CN105161820A - Radar sensor double-antenna structure - Google Patents

Abstract

The invention discloses a radar sensor double-antenna structure, and the structure comprises a support, a first antenna, a second antenna, and a radar housing. The first and second antennas are connected with the support, and the top of the first antenna is connected with the bottom of the second antenna. The support is connected with the radar housing. An inclined angle between the first antenna and a horizontal plane is (90-theta 1) degrees, and an inclined angle between the second antenna and the horizontal plane is (90-theta 2) degrees. The structure is simple, is convenient to install and operate, does not need to carry out angle correction, and avoids the impact from angle errors.

Description

Radar sensor double-antenna structure

Technical field

The present invention relates to radar sensor technical field, be specifically related to a kind of radar sensor double-antenna structure.

Background technology

Radar velocity measurement is based on electromagnetic Doppler effect.So-called Doppler effect refers to the relative motion due to transmitter and receiver, causes sound wave, phenomenon that wave frequency changes, and this frequency change is called as Doppler frequency shift, and it is directly proportional to relative velocity, is inversely proportional to the wavelength of ripple.

Single antenna can run into following problem in railway locomotive velocity radar applied environment:

1. reflectance target is numerous, and complicated.In railroad track environment lower railway, track switch, track, equipment, sleeper, rail clip, ballast aggregate stone etc. are reflectance target, and under Railway Environment, reflectance target can than stronger simultaneously.Thus radar can be caused to detect the speed of the multiple transmitting targets in beam area.

2. road environment is changeable.Ponding can be run in actual railway road environment, cover the multiple different road environment such as ice and snow, sand and dust.In station and in non-fragment orbit, have smooth cement simultaneously, form similar mirror reflection effect, thus radar reflection echo can be caused sharply to diminish.

3. locomotive itself vibrates.Railway locomotive velocity radar is generally all arranged on bottom Power output locomotive, no matter is diesel locomotive or electrically-driven car, and the microphonics that locomotive itself vibrates is formed all can cause the fluctuation of radar velocity measurement result.

4. the round-the-clock characteristic of locomotive application environment.Railway locomotive has all weather operations characteristic, and radio-frequency unit is easily subject to the change of temperature and changes.

5. setting angle impact.Most important for the impact of final data result by velocity radar operation principle known radar beam θ.Affect in locomotive environment θ because have: locomotive displacement attitude and rail level situation can cause θ to have instantaneous change; The change of the θ caused after mounting bracket is subject to vibratory impulse and loosens; The transient change of instantaneous strong reflection target and radar emission wave beam θ.

6. the transient response of acceleration is not enough.In order to the stability that tests the speed under improving single antenna and accuracy, adopt for one time the mode of multiframe rate smoothing and filtering to carry out further stability radar speed to export, but this kind of algorithm process can cause the loss of losing locomotive acceleration analysis, thus impact traction and braking control system.

Above many factors can cause single antenna radar to produce following problem under locomotive environment:

1. fluctuation of testing the speed is larger.

2. have velocity jump.

3. road worthiness is poor.

4. error is larger.

5. acceleration responsive is deteriorated, and causes locomotive traction or braking control system to report an error.

6. install comparatively complicated.Installing in locomotive radar at present needs laser angle to calibrate.

Summary of the invention

The object of this invention is to provide a kind of radar sensor double-antenna structure, structure is simple, and fitting operation is convenient, does not need to carry out angle correction, thus avoids the impact of angle error.

For achieving the above object, the technical scheme that the present invention takes is:

Radar sensor double-antenna structure, comprises support, antenna one, antenna two, radar shell; Antenna one is all connected with support with antenna two, and the top of antenna one is connected with the bottom of antenna two, and support is connected with radar shell, described antenna one be (90-θ with the angle of horizontal plane ₁) °, antenna two is (90-θ with the angle of horizontal plane ₂) °.

Wherein, under high-speed motion environment, the horizontal sextant angle of antenna one is little as far as possible, according to the installation situation angle theta of different structural housing spaces with the equipment of use ₁be 20 ~ 40 degree, good performance can be obtained, increase this angle as far as possible when space allows; The horizontal sextant angle θ of antenna two ₂for θ ₁+ 5 degree ~ θ ₁+ 15 degree; The lateral separation of the distributing point of 2 antennas should be made minimum when meeting above-mentioned constraint for best.

Wherein, the horizontal sextant angle θ of antenna one ₁value is between 20 ~ 40 degree; The horizontal sextant angle θ of antenna two ₂value is at θ ₁+ 5 degree ~ θ ₁between+15 degree, when extreme spatial is limited, antenna two stops that the surface area of antenna one can not more than 5mm on the surperficial vertical line direction of antenna one.

The observed value of two radars on described antenna one, antenna two is respectively:

v ₁＝vcosθ ₁

$\begin{array}{c}{v}_2-v\cos ({\mathrm{\θ}}_1+\mathrm{\α})-{\mathrm{vcos\θ}}_1\cos \mathrm{\α}-{\mathrm{vsin\θ}}_1\sin \mathrm{\α}\\ =v_1\cos \mathrm{\α}-\sqrt{v^2-v_1^2}sin\mathrm{\α}\end{array}$

Transposition abbreviation,

$\sqrt{v^2-v_1^2}sin\mathrm{\α}=v_{1}cos\mathrm{\α}-v_2$

$v^2{\sin }^2\mathrm{\α}=v_1^2+v_2^2-2v_1{v}_{2}cos\mathrm{\α}$

Finally obtain

$v=\frac{\sqrt{v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α}}}{\sin \mathrm{\α}}.$

The actual error brought with rail level variable angle of antenna is solved by double antenna design in the present invention; This kind of change can be: the angle change that the transient change that the mounting bracket change that the transient change that road environment difference causes, locomotive vibration cause, locomotive operation attitude difference cause, mounting bracket self deterioration cause.By this kind of double antenna aft antenna, angle is installed, in the setting angle situation of ± 5 degree, can not has an impact to the result that finally tests the speed.

The present invention has following beneficial effect:

1. higher rate accuracy: when radar beam irradiates the multiple reflectance target in below, double antenna can have the effective problem solving velocity perturbation.Each antenna launch separately different frequencies to reflectance target, after reflectance target reflection, processor is by after carrying out frequency domain process to radar echo signal, multiple velocity measurement value can be detected in single echo, these velocity measurement values are then the true relative velocity of multiple launching objects in beam area, then by after data volume measured value carries out Data Fusion separately by double antenna, thus accurate speed can be obtained.

2. improve acceleration transient response: the double antenna rate signal measured in the cycle of testing the speed because double antenna is each can carry out melting merging treatment and obtain a good measurement, good reflection road surface no longer needs multiframe data smoothing, frame speed measurement before complex road surface only needs, thus greatly improve the Instantaneous Phase to acceleration.By to integration test under current Railway Environment, in 10 milliseconds, this double antenna radar and an exportable preferably velocity measurement result.

3. icing or covering foreign matter position judgment: locomotive radar surface is very easily covered by ice and snow or foreign matter in practice environment.In the locomotive radar used at present, if run into the situations such as snow and ice cover, radar system is cisco unity malfunction then.This radar is by analyzing double antenna wave beam backward energy, can learn whether antenna is covered by ice and snow or foreign matter, if capped, simultaneously can to double antenna backward energy analysis separately, the part that is capped and thickness can be judged accurately, covering part and thickness are led to information interaction to ice-melt treatment system, carry out intelligent ice-melt process

Accompanying drawing explanation

Fig. 1 is the schematic diagram of embodiment of the present invention radar sensor double-antenna structure.

Fig. 2 is the mounting structure schematic diagram of the embodiment of the present invention 2 and embodiment 3.

Embodiment

In order to make objects and advantages of the present invention clearly understand, below in conjunction with embodiment, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

As shown in Figure 1, embodiments provide a kind of radar sensor double-antenna structure, comprise support 6, antenna 1, antenna 21, radar shell 5; Antenna 1 is all connected with support 6 with antenna 21, and the top of antenna 1 is connected with the bottom of antenna 21, and support 6 is connected with radar shell 5, described antenna 1 be (90-θ with the angle 4 of horizontal plane ₁) °, antenna 21 is (90-θ with the angle 2 of horizontal plane ₂) °.

Embodiment 1

As shown in Figure 2, under high-speed motion environment, the horizontal sextant angle of antenna 1 is little as far as possible, according to the installation situation angle theta of different structural housing spaces with the equipment of use ₁be 20 ~ 40 degree, good performance can be obtained, increase this angle as far as possible when space allows; The horizontal sextant angle θ of antenna 21 ₂for θ ₁+ 5 degree ~ θ ₁+ 15 degree; The lateral separation of the distributing point of 2 antennas should be made minimum when meeting above-mentioned constraint for best.

Embodiment 2

As shown in Figure 2, under the mounting means that some volumes are limited, need compression velocity radar Whole Equipment shell further, under so just needing to adopt which, carry out astronomical cycle.Now horizontal sextant angle θ 1 value of antenna 1 is between 20 ~ 40 degree; The horizontal sextant angle θ of antenna 21 ₂value is at θ ₁+ 5 degree ~ θ ₁between+15 degree, when extreme spatial is limited, antenna two stops that the surface area of antenna one can not more than 5mm on the surperficial vertical line direction of antenna one.

The observed value of two radars on described antenna 1, antenna 21 is respectively:

v ₁＝vcosθ ₁

$\begin{array}{c}{v}_2-v\cos ({\mathrm{\θ}}_1+\mathrm{\α})-{\mathrm{vcos\θ}}_1\cos \mathrm{\α}-{\mathrm{vsin\θ}}_1\sin \mathrm{\α}\\ =v_1\cos \mathrm{\α}-\sqrt{v^2-v_1^2}sin\mathrm{\α}\end{array}$

Transposition abbreviation,

$\sqrt{v^2-v_1^2}sin\mathrm{\α}=v_{1}cos\mathrm{\α}-v_2$

$v^2{\sin }^2\mathrm{\α}=v_1^2+v_2^2-2v_1{v}_{2}cos\mathrm{\α}$

Finally obtain

$v=\frac{\sqrt{v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α}}}{\sin \mathrm{\α}}$

Error analysis:

Local derviation is asked to (3) formula

$\begin{array}{c}dv=\frac{v_1{v}_2}{\sqrt{v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α}}}d\mathrm{\α}-\frac{\sqrt{v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α}}}{{\sin }^2\mathrm{\α}}\cos \mathrm{\α}d\mathrm{\α}\\ +\frac{v_1-v_2\cos \mathrm{\α}}{\sin \mathrm{\α}\sqrt{v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α}}}{\mathrm{dv}}_1+\frac{v_2{v}_1\cos \mathrm{\α}}{\sin \mathrm{\α}\sqrt{v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α}}}{\mathrm{dv}}_2\\ -\frac{v_1{v}_2-(v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α})\cos \mathrm{\α}}{{\sin }^2\mathrm{\α}\sqrt{v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α}}}d\mathrm{\α}\\ +\frac{v_1-v_2\cos \mathrm{\α}}{{\sin }^2\mathrm{\α}\sqrt{v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α}}}{\mathrm{dv}}_1+\frac{v_2-v_1\cos \mathrm{\α}}{\sin \mathrm{\α}\sqrt{v_1^2+v_2^2-2v_1{v}_2\cos \mathrm{\α}}}{\mathrm{dv}}_2\end{array}$

Angle α should be selected to make error little as far as possible.D α contains the error of antenna direction, and make d α very little by improving technique, Section 1 can think event.

Under actual railway locomotive application environment, angle theta is installed and is limited to environment bottom locomotive simultaneously, if θ is less, radar front portion is needed to have more clearance spaces, thus cause locomotive radar to use condition harsh, by constantly test θ get under locomotive operation environment 30 ~ 50 degree comparatively suitable.

The actual error brought with rail level variable angle of antenna is solved by double antenna design in this embodiment; This kind of change can be: the angle change that the transient change that the mounting bracket change that the transient change that road environment difference causes, locomotive vibration cause, locomotive operation attitude difference cause, mounting bracket self deterioration cause.By this kind of double antenna aft antenna, angle is installed, in the setting angle situation of ± 5 degree, can not has an impact to the result that finally tests the speed.

This concrete enforcement has higher rate accuracy: when radar beam irradiates the multiple reflectance target in below, and double antenna can have the effective problem solving velocity perturbation.Each antenna launch separately different frequencies to reflectance target, after reflectance target reflection, processor is by after carrying out frequency domain process to radar echo signal, multiple velocity measurement value can be detected in single echo, these velocity measurement values are then the true relative velocity of multiple launching objects in beam area, then by after data volume measured value carries out Data Fusion separately by double antenna, thus accurate speed can be obtained.Improve acceleration transient response: the double antenna rate signal measured in the cycle of testing the speed because double antenna is each can carry out melting merging treatment and obtain a good measurement, good reflection road surface no longer needs multiframe data smoothing, frame speed measurement before complex road surface only needs, thus greatly improve the Instantaneous Phase to acceleration.By to integration test under current Railway Environment, in 10 milliseconds, this double antenna radar and an exportable preferably velocity measurement result.In practice environment, locomotive radar surface is very easily covered by ice and snow or foreign matter.In the locomotive radar used at present, if run into the situations such as snow and ice cover, radar system is cisco unity malfunction then.This radar is by analyzing double antenna wave beam backward energy, can learn whether antenna is covered by ice and snow or foreign matter, if capped, simultaneously can to double antenna backward energy analysis separately, the part that is capped and thickness can be judged accurately, covering part and thickness are led to information interaction to ice-melt treatment system, carry out intelligent ice-melt process.

The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (3)

1. radar sensor double-antenna structure, is characterized in that, comprises support (6), antenna one (3), antenna two (1), radar shell (5); Antenna one (3) is all connected with support (6) with antenna two (1), and the top of antenna one (3) is connected with the bottom of antenna two (1), and support (6) is connected with radar shell (5), described antenna one (3) be (90-θ with the angle (4) of horizontal plane ₁) °, antenna two (1) is (90-θ with the angle (2) of horizontal plane ₂) °.

2. radar sensor double-antenna structure according to claim 1, is characterized in that, under high-speed motion environment, and the horizontal sextant angle θ of antenna one (3) ₁be 20 ~ 40 degree, the horizontal sextant angle θ of antenna two (1) ₂for (θ ₁+ 5) degree ~ (θ ₁+ 15) spend; Antenna one (3) should be made to be minimum with the lateral separation of the distributing point of antenna two (1) when meeting above-mentioned constraint.

3. radar sensor double-antenna structure according to claim 1, is characterized in that, the horizontal sextant angle θ of antenna one (3) ₁value is between 20 ~ 40 degree; The horizontal sextant angle θ of antenna two (1) ₂value is at (θ ₁+ 5) degree ~ (θ ₁+ 15), between degree, when extreme spatial is limited, antenna two stops that the surface area of antenna one can not more than 5mm on the surperficial vertical line direction of antenna one.