A method, apparatus and related vehicle-mounted radar for controlling transmitted signals

Abstract

This invention provides a method, device, and related vehicle-mounted radar for controlling vehicle-mounted radar transmission signals, relating to the field of autonomous driving environmental perception. The method includes: pre-classifying N states based on the vehicle's driving direction and / or lane information, and setting N sets of transmission signal waveform parameters corresponding one-to-one with each of the N states; determining the preset state type of the vehicle based on its driving direction and location; selecting the radar transmission signal waveform parameters; and generating radar transmission signal waveform control commands to control the radar to transmit signals that meet the corresponding parameters. This invention does not require additional interference monitoring hardware, has low equipment costs, effectively avoids mutual interference between vehicle-mounted radars, and provides a reasonable, feasible, and easier-to-implement approach for the widespread use of vehicle-mounted radar.

Description

Technical Field

[0001] This invention belongs to the field of autonomous driving environmental perception and is applicable to vehicles equipped with vehicle-mounted radar. In particular, it relates to a method, device and related vehicle-mounted radar for controlling the transmission signal of vehicle-mounted radar. Background Technology

[0002] Automotive radar is an indispensable sensor for achieving autonomous driving, offering advantages such as speed measurement capabilities and all-weather, 24 / 7 operation. However, automotive radar also faces several technical challenges, one of which is interference avoidance. As the number of vehicles equipped with automotive radar increases, the electromagnetic spectrum environment on the road becomes more congested. As active radiating sensors, radars are susceptible to interference from each other, leading to false alarms, missed alarms, and reduced detection range, which can even cause traffic accidents in severe cases. Reducing mutual interference between automotive radars is a crucial prerequisite for their engineering and widespread adoption.

[0003] Passive anti-jamming refers to suppressing or eliminating the adverse effects of interference signals on useful signals through multi-domain signal processing algorithms involving time, space, and frequency within the radar receiver. Chinese Patent CN109856600A, published on June 7, 2019, discloses a method for anti-jamming millimeter-wave collision avoidance radar, which falls under the category of passive anti-jamming methods. This invention demodulates the received radar signal, performs two-dimensional FFT processing on the demodulated result, and then performs CFAR detection processing based on the two-dimensional FFT result, thereby filtering out interference signals and reducing their impact to a certain extent. While passive anti-jamming methods can achieve certain results, current methods like these have limitations. On the one hand, many methods, while suppressing interference signals, lead to the loss of useful signals, degrading the overall signal quality and significantly impacting the system's detection performance, posing serious safety hazards to autonomous driving. On the other hand, these methods are relatively complex, requiring high signal processing capabilities from the system, increasing the signal processing burden and cost significantly.

[0004] Active anti-interference refers to proactively avoiding interference by adjusting the waveform parameters of the transmitted signal and adaptively adjusting the antenna pattern, thus preventing interference signals from entering the receiver and reducing mutual interference between vehicle radars at the source. Chinese patent CN112099013A, published on December 18, 2020, discloses a waveform adaptive adjustment method for vehicle radar anti-interference, which falls under the category of active anti-interference methods. This patent first detects the frequency and modulation slope of the interference signal, and then adaptively adjusts the waveform parameters of its own transmitted signal based on the interference information to minimize or reduce the impact of interference on its own radar system. Chinese patent CN113567937A, published on October 29, 2021, discloses a method, device, equipment, and system for preventing interference with vehicle radar. This method first acquires the position information and radar frequencies of at least two vehicles; then compares the radar frequencies of the vehicles; if multiple radar frequencies are the same or the numerical difference is less than a set threshold, the radar frequencies of vehicles within the set area are adjusted to be different or the numerical difference is greater than the set threshold to avoid mutual interference between radars. Chinese patent CN106461771B, published on February 22, 2017, discloses a vehicle-mounted radar device that uses an interference detection unit to determine whether there is interference between radar signals, and then changes the center frequency of the radar signal according to the interference situation. The aforementioned methods for adjusting transmitted signals rely on the detection of environmental signals or communication between radars, requiring additional signal measurement procedures and hardware equipment, thus increasing product costs. Furthermore, in complex, time-varying environments, this leads to frequent adjustments to the radar transmitted signal waveform parameters, reducing radar stability.

[0005] Some millimeter-wave radar manufacturers have also proposed solutions to address mutual interference between multiple radars. A paper published by Gateland Microelectronics (https: / / www.elecfans.com / d / 1311187.html) proposes frequency hopping, chirp shifting, and phase scrambling modes to dynamically adjust the transmission signals of each radar, thereby reducing the probability of mutual interference. These methods, based on random changes in frequency and phase, can only reduce the probability of interference, but cannot eliminate the risks posed by mutual interference. A paper published by Xi'an University of Electronic Science and Technology (https: / / zhuanlan.zhihu.com / p / 487977364) introduces the interference avoidance scheme adopted by TI's millimeter-wave radar. In addition to the traditional frequency hopping mode, it proposes a transmission signal control method based on time slot synchronization to avoid interference. This method synchronizes all radars to a single clock, and then assigns different working time slots to different radars, thus avoiding interference between radars. However, the time slot-based method still faces some implementation challenges. On the one hand, the synchronization accuracy of the radar clocks of each vehicle is difficult to guarantee; on the other hand, the time slot division reduces the available time of the vehicle radar, introducing uncertainties to driving safety. Summary of the Invention

[0006] The purpose of this invention is to provide a method, device, and related vehicle-mounted radar for controlling the transmission signal of a vehicle-mounted radar, so as to solve the problems mentioned in the background art.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for controlling the transmission signal of a vehicle-mounted radar, comprising the following steps:

[0008] Step 1: Pre-divide N states based on the vehicle's driving direction and / or the lane information, and set N sets of transmission signal waveform parameters. The N states do not overlap, the N sets of transmission signal waveforms do not interfere with each other, and the N sets of transmission signal waveforms correspond one-to-one with the N states.

[0009] Step 2: Determine the preset state type of the vehicle based on its driving direction and location;

[0010] Step 3: Select the radar transmission signal waveform parameters based on the vehicle status type determined in Step 2 and the preset correspondence in Step 1;

[0011] Step 4: Based on the radar transmission signal waveform parameters selected in Step 3, generate radar transmission signal waveform control commands to control the radar to transmit signals corresponding to the radar transmission signal waveform parameters selected in Step 3.

[0012] Furthermore, in step 1, the basis for pre-dividing N states is the vehicle's driving direction. Specifically, the horizontal 360° is divided into L non-overlapping angle ranges, and the L angle ranges correspond to L states.

[0013] The basis for pre-dividing N states is the lane information of the vehicle. Specifically, each lane of the road on which the vehicle travels corresponds to one state.

[0014] The basis for pre-dividing N states is the vehicle's driving direction and the lane information. The specific method is to first divide the horizontal 360° into L non-overlapping angle ranges, and then divide each direction into M states corresponding to different lanes, for a total of N states, N=L*M.

[0015] Furthermore, in step 1, the N sets of transmitted signal waveform parameters are either the frequency parameters of the frequency division orthogonal waveform signal or the modulation parameters of the code division orthogonal waveform signal.

[0016] Furthermore, in step 2, the vehicle's driving direction and location information are obtained through the vehicle navigation device, GPS receiver, MEMS micro-electromechanical system gyroscope, and camera sensor.

[0017] Furthermore, in step 4, the generated radar transmission signal waveform control command is either a radar transmission signal waveform frequency control command or a radar transmission signal waveform selection command.

[0018] Frequency division orthogonal waveform signals achieve orthogonality by controlling the frequencies to prevent them from overlapping. For frequency division orthogonal waveform signals, radar needs to generate frequency control commands for the radar transmitted signal waveform.

[0019] Code division orthogonal waveform signals achieve orthogonality through encoding. Orthogonal waveforms are generated and saved in advance through encoding and retrieved as needed. For code division orthogonal waveform signals, radar needs to generate radar transmit signal waveform selection instructions.

[0020] The radar transmit signal waveform frequency control command or radar transmit signal waveform selection command is implemented through the vehicle-mounted radar FPGA chip or DSP chip.

[0021] The non-interfering waveforms involved in this invention fall into two categories: frequency division orthogonal (FDI) and code division orthogonal (CDI). Orthogonality means non-interference. FDI achieves orthogonality by controlling frequencies to prevent overlap, so this type of radar requires the generation of frequency control commands. Specifically, depending on the existing automotive millimeter-wave radar chip, this can be divided into two categories: one achieved by adjusting the input voltage of the VCO (voltage-controlled oscillator) (different input voltages generate different frequency signals), and the other directly configured in the parameter settings. CDI signals achieve orthogonality through encoding, which is pre-stored in this invention and retrieved as needed. Therefore, a transmit signal waveform selection command needs to be generated, i.e., selecting which waveform to use.

[0022] These instructions are generated in the vehicle radar FPGA or DSP chip. Different voltages are digital values ​​of the FPGA output voltage, which are converted into voltage signals after passing through a DAC.

[0023] Step 3 determines whether the radar needs to transmit a frequency division orthogonal signal or selects a code division orthogonal signal waveform for transmission. Step 4 implements and executes the specific implementation by controlling the millimeter-wave radar chip to transmit a frequency division orthogonal signal or a code division orthogonal signal waveform through the corresponding millimeter-wave chip configuration parameters, VCO control voltage, or transmit signal waveform selection command.

[0024] Furthermore, in step 4, the frequency control command for the radar transmitted signal waveform is voltage information, which controls the radar voltage-controlled oscillator to generate a signal of the corresponding frequency.

[0025] Furthermore, in step 4, the radar transmit signal waveform frequency control command includes the signal start frequency, modulation frequency, and termination frequency.

[0026] This invention provides a vehicle-mounted radar transmission signal control device, including a preset information storage module, a status judgment module, a transmission signal waveform parameter generation module, and a radar transmission signal control module;

[0027] The preset information storage module is used to store N preset vehicle states and their classification criteria, N sets of transmitted signal waveform parameters, and the correspondence between the N sets of transmitted signal waveforms and the N states; the N states have no overlap, the N sets of transmitted signal waveforms do not interfere with each other, and the N sets of transmitted signal waveforms correspond one-to-one with the N states;

[0028] The state determination module is used to determine the preset state type of the vehicle based on the vehicle's driving direction and location.

[0029] The transmitted signal waveform parameter generation module is used to select preset radar transmitted signal waveform parameters based on the preset state type of the vehicle determined by the state judgment module and the corresponding relationship stored in the preset information storage module.

[0030] The radar transmission signal control module is used to generate a radar transmission signal waveform control command based on the radar transmission signal waveform parameters selected by the transmission signal waveform parameter generation module, and to control the radar to transmit a signal corresponding to the radar transmission signal waveform parameters selected by the transmission signal waveform parameter generation module.

[0031] The preset information storage module, status judgment module, transmitted signal waveform parameter generation module, and radar transmitted signal control module are functional modules in FPGA or DSP chips.

[0032] Furthermore, the division of the N states stored in the preset information storage module is based on the vehicle's driving direction. Specifically, the horizontal 360° is divided into L non-overlapping angle ranges, and the L angle ranges correspond to the N states.

[0033] The N states stored in the preset information storage module are divided based on the lane information of the vehicle. Specifically, each lane of the road on which the vehicle travels corresponds to one state.

[0034] The N states stored in the preset information storage module are divided based on the vehicle's driving direction and the lane information it is in. Specifically, the horizontal 360° is first divided into L non-overlapping angle ranges, and each direction is further divided into M states corresponding to different lanes, for a total of N states, N=L*M.

[0035] Furthermore, the N sets of transmitted signal waveform parameters stored in the preset information storage module are either frequency parameters of frequency division orthogonal waveform signals or modulation parameters of code division orthogonal waveform signals.

[0036] Furthermore, the vehicle-mounted radar transmission signal control device also includes a communication module, which is used to receive information about the vehicle's driving direction and location, and send this information to the status judgment module.

[0037] Furthermore, the radar transmission signal waveform control command generated by the radar transmission signal control module is either a radar transmission signal waveform frequency control command or a radar transmission signal waveform selection command.

[0038] Frequency division orthogonal waveform signals achieve orthogonality by controlling the frequencies to prevent them from overlapping. For frequency division orthogonal waveform signals, radar needs to generate frequency control commands for the radar transmitted signal waveform.

[0039] Code division orthogonal waveform signals achieve orthogonality through encoding. Orthogonal waveforms are generated and saved in advance through encoding and retrieved as needed. For code division orthogonal waveform signals, radar needs to generate radar transmit signal waveform selection instructions.

[0040] The radar transmit signal waveform frequency control command or radar transmit signal waveform selection command is implemented through the vehicle-mounted radar FPGA chip or DSP chip.

[0041] Furthermore, the frequency control command for the radar transmission signal waveform generated by the radar transmission signal control module is voltage information, which controls the radar voltage-controlled oscillator to generate a signal of the corresponding frequency.

[0042] Furthermore, the frequency control command for the radar transmission signal waveform generated by the radar transmission signal control module includes the signal start frequency, modulation frequency, and termination frequency.

[0043] This invention provides a vehicle-mounted radar that employs the aforementioned vehicle-mounted radar transmission signal control method.

[0044] The present invention provides a vehicle-mounted radar, and includes the aforementioned vehicle-mounted radar transmission signal control device.

[0045] The present invention provides a computer-readable access medium storing a computer program, which, when executed by a processor, implements the above-described vehicle-mounted radar transmission signal control method.

[0046] Vehicle-mounted radar generates signals through a radio frequency front-end and transmits them via a transmitting antenna. These signals are reflected back from the target and received by a receiving antenna. By processing and analyzing the received signals, information such as the target's distance, angle, and speed can be obtained. Vehicle-mounted radar is a sensor with its own radiation source. With the increasing application of vehicle-mounted radar, the number of such radars on the road is growing, leading to mutual interference and increasingly serious problems. The most severe interference occurs in the following two scenarios:

[0047] 1) Heading towards each other. Two vehicles are traveling towards each other; we'll refer to them as the jamming radar and the jammed radar, respectively. The target echo signal power of the jammed radar is shown in the radar equation below.

[0048] (1)

[0049] In equation (1), The transmitted power of the jammed radar. The gain of the transmitting antenna of the jammed radar. R represents the gain of the radar receiving antenna being jammed, and R represents the target range. The target radar backscattering cross section, The wavelength is the radar signal wavelength.

[0050] The signal power of the jamming radar entering the jammed radar is shown in the following jamming equation.

[0051] (2)

[0052] In equation (2), To interfere with radar transmission power, To interfere with the gain of the radar transmitting antenna, Let be the antenna gain of the radar being jammed relative to the jamming radar. This is assumed when both radars have the same transmit power and are moving towards each other, with the jamming radar located on the main lobe of the radar being jammed. , , Equation (2) can be written as

[0053] (3)

[0054] Comparing equations (1) and (3), it can be seen that when two radars are moving towards each other, the power of the jamming radar entering the jammed radar is quadratic with respect to the distance, while the target echo power of the jammed radar is quadratic with respect to the distance. In most range segments, the jamming signal power is much greater than the target echo signal power, which will cause serious interference to the radar.

[0055] 2) Traveling in the same direction. Two vehicles travel at a certain distance from each other; we will refer to them as the jamming radar and the jammed radar, respectively. The reflected signal from the jamming radar after illuminating the target will enter the receiving antenna of the jammed radar. The power of the echo signal received by the jammed radar from the jamming radar is shown in the following bistatic radar equation.

[0056] (4)

[0057] In equation (2), To interfere with radar transmission power, To interfere with the gain of the radar transmitting antenna, The antenna gain of the jammed radar relative to the target direction. Let be the bistatic cross-section of the target. For targets such as vehicles and pedestrians, when the bistatic angle is not large, it can be considered as... R is the distance between the target and the jammed radar, and R1 is the distance between the target and the jamming radar.

[0058] Considering that both radars have the same transmit power and the target's bistatic cross-sectional area and backscatter cross-sectional area are the same, comparing equations (1) and (3) shows that when the distance between the target and the jamming radar is less than the distance between the target and the jammed radar, the echo signal generated by the jamming radar is greater than the target echo power of the jammed radar, which is equivalent to forming a false large target; when the distance between the target and the jamming radar is greater than the distance between the target and the jammed radar, the echo signal generated by the jamming radar is less than the target echo power of the jammed radar, which is equivalent to forming a false small target. Furthermore, the two-way delay of the two radars will also cause distortion in the target distance measured by the radar, resulting in false dots at the wrong location, which will affect driving.

[0059] To better avoid mutual interference between vehicle-mounted radars, especially to effectively address interference issues in scenarios where vehicles are traveling in opposite directions or in the same direction, this invention proposes a method for controlling the radar transmission signal waveform parameters based on vehicle travel direction and lane information. This method links travel direction, lane information, and radar transmission waveform parameters. When vehicles are traveling in different directional angle ranges and in different lanes, mutually orthogonal transmission waveforms are used. These orthogonal waveforms satisfy the following conditions:

[0060] (5)

[0061] In equation (5), This is the first orthogonal waveform. This is the second orthogonal waveform. For delay.

[0062] In this way, the echo signals generated by the two radars illuminating each other will not interfere with each other, effectively avoiding mutual interference.

[0063] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0064] (1) The present invention provides a vehicle radar transmission signal control method, device and related vehicle radar, which combines transmission signal waveform control and vehicle status, and selects non-interfering signals according to the vehicle status, especially the easily interfered oncoming and same-direction forward and backward driving states, and divides different states, using mutually orthogonal signals in different states, which effectively reduces the interference between radars in these severe interference scenarios.

[0065] (2) This invention does not require additional interference monitoring hardware, effectively avoids mutual interference during the operation of vehicle radar, and has low equipment cost, providing a reasonable, feasible and easier way to popularize vehicle radar.

[0066] The accompanying drawings further illustrate the concept, specific structure, and technical effects of the present invention, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0067] Figure 1 A flowchart of the steps of a vehicle-mounted radar transmission signal control method provided by the present invention;

[0068] Figure 2 This is a schematic diagram of the vehicle's movement in Example 1;

[0069] Figure 3 This is a diagram illustrating the mutual interference analysis of vehicle-mounted radars in Example 1;

[0070] Figure 4 This is a schematic diagram of the vehicle's movement in Example 2;

[0071] Figure 5 This is a diagram illustrating the mutual interference analysis of vehicle-mounted radars in Example 2;

[0072] Figure 6 This is a schematic diagram of the vehicle's movement in Example 3;

[0073] Figure 7 This is a diagram illustrating the mutual interference analysis of vehicle-mounted radars in Example 3. Detailed Implementation

[0074] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0075] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0076] like Figure 1 The diagram shown is a flowchart of the steps in a vehicle-mounted radar transmission signal control method provided by the present invention. All embodiments provided by the present invention follow... Figure 1 The steps shown are followed.

[0077] Example 1

[0078] like Figures 2-3As shown, this embodiment provides a vehicle-mounted radar, employing the following vehicle-mounted radar transmission signal control method and setting up a vehicle-mounted radar transmission signal control device including a preset information storage module, a status judgment module, a transmission signal waveform parameter generation module, a radar transmission signal control module, and a communication module, as detailed below:

[0079] Step 1:

[0080] The preset information storage module in the vehicle radar transmission signal control device uses the FPGA's built-in block RAM to pre-store four different states and their division criteria based on the vehicle's driving direction. Specifically, the horizontal 360° is divided into four angular ranges, with due north as 0°. The first state is when the driving direction is within 315°~45° (inclusive of 315°, exclusive of 45°), the second state is when the driving direction is within 135°~225° (inclusive of 135°, exclusive of 225°), the third state is when the driving direction is within 45°~135° (inclusive of 45°, exclusive of 135°), and the fourth state is when the driving direction is within 225°~315° (inclusive of 45°, exclusive of 135°).

[0081] The preset information storage module in the vehicle-mounted radar transmission signal control device stores four pre-set, non-interfering transmission signal waveform parameters, as follows: Signal 1 has a frequency range of 77.0 GHz (start frequency) to 77.2 GHz (end frequency) and a modulation frequency of 10 MHz / µs (MFM), and is a linear frequency modulation (LFM) signal; Signal 2 has a frequency range of 77.3 GHz (start frequency) to 77.5 GHz (end frequency) and a MFM of 10 MHz / µs, and is a LFM signal; Signal 3 has a frequency range of 77.6 GHz (start frequency) to 77.8 GHz (end frequency) and a MFM of 10 MHz / µs, and is a LFM signal; Signal 4 has a frequency range of 77.9 GHz (start frequency) to 78.1 GHz (end frequency) and a MFM of 10 MHz / µs, and is a LFM signal.

[0082] The preset information storage module in the vehicle-mounted radar transmission signal control device stores the pre-set correspondence between state types and waveforms as follows: vehicle state 1 corresponds to signal parameter 1; vehicle state 2 corresponds to signal parameter 2; vehicle state 3 corresponds to signal parameter 3; and vehicle state 4 corresponds to signal parameter 2.

[0083] Step 2:

[0084] Vehicles as attached Figure 2 When the vehicle is in motion, the communication module in the vehicle radar transmission signal control device of vehicle A receives the vehicle navigation and GPS signals via the vehicle bus, indicating a driving direction of 0°.

[0085] The state judgment module in the vehicle radar transmission signal control device of vehicle A compares the received vehicle driving direction with the preset type judgment conditions to determine that vehicle A is in state 1.

[0086] Step 3:

[0087] The transmission signal waveform parameter generation module in the vehicle-mounted radar transmission signal control device of vehicle A selects the preset radar transmission signal waveform parameters as signal 1 parameters according to the vehicle status and the preset correspondence in the preset information storage module. The preset frequency is 77.0 GHz, the stop frequency is 77.2 GHz, the modulation frequency is 10 MHz / us, and the signal type is linear frequency modulation signal.

[0088] Step 4:

[0089] The radar transmission signal control module in the vehicle radar transmission signal control device of vehicle A completes the configuration of the Chirp RAM and Chirp Profiles of the vehicle radar millimeter-wave chip AWR1243 according to the parameters of radar waveform signal 1. The configuration start frequency is 77.0GHz, the frequency slope is 10MHz / us, the slope end time is 20us, and the vehicle radar radiates signal 1.

[0090] Similarly, it can be seen that the vehicle radar transmission signal control device of vehicle B controls the vehicle radar radiation signal 2, the vehicle radar transmission signal control device of vehicle C controls the vehicle radar radiation signal 3, and the vehicle radar transmission signal control device of vehicle D controls the vehicle radar radiation signal 4.

[0091] Appendix Figure 3 Taking vehicle A's radar as an example, the mutual interference between vehicle radars is illustrated. To simplify the analysis, the mixing local oscillator signal of vehicle A's radar is set to a fixed frequency of 77GHz. The intermediate frequency (IF) signal of vehicle A's own radar after mixing and reception is 0~200MHz, while the signals from the other three radars, after mixing in vehicle A's radar, have frequencies of 300~500MHz, 600~800MHz, and 900~1100MHz, respectively. Considering the narrow bandwidth of the radar IF receiver, only vehicle A's radar signal can enter its receiver. The signals from vehicle B, vehicle C, and vehicle D, after mixing, all fall outside the IF receiver's bandwidth, effectively avoiding mutual interference.

[0092] It should be noted that the division of driving direction areas can be arbitrary, and the division of each direction area does not necessarily need to be equal; it can be based on the actual road conditions. In addition to dividing areas based on actual spatial direction, another optional division method is based on road direction. For example, the driving direction from the starting point (point A) to the ending point (point B) of the road is defined as state 1, while the driving direction from the ending point (point B) to the starting point (point A) of the road is defined as state 2.

[0093] Example 2

[0094] like Figures 4-5 As shown, this embodiment provides a vehicle-mounted radar, employing the following vehicle-mounted radar transmission signal control method and setting up a vehicle-mounted radar transmission signal control device including a preset information storage module, a status judgment module, a transmission signal waveform parameter generation module, a radar transmission signal control module, and a communication module, as detailed below:

[0095] Step 1:

[0096] The preset information storage module in the vehicle radar transmission signal control device uses the FPGA's built-in block RAM to store three different states and their classification criteria based on the vehicle's lane, as follows: the vehicle is in the fastest lane (the leftmost lane) in state 1, the vehicle is in the second lane from the left in state 2, and the vehicle is in the third lane from the left in state 3.

[0097] The preset information storage module in the vehicle-mounted radar transmission signal control device stores three pre-set, non-interfering transmission signal waveform parameters, as follows: Signal 1 is a linear frequency modulated signal with a frequency range of 24.0~24.08GHz and a modulation frequency of 10MHz / us; Signal 2 is a linear frequency modulated signal with a frequency range of 24.1~24.18GHz and a modulation frequency of 10MHz / us; and Signal 3 is a linear frequency modulated signal with a frequency range of 24.2~24.28GHz and a modulation frequency of 10MHz / us.

[0098] The preset information storage module in the vehicle-mounted radar transmission signal control device stores the pre-set correspondence between state types and waveforms as follows: vehicle state 1 corresponds to signal parameter 1; vehicle state 2 corresponds to signal parameter 2; and vehicle state 3 corresponds to signal parameter 3.

[0099] Step 2:

[0100] Vehicles as attached Figure 4 When the vehicle is in motion, the communication module in the vehicle radar signal control device of vehicle A receives the location information from the vehicle navigation and GPS and the lane information determined by the camera through the vehicle bus, and determines that vehicle A is in the fastest lane.

[0101] The status judgment module in the vehicle radar transmission signal control device of vehicle A compares the received vehicle position and lane information with the preset type judgment conditions to determine that vehicle A is in state 1.

[0102] Step 3:

[0103] The transmission signal waveform parameter generation module in the vehicle-mounted radar transmission signal control device of vehicle A selects the preset radar transmission signal waveform parameter as signal 1 parameter, which is a linear frequency modulated signal with a frequency range of 24.0~24.08GHz and a modulation frequency of 10MHz / us, according to the vehicle status and the preset correspondence in the preset information storage module.

[0104] Step 4:

[0105] The radar transmission signal control module in the vehicle-mounted radar transmission signal control device of vehicle A, based on the parameters of radar waveform signal 1, generates the tuning voltage input of the COARSE and FINE pins of the millimeter-wave radar chip BGT24MTR12 by DAC, and controls the vehicle-mounted radar radiation signal 1.

[0106] Similarly, the vehicle radar transmission signal control device of vehicle B controls the vehicle radar radiation signal 2, and the vehicle radar transmission signal control device of vehicle C controls the vehicle radar radiation signal 3.

[0107] Appendix Figure 5 Taking vehicle A's radar as an example, the interference situation of radars from three vehicles traveling in different lanes is presented. To simplify the analysis, the mixing local oscillator signal of vehicle A's radar is set to a fixed frequency signal of 24GHz. It can be seen that the intermediate frequency (IF) signal of vehicle A's own radar after mixing and reception is 0~80MHz, while the frequencies of the signals from the other two radars after mixing in vehicle A's radar are 100~180MHz and 200~280MHz, respectively. Considering the bandwidth range of the radar IF receiver, only vehicle A's radar signal can enter vehicle A's radar receiver. The signals from vehicle B and vehicle C, after mixing, fall outside the IF receiver's bandwidth, effectively avoiding mutual interference.

[0108] Example 3

[0109] like Figures 6-7 As shown, this embodiment provides a vehicle-mounted radar, employing the following vehicle-mounted radar transmission signal control method and setting up a vehicle-mounted radar transmission signal control device including a preset information storage module, a status judgment module, a transmission signal waveform parameter generation module, a radar transmission signal control module, and a communication module, as detailed below:

[0110] Step 1:

[0111] The preset information storage module in the vehicle-mounted radar transmission signal control device uses the FPGA's built-in block RAM to store eight different states and their classification criteria based on the vehicle's driving direction and lane. The four different driving directions are classified as follows: the horizontal 360° is divided into four angular ranges, with true north as 0°. Direction 1 is a driving direction within 315°~45° (inclusive), direction 2 is a driving direction within 135°~225° (inclusive), direction 3 is a driving direction within 45°~135° (inclusive), and direction 4 is a driving direction within 225°~315° (inclusive). The vehicle is in the fastest lane (the leftmost lane) as lane a, and in the second lane from the left as lane b. These eight non-overlapping states are created by combining the vehicle's driving direction and lane location. Specifically, the following states apply: 1a (vehicle traveling in the first direction and in lane a), 1b (vehicle traveling in the first direction and in lane b), 2a (vehicle traveling in the second direction and in lane a), 2b (vehicle traveling in the second direction and in lane b), 3a (vehicle traveling in the third direction and in lane a), 3b (vehicle traveling in the third direction and in lane b), 4a (vehicle traveling in the fourth direction and in lane a), and 4b (vehicle traveling in the fourth direction and in lane b).

[0112] The preset information storage module in the vehicle-mounted radar transmission signal control device stores eight pre-set, non-interfering transmission signal waveform parameters, as follows: Signal 1 is a linear frequency modulated (LFM) signal with a frequency range of 77.0~77.4GHz and a modulation frequency of 10MHz / us; Signal 2 is a LFM signal with a frequency range of 77.5~77.9GHz and a modulation frequency of 10MHz / us; Signal 3 is a LFM signal with a frequency range of 78.0~78.4GHz and a modulation frequency of 10MHz / us; Signal 4 is a LFM signal with a frequency range of 78.5~78.4GHz and a modulation frequency of 10MHz / us; and Signal 5 is a LFM signal with a frequency range of 78.5~78.4GHz and a modulation frequency of 10MHz / us. Signal 5 is a linear frequency modulation (FM) signal with a frequency range of 79.0~79.4GHz and a frequency modulation (FM) of 10MHz / us. Signal 6 is a FM signal with a frequency range of 79.5~79.9GHz and a frequency modulation (FM) of 10MHz / us. Signal 7 is a FM signal with a frequency range of 80.0~80.4GHz and a frequency modulation (FM) of 10MHz / us. Signal 8 is a FM signal with a frequency range of 80.5~80.9GHz and a frequency modulation (FM) of 10MHz / us.

[0113] The preset information storage module in the vehicle-mounted radar transmission signal control device pre-sets the correspondence between the state type and the waveform as follows: vehicle state 1a corresponds to signal parameter 1; vehicle state 1b corresponds to signal parameter 2; vehicle state 2a corresponds to signal parameter 3; vehicle state 2b corresponds to signal parameter 4; vehicle state 3a corresponds to signal parameter 5; vehicle state 3b corresponds to signal parameter 6; vehicle state 4a corresponds to signal parameter 7; and vehicle state 4b corresponds to signal parameter 8.

[0114] Step 2:

[0115] Vehicles as attached Figure 6 When the vehicle is in motion, the communication module in the vehicle radar signal control device of vehicle A receives the driving direction from the vehicle navigation system, the location information from the GPS, and the direction and lane information determined by the camera through the vehicle bus. It then determines that the driving direction of vehicle A is 0° and that it is located in the fastest lane.

[0116] The state judgment module in the vehicle radar transmission signal control device of vehicle A compares the received vehicle driving direction, position and lane information with the preset type judgment conditions to determine that vehicle A is in state 1a.

[0117] Step 3:

[0118] The transmission signal waveform parameter generation module in the vehicle-mounted radar transmission signal control device of vehicle A selects the preset radar transmission signal waveform parameter as signal 1 parameter, which is a linear frequency modulated signal with a frequency range of 77.0~77.4GHz and a modulation frequency of 10MHz / us, according to the vehicle status and the preset correspondence in the preset information storage module.

[0119] Step 4:

[0120] The radar transmission signal control module in the vehicle radar transmission signal control device of vehicle A completes the configuration of the Chirp RAM and Chirp Profiles of the vehicle radar millimeter-wave chip AWR1243 according to the parameters of radar waveform signal 1. The configuration start frequency is 77.0GHz, the frequency slope is 10MHz / us, the slope end time is 40us, and the vehicle radar radiates signal 1.

[0121] Similarly, the vehicle-mounted radar transmission signal control devices of vehicles B, C, D, E, F, G, and H respectively control the vehicle-mounted radar radiation signals 2, 3, 4, 5, 6, 7, and 8.

[0122] Appendix Figure 7Taking vehicle A's radar as an example, the interference between radars traveling in different directions and lanes is illustrated. To simplify the analysis, the mixing local oscillator signal of vehicle A's radar is set to a fixed frequency signal of 77GHz. It can be seen that only the signal from vehicle A's radar can enter the receiver of radar A; the signals from other radars, after mixing, all fall outside the intermediate frequency receiver band, effectively avoiding mutual interference.

[0123] In the embodiments, the radars are all fixed on the vehicle. Taking a forward-facing radar as an example, the vehicle's driving direction is considered to be consistent with the normal direction of the radar antenna. If the normal direction of the radar antenna rotates later, the driving direction is simply superimposed with the antenna rotation angle to further determine the current state, which is still considered to fall within the scope of protection of this patent.

[0124] In this invention, the signals that do not interfere with each other can be frequency division quadrature signals or code division quadrature signals. These signals can be pre-stored and recalled for use, or they can be generated through real-time frequency modulation or phase modulation.

[0125] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method of controlling transmission of a signal from a vehicle-mounted radar, characterized by, The method comprises the following steps: Step 1: N states are divided in advance according to the vehicle driving direction and / or lane information, and N groups of transmission signal waveform parameters are set, the N states have no intersection, the N groups of transmission signal waveforms do not interfere with each other, and the N groups of transmission signal waveforms correspond to the N states one by one; In step 1, the basis for dividing the N states is the vehicle driving direction, and the specific method is to divide the horizontal direction 360° into L non-overlapping angle ranges, and the L angle ranges correspond to L states; The basis for dividing the N states is the lane information of the vehicle, and the specific method is that each lane of the vehicle driving road corresponds to a state; The basis for dividing the N states is the vehicle driving direction and the lane information of the vehicle, and the specific method is to divide the horizontal direction 360° into L non-overlapping angle ranges, and each direction is divided into M states corresponding to different lanes, a total of N states, N=L*M; Step 2: Determine the preset state category of the vehicle according to the vehicle driving direction and the position; Step 3: Select the radar transmission signal waveform parameters according to the vehicle state category determined in step 2 and the corresponding relationship preset in step 1; Step 4: Generate radar transmission signal waveform control instructions according to the radar transmission signal waveform parameters selected in step 3, and control the radar to transmit the signal corresponding to the radar transmission signal waveform parameters selected in step 3.

2. The vehicle-mounted radar transmission signal control method according to claim 1, characterized by, In step 1, the N groups of transmission signal waveform parameters are frequency parameters of frequency division orthogonal waveform signals or modulation parameters of code division orthogonal waveform signals.

3. The vehicle-mounted radar transmission signal control method according to claim 2, characterized by, In step 4, the generated radar transmission signal waveform control instructions are radar transmission signal waveform frequency control instructions or radar transmission signal waveform selection instructions; The frequency division orthogonal waveform signals realize orthogonality by controlling the non-overlapping frequencies, and the radar needs to generate radar transmission signal waveform frequency control instructions for the frequency division orthogonal waveform signals; The code division orthogonal waveform signals realize orthogonality by coding, and the orthogonal waveforms are generated and saved in advance, and are retrieved as needed during use, and the radar needs to generate radar transmission signal waveform selection instructions for the code division orthogonal waveform signals; The radar transmission signal waveform frequency control instructions or the radar transmission signal waveform selection instructions are realized by a vehicle-mounted radar FPGA chip or a DSP chip.

4. The vehicle-mounted radar transmission signal control method according to claim 3, characterized by, In step 4, the radar transmission signal waveform frequency control instructions are voltage information, and the voltage information controls the radar voltage-controlled oscillator to generate a signal with a corresponding frequency.

5. The vehicle-mounted radar transmission signal control method according to claim 3, wherein In step 4, the radar transmission signal waveform frequency control instructions include a signal starting frequency, a frequency modulation rate, and a terminal frequency.

6. An on-vehicle radar transmission signal control device characterized by comprising: The method comprises a preset information storage module, a state judgment module, a transmission signal waveform parameter generation module, and a radar transmission signal control module; The preset information storage module is used to store the preset N states of the vehicle, the division basis, the N groups of transmission signal waveform parameters, and the corresponding relationship between the N groups of transmission signal waveforms and the N states; the N states have no intersection, the N groups of transmission signal waveforms do not interfere with each other, and the N groups of transmission signal waveforms correspond to the N states one by one; The N states stored in the preset information storage module are divided according to the driving direction of the vehicle, and the specific method is to divide the horizontal direction of 360° into L non-overlapping angle ranges, and the L angle ranges correspond to L states; The N states stored in the preset information storage module are divided according to the lane information of the vehicle, and the specific method is that each lane of the driving road of the vehicle corresponds to a state; The N states stored in the preset information storage module are divided according to the driving direction of the vehicle and the lane information of the vehicle, and the specific method is to first divide the horizontal direction of 360° into L non-overlapping angle ranges, and then divide each direction into M states corresponding to different lanes, so as to obtain a total of N states, N=L*M; The state judgment module is configured to determine the preset state category to which the vehicle belongs according to the driving direction and the position of the vehicle; The radar signal waveform parameter generation module is configured to select the preset radar signal waveform parameter according to the preset state category to which the vehicle belongs determined by the state judgment module and the corresponding relationship stored in the preset information storage module; The radar signal control module is configured to generate a radar signal waveform control instruction according to the radar signal waveform parameter selected by the radar signal waveform parameter generation module, and control the radar to emit a signal corresponding to the radar signal waveform parameter selected by the radar signal waveform parameter generation module.

7. A vehicle-mounted radar, characterized by comprising: The vehicle-mounted radar signal control method according to any one of claims 1-5 is adopted.

8. A vehicle-mounted radar, characterized by comprising: The vehicle-mounted radar signal control device according to claim 6 is provided.

9. A computer readable access medium, characterized in that, A computer program is stored on a computer readable access medium, and the computer program is executed by a processor to implement the vehicle-mounted radar signal control method according to any one of claims 1-5.

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