JP2007121043A

JP2007121043A - Pulse radar device

Info

Publication number: JP2007121043A
Application number: JP2005311869A
Authority: JP
Inventors: Naoto Terada; 直人寺田
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 2005-10-26
Filing date: 2005-10-26
Publication date: 2007-05-17
Anticipated expiration: 2025-10-26
Also published as: JP4788290B2

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect the distance to a detecting object and its directional angle by a pulse radar device. <P>SOLUTION: The pulse radar device 1 includes one transmission system 2, two reception systems 4 and 5, a distance detection part 7, and a directional angle detection part 8. The transmission system 2 comprises a transmission part 3 and a transmission antenna 2a for transmitting a pulse-like transmission signal "a". The reception systems 4 and 5 comprise reception antennas 4a and 5a for receiving a reflected wave from an object, and mixers 61 and 62 for outputting mixing signals m1 and m2 obtained by mixing these reception signals b1 and b2 with the transmission signal "a". The detection part 7 calculates the distance to the object based on the mixing signal m1 or m2. The detection part 8 calculates a phase difference between the reception signals b1 and b2 based on the mixing signals m1 and m2 to therefrom calculate the directional angle of the object. Herein, the distance to the object and its directional angle can be accurately detected since the phase difference between the reception signals b1 and b2 is accurately calculated from the measurement of delay time of the mixing signals m1 and m2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、電波を送受信して、対象物までの距離と方位を検出するレーダ装置に関する。 The present invention relates to a radar apparatus that detects the distance and direction to an object by transmitting and receiving radio waves.

従来のパルスレーダ装置による対象物検出動作の様子を図１１に示す。このパルスレーダ装置は、送信アンテナ１０１を備えた送信系を１つ、受信アンテナ１０２を備えた受信系を１つを有して、送信アンテナ１０１と受信アンテナ１０２による送受信信号により距離Ｒを検知し、検知エリアの領域Ｅに存在する検知対象物の位置を検出する。このような構成のパルスレーダ装置においては、送信から受信までの時間から距離Ｒを求めることができるが、検知対象物１０３の方位を求めることはできない。 FIG. 11 shows an object detection operation by a conventional pulse radar device. This pulse radar apparatus has one transmission system provided with the transmission antenna 101 and one reception system provided with the reception antenna 102, and detects the distance R based on transmission / reception signals transmitted by the transmission antenna 101 and the reception antenna 102. The position of the detection object existing in the area E of the detection area is detected. In the pulse radar device having such a configuration, the distance R can be obtained from the time from transmission to reception, but the azimuth of the detection object 103 cannot be obtained.

この方位を検出できるレーダとして、１つのビーム位置で、１つのパルス（モノパルス）を処理して距離・方位情報を得るモノパルス方式レーダやアンテナビームを対象物の近傍を連続して走査するビーム走査方式レーダがある。特に、モノパルス方式レーダは、受信時刻の異なる複数のビームを走査して計測するビーム走査方式レーダと違って時間的な変動の影響を受けないため精度の高い距離、方位情報が得られる。このモノパルス方式には、振幅を検出する振幅比較モノパルス方式と位相を検出する位相比較モノパルス方式（位相モノパルス方式）がある。 As a radar that can detect this azimuth, a monopulse radar that processes one pulse (monopulse) at one beam position to obtain distance and azimuth information, and a beam scanning system that continuously scans the vicinity of an object with an antenna beam There is a radar. In particular, unlike a beam scanning radar that scans and measures a plurality of beams having different reception times, the monopulse radar is not affected by temporal fluctuations, and therefore, highly accurate distance and azimuth information can be obtained. The monopulse method includes an amplitude comparison monopulse method for detecting amplitude and a phase comparison monopulse method (phase monopulse method) for detecting phase.

この位相モノパルス方式のレーダ装置による対象物検出動作の様子を図１２に示す。このレーダ装置は、対象物からの反射波を２個以上のアンテナで受信するものであり、受信アンテナの位置が異なるので、受信アンテナ間で角度差が生じる。この角度差を検出することで検知対象物の方位角θを検出することができ、そのため、ビーム走査することなく方位角θの検出が可能である。 FIG. 12 shows an object detection operation performed by the phase monopulse radar apparatus. This radar apparatus receives reflected waves from an object with two or more antennas, and since the positions of the receiving antennas are different, an angular difference occurs between the receiving antennas. By detecting this angular difference, it is possible to detect the azimuth angle θ of the object to be detected. Therefore, it is possible to detect the azimuth angle θ without performing beam scanning.

この方位角θの導出について説明する。２つの受信アンテナ１０２ａ、１０２ｂ間の距離をｄ、検知対象物１０３の方位角をθ、レーダ波の波長をλとしたとき、２つの受信アンテナ１０２ａ、１０２ｂが受信する信号の位相差Δφは、
Δφ＝（２πｄｓｉｎθ）／λ ・・・（１）
となり、従って、対象物１０３の方位角θは、
θ＝ａｒｃｓｉｎ（Δφ・λ／２πｄ）・・（２）
となる。このようにして受信信号の位相差Δφから対象物１０３の方位角θを求めることができる。なお、ここでいう位相差Δφは、１波長（λ）に対するレーダ波の経路差（２πｄ・ｓｉｎθ）の割合として定義される。 Derivation of this azimuth angle θ will be described. When the distance between the two receiving antennas 102a and 102b is d, the azimuth angle of the detection target 103 is θ, and the wavelength of the radar wave is λ, the phase difference Δφ of the signals received by the two receiving antennas 102a and 102b is
Δφ = (2πd sin θ) / λ (1)
Therefore, the azimuth angle θ of the object 103 is
θ = arcsin (Δφ · λ / 2πd) (2)
It becomes. In this way, the azimuth angle θ of the object 103 can be obtained from the phase difference Δφ of the received signal. The phase difference Δφ here is defined as the ratio of the radar wave path difference (2πd · sin θ) to one wavelength (λ).

上記のような位相モノパルス方式のレーダの応用として、アレーアンテナと、マルチビーム形成手段と、ピーク検出手段と、高分解能処理器とを備えたレーダ装置が知られている（例えば、特許文献１参照）。また、同様にアレーアンテナと、アンテナビーム形状を鋭角・遠距離もしくは広角・近距離に切り換えるためのアンテナスイッチと、アンテナスイッチを切り換える切換制御装置とを備えたモノパルスレーダシステムが知られている（例えば、特許文献２参照）。上述した特許文献１、２に示されるような装置においては、いずれも検出精度の向上を図るには、構成が複雑となり高価なものとなる。
特開２００３−１３９８４９号公報特開２００３−２４８０５５号公報 As an application of the above-described phase monopulse radar, a radar apparatus including an array antenna, a multi-beam forming unit, a peak detecting unit, and a high resolution processor is known (for example, see Patent Document 1). ). Similarly, a monopulse radar system including an array antenna, an antenna switch for switching the antenna beam shape to an acute angle / long distance or wide angle / short distance, and a switching control device for switching the antenna switch is known (for example, , See Patent Document 2). In the devices as disclosed in Patent Documents 1 and 2 described above, in order to improve the detection accuracy, the configuration becomes complicated and expensive.
JP 2003-139849 A Japanese Patent Laid-Open No. 2003-248055

本発明は、上記の問題を解決するためになされたものであり、上述のパルス方式と位相モノパルス方式の考え方を基に、構成が簡単で安価に、検知対象物までの距離、方位角を精度良く検出することができるパルスレーダ装置を提供することを目的とする。 The present invention has been made to solve the above problems, and based on the above-described concept of the pulse method and the phase monopulse method, the configuration is simple and inexpensive, and the distance to the detection object and the azimuth angle are accurate. An object of the present invention is to provide a pulse radar device that can detect well.

上記目的を達成するために請求項１の発明は、１つの送信系と複数の受信系を用いて物体までの距離、及び方位角を検出するパルスレーダ装置において、パルス状の送信信号を送信する送信手段と、前記物体から反射した反射波を受信する前記複数の受信系に対応して設けられた受信手段と、前記受信手段からの各受信信号を前記送信信号とミキシングしてミキシング信号をそれぞれ得るミキシング手段と、前記少なくとも１つのミキシング信号の出力に基づいて前記物体までの距離を算出する距離検出手段と、前記複数のミキシング信号の出力に基づいて各受信系における受信信号の位相差を算出し、この位相差より前記物体の方位角を求める方位角検出手段と、を備えるものである。 In order to achieve the above object, the invention according to claim 1 transmits a pulsed transmission signal in a pulse radar device that detects a distance to an object and an azimuth angle by using one transmission system and a plurality of reception systems. Transmitting means; receiving means provided corresponding to the plurality of receiving systems that receive the reflected waves reflected from the object; and mixing the received signals from the receiving means with the transmission signals, respectively. Obtaining mixing means; distance detecting means for calculating a distance to the object based on an output of the at least one mixing signal; and calculating a phase difference of received signals in each receiving system based on the outputs of the plurality of mixing signals. And azimuth angle detecting means for obtaining the azimuth angle of the object from the phase difference.

請求項２の発明は、請求項１に記載のパルスレーダ装置において、予め所望の検出距離及び方位角を記憶するための記憶装置をさらに備え、前記距離検出手段及び方位角検出手段で検出された距離及び方位角が、前記記憶装置に記憶された距離及び方位角の設定範囲内にあるときにのみ検出距離及び方位角を出力するものである。 The invention according to claim 2 is the pulse radar device according to claim 1, further comprising a storage device for storing a desired detection distance and azimuth angle in advance, and detected by the distance detection means and the azimuth angle detection means. The detection distance and azimuth angle are output only when the distance and azimuth angle are within the distance and azimuth angle setting range stored in the storage device.

請求項３の発明は、請求項１に記載のパルスレーダ装置において、前記ミキシング手段は前記複数の受信系に対応してそれぞれ設けられ、前記方位角検出手段は、前記各ミキシング手段で得られたミキシング信号と、前記ミキシング信号と前記送信信号を９０°移相した信号をミキシングしたミキシング信号を用いて前記物体の方位角を求めるものである。 According to a third aspect of the present invention, in the pulse radar device according to the first aspect, the mixing means is provided corresponding to each of the plurality of receiving systems, and the azimuth angle detecting means is obtained by each of the mixing means. The azimuth angle of the object is obtained by using a mixing signal and a mixing signal obtained by mixing a signal obtained by shifting the mixing signal and the transmission signal by 90 °.

請求項４の発明は、請求項３に記載のパルスレーダ装置において、前記方位角検出手段は、前記ミキシング信号の振幅より位相を検出し、検出物体の方位角を求めるものである。 According to a fourth aspect of the present invention, in the pulse radar device according to the third aspect, the azimuth angle detecting means detects the phase from the amplitude of the mixing signal and obtains the azimuth angle of the detected object.

請求項５の発明は、請求項３に記載のパルスレーダ装置において、前記方位角検出手段は、前記ミキシング信号の時間差より位相を検出し、検出物体の方位角を求めるものである。 According to a fifth aspect of the present invention, in the pulse radar device according to the third aspect, the azimuth angle detecting means detects the phase from the time difference of the mixing signal and obtains the azimuth angle of the detected object.

請求項６の発明は、請求項３に記載のパルスレーダ装置において、前記方位角検出手段は、前記ミキシング信号をサンプリング処理するために等価サンプリングによるサンプリング手段を備えたものである。 According to a sixth aspect of the present invention, in the pulse radar device according to the third aspect, the azimuth angle detecting means includes a sampling means based on equivalent sampling in order to sample the mixing signal.

請求項７の発明は、請求項１に記載のパルスレーダ装置において、前記ミキシング信号をパルス積分して前記距離検出手段及び方位角検出手段に入力するものである。 A seventh aspect of the present invention is the pulse radar device according to the first aspect, wherein the mixing signal is pulse-integrated and input to the distance detecting means and the azimuth angle detecting means.

請求項８の発明は、請求項１に記載のパルスレーダ装置において、前記ミキシング信号を自動利得制御して前記距離検出手段及び方位角検出手段に入力するものである。 According to an eighth aspect of the present invention, in the pulse radar device according to the first aspect, the mixing signal is automatically gain-controlled and input to the distance detecting means and the azimuth angle detecting means.

請求項９の発明は、請求項１に記載のパルスレーダ装置において、前記複数の受信系の受信手段間の配置距離は、前記送信信号の周波数の１／２波長以下とするものである。 According to a ninth aspect of the present invention, in the pulse radar device according to the first aspect, the arrangement distance between the receiving means of the plurality of receiving systems is set to a half wavelength or less of the frequency of the transmission signal.

請求項１の発明によれば、受信信号と送信信号とのミキシング信号を基に物体距離を算出し、複数の受信系の受信信号の位相差を算出して物体の方位角を求めるので、物体までの距離と方位角を精度良く検出することができる。 According to the first aspect of the present invention, the object distance is calculated based on the mixing signal of the reception signal and the transmission signal, and the phase difference between the reception signals of the plurality of reception systems is calculated to obtain the azimuth angle of the object. Distance and azimuth angle can be detected with high accuracy.

請求項２の発明によれば、予め必要な検出距離と方位角を設定できるので、不必要な検出と演算を省き、ユーザが所望する領域範囲内にある対象物のみを容易に早期に検出することができる。 According to the second aspect of the present invention, since the necessary detection distance and azimuth can be set in advance, unnecessary detection and calculation can be omitted, and only the target object within the area range desired by the user can be detected easily and early. be able to.

請求項３の発明によれば、１つの受信信号を用いて位相の異なる２つのミキシング信号が得られるので、ミキシング信号間の立上り時間差をより正確に検出することができる。 According to the invention of claim 3, since two mixing signals having different phases can be obtained by using one received signal, the rise time difference between the mixing signals can be detected more accurately.

請求項４の発明によれば、位相の異なる２つのミキシング信号の振幅を用いてミキシング信号の位相の検出を行うので、方位角の検出が容易となる。 According to the fourth aspect of the invention, since the phase of the mixing signal is detected using the amplitudes of the two mixing signals having different phases, the azimuth angle can be easily detected.

請求項５の発明によれば、位相の異なる２つのミキシング信号の位相差を受信時間差により検出するので、受信信号の位相差の測定精度が高まる。 According to the fifth aspect of the present invention, since the phase difference between two mixing signals having different phases is detected based on the reception time difference, the measurement accuracy of the phase difference between the reception signals is increased.

請求項６の発明によれば、等価的に高速のサンプリングにより高精度に波形の観測ができるので、複数の検出対象物が異なる距離に配置されている場合にも、観測波形が重ならず、最も近い対象物から順次、方位角を検出することができる。 According to the invention of claim 6, since the waveform can be observed with high accuracy by high-speed sampling equivalently, even when a plurality of detection objects are arranged at different distances, the observed waveforms do not overlap, The azimuth angle can be detected sequentially from the closest object.

請求項７の発明によれば、ミキシング信号がパルス積分されてその雑音成分が抑制されるので、距離検出手段及び方位角検出手段における演算処理の誤りが低減され、最大検知距離を延ばすことができると共に、方位角の測定精度を高めることができる。 According to the seventh aspect of the present invention, since the mixing signal is pulse-integrated and its noise component is suppressed, errors in calculation processing in the distance detection means and the azimuth angle detection means are reduced, and the maximum detection distance can be extended. At the same time, the measurement accuracy of the azimuth can be increased.

請求項８の発明によれば、受信手段からの受信信号レベルが大きくても小さくても、距離検出手段及び方位角検出手段に入力するミキシング信号のレベルがほぼ一定となるので、対象物の遠近に拘わらず安定した距離、方位角の検出を行うことができる。 According to the eighth aspect of the present invention, the level of the mixing signal input to the distance detection means and the azimuth angle detection means is substantially constant regardless of whether the reception signal level from the reception means is large or small. Regardless of this, stable distance and azimuth can be detected.

請求項９の発明によれば、受信手段間における受信信号の位相差を１／２波長以下に抑えることができるので、１／２波長を越える位相差の検出をなくし、前方１８０度の方位角検出が可能となる。 According to the ninth aspect of the present invention, since the phase difference of the received signal between the receiving means can be suppressed to ½ wavelength or less, detection of the phase difference exceeding ½ wavelength is eliminated, and the azimuth angle of 180 degrees forward Detection is possible.

以下、本発明の実施形態に係るパルスレーダ装置について、図面を参照して説明する。図１は第１の実施形態によるパルスレーダ装置１（以下、本装置という）の構成を示す。本装置１は、１つの送信系２と、２つの受信系４、５とを備える。送信系２は、パルス状の送信信号ａを出力する送信部３（送信手段）と、この送信部３から出力される送信信号ａを電波として送出する送信アンテナ２ａ（送信手段）とを有する。受信系４、５は、送信系２によって送信された電波が物体（検知対象物）により反射された反射波を受信する２つの受信アンテナ４ａ、５ａ（受信手段）と、これらに接続される受信部６ａ、６ｂ（受信手段）とをそれぞれ備える。これらの受信部６ａ、６ｂは、各受信アンテナ４ａ、５ａからの第１、第２の受信信号ｂ１、ｂ２を送信信号ａとミキシングしてミキシング信号ｍ１、ｍ２を得るミキサ６１、６２（ミキシング手段）を備える。さらに、本装置１は、ミキシング信号ｍ１又はｍ２に基づいて物体の距離を算出する距離検出部７（距離検出手段）と、ミキシング信号ｍ１及びｍ２に基づいて受信信号ｂ１、ｂ２の位相差を算出し、これより物体の方位角を算出する方位角検出部８（方位角検出手段）とを備える。 Hereinafter, a pulse radar device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a pulse radar apparatus 1 (hereinafter referred to as the present apparatus) according to the first embodiment. The apparatus 1 includes one transmission system 2 and two reception systems 4 and 5. The transmission system 2 includes a transmission unit 3 (transmission unit) that outputs a pulsed transmission signal a, and a transmission antenna 2a (transmission unit) that transmits the transmission signal a output from the transmission unit 3 as a radio wave. The reception systems 4 and 5 are two reception antennas 4a and 5a (reception means) that receive a reflected wave in which the radio wave transmitted by the transmission system 2 is reflected by an object (detection target), and reception connected thereto. Units 6a and 6b (reception means). These receiving units 6a and 6b are mixers 61 and 62 (mixing means) for mixing the first and second received signals b1 and b2 from the receiving antennas 4a and 5a with the transmission signal a to obtain mixing signals m1 and m2. ). Further, the apparatus 1 calculates a phase difference between the reception signals b1 and b2 based on the distance detection unit 7 (distance detection unit) that calculates the distance of the object based on the mixing signal m1 or m2, and the mixing signals m1 and m2. Then, an azimuth angle detector 8 (azimuth angle detector) for calculating the azimuth angle of the object is provided.

送信部３は、送信信号ａを出力するための発振器３ａと、クロック発生器３ｂとを備え、送信アンテナ２ａより送信信号ａを送出すると共に、送信信号ａの送信タイミングｔ１を距離検出部７に伝える。距離検出部７は、受信部６ａ、６ｂの各ミキサ６１、６２で得られたミキシング信号ｍ１、ｍ２の波形の立上りを検出する波形立上り検出器７ａと、物体までの距離を算出する距離演算器７ｂを備えている。この距離演算器７ｂは、波形立上り検出器７ａの出力情報であるミキシング信号ｍ１又はｍ２の立上り時刻（受信時刻）ｔ２及び発振器３ａからの出力情報である送信時刻ｔ１に基づいて物体までの距離を算出する。方位角検出部８は、ミキシング信号ｍ１、ｍ２の各波形の立上りを検出する波形立上り検出器８ａと、波形立上り検出器８ａで検出されるミキシング信号ｍ１とｍ２の立上り時刻ｔ２、ｔ３から方位角θを算出する方位角演算器８ｂとを備える。 The transmission unit 3 includes an oscillator 3a for outputting the transmission signal a and a clock generator 3b. The transmission unit 3 transmits the transmission signal a from the transmission antenna 2a and transmits the transmission timing t1 of the transmission signal a to the distance detection unit 7. Tell. The distance detector 7 includes a waveform rising detector 7a that detects rising of the waveform of the mixing signals m1 and m2 obtained by the mixers 61 and 62 of the receivers 6a and 6b, and a distance calculator that calculates the distance to the object. 7b. The distance calculator 7b calculates the distance to the object based on the rising time (reception time) t2 of the mixing signal m1 or m2 that is output information of the waveform rising detector 7a and the transmission time t1 that is output information from the oscillator 3a. calculate. The azimuth angle detection unit 8 detects a rising edge of each waveform of the mixing signals m1 and m2, and an azimuth angle from the rising times t2 and t3 of the mixing signals m1 and m2 detected by the waveform rising detector 8a. and an azimuth calculator 8b for calculating θ.

図２は本装置１の動作を説明するための各種信号波形を示す。図２において、ａは送信信号、ｂ１、ｂ２は第１、第２の受信信号、ｍ１、ｍ２は送信信号ａと受信信号ｂ１、ｂ２とのミキシングによる第１、第２のミキシング信号である。 FIG. 2 shows various signal waveforms for explaining the operation of the apparatus 1. In FIG. 2, a is a transmission signal, b1 and b2 are first and second reception signals, and m1 and m2 are first and second mixing signals obtained by mixing the transmission signal a and the reception signals b1 and b2.

本装置１においては、送信部３よりパルス化された送信信号ａを送信アンテナ２ａより検知対象物に向けて送信し、検知対象物で反射させ、その反射信号を受信アンテナ４ａ、５ａで受信信号ｂ１、ｂ２として受信し、受信部６ａ、６ｂのミキサ６１、６２により受信信号ｂ１、ｂ２を送信信号ａとミキシングしてミキシング信号ｍ１、ｍ２を得る。このミキシング信号ｍ１とｍ２の立ち上がり時刻ｔ２、ｔ３と送信時刻ｔ１とを用いて、距離検出部７は距離を検出し、方位角検出部８は方位角を検出する。このように、ミキシング信号ｍ１、ｍ２の立上り時刻の検出により簡単に受信時間差を得ることができるので、対象物までの距離と方位角を容易に得ることができる。また、得られた受信時刻、受信時間差からの距離、方位角の算出も複雑な演算処理を必要としないので、距離演算器７ｂ及び方位角演算器８ｂの演算時間を短縮でき、応答を速めることができる。 In this apparatus 1, the transmission signal a pulsed from the transmission unit 3 is transmitted from the transmission antenna 2a toward the detection target, reflected by the detection target, and the reflected signal is received by the reception antennas 4a and 5a. The signals are received as b1 and b2, and the reception signals b1 and b2 are mixed with the transmission signal a by the mixers 61 and 62 of the reception units 6a and 6b to obtain mixing signals m1 and m2. Using the rising times t2 and t3 of the mixing signals m1 and m2 and the transmission time t1, the distance detector 7 detects the distance, and the azimuth angle detector 8 detects the azimuth angle. Thus, since the reception time difference can be easily obtained by detecting the rising times of the mixing signals m1 and m2, the distance to the object and the azimuth angle can be easily obtained. Also, since the calculation of the distance and azimuth angle from the obtained reception time and reception time difference does not require complicated calculation processing, the calculation time of the distance calculator 7b and the azimuth calculator 8b can be shortened and the response can be accelerated. Can do.

次に、対象物までの距離Ｒの求め方について説明する。図２に示すように、送信信号ａの送信から受信までの時間差Ｔａは、送信信号ａの送信時刻ｔ１と、送信信号ａと第１の受信信号ｂ１のミキシング信号ｍ１の立上り時刻ｔ２の時間差Ｔａ＝ｔ２−ｔ１で得られ、距離Ｒは、Ｒ＝Ｔａ×Ｃ／２（ただし、Ｃは光速）で求められる。具体的には、クロック発生器３ｂ（ＣＬ）が発生する時間基準パルスの数をカウンタで送信時刻ｔ１から数え始め、受信時刻ｔ２に数え終わったときのパルス数とパルス間隔とからＴａ、従って距離Ｒが得られる。 Next, how to obtain the distance R to the object will be described. As shown in FIG. 2, the time difference Ta from the transmission to the reception of the transmission signal a is the time difference Ta between the transmission time t1 of the transmission signal a and the rising time t2 of the mixing signal m1 of the transmission signal a and the first reception signal b1. = T2−t1, and the distance R is obtained by R = Ta × C / 2 (where C is the speed of light). Specifically, the counter starts counting the number of time reference pulses generated by the clock generator 3b (CL) from the transmission time t1, and Ta from the pulse number and pulse interval when counting is completed at the reception time t2. R is obtained.

また、方位角θは、第１の受信アンテナ４ａと第２の受信アンテナ５ａの間隔をｄとし、第１の受信アンテナ４ａと第２の受信アンテナ５ａでの受信時刻ｔ２、ｔ３をミキシング信号ｍ１、ｍ２の立上り時刻から求め、送信信号ａの周波数をｆａ、周期をＴｆとして、受信信号ｂ１、ｂ２間の位相差Δφは、次式で求められる。
Δφ＝２π（ｔ３−ｔ２）／Ｔｆ・・・（３）
従って、方位角θは、前述の式（２）を用いて、
θ＝ａｒｃｓｉｎΔφ・λ／２πｄ＝ａｒｃｓｉｎ（ｔ３−ｔ２）λ／（Ｔｆ・ｄ）
より、容易に求められる。 Further, the azimuth angle θ is defined as d between the first receiving antenna 4a and the second receiving antenna 5a, and the reception times t2 and t3 at the first receiving antenna 4a and the second receiving antenna 5a are mixed signals m1. , M2, and the phase difference Δφ between the received signals b1 and b2 is obtained by the following equation, where the frequency of the transmission signal a is fa and the period is Tf.
Δφ = 2π (t3−t2) / Tf (3)
Therefore, the azimuth angle θ is calculated using the above-described equation (2).
θ = arcsin Δφ · λ / 2πd = arcsin (t3-t2) λ / (Tf · d)
More easily required.

なお、図２におけるミキシング信号ｍ１、ｍ２の各波形は、検知対象物が静止状態である場合を示しているが、反射波が移動物体から反射された場合は、ドップラ効果により、ミキシング信号はドップラ信号となり周波数変動しているのでその波形は、立上り検出波形Ｄに示すように、略ＳＩＮ波形を成す。この場合も、このＳＩＮ波形の立上りを検出することにより、２つの受信信号ｂ１、ｂ２の受信時刻の検出が可能であり、距離及び方位角を検出することができる。 Note that the waveforms of the mixing signals m1 and m2 in FIG. 2 show the case where the detection target is stationary, but when the reflected wave is reflected from the moving object, the mixing signal is Doppler due to the Doppler effect. Since the frequency becomes a signal and fluctuates, the waveform forms a substantially SIN waveform as shown in the rising detection waveform D. Also in this case, by detecting the rising edge of the SIN waveform, it is possible to detect the reception times of the two reception signals b1 and b2, and it is possible to detect the distance and the azimuth angle.

上述した本実施形態によれば、送信信号ａの送信時刻ｔ１と受信信号ｂ１の受信時刻ｔ２による到達所要時間（ｔ２−ｔ１）と、受信信号ｂ１及び受信信号ｂ２の受信時間差（ｔ３−ｔ２）を、各ミキシング信号の立上り波形を基に直接各受信時刻を検出して求めることができる。従って、精度の良い受信時間差情報が簡単に得られ、検知対象物までの正確な距離、及び方位角の検出を容易に行うことができる。 According to the above-described embodiment, the required arrival time (t2−t1) between the transmission time t1 of the transmission signal a and the reception time t2 of the reception signal b1 and the reception time difference (t3−t2) between the reception signal b1 and the reception signal b2. Can be obtained by directly detecting each reception time based on the rising waveform of each mixing signal. Accordingly, accurate reception time difference information can be easily obtained, and the accurate distance to the detection target and the azimuth can be easily detected.

図３は本発明の第２の実施形態に係るパルスレーダ装置１の構成を示す。本装置１は、予め所望の検出距離及び方位角の情報を記憶するための記憶装置９と、記憶した距離・方位角情報と測定された距離・方位角とを比較するための比較器１１をさらに備え、距離検出部７及び方位角検出部８で検出された距離及び方位角が、記憶装置９に記憶された距離及び方位角の設定範囲内にあるときにのみ検出距離及び方位角を出力するものである。本実施形態は、この記憶装置９と、比較器１１を備えた点以外は、前記実施形態と同様である。図３において、第１の実施形態と同一部材には、同一符号を付す（以下、同様）。 FIG. 3 shows a configuration of a pulse radar apparatus 1 according to the second embodiment of the present invention. The apparatus 1 includes a storage device 9 for storing information on a desired detection distance and azimuth angle in advance, and a comparator 11 for comparing the stored distance / azimuth angle information with the measured distance / azimuth angle. In addition, the detected distance and azimuth are output only when the distance and azimuth detected by the distance detector 7 and the azimuth detector 8 are within the distance and azimuth setting range stored in the storage device 9. To do. The present embodiment is the same as the above embodiment except that the storage device 9 and the comparator 11 are provided. In FIG. 3, the same members as those in the first embodiment are denoted by the same reference numerals (hereinafter the same).

本装置１は、ミキサ６１、６２からのミキシング信号を用いて距離検出部７により距離、方位角検出部８により方位角をそれぞれ検出する。この検出された距離・方位角情報は、記憶装置９に予め記憶されている所望の距離・方位角のデータと比較器１１にて比較され、検出データが所望の範囲のエリアＢ内にあれば検出結果として出力する。 The apparatus 1 detects the distance by the distance detection unit 7 and the azimuth angle by the azimuth angle detection unit 8 using the mixing signals from the mixers 61 and 62. The detected distance / azimuth angle information is compared with the desired distance / azimuth data stored in advance in the storage device 9 by the comparator 11, and if the detected data is within the area B of the desired range. Output as detection result.

図４は本装置１の検知可能なエリアを示す。本装置１においては、検知可能なエリアＡが一意に定まるため、ユーザが所望しないエリアの対象物を検知する虞がある。このため、本装置１は予め所望の範囲のエリアＢを記憶装置９に記憶しておき、この記憶したデータと検知した距離・方位角とを比較器１１で比較し、検知データが所望の範囲のエリアＢ内であれば検知結果として出力することにより所望の検知結果を得る。これにより、ユーザが所望しないエリアの対象物を検出することがなくなると共に、不要な検出演算を省いて出力応答を速くし、ユーザの利便性を高めることができる。 FIG. 4 shows a detectable area of the apparatus 1. In the present apparatus 1, since the detectable area A is uniquely determined, there is a possibility of detecting an object in an area not desired by the user. Therefore, the device 1 stores an area B of a desired range in the storage device 9 in advance, and compares the stored data with the detected distance / azimuth by the comparator 11, and the detected data is within the desired range. If it is within the area B, a desired detection result is obtained by outputting it as a detection result. As a result, the object in the area not desired by the user is not detected, unnecessary detection calculation is omitted, the output response is accelerated, and the convenience of the user can be enhanced.

図５、本発明の第３の実施形態に係るパルスレーダ装置の構成を示す。本装置１は、２つの受信系４、５に対応する受信部６ａ、６ｂにそれぞれ２つずつ設けたミキサ（６１と６３、及び６２と６４）と、送信信号ａを９０°移相するπ／２移相器１２と、をさらに備える。図６は本装置１の動作を説明するための各種信号波形を示す。 FIG. 5 shows a configuration of a pulse radar apparatus according to the third embodiment of the present invention. This apparatus 1 includes two mixers (61 and 63 and 62 and 64) provided in each of the receiving units 6a and 6b corresponding to the two receiving systems 4 and 5, and π that shifts the transmission signal a by 90 °. / 2 phase shifter 12. FIG. 6 shows various signal waveforms for explaining the operation of the apparatus 1.

本装置１において、送信部３よりパルス化された送信信号ａは送信アンテナ２ａより発射され、検知対象物で反射され、この反射波を受信アンテナ４ａ、５ａで第１及び第２の受信信号ｂ１、ｂ２として受信する。この受信アンテナ４ａで受信された第１の受信信号ｂ１と送信信号ａは、受信部６ａのミキサ６１でミキシングされ、第１のミキシング信号が得られる。また、π／２移相器１２で９０°移相された送信信号ａと第１の受信信号ｂ１はミキサ６３でミキシングされ、第３のミキシング信号ｍ３が得られる。同様に、受信アンテナ５ａで受信された第２の受信信号ｂ２と送信信号ａはミキサ６２でミキシングされ、第２のミキシング信号ｍ２が得られると共に、π／２移相器１２で９０°移相された送信信号ａと、第２の受信信号ｂ２がミキサ６４でミキシングされ、第４のミキシング信号ｍ４が得られる。これらの得られた第１〜第４のミキシング信号ｍ１〜ｍ４は、方位角検出部８に加えられ、距離検出部７には、ミキシング信号ｍ１、ｍ２と、少なくともミキシング信号ｍ３、ｍ４のいずれかが加えられる。 In the present apparatus 1, the transmission signal a pulsed from the transmission unit 3 is emitted from the transmission antenna 2a, reflected by the object to be detected, and the reflected waves are received by the reception antennas 4a and 5a as the first and second reception signals b1. , B2. The first reception signal b1 and the transmission signal a received by the reception antenna 4a are mixed by the mixer 61 of the reception unit 6a to obtain a first mixing signal. In addition, the transmission signal a and the first reception signal b1 phase-shifted by 90 ° by the π / 2 phase shifter 12 are mixed by the mixer 63 to obtain a third mixing signal m3. Similarly, the second reception signal b2 and the transmission signal a received by the reception antenna 5a are mixed by the mixer 62 to obtain the second mixing signal m2, and the π / 2 phase shifter 12 performs a 90 ° phase shift. The transmitted signal a and the second received signal b2 are mixed by the mixer 64 to obtain a fourth mixing signal m4. The obtained first to fourth mixing signals m1 to m4 are applied to the azimuth angle detection unit 8, and the distance detection unit 7 is supplied with any one of the mixing signals m1 and m2 and at least the mixing signals m3 and m4. Is added.

方位角検出部８は、波形立上り検出器８ａにおいて、図６に示される第１、第３のミキシング信号ｍ１、ｍ３の検出振幅Ｖ１、Ｖ３を検出し、この振幅により第１の受信信号ｂ１の位相を検出する。ここで、例えば、検出振幅Ｖ１、Ｖ３が等しい場合は、送信信号ａと第１の受信信号ｂ１の位相が４５°となり、一方、検出振幅Ｖ１、Ｖ３が互いに＋−逆符号でそれらの絶対値が等しい場合は、位相は−４５°となる。このようにして、ミキシング信号の振幅により位相φ１を一意的に検出することができる。同様に、第２、第４のミキシング信号ｍ２、ｍ４の検出振幅Ｖ２、Ｖ４より、位相φ２を検出することができる。従って、φ２とφ１の差をとれば、２つの受信アンテナ４ａ、５ａ間の受信信号ｂ１、ｂ２の位相差Δφを得ることができる。このΔφと前述の式（２）を用いて、方位角演算器８ｂによる演算により方位角θを求めることができる。 The azimuth angle detection unit 8 detects the detection amplitudes V1 and V3 of the first and third mixing signals m1 and m3 shown in FIG. 6 in the waveform rising detector 8a, and the first reception signal b1 is detected based on this amplitude. Detect the phase. Here, for example, when the detection amplitudes V1 and V3 are equal, the phase of the transmission signal a and the first reception signal b1 is 45 °, while the detection amplitudes V1 and V3 are +/- opposite signs and their absolute values. Are equal, the phase is −45 °. In this way, the phase φ1 can be uniquely detected by the amplitude of the mixing signal. Similarly, the phase φ2 can be detected from the detection amplitudes V2 and V4 of the second and fourth mixing signals m2 and m4. Therefore, if the difference between φ2 and φ1 is taken, the phase difference Δφ of the received signals b1 and b2 between the two receiving antennas 4a and 5a can be obtained. Using this Δφ and the above equation (2), the azimuth angle θ can be obtained by calculation by the azimuth angle calculator 8b.

また、方位角検出部８は、図６に示すように、波形立上り検出器８ａで検出されるミキシング信号ｍ１とｍ２間、又はミキシング信号ｍ３とｍ４間の立上り波形のいずれか又は両方の立上り時刻差を用いて、第１の受信信号ｂ１と第２の受信信号ｂ２間の受信時間差Ｔｂ（＝ｔ３−ｔ２）を検出できる。これにより、前記と同様に、２つの受信アンテナ４ａ、５ａ間の受信信号ｂ１、ｂ２の位相差Δφを２πＴｂ／Ｔｆから得ることができ、前述の式（２）を用いて、方位角演算器８ｂにおいて方位角θを求めることができる。この測定は、時間検出から方位角を求めるので、測定精度がより高くなる。また、ミキシング信号ｍ１、ｍ３及びｍ２、ｍ４の電圧の検出振幅Ｖ１、Ｖ３及びＶ２、Ｖ４のそれぞれの絶対値を取って合成することにより、常に正符号の検出電圧を得ることができるので、この絶対値処理により正確で安定した立上り検出を行うことができ、さらに精度の良い位相検出を行うことができる。なお、図６では、検知対象物が静止状態である場合のミキシング信号波形を示して説明したが、検知対象物が移動状態であっても前記と同様に距離、方位角を検出することができる。 Further, as shown in FIG. 6, the azimuth angle detector 8 rises either or both of the rising waveforms between the mixing signals m1 and m2 detected by the waveform rising detector 8a or between the mixing signals m3 and m4. Using the difference, the reception time difference Tb (= t3−t2) between the first reception signal b1 and the second reception signal b2 can be detected. As a result, the phase difference Δφ of the received signals b1 and b2 between the two receiving antennas 4a and 5a can be obtained from 2πTb / Tf in the same manner as described above. In 8b, the azimuth angle θ can be obtained. In this measurement, since the azimuth is obtained from time detection, the measurement accuracy becomes higher. Further, since the absolute values of the detection amplitudes V1, V3, V2, and V4 of the mixing signals m1, m3, m2, and m4 are taken and combined, a positive sign detection voltage can always be obtained. Accurate and stable rising edge detection can be performed by absolute value processing, and more accurate phase detection can be performed. Note that FIG. 6 illustrates the mixing signal waveform when the detection target is stationary, but the distance and azimuth can be detected in the same manner as described above even when the detection target is in a moving state. .

図７は本発明の第４の実施形態に係るパルスレーダ装置１の構成を示す。本装置１は、前記第１の実施形態において、受信部６ａ、６ｂと距離検出部７及び方位角検出部８との間に、繰り返し入力に対し等価的に高速のサンプリングを行える等価サンプリング部１０をさらに備えたものである。この等価サンプリング部１０は、受信部６ａ、６ｂからのミキシング信号ｍ１、ｍ２を送信部３から送出される第１のパルス信号（以下、第１のパルスという）を生成する第１パルス生成手段１３と、第１のパルスの周波数と異なる周波数を有する第２のパルス信号（以下、第２のパルスという）を生成する第２パルス生成手段１４と、第１及び第２のパルスの同期を検出する同期検出手段１５と、受信部６ａ、６ｂからのミキシング信号ｍ１、ｍ２をサンプリングするサンプリング手段１６とを備える。 FIG. 7 shows a configuration of a pulse radar device 1 according to the fourth embodiment of the present invention. In the first embodiment, the apparatus 1 is equivalent to the equivalent sampling unit 10 capable of equivalently high-speed sampling with respect to repeated input between the receiving units 6a and 6b and the distance detection unit 7 and the azimuth angle detection unit 8. Is further provided. The equivalent sampling unit 10 generates a first pulse signal (hereinafter referred to as a first pulse) sent from the transmission unit 3 from the mixing signals m1 and m2 from the reception units 6a and 6b. And second pulse generation means 14 for generating a second pulse signal (hereinafter referred to as a second pulse) having a frequency different from the frequency of the first pulse, and the synchronization of the first and second pulses is detected. A synchronization detection unit 15 and a sampling unit 16 that samples the mixing signals m1 and m2 from the reception units 6a and 6b are provided.

上記第１パルス生成手段１３で生成された第１のパルスは、送信部３のクロック発生器３ｂのクロック信号と同期されており、この第１のパルスと第２パルス生成手段１４で生成された第２のパルスを同期検出手段１５で同期を検出した時、２番目以降の第１のパルスの発生時刻が第２のパルスに対し順次、Δｔずつ進むように構成されている。また、同期検出手段１５は、サンプリング手段１６でのサンプリングを開始するためのトリガとなる同期信号を形成する。 The first pulse generated by the first pulse generation unit 13 is synchronized with the clock signal of the clock generator 3b of the transmission unit 3, and is generated by the first pulse and the second pulse generation unit 14. When synchronization is detected in the second pulse by the synchronization detection means 15, the generation time of the second and subsequent first pulses is sequentially advanced by Δt with respect to the second pulse. Further, the synchronization detection means 15 forms a synchronization signal that serves as a trigger for starting sampling by the sampling means 16.

図８は本装置１の動作を説明するための波形を示す。送信部３は、第１パルス生成手段１３でパルス化された第１のパルスを送信出力する。この送信信号ａは検知対象物で反射され、その反射信号は受信アンテナ４ａ、５ａ（図１参照）で受信されて２つの受信信号ｂ１、ｂ２が得られる。この受信信号ｂ１、ｂ２は受信部６ａ、６ｂのミキサ６１、６２でミキシング信号ｍ１、ｍ２に変換される。第２パルス生成手段１４は、第１のパルス周波数と異なる（低い）周波数でなる第２のパルス（この２発目は、第１のパルスのそれよりΔｔだけ遅い）を生成する。同期検出手段１５は、第１パルス生成手段１３のパルス立ち上がりと第２パルス生成手段１４のパルス立ち上がりが一致する時刻（Ｔ１）を同期として検出する。サンプリング手段１６は、同期検出手段１５から出力される同期信号をトリガとしてミキシング信号ｍ１（ｍ２）のサンプリングを第２のパルスのタイミングで開始し、次の同期信号が入力されるまで、つまりミキシング信号ｍ１（ｍ２）と第２のパルスの立ち上がりが一致する時刻（Ｔ２）まで行う。このように、サンプリング手段１６は、繰り返し入力されるパルスレーダのミキシング信号に対し、第１パルスからΔｔだけ少しずつずらした第２パルスでサンプリングすることにより、等価的にミキシング信号の波形期間を細かくサンプリングする高速のサンプリングとなる等価サンプリング形式を取っている。このサンプリング結果より距離検出部７と方位角検出部８は、それぞれ距離、方位角を精度良く算出することができる。 FIG. 8 shows waveforms for explaining the operation of the apparatus 1. The transmission unit 3 transmits and outputs the first pulse pulsed by the first pulse generation means 13. The transmission signal a is reflected by the object to be detected, and the reflected signal is received by the reception antennas 4a and 5a (see FIG. 1) to obtain two reception signals b1 and b2. The received signals b1 and b2 are converted into mixing signals m1 and m2 by the mixers 61 and 62 of the receiving units 6a and 6b. The second pulse generating means 14 generates a second pulse having a frequency different from (lower than) the first pulse frequency (this second pulse is delayed by Δt from that of the first pulse). The synchronization detection means 15 detects the time (T1) at which the pulse rise of the first pulse generation means 13 and the pulse rise of the second pulse generation means 14 coincide with each other as a synchronization. The sampling means 16 starts sampling of the mixing signal m1 (m2) at the timing of the second pulse using the synchronization signal output from the synchronization detection means 15 as a trigger, that is, until the next synchronization signal is input, that is, the mixing signal. This is performed until time (T2) when the rising edges of m1 (m2) and the second pulse coincide. In this way, the sampling means 16 samples the repeatedly input pulse radar mixing signal with the second pulse that is slightly shifted by Δt from the first pulse, thereby equivalently reducing the waveform period of the mixing signal. The equivalent sampling format is used for high-speed sampling. From this sampling result, the distance detection unit 7 and the azimuth angle detection unit 8 can calculate the distance and the azimuth angle with high accuracy, respectively.

ここでの距離の算出は、サンプリング手段１６において、第２のパルスのタイミングでミキシング信号ｍ１（ｍ２）をサンプリングするため、第１のパルスの周波数をｆｃ１、第２のパルスの周波数をｆｃ２とすると、距離精度は、（１／ｆｃ２−１／ｆｃ１）×ｃ／２となる。例えば、ｆｃ１＝４．００４００４…ＭＨｚ、ｆｃ２＝４ＭＨｚ、媒体を光又は電波（ｃ≒３．０×１０^８ｍ）とした場合、距離精度は３．７５ｃｍ（＝０．２５ｎｓ）となる。距離Ｒは、距離検出部７にてサンプリング信号のｎ番目にて対象物を検知できたとすると、
Ｒ＝（１／ｆｃ２−１／ｆｃ１）×ｃ×ｎ／２
で求められ、精度良く距離の検出ができる。また、方位角検出に関しても、従来では複数の対象物が異なる距離で配置されていた場合は、クロックをカウントするタイミングによって複数の波形が重なってしまい、方位角を検出できない恐れがあったが、この手法により、サンプリングする第２のパルスの位相が常に移動していることにより波形が重ならないため、最も近い対象物から順次、方位角の検出が可能とある。なお、２つのパルス周波数の設定は、一方のパルスが他方のパルスとある周期毎に正確に同期する周波数を選択しなければならない。 Here, the distance is calculated when the sampling means 16 samples the mixing signal m1 (m2) at the timing of the second pulse, so that the frequency of the first pulse is fc1 and the frequency of the second pulse is fc2. The distance accuracy is (1 / fc2-1 / fc1) × c / 2. For example, when fc1 = 4.0004004... MHz, fc2 = 4 MHz, and the medium is light or radio waves (c≈3.0 × 10 ⁸ m), the distance accuracy is 3.75 cm (= 0.25 ns). The distance R is assumed to be detected by the distance detection unit 7 at the nth sampling signal.
R = (1 / fc2-1 / fc1) × c × n / 2
The distance can be detected with high accuracy. In addition, regarding azimuth detection, conventionally, when a plurality of objects are arranged at different distances, a plurality of waveforms overlap depending on the timing of counting the clock, and there is a possibility that the azimuth cannot be detected. By this method, since the waveforms do not overlap because the phase of the second pulse to be sampled always moves, it is possible to detect the azimuth sequentially from the nearest object. In setting the two pulse frequencies, it is necessary to select a frequency at which one pulse is accurately synchronized with the other pulse every certain period.

図９は、本発明の第５の実施形態に係るパルスレーダ装置の構成を示す。本装置１は、前記第１の実施形態において、受信部６ａ、６ｂと距離検出部７及び方位角検出部８の間にパルス積分器１７をさらに備えている。 FIG. 9 shows a configuration of a pulse radar apparatus according to the fifth embodiment of the present invention. The apparatus 1 further includes a pulse integrator 17 between the receiving units 6a and 6b, the distance detecting unit 7, and the azimuth detecting unit 8 in the first embodiment.

本装置１において、送信部３よりのパルス化された送信信号ａは検知対象物で反射され、その反射波を受信アンテナ４ａ、５ａで受信する。反射波の受信信号ｂ１、ｂ２と送信信号ａをミキシングしたミキシング信号ｍ１、ｍ２は、パルス積分器１７でパルス積分されることにより雑音成分が低減されて距離検出部７、及び方位角検出部８に加えられる。距離検出部７、及び方位角検出部８は、この雑音成分が抑圧されたミキシング信号ｍ１、ｍ２を用いて距離演算器７ｂ及び方位角演算器７ｂにおいてそれぞれ演算処理を行うので、演算処理の誤りが低減される。これにより、距離検出部７、及び方位角検出部８における各受信信号時間の検出精度が向上し、最大検知距離を延ばすことができ、方位角の測定精度を向上することができる。 In the present apparatus 1, the pulsed transmission signal a from the transmission unit 3 is reflected by the object to be detected, and the reflected waves are received by the reception antennas 4a and 5a. The mixing signals m1 and m2 obtained by mixing the reception signals b1 and b2 of the reflected wave and the transmission signal a are pulse-integrated by the pulse integrator 17 so that the noise component is reduced, and the distance detector 7 and the azimuth detector 8 Added to. Since the distance detection unit 7 and the azimuth angle detection unit 8 perform the calculation process in the distance calculator 7b and the azimuth angle calculator 7b using the mixing signals m1 and m2 in which the noise components are suppressed, an error in the calculation process Is reduced. Thereby, the detection accuracy of each reception signal time in the distance detection unit 7 and the azimuth angle detection unit 8 is improved, the maximum detection distance can be extended, and the azimuth angle measurement accuracy can be improved.

図１０は、本発明の第６の実施形態に係るパルスレーダ装置１の構成を示す。本装置１は、前記第１の実施形態において、受信部６ａ、６ｂと距離検出部７及び方位角検出部８の間に自動利得制御器１８をさらに備えている。 FIG. 10 shows a configuration of a pulse radar device 1 according to the sixth embodiment of the present invention. In the first embodiment, the apparatus 1 further includes an automatic gain controller 18 between the receiving units 6a and 6b, the distance detecting unit 7, and the azimuth detecting unit 8.

本装置１において、送信部３で生成された送信信号ａは、送信アンテナ２ａより送信され、検知対象物にあたって反射されて反射信号となり、この反射信号は受信アンテナ４ａ、５ａで受信信号ｂ１、ｂ２として受信される。受信信号ｂ１、ｂ２は受信部６ａ、６ｂのミキサ６１、６２で送信信号ａとミキシングされ、ミキシング信号ｍ１、ｍ２に変換される。このミキシング信号ｍ１、ｍ２は自動利得制御器１８により利得が制御され出力レベルが一定化される。この一定化されたミキシング信号ｍ１、ｍ２は、距離検出部７及び方位角検出部８に入力され演算処理されて、距離及び方位角がそれぞれ検出される。 In the present apparatus 1, the transmission signal a generated by the transmission unit 3 is transmitted from the transmission antenna 2a, reflected by the object to be detected and becomes a reflected signal, and the reflected signal is received by the receiving antennas 4a and 5a. As received. The reception signals b1 and b2 are mixed with the transmission signal a by the mixers 61 and 62 of the reception units 6a and 6b, and converted into mixing signals m1 and m2. The gains of the mixing signals m1 and m2 are controlled by the automatic gain controller 18 to make the output level constant. The fixed mixing signals m1 and m2 are input to the distance detection unit 7 and the azimuth angle detection unit 8 and processed to detect the distance and the azimuth angle, respectively.

通常、レーダ装置においては、対象物からの受信波は検出物体の距離に著しく左右されるため、その出力は至近距離と遠方では数十ｄＢ以上のレベル差を生じる。そのため、自動利得制御を行なうことにより、近距離では目標を見失わない範囲で利得を下げて感度を抑制し、遠距離になるに従って感度を上げていくことが可能になる。また、図１０の構成では、ミキシング信号ｍ１、ｍ２を自動利得制御器１８に入力する構成となっているが、ミキシング前に自動利得制御器１８を設置して受信アンテナからの受信信号（ＲＦ信号）そのものを利得制御する構成も可能である。 Usually, in a radar device, a received wave from an object is significantly influenced by the distance of a detected object, and therefore the output has a level difference of several tens of dB or more between a close distance and a distant place. Therefore, by performing automatic gain control, it is possible to reduce the gain and suppress the sensitivity within a range where the target is not lost at a short distance, and to increase the sensitivity as the distance increases. In the configuration of FIG. 10, the mixing signals m1 and m2 are input to the automatic gain controller 18. However, before mixing, the automatic gain controller 18 is installed to receive signals (RF signals) from the receiving antenna. It is also possible to adopt a configuration in which the gain is controlled.

次に、本発明の第７の実施形態に係るパルスレーダ装置（図示なし）について説明する。本実施形態は、第１の実施形態と同様の構成において、２つの受信アンテナの間隔を送信信号の周波数の１／２波長以内に配置したものである。通常、レーダ装置では、方位角を測定するには、受信アンテナを２個配置する必要があるが、アンテナ間距離を広くすると、前記式（１）より、例えば、対象物の方位角θがπ／２近くになれば、位相差が１／２波長以上になる。この時、比較する送信信号ａと受信信号ｂ１（又はｂ２）の観測する波形の対応する周期位置がずれてくる可能性があるため、送受信信号間で対応する波形の正確な位相比較ができず、方位角の検出ができなくなる虞がある。本実施形態では、２つの受信アンテナ間距離ｄを半波長（λ／２）内にすることにより、両受信アンテナ間隔が最大でλ／２しかずれないので、観測する送受信信号の波形の対応する周期位置のずれ（本来、比較すべき波形を誤って次の周期の波形を観測する）を防ぎ、送受信信号間で正確な対応波形による位相比較ができるので、前方１８０°の方位角の検出が可能となる。 Next, a pulse radar device (not shown) according to a seventh embodiment of the present invention will be described. In the present embodiment, in the same configuration as that of the first embodiment, the interval between two reception antennas is arranged within ½ wavelength of the frequency of the transmission signal. Usually, in a radar apparatus, two receiving antennas are required to measure the azimuth angle. However, when the distance between the antennas is increased, for example, the azimuth angle θ of the object is π from the equation (1). If it is close to / 2, the phase difference becomes 1/2 wavelength or more. At this time, there is a possibility that the corresponding periodic positions of the observed waveforms of the transmission signal a and the received signal b1 (or b2) to be compared may be shifted, so that an accurate phase comparison of the corresponding waveforms cannot be performed between the transmission and reception signals. The azimuth angle may not be detected. In the present embodiment, by setting the distance d between the two receiving antennas to be within a half wavelength (λ / 2), the distance between the two receiving antennas is shifted by λ / 2 at the maximum, so that the waveform of the transmitted / received signal to be observed corresponds. Since it is possible to prevent phase shift (originally, the waveform to be compared is erroneously observed and observe the waveform of the next cycle) and to accurately compare the phases between the transmitted and received signals, the azimuth angle of 180 ° forward can be detected. It becomes possible.

上述した各種実施形態に係るパルスレーダ装置１においては、１つの送信系２と、２つの受信系４、５を備え、送信アンテナ２ａからの送信信号ａの検知対象物による反射波を各受信アンテナ４ａ、５ａで受信した受信信号ｂ１、ｂ２と送信信号ａとをミキサ６１、６２でミキシングすることにより、時間差を持つミキシング信号ｍ１、ｍ２を容易に得ることができる。このミキシング信号ｍ１、ｍ２を基に、これらの検出時間差から検知対象物までの距離及び方位角を簡単な構成で精度良く検出することができる。 In the pulse radar device 1 according to the various embodiments described above, one transmission system 2 and two reception systems 4 and 5 are provided, and the reflected wave from the detection target of the transmission signal a from the transmission antenna 2a is received by each reception antenna. By mixing the reception signals b1 and b2 received by 4a and 5a and the transmission signal a by the mixers 61 and 62, the mixing signals m1 and m2 having a time difference can be easily obtained. Based on the mixing signals m1 and m2, the distance and azimuth from the detection time difference to the detection target can be accurately detected with a simple configuration.

本発明の第１の実施形態に係るパルスレーダ装置の構成図。1 is a configuration diagram of a pulse radar device according to a first embodiment of the present invention. 同上装置の動作を説明するための波形図。The wave form diagram for demonstrating operation | movement of an apparatus same as the above. 本発明の第２の実施形態に係るパルスレーダ装置の構成図。The block diagram of the pulse radar apparatus which concerns on the 2nd Embodiment of this invention. 同装置の検知領域を示す図。The figure which shows the detection area | region of the same apparatus. 本発明の第３の実施形態に係るパルスレーダ装置の構成図。The block diagram of the pulse radar apparatus which concerns on the 3rd Embodiment of this invention. 同上装置の動作を説明するための波形図。The wave form diagram for demonstrating operation | movement of an apparatus same as the above. 本発明の第４の実施形態に係るパルスレーダ装置の構成図。The block diagram of the pulse radar apparatus which concerns on the 4th Embodiment of this invention. 同上装置の動作を説明するための波形図。The wave form diagram for demonstrating operation | movement of an apparatus same as the above. 本発明の第５の実施形態に係るパルスレーダ装置の構成図。The block diagram of the pulse radar apparatus which concerns on the 5th Embodiment of this invention. 本発明の第６の実施形態に係るパルスレーダ装置の構成図。The block diagram of the pulse radar apparatus which concerns on the 6th Embodiment of this invention. 従来のレーダ装置の検出動作を説明するための図。The figure for demonstrating the detection operation of the conventional radar apparatus. 別の従来のレーダ装置の検出動作を説明するための図。The figure for demonstrating the detection operation of another conventional radar apparatus.

Explanation of symbols

１パルスレーダ装置
２送信系
２ａ送信アンテナ（送信手段）
３送信部（送信手段）
４、５受信系
４ａ、５ａ受信アンテナ（受信手段）
６ａ、６ｂ受信部（受信手段）
６１〜６４ミキサ（ミキシング手段）
７距離検出部（距離検出手段）
８方位角検出部（方位角検出手段）
１０等価サンプリング部
１１記憶装置
１２９０°移相器
１６サンプリング手段
１７パルス積分器
１８自動利得制御器 DESCRIPTION OF SYMBOLS 1 Pulse radar apparatus 2 Transmission system 2a Transmission antenna (transmission means)
3 Transmitter (transmission means)
4, 5 receiving system 4a, 5a receiving antenna (receiving means)
6a, 6b Receiving part (receiving means)
61-64 mixer (mixing means)
7 Distance detector (distance detection means)
8 Azimuth angle detector (azimuth angle detector)
DESCRIPTION OF SYMBOLS 10 Equivalent sampling part 11 Memory | storage device 12 90 degree phase shifter 16 Sampling means 17 Pulse integrator 18 Automatic gain controller

Claims

In a pulse radar device that detects a distance to an object and an azimuth angle using one transmission system and a plurality of reception systems,
A transmission means for transmitting a pulsed transmission signal;
Receiving means provided corresponding to the plurality of receiving systems for receiving reflected waves reflected from the object;
Mixing means for obtaining each mixing signal by mixing each reception signal from the receiving means with the transmission signal;
Distance detecting means for calculating a distance to the object based on an output of the at least one mixing signal;
A pulse radar apparatus comprising: an azimuth angle detection unit that calculates a phase difference of reception signals in each reception system based on outputs of the plurality of mixing signals and obtains an azimuth angle of the object from the phase difference. .

A storage device for storing a desired detection distance and azimuth angle in advance;
The detection distance and azimuth angle are output only when the distance and azimuth angle detected by the distance detection means and azimuth angle detection means are within the distance and azimuth angle setting range stored in the storage device. The pulse radar device according to claim 1.

The mixing means is provided corresponding to each of the plurality of receiving systems, and the azimuth angle detecting means is a signal obtained by shifting the mixing signal obtained by each mixing means, and the mixing signal and the transmission signal by 90 °. The pulse radar apparatus according to claim 1, wherein an azimuth angle of the object is obtained using a mixing signal obtained by mixing the signals.

4. The pulse radar apparatus according to claim 3, wherein the azimuth angle detection means detects a phase from the amplitude of the mixing signal and obtains the azimuth angle of the detected object.

4. The pulse radar device according to claim 3, wherein the azimuth angle detecting means detects a phase from a time difference of the mixing signal and obtains an azimuth angle of the detected object.

4. The pulse radar device according to claim 3, wherein the azimuth angle detection means includes sampling means based on equivalent sampling in order to sample the mixing signal.

2. The pulse radar device according to claim 1, wherein the mixing signal is pulse-integrated and input to the distance detection means and the azimuth angle detection means.

2. The pulse radar apparatus according to claim 1, wherein the mixing signal is automatically gain-controlled and input to the distance detection unit and the azimuth angle detection unit.

2. The pulse radar device according to claim 1, wherein an arrangement distance between receiving means of the plurality of receiving systems is set to a half wavelength or less of a frequency of the transmission signal.