)。測距が
開始されると(S40)送光部13は、LED15およ
びLD17により前方に向けて光を所定のパルス幅(例
えば130nsec)及びパルス間隔(例えば6μse
c)にて所定時間内に所定回数送光し(S41)、受光
部19は物標からの反射光をホトダイオード(PD)等
の受光素子により受光する(S42)。反射光の受光か
ら加算処理に至る流れは(S43,44)、既に説明し
たフロー(S7〜9)と同様であり、加算処理が終了す
る(S45)。 ここで、加算値レベルのピークを示し
ている箇所の加算値(Pk)を検査し(S46)、ステ
ップ47での判定によりPkが7900以上であるか否
かを判定する。Pkが7900以上である場合は、加算
値飽和もしくはそれに限りなく近い状態であり、4つの
サンプリング点における加算値を利用した距離演算方法
は、それを正確に演算することができないため、ステッ
プS48に進み、増幅度を図5において1段低下させ
る。そして、ステップS40に戻り、測距を再び最初か
らやり直す。一方、Pkが7900未満である場合は、
ステップS49に進み、そのPkが5000未満である
かどうかを判定する。Pkが5000未満である場合
は、精度良く距離を演算することができないので、ステ
ップS50にて増幅度を図5において1段向上させた
後、ステップS40に戻り、測距を再びやり直す。な
お、前記同様、増幅度が第9段階(最大増幅度)にまで
上げられた後は、加算ピークが5000未満であったと
しても、これ以上向上させる動作は行わない。Pkが5
000以上である場合には、距離演算に十分な加算結果
であるので、加算ピークとなる点を含む4つのサンプリ
ング点における加算値を用い、下式に従って距離演算を
行う(S51)。Next, the operation when the distance to the vehicle in front exceeds 15 m in step S25 will be described. If the distance exceeds 15 m, it may not be possible to detect the vehicle ahead by the LED 15 alone.
The LD 17 is also caused to emit light along with 15 (S39). When the distance measurement is started (S40), the light transmitter 13 directs the light forward by the LED 15 and the LD 17 at a predetermined pulse width (for example, 130 nsec) and pulse interval (for example, 6 μse).
In c), light is transmitted a predetermined number of times within a predetermined time (S41), and the light receiving unit 19 receives the reflected light from the target by a light receiving element such as a photodiode (PD) (S42). The flow from the reception of the reflected light to the addition process (S43, 44) is the same as the flow (S7 to 9) already described, and the addition process ends (S45). Here, the added value (Pk) at the portion showing the peak of the added value level is inspected (S46), and it is determined in step 47 whether Pk is 7900 or more. When Pk is 7900 or more, it is in a state where the added value is saturated or is infinitely close to it, and the distance calculation method using the added value at the four sampling points cannot accurately calculate it. Then, the amplification degree is lowered by one step in FIG. Then, the process returns to step S40, and the distance measurement is restarted from the beginning. On the other hand, when Pk is less than 7900,
In step S49, it is determined whether the Pk is less than 5000. If Pk is less than 5000, the distance cannot be calculated accurately, so the amplification factor is increased by one step in FIG. 5 in step S50, and then the process returns to step S40 to perform distance measurement again. It should be noted that, similarly to the above, after the amplification degree is increased to the ninth stage (maximum amplification degree), even if the added peak is less than 5000, the operation for further improving is not performed. Pk is 5
If it is 000 or more, the addition result is sufficient for the distance calculation, so the distance calculation is performed according to the following equation using the addition values at the four sampling points including the point that becomes the addition peak (S51).
【0045】 D=(vlx2-v2xl-v3x4+v4x3 )/(v1-v2-v3+V4 ) 距離演算を終了した後には、直ちにステップS1に戻
る。D = (vlx2-v2xl-v3x4 + v4x3) / (v1-v2-v3 + V4) After the distance calculation is completed, the process immediately returns to step S1.
【0046】これにより、車間距離レーダの測距範囲内
のいかなる地点においても、自車両と先行車両との車間
距離を高精度に計測できる。また、LD17の点灯時間
を従来に比べて短縮し、発光素子の長寿命化が可能とな
り、レーダ装置の信頼性を向上できる。As a result, the inter-vehicle distance between the host vehicle and the preceding vehicle can be measured with high accuracy at any point within the range of the inter-vehicle distance radar. Further, the lighting time of the LD 17 can be shortened as compared with the conventional case, the life of the light emitting element can be extended, and the reliability of the radar device can be improved.
【0047】[0047]
【発明の効果】以上説明したように、第1の発明は、送
光信手段の第1の発光素子および第2の発光素子から送
光信された光が前方の物標により反射される反射光の受
信信号が増幅、加算される。演算後、発光素子選択手段
により、演算された距離と自車両の車速とに基づいて、
送光信手段の第1の発光素子と第2の発光素子とが選択
されるので、車間距離レーダの測距範囲内での測定した
距離と実際の距離との誤差を少なくして高精度の距離計
測を行うとともに、レーザダイオードの点灯時間を従来
に比べて短縮し、発光素子の長寿命化を図り、レーダ装
置の信頼性の向上を実現できる。As described above, according to the first aspect of the invention, the light transmitted from the first light emitting element and the second light emitting element of the light transmitting means is the reflected light reflected by the target in front. The received signals are amplified and added. After the calculation, the light emitting element selection means, based on the calculated distance and the vehicle speed of the own vehicle,
Since the first light emitting element and the second light emitting element of the light transmitting means are selected, it is possible to reduce the error between the measured distance and the actual distance within the distance measurement range of the inter-vehicle distance radar, and to achieve a highly accurate distance. While performing the measurement, the lighting time of the laser diode can be shortened as compared with the conventional one, the life of the light emitting element can be extended, and the reliability of the radar device can be improved.
【0048】第2の発明は、前記発光素子選択手段は、
前記車速検出手段の検出により自車両が停止中の場合に
前記送光手段の第1の発光素子を選択するので、第1の
発明と同様に高精度の距離計測を行うとともに、レーザ
ダイオードの点灯時間を従来に比べて短縮し、発光素子
の長寿命化を図り、レーダ装置の信頼性の向上を実現で
きる。In a second invention, the light emitting element selecting means is
Since the first light emitting element of the light transmitting means is selected when the host vehicle is stopped by the detection of the vehicle speed detecting means, the distance measurement is performed with high accuracy as in the first aspect of the invention, and the laser diode is turned on. The time can be shortened as compared with the conventional one, the life of the light emitting element can be extended, and the reliability of the radar device can be improved.
【0049】第3の発明は、前記発光素子選択手段は、
前記車速検出手段により自車両が走行中の場合で、且
つ、前記距離演算手段により前方の物標との距離が検出
されない場合に前記送光手段の第2の発光素子を選択す
るので、第1の発明と同様に高精度の距離計測を行うと
ともに、レーザダイオードの点灯時間を従来に比べて短
縮し、発光素子の長寿命化を図り、レーダ装置の信頼性
の向上を実現できる。In a third invention, the light emitting element selecting means is
Since the second light emitting element of the light transmitting means is selected when the own vehicle is traveling by the vehicle speed detecting means and when the distance to the target ahead is not detected by the distance calculating means, the first light emitting element is selected. As in the invention described above, the distance measurement can be performed with high accuracy, the lighting time of the laser diode can be shortened as compared with the prior art, the life of the light emitting element can be extended, and the reliability of the radar device can be improved.
【0050】第4の発明は、前記発光素子選択手段は、
前記車速検出手段により自車両が走行中の場合で、且
つ、前記距離演算手段により前方の物標との距離が所定
値以上の場合に前記送光手段の第1の発光素子および第
2の発光素子を選択するので、第1の発明と同様に高精
度の距離計測を行うとともに、レーザダイオードの点灯
時間を従来に比べて短縮し、発光素子の長寿命化を図
り、レーダ装置の信頼性の向上を実現できる。In a fourth invention, the light emitting element selecting means is
The first light emitting element and the second light emission of the light transmitting means when the own vehicle is traveling by the vehicle speed detecting means and when the distance to the target in front by the distance calculating means is a predetermined value or more. Since the element is selected, the distance measurement can be performed with high accuracy as in the first aspect of the invention, the lighting time of the laser diode can be shortened as compared with the conventional one, and the life of the light emitting element can be extended to improve the reliability of the radar device. Improvement can be realized.
【0051】第5の発明は、前記発光素子選択手段は、
前記車速検出手段により自車両が走行中の場合で、且
つ、前記距離演算手段により前方の物標との距離が所定
値未満の場合に前記送光手段の第1の発光素子を選択す
るので、第1の発明と同様に高精度の距離計測を行うと
ともに、レーザダイオードの点灯時間を従来に比べて短
縮し、発光素子の長寿命化を図り、レーダ装置の信頼性
の向上を実現できる。In a fifth aspect of the present invention, the light emitting element selecting means is
Since the first light emitting element of the light transmitting means is selected when the own vehicle is traveling by the vehicle speed detecting means and when the distance to the front target is less than the predetermined value by the distance calculating means, As in the first aspect, the distance measurement can be performed with high accuracy, the lighting time of the laser diode can be shortened as compared with the conventional one, the life of the light emitting element can be extended, and the reliability of the radar device can be improved.
【0052】第6の発明は、前記加算手段により加算さ
れる受光信号の加算値に対応して前記増幅手段の増幅す
る増幅率を変更するので、第1の発明と同様に高精度の
距離計測を行うとともに、レーザダイオードの点灯時間
を従来に比べて短縮し、発光素子の長寿命化を図り、レ
ーダ装置の信頼性の向上を実現できる。According to the sixth aspect of the invention, the amplification factor amplified by the amplifying means is changed in accordance with the added value of the received light signals added by the adding means. In addition, the lighting time of the laser diode can be shortened as compared with the conventional case, the life of the light emitting element can be extended, and the reliability of the radar device can be improved.
【0053】第7の発明は、前記加算手段により加算さ
れる受光信号の加算値のピーク値が所定値以上の場合に
前記増幅率変更手段の増幅する増幅率を所定値未満にす
るので、第1の発明と同様に高精度の距離計測を行うと
ともに、レーザダイオードの点灯時間を従来に比べて短
縮し、発光素子の長寿命化を図り、レーダ装置の信頼性
の向上を実現できる。In the seventh invention, when the peak value of the added value of the received light signals added by the adding means is equal to or more than a predetermined value, the amplification factor to be amplified by the amplification factor changing means is set to be less than the predetermined value. As in the first aspect of the invention, the distance measurement can be performed with high accuracy, the lighting time of the laser diode can be shortened as compared with the conventional case, the life of the light emitting element can be extended, and the reliability of the radar device can be improved.
【0054】第8の発明は、前記加算手段により加算さ
れた受光信号の加算値のピーク値が所定値未満の場合に
前記増幅手段の増幅する増幅率を所定値以上にするの
で、第1の発明と同様に高精度の距離計測を行うととも
に、レーザダイオードの点灯時間を従来に比べて短縮
し、発光素子の長寿命化を図り、レーダ装置の信頼性の
向上を実現できる。In the eighth invention, when the peak value of the added value of the received light signals added by the adding means is less than a predetermined value, the amplification factor amplified by the amplifying means is set to a predetermined value or more. As in the invention, the distance measurement can be performed with high accuracy, the lighting time of the laser diode can be shortened as compared with the conventional case, the life of the light emitting element can be extended, and the reliability of the radar device can be improved.
【0055】第9の発明は、前記送光手段の第1の発光
素子に発光ダイオードを、第2の発光素子にレーザダイ
オードを用いたので、前方の物標との距離等に対応して
発光素子の選択を実現できる。In the ninth invention, since the light emitting diode is used as the first light emitting element and the laser diode is used as the second light emitting element of the light transmitting means, light is emitted in accordance with the distance to the target in front. Selection of elements can be realized.
【図1】本発明を示すクレーム対応図である。FIG. 1 is a claim correspondence diagram showing the present invention.
【図2】本発明の車間距離レーダ装置に係る一実施例の
構成を示すブロック図である。FIG. 2 is a block diagram showing the configuration of an embodiment of an inter-vehicle distance radar device of the present invention.
【図3】本発明の動作を示すフローチャートである。FIG. 3 is a flowchart showing the operation of the present invention.
【図4】本発明の動作を示すフローチャートである。FIG. 4 is a flowchart showing the operation of the present invention.
【図5】増幅度段階設定を示す図である。FIG. 5 is a diagram showing amplification level setting.
【図6】距離演算精度とピーク加算値との関係を示す図
である。FIG. 6 is a diagram showing a relationship between a distance calculation accuracy and a peak addition value.
【図7】従来の構成を示すブロック図である。FIG. 7 is a block diagram showing a conventional configuration.
【図8】従来の動作を示すタイムチャートである。FIG. 8 is a time chart showing a conventional operation.
1 CPU 3 信号処理部 7 車速センサ 9 送受光素子選択回路 11 駆動回路 15 LED 17 LD 23 増幅率制御回路 101 車速検出手段 103 第1の発光素子 105 第2の発光素子 107 送信手段 109 増幅手段 111 加算手段 113 車間距離演算手段 115 発光素子選択手段 DESCRIPTION OF SYMBOLS 1 CPU 3 Signal processing unit 7 Vehicle speed sensor 9 Transmitting / receiving element selection circuit 11 Driving circuit 15 LED 17 LD 23 Amplification factor control circuit 101 Vehicle speed detecting means 103 First light emitting element 105 Second light emitting element 107 Transmitting means 109 Amplifying means 111 Adding means 113 inter-vehicle distance calculating means 115 light emitting element selecting means
Claims (9)
と、 前方の物標に対して光を送光する第1の発光素子および
第2の発光素子から所定時間内に所定回数の光を前方の
物標に送光する送光手段と、 この送光手段から送光された光が前方の物標により反射
され、当該反射された反射光の受光信号を増幅する増幅
手段と、 この増幅手段により増幅された受光信号をサンプリング
して加算する加算手段と、 この加算手段により加算された受光信号から前方の物標
と自車両との距離を演算する距離演算手段と、 この距離演算手段により演算された距離と前記車速検出
手段により検出された自車両の車速とに基づいて前記送
光手段の第1の発光素子と第2の発光素子とを選択して
発光させる発光素子選択手段と、 を備えたことを特徴とする車間距離レーダ装置。1. A vehicle speed detecting means for detecting a vehicle speed of a host vehicle, and a first light emitting element and a second light emitting element for transmitting light to a target in front of the vehicle. Light transmitting means for transmitting light to the target in front, amplification means for amplifying the light reception signal of the reflected light reflected by the target in front of the light transmitted from the light transmitting means, and this amplifying means. Adding means for sampling and adding the received light signals amplified by the means, distance calculating means for calculating the distance between the front target and the vehicle from the received light signals added by the adding means, and the distance calculating means Light emitting element selecting means for selecting and emitting light from the first light emitting element and the second light emitting element of the light transmitting means based on the calculated distance and the vehicle speed of the vehicle detected by the vehicle speed detecting means, Inter-vehicle distance characterized by having Radar equipment.
手段の検出により自車両が停止中の場合に前記送光手段
の第1の発光素子を選択することを特徴とする請求項1
記載の車間距離レーダ装置。2. The light emitting element selecting means selects the first light emitting element of the light transmitting means when the host vehicle is stopped by the detection of the vehicle speed detecting means.
The inter-vehicle distance radar device described.
手段により自車両が走行中の場合で、且つ、前記距離演
算手段により前方の物標との距離が検出されない場合に
前記送光手段の第2の発光素子を選択することを特徴と
する請求項1記載の車間距離レーダ装置。3. The light emitting element selecting means of the light transmitting means when the own vehicle is traveling by the vehicle speed detecting means and when the distance calculating means does not detect the distance to the target in front. The inter-vehicle distance radar device according to claim 1, wherein the second light emitting element is selected.
手段により自車両が走行中の場合で、且つ、前記距離演
算手段により前方の物標との距離が所定値以上の場合に
前記送光手段の第1の発光素子および第2の発光素子を
選択することを特徴とする請求項1記載の車間距離レー
ダ装置。4. The light emitting element selecting means transmits the light when the vehicle speed is detected by the vehicle speed detecting means and when the distance calculating means calculates a distance to a target ahead of the vehicle is a predetermined value or more. 2. The inter-vehicle distance radar device according to claim 1, wherein the first light emitting element and the second light emitting element of the means are selected.
手段により自車両が走行中の場合で、且つ、前記距離演
算手段により前方の物標との距離が所定値未満の場合に
前記送光手段の第1の発光素子を選択することを特徴と
する請求項1記載の車間距離レーダ装置。5. The light emitting element selection means is configured to transmit the light when the vehicle speed is detected by the vehicle speed detection means and when the distance calculation means determines that the distance to the target ahead is less than a predetermined value. 2. The inter-vehicle distance radar device according to claim 1, wherein the first light emitting element of the means is selected.
の加算値に対応して前記増幅手段の受光信号を増幅する
増幅率を変更することを特徴とする請求項1から請求項
5記載の車間距離レーダ装置。6. The inter-vehicle distance according to claim 1, wherein the amplification factor for amplifying the light receiving signal of the amplifying means is changed according to the added value of the light receiving signals added by the adding means. Range radar device.
の加算値のピーク値が所定値以上の場合に前記増幅手段
の受光信号を増幅する増幅率を所定値未満にすることを
特徴とする請求項6記載の車間距離レーダ装置。7. The amplification factor for amplifying the light receiving signal of the amplifying means is set to be less than a predetermined value when the peak value of the added value of the light receiving signals added by the adding means is equal to or more than a predetermined value. Item 6. The inter-vehicle distance radar device according to item 6.
の加算値のピーク値が所定値未満の場合に前記増幅手段
の受光信号を増幅する増幅率を所定値以上にすることを
特徴とする請求項6記載の車間距離レーダ装置。8. The amplification factor for amplifying the light receiving signal of the amplifying means is set to a predetermined value or more when the peak value of the added value of the light receiving signals added by the adding means is less than a predetermined value. Item 6. The inter-vehicle distance radar device according to item 6.
イオードを、第2の発光素子にレーザダイオードを用い
たことを特徴とする請求項1から請求項5記載の車間距
離レーダ装置。9. The inter-vehicle distance radar device according to claim 1, wherein a light emitting diode is used for the first light emitting element and a laser diode is used for the second light emitting element of said light transmitting means.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6093324A JPH07301672A (en) | 1994-05-02 | 1994-05-02 | Inter-vehicle distance radar device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6093324A JPH07301672A (en) | 1994-05-02 | 1994-05-02 | Inter-vehicle distance radar device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH07301672A true JPH07301672A (en) | 1995-11-14 |
Family
ID=14079109
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP6093324A Pending JPH07301672A (en) | 1994-05-02 | 1994-05-02 | Inter-vehicle distance radar device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH07301672A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2013519092A (en) * | 2010-02-01 | 2013-05-23 | マイクロソフト コーポレーション | Multiple synchronized light sources for time-of-flight range detection systems |
JP2022537248A (en) * | 2019-05-09 | 2022-08-25 | アクチエボラゲット エレクトロルックス | Object detection using line arrays |
-
1994
- 1994-05-02 JP JP6093324A patent/JPH07301672A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2013519092A (en) * | 2010-02-01 | 2013-05-23 | マイクロソフト コーポレーション | Multiple synchronized light sources for time-of-flight range detection systems |
US8891067B2 (en) | 2010-02-01 | 2014-11-18 | Microsoft Corporation | Multiple synchronized optical sources for time-of-flight range finding systems |
US10113868B2 (en) | 2010-02-01 | 2018-10-30 | Microsoft Technology Licensing, Llc | Multiple synchronized optical sources for time-of-flight range finding systems |
JP2022537248A (en) * | 2019-05-09 | 2022-08-25 | アクチエボラゲット エレクトロルックス | Object detection using line arrays |
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