阅读说明：本技术 一种车载毫米波雷达及其目标高度测量方法 (A kind of vehicle-mounted millimeter wave radar and its object height measurement method ) 是由 王渊 刘征东 杜锐锋 杨元海 于 2019-08-20 设计创作，主要内容包括：本发明公开了一种车载毫米波雷达及其目标高度测量方法,所述毫米波雷达设有n根天线,其中,第1至n-1根天线成水平线性阵列排布,第n根天线设置于所述第1至n-1根天线连线的下侧,且第n根天线与第n-1根天线间的连线与所述第1至n-1根天线的连线间的夹角γ为钝角。通过以本发明设置的阵列形式加入的第n根天线,既没有损失水平方向天线孔径,同时也增加了俯仰孔径。即,第n根天线与其余天线的相位差,不仅有目标水平角度信息,同时有目标的俯仰信息,天线有效孔径大大提高,大大增强了系统探测效能。且天线孔径越大,天线波束越窄,雷达探测精度越高。从而采用本天线阵列设置可以提高天线的利用效率。(The invention discloses a kind of vehicle-mounted millimeter wave radar and its object height measurement methods, the millimetre-wave radar is equipped with n root antenna, wherein, 1st arranges to n-1 root antenna at horizontal linear array, n-th antenna is set to the described 1st to the downside of n-1 root antenna connection, and the line and the described 1st to the angle γ between the line of n-1 root antenna between n-th antenna and (n-1)th antenna is obtuse angle.N-th antenna being added by the array format being arranged with the present invention, both without loss level directional aerial aperture, while also increasing pitching aperture.That is, the phase difference of n-th antenna and remaining antenna, not only there is target level angle information, while there is the pitch information of target, antenna effective aperture greatly improves, and greatly strengthens system detection efficiency.And antenna aperature is bigger, antenna beam is narrower, and radar detection precision is higher.To which the utilization efficiency of antenna can be improved using the setting of this aerial array.)

1. a kind of vehicle-mounted millimeter wave radar, which is characterized in that the millimetre-wave radar is equipped with n root antenna, wherein the 1st to n-1 root Antenna is arranged at horizontal linear array, and n-th antenna is set to the described 1st to the downside of n-1 root antenna connection, and n-th day Line and the described 1st to the angle γ between the line of n-1 root antenna between line and (n-1)th antenna are obtuse angle.

2. a kind of vehicle-mounted millimeter wave radar as described in claim 1, which is characterized in that n-th antenna and (n-1)th day Line and the described 1st to the angle γ between the line of n-1 root antenna between line are 135 °.

3. a kind of vehicle-mounted millimeter wave radar as claimed in claim 2, which is characterized in that the millimetre-wave radar is equipped with 4 days Line.

4. a kind of object height measurement method of vehicle-mounted millimeter wave radar, which is characterized in that the antenna of the millimetre-wave radar is adopted It is structured the formation with the mode of structuring the formation as claimed in claim 1, the object height measurement method includes the following steps:

Step 1: obtaining the initial data in each channel of radar；

Step 2: measurement distance r of the target away from radar；

Step 3: based on reception array element component space matrix；

Step 4: completing the calculating of target angle of arrival；

Step 5: object height h is calculated according to angle of arrival and the target range r of measurement₁。

5. a kind of object height measurement method of vehicle-mounted millimeter wave radar as claimed in claim 4, which is characterized in that the step The construction method of space matrix includes: in rapid 3

Equipped with K target relative to receive array element angle of arrival be θ_K, K target echo of reception of radar is by matched filter The matrix form of array output model afterwards may be expressed as:

X (t)=As (t)+N (t)

In formula, direction matrix is A=[a (θ₁),a(θ₂),…,a(θ_K)]∈C^M*K, t is time variable,

K-th target direction vector is a (θ_K)=exp [- j2 π sin (θ_K)],

S=[s (1), s (2) ..., s (N)]^T∈C^L*KAnd N=C^MN*KIt is the white Gaussian noise that 0 variance is σ for mean value, M is transmitting Array number, N are to receive array number, and j indicates imaginary part；

The covariance matrix of array is R_X=E { XX^HFeature decomposition is carried out to the covariance matrix Rx of output signal are as follows:

R_X=E_SD_SE^H _S+E_ND_NE^H _N

D in formula_SAnd D_NRespectively K maximum eigenvalue composition K*K diagonal matrix and residue character value composition to angular moment Battle array；E_SAnd E_NThe feature vector and the corresponding feature vector of residue character value of K maximum eigenvalue are corresponded respectively to, it is right respectively It should be signal subspace and noise subspace.

6. a kind of object height measurement method of vehicle-mounted millimeter wave radar as claimed in claim 5, which is characterized in that the step In rapid 4, the calculating for completing target angle of arrival includes:

It is available by MUSIC algorithm,

Target is acquired up to angle θ by finding spectral peak₁And θ₂。

7. a kind of object height measurement method of vehicle-mounted millimeter wave radar as claimed in claim 6, which is characterized in that the step In rapid 5, object height h is calculated₁It is obtained by following calculating formula:

Wherein, α and β respectively corresponds the angle of arrival θ measured in step 4₁And θ₂, a is target position in radar horizon detection direction Projector distance, b are that target position is structured the formation the projector distance on direction in the n-th antenna.

8. a kind of object height measurement method of vehicle-mounted millimeter wave radar as claimed in claim 4, which is characterized in that step 1 The middle initial data for obtaining each channel of radar includes: obtaining the transmitting signal data in each channel of radar and receives signal data.

Technical field

It structures the formation mode and elevation carrection field more particularly to a kind of vehicle-mounted millimeter the present invention relates to the antenna of millimetre-wave radar Wave radar and its object height measurement method.

Background technique

Automatic Pilot in the industry, millimetre-wave radar sensor is because of its moderate cost, environmental suitability is strong and remote visits Survey ability is preferably and as one of mainstream detection sensor.The working frequency range target of vehicle-mounted millimeter wave Radar Products includes 24GHz And 77GHz.With going deep into for product development in the industry, the cost of 77GHz frequency range series of products is constantly reduced, and its is small in size, visits Ranging becomes increasingly conspicuous from remote advantage, and therefore, it has become one of mains direction of studying of trailer-mounted radar from now on.

Millimetre-wave radar major function is position and the relative velocity of determining target, and position just includes opposite distance, Pitch angle (height) and level angle.It is wherein used as advanced vehicle radar system, needs to distinguish the height of object, such as well Lid, overline bridge etc., therefore the measurement of the pitch angle or height to object becomes extremely important.On the basis of limited antenna number On, the measurement of level angle was both taken into account, while being also required to take into account the measurement of pitch angle, and had been always the important of radar angular detection Work.

Traditional Radar Target Elevation measurement, as shown in figure, generally by antenna in the consistent feelings of level angle Under condition, there is distance difference in the pitch direction, calculates target by there is the object back wave of height to reach the phase difference of antenna Pitch angle.But aerial array is arranged according to such demand, the horizontal angle detectivity of antenna will be lost.

Summary of the invention

It is an object of the present invention to overcome, prior art defect proposes a kind of vehicle-mounted millimeter wave radar and its target is high Measurement method is spent, so that antenna system while having elevation carrection ability, does not lose the horizontal aperture of antenna system, no Influence the detection performance of radar horizon angle.

The object of the invention is realized by following technical proposals:

A kind of vehicle-mounted millimeter wave radar, the millimetre-wave radar are equipped with n root antenna, wherein the 1st to n-1 root antenna Cheng Shui Horizontal line array arrangement, n-th antenna is set to the described 1st to the downside of n-1 root antenna connection, and n-th antenna and (n-1)th Line and the described 1st to the angle γ between the line of n-1 root antenna between root antenna are obtuse angle.

It is arranged by the position of n-th antenna in this radar, so that the phase difference of n-th antenna and remaining antenna, not only There is target level angle information, while having the pitch information of target, increases the effective aperture of antenna.Antenna aperature is bigger, day Line wave beam is narrower, and radar detection precision is higher.To which the utilization efficiency of antenna can be improved using the setting of this aerial array.

According to a preferred embodiment, line between n-th antenna and (n-1)th antenna with the described 1st to Angle γ between the line of n-1 root antenna is 135 °.By the way that the position of n-th antenna to be arranged, enabling to the antenna is mesh Cursor position measurement provides optimal level angle information and pitch angle information.

According to a preferred embodiment, the millimetre-wave radar is equipped with 4 antennas.

A kind of object height measurement method of vehicle-mounted millimeter wave radar, the millimetre-wave radar are equipped with n root antenna, wherein 1st arranges to n-1 root antenna at horizontal linear array, and n-th antenna is set to the described 1st to the downside of n-1 root antenna connection, And the line and the described 1st to the angle γ between the line of n-1 root antenna between n-th antenna and (n-1)th antenna is obtuse angle.Its In, the object height measurement method includes the following steps: step 1: obtaining the initial data in each channel of radar；Step 2: measurement Distance r of the target away from radar；Step 3: based on reception array element component space matrix；Step 4: completing the calculating of target angle of arrival； Step 5: object height h is calculated according to angle of arrival and the target range r of measurement₁。

It is arranged by the position of n-th antenna in this radar, so that the phase difference of n-th antenna and remaining antenna, not only There is target level angle information, while having the pitch information of target, is cooperated by this object height measurement method and aerial array It can be improved the utilization efficiency of antenna, it is fuzzy to generate pitch angle detection while increasing antenna horizontal aperture.It is In The detecting error of level angle will not be introduced while parsing the pitch angle information of target.

According to a preferred embodiment, the construction method of space matrix includes: equipped with K target in the step 3 It is θ relative to the angle of arrival for receiving array element_K, array output mould of the K target echo of reception of radar after matched filter The matrix form of type may be expressed as:

X (t)=As (t)+N (t)

In formula, direction matrix is A=[a (θ₁),a(θ₂),…,a(θ_K)]∈C^M*K, t is time variable；

K-th target direction vector is a (θ_K)=exp [- j2 π sin (θ_K)], S=[s (1), s (2) ..., s (N)]^T∈C^{L *K}And N=C^MN*KIt is the white Gaussian noise that 0 variance is σ for mean value, M is transmitting array number, and N is to receive array number, and j indicates plural number Imaginary part；

The covariance matrix of array is R_X=E { XX^HFeature decomposition is carried out to the covariance matrix Rx of output signal are as follows:

R_X=E_SD_SE^H _S+E_ND_NE^H _N

D in formula_SAnd D_NThe diagonal matrix and residue character value of the K*K of respectively K maximum eigenvalue composition forms diagonal Matrix；E_SAnd E_NThe feature vector and the corresponding feature vector of residue character value of K maximum eigenvalue are corresponded respectively to, respectively Correspond to signal subspace and noise subspace.

According to a preferred embodiment, in the step 4, the calculating for completing target angle of arrival includes:

It is available by MUSIC algorithm,

Target is acquired up to angle θ by finding spectral peak₁And θ₂。

According to a preferred embodiment, in the step 5, calculate object height h₁It is obtained by following calculating formula:

Wherein, α and β respectively corresponds the angle of arrival θ measured in step 4₁And θ₂, a is target position in radar horizon detection side To projector distance, b is that target position is structured the formation the projector distance on direction in the n-th antenna.

According to a preferred embodiment, the initial data that each channel of radar is obtained in step 1 includes: it is each to obtain radar The transmitting signal data in channel and receive signal data.

The foregoing main solution of the present invention and further alternatives thereof can be freely combined to form multiple schemes, be this Invention can be used and claimed scheme；And it is of the invention, between (each non conflicting selection) selection and between other selections It can also be freely combined.Those skilled in the art, which can be illustrated after understanding the present invention program according to the prior art and common knowledge, to be had Multiple combinations are the claimed technical solution of the present invention, do not do exhaustion herein.

Beneficial effects of the present invention: n-th antenna being added by the array format being arranged with the present invention did not both lose Horizontal direction antenna aperature, while also increasing pitching aperture.It is that the phase difference of n-th antenna and remaining antenna not only has Target level angle information, while having the pitch information of target, antenna effective aperture greatly improves, and greatly strengthens system detection Efficiency.And antenna aperature is bigger, antenna beam is narrower, and radar detection precision is higher.It can be with to use this aerial array to be arranged Improve the utilization efficiency of antenna.Meanwhile the benefit of antenna can be improved by this object height measurement method and aerial array cooperation It is fuzzy that pitch angle detection will not be generated with efficiency, while increasing antenna horizontal aperture.It is, in the pitching for parsing target The detecting error of level angle will not be introduced while angle information.

Detailed description of the invention

Fig. 1 be traditional trailer-mounted radar be 4 antenna when schematic diagram of structuring the formation；

Fig. 2, which is vehicle-mounted millimeter wave radar of the present invention, to structure the formation schematic diagram when being 4 antenna；

Each aerial position relation schematic diagram when being 4 antenna that Fig. 3 is vehicle-mounted millimeter wave radar of the present invention；

Fig. 4 is the auxiliary space coordinate system that the method for the present invention object height measurement method is constructed；

Detection accuracy parameter comparison that Fig. 5 is the method for the present invention detection angle precision and conventional radar antenna is structured the formation；

In figure, 1- first antenna, the second antenna of 2-, 3- third antenna, the 4th antenna of 4-, first antenna of 101-, 102- Second antenna, (n-1)th antenna of 103-, n-th antenna of 104-.

Specific embodiment

Following non-limiting examples are for illustrating the present invention.