A kind of the most laterally illuminating method and the support Design of road monitoring radarTechnical field
This patent relates to electronic information and field of traffic safety, and a kind of side dress proposing road monitoring radar is the most horizontalTo illuminating method and support Design.
Technical background
Road vehicle monitoring radar plays an important role on traffic safety management.In the application, monitoring radarThere are two kinds of typical mounting means: side dress and top fill.Top dress mode is radar to be arranged on each track just go upThe about 6～8 meters of eminences in side, need to utilize portal frame or long-armed pillar (lamp stand) to realize this mounting means.May utilize without suitable existing portal frame or long-armed pillar, the material engineering expense that top dress mode needsThe highest.Side dress mode is generally used for electronic police class measuring speed and taking snap pictures system.Radar is placed in roadside, makes radarWave beam longitudinally becomes 25 °～30 ° of angles with road.Radar beam under this mode can irradiate multiple track, eachOn track, vehicle entrance irradiated region can cause radar to trigger high definition camera work, and causes thunder on each trackThe positional distance reaching triggering differs greatly, it is desirable to viewing field of camera covers width, and resolution is high simultaneously, it is meant that phaseMachine price is high.In accompanying drawing 1 and accompanying drawing 2, show the typical mounting means of described two kind, illustrate in the drawingsTrack, radar site, vehicle trigger position, radar beam irradiated region etc..For the sake of distinguishing,The mounting means of Fig. 1 is referred to as top dress forward irradiate；And the radiation modality of Fig. 2 is referred to as side dress and the most longitudinally shinesPenetrate.
In the application in order to reduce installing engineering cost, install without long-armed pillar (lamp stand) roadside or lateralInstallation is preferably to select.Accompanying drawing 3 and accompanying drawing 4 show the side dress application mode that this patent proposes.
In the side dress mode example of accompanying drawing 3 signal, 3 radars are arranged on a galianconism of roadside lamp stand, fromGround level is 6～8 meters of (not shown), and every radar irradiates a track, irradiation distance 18～28 meters, 3Individual irradiated region alinement is vertical with direction, track.In this patent, this radiation modality is referred to as carThe side dress in road the most laterally irradiates, or abbreviation laterally irradiates.Under this mode, radar installation cost is relatively low, phaseThe covering visual field of machine is little, advantageously reduces the cost of bayonet socket monitoring system.Fig. 4 is also the most laterally to irradiate,Relative to Fig. 3, Fig. 4 replaces 3 narrow beam radars with the radar of an one side broad beam.Actual at someUnder environment, having a lot of social connections but not bery regular in such as road, vehicle density ratio is sparse, to differentiation track without being strict with,The scheme of Fig. 4 can save radar.If but required, for the system schema energy of Fig. 4 distinguishing trackEnough application, it is necessary to use radar more advanced in system, such as frequency shift keying (FSK) radar, linear frequency modulation (LFM)Radar etc..Either Fig. 3 or Fig. 4, is to reduce road monitoring system price to provide probability.
Fig. 5 is the schematic diagram example that side dress radar laterally irradiates multiple track.In Fig. 5, numeral 1～8 mark 8Individual different track, can be divided into come to whereabouts two groups.11 signal radar installation site in Fig. 5；12 showThe oval irradiated region that under common a kind of horizontal radiation situation of anticipating, radar beam is formed on road surface, this irradiatesMajor axis and radar pillar that district is oval form a plane being perpendicular to road surface.Especially, irradiated region is inThe radiation modality of 12 positions is referred to as the most laterally irradiating.The traffic flow detection radar used in traffic administration at present,The most domestic or import, all uses this just laterally radiation modality.Just laterally radiation modality is suitable for linearlyFrequency modulation (LFM) radar, it is possible to detect in whether vehicle is present in irradiated region with relatively simple algorithm and determineSurely which track it is in.The traffic flow detection radar of this system cannot utilize Doppler effect directly to measure carBy time speed, it has to use some householder methods to obtain velocity estimation value, such as, utilize double waveBundle or section bin count are average.Velocity accuracy is the highest can affect vehicle commander's estimation, vehicle classification etc..More reasonableRadiation modality be to use tiltedly laterally to irradiate.In Fig. 5, the irradiated region in position 13 illustrates the most laterally irradiationExample, at this moment irradiated region transverse is with radar pillar the most in one plane.One traffic flow detection radarThe most laterally irradiating if used, advantage is can directly to detect car speed, and cost is to change radarModulation system and detection algorithm, it is achieved multiple target distinguish.But this is technological progress undoubtedly.
This patent is concerned with implementation method and the support Design the most laterally irradiated.
Typical road monitoring radar antenna is micro-strip array antenna, and antenna beam has ellipse, such as-3dB beam angle is 4 ° × 5 °, 4 ° × 7 °, 4 ° × 12 °, 4 ° × 16 °, 5 ° × 12 °, etc., antenna beam is on roadForm an irradiated region, generally define irradiated region by the isophote of-3dB or-7dB exposure rate distribution,It has ellipse.Illustrate the ellipse of antenna beam irradiated region in figs. 3 and 4.In figure 3,3Irradiated region ellipse alinement, this straight line is vertical with direction, track, and 3 irradiated regions each irradiate oneTrack.A Long Circle irradiated region covers 3 tracks in the diagram, and transverse is vertical with direction, track.As previously described, in the radiation modality of Fig. 3 and Fig. 4 and Fig. 5, the radiation modalities of 13 marks are in this patentIt is referred to as the most laterally irradiating.Problem be how to arrange radar antenna towards realizing this tiltedly the most horizontal side of irradiationFormula？First this patent proposes the geometrical principle realizing laterally irradiating, and proposes one on this basis and has two degreeThe supporting structure rotated, can conveniently realize the radar mounting means the most laterally irradiated.
Summary of the invention
Specifying the micro-strip array antenna that radar uses in the present invention, its wave beam has oblateness.Antenna is justWhen overlooking ground irradiation road, an oval irradiated region, oval major axis and radar sky can be formed on roadThe normal of line plane is perpendicular, parallels with antenna plane in other words.If it is constant, at water just to overlook postureRotating radar in plane, oval irradiated region on the ground also moves, and keeps transverse and antennaPlane is parallel.Easy to understand, side dress radar in such a way, its irradiated region will not meet wanting of laterally irradiationAsk: the long axis direction of oval irradiated region can rotate with radar and rotate, and will not remain perpendicular to track.
Consider the geometrical relationship of Fig. 6.Hexahedron in this figure is a radar schematic diagram, the sky in radar frontBeta radiation electromagnetic wave, wave beam has oblateness, and the irradiated region on pavement of road is oval.Assuming that radar is notIt is to rotate by horizontal plane, but with the longitudinal axis vertical with antenna plane normal of radar solid for rotatingAxle rotates, and radar beam spatially will form the disk of a CD type after 360 ° rotate, thisDisk will be the narrow strips of straight line shape with the friendship of ground level.Further, wave beam rotary irradiation is on groundNecessarily having a little minimum with the distance of radar on the linear bands of upper formation, the central point in radar illumination district isIn the case of small distance point, the hexahedral attitude of radar is referred to as just vertical view over the ground.Now consider that radar is laterally pacifiedThe situation of dress, it is assumed that when radar is just overlooked, the projection on the ground of radar antenna plane normal and road directionParallel.Allowing radar rotate by the hexahedro solid longitudinal axis, the hexahedral attitude of radar will deviate from just overlooking, and becomesOblique vertical view over the ground.And radar beam will scan one linear band of formation on road surface, this band will hang downStraight in road direction.According to the method, it becomes possible to use 3 radars, in the way of tiltedly vertical view, Fig. 3 is realizedSide dress tiltedly laterally irradiate or the most laterally irradiate, irradiate 3 tracks respectively；It also is able to side and fills an one side widthBeam radar covers 3 or more track with the most laterally radiation modality.
According to irradiating geometrical principle above, it is possible to sort out the method main points realizing the most laterally irradiating.(1) wholeIndividual radar is necessarily mounted at one and can adjust on the support of pitch attitude, it means that one must be had to fixIn mounting column, the base of formation horizontal plane reference, and a pitching adjusting pole being connected with base, thunderReach be arranged on can pitching adjust support supporting surface on；(2) radar antenna plane normal side when just overlooking is takenTo the projection on ground parallel with road direction (briefly, taking radar illumination direction for ahead running direction, road)；(3) adjust the angle of pitch, make radar reach the distance specified in the irradiated region on ground；(4) radar allows forPitching adjusting pole supporting surface is carried out orientation to rotation adjust, become tiltedly overlook photograph by just overlooking irradiationPenetrate, make beam district fall on the centrage of specific lane, or cover the one or more tracks specified.
It is capable of the supporting structure example of described illuminating method as shown in Fig. 7～11.
In supporting structure shown in Fig. 7,1 is base, and it needs be fixed on road collateral branch strut oneOn horizontal mounting arm, and ensure that its basal plane (the typically bottom surface of understructure) can be as horizontal planeReference；2 is pitching adjusting pole, and this support is with base chain even, it is possible to carries out pitch orientation relative to base and turnsDynamic, this support has the plane (such as end face) can be as the supporting surface of radar simultaneously, it means that pitchingSupporting surface on adjusting pole can adjust with the angle i.e. angle of pitch of horizontal plane, in the side of pitching adjusting poleFace manufactures scale, it is possible to indicate the angle of pitch easily；3 is radar protective cover stiffener, and it and radar are protectedCover secure bond, to strengthen the fastness of radar protective cover, but protective cover is adjusted relative to pitching together with stiffenerWhole support can carry out orientation to rotation；4 is radar protective cover；5 is the radar being placed in protective cover；6 is radar beam direction of illumination.Also show radar supports in the figure 7 and be not 0 and be 0 two kinds when the angle of pitchUnitary side diagram under attitude.
Fig. 8 is the single-piece pattern example of a kind of pitching adjusting pole, and Fig. 9 is its three-view diagram.
Figure 10 shows that in the way of top view radar protective cover is adjusted relative to pitching together with stiffener and radarThe situation that whole support rotates.In Figure 10,2 is pitching adjusting pole, and 3 is that radar protective cover strengthens structurePart, 4 is radar protective cover, and radar is installed in protective cover.When radar protective cover is together with stiffener and radarWhen rotating, radar visual angle in orientation just can become right stravismus or left stravismus from facing, and tiltedlyDepending on azimuth can read out from pitching adjusting pole end face.
Figure 11 is the three-view diagram of a kind of configuration example of radar protective cover.Figure 10 is can easily understand that by Figure 11Rotating manner.
Accompanying drawing explanation
The top dress forward radiation modality of Fig. 1 road vehicle monitoring radar
A kind of side dress the most longitudinal radiation modality of the routine of Fig. 2 road vehicle monitoring radar
A kind of side dress mode of Fig. 3 road vehicle monitoring radar: bicycle road, the most laterally radiation modality
A kind of side dress mode of Fig. 4 road vehicle monitoring radar: multilane, the most laterally radiation modality
Fig. 5 side dress radar the most laterally irradiates and the most laterally irradiates the mode in multiple tracks
Fig. 6 radar side dress realizes the geometrical principle laterally irradiated
Fig. 7 realizes a kind of supporting structure unitary side view that side dress the most laterally irradiates
The single-piece pattern example of Fig. 8 a kind of pitching adjusting pole
The three-view diagram of pitching adjusting pole in Fig. 9 Fig. 8
Figure 10 illustrates that in the way of top view radar guard shield adjusts relative to pitching together with stiffener and radarSupport carries out the orientation situation to deflection.
The three-view diagram of Figure 11 a kind of radar cover structure example
Figure 12 determines that radar installs the angle of pitch and azimuthal solid geometry
Detailed description of the invention
Utilizing the radar mounting bracket of invention, implementing the radar installation method in invention needsThe angle of pitch of calculated in advance radar installation and azimuth, this can utilize the geometrical relationship of Figure 12 to carry out.FigureIn 12,1 is radar setting height(from bottom), is designated as h；2 is irradiated region longitudinal centre line to roadside mounting columnShort distance, is designated as c；3 is the irradiated region cross central line distance to roadside mounting column, is designated as l；4 areIrradiated region lateral dimension, is designated as d.Radar antenna normal may be calculated as relative to the angle of pitch looked squarely
And radar antenna normal may be calculated as relative to the drift angle, orientation of positive forward sight
Angle of pitch α and azimuthal angle beta can utilize the angle index on pitching adjusting pole to set up easily.
Meanwhile, the geometry of Figure 12 is utilized, it is possible to determine the requirement of irradiated region size to radar according to applicationThe technology requirement of beam directional.In order to ensure that-7dB the irradiated region of wave beam meets the geometry requirement of Figure 12,-7dB the width of wave beam is calculated as follows
The technical method provided according to this patent and mounting bracket, it is achieved any laterally irradiation can very specificationCarry out easily.As long as measuring sized data h, c, l of engineering site, angle of pitch α and azimuthal angle betaCan set on support.As long as ensureing base level in an installation, it becomes possible to ensure the accurate of irradiation areaProperty.This patent provides the method determining that beam angle technology requires simultaneously.These results can be used in advanced personThe design of vehicle monitoring system and enforcement.