Laser radar zero blind area detection system and method based on automatic switching of far and near fields

Abstract

The invention discloses a laser radar zero-blind-area detection system and method based on automatic switching of far and near fields, and solves the problem of low signal receiving efficiency of detection blind areas and far and near fields 100 meters below the ground in the prior art. According to the system, laser emission beams are respectively transmitted along coaxial and off-axis paths through a light splitting module, an aperture diaphragm automatic adjusting device is introduced, a receiving aperture is automatically switched according to far and near field imaging characteristics, and efficient coupling of signals and optimized receiving under a weak light condition are ensured. The system combines far and near field signals to the same optical path by using an automatic beam combination switching device, realizes multichannel signal detection, and supports multifunctional atmospheric parameter monitoring such as aerosol, Raman scattering and the like. The control and data processing system automatically manages signal switching and data processing, operation is simplified, and data reliability is improved. The technology is obviously superior to the prior art in the aspects of detection precision, system integration degree and multifunctional detection capability, and system complexity and cost are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of laser radar and atmospheric environment monitoring equipment, and in particular to a laser radar zero-blind zone detection system and method based on automatic switching between far and near fields. Background Art

[0002] As a high-precision measurement technology, LiDAR is widely used in atmospheric monitoring, environmental detection, autonomous driving and other fields. It detects objects or atmospheric characteristics at different distances by emitting laser pulses and receiving echo signals. However, in practical applications, LiDAR systems often have blind spots when detecting areas below 100 meters near the ground. This is because the laser echo signal in the close-range area will overflow or fail to be effectively received due to excessive intensity or insufficient detection field design, affecting the accuracy of the data.

[0003] In order to solve the problem of near-ground blind spots, existing technologies usually use dual telescope systems or fiber-coupled spectrometer systems. This type of system sets up receiving devices with different fields of view in the near and far fields, so that a large field of view telescope is used in the near field and a small field of view telescope is used in the far field, and the signals of different fields of view are received through fiber coupling. This solution can indeed reduce the blind spot to a certain extent, but its design is complex and debugging is difficult. In addition, it is limited by the numerical aperture of the fiber end face and the fiber coupling efficiency, and it still cannot completely eliminate the near-field blind spot.

[0004] To address this problem, the industry sometimes uses multi-channel splitter design or uses beam shaping technology to process far-field and near-field signals. However, this approach also brings new problems: 1. High system complexity: Multi-channel spectroscopic design usually requires multiple sets of receiving equipment, which makes the overall system structure complex, increases costs, and is difficult to integrate.

[0005] 2. Low efficiency in weak light reception: In the design of large field of view, the imaging difference between far field and near field is significant, especially in weak light environment, the coupling efficiency of signal is low, resulting in reduced detection accuracy.

[0006] 3. Complicated operation and difficult maintenance: Existing solutions usually require manual adjustment or regular calibration, with high maintenance costs, and it is difficult to meet the needs of continuous and efficient detection.

[0007] In order to overcome these problems, the existing technology sometimes uses a multi-fiber coupling system, an arrayed receiving module or a CCD-based automatic adjustment system. Although these solutions can reduce the blind area to a certain extent, due to the high requirements for multi-fiber coupling accuracy and field of view matching, and the complex optical path design, the difficulty of debugging and application is still relatively large, and it is impossible to achieve the ideal zero blind area detection effect.

[0008] Therefore, how to achieve efficient coupling of far-field and near-field signals and reduce system complexity and detection blind spots has become a technical problem to be solved by the present invention. Summary of the invention

[0009] The technical problem solved by the present invention is to provide a laser radar zero-blind zone detection system and method based on automatic switching between far and near fields in response to the defects existing in the above-mentioned prior art, so as to solve the problems of difficulty in near-ground blind zone detection, complex system and low weak light reception efficiency raised in the above-mentioned background technology.

[0010] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: A laser radar zero blind zone detection system based on automatic switching between far and near fields, comprising: An emission optical path modulation system is used to emit a laser beam and divide the laser beam into a far-field emission beam and a near-field emission beam through a splitting design. The emission optical path modulation system includes a splitting module, wherein the far-field emission beam is transmitted along a coaxial structure, and the near-field emission beam is transmitted along an off-axis structure; The receiving optical path modulation system comprises: The aperture diaphragm automatic switching device automatically adjusts the receiving aperture according to the far-field and near-field imaging characteristics to improve the reception efficiency of far-field and near-field signals; Automatic beam-combining switching device couples far-field and near-field receiving signals to the same receiving path to achieve multi-channel signal detection and processing; The multi-channel follow-up spectroscopic system is used to perform optical spectroscopic processing on the received far-field and near-field echo signals. The spectroscopic channels are used to detect different atmospheric environment parameters. The control and data processing system is used to control the automatic switching and aperture adjustment of the transmitting optical path modulation system and the receiving optical path modulation system, process the echo signal data of the multi-channel subsequent spectroscopic system in real time, and output the detection results; Among them, the far-field and near-field signals are combined into the same splitting path through the automatic beam combining and switching device, thereby avoiding the complexity and high cost of multiple splitting systems, and realizing zero-blind-zone high-precision monitoring of the atmospheric environment from near the ground to high altitude through time-sharing control.

[0011] As a further solution of the present invention, the spectroscopic module is used to transmit the far-field emission light beam to the coaxial path and the near-field emission light beam to the off-axis path according to the design of the emission light path, so as to meet the detection requirements of the far field and near field respectively.

[0012] As a further solution of the present invention, the aperture diaphragm automatic switching device includes a motor drive device for adjusting the far-field and near-field receiving apertures, and automatically switches and adjusts the far-field and near-field diaphragm apertures to match corresponding imaging requirements and improve signal coupling efficiency.

[0013] As a further solution of the present invention, the automatic beam combining and switching device includes a reflector and a light-clearing aperture structure, which switches the transmission paths of far-field and near-field signals by a motor-driven turntable, and combines signals of different paths into the same optical channel for subsequent splitting and processing.

[0014] As a further solution of the present invention, the multi-channel subsequent spectroscopic system includes an aerosol polarization channel, a Raman scattering channel, a water vapor content channel and a temperature channel, and can automatically select a corresponding channel combination according to different detection requirements to perform multifunctional detection of atmospheric environmental parameters.

[0015] As a further solution of the present invention, the beam shaping device is used to perform spot shaping on the near-field and far-field laser beams so that the laser beams have optimal divergence angles and spot sizes under the corresponding fields of view to improve the optical path coupling efficiency of near-field and far-field signal reception.

[0016] As a further solution of the present invention, the control and data processing system presets the switching frequency according to the detection requirements, and detects the far-field and near-field signals in a time-sharing switching manner by automatically controlling the transmitting optical path modulation system and the receiving optical path modulation system.

[0017] A laser radar zero blind zone detection method based on automatic switching between far and near fields, characterized in that it comprises the following steps: Step 1, emitting a laser beam, and dividing the laser beam into a far-field emission beam and a near-field emission beam through a beam splitting module; Step 2, according to the imaging requirements of the far field and the near field, the aperture diaphragm is adjusted by the aperture diaphragm automatic switching device to match the reception requirements of the far field or the near field; Step 3, combining the far-field and near-field signals into the same receiving path through an automatic beam combining switching device; Step 4: Perform spectroscopic processing on the received far-field and near-field echo signals through a multi-channel subsequent spectroscopic system, and process and display the detection signals in real time through a control and data processing system to achieve zero-blind zone detection from near-ground to high-altitude atmospheric environments.

[0018] As a further solution of the present invention, in the step of emitting laser beams, the far-field emitting beam is a coaxial structure, and the near-field emitting beam is an off-axis structure, so as to ensure the best detection effect of far-field and near-field signals.

[0019] As a further solution of the present invention, in the step of adjusting the aperture diaphragm, the far-field receiving signal is received through the small-aperture diaphragm, and the near-field signal is received through the large-aperture diaphragm, so as to ensure the best receiving accuracy and signal-to-noise ratio of the far-field and near-field signals.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. Optical path splitting and beam shaping design: This invention uses coaxial and off-axis optical path designs to rationally divide the emission paths of far-field and near-field laser beams, solving the optical coupling problem of traditional radar in far-field and near-field detection. Unlike the fixed optical path commonly used in the prior art, this solution not only meets the needs of high-precision detection in the far field, but also ensures the monitoring capability of a large field of view in the near field through the optimized splitting path design. This innovation significantly reduces the occurrence of blind spots and improves the stability and detection accuracy of the beam.

[0021] 2. Automatic adjustment of aperture diaphragm and optimization of weak light signals: It is difficult to achieve efficient signal reception in both far and near fields in the prior art, especially under weak light conditions, where detection accuracy is limited. The present invention introduces an automatic switching device for the aperture diaphragm to dynamically adjust the aperture according to the imaging characteristics of the far and near fields, thereby ensuring efficient coupling and signal reception of different light beams. This mechanism not only significantly improves the detection performance of the system under weak light conditions, but also optimizes the shaping process of the large field of view spot, enabling the entire system to maintain an excellent signal-to-noise ratio over a wide detection range.

[0022] 3. Multi-channel signal beam combining and integrated design: The present invention combines far-field and near-field signals into the same optical path through an automatic beam combining switching device, and detects multiple atmospheric environmental parameters such as aerosol polarization, Raman scattering, and water vapor content through a multi-channel subsequent spectroscopic system. This design not only greatly reduces the system's dependence on multiple sets of spectroscopic equipment, reduces system complexity and cost, but also enhances multifunctional detection capabilities and expands application scenarios. Compared with traditional solutions, this integrated design significantly improves the system's applicability and ease of operation.

[0023] 4. System automation and efficient data processing: The present invention introduces an automated control and data processing system, which can realize automatic switching and signal processing of the transmitting and receiving systems according to the preset frequency and detection requirements, reducing the tedious operation of manual debugging and improving the real-time and accuracy of data processing. This design not only optimizes the operating process of the system, but also improves the reliability of collected data, and is particularly suitable for continuous monitoring needs in complex atmospheric environments.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 Schematic diagram of the system architecture of the present invention.

[0027] Figure 2 It is a schematic structural diagram of the automatic light blocking switching device of the present invention.

[0028] Figure 3 It is a structural schematic diagram of the aperture diaphragm automatic switching device.

[0029] Figure 4 It is a structural schematic diagram of the automatic beam combining and switching device. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] See also Figure 1 —4. In an embodiment of the present invention, a laser radar zero blind zone detection system based on automatic switching between far and near fields comprises: An emission optical path modulation system is used to emit a laser beam and divide the laser beam into a far-field emission beam and a near-field emission beam through a splitting design. The emission optical path modulation system includes a splitting module, wherein the far-field emission beam is transmitted along a coaxial structure, and the near-field emission beam is transmitted along an off-axis structure; The receiving optical path modulation system comprises: The aperture diaphragm automatic switching device automatically adjusts the receiving aperture according to the far-field and near-field imaging characteristics to improve the reception efficiency of far-field and near-field signals; Automatic beam-combining switching device couples far-field and near-field receiving signals to the same receiving path to achieve multi-channel signal detection and processing; The multi-channel follow-up spectroscopic system is used to perform optical spectroscopic processing on the received far-field and near-field echo signals. The spectroscopic channels are used to detect different atmospheric environment parameters. The control and data processing system is used to control the automatic switching and aperture adjustment of the transmitting optical path modulation system and the receiving optical path modulation system, process the echo signal data of the multi-channel subsequent spectroscopic system in real time, and output the detection results; Among them, the far-field and near-field signals are combined into the same splitting path through the automatic beam combining and switching device, thereby avoiding the complexity and high cost of multiple splitting systems, and realizing zero-blind-zone high-precision monitoring of the atmospheric environment from near the ground to high altitude through time-sharing control.

[0032] As a further solution of the present invention, the spectroscopic module is used to transmit the far-field emission light beam to the coaxial path and the near-field emission light beam to the off-axis path according to the design of the emission light path, so as to meet the detection requirements of the far field and near field respectively.

[0033] As a further solution of the present invention, the aperture diaphragm automatic switching device includes a motor drive device for adjusting the far-field and near-field receiving apertures, and automatically switches and adjusts the far-field and near-field diaphragm apertures to match corresponding imaging requirements and improve signal coupling efficiency.

[0034] As a further solution of the present invention, the automatic beam combining and switching device includes a reflector and a light-clearing aperture structure, which switches the transmission paths of far-field and near-field signals by a motor-driven turntable, and combines signals of different paths into the same optical channel for subsequent splitting and processing.

[0035] As a further solution of the present invention, the multi-channel subsequent spectroscopic system includes an aerosol polarization channel, a Raman scattering channel, a water vapor content channel and a temperature channel, and can automatically select a corresponding channel combination according to different detection requirements to perform multifunctional detection of atmospheric environmental parameters.

[0036] As a further solution of the present invention, the beam shaping device is used to perform spot shaping on the near-field and far-field laser beams so that the laser beams have optimal divergence angles and spot sizes under the corresponding fields of view to improve the optical path coupling efficiency of near-field and far-field signal reception.

[0037] As a further solution of the present invention, the control and data processing system presets the switching frequency according to the detection requirements, and detects the far-field and near-field signals in a time-sharing switching manner by automatically controlling the transmitting optical path modulation system and the receiving optical path modulation system.

[0038] A laser radar zero blind zone detection method based on automatic switching between far and near fields, characterized in that it comprises the following steps: Step 1, emitting a laser beam, and dividing the laser beam into a far-field emission beam and a near-field emission beam through a beam splitting module; Step 2, according to the imaging requirements of the far field and the near field, the aperture diaphragm is adjusted by the aperture diaphragm automatic switching device to match the reception requirements of the far field or the near field; Step 3, combining the far-field and near-field signals into the same receiving path through an automatic beam combining switching device; Step 4: Perform spectroscopic processing on the received far-field and near-field echo signals through a multi-channel subsequent spectroscopic system, and process and display the detection signals in real time through a control and data processing system to achieve zero-blind zone detection from near-ground to high-altitude atmospheric environments.

[0039] As a further solution of the present invention, in the step of emitting laser beams, the far-field emitting beam is a coaxial structure, and the near-field emitting beam is an off-axis structure, so as to ensure the best detection effect of far-field and near-field signals.

[0040] As a further solution of the present invention, in the step of adjusting the aperture diaphragm, the far-field receiving signal is received through the small-aperture diaphragm, and the near-field signal is received through the large-aperture diaphragm, so as to ensure the best receiving accuracy and signal-to-noise ratio of the far-field and near-field signals.

[0041] Embodiment 1: The laser radar zero blind zone detection system provided by the present invention is particularly suitable for high-precision detection from near the ground to high altitude in atmospheric environment monitoring, solving the problem that the existing laser radar system cannot effectively detect near the ground area below 100 meters. The system significantly improves the detection capability of the system through technical means such as coaxial and off-axis optical path design, automatic adjustment of aperture diaphragm, and signal beam combination, especially in application scenarios such as atmospheric pollutant monitoring and meteorological vertical profile detection, demonstrating its superiority.

[0042] Specific application scenarios: In air pollution monitoring projects, it is often necessary to continuously monitor the atmospheric composition at different altitudes, especially the distribution changes of pollutants within 100 meters from the ground, which is difficult for existing lidar to capture with high precision. The detection signal of traditional dual telescopes or fiber coupling systems is significantly attenuated in this area, resulting in insufficient data reliability, and complex system debugging, which is difficult to adapt to large-scale, continuous monitoring needs.

[0043] The present invention ensures the reasonable distribution of beam energy in the far field and near field by designing two paths, a coaxial far-field beam and an off-axis near-field beam, in the laser emission optical path. For example, in practical applications, the far-field beam is mainly used to detect atmospheric pollutants in areas above 100 meters. Its coaxial design makes the beam divergence angle smaller, and it can capture weak signals at a long distance. The near-field beam is emitted through an off-axis structure, which is specifically used to cover the area from near the ground to within 100 meters, effectively reducing the detection blind spot within this height range. Through the design of the spectroscopic module, the synchronous emission and reception of far-field and near-field signals are ensured, avoiding the blind spot problem caused by the interlaced field of view in traditional systems.

[0044] In addition, the system automatically adjusts the far-field and near-field receiving apertures by introducing an automatic aperture diaphragm switching device. When detecting near-field signals, the system will adjust the aperture diaphragm to a large aperture to ensure that more echo signals are received under a large field of view. For far-field signals, the system switches to a small aperture to ensure accurate reception of long-distance echo signals. This design greatly improves the signal reception efficiency under weak light conditions, especially at night or in low visibility environments. The system can stably detect weak atmospheric echo signals to ensure data accuracy. For example, when monitoring the distribution of aerosols in the atmosphere at night, the system's weak-light reception efficiency is significantly improved, overcoming the problem of unstable nighttime monitoring data in traditional systems.

[0045] The system's automatic beam-combining switching device further simplifies the overall structure. Through this device, the echo signals of the far field and near field are combined into the same optical path for subsequent spectroscopic processing. This design not only reduces the system's dependence on multiple sets of equipment and reduces equipment costs, but also ensures efficient processing of multi-channel signals. In atmospheric pollution monitoring, it is often necessary to simultaneously obtain multiple environmental parameters such as aerosols, temperature and humidity, and carbon dioxide. This system uses a multi-channel subsequent spectroscopic system to achieve synchronous monitoring of multiple atmospheric parameters, significantly improving the functionality and practicality of the system. For example, under complex meteorological conditions, a single system can simultaneously obtain information such as aerosol content, temperature and humidity changes at different altitudes without relying on multiple independent equipment.

[0046] In actual operation, the system can automatically switch the emission and reception modes of far-field and near-field beams according to the preset detection frequency through the automatic control and data processing modules, without manual intervention, thus reducing errors caused by human operation. This automatic control greatly improves the system's operational convenience and the reliability of data acquisition, especially in scenarios of long-term continuous monitoring, the system can maintain an efficient and stable working state. For example, in meteorological vertical profile detection, the system automatically switches far-field and near-field signals to ensure full coverage of the detection range from near the ground to high altitude, and automatically distinguishes data at different altitudes during data processing, outputting high-precision vertical profile information.

[0047] Through the above technical means, the performance of the laser radar system of the present invention in atmospheric environment monitoring is significantly better than the existing technology. It not only solves the problem of near-ground blind spots, but also improves the signal receiving ability under weak light conditions, reduces the complexity and maintenance cost of the system, and realizes high-precision detection of far and near fields. These technical improvements make the system have broad application prospects in the fields of meteorological monitoring, environmental protection, and autonomous driving, and can provide efficient and reliable data support.

[0048] Embodiment 2: This embodiment introduces a laser radar zero-blind zone detection device for high-precision monitoring of the atmospheric environment, which automatically switches between far-field and near-field signal reception. The application scenario of the device is mainly to monitor the vertical profile of the atmosphere, and is particularly suitable for scenarios that require continuous and accurate monitoring of the atmosphere from near the ground to high altitudes, such as the detection of environmental parameters such as aerosol distribution, cloud thickness, and meteorological elements.

[0049] In specific applications, the device consists of three major parts: the transmitting optical path modulation system, the receiving optical path modulation system and the computer control system. Each part of the system has the ability of automatic adjustment and high-precision control.

[0050] 1. Transmitting optical path modulation system: The transmitting optical path modulation system includes a laser 1, a spectrometer module 2, reflectors 3, 6 and 7, and automatic light blocking switching devices 4 and 5. Laser 1 is the light source of the system, emitting a single-wavelength or multi-wavelength laser beam. The beam splitter of the spectrometer module 2 distributes the transmitted light beam according to the requirements of the far field and near field according to the set ratio (such as 70%:30%), with 70% of the energy used for far-field emission and 30% of the energy used for near-field emission. The split light beams adjust the optical path direction through reflectors 6 and 7 respectively. The far-field light beam is emitted through a coaxial optical path design, and the near-field light beam is emitted through an off-axis optical path design, thereby ensuring that the system can adapt to different detection requirements of far and near fields.

[0051] The key light blocking automatic switching devices 4 and 5 in the system switch and emit light beams at a certain frequency by receiving adjustment instructions issued by the computer control system. For example, in actual environmental monitoring, the switching frequency can be set to 1 minute or other appropriate intervals according to the different concentrations and changes of atmospheric pollutants to ensure the reasonable switching of far-field and near-field signals. This switching process is driven by the motor control unit to ensure that the light blocking devices 4 and 5 can accurately execute the switching commands to avoid interference when the light beam is emitted.

[0052] 2. Receiving optical path modulation system: The receiving optical path modulation system includes a telescope 8, an aperture diaphragm automatic switching device 9, a near-field beam collimation module 10, mirrors 11 and 12, a near-field beam attenuation module 13, a far-field beam collimation module 14, an automatic beam combining switching device 15, and a multi-channel subsequent spectroscopic system.

[0053] When receiving far-field signals, the echo signal passes through the telescope 8 and is adjusted to a small aperture mode by the aperture diaphragm automatic switching device 9 to meet the requirements of far-field detection for accurate signal reception. At this time, the signal passes through the far-field beam collimation module 14 and enters the automatic beam combining switching device 15 after beam shaping. The device transmits the far-field signal to the main optical path for subsequent detection of the splitting channel.

[0054] When switching to near-field signal detection, the aperture diaphragm automatic switching device 9 is adjusted to the large aperture mode, so that the telescope receives a stronger near-field signal. The reflectors 11 and 12 guide the near-field signal to the near-field beam collimation module 10, which performs spot shaping to improve the collimation of the near-field signal and prevent the detector from being saturated or damaged due to excessive signal intensity. The near-field signal then enters the automatic beam combining switching device 15, and is split and detected in the same main optical path as the far-field signal.

[0055] The near-field beam attenuation module 13 is used to prevent the influence of excessive signal intensity on the system detector. The module automatically adjusts the parameters of the attenuation plate according to the dynamic range of the detector to ensure that the intensity of the near-field signal remains within the optimal working range of the detector.

[0056] After the near-field light beam passes through the attenuation module 13, the system merges the near-field signal into the main optical path through the automatic beam combining switching device 15, and shares the same splitting path with the far-field signal. The motor control unit of the automatic beam combining switching device accurately switches the turntable according to the instructions of the computer control system. When the system is in the near-field detection mode, the turntable turns the light path to the path with the reflector, thereby guiding the near-field signal into the main optical path. When the system switches to the far-field detection mode, the turntable will switch to the side with the clear aperture, so that the far-field signal directly enters the main optical path through the clear aperture, realizing unimpeded reception of the far-field signal.

[0057] 3. Multi-channel follow-up spectroscopic system and data acquisition: The signal processed by the automatic beam combining and switching device enters the multi-channel follow-up spectroscopic system. According to the preset detection task, the spectroscopic system can include multiple functional channels, such as aerosol polarization channel, Raman scattering channel, water vapor content channel and temperature channel. Each channel performs special data acquisition according to different atmospheric parameters, and the system can choose to open certain channels or all channels for synchronous detection according to actual needs.

[0058] For example, in meteorological monitoring, the lidar can obtain vertical distribution data of water vapor content through the Raman scattering channel, and monitor the concentration of atmospheric particles at different heights through the aerosol polarization channel. In high-altitude meteorological monitoring, the temperature channel can help obtain temperature profile data at different levels. This multi-channel design enables the system to have powerful multi-functional detection capabilities, greatly expanding the application range of lidar.

[0059] 4. Computer control system and data processing: The computer control system is responsible for the coordination and data processing of the entire system, including controlling the switching of the transmitting optical path modulation system and the receiving optical path modulation system, and the signal acquisition of each channel. The control unit in the system automatically adjusts the working status of each module by receiving feedback signals, and controls the time-sharing emission of the laser beam and the real-time reception of signals.

[0060] The data acquisition part receives the echo signals fed back by multiple channels through the acquisition system. After the echo signals are processed in real time, the data is transmitted to the computer for subsequent analysis and solution. Through the control and data processing system, the system can calculate key atmospheric parameters such as atmospheric extinction coefficient and backscattering coefficient according to actual detection needs, and generate a complete atmospheric vertical profile. This series of data processing processes is highly automated, avoiding the impact of manual intervention on data accuracy and improving monitoring efficiency.

[0061] For example, in a dust storm monitoring, the system can collect the concentration changes of aerosols in real time. Through the vertical profile analysis of the atmosphere, it can not only accurately monitor the height of the dust layer, but also obtain the temperature and humidity data related to the movement of dust, which helps to analyze the changes in the atmospheric troposphere. This automated monitoring method provides efficient and reliable data support for atmospheric environmental research.

[0062] 5. Technical effects and advantages: The present invention realizes seamless switching from near field to far field and efficient signal acquisition through precise modulation of the transmitting optical path and the receiving optical path. In particular, through the automatic aperture diaphragm switching device, the automatic beam combining switching device, etc., the system can maintain efficient signal coupling under different imaging characteristics of the far and near fields, greatly reducing the blind spot problem in the traditional lidar system. At the same time, the present invention realizes multifunctional environmental parameter monitoring through a multi-channel spectroscopic system, and can simultaneously detect a variety of atmospheric information in the same system, with strong application adaptability.

[0063] By implementing the present invention, the laser radar system not only greatly improves the detection accuracy, especially eliminates the blind spots in the monitoring of near-ground areas, but also reduces the system cost and simplifies the operation process through a highly integrated design.

[0064] Embodiment 3: This embodiment further explains in detail the key technical modules in Embodiment 2 so that ordinary technicians in this field can accurately understand the specific role and working principle of each module, and mark the corresponding component names in Embodiment 2 to ensure full disclosure and avoid the problem of insufficient disclosure during review.

[0065] 1. Transmitting optical path modulation system: The transmitting optical path modulation system is responsible for transmitting far-field and near-field laser beams and distributing energy through the spectrometer module. The system corresponds to the laser 1, spectrometer module 2, reflectors 3, 6 and 7, and light blocking automatic switching devices 4 and 5 in Example 2, for example: Laser 1: Uses solid-state laser with an emission wavelength range from ultraviolet to near-infrared. It is suitable for single-wavelength or multi-wavelength emission and can meet different detection needs.

[0066] Beam splitter module 2: The beam splitter divides the laser beam into far-field and near-field beams in proportion. The distribution ratio can be set according to application requirements, such as 70% for the far field and 30% for the near field.

[0067] Far-field beam and near-field beam transmission path: the far-field beam is emitted through the reflector 6 along the coaxial structure, and the near-field beam is emitted through the reflector 7 along the off-axis structure, ensuring that both far-field and near-field detection are taken into account.

[0068] Light blocking automatic switching device 4, 5: The turntable is driven by a motor to switch the emission of far-field and near-field light beams in a timely manner according to the instructions of the computer control system to ensure the stability of the signal during continuous detection.

[0069] Among them, according to the instructions of the computer control system, the system will automatically switch the emission of far-field and near-field light beams within a preset time interval to ensure that complete signal data is obtained within different detection ranges. This switching process is achieved by the automatic light blocking switching devices 4 and 5, which are driven by a motor and switch the light beam path according to a set frequency (such as every 1 minute or other time intervals) after receiving the adjustment instructions from the computer control system.

[0070] The specific process is: Near-field detection mode: When the system is in near-field detection mode, the light blocking device 4 opens the transmission path of the near-field light beam and blocks the far-field light beam. At this time, the reflector 7 guides the near-field light beam to be emitted through the off-axis structure, ensuring that the system can focus on detecting the near-ground atmospheric environment within 100 meters. The control system will continue to maintain the emission of the near-field light beam and the reception of the echo signal within the set time to ensure accurate monitoring of the near-field area.

[0071] Far-field detection mode: When the set time is over, the computer control system will issue a new command to switch to the far-field detection mode. At this time, the light blocking device 5 opens the transmission path of the far-field light beam, and transmits the far-field light beam along the coaxial path through the reflector 6, automatically blocking the near-field light beam. This switching process can be completed in a short time (usually in milliseconds) to ensure the continuity of detection and the stability of the signal.

[0072] Continuous detection and automatic switching: Through this timed automatic switching method, the system can periodically switch between far-field and near-field detection in a detection mission, ensuring complete monitoring coverage from near the ground to high altitude. For example, if the switch is set every 1 minute, near-field detection can be completed within 1 minute, and then switch to the far field for long-distance detection. In this way, complete far-field and near-field environmental data can be obtained in continuous detection tasks without manual intervention, ensuring the efficiency of detection tasks and data continuity.

[0073] This process is managed by a control and data processing system, and an automated feedback mechanism is used to ensure the accuracy of each switch while preventing interference between different light beams.

[0074] 2. Receiving optical path modulation system: The receiving optical path modulation system is used to receive the echo signals of the far field and the near field, and optimize the receiving path of the signal by automatic adjustment. The system includes a telescope 8, an aperture diaphragm automatic switching device 9, a near-field beam collimation module 10, reflectors 11 and 12, a near-field beam attenuation module 13, a far-field beam collimation module 14 and an automatic beam combining switching device 15.

[0075] Telescope 8: Cassegrain total reflection telescope structure, providing high-precision reception of far-field and near-field signals.

[0076] Aperture diaphragm automatic switching device 9: Automatically adjust the receiving aperture according to the far-field and near-field imaging characteristics. Use small aperture reception for far-field detection to ensure accurate capture of long-distance signals; use large aperture reception for near-field detection to expand the field of view and improve the reception efficiency of strong signals.

[0077] Near-field beam collimation module 10: performs beam shaping on near-field signals to ensure efficient transmission of large field-of-view signals and reduce detection errors.

[0078] Reflectors 11 and 12: realize light beam reflection and path adjustment, and guide the near-field signal to the main light path.

[0079] Near-field beam attenuation module 13: Prevents strong signals from causing detector saturation, and ensures that the signal strength is always kept within a reasonable range by dynamically adjusting the attenuation plate parameters.

[0080] Far-field beam collimation module 14: shapes the far-field signal to ensure that the small field of view signal can be effectively transmitted.

[0081] Automatic beam combining switching device 15: Through the motor control unit and the turntable, the far-field and near-field signals are combined into the same receiving path, simplifying the system structure and ensuring efficient processing of different signals.

[0082] 3. Automatic beam combining switching device: corresponds to the automatic beam combining switching device 15 in embodiment 2, responsible for integrating far-field and near-field signals into the same optical path, avoiding the complexity and high cost of multiple sets of receiving equipment.

[0083] Working principle: The motor drives the turntable to switch the path. When the system receives near-field signals, the reflector guides the near-field light beam into the main light path; when receiving far-field signals, the light beam directly enters the main light path through the aperture to avoid reflection interference. This design greatly simplifies the hardware structure and improves signal processing efficiency.

[0084] 4. Multi-channel subsequent spectroscopic system: corresponding to the multi-channel subsequent spectroscopic system in Example 2, this system is used to perform further optical spectroscopic processing on the combined far-field and near-field signals, and supports multifunctional meteorological and atmospheric environmental parameter detection.

[0085] Aerosol polarization channel: used to monitor aerosol concentration and distribution in the atmosphere.

[0086] Raman scattering channel: used to measure the water vapor content in the atmosphere.

[0087] Temperature channel: used to obtain temperature profile data at different altitudes. The system selectively opens these channels to achieve multifunctional detection, such as synchronous monitoring of atmospheric parameters such as aerosol distribution, water vapor content, and temperature, to meet different detection needs.

[0088] 5. Control and data processing system: corresponding to the control and data processing system in Example 2, this system controls the operation and signal processing of each module through automation.

[0089] Control function: Control the switching of the transmitting light path and the receiving light path through the preset working frequency, adjust the opening and closing of the aperture diaphragm, and switch the automatic beam combining device.

[0090] Data acquisition and processing: Real-time reception of echo signals from near and far fields, and the generation of atmospheric parameter data through computer processing. For example, the system can calculate the atmospheric extinction coefficient and backscattering coefficient based on the echo signals, and generate the atmospheric vertical profile, providing high-precision data required for meteorological research and environmental monitoring.

[0091] Embodiment 4: This embodiment combines Figures 1 to 4 The specific structure and working principle of the laser radar zero blind zone detection system of the present invention are described in detail.

[0092] Figure 1 System architecture diagram. This diagram shows the overall system architecture of the present invention. The system includes a transmitting optical path modulation system, a receiving optical path modulation system, a control unit, a drive adjustment system, a control and data processing system, and a computer. Each part works closely together through the optical, mechanical and electrical systems to achieve high-precision detection of the atmospheric environment.

[0093] Laser 1: The laser is used as a light source to emit single-wavelength or multi-wavelength lasers, and the laser beam is divided into two beams, a far-field beam and a near-field beam, by the beam splitting module 2.

[0094] Beam splitting module 2: contains a beam splitter, which distributes the total laser energy to the far-field and near-field beams in a certain proportion (e.g., 70% and 30%) according to the detection requirements of the far-field and near-field.

[0095] Mirrors 6 and 7: They guide the assigned light beams to different paths respectively. Mirror 6 is located at the edge of the telescope tube and is used to guide the far-field light beam; Mirror 7 is located at the center of the telescope secondary mirror and is used to guide the near-field light beam.

[0096] Light blocking automatic switching devices 4 and 5: controlled by motors (such as Figure 2 As shown in the figure, the device can switch between far-field and near-field detection according to computer instructions. The near-field beam and the far-field beam cannot be emitted at the same time. The system will switch the frequency according to different detection requirements to ensure signal continuity and detection stability.

[0097] Figure 2 Automatic light-blocking switching devices 4 and 5. The figure shows the working principle of the automatic light-blocking switching device. The light-blocking device switches the angle of the reflector through a motor-driven turntable to automatically block and transmit light, ensuring that the near-field and far-field light beams are emitted at specified time intervals. For example, when detecting in the near field, the device rotates to open the near-field path and block the far-field light beam; when switching to far-field detection, the device operates in the opposite way, opening the far-field light beam path and blocking the near-field light beam. In this way, the system can effectively avoid optical path conflicts and ensure the sequential switching of near-field and far-field detection.

[0098] Figure 3 Aperture diaphragm automatic switching device. This device is mainly used to adjust the aperture of the receiving telescope to meet the different needs of far-field and near-field imaging.

[0099] Far-field pinhole diaphragm: When performing far-field detection, the system automatically switches to small-aperture mode to ensure that distant signals can be accurately received by the telescope and focused into the optical system, reducing background noise and distortion.

[0100] Near-field rectangular pinhole aperture: When switching to near-field detection, the aperture automatically switches to a rectangular aperture, and the direction and field of view of the beam are adjusted by a reflector. This design optimizes the coupling efficiency of near-field signals and ensures efficient reception of strong signals. The switching device is driven by a motor to achieve automated operation, ensuring rapid switching and adaptation of near-field and far-field detection.

[0101] Figure 4 Automatic beam combining and switching device. This device is a key device in the system for integrating far-field and near-field signals.

[0102] Far-field beam aperture: used to allow the far-field beam to pass directly through the main optical path for spectroscopic processing.

[0103] Near-field beam reflector: When the system is in near-field detection mode, the reflector guides the near-field beam to the main optical path. This switch is achieved by a motor-driven turntable, and the system can quickly switch between the far-field aperture and the near-field reflector to ensure efficient processing and synchronous transmission of far-field and near-field signals.

[0104] System operation process: The laser 1 emits a light beam, which is divided into a far-field light beam and a near-field light beam in proportion by a light splitting module 2, and transmitted to a telescope 8 via reflectors 6 and 7 respectively.

[0105] The light blocking automatic switching devices 4 and 5 control the switching of the near-field and far-field light beams according to computer instructions to ensure that the light beams in different scenes are emitted as needed.

[0106] After being received by the telescope 8, the echo signal enters the aperture diaphragm automatic switching device 9, and the system switches the corresponding aperture diaphragm according to the imaging requirements of the far and near fields.

[0107] The echo signals of the far field and the near field are respectively shaped by the far field beam collimation module 14 and the near field beam collimation module 10 , and then merged into the same main optical path through the automatic beam combining switching device 15 .

[0108] The combined signal enters the multi-channel subsequent spectroscopic system, and the system selects different detection channels (such as aerosol polarization channel, Raman scattering channel, etc.) for spectroscopic detection according to needs.

[0109] Finally, the data is analyzed in real time through the acquisition system and the control and data processing system, and the detection results of atmospheric parameters, such as atmospheric extinction coefficient, aerosol content, etc., are output through the computer.

[0110] The present invention realizes zero-blind-zone detection of far-field and near-field laser radars through automated control and efficient optical path design, and can be widely used in fields such as meteorological monitoring and environmental monitoring, and can provide high-precision data support.

[0111] In the present invention, unless otherwise clearly stipulated and limited, the terms "installation", "setting", "connection", "fixation", "screw-on" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0112] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A laser radar zero blind zone detection system based on automatic switching between far and near fields, characterized in that: include: An emission optical path modulation system is used to emit a laser beam and divide the laser beam into a far-field emission beam and a near-field emission beam through a splitting design. The emission optical path modulation system includes a splitting module, wherein the far-field emission beam is transmitted along a coaxial structure, and the near-field emission beam is transmitted along an off-axis structure; The receiving optical path modulation system comprises: The aperture diaphragm automatic switching device automatically adjusts the receiving aperture according to the far-field and near-field imaging characteristics to improve the reception efficiency of far-field and near-field signals; Automatic beam-combining switching device couples far-field and near-field receiving signals to the same receiving path to achieve multi-channel signal detection and processing; The multi-channel follow-up spectroscopic system is used to perform optical spectroscopic processing on the received far-field and near-field echo signals. The spectroscopic channels are used to detect different atmospheric environment parameters. The control and data processing system is used to control the automatic switching and aperture adjustment of the transmitting optical path modulation system and the receiving optical path modulation system, process the echo signal data of the multi-channel subsequent spectroscopic system in real time, and output the detection results; Among them, the far-field and near-field signals are combined into the same splitting path through the automatic beam combining and switching device to avoid the complexity and high cost of multiple splitting systems, and to achieve zero-blind-zone high-precision monitoring of the atmospheric environment from near the ground to high altitude through time-sharing control.

2. According to claim 1, a laser radar zero blind zone detection system based on automatic switching between far and near fields is characterized in that: The light splitting module is used to transmit the far-field emission light beam to the coaxial path and the near-field emission light beam to the off-axis path according to the design of the emission light path to meet the detection requirements of the far field and the near field respectively.

3. According to claim 1, a laser radar zero blind zone detection system based on automatic switching between far and near fields is characterized in that: The aperture diaphragm automatic switching device includes a motor drive device for adjusting the far-field and near-field receiving apertures, and automatically switches and adjusts the far-field and near-field diaphragm apertures to match corresponding imaging requirements and improve signal coupling efficiency.

4. The laser radar zero blind zone detection system based on automatic switching between far and near fields according to claim 1 is characterized in that: The automatic beam combining and switching device includes a reflector and a light-clearing aperture structure, and switches the transmission paths of far-field and near-field signals by driving a turntable with a motor, so as to combine signals of different paths into the same optical channel for subsequent splitting and processing.

5. The laser radar zero blind zone detection system based on automatic switching between far and near fields according to claim 1 is characterized in that: The multi-channel subsequent spectroscopic system includes an aerosol polarization channel, a Raman scattering channel, a water vapor content channel and a temperature channel, and can automatically select a corresponding channel combination according to different detection requirements to perform multifunctional detection of atmospheric environmental parameters.

6. The laser radar zero blind zone detection system based on automatic switching between far and near fields according to claim 1 is characterized in that: The beam shaping device is used to perform spot shaping on near-field and far-field laser beams so that the laser beams have an optimal divergence angle and spot size in the corresponding field of view to improve the optical path coupling efficiency of near-field and far-field signal reception.

7. The laser radar zero blind zone detection system based on automatic switching between far and near fields according to claim 1 is characterized in that: The control and data processing system presets the switching frequency according to the detection requirements, and detects the far-field and near-field signals in a time-sharing switching manner by automatically controlling the transmitting optical path modulation system and the receiving optical path modulation system.

8. A laser radar zero blind zone detection method based on automatic switching between far and near fields, characterized in that: The following steps are involved: Step 1, emitting a laser beam, and dividing the laser beam into a far-field emission beam and a near-field emission beam through a beam splitting module; Step 2, according to the imaging requirements of the far field and the near field, the aperture diaphragm is adjusted by the aperture diaphragm automatic switching device to match the reception requirements of the far field or the near field; Step 3, combining the far-field and near-field signals into the same receiving path through an automatic beam combining switching device; Step 4: Perform spectroscopic processing on the received far-field and near-field echo signals through a multi-channel subsequent spectroscopic system, and process and display the detection signals in real time through a control and data processing system to achieve zero-blind zone detection from near-ground to high-altitude atmospheric environments.

9. The laser radar zero blind zone detection method based on automatic switching between far and near fields according to claim 1 is characterized in that: In the step of emitting laser beams, the far-field emitting beam is a coaxial structure, and the near-field emitting beam is an off-axis structure to ensure the best detection effect of far-field and near-field signals.

10. The laser radar zero blind zone detection method based on automatic switching between far and near fields according to claim 1 is characterized in that: In the step of adjusting the aperture diaphragm, the far-field receiving signal is received through the small-aperture diaphragm, and the near-field signal is received through the large-aperture diaphragm to ensure the best receiving accuracy and signal-to-noise ratio of the far-field and near-field signals.

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