JP3606032B2 - Axle detection device and passage fee calculation device - Google Patents

Description

【００５２】
ここで、（ｘ_ｉ，ｙ_ｉ）は、算出されたスポット光の座標、（ｘ_{ｉＭｏｄｅｌ}，ｙ_{ｉＭｏｄｅｌ}）は、予め記憶されたタイヤの座標である。
【００５３】
このように道路を横切るように光束を走査し、その反射光を受光して反射点に応じた位置のデータを算出し、この算出された位置データと、予め記憶されている車軸の基準位置データとを比較して車軸を検出するので、一走査毎の位置データによって車軸を検出できることになり、高速処理が可能となる。
【００５４】
しかも、路面に埋設する必要がなく、通行止めをすることなく設置が可能で、メンテナンスが容易である。また、道路の片側のみに設置すればよく、省スペース化を図ることができる。
【００５５】
上述の実施の形態では、予め記憶された車両のタイヤが存在するときの基準位置データであるモデルデータと、算出された位置データとを比較して車軸を検出したけれども、本発明の他の実施の形態として、図５（Ａ）に示されるような車両が存在しない路面に光束を走査した場合の路面の位置データを予め記憶しておき、この路面の位置データと車軸検出演算部４８で演算された位置データとの差分、すなわち、高さ情報を算出し、この高さ情報のみをモデルデータと比較して車軸を検出するようにしてもよく、この場合には、高さ情報のみの処理となるので処理すべきデータ数が削減されて一層高速な処理が可能となる。
【００５６】
また、車軸検出装置１を設置したときに、路面の位置データを基礎データ記憶部４７に記憶させるための初期設定用のスイッチを、基礎データ記憶部４７が実装されている回路に取り付け、車軸検出装置１の設置時には、路面を数回走査し、そのときの位置データの平均値を路面の基準となる位置データとして記憶しておくようにしてもよい。これによって、設置場所に即した路面の位置データを記憶できるとともに、数走査分の平均値を用いることによって、バラツキの影響が少なく、精度の高い車軸検出が可能となる。
【００５７】
さらに、本発明の他の実施の形態として、設置時に、予め路面の位置データを記憶しておき、車軸検出演算部４８で路面と判定されたときには、得られた路面の位置データと予め記憶されている路面の位置データとの平均を算出してそれを新たな位置データとして更新記憶するようにして、例えば、轍などの路面の変化に対応できるようにしてもよい。あるいは、設置時に予め記憶した路面の位置データと計測された路面の位置データとを比較することにより、路面形状の経時変化が測定できることになり、轍などを検出して路面の修復を適切なタイミングで行えるようにしてもよい。
【００５８】
また、本発明の他の実施の形態として、基礎データ記憶部４７に、路面の位置データに加えて、路面の受光量を予め記憶させ、この受光量データを用いて投光パワーを調節してもよい。すなわち、検出した受光量と記憶している受光量とを比較し、受光量が、天候や光学窓の汚れなどのために減少したときは、投光パワーを増加させ、例えば記憶している受光量と等しくなるように制御するのである。これによって、常に安定した受光量を得ることができるので、環境に左右されない安定した検出が可能となる。
【００５９】
また、本発明の他の実施の形態として、例えば、雨天時などの車の泥跳ねや水しぶきにより光学窓が汚れ、あるいは、経時的に光学窓に汚れが付着して受光量があるレベル以下となる状態が数走査以上連続的に続いたときには、異常信号を出力するように構成してメンテナンスのタイミングを知らせ、これによって誤動作を未然に防止できるようにしてもよい。
【００６０】
本発明の他の実施の形態として、図９に示されるように、車軸検出装置１_１の前面部に光学窓４３，４４を有する開閉扉４９を設けた構成とし、都市部の高速道路の高欄などに埋め込み設置した後のメンテナンスを容易に行えるようにしてもよい。
【００６１】
本発明の他の実施の形態として、車軸検出装置１が縁石上に設置されるような場合には、図１０に示されるように、縁石５０に切り込み５１を形成して受光視野を広げるのが好ましい。
【００６２】
上述の実施の形態では、車軸検出装置１を、車両の進行方向に垂直に設置したけれども、本発明の他の実施の形態として、車軸検出装置１_２を、車両５２の進行方向に垂直ではなく、図１１および図１２に示されるように、進行方向に対して傾きをもって設置し、ボディに映り込む迷光の影響を低減するようにしてもよい。
【００６３】
本発明の他の実施の形態として、タイヤが検出されている期間と車速とによってタイヤサイズを検出できるように構成してもよい。車軸検出モジュール７でタイヤを検出している期間Ｔ１、すなわち、タイヤであると判定された走査が連続している期間は、図１３に示されるように、車軸検出信号が出力されており、この期間は、車軸検出装置１の前を通過するタイヤ５３の通過時間に相当するので、車両４の車速を用いて、（タイヤの検出期間）×（車速）の演算を行うことにより、タイヤ５３の大きさ、すなわち、タイヤサイズを検出できることになり、大型車や小型車の車種判別に用いることができる。
【００６４】
なお、車速の検出は、例えば、図１４に示されるように、本車軸検出装置１を、もう一台車両の進行方向に一定距離離れた地点に設置し、各装置１，１の車軸検出のタイミングの時間差を測定し、この時間差と装置１，１間の距離とから車速を演算するようにしてもよいし、別に車速センサを設けてもよい。また、図１４のように、車軸検出装置を２台設置することにより、前後進の判別も行える。なお、道路を挟んで両サイドに車軸検出装置１，１を設置してもよい。
【００６５】
本発明のさらに他の実施の形態として、図１５に示されるように、車軸検出の時間間隔Ｔを計測し、（車軸検出の時間間隔）×（車速）の演算を行うことにより、車両４の車軸と車軸との間の距離、すなわち、軸距を検出できるように構成してもよい。図１５の時間間隔は、１軸目の車軸（タイヤ）５４の検出期間の１／２と、２軸目の車軸（タイヤ）５５の検出期間の１／２と、１軸目の車軸５４が検出されなくなってから２軸目の車軸５５の検出が開始されるまでの期間の和として算出でき、あるいは、車軸検出信号の立ち上がりから立ち上がりまでの期間あるいは立ち下がりから立ち下がりまでの期間として算出してもよい。
【００６６】
また、本発明の他の実施の形態として、予め記憶している路面の位置データと、算出された位置データとの差分をとって高さ情報が得られるか否かを判定することにより、車両の有無を検出してもよい。すなわち、高さ情報があるときには、車両有りと判定し、高さ情報がないときには、車両無しと判定するものである。さらに、車両有りと判定されている期間において、車軸を検出する回数を計数することにより、車両の軸数を検出するようにしてもよい。
【００６７】
さらに、車軸検出装置１を、自動料金収受システムに適用してもよい。
【００６８】
自動料金収受システムにおいては、料金収受処理を行う車載機を搭載した車両が、道路料金所ブースを通過すると、車載機と路側システムとの間で交信して料金の決済を行うのであるが、交信の際の車両情報が、車軸検出装置によって検出された軸数と異なるときには、車種が一致しないとして料金収受処理を行わないようにして不正防止を図るようにしてもよい。
【００６９】
また、車軸検出装置で検出された軸数、軸距およびタイヤサイズ等の車軸データに基づいて、車種を判別し、車種に応じた通行料金を算出するようにしてもよい。
【００７０】
本発明の他の実施の形態として、路面の位置データと車両のボディの位置データとに基づいて、路面からボディまでの高さを計測し、この高さが法定の高さに違反しているときには、それを報知するようにしてもよい。
【００７１】
また、本発明の検出装置と、例えば、透過型の光電センサを鉛直方向に並設した車両検出センサ（車両分離センサ）とを組み合わせて、車両検出センサで車両が検出されていないにも拘わらず、本発明の検出装置で高さ情報が得られた時、すなわち、何らかの物体が検出された時には、路上に車両以外の落下物などが存在していると判定して報知するようにしてもよい。
【００７２】
上述の実施の形態では、車軸の検出に適用して説明したけれども、本発明は、車軸に限るものではなく、種々の対象物を検出できるものである。
【００７３】
上述の実施の形態では、位置データとして、ＸＹ座標の値を用いたけれども、本発明の他の実施の形態として、受光手段から反射点までの距離データまたは受光手段から見た反射点の方向を示す方向データを位置データとして用いてもよい。
【００７４】
【発明の効果】
以上のように本発明によれば、予めタイヤなどの検出すべき対象物に対応する基準位置データを記憶しておき、受光した反射光の受光位置から算出される位置データと、前記基準位置データとを比較することにより、対象物を検出するので、設置やメンテナンスが容易で、しかも、精度高く対象物を検出できる。
【００７５】
また、少なくとも近傍と遠方とに対応した複数の受光手段を備えているので、広い検出範囲で対象物を確実に検出することができる。
【００７６】
さらに、ケースの窪み部に光学窓を設置しているので、光学窓が雨や泥なとが付着しにくくなるとともに、周囲光が入射しにくくなり、高精度で検出できる。
【００７７】
また、投光手段による投光方向を、対象物の移動方向に対して直交しないように前記移動方向に対して傾けて設置したので、対象物以外で反射した迷光の影響を低減できることになる。
【００７８】
また、対象物が検出されている検出期間と、対象物の速度とから対象物の大きさを検出することができ、例えば、タイヤサイズを検出することができる。
【００８０】
また、本発明の検出装置によって検出される車軸の検出間隔と車速とによって軸距離を検出できることになる。
【００８１】
また、本発明の検出装置によって検出される車両および車軸に基づいて車両の軸数を検出できることになる。
【００８２】
さらに、本発明の検出装置によって検出された車軸データに基づいて車種を判別して車両の通過料金を算出することができる。
【図面の簡単な説明】
【図１】本発明に係る車軸検出装置が設置された料金所の概略図である。
【図２】図１の車軸検出装置の概略断面図である。
【図３】図１の車軸検出装置のブロック図である。
【図４】本発明を説明するための光束の軌跡を模式的に示した図である。
【図５】図４の光束の軌跡の位置をＸＹ座標で示した図である。
【図６】図３の走査タイミング回路を示す図である。
【図７】光学窓の設置状態を示す概略断面図である。
【図８】ＸＹ座標への座標変換を説明するための図である。
【図９】本発明の他の実施の形態の斜視図である。
【図１０】本発明のさらに他の実施の形態の斜視図である。
【図１１】本発明のさらに他の実施の形態の斜視図である。
【図１２】図１１の実施の形態の設置状態を示す図である。
【図１３】タイヤサイズの検出を説明するための図である。
【図１４】車速の検出のための設置状態を示す図である。
【図１５】軸距の検出を説明するための図である。
【符号の説明】
１，１_１，１_２ 車軸検出装置
４，５２ 車両
５ 投光モジュール
６ 受光モジュール
７ 車軸検出モジュール
１１ 筺体
１２ 路面
１５，５３，５４，５５ タイヤ
１７ ボディ
４３，４４ 光学窓[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a detection device suitable for detecting an object such as a tire (axle) of a vehicle, for example, a vehicle measurement device, an axle detection device, and a passage fee calculation device using the detection device. The present invention relates to a detection device, a vehicle measurement device, an axle detection device, and a passage fee calculation device suitable for a toll collection system that detects a vehicle axle in a toll parking lot or the like, discriminates a vehicle type based on the detected vehicle axle, and collects a fee.
[0002]
.
[Prior art]
In toll collection systems such as toll roads and toll parking lots, the vehicle type of the passing vehicle is determined and a fee is collected according to the vehicle type. As a method of automatically discriminating the vehicle type, there is a method of detecting the number of axles of the vehicle (the number of tires in the traveling direction) and discriminating from the number of axles.
[0003]
As this type of conventional axle detection device, a tread board is embedded in the road and the axle is detected by turning on / off the tread board switch. The vicinity of the tire of the passing vehicle is imaged by a camera, and the tire contour is image recognition processing. There is something to detect (Japanese Patent Laid-Open No. 3-260897).
[0004]
[Problems to be solved by the invention]
Of the conventional axle detection devices described above, those that use the footboard switch must embed the footboard on the road, so when installing the equipment, long-time vehicle closure is required, and a toll booth is installed on the viaduct It is difficult to use on highways. In addition, since the measurement with the tread is a contact method performed by stepping on the tire, the service life is remarkably short, and there is a problem that the tread must be periodically replaced during the operation period.
[0005]
In addition, the method of recognizing the outline of a tire by image processing by reading the image of the vehicle with a camera is difficult to recognize the boundary between the tire and other body parts and the road surface, and requires very high accuracy for image processing. There is a problem.
[0006]
The present invention has been made in view of the above-described points, and is a detection device that is easy to install and maintain, can accurately detect an object such as a tire, a vehicle measurement device, and an axle detection device using the detection device. And it aims at providing a passage charge calculation device.
[0007]
[Means for Solving the Problems]
The present invention is configured as follows in order to achieve the above-described object.
[0008]
That is, the axle detection device of the present invention according to claim 1 is:A light projecting means for scanning a light beam along a road crossing direction with respect to a road surface or a vehicle, a light receiving means for receiving a reflected light beam of the scanned light beam, and a position corresponding to a reflection point reflected by the road surface or the vehicle The coordinate conversion means for calculating the coordinates to XY coordinates, the axle detection means for detecting the axle based on the coordinate-converted position data, and the respective means are controlled, and the axle detection result is communicated to an external device. Control means for performing communication control for the vehicle, the axle detection device comprising an XY coordinate pattern when the vehicle is not present and an XY coordinate when the vehicle tire is present And the pattern of the XY coordinates when the vehicle body exists, the presence of the vehicle tire is detected, and the detection result is referred to as the axle detection result.To do.
[0009]
Claim 2 of the present inventionaxleIn the configuration of the first aspect, the detection device includes a plurality of the light receiving units whose light receiving surfaces face in different directions, and the plurality of light receiving units are separated from the light receiving unit facing the vicinity of the detection device. Directed light receiving means.
[0010]
Claim 3 of the present inventionaxleThe detection device includes a case in which at least the light projecting unit and the light receiving unit are accommodated in the configuration according to claim 1, wherein the case has a hollow portion that is recessed inwardly. The light receiving means projects and receives light through optical windows installed in the recess.
[0011]
Claim 4 of the present inventionaxleThe detection device according to any one of claims 1 to 3, wherein the light projecting direction of the light projecting unit is inclined with respect to the moving direction so as not to be orthogonal to the moving direction of the object. It is.
[0012]
Claim 5 of the present inventionaxleThe detection apparatus according to any one of claims 1 to 4, wherein a detection period measuring means for measuring a period during which the object is detected, a speed detection means for detecting the speed of the object, and the detected object And a size calculating means for calculating the size of the object from the measured speed and the measured detection period.
[0014]
Claim6Of the present inventionaxleThe detection device according to any one of claims 1 to 5.axleDetector and thisaxleAn axial distance is calculated from a detection interval measuring means for measuring an axle detection interval as an object detected by the detection device, a vehicle speed detecting means for detecting a vehicle speed, and the detected vehicle speed and the measured axle detection interval. And an axial distance calculating means.
[0015]
Claim7An axle detection device according to the present invention is any one of claims 1 to 5.axleDetector and thisaxleA number-of-axis measuring means for measuring the number of axes based on the detection output of the vehicle and the axle from the detection device is provided.
[0016]
Claim8The passage fee calculation device of the present invention according to any one of claims 1 to 5axleDetector and thisaxleCharge calculation means for calculating a vehicle passage charge based on axle data detected by the detection device.
[0017]
According to the first aspect of the present invention, reference position data corresponding to an object to be detected such as a tire is stored in advance, position data calculated from a light receiving position of the received reflected light, and the reference position data. Is detected, the installation and maintenance is easy, and the object can be detected with high accuracy.
[0018]
According to the present invention of claim 2, since the plurality of light receiving means corresponding to at least the near position and the far position are provided, the object can be reliably detected in a wide detection range.
[0019]
According to the third aspect of the present invention, since the optical window is installed in the recess of the case, rain and mud are less likely to adhere to the optical window, and ambient light is less likely to enter, with high accuracy. It can be detected.
[0020]
According to the fourth aspect of the present invention, since the light projecting direction by the light projecting unit is inclined with respect to the moving direction so as not to be orthogonal to the moving direction of the target object, stray light reflected from other than the target object The influence of can be reduced.
[0021]
According to the present invention of claim 5, the size of the object can be detected from the detection period in which the object is detected and the speed of the object.
[0023]
Claim6According to the present invention, the axial distance can be detected by the detection interval of the axle detected by the detection device of the present invention and the vehicle speed.
[0024]
Claim7According to the present invention, the present inventionaxleThe number of axles of the vehicle can be detected based on the vehicle and axle detected by the detection device.
[0025]
Claim8According to the present invention, the present inventionaxleBased on the axle data detected by the detection device, the vehicle type can be determined and the vehicle passage fee can be calculated.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0027]
FIG. 1 is a schematic view showing a state in which an axle detection device 1 according to one embodiment of the present invention is installed at a toll gate.
[0028]
The axle detection device 1 of this embodiment is provided near the entrance on the island 3 where the toll booth 2 is installed, and for determining the vehicle type of the passing vehicle 4, the axle ( The number of tires) is detected as described below.
[0029]
FIG. 2 is a schematic cross-sectional view of the axle detection device 1, and FIG. 3 is a block diagram showing its internal configuration.
[0030]
The axle detection device 1 according to this embodiment is scanned with a light projecting module 5 that scans a light beam with respect to the road surface 12 or the vehicle 4 along the direction across the road, that is, perpendicular to the traveling direction of the vehicle 4. A light receiving module 6 that receives a reflected light beam of the reflected light beam and calculates the center of gravity of the light amount, and triangulation from the light amount center of gravity, the distance and direction from the spot of the light beam irradiated to the road surface or the vehicle to the light receiving optical system, that is, the road surface or A position corresponding to the reflection point reflected by the vehicle is calculated and coordinate-converted into XY coordinates. Based on the coordinate-converted position data and model data which is reference position data corresponding to an axle (tire) stored in advance. An axle detection module 7 that detects the axle, and a control module 8 that controls each part and performs communication control for communicating the axle detection result to an external device; A power supply 9 supplies power to each unit, and is configured from a casing for accommodating them (case).
[0031]
Here, the basic concept of axle detection according to this embodiment will be described.
[0032]
FIG. 4 is a diagram schematically showing the trajectory of the light beam for one scan when the light beam is scanned with respect to the road surface 12 or the vehicle (tire, body) 4, and when the vehicle 4 does not exist in the scanning region. The spot light spot 14 of the light beam is all irradiated on the road surface 12, and when the tire 15 of the vehicle 4 is present in the scanning region, the spot light spot 16 of the light beam is irradiated on the road surface 12, When the body 17 of the vehicle 4 is present in the scanning region, the spot light spot 18 of the light beam is irradiated on the road surface 12 and The part is irradiated to the body 17 located away from the road surface 12.
[0033]
FIG. 5 is a diagram in which the position data of these spot light spots, that is, the position data of the reflection points are expressed in XY coordinates. When the vehicle 4 does not exist, all the spot light spots 14 of the luminous flux are irradiated onto the road surface. Therefore, as shown in FIG. 5A, the coordinates in the Y-axis direction are all 0, there is no height component, and change along the X-axis direction, and the tire 15 of the vehicle 4 exists. In this case, the spot light spot 16 of the light beam is irradiated on the road surface 12 and continuously irradiated upward from the middle of the tire 15 as shown in FIG. When the vehicle body 17 is present, the spot light spot 18 of the light beam is irradiated on the road surface 12 and partly when the vehicle body 17 is present. Is away from the road 12 Since the irradiated upward of the body 17, with varying along the X-axis direction will vary in the Y-axis direction at intervals in the middle.
[0034]
Thus, the pattern of the position data corresponding to the reflection point obtained when the light beam is scanned on the road surface 12, the tire 15 of the vehicle 4 or the body 17 of the vehicle 4 is clearly different. Therefore, in this embodiment, the position data of the reflection point as shown in FIG. 5B obtained when scanning the light beam in the state where the vehicle tire is present is stored in advance as model data for reference. When the position data of the spot light spot of the light beam is measured and the pattern of the measured position data is similar to the pattern of the model data when there is a tire stored in advance, The tire is determined to be a tire, that is, the axle is detected.
[0035]
Referring to FIG. 3 again, the light projecting module 5 converts a laser diode (LD) 19, an LD driving circuit 20 that drives the laser diode 19 to perform pulse modulation, and light emitted from the laser diode 19 into parallel light. A projection lens (collimator) 21, a polygon mirror 22 that scans the parallel light converted by the projection lens 21 along the road crossing direction, a polygon motor drive circuit 23 that rotates the polygon mirror 22, and each scan. And a scanning timing circuit 24 for generating the above timing.
[0036]
As a means for scanning the spot light, a plane mirror may be reciprocally rotated by a galvano motor.
[0037]
The scanning timing circuit 24 includes a sensor unit 25 and a timing generation unit 26 as shown in FIG. 6, and the sensor unit 25 projects a light projecting circuit 27 that projects light toward the polygon mirror 22, a light projecting element 28, and the like. A light projecting unit including a light projecting lens 29 and a light receiving unit including a light receiving lens 30 that receives reflected light from the polygon mirror 22, a light receiving element 31, and a light receiving circuit 32 are provided. Since the polygon mirror 22 is rotated as indicated by an arrow A, the reflected light is applied to the light receiving unit only when the polygon mirror 22 is positioned at a certain angle as shown in FIG. Incident. Therefore, the light receiving unit outputs a signal when the reflected light is incident once per scan. Note that the scan timing circuit may generate a timing signal for each scan using an encoder.
[0038]
In this embodiment, as shown in FIG. 2, the light receiving module 6 is provided with two light receiving means 33 and 34 corresponding to the vicinity and the distance, and each light receiving means 33 and 34 is shown in FIG. As shown, optical filters 35 and 36, PSDs (Positive Sensitive Devices) 37 and 38 as light receiving elements that receive the reflected light beam of the scanned light beam, and an optical lens 39 that condenses the reflected light beam on the PSDs 37 and 38, respectively. , 40 and center-of-gravity calculation circuits 41, 42 for calculating the center of light intensity of the reflected light flux. The lens diameter of the light receiving means 34 corresponding to the far detection area S2 shown in FIG. 2 is larger than the lens diameter of the light receiving means 33 corresponding to the detection area S1 in the vicinity. Further, in this embodiment, light is projected from above and received by the lower light receiving means 33 and 34, thereby increasing the amount of light received by the light receiving means to improve detection accuracy.
[0039]
Each center-of-gravity calculation circuit 41, 42 has two outputs v from PSDs 37, 38.₁, V₂Are amplified after current-voltage conversion, respectively (v₁-V₂) / (V₁+ V₂) Is performed, and the light intensity centroid collected on the PSD as the calculation result is calculated.
[0040]
When a CCD or PD array is used as the light receiving element, the light quantity centroid is calculated by using the distribution of the amount of received light on the element in the centroid calculating circuit.
[0041]
In this embodiment, as shown in FIG. 7, the casing 11 that houses each module has upper and lower recessed portions 11 a and 11 b in which a part of the surface on the road surface is recessed inward. An optical window 43 desired for the polygon mirror 22 of the light projecting module 5 is obliquely installed in the upper depression 11a, while an optical window 44 desired for the two light receiving means 33 and 34 is provided in the lower depression 11b. Is installed diagonally.
[0042]
In this way, since light is projected or received through the optical windows 43 and 44 installed in the recesses 11a and 11b of the housing 11, rain and mud are not easily attached, and ambient light is difficult to enter, and accuracy is improved. High detection is possible. Further, by applying a coating having a photocatalytic effect to the optical windows 43 and 44, dirt due to exhaust gas, rain, etc. may be easily removed.
[0043]
Referring again to FIG. 3, the axle detection module 7 includes three blocks including a center-of-gravity data storage unit 45, 46, a basic data storage unit 47, and an axle detection calculation unit 48.
[0044]
The center-of-gravity data storage units 45 and 46 store the light amount center-of-gravity data output from the light receiving module 6 for each scan using information from the scanning timing circuit 24. The centroid data storage units 45 and 46 can be realized by a dual port memory.
[0045]
The basic data storage unit 47 stores parameter values for use in distance calculation / axle determination and the tire model data described above, and transfers the stored contents to the axle detection calculation unit 48 when necessary. As the basic data storage unit 47, for example, RAM or ROM is used. If the EEPROM is used, the retained data can be easily changed even after the axle detection device is installed in the field, which facilitates maintenance and the like.
[0046]
The axle detection calculation unit 48 constituted by a DSP or MPU stores the light intensity barycentric data for each scan stored in the barycentric data storage units 45 and 46, the signal of the scanning timing circuit 24, and the basic data storage unit 47. The detected parameter value is used to calculate the axle, and the detection result is output to the control module 8. The calculation for detecting the axle uses the sum of the squares of the Euclidean distance between the position data and the tire model data as a correlation value, and when this value becomes similar to the threshold level, the tire is detected as the axle. Is.
[0047]
The operation of the axle detection calculation unit 48 will be described in more detail. First, the coordinates of the spot light spot of the light beam connected to the road surface or the vehicle, that is, the position of the reflection point, based on the light intensity centroid data and the parameter value for calculation. The position data converted into XY coordinates is calculated.
[0048]
Derivation of this X, Y coordinate conversion formula will be described.
[0049]
As shown in FIG. 8, the center of the PSD light receiving surface is defined as Q (x_Q, Y_Q), The imaging point of the laser spot light on the PSD light-receiving surface is P_o(X_Po, Y_Po), The laser spot light spot on the object surface, that is, the reflection point is represented by P (x_P, Y_P), The center of the light receiving lens (optical lens) as S (0, h₁), The laser spot light spot on the polygon mirror surface is represented by O (x_O, H₂), The distance between the center of the light receiving lens and the center of the PSD is f, and the inclination of the light receiving lens measured from the horizontal component is β_o, The length of the PSD light-receiving surface is l, and the inclination of the PSD light-receiving surface measured from the horizontal component is η_OThen,
The coordinates of the point Q are Q (x_Q, Y_Q) = (− F cos β_o, H₁+ Fsin β_o)
PSD output v₁, V₂Then, Δl is from the characteristics of PSD,
Δl = (l / 2) · {(v₁-V₂) / (V₁+ V₂)}
P_oThe coordinates of P are_o(X_Po, Y_Po) = (X_Q+ Δlcosη_O, Y_Q+ Δlsinη_O) = (− F cos β_o+ Δlcosη_O, H₁+ Fsin β_o+ Δlsinη_O)
Straight line P_OS is
yh₁= {(Y_Po-H₁) / X_Po} X
Therefore, y = {(y_Po-H₁) / X_Po} X + h₁            ...... (1)
The straight line OP is
yh₂= Tan (−α) (xx_O)
The coordinates of P are (x_P, Tan (−α) (x_P-X_O) + H₂)
Point P is straight line P_OSince it is also a point on S, substitute it into the above equation (1),
tan (−α) (x_P-X_O) + H₂= {(Y_Po-H₁) / X_Po} X_P+ H₁
Where (y_Po-H₁) / X_Po= K_SAnd arrange it,
{Tan (-α) -K_S} X_P= Tan (-α) x_O+ (H₁-H₂)
Therefore, x_P= {Tan (-α) x_O+ (H₁-H₂)} / {Tan (-α) -K_S}
Therefore, y_P= Tan (−α) (x_P-X_O) + H₂= {Tan (-α) h₁+ X_OK_Stan (-α) -K_Sh₂} / (Tan (-α) -K_S)
It becomes.
[0050]
However, K_S= (Y_Po-H₁) / X_Po= (Fsinβ_o+ Δlsinη_O) / (-Fcosβ_o+ Δlcosη_O)
The sum of the squares of the Euclidean distance between the position data for one scan of the XY coordinates of the spot light spot of the light beam connected to the road surface or vehicle calculated as described above and the tire model data stored in advance. When the calculation is performed according to the following equation and the calculated value is similar to the threshold level, the tire is detected as an axle.
[0051]
[Expression 1]

[0052]
Where (x_i, Y_i) Is the calculated spot light coordinates, (x_iModel, Y_iModel) Is a tire coordinate stored in advance.
[0053]
In this way, the light beam is scanned across the road, the reflected light is received, the position data corresponding to the reflection point is calculated, and the calculated position data and the reference position data of the axle stored in advance are calculated. And the axle is detected, the axle can be detected from the position data for each scan, and high-speed processing is possible.
[0054]
Moreover, there is no need to embed it on the road surface, installation is possible without blocking traffic, and maintenance is easy. Moreover, it is sufficient to install only on one side of the road, and space saving can be achieved.
[0055]
In the above-described embodiment, the axle is detected by comparing the model data, which is the reference position data when the vehicle tire stored in advance, is present, with the calculated position data. 5A, the road surface position data when the light beam is scanned on the road surface where no vehicle exists as shown in FIG. 5A is stored in advance, and the road surface position data and the axle detection calculation unit 48 calculate It is also possible to calculate the difference from the measured position data, that is, the height information, and detect the axle by comparing only the height information with the model data. In this case, only the height information is processed. Therefore, the number of data to be processed is reduced and higher speed processing is possible.
[0056]
In addition, when the axle detection device 1 is installed, an initial setting switch for storing road surface position data in the basic data storage unit 47 is attached to a circuit in which the basic data storage unit 47 is mounted. When the apparatus 1 is installed, the road surface may be scanned several times, and the average value of the position data at that time may be stored as position data serving as a reference for the road surface. As a result, road surface position data corresponding to the installation location can be stored, and by using an average value for several scans, the influence of variation is small and highly accurate axle detection can be performed.
[0057]
Furthermore, as another embodiment of the present invention, road surface position data is stored in advance at the time of installation, and when it is determined as a road surface by the axle detection calculation unit 48, the obtained road surface position data is stored in advance. For example, an average with the position data of the road surface that is present may be calculated and updated and stored as new position data so that, for example, it is possible to cope with changes in the road surface such as dredging. Alternatively, by comparing the road surface position data stored in advance at the time of installation with the measured road surface position data, it is possible to measure changes in the road surface shape over time. You may be able to do it.
[0058]
As another embodiment of the present invention, in addition to the road surface position data, the basic data storage unit 47 stores the road surface received light amount in advance, and adjusts the light projection power using the received light amount data. Also good. That is, the detected light reception amount is compared with the stored light reception amount, and when the light reception amount decreases due to weather or dirt on the optical window, the light projection power is increased, for example, stored light reception Control is made to be equal to the quantity. As a result, a stable amount of received light can always be obtained, so that stable detection independent of the environment is possible.
[0059]
Further, as another embodiment of the present invention, for example, the optical window becomes dirty due to splashing or splashing of a car in rainy weather or the like. When such a state continues continuously for several scans or more, it may be configured to output an abnormal signal to notify the maintenance timing, thereby preventing malfunction.
[0060]
As another embodiment of the present invention, as shown in FIG.₁The front door may be provided with an opening / closing door 49 having optical windows 43 and 44 so that maintenance after being embedded in a railing of an expressway in an urban area can be easily performed.
[0061]
As another embodiment of the present invention, when the axle detection device 1 is installed on a curb, as shown in FIG. 10, a notch 51 is formed in the curb 50 to widen the light receiving field. preferable.
[0062]
In the above-described embodiment, the axle detection device 1 is installed perpendicular to the traveling direction of the vehicle. However, as another embodiment of the present invention, the axle detection device 1 is provided.₂May be installed with an inclination with respect to the traveling direction, as shown in FIGS. 11 and 12, instead of being perpendicular to the traveling direction of the vehicle 52, to reduce the influence of stray light reflected on the body.
[0063]
As another embodiment of the present invention, the tire size may be detected by the period in which the tire is detected and the vehicle speed. As shown in FIG. 13, the axle detection signal is output during the period T1 in which the axle detection module 7 detects the tire, that is, the period in which the scan determined to be the tire continues. Since the period corresponds to the passage time of the tire 53 passing in front of the axle detection device 1, the calculation of (tire detection period) × (vehicle speed) is performed using the vehicle speed of the vehicle 4. The size, that is, the tire size can be detected, and can be used for discriminating the type of a large vehicle or a small vehicle.
[0064]
For example, as shown in FIG. 14, the vehicle speed is detected by installing the present axle detection device 1 at a point a certain distance away in the traveling direction of the other vehicle, and detecting the axles of the devices 1 and 1. A time difference in timing may be measured, and the vehicle speed may be calculated from the time difference and the distance between the devices 1 and 1, or a vehicle speed sensor may be provided separately. Further, as shown in FIG. 14, by installing two axle detection devices, it is possible to determine forward / reverse travel. In addition, you may install the axle detectors 1 and 1 on both sides across a road.
[0065]
As yet another embodiment of the present invention, as shown in FIG. 15, the time interval T for detecting the axle is measured, and the calculation of (time interval for detecting the axle) × (vehicle speed) is performed. You may comprise so that the distance between an axle and an axle, ie, an axle distance, can be detected. The time intervals in FIG. 15 are 1/2 of the detection period of the first axle (tire) 54, 1/2 of the detection period of the second axle (tire) 55, and the first axle 54. It can be calculated as the sum of the period from when it is no longer detected until the detection of the second axle 55 is started, or as the period from the rise to the rise of the axle detection signal or the period from the fall to the fall. May be.
[0066]
Further, as another embodiment of the present invention, a vehicle is determined by determining whether or not height information can be obtained by taking a difference between pre-stored road position data and calculated position data. The presence or absence of may be detected. That is, when there is height information, it is determined that there is a vehicle, and when there is no height information, it is determined that there is no vehicle. Furthermore, the number of axles of the vehicle may be detected by counting the number of times the axle is detected during the period in which it is determined that the vehicle is present.
[0067]
Further, the axle detection device 1 may be applied to an automatic fee collection system.
[0068]
In the automatic toll collection system, when a vehicle equipped with an in-vehicle device that performs toll collection processing passes the road toll booth, it communicates between the in-vehicle device and the roadside system to settle the fee. If the vehicle information at this time is different from the number of axes detected by the axle detection device, it is possible to prevent fraud by not performing the fee collection process because the vehicle types do not match.
[0069]
Alternatively, the vehicle type may be determined based on the axle data such as the number of axles, the axle distance, and the tire size detected by the axle detection device, and the toll according to the vehicle type may be calculated.
[0070]
As another embodiment of the present invention, the height from the road surface to the body is measured based on the road surface position data and the vehicle body position data, and this height violates the legal height. Sometimes, it may be notified.
[0071]
In addition, the detection device of the present invention is combined with, for example, a vehicle detection sensor (vehicle separation sensor) in which transmissive photoelectric sensors are arranged in parallel in the vertical direction, even though the vehicle is not detected by the vehicle detection sensor. When the height information is obtained by the detection device of the present invention, that is, when any object is detected, it may be determined that a fallen object other than the vehicle is present on the road and notified. .
[0072]
In the above-described embodiment, the present invention is applied to the detection of an axle. However, the present invention is not limited to an axle, and can detect various objects.
[0073]
In the above-described embodiment, the value of the XY coordinate is used as the position data. However, as another embodiment of the present invention, the distance data from the light receiving means to the reflection point or the direction of the reflection point viewed from the light receiving means is used. The direction data shown may be used as position data.
[0074]
【The invention's effect】
As described above, according to the present invention, the reference position data corresponding to the object to be detected such as a tire is stored in advance, the position data calculated from the light receiving position of the received reflected light, and the reference position data Is detected, the installation and maintenance is easy, and the object can be detected with high accuracy.
[0075]
In addition, since a plurality of light receiving means corresponding to at least the vicinity and the distant are provided, the object can be reliably detected in a wide detection range.
[0076]
Furthermore, since the optical window is installed in the hollow portion of the case, it becomes difficult for the optical window to adhere to rain and mud, and ambient light does not easily enter, and can be detected with high accuracy.
[0077]
In addition, since the light projecting direction by the light projecting unit is tilted with respect to the moving direction so as not to be orthogonal to the moving direction of the object, the influence of stray light reflected from other than the object can be reduced.
[0078]
Further, the size of the object can be detected from the detection period in which the object is detected and the speed of the object, for example, the tire size can be detected.
[0080]
Further, the axial distance can be detected based on the detection interval of the axle detected by the detection device of the present invention and the vehicle speed.
[0081]
Further, the number of axes of the vehicle can be detected based on the vehicle and the axle detected by the detection device of the present invention.
[0082]
Furthermore, it is possible to determine the vehicle type based on the axle data detected by the detection device of the present invention and calculate the vehicle passage fee.
[Brief description of the drawings]
FIG. 1 is a schematic view of a toll gate in which an axle detection device according to the present invention is installed.
FIG. 2 is a schematic cross-sectional view of the axle detection device of FIG.
FIG. 3 is a block diagram of the axle detection device of FIG. 1;
FIG. 4 is a diagram schematically showing a locus of a light beam for explaining the present invention.
5 is a diagram showing the position of the locus of the light beam in FIG. 4 in XY coordinates.
6 is a diagram showing the scanning timing circuit of FIG. 3. FIG.
FIG. 7 is a schematic cross-sectional view showing an installed state of an optical window.
FIG. 8 is a diagram for explaining coordinate conversion to XY coordinates;
FIG. 9 is a perspective view of another embodiment of the present invention.
FIG. 10 is a perspective view of still another embodiment of the present invention.
FIG. 11 is a perspective view of still another embodiment of the present invention.
12 is a diagram showing an installation state of the embodiment of FIG.
FIG. 13 is a diagram for explaining detection of a tire size.
FIG. 14 is a diagram showing an installation state for detecting the vehicle speed.
FIG. 15 is a diagram for explaining detection of an axial distance;
[Explanation of symbols]
1,1₁, 1₂                Axle detection device
4,52 vehicles
5 Floodlight module
6 Light receiving module
7 Axle detection module
11 frame
12 Road surface
15, 53, 54, 55 tires
17 body
43, 44 Optical window

Claims (8)

A light projecting means for scanning a light beam with respect to a road surface or a vehicle along a crossing direction of the road;
A light receiving means for receiving a reflected light beam of the scanned light beam;
Coordinate conversion means for calculating a position corresponding to the reflection point reflected by the road surface or the vehicle and converting the coordinates to XY coordinates;
Axle detection means for detecting an axle based on the coordinate-converted position data;
A control means for controlling each of the means and performing communication control for communicating an axle detection result to an external device,
The axle detection means is
XY coordinate pattern when there is no vehicle,
XY coordinate pattern when the vehicle tire is present,
XY coordinate pattern when the vehicle body exists,
An axle detection device characterized in that the presence of a vehicle tire is detected and the detection result is used as the axle detection result. The light receiving surface includes a plurality of light receiving units facing in different directions, and the plurality of light receiving units include a light receiving unit facing near the detection device and a light receiving unit facing far away. Axle detecting device as described. A case in which at least the light projecting unit and the light receiving unit are accommodated, the case having a recessed portion recessed inward; and The axle detection device according to claim 1, wherein light is projected and received through a window. The axle detection device according to any one of claims 1 to 3, wherein a light projecting direction by the light projecting unit is installed to be inclined with respect to the moving direction so as not to be orthogonal to the moving direction of the object. The detection period measuring means for measuring the period during which the object is detected, the speed detecting means for detecting the speed of the object, the speed of the detected object, and the size of the object from the measured detection period. The axle detection device according to any one of claims 1 to 4, further comprising: a magnitude calculating means for calculating. An axle detection device according to any one of claims 1 to 5, a detection interval measurement means for measuring an axle detection interval as an object detected by the axle detection device, a vehicle speed detection means for detecting a vehicle speed, An axle detection device comprising: an axial distance calculation means for calculating an axial distance from the detected vehicle speed and the measured axle detection interval. An axle detection device comprising: the axle detection device according to any one of claims 1 to 5; and an axle number measuring means for measuring the number of axes based on a vehicle and an axle detection output from the axle detection device. apparatus. An axle detecting device according to any one of claims 1 to 5, passes charge calculation device, characterized in comprising a charge calculation means for calculating the passing rates of the vehicle based on axle data detected by the axle detector .

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