Laser ranging method and device based on ADC chip for use in rainy and foggy days

Abstract

The invention relates to a laser distance measurement method and device based on an ADC chip for use in rainy and foggy days. The laser distance measurement method comprises: converting a reflected current laser signal into an analog signal through a laser receiving module; converting the analog signal into a digital signal through an ADC chip; identifying and processing the digital signal through an FPGA chip to screen out two waveforms with larger amplitudes, and filtering the waveform of a first signal of the two waveforms based on the interval time from the emission of the current laser signal corresponding to the two waveforms to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms to retain the waveform of a second signal of the two waveforms; wherein the first signal is a laser signal reflected back by water mist in rainy and foggy days, and the second signal is a laser signal reflected back by a measured object; based on the waveform of the second signal, determining the measured distance to the measured object, thereby improving the accuracy of the distance measurement result in rainy and foggy days.

Description

Technical Field

[0001] The invention relates to the field of laser distance measurement, and in particular to a laser distance measurement method and device based on an ADC chip for use in rainy and foggy days. Background Art

[0002] When using a laser rangefinder to measure distance in rainy and foggy weather, due to the presence of water mist in the air, the laser will be refracted or reflected after being emitted, which will seriously affect the distance measurement effect.

[0003] At present, in order to reduce the impact of rain and fog on measurement, the existing laser rangefinder uses TOF (Time offlight) chip for signal acquisition, and transmits the acquired signal directly to the MCU chip of the laser rangefinder, which processes the signal and outputs the result. In fact, ToF is a distance measurement method. ToF cameras generally need to use specific artificial light sources for measurement, that is, by measuring the "flight time" of signals such as ultrasound, microwaves and light between the transmitter and the reflector to calculate the distance between the two. In addition, ToF sensors use tiny transmitters to emit infrared light or lasers, the light generated will bounce off any object and return to the sensor, and based on the time difference between the emission of light and the return to the sensor after being reflected by the object, the sensor can measure the distance between the object and the sensor.

[0004] However, when using TOF chips for measurement, due to the problem of unstable test data, when measuring a position multiple times, there will be data jumps and the output value is not fixed. Therefore, the existing laser rangefinder at least has the problem of low measurement accuracy. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a laser ranging method and device based on an ADC chip for use in rainy and foggy days, which solves the technical problem of low accuracy of measurement results in the prior art.

[0007] (II) Technical solution

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0009] In a first aspect, an embodiment of the present invention provides a laser ranging method for use in rainy and foggy days based on an ADC chip. The laser ranging method is applied to an MCU controller in a laser rangefinder. The laser rangefinder includes a laser receiving module, an ADC chip, an FPGA chip and an MCU controller. The laser ranging method includes: converting a reflected current laser signal into an analog signal through a laser receiving module; converting the analog signal into a digital signal through an ADC chip; identifying and processing the digital signal through an FPGA chip to screen out two waveforms with larger amplitudes, and filtering the waveform of the first signal of the two waveforms based on the interval time from the emission of the current laser signal corresponding to the two waveforms to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms to retain the waveform of the second signal of the two waveforms; wherein the first signal is a laser signal reflected back by water mist in rainy and foggy days, and the second signal is a laser signal reflected back by an object to be measured; based on the waveform of the second signal, determining the measured distance between the object to be measured.

[0010] With the aid of the above technical solution, the embodiment of the present application can filter out the laser signal reflected back by water mist in rainy and foggy days, thereby improving the accuracy of the ranging results in rainy and foggy days compared to the existing laser ranging method.

[0011] In some possible embodiments, based on the interval time from the emission of the current laser signal corresponding to the two waveforms to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms, a filtering operation is performed on the waveform of the first signal of the two waveforms, including: when the difference between the pulse amplitudes of the two waveforms is less than or equal to a preset pulse amplitude, the waveform with the smaller interval time of the two waveforms is determined as the waveform of the first signal, and the waveform of the first signal is filtered.

[0012] In some possible embodiments, based on the time from the emission of the current laser signal to the reaching of the maximum amplitude of the corresponding waveform corresponding to the two waveforms and the pulse width of the two waveforms, a filtering operation is performed on the waveform of the first signal of the two waveforms, including: when the time difference between the interval times corresponding to the two waveforms is less than or equal to a preset time, the waveform with the smaller pulse width of the two waveforms is determined as the waveform of the first signal, and the waveform of the first signal is filtered.

[0013] In some possible embodiments, based on the time from the emission of the current laser signal corresponding to the two waveforms to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms, a filtering operation is performed on the waveform of the first signal of the two waveforms, including: when the difference in the pulse amplitudes of the two waveforms is greater than a preset pulse amplitude and the time difference in the interval time corresponding to the two waveforms is greater than a preset time, determining the waveform with the smaller interval time of the two waveforms as the waveform of the first signal, and filtering the waveform of the first signal.

[0014] In some possible embodiments, the width of the first signal ranges from 0 to 1 ms.

[0015] In a second aspect, an embodiment of the present invention provides a laser ranging device based on an ADC chip for use in rainy and foggy days. The laser ranging device is applied to an MCU controller in a laser ranging instrument. The laser ranging instrument includes a laser receiving module, an ADC chip, an FPGA chip and an MCU controller. The laser ranging device includes: a first conversion module, which is used to convert the reflected current laser signal into an analog signal through the laser receiving module; a second conversion module, which is used to convert the analog signal into a digital signal through the ADC chip; a filtering module, which is used to identify and process the digital signal through the FPGA chip to screen out two waveforms with larger amplitudes, and based on the interval time from the emission of the current laser signal to the maximum amplitude of the corresponding waveform corresponding to the two waveforms and the pulse width of the two waveforms, the waveform of the first signal in the two waveforms is filtered to retain the waveform of the second signal in the two waveforms; wherein the first signal is a laser signal reflected back by water mist in rainy and foggy days, and the second signal is a laser signal reflected back by the object to be measured; a determination module, which is used to determine the measured distance between the object to be measured based on the waveform of the second signal.

[0016] In some possible embodiments, the filtering module is specifically used to determine the waveform with a smaller interval between the two waveforms as the waveform of the first signal when the difference between the pulse amplitudes of the two waveforms is less than or equal to a preset pulse amplitude, and perform a filtering operation on the waveform of the first signal.

[0017] In some possible embodiments, the filtering module is specifically used to determine the waveform with the smaller pulse width of the two waveforms as the waveform of the first signal when the time difference between the interval times corresponding to the two waveforms is less than or equal to a preset time, and perform a filtering operation on the waveform of the first signal.

[0018] In some possible embodiments, the filtering module is specifically used to determine the waveform with the smaller interval time between the two waveforms as the waveform of the first signal when the difference in pulse amplitudes of the two waveforms is greater than a preset pulse amplitude and the time difference between the interval times corresponding to the two waveforms is greater than a preset time, and perform a filtering operation on the waveform of the first signal.

[0019] In some possible embodiments, the width of the first signal ranges from 0 to 1 ms.

[0020] In a third aspect, an embodiment of the present application provides a storage medium having a computer program stored thereon, and the computer program is executed by a processor to execute the method described in the first aspect or any optional implementation of the first aspect.

[0021] In a fourth aspect, an embodiment of the present application provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are executed by the processor, the method described in the first aspect or any optional implementation method of the first aspect is performed.

[0022] In a fifth aspect, the present application provides a computer program product, which, when running on a computer, enables the computer to execute the method in the first aspect or any possible implementation of the first aspect.

[0023] In order to make the above-mentioned objectives, features and advantages to be achieved by the embodiments of the present application more obvious and understandable, the following specifically cites preferred embodiments and describes them in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A flow chart of a laser ranging method based on an ADC chip for use in rainy and foggy days provided in an embodiment of the present application is shown;

[0026] Figures 2A to 2C A schematic diagram showing a pulse signal received on a sunny day provided by an embodiment of the present application is shown;

[0027] FIG. 3A to FIG. 3E A schematic diagram of a pulse signal received in rainy and foggy weather provided by an embodiment of the present application is shown;

[0028] Figure 4 A schematic structural diagram of a laser ranging device based on an ADC chip for use in rainy and foggy days provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0030] In order to solve the problem of insufficient measurement accuracy of existing laser rangefinders, the embodiment of the present application discloses a laser ranging method and device based on an ADC chip for use in rainy and foggy days. By replacing the existing TOF chip with an ADC chip and an FPGA chip, after the laser is emitted, the reflected laser light signal is converted into an analog signal by a laser receiver, and the analog signal is converted into a digital signal by the ADC chip. The digital signal identified as interference is filtered by the FPGA chip, and the filtered signal is sent to the MCU controller. The MCU controller then processes the filtered signal and displays the distance to the object to be measured on the screen, thereby improving the ranging accuracy by obtaining an accurate reflection signal of the object to be measured.

[0031] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0032] See also Figure 1 , Figure 1 The flowchart of a laser ranging method based on an ADC chip for use in rainy and foggy days provided in an embodiment of the present application is shown. Specifically, the laser ranging method is applied to an MCU controller in a laser rangefinder, which includes a laser transmitting module TX, a laser receiving module RX, an ADC chip, an FPGA chip and an MCU controller; the laser ranging method includes:

[0033] Step S110, converting the reflected current laser signal into an analog signal through the laser receiving module RX; wherein the current laser can be any laser emitted by the laser emitting module TX. For example, the current laser can be the first laser emitted by the laser emitting module TX, or the third laser emitted by the laser emitting module TX, etc.;

[0034] Step S120, converting the analog signal into a digital signal through an ADC chip;

[0035] Step S130, identifying and processing the digital signal through the FPGA chip to screen out two waveforms with larger amplitudes, and filtering the waveform of the first signal of the two waveforms based on the interval time from the emission of the current laser signal corresponding to the two waveforms to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms, so as to retain the waveform of the second signal of the two waveforms; wherein the first signal is the laser signal reflected back by the water mist in the rainy and foggy day, and the second signal is the laser signal reflected back by the measured object;

[0036] Step S140: determining the measurement distance to the object to be measured based on the waveform of the second signal.

[0037] Therefore, with the aid of the above technical solution, the embodiment of the present application can filter out the laser signal reflected back by the water mist in rainy and foggy days, thereby improving the accuracy of the ranging results in rainy and foggy days compared to the existing laser ranging method.

[0038] To facilitate understanding of the embodiments of the present application, the following is an explanation by comparing signals on a sunny day and on a rainy or foggy day.

[0039] Specifically, see Figures 2A to 2C , Figures 2A to 2C FIG. 1 is a schematic diagram showing a pulse signal received on a sunny day provided by an embodiment of the present application. Figure 2A and 2C In the figure, D1, D2 and D3 represent different measuring distances, and D2<D1<D3, and t1, t2 and t3 represent different interval times, and the interval time refers to the time from the emission of the laser signal to the reaching of the maximum amplitude of the corresponding waveform, that is, the starting point of the interval time is the time point of emitting the laser signal, and the end point of the interval time is the time point of the maximum amplitude of the initial waveform of the current waveform, and d1 and d2 represent different signal wave widths.

[0040] like Figure 2A and 2C As shown in the figure, when the distance between the laser rangefinder and the object is farther, the time t is longer and the signal wave width is smaller. When the object reaches a certain distance, the signal wave width is 0, and the shorter the distance to the object, the stronger the signal. In addition, in good weather, the signal received by the laser receiving module RX is the reflected signal of the object, without interference from other medium reflected signals.

[0041] However, in rainy and foggy days, the air contains a large number of water molecules. Since light will have certain reflection and refraction when passing through water mist, a "water mist wall" will be formed within a certain distance (for example, within 40 meters), thereby reflecting part of the laser signal back, so that the laser receiving module RX can capture the reflected first signal, and the signal reflected back by the normal light beam after contacting the object to be measured is received by the laser receiving module RX again to form a second signal, thereby affecting the measurement result. Among them, the width range of the first signal is 0~1ms.

[0042] See also FIG. 3A to FIG. 3E , FIG. 3A to FIG. 3E A schematic diagram of a pulse signal received in rainy and foggy weather provided by an embodiment of the present application is shown. FIG. 3A to FIG. 3D is the possible return time and waveform of the first signal when measuring the same close distance, and Figure 3E When measuring long distance, the signal waveform returned by the object being measured may be similar to the signal waveform returned by the "water mist wall". The short-distance measurement distance can be within 40 meters; the long-distance measurement distance can be more than 100 meters.

[0043] like FIG. 3A to FIG. 3E As shown in the figure, when the "water mist wall" is closer, the first signal is stronger, at this time, t1 is smaller, and the signal width is wider. When the "water mist wall" is farther away, the first signal is weaker, at this time, t2 is larger, and the signal width is narrower. When the "water mist wall" reaches a certain distance, the time t increases, and the signal width approaches 0. In addition, depending on the reflectivity of the medium, the signal width approaches 0 when the time t is smaller.

[0044] Also, the laser rangefinder will always send out laser signals during the measurement process, but the laser receiving module RX receives one of the laser signals sent out and returned as the ranging signal, which can be the laser signal sent out for the first time or the laser signal sent out for the nth time. Wherein, n is a positive integer greater than or equal to 2. Also, after obtaining one of the returned laser signals, the laser receiving module RX converts the reflected current laser signal into an analog signal, and then the ADC chip converts the analog signal into a digital signal, thereby outputting a digital waveform, and then the FPGA chip identifies and processes the digital signal to filter out the two waveforms with larger amplitudes, and after comparing the interval time from the self-emission of the current laser signal corresponding to the two waveforms to the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms, the waveform of the first signal in the two waveforms is filtered, so that only the waveform of the second signal is left, and finally, according to the time t taken for the waveform of the second signal to reach the maximum amplitude, the distance to the measured object is calculated according to the speed of light and time t.

[0045] It should be noted here that the signal filtering of the present application is to filter out the clutter signal in a waveform, and the waveforms mainly filtered are based on the waveform signals returned by the "water mist wall", which are sharp waves or digital waveforms of different widths and amplitudes.

[0046] Furthermore, when the distance to the object under test is far, the first signal may be similar to or identical to the second signal. In this case, the interference signal and the object under test signal may be distinguished by obtaining the time t to reach the maximum amplitude, thereby filtering the first signal.

[0047] For example, when the distance to the object under test is far, when the difference between the pulse amplitudes of the two waveforms is less than or equal to the preset pulse amplitude, the waveform with the smaller interval time between the two waveforms is determined as the waveform of the first signal (or the waveform of the interference signal), and the waveform of the first signal is filtered.

[0048] Furthermore, if a close object is measured, due to the existence of the "water mist wall", the first signal returned by the "water mist wall" will be mixed in the second signal returned by the measured object, thereby causing greater interference to the second signal returned by the close object. Therefore, after the laser receiving module RX receives the first signal and the second signal, the existing ADC circuit converts the analog signal into a digital signal, and then the FPGA circuit obtains the signal width d in the digital signal according to the characteristics of the digital signal. Since the signal width of the first signal returned by the "water mist wall" is smaller than the signal width of the second signal returned by the measured object, the MCU separates the first signal and the second signal according to the size of the signal width, and filters the first signal to obtain an interference-free second signal, thereby improving the measurement accuracy of the laser rangefinder in rainy and foggy days.

[0049] For example, when measuring a close object, when the time difference between the interval times corresponding to the two waveforms is less than or equal to the preset time, the waveform with the smaller pulse width of the two waveforms is determined as the waveform of the first signal, and the waveform of the first signal is filtered;

[0050] For another example, when the difference between the pulse amplitudes of the two waveforms is greater than the preset pulse amplitude and the time difference between the intervals corresponding to the two waveforms is greater than the preset time, the waveform with the smaller interval between the two waveforms is determined as the waveform of the first signal, and the waveform of the first signal is filtered. Because during measurement, when the signal reaches the object to be measured, it will not continue to move forward, it will be reflected, and the interference of the water mist wall will only be between the rangefinder and the object to be measured. Therefore, the time of the second signal is greater than or equal to the time of the first signal, and will not be less than the time of the first signal.

[0051] It should be understood that the above-mentioned laser ranging method based on ADC chip for use in rainy and foggy days is only exemplary, and those skilled in the art can make various modifications based on the above-mentioned method, and the modified or deformed content is also within the protection scope of this application.

[0052] See also Figure 4 , Figure 4 The structure diagram of a laser distance measuring device 400 based on an ADC chip for use in rainy and foggy days provided in an embodiment of the present application is shown. Specifically, the laser distance measuring device 400 is applied to an MCU controller in a laser distance meter, and the laser distance meter includes a laser receiving module, an ADC chip, an FPGA chip, and an MCU controller; the laser distance measuring device 400 includes

[0053] A first conversion module 410 is used to convert the current laser signal reflected back into an analog signal through the laser receiving module;

[0054] A second conversion module 420, configured to convert the analog signal into a digital signal through an ADC chip;

[0055] The filtering module 430 is used to identify and process the digital signal through the FPGA chip to filter out the two waveforms with larger amplitudes, and based on the interval time from the emission of the current laser signal corresponding to the two waveforms to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms, filter the waveform of the first signal of the two waveforms to retain the waveform of the second signal of the two waveforms; wherein the first signal is the laser signal reflected back by the water mist in the rainy and foggy day, and the second signal is the laser signal reflected back by the measured object;

[0056] The determination module 440 is used to determine the measurement distance between the measured object and the measured object based on the waveform of the second signal.

[0057] In a possible embodiment, the filtering module 430 is specifically used to determine the waveform with a smaller interval between the two waveforms as the waveform of the first signal when the difference between the pulse amplitudes of the two waveforms is less than or equal to a preset pulse amplitude, and perform a filtering operation on the waveform of the first signal.

[0058] In a possible embodiment, the filtering module 430 is specifically used to determine the waveform with the smaller pulse width of the two waveforms as the waveform of the first signal when the time difference between the interval times corresponding to the two waveforms is less than or equal to a preset time, and perform a filtering operation on the waveform of the first signal.

[0059] In one possible embodiment, the filtering module 430 is specifically used to determine the waveform with the smaller interval time between the two waveforms as the waveform of the first signal when the difference in pulse amplitudes of the two waveforms is greater than a preset pulse amplitude and the time difference between the interval times corresponding to the two waveforms is greater than a preset time, and to perform a filtering operation on the waveform of the first signal.

[0060] In a possible embodiment, the width of the first signal ranges from 0 to 1 ms.

[0061] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the device described above can refer to the corresponding process in the aforementioned method, and will not be described in detail here.

[0062] The present application also provides a storage medium, on which a computer program is stored. When a processor runs the computer program, the method described in the method embodiment is executed.

[0063] The present application also provides a computer program product, which, when executed on a computer, enables the computer to execute the method described in the method embodiment.

[0064] It should be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0065] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions.

[0066] It should be noted that in the claims, any reference numerals placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In the claims enumerating several means, several of these means may be embodied by the same hardware. The use of the words first, second, third, etc., is for convenience of expression only and does not indicate any order. These words may be understood as part of the component name.

[0067] In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0068] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments after knowing the basic creative concept. Therefore, the claims should be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0069] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention should also include these modifications and variations.

Claims

1. A laser ranging method based on an ADC chip for use in rainy and foggy days, characterized in that: The laser distance measurement method is applied to an MCU controller in a laser distance meter, and the laser distance meter includes a laser receiving module, the ADC chip, an FPGA chip and the MCU controller; the laser distance measurement method includes: The laser receiving module converts the reflected current laser signal into an analog signal; Converting the analog signal into a digital signal by using the ADC chip; The digital signal is identified and processed by the FPGA chip to screen out two waveforms with larger amplitudes, and based on the interval time from the emission of the current laser signal to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms, the waveform of the first signal of the two waveforms is filtered to retain the waveform of the second signal of the two waveforms; wherein the first signal is a laser signal reflected back by the water mist in the rainy and foggy day, and the second signal is a laser signal reflected back by the object to be measured; Determining a measurement distance to the object under test based on a waveform of the second signal; The filtering operation is performed on the waveform of the first signal of the two waveforms based on the interval time from the emission of the current laser signal corresponding to the two waveforms to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms, including: When the difference between the pulse amplitudes of the two waveforms is less than or equal to the preset pulse amplitude, the waveform with the smaller interval time between the two waveforms is determined as the waveform of the first signal, and a filtering operation is performed on the waveform of the first signal.

2. The laser ranging method according to claim 1, characterized in that: The filtering operation is performed on the waveform of the first signal of the two waveforms based on the time from the emission of the current laser signal corresponding to the two waveforms to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms, including: When the time difference between the interval times corresponding to the two waveforms is less than or equal to the preset time, the waveform with the smaller pulse width of the two waveforms is determined as the waveform of the first signal, and the waveform of the first signal is filtered.

3. The laser ranging method according to claim 1, characterized in that: The filtering operation is performed on the waveform of the first signal of the two waveforms based on the time from the emission of the current laser signal corresponding to the two waveforms to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms, including: When the difference in pulse amplitudes of the two waveforms is greater than a preset pulse amplitude and the time difference in interval times corresponding to the two waveforms is greater than a preset time, the waveform with a smaller interval time among the two waveforms is determined as the waveform of the first signal, and a filtering operation is performed on the waveform of the first signal.

4. The laser ranging method according to any one of claims 1 to 3, characterized in that: The width of the first signal ranges from 0 to 1 ms.

5. A laser distance measuring device based on an ADC chip for use in rainy and foggy days, characterized in that: The laser distance measuring device is applied to the MCU controller in the laser distance measuring instrument, and the laser distance measuring instrument comprises a laser receiving module, the ADC chip, the FPGA chip and the MCU controller; the laser distance measuring device comprises: A first conversion module, used for converting the current laser signal reflected back by the laser receiving module into an analog signal; A second conversion module, used for converting the analog signal into a digital signal through the ADC chip; A filtering module, for identifying and processing the digital signal through the FPGA chip to screen out two waveforms with larger amplitudes, and filtering the waveform of the first signal of the two waveforms based on the interval time from the emission of the current laser signal to the reaching of the maximum amplitude of the corresponding waveform and the pulse width of the two waveforms to retain the waveform of the second signal of the two waveforms; wherein the first signal is a laser signal reflected back by the water mist in the rainy and foggy day, and the second signal is a laser signal reflected back by the object to be measured; A determination module, configured to determine a measurement distance from the object to be measured based on a waveform of the second signal; The filtering module is specifically used to determine the waveform with a smaller interval time between the two waveforms as the waveform of the first signal when the difference between the pulse amplitudes of the two waveforms is less than or equal to the preset pulse amplitude, and perform a filtering operation on the waveform of the first signal.

6. The laser distance measuring device according to claim 5, characterized in that: The filtering module is specifically used to determine the waveform with the smaller pulse width of the two waveforms as the waveform of the first signal when the time difference between the interval times corresponding to the two waveforms is less than or equal to a preset time, and perform a filtering operation on the waveform of the first signal.

7. The laser distance measuring device according to claim 5, characterized in that: The filtering module is specifically used to determine the waveform with the smaller interval time between the two waveforms as the waveform of the first signal when the difference between the pulse amplitudes of the two waveforms is greater than the preset pulse amplitude and the time difference between the interval times corresponding to the two waveforms is greater than the preset time, and to perform a filtering operation on the waveform of the first signal.

8. The laser distance measuring device according to any one of claims 5 to 7, characterized in that: The width of the first signal ranges from 0 to 1 ms.

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