CN105842675A - RCS real-time estimation method for vehicle radar target - Google Patents

Abstract

The invention discloses an RCS (radar cross-section) real-time estimation method for a vehicle radar target. The method specifically includes the following steps that: a geometric model of a target under moving trajectories is constructed, and the surface of the target is divided into a plurality of simple surface elements according to the two-dimensional curvature of the surface of the target; as for each simple surface element, the incidence directions of incident waves are decomposed, and the incidence directions of the incident waves are decomposed into a vertical simple surface element incidence direction and a parallel simple surface element incidence direction, and the influence of incident waves of which the incidence direction is the parallel simple surface element incidence direction, on an RCS, can be neglected; and the projection area A, reflectivity R and directional coefficient D of each simple surface element are calculated, the RCS value of each simple surface element is calculated according to a formula, and the RCS values of the simple surface elements are superposed, so that the RCS value of the target can be obtained. Compared with the prior art, the computation amount of the method of the invention is greatly reduced, and real-time estimation of the vehicle radar target can be realized. As verified by an experiment, the estimation method of the invention has high accuracy.

Description

A kind of RCS real-time estimating method for car radar target

Technical field

The invention belongs to vehicle intellectualized technical field, be specifically related to a kind of for car radar mesh The real-time estimating method of mark RCS.

Background technology

Radar is a kind of to utilize electromagnetic wave to carry out the equipment detecting and measuring, and its performance is not only Relevant to radar self, the most also restricted by factors such as target and background environment.Target radar dissipates Penetrating sectional area RCS (Radar Cross Section, RCS) is to weigh target scattering characteristics Important parameter, typically defines target RCS by the intensity of back scattering energy.Target RCS Main and the structure of target and surface dielectric, radar frequency, polarization mode and object attitude angle etc. Factor is relevant.

Along with the development of intelligent automobile, intelligent automobile needs fill radar, for detection with crashproof. In car radar detection process, the RCS change of obstacle target need to be paid close attention in real time.Obtain at present The method taking target RCS mainly has experiment to measure and emulation estimation, and experiment was measured due to the cycle Long, high in cost of production problem, application is restricted；Though the existing classical theory of RCS emulation estimation is propped up Support, but existing estimation theory is only suitable for " far field " pattern, it is impossible to and " directly transplanting " is to automobile Radar target RCS estimates；Additionally, existing estimation theory is usually taken " finite element " Thought, for " electrically large sizes " target, amount of calculation will be the hugest, it is impossible to realizes real Time estimation.

Summary of the invention

The present invention provides a kind of real-time estimating method for car radar target RCS, this Bright employing modular design concept, according to target surface curvature, target is divided into some simply Bin, compared to existing technology, computation amount, it is achieved that the reality to car radar target Time estimation.

The present invention is by the following technical solutions:

A kind of real-time estimating method for car radar target RCS, comprises the following steps:

A. target static geometric model under movement locus is determined, on the basis of geometrical model, According to bidimensional curvature, target surface is decomposed into several simple bins；

B. for each simple bin, incidence wave is decomposed into vertical simple bin incident direction and Parallel simple bin incident direction, and ignore parallel simple bin incident direction to RCS's Impact；

C. calculating projected area A of each simple bin, computing formula is:

A=x*w

In formula, x represents the projection line length of simple bin, and w represents the projection line of simple bin Width；

D. calculating the reflectivity R of target, computing formula is:

R=| ξ-j60 λ μ |

In formula, ξ represents the dielectric constant of target material, and μ represents the magnetic conductive rate of target material, λ represents radar operation wavelength, and j represents imaginary unit；

E. calculating the directivity factor D of each simple bin, the calculating of directivity factor uses rule The method that then shape is analogized, regular shape includes sphere, cylindrical side and plane, computing formula For:

In formula, l is cylinder bus length, and θ is the angle of incident electromagnetic wave and cylinder bus, a With the bidimensional linear dimension that b is plane, ψ is the horizontal angle of incident electromagnetic wave and plane, and φ is for entering Radio magnetic wave and the angle of plane normal；

F. the RCS computing formula of all simple bins of cycle calculations is:

RCS=A*R*D

In formula, A represents projected area；R represents reflectivity；D represents directivity factor；；

G. judge whether to travel through all bins；

H. by the RCS superposition of all simple bins.

Beneficial effects of the present invention: the present invention uses modular design concept, according to target surface Curvature, is divided into some simple bins, compared to existing technology, computation amount by target, Achieve the real-time estimation to car radar target；In addition the evaluation method of the present invention is through testing Card, has higher accuracy.

Accompanying drawing explanation

Fig. 1 is the inventive method flow chart；

Fig. 2 is embodiment 1 annular road conditions schematic diagram；

Fig. 3 is embodiment 1 annular road conditions, model assessment value and business software FEKO simulation value Comparison diagram；

Fig. 4 is embodiment 2 climb and fall road driving scene schematic diagram；

Fig. 5 is embodiment 2 uphill way, model assessment value and business software FEKO simulation value Comparison diagram；

Fig. 6 is embodiment 2 descending section, model assessment value and business software FEKO simulation value Comparison diagram.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, to the technical side in the embodiment of the present invention Case is clearly and completely described, it is clear that described embodiment is only the present invention one Divide embodiment rather than whole embodiments.Based on the embodiment in the present invention, this area is general The every other embodiment that logical technical staff is obtained under not making creative work premise, Broadly fall into the scope of this protection.

Reference Fig. 1, a kind of RCS real-time estimating method for car radar target of the present invention, Concrete steps include:

A. target static geometric model under movement locus is determined, on the basis of geometrical model, According to bidimensional radius of curvature, target surface is decomposed into several simple bins.

B. for each simple bin, incidence wave is decomposed into vertical simple bin incident direction and Parallel simple bin incident direction, and ignore and be parallel to simple bin incident direction to RCS Impact.

C. calculating projected area A of each simple bin, computing formula is:

A=x*w

In formula, x represents the projection line length of simple bin, and w represents the projection of simple bin Line width.

D. calculating the reflectivity R of target, computing formula is:

R=| ξ-j60 λ μ |

In formula, ξ represents the dielectric constant of target material, and μ represents the magnetic conductive rate of target material, λ represents radar operation wavelength, and j represents imaginary unit.

E. calculating the directivity factor D of each simple bin, the calculating of directivity factor uses rule The method that then shape is analogized, regular shape includes sphere, cylindrical side and plane, computing formula For:

In formula, l is cylinder bus length, and θ is the angle of incident electromagnetic wave and cylinder bus, a With the bidimensional linear dimension that b is plane, ψ is the horizontal angle of incident electromagnetic wave and plane, and φ is for entering Radio magnetic wave and the angle of plane normal.

F. the RCS of all simple bins of cycle calculations, computing formula is:

RCS=A*R*D

In formula, A represents projected area；R represents reflectivity；D represents directivity factor.

G. judge whether to travel through all bins.

H. by the RCS superposition of all simple bins.

The radar frequency installed for the main car of monitoring in following embodiment is 76.5GHz, mesh Mark special bus is 2010 sections of Mazdas 6.

Embodiment 1

Set up target special bus in round driving scene, real time record RCS value, this scene The insolation level angle change impact on RCS.

As in figure 2 it is shown, the main car equipped with radar is parked in 0 degree of position, target traffic vehicle and horse are certainly Reach from 0 degree, at the uniform velocity drive to 45 degree of positions with the speed of 20km/h, at interval of 2.5 A degree RCS value of record.Annular road conditions, model assessment value emulates with business software FEKO Value contrast is shown in that Fig. 3, the mean absolute difference of model assessment value and FEKO simulation value are 0.132, Illustrate that evaluation method accuracy of the present invention is preferable.

Embodiment 2

Set up target carriage to examine in climb and fall road driving scene, real time record RCS value, this scene Test the angle of pitch change impact on RCS.

As shown in Figure 4, go up a slope segment length 100m, and slope angle 30 degree, the main car equipped with radar stops Being placed on starting point (minimum point) position, target special bus Mazda is from starting point, with 5m/s Speed at the uniform velocity up-hill journey, 20s reaches uphill way peak, during upward slope, every A RCS value is recorded every 4s.

As shown in Figure 4, downhill path segment length 100m, slope angle 30 degree, the main car equipped with radar stops Being placed on starting point (peak) position, target special bus Mazda is from starting point, with 5m/s Speed at the uniform velocity descent run, 20s reaches descending section minimum point, during descending, every A RCS value is recorded every 4s.

Uphill way, model assessment value is shown in Fig. 5, mould with the contrast of business software FEKO simulation value Type estimated value is 0.286 with the mean absolute difference of business software FEKO simulation value, and this is described Invention evaluation method accuracy is preferable；Descending section, model assessment value and business software FEKO The average absolute of Fig. 6, model assessment value and business software FEKO simulation value is shown in simulation value contrast Difference is 0.172, illustrates that evaluation method accuracy of the present invention is preferable.

Although an embodiment of the present invention has been shown and described, for the ordinary skill of this area For personnel, it is possible to understand that without departing from the principles and spirit of the present invention can be to this A little embodiments carry out multiple change, revise, replace and modification, and the scope of the present invention is by appended power Profit requires and equivalent limits.

Claims (1)

1. the real-time estimating method for car radar target RCS, it is characterised in that Comprise the following steps:

A. target static geometric model under movement locus is determined, on the basis of geometrical model, According to bidimensional curvature, target surface is decomposed into several simple bins；

B. for each simple bin, incidence wave is decomposed into vertical simple bin incident direction and Parallel simple bin incident direction, and ignore and be parallel to simple bin incident direction to RCS Impact；

C. calculating projected area A of each simple bin, computing formula is:

A=x*w

In formula, x represents the projection line length of simple bin, and w represents the projection line of simple bin Width；

D. calculating the reflectivity R of target, computing formula is:

R=| ξ-j60 λ μ |

In formula, ξ represents the dielectric constant of target material, and μ represents the magnetic conductive rate of target material, λ represents radar operation wavelength, and j represents imaginary unit；

E. calculating the directivity factor D of each simple bin, the calculating of directivity factor uses rule The method that then shape is analogized, regular shape includes sphere, cylindrical side and plane, computing formula For:

In formula, l is cylinder bus length, and θ is the angle of incident electromagnetic wave and cylinder bus, a With the bidimensional linear dimension that b is plane, ψ is the horizontal angle of incident electromagnetic wave and plane, and φ is for entering Radio magnetic wave and the angle of plane normal；

F. the RCS of all simple bins of cycle calculations, computing formula is:

RCS=A*R*D

In formula, A represents projected area；R represents reflectivity；D represents directivity factor；

G. judge whether to travel through all bins；

H. by the RCS superposition of all simple bins.