Modulation Method, Device, Electronic Device, and Storage Medium with Automatic Enhancement of Retroreflection Based on Ambient Dust Content

Abstract

The present invention discloses a modulation method, system, device, electronic device and storage medium with automatically enhanced retroreflection based on environmental dust content, belonging to the field of laser scanning. First, the measured retroreflection signal is obtained, and the amplitude of the digital signal is judged. If the signal recognition requirement is not met, the digital signal is subjected to gain processing: the dust content value of the external environment is obtained, the gain interval is determined according to the dust content value, and the digital signal is subjected to gain processing from small to large within the gain interval until the signal recognition requirement is met. The present invention can perform gain adjustment on signals exceeding the threshold, avoid the signal being too large or too small, thereby improving the accuracy of the phase discrimination result, and further improving the accuracy of laser scanning ranging.

Description

Technical Field

[0001] The present invention belongs to the field of laser scanning, and particularly relates to a modulation method and device for automatically enhancing the return light based on the environmental dust content. Background Art

[0002] Currently, in the industrial field, such as precision machinery manufacturing, remote sensing detection, intelligent driving and other fields, the accurate measurement of the absolute distance has become a crucial step. The measurement range of three-dimensional scanning can reach thousands of meters, and the laser absolute distance measurement technology has developed rapidly and has become a research hotspot.

[0003] The light beam takes air as the transmission medium, and the characteristics of air have a great influence on the propagation of the light beam. The suspended substances in the air have an absorption and scattering effect on the light beam, which will cause the loss and deflection of the light beam energy. When light propagates in a gas, how to solve the scattering problem when light interacts with matter is the core content of the light propagation problem.

[0004] After the measured light returns, through the photoelectric conversion of the photodetector and the conditioning of the subsequent circuit, the signal amplitude will change with the size and content of the dust particles in the scanner's on-site environment. Whether the signal amplitude is too large or too small is not conducive to the operation of the phase discrimination unit. If the signal is too large, it may cause saturation or signal distortion of the analog-to-digital converter (ADC), and if the signal is too small, it will result in too small a resolution of the ADC sampling result and loss of phase information. To ensure that the phase discrimination unit obtains a signal carrying complete phase information, it is necessary to adjust the gain of the measured light amplitude signal after photoelectric conversion. Summary of the Invention

[0005] To overcome the problems existing in the prior art, the present invention provides a modulation method, device, electronic device and storage medium for automatically enhancing the return light based on the environmental dust content, so as to improve the accuracy of laser scanning ranging.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A modulation method for automatically enhancing the return light based on the environmental dust content, comprising the following steps:

[0008] S1, obtaining the measured return light signal:

[0009] The laser emitted by the laser is reflected by the measured target, and is affected by environmental dust, resulting in energy loss and deflection. Measure the return light signal and convert it into a digital signal;

[0010] S2, judging the amplitude of the digital signal:

[0011] Judge whether the requirements for signal recognition are met according to the amplitude value of the digital signal. If not, enter step S3. If so, no processing is required;

[0012] S3. Perform gain processing on the digital signal:

[0013] Obtain the dust content value of the external environment, determine the gain interval according to the dust content value, and perform gain processing on the digital signal from small to large within the gain interval until the requirements for signal recognition are met.

[0014] Furthermore, when determining whether the requirements for signal recognition are met in step S2, a preset amplitude interval [Imin, Imax] is set according to the signal recognition requirements. If the amplitude of the digital signal falls within the amplitude interval, the requirements are met.

[0015] Furthermore, the amplitude interval is determined by the signal sampling rate and the performance of the phase discriminator.

[0016] Furthermore, the method for determining the gain interval in step S3 is as follows:

[0017] S31. Divide the dust content into different grades, and collect the digital signals corresponding to the retroreflection under different dust grades;

[0018] S32. For the highest dust content value in each grade, adjust the optimal magnification so that the digital signal can meet the amplitude interval, and record the magnification L1; for the lowest dust content value in the same grade, adjust the optimal magnification so that the digital signal can meet the amplitude interval, and record the magnification L2; take [L2, L1] as the gain interval corresponding to a certain grade of dust content under this amplitude interval.

[0019] Furthermore, the intensity of the retroreflection signal and the thickness of the dust medium layer satisfy the Lambert-Beer extinction theorem.

[0020] A modulation device based on automatic enhancement of retroreflection according to environmental dust content is used to implement the above-mentioned modulation method based on automatic enhancement of retroreflection according to environmental dust content.

[0021] An electronic device includes a memory and a processor;

[0022] The memory is used to store a computer program;

[0023] The processor is used to implement the above-mentioned modulation method based on automatic enhancement of retroreflection according to environmental dust content when executing the computer program.

[0024] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the above-mentioned modulation method based on automatic enhancement of retroreflection according to environmental dust content.

[0025] Advantages of the present invention: According to the information on the dust content in the scanning environment, it is possible to determine whether the digital signal corresponding to the retroreflection signal exceeds the threshold of the said interval, and when the digital signal exceeds the threshold, adjust the signal gain, which can avoid the signal being too large or too small, thereby improving the accuracy of the phase discrimination result and expanding the application scenarios of the device. Description of the Drawings

[0026] Figure 1 It is a step diagram of the modulation method based on automatic enhancement of retroreflection according to the environmental dust content shown in the present invention;

[0027] Figure 2 It is a principle block diagram of the modulation device based on automatic enhancement of retroreflection according to the environmental dust content shown in the present invention;

[0028] Figure 3 It is a module division diagram of the modulation device based on automatic enhancement of retroreflection according to the environmental dust content shown in the present invention. Detailed Embodiments

[0029] To make the objectives, features, and advantages of the present invention more obvious and understandable, preferred embodiments are specifically given and described in detail in conjunction with the accompanying drawings as follows. As Figure 1 and Figure 3 shown, the present invention provides a modulation method based on automatic enhancement of retroreflection according to the environmental dust content, including:

[0030] During the process of measuring the laser returning to the receiver after passing through the object to be measured, the amount of retroreflection deflects and refracts due to the change in the dust content in the environment, resulting in the change of the retroreflection signal. The intensity of the retroreflection signal and the thickness of the dust medium layer satisfy the Lambert-Beer extinction theorem, that is where I o is the incident light intensity, I is the outgoing light intensity, λ is the wavelength of the light used, z is the thickness of the particle medium layer, that is, the penetration distance, and τ(λ) is the attenuation coefficient; subsequently, it leads to the change of the digital signal after photoelectric conversion and analog-to-digital conversion;

[0031] Judge whether the amplitude of the digital signal exceeds the upper and lower thresholds of the set interval;

[0032] When the amplitude of the digital signal is higher or lower than the threshold of the set interval, modulate the digital signal corresponding to the retroreflection through the gain amplification module so that the digital signal can be accurately recognized in the phase discrimination module.

[0033] In a specific implementation of the present invention, the attenuation coefficient and the extinction coefficient satisfy the relationship where, Q extis the extinction coefficient, which is jointly determined by the particle refractive index m = a + ib, where m is the complex refractive index, a is the real part of the complex refractive index, b is the imaginary part of the complex refractive index, the particle size D, and the wavelength λ. v(D) is the normalized particle volume frequency distribution, and C v is the volume concentration of the particles and is the normalized particle volume frequency distribution. It is assumed that the dust particles are spherical and isotropic.

[0034] In this embodiment, when the amplitude of the digital signal exceeds the threshold of the set interval, the digital signal corresponding to the return light is modulated by the gain amplification module, including:

[0035] First, establish a mode of centralized signal processing. By combining the control and judgment module, the sensing module, and the gain amplification module, it is possible to detect the change in the dust content in the laser scanning environment, and process the digital signal corresponding to the return light signal by combining the dust content and the magnitude of the return light signal.

[0036] The control and judgment module is used to receive the digital signal and judge whether its amplitude is within the set amplitude interval [Imin, Imax]. The amplitude interval is comprehensively determined by factors such as the ADC sampling rate and the performance of the phase discrimination module. When the control and judgment module determines that the digital signal exceeds the threshold, it requests environmental parameter information from the external sensing module. In this embodiment, the environmental parameter information is the dust content in the environment. At the same time, the control and judgment module is also used to send a control instruction to the gain amplification module to control the amplification factor of the gain amplification module for the digital signal.

[0037] The gain amplification module is used to perform gain modulation on the digital signal according to the control instruction of the control and judgment module, and adjust the magnitude of the digital signal to within the set interval [Imin, Imax].

[0038] In a specific implementation of the present invention, the dust content is divided into grades, analysis models are established for different grades of dust content respectively, gain intervals corresponding to different digital signal intervals and dust contents are obtained, and different modes of the system are divided accordingly.

[0039] For example, design an experiment. For a certain determined amplitude interval [Imin, Imax], collect the digital signals obtained by the analog-to-digital conversion module under different dust contents; divide the dust content into different grades, such as high content, medium content, and low content;

[0040] Taking the medium content as an example, for the lowest dust content value in the medium dust content level, set the magnification so that the digital signal can meet the amplitude range determined by the phase discrimination module, and record this magnification L1; for the highest dust content value in the medium dust content level, set the magnification so that the digital signal can meet the amplitude range determined by the phase discrimination module, and record this magnification L2. Therefore, for a certain determined amplitude range [Imin, Imax], when the dust content is at the medium level, the gain range is [L1, L2]. Similarly, the gain ranges corresponding to different dust levels obtained by division can be obtained.

[0041] In addition to the three dust levels of high content, medium content, and low content described in this embodiment, further subdivision can be continued according to actual situations.

[0042] During the test process, first, evaluate the dust content in the environment through an external sensor. Select the corresponding mode according to the dust content, and the gain range corresponding to this module can be directly obtained. Only adjust the magnification from small to large within this gain range, which can reduce the amount of data processing.

[0043] In a second aspect, the present invention provides a device for automatically enhancing the reflected light based on the environmental dust content, as Figure 2 shown, including:

[0044] A photoelectric conversion module, which is used to convert the reflected light signal into an analog electrical signal and convert it into a digital electrical signal through an analog-to-digital converter (ADC);

[0045] A control and judgment module, implemented using an FPGA chip, which is used to compare the amplitude of the obtained digital electrical signal with the set amplitude range [Imin, Imax], judge whether gain modulation is required. If so, confirm the modulation mode and send a control signal to the gain amplification module to control the magnification of the gain amplification module to adjust the gain of the digital signal. In this embodiment, a dual-channel gain amplifier can be used to expand the amplification range.

[0046] A sensing module, which is used to observe the change in the dust content in the environment to control the judgment module to select the modulation mode;

[0047] A gain amplification module, which is used to receive the control signal sent by the control and judgment module, change the gain of the gain amplifier, and perform gain modulation on the digital signal.

[0048] A phase discrimination module, which is used to obtain the amplified digital signal and identify it.

[0049] The above modules can form a device for automatically enhancing the retroreflection based on the environmental dust content. For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the partial descriptions of the method embodiments. The device embodiments described above are merely illustrative, and the constituent modules therein may or may not be physically separated. Additionally, in the present invention, the various functional modules can be integrated in a processing unit, or each module can exist physically alone, or two or more modules can be integrated in one unit. The programs in the above modules are all processed by the processor when executed.

[0050] In a third aspect, the present invention provides an electronic device, including:

[0051] a processor;

[0052] a memory for storing executable instructions executable by the processor;

[0053] wherein, when the processor executes the executable instructions in the memory, the modulation method for automatically enhancing the retroreflection based on the environmental dust content as described above is implemented.

[0054] In a fourth aspect, the present invention provides a non-transitory computer-readable storage medium, when the instructions in the storage medium are executed by the processor, the modulation method for automatically enhancing the retroreflection based on the environmental dust content as described above is implemented.

[0055] In addition, the logical instructions in the above memory can be implemented in the form of software functional units and when sold or used as an independent product, they can be stored in a computer-readable storage medium. As a computer-readable storage medium, the memory can be set to store software programs, computer-executable programs, such as the program instructions or modules corresponding to the system in the embodiments of the present disclosure. The processor executes functional applications and data processing by running the software programs, instructions or modules stored in the memory, that is, the functions in the above embodiments are implemented. For example, various media such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks or optical discs that can store program codes can also be transient storage media. In addition, the specific processes of loading and executing multiple instructions in the above storage medium and the electronic device have been described in detail above.

[0056] The content described in the embodiments of this specification is merely an enumeration of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments, and the protection scope of the present invention also extends to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept of the present invention.

Claims

1. A modulation method for automatically enhancing the retroreflection based on the environmental dust content, characterized in that, it includes the following steps: S1. Obtain the measured retroreflection signal: The laser emitted by the laser is reflected by the target to be measured, and its energy is lost and deflected due to the influence of environmental dust. Measure the retroreflection signal and convert it into a digital signal; S2. Judge the amplitude of the digital signal: Judge whether the requirements for signal recognition are met according to the amplitude value of the digital signal. If not, go to step S3; if so, no processing is required; S3. Perform gain processing on the digital signal: Obtain the dust content value of the external environment, determine the gain interval according to the dust content value, and perform gain processing on the digital signal from small to large within the gain interval until the requirements for signal recognition are met; The method for determining the gain interval described in step S3 is: S31. Divide the dust content into different levels, and collect the digital signals corresponding to the retroreflection under different dust levels; S32. For the lowest dust content value in the same level, adjust the optimal magnification so that the digital signal can meet the amplitude interval, and record the magnification L1; for the highest dust content value in each level, adjust the optimal magnification so that the digital signal can meet the amplitude interval, and record the magnification L2. Take [L1, L2] as the gain interval corresponding to a certain level of dust content under this amplitude interval.

2. The modulation method for automatically enhancing the retroreflection based on the environmental dust content according to claim 1, characterized in that, when judging whether the requirements for signal recognition are met in step S2, preset the amplitude interval [Imin, Imax] according to the signal recognition requirements. If the amplitude value of the digital signal falls within the amplitude interval, the requirements are met.

3. The modulation method for automatically enhancing the retroreflection based on the environmental dust content according to claim 2, characterized in that, the amplitude interval is determined by the signal sampling rate and the performance of the phase discriminator.

4. The modulation method for automatically enhancing the retroreflection based on the environmental dust content according to claim 1, characterized in that, the intensity of the retroreflection signal and the thickness of the dust medium layer satisfy the Lambert-Beer extinction theorem.

5. A modulation device for automatically enhancing the retroreflection based on the environmental dust content, which is used to implement the modulation method for automatically enhancing the retroreflection based on the environmental dust content described in claim 1, characterized in that, the modulation device includes: An optoelectronic conversion module, which is used to convert the retroreflection signal into an analog electrical signal and convert it into a digital electrical signal through an analog-to-digital converter; A control and judgment module, which is used to compare the amplitude of the obtained digital electrical signal with the set amplitude interval, judge whether gain modulation is required, and if so, confirm the modulation mode and send a control signal to the gain amplification module to control the magnification of the gain amplification module to adjust the gain of the digital signal; A sensing module, which is used to observe the change of the dust content in the environment to control the judgment module to select the modulation mode; A gain amplification module, which is used to receive the control signal sent by the control and judgment module, change the gain of the gain amplifier, and perform gain modulation on the digital signal; A phase discrimination module, which is used to obtain the amplified digital signal and identify it.

6. A modulation device based on automatic backlight enhancement according to the dust content in the environment as claimed in claim 5, characterized in that, the gain amplification module adopts a dual-channel gain amplifier.

7. A modulation device based on automatic backlight enhancement according to the dust content in the environment as claimed in claim 5, characterized in that, the control and judgment module adopts an FPGA chip.

8. An electronic device, characterized in that, it includes a memory and a processor; the memory is used for storing a computer program; the processor is used for, when executing the computer program, implementing the modulation method based on automatic backlight enhancement according to the dust content in the environment as claimed in any one of claims 1 to 4.

9. A computer-readable storage medium, on which a computer program is stored, characterized in that, when the computer program is executed by a processor, it implements the modulation method based on automatic backlight enhancement according to the dust content in the environment as claimed in any one of claims 1 to 4.

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