JP3718751B2 - Method and apparatus for guiding unmanned driving vehicles - Google Patents

Description

【００２３】
以下が、上記直線測定式の数学的証明である。ここにおいて、各用語の定義をすれば、垂直線から時計方向（ｃｗ）の角度がプラスの角度である。「半径ｒ」はコイル１８，２０の中心と案内ケーブル１２の中心との間の線／距離として規定される。
「電流」はワイヤー中の電流として規定される。
「周波数」は該電流の周波数として規定される。
「高さｈ」は案内ケーブル１２からコイル１８，２０が移動する水平面までの縦方向距離である。
「距離ｄ（＋／−エラー）」は案内ケーブル１２からコイルの中心までの水平方向に沿う距離である。
「コイル１のアルファ角度」はコイル１（＋４５）の縦方向偏位角度である。
「コイル２のアルファ角度」はコイル２（−４５）の縦方向偏位角度である。
「シータ」は半径と高さの間のエラー角度である。
「ｋ１」は電流、周波数及びインダクタンスに比例するとともに半径に反比例する定数である。
【００２４】
コイル１の信号値＝Ｋ₁×ｓｉｎ（コイル１の角度ベータ）・・・（式１）
コイル２の信号値＝Ｋ₁×ｓｉｎ（コイル２の角度ベータ）・・・（式２）
【００２５】
図からわかるように、コイル１の角度ベータ＝角度シータ−コイル１の角度アルファであり、又、コイル２の角度ベータ＝角度シータ−コイル２の角度アルファである。これは、角度シータ＝コイル１の角度アルファのとき、コイル１の角度ベータはゼロになり、又、角度シータがコイル２の角度アルファのとき、コイル２の角度ベータはゼロになる。
【００２６】
従って、
コイル１の信号値＝Ｋ₁×ｓｉｎ（角度シータ−コイル１の角度アルファ）・・・（式３）
コイル２の信号値＝Ｋ₁×ｓｉｎ（角度シータ−コイル２の角度アルファ）・・・（式４）
【００２７】
三角関数 ｓｉｎ（Ａ−Ｂ）＝ｓｉｎ（Ａ）×ｃｏｓ（Ｂ）−ｃｏｓ（Ａ）×ｓｉｎ（Ｂ）の公式より、
上記の式３，４は以下のように展開される。
【００２８】
すなわち、
コイル１の信号値＝Ｋ₁×（（ｓｉｎ（角度シータ））×ｃｏｓ（コイル１の角度アルファ）−ｃｏｓ（角度シータ）×ｓｉｎ（コイル１の角度アルファ））・・・（式５）
コイル２の信号値＝Ｋ₁×（（ｓｉｎ（角度シータ））×ｃｏｓ（コイル２の角度アルファ）−ｃｏｓ（角度シータ）×ｓｉｎ（コイル２の角度アルファ））・・・（式６）
【００２９】
コイル１の角度アルファ＝＋４５度＋コイル２の角度アルファ＝−４５度
であるから、
ｓｉｎ（コイル１の角度アルファ）＝ｃｏｓ（コイル１の角度アルファ）
＝−ｓｉｎ（コイル２の角度アルファ）＝ｃｏｓ（コイル２の角度アルファ）
ここにおいて、全ての量は２の平方根／２であり、すなわち、これはおおむね０．７０７・・・に等しい。
【００３０】
更に、図２に示された幾何学的構成より以下のことが認められる。
すなわち、ｓｉｎ（角度シータ）＝距離／半径＝ｄ／ｒ
及びｃｏｓ（角度シータ）＝高さ／半径＝ｈ／ｒ
である。
【００３１】
前記式５，６は以下の置き換えにより単純化し得る。
すなわち、
コイル１の信号値＝Ｋ₁×（（ｄ／ｒ）×０．７０７−（ｈ／ｒ）×０．７０７）コイル２の信号値＝Ｋ₁×（（ｄ／ｒ）×０．７０７＋（ｈ／ｒ）×０．７０７）ここで、Ｋ’＝（Ｋ₁×０．７０７）／ｒとすると、
コイル１の信号値＝Ｋ’×（ｄ−ｈ）
コイル２の信号値＝Ｋ’×（ｄ＋ｈ）
となる。
【００３２】
センサの高さ（ｈ）に換算して所望のエラー距離（＋／−ｄ）の値を求めるために、２つのコイル出力が以下の数３の数式のように組合わされる。
【００３３】
【数３】

【００３４】
故に数４の数式が結果として得られる。
【００３５】
【数４】

【００３６】
上記の数式の解法を用いれば、無人運転車両の操縦のための公知装置との組合せで、図３に示すブロック図のように実行される。
【００３７】
図３でわかるように、この解法の実行に必要なのは、単純に加算、減算、除算、乗算のみであり、アナログ又はデジタルの電子部品によって取扱い得る。フィルタリング、ＡＣ復調、アナログ／デジタル（Ａ／Ｃ）変換などの更なる信号処理が容易に実行される。
【００３８】
センサ１６を用いるために、コイル１８，２０の出力は同期して復調されなければならない。これは、符号情報を維持するためである。
【００３９】
図４には、ブロック図の態様で、Ｘ字形のコイルセンサ１６を無人運転車両１０の操縦システムに実施させる一方法が示されている。
【００４０】
図４において、上述したＸ字形のコイル構成例が車両１０の操縦のために設計され、ここにおいて、作動高さ（ｗｏｒｋｉｎｇ ｈｅｉｇｈｔ）は１００ミリアンペアの案内通路（ｇｕｉｄｅ ｐａｔｈ）のケーブル上方、３インチ（７．６２ｃｍ）であり、プラス・マイナス（＋／−）３インチ（７．６２ｃｍ）のハードウエアのガイドセーフ（ｇｕｉｄｅ ｓａｆｅ）を与える。しかし、センサ高さ（ｈ）が、より高いかより低い場合には、以下に記載のソフトウエアのガイドセーフが採用され、それによって、センサ１６が１〜６インチ（２．５４〜１５．２４ｃｍ）の高さ範囲を容易にカバーする。
【００４１】
自動ゲインコントロール（ＡＧＣ）を用いれば、デジタル操縦パッケージ（ｐａｃｋａｇｅ）は、電流範囲が２０〜４００ミリアンペア、高さ範囲が１〜６インチ（２．５４〜１５．２４ｃｍ）及び水平偏位範囲がプラス／マイナス（＋／−）１２インチ（３０．４８ｃｍ）のケーブルを取扱い得る。
【００４２】
狭い周波数レスポンスを有する、いわゆる高Ｑフィルタ（ｈｉｇｈ Ｑ ｆｉｌｔｅｒｓ）及び同期復調器を用いれば、周波数及び相が同期しない外部の全ての信号が拒絶される。しかし、拒絶されない１つの信号は、例えば通路内のリターンカット（ｒｅｔｕｒｎ ｃｕｔ）を有するような同じワイヤーの近傍にある。リターンカットは電気的導通性を与えるために設置されるが、案内通路の一部を構成しないケーブルを意味する。リターンカットは電磁界を歪め、それによってセンサによって検出される零（ｎｕｌｌ）をシフトする。この歪みによって、各ケーブルまでのセンサの距離に直接比例する零シフトを引起こす。例えば、高さが３インチ（７．６２ｃｍ）、リターンカットが２４インチ（６０．９６ｃｍ）の場合、ｎｕｌｌは単一の出力位置（３インチ（７．６２ｃｍ））高さのところで３インチ（７．６２ｃｍ）の３／２４回シフトする。すなわち、３／２４×３＝３／８（インチ）、ここにおいて、シフトの方向はリターンカットの相に依存する。
【００４３】
２つのケーブル間の距離の半分のところで、全てがその結果の円方向ベクトルとしてならず、除算がゼロになる。そして、２０フィート（約６．１ｍ）に近似するリターンカットのために１０〜１２インチ（２５．４〜５０．８ｃｍ）の範囲で直線性も又なくなる。このため、水平偏位プラス／マイナス（＋／−）８インチ（２０．３２ｃｍ）のところで、電流パッケージはセンサの出力信号をプラス／マイナス（＋／−）の最大範囲にまで比例して設定する。
【００４４】
従って、センサ１６によって確認される領域が、左舷及び右舷方向を失うことなく大幅に増大する。これによって、オフ・ワイヤー操縦（ｏｆｆ−ｗｉｒｅ ｍａｎｅｕｖｅｒ）回復手続が改善される。又、直線性及び車両センサ高さのエントリーのための電流供給の大幅な改善により、全ての出力がプラス／マイナス（＋／−）８インチ（２０．３２ｃｍ）の均等の比率となり、これによって、リターン・カットないし路面上でのセンターリングをなす、プラス／マイナス４インチ（１０．１６ｃｍ）のオフ・ワイヤー操縦調整が提供される。
【００４５】
広い検出領域と直線性とが可変のプログラム化されたガイド・セーフ（ｇｕｉｄｅ ｓａｆｅ）限界を与える。この特徴はＡＮＳＩ（アメリカン・ナショナル・スタンダード・インスティテュート）の仕様により、このような動作のためのプラス／マイナス（＋／−）６インチ（１５．２４ｃｍ）のガイド・セーフ・ウインドウが許容されるので、オフ・ワイヤー操縦のモニタリングにおいて極めて有用であることが判明した。インターナル・ハードウエア・フエーズ・コンパレータは基本となるプラス／マイナス（＋／−）ガイド・セーフ出力を提供する。しかし、このウインドウは全てのセンサ高さについてプラス／マイナス（＋／−）３インチ（７．６２ｃｍ）にはセットされない。
【００４６】
Ｘ字形のコイル構成において、プラス／マイナス（＋／−）ガイド・セーフ・ウインドウはワイヤー上方でコイル１８，２０の高さ（ｈ）に等しくなる。すなわち、センサ１６がワイヤーの中心位置で３インチ（７．６２ｃｍ）上方にある。このとき、ガイド・セーフ・ウインドウはプラス／マイナス（＋／−）３インチ（７．６２ｃｍ）となり、もし、ワイヤー深さの変化がプラス／マイナス（＋／−）１／２インチ（１．２７ｃｍ）ならばプラス／マイナス（＋／−）１／２インチ（１．２７ｃｍ）変動する。車両のマイクロプロセッサの制御の下で、デジタル・ステアリング・ソフトウエアがアクティブなガイド・セーフ信号の１つ又は双方をコントロールする。
【００４７】
以上本発明の好ましい実施の形態を図面を参照して説明したが、本発明はこれに限定されることなく、種々の変形構成を含み得るものである。
【００４８】
【発明の効果】
以上のように、本発明によれば、路面に配置した案内ケーブルに沿って無人運転車両を、該案内ケーブルからの車両の横方向の偏位を測定して案内することができ、この種の従来の装置以上にケーブルの検出領域が増大し、かつ、正確な車両操縦が可能となる。
【図面の簡単な説明】
【図１】案内ケーブル上で案内される無人運転車両のフロント側又はリヤ側の概略図である。
【図２】水平に対しておおむねプラス／マイナス４５度の角度で取付けられた本発明に係る第１及び第２のコイル及び交流を担持する案内ケーブルによる電磁界内でのフィールド線及び電圧ベクトルをそれぞれ表わした概要図である。
【図３】検出コイルに生じる種々の電圧及びそれを出力オフセンター距離測定信号に変換する態様を示すブロック図である。
【図４】本発明の一つの実施の形態を具体化した概略のブロック図である。
【符号の説明】
１０ 無人運転車両
１２ 案内ケーブル
１６ センサ
１８ 検出コイル
２０ 検出コイル[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and a method for guiding an unmanned driving vehicle called a so-called driverless vehicle along a guide cable embedded in a road surface, and more particularly to an electromagnetic field regardless of the magnitude of a spatial electromagnetic field. In order to detect the direction vector, two detection coils arranged in an X shape on the vehicle are used, and the lateral displacement of the vehicle with respect to the guide cable is measured using information from this, and the vehicle is moved along the guide cable. It is related with the apparatus and method which steer so
[0002]
[Prior art]
2. Description of the Related Art There is known a device in which a coil arranged in a vertical state is mounted on an unmanned driving vehicle, thereby detecting an electromagnetic field surrounding the guide cable and automatically guiding the unmanned driving vehicle along the guide cable. In this known device, one coil is arranged vertically and the other coil is arranged horizontally. The voltages induced in these coils are compared and used to determine the lateral position of these coils with respect to the guide cable. This position information is processed and used for vehicle operation.
[0003]
The output voltage that cooperates with these coils is the frequency of the current flowing through the guide cable, the amount of current, the distance from the guide cable, the coil core dimensions, the number of turns of the coil, and the main axis of the coil with respect to the wire from the guide cable to the coil It changes in proportion to the angle between them (this is called “beta angle”).
[0004]
As each coil rotates in a plane perpendicular to the cable producing the electromagnetic field, its output is maximized when the core of the coil is parallel to the circular line of magnetic flux. Also, the output is minimized (zero) when the coil core is perpendicular to the magnetic flux, ie, toward or away from the guide cable. Thus, the relative effectiveness of the coils varies as the “sine” of the beta angle.
[0005]
The value of sine (beta) is reflected in the ratio of the radial / circular field detected at each coil position and affects the output of the sensor. Therefore, the difference in the amount detected between the two coils is based on the radial value, the distance between the coils, and the current of the guide cable. Changes in any of these factors have a significant effect on the output signal.
[0006]
Further, depending on the beta angle, some of the radial or circular field information that works with conventional equipment must be discarded, resulting in a signal / noise ratio that is never ideal.
[0007]
A further disadvantage of the conventional coil arrangement is that the information provided by the coil only indicates the approximate lateral deviation from the guide cable, not the measured value or distance of the lateral deviation.
[0008]
Therefore, vehicle steering corrections are only made in the direction opposite to the deflection and are inaccurate.
[0009]
[Problems to be solved by the invention]
An object of the present invention is to provide an apparatus for guiding an unmanned driving vehicle along a guide cable arranged on a road surface and measuring a lateral deviation of the vehicle from the guide cable.
[0010]
Another object of the present invention is to provide an apparatus that guides an unmanned vehicle along a guide cable disposed on a road surface and has an increased cable detection area as compared with a conventional apparatus.
[0011]
Another object of the present invention is to provide a vertically arranged coil that provides center misalignment measurement information for guiding an unmanned vehicle based on a detected deviation from a guide cable arranged on a road surface. The directional excursion is determined only from the direction vector of the electromagnetic field and provides a device having a configuration independent of all electromagnetic field components.
[0012]
Yet another object of the present invention is to provide a method for detecting the direction vector of an electromagnetic field at a single spatial point that provides an error signal defining a measure for guiding an unmanned vehicle on a guide cable placed on the road surface. is there.
[0013]
[Means for Solving the Problems]
In order to achieve the above object of the present invention, in the apparatus according to the present invention for guiding an unmanned driving vehicle along a path defined by a guide cable disposed in a horizontal road surface, the guide cable includes the cable. An electric current that generates an electromagnetic field is carried in the surrounding space, and the apparatus includes a detection unit that detects the direction and magnitude of the electromagnetic field around the guide cable. This detection means is defined by first and second spaced apart detection coils which have a main shaft and are mounted on the vehicle in an X-shape, the main shafts intersecting in the direction of current and against the road surface Each is positioned at an angle of approximately plus / minus 45 degrees. Each detection coil detects the radial and circular field vectors of the electromagnetic field at a predetermined position, and a processor connected to the first and second detection coils converts the radial vector quantity into the circular vector quantity. In comparison, this determines the dimension of the lateral position of the detection means relative to the guide cable.
[0014]
In a direction according to the present invention for guiding an unmanned vehicle along a path defined by a guide cable arranged in a horizontal road surface, the guide cable carries an electric current that generates an electromagnetic field in the space surrounding it. And
A first coil having a main coil axis is mounted on the vehicle at an angle of plus 45 degrees to the horizontal;
A second coil having a main coil axis is mounted on the vehicle at an angle of minus 45 degrees with respect to the horizontal so that the main coil axes of the first and second coils cross in the current direction;
Each coil detects both radial and circular field vectors of the electromagnetic field,
Compare the vector amount in the radial direction and the vector amount in the circular direction, determine the lateral position of the crossing point of the main coil axis of the coil with respect to the center position deviation information of the path
This information is transmitted to the steering assembly to steer the vehicle.
It includes a step consisting of:
[0015]
Other objects, features, and advantages of the present invention will be more readily understood from the embodiments of the present invention described below with reference to the accompanying drawings.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 10 denotes an unmanned driving vehicle, which is a schematic view seen from the front side or the rear side. Reference numeral 12 denotes a guide cable, which is arranged in an embedded state on a horizontal road surface 14, and the unmanned vehicle 10 is guided along the cable 12. The unmanned vehicle 10 is provided with a sensor 16 serving as detection means, and the sensor 16 is constituted by two detection coils 18 and 20. One coil 18 of the coil is arranged at an angle of plus (+) 45 degrees with respect to the road surface 14, and the other coil 20 is arranged at an angle of minus (−) 45 degrees. Here, the terms of plus 45 degrees and minus 45 degrees are for the coil axis relative to the road surface 14 or the horizontal plane or the axis of the core thereof. The axes of both coils 16 and 18 intersect in the current direction. The guide cable 12 carries alternating current and, when undisturbed, has a circular magnetic field line, which generates a voltage in the coils 18 and 20, which is the lateral center position of the vehicle 10 relative to the guide cable 12. The deviation is measured, and then the vehicle 10 is steered along the guide cable 12.
[0017]
Next, a mode in which the unmanned vehicle 10 is guided on the guide cable 12 will be described with reference to FIGS. In FIG. 2, the dotted line represents the circular vector of the magnetic field around the guide cable 12. These magnetic field lines indicate the case where there is no ferromagnetic object in the vicinity of the guide cable 12 and there is no other current carrier that obstructs the line circular section of the magnetic field. The vertical position or height h of the detection coils 18 and 20 is constant.
[0018]
Because of the mounting configuration in which the main axes of the coils 18 and 20 are at an angular position of plus / minus (+/−) 45 degrees with respect to the horizontal, each coil is a horizontal portion of the cylindrical electromagnetic field of the guide cable 12. And an output voltage that is the vector sum of both the vertical part. When the sensor 16 is in the center on the guide cable 12, each coil 18, 20 detects the same amount of signal in the horizontal and vertical directions. However, the sign of each signal is opposite because each coil 18, 20 detects a source on a different side of its main axis. When the sensor 16 is moved laterally to the left or right of the guide cable 12, the output of each coil 18, 20 is the sum of its orientation relative to the horizontal plane (+/− 45 degrees) and the error angle theta in the longitudinal plane. As a function of.
[0019]
The coil signal or coil voltage is maximum when the main axis is perpendicular to the guide cable 12 and is minimum when the main axis is in the direction toward the guide cable 12. Since these coils 18 and 20 move in a plane parallel to the guide cable 12 while cutting their cylindrical electromagnetic field, the form of the output signal is a sine of the beta coil 1 angle or the beta coil 2 angle. Proportional.
[0020]
Accordingly, the true position of the sensor 16 or the error position information of the feedback loop described below is found by dividing or dividing the radial direction vector difference by the sum of the circle vectors detected by both coils 18, 20. The actual sign means the sum of radial direction vectors divided by the circle vector difference. However, in order to maintain hardware phase comparator operation for monitoring guide safe, the polarity of both coils 18, 20 is such that when the sensor 16 is in the center position on the guide cable 12, The output of the coil is selected to be 180 degrees outside the phase. “Guide safe” is an electrical signal indicating that the vehicle operates within a defined safety distance of the guide passage. Thus, when the sensor 16 is in the center position on the guide cable 12, these vectors are equal and of opposite sign, the radial vector cancels in the numerator, while the circular vector adds doubly in the denominator. When the height h remains positive, i.e. when the sensor 16 is above the guide cable 12, the denominator will never be zero, causing an invalid division operation.
[0021]
With respect to FIG. 2, the following equations apply:
Coil 1 signal value = K ₁ × sin (coil 1 angle beta)
Signal value of coil 2 = K ₁ × sin (angle beta of coil 2)
From this, the mathematical formula of Formula 2 is given.
[0022]
[Expression 2]

[0023]
The following is a mathematical proof of the above linear measurement formula. Here, if each term is defined, the angle in the clockwise direction (cw) from the vertical line is a positive angle. “Radius r” is defined as the line / distance between the center of the coils 18, 20 and the center of the guide cable 12.
“Current” is defined as the current in the wire.
“Frequency” is defined as the frequency of the current.
“Height h” is a vertical distance from the guide cable 12 to the horizontal plane on which the coils 18 and 20 move.
“Distance d (+/− error)” is a distance along the horizontal direction from the guide cable 12 to the center of the coil.
“Alpha angle of coil 1” is a longitudinal displacement angle of coil 1 (+45).
The “alpha angle of coil 2” is the vertical deviation angle of coil 2 (−45).
“Theta” is the error angle between radius and height.
“K1” is a constant proportional to the current, frequency, and inductance, and inversely proportional to the radius.
[0024]
Signal value of coil 1 = K ₁ × sin (angle beta of coil 1) (Equation 1)
Signal value of coil 2 = K ₁ × sin (angle beta of coil 2) (Expression 2)
[0025]
As can be seen, the angle beta of coil 1 = angle theta-angle alpha of coil 1 and angle beta of coil 2 = angle theta-angle alpha of coil 2. This is because when the angle theta = the angle alpha of the coil 1, the angle beta of the coil 1 becomes zero, and when the angle theta is the angle alpha of the coil 2, the angle beta of the coil 2 becomes zero.
[0026]
Therefore,
Signal value of coil 1 = K ₁ × sin (angle theta−angle alpha of coil 1) (Equation 3)
Signal value of coil 2 = K ₁ × sin (angle theta—angle alpha of coil 2) (Equation 4)
[0027]
From the formula trigonometric function sin (A−B) = sin (A) × cos (B) −cos (A) × sin (B),
The above equations 3 and 4 are expanded as follows.
[0028]
That is,
Signal value of coil 1 = K ₁ × ((sin (angle theta)) × cos (angle alpha of coil 1) −cos (angle theta) × sin (angle alpha of coil 1)) (Formula 5)
Signal value of coil 2 = K ₁ × ((sin (angle theta)) × cos (angle alpha of coil 2) −cos (angle theta) × sin (angle alpha of coil 2)) (Formula 6)
[0029]
Since the angle alpha of the coil 1 is +45 degrees + the angle alpha of the coil 2 is −45 degrees,
sin (angle alpha of coil 1) = cos (angle alpha of coil 1)
= −sin (angle alpha of coil 2) = cos (angle alpha of coil 2)
Here, all quantities are the square root of 2, ie, this is approximately equal to 0.707.
[0030]
Further, the following can be recognized from the geometrical configuration shown in FIG.
That is, sin (angle theta) = distance / radius = d / r
And cos (angle theta) = height / radius = h / r
It is.
[0031]
Equations 5 and 6 can be simplified by the following replacement.
That is,
Signal value of coil 1 = K ₁ × ((d / r) × 0.707− (h / r) × 0.707) Signal value of coil 2 = K ₁ × ((d / r) × 0.707 + ( h / r) × 0.707) where K ′ = (K ₁ × 0.707) / r,
Signal value of coil 1 = K ′ × (d−h)
Signal value of coil 2 = K ′ × (d + h)
It becomes.
[0032]
In order to obtain the value of the desired error distance (+/− d) in terms of the sensor height (h), the two coil outputs are combined as shown in Equation 3 below.
[0033]
[Equation 3]

[0034]
Therefore, the mathematical formula 4 is obtained as a result.
[0035]
[Expression 4]

[0036]
If the solution of said numerical formula is used, it will carry out like the block diagram shown in FIG. 3 in combination with the well-known apparatus for operation of an unmanned driving vehicle.
[0037]
As can be seen in FIG. 3, all that is required to perform this solution is simply addition, subtraction, division, and multiplication, which can be handled by analog or digital electronic components. Further signal processing such as filtering, AC demodulation, analog / digital (A / C) conversion, etc. is easily performed.
[0038]
In order to use sensor 16, the outputs of coils 18 and 20 must be demodulated synchronously. This is to maintain the code information.
[0039]
FIG. 4 shows a method for causing the maneuvering system of the unmanned driving vehicle 10 to implement the X-shaped coil sensor 16 in the form of a block diagram.
[0040]
In FIG. 4, the X-shaped coil configuration example described above is designed for maneuvering the vehicle 10, where the working height is 3 inches above the cable in a 100 milliamp guide path. 7.62 cm) and provides a plus / minus (+/−) 3 inch (7.62 cm) hardware guide safe. However, if the sensor height (h) is higher or lower, the software guide safety described below will be employed, so that the sensor 16 is 1-6 inches (2.54-15.24 cm). ) Easily cover the height range.
[0041]
With automatic gain control (AGC), the digital steering package has a current range of 20-400 mA, a height range of 1-6 inches (2.54-15.24 cm) and a horizontal deflection range plus / Minus (+/-) 12 inch (30.48 cm) cable can be handled.
[0042]
With so-called high Q filters and synchronous demodulators with a narrow frequency response, all external signals whose frequency and phase are not synchronized are rejected. However, one signal that is not rejected is in the vicinity of the same wire, for example with a return cut in the passage. A return cut refers to a cable that is installed to provide electrical continuity but does not form part of the guide passage. The return cut distorts the electromagnetic field, thereby shifting the null detected by the sensor. This distortion causes a zero shift that is directly proportional to the distance of the sensor to each cable. For example, if the height is 3 inches (7.62 cm) and the return cut is 24 inches (60.96 cm), null is 3 inches (7 inches) at a single output position (3 inches (7.62 cm)) height. .62 cm) for 3/24 times. That is, 3/24 × 3 = 3/8 (inch), where the shift direction depends on the return cut phase.
[0043]
At half the distance between the two cables, not all result in a circular vector and the division is zero. And the linearity also disappears in the range of 10-12 inches (25.4-50.8 cm) due to a return cut approximating 20 feet (about 6.1 m). For this reason, at horizontal deviation plus / minus (+/−) 8 inches (20.32 cm), the current package sets the output signal of the sensor in proportion to the maximum range of plus / minus (+/−). .
[0044]
Accordingly, the area identified by the sensor 16 is greatly increased without losing the port and starboard directions. This improves the off-wire maneuver recovery procedure. In addition, due to the significant improvement in current supply for entry of linearity and vehicle sensor height, all outputs have an equal ratio of plus / minus (+/-) 8 inches (20.32 cm), A plus / minus 4 inch (10.16 cm) off-wire steering adjustment is provided that provides a return cut or centering on the road surface.
[0045]
Wide detection area and linearity provide a programmable guide safe limit with variable. This feature is due to the ANSI (American National Standard Institute) specification allowing a plus / minus (+/-) 6 inch (15.24 cm) guide-safe window for such operation. , Proved extremely useful in off-wire maneuvering monitoring. The internal hardware phase comparator provides a basic plus / minus (+/-) guide safe output. However, this window is not set to plus / minus (+/−) 3 inches (7.62 cm) for all sensor heights.
[0046]
In an X-shaped coil configuration, the plus / minus (+/−) guide safe window is equal to the height (h) of the coils 18, 20 above the wire. That is, the sensor 16 is 3 inches (7.62 cm) above the center of the wire. At this time, the guide safe window becomes plus / minus (+/−) 3 inches (7.62 cm), and if the change of the wire depth is plus / minus (+/−) 1/2 inches (1.27 cm). ) Will change plus / minus (+/−) 1/2 inch (1.27 cm). Under control of the vehicle's microprocessor, digital steering software controls one or both of the active guide safe signals.
[0047]
Although the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to these and can include various modifications.
[0048]
【The invention's effect】
As described above, according to the present invention, an unmanned driving vehicle can be guided along a guide cable arranged on a road surface by measuring the lateral deviation of the vehicle from the guide cable. The detection area of the cable is increased as compared with the conventional apparatus, and accurate vehicle operation is possible.
[Brief description of the drawings]
FIG. 1 is a schematic view of a front side or a rear side of an unmanned driving vehicle guided on a guide cable.
FIG. 2 shows field lines and voltage vectors in an electromagnetic field by first and second coils and guide cables carrying alternating current according to the present invention mounted at an angle of approximately plus / minus 45 degrees to the horizontal. FIG.
FIG. 3 is a block diagram showing various voltages generated in a detection coil and how they are converted into output off-center distance measurement signals.
FIG. 4 is a schematic block diagram embodying one embodiment of the present invention.
[Explanation of symbols]
10 Unmanned Driving Vehicle 12 Guide Cable 16 Sensor 18 Detection Coil 20 Detection Coil

Claims (11)

An apparatus for guiding an unmanned driving vehicle along a path defined by a guide cable arranged in a horizontal road surface, wherein the guide cable carries an electric current for generating an electromagnetic field in a space surrounding the cable. In
Detecting means for detecting the direction and magnitude of the electromagnetic field;
The detection means has first and second detection coils provided in the longitudinal direction with an X-shaped coil configuration on the vehicle, and the main coil shafts of these coils are seen in the longitudinal direction of vehicle travel. Crossing each other at the center of both coils and being disposed at an angle of approximately plus / minus 45 degrees with respect to the road surface;
Each of the detection coils detects a magnetic field vector in both a radial direction and a circular direction of the electromagnetic field;
A comparison unit that cooperates with the first and second detection coils to compare a circular vector amount and a radial vector amount to determine a lateral position of the detection unit with respect to the guide cable;
A device for guiding an unmanned driving vehicle. The apparatus of claim 1, wherein the first and second coils have a core length and a core diameter, and the space between the coils is at least equal to one core length. The board further includes a mounting board fixed to the vehicle, the first detection coil being attached to the first side surface of the board at an angle of plus 45 degrees, and the second detection coil being attached at an angle of minus 45 degrees. 2. The device of claim 1, wherein the device is attached to the second side surface of the device. The comparison means divides the detected radial vector of the electromagnetic field by the circular vector, whereby the ratio is divided by the height of the detection means on the guide cable. The apparatus of claim 2, wherein the apparatus is proportional to the position. The apparatus of claim 4 further comprising steering means associated with the comparing means for steering the vehicle in response to an output received from the comparing means. 6. A device according to claim 5, wherein the steering means comprises a digital steering system. 6. A device according to claim 5, wherein the steering means comprises an analog steering system. A method for guiding an unmanned driving vehicle along a path defined by a guide cable arranged in a horizontal road surface, wherein the guide cable carries an electric current for generating an electromagnetic field in a space surrounding the cable. In
Mounting a first coil having a main coil axis at an angle of plus 45 degrees to the horizontal on the vehicle;
A second coil having a main coil axis is mounted on the vehicle at an angle of plus 45 degrees with respect to the horizontal, and the main coil axes of the first and second coils are both viewed in the longitudinal direction of the vehicle travel. Cross each other in the middle of the coil,
Each coil detects both radial and circular vectors of the electromagnetic field,
Comparing the radial direction vector quantity and the circular direction vector quantity for each coil such that the lateral position of the crossing point of the coil is determined with respect to the guide cable and indicates the lateral deviation of the vehicle with respect to the passage;
A method for guiding a driving vehicle. The method according to claim 8, wherein the second coil attachment is performed by separating the two coils by at least one coil core length apart in the longitudinal direction. 10. The method of claim 9, further comprising communicating the lateral deviation information to a controller for vehicle steering. The lateral position of the crossing point of the coil axis is defined by the following mathematical formula (1):

In the above mathematical formula 1,
“Distance (+/− error)” indicates the horizontal distance from the guide cable to the coil center, and “Height” indicates the vertical distance from the guide cable to the horizontal plane to which the coil can move.
The method of claim 8.

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