An environmentally adaptive composite radar system

Abstract

This invention relates to an environmentally adaptive composite radar system, belonging to the field of radar detection technology. It solves the problems of weak environmental adaptability, low single-detection accuracy, and insufficient reliability and stability in existing technologies. The system includes: a laser generation module that outputs multiple laser beams; a microwave radar module that receives a first and second laser beam, modulates the first laser beam with a radio frequency signal to generate a microwave radar transmission signal, and transmits it to the target; a coherent lidar module that receives a third and a fourth laser beam, generates a laser transmission signal based on the third laser beam, and transmits it; receives laser echo signals, and obtains a coherent intermediate frequency (IF) signal based on the laser echo signal and the fourth laser beam, which is then transmitted to a control module; and a control module that processes the IF echo signal and the coherent IF signal to generate characteristic parameters of the target, and controls the operation of the microwave radar module and the coherent lidar module.

Description

Technical Field

[0001] This invention relates to the field of radar technology, and in particular to an environment-adaptive composite radar system. Background Technology

[0002] In current radar applications, such as intelligent transportation, security monitoring, and industrial inspection, the requirements for the adaptability of radar systems are increasing. Traditional single radar systems, whether microwave radar or lidar, have certain limitations.

[0003] Microwave radar is relatively less affected by weather, but its resolution is limited, making it difficult to obtain precise details about targets when performing detailed detection. For example, in the field of intelligent transportation, microwave radar may not be able to accurately distinguish the specific model and characteristics of small vehicles at long distances.

[0004] While coherent lidar boasts high resolution and can acquire detailed target features, it is extremely sensitive to weather conditions. In adverse weather conditions, such as heavy fog, torrential rain, or sandstorms, laser transmission is severely attenuated, leading to weakened radar signal strength or even malfunction. For example, in heavy fog, the detection range of coherent lidar is significantly reduced, severely impacting its effectiveness in scenarios such as traffic monitoring. Therefore, a radar system is needed that can comprehensively utilize the advantages of microwave radar and coherent lidar, and adaptively adjust its operating mode according to environmental conditions. Summary of the Invention

[0005] Based on the above analysis, the embodiments of the present invention aim to provide an environment-adaptive composite radar system to solve the problems of weak environmental adaptability, low single detection accuracy, and insufficient reliability and stability of existing systems.

[0006] This invention provides an environment-adaptive composite radar system, comprising:

[0007] The laser generation module is used to output the first and second laser beams to the microwave radar module, and to output the third and fourth laser beams to the coherent radar module.

[0008] The microwave radar module is used to receive the first and second laser beams emitted by the beam splitter, modulate the first laser beam with radio frequency signals to generate a microwave radar transmission signal and transmit it to the target; it is also used to receive microwave radar echo signals, and modulate the second laser beam with microwave radar echo signals and radio frequency signals to generate an intermediate frequency echo signal and transmit it to the control module.

[0009] The coherent lidar module is used to receive the third and fourth laser beams after beam splitting, generate a laser emission signal based on the third laser beam and emit it; it receives the laser echo signal, and obtains a coherent intermediate frequency signal based on the laser echo signal and the third laser beam, which is then transmitted to the control module.

[0010] The control module is used to process the received intermediate frequency echo signal from the microwave radar module and the coherent intermediate frequency signal from the coherent lidar module to generate the characteristic parameters of the target; and to obtain the intensity attenuation value of the intermediate frequency echo signal and the coherent intermediate frequency signal, and control the operation of the microwave radar module and the coherent lidar module based on the environmental parameters and the intensity attenuation value.

[0011] The sensor module is used to collect environmental parameters and transmit them to the control module.

[0012] As a further improvement to this application, the sensor module includes a turbidity sensor and a humidity sensor; wherein, the environmental parameters include turbidity parameters and humidity parameters;

[0013] Turbidity sensors are used to collect turbidity parameters of the environment in which the radar system is located;

[0014] Humidity sensors are used to collect humidity parameters of the environment in which the radar system is located.

[0015] As a further improvement to this application, the control of the microwave radar module and the coherent lidar module based on environmental parameters and intensity attenuation values ​​includes:

[0016] Based on the collected turbidity parameters, humidity parameters, and intensity attenuation values ​​of intermediate frequency echo signals and coherent intermediate frequency signals, the operating mode of the radar system is determined.

[0017] The operation of the microwave radar module and the coherent lidar module is controlled based on the working mode.

[0018] As a further improvement to this application, based on the collected turbidity parameters, humidity parameters, and intensity attenuation values ​​of the intermediate frequency echo signal and the coherent intermediate frequency signal, the operating mode of the radar system is determined to include:

[0019] When the turbidity parameter collected by the turbidity sensor is higher than the first preset turbidity threshold, and the humidity parameter collected by the humidity sensor is higher than the first preset humidity threshold, and at the same time the intensity attenuation value of the intermediate frequency echo signal is less than the intensity attenuation value of the coherent intermediate frequency signal,

[0020] The operating mode is determined to be microwave radar standalone operating mode;

[0021] When the current turbidity parameter collected by the turbidity sensor is lower than the second preset turbidity threshold, and the current humidity parameter collected by the humidity sensor is lower than the second preset humidity threshold, and at the same time the intensity attenuation value of the coherent intermediate frequency signal is less than the intensity attenuation value of the intermediate frequency echo signal, the working mode is determined to be the coherent lidar standalone working mode.

[0022] In other cases, the operating mode is determined to be a combined microwave radar and coherent lidar operating mode.

[0023] As a further improvement of this application, the microwave radar module includes: a radio frequency signal generator, a first optoelectronic modulator, a second optoelectronic modulator, a first optoelectronic conversion unit, a second optoelectronic conversion unit, and a transceiver unit;

[0024] The radio frequency signal generator is used to generate a first radio frequency signal and a programmable radio frequency signal and send them to a first optoelectronic modulator; it is also used to generate a second radio frequency signal and send it to a second optoelectronic modulator.

[0025] The first optoelectronic modulator modulates the first laser based on the programmable radio frequency signal and the first radio frequency signal, and sends the modulated optical signal to the first optoelectronic conversion unit for optoelectronic conversion to obtain a microwave radar transmission signal, which is then transmitted by the transceiver unit.

[0026] The transceiver unit receives microwave radar echo signals and transmits them to the second optoelectronic modulator.

[0027] The second optoelectronic modulator modulates the second laser based on the microwave radar echo signal and the second radio frequency signal to generate a modulated optical signal, which is then sent to the second optoelectronic conversion unit for optoelectronic conversion to obtain an intermediate frequency echo signal. The intermediate frequency echo signal is then transmitted to the control module.

[0028] As a further improvement of this application, the radio frequency signal generator includes: a waveform generator, a radio frequency source, a mixer, and a first bandpass filter;

[0029] A radio frequency (RF) source is used to generate a first RF signal that is transmitted to a mixer; and to generate a second RF signal that is transmitted to a second opto-modulator.

[0030] A waveform generator is used to generate intermediate frequency signals and transmit them to a mixer.

[0031] A mixer mixes the first radio frequency signal and the intermediate frequency signal to generate a programmable radio frequency signal, which is then transmitted to a first bandpass filter.

[0032] The first bandpass filter is used to filter the programmable radio frequency signal and transmit the filtered programmable radio frequency signal to the first modulation unit.

[0033] As a further improvement to this application, the coherent lidar module includes:

[0034] Laser modulation unit, transceiver optical system, coherent detection unit;

[0035] The laser modulation unit is used to receive the third laser beam emitted by the beam splitter, modulate the third laser beam to generate a laser emission signal, and emit the laser emission signal through the transceiver optical system.

[0036] The transceiver optical system receives the laser echo signal and transmits it to the coherent detection unit.

[0037] The coherent detection unit is used to receive the laser echo signal and the fourth laser, and to obtain a coherent intermediate frequency signal based on the laser echo signal and the fourth laser and transmit it to the control module.

[0038] As a further improvement of this application, the first photoelectric conversion unit includes: a first optical amplifier, used to amplify the modulated optical signal sent by the first photoelectric modulator and then transmit it to the first optical filter;

[0039] The first optical filter is used to filter the amplified optical signal before transmitting it to the first photodetector.

[0040] The first photodetector is used to convert the filtered optical signal into a microwave radar transmission signal and transmit it to the transceiver unit for transmission.

[0041] The second photoelectric conversion unit includes:

[0042] Second optical filter, second photodetector, second bandpass filter;

[0043] The second optical filter is used to receive the optical signal generated by the second photoelectric modulator, filter the optical signal and then transmit it to the second photodetector.

[0044] The second photodetector is used to convert the filtered optical signal into an intermediate frequency echo signal and transmit it to the second bandpass filter.

[0045] The second bandpass filter is used to filter the intermediate frequency echo signal and transmit it to the control module.

[0046] As a further improvement to this application, the laser modulation unit includes:

[0047] The third optoelectronic modulator is used to receive the third laser beam emitted by the beam splitter, modulate the third laser beam to generate a laser emission signal, and transmit it to the second optical amplifier.

[0048] The second optical amplifier is used to amplify the laser emission signal and transmit the amplified laser emission signal to the transceiver optical system.

[0049] The coherent detection unit includes: an optical coupler and a third photodetector;

[0050] An optical coupler is used to receive the laser echo signal and the third laser emitted by the beam splitter, obtain a coherent optical signal based on the laser echo signal and the third laser, and transmit the coherent optical signal to the third photodetector.

[0051] The third photodetector is used to convert coherent optical signals into electrical signals and transmit them to the control module;

[0052] The transceiver optical system includes: an optical circulator, an optical transmission system, and a galvanometer;

[0053] An optical circulator is used to receive laser emission signals and transmit them to an optical transmission system; and to transmit laser echo signals transmitted by the optical transmission system to a coherent detection unit.

[0054] An optical transmission system is used to collimate the laser emission signal and transmit it to a galvanometer; and to collimate the laser echo signal and transmit it to an optical circulator.

[0055] A galvanometer is used to scan a target based on the collimated laser emission signal and to receive the laser echo signal returned from the target and transmit it to an optical transmission system.

[0056] As a further improvement to this application, the characteristic parameters of the target generated by processing the received intermediate frequency echo signal from the microwave radar module and the coherent intermediate frequency signal from the coherent lidar module include:

[0057] The target velocity information is obtained by weighted averaging the first velocity information obtained based on the intermediate frequency echo signal and the second velocity information obtained based on the coherent intermediate frequency signal, as shown in the calculation formula (1).

[0058] V = αV1 + (1 - α)V2; (1)

[0059] Where V represents the target velocity information, V1 represents the first velocity information, V2 represents the second velocity information, and α represents the velocity weight.

[0060] The first distance information obtained based on the intermediate frequency echo signal and the second distance information obtained based on the coherent intermediate frequency signal are weighted and averaged to obtain the target distance information as shown in the calculation formula (4);

[0061] R=βR1+γR2 (2)

[0062] Where R represents the target distance information, R1 represents the first distance information, R2 represents the second distance information, and β and γ represent the distance weights.

[0063] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0064] 1. This invention improves the radar system's adaptability to different environments by collecting environmental turbidity and humidity parameters in real time, and by determining and selecting the working mode of the radar system based on environmental parameters and the intensity attenuation values ​​of intermediate frequency echo signals and coherent intermediate frequency signals. This effectively solves the problem of limited radar detection performance in harsh environments.

[0065] 2. This invention utilizes a microwave radar module and a coherent lidar module for collaborative detection. The microwave radar module modulates the laser emission and echo using radio frequency signals, while the coherent lidar module performs coherent detection of the laser emission and echo. This allows for the acquisition of target information from different angles, and the target information is then weighted and averaged, thereby improving the reliability and accuracy of the detection results.

[0066] 3. In this invention, the microwave radar module is based on microwave photonics technology to construct a new microwave-laser composite detection architecture in which all components except the microwave antenna / optical lens and TR components are uniformly processed in the photonic domain. This all-optical processing architecture does not require a parallel or multiplexed high-frequency electronic architecture, has a simpler system structure, uses an arbitrary waveform generator to generate a programmable intermediate frequency signal, and generates radar signals through photonic frequency conversion methods, achieving higher bandwidth, flexibility and coherence.

[0067] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0068] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0069] Figure 1 This is a schematic diagram of the structure of an environment-adaptive composite radar system provided in an embodiment of the present invention. Detailed Implementation

[0070] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0071] One specific embodiment of the present invention discloses an environment-adaptive composite radar system, comprising:

[0072] The laser generation module is used to output the first and second laser beams to the microwave radar module, and to output the third and fourth laser beams to the coherent radar module.

[0073] The microwave radar module is used to receive the first and second laser beams emitted by the beam splitter, modulate the first laser beam with radio frequency signals to generate a microwave radar transmission signal and transmit it to the target; it is also used to receive microwave radar echo signals, and modulate the second laser beam with microwave radar echo signals and radio frequency signals to generate an intermediate frequency echo signal and transmit it to the control module.

[0074] The coherent lidar module is used to receive the third and fourth laser beams after beam splitting, generate a laser emission signal based on the third laser beam and emit it; it receives the laser echo signal, and obtains a coherent intermediate frequency signal based on the laser echo signal and the third laser beam, which is then transmitted to the control module.

[0075] The control module is used to process the received intermediate frequency echo signal from the microwave radar module and the coherent intermediate frequency signal from the coherent lidar module to generate the characteristic parameters of the target; and to obtain the intensity attenuation value of the intermediate frequency echo signal and the coherent intermediate frequency signal, and control the operation of the microwave radar module and the coherent lidar module based on the environmental parameters and the intensity attenuation value.

[0076] The sensor module is used to collect environmental parameters and transmit them to the control module.

[0077] like Figure 1 As shown.

[0078] The laser generation module outputs the first and second laser beams to the microwave radar module, and the third laser beam to the single-photon lidar module. The laser generation module includes a laser 1 and a beam splitter 2. The continuous laser beam generated by laser 1 is split into multiple beams by beam splitter 2, which are then transmitted to the microwave radar module and the single-photon lidar module respectively. Beam splitter 2 is an optical element used to split the laser beam emitted by laser 1 into three beams: the first and second beams are transmitted to the microwave radar module, and the third beam is transmitted to the single-photon lidar module.

[0079] The microwave radar module receives the first and second laser beams emitted by beam splitter 2. It modulates the first laser beam using radio frequency signals to generate a microwave radar transmit signal, which is then transmitted to the target. It also receives microwave radar echo signals and modulates the second laser beam using the microwave radar echo signal and radio frequency signals to generate an intermediate frequency echo signal, which is then transmitted to the feature generation module and the control module.

[0080] Specifically, the microwave radar module includes: a radio frequency signal generator, a first optoelectronic modulator, a second optoelectronic modulator, a first optoelectronic conversion unit, a second optoelectronic conversion unit, and a transceiver unit;

[0081] The radio frequency signal generator is used to generate a first radio frequency signal and a programmable radio frequency signal and send them to a first optoelectronic modulator; it is also used to generate a second radio frequency signal and send it to a second optoelectronic modulator.

[0082] The radio frequency (RF) signal generator is used to generate RF signals for radar detection. The RF signal generator includes: a waveform generator 4, an RF source 3, a mixer 5, and a first bandpass filter 6. The RF source 3 generates a first RF signal which is transmitted to the mixer 5, and generates a second RF signal which is transmitted to the second optoelectronic modulator 13 for modulating a second laser beam.

[0083] Waveform generator 4 is used to generate intermediate frequency (IF) signals and transmit them to mixer 5. The IF signal is a fixed frequency signal used for signal processing and modulation in the radar system, with a frequency between that of radio frequency (RF) signals and baseband signals.

[0084] Mixer 5 mixes the first radio frequency signal and the intermediate frequency signal to generate a programmable radio frequency signal, which is then transmitted to the first bandpass filter 6. The programmable radio frequency signal can be programmed as needed to adapt to different detection conditions and target characteristics.

[0085] The first bandpass filter 6 is used to filter the programmable radio frequency signal to ensure that the frequency characteristics of the signal meet the system requirements. The filtered programmable radio frequency signal is then transmitted to the first modulation unit.

[0086] The first optoelectronic modulator 7 modulates the first laser beam based on the programmable radio frequency signal and the first radio frequency signal, and sends the modulated optical signal to the first optoelectronic conversion unit for optoelectronic conversion to obtain a microwave radar transmission signal, which is then transmitted by the transceiver unit. The second optoelectronic modulator 13 modulates the second laser beam based on the microwave radar echo signal and the second radio frequency signal to generate a modulated optical signal, which is then sent to the second optoelectronic conversion unit for optoelectronic conversion to obtain an intermediate frequency echo signal, which is then transmitted to the control and acquisition processing module 29.

[0087] The first optoelectronic modulator 7 modulates the first laser beam with a programmable radio frequency signal generated by the radio frequency signal generator and a first radio frequency signal, changing the phase or amplitude of the laser to carry the information required for radar detection. The second optoelectronic modulator 13 receives the target-reflected microwave radar echo signal from the transceiver unit and modulates the second laser beam together with the second radio frequency signal, changing the phase or amplitude of the laser. Modulation is the process of encoding information onto a carrier wave in a radar signal. In the optoelectronic modulator, the characteristics of the laser, such as amplitude, frequency, or phase, are changed to carry the information to be transmitted.

[0088] Furthermore, the first photoelectric conversion unit includes:

[0089] The first optical amplifier 8 amplifies the modulated optical signal sent by the first photoelectric modulator 7 before transmitting it to the first optical filter. The first optical amplifier 8 amplifies the modulated optical signal to increase its intensity.

[0090] The first optical filter 9 is used to filter the amplified optical signal before transmitting it to the first photodetector, removing unwanted frequency components to improve signal quality.

[0091] The first photodetector 10 is used to convert the filtered optical signal into a corresponding electrical signal, namely the microwave radar transmission signal, and transmit the microwave radar transmission signal to the transceiver unit for transmission.

[0092] The transceiver unit includes a TR component 11 and an antenna 12. The TR component 11 includes a transmitter and a receiver. In transmit mode, the TR component 11 transmits microwave radar signals to the target via the antenna 12. In receive mode, the TR component 11 receives echo signals reflected from the target.

[0093] The second photoelectric conversion unit includes: a second optical filter 14, a second photodetector 15, and a second bandpass filter 16.

[0094] The second optical filter 14 is used to receive the optical signal modulated by the second photoelectric modulator 13, filter the optical signal to remove unwanted frequency components or noise, and transmit the filtered signal to the second photodetector.

[0095] The second photodetector 15 is used to convert the filtered optical signal into an electrical signal, namely an intermediate frequency echo signal, and transmit it to the second bandpass filter 16.

[0096] The second bandpass filter 16 is used to further filter the intermediate frequency echo signal to extract useful signal components, remove unwanted frequencies or noise, and transmit the signal to the control and acquisition processing module 29.

[0097] The microwave radar transmits signals as shown in calculation formula (1);

[0098] ω Radar =m·ω RF1 -n·ω RF2 -m·[ω IF -BW / 2+BW·t / T]

[0099] Where, ω Radar ω is the angular frequency of the microwave radar transmitted signal. RF1 Let ω be the angular frequency of the first radio frequency signal. RF2 ω is the angular frequency of the second radio frequency signal. IFω is the angular frequency of the programmable radio frequency signal, m and n are the laser modulation order, BW is the bandwidth of the programmable radio frequency signal, T is the pulse width of the programmable radio frequency signal, and t is the modulation time.

[0100] The intermediate frequency echo signal is shown in calculation formula (2);

[0101] ω' IF =k·ω RF3 -ω' Radar

[0102] Where, ω RF3 Let ω′ be the angular frequency of the third radio frequency signal. Radar Let ω' be the angular frequency of the microwave radar echo signal. IF ω is the angular frequency of the intermediate frequency echo signal, and k is the laser modulation order.

[0103] Furthermore, the coherent lidar module includes:

[0104] Laser modulation unit, transceiver optical system, coherent detection unit;

[0105] The laser modulation unit is used to receive the third laser beam emitted by the beam splitter, modulate the third laser beam to generate a laser emission signal, and emit the laser emission signal through the transceiver optical system.

[0106] The transceiver optical system receives the laser echo signal and transmits it to the coherent detection unit.

[0107] The coherent detection unit is used to receive the laser echo signal and the fourth laser, and to obtain a coherent intermediate frequency signal based on the laser echo signal and the fourth laser and transmit it to the control and acquisition processing module.

[0108] Coherent lasers refer to two or more beams of light that maintain the same phase difference, have the same frequency, or have completely identical waveforms during propagation. Coherent lasers can produce stable interference phenomena during propagation, namely constructive interference and destructive interference.

[0109] Specifically, the laser modulation unit includes:

[0110] The third optoelectronic modulator 17 is used to receive the third laser emitted by the beam splitter 2, modulate the third laser, change the phase, frequency or amplitude of the third laser, generate a laser emission signal for detection and transmit it to the second optical amplifier 18.

[0111] The second optical amplifier 18 is used to amplify the laser emission signal to ensure that the laser emission signal has a sufficient power level and to transmit the amplified laser emission signal to the transceiver optical system.

[0112] The coherent detection unit includes: an optical coupler 22 and a third photodetector 28;

[0113] Optical coupler 22 is used to receive the laser echo signal and the fourth laser emitted by beam splitter 2, obtain a coherent optical signal based on the laser echo signal and the fourth laser, and transmit the coherent optical signal to the third photodetector 28. Optical coupler 22 mixes the laser echo signal and the fourth laser, and uses the phase difference between the laser echo signal and the fourth laser to generate a coherent optical signal.

[0114] The third photodetector 28 is used to convert coherent optical signals into electrical signals and transmit them to the control and acquisition processing module.

[0115] The transceiver optical system includes: an optical circulator 19, an optical transmission system 20, and a galvanometer 21;

[0116] The optical circulator 19 is used to receive laser emission signals and transmit them to the optical transmission system; and to transmit the laser echo signals transmitted by the optical transmission system to the coherent detection unit.

[0117] The optical circulator 19 is a non-reciprocal optical element that allows light signals to travel in one direction without reflection. The optical circulator 19 receives the laser emission signal from the second optical amplifier 18 and transmits it to the optical transmission system. When the laser echo signal is reflected back from the target, the optical circulator 19 transmits the laser echo signal to the coherent detection unit for coherent detection and signal processing.

[0118] The optical transmission system 20 is used to collimate the laser emission signal and transmit it to the galvanometer 21; and to converge the laser echo signal and transmit it to the optical circulator 19. The optical transmission system 20 collimates the laser emission signal, that is, it focuses the laser beam into a parallel beam to improve its directional stability and energy concentration during propagation.

[0119] Galvanometer 21 is used to scan the target based on the collimated laser emission signal and to receive the laser echo signal returned from the target and transmit it to the optical transmission system 20. Galvanometer 21 is a fast-response optical scanner that guides the direction of the laser beam by controlling the deflection angle of a mirror. Galvanometer 21 receives the collimated laser emission signal and scans the target according to the instructions of the control and acquisition processing module 29. Galvanometer 21 also reflects the laser echo signal returned from the target back to the optical transmission system 20 for subsequent signal processing.

[0120] Furthermore, the sensor module is used to collect environmental parameters and transmit the collected environmental parameters to the control module. The sensor module includes a turbidity sensor and a humidity sensor; wherein the environmental parameters include turbidity parameters and humidity parameters; the turbidity sensor is used to collect the turbidity parameters of the environment in which the radar system is located; the humidity sensor is used to collect the humidity parameters of the environment in which the radar system is located.

[0121] A turbidity sensor based on infrared light scattering can be selected. When infrared light shines on particles suspended in a liquid or gas, scattering occurs, and the intensity of the scattered light is related to the particle concentration (i.e., turbidity). By detecting the intensity of the scattered light, the turbidity of the environment can be indirectly measured. Infrared light scattering turbidity sensors are more sensitive to the detection of small particles and are suitable for measuring atmospheric turbidity under various weather conditions. The turbidity sensor is installed on the outside of the radar system housing in a well-ventilated, unobstructed location to ensure that the sensor has sufficient contact with the ambient air and obtains accurate environmental turbidity information.

[0122] A capacitive humidity sensor can be selected. When moisture in the environment is adsorbed onto the hygroscopic material of the humidity sensor, it changes the dielectric constant of the material, thus changing the sensor's capacitance. By detecting the change in capacitance, the relative humidity of the environment can be calculated. The humidity sensor is also installed on the outside of the radar system housing, maintaining an appropriate distance from the turbidity sensor to avoid mutual interference.

[0123] The control module 24 is used to process the received intermediate frequency echo signal from the microwave radar module and the coherent intermediate frequency signal from the coherent lidar module to generate the characteristic parameters of the target; and to obtain the intensity attenuation value of the intermediate frequency echo signal and the coherent intermediate frequency signal, and control the operation of the microwave radar module and the coherent lidar module based on the environmental parameters and the intensity attenuation value.

[0124] Specifically, controlling the operation of the microwave radar module and the coherent lidar module includes:

[0125] Based on the collected turbidity parameters, humidity parameters, and intensity attenuation values ​​of intermediate frequency echo signals and coherent intermediate frequency signals, the operating mode of the radar system is determined.

[0126] The operation of the microwave radar module and the coherent lidar module is controlled based on the working mode.

[0127] The intensity attenuation value of microwave radar modules and coherent lidar modules refers to the degree of power reduction of the transmitted signal as it propagates to the target and returns, reflecting the change between the signal strength emitted from the transmitter and the echo signal strength received at the receiver. During signal propagation, various factors (such as distance, atmospheric absorption, scattering, and reflection) cause energy loss. The signal is absorbed by gas molecules in the atmosphere and scattered by factors such as the roughness of the target object's surface, all of which contribute to a decrease in signal strength.

[0128] A microwave radar module can use a power meter to measure the intensity of the radar echo, while a lidar module can use a light intensity meter to measure the intensity of the laser echo. Specifically, the power meter can be placed between the antenna 12 and the TR component 11 in the signal transmission path. When in receiving mode, the antenna 12 transmits the microwave radar echo signal to the receiver of the TR component 11. The power meter measures the power value of the microwave radar echo signal and transmits this power value to the control module. The control module calculates the difference between the power value of the microwave radar transmitted signal and the power value of the microwave radar echo signal, thereby obtaining the intensity attenuation value of the microwave radar module.

[0129] A light intensity meter can be installed on the optical transmission path between the optical transmission system 20 and the optical circulator 19 in the coherent lidar module's transceiver optical system. When the optical transmission system 20 transmits the laser echo signal to the optical circulator 19, the light intensity meter measures the light intensity of the laser echo signal and sends the laser echo light intensity value to the control module. The control module calculates the difference between the light intensity of the emitted laser signal and the light intensity of the echo signal, thereby obtaining the intensity attenuation value of the lidar module. When the turbidity parameter collected by the turbidity sensor is higher than a first preset turbidity threshold, and the humidity parameter collected by the humidity sensor is higher than a first preset humidity threshold, and the intensity attenuation value of the intermediate frequency echo signal is less than the intensity attenuation value of the coherent intermediate frequency signal, the operating mode is determined to be the microwave lidar standalone operating mode.

[0130] When the current turbidity parameter collected by the turbidity sensor is lower than the second preset turbidity threshold, and the current humidity parameter collected by the humidity sensor is lower than the second preset humidity threshold, and at the same time the intensity attenuation value of the coherent intermediate frequency signal is less than the intensity attenuation value of the intermediate frequency echo signal, the working mode is determined to be the coherent lidar standalone working mode.

[0131] In other cases, the operating mode is determined to be a combined microwave radar and coherent lidar operating mode.

[0132] Setting the first preset turbidity threshold, the second preset turbidity threshold, the first preset humidity threshold, and the second preset humidity threshold requires first collecting performance data of the radar system under different environmental conditions. The first preset turbidity threshold should be such that the microwave radar begins to exhibit relatively superior performance at or above this turbidity value. Generally, it is selected near the turbidity value at which the performance of the coherent lidar begins to decline significantly, while the microwave lidar still maintains a certain detection capability. The second preset turbidity threshold is set based on the turbidity value at which the coherent lidar can exert its high-resolution advantage at low turbidity. At the second preset turbidity threshold, the performance of the coherent lidar is significantly better than that of the microwave lidar.

[0133] Similarly, the first preset humidity threshold is a humidity value that significantly affects the performance of coherent lidar while maintaining relatively stable performance of microwave lidar. The second preset humidity threshold is a humidity value that significantly outperforms microwave lidar in detection performance.

[0134] When the operating mode is a combined microwave radar and coherent lidar mode, the characteristic parameters of the target are generated by processing the received intermediate frequency echo signal from the microwave radar module and the coherent intermediate frequency signal from the coherent lidar module.

[0135] The target velocity information is obtained by weighted averaging the first velocity information obtained based on the intermediate frequency echo signal and the second velocity information obtained based on the coherent intermediate frequency signal, as shown in the calculation formula (3).

[0136] V = αV1 + (1 - α)V2; (3)

[0137] Where V represents the target velocity information, V1 represents the first velocity information, V2 represents the second velocity information, and α represents the velocity weight;

[0138] The first velocity information obtained based on the intermediate frequency echo signal includes:

[0139] The Doppler frequency shift is obtained by performing spectral analysis on the intermediate frequency echo signal;

[0140] The first velocity information is shown in calculation formula (4);

[0141]

[0142] Where λ1 is the wavelength of the microwave radar transmitted signal, and Δf1 is the Doppler frequency shift;

[0143] The second velocity information obtained based on the coherent intermediate frequency signal includes:

[0144] Frequency change is obtained by performing frequency analysis on the coherent intermediate frequency signal;

[0145] The second speed information is shown in calculation formula (5);

[0146]

[0147] Where λ2 is the wavelength of the laser emission signal, and Δf2 is the frequency change.

[0148] The first distance information obtained based on the intermediate frequency echo signal and the second distance information obtained based on the coherent intermediate frequency signal are weighted and averaged to obtain the target distance information as shown in the calculation formula (6);

[0149] R=βR1+γR2 (6)

[0150] Where R is the target distance information, R1 is the first distance information, R2 is the second distance information, and β and γ are the distance weights;

[0151] The first distance information is obtained based on the intermediate frequency echo signal as shown in the calculation formula (7);

[0152]

[0153] Where R1 represents the first distance information, c represents the speed of light, t1 represents the arrival time of the microwave radar echo pulse, and t 01 This refers to the transmission time of the microwave radar signal.

[0154] The second distance information is obtained based on the coherent echo signal, and the second distance information is shown in the calculation formula (8).

[0155]

[0156] Where R2 is the second distance information, and τ2 is the laser pulse width of the laser emission signal.

[0157] When the working mode is microwave radar standalone working mode, the target velocity information and target range information are obtained only based on the intermediate frequency echo signal. The target velocity information is shown in calculation formula (4), and the target range information is shown in calculation formula (7).

[0158] When the working mode is the coherent lidar module working mode, the target velocity information and target distance information are obtained only based on the coherent intermediate frequency signal. The target velocity information is shown in the calculation formula (5), and the target distance information is shown in the calculation formula (8).

[0159] The above embodiments of the present invention have the following beneficial effects: By collecting environmental turbidity and humidity parameters in real time, and judging and selecting the working mode of the radar system based on environmental parameters and the intensity attenuation values ​​of intermediate frequency echo signals and coherent intermediate frequency signals, the adaptability of the radar system to different environments is improved, effectively solving the problem of limited radar detection performance in harsh environments; through the collaborative detection of microwave radar module and coherent lidar module, the microwave radar module uses radio frequency signals to modulate the laser emission and echo processing, and the coherent lidar module performs coherent detection of the laser emission and echo, acquiring target information from different angles, and performing weighted averaging processing on the target information, thereby improving the reliability and accuracy of the detection results.

[0160] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0161] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An environment-adaptive composite radar system, characterized in that, include: The laser generation module is used to output the first and second laser beams to the microwave radar module, and to output the third and fourth laser beams to the coherent radar module. The microwave radar module is used to receive the first and second laser beams emitted by the beam splitter, modulate the first laser beam with radio frequency signals to generate a microwave radar transmission signal and transmit it to the target; it is also used to receive microwave radar echo signals, and modulate the second laser beam with microwave radar echo signals and radio frequency signals to generate an intermediate frequency echo signal and transmit it to the control module. The coherent lidar module is used to receive the third and fourth laser beams after beam splitting, generate a laser emission signal based on the third laser beam and emit it; it receives the laser echo signal, and obtains a coherent intermediate frequency signal based on the laser echo signal and the third laser beam, which is then transmitted to the control module. The control module is used to process the received intermediate frequency echo signal from the microwave radar module and the coherent intermediate frequency signal from the coherent lidar module to generate the characteristic parameters of the target; and to obtain the intensity attenuation value of the intermediate frequency echo signal and the coherent intermediate frequency signal, and control the operation of the microwave radar module and the coherent lidar module based on the environmental parameters and the intensity attenuation value. The sensor module is used to collect environmental parameters and transmit them to the control module.

2. The system according to claim 1, characterized in that, The sensor module includes a turbidity sensor and a humidity sensor; wherein, the environmental parameters include turbidity parameters and humidity parameters; Turbidity sensors are used to collect turbidity parameters of the environment in which the radar system is located; Humidity sensors are used to collect humidity parameters of the environment in which the radar system is located.

3. The system according to claim 2, characterized in that, The control of the microwave radar module and the coherent lidar module based on environmental parameters and intensity attenuation values ​​includes: Based on the collected turbidity parameters, humidity parameters, and intensity attenuation values ​​of intermediate frequency echo signals and coherent intermediate frequency signals, the operating mode of the radar system is determined. The operation of the microwave radar module and the coherent lidar module is controlled based on the working mode.

4. The system according to claim 3, characterized in that, Based on the collected turbidity parameters, humidity parameters, and intensity attenuation values ​​of the intermediate frequency echo signal and the coherent intermediate frequency signal, the operating modes of the radar system are determined as follows: When the turbidity parameter collected by the turbidity sensor is higher than the first preset turbidity threshold, and the humidity parameter collected by the humidity sensor is higher than the first preset humidity threshold, and the intensity attenuation value of the intermediate frequency echo signal is less than the intensity attenuation value of the coherent intermediate frequency signal, the working mode is determined to be the microwave radar standalone working mode. When the current turbidity parameter collected by the turbidity sensor is lower than the second preset turbidity threshold, and the current humidity parameter collected by the humidity sensor is lower than the second preset humidity threshold, and at the same time the intensity attenuation value of the coherent intermediate frequency signal is less than the intensity attenuation value of the intermediate frequency echo signal, the working mode is determined to be the coherent lidar standalone working mode. In other cases, the operating mode is determined to be a combined microwave radar and coherent lidar operating mode.

5. The system according to claim 1, characterized in that, The microwave radar module includes: a radio frequency signal generator, a first optoelectronic modulator, a second optoelectronic modulator, a first optoelectronic conversion unit, a second optoelectronic conversion unit, and a transceiver unit; The radio frequency signal generator is used to generate a first radio frequency signal and a programmable radio frequency signal and send them to a first optoelectronic modulator; it is also used to generate a second radio frequency signal and send it to a second optoelectronic modulator. The first optoelectronic modulator modulates the first laser based on the programmable radio frequency signal and the first radio frequency signal, and sends the modulated optical signal to the first optoelectronic conversion unit for optoelectronic conversion to obtain a microwave radar transmission signal, which is then transmitted by the transceiver unit. The transceiver unit receives microwave radar echo signals and transmits them to the second optoelectronic modulator. The second optoelectronic modulator modulates the second laser based on the microwave radar echo signal and the second radio frequency signal to generate a modulated optical signal, which is then sent to the second optoelectronic conversion unit for optoelectronic conversion to obtain an intermediate frequency echo signal. The intermediate frequency echo signal is then transmitted to the control module.

6. The system according to claim 5, characterized in that, The radio frequency signal generator includes: a waveform generator, a radio frequency source, a mixer, and a first bandpass filter; A radio frequency (RF) source is used to generate a first RF signal that is transmitted to a mixer; and to generate a second RF signal that is transmitted to a second opto-modulator. A waveform generator is used to generate intermediate frequency signals and transmit them to a mixer. A mixer mixes the first radio frequency signal and the intermediate frequency signal to generate a programmable radio frequency signal, which is then transmitted to a first bandpass filter. The first bandpass filter is used to filter the programmable radio frequency signal and transmit the filtered programmable radio frequency signal to the first modulation unit.

7. The system according to claim 1, characterized in that, The coherent lidar module includes: Laser modulation unit, transceiver optical system, coherent detection unit; The laser modulation unit is used to receive the third laser beam emitted by the beam splitter, modulate the third laser beam to generate a laser emission signal, and emit the laser emission signal through the transceiver optical system. The transceiver optical system receives the laser echo signal and transmits it to the coherent detection unit. The coherent detection unit is used to receive the laser echo signal and the fourth laser, and to obtain a coherent intermediate frequency signal based on the laser echo signal and the fourth laser and transmit it to the control module.

8. The system according to claim 5, characterized in that, The first photoelectric conversion unit includes: a first optical amplifier, used to amplify the modulated optical signal sent by the first photoelectric modulator and then transmit it to the first optical filter; The first optical filter is used to filter the amplified optical signal before transmitting it to the first photodetector. The first photodetector is used to convert the filtered optical signal into a microwave radar transmission signal and transmit it to the transceiver unit for transmission. The second photoelectric conversion unit includes: Second optical filter, second photodetector, second bandpass filter; The second optical filter is used to receive the optical signal generated by the second photoelectric modulator, filter the optical signal and then transmit it to the second photodetector. The second photodetector is used to convert the filtered optical signal into an intermediate frequency echo signal and transmit it to the second bandpass filter. The second bandpass filter is used to filter the intermediate frequency echo signal and transmit it to the control module.

9. The system according to claim 7, characterized in that, The laser modulation unit includes: The third optoelectronic modulator is used to receive the third laser beam emitted by the beam splitter, modulate the third laser beam to generate a laser emission signal, and transmit it to the second optical amplifier. The second optical amplifier is used to amplify the laser emission signal and transmit the amplified laser emission signal to the transceiver optical system. The coherent detection unit includes: an optical coupler and a third photodetector; An optical coupler is used to receive the laser echo signal and the third laser emitted by the beam splitter, obtain a coherent optical signal based on the laser echo signal and the third laser, and transmit the coherent optical signal to the third photodetector. The third photodetector is used to convert coherent optical signals into electrical signals and transmit them to the control module; The transceiver optical system includes: an optical circulator, an optical transmission system, and a galvanometer; An optical circulator is used to receive laser emission signals and transmit them to an optical transmission system; and to transmit laser echo signals transmitted by the optical transmission system to a coherent detection unit. An optical transmission system is used to collimate the laser emission signal and transmit it to a galvanometer; and to collimate the laser echo signal and transmit it to an optical circulator. A galvanometer is used to scan a target based on the collimated laser emission signal and to receive the laser echo signal returned from the target and transmit it to an optical transmission system.

10. The system according to claim 1, characterized in that, The characteristic parameters of the target are generated by processing the received intermediate frequency echo signal from the microwave radar module and the coherent intermediate frequency signal from the coherent lidar module. When the microwave radar module and the single-photon lidar module work simultaneously, the first velocity information obtained based on the intermediate frequency echo signal and the second velocity information obtained based on the coherent intermediate frequency signal are weighted and averaged to obtain the target velocity information, as shown in the calculation formula (1). V = αV1 + (1 - α)V2; (1) Where V represents the target velocity information, V1 represents the first velocity information, V2 represents the second velocity information, and α represents the velocity weight; The first distance information obtained based on the intermediate frequency echo signal and the second distance information obtained based on the coherent intermediate frequency signal are weighted and averaged to obtain the target distance information as shown in the calculation formula (4); R=βR1+γR2 (2) Where R represents the target distance information, R1 represents the first distance information, R2 represents the second distance information, and β and γ represent the distance weights.

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