JP3339388B2 - Doppler ground speed detector - Google Patents
Doppler ground speed detectorInfo
- Publication number
- JP3339388B2 JP3339388B2 JP31231797A JP31231797A JP3339388B2 JP 3339388 B2 JP3339388 B2 JP 3339388B2 JP 31231797 A JP31231797 A JP 31231797A JP 31231797 A JP31231797 A JP 31231797A JP 3339388 B2 JP3339388 B2 JP 3339388B2
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- road surface
- surface reflection
- peak
- reflection component
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
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- Radar Systems Or Details Thereof (AREA)
- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明はドップラ式対地車速
検出装置に関し、ドップラシフト周波数から対地車速を
検出するドップラ式対地車速検出装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Doppler-type ground vehicle speed detecting device, and more particularly to a Doppler-type ground vehicle speed detecting device for detecting a ground vehicle speed from a Doppler shift frequency.
【０００２】[0002]
【従来の技術】従来より車両からミリ波等の電磁波や超
音波を地面に照射してドップラシフト周波数を観測し、
ドップラシフト周波数から対地車速を検出するドップラ
式対地車速検出装置がある。例えば、特開平７−１７４
８５０号には、路面に向けて信号を送信し、路面で反射
された信号を受信して、送信信号と受信信号とのビート
信号を周波数分析して、最大信号強度を持つドップラシ
フト周波数から対地車速を検出することが記載されてい
る。2. Description of the Related Art Conventionally, a vehicle is irradiated with electromagnetic waves such as millimeter waves or ultrasonic waves on the ground to observe a Doppler shift frequency.
There is a Doppler ground vehicle speed detection device that detects the ground vehicle speed from the Doppler shift frequency. For example, JP-A-7-174
No. 850 transmits a signal toward the road surface, receives a signal reflected from the road surface, analyzes the beat signal between the transmitted signal and the received signal, and performs ground analysis on the ground from the Doppler shift frequency having the maximum signal strength. It describes that the vehicle speed is detected.
【０００３】[0003]
【発明が解決しようとする課題】従来のドップラ式対地
車速検出装置では、例えば雨天等で走行路面が濡れ、水
溜まりが生じた場合や、冠水路を走行する場合には、走
行する車両によって巻き上げられたり、風に吹かれた水
飛沫で送信信号が反射され、路面で反射された信号と共
にアンテナで受信される。水飛沫は大半が車両と同一方
向に飛散するため車両の対地速度より低い相対速度の速
度ベクトルを持っている。In a conventional Doppler type vehicle speed detector, when a running road surface is wet due to, for example, rain or the like, and water is accumulated, or when the vehicle is running on a flooded road, the vehicle is wound up by the running vehicle. Or the transmission signal is reflected by water droplets blown by the wind, and is received by the antenna together with the signal reflected by the road surface. Most of the water droplets scatter in the same direction as the vehicle, and therefore have a velocity vector of a relative speed lower than the ground speed of the vehicle.
【０００４】このため、上記受信信号と送信信号とのビ
ート信号を生成し、このビート信号のパワー周波数スペ
クトラム得た場合、車両の対地速度のドップラシフト周
波数成分の他に水飛沫速度（車両の対地速度より小さ
い）のドップラシフト周波数成分が現れ、場合によって
は、水飛沫速度の周波数成分の信号強度が車両の対地速
度の周波数成分の信号強度より大きくなる場合がある。
このような場合、最大信号強度を持つドップラシフト周
波数から対地車速を検出すると水飛沫の速度を検出する
ことになり、対地速度を誤って検出してしまうという問
題があった。For this reason, when a beat signal of the received signal and the transmitted signal is generated and the power frequency spectrum of the beat signal is obtained, in addition to the Doppler shift frequency component of the ground speed of the vehicle, the water droplet speed (ground speed of the vehicle) Doppler shift frequency component (smaller than the speed) appears, and in some cases, the signal strength of the frequency component of the water droplet speed becomes larger than the signal strength of the frequency component of the ground speed of the vehicle.
In such a case, if the ground speed is detected from the Doppler shift frequency having the maximum signal strength, the speed of the water droplets is detected, and there is a problem that the ground speed is erroneously detected.
【０００５】本発明は上記の点に鑑みなされたもので、
パワー周波数スペクトラムから基底レベルより所定値高
いレベルの基準周波数を検出して、基準周波数と路面反
射成分のピーク周波数との関係に基づき路面反射成分の
ピーク周波数を推定することにより、水飛沫が発生した
場合にも対地車速を高精度に検出するドップラ式対地車
速検出装置を提供することを目的とする。[0005] The present invention has been made in view of the above points,
By detecting a reference frequency at a level higher than the base level by a predetermined value from the power frequency spectrum and estimating the peak frequency of the road surface reflection component based on the relationship between the reference frequency and the peak frequency of the road surface reflection component, water droplets were generated. It is another object of the present invention to provide a Doppler-type ground vehicle speed detection device that detects the ground vehicle speed with high accuracy.
【０００６】[0006]
【課題を解決するための手段】請求項１に記載の発明
は、路面に向けて送信された送信信号と、前記路面で反
射され受信される受信信号とのビート信号のドップラシ
フト周波数から対地車速を検出するドップラ式対地車線
検出装置において、前記ビート信号を一定レベルに増幅
調整する増幅調整手段と、前記増幅調整されたビート信
号のパワー周波数スペクトラムを検出するパワー周波数
スペクトラム検出手段と、前記パワー周波数スペクトラ
ムから基底レベルより所定値高いレベルの基準周波数を
検出する基準周波数検出手段と、前記基準周波数と路面
反射成分のピーク周波数との関係に基づき、前記基準周
波数から路面反射成分のピーク周波数を推定するピーク
周波数推定手段と、推定された路面反射成分のピーク周
波数から対地速度を算出する対地速度算出手段と、水飛
沫を検出する水飛沫検出手段と、前記水飛沫が検出され
ないとき前記パワー周波数スペクトラムの最大レベルの
周波数を前記路面反射成分のピーク周波数として、前記
基準周波数と路面反射成分のピーク周波数との関係を記
憶する記憶手段とを有し、前記水飛沫が検出されたとき
前記記憶手段の基準周波数と路面反射成分のピーク周波
数との関係を用いて前記ピーク周波数推定手段で路面反
射成分のピーク周波数を推定する。ここで、水飛沫がな
いときパワー周波数スペクトラムが路面反射成分である
ため、パワー周波数スペクトラムの最大レベルの周波数
を路面反射成分のピーク周波数として、基準周波数と路
面反射成分のピーク周波数との関係を記憶して、これを
路面反射成分のピーク周波数を推定する際に使用するこ
とができる。 According to a first aspect of the present invention, there is provided a vehicle having a ground speed based on a Doppler shift frequency of a beat signal between a transmission signal transmitted toward a road surface and a reception signal reflected and received on the road surface. In the Doppler type anti-ground lane detection device for detecting the power frequency, amplification adjustment means for amplifying and adjusting the beat signal to a certain level, power frequency spectrum detection means for detecting the power frequency spectrum of the amplified and adjusted beat signal, Reference frequency detecting means for detecting a reference frequency at a level higher than a base level by a predetermined value from a spectrum; and estimating a peak frequency of a road surface reflection component from the reference frequency based on a relationship between the reference frequency and a peak frequency of the road surface reflection component. A peak frequency estimating means, and calculating a ground speed from the estimated peak frequency of the road surface reflection component. And ground speed calculation means for output, elutriation
A water droplet detecting means for detecting water droplets, wherein the water droplets are detected
When there is no maximum level of the power frequency spectrum
Frequency as the peak frequency of the road surface reflection component,
Describe the relationship between the reference frequency and the peak frequency of the road surface reflection component.
Storage means for remembering when the water droplets are detected
The reference frequency of the storage means and the peak frequency of the road surface reflection component
The peak frequency estimation means using the relationship with the road surface
The peak frequency of the radiation component is estimated. Here, water splashes
The power frequency spectrum is the road surface reflection component
Therefore, the frequency of the maximum level of the power frequency spectrum
Is the peak frequency of the road surface reflection component,
The relationship between the surface reflection component and the peak frequency is stored and
Used for estimating the peak frequency of the road reflection component.
Can be.
【０００７】[0007]
【０００８】[0008]
【０００９】請求項２に記載の発明は、請求項１記載の
ドップラ式対地車速検出装置において、前記記憶手段
は、逐次、前記基準周波数と路面反射成分のピーク周波
数との関係を記憶する。[0009] According to a second aspect of the invention, the Doppler ground speed detecting apparatus according to claim 1, wherein said storage means sequentially stores the relationship between the peak frequency of the reference frequency and the road surface reflection component.
【００１０】このように、基準周波数と路面反射成分の
ピーク周波数との関係を逐次記憶して学習することによ
り、経年変化の影響を受けない正確な対地車速を検出す
ることができる。As described above, by sequentially storing and learning the relationship between the reference frequency and the peak frequency of the road surface reflection component, it is possible to detect an accurate ground vehicle speed which is not affected by aging.
【００１１】[0011]
【発明の実施の形態】図１は本発明の一実施例の機能ブ
ロック図を示す。同図中、発振回路１０は、例えばミリ
波帯域の発振信号を生成し、このミリ波信号はパワーア
ンプ１２で電力増幅されて送受信センサ１４に供給され
る。送受信センサ１４は車両の後部に路面に向けて取り
付けられており、上記ミリ波の送信信号が送受信センサ
１４から路面１６に向けて照射される。路面１６で反射
されたミリ波信号の一部は送受信センサ１４で受信され
る。送受信センサ１４はパワーアンプ１２から供給され
る送信信号の一部を分岐して、路面反射の受信信号と混
合し、これによって得られたビート信号を出力する。FIG. 1 is a functional block diagram of an embodiment of the present invention. In FIG. 1, an oscillation circuit 10 generates an oscillation signal in, for example, a millimeter wave band, and the millimeter wave signal is power-amplified by a power amplifier 12 and supplied to a transmission / reception sensor 14. The transmission / reception sensor 14 is attached to the rear portion of the vehicle toward the road surface, and the transmission signal of the millimeter wave is emitted from the transmission / reception sensor 14 toward the road surface 16. A part of the millimeter wave signal reflected on the road surface 16 is received by the transmission / reception sensor 14. The transmission / reception sensor 14 branches a part of the transmission signal supplied from the power amplifier 12, mixes it with the reception signal of the road surface reflection, and outputs a beat signal obtained thereby.
【００１２】このビート信号はプリアンプ１８において
増幅された後、ＡＧＣアンプ２０で利得調整されて増幅
される。ＡＧＣアンプ２０の出力するビート信号はＦＦ
Ｔ（高速フーリエ変換回路）２２に供給され、ここで周
波数分析されてパワー周波数スペクトラムが得られ、電
子制御装置（ＥＣＵ）２４に供給される。ＥＣＵ２４は
このパワー周波数スペクトラムを分析して対地車速を検
出する。The beat signal is amplified by a preamplifier 18 and then gain-adjusted by an AGC amplifier 20 to be amplified. The beat signal output from the AGC amplifier 20 is FF
The signal is supplied to a T (fast Fourier transform circuit) 22, where it is subjected to frequency analysis to obtain a power frequency spectrum, which is supplied to an electronic control unit (ECU) 24. The ECU 24 analyzes the power frequency spectrum to detect the ground speed.
【００１３】図２はＡＧＣアンプ２０の一実施例のブロ
ック図を示す。演算増幅器（オペアンプ）で構成された
可変利得増幅器３０にはプリアンプ１８からビート信号
が供給される。可変利得増幅器３０の出力信号はＦＦＴ
２２に供給されると共に、全波整流回路３２に供給さ
れ、ここで全波整流されて実効電圧が得られる。この時
に、微小ノイズや瞬間的な大信号レベルが除去される。
実効電圧はゲイン設定回路３４に供給され、実効電圧に
応じた制御電圧が生成されてＡＧＣアンプ２０に供給さ
れる。これによって、実効電圧が高いときＡＧＣアンプ
２０の利得が下げられ、実効電圧が低いときＡＧＣアン
プ２０の利得が上げられるよう制御が行われ、ＡＧＣア
ンプ２０の出力するビート信号の振幅は一定になる。FIG. 2 is a block diagram showing an embodiment of the AGC amplifier 20. A beat signal is supplied from a preamplifier 18 to a variable gain amplifier 30 composed of an operational amplifier (operational amplifier). The output signal of the variable gain amplifier 30 is FFT
The signal is supplied to a full-wave rectifier circuit 32, where it is subjected to full-wave rectification to obtain an effective voltage. At this time, minute noises and instantaneous large signal levels are removed.
The effective voltage is supplied to the gain setting circuit 34, and a control voltage corresponding to the effective voltage is generated and supplied to the AGC amplifier 20. Thus, the gain of the AGC amplifier 20 is reduced when the effective voltage is high, and the gain of the AGC amplifier 20 is increased when the effective voltage is low, and the amplitude of the beat signal output from the AGC amplifier 20 becomes constant. .
【００１４】例えば、図３（Ａ）に示すような大振幅の
プリアンプ出力が供給された場合は、利得が小さくなり
図３（Ｂ）に示すような一定振幅の信号がＡＧＣアンプ
２０から出力され、図４（Ａ）に示すような小振幅のプ
リアンプ出力が供給された場合は、利得が大きくなり図
４（Ｂ）に示すような一定振幅の信号がＡＧＣアンプ２
０から出力される。この結果、ＡＧＣアンプ２０出力に
含まれるノイズレベルもほぼ一定となる。図３（Ｃ）は
図３（Ｂ）に示すビート信号をＦＦＴ２２で周波数解析
して得たパワー周波数スペクトラムであり、図４（Ｃ）
は図４（Ｂ）に示すビート信号をＦＦＴ２２で周波数解
析して得たパワー周波数スペクトラムである。図３
（Ｃ），図４（Ｃ）それぞれのノイズレベルはほぼ同程
度である。For example, when a large-amplitude preamplifier output as shown in FIG. 3A is supplied, the gain becomes small and a signal with a constant amplitude as shown in FIG. When a small-amplitude preamplifier output as shown in FIG. 4A is supplied, the gain increases and a signal with a constant amplitude as shown in FIG.
Output from 0. As a result, the noise level included in the output of the AGC amplifier 20 becomes substantially constant. FIG. 3C is a power frequency spectrum obtained by frequency-analyzing the beat signal shown in FIG. 3B by the FFT 22, and FIG.
Is a power frequency spectrum obtained by frequency-analyzing the beat signal shown in FIG. FIG.
The noise levels of (C) and FIG. 4 (C) are almost the same.
【００１５】ここで、水飛沫が無い場合のパワー周波数
スペクトラムは図３（Ｃ），図４（Ｃ）に示すように周
波数軸に対し左右対称である。これに対し、水飛沫で送
信信号の反射が起こる場合には図５に示すような左右非
対称のパワー周波数スペクトラムとなる。水飛沫は大半
が車両と同一方向に飛散するため、車両の対地速度より
低い相対速度のパワー周波数スペクトラム成分となり、
対地速度のパワー周波数スペクトラム成分より右側に現
れる。図５のパワー周波数スペクトラムで対地速度のピ
ーク周波数より左側では水飛沫が無い場合と同じ分布と
なる。つまり、破線で示すようにピーク周波数Ｐで左右
対称の路面反射のパワー周波数スペクトラム成分に、ピ
ーク周波数ＤＰの水飛沫のパワー周波数スペクトラム成
分が重畳されている。Here, the power frequency spectrum when there is no water droplet is symmetric with respect to the frequency axis as shown in FIGS. 3 (C) and 4 (C). On the other hand, when the transmission signal is reflected by water droplets, the power frequency spectrum becomes asymmetrical as shown in FIG. Since most of the water splashes scatter in the same direction as the vehicle, it becomes a power frequency spectrum component with a relative speed lower than the ground speed of the vehicle,
Appears to the right of the power frequency spectrum component of ground speed. On the left side of the peak frequency of the ground speed in the power frequency spectrum of FIG. 5, the distribution is the same as when there is no water droplet. That is, as shown by the broken line, the power frequency spectrum component of the water droplet having the peak frequency DP is superimposed on the power frequency spectrum component of the road surface reflection symmetrical at the peak frequency P.
【００１６】本発明では、破線で示す路面反射のパワー
周波数スペクトラム成分がＡＧＣアンプ２０の効果もあ
って左右対称で常に一定の分布であることに基づいて、
ノイズレベル（基底レベル）ＮＲより所定レベルαだけ
高いレベルの周波数βを検出し、この周波数βとピーク
周波数Ｐとの周波数差が一定であることから、周波数β
から所定周波数γだけ低い周波数を路面反射のパワー周
波数スペクトラム成分のピーク周波数Ｐとして推定す
る。In the present invention, based on the fact that the power frequency spectrum component of the road surface reflection indicated by the broken line is always symmetrical and constantly distributed due to the effect of the AGC amplifier 20,
A frequency β higher than the noise level (base level) NR by a predetermined level α is detected, and since the frequency difference between this frequency β and the peak frequency P is constant, the frequency β
Is estimated as the peak frequency P of the power frequency spectrum component of the road surface reflection.
【００１７】図６は本発明のドップラ式対地車速検出装
置の主要部、特にＥＣＵ２４が実行する対地車速検出処
理のフローチャートを示す。同図中、ステップＳ１０で
はＡＧＣアンプ２０においてビート信号の振幅が一定と
なるよう利得制御を行う。そして、ステップＳ１２では
ＦＦＴ２２によるビート信号の周波数解析を行い、パワ
ーパワー周波数スペクトラムを得る。この後の処理はＥ
ＣＵ２４が実行する。FIG. 6 is a flow chart of a main part of the Doppler ground speed detecting apparatus according to the present invention, in particular, a ground speed detecting process executed by the ECU 24. In FIG. 5, in step S10, gain control is performed in the AGC amplifier 20 so that the amplitude of the beat signal becomes constant. In step S12, the frequency of the beat signal is analyzed by the FFT 22, and a power power frequency spectrum is obtained. The subsequent processing is E
The CU 24 executes.
【００１８】次に、ステップＳ１４でＥＣＵ２４は所定
レベルα（固定値）を設定し、この後、ステップＳ１６
でパワー周波数スペクトラムを最大周波数からサーチし
てノイズレベルＮＲより所定レベルαだけ高いレベルの
周波数βを検出する。次のステップＳ１８でパワー周波
数スペクトラムがピークを中心として左右対称か否かに
より水飛沫が存在するか否かを判別する。Next, in step S14, the ECU 24 sets a predetermined level α (fixed value).
The power frequency spectrum is searched from the maximum frequency to detect a frequency β having a level higher than the noise level NR by a predetermined level α. In the next step S18, it is determined whether or not water droplets are present based on whether or not the power frequency spectrum is symmetric about the peak.
【００１９】パワー周波数スペクトラムがピークを中心
として左右対称で水飛沫が存在しない場合にはステップ
Ｓ２０に進み、ここで路面反射のパワー周波数スペクト
ラム成分のピーク周波数Ｐを検出し、先に検出したノイ
ズレベルＮＲより所定レベルαだけ高いレベルの周波数
βとの周波数差γを求める。その後、ステップＳ２２で
周波数差γを学習する。ここでは例えば過去数１０回分
のγの平均を記憶しておく。ステップＳ２４では、先に
ステップＳ２０で得た周波数Ｐを出力する。次に、ステ
ップＳ２６に進み、周波数Ｐから対地速度を演算し、こ
の対地速度をステップＳ２８で出力する。If the power frequency spectrum is bilaterally symmetrical with respect to the peak and there is no water splash, the process proceeds to step S20, where the peak frequency P of the power frequency spectrum component of the road surface reflection is detected, and the noise level detected earlier is detected. A frequency difference γ from a frequency β that is higher than NR by a predetermined level α is obtained. After that, the frequency difference γ is learned in step S22. Here, for example, the average of γ values for the past several tens of times is stored. In step S24, the frequency P previously obtained in step S20 is output. Next, the process proceeds to step S26, where a ground speed is calculated from the frequency P, and this ground speed is output in step S28.
【００２０】なお、ステップＳ２６では、次式により対
地速度Ｖを演算する。In step S26, the ground speed V is calculated by the following equation.
【００２１】[0021]
【数１】 (Equation 1)
【００２２】但し、Ｐはピーク周波数（ドップラシフト
周波数）、Ｆ0 は送信信号の周波数、Ｃは光速（３・１
０8 ｍ／ｓ）、θは送受信アンテナ１４と地面の俯角で
ある。一方、パワー周波数スペクトラムがピークを中心
として左右対称で無く水飛沫が存在する場合にはステッ
プＳ３０に進み、既に学習されている周波数差γを読み
出す。そして、ステップＳ３２で先に検出したノイズレ
ベルＮＲより所定レベルαだけ高いレベルの周波数βか
ら周波数差γだけ低い周波数を路面反射のパワーパワー
周波数スペクトラム成分のピーク周波数Ｐと推定し、推
定したピーク周波数Ｐを出力する。次に、ステップＳ２
６に進み、周波数Ｐから対地速度を演算し、この対地速
度をステップＳ２８で出力する。Where P is the peak frequency (Doppler shift frequency), F 0 is the frequency of the transmission signal, and C is the speed of light (3.1
0 8 m / s) and θ is the depression angle between the transmitting / receiving antenna 14 and the ground. On the other hand, when the power frequency spectrum is not bilaterally symmetrical with respect to the peak and there is water droplets, the process proceeds to step S30, and the frequency difference γ already learned is read. Then, a frequency lower by a frequency difference γ from a frequency β higher by a predetermined level α than the noise level NR previously detected in step S32 is estimated as a peak frequency P of the power power frequency spectrum component of the road surface reflection, and the estimated peak frequency Outputs P. Next, step S2
The process proceeds to step S6, where a ground speed is calculated from the frequency P, and this ground speed is output in step S28.
【００２３】ここで、一定レベルに増幅調整されたビー
ト信号のパワー周波数スペクトラムでは基底レベルがほ
ぼ一定のレベルとなり、パワー周波数スペクトラムから
基底レベルより所定値高いレベルの基準周波数を検出し
て、基準周波数と路面反射成分のピーク周波数との関係
に基づき路面反射成分のピーク周波数を推定するため、
水飛沫に影響されない路面反射成分のピーク周波数を求
め、水飛沫が発生した場合にも正確な対地車速を高精度
に検出するることができる。Here, in the power frequency spectrum of the beat signal amplified and adjusted to a constant level, the base level becomes substantially constant, and a reference frequency having a level higher than the base level by a predetermined value is detected from the power frequency spectrum, and the reference frequency is detected. To estimate the peak frequency of the road surface reflection component based on the relationship between the peak frequency of the road surface reflection component and
The peak frequency of the road surface reflection component that is not affected by water droplets is obtained, and even when water droplets occur, the accurate ground vehicle speed can be detected with high accuracy.
【００２４】また、水飛沫がないときパワー周波数スペ
クトラムが路面反射成分であるため、パワー周波数スペ
クトラムの最大レベルの周波数を路面反射成分のピーク
周波数として、基準周波数と路面反射成分のピーク周波
数との関係を記憶して、これを路面反射成分のピーク周
波数を推定する際に使用することができる。更に、基準
周波数と路面反射成分のピーク周波数との関係を逐次記
憶して学習することにより、経年変化の影響を受けない
正確な対地車速を検出することができる。Further, since the power frequency spectrum is a road surface reflection component when there is no water splash, the maximum frequency of the power frequency spectrum is defined as the peak frequency of the road surface reflection component, and the relationship between the reference frequency and the peak frequency of the road surface reflection component is obtained. And can be used in estimating the peak frequency of the road surface reflection component. Further, by sequentially storing and learning the relationship between the reference frequency and the peak frequency of the road surface reflection component, it is possible to detect an accurate ground vehicle speed which is not affected by aging.
【００２５】このため、水飛沫のによる送信信号の反射
が小さく、図７に示すように水飛沫のパワー周波数スペ
クトラム成分のピーク周波数ＤＰのレベルが路面反射の
パワーパワー周波数スペクトラム成分のピーク周波数Ｐ
のレベルより低い場合は勿論、水飛沫のによる送信信号
の反射が大きく、図８に示すように水飛沫のパワー周波
数スペクトラム成分のピーク周波数ＤＰのレベルが路面
反射のパワー周波数スペクトラム成分のピーク周波数Ｐ
のレベルより高い低い場合においても、路面反射のパワ
ー周波数スペクトラム成分のピーク周波数Ｐを正確に推
定して、正確な対地速度を求めることができる。For this reason, the reflection of the transmission signal due to the water droplets is small, and the level of the peak frequency DP of the power frequency spectrum component of the water droplets is equal to the peak frequency P of the power power frequency spectrum component of the road surface reflection as shown in FIG.
Of course, the reflection of the transmission signal due to the water droplets is large, and as shown in FIG. 8, the level of the peak frequency DP of the power frequency spectrum component of the water droplet is the peak frequency P of the power frequency spectrum component of the road surface reflection as shown in FIG.
, The peak frequency P of the power frequency spectrum component of road surface reflection can be accurately estimated, and an accurate ground speed can be obtained.
【００２６】なお、ＡＧＣアンプ２０が増幅調整手段に
対応し、ＦＦＴ２４がパワー周波数スペクトラム検出手
段に対応し、ステップＳ１６が基準周波数検出手段に対
応し、ステップＳ３０，Ｓ３２がピーク周波数推定手段
に対応し、ステップＳ２６が対地速度算出手段に対応
し、ステップＳ１８が水飛沫検出手段に対応し、ステッ
プＳ２２が記憶手段に対応する。Note that the AGC amplifier 20 corresponds to the amplification adjusting means, the FFT 24 corresponds to the power frequency spectrum detecting means, step S16 corresponds to the reference frequency detecting means, and steps S30 and S32 correspond to the peak frequency estimating means. , Step S26 corresponds to ground speed calculation means, step S18 corresponds to water droplet detection means, and step S22 corresponds to storage means.
【００２７】[0027]
【発明の効果】上述の如く、請求項１に記載の発明は、
路面に向けて送信された送信信号と、前記路面で反射さ
れ受信される受信信号とのビート信号のドップラシフト
周波数から対地車速を検出するドップラ式対地車線検出
装置において、前記ビート信号を一定レベルに増幅調整
する増幅調整手段と、前記増幅調整されたビート信号の
パワー周波数スペクトラムを検出するパワー周波数スペ
クトラム検出手段と、前記パワー周波数スペクトラムか
ら基底レベルより所定値高いレベルの基準周波数を検出
する基準周波数検出手段と、前記基準周波数と路面反射
成分のピーク周波数との関係に基づき、前記基準周波数
から路面反射成分のピーク周波数を推定するピーク周波
数推定手段と、推定された路面反射成分のピーク周波数
から対地速度を算出する対地速度算出手段と、水飛沫を
検出する水飛沫検出手段と、前記水飛沫が検出されない
とき前記パワー周波数スペクトラムの最大レベルの周波
数を前記路面反射成分のピーク周波数として、前記基準
周波数と路面反射成分のピーク周波数との関係を記憶す
る記憶手段とを有し、前記水飛沫が検出されたとき前記
記憶手段の基準周波数と路面反射成分のピーク周波数と
の関係を用いて前記ピーク周波数推定手段で路面反射成
分のピーク周波数を推定する。ここで、水飛沫がないと
きパワー周波数スペクトラムが路面反射成分であるた
め、パワー周波数スペクトラムの最大レベルの周波数を
路面反射成分のピーク周波数として、基準周波数と路面
反射成分のピーク周波数との関係を記憶して、これを路
面反射成分のピーク周波数を推定する際に使用すること
ができる。 As described above, the first aspect of the present invention provides
In a Doppler ground-to-ground lane detection device that detects a ground vehicle speed from a Doppler shift frequency of a beat signal of a transmission signal transmitted toward a road surface and a reception signal reflected and received on the road surface, the beat signal is set to a constant level. Amplification adjustment means for amplifying and adjusting; power frequency spectrum detection means for detecting a power frequency spectrum of the amplified and adjusted beat signal; and reference frequency detection for detecting a reference frequency having a level higher than a base level by a predetermined value from the power frequency spectrum. Means, a peak frequency estimating means for estimating a peak frequency of the road surface reflection component from the reference frequency based on a relationship between the reference frequency and a peak frequency of the road surface reflection component, and a ground speed based on the estimated peak frequency of the road surface reflection component. a ground speed calculation means for calculating, water splash
Water droplet detecting means for detecting, the water droplet is not detected
When the frequency of the maximum level of the power frequency spectrum
Number as the peak frequency of the road surface reflection component,
Stores the relationship between the frequency and the peak frequency of the road surface reflection component
Storage means, and when the water droplets are detected,
The reference frequency of the storage means and the peak frequency of the road surface reflection component
Of the road surface reflection by the peak frequency estimating means using the relationship
Estimate the peak frequency in minutes. Here, if there is no water splash
Power frequency spectrum is the road surface reflection component
The frequency of the maximum level of the power frequency spectrum.
The reference frequency and the road surface are used as the peak frequency of the road surface reflection component.
The relationship between the reflection component and the peak frequency is stored and this
Used to estimate the peak frequency of the surface reflection component
Can be.
【００２８】[0028]
【００２９】[0029]
【００３０】請求項２に記載の発明は、請求項１記載の
ドップラ式対地車速検出装置において、前記記憶手段
は、逐次、前記基準周波数と路面反射成分のピーク周波
数との関係を記憶する。The invention described in claim 2 is the Doppler ground speed detecting apparatus according to claim 1, wherein said storage means sequentially stores the relationship between the peak frequency of the reference frequency and the road surface reflection component.
【００３１】このように、基準周波数と路面反射成分の
ピーク周波数との関係を逐次記憶して学習することによ
り、経年変化の影響を受けない正確な対地車速を検出す
ることができる。As described above, by sequentially storing and learning the relationship between the reference frequency and the peak frequency of the road surface reflection component, it is possible to detect an accurate ground vehicle speed which is not affected by aging.
【図１】本発明の一実施例の機能ブロック図である。FIG. 1 is a functional block diagram of an embodiment of the present invention.
【図２】ＡＧＣアンプ２０の一実施例のブロック図であ
る。FIG. 2 is a block diagram of an embodiment of the AGC amplifier 20.
【図３】大振幅のビート信号でのＡＧＣアンプ出力及び
パワー周波数スペクトラムを説明するための図である。FIG. 3 is a diagram for explaining an AGC amplifier output and a power frequency spectrum with a large amplitude beat signal.
【図４】小振幅のビート信号でのＡＧＣアンプ出力及び
パワー周波数スペクトラムを説明するための図である。FIG. 4 is a diagram for explaining an AGC amplifier output and a power frequency spectrum with a beat signal having a small amplitude.
【図５】水飛沫で送信信号の反射が起こる場合のパワー
周波数スペクトラムを示す図である。FIG. 5 is a diagram illustrating a power frequency spectrum when a transmission signal is reflected by water droplets.
【図６】本発明のドップラ式対地車速検出装置の対地車
速検出処理のフローチャートである。FIG. 6 is a flowchart of a ground vehicle speed detection process of the Doppler ground vehicle speed detection device of the present invention.
【図７】水飛沫で送信信号の反射が起こる場合のパワー
周波数スペクトラムを示す図である。FIG. 7 is a diagram showing a power frequency spectrum when a transmission signal is reflected by water droplets.
【図８】水飛沫で送信信号の反射が起こる場合のパワー
周波数スペクトラムを示す図である。FIG. 8 is a diagram illustrating a power frequency spectrum when a transmission signal is reflected by water droplets.
１０ 発信器 １２ パワーアンプ１２ １４ 送受信センサ １６ 路面 １８ プリアンプ ２０ ＡＧＣアンプ ２２ ＦＦＴ（高速フーリエ変換回路） ２４ 電子制御装置（ＥＣＵ） ３０ 可変利得増幅器 ３２ 全波整流回路 ３４ ゲイン設定回路 Reference Signs List 10 transmitter 12 power amplifier 12 14 transmission / reception sensor 16 road surface 18 preamplifier 20 AGC amplifier 22 FFT (fast Fourier transform circuit) 24 electronic control unit (ECU) 30 variable gain amplifier 32 full-wave rectifier circuit 34 gain setting circuit
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) G01S 7/00 - 7/42 G01S 13/00 - 13/95 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. 7 , DB name) G01S 7 /00-7/42 G01S 13/00-13/95
Claims (2)
記路面で反射され受信される受信信号とのビート信号の
ドップラシフト周波数から対地車速を検出するドップラ
式対地車線検出装置において、 前記ビート信号を一定レベルに増幅調整する増幅調整手
段と、 前記増幅調整されたビート信号のパワー周波数スペクト
ラムを検出するパワー周波数スペクトラム検出手段と、 前記パワー周波数スペクトラムから基底レベルより所定
値高いレベルの基準周波数を検出する基準周波数検出手
段と、 前記基準周波数と路面反射成分のピーク周波数との関係
に基づき、前記基準周波数から路面反射成分のピーク周
波数を推定するピーク周波数推定手段と、 推定された路面反射成分のピーク周波数から対地速度を
算出する対地速度算出手段と、 水飛沫を検出する水飛沫検出手段と、 前記水飛沫が検出されないとき前記パワー周波数スペク
トラムの最大レベルの周波数を前記路面反射成分のピー
ク周波数として、前記基準周波数と路面反射成分のピー
ク周波数との関係を記憶する記憶手段とを有し、 前記水飛沫が検出されたとき前記記憶手段の基準周波数
と路面反射成分のピーク周波数との関係を用いて前記ピ
ーク周波数推定手段で路面反射成分のピーク周波数を推
定する ことを特徴とするドップラ式対地車速検出装置。1. A Doppler ground-to-ground lane detecting device for detecting ground vehicle speed from a Doppler shift frequency of a beat signal between a transmission signal transmitted toward a road surface and a reception signal reflected and received on the road surface, Amplification adjusting means for amplifying and adjusting the signal to a constant level; power frequency spectrum detecting means for detecting a power frequency spectrum of the amplified and adjusted beat signal; and a reference frequency having a level higher than a base level by a predetermined value from the power frequency spectrum. A reference frequency detecting means for detecting, a peak frequency estimating means for estimating a peak frequency of the road surface reflection component from the reference frequency based on a relationship between the reference frequency and a peak frequency of the road surface reflection component, a ground speed calculating means for calculating a ground speed from peak frequency, the water splashing Water splash detecting means for output, the power frequency spectrum when the water splashes is not detected
The frequency of the maximum level of the tram is determined by the peak of the road surface reflection component.
The peak frequency of the reference frequency and the road surface reflection component
Storage means for storing a relationship with the reference frequency, the reference frequency of the storage means when the water droplets are detected
And the peak frequency of the road surface reflection component using the
Peak frequency of road surface reflection component
Doppler ground speed detecting apparatus characterized by a constant.
装置において、 前記記憶手段は、逐次、前記基準周波数と路面反射成分
のピーク周波数との関係を記憶する ことを特徴とするド
ップラ式対地車速検出装置。2. The Doppler type ground vehicle speed detection according to claim 1.
In the apparatus, the storage means sequentially stores the reference frequency and a road surface reflection component.
A Doppler-type ground vehicle speed detecting device for storing a relationship with a peak frequency of a vehicle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31231797A JP3339388B2 (en) | 1997-11-13 | 1997-11-13 | Doppler ground speed detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31231797A JP3339388B2 (en) | 1997-11-13 | 1997-11-13 | Doppler ground speed detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11142509A JPH11142509A (en) | 1999-05-28 |
| JP3339388B2 true JP3339388B2 (en) | 2002-10-28 |
Family
ID=18027795
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31231797A Expired - Fee Related JP3339388B2 (en) | 1997-11-13 | 1997-11-13 | Doppler ground speed detector |
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| Country | Link |
|---|---|
| JP (1) | JP3339388B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013105359A1 (en) | 2012-01-10 | 2013-07-18 | 三菱電機株式会社 | Travel distance measurement device |
| US9336683B2 (en) | 2012-01-10 | 2016-05-10 | Mitsubishi Electric Corporation | Travel distance measurement device |
| KR101885065B1 (en) * | 2017-11-06 | 2018-08-03 | 대한민국 | Method, Apparatus and Computer Program for estimating the speed of a vehicle passing through a horizontal-grooved road using acoustic analysis |
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1997
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Also Published As
| Publication number | Publication date |
|---|---|
| JPH11142509A (en) | 1999-05-28 |
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