WO2021102648A1 - Reflectivity measurement method and apparatus, movable platform and computer-readable medium - Google Patents

Abstract

Disclosed are a reflectivity measurement method, a reflectivity measurement apparatus (1000), a movable platform (1100) and a computer-readable storage medium. The method comprises: transmitting an optical pulse signal to a tested object; receiving a reflected pulse signal corresponding to the optical pulse signal; sampling the reflected pulse signal to obtain a sampling result; and determining a feature value of the reflected pulse signal on the basis of the sampling result, calculating, on the basis of a preset response function of a detection apparatus that emits the optical pulse signal, a pulse energy value corresponding to the feature value, and calculating the reflectivity of the tested object on the basis of the pulse energy value. According to the reflectivity measurement method, the reflectivity measurement apparatus (1000), the movable platform (1100) and the computer-readable storage medium of the embodiments, a pulse energy value of a received reflected pulse signal is calculated on the basis of a preset response function of a detection apparatus that emits an optical pulse signal, and the reflectivity of a tested object is calculated on the basis of the pulse energy value, such that an accurate reflectivity measurement result can be efficiently obtained.

Description

Reflectance measuring method, device, movable platform and computer readable medium

Manual

Technical field

This application generally relates to the field of laser detection technology, and more specifically relates to a reflectance measurement method, device, movable platform, and computer-readable storage medium.

Background technique

The three-dimensional point cloud detection system including lidar emits pulsed laser light from the transmitting end, which is reflected by the object, and the receiving end of the detection system receives the reflected pulse to obtain the object's spatial position and reflectivity information. There are different objects in the actual scene, and the reflectivity between different measured objects is different. Reflectance supplements information about another dimension of the surface of the measured object, which can further help point cloud-based object detection and recognition, high-precision map mapping, and so on. Therefore, the measurement of reflectivity is very important.

Summary of the invention

The embodiment of the present application provides a reflectivity measurement solution, which can efficiently obtain accurate reflectivity measurement results. The following briefly describes the reflectance measurement scheme proposed in the present application, and more details will be described in the specific implementation in conjunction with the accompanying drawings.

According to one aspect of the present application, there is provided a method for measuring reflectivity, the method comprising: transmitting a light pulse signal to an object to be measured; receiving a reflected pulse signal corresponding to the light pulse signal; sampling the reflected pulse signal Obtain the sampling result; determine the characteristic value of the reflected pulse signal based on the sampling result, calculate the pulse energy value corresponding to the characteristic value based on the preset response function of the detection device emitting the optical pulse signal, and based on the The pulse energy value calculates the reflectivity of the measured object.

According to another aspect of the present application, there is provided a reflectance measuring device, the device comprising: a transmitter, a receiver, a sampler, and a processor, wherein: the transmitter is used to transmit a light pulse signal to an object to be measured; The receiver is used for receiving the reflected pulse signal corresponding to the optical pulse signal; the sampler is used for sampling the reflected pulse signal to obtain a sampling result; the processor is used for determining the reflected pulse signal based on the sampling result Calculate the pulse energy value corresponding to the characteristic value based on the preset response function of the detection device emitting the optical pulse signal, and calculate the reflectance of the measured object based on the pulse energy value.

According to another aspect of the present application, there is provided a movable platform, the movable platform comprising: a fuselage; a power system installed on the fuselage for providing movement power; the above-mentioned reflectance measuring device, installed On the fuselage, it is used to perceive the environment where the movable platform is located and generate point cloud information.

According to yet another aspect of the present application, a computer-readable storage medium is provided, and a computer program is stored on the computer-readable storage medium, and the computer program executes the above-mentioned reflectance measurement method during operation.

The reflectance measurement method, device, movable platform, and computer-readable storage medium according to the embodiments of the present application calculate the pulse energy value of the received reflected pulse signal based on the preset response function of the detection device that emits the optical pulse signal, and Calculating the reflectance of the measured object based on the pulse energy value can efficiently obtain accurate reflectance measurement results.

Description of the drawings

Fig. 1 shows a schematic flowchart of a method for measuring reflectivity according to an embodiment of the present application.

Fig. 2 shows a schematic flowchart of a first obtaining process of a preset response function of a detection device used in a method for measuring reflectivity according to an embodiment of the present application.

FIG. 3 shows a schematic diagram of a first calibration scene of the detection device used in the reflectance measurement method according to an embodiment of the present application.

FIG. 4 shows a schematic diagram of a second calibration scene of the detection device used in the method for measuring reflectivity according to an embodiment of the present application.

FIG. 5 shows a schematic diagram of a third calibration scene of the detection device used in the reflectance measurement method according to an embodiment of the present application.

Fig. 6 shows a schematic diagram of a second acquisition process of the preset response function of the detection device used in the method for measuring reflectivity according to an embodiment of the present application.

Fig. 7 shows a schematic diagram of a third acquisition process of the preset response function of the detection device used in the method for measuring reflectivity according to an embodiment of the present application.

Figures 8A and 8B show schematic diagrams of receiving multiple reflected pulse signals and including additional reflected signals of the detection device itself in the method for measuring reflectivity according to an embodiment of the present application.

9A and 9B show schematic diagrams of multiple reflected pulse signals received in the method for measuring reflectivity according to an embodiment of the present application and which are true reflected signals of multiple measured objects.

Fig. 10 shows a schematic block diagram of a reflectance measuring device according to an embodiment of the present application.

Fig. 11 shows a schematic block diagram of a movable platform according to an embodiment of the present application.

Detailed ways

In order to make the objectives, technical solutions, and advantages of the present application more obvious, the exemplary embodiments according to the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited by the exemplary embodiments described herein.

In the following description, a lot of specific details are given in order to provide a more thorough understanding of this application. However, it is obvious to those skilled in the art that this application can be implemented without one or more of these details. In other examples, in order to avoid confusion with this application, some technical features known in the art are not described.

It should be understood that this application can be implemented in different forms and should not be construed as being limited to the embodiments presented here. On the contrary, the provision of these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

The purpose of the terms used here is only to describe specific embodiments and not as a limitation of the present application. When used herein, the singular forms "a", "an" and "the/the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "composition" and/or "including", when used in this specification, determine the existence of the described features, integers, steps, operations, elements and/or components, but do not exclude one or more other The existence or addition of features, integers, steps, operations, elements, parts, and/or groups. As used herein, the term "and/or" includes any and all combinations of related listed items.

In order to thoroughly understand this application, detailed steps and detailed structures will be presented in the following description to explain the technical solutions proposed by this application. In addition to the implementation exceptions described in detail in this application, this application may also have other implementation modes.

Radar is an active sensing sensor. Its basic principle is that the radar actively emits light pulse signals. The signal encounters objects in the propagation path and produces reflected echoes. Part of the echo signals are captured by the radar's receiving module, which is transmitted and received by the radar. The time difference between the signals calculates the depth of the measured object from the radar. According to the radar's transmitting direction, the angle information of the measured object relative to the radar is obtained. Based on the depth and angle information, the three-dimensional space position of the measured object relative to the radar can be calculated.

In addition to outputting the three-dimensional spatial position information of the measured object, the radar can also output the reflectance information of the measured object. Reflectance can provide important information about the surface of the measured object, thereby optimizing algorithms based on point cloud segmentation, clustering, visualization, and high-precision map mapping. The reflectance measurement can be based on the following physical model described in formula (1):

In the physical model, ρ is a reflectivity of the measured object, P _e is the energy of the emitted light pulses, P _r is the received energy of the reflected pulse, D _r is the receive aperture, η atmospheric attenuation and energy systems, L Is the depth of the measured object from the radar, and α is the incident angle of the light hitting the measured object.

For a given detection device, P _e , _Dr and η can be obtained through pre-measurement, while α and L are independent of the reflectivity of the measured object surface, where L is calculated by the time difference between the radar transmitting and receiving pulse signals, And α can be calculated by fitting the surface normal vector and emission direction of the measured object with multiple consecutive points. Therefore, in a signal processing process of light emission/reception, in order to calculate the reflectivity of the measured object surface, it is mainly necessary to calculate P _r . Among them, the detection device in this application includes but is not limited to radar, and the radar in this application includes but is not limited to: lidar, electromagnetic wave radar, millimeter wave radar, or ultrasonic radar.

The following describes a schematic flowchart of a method 100 for measuring reflectance according to an embodiment of the present application with reference to FIG. 1. As shown in FIG. 1, the reflectance measurement method 100 may include the following steps:

In step S110, a light pulse signal is emitted to the object to be measured.

In step S120, a reflected pulse signal corresponding to the optical pulse signal is received.

In the embodiment of the present application, a detection device may be used to transmit a light pulse signal to the object to be measured, and receive a reflected pulse signal corresponding to the light pulse signal. Wherein, the detection device includes, but is not limited to, laser radar, electromagnetic wave radar, millimeter wave radar, or ultrasonic radar.

In step S130, the reflected pulse signal is sampled to obtain a sampling result.

In an embodiment of the present application, the reflected pulse signal can be sampled based on a time-to-digital converter (TDC). Among them, sampling the reflected pulse signal based on the time-to-digital converter is to set multiple trigger voltage thresholds, for example, expressed as {V1, V2, V3,..., Vn} (where n is a natural number), and each sampling is performed on the rising edge of the signal and When the falling edge voltage reaches the set voltage threshold, the sampling is triggered, and the corresponding time information is recorded, for example, expressed as {(t11,t12),(t21,t22),...,(tn1,tn2)}, so as to obtain the sampling result p = {(V1, t11, t12), (V2, t21, t22),..., (Vn, tn1, tn2)}. Therefore, sampling the reflected pulse signal based on the time-to-digital converter may include: multi-channel sampling of the reflected pulse signal, each sampling obtains a rising edge sampling point and a falling edge sampling point, the rising edge sampling point and The falling edge sampling points have the same voltage value and different time values.

In another embodiment of the present application, the reflected pulse signal can be sampled based on an analog-to-digital converter (ADC). Among them, the sampling of the reflected pulse signal based on the analog-digital converter is sampling at equal time intervals, that is, the reflected pulse signal is sampled every fixed time, and the voltage information corresponding to each time point is recorded, for example, expressed as {V1,V2,V3 ,...,Vn} (where n is a natural number), so as to obtain the sampling result p={(t1,V1),(t2,V2),(t3,V3),...,(tn,Vn)}. Therefore, sampling the reflected pulse signal based on the analog-digital converter may include: sampling the reflected pulse signal at equal intervals to obtain multiple sampling points, and the equal interval sampling refers to sampling the reflected pulse signal at regular intervals. Once, each sampling point corresponds to a voltage value and a time value.

In the following description of the present application, the description is mainly based on sampling the reflected pulse signal based on a time-to-digital converter, but it should be understood that the solution of the present application is also applicable to a scenario where the reflected pulse signal is sampled based on an analog-digital converter.

In step S140, the characteristic value of the reflected pulse signal is determined based on the sampling result, the pulse energy value corresponding to the characteristic value is calculated based on the preset response function of the detection device emitting the optical pulse signal, and based on the The pulse energy value calculates the reflectivity of the measured object.

As mentioned above, the calculation of reflectivity can be based on the physical model described in the above formula (1), because P _e , _Dr and η in the model are all related to the detection device and can be obtained through pre-measurement, α and the measured The reflectivity of the object surface is irrelevant. Therefore, in the embodiment of this application, these parameters can be abstracted as a coefficient k, and it is assumed that only normal incidence is considered, that is, α=0, to simplify the following model, such as formula (2) Shown:

ρ=kL ² P _r formula (2)

In formula (2):

The depth L of the measured object from the detection device can be obtained by calculation. Therefore, only the energy P _{r of the} received reflected pulse needs to be calculated to obtain the reflectance ρ of the measured object.

The energy P _r of the received reflected pulse is obtained based on the received reflected pulse signal. Assuming that the received reflected pulse signal is expressed as p, in the embodiment of the present application, a characteristic value (also It is called a characterization quantity), for example expressed as x, and P _r is calculated based on the characteristic value, where P _r =f(x), where f(x) is the preset value of the detection device that emits the optical pulse signal in step S110 Assume that the response function is a monotonic mapping relationship between x and f(x).

In the embodiment of the present application, the determining the characteristic value of the reflected pulse signal based on the sampling result may include: determining the value of any parameter of the echo corresponding to the sampling result based on the sampling result , As the characteristic value of the reflected pulse signal; or determine the value of multiple parameters of the echo corresponding to the sampling result based on the sampling result, and determine the value of the multiple parameters based on the combination of the multiple parameter values The characteristic value of the reflected pulse signal. Among them, the parameters of the echo may include, but are not limited to, the pulse width (that is, the difference between the time for the rising edge and the falling edge to reach a certain voltage value), the sum of multiple pulse widths, the echo height, or the echo area (such as the integral height). ) One or more of.

For example, use the information of p to obtain the scalar x through the mapping relationship of x=u(p), and then use other methods such as polynomial, exponential function, power function, spline and other parameterized function forms or look-up tables to establish P _r = Model of f(x). Among them, the way to obtain u(p) includes, but is not limited to, the difference between the rising edge and the falling edge obtained by a single-channel sampling of the time-to-digital converter (ie pulse width), the sum of multiple pulse widths, the echo height, and the echo area (Such as integral height) or the feature value estimated through the above combination of features, etc. Taking the pulse width collected by the first-stage time-to-digital converter (the aforementioned threshold voltage is V1) as an example, the characteristic value x=u(p) is as shown in formula (4):

x=u(p)=t12-t11 Formula (4)

For another example, taking a power function as an example to establish f(x), the energy of the reflected pulse P _r =f(x) is as shown in formula (5):

P _r =f(x)=ax ^b +cx ^d +e formula (5)

Based on the above formula (2) to formula (5), the characteristic value of the reflected pulse signal, the pulse energy value of the reflected pulse signal, and the reflectivity of the measured object can be calculated. Among them, the coefficient in formula (5) can be obtained by calibration. In addition, in the embodiment of the present application, since the coefficient k expressed by formula (3) and the preset response function f(x) are related to the detection device that emits the optical pulse signal in step S110, the detection device can be Perform calibration to obtain the function model of the preset response function f(x) and its coefficients. The calibration process is further described below. When the preset response function f(x) of the detection device is obtained through calibration, the reflection can be calculated based on the preset response function f(x) and the characteristic value of the reflected pulse signal x=u(p) The pulse energy value P _r of the pulse signal, and the calculated pulse energy value is the pulse energy value associated with the reflected pulse signal itself.

In another embodiment of the present application, the coefficient k and the preset response function f(x) can be combined for unified calibration, using the following relationship shown in formula (6):

Based on this, g(x) can be obtained by using a calibration plate with known true values of reflectivity and distance, and reflectivity information can be obtained ^{through ρ=g(x)·L 2 when calculating the point cloud in real time.} In this embodiment, g(x) is used as the preset response function of the detection device. When the preset response function g(x) of the detection device is obtained by calibration, the pulse energy value kP of the reflected pulse signal can be calculated based on the preset response function g(x) and the characteristic value of the reflected pulse signal x=u(p) _r , the calculated pulse energy value is the pulse energy value associated with the reflected pulse signal itself and the system parameter k of the detection device.

The calibration process of the detection device emitting the optical pulse signal in step S110 is described below with reference to FIG. 2. The calibration process refers to obtaining f(x) or g(x) model parameters through a certain method.

FIG. 2 shows a schematic flowchart of the first obtaining process 200 of the preset response function of the detection device used in the reflectance measurement method of the embodiment of the present application. As shown in FIG. 2, the first acquisition process 200 may include the following steps:

In step S210, a light pulse signal is transmitted to a plurality of objects with known true reflectivity values.

In step S220, the reflected pulse signals of the plurality of objects with known true reflectivities are received.

In step S230, the reflected pulse signal of each object is sampled to obtain a sampling result.

In step S240, the characteristic value of the reflected pulse signal of each object is determined based on the sampling result of the reflected pulse signal of each object.

In step S250, a relationship curve is fitted based on the true value of the reflectivity of each object, the true value of the distance between each object and the detection device, and the characteristic value of the reflected pulse signal of each object to obtain The preset response function.

In an embodiment of the present application, the multiple objects with known true reflectivity values in step S210 can be placed on multiple calibration targets, and each target is placed on one type of true reflectivity object or multiple true reflectivity objects. For objects, the distance and/or height of each target from the detection device are not completely the same. For example, as shown in the first calibration scene shown in Figure 3, a plurality of calibration targets are set in the scene, and a variety of objects with known true reflectivity values are placed on each target. The distance and height of each target from the detection device are different. the same. In this embodiment, the detection device can use a scanning mode (that is, the light emission direction is continuously changed) to emit the light pulse signal. In addition, the position of each target can be accurately calculated, so that the obtained energy value covers all possible situations, and at the same time, a trade-off is made between the size of the target and the acquisition time to ensure that there are enough points to meet the calculation requirements.

In another embodiment of the present application, multiple objects with known true reflectivity values in step S210 can be placed on the same calibration target, and the detection device is placed on a target object (such as On a guide rail or a moving trolley, etc.), the detection device emits a light pulse signal to the calibration target while moving, and the detection device is at a different distance from the calibration target when it moves to different positions. When moving to different positions, light pulse signals are respectively emitted to the calibration target. For example, as shown in the second calibration scene shown in FIG. 4, the detection device moves on the guide rail. The target includes high-reflectivity objects, low-reflectivity objects and total reflection sheets, and the detection device adopts a scanning method. In this embodiment, the detection device can use a scanning method to emit light pulse signals to emit light pulse signals to multiple objects with known reflectivity true values at different positions on the same calibration target. Among them, the scanning mode refers to the rotation of the prism of the detection device, and the laser emission direction continuously changes. In addition, the moving speed of the detection device can be designed to ensure that enough points are collected to meet the calculation requirements and will not contain too many redundant points.

In another embodiment of the present application, the multiple objects with known true reflectivity values in step S210 may be placed on the same calibration target, and the calibration target is placed on a target object that can move the calibration target (such as On a guide rail or a moving trolley, etc.), the calibration target receives a light pulse signal from the detection device while moving, and the calibration target has a different distance from the detection device when it moves to different positions, and the detection devices are respectively The light pulse signal is emitted to the calibration target moved to a different position. For example, as shown in the third calibration scene shown in FIG. 5, the target moves on the guide rail. The target includes high-reflectivity objects, low-reflectivity objects and total reflection sheets, and the detection device adopts a scanning method. In this embodiment, the detection device can use a scanning method to emit light pulse signals to emit light pulse signals to multiple objects with known reflectivity true values at different positions on the same calibration target. In addition, the speed of the target movement can be designed to ensure that enough points are collected to meet the calculation requirements and will not contain too many redundant points.

In another embodiment of the present application, the multiple objects with known true reflectivity values in step S210 may be placed on multiple calibration targets, and an object with a reflectivity is placed on each target, and the multiple calibration targets Placed in a predetermined position in turn, the detection device is placed on a target object (such as a guide rail or a mobile trolley, etc.) that can move the detection device, and the detection device moves to a calibration target at the predetermined position. Transmitting a light pulse signal, the detection device is at a different distance from the calibration target at the predetermined position when moving to different positions, and the detection device emits to the calibration target at the predetermined position when moving to different positions Light pulse signal. For example, in the second calibration scene shown in Figure 4, three targets can also be used, one of which contains a high-reflectivity object, the other contains a low-reflectivity object, and the third target contains a total reflection sheet, and the detection device The signal can be transmitted in a fixed-point mode or a scanning mode. Among them, the fixed-point method means that the laser emission direction of the detection device does not change. In this embodiment, the detection device can use a fixed-point method (that is, the light emitting direction remains unchanged) or a scanning method to emit light pulse signals to emit light pulses to multiple objects with known reflectivity at similar positions on different calibration targets. Light pulse signal. In addition, the moving speed of the detection device can be designed to ensure that enough points are collected to meet the calculation requirements and will not contain too many redundant points.

In another embodiment of the present application, the multiple objects with known true reflectivity values in step S210 may be placed on multiple calibration targets, and an object with a reflectivity is placed on each target, and the multiple calibration targets Placed in turn on a target object (such as a guide rail or a mobile car, etc.) that can move the calibration target, each calibration target receives an optical pulse signal from the detection device while moving, and each calibration target is moving to a different position The distance between the time and the detection device is different, and the detection device respectively emits light pulse signals to any calibration target that moves to different positions. For example, in the third calibration scene shown in FIG. 5, three targets may also be used, and each target only contains an object with one type of reflectivity, and the detection device emits signals in a fixed-point mode or a scanning mode. In this embodiment, the detection device can use a fixed-point method (that is, the light emitting direction remains unchanged) or a scanning method to emit light pulse signals to emit light pulses to multiple objects with known reflectivity at similar positions on different calibration targets. Light pulse signal. In addition, the speed of the target movement can be designed to ensure that enough points are collected to meet the calculation requirements and will not contain too many redundant points.

The above-mentioned calibration scenarios have their own advantages: the first calibration scenario has the advantage that it does not require moving detection devices and targets, and the processing time is fast. The advantage of the second calibration scenario is that the collected data is continuous and the amount of data is sufficient. The advantages of the third calibration scene are the same as those of the second calibration scene. The last two scenes are not shown in the drawings, and their advantages are similar to the second calibration scene and the third calibration scene respectively. In actual operation, you can select the appropriate calibration scene according to your needs. Of course, the above scenes are only exemplary, and any other suitable calibration scenes can also be adopted.

Further, in the above-mentioned calibration scene, each of the multiple objects with known true reflectivity values in step S210 has different reflectivity, and the multiple objects with known true reflectivity values may satisfy at least one of the following conditions: The reflectance of some objects in the plurality of objects is less than or equal to a first threshold; the reflectance of some objects in the plurality of objects is greater than or equal to a second threshold, wherein the first threshold is less than or equal to the second threshold ; Part of the objects in the plurality of objects are total reflection objects. Among them, objects with reflectivity less than or equal to the first threshold can be defined as objects with low reflectivity, and objects with reflectivity greater than or equal to the second threshold can be defined as objects with high reflectivity. In this embodiment, one or a combination of objects with high reflectivity, objects with low reflectivity, and objects with total reflectivity can be used for calibration, so that the final calibration result is more accurate.

_{After implementing the above calibration scenario, ρ i} /L _i ² corresponding to each sampling point i can be calculated according to multiple sets of true reflectance values and distance true values, and the characteristic value x _i can be calculated from the echo information of the corresponding sampling points. Among them, the true value of reflectivity can be measured by a measurement method such as a spectrometer, and the true value of the distance can be measured by various ranging methods such as radar. Then, according to the obtained characteristic value x and the corresponding ρ/L ² , the relationship between the two is fitted to obtain g(x). _{Similarly, ρ i} /kL _i ² corresponding to each sampling point i can be calculated according to multiple sets of true reflectance values, distance true values, and coefficient k true values, and the characteristic value x _i can be calculated from the echo information of the corresponding sampling points. Then, according to the obtained eigenvalue x and the corresponding ρ/kL ² , the relationship between the two is fitted to obtain f(x).

Due to individual differences in detection devices, the preset response function of each detection device may be different. Therefore, when a detection device is used for reflectance measurement, it is necessary to obtain the preset response function of the detection device. In an embodiment of the present application, the detection device can be directly calibrated through the above-mentioned calibration method to obtain the preset response function of the detection device. In another embodiment of the present application, the preset response function of other detection devices may be obtained based on the preset response function of the calibrated detection device. Among them, the calibrated detection device can be called a gold machine or a reference detection device. The following is an example when the preset response function of the reference detection device is g(x).

In an example, the preset response function of other detection devices to be calibrated can be obtained by further calibrating the preset response function of the reference detection device. In this example, the reference detection device can be placed in the calibration scene, some objects on several targets can be selected, and the corresponding true value ρ _i /L _i ² and characteristic value x _i can be calculated. Then, use these characteristic values and the g(x) of the reference detection device to calculate a series of calculated values g(x _i ) before calibration. Take these true and calculated values as calibration points, as shown by the points on the curve in Figure 6. Finally, fit the calculated curve of g(x) and the true value ρ/L ² to obtain h[g(x )], as shown by the curve in Figure 6. Thereby, the preset response function of the detection device to be calibrated is obtained.

In another example, the functional form of other detection devices to be calibrated can continue to adopt the function form of the preset response function of the reference detection device, but the characteristic value of the detection device to be calibrated can be based on the characteristics of the reflected pulse signal received by the reference detection device The value is calibrated. In this example, you can place the reference detection device in the calibration scene, select some objects on several targets, calculate the corresponding true value ρ/L ² and the characteristic value, as the calibration point, as shown in Figure 7 on the curve. As shown, the curve shown in Fig. 7 is a fitting curve of the reference detection device. Then, remove the reference detection device, place the detection device to be calibrated in the same position, select the same object on the same target (same as the true value ρ/L ^{2 of the} calibration point), and calculate the corresponding characteristic value, as shown in the curve in Figure 7 The outer dots are shown. Finally, calculate the ratio of the characteristic value of the point on the curve to the characteristic value of the point outside the curve, fit the calibration curve m(x) according to the characteristic value and ratio of the point outside the curve, and substitute the characteristic value of the detection device to be calibrated into the calibration curve After m(x), a new characteristic value is obtained, which can be brought into the preset response function of the reference detection device, that is, the preset response function of the detection device to be calibrated is g[m(x)].

The above exemplarily shows that the preset response function of the detection device is obtained by means of calibration or calibration.

In another embodiment of the present application, the preset response function of the detection device emitting the optical pulse signal in step S110 may also be a neural network trained in advance based on the true value of the sampling result and the true value of the pulse energy value. In this embodiment, the received original signal p can be directly used as the vector x to construct f(x), f(x) can be a neural network, the input is the sampling result of the received reflected pulse signal, and the output is the The pulse energy value of the received reflected pulse signal, so the neural network can be trained using the true value of the reflected pulse signal sampling result and the corresponding pulse energy value. Based on the trained neural network, when the sampling result of any reflected pulse signal is obtained, the pulse energy value corresponding to the sampling result can be calculated based on the neural network, so as to calculate the corresponding reflectivity.

In a further embodiment of the present application, receiving the reflected pulse signal corresponding to the optical pulse signal in step S120 may include: receiving multiple reflected pulse signals corresponding to the optical pulse signal, wherein the multiple reflected pulse signals include The additional reflection signal of the detection device itself and the real reflection signal of the measured object. When the additional reflection signal and the real reflection signal are fused, the calculating the reflectance of the measured object may further include : Determining the characteristic value of the fused reflection signal and the characteristic value of the additional reflection signal; determining the characteristic value of the true reflection signal based on the characteristic value of the fusion reflection signal and the characteristic value of the additional reflection signal; Calculate the reflectance of the measured object based on the characteristic value of the true reflection signal.

In this embodiment, the reflectivity calculation problem under the influence of multi-pulse is considered. In some cases, the detection device may receive more than one pulse during a laser emission-reception process. For example, because the optical system of the detection device may be designed with the emission-reception co-optical axis, the optical system itself will reflect A small part of the laser energy, so that an additional signal caused by a system is received before the real pulse signal. In order to distinguish each other, the real reflected pulse signal can be referred to as the real reflected signal, and the extra signal caused by the system can be referred to as the extra reflected signal.

This will be described with reference to FIGS. 8A and 8B. As shown in Figure 8A, when the detection device is far away from the measured object, the additional reflected signal T0 and the real reflected signal T1 can be completely separated from each other in waveform. At this time, the reflectivity of the measured object may not be calculated. Consider the existence of T0. As shown in Fig. 8B, when the detection device is close to the measured object, T1 and T0 are fused. At this time, it is necessary to remove the influence of T0 when calculating the reflectivity of the measured object. And T0 is caused by the system, so for a certain system, this part belongs to known information, which can be obtained by calibrating each detection device before leaving the factory. When calculating the reflectance with the measured object, the calibration result is included. The influence of T0 can be removed. For example, when the echo area is used as the characteristic value of the reflected pulse signal, the characteristic information of the detection device T0 can be counted when calibrated before leaving the factory, for example, the average value is

Alternatively, the relationship between the echo area and different motor angle combinations/different positions in the field of view/rising edge slope, etc. is expressed as A(T0)=1(...). Based on this, when calculating the characteristic value of the reflected pulse signal, the overall echo area after fusion can be calculated first, and then the area of the additional reflected signal T0 can be subtracted to obtain the characteristic value of the true reflected signal. Taking the statistical average value as an example, the characteristic value of the true reflection signal is shown in the following formula (7):

In another embodiment of the present application, when multiple reflected pulse signals corresponding to one optical pulse signal are received in step S120, and wherein the multiple reflected pulse signals include true reflected signals of multiple measured objects, The calculating the reflectivity of the measured object may further include: determining the characteristic value of each true reflection signal among the real reflection signals of the plurality of measured objects; calculating the characteristic value of each true reflection signal based on the characteristic value of each true reflection signal. The reflectance of each measured object in the plurality of measured objects is corrected by combining the point cloud in the offline post-processing to correct the calculated reflectance of each measured object.

In this embodiment, the reflectivity calculation problem when there are multiple real reflected signals under the influence of multi-pulse is considered. Generally, the following two situations will cause multiple true reflection signals to appear. This will be described in conjunction with FIG. 9A and FIG. 9B. As shown in Fig. 9A, since the light spot of the detection device has a certain size, one light spot may hit two or more objects before and after, so that two or more pulse signals T1 and T2 are received at the receiving end. As shown in Figure 9B, when the measured object 1 is a transparent object (such as glass), part of the energy may pass through it to reach the measured object 2 behind. In this scenario, the receiving end of the detection device may also receive two One or more pulse signals. In the above case, it is still possible to calculate the pulse signal strength of each echo from the measured object. In real-time calculation, the intensity of the echo signal is directly used to convert the reflectivity, so the result will be coupled into various information of the light spot hitting the object. In offline post-processing, combined with point cloud information, this part of the information can be inferred and decoupled, thereby correcting the reflectance information.

In a further embodiment of the present application, the method 100 may further include (not shown in FIG. 1): after calculating the reflectance of the measured object based on the pulse energy value, according to the measured object Reflectance for object detection and recognition, or for map surveying and mapping.

Based on the above description, the reflectance measurement method according to the embodiment of the present application calculates the pulse energy value of the received reflected pulse signal based on the preset response function of the detection device that emits the optical pulse signal, and calculates the pulse energy value based on the pulse energy value. Measure the reflectivity of the object, can efficiently obtain accurate reflectivity measurement results.

The above exemplarily describes the reflectance measurement method according to the embodiment of the present application. The reflectance measuring device 1000 provided according to another aspect of the present application will be described below with reference to FIG. 10. The reflectance measurement device 1000 according to the embodiment of the present application may be used to implement the reflectance measurement method 100 according to the embodiment of the present application described above. For the sake of brevity, only the main structure and function of the reflectance measuring device 1000 are described below, and some of the specific details already described above are omitted.

As shown in FIG. 10, the reflectance measurement device 1000 may include a transmitter 1010, a receiver 1020, a sampler 1030, and a processor 1040, wherein the transmitter 1010 is used to transmit an optical pulse signal to the object to be measured. The receiver 1020 is used to receive the reflected pulse signal corresponding to the optical pulse signal. The sampler 1030 is used to sample the reflected pulse signal to obtain a sampling result. The processor 1040 is configured to determine the characteristic value of the reflected pulse signal based on the sampling result, calculate the pulse energy value corresponding to the characteristic value based on the preset response function of the detection device emitting the optical pulse signal, and The reflectance of the object to be measured is calculated based on the pulse energy value. Exemplarily, the reflectance measuring device 1000 may include, but is not limited to, laser radar, electromagnetic wave radar, millimeter wave radar, or ultrasonic radar.

According to another aspect of the present application, a movable platform is also provided. The following describes a schematic block diagram of a movable platform 1100 according to another aspect of the present application in conjunction with FIG. 11. As shown in FIG. 11, the movable platform 1100 may include a body 1110, a power system 1120, and a reflectance measuring device 1130. Wherein, the power system 1120 can be installed on the fuselage 1110 to provide power, where the power can be mobile power or flight power. The reflectance measuring device 1130 can be installed on the fuselage 1110 for sensing the environment where the movable platform 1100 is located and generating point cloud information. The reflectance measuring device 1130 may be the reflectance measuring device 1000 described above. Exemplarily, the movable platform 1100 may be a drone. Exemplarily, the reflectance measuring device 1130 may include, but is not limited to, laser radar, electromagnetic wave radar, millimeter wave radar, or ultrasonic radar.

According to another aspect of the present application, there is also provided a computer-readable storage medium having a computer program stored on the computer-readable storage medium, and the computer program, when run by the above-mentioned processor, executes the Reflectance measurement method. The computer-readable storage medium may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk Read only memory (CD-ROM), USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

Based on the above description, the reflectance measurement method, device, movable platform, and computer-readable storage medium according to the embodiments of the present application calculate the value of the received reflected pulse signal based on the preset response function of the detection device that emits the optical pulse signal. Pulse energy value, and calculate the reflectance of the measured object based on the pulse energy value, which can efficiently obtain accurate reflectance measurement results.

Although the exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above-described exemplary embodiments are merely exemplary, and are not intended to limit the scope of the present application thereto. A person of ordinary skill in the art can make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

A person of ordinary skill in the art may realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for specific applications to implement the described functions, but such implementation should not be considered beyond the scope of this application.

In the several embodiments provided in this application, it should be understood that the disclosed device and method may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or It can be integrated into another device, or some features can be ignored or not implemented.

In the instructions provided here, a lot of specific details are explained. However, it can be understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail, so as not to obscure the understanding of this specification.

Similarly, it should be understood that, in order to simplify this application and help understand one or more of the various aspects of the invention, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment or figure. , Or in its description. However, the method of this application should not be interpreted as reflecting the intention that the claimed application requires more features than those clearly stated in the claims. More precisely, as reflected in the corresponding claims, the point of the invention is that the corresponding technical problems can be solved with features that are less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are thus clearly incorporated into the specific embodiment, wherein the claims themselves are all regarded as separate embodiments of the present application.

Those skilled in the art can understand that, in addition to mutual exclusion between the features, any combination of all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and any method or device disclosed in this way can be used in any combination. Processes or units are combined. Unless expressly stated otherwise, the features disclosed in this specification (including the accompanying claims, abstract and drawings) may be replaced by alternative features that provide the same, equivalent or similar purpose.

In addition, those skilled in the art can understand that although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments means that they are within the scope of the present application. Within and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

The various component embodiments of the present application may be implemented by hardware, or by software modules running on one or more processors, or by a combination of them. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) may be used in practice to implement some or all of the functions of some modules according to the embodiments of the present application. This application can also be implemented as a device program (for example, a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing the present application may be stored on a computer-readable storage medium, or may have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be constructed as a limitation to the claims. The application can be realized by means of hardware including several different elements and by means of a suitably programmed computer. In the unit claims listing several devices, several of these devices may be embodied in the same hardware item. The use of the words first, second, and third, etc. do not indicate any order. These words can be interpreted as names.

The above are only specific implementations of this application or descriptions of specific implementations. The scope of protection of this application is not limited to this. Anyone skilled in the art can easily fall within the technical scope disclosed in this application. Any change or replacement should be covered within the scope of protection of this application. The protection scope of this application shall be subject to the protection scope of the claims.

Claims (64)

1. A method for measuring reflectivity, characterized in that the method includes:

   Transmit light pulse signal to the measured object;

   Receiving a reflected pulse signal corresponding to the optical pulse signal;

   Sampling the reflected pulse signal to obtain a sampling result;

   Determine the characteristic value of the reflected pulse signal based on the sampling result, calculate the pulse energy value corresponding to the characteristic value based on the preset response function of the detection device emitting the optical pulse signal, and calculate based on the pulse energy value The reflectivity of the measured object.
2. The method according to claim 1, wherein the determining the characteristic value of the reflected pulse signal based on the sampling result comprises:

   Determine the value of any parameter of the echo corresponding to the sampling result based on the sampling result as the characteristic value of the reflected pulse signal; or

   The values of multiple parameters of the echo corresponding to the sampling result are determined based on the sampling result, and the characteristic value of the reflected pulse signal is determined based on the combination of the values of the multiple parameters.
3. The method according to claim 2, wherein the parameters of the echo include one or more of pulse width, sum of multiple pulse widths, echo height, or echo area.
4. The method according to any one of claims 1 to 3, wherein the preset response function is obtained by calibrating the detection device.
5. The method according to claim 4, wherein the calibration comprises the following operations performed by the detection device:

   Transmit light pulse signals to multiple objects with known true reflectivity values;

   Receiving the reflected pulse signals of the plurality of objects with known true reflectivities;

   Sampling the reflected pulse signal of each object to obtain a sampling result;

   Determining the characteristic value of the reflected pulse signal of each object based on the sampling result of the reflected pulse signal of each object;

   Fitting the relationship curve based on the true value of the reflectivity of each object, the true value of the distance between each object and the detection device, and the characteristic value of the reflected pulse signal of each object, to obtain the preset Response function.
6. The method according to claim 5, wherein the plurality of objects with known true reflectivity values are placed on a plurality of calibration targets, or each target is placed with objects with multiple reflectances, and the plurality of The distance and/or height of the calibration target from the detection device are not completely the same.
7. The method according to claim 5, wherein the multiple objects with known true reflectivity values are placed on the same calibration target, and the detection device is placed on a target object that can move the detection device, The detection device emits a light pulse signal to the calibration target while moving, and the detection device has a different distance from the calibration target when it moves to different positions.
8. 8. The method according to claim 7, wherein the transmitting light pulse signals to multiple objects with known true reflectivity values comprises:

   The detection device respectively emits light pulse signals to the calibration target when it moves to different positions.
9. The method according to claim 5, wherein the multiple objects with known true reflectivity values are placed on the same calibration target, and the calibration target is placed on a target object capable of moving the calibration target, The calibration target receives a light pulse signal from the detection device while moving, and the calibration target has a different distance from the detection device when it moves to different positions.
10. 9. The method according to claim 9, wherein the transmitting light pulse signals to a plurality of objects with known true reflectivity values comprises:

    The detection device respectively emits light pulse signals to the calibration targets moved to different positions.
11. The method according to any one of claims 6-10, wherein the mode of the detection device emitting light pulse signals is a scanning mode.
12. The method according to claim 5, wherein the plurality of objects with known true reflectivity values are placed on a plurality of calibration targets, and an object with a reflectivity is placed on each target, and the plurality of calibration targets Placed in turn on the target object that can move the calibration target, each calibration target receives a light pulse signal from the detection device while moving, and the distance between each calibration target and the detection device when it moves to a different position different.
13. The method according to claim 12, wherein the transmitting light pulse signals to multiple objects with known true reflectivity values comprises:

    The detection device respectively emits light pulse signals to any calibration target moved to different positions.
14. The method according to claim 5, wherein the plurality of objects with known true reflectivity values are placed on a plurality of calibration targets, and an object with a reflectivity is placed on each target, and the plurality of calibration targets The detection device is placed at a predetermined position in turn, the detection device is placed on a target object that can move the detection device, and the detection device transmits a light pulse signal to a calibration target at the predetermined position while moving, and the detection device When the device moves to different positions, the distance from the calibration target at the predetermined position is different.
15. The method according to claim 14, wherein the transmitting light pulse signals to multiple objects with known true reflectivity values comprises:

    When the detection device moves to different positions, the optical pulse signals are respectively emitted to the calibration targets at the predetermined positions.
16. The method according to any one of claims 12-15, wherein the method for the detection device to emit the optical pulse signal is a fixed-point method.
17. The method according to any one of claims 7-16, wherein the target object is a guide rail or a mobile trolley.
18. The method according to any one of claims 5-17, wherein the reflectivity of each of the plurality of objects with known true reflectivity values is different, and the plurality of objects with known reflectivity true values satisfy At least one of the following conditions:

    The reflectivity of some objects in the plurality of objects is less than or equal to a first threshold;

    The reflectivity of some of the objects in the plurality of objects is greater than or equal to a second threshold, wherein the first threshold is less than or equal to the second threshold;

    Part of the objects in the plurality of objects are total reflection objects.
19. The method according to any one of claims 1 to 3, wherein the preset response function is obtained by calibrating the calibrated response function of the calibrated detection device.
20. The method according to any one of claims 1 to 3, wherein the function form of the preset response function adopts the function form of the calibrated response function of a calibrated detection device, and the function is based on the sampling result The determined characteristic value is calibrated according to the corresponding characteristic value of the calibrated detection device, and the calibrated characteristic value is used to calculate the pulse energy value based on the preset response function.
21. The method according to claim 1, wherein the preset response function is a neural network trained in advance based on the true value of the sampling result and the true value of the pulse energy;

    The determining the characteristic value of the reflected pulse signal based on the sampling result includes: directly using the sampling result as the characteristic value of the reflected pulse signal;

    The calculating the pulse energy value corresponding to the characteristic value based on the preset response function of the detection device emitting the optical pulse signal includes: calculating the pulse energy value corresponding to the sampling result based on the neural network.
22. The method according to any one of claims 1-21, wherein the sampling the reflected pulse signal comprises:

    Multi-channel sampling is performed on the reflected pulse signal, each sampling obtains a rising edge sampling point and a falling edge sampling point, the rising edge sampling point and the falling edge sampling point have the same voltage value and different time values .
23. The method according to claim 22, wherein the sampling of the reflected pulse signal is implemented based on a time-to-digital converter.
24. The method according to any one of claims 1-21, wherein the sampling the reflected pulse signal comprises:

    Sampling the reflected pulse signal at equal intervals to obtain multiple sampling points. The equal interval sampling refers to sampling the reflected pulse signal at regular intervals, and each sampling point corresponds to a voltage value and a time value.
25. The method according to claim 24, wherein the sampling of the reflected pulse signal is implemented based on an analog-to-digital converter.
26. The method according to any one of claims 1-25, wherein the receiving the reflected pulse signal corresponding to the optical pulse signal comprises: receiving a plurality of reflected pulse signals corresponding to the optical pulse signal, wherein The multiple reflected pulse signals include the additional reflected signal of the detection device itself and the real reflected signal of the measured object. When the additional reflected signal and the real reflected signal are fused, the calculated is The reflectivity of the measured object further includes:

    Determining the characteristic value of the fused reflection signal and the characteristic value of the additional reflection signal;

    Determining the characteristic value of the true reflected signal based on the characteristic value of the fused reflected signal and the characteristic value of the additional reflected signal;

    Calculate the reflectance of the measured object based on the characteristic value of the true reflection signal.
27. The method according to claim 26, wherein the characteristic value of the additional reflected signal is calibrated when the detection device leaves the factory.
28. The method according to claim 26 or 27, wherein when the characteristic value is the echo area, the characteristic value of the true reflected signal is equal to the characteristic value of the fused reflected signal minus the additional The characteristic value of the reflected signal.
29. The method according to any one of claims 1-28, wherein the receiving the reflected pulse signal corresponding to the optical pulse signal comprises: receiving a plurality of reflected pulse signals corresponding to the optical pulse signal, wherein The multiple reflected pulse signals include true reflected signals of multiple measured objects, and the calculating the reflectivity of the measured object further includes:

    Determining the characteristic value of each real reflection signal among the real reflection signals of the plurality of measured objects;

    Calculate the reflectance of each measured object in the multiple measured objects based on the characteristic value of each true reflection signal, and combine the point cloud to the calculated value of each measured object in offline post-processing. The reflectivity is corrected.
30. The method according to any one of claims 1-29, wherein the method further comprises: after calculating the reflectivity of the measured object based on the pulse energy value, according to the measured object Reflectivity for object detection and recognition, or for map surveying and mapping.
31. A reflectance measuring device, characterized in that the device includes a transmitter, a receiver, a sampler and a processor, wherein:

    The transmitter is used to emit a light pulse signal to the object to be measured;

    The receiver is used to receive the reflected pulse signal corresponding to the optical pulse signal;

    The sampler is used to sample the reflected pulse signal to obtain a sampling result;

    The processor is configured to determine the characteristic value of the reflected pulse signal based on the sampling result, calculate the pulse energy value corresponding to the characteristic value based on the preset response function of the detection device emitting the optical pulse signal, and based on the The pulse energy value calculates the reflectivity of the measured object.
32. The device according to claim 31, wherein the processor determining the characteristic value of the reflected pulse signal based on the sampling result comprises:

    Determine the value of any parameter of the echo corresponding to the sampling result based on the sampling result as the characteristic value of the reflected pulse signal; or

    The values of multiple parameters of the echo corresponding to the sampling result are determined based on the sampling result, and the characteristic value of the reflected pulse signal is determined based on the combination of the values of the multiple parameters.
33. The device according to claim 32, wherein the parameters of the echo include one or more of pulse width, sum of multiple pulse widths, echo height, or echo area.
34. The device according to any one of claims 31-33, wherein the preset response function is obtained by calibrating the detection device.
35. The device according to claim 34, wherein the calibration comprises the following operations:

    The transmitter is also used to emit light pulse signals to multiple objects with known true values of reflectivity;

    The receiver is further configured to receive reflected pulse signals of the multiple objects with known true reflectivities;

    The sampler is also used to sample the reflected pulse signal of each object to obtain a sampling result;

    The processor is further configured to determine the characteristic value of the reflected pulse signal of each object based on the sampling result of the reflected pulse signal of each object;

    The processor is further configured to fit the relationship based on the true value of the reflectivity of each object, the true value of the distance between each object and the detection device, and the characteristic value of the reflected pulse signal of each object Curve to obtain the preset response function.
36. The device according to claim 35, wherein the plurality of objects with known true reflectivity values are placed on a plurality of calibration targets, or each target is placed with objects with multiple reflectances, and the plurality of The distance and/or height of the calibration target from the detection device are not completely the same.
37. The device according to claim 35, wherein the multiple objects with known true reflectivity values are placed on the same calibration target, and the detection device is placed on a target object capable of moving the detection device, The detection device emits a light pulse signal to the calibration target while moving, and the detection device has a different distance from the calibration target when it moves to different positions.
38. The device according to claim 37, wherein the transmitter is used to emit light pulse signals to a plurality of objects with known true reflectivity values, comprising:

    The transmitter is used to respectively emit light pulse signals to the calibration target when moving to different positions.
39. The device according to claim 35, wherein the plurality of objects with known true reflectivity values are placed on the same calibration target, and the calibration target is placed on a target object capable of moving the calibration target, The calibration target receives a light pulse signal from the detection device while moving, and the calibration target has a different distance from the detection device when it moves to different positions.
40. The device according to claim 39, wherein the transmitter is configured to emit light pulse signals to a plurality of objects with known true reflectivity values, comprising:

    The transmitter is used to respectively emit light pulse signals to the calibration targets moved to different positions.
41. The device according to any one of claims 36-40, wherein the detection device emits a light pulse signal in a scanning mode.
42. The device according to claim 35, wherein the plurality of objects with known true reflectivity values are placed on a plurality of calibration targets, and an object with a reflectivity is placed on each target, and the plurality of calibration targets Placed in turn on the target object that can move the calibration target, each calibration target receives a light pulse signal from the detection device while moving, and the distance between each calibration target and the detection device when it moves to a different position different.
43. The device according to claim 42, wherein the transmitter is configured to emit light pulse signals to a plurality of objects with known true reflectivity values, comprising:

    The transmitter is used to respectively emit light pulse signals to any calibration target moved to different positions.
44. The device according to claim 35, wherein the plurality of objects with known true reflectivity values are placed on a plurality of calibration targets, and an object with a reflectivity is placed on each target, and the plurality of calibration targets The detection device is placed at a predetermined position in turn, the detection device is placed on a target object that can move the detection device, and the detection device transmits a light pulse signal to a calibration target at the predetermined position while moving, and the detection device When the device moves to different positions, the distance from the calibration target at the predetermined position is different.
45. The device according to claim 44, wherein the transmitter is configured to emit light pulse signals to a plurality of objects with known true reflectivity values, comprising:

    The transmitter is used to respectively emit light pulse signals to the calibration targets at the predetermined positions when moving to different positions.
46. The device according to claims 42-45, wherein the mode of the detection device emitting the optical pulse signal is a fixed-point mode.
47. The method according to any one of claims 37-46, wherein the target object is a guide rail or a moving trolley.
48. The device according to any one of claims 35-47, wherein the reflectivity of each of the plurality of objects with known true reflectivity values is different, and the plurality of objects with known reflectivity true values satisfy At least one of the following conditions:

    The reflectivity of some objects in the plurality of objects is less than or equal to a first threshold;

    The reflectivity of some of the objects in the plurality of objects is greater than or equal to a second threshold, wherein the first threshold is less than or equal to the second threshold;

    Part of the objects in the plurality of objects are total reflection objects.
49. The device according to any one of claims 31-33, wherein the preset response function is obtained by calibrating a calibrated response function of a calibrated detection device.
50. The device according to any one of claims 31-33, wherein the functional form of the preset response function adopts the functional form of the calibrated response function of a calibrated detection device, and the sampler is based on the The characteristic value determined by the sampling result is calibrated according to the corresponding characteristic value of the calibrated detection device, and the calibrated characteristic value is used to calculate the pulse energy value based on the preset response function.
51. The device according to claim 31, wherein the preset response function is a neural network trained in advance based on the true value of the sampling result and the true value of the pulse energy value;

    The processor determining the characteristic value of the reflected pulse signal based on the sampling result includes: directly using the sampling result as the characteristic value of the reflected pulse signal;

    The processor calculating the pulse energy value corresponding to the characteristic value based on the preset response function of the detection device emitting the optical pulse signal includes: calculating the pulse energy value corresponding to the sampling result based on the neural network.
52. The device according to any one of claims 31-51, wherein the sampling of the reflected pulse signal by the sampler comprises:

    Multi-channel sampling is performed on the reflected pulse signal, each sampling obtains a rising edge sampling point and a falling edge sampling point, the rising edge sampling point and the falling edge sampling point have the same voltage value and different time values .
53. The apparatus of claim 52, wherein the sampler is a time-to-digital converter.
54. The device according to any one of claims 31-51, wherein the sampling of the reflected pulse signal by the sampler comprises:

    Sampling the reflected pulse signal at equal intervals to obtain multiple sampling points. The equal interval sampling refers to sampling the reflected pulse signal at regular intervals, and each sampling point corresponds to a voltage value and a time value.
55. The device of claim 54, wherein the sampler is an analog-to-digital converter.
56. The device according to any one of claims 31-55, wherein the receiver receives multiple reflected pulse signals corresponding to the optical pulse signal, wherein the multiple reflected pulse signals include the detection The additional reflection signal of the device itself and the real reflection signal of the measured object, when the additional reflection signal and the real reflection signal are fused, the processor calculating the reflectance of the measured object further includes:

    Determining the characteristic value of the fused reflection signal and the characteristic value of the additional reflection signal;

    Determining the characteristic value of the true reflected signal based on the characteristic value of the fused reflected signal and the characteristic value of the additional reflected signal;

    Calculate the reflectance of the measured object based on the characteristic value of the true reflection signal.
57. The device according to claim 56, wherein the characteristic value of the additional reflected signal is calibrated when the detection device leaves the factory.
58. The device according to claim 56 or 57, wherein when the characteristic value is the echo area, the characteristic value of the true reflected signal is equal to the characteristic value of the fused reflected signal minus the additional The characteristic value of the reflected signal.
59. The device according to any one of claims 31-58, wherein the receiver receives multiple reflected pulse signals corresponding to the optical pulse signal, wherein the multiple reflected pulse signals include multiple For the real reflection signal of the measured object, the processor calculating the reflectance of the measured object further includes:

    Determining the characteristic value of each real reflection signal among the real reflection signals of the plurality of measured objects;

    Calculate the reflectance of each measured object in the multiple measured objects based on the characteristic value of each true reflection signal, and combine the point cloud to the calculated value of each measured object in offline post-processing. The reflectivity is corrected.
60. The device according to any one of claims 31-59, wherein the processor is further configured to: after calculating the reflectance of the measured object based on the pulse energy value, according to the measured object Measure the reflectivity of the object for object detection and identification, or for map surveying and mapping.
61. The device according to any one of claims 31-60, wherein the reflectance measurement device is the detection device, and the detection device includes a laser radar, an electromagnetic wave radar, a millimeter wave radar, or an ultrasonic radar .
62. A movable platform, characterized in that, the movable platform includes:

    body;

    The power system is installed on the fuselage to provide movement power;

    The reflectance measurement device according to any one of claims 31-61, which is installed on the fuselage, and is used to perceive the environment where the movable platform is located and generate point cloud information.
63. The movable platform according to claim 62, wherein the reflectivity measurement device comprises laser radar, electromagnetic wave radar, millimeter wave radar, or ultrasonic radar.
64. A computer-readable storage medium, characterized in that, a computer program is stored on the computer-readable storage medium, and the computer program is executed by a processor as described in any one of claims 1-30. Reflectance measurement method.

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