A method of measuring reflectivity, a laser radar device, and a storage medium

Abstract

The application discloses a reflectivity measuring method, a laser radar device and a storage medium, and relates to the technical field of reflectivity measurement. The reflectivity measuring method comprises the following steps: acquiring the distance between a laser radar device and a measured object and the characteristic parameters of a return signal; acquiring a first preset characteristic relationship; and calculating the reflectivity of the measured object according to the first preset characteristic relationship. The first preset characteristic relationship is a corresponding relationship between the characteristic parameters and the reflectivity which is stored in advance. The measured object does not need to be moved multiple times to obtain different distances. According to the acquired first preset characteristic relationship, the reflectivity of the measured object at any distance can be directly calculated according to the characteristic parameters and the distance. The measuring method is simple, the calibration process is simple, and the measuring efficiency of the surface reflectivity of the measured object is improved.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and more particularly to a method for measuring reflectivity, a lidar device, and a storage medium. Background Technology

[0002] With the development of LiDAR technology, its applications are becoming increasingly widespread, with the largest application area being autonomous vehicles. As the "eyes" of autonomous vehicles, LiDAR boasts superior detection accuracy compared to other sensors, capable of sensing the distance to objects around the vehicle, making it an indispensable sensor for autonomous driving. Besides detecting distance, LiDAR can also perceive the reflectivity of an object by analyzing the laser echo energy obtained from the object being measured. Reflectivity can characterize the color and material of the object to some extent, further increasing the information about the object and facilitating its identification and classification. However, the laser echo energy obtained by LiDAR is limited by different LiDAR designs and is also affected by the distance to the object; therefore, the laser echo energy cannot be directly correlated with the reflectivity of the object.

[0003] Currently, the common method is to calibrate the test object at different distances using various known standard reflectivities to obtain the relationship between the laser echo energy received by the lidar and the reflectivity of the test object and the distance. However, test objects with different reflectivities require different distances to be moved, making the calibration process very complex, demanding on production facilities, inefficient, and unsuitable for mass production. Summary of the Invention

[0004] Therefore, it is necessary to address the problems mentioned in the background art by providing a method for measuring reflectivity, a lidar device, and a storage medium. This method allows the lidar device to be calibrated using multiple known reflectivities at a fixed distance, and the reflectivity of the object being measured to be calculated, thereby improving the production efficiency of lidar.

[0005] To achieve the above objectives, a first aspect of the present invention provides a method for measuring reflectivity, comprising:

[0006] Acquire the distance between the lidar device and the object being measured, as well as the characteristic parameters of the echo signal;

[0007] Obtain the first preset feature relation;

[0008] The reflectance of the object under test is calculated according to the first preset feature relationship formula; wherein, the first preset feature relationship formula is a pre-stored correspondence formula between the feature parameters and the reflectance.

[0009] Optionally, the characteristic parameters include at least one of pulse width, waveform area, rising edge, falling edge, and amplitude.

[0010] Optionally, the characteristic parameters have a monotonic relationship with the echo signal energy.

[0011] Optionally, obtaining the first preset feature relation includes:

[0012] Obtain the preset reflectance fitting formula and the second preset feature formula;

[0013] The first preset feature relationship is generated based on the preset reflectance fitting relationship and the second preset feature relationship.

[0014] Optionally, obtaining the preset reflectance fitting formula includes:

[0015] Several standard diffuse reflective plates with different reflectivities are pre-set;

[0016] Acquire the energy of several preset calibration echo signals reflected by the standard diffuse reflector with different reflectivities at a preset calibration spacing;

[0017] Based on the preset calibration echo signal energy, determine the inverse proportional relationship between the different echo signal energies corresponding to different spacings;

[0018] Based on the preset calibration echo signal energy, the inverse proportional relationship, and the mapping relationship between reflectivity and echo signal energy, a preset echo signal energy mapping relationship table corresponding to the standard diffuse reflector with different reflectivity at different spacings is obtained.

[0019] The preset echo signal energy mapping relationship table is fitted to obtain the preset reflectivity fitting relationship.

[0020] Optionally, the feature parameters include pulse width; obtaining the second preset feature relation includes:

[0021] Obtain the first mapping table between pulse width and energy;

[0022] Based on the mapping relationship between reflectivity and echo signal energy and the first mapping relationship table, the second preset characteristic relationship between echo signal energy and pulse width is determined.

[0023] Optionally, the feature parameter includes the waveform area; obtaining the second preset feature relationship further includes:

[0024] Obtain the second mapping table between waveform area and energy;

[0025] Based on the mapping relationship between reflectivity and echo signal energy and the second mapping relationship table, the second preset characteristic relationship between the echo signal energy and the waveform area is determined.

[0026] A second aspect of the present invention provides a lidar device, comprising: a light-emitting unit, a receiving unit, a mirror module, and a main control unit;

[0027] The light-emitting unit is connected to the main control module and is used to radiate a ranging laser according to the light-emitting control signal provided by the main control module;

[0028] The mirror unit is used to converge the diffuse reflection ranging laser signal reflected from the object being measured onto the receiving unit.

[0029] The receiving unit is used to convert the diffuse reflection ranging laser signal into an optical signal and amplify the optical signal to generate an echo signal.

[0030] The main control module, connected to the receiving unit, is configured as follows:

[0031] The distance between the lidar device and the object under test and the characteristic parameters of the echo signal are obtained;

[0032] Obtain the first preset feature relation;

[0033] The reflectance of the object under test is calculated according to the first preset feature relationship formula; wherein, the first preset feature relationship formula is a pre-stored correspondence formula between the feature parameters and the reflectance.

[0034] Optionally, obtaining the first preset feature relation includes:

[0035] Obtain the preset reflectance fitting formula and the second preset feature formula;

[0036] The first preset feature relationship is generated based on the preset reflectance fitting relationship and the second preset feature relationship.

[0037] Optionally, obtaining the preset reflectance fitting formula includes:

[0038] Several standard diffuse reflective plates with different reflectivities are pre-set;

[0039] Acquire the energy of several preset calibration echo signals reflected by the standard diffuse reflector with different reflectivities at a preset calibration spacing;

[0040] Based on the preset calibration echo signal energy, determine the inverse proportional relationship between the different echo signal energies corresponding to different spacings;

[0041] Based on the preset calibration echo signal energy, the inverse proportional relationship, and the mapping relationship between reflectivity and echo signal energy, a preset echo signal energy mapping relationship table corresponding to the standard diffuse reflector with different reflectivity at different spacings is obtained.

[0042] The preset echo signal energy mapping relationship table is fitted to obtain the preset reflectivity fitting relationship.

[0043] Optionally, the lens assembly unit includes:

[0044] The emitting mirror group, located between the light-emitting unit and the object being measured, is used to optically collimate the ranging laser.

[0045] A receiving mirror assembly, located between the receiving unit and the object being measured, is used to converge the diffuse reflection ranging laser signal onto the receiving unit.

[0046] A third aspect of the invention also provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0047] In the reflectivity measurement method provided by this invention, the distance and characteristic parameters between the device and the object to be measured are obtained in advance, and a first preset characteristic relationship is obtained. Then, the reflectivity of the object to be measured is calculated according to the first preset characteristic relationship. The first preset characteristic relationship is a pre-stored correspondence between characteristic parameters and reflectivity. The characteristic parameters have a monotonic relationship with the echo signal energy. It is not necessary to move the object to be measured multiple times to obtain different distances. The reflectivity measurement method proposed by this invention is based on the obtained first preset characteristic relationship. The reflectivity of the object to be measured at any distance is directly calculated according to the characteristic parameters and the distance. This measurement method is simple, the calibration process is simple, and the measurement efficiency of the surface reflectivity of the object to be measured is improved.

[0048] In the lidar device provided by this invention, the main control module is configured to: obtain a first preset feature relationship based on the characteristic parameters of the received echo signal and the distance between the device and the object being measured; the first preset feature relationship is a pre-stored correspondence between the characteristic parameters and the reflectivity; and calculate the reflectivity of the object being measured based on the distance and the characteristic parameters, according to the first preset feature relationship. The lidar device proposed in this invention is simple, adaptable to various measurement sites, eliminates the need for multiple movements of the object being measured to obtain different distances, simplifies the process of measuring the reflectivity of the object, has high measurement efficiency, and is suitable for mass production. Attached Figure Description

[0049] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0050] Figure 1 This is a schematic diagram of the structure of a lidar device provided in one embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of a lidar device provided in another embodiment of the present invention;

[0052] Figure 3 This is a flowchart illustrating an emissivity measurement method provided in one embodiment of the present invention;

[0053] Figure 4 This is a partial flowchart illustrating an emissivity measurement method provided in the first embodiment of the present invention;

[0054] Figure 5 This is a partial flowchart illustrating an emissivity measurement method provided in the second embodiment of the present invention;

[0055] Figure 6 This is a partial flowchart illustrating an emissivity measurement method provided in the third embodiment of the present invention;

[0056] Figure 7 This is a partial flowchart of an emissivity measurement method provided in the fourth embodiment of the present invention.

[0057] Explanation of reference numerals in the attached diagram: 10, main control module; 20, light-emitting unit; 30, mirror group unit; 31, transmitting mirror group; 32, receiving mirror group; 40, receiving unit. Detailed Implementation

[0058] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0060] When using the terms “including,” “having,” and “comprising” as described herein, another component may be added unless explicitly qualifying terms such as “only,” “consisting of,” etc. are used. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0061] It should be understood that although the terms "first," "second," etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of the invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0062] In this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal connection of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0063] To illustrate the above-described technical solution of the present invention, specific embodiments are described below.

[0064] In one embodiment of the present invention, a lidar device is provided, such as Figure 1 As shown, the lidar device includes a main control module 10, a light-emitting unit 20, a mirror assembly unit 30, and a receiving unit 40. The light-emitting unit 20 is connected in series between the output terminal of the main control module 10 and the input terminal of the mirror assembly unit 30, and the receiving unit 40 is connected in series between the input terminal of the main control module 10 and the output terminal of the mirror assembly unit 30.

[0065] Specifically, the emitting unit 20 is controlled by the main control module 10 and radiates a ranging laser according to the emitting control signal provided by the main control module 10; the mirror group unit 30 is used to converge the diffuse reflection ranging laser signal reflected from the measured object to the receiving unit 40; the receiving unit 40 is used to convert the diffuse reflection ranging laser signal into an optical signal and amplify the optical signal to generate an echo signal; the main control module 10 is connected to the receiving unit 40 and is configured to perform at least the following steps:

[0066] Step 10: Obtain the distance between the lidar device and the object being measured, as well as the characteristic parameters of the echo signal;

[0067] Step 20: Obtain the first preset feature relation;

[0068] Step 30: Calculate the reflectivity of the object under test according to the first preset feature relationship formula; wherein, the first preset feature relationship formula is the correspondence between the pre-stored feature parameters and the reflectivity.

[0069] Specifically, the main control module 10 calculates the reflectivity of the object under test based on the acquired spacing and feature parameters and through the first preset feature relationship formula.

[0070] In the reflectivity measurement method provided in the above embodiments, the distance and characteristic parameters between the device and the object to be measured are obtained in advance, and a first preset characteristic relationship is obtained. Then, the reflectivity of the object to be measured is calculated according to the first preset characteristic relationship. The first preset characteristic relationship is a pre-stored correspondence between characteristic parameters and reflectivity. The characteristic parameters have a monotonic relationship with the echo signal energy. It is not necessary to move the object to be measured multiple times to obtain different distances. The reflectivity measurement method proposed in this invention is based on the obtained first preset characteristic relationship. The reflectivity of the object to be measured at any distance is directly calculated according to the characteristic parameters and the distance. This measurement method is simple, the calibration process is simple, and the measurement efficiency of the surface reflectivity of the object to be measured is improved.

[0071] In one embodiment, the characteristic parameters include at least one of pulse width, waveform area, rising edge, falling edge, and amplitude; the characteristic parameters have a monotonic relationship with the echo signal energy. It should be noted that other parameters in the echo signal that have a monotonic relationship with energy can also be used as characteristic parameters.

[0072] As an example, the monotonic relationship between the characteristic parameter and the echo signal energy means that when the echo signal energy increases, the characteristic parameter also increases; when the echo signal energy decreases, the characteristic parameter also decreases. The slope of the increase or decrease in echo signal energy may be the same as or different from the slope of the corresponding increase or decrease in the characteristic parameter; this invention does not impose any limitation on this.

[0073] In one embodiment, step S10: obtaining the distance between the lidar device and the object being measured includes the following steps:

[0074] Step S11: Obtain the time difference between the emitted light control signal and the received laser echo signal;

[0075] Step S12: Calculate the distance between the lidar device and the object being measured based on the time difference.

[0076] In one embodiment, such as Figure 2As shown, the mirror unit includes a transmitting mirror group 31 and a receiving mirror group 32. The transmitting mirror group 31 is located between the emitting unit and the object being measured; the receiving mirror group 32 is located between the receiving unit 40 and the object being measured. The transmitting mirror group 31 is used to optically collimate the ranging laser; the receiving mirror group 32 is used to focus the diffuse reflection ranging laser signal onto the receiving unit 40.

[0077] In one embodiment, the main control module 10 is further configured to: obtain a preset reflectivity fitting formula and a second preset feature formula; and generate a first preset feature formula based on the preset reflectivity fitting formula and the second preset feature formula.

[0078] In one embodiment, the main control module 10 is further configured to: preset a plurality of standard diffuse reflectors with different reflectivities; acquire a plurality of preset calibration echo signal energies reflected by the standard diffuse reflectors with different reflectivities at preset calibration intervals; determine the inverse proportional relationship between the different echo signal energies corresponding to different intervals based on each preset calibration echo signal energy; obtain a preset echo signal energy mapping relationship table corresponding to the standard diffuse reflectors with different reflectivities at different intervals based on each preset calibration echo signal energy, the inverse proportional relationship, and the mapping relationship between reflectivity and echo signal energy; and perform fitting processing on the preset echo signal energy mapping relationship table to obtain a preset reflectivity fitting relationship.

[0079] like Figure 3 As shown, in one embodiment of the present invention, a method for measuring reflectance is also provided, comprising the following steps:

[0080] Step 10: Obtain the distance between the lidar device and the object being measured, as well as the characteristic parameters of the echo signal;

[0081] Step 20: Obtain the first preset feature relation;

[0082] Step 30: Calculate the reflectivity of the object under test according to the first preset feature relationship formula; wherein, the first preset feature relationship formula is the correspondence between the pre-stored feature parameters and the reflectivity.

[0083] In the reflectivity measurement method provided in the above embodiments, the distance and characteristic parameters between the device and the object to be measured are obtained in advance, and a first preset characteristic relationship is obtained. Then, the reflectivity of the object to be measured is calculated according to the first preset characteristic relationship. The first preset characteristic relationship is a pre-stored correspondence between characteristic parameters and reflectivity. The characteristic parameters have a monotonic relationship with the echo signal energy. It is not necessary to move the object to be measured multiple times to obtain different distances. The reflectivity measurement method proposed in this invention is based on the obtained first preset characteristic relationship. The reflectivity of the object to be measured at any distance is directly calculated according to the characteristic parameters and the distance. This measurement method is simple, the calibration process is simple, and the measurement efficiency of the surface reflectivity of the object to be measured is improved.

[0084] In one embodiment, the characteristic parameters include at least one of pulse width, waveform area, rising edge, falling edge, and amplitude; the characteristic parameters have a monotonic relationship with the echo signal energy. It should be noted that other parameters in the echo signal that have a monotonic relationship with energy can also be used as characteristic parameters.

[0085] As an example, the monotonic relationship between the characteristic parameter and the echo signal energy means that when the echo signal energy increases, the characteristic parameter also increases; when the echo signal energy decreases, the characteristic parameter also decreases. The slope of the increase or decrease in echo signal energy may be the same as or different from the slope of the corresponding increase or decrease in the characteristic parameter; this invention does not impose any limitation on this.

[0086] In one embodiment, based on the above-described lidar device, the lidar ranging equation is obtained as follows:

[0087]

[0088] Where P is the echo signal energy, D is the aperture of the receiving mirror group, and P T The power of the ranging laser. S represents the transmission efficiency of the lidar device, and S represents the distance between the lidar device and the object being measured.

[0089] Specifically, the aperture D of the receiving mirror group and the power P of the ranging laser. T and the transmission efficiency of lidar devices Given all parameters, it can be seen that the echo signal energy P is inversely proportional to the square of the spacing S.

[0090] In one embodiment, such as Figure 4 As shown, step S20: Obtaining the first preset feature relation includes the following steps:

[0091] Step S21: Obtain the preset reflectance fitting formula and the second preset feature formula;

[0092] Step S22: Generate the first preset feature relationship based on the preset reflectance fitting relationship and the second preset feature relationship.

[0093] Specifically, the preset reflectivity fitting formula is the relationship between reflectivity, spacing, and echo signal energy; the second preset characteristic formula is the relationship between characteristic parameters and echo signal energy. Substituting the second preset characteristic formula into the preset reflectivity fitting formula yields the first preset characteristic formula.

[0094] In one embodiment, such as Figure 5 As shown, step S21: Obtain the preset reflectance fitting formula, including the following steps:

[0095] Step S211: Pre-set several standard diffuse reflection plates with different reflectivities;

[0096] Step S212: Obtain the energy of several preset calibration echo signals reflected by a standard diffuse reflector with different reflectivities at a preset calibration spacing;

[0097] Step S213: Determine the inverse proportional relationship between the different echo signal energies corresponding to different spacings based on the preset calibration echo signal energies;

[0098] Step S214: Based on the preset calibration echo signal energy, inverse ratio formula and mapping relationship between reflectivity and echo signal energy, obtain the preset echo signal energy mapping relationship table corresponding to standard diffuse reflective plates with different reflectivities at different spacings;

[0099] Step S215: Fit the preset echo signal energy mapping relationship table to obtain the preset reflectivity fitting relationship.

[0100] Specifically, in step S212, the calibration process is as follows: n standard diffuse reflective plates with different reflectivities are selected, with reflectivities ranging from low to high as ρ1, ρ2…ρ… n , ρ n For high reflectivity, ρ1 represents low reflectivity; a standard diffuse reflector with reflectivity ρ1 is placed at a distance S1, and a ranging laser illuminates the standard diffuse reflector to obtain the echo signal energy P1 corresponding to reflectivity ρ1 and distance S1. Characteristic parameters corresponding to the echo signal energy P1, such as the pulse width of the echo signal. Or the waveform area of ​​the echo signal energy Keeping the spacing S1 constant, the reflectivity ρ2…ρ is changed sequentially. n Using a standard diffuse reflector, repeat the above process to calculate the energy of n preset calibration echo signals, denoted as follows: Where, the spacing S1, and the reflectivity of the standard diffuse reflector are ρ n The time echo signal energy is denoted as The corresponding pulse width is denoted as The corresponding waveform area is denoted as

[0101] Specifically, in step S213, the maximum measurement interval of the lidar device is set to S. m In S1 and S m Interpolating m distance values, and based on the aforementioned lidar ranging equation, with reflectivity ρ1 and spacing S1, the formula is transformed to obtain the inverse proportional relationship for standard diffuse reflective plates with known reflectivities at different spacings: Spacing S m The reflectivity of a standard diffuse reflector is ρ. n The energy of the echo signal at that time.

[0102] As an example, the preset calibration echo signal energy distribution of standard diffuse reflectors with different reflectivities at different spacings is shown in Table 1 below:

[0103]

[0104] Based on the inverse proportional relationship, Table 1 above is converted into Table 2 below:

[0105]

[0106] Specifically, in step S214, the mapping relationship between reflectivity and echo signal energy is known: The above Table 2 is converted to obtain the preset echo signal energy mapping relationship table for standard diffuse reflectors with different reflectivities at different spacings, as shown in Table 3 below:

[0107]

[0108]

[0109] Specifically, by fitting the preset echo signal energy mapping relationship table, the preset reflectivity fitting relationship between reflectivity, spacing, and echo signal energy is calculated:

[0110]

[0111] Where ρ is the reflectivity of the object being measured, and S is the distance between the object being measured and the lidar device. The echo signal energy is given when the reflectivity of the standard diffuse reflector is ρ1 and the preset calibration spacing is S1.

[0112] The above method for measuring reflectivity, by using a preset calibration spacing S1 and knowing the energies of several preset calibration echo signals under a standard diffuse reflector with different reflectivities, yields an inverse proportional relationship. Based on the inverse proportional relationship, the mapping relationship between reflectivity and echo signal energy, and the preset calibration echo signal energy, a preset echo signal energy mapping relationship table corresponding to standard diffuse reflectors with different reflectivities at different spacings is calculated. This table is then fitted to obtain a preset reflectivity fitting relationship. At the preset calibration spacing, the preset reflectivity fitting relationship between reflectivity, spacing, and echo signal energy is obtained through the above calculations. This measurement and calibration method is simple and easy to implement.

[0113] In one embodiment, such as Figure 6 As shown, the feature parameters include pulse width; Step S21: Obtain the second preset feature relation, including the following steps:

[0114] Step S201: Obtain the first mapping table between pulse width and energy;

[0115] Step S202: Based on the mapping relationship between reflectivity and echo signal energy and the first mapping relationship table, determine the second preset characteristic relationship between echo signal energy and pulse width.

[0116] Specifically, the first mapping relationship between pulse width and energy is shown in Table 4 below:

[0117]

[0118] Based on the mapping relationship between reflectivity and echo signal energy, the first mapping relationship table is replaced to determine the second preset feature relationship: P = B{PW}, and the corresponding first preset feature relationship is: ρ = A{S, B{PW}}; where ρ is the reflectivity of the object being measured, S is the distance between the object being measured and the lidar device, P is the echo signal energy, and PW is the pulse width.

[0119] In one embodiment, such as Figure 7 As shown, the feature parameters include the waveform area; obtaining the second preset feature relation also includes the following steps:

[0120] Step S203: Obtain the second mapping table corresponding to waveform area and energy;

[0121] Step S204: Based on the mapping relationship between reflectivity and echo signal energy and the second mapping relationship table, determine the second preset characteristic relationship between echo signal energy and waveform area.

[0122] Specifically, the second mapping relationship between waveform area and energy is shown in Table 5 below:

[0123]

[0124]

[0125] Based on the mapping relationship between reflectivity and echo signal energy, the second mapping relationship table is replaced to determine the second preset feature relationship: P = C{Area}, and the corresponding first preset feature relationship is: ρ = A{S, C{Area}}; where ρ is the reflectivity of the object being measured, S is the distance between the object being measured and the lidar device, P is the echo signal energy, and Area is the waveform area.

[0126] In one embodiment of the present invention, a storage medium is also provided on which a computer program is stored, which, when executed by a processor, implements the steps of the method described above.

[0127] For specific limitations on the reflectance measurement method in the above embodiments, please refer to the limitations on the reflectance measurement method above, which will not be repeated here.

[0128] It should be understood that, unless otherwise expressly stated herein, there is no strict order in which the steps are performed, and these steps may be performed in other orders. Moreover, at least some of the steps may include multiple sub-steps or multiple stages, which are not necessarily completed at the same time, but may be performed at different times, and the execution order of these sub-steps or stages is not necessarily sequential, but may be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0129] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method of measuring reflectivity, characterized by, The method comprises: obtaining a distance between a laser radar device and a measured object and a characteristic parameter of a return signal, wherein the characteristic parameter and the return signal energy have a corresponding monotonic relationship; obtaining a first preset characteristic relationship; calculating the reflectivity of the measured object according to the first preset characteristic relationship; wherein the first preset characteristic relationship is a corresponding relationship between the characteristic parameter and the reflectivity which is pre-stored; the first preset characteristic relationship is obtained by obtaining a preset reflectivity fitting relationship and a second preset characteristic relationship; the first preset characteristic relationship is generated according to the preset reflectivity fitting relationship and the second preset characteristic relationship; wherein the preset reflectivity fitting relationship is a relationship among reflectivity, distance and return signal energy, and the second preset characteristic relationship is a relationship between the characteristic parameter and the return signal energy; the preset reflectivity fitting relationship is obtained by pre-setting a plurality of standard diffuse reflection plates with different reflectivities; a plurality of preset calibration return signal energies reflected by the standard diffuse reflection plates with different reflectivities at a preset calibration distance are obtained; an inverse relationship of different return signal energies corresponding to different distances is determined according to each preset calibration return signal energy; a preset return signal energy mapping relationship table corresponding to the standard diffuse reflection plates with different reflectivities at different distances is obtained according to each preset calibration return signal energy, the inverse relationship and a mapping relationship between reflectivity and return signal energy; and the preset return signal energy mapping relationship table is fitted to obtain the preset reflectivity fitting relationship.

2. The method of measuring reflectivity according to claim 1, wherein, The characteristic parameter comprises at least one of pulse width, waveform area, rising edge, falling edge and amplitude.

3. The method of measuring reflectivity according to claim 1 or 2, characterized in that, The characteristic parameter comprises pulse width; the second preset characteristic relationship is obtained by: obtaining a first mapping relationship table corresponding to pulse width and energy; determining the second preset characteristic relationship between the return signal energy and the pulse width based on the mapping relationship between the reflectivity and the return signal energy and the first mapping relationship table.

4. The method of measuring reflectivity according to claim 1 or 2, wherein The characteristic parameter comprises waveform area; the second preset characteristic relationship is obtained by: obtaining a second mapping relationship table corresponding to waveform area and energy; determining the second preset characteristic relationship between the return signal energy and the waveform area based on the mapping relationship between the reflectivity and the return signal energy and the second mapping relationship table.

5. A lidar apparatus, characterized by, The method comprises: a light emitting unit, a receiving unit, a mirror group module and a main control module; the light emitting unit is connected with the main control module and is used for radiating ranging laser according to the light emitting control signal provided by the main control module; the mirror group unit is used for converging the diffuse reflection ranging laser signal reflected by the measured object on the receiving unit; the receiving unit is used for converting the diffuse reflection ranging laser signal into an optical signal and amplifying the optical signal to generate a return signal; the main control module is connected with the receiving unit and is configured to: acquire a distance between the laser radar device and the measured object and a characteristic parameter of the echo signal, wherein the characteristic parameter and the echo signal energy have a corresponding monotonic relationship; acquire a first preset characteristic relationship; calculate the reflectivity of the measured object according to the first preset characteristic relationship, wherein the first preset characteristic relationship is a corresponding relationship between the characteristic parameter and the reflectivity which is pre-stored; the acquiring of the first preset characteristic relationship comprises: acquiring a preset reflectivity fitting relationship and a second preset characteristic relationship; and generating the first preset characteristic relationship according to the preset reflectivity fitting relationship and the second preset characteristic relationship; wherein the preset reflectivity fitting relationship is a relationship among reflectivity, distance and echo signal energy, and the second preset characteristic relationship is a relationship between the characteristic parameter and the echo signal energy; the acquiring of the preset reflectivity fitting relationship comprises: presetting a plurality of standard diffuse reflection plates with different reflectivities; acquiring a plurality of preset calibration echo signal energies reflected by the standard diffuse reflection plates with different reflectivities at a preset calibration distance; determining an inverse relationship of different echo signal energies corresponding to different distances according to each preset calibration echo signal energy; obtaining a preset echo signal energy mapping relationship table corresponding to the standard diffuse reflection plates with different reflectivities at different distances according to each preset calibration echo signal energy, the inverse relationship and a mapping relationship between reflectivity and echo signal energy; and performing fitting processing on the preset echo signal energy mapping relationship table to obtain the preset reflectivity fitting relationship.

6. A storage medium having stored thereon a computer program, characterized in that the computer program is executed by a processor to realize the steps of the method of any one of claims 1 to 4.

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