JP2011128101A - Positioning receiver - Google Patents

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JP2011128101A
JP2011128101A JP2009289087A JP2009289087A JP2011128101A JP 2011128101 A JP2011128101 A JP 2011128101A JP 2009289087 A JP2009289087 A JP 2009289087A JP 2009289087 A JP2009289087 A JP 2009289087A JP 2011128101 A JP2011128101 A JP 2011128101A
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vehicle speed
correlation value
direct wave
change
correlation
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JP5581686B2 (en
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Akihiro Yanagiuchi
昭宏 柳内
Yoshinori Kadowaki
美徳 門脇
Hiroshi Sato
洋 佐藤
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Toyota Motor Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning receiver capable of distinguishing noise from a direct wave with high accuracy. <P>SOLUTION: The positioning receiver receives spectrum-spread signals from positioning satellites such as a GPS satellite, and the receiver includes: a correlator 3 for calculating a correlation value of a signal received by an antenna 1 within a period of time determined in accordance with a vehicle speed with respect to a spreading code; and a determination part 6 for determining whether the signal received within the period of time determined in accordance with the vehicle speed is a direct wave or noise depending on whether a change in the correlation value calculated by the correlator 3 correlates with the vehicle speed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、スペクトラム拡散された信号を受信する測位用受信装置に関する。   The present invention relates to a positioning receiver that receives a spectrum-spread signal.

従来、マルチパスによって測位精度の悪化を防止する技術が知られている（例えば、特許文献１，２参照）。   Conventionally, techniques for preventing deterioration in positioning accuracy by multipath are known (see, for example, Patent Documents 1 and 2).

特許文献１に開示の受信装置は、ＰＮコードが入力されたときの相関出力のレベルと該ＰＮコードの位相を時間的に前の位相にずらしたときにおける相関出力のレベルとを比較し、レベルの大きいほうの相関出力を直接波による相関出力とする信号判定手段を備えるものである（図１（ａ）参照）。   The receiving apparatus disclosed in Patent Document 1 compares the level of the correlation output when the PN code is input with the level of the correlation output when the phase of the PN code is shifted to the previous phase in time, 1 is provided with a signal determination means for using the larger correlation output as the correlation output by the direct wave (see FIG. 1A).

特許文献２に開示の受信装置は、検出した複数の相関ピーク点の中から位相遅延が最も小さい相関ピーク点を検出して、直接波のコード位相を捕捉するものである（図１（ｃ）参照）。   The receiving device disclosed in Patent Document 2 detects a correlation peak point having the smallest phase delay from a plurality of detected correlation peak points, and captures the code phase of the direct wave (FIG. 1 (c)). reference).

特許第３２８３９１３号Japanese Patent No. 3283913 特開２００５−２６０７８１号公報Japanese Patent Laid-Open No. 2005-260781

ところで、スペクトラム拡散された信号を用いて車両制御を行う場合、その信号の直接波を的確に捉えることが非常に重要であるため、直接波の成否によっては車両制御性能に大きな差がでる。   By the way, when vehicle control is performed using a spectrum-spread signal, it is very important to accurately capture the direct wave of the signal, so that there is a great difference in vehicle control performance depending on the success or failure of the direct wave.

しかしながら、レベルの大きい方を直接波と判定する特許文献１の開示技術では、例えば直接波のみが木陰等で遮られることにより、直接波のレベルが低くなり反射波のレベルが相対的に高くなると、反射波を直接波と誤って判定するおそれがある（図１（ｂ）参照）。また、時間的に早いピークを直接波と判定する特許文献２の開示技術では、例えばＳＮ比が低い場合（電波強度が弱い場合など）、ノイズを直接波と誤って判定するおそれがある（図１（ｄ）参照）。積算してノイズ成分を低減する手法もあるが、車両の移動中はその効果が十分ではない場合がある。   However, in the disclosed technique of Patent Document 1 in which the higher level is determined as a direct wave, for example, when only the direct wave is blocked by a shade or the like, the level of the direct wave is lowered and the level of the reflected wave is relatively increased. The reflected wave may be erroneously determined as a direct wave (see FIG. 1B). Further, in the disclosed technique of Patent Document 2 in which a peak that is early in time is determined to be a direct wave, for example, when the SN ratio is low (such as when the radio wave intensity is weak), there is a risk that noise is erroneously determined as a direct wave (see FIG. 1 (d)). Although there is a method of integrating and reducing the noise component, the effect may not be sufficient while the vehicle is moving.

そこで、本発明は、直接波とノイズを精度良く判別することができる、測位用受信装置の提供を目的とする。   Accordingly, an object of the present invention is to provide a positioning receiving apparatus that can accurately discriminate between direct waves and noise.

上記目的を達成するため、本発明に係る測位用受信装置は、
スペクトラム拡散された信号を受信する測位用受信装置であって、
車速に応じて決められた時間内に受信した信号と拡散コードとの相関値を算出する相関器と、
前記相関器によって算出された相関値の変化が車速と相関しているか否かによって、前記時間内に受信した信号が直接波であるのかノイズであるのかを判定する判定部とを備えることを特徴とするものである。 In order to achieve the above object, a positioning receiving apparatus according to the present invention includes:
A positioning receiver for receiving a spread spectrum signal,
A correlator for calculating a correlation value between a signal received in a time determined according to the vehicle speed and a spreading code;
A determination unit that determines whether a signal received within the time is a direct wave or noise depending on whether or not a change in a correlation value calculated by the correlator correlates with a vehicle speed. It is what.

本発明によれば、直接波とノイズを精度良く判別することができる。   According to the present invention, it is possible to accurately discriminate between direct waves and noise.

直接波の従来の判別方法を説明するための図である。It is a figure for demonstrating the conventional discrimination method of a direct wave. 本発明の実施形態である測位用受信装置の構成例を示したブロック図である。It is the block diagram which showed the structural example of the receiving apparatus for positioning which is embodiment of this invention. 相関器３によって算出された相関値の車速による違いを示した図である。It is the figure which showed the difference by the vehicle speed of the correlation value calculated by the correlator. 本発明の実施形態の測位用受信装置で行われる直接波とノイズの判定方法の一例を示したフローチャートである。It is the flowchart which showed an example of the determination method of the direct wave and noise performed with the receiving apparatus for positioning of embodiment of this invention. 車速Ｖに対する時間Ｔａを決定するための対応関係の一例を示した図である。It is the figure which showed an example of the correspondence for determining time Ta with respect to the vehicle speed V. FIG. 相関値の変動周期（変動周波数）の車速による違いを示した図である。It is the figure which showed the difference by the vehicle speed of the fluctuation period (fluctuation frequency) of a correlation value. 直接波とノイズの判定マップの一例である。It is an example of the determination map of a direct wave and noise. 相関値の変化率の車速による違いを示した図である。It is the figure which showed the difference by the vehicle speed of the change rate of a correlation value. 直接波とノイズの判定マップの一例である。It is an example of the determination map of a direct wave and noise. 相関器３によって算出された相関値の車速による違いを示した図である。It is the figure which showed the difference by the vehicle speed of the correlation value calculated by the correlator. 本発明の実施形態の測位用受信装置で行われる直接波とノイズの判定方法の一例を示したフローチャートである。It is the flowchart which showed an example of the determination method of the direct wave and noise performed with the receiving apparatus for positioning of embodiment of this invention. 直接波とノイズの判定マップの一例である。It is an example of the determination map of a direct wave and noise.

以下、図面を参照しながら、本発明を実施するための形態の説明を行う。図２は、本発明の実施形態である測位用受信装置の構成例を示したブロック図である。図２には、直接拡散方式によりスペクトラム拡散された信号をＧＰＳ衛星などの測位用衛星から受信する測位用受信装置が示されている。図２（ａ）に示される測位用受信装置１０は、車速に応じて決められた時間Ｔａ内に受信した信号と拡散コードとの相関値を算出する相関器３と、相関器３によって算出された相関値の変化が車速と相関しているか否かによって、時間Ｔａ内に受信した信号が直接波であるのかノイズであるのかを判定する判定部６とを備えている。車速とは、測位用受信装置１０を搭載する車両の走行速度である。車速は、車速センサの出力信号に基づいて得られる。また、相関器３は複数備えられていてもよく、図２（ｂ）に示される測位用受信装置２０は、相関器３として、２つの相関器３Ａ，３Ｂが並列に備えられている。   Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 2 is a block diagram showing a configuration example of the positioning receiving apparatus according to the embodiment of the present invention. FIG. 2 shows a positioning receiving apparatus that receives a spectrum spread signal by a direct spreading method from a positioning satellite such as a GPS satellite. The positioning receiving device 10 shown in FIG. 2A is calculated by a correlator 3 that calculates a correlation value between a signal received within a time Ta determined according to the vehicle speed and a spreading code, and the correlator 3. The determination unit 6 determines whether the signal received within the time Ta is a direct wave or noise depending on whether the change in the correlation value correlates with the vehicle speed. The vehicle speed is a traveling speed of a vehicle on which the positioning receiving device 10 is mounted. The vehicle speed is obtained based on the output signal of the vehicle speed sensor. A plurality of correlators 3 may be provided, and the positioning receiver 20 shown in FIG. 2B includes two correlators 3A and 3B in parallel as the correlator 3.

図３は、相関器３によって算出された相関値の車速による違いを示した図である。図３内の各図の横軸は、拡散コードの位相を表し、縦軸は、相関値の大きさを表している。また、黒矢印は、受信した信号が直接波のときの相関値の変化を示し、白矢印は、受信した信号がノイズのときの相関値の変化を示している。図３に示されるように、直接波の相関値は車速と相関して変化し、ノイズの相関値は車速と相関無く変化する。本願発明はこの点に着目したものであって、判定部６は、相関器３によって算出された相関値の変化が車速と相関している場合、受信した信号は直接波であると判定し、相関器３によって算出された相関値の変化が車速と相関していない場合、受信した信号はノイズであると判定する。つまり、判定部６は、車速と相関して変化する相関値を直接波に基づいて算出された相関値と判定し、車速と相関無く変化する相関値をノイズに基づいて算出された相関値と判定する。   FIG. 3 is a diagram illustrating a difference in correlation value calculated by the correlator 3 depending on the vehicle speed. The horizontal axis of each figure in FIG. 3 represents the phase of the spreading code, and the vertical axis represents the magnitude of the correlation value. A black arrow indicates a change in the correlation value when the received signal is a direct wave, and a white arrow indicates a change in the correlation value when the received signal is noise. As shown in FIG. 3, the correlation value of the direct wave changes in correlation with the vehicle speed, and the correlation value of noise changes without correlation with the vehicle speed. The present invention focuses on this point, and the determination unit 6 determines that the received signal is a direct wave when the change in the correlation value calculated by the correlator 3 correlates with the vehicle speed. When the change in the correlation value calculated by the correlator 3 is not correlated with the vehicle speed, it is determined that the received signal is noise. That is, the determination unit 6 determines the correlation value that changes in correlation with the vehicle speed as a correlation value calculated based on the direct wave, and the correlation value that changes without correlation with the vehicle speed as the correlation value calculated based on the noise. judge.

したがって、上述の測位用受信装置によれば、木陰などで直接波の電波強度が弱くなる場面であっても、自車両が移動中であっても、相関値の変化と車速との相関関係を観測することによって、直接波とノイズを的確に判別することができる。その結果、直接波を適切に捕捉することができるので、自車両の測位を高精度に実施することが可能になる。   Therefore, according to the positioning receiver described above, the correlation between the change in the correlation value and the vehicle speed can be obtained regardless of whether the radio wave intensity of the direct wave is weak due to a shade or the like, or the host vehicle is moving. By observing, it is possible to accurately discriminate between direct waves and noise. As a result, the direct wave can be appropriately captured, so that positioning of the host vehicle can be performed with high accuracy.

また、直接波の相関値は車速が速くなるほど速く変化し、ノイズの相関値は車速に関係なく変化するので、車速に応じて決められた時間Ｔａ内に受信した信号に基づいて算出された相関値の変化が車速と相関しているか否かによって直接波かノイズかの判定を行うことによって、必要最小限の時間で、当該判定を効率的に実施することができる。例えば、車速が速い場合の時間Ｔａの長さが、車速が遅い場合に比べて短い時間に設定されるように決められることによって、必要最小限の時間で当該判定を効率的に実施することができる。   Further, since the correlation value of the direct wave changes faster as the vehicle speed becomes faster, and the correlation value of noise changes regardless of the vehicle speed, the correlation calculated based on the signal received within the time Ta determined according to the vehicle speed. By determining whether the change in the value correlates with the vehicle speed, whether it is a direct wave or noise, the determination can be performed efficiently in the minimum necessary time. For example, by determining that the length of the time Ta when the vehicle speed is high is set to be shorter than when the vehicle speed is low, the determination can be efficiently performed in the minimum necessary time. it can.

次に、図２に示された測位用受信装置の構成について、より詳細に説明する。図２に示された測位用受信装置は、車両に搭載され、アンテナ１と、高周波回路２と、相関器３と、記憶部４と、変化検出部５と、判定部６とを備える。   Next, the configuration of the positioning receiving device shown in FIG. 2 will be described in more detail. The positioning receiving apparatus shown in FIG. 2 is mounted on a vehicle and includes an antenna 1, a high frequency circuit 2, a correlator 3, a storage unit 4, a change detection unit 5, and a determination unit 6.

アンテナ１によって受信された信号は、高周波回路２に入力される。高周波回路２は、アンテナ１によって受信された信号を中間周波信号にダウンコンバートし、その中間周波信号をＡＤ変換によってデジタル信号に変換して、相関器３に供給する。   A signal received by the antenna 1 is input to the high frequency circuit 2. The high frequency circuit 2 down-converts the signal received by the antenna 1 into an intermediate frequency signal, converts the intermediate frequency signal into a digital signal by AD conversion, and supplies the digital signal to the correlator 3.

相関器３は、測位用受信装置の拡散コード生成部（不図示）で生成された拡散コードに基づいて、デジタルの中間周波信号に変換された受信信号を逆拡散する。すなわち、受信信号と拡散コードとの相関値を算出する。拡散コードとして、例えば、擬似雑音（ＰＮ：Pseudo Noise）符号が挙げられる。拡散コード生成部で生成される拡散コードの位相が順次変更するように制御されることにより、相関器３によって算出される相関値が所定値以上になる位相が探索され、当該所定値以上の相関値が位相毎に記憶部４に記憶される。特に、記憶部４の記憶容量を削減できるという点で、当該所定値以上の複数の相関値の中での極大値が記憶部４に記憶されてもよい。   The correlator 3 despreads the received signal converted into the digital intermediate frequency signal based on the spreading code generated by the spreading code generator (not shown) of the positioning receiver. That is, the correlation value between the received signal and the spreading code is calculated. Examples of the spreading code include a pseudo noise (PN) code. By controlling so that the phase of the spreading code generated by the spreading code generator is sequentially changed, the phase where the correlation value calculated by the correlator 3 becomes a predetermined value or more is searched, and the correlation more than the predetermined value is found. The value is stored in the storage unit 4 for each phase. In particular, a maximum value among a plurality of correlation values that are equal to or greater than the predetermined value may be stored in the storage unit 4 in that the storage capacity of the storage unit 4 can be reduced.

相関器３は、車速に応じて決められた時間Ｔａ内に受信した信号を逆拡散することによって、相関値を算出する。相関器３によって算出された相関値の変化が車速と所定の相関関係を有している場合、時間Ｔａ内に受信した信号が直接波と判定される。したがって、時間Ｔａの長さが、車速が速くなるにつれて短くなるように決められることによって、必要最小限の時間で、直接波の判定を効率的に実施することができる。   The correlator 3 calculates a correlation value by despreading the signal received within the time Ta determined according to the vehicle speed. When the change in the correlation value calculated by the correlator 3 has a predetermined correlation with the vehicle speed, the signal received within the time Ta is determined as a direct wave. Therefore, since the length of the time Ta is determined so as to become shorter as the vehicle speed increases, the direct wave determination can be efficiently performed in the minimum necessary time.

変化検出部５は、相関器３によって算出され記憶部４に拡散コードの位相毎に記憶された複数の相関値に基づいて、相関値の変化態様を検知する。例えば、変化検出部５は、相関値の変化態様を検知するために、車速に応じて決められた時間Ｔａ内に受信した信号に基づいて算出された相関値に基づいて相関値の変化態様を表す状態量を算出する。その状態量の具体例として、相関値の変動周期（変動周波数でもよい）や、相関値の変化率などが挙げられる。したがって、変化検出部５は、車速に応じて決められた時間Ｔａ内に受信した信号に基づいて算出された相関値に基づいて、相関値の変動周期（変動周波数）及び／又は変化率を算出することによって、相関値の変化態様を検知することができる。   The change detection unit 5 detects a change mode of the correlation value based on a plurality of correlation values calculated by the correlator 3 and stored in the storage unit 4 for each phase of the spreading code. For example, the change detection unit 5 detects the change mode of the correlation value based on the correlation value calculated based on the signal received within the time Ta determined according to the vehicle speed in order to detect the change mode of the correlation value. The state quantity to be expressed is calculated. Specific examples of the state quantity include a correlation value fluctuation cycle (may be a fluctuation frequency), a correlation value change rate, and the like. Therefore, the change detection unit 5 calculates the fluctuation period (fluctuation frequency) and / or the change rate of the correlation value based on the correlation value calculated based on the signal received within the time Ta determined according to the vehicle speed. By doing so, the change mode of the correlation value can be detected.

判定部６は、車速センサによって検知された車速と変化検出部５によって検知された相関値の変化態様に基づいて、受信信号が直接波であるのかノイズであるのかを判定する。具体的には、判定部６は、相関値の変化が車速と相関しているか否かを判断し、車速と相関して変化する相関値を直接波から算出された相関値と判定し、車速と相関無く変化する相関値をノイズから算出された相関値と判定する。   The determination unit 6 determines whether the received signal is a direct wave or noise based on the vehicle speed detected by the vehicle speed sensor and the change mode of the correlation value detected by the change detection unit 5. Specifically, the determination unit 6 determines whether or not the change in the correlation value correlates with the vehicle speed, determines that the correlation value that changes in correlation with the vehicle speed is a correlation value calculated from the direct wave, and determines the vehicle speed. The correlation value that changes without correlation is determined as the correlation value calculated from the noise.

図４は、本発明の実施形態の測位用受信装置で行われる直接波とノイズの判定方法の一例を示したフローチャートである。本判定方法は、例えば、測位用受信装置に内蔵のマイクロコンピュータによって行われる。ステップＳ１０１において、タイマーによるカウントアップが行われ、ステップＳ１０２において、カウンタの値Ｎが車速Ｖに応じて決められた時間Ｔａ（すなわち、時間Ｔａに相当する上限値Ｆ（車速））に達したかどうかが判定される。   FIG. 4 is a flowchart illustrating an example of a direct wave and noise determination method performed by the positioning receiver according to the embodiment of the present invention. This determination method is performed, for example, by a microcomputer built in the positioning receiving device. In step S101, the timer counts up. In step S102, whether the counter value N has reached a time Ta determined according to the vehicle speed V (that is, an upper limit value F (vehicle speed) corresponding to the time Ta). Whether it is determined.

時間Ｔａは、車速Ｖと時間Ｔａとの予め定められた対応関係に基づいて決められる。車速Ｖと時間Ｔａとの対応関係の一例を図５に示す。図５によれば、時間Ｔａは、車速Ｖに反比例するように決められる。例えば、車速が速くなるにつれて時間Ｔａの設定時間は短くなり、車速が遅くなるにつれて時間Ｔａの設定時間は長くなる。   The time Ta is determined based on a predetermined correspondence between the vehicle speed V and the time Ta. An example of the correspondence between the vehicle speed V and the time Ta is shown in FIG. According to FIG. 5, the time Ta is determined to be inversely proportional to the vehicle speed V. For example, the set time for the time Ta becomes shorter as the vehicle speed becomes faster, and the set time for the time Ta becomes longer as the vehicle speed becomes slower.

時間Ｔａに達していない場合、ステップＳ１０１に戻る。時間Ｔａに達している場合、タイマーはリセットされ（ステップＳ１０３）、時間Ｔａ内に受信した信号を逆拡散することによって算出された相関値の変化態様を表す状態量が算出されることによって、相関値の変化が検知される（ステップＳ１０４）。   If the time Ta has not been reached, the process returns to step S101. If the time Ta has been reached, the timer is reset (step S103), and a state quantity representing a change mode of the correlation value calculated by despreading the signal received within the time Ta is calculated, thereby calculating the correlation. A change in value is detected (step S104).

ステップＳ１０５において、判定部６は、車速と相関値の変化の検知結果に基づいて、相関値の変化が車速と所定の相関関係を有しているか否かを判定する。判定部６は、相関値が車速と相関して変化している場合には、受信信号が直接波であると判定し（ステップＳ１０６）、相関値が車速と相関無く変化している場合には、受信信号がノイズであると判定する（ステップＳ１０７）。   In step S105, the determination unit 6 determines whether the change in the correlation value has a predetermined correlation with the vehicle speed based on the detection result of the change in the vehicle speed and the correlation value. The determination unit 6 determines that the received signal is a direct wave when the correlation value changes in correlation with the vehicle speed (step S106), and when the correlation value changes without correlation with the vehicle speed. Then, it is determined that the received signal is noise (step S107).

ステップＳ１０４において、変化検出部５は、例えば、相関器３によって算出され記憶部４に記憶された相関値の極大値間の時間（極小値間の時間でもよい）に基づいて（図６参照）、相関値の変化態様を表す状態量として、相関値の変動周期（変動周波数）を算出する。   In step S104, the change detection unit 5 is based on, for example, the time between the maximum values of correlation values calculated by the correlator 3 and stored in the storage unit 4 (it may be the time between the minimum values) (see FIG. 6). Then, the fluctuation period (fluctuation frequency) of the correlation value is calculated as the state quantity representing the change mode of the correlation value.

図６は、相関値の変動周期（変動周波数）の車速による違いを示した図である。車速が速いときに受信した直接波Ａ１に基づいて算出される相関値の変動周期は、車速が遅いときに受信した直接波Ａ２に基づいて算出される相関値の変動周期に比べて短い。言い換えれば、車速が速いときに受信した直接波Ａ１に基づいて算出される相関値の変動周波数は、車速が遅いときに受信した直接波Ａ２に基づいて算出される相関値の変動周波数に比べて高い。   FIG. 6 is a diagram showing the difference in the fluctuation period (fluctuation frequency) of the correlation value depending on the vehicle speed. The fluctuation period of the correlation value calculated based on the direct wave A1 received when the vehicle speed is high is shorter than the fluctuation period of the correlation value calculated based on the direct wave A2 received when the vehicle speed is low. In other words, the fluctuation frequency of the correlation value calculated based on the direct wave A1 received when the vehicle speed is high is compared with the fluctuation frequency of the correlation value calculated based on the direct wave A2 received when the vehicle speed is slow. high.

この点に着目して、判定部６は、例えば、実際に検知された車速及び算出された相関値の変動周期（変動周波数）に基づき、図７に例示される直接波とノイズの判定マップに従って、直接波とノイズの判定を実施する。判定部６は、車速ｖのときに受信した信号を逆拡散することによって算出された相関値の変動周波数ｑが、車速Ｖに対する変動周波数Ｑの増加率が所定の範囲内である領域Ｄ１に属する場合（すなわち、車速Ｖと変動周波数Ｑとの関係が所定の比例範囲Ｄ１に属する場合）、相関値の変化が車速に相関しているとみなして、受信した信号は直接波と判定する。これにより、判定部６は、信号Ａ１を受信したときの車速と信号Ａ１に基づき算出された変動周波数との組み合わせデータも、信号Ａ２を受信したときの車速と信号Ａ２に基づき算出された変動周波数との組み合わせデータも、領域Ｄ１に属するため、車速が速いときに受信した信号Ａ１も車速が遅いときに受信した信号Ａ２も直接波と判定することができる。   Focusing on this point, for example, the determination unit 6 follows the direct wave and noise determination map illustrated in FIG. 7 based on the actually detected vehicle speed and the calculated fluctuation period (fluctuation frequency) of the correlation value. Execute direct wave and noise determination. The determination unit 6 belongs to a region D1 in which the fluctuation frequency q of the correlation value calculated by despreading the signal received at the vehicle speed v is within a predetermined range of the increase rate of the fluctuation frequency Q with respect to the vehicle speed V. In this case (that is, when the relationship between the vehicle speed V and the fluctuation frequency Q belongs to the predetermined proportional range D1), it is determined that the change in the correlation value is correlated with the vehicle speed, and the received signal is determined as a direct wave. As a result, the determination unit 6 uses the combined data of the vehicle speed when the signal A1 is received and the fluctuation frequency calculated based on the signal A1 as well as the fluctuation frequency calculated based on the vehicle speed when the signal A2 is received and the signal A2. Since the combined data also belongs to the region D1, the signal A1 received when the vehicle speed is high and the signal A2 received when the vehicle speed is low can be determined to be direct waves.

一方、判定部６は、車速ｖのときに受信した信号を逆拡散することによって算出された相関値の変動周波数ｑが、車速Ｖに対する変動周波数Ｑの増加率が所定範囲以上である領域Ｎ１又は所定範囲以下である領域Ｎ２に属する場合（すなわち、車速Ｖと変動周波数Ｑとの関係が所定の比例範囲Ｄ１に属さない場合）、相関値の変化が車速に相関していないとみなして、受信した信号はノイズと判定する。これにより、判定部６は、信号Ｂを受信したときの車速と信号Ｂに基づき算出された変動周波数との組み合わせデータが領域Ｎ２に属するため、受信した信号Ｂをノイズと判定することができる。   On the other hand, the determination unit 6 determines that the fluctuation frequency q of the correlation value calculated by despreading the signal received at the vehicle speed v is a region N1 where the rate of increase of the fluctuation frequency Q with respect to the vehicle speed V is greater than or equal to a predetermined range. When it belongs to the region N2 that is equal to or less than the predetermined range (that is, when the relationship between the vehicle speed V and the fluctuation frequency Q does not belong to the predetermined proportional range D1), it is considered that the change in the correlation value is not correlated with the vehicle speed. The determined signal is determined as noise. Thereby, since the combination data of the vehicle speed when the signal B is received and the fluctuation frequency calculated based on the signal B belong to the region N2, the determination unit 6 can determine the received signal B as noise.

また、ステップＳ１０４において、変化検出部５は、例えば、相関器３によって算出され記憶部４に記憶された、位相が隣り合う複数の相関値に基づいて、相関値の変化態様を表す状態量として、相関値の変化率を算出してもよい。   Moreover, in step S104, the change detection unit 5 is, for example, a state quantity that represents a change mode of the correlation value based on a plurality of correlation values whose phases are adjacent and calculated by the correlator 3 and stored in the storage unit 4. The rate of change of the correlation value may be calculated.

図８は、相関値の変化率の車速による違いを示した図である。図８は、図６上の点線で囲まれた部分を示している。相関値の変化率Ｒは、単位時間ΔＴ当たりの相関値の変化量ΔＰで表すことができる。車速が速いときに受信した直接波Ａ１に基づいて算出される相関値の変化率は、車速が遅いときに受信した直接波Ａ２に基づいて算出される相関値の変化率に比べて大きい。   FIG. 8 is a diagram illustrating the difference in the change rate of the correlation value depending on the vehicle speed. FIG. 8 shows a portion surrounded by a dotted line in FIG. The correlation value change rate R can be expressed as a correlation value change amount ΔP per unit time ΔT. The change rate of the correlation value calculated based on the direct wave A1 received when the vehicle speed is high is larger than the change rate of the correlation value calculated based on the direct wave A2 received when the vehicle speed is low.

この点に着目して、判定部６は、例えば、実際に検知された車速及び算出された相関値の変化率に基づき、図９に例示される直接波とノイズの判定マップに従って、直接波とノイズの判定を実施する。判定部６は、車速ｖのときに受信した信号を逆拡散することによって算出された相関値の変化率ｒが、車速Ｖに対する変化率Ｒの増加率が所定範囲内である領域Ｄ２に属する場合（すなわち、車速Ｖと変化率Ｒとの関係が所定の比例範囲Ｄ２に属する場合）相関値の変化が車速に相関しているとみなして、受信した信号は直接波と判定する。これにより、判定部６は、上述と同様に、車速が速いときに受信した信号Ａ１も車速が遅いときに受信した信号Ａ２も直接波と判定することができる。   Focusing on this point, for example, the determination unit 6 determines whether a direct wave is detected according to the direct wave and noise determination map illustrated in FIG. 9 based on the actually detected vehicle speed and the calculated correlation value change rate. Perform noise determination. In the case where the change rate r of the correlation value calculated by despreading the signal received at the vehicle speed v belongs to the region D2 in which the increase rate of the change rate R with respect to the vehicle speed V is within a predetermined range. (That is, when the relationship between the vehicle speed V and the rate of change R belongs to the predetermined proportional range D2) The received signal is determined to be a direct wave, assuming that the change in the correlation value is correlated with the vehicle speed. Accordingly, the determination unit 6 can determine that the signal A1 received when the vehicle speed is high and the signal A2 received when the vehicle speed is low are also direct waves, as described above.

一方、判定部６は、車速ｖのときに受信した信号を逆拡散することによって算出された相関値の変化率ｒが、車速Ｖに対する変化率Ｒの増加率が所定範囲以上である領域Ｎ３又は所定範囲以下である領域Ｎ４に属する場合（すなわち、車速Ｖと変化率Ｒとの関係が所定の比例範囲Ｄ２に属さない場合）、相関値の変化が車速に相関していないとみなして、受信した信号はノイズと判定する。これにより、判定部６は、上述と同様に、受信した信号Ｂをノイズと判定することができる。   On the other hand, the determination unit 6 determines that the change rate r of the correlation value calculated by despreading the signal received at the vehicle speed v is a region N3 in which the increase rate of the change rate R with respect to the vehicle speed V is greater than or equal to a predetermined range. When it belongs to the region N4 that is equal to or less than the predetermined range (that is, when the relationship between the vehicle speed V and the rate of change R does not belong to the predetermined proportional range D2), it is considered that the change in the correlation value is not correlated with the vehicle speed. The determined signal is determined as noise. Thereby, the determination part 6 can determine the received signal B as noise similarly to the above-mentioned.

以上、本発明の好ましい実施例について詳説したが、本発明は、上述した実施例に制限されることはなく、本発明の範囲を逸脱することなく、上述した実施例に種々の変形及び置換を加えることができる。   The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

例えば、判定部６は、相関器３によって算出された相関値の変化が車速と相関しているか否かを複数回確認することによって、時間Ｔａ内に受信した信号が直接波であるのかノイズであるのかを判定してもよい。図１０に示されるように、直接波の相関値は車速と相関して変化し、ノイズの相関値は車速と相関無く変化するが、ノイズの形態は時々刻々と変化し、想定外のノイズが発生する場合もありうる。そこで、相関値の変化と車速との相関関係を複数回観測することによって、木陰などで直接波の電波強度が弱くなる場面であっても、自車両が移動中であっても、直接波とノイズをより的確に判別することができる。その結果、直接波を適切に捕捉することができるので、自車両の測位をより高精度に実施することが可能になる。   For example, the determination unit 6 confirms whether or not the change in the correlation value calculated by the correlator 3 correlates with the vehicle speed a plurality of times, thereby determining whether the signal received within the time Ta is a direct wave or noise. You may determine whether there is. As shown in FIG. 10, the correlation value of the direct wave changes in correlation with the vehicle speed, and the correlation value of noise changes without correlation with the vehicle speed. However, the form of the noise changes every moment, and unexpected noise is generated. It can happen. Therefore, by observing the correlation between the change in the correlation value and the vehicle speed multiple times, even if it is a scene where the radio wave intensity of the direct wave becomes weak due to a shade, etc. Noise can be determined more accurately. As a result, the direct wave can be appropriately captured, so that positioning of the host vehicle can be performed with higher accuracy.

図１１は、相関値の変化と車速との相関関係を複数回観測する場合の、本発明の実施形態の測位用受信装置で行われる直接波とノイズの判定方法の一例を示したフローチャートである。ステップＳ１１１〜Ｓ１１３は、図４のステップＳ１０１〜Ｓ１０３と同様のため、説明を省略する。   FIG. 11 is a flowchart illustrating an example of a direct wave and noise determination method performed by the positioning receiver of the embodiment of the present invention when the correlation between the change in the correlation value and the vehicle speed is observed a plurality of times. . Steps S111 to S113 are the same as steps S101 to S103 in FIG.

ステップＳ１１４において、時間Ｔａ内に受信した信号を逆拡散することによって算出された相関値の変化態様を表す状態量が算出されることによって、相関値の変化が検知されるとともに、時間Ｔａ内に信号を受信したときの車速が検知される。   In step S114, a change in the correlation value is detected by calculating a state quantity indicating a change mode of the correlation value calculated by despreading the signal received within the time Ta, and at the time Ta. The vehicle speed when the signal is received is detected.

ステップＳ１１５において、カウンタによるカウントアップが行われ、ステップＳ１１６において、カウンタ値Ｍが所定の定数Ｍｓに達したかどうかが判定される。カウンタ値Ｍは、ステップＳ１１４の実行回数を表す。定数Ｍｓは、一定値でもよいし、車速に応じて決められる回数でもよい。例えば、定数Ｍｓは、車速Ｖに比例するように決められる。例えば、車速が速くなるにつれて定数Ｍｓの設定値は大きくなり、車速が遅くなるにつれて定数Ｍｓの設定値は小さくなる。   In step S115, the counter is incremented, and in step S116, it is determined whether or not the counter value M has reached a predetermined constant Ms. The counter value M represents the number of executions of step S114. The constant Ms may be a constant value or a number determined according to the vehicle speed. For example, the constant Ms is determined to be proportional to the vehicle speed V. For example, the set value of the constant Ms increases as the vehicle speed increases, and the set value of the constant Ms decreases as the vehicle speed decreases.

定数Ｍｓに達していない場合、ステップＳ１１１に戻る。これにより、相関値の変化と車速の検知を時間的にずらして複数回行うことができる。定数Ｍｓに達している場合、カウンタ値はリセットされ（ステップＳ１１７）、判定部６は、車速と相関値の変化の複数回の検知結果に基づいて、相関値の変化が車速と所定の相関関係を有しているか否かを判定する（ステップＳ１１８）。判定部６は、相関値が車速と相関して変化している場合には、受信信号が直接波であると判定し（ステップＳ１１９）、相関値が車速と相関無く変化している場合には、受信信号がノイズであると判定する（ステップＳ１２０）。   If the constant Ms has not been reached, the process returns to step S111. Thereby, the change of the correlation value and the detection of the vehicle speed can be performed a plurality of times while being shifted in time. When the constant Ms is reached, the counter value is reset (step S117), and the determination unit 6 determines that the change in the correlation value is a predetermined correlation with the vehicle speed based on the detection results of the vehicle speed and the change in the correlation value. Is determined (step S118). The determination unit 6 determines that the received signal is a direct wave when the correlation value changes in correlation with the vehicle speed (step S119), and when the correlation value changes without correlation with the vehicle speed. Then, it is determined that the received signal is noise (step S120).

ステップＳ１１８において、判定部６は、例えば、図１０に示されるような信号の各受信タイミングにおける車速及び相関値の変動周波数Ｑ（及び／又は、変化率Ｒ）の検知結果に基づいて、図１２に例示される直接波とノイズの判定マップに従って、直接波とノイズの判定を実施する。例えば、複数の検知結果のそれぞれを当該判定マップに反映することによって得られる判定結果の多数決によって、直接波とノイズの最終的な判定を実施するとよい。これにより、判定部６は、車速ｖのときに受信した信号Ｂｂを逆拡散することによって算出された相関値の変動周波数ｑ２（又は、変化率ｒ２）が、車速Ｖに対する変動周波数Ｑ（又は、変化率Ｒ）の増加率が所定の範囲内である領域Ｄに属する場合であっても、判定結果の多数決を実施することによって、確実に直接波を捕捉することができる。   In step S118, the determination unit 6 performs, for example, based on the detection result of the vehicle speed and the fluctuation frequency Q (and / or the rate of change R) of the correlation value at each signal reception timing as illustrated in FIG. The direct wave and noise are determined according to the direct wave and noise determination map illustrated in FIG. For example, the final determination of the direct wave and the noise may be performed by majority decision of the determination result obtained by reflecting each of the plurality of detection results on the determination map. As a result, the determination unit 6 uses the fluctuation frequency q2 (or rate of change r2) of the correlation value calculated by despreading the signal Bb received at the vehicle speed v as the fluctuation frequency Q (or Even when the rate of increase of the change rate R) belongs to the region D within the predetermined range, the direct wave can be reliably captured by executing the majority of the determination results.

１ アンテナ
２ 高周波回路
３ 相関器
４ 記憶部
５ 変化検出部
６ 判定部 DESCRIPTION OF SYMBOLS 1 Antenna 2 High frequency circuit 3 Correlator 4 Memory | storage part 5 Change detection part 6 Judgment part

Claims (1)

スペクトラム拡散された信号を受信する測位用受信装置であって、
車速に応じて決められた時間内に受信した信号と拡散コードとの相関値を算出する相関器と、
前記相関器によって算出された相関値の変化が車速と相関しているか否かによって、前記時間内に受信した信号が直接波であるのかノイズであるのかを判定する判定部とを備えることを特徴とする、測位用受信装置。 A positioning receiver for receiving a spread spectrum signal,
A correlator for calculating a correlation value between a signal received in a time determined according to the vehicle speed and a spreading code;
A determination unit that determines whether a signal received within the time is a direct wave or noise depending on whether or not a change in a correlation value calculated by the correlator correlates with a vehicle speed. A positioning receiving device.
JP2009289087A 2009-12-21 2009-12-21 Positioning receiver Expired - Fee Related JP5581686B2 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005326198A (en) * 2004-05-13 2005-11-24 Alpine Electronics Inc Gps satellite positioning device and method, and navigation device using them
JP2009060280A (en) * 2007-08-30 2009-03-19 Toyota Motor Corp Transmission device, reception device, wireless communication system, and communication method
JP2009103509A (en) * 2007-10-22 2009-05-14 Toyota Motor Corp Gnss receiving device and positioning method
JP2009129074A (en) * 2007-11-21 2009-06-11 Hitachi Ltd Vehicle information management device, method, and program
JP2009186267A (en) * 2008-02-05 2009-08-20 Yupiteru Corp On-vehicle electronic device and moving locus display system
JP2009250691A (en) * 2008-04-02 2009-10-29 Toyota Motor Corp Gnss positioning apparatus and method

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005326198A (en) * 2004-05-13 2005-11-24 Alpine Electronics Inc Gps satellite positioning device and method, and navigation device using them
JP2009060280A (en) * 2007-08-30 2009-03-19 Toyota Motor Corp Transmission device, reception device, wireless communication system, and communication method
JP2009103509A (en) * 2007-10-22 2009-05-14 Toyota Motor Corp Gnss receiving device and positioning method
JP2009129074A (en) * 2007-11-21 2009-06-11 Hitachi Ltd Vehicle information management device, method, and program
JP2009186267A (en) * 2008-02-05 2009-08-20 Yupiteru Corp On-vehicle electronic device and moving locus display system
JP2009250691A (en) * 2008-04-02 2009-10-29 Toyota Motor Corp Gnss positioning apparatus and method

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