Vehicle-mounted multi-millimeter-wave radar anti-interference processing method, system and platform based on time delay and frequency diversity

Abstract

The invention discloses a vehicle-mounted multi-millimeter-wave radar anti-interference processing method, system and platform based on time delay and frequency diversity. First data corresponding to at least two millimeter-wave radar vehicle systems are produced and acquired through the method; controlling each millimeter wave radar to asynchronously transmit a frequency modulation continuous wave pulse train based on the corresponding first data; according to the configuration of the first data, the interference intermediate frequency signal frequency introduced by the frame start time difference between any two millimeter-wave radars exceeds the cut-off frequency of a low-pass filter on a millimeter-wave radar receiving link, and the system and the platform corresponding to the method can simply complete configuration at a high speed. The method is not limited by the performance of a radar computing platform, only depends on the radar itself, and does not need to introduce other types of sensors. The method is suitable for traditional and new-generation vehicle-mounted millimeter wave radars, and the radar interference probability is greatly reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of automotive electronic vehicle-mounted radar, and particularly relates to a vehicle-mounted multi-millimeter wave radar anti-interference processing method, system and platform based on time delay and frequency diversity. BACKGROUND

[0002] In an automatic driving system, a vehicle-mounted millimeter wave radar is one of important sensors, which is responsible for detecting perception and realizing target positioning. Compared with other sensors such as cameras and laser radars, the vehicle-mounted millimeter wave radar has the advantages of low cost, long detection distance, all-weather operation, and direct acquisition of Doppler velocity.

[0003] In recent years, with a series of supporting policies gradually implemented and orderly development of pilot work in various places, the development momentum of the automatic driving field is good. At present, the millimeter wave radar has developed to 4D millimeter wave radar: in addition to the ranging, speed measurement, and azimuth angle (3D) measurement of traditional radars, there is also the 1D dimension of the pitch angle measurement. The millimeter wave radar can realize accurate perception and identification of vehicles, pedestrians, bicycles, motorcycles and other traffic participants, thereby improving the safety and efficiency of traffic, reducing traffic accidents and congestion, reducing energy consumption and emissions, and improving the comfort and convenience of travel. The millimeter wave radar can also be combined with Internet of Vehicles, cloud computing, big data and other technologies to realize real-time collection, analysis and sharing of traffic information, thereby providing strong support for planning, management and service of intelligent transportation and smart city.

[0004] In addition, the millimeter wave radar can also be applied to other fields such as security, medical treatment, industry, agriculture and the like, and shows broad market prospects and social value.

[0005] With the rapid evolution of intelligent driving technology to L3 level, the anti-interference capability of the vehicle-mounted millimeter wave radar as a core environmental perception sensor has become a key node of the industry technology challenge. At present, the technical challenge mainly comes from two dimensions: spectrum resource bottleneck, the 3GHz bandwidth of the existing vehicle-mounted 77GHz frequency band (76-79GHz) is already very crowded, and all vehicle-mounted millimeter wave radars use the 3GHz spectrum resource. The 24GHz frequency band will be globally retired in 2028, further compressing the available spectrum space; a large number of vehicles are equipped with 1 to 5 vehicle-mounted millimeter wave radars, and many vehicle manufacturers use products provided by the same brand radar manufacturer, and the parameters and configurations are often the same, so it is easier to interfere with each other.

[0006] Now the industry proposes three main technical paths to resist interference: encoding reconstruction, using random frequency hopping FMCW waveform, so that the interference signal presents a pseudo-random distribution in the range-Doppler domain, which can realize 83% improvement of interference isolation; AI filtering, the AI filter can dynamically identify more than 87% of the same frequency interference characteristics through online learning; Heterogeneous fusion, Tesla HW5.0 scheme proves that the fusion of millimeter wave radar point cloud and camera pixel level can reduce the false alarm rate to 0.2 times per thousand kilometers.

[0007] The above solutions have two limitations: high demand for computing resources. For example, the memory resources (several tens of Mbytes) and computing power required to deploy AI models are often impractical for vehicle-mounted millimeter wave radars (the memory is usually less than 10 Mbytes); second, other types of sensors need to be introduced, and the radar algorithm alone is not enough to solve the problem. For example: for a common scenario: every car produced by a certain car manufacturer is equipped with several millimeter wave radars manufactured by the same supplier, and there are a large number of cars produced by the car manufacturer on the road in the same area.

[0008] Therefore, in view of the above technical problems and defects, it is urgent to design and develop a vehicle-mounted multi-millimeter wave radar anti-interference processing method, system and platform based on time delay and frequency diversity. SUMMARY

[0009] In order to overcome the deficiencies and difficulties of the prior art, the purpose of the present application is to provide a vehicle-mounted multi-millimeter wave radar anti-interference processing method, system and platform based on time delay and frequency diversity, which can be configured simply and quickly, is not limited by the performance of the radar computing platform, and only relies on the radar itself without introducing other types of sensors; suitable for traditional and new generation vehicle-mounted millimeter wave radars, greatly reducing the probability of radar being interfered.

[0010] The first purpose of the present application is to provide a vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity; the second purpose of the present application is to provide a vehicle-mounted multi-millimeter wave radar anti-interference processing system based on time delay and frequency diversity; the third purpose of the present application is to provide a vehicle-mounted multi-millimeter wave radar anti-interference processing platform based on time delay and frequency diversity.

[0011] The first purpose of the present application is achieved as follows: the method comprises the following steps:

[0012] The method is applied to a vehicle system comprising at least two millimeter wave radars; the method comprises the steps of:

[0013] The first data corresponding to the at least two millimeter wave radar vehicle systems is produced and obtained; wherein the first data is the frame transmission delay time, and the frame transmission delay time is the delay amount of the starting transmission time of the first pulse of each millimeter wave radar per frame signal relative to a common time reference;

[0014] The control of each of the millimeter wave radars is based on its corresponding first data, and the frequency-modulated continuous wave pulse trains are transmitted asynchronously; wherein the configuration of the first data is such that the interference introduced by the difference in frame start time between any two millimeter wave radars is beyond the cutoff frequency of the low-pass filter on the millimeter wave radar receiving link.

[0015] Further, the value range of the first data is between 5 microseconds and one half of the period of a single frequency-modulated continuous wave pulse.

[0016] Further, the configuration of different frame transmission delay times for each millimeter wave radar in the vehicle system specifically includes:

[0017] One millimeter wave radar in the vehicle system is designated as the master radar;

[0018] The master radar sends a trigger signal to other millimeter wave radars as slave radars when it starts to transmit its frame signal;

[0019] Each of the slave millimeter wave radars waits for the specific frame transmission delay time configured for itself after receiving the trigger signal, and then starts to transmit the respective frame signal.

[0020] Further, the control of each of the millimeter wave radars based on its corresponding first data and the asynchronous transmission of the frequency-modulated continuous wave pulse trains further includes:

[0021] Each millimeter wave radar in the vehicle system is assigned a different operating center frequency; wherein the operating bandwidth of each millimeter wave radar is set based on the center frequency assigned to it, and the operating frequency bands of any two radars do not overlap or overlap minimally.

[0022] Further, the allocation strategy of the operating center frequency and the operating bandwidth is:

[0023] The front-facing radar located at the front of the vehicle, which requires the highest detection accuracy, is assigned the lowest center frequency and the largest operating bandwidth;

[0024] The corner radars located at the four corners of the vehicle are assigned higher center frequencies and relatively smaller operating bandwidths.

[0025] The second object of the present application is achieved in that: the system is used to implement the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity, and the system comprises:

[0026] The data generation acquisition unit is configured to generate and acquire first data corresponding to at least two millimeter wave radar vehicle systems; wherein the first data is frame transmission delay time, and the frame transmission delay time is a delay amount of a starting transmission time of a first pulse of each millimeter wave radar per frame signal relative to a common time reference;

[0027] The data reflection control unit is configured to control each millimeter wave radar to transmit a frequency-modulated continuous wave pulse train based on the corresponding first data and asynchronously; wherein the first data is configured such that the interference intermediate frequency signal frequency introduced by the frame starting time difference between any two millimeter wave radars exceeds the cutoff frequency of a low-pass filter on the millimeter wave radar receiving link.

[0028] Further, the value range of the first data is between 5 microseconds and one half of the period of a single frequency-modulated continuous wave pulse;

[0029] The data reflection control unit further comprises:

[0030] The frequency configuration module is configured to assign different operating center frequencies to each millimeter wave radar in the vehicle system; wherein the operating bandwidth of each millimeter wave radar is set based on the assigned center frequency, and the operating frequency bands of any two radars do not overlap or overlap minimally.

[0031] Further, the different frame transmission delay times of each millimeter wave radar in the vehicle system specifically include:

[0032] One millimeter wave radar in the vehicle system is designated as the master radar;

[0033] The master radar sends a trigger signal to other millimeter wave radars as slave radars when it starts transmitting its frame signal;

[0034] Each slave millimeter wave radar waits for a specific frame transmission delay time configured for itself after receiving the trigger signal, and then starts transmitting its own frame signal;

[0035] The allocation strategy of the operating center frequency and the operating bandwidth is:

[0036] The forward radar located at the front of the vehicle, which requires the highest detection accuracy, is assigned the lowest center frequency and the largest operating bandwidth;

[0037] The corner radars located at the four corners of the vehicle are assigned higher center frequencies and relatively smaller operating bandwidths.

[0038] The third object of the present application is achieved by comprising a processor, a memory and a time delay and frequency diversity based anti-interference processing platform control program for vehicle-mounted multi-millimeter wave radar; wherein the processor executes the time delay and frequency diversity based anti-interference processing platform control program for vehicle-mounted multi-millimeter wave radar, the time delay and frequency diversity based anti-interference processing platform control program for vehicle-mounted multi-millimeter wave radar is stored in the memory, and the time delay and frequency diversity based anti-interference processing platform control program for vehicle-mounted multi-millimeter wave radar implements the time delay and frequency diversity based anti-interference processing method for vehicle-mounted multi-millimeter wave radar.

[0039] The present application produces and obtains first data corresponding to at least two millimeter wave radar vehicle systems by a method; wherein the first data is frame transmission delay time, and the frame transmission delay time is the delay amount of the starting transmission time of the first pulse of each millimeter wave radar per frame signal relative to a common time reference; each millimeter wave radar transmits a frequency-modulated continuous wave pulse train based on its corresponding first data and asynchronously; wherein the configuration of the first data makes the interference intermediate frequency signal frequency introduced by the difference in frame starting time between any two millimeter wave radars exceed the cutoff frequency of the low-pass filter on the millimeter wave radar receiving link, and the system and platform corresponding to the method can be simply and quickly completed, and are not limited by the performance of the radar computing platform, and only rely on the radar itself without introducing other sensors; suitable for traditional and new generation vehicle-mounted millimeter wave radars, greatly reducing the probability of radar interference. That is, by configuring different frame transmission delay times and working center frequencies for vehicle-mounted millimeter wave radars, using time delay and frequency diversity technology, the same frequency interference signals between homologous radars can be filtered out at low cost and high efficiency only by the radars themselves, the false target detection probability is significantly reduced, and the reliability and safety of the intelligent driving system in a radar dense environment are greatly improved.

[0040] That is, by configuring different frame transmission delay times and working center frequencies for vehicle-mounted millimeter wave radars, using time delay and frequency diversity technology, the same frequency interference signals between homologous radars can be filtered out at low cost and high efficiency only by the radars themselves, the false target detection probability is significantly reduced, and the reliability and safety of the intelligent driving system in a radar dense environment are greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0042] Figure 1 The scenario to be dealt with by the present application: multiple vehicles on the road are equipped with radars of the same configuration produced by the same manufacturer, which interfere with each other, and the fan-shaped diagram is a schematic diagram of the detection area of the vehicle-mounted millimeter wave radar.

[0043] Figure 2 A schematic diagram of each frequency-modulated continuous wave (FMCW) pulse of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application;

[0044] Figure 3 A schematic diagram of pulse train sampling and processing (the local oscillator signal in the figure is the transmission waveform) of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application; Figure 2

[0045] Figure 4 A schematic diagram of the waveforms of two adjacent frames of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application;

[0046] Figure 5 A schematic diagram of normal echo (dashed line) and interference waveform (dotted line), and the intermediate frequency signal generated by the difference frequency thereof and the transmission waveform of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application;

[0047] Figure 6 A schematic diagram of the intermediate frequency signal corresponding to the normal echo (dashed line) and interference waveform (dotted line) of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application;

[0048] Figure 7 A schematic diagram of the time delay anti-interference scheme of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application;

[0049] Figure 8 A schematic diagram of the arrangement of the radar on the vehicle body of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application;

[0050] Figure 9 A schematic diagram of the relative relationship of the time delay of each radar when transmitting a frame of waves of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application;

[0051] Figure 10 A schematic diagram of the arrangement of the radar on the vehicle body of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application;

[0052] Figure 11 A schematic diagram of the relative relationship of the center frequency of each radar of the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity of the present application;

[0053] Figure 12 ​A radar frequency diversity schematic diagram for an assumed radar frequency diversity of a vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity;

[0054] Figure 13 A flow step schematic diagram for a vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity;

[0055] Figure 14 A system architecture schematic diagram for a vehicle-mounted multi-millimeter wave radar anti-interference processing system based on time delay and frequency diversity;

[0056] Figure 15 A platform architecture schematic diagram for a vehicle-mounted multi-millimeter wave radar anti-interference processing platform based on time delay and frequency diversity. DETAILED DESCRIPTION

[0057] In order to better understand the purpose, technical scheme and advantages of the present application, the present application will be further described below in combination with the drawings and specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present specification.

[0058] The present application can also be implemented or applied through other different specific examples, and various modifications and changes can be made to the details in the specification based on different views and applications without departing from the spirit of the present application.

[0059] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0060] In addition, if the embodiments of the present application involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. Secondly, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of a person skilled in the art, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0061] Preferably, the time delay and frequency diversity based anti-interference processing method for vehicle-mounted multi-millimeter wave radar is applied in one or more terminals or servers. The terminal is a device capable of automatically performing numerical calculation and / or information processing according to pre-set or stored instructions, and the hardware thereof includes but is not limited to a microprocessor, an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), an embedded device, etc.

[0062] The terminal can be a desktop computer, a notebook computer, a palm computer, a cloud server, and the like. The terminal can interact with a user through a keyboard, a mouse, a remote controller, a touchpad, a voice control device, and the like.

[0063] The present application provides a time delay and frequency diversity based anti-interference processing method for vehicle-mounted multi-millimeter wave radar, a system and a platform.

[0064] As shown in Figure 13 FIG. 1 is a flowchart of the time delay and frequency diversity based anti-interference processing method for vehicle-mounted multi-millimeter wave radar provided by the present application.

[0065] In the present embodiment, the time delay and frequency diversity based anti-interference processing method for vehicle-mounted multi-millimeter wave radar can be applied in a terminal with display function or a fixed terminal, and the terminal is not limited to a personal computer, a smart phone, a tablet computer, a desktop computer or an all-in-one computer with a camera, etc.

[0066] The time delay and frequency diversity based anti-interference processing method for vehicle-mounted multi-millimeter wave radar can also be applied in a hardware environment composed of a terminal and a server connected to the terminal through a network. The network includes but is not limited to a wide area network, a metropolitan area network or a local area network. The time delay and frequency diversity based anti-interference processing method for vehicle-mounted multi-millimeter wave radar of the present application can be executed by the server, or by the terminal, or by both the server and the terminal.

[0067] For example, for a terminal that needs to perform time delay and frequency diversity based anti-jamming processing of vehicle-mounted multi-millimeter wave radar, the time delay and frequency diversity based anti-jamming processing function of vehicle-mounted multi-millimeter wave radar provided by the method of the present application can be directly integrated on the terminal, or a client for implementing the method of the present application can be installed. For another example, the method provided by the present application can also run on a server or the like in the form of a software development kit (SDK), and provide an interface of the time delay and frequency diversity based anti-jamming processing function of vehicle-mounted multi-millimeter wave radar in the form of the SDK, so that a terminal or other device can implement the time delay and frequency diversity based anti-jamming processing function of vehicle-mounted multi-millimeter wave radar through the provided interface. The present application is further described below in conjunction with the accompanying drawings.

[0068] As shown in Figure 13 The present application provides a time delay and frequency diversity based anti-jamming processing method of vehicle-mounted multi-millimeter wave radar, which is applied to a vehicle system comprising at least two millimeter wave radars; the method comprises the steps of:

[0069] S1, producing and obtaining first data corresponding to the vehicle system of the at least two millimeter wave radars; wherein the first data is a frame transmission delay time, and the frame transmission delay time is a delay amount of a starting transmission time of a first pulse of each frame signal of each millimeter wave radar relative to a common time reference;

[0070] S2, controlling each millimeter wave radar to transmit a frequency-modulated continuous wave pulse train asynchronously based on the corresponding first data; wherein the configuration of the first data is such that the interference intermediate frequency signal frequency introduced by the difference in frame starting time between any two millimeter wave radars exceeds the cutoff frequency of the low-pass filter on the millimeter wave radar receiving link.

[0071] The value range of the first data is between 5 microseconds and one half of the period of a single frequency-modulated continuous wave pulse.

[0072] The configuration of different frame transmission delay times for each millimeter wave radar in the vehicle system specifically comprises:

[0073] One millimeter wave radar in the vehicle system is designated as a master radar;

[0074] The master radar sends a trigger signal to other millimeter wave radars as slave radars when starting to transmit its frame signal;

[0075] Each slave millimeter wave radar waits for a specific frame transmission delay time configured for itself before starting to transmit its own frame signal after receiving the trigger signal.

[0076] The method of controlling each of the millimeter-wave radars to asynchronously transmit frequency-modulated continuous wave pulse trains based on their corresponding first data also includes:

[0077] S21. Assign different operating center frequencies to each millimeter-wave radar in the vehicle system; wherein, the operating bandwidth of each millimeter-wave radar is set based on its assigned center frequency, and the operating frequency bands of any two radars do not overlap or overlap very little.

[0078] The allocation strategy for the working center frequency and working bandwidth is as follows:

[0079] The lowest center frequency and the largest operating bandwidth are allocated to the forward-facing radar located directly in front of the vehicle, which has the highest detection accuracy requirements.

[0080] Assign higher center frequencies and relatively smaller operating bandwidths to the corner radars located at the four corners of the vehicle.

[0081] Specifically, in this embodiment of the invention, the vehicle-mounted millimeter-wave radar transmits a frequency-modulated continuous wave (FMCW) pulse train, sending one frame of the FMCW pulse train every 50ms to 100ms. The duration of the pulse train is typically 10-30ms, and the remaining non-transmission time of each frame is used for algorithm and software control. The duration of each FMCW pulse is approximately tens to 150µs.

[0082] like Figure 2 The diagram shows an FMCW pulse and its echo. t_delay is the round-trip time of the radar pulse, calculated using t_delay = 2R / c, where c is the speed of light and R is the distance from the radar to the target. Currently, the maximum detection range of vehicle-mounted millimeter-wave radar is within 400m; substituting this into the formula, the corresponding upper limit of t_delay is 2.67µs.

[0083] The solid line represents the transmitted waveform, and the dashed line represents the returned waveform corresponding to a specific target. After passing through a mixer, the two waveforms are essentially converted into a frequency difference. The intermediate frequency (IF) corresponding to a specific target is a fixed-frequency sine / cosine signal, which is proportional to the distance. The maximum frequency of this IF signal is limited by the cutoff frequency of the radar's low-pass filter. The cutoff frequency of the radar's low-pass filter is related to the front-end RF chip platform of the millimeter-wave radar; commercially available products are all within 40MHz, and frequencies exceeding this will be filtered out by the radar's low-pass filter.

[0084] like Figure 5 As shown, this is a scenario with interference waveforms. The interference waveform (generated by another radar) indicated by the dotted line causes an intermediate frequency signal. If it falls within the radar's low-pass filter band, it will generate a false target.

[0085] The relationship between the intermediate frequency (IF), the slope (S) of the pulse waveform, and the pulse transmit / receive time delay (t_delay) is as follows:

[0086] IF = S * t_delay (1)

[0087] From the foregoing, the vehicle-mounted millimeter wave radar transceiver delay t_delay≤2.67us. The pulse slope S is related to the radar system index, usually between 5MHz / us to 20MHz / us. The radar low-pass filter bandwidth is related to the chip platform used, usually within 40MHz. Therefore, it can be conceived that the first pulse of each frame of different radars installed on the vehicle is staggered by a fixed time delay, that is, the pulses are also staggered by such a delay. So that the intermediate frequency frequency generated by the interference of one radar to another radar falls outside the cut-off frequency of the radar low-pass filter, so that it is filtered by the filter and cannot produce false targets.

[0088] Take a typical design of a vehicle-mounted millimeter wave radar as an example: frame period 50ms, pulse slope S is 10MHz / us, radar low-pass filter bandwidth 25MHz, each pulse duration 50us, pulse period 60us. Let the starting time of each frame of the two radars (i.e. the starting time of the first pulse) be delayed by 10us, and the corresponding intermediate frequency signal frequency is calculated by formula (1) to be 250MHz, which exceeds the low-pass filter cut-off frequency of 25MHz. The electromagnetic wave signals of the two radars do not interfere with each other. The delay of 10us accounts for 10 / 50000 of the frame period of 50ms, which is very small and will not affect the performance of the radar.

[0089] However, it is meaningless to delay the starting time of each frame too much, for example, to increase the delay to 60us. Although the first pulse of each frame of the two radars will not interfere with each other (because the corresponding intermediate frequency signal is 600MHz, far exceeding the low-pass filter cut-off frequency), the first pulse of the radar that delays 60us will coincide with the second pulse of the other radar (pulse period 60us), which will interfere with all the subsequent pulses of the second pulse. Increase the delay more than 60us, for example, delay 70us, because of the periodicity of the pulse, it is equivalent to the effect of delaying 10us. Therefore, the selection of the delay time should be carefully considered according to the specific radar waveform. For N radar scenarios, the delay time is usually selected between 5us and 1 / 2N of the pulse period.

[0090] As shown in Figure 7 , a diagram of the foregoing anti-interference principle: a pulse of the radar that emits interfering waveform (dotted line) is delayed t_delay (interference) relative to the other radar (solid line). The intermediate frequency of the interference signal generated by this time delay exceeds the upper limit of the intermediate frequency determined by the low-pass filter and is filtered by the filter.

[0091] A typical layout of 5 radars around a bus. The timing of the wave is taken as reference for the front corner radar 1, the delay of the front corner radar 2 is Td_2 and has a size of delta; the delay of the back corner radar 3 is Td_3 and has a size of 2 delta; the delay of the back corner radar 4 is Td_4 and has a size of 3 delta; the delay of the front radar is Td_F and has a size of 4 delta. The value of delta ranges from 5us to 1 / 10 of the pulse period. A simple way to achieve synchronization between radars is to use a master / slave mode. In this scheme, one radar is designated as master. This radar generates a trigger signal to the slave radars when sending a frame. The slave radars then delay and use this signal to trigger their own frame after a precisely defined delay.

[0092] On the basis of the time-delay anti-jamming scheme, frequency diversity anti-jamming measures can be superimposed to enhance the robustness of the system against jamming. Specifically, as shown in FIG. 6, the radar system can be divided into two groups, and the radars in each group are synchronized with each other. The radars in the two groups are synchronized with each other with a time delay of Td. Figures 10-11As shown, the front radar center frequency is set to 76.5 GHz, the front corner radar 1 center frequency is set to 78.75 GHz, the front corner radar 2 center frequency is set to 77.25 GHz, the rear corner radar 3 center frequency is set to 77.75 GHz, and the rear corner radar 4 center frequency is set to 78.25 GHz 【The bandwidth used by a vehicle-mounted millimeter wave radar in the mode of driving on the road is usually not more than 1 GHz. Only in the parking mode will a large bandwidth of more than 1 GHz be used, and the anti-interference problem does not need to be considered temporarily in the parking mode because there are much fewer interfering vehicles in the parking scene than when driving on the road. The larger the bandwidth, the higher the distance resolution and the higher the distance accuracy. On the premise of the driving mode on the road, the front radar center frequency is set to 76.5 GHz, which can be designed to occupy a working frequency band range of 76 GHz to 77 GHz; the corner radar detection accuracy requirement is lower than that of the front radar, and a lower bandwidth, for example, within 500 MHz, can be allocated to them. The front corner radar 1 center frequency is set to 78.75 GHz, and the frequency band occupied is 78.5 GHz to 79 GHz; the front corner radar 2 center frequency is set to 77.25 GHz, and the frequency band occupied is 77 GHz to 77.5 GHz; the rear corner radar 3 center frequency is set to 77.75 GHz, and the frequency band occupied is 77.5 GHz to 78 GHz; and the rear corner radar 4 center frequency is set to 78.25 GHz, and the frequency band occupied is 78 GHz to 78.5 GHz. Under this design, the frequency bands of the 5 radars do not overlap, and mutual interference does not occur. If there is slight overlap in the frequency band design under special circumstances, the method of wave delay can be relied on to suppress it. The working bandwidth of each vehicle-mounted millimeter wave radar is usually 200 MHz-1000 MHz. Proper design can ensure that the overlapping part of the vehicle field of view area leading to the lane is in different frequency bands, so that mutual interference does not occur. Even if the overlap of the frequency bands of the radars cannot be avoided, the time delay anti-interference scheme can be used as an enhancement measure to remedy it. Time delay anti-interference and frequency diversity anti-interference can effectively deal with the radar mutual interference problem in the scene where “each vehicle produced by a certain automobile manufacturer is equipped with several millimeter wave radars manufactured by the same supplier, and a large number of vehicles produced by the automobile manufacturer are driving on the road in the same area.”

[0093] There are the following 3 technical paths for existing vehicle-mounted millimeter wave radar anti-interference:

[0094] 1. Coding reconstruction: random frequency hopping FMCW waveform is used, so that the interference signal presents a pseudo-random distribution in the range-Doppler domain, and the interference isolation degree can be improved by 83%;

[0095] 2. AI filtering: an AI filter can dynamically identify more than 87% of the same frequency interference characteristics through online learning;

[0096] 3, Heterogeneous fusion: Tesla HW5.0 scheme proves that the fusion of millimeter wave radar point cloud and camera pixel level can reduce the false alarm rate to 0.2 times per thousand kilometers. 【The existing technical scheme refers to the technical scheme researched in the industry, among which schemes 1 and 2 are extremely difficult, and the company does not have such technology. Except for the pre-research scheme, there is no news about these technologies being put into mass production. The difficulty lies in the need to consume huge computing power and memory, such as AI filtering, which requires tens of MB of memory to store AI deep learning models. And the current mass-produced radar processor memory is less than 8MB. It cannot be put into mass production projects.

[0097] Scheme 3 is radar and camera fusion to overcome interference, which is Tesla's technology, and the company does not adopt it, so it cannot give a simulation and measurement comparison.

[0098] The above solutions aim to solve the radar anti-interference problem in any scene, and there are two limitations: 1. High demand for computing resources. For example, the memory resources (tens of Mbytes) and computing power required to deploy AI models are often impractical for vehicle millimeter wave radars (memory is usually less than 10Mbytes); 2. Other types of sensors need to be introduced, and radar algorithms alone are not enough to solve the problem.

[0099] The present scheme does not seek to solve the radar anti-interference problem in any scene, but mainly for such a common scenario: every vehicle produced by a certain automobile manufacturer is equipped with several millimeter wave radars manufactured by the same supplier, and there are a large number of vehicles produced by the same automobile manufacturer on the road in the same area. This scenario has very practical significance. A car manufacturer will often equip the same radar supplier's products for the same model, and there is little prospect of mixing different suppliers' radars for the same model. For this scenario, the present scheme proposes a simple and easy-to-implement radar anti-interference solution that combines time delay and frequency diversity, which can be completed simply and quickly, and is not limited by the performance of the radar computing platform. It only relies on the radar itself and does not need to introduce other types of sensors. It is suitable for traditional and new generation vehicle millimeter wave radars, greatly reducing the probability of radar being interfered.

[0100] To achieve the above purpose, the present application also provides a vehicle-mounted multi-millimeter wave radar anti-interference processing system based on time delay and frequency diversity, as shown in Figure 14 The system is used to implement the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity, and the system comprises:

[0101] A data generation and acquisition unit is configured to generate and acquire first data corresponding to at least two millimeter wave radar vehicle systems; wherein the first data is a frame transmission delay time, and the frame transmission delay time is a delay amount of a starting transmission time of a first pulse of each millimeter wave radar per frame signal relative to a common time reference;

[0102] The data reflection control unit is configured to control each of the millimeter wave radars to transmit a frequency-modulated continuous wave pulse train based on the corresponding first data in an asynchronous manner, wherein the first data is configured such that the interference intermediate frequency signal frequency introduced by the frame start time difference between any two millimeter wave radars exceeds the cutoff frequency of a low-pass filter on a millimeter wave radar receiving link.

[0103] The value range of the first data is between 5 microseconds and one half of a single frequency-modulated continuous wave pulse period.

[0104] The data reflection control unit further comprises:

[0105] The frequency configuration module is configured to assign different operating center frequencies to each of the millimeter wave radars in the vehicle system, wherein the operating bandwidth of each millimeter wave radar is set based on the assigned center frequency, and the operating frequency bands of any two radars do not overlap or overlap minimally.

[0106] The different frame transmission delay times of each of the millimeter wave radars in the vehicle system specifically include:

[0107] One of the millimeter wave radars in the vehicle system is designated as a master radar.

[0108] The master radar sends a trigger signal to other millimeter wave radars as slave radars when starting to transmit the frame signal.

[0109] Each of the slave millimeter wave radars waits for the specific frame transmission delay time configured for itself before starting to transmit the respective frame signal after receiving the trigger signal.

[0110] The assignment strategy of the operating center frequency and the operating bandwidth is as follows:

[0111] The forward radar located at the front of the vehicle and requiring the highest detection accuracy is assigned the lowest center frequency and the largest operating bandwidth.

[0112] The corner radars located at the four corners of the vehicle are assigned higher center frequencies and relatively smaller operating bandwidths.

[0113] In the system scheme embodiment of the present application, the method steps involved in the vehicle-mounted multi-millimeter wave radar anti-interference processing based on time delay and frequency diversity have been described in detail above, that is, the functional components in the system are used to realize the steps or sub-steps in the above method embodiments, which will not be described here.

[0114] To achieve the above-mentioned purpose, the present application further provides a vehicle-mounted multi-millimeter wave radar anti-interference processing platform based on time delay and frequency diversity, like Figure 15The shown, including processor, memory and delay and frequency diversity based vehicle multi-millimeter wave radar anti-jamming processing platform control program;Wherein, in the processor executes the delay and frequency diversity based vehicle multi-millimeter wave radar anti-jamming processing platform control program, the delay and frequency diversity based vehicle multi-millimeter wave radar anti-jamming processing platform control program is stored in the memory, the delay and frequency diversity based vehicle multi-millimeter wave radar anti-jamming processing platform control program, realize the delay and frequency diversity based vehicle multi-millimeter wave radar anti-jamming processing method steps.For example:

[0115] S1, production and acquisition corresponding to at least two millimeter wave radar vehicle system first data;Wherein, the first data is frame transmission delay time, the frame transmission delay time is each millimeter wave radar first pulse of each frame signal starting transmission time relative to a common time reference delay amount;

[0116] S2, control each millimeter wave radar based on its corresponding first data, and asynchronously transmit frequency modulation continuous wave pulse string;Wherein, the configuration of the first data makes the interference frequency signal frequency introduced by the frame start time difference between any two millimeter wave radars exceed the cutoff frequency of the low pass filter on the millimeter wave radar receiving link.

[0117] The specific details of the steps have been described above, and will not be repeated here.

[0118] In the embodiment of the application, the delay and frequency diversity based vehicle multi-millimeter wave radar anti-jamming processing platform built-in processor can be composed of integrated circuits, for example, it can be composed of a single packaged integrated circuit, or it can be composed of multiple packaged integrated circuits with the same function or different functions, including one or more central processing units (CPU), microprocessors, digital processing chips, graphics processors and combinations of various control chips, etc.Processor uses various interfaces and lines to connect various components, and executes the program or unit stored in the memory and calls the data stored in the memory to execute the delay and frequency diversity based vehicle multi-millimeter wave radar anti-jamming processing various functions and processing data;

[0119] The memory is used to store program codes and various data, installed in the delay and frequency diversity based vehicle multi-millimeter wave radar anti-jamming processing platform, and realizes high-speed, automatic program or data access during running.

[0120] The memory includes Read-Only Memory (ROM), Random Access Memory (RAM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), One-time Programmable Read-Only Memory (OTPROM), Electrically-Erasable Programmable Read-Only Memory (EEPROM), Compact Disc Read-Only Memory (CD-ROM) or other optical disk memory, magnetic disk memory, magnetic tape memory, or any other medium capable of carrying or storing data that is readable by a computer.

[0121] The application produces and obtains first data corresponding to at least two millimeter wave radar vehicle systems by a method; wherein the first data is frame transmission delay time, and the frame transmission delay time is the delay amount of the starting transmission time of the first pulse of each millimeter wave radar per frame signal relative to a common time reference; each millimeter wave radar transmits a frequency-modulated continuous wave pulse train based on its corresponding first data and asynchronously; wherein the configuration of the first data makes the interference intermediate frequency signal frequency introduced by the difference in frame starting time between any two millimeter wave radars exceed the cutoff frequency of the low-pass filter on the millimeter wave radar receiving link, and the system and platform corresponding to the method can be configured simply and quickly, are not limited by the performance of the radar computing platform, only rely on the radar itself, without introducing other sensors; suitable for traditional and new generation vehicle-mounted millimeter wave radars, greatly reducing the probability of radar interference. That is, by relying only on the radar itself, the mutual interference probability between radars of the same type can be significantly reduced by configuring the radar itself, which is particularly suitable for scenarios where a large number of radars of the same type are deployed by the same vehicle manufacturer.

[0122] That is, by configuring different frame transmission delay times and working center frequencies for vehicle-mounted millimeter wave radars, using time delay and frequency diversity technology, and relying only on the radar itself, the same frequency interference signals between radars of the same type can be filtered out at low cost and high efficiency, the probability of false target detection can be significantly reduced, and the reliability and safety of the intelligent driving system in a radar-dense environment can be greatly improved.

[0123] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A time-delay and frequency-diversity based anti-jamming processing method for vehicle-mounted multi-millimeter wave radars, characterized in that, The method is applied to a vehicle system comprising at least two millimeter wave radars; the method comprises the steps of: producing and obtaining first data corresponding to the vehicle system of at least two millimeter wave radars; wherein the first data is frame transmission delay time, which is the delay amount of the starting transmission time of the first pulse of each millimeter wave radar per frame signal relative to a common time reference; controlling each of the millimeter wave radars to transmit a frequency-modulated continuous wave pulse train asynchronously based on its corresponding first data; wherein the configuration of the first data is such that the interference intermediate frequency signal frequency introduced by the difference in frame starting time between any two millimeter wave radars exceeds the cutoff frequency of the low-pass filter on the millimeter wave radar receiving link.

2. The anti-jamming processing method based on time delay and frequency diversity for vehicle-mounted multi-millimeter wave radar according to claim 1, characterized in that, The value range of the first data is between 5 microseconds and one half of the period of a single frequency-modulated continuous wave pulse.

3. The anti-jamming processing method based on time delay and frequency diversity for vehicle-mounted multi-millimeter wave radar according to claim 1 or 2, characterized in that, The configuration of different frame transmission delay times for each millimeter wave radar in the vehicle system specifically comprises: designating one millimeter wave radar in the vehicle system as the master radar; the master radar sends a trigger signal to other millimeter wave radars as slave radars when it starts transmitting its frame signal; each of the slave millimeter wave radars waits for the specific frame transmission delay time configured for itself before starting to transmit its own frame signal after receiving the trigger signal.

4. The anti-jamming processing method based on time delay and frequency diversity for vehicle-mounted multi-millimeter wave radar according to claim 1, characterized in that, The control of each of the millimeter wave radars to transmit a frequency-modulated continuous wave pulse train asynchronously based on its corresponding first data further comprises: allocating different operating center frequencies to each millimeter wave radar in the vehicle system; wherein the operating bandwidth of each millimeter wave radar is set based on the center frequency allocated to it, and the operating frequency bands of any two radars do not overlap or overlap minimally.

5. The anti-jamming processing method based on time delay and frequency diversity for vehicle-mounted multi-millimeter wave radar according to claim 4, characterized in that, The allocation strategy for the operating center frequency and operating bandwidth is: allocating the lowest center frequency and the largest operating bandwidth to the front-facing radar located directly in front of the vehicle, which requires the highest detection accuracy; allocating a higher center frequency and a relatively smaller operating bandwidth to the corner radars located at the four corners of the vehicle.

6. A time-delay and frequency-diversity based anti-jamming processing system for vehicular multi-millimeter wave radars, characterized in that, The system is used to implement the time delay and frequency diversity-based anti-interference processing method for vehicle-mounted multiple millimeter wave radars as claimed in any one of claims 1 to 5, and the system comprises: a data generation and acquisition unit for producing and obtaining first data corresponding to the vehicle system of at least two millimeter wave radars; wherein the first data is frame transmission delay time, which is the delay amount of the starting transmission time of the first pulse of each millimeter wave radar per frame signal relative to a common time reference; a data reflection control unit for controlling each of the millimeter wave radars to transmit a frequency-modulated continuous wave pulse train asynchronously based on its corresponding first data; wherein the configuration of the first data is such that the interference intermediate frequency signal frequency introduced by the difference in frame starting time between any two millimeter wave radars exceeds the cutoff frequency of the low-pass filter on the millimeter wave radar receiving link.

7. The anti-jamming processing system based on time delay and frequency diversity for vehicle-mounted multi-millimeter wave radar according to claim 6, characterized in that, The value range of the first data is between 5 microseconds and one half of the period of a single frequency-modulated continuous wave pulse. The data reflection control unit further comprises: A frequency configuration module is configured to assign different center frequencies to each millimeter wave radar in the vehicle system; wherein the working bandwidth of each millimeter wave radar is set based on the center frequency assigned to it, and the working frequency bands of any two radars do not overlap or overlap minimally.

8. The anti-jamming processing system based on time delay and frequency diversity for vehicle-mounted multi-millimeter wave radar according to claim 7, characterized in that, The different frame transmission delay time of each millimeter wave radar in the vehicle system specifically includes: One millimeter wave radar in the vehicle system is designated as the master radar; The master radar sends a trigger signal to other millimeter wave radars as slave radars when it starts transmitting its frame signal; Each slave millimeter wave radar waits for a specific frame transmission delay time configured for it after receiving the trigger signal, and then starts transmitting its own frame signal; The allocation strategy of the working center frequency and the working bandwidth is: The forward radar located in the front of the vehicle, which requires the highest detection accuracy, is assigned the lowest center frequency and the largest working bandwidth; The corner radars located at the four corners of the vehicle are assigned higher center frequencies and relatively smaller working bandwidths. 9.A time-delay and frequency-diversity based anti-jamming processing platform for vehicle-mounted multi-millimeter wave radars, characterized in that, The processor, memory and the vehicle-mounted multi-millimeter wave radar anti-interference processing platform control program based on time delay and frequency diversity; wherein the processor executes the vehicle-mounted multi-millimeter wave radar anti-interference processing platform control program based on time delay and frequency diversity, the vehicle-mounted multi-millimeter wave radar anti-interference processing platform control program based on time delay and frequency diversity is stored in the memory, and the vehicle-mounted multi-millimeter wave radar anti-interference processing platform control program based on time delay and frequency diversity realizes the vehicle-mounted multi-millimeter wave radar anti-interference processing method based on time delay and frequency diversity as claimed in any one of claims 1 to 5.

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