阅读说明：本技术 一种用于高效速度解模糊的汽车毫米波雷达波形设计方法 (Automobile millimeter wave radar waveform design method for high-efficiency speed ambiguity resolution ) 是由 房旭龙 厉瀚杰 王阶 孙双锁 于 2020-06-08 设计创作，主要内容包括：本发明提供一种用于高效速度解模糊的汽车毫米波雷达波形设计方法,包括：设定系统周期,并设定多种雷达波形的参数；对雷达目标在多个连续系统周期内交替发射多种雷达波形的信号,且每一系统周期内只发射一种雷达波形的信号；在每个系统周期,对雷达波形进行ADC采样；对其进行信号处理,以获得当前雷达目标的信息列表,并其记录到存储器中；根据当前和之前N个系统周期的雷达目标的信息列表进行速度解模糊,N≤M-1；进行目标信息的校对；更新校对通过的雷达目标的速度信息。本发明的雷达波形设计方法每个系统周期只发射一种波形,以有效缩短系统波形的发射时间,减少整个雷达系统的更新周期；且减少所需的存储容量,降低解模糊出错的风险。(The invention provides a method for designing a waveform of an automotive millimeter wave radar for high-efficiency speed ambiguity resolution, which comprises the following steps: setting a system period and setting parameters of various radar waveforms; alternately transmitting signals of various radar waveforms to a radar target in a plurality of continuous system periods, and only transmitting signals of one radar waveform in each system period; in each system period, ADC sampling is carried out on the radar waveform; performing signal processing on the radar target to obtain an information list of the current radar target, and recording the information list into a memory; performing speed ambiguity resolution according to the information lists of the radar targets of the current and previous N system periods, wherein N is less than or equal to M-1; checking the target information; and updating the speed information of the passing radar target. According to the radar waveform design method, only one waveform is transmitted in each system period, so that the transmission time of the system waveform is effectively shortened, and the update period of the whole radar system is reduced; and the required storage capacity is reduced, and the risk of resolving fuzzy errors is reduced.)

1. A method for designing automotive millimeter wave radar waveforms for efficient speed ambiguity resolution, which is applied to a radar system, is characterized by comprising the following steps:

step S1: setting a system period, and respectively setting specific parameters of various radar waveforms; the types and the number of the radar waveforms are M, and M is at least 2;

step S2: alternately transmitting signals of a plurality of radar waveforms in a plurality of continuous system periods for at least one radar target, and only transmitting signals of one radar waveform in each system period;

step S3: respectively carrying out ADC sampling on the radar waveform in each system period to obtain ADC data of the current system period;

step S4: performing signal processing on ADC data of the current system period to obtain an information list of a radar target of the current system period, and recording the information list into a memory;

step S5: performing speed ambiguity resolution according to the information list of the radar target of the current system period and the information lists of the radar targets of the previous N system periods to acquire the real speed of the radar target;

step S6: performing target information proofreading on the radar target with the real speed by using the information list of the radar target in the current system period and the information lists of the radar targets in the previous N system periods in the step S4;

step S7: updating the speed information of the radar target passing through the proofreading into the real speed in the current system period;

step S8: repeating the steps S3 to S7;

wherein N is more than or equal to 1 and less than or equal to M-1, and N is an integer.

2. The method as claimed in claim 1, wherein in step S1, the specific parameters of the radar waveforms include idle time, rising edge time, falling edge time and rising edge slope of each radar waveform, ADC sampling frequency, the number of ADC sampling points of each radar waveform and the number of the radar waveforms in the corresponding system period, and the periods of the radar waveforms are different from each other.

3. The method for designing automotive millimeter wave radar waveforms for efficient speed disambiguation according to claim 1, wherein in the step S1, the number of types of radar waveforms is two, including a first waveform and a second waveform.

4. The method as claimed in claim 1, wherein in step S4, the signal processing includes windowing, 2D-FFT processing, multi-channel incoherent accumulation, peak detection and constant false alarm rate detection, so as to obtain a two-dimensional FFT result graph of the radar waveform of the current system cycle, and further obtain an information list of the radar target of the current system cycle.

5. The method as claimed in claim 1, wherein in step S4, the information list of the radar target in the current period includes energy, signal-to-noise ratio, scattering area of the radar target, distance dimension index value of the radar target, and doppler dimension index value of the radar target, where the energy, signal-to-noise ratio, scattering area of the radar target, distance dimension index value of the radar target, and doppler dimension index value of the radar target are obtained by processing each of multiple radar waveforms, and the distance dimension index of the radar target is frequency shift f of the radar target due to distance_R1Index value of Doppler dimension of radar target, i.e. Doppler frequency f of radar target caused by velocity_d1。

6. The automotive millimeter wave radar waveform design method for efficient speed disambiguation according to claim 1, wherein the step S5 includes:

step S51: according to the information list of the radar target of the current system period, the distance R of each radar target in the current system period is obtained₁And a fuzzy velocity V₁₀(ii) a According to the previous radar target information list of N system periods, obtaining the distance R of each radar target in the previous N system periods_iAnd a moldPaste velocity V_i0，i＝2,3,…N+1；

Step S52: and screening out radar targets serving as equidistant radar targets according to the distances of the radar targets in the current system period and the previous N system periods, and performing speed matching on the equidistant radar targets to obtain the true speed value of each radar target serving as the equidistant radar target.

7. The method as claimed in claim 6, wherein in step S51, the distance R of the radar target in the current system cycle is₁Comprises the following steps:

wherein f is_R1Frequency shift of radar target due to distance, c is speed of light, μ₁The slope of the rising edge of the radar waveform of the current system period;

and the fuzzy velocity V of the radar target in the current system period₁₀Comprises the following steps:

wherein f is_d1Doppler frequency, lambda, due to velocity of radar target₁The wavelength of the radar waveform of the current system cycle.

8. The method as claimed in claim 6, wherein in step S52, the radar targets are selected as equidistant radar targets by traversing within a preset distance difference threshold Δ R according to the distance between the current system cycle and the previous N system cycles.

9. The method for designing automotive millimeter wave radar waveform for efficient speed disambiguation according to claim 6, wherein in said step S52, performing speed matching on a peer-to-peer radar target comprises:

fuzzy velocity V of radar target as equidistant radar target in current system period₁₀The fuzzy speeds of the radar target in the previous N system periods are equal or different from each other by less than a speed difference threshold value V_TAnd then the speed truth value V of the radar target in the current system period₁Is equal to the fuzzy velocity V of the radar target in the current system period₁₀A true speed value V of the radar target in the previous i-th system cycle_iIs equal to the fuzzy velocity V of the radar target in the previous i-th system period_i0I ═ 2,3, … N + 1; the speed truth value V of the radar target is selected based on practical application, and the speed truth value V is the average value of the speed truth values of the radar target in the current system period and the previous N system periods, or the speed truth value V of the radar target in the current system period₁；

Fuzzy velocity V of radar target as equidistant radar target in current system period₁₀In the fuzzy speeds of the previous N system periods of the radar target, the difference value of any two fuzzy speeds is larger than the speed difference threshold value V_TAnd then the speed truth value V of the radar target in the current system period₁Possible values of (A) include V₁₀±m*V_max1Possible values of the speed true value Vi of the radar target in the previous i-th system cycle include V_i0±n*V_maxi，i＝2,3,…N+1，V₁₀Is the fuzzy speed, V, of the radar target in the current system period_max1Is the maximum value of the target speed, V, detected by the radar waveform transmitted in the current system period_i0Is the fuzzy velocity, V, of the radar target in the previous i-th system period_maxiThe maximum value of the target speed which can be detected by the radar waveform transmitted in the previous ith system period; then compare V₁Possible values of (1) and (V)_iWhen the difference between the two is less than the speed difference threshold V_TAt this time, V₁Possible values of (1) and (V)_iIs the true value V of the radar target speed in the current system cycle₁And the speed truth value V of the previous ith system period of the equidistant radar target_i(ii) a The speed truth value V of the radar target is the average value of the speed truth values of the radar target in the current system period and the previous N system periods, or the speed truth value V of the radar target in the current system period₁。

10. The automotive millimeter wave radar waveform design method for high-efficiency speed ambiguity resolution of claim 6, wherein in the step S6, the corrected target information includes angle, energy; the proofreading includes: and checking target information in the information list of the radar target with the real speed in the current system period and the information list of the radar targets with the N previous system periods, if the difference value of the checked target information is larger than a parameter setting threshold value, directly discarding the radar target, otherwise, checking the radar target to pass.

Technical Field

The invention belongs to the field of automobile millimeter wave radar design, and particularly relates to an automobile millimeter wave radar waveform design method for high-efficiency speed ambiguity resolution.

Background

With the rapid development of the current automatic driving industry, the millimeter wave radar sensor is used as an important component unit of an automobile intelligent driving auxiliary system, and the performance requirements of people are higher and higher. Generally, an automotive radar system needs to accurately measure information such as distance, speed and angle of a target object in real time, and even in the case of multiple targets, the targets need to be accurately distinguished and tracked through speed ambiguity resolution. To fulfill this requirement, the waveform design of millimeter wave radar sensors is a very important part of the design of radar systems. However, the conventional millimeter wave radar waveform design has the defects of large capacity required by the RAM, long update period and the like.

Fig. 1 is a schematic diagram of a single waveform of a typical transmit waveform, which is a fast sawtooth waveform. It can be seen that a transmit waveform includes idle time t1, rising edge time t2, and falling edge time t3 (where idle time t1 can be omitted for simplicity), and the idle time t1, rising edge time t2, and falling edge time t3 form a period of the transmit waveform.

As shown in fig. 2, currently, when a millimeter wave radar obtains a speed of a radar target through speed ambiguity resolution, the requirement of a vehicle-mounted auxiliary system on performance indexes such as a maximum speed range, a speed resolution and the like of the millimeter wave radar is limited, and usually a system update period T is required_STwo kinds of first waveform A and second waveform B (AB wave) with different periods are internally transmitted to obtain actual speed information of the target. Specifically, at present, in terms of waveform design of millimeter wave radar, in one system update period T for speed deblurring_SThe waveform generator generally comprises L1 first waveforms A and L2 second waveforms B, wherein the rising edge slope, the rising edge time, the idle time and the falling edge time (only the falling edge can be set) of the first waveforms A and the second waveforms B are set, and the period T of the first waveform A is generally_AAnd a period of the second waveform B, wherein a period refers to a time of one complete waveform. However, the waveform design occupies a relatively large amount of RAM space of the whole vehicle-mounted auxiliary systemIn addition, due to waveform design and the requirement for speed ambiguity resolution, the data volume required to be stored and processed in each system period can be rapidly increased along with the improvement of indexes such as speed resolution and the like, so that the requirement of the whole millimeter wave radar system on the capacity of the RAM is high; meanwhile, due to the long period and high optimization difficulty, the system updating period of the whole millimeter wave radar system is difficult to shorten, so that the increasingly urgent requirements of customers such as host factories on the shortening of the updating and alarming periods of the millimeter wave radar sensor are difficult to meet, and the period of the whole system is difficult to be reduced to be less than 40 ms.

Disclosure of Invention

The invention aims to provide a method for designing a waveform of an automotive millimeter wave radar for high-efficiency speed ambiguity resolution, so as to reduce the required storage capacity, reduce the system period and reduce the risk of ambiguity resolution errors.

In order to achieve the above object, the present invention provides a method for designing a millimeter wave radar waveform for an automobile with efficient speed ambiguity resolution, which is used for a radar system, and comprises:

step S1: setting a system period, and respectively setting specific parameters of various radar waveforms; the types and the number of the radar waveforms are M, and M is at least 2;

step S2: alternately transmitting signals of a plurality of radar waveforms in a plurality of continuous system periods for at least one radar target, and only transmitting signals of one radar waveform in each system period;

step S3: respectively carrying out ADC sampling on the radar waveform in each system period to obtain ADC data of the current system period;

step S4: performing signal processing on ADC data of the current system period to obtain an information list of a radar target of the current system period, and recording the information list into a memory;

step S5: performing speed ambiguity resolution according to the information list of the radar target of the current system period and the information lists of the radar targets of the previous N system periods to acquire the real speed of the radar target;

step S6: performing target information proofreading on the radar target with the real speed by using the information list of the radar target in the current system period and the information lists of the radar targets in the previous N system periods in the step S4;

step S7: updating the speed information of the radar target passing through the proofreading into the real speed in the current system period;

step S8: repeating the steps S3 to S7;

wherein N is more than or equal to 1 and less than or equal to M-1, and N is an integer.

In step S1, the specific parameters of the radar waveforms include idle time, rising edge time, falling edge time, and rising edge slope of each radar waveform, ADC sampling frequency, the number of ADC sampling points of each radar waveform, and the number of wave emissions of each radar waveform in a corresponding system period, where the periods of the radar waveforms are different from each other.

In step S1, the number of types of radar waveforms is two, including a first waveform and a second waveform.

In the step S4, the signal processing includes windowing, 2D-FFT processing, multi-channel incoherent accumulation, peak detection, and constant false alarm rate detection, so as to obtain a two-dimensional FFT result diagram of the radar waveform of the current system period, and further obtain an information list of the radar target of the current system period.

In step S4, the information list of radar targets in the current cycle includes energy, signal-to-noise ratio, scattering area, distance dimension index value and doppler dimension index value of radar target, which are obtained by processing each of multiple radar waveforms, and the distance dimension index, i.e. frequency shift f of radar target due to distance_R1Index value of Doppler dimension of radar target, i.e. Doppler frequency f of radar target caused by velocity_d1。

The step S5 includes:

step S51: according to the information list of the radar target of the current system period, the distance R of each radar target in the current system period is obtained₁And a fuzzy velocity V₁₀(ii) a According to the previous radar target information list of N system periods, obtaining the distance R of each radar target in the previous N system periods_iAnd a fuzzy velocity V_i0，i＝2,3,…N+1；

Step S52: and screening out radar targets serving as equidistant radar targets according to the distances of the radar targets in the current system period and the previous N system periods, and performing speed matching on the equidistant radar targets to obtain the true speed value of each radar target serving as the equidistant radar target.

In the step S51, the distance R of the radar target in the current system cycle₁Comprises the following steps:

wherein f is_R1Frequency shift of radar target due to distance, c is speed of light, μ₁The slope of the rising edge of the radar waveform of the current system period;

and the fuzzy velocity V of the radar target in the current system period₁₀Comprises the following steps:

wherein f is_d1Doppler frequency, lambda, due to velocity of radar target₁The wavelength of the radar waveform of the current system cycle.

In step S52, according to the distances of the radar targets in the current system cycle and the previous N system cycles, the radar targets are screened out as equidistant radar targets by traversing within a preset distance difference threshold Δ R.

In step S52, performing speed matching on the peer-to-peer distance radar target includes:

fuzzy velocity V of radar target as equidistant radar target in current system period₁₀The fuzzy speeds of the radar target in the previous N system periods are equal or different from each other by less than a speed difference threshold value V_TAnd then the speed truth value V of the radar target in the current system period₁Is equal to the fuzzy velocity V of the radar target in the current system period₁₀A true speed value V of the radar target in the previous i-th system cycle_iIs equal to the fuzzy velocity V of the radar target in the previous i-th system period_i0I ═ 2,3, … N + 1; the speed truth value V of the radar target is selected based on practical application, and the speed truth value V is the average value of the speed truth values of the radar target in the current system period and the previous N system periods, or the speed truth value V of the radar target in the current system period₁；

Fuzzy velocity V of radar target as equidistant radar target in current system period₁₀In the fuzzy speeds of the previous N system periods of the radar target, the difference value of any two fuzzy speeds is larger than the speed difference threshold value V_TAnd then the speed truth value V of the radar target in the current system period₁Possible values of (A) include V₁₀±m*V_max1Possible values of the speed true value Vi of the radar target in the previous i-th system cycle include V_i0±n*V_maxi，i＝2,3,…N+1，V₁₀Is the fuzzy speed, V, of the radar target in the current system period_max1Is the maximum value of the target speed, V, detected by the radar waveform transmitted in the current system period_i0Is the fuzzy velocity, V, of the radar target in the previous i-th system period_maxiThe maximum value of the target speed which can be detected by the radar waveform transmitted in the previous ith system period; then compare V₁Possible values of (1) and (V)_iWhen the difference between the two is less than the speed difference threshold V_TAt this time, V₁Possible values of (1) and (V)_iIs the true value V of the radar target speed in the current system cycle₁And the speed truth value V of the previous ith system period of the equidistant radar target_i(ii) a The speed truth value V of the radar target is the average value of the speed truth values of the radar target in the current system period and the previous N system periods, or the radar target is in the current system periodSpeed truth value V of front system period₁。

In the step S6, the corrected target information includes an angle and an energy; the proofreading includes: and checking target information in the information list of the radar target with the real speed in the current system period and the information list of the radar targets with the N previous system periods, if the difference value of the checked target information is larger than a parameter setting threshold value, directly discarding the radar target, otherwise, checking the radar target to pass.

According to the automobile millimeter wave radar waveform design method for high-efficiency speed ambiguity resolution, only one waveform is transmitted in each system period, so that the transmission time of the system waveform can be effectively shortened, the updating period of the whole radar system is reduced, the response rate of the whole radar system is improved, the requirements of customers such as a host factory are met better, and a faster system alarm period is provided; in addition, the automobile millimeter wave radar waveform design method for high-efficiency speed ambiguity resolution can be quickly optimized on the basis of the existing waveform, the implementation difficulty is low, meanwhile, the memory only needs to record the information list of the radar target in each period, and the storage space of the memory except the information list of the radar target in signal processing can be reused in each system period, so that the required storage capacity of the memory is reduced, the method has more advantages in device selection, the cost of the whole system is effectively reduced, and the processing space is provided for the more complex automatic driving function; in addition, the invention can effectively reduce the risk of speed ambiguity resolution error and improve the stability and reliability of the whole sensor system by increasing the proofreading of indexes such as angle, energy and the like of the same target.

Drawings

FIG. 1 is a schematic diagram of a single waveform of a typical fast sawtooth.

Fig. 2 is a timing diagram of transmission of a conventional first waveform and a second waveform.

FIG. 3 is a basic flow diagram of an automotive millimeter wave radar waveform design method for efficient speed disambiguation according to one embodiment of the invention.

FIG. 4 is a timing diagram of the transmission of the first waveform and the second waveform after optimization according to the method for designing the automotive millimeter wave radar waveform for efficient speed ambiguity resolution.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 3 shows a method for designing a millimeter wave radar waveform for an automobile for efficient speed ambiguity resolution according to an embodiment of the present invention, which is applied to a radar system, especially a millimeter wave radar system. The technical idea of the automobile millimeter wave radar waveform design method for high-efficiency speed ambiguity resolution is as follows: the method comprises the steps of splitting a first waveform and a second waveform which are originally transmitted in one system period, sequentially transmitting the first waveform and the second waveform in adjacent system periods, then carrying out speed deblurring on target information obtained after signal processing of the current system period and the previous period to obtain actual speed information of a target, and carrying out proofreading through information such as energy and angle of the target to prevent the situation of speed deblurring errors.

Based on the principle, the automobile millimeter wave radar waveform design method for high-efficiency speed ambiguity resolution comprises the following steps:

step S1: configuring a radar waveform, specifically comprising: setting a system period T_SSetting specific parameters of various radar waveforms respectively;

the specific parameters of the multiple radar waveforms include respective idle time, rising edge time, falling edge time, rising edge slope, ADC sampling frequency, ADC sampling point number of each radar waveform, wave sending number of the multiple radar waveforms in a corresponding system period, and the like. The periods (idle time + rising edge time + falling edge time) of the plurality of radar waveforms are different from each other.

In the present embodiment, the number of radar waveforms is two, including a first waveform a and a second waveform B, and the periods of the first waveform a and the second waveform B are different. The idle time, rising edge time, falling edge time and rising edge slope of the first waveform a and the second waveform B, the ADC sampling frequency, the number of ADC sampling points of each radar waveform, and the number of transmit waves of the plurality of radar waveforms in the corresponding system period may be the same or different. In other embodiments, the number of types of radar waveforms is M, and M is at least 2 and is not limited to 2.

The specific parameters of the plurality of radar waveforms do not include a falling edge slope because no additional falling edge slope is required.

Step S2: signals of a plurality of radar waveforms are alternately transmitted in a plurality of continuous system periods for at least one radar target, and only signals of one radar waveform are transmitted in each system period.

As shown in fig. 4, since the radar waveform includes the first waveform a and the second waveform B in the present embodiment, the first waveform a and the second waveform B are sequentially transmitted in two adjacent system periods, and only one radar waveform is transmitted in each system period; the emission timing diagrams of the optimized first waveform a and the second waveform B are shown in fig. 4. In the present embodiment, the first waveform a and the second waveform B are fast sawtooth waveforms, but the present invention is not limited to such radar waveforms, for example, the present invention can also be applied to waveforms such as fast sawtooth and its variants, LFMSK, etc. Therefore, the automobile millimeter wave radar waveform design method for high-efficiency speed ambiguity resolution can be quickly optimized on the basis of the existing waveform, and the realization difficulty is low.

Step S3: and in each system period, respectively carrying out ADC sampling on the radar waveform transmitted in the current system period to obtain ADC data of the current system period.

Wherein the ADC sampling is only performed on the rising edge of each radar waveform, so as to acquire ADC data of a plurality of sampling points on each rising edge, and not performed in idle time and part of the falling edge.

The number of ADC data sampled by the rising edge of different types of radar waveforms transmitted in different system periods may be the same or different, and the different types of radar waveforms may be different.

Specifically, in the present embodiment, the radar waveform includes a first waveform a and a second waveform B. Thus, in the transmittingA system period of waveform A, N is obtained by collecting the rising edge of each first waveform A_AData of ADC (analog to digital converter) of sampling points, N is sampled in total in one system period_A*L_AA sampling point, N_AFor each number of sampling points, L, of the first waveform A_AThe number of wave sending of the first waveform A in the corresponding system period is shown; similarly, during the system period of transmitting the second waveform B, N is sampled in total in one system period_B*L_BA sampling point, N_BFor each second waveform B number of samples, L_BThe number of the wave-sending of the second waveform B in the corresponding system period.

For convenience of description, it is assumed in this embodiment that the numbers of ADC data sampled at the rising edge of each of the first waveform a and the second waveform B are the same, and are both N_{Wave form}The number of wave sending of the first waveform A and the second waveform B in each system period is L, and N is collected in one system period when the first waveform A and the second waveform B are transmitted_{Wave form}L sampling points. The number L of wave emissions of the first waveform a and the second waveform B per system period is an exponential power of 2.

Step S4: and processing the ADC data of the current system period to obtain an information list of the radar target of the current system period, and recording the information list into a RAM to record the information list of the radar target of the current system period and the information lists of the radar targets of a plurality of previous system periods.

Therefore, the RAM only needs to record the information lists of the radar targets in each period, wherein the information lists comprise the information list of the radar target in the current system period and the information lists of the radar targets in a plurality of previous system periods, the storage space of the RAM except the information lists of the radar targets is reusable, and after the algorithm processing in each period is completed, the information lists of the radar targets are obtained and then automatically released.

The signal processing is performed according to a conventional radar signal processing flow, which includes but is not limited to windowing, 2D-FFT processing, multi-channel incoherent accumulation, peak detection, and Constant False Alarm Rate (CFAR) detection, to process the two signals to obtain a radar waveform of the current system periodAnd (4) a dimensional FFT result graph, namely obtaining corresponding points of each radar target on a two-dimensional FFT result graph axis, and further obtaining an information list of the radar target in the current system period. The information list of the radar target of the current system period mainly includes an angle, energy, a signal-to-noise ratio (SNR) of the radar target, a scattering area (RCS) of the radar target, a distance dimension index value of the radar target, a doppler dimension index value of the radar target, and the like, wherein the distance dimension index of the radar target is a frequency shift f of the radar target due to distance_R1Index value of Doppler dimension of radar target, i.e. Doppler frequency f of radar target caused by velocity_d1. These two values can be directly obtained in the two-dimensional FFT result map.

Step S5: performing speed ambiguity resolution according to the information list of the radar target in the current system period and the information lists of the radar targets in N system periods before the current system period to obtain the real speed V of the radar target;

when the number of the types of the radar waveforms is M and more than two, the data of the current system period can be compared with the data of the previous period only, and can also be compared with the data of the previous M-1 system periods, so that N is more than or equal to 1 and less than or equal to M-1, N is an integer, and the specific numerical value of N is determined according to practical application.

Wherein the velocity deblurring is based mainly on the following principle:

maximum value V of target speed capable of being detected by multiple radar waveforms_maxRespectively as follows:

where λ is the wavelength of the radar waveform, T_chirpThe period of the radar waveform.

Therefore, the velocity measurement ranges of the various radar waveforms are different.

Specifically, when the number of radar waveforms is two, including the first waveform a and the second waveform B, the maximum value V of the target speed that can be detected by the first waveform a without speed deblurring is performed_maxAAnd do not perform velocity solutionMaximum value V of target speed capable of being detected by second waveform B under fuzzy condition_maxBDifferent. That is, for the first waveform A, the velocity measurement range without velocity deblurring is-V_maxA～V_maxAThe velocity measurement range of the second waveform B is-V_maxB～V_maxBTheir values are different.

For convenience of description, it is assumed that the number of ADC sampling points of multiple radar waveforms in one system period is identical, and is N_{Wave form}L. In adjacent system periods, the distances of the same radar target on the one-dimensional FFT corresponding to the various radar waveforms are very close and can basically correspond to one another. But since the actual sampling rate fs isAnd the periods of the various radar waveforms are different from each other, so that the actual sampling rates of the various radar waveforms are different. This also causes the resolution bandwidths fs/L of the two-dimensional FFT result graphs corresponding to the multiple radar waveforms to be different, and further, for the same radar target, the doppler dimension index values (i.e., velocity units) of the radar targets corresponding to the multiple radar waveforms are also different.

The step S5 specifically includes:

step S51: according to the information list of the radar target of the current system period, the distance R of each radar target in the current system period is obtained₁And a fuzzy velocity V₁₀(ii) a According to the previous radar target information list of N system periods, obtaining the distance R of each radar target in the previous N system periods_iAnd a fuzzy velocity V_i0(i ═ 2,3, … N +1) (1 ≦ N ≦ M-1 and N is an integer).

Distance R of radar target in current system period₁Comprises the following steps:

wherein f is_R1Frequency shift of radar target due to distance, c is speed of light, μ₁Of radar waveforms for the current system periodThe slope of the rising edge.

Fuzzy velocity V of radar target in current system period₁₀Comprises the following steps:

wherein f is_d1Doppler frequency, lambda, due to velocity of radar target₁The wavelength of the radar waveform of the current system cycle.

And the distance and the fuzzy speed of each radar target in the previous N system periods can be obtained by the same method.

Step S52: screening out radar targets serving as equidistant radar targets according to the distance between each radar target in the current system period and N (N is more than or equal to 1 and less than or equal to M-1, and N is an integer) previous system periods, and performing speed matching on the equidistant radar targets to obtain a true speed value of each radar target;

because the targets of the same radar target are very close in the adjacent M system periods, the distances of the same radar target in the current system period and the previous N system periods are very close (the distance difference is smaller than a preset distance difference threshold), and therefore, the radar targets serving as equidistant radar targets are screened out by traversing within a preset distance difference threshold Δ R according to the distances of the radar targets in the current system period and the previous N system periods. The screened equidistant radar targets are possibly the same radar target, and the number of the screened equidistant radar targets can be one or more.

The speed matching of the equal-distance radar target specifically comprises the following steps:

fuzzy velocity V of radar target as equidistant radar target in current system period₁₀Are all equal to or differ by less than a speed difference threshold V from their previous fuzzy speeds of N system cycles_TThe time is that the real speed V of the target is less than or equal to the maximum value V of the target speeds which can be detected by various radar waveforms_maxOf (V) when the radar waveform includes a first waveform A and a second waveform B<min(V_maxA，V_maxB) Speed does not return, then the true speed value V of the radar target in the current system period₁Is equal to the fuzzy velocity V of the radar target in the current system period₁₀A true speed value V of the radar target in the ith previous system cycle (i.e., the ith last system cycle)_iIs equal to the fuzzy velocity V of the radar target in the previous i-th system period_i0(i ═ 2,3, … N + 1). At this time, the radar target as the equidistant radar target obtains a true speed value, the true speed value V is selected according to practical application, and may be an average value of true speed values of the radar target in the current system period and the previous N system periods, or a true speed value V of the radar target in the current system period₁。

Fuzzy velocity V of radar target as equidistant radar target in current system period₁₀The fuzzy speed of the previous N system cycles is compared with the fuzzy speed, and the difference value of any two fuzzy speeds is larger than the speed difference threshold value V_TTime (V)₁≠V_i) Meaning that the target true velocity V is greater than the maximum value V of the target velocities that can be detected by the various radar waveforms_maxIf the speed is the return, the calculated speed truth values of the equidistant radar target in the current system period and the previous N system periods are subjected to return processing, namely the calculated speed truth value V of the equidistant radar target in the current system period is considered₁Possible values of (A) include V₁₀±m*V_max1Possible values of the velocity true value Vi of the equidistant radar target in the previous i-th system cycle include V_i0±n*V_maxiI is 2,3, … N +1, wherein V₁₀Is the fuzzy speed, V, of the radar target in the current system period_max1Is the maximum value of the target speed, V, detected by the radar waveform transmitted in the current system period_i0Is the fuzzy velocity, V, of the radar target in the previous i-th system period_maxiThe maximum value of the target speed which can be detected by the radar waveform transmitted in the previous ith system period; then comparing the speed truth value V of the radar target in the current system period₁Multiple possible values ofAnd a true speed value V of the radar target in the previous i-th system period_iWhen V is a plurality of possible values₁Possible values of (1) and (V)_iIs less than the speed difference threshold V_TAt this time, V₁Possible values of (1) and (V)_iIs the true value V of the radar target speed in the current system cycle₁And a true speed value V of the radar target in the previous i-th system period_i. At this time, the radar target as the equidistant radar target obtains a true speed value, the true speed value V is selected according to practical application, and may be an average value of true speed values of the radar target in the current system period and the previous N system periods, or a true speed value V of the radar target in the current system period₁。

Wherein, V₁And V_iGet V at most_max1And N number of V_maxiLeast common multiple V of_cmAnd (i is 2,3, … N +1), if the value is larger than the least common multiple, the speed measurement range of the ambiguity resolution algorithm is exceeded, and the real speed of the target cannot be obtained at the moment. Thus, m has a value in the range of (-V)_cm/V_max1)～(V_cm/V_max1) Where n is an integer having a value in the range of (-V)_cm/V_maxi)～(V_cm/V_maxi) The whole number of (c). Said speed difference threshold value V_TThe flexible adjustment setting is performed based on radar characteristics, speed resolution, application examples and the like, and is not a fixed formula.

Step S6: and performing target information proofreading on the radar target with the real speed V by using the information list of the radar target in the current system period and the information lists of the radar targets in the previous N system periods in the step S4.

In this embodiment, the collated object information includes an angle and energy, and in other embodiments, the collated object information may further include object information such as RCS of the object.

The proofreading includes: and (4) checking target information in the information list of the radar target with the real speed V in the current system period and the information list of the radar targets with the previous N system periods, if the difference value of the checked target information in the information lists is larger than a parameter setting threshold value, directly discarding the radar target, otherwise, checking the radar target to be passed, and executing the step S7.

Step S7: and updating the speed information of the radar target passing through the proofreading into the real speed V in the current system period.

Because the number of the radar targets obtaining the real speed V can be multiple, and the number of the radar targets passing through the calibration can also be multiple, the radar targets can be multiple radar targets updated simultaneously, and the speed information of each radar target is updated respectively according to the above ambiguity resolution method.

Further, step S8 is included: the steps S3 to S7 are repeated to realize the cyclic operation of the radar system. For example, the radar waveform comprises a first waveform A and a second waveform B, the transmitted waveform in the period is the second waveform B, and then the speed deblurring and the correction updating are carried out on the target information list obtained from the first waveform A in the previous period; the waveform transmitted in the period is the first waveform A, and then the speed deblurring and the correction updating are carried out on the target information list obtained by the second waveform B in the previous period.

As described above, the present invention is only a preferred embodiment, and is not intended to limit the scope of the present invention, and various changes may be made in the above embodiments of the present invention, for example, the method for designing a millimeter wave radar waveform for an automobile with high-efficiency speed ambiguity resolution may also be applied to a transmission method of a MIMO type radar waveform, and an improvement of the transmission method of the MIMO type radar waveform is that a waveform corresponds to one system period, and meanwhile, improvement, simplification, addition of a redundant unit, and the like according to the waveform design idea and a system processing strategy should also be considered as a protection scope of the present application. All simple and equivalent changes and modifications made according to the claims and the content of the specification of the present application fall within the scope of the claims of the present patent application. The invention has not been described in detail in order to avoid obscuring the invention.