CN118584499A

CN118584499A - Ranging method, laser radar, device and storage medium

Info

Publication number: CN118584499A
Application number: CN202411052650.0A
Authority: CN
Inventors: 欧阳家斌; 陈悦
Original assignee: Shenzhen Huanchuang Technology Co ltd
Current assignee: Shenzhen Huanchuang Technology Co ltd
Priority date: 2024-08-02
Filing date: 2024-08-02
Publication date: 2024-09-03
Anticipated expiration: 2044-08-02
Also published as: CN118584499B

Abstract

The invention discloses a ranging method, a laser radar, equipment and a storage medium, wherein the method comprises the steps of establishing a calibration table for distance calibration, wherein the calibration table comprises calibration data under a plurality of different calibration distances, the calibration data under each calibration distance comprises a calibration point position, a calibration distance, measurement distances and reflection values of calibration targets with different reflectivities, and fitting distance values of the calibration targets, the measurement distances and the reflection values are data output by the laser radar under the calibration distances, and the fitting distance values are calculated based on the measurement distances and the reflection values of the calibration targets; when the laser radar measures the distance of a target object, acquiring an original distance measurement value and an actual measurement reflection value of the target object output by the laser radar; and correcting the original ranging value based on the calibration table, the original ranging value and the actually measured reflection value to obtain a corrected ranging value of the target object.

Description

Ranging method, laser radar, device and storage medium

Technical Field

The invention relates to the technical field of automatic driving, in particular to a ranging method, a laser radar, autonomous mobile equipment and a computer readable storage medium.

Background

The laser radar generally comprises a laser transmitting end and a receiving end on a ranging system, the laser transmitting end is controlled by a controller to continuously transmit pulse signals to a target object (such as an obstacle in the range of the laser radar), a photosensitive device of the receiving end receives light energy information, and the distance from the laser radar to the target object is calculated through the time difference between the laser radar and the receiving end.

The calibration algorithm in the prior art is too complex, the parameters are too many, the operation amount is large, and in the ranging process of the laser radar, stable and good point cloud forms cannot be obtained, so that the deviation between the measured distance obtained by the laser radar and the actual distance is large.

Disclosure of Invention

In order to solve the existing technical problems, the embodiment of the invention provides a ranging method, a laser radar, an autonomous mobile device and a computer readable storage medium, which can obtain a relatively stable and relatively good point cloud form, thereby more accurately correcting the ranging of the laser radar and improving the ranging precision.

In a first aspect, there is provided a ranging method, comprising: establishing a calibration table for distance calibration, wherein the calibration table comprises calibration data under a plurality of different calibration distances, the calibration data under each calibration distance comprises a calibration point position, a calibration distance, measurement distances and reflection values of calibration targets with different reflectivities, and fitting distance values of the calibration targets, wherein the measurement distances and the reflection values are data output by the laser radar under the calibration distances, and the fitting distance values are calculated based on the measurement distances and the reflection values of the calibration targets;

When the laser radar measures the distance of a target object, acquiring an original distance measurement value and an actual measurement reflection value of the target object output by the laser radar;

And correcting the original ranging value based on the calibration table, the original ranging value and the actually measured reflection value to obtain a corrected ranging value of the target object.

In a second aspect, there is provided a lidar comprising at least one processor; and

A memory communicatively coupled to the at least one processor; wherein,

The memory stores instructions executable by the at least one processor to enable the at least one processor to perform the steps of the ranging method provided by the embodiments of the present application.

In a third aspect, an autonomous mobile device is provided, including a lidar provided by an embodiment of the present application.

In a fourth aspect, a storage medium is provided, in which a computer program is stored which, when being executed by a processor, causes the processor to perform the steps of the ranging method provided by the embodiment of the present application.

The embodiment of the application provides a ranging method, a laser radar, an autonomous mobile device and a computer readable storage medium, which have at least the following beneficial effects: the calibration table comprises calibration data of a plurality of different calibration distances, calibration targets with different reflectivities are arranged at the same calibration distance, the laser radar outputs measurement distances and reflection values corresponding to the calibration targets at the plurality of different calibration distances, and fitting distance values of the calibration targets are obtained through calculation, so that the original ranging values of target objects in the actual ranging process can be accurately corrected according to the calibration table, stable and good point cloud forms can be obtained, the ranging of the laser radar can be accurately corrected, and the ranging precision is improved.

Drawings

FIG. 1 is a diagram of an application environment of a ranging method according to an embodiment;

FIG. 2 is a schematic diagram of ranging principle of TOF lidar according to an embodiment;

FIG. 3 is a flow chart of a ranging method in an embodiment;

FIG. 4 is a flow chart of a ranging method according to another embodiment;

FIG. 5 is a flowchart of a ranging method based on a correction strategy corresponding to a normal tilt degree according to an embodiment;

FIG. 6 is a flow chart of determining a precise positioning interval in a ranging method according to an embodiment;

FIG. 7 is a flowchart of a ranging method based on a correction strategy corresponding to an abnormal tilt level according to an embodiment;

FIG. 8 is a flowchart of calculating a first estimated reflection value and a first estimated target distance value in a ranging method according to an embodiment;

FIG. 9 is a flowchart of calculating a second estimated reflection value and a second estimated target distance value in a ranging method according to an embodiment;

FIG. 10 is a flow chart of a ranging method in another embodiment;

FIG. 11 is a schematic diagram of a ranging apparatus according to an embodiment;

fig. 12 is a schematic diagram of an autonomous mobile device in an embodiment.

Detailed Description

The technical scheme of the invention is further elaborated below by referring to the drawings in the specification and the specific embodiments.

Unless defined otherwise, 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 belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the scope of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

In the following description, reference is made to the expression "some embodiments" which describe a subset of all possible embodiments, but it should be understood that "some embodiments" may be the same subset or a different subset of all possible embodiments and may be combined with each other without conflict.

Referring to fig. 1, an application environment of a ranging method in an embodiment is shown. The ranging method is applied to the laser radar 10, and the laser radar 10 is arranged on the autonomous mobile device 20, for example, in front of the autonomous mobile device 20, and is used for acquiring obstacles in front of the autonomous mobile device 20. Before the lidar 10 is arranged in the autonomous mobile device 20, calibration of different calibration distances is performed on the lidar 10 to obtain a calibration table, then the calibration table is pre-stored in the lidar 10 or the autonomous mobile device 20, in the autonomous running process of the autonomous mobile device 20, the lidar 10 measures the distance of a target object in a distance measurement range, and based on the calibration table, the original distance measurement value output by the lidar 10 is calibrated, so that a real distance measurement value corresponding to the target object is obtained.

Wherein lidar 10 includes, but is not limited to, a pulsed lidar, a continuous wave lidar, and the like. The laser radar 10 is configured to emit a laser beam such that the laser beam is reflected after reaching a target object (e.g., an obstacle in a range), such that the laser radar 10 receives the reflected laser beam, and to determine a distance between the laser radar 10 and the target object, i.e., an original range value, based on a time difference between transmitting the laser beam and receiving the emitted laser beam.

Wherein the autonomous mobile apparatus 20 is an apparatus mounted on any type of mobile body capable of autonomous movement, such as a vehicle, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobile apparatus, an airplane, an unmanned aerial vehicle, a boat or robot, or the like.

In some embodiments, lidar 10 includes: a transmitting end (transmitter), a receiving end (receiver), a processor and a rotating mechanism. The emitting end is a laser emitting device, and may be, for example, a gas laser, a solid state laser, a semiconductor laser, a free electron laser, or the like. The receiving end is a laser receiving device, and can be a photosensitive coupling component (Charge coupled Device, CCD) for example. The receiving end can output the actually measured transmitting value of the target object.

Taking a TOF laser radar as an example, a ranging principle of the laser radar is described, the TOF laser radar determines a measured distance based on a time difference from emission to reflection of a measurement laser pulse, wherein a TOF sensor is mounted on the laser radar and can be used to implement a function of measuring the distance, fig. 2 is a schematic diagram of the ranging principle of the TOF laser radar in an embodiment. The TOF ranging method mainly comprises the steps of emitting a laser beam to a target object through a laser radar, directly measuring the flight time of the laser beam emitted by the laser radar, striking the target object and returning to a receiver, wherein T1 is the time required for emitting the laser beam to the target object, T2 is the time required for emitting the laser beam back to the target object to a receiving end, and then calculating the value (T1+T2) multiplied by the speed of light/2, namely the calculated distance from the transmitting end to the target object. By adopting a TOF ranging method, a photosensitive chip of the laser radar outputs a TOF (Time-of-Flight) value, a reflectivity value (Peak value) related to the reflectivity of a material and a background Noise value (Noise value). The TOF value can be understood as a time-of-flight value from the laser radar to the target object, the reflectivity value is related to the material, and the TOF value can be understood as a light intensity value acquired by the photosensitive chip after laser strikes the target object. Under the same distance, the light intensity value of the high-reflection material is larger than that of the low-reflection material, under the same material, the distance is larger, the TOF value is higher, the physical meaning represented by the TOF value is the flight time of laser, and the original ranging value of the target object output by the laser radar can be calculated according to the TOF value.

Referring to fig. 3, a flowchart of a ranging method according to an embodiment of the application is shown. The ranging method is applied to the laser radar and comprises the following steps:

S11, establishing a calibration table for distance calibration.

Before the laser radar 10 works normally, the distance calibration needs to be performed on the laser radar 10, the purpose of the distance calibration is to enable the original distance value output by the laser radar 10 to approach to the real distance value, a calibration table is obtained in the calibration process, and in the actual distance measurement process of the laser radar 10, the original distance value output by the laser radar 10 can be corrected by using parameters in the calibration table, so that a more accurate corrected distance value is obtained.

In this embodiment, the calibration table includes calibration data at a plurality of different calibration distances, where the calibration data at each calibration distance includes a calibration point location, a calibration distance, a measurement distance and a reflection value of each calibration target having a different reflectivity, and a fitting distance value of each calibration target, where the measurement distance and the reflection value are data output by the laser radar at the calibration distance, and the fitting distance value is calculated based on the measurement distance and the reflection value of each calibration target.

In the calibration process, a plurality of calibration distances are set in the range of the laser radar 10, for example, the calibration distances are respectively set at positions of 0.1m, 0.2m, 0.3m, 0.4m, 0.5m, 0.6m, 0.7m, 0.8m, 0.9m and 1m of the laser radar 10, and different intervals and the number of the calibration distances can be set according to the calibration requirements. And under the same calibration distance, respectively setting calibration targets with different reflectivities, wherein the calibration targets are used for reflecting laser beams emitted by the laser radar. In this embodiment, three kinds of calibration targets are set, that is, upper, middle and lower three layers are set, and the materials from top to bottom are respectively set up lattice target/3M target, white target and black target, wherein the emissivity of the lattice target/3M target is greater than that of the white target, and the emissivity of the white target is greater than that of the black target. Different reflectivities correspond to different brightness values, the reflectivity corresponding to the black target is the smallest, the brightness value is the smallest, the reflectivity of the white target is the largest, and the brightness value is the largest. Therefore, three calibration points, namely a lattice target/3M target, a white target and a black target, are correspondingly arranged at the same calibration distance. And respectively carrying out sequential labeling on the calibration points according to the sequence of the calibration distances, namely, each calibration point corresponds to one point sequence number.

Under the same calibration distance, the laser radar 10 irradiates laser onto three different calibration targets, and the measurement distance and the emission value corresponding to each calibration target are obtained respectively, wherein the measurement distance and the reflection value are data output by the laser radar 10 under the calibration distance.

In laser ranging, because the laser radar form reason, the transmitting end and the receiving end are not coaxial, but a base line exists, so that light spots cannot fall into a photosensitive chip completely in a short distance, at the moment, the light energy received by the photosensitive chip is derived from the inside of a lens barrel of the receiving end, meanwhile, for a high-reflectivity material, the returned light spots are larger than those of other materials, based on the high-reflectivity material, the phenomenon of an original distance value change curve output in the short distance section can exist along with the increase of the distance of a target object, the original distance value is firstly enlarged and then reduced, the characteristic change condition is inconvenient for subsequent analysis, the distribution condition of the original distance value is enabled to be better in linearity, and therefore, the fitting distance value of each calibration target is required to be processed, and the subsequent more accurate correction distance in the actual ranging process is facilitated.

Because SPAD (single photon avalanche diode) characteristics in the photosensitive chip, under the same calibration distance, the measurement distances of different reflectivities are different, so that under the point position of the calibration distance, three different measurement distance change curves exist for three targets, and similarly, three change curves with different distribution exist for the reflection values.

With the above analysis, in some embodiments, calculating a fitting distance value for each calibration target based on the measured distance and the reflection value for each calibration target includes:

obtaining a calibration distance and a measurement distance corresponding to a calibration target with the same reflectivity, and fitting to obtain a calibration distance-measurement distance model;

obtaining a fitting target value corresponding to a calibration target with the same reflectivity based on the calibration distance-measurement distance model;

Obtaining a difference value corresponding to the calibration target with the same reflectivity based on the fitting target value corresponding to the calibration target with the same reflectivity and the corresponding measurement distance value;

fitting the corresponding difference value of the calibration targets with the same reflectivity and the corresponding reflection value to obtain a reflection value-fitting distance difference model;

forming input data of a reflection value-fitting distance difference model based on the reflection values of the calibration targets, and calculating fitting distance differences corresponding to the calibration targets;

And calculating the fitting distance value corresponding to each calibration target based on the fitting distance difference value corresponding to each calibration target and the measurement distance of the calibration target.

Specifically, for a calibration target, the fitting distance value corresponding to the calibration target is the sum of the fitting distance difference value corresponding to the calibration target and the measurement distance of the calibration target.

S12, when the laser radar measures the distance of the target object, acquiring an original distance measurement value and an actual measurement reflection value of the target object output by the laser radar.

And S13, correcting the original ranging value based on the calibration table, the original ranging value and the actually measured reflection value to obtain a corrected ranging value of the target object.

In the above embodiment, the calibration table includes calibration data at a plurality of different calibration distances, calibration targets with different reflectivities are set at the same calibration distance, the laser radar outputs measurement distances and reflection values corresponding to the calibration targets at a plurality of different calibration distances, and the fitting distance value of each calibration target is obtained by calculation, so that the original ranging value of the target object in the actual ranging process can be corrected more accurately according to the calibration table, a more stable and better point cloud form can be obtained, and the ranging accuracy is improved.

In some embodiments, as shown in fig. 4, a flowchart of a ranging method according to an embodiment of the present application is provided. The ranging method is applied to the laser radar and comprises the following steps:

S11, establishing a calibration table for distance calibration.

S13, calculating a gradient coefficient, wherein the gradient coefficient indicates the relationship between the calibration distance and the measurement distance.

And S14, if the inclination degree coefficient is larger than a preset inclination degree value, executing a correction strategy corresponding to the normal inclination degree.

In this embodiment, the inclination degree coefficient represents the degree of deviation between the calibration distance and the measured distance, and the larger the inclination degree coefficient is, the smaller the degree of deviation is. If the inclination degree coefficient is larger than the preset inclination degree value, executing a correction strategy corresponding to the normal inclination degree, indicating that the reflection value output by the laser radar cannot be trusted, and estimating the estimated distance value and the estimated deviation value based on the correction table to estimate the corrected distance value of the target object.

And S15, if the inclination degree coefficient is not larger than a preset inclination degree value, executing a correction strategy corresponding to the abnormal inclination degree.

In this embodiment, the inclination degree coefficient represents the deviation degree between the calibration distance and the measured distance, the smaller the inclination degree coefficient is, the larger the deviation degree is, if the inclination degree coefficient is not greater than the preset inclination degree value, the correction strategy corresponding to the abnormal inclination degree is executed, which represents that the reflection value output by the laser radar cannot be trusted, and the estimated reflection value and the estimated target distance value need to be estimated based on the correction table, so as to estimate the corrected ranging value of the target object.

In the above embodiment, according to the difference of the deviation degree between the calibration distance and the measured distance, when the inclination degree coefficient is not greater than the preset inclination degree value, the correction strategy corresponding to the abnormal inclination degree is executed, the inclination degree coefficient is greater than the preset inclination degree value, the correction strategy corresponding to the normal inclination degree is executed, and different correction strategies are executed according to different meeting conditions, so that the more stable and better point cloud form can be obtained, the ranging of the laser radar can be corrected more accurately, and the ranging accuracy is improved.

In some embodiments, as shown in fig. 5, fig. 5 is a flowchart of a ranging method based on a correction strategy corresponding to a normal inclination degree in an embodiment, and step S14 includes:

s141, calculating a fitting target distance value corresponding to the target object based on the actually measured reflection value and the calibration table.

In this embodiment, calculating the fitting target distance value corresponding to the target object includes:

calculating a reflection value-fitting distance difference model based on the correction table, namely a tenth fitting model to be mentioned later;

Then, based on the actually measured reflection value, input data of a reflection value-fitting distance difference model is formed, and a fitting distance difference is calculated;

And calculating a fitting target distance value corresponding to the target object based on the fitting distance difference value and the original distance measurement value, namely, fitting target distance value = fitting distance difference value + original distance measurement value.

S142, obtaining the accurate positioning interval closest to the target object based on the fitting target distance value and the calibration table.

S143, calculating estimated distance values corresponding to all the accurate calibration points based on the actually measured reflection values and the calibration data corresponding to all the accurate calibration points in the accurate positioning interval.

S144, calculating estimated deviation values corresponding to all the accurate calibration points based on the actually measured reflection values and the calibration data corresponding to all the accurate calibration points in the accurate positioning interval.

S145, calculating an estimated deviation value corresponding to the target object based on the original ranging value, the estimated distance value corresponding to each accurate calibration point and the estimated deviation value corresponding to each accurate calibration point.

S146, correcting the original ranging value based on the estimated deviation value corresponding to the target object to obtain a corrected ranging value of the target object.

In this embodiment, if the inclination degree coefficient is greater than a preset inclination degree value, and the original ranging value is greater than the estimated deviation value corresponding to the target object and the estimated deviation value corresponding to the target object is greater than 0, the corrected ranging value of the target object is the difference between the original ranging value and the estimated deviation value corresponding to the target object;

and if the inclination degree coefficient is larger than the preset inclination degree value and the original ranging value is not larger than the estimated deviation value corresponding to the target object, taking the original ranging value as the corrected ranging value of the target object.

In the above embodiment, the accurate positioning interval close to the target object is found first, then, based on calibration data, such as measurement distance and reflection value, corresponding to each accurate calibration point in the calibration table, the estimated distance value and the estimated offset value, corresponding to each accurate calibration point, are estimated, the estimated distance value and the estimated offset value, corresponding to each accurate calibration point, are fitted, and based on the original ranging value, the estimated offset value, corresponding to the target object, is obtained, so as to obtain the corrected ranging value of the target object.

In some embodiments, the precise location interval represents a calibration point closest to the target object. In an alternative implementation, as shown in fig. 6, a flowchart of determining an accurate positioning interval in the ranging method in an embodiment, S142 specifically includes:

S1421, comparing the fitting target distance value with the fitting distance value corresponding to the lowest-reflectivity calibration target and the fitting distance value corresponding to the highest-reflectivity calibration target in different calibration distances in the calibration table respectively, and determining a coarse positioning interval corresponding to the target object.

In an alternative implementation, S1421 specifically includes:

Comparing the fitting target distance value with the fitting distance value corresponding to the calibration target with the lowest reflectivity under different calibration distances in the calibration table, and determining a first calibration point which is smaller than the fitting target distance value and is closest to the fitting target distance value;

Comparing the fitting target distance value with the fitting distance value corresponding to the calibration target with the highest reflectivity under different calibration distances in the calibration table, and determining a second calibration point which is smaller than the fitting target distance value and is closest to the fitting target distance value;

and determining a coarse positioning interval based on the first calibration point and the second calibration point.

In this embodiment, for example, a calibration target with the lowest reflectivity is taken as a black target, a calibration target with the highest reflectivity is taken as a lattice target for description, but the method is not limited to, a fitting target distance value of a target object is respectively compared with corresponding fitting distance values of all black targets under all calibration distances to obtain a first calibration point, a point position serial number of the first calibration point is represented by a, a fitting target distance value is compared with fitting distance values corresponding to lattice targets under different calibration distances to obtain a second calibration point, and a point position serial number of the second calibration point is represented by B. And the minimum point position serial number is the minimum point position serial number of the first calibration point position A and the second calibration point position B, namely min (A, B), and the maximum point position serial number is the maximum point position serial number of the first calibration point position A and the second calibration point position B, namely max (A, B). If the point position serial number of the first calibration point position A is equal to the point position serial number of the second calibration point position B, the minimum point position serial number is equal to the maximum point position serial number, and the coarse positioning interval is [ min (A, B), max (A, B) ]basedon the point position serial number.

If the serial number of the minimum point position of the coarse positioning interval is greater than 1, subtracting 1 from the value, otherwise setting the serial number to be 1, if the serial number of the maximum point position of the coarse positioning interval is smaller than the serial number Len of the maximum point position of the target plate, adding 1, otherwise setting the serial number Len of the maximum point position of the target material. For this purpose, a coarse positioning expansion interval is obtained, and the coarse positioning expansion interval may have the following range: [1, max (A, B) ], [ min (A, B) -1, max (A, B) +1], [ min (A, B) -1, len ].

S1422, comparing the actually measured reflection value with the reflection value of the calibration target with the middle reflectivity corresponding to each calibration point in the coarse positioning interval, determining a fitting model corresponding to each calibration point in the coarse positioning interval, and calculating an estimated fitting distance value corresponding to each calibration point in the coarse positioning interval based on the fitting model corresponding to each calibration point in the coarse positioning interval and the actually measured reflection value.

In this embodiment, the fitting model corresponding to each calibration point location represents a relationship between the reflection intensity and the fitting distance, and the estimated fitting distance value corresponding to each calibration point location can be obtained through the fitting model corresponding to each calibration point location. And in the fitting model corresponding to the calibration point position, the reflection intensity is taken as an independent variable, and the fitting distance is taken as a dependent variable. The fitting model corresponding to the calibration point position comprises, but is not limited to, a linear model and a nonlinear model.

In this embodiment, the calibration target with the lowest reflectivity is taken as a black target, the calibration target with the highest reflectivity is taken as an example, the calibration target with the middle reflectivity is taken as a white target, and the description is taken as an example, but the description is not limited, wherein the white target corresponding to the calibration point position is the white target under the calibration distance corresponding to the calibration point position. And comparing the actually measured reflection value with the reflection value of the white target corresponding to the calibration point, and if the actually measured reflection value is larger than the reflection value of the white target corresponding to the calibration point, adopting the reflection values and fitting distance values corresponding to the white target and the lattice target to establish a fitting model corresponding to the calibration point. If the measured reflection value is not greater than the reflection value of the white target corresponding to the calibration point, adopting the reflection values and fitting distance values corresponding to the white target and the black target to establish a fitting model corresponding to the calibration point.

And taking the measured reflection value as input data of a fitting model corresponding to the calibration point, and calculating an estimated fitting distance value corresponding to the calibration point.

S1423, comparing the fitting target distance value with the estimated fitting distance value corresponding to each calibration point in the coarse positioning interval, determining the nearest calibration point, and determining the accurate positioning interval based on the nearest calibration point.

In this embodiment, the estimated fitting distance value of the nearest calibration point is greater than the fitting target distance value and closest to the estimated fitting distance value. Comparing the fitting target distance value with an estimated fitting distance value corresponding to each calibration point to obtain a nearest calibration point, wherein the point number of the nearest calibration point is represented by X, if the nearest calibration point is equal to min (A, B), judging whether X is smaller than or equal to 1, namely the nearest calibration point is equal to min (A, B), and if X is smaller than or equal to 1, the fine positioning interval is [1,2]; if the nearest calibration point X is equal to min (A, B), and X is greater than 1, the fine positioning interval is [ X-1, X ]; if X is greater than or equal to max (A, B), judging whether (X+1) is greater than or equal to Len, namely X is greater than or equal to max (A, B), and if (X+1) is greater than or equal to Len, the accurate positioning interval is [ Len-1, len ], and if X is greater than or equal to max (A, B), and (X+1) is less than Len, the accurate positioning interval is [ X-1, X ]; if the nearest calibration point X is not equal to min (A, B) and X is smaller than max (A, B), the fine positioning interval is [ X-1, X ].

It will be appreciated that fig. 6 is a method for calculating a precise positioning interval according to an embodiment of the present application, and other methods may be used to calculate the precise positioning interval.

In the above embodiment, the coarse positioning section close to the target object is found first, and then the accurate positioning section is determined based on the coarse positioning section, so that a more accurate positioning section can be obtained, and a more accurate correction ranging value can be obtained based on the estimated distance value and the estimated deviation value corresponding to each accurate calibration point.

In an alternative embodiment, step S143 includes:

comparing the measured reflection value with the reflection value of the middle reflectivity calibration target corresponding to any accurate calibration point to obtain a first fitting model corresponding to any accurate calibration point;

Based on the actually measured reflection values, the input data of a first fitting model corresponding to any accurate calibration point position is formed, an estimated distance value corresponding to any accurate calibration point position is obtained through calculation, and other accurate calibration point positions are calculated continuously until the estimated distance values corresponding to all the accurate calibration point positions are calculated.

In this embodiment, the fitting model corresponding to any one of the accurate calibration points represents the relationship between the reflection intensity and the estimated distance. And if the actually measured reflection value is larger than the reflection value of the middle-reflectivity calibration target corresponding to any accurate calibration point, fitting the measured distance and the reflection value of the middle-reflectivity calibration target corresponding to any accurate calibration point and the measured distance and the reflection value of the corresponding highest-reflectivity calibration target to obtain a first fitting model corresponding to any accurate calibration point. For example, for the accurate calibration point C, if the measured reflection value is greater than the reflection value of the white target corresponding to the accurate calibration point C, fitting the measurement distance and the reflection value corresponding to the white target corresponding to the accurate calibration point C, and the measurement distance and the reflection value corresponding to the lattice target corresponding to the accurate calibration point C to obtain a first fitting model corresponding to the accurate calibration point C.

And if the measured reflection value is smaller than or equal to the reflection value of the middle reflectivity calibration target corresponding to any accurate calibration point, fitting the measurement distance and the reflection value of the middle reflectivity calibration target corresponding to any accurate calibration point, and the measurement distance and the reflection value of the corresponding lowest reflectivity calibration target to obtain a first fitting model corresponding to any accurate calibration point. For example, for the accurate calibration point C, if the measured reflection value is not greater than the reflection value of the white target corresponding to the accurate calibration point C, fitting the measurement distance and the reflection value corresponding to the white target corresponding to the accurate calibration point C and the measurement distance and the reflection value corresponding to the black target corresponding to the accurate calibration point C to obtain a first fitting model corresponding to the accurate calibration point C.

For example, the accurate positioning interval includes two accurate calibration points, and by using the step S143, estimated distance values corresponding to the two accurate calibration points, that is, TOF1 and TOF2, respectively, can be obtained.

In the above embodiment, the measured reflection value is compared with the reflection value of the middle reflectivity calibration target corresponding to any precise calibration point, and then the first fitting model corresponding to any precise calibration point is obtained based on the measured distances and the reflection values corresponding to different targets under the same calibration distance corresponding to the precise calibration point, so as to obtain more accurate estimated distance values corresponding to each precise calibration point, thereby facilitating the subsequent obtaining of more accurate corrected distance measurement values and improving the distance measurement precision.

In an alternative embodiment, step S144 includes:

comparing the measured reflection value with the reflection value of the calibration target with intermediate reflectivity corresponding to any accurate calibration point to obtain a second fitting model corresponding to any accurate calibration point;

And forming input data of a second fitting model corresponding to any accurate calibration point based on the actually measured reflection value, calculating to obtain an estimated deviation value corresponding to any accurate calibration point, and continuously calculating other accurate calibration points until the estimated deviation values corresponding to all the accurate calibration points are calculated.

In this embodiment, if the measured reflection value is greater than the reflection value of the intermediate reflectivity calibration target corresponding to any precise calibration point, fitting the measured distance deviation value and reflection value of the intermediate reflectivity calibration target corresponding to any precise calibration point, and the measured distance deviation value and reflection value of the corresponding calibration target with the highest reflectivity, to obtain a second fitting model corresponding to any precise calibration point. The measured distance deviation is the deviation between the measured distance and the corresponding calibration distance, and the second fitting model represents the relation between the reflection intensity and the distance deviation. For example, for the accurate calibration point C, if the measured reflection value is greater than the reflection value of the white target corresponding to the accurate calibration point C, fitting the measured distance deviation value and the reflection value corresponding to the white target corresponding to the accurate calibration point C, and the measured distance deviation value and the reflection value corresponding to the lattice target corresponding to the accurate calibration point C to obtain a second fitting model corresponding to the accurate calibration point C.

And if the measured reflection value is smaller than or equal to the reflection value of the middle-reflectivity calibration target corresponding to any accurate calibration point, fitting the measured distance deviation value and the reflection value of the middle-reflectivity calibration target corresponding to any accurate calibration point, and the measured distance deviation value and the reflection value of the corresponding lowest-reflectivity calibration target to obtain a second fitting model corresponding to any accurate calibration point. For example, for the accurate calibration point C, if the measured reflection value is not greater than the reflection value of the white target corresponding to the accurate calibration point C, fitting the measured distance deviation value and the reflection value corresponding to the white target corresponding to the accurate calibration point C, and the measured distance deviation value and the reflection value corresponding to the black target corresponding to the accurate calibration point C to obtain a second fitting model corresponding to the accurate calibration point C.

For example, the accurate positioning interval includes two accurate calibration points, and by using the step S144, estimated distance values corresponding to the two accurate calibration points can be obtained respectively, that is, bias1 and Bias2 respectively.

In the above embodiment, the measured reflection value is compared with the reflection value of the calibration target with the intermediate reflectivity corresponding to any precise calibration point, and then the second fitting model corresponding to any precise calibration point is obtained based on the measured distance deviation values and the reflection values corresponding to different targets at the same calibration distance corresponding to the precise calibration point, so as to obtain more accurate estimated deviation values corresponding to each precise calibration point, thereby facilitating the subsequent obtaining of more accurate corrected ranging values and improving the ranging accuracy.

In an alternative implementation, step S145 includes:

Fitting the estimated distance value corresponding to each accurate calibration point and the estimated deviation value corresponding to each accurate calibration point to obtain a third fitting model, wherein the third fitting model represents the relationship between the distance and the distance deviation;

and forming input data of a third fitting model based on the original ranging value, and calculating an estimated deviation value corresponding to the target object.

And the distance in the third fitting model is an independent variable, and the distance deviation is an independent variable. For example, the accurate positioning interval comprises two accurate calibration points, TOF1 and TOF2, bias1 and Bias2 are obtained by the steps, one point is (TOF 1 and Bias 1), the other point is (TOF 2 and Bias 2), and a third fitting model is obtained by fitting. And substituting the original ranging value into a third fitting model to obtain an estimated deviation value corresponding to the target object.

In the above embodiment, fitting is performed based on the estimated distance values and the estimated offset values corresponding to the plurality of accurate calibration points, so as to obtain a third fitting model, thereby obtaining a more accurate estimated offset value, facilitating the subsequent obtaining of a more accurate corrected ranging value, and improving ranging accuracy.

In some embodiments, as shown in fig. 7, fig. 7 is a flowchart of a ranging method based on a correction strategy corresponding to an abnormal inclination degree in an embodiment, which specifically includes:

S151, a first accurate positioning interval is acquired, and a first estimated reflection value and a first estimated target distance value corresponding to the target object are acquired based on the first accurate positioning interval.

S152, acquiring a second accurate positioning interval, and acquiring a second estimated reflection value and a second estimated target distance value corresponding to the target object based on the second accurate positioning interval.

And S153, fitting by using a first estimated reflection value and a first estimated target distance value corresponding to the target object, and a second estimated reflection value and a second estimated target distance value corresponding to the target object to obtain a fourth fitting model, wherein the fourth fitting model represents the relation between the reflection intensity and the target distance.

In this embodiment, in the fourth fitting model, the reflection intensity is an independent variable and the target distance is a dependent variable. For example, the first estimated reflection value is represented by Peak1, the first estimated target distance value is represented by target_dist1, the second estimated reflection value is represented by Peak2, and the second estimated target distance value is represented by target_dist2, then a fourth fitting model can be obtained by fitting based on (Peak 1, target_dist1), (Peak 2, target_dist2).

And S154, forming input data of a fourth fitting model based on the actually measured reflection value, calculating an output distance value, and taking the output distance value as a corrected distance measurement value of the target object.

In the above embodiment, two accurate positioning intervals are determined according to different accurate positioning methods, two estimated reflection values and two estimated distance values corresponding to the target object are calculated based on the relation between the fitting distance values and the reflection values corresponding to the calibration points in the two accurate positioning intervals, and then the relation between the reflection intensity and the target distance is fitted based on the two estimated reflection values and the two estimated distance values corresponding to the target object, so that the corrected distance measurement value of the target object is estimated, and the distance measurement accuracy is improved.

In some embodiments, as shown in fig. 8, fig. 8 is a flowchart of calculating a first estimated reflection value and a first estimated target distance value in the ranging method according to an embodiment; step S151 includes:

S1511, calculating a fitting target distance value corresponding to the target object based on the actually measured reflection value and the calibration table.

S1512, comparing the fitting target distance value with the fitting distance value of the calibration target with the middle reflectivity in the calibration table, determining a first target calibration point location, and determining the first accurate positioning interval based on the first target calibration point location.

In this embodiment, a fitting distance value smaller than the fitting target distance value and closest to the fitting target distance value is determined, a calibration point corresponding to the determined fitting distance value is determined as a first target calibration point, and a first accurate positioning interval is determined based on the first target calibration point.

Specifically, the fitting target distance value is compared with the fitting distance value of each white target in the calibration table, a first target calibration point is determined, if the point sequence number of the first target calibration point is X, the first accurate positioning interval is [ X, X+1], and if X is Len, the accurate positioning interval is [ X-1, len ].

S1513, fitting by using the reflection value and the fitting distance value corresponding to the middle reflectivity calibration target of each calibration point in the first accurate positioning interval to obtain a fifth fitting model.

In this embodiment, the fifth fitting model represents a relationship between the reflection intensity and the fitting distance, where the fitting distance is an independent variable and the reflection intensity is an independent variable. Specifically, fitting is carried out according to the reflection values and the fitting distance values corresponding to the white targets corresponding to the calibration points, so as to obtain a fifth fitting model.

S1514, based on the fitting target distance value, forming input data of the fifth fitting model, and outputting a first estimated reflection value corresponding to the target object.

In this embodiment, the fitting target distance value is substituted into the fifth fitting model, and the first estimated reflection value corresponding to the target object is output, for example, denoted by Peak 1.

S1515, fitting is carried out according to fitting distance values and the calibration distances corresponding to the calibration targets of the middle reflectivity of each calibration point in the first accurate positioning interval, and a sixth fitting model is obtained.

In this embodiment, the sixth mold closing model represents a fitting model of a relationship between a fitting distance and a calibration distance, the fitting distance is taken as an independent variable, and the calibration distance is taken as a dependent variable. Specifically, fitting is carried out according to fitting distance values and calibration distances corresponding to the white targets corresponding to the calibration points, so that a sixth fitting model is obtained.

S1516, based on the fitting target distance value, forming input data of a sixth fitting model, and outputting a first estimated target distance value corresponding to the target object.

In this embodiment, the fitting target distance value is substituted into the sixth fitting model, and the first estimated target distance value corresponding to the target object is output, for example, denoted by target_dist1.

In the above embodiment, a precise positioning interval is determined according to a precise positioning method, and an estimated reflection value and an estimated distance value corresponding to a target object are calculated based on the relationship between the fitting distance value and the reflection value corresponding to each calibration point in the precise positioning interval, so that the relationship between the reflection intensity and the target distance is conveniently fitted subsequently, the corrected distance measurement value of the target object is deduced, and the distance measurement accuracy is improved.

In some embodiments, as shown in fig. 9, fig. 9 is a flowchart of calculating a second estimated reflection value and a second estimated target distance value in the ranging method according to an embodiment; step S152 includes:

S1521, determining a second target calibration point based on the actually measured reflection value and a first estimated reflection value corresponding to the target object, determining the second accurate positioning interval based on the second target calibration point, and determining reflection values and fitting distance values corresponding to the calibration points of the second accurate positioning interval.

In this embodiment, if the measured reflection value is smaller than the first estimated reflection value corresponding to the target object, the fitting target distance value is compared with the fitting distance value of the calibration target with the lowest reflectivity in the calibration table, a second target calibration point location is determined, the second accurate positioning interval is determined based on the second target calibration point location, and the fitting distance value corresponding to the second target calibration point location is smaller than the fitting target distance value and is closest to the fitting target distance value. The reflection value and the fitting distance value of the calibration target with the lowest reflectivity in each calibration point position of the second accurate positioning interval are determined to be the reflection value and the fitting distance value corresponding to each calibration point position of the second accurate positioning interval;

And if the measured reflection value is not smaller than the first estimated reflection value corresponding to the target object, comparing the fitting target distance value with the fitting distance value of the calibration target with the highest reflectivity in the calibration table, determining the fitting target distance value as a second target calibration point, determining the second accurate positioning interval based on the second target calibration point, and enabling the fitting distance value corresponding to the second target calibration point to be smaller than the fitting target distance value and closest to the fitting target distance value. And determining the reflection value and the fitting distance value of the calibration target with the highest reflectivity in each calibration point in the second accurate positioning interval as the reflection value and the fitting distance value corresponding to each calibration point in the second accurate positioning interval.

In an alternative implementation, if the point number of the second target calibration point is X, the second precise positioning interval is [ X, x+1], and if X is Len, the second precise positioning interval is [ X-1, len ].

S1522, fitting is carried out by using the reflection values and the fitting distance values corresponding to the calibration points of the second accurate positioning interval, and a seventh fitting model is obtained.

In this embodiment, the seventh fitting model represents a relationship between the reflection intensity and the fitting distance, and the fitting distance is a dependent variable with the reflection intensity as an independent variable.

S1523, based on the fitting target distance value, forming input data of a seventh fitting model, and outputting a second estimated reflection value corresponding to the target object.

In this embodiment, the fitted target distance value is substituted into the seventh fitting model to obtain a second estimated reflection value corresponding to the target object, for example, denoted by Peak 2.

S1524, fitting is carried out according to fitting distance values and calibration distances corresponding to the calibration points of the second accurate positioning interval, and an eighth fitting model is obtained.

In this embodiment, the eighth fitting model represents a relationship between the fitting distance and the estimated distance, and the estimated distance is a dependent variable with the fitting distance as an independent variable.

S1525, based on the fitting target distance value, forming input data of the eighth fitting model, and outputting a second estimated target distance value corresponding to the target object.

In this embodiment, the fitting target distance value is substituted into the eighth fitting model to obtain a second estimated target distance value corresponding to the target object, for example, denoted by target_dist2.

In some embodiments, in the above-mentioned correction strategy corresponding to the normal inclination degree and the correction strategy corresponding to the normal inclination degree, the fitting target distance value corresponding to the target object needs to be calculated. In an alternative implementation, calculating the fitted target distance value corresponding to the target object based on the measured reflection value and the calibration table includes:

Fitting the calibration distance and the measurement distance corresponding to the calibration target with the same reflectivity obtained from the calibration table to obtain a ninth fitting model, wherein the ninth fitting model represents the relationship between the calibration distance and the measurement distance corresponding to the calibration target with the same reflectivity, and based on the ninth fitting model, fitting target values corresponding to the calibration target with the same reflectivity are obtained;

Obtaining a difference value corresponding to the calibration target with the same reflectivity based on a fitting target value corresponding to the calibration target with the same reflectivity and a corresponding measurement distance value, and fitting the difference value corresponding to the calibration target with the same reflectivity and the corresponding reflection value to obtain a tenth fitting model, wherein the tenth fitting model represents the relation between the reflection value and the fitting distance difference value;

and forming input data of the tenth fitting model based on the actually measured reflection value, calculating a fitting distance difference value corresponding to the target object, and calculating a fitting target distance value corresponding to the target object based on the fitting distance difference value and an original ranging value.

In some embodiments, fig. 10 is a flow chart of a ranging method in another embodiment,

S21, establishing a calibration table for distance calibration.

S22, when the laser radar measures the distance of the target object, acquiring an original distance measurement value and an actual measurement reflection value of the target object output by the laser radar.

S23, calculating a fitting target distance value corresponding to the target object based on the actually measured reflection value and the calibration table.

S24, obtaining the accurate positioning interval closest to the target object based on the fitting target distance value and the calibration table.

S25, calculating estimated distance values corresponding to all the accurate calibration points based on the actually measured reflection values and the calibration data corresponding to all the accurate calibration points in the accurate positioning interval.

S26, calculating the inclination degree coefficient according to the estimated distance value and the calibration distance corresponding to each accurate calibration point.

In this embodiment, two accurate calibration points may be selected from the accurate calibration points to calculate, and then the inclination coefficient=the difference between the estimated distance values of the two accurate calibration points/the difference between the calibration distances of the two accurate calibration points.

And S27, if the inclination degree coefficient is larger than a preset inclination degree value, executing a correction strategy corresponding to the normal inclination degree.

In this embodiment, as can be seen from fig. 5 of the above embodiment, in this flowchart, S23-S25 are already executed, and specific steps in step S27 include S144-S146 in fig. 5, which are not described herein.

And S28, if the inclination degree coefficient is not larger than a preset inclination degree value, executing a correction strategy corresponding to the abnormal inclination degree.

Step S21 is the same as step S11, step S22 is the same as step S12, and steps S23 to S25 are the same as steps S141 to S143 in fig. 5, respectively, and step S28 is the same as step S15, and will not be described again.

In another aspect of the application, a computer program product is provided, comprising a computer program which, when executed by a processor, implements a ranging method according to any of the embodiments of the application.

In the computer program product, an alternative implementation form of a program module architecture of a computer program for implementing the steps of the ranging method may be a ranging device.

Referring to fig. 11, an embodiment of the present application provides a ranging apparatus, including: the calibration module 111 is configured to establish a calibration table for distance calibration, where the calibration table includes calibration data at a plurality of different calibration distances, the calibration data at each calibration distance includes a calibration point location, a calibration distance, a measurement distance and a reflection value of each calibration target having different reflectivities, and a fitting distance value of each calibration target, where the measurement distance and the reflection value are data output by the laser radar at the calibration distance, and the fitting distance value is calculated based on the measurement distance and the reflection value of each calibration target; the obtaining module 112 is configured to obtain an original ranging value and an actually measured reflection value of the target object output by the laser radar when the laser radar ranges the target object;

And the correction module 113 is configured to correct the original ranging value based on the calibration table, the original ranging value and the actually measured reflection value, so as to obtain a corrected ranging value of the target object.

Optionally, the correction module 113 is further configured to:

Calculating a tilt degree coefficient, wherein the tilt degree coefficient indicates the relation between the calibration distance and the measurement distance, and executing a correction strategy corresponding to the normal tilt degree if the tilt degree coefficient is larger than a preset tilt degree value;

And if the inclination degree coefficient is not greater than the preset inclination degree value, executing a correction strategy corresponding to the abnormal inclination degree.

Optionally, the correction module 113 is further configured to:

Calculating a fitting target distance value corresponding to the target object based on the actually measured reflection value and the calibration table;

obtaining an accurate positioning interval closest to the target object based on the fitting target distance value and the calibration table;

Calculating estimated distance values corresponding to all the accurate calibration points based on the actually measured reflection values and the calibration data corresponding to all the accurate calibration points in the accurate positioning interval;

calculating estimated deviation values corresponding to all the accurate calibration points based on the actually measured reflection values and the calibration data corresponding to all the accurate calibration points in the accurate positioning interval;

calculating an estimated deviation value corresponding to the target object based on the original ranging value, the estimated distance value corresponding to each accurate calibration point and the estimated deviation value corresponding to each accurate calibration point;

and correcting the original ranging value based on the estimated deviation value corresponding to the target object to obtain a corrected ranging value of the target object.

Optionally, the correction module 113 is further configured to:

Comparing the fitting target distance value with the fitting distance value corresponding to the calibration target with the lowest reflectivity under different calibration distances in the calibration table and the fitting distance value corresponding to the calibration target with the highest reflectivity respectively, and determining a coarse positioning interval corresponding to the target object;

Comparing the actually measured reflection value with the reflection value of the calibration target with middle reflectivity corresponding to each calibration point in the coarse positioning interval, determining a fitting model corresponding to each calibration point in the coarse positioning interval, wherein the fitting model corresponding to each calibration point represents the relation between the reflection intensity and the fitting distance, and calculating an estimated fitting distance value corresponding to each calibration point in the coarse positioning interval based on the fitting model corresponding to each calibration point in the coarse positioning interval and the actually measured reflection value;

And comparing the fitting target distance value with an estimated fitting distance value corresponding to each calibration point in the coarse positioning interval, determining a nearest calibration point, and determining the precise positioning interval based on the nearest calibration point.

Optionally, the correction module 113 is further configured to:

comparing the fitting target distance value with fitting distance values corresponding to the calibration targets with the lowest reflectivity at different calibration distances in the calibration table, and determining a first calibration point position;

comparing the fitting target distance value with a fitting distance value corresponding to a calibration target with highest reflectivity at different calibration distances in the calibration table, and determining a second calibration point position;

Optionally, the correction module 113 is further configured to:

comparing the measured reflection value with the reflection value of the middle-reflectivity calibration target corresponding to any precise calibration point, wherein the lowest reflectivity is smaller than the middle reflectivity, the middle reflectivity is smaller than the highest reflectivity, and if the measured reflection value is larger than the reflection value of the middle-reflectivity calibration target corresponding to any precise calibration point, fitting the measured distance and the reflection value of the middle-reflectivity calibration target corresponding to any precise calibration point and the measured distance and the reflection value of the corresponding highest-reflectivity calibration target to obtain a first fitting model corresponding to any precise calibration point, wherein the fitting model corresponding to any precise calibration point represents the relation between the reflection intensity and the estimated distance;

if the measured reflection value is smaller than or equal to the reflection value of the middle reflectivity calibration target corresponding to any accurate calibration point, fitting the measurement distance and the reflection value of the middle reflectivity calibration target corresponding to any accurate calibration point and the measurement distance and the reflection value of the corresponding calibration target with the lowest reflectivity to obtain a first fitting model corresponding to any accurate calibration point;

and forming input data of a first fitting model corresponding to any accurate calibration point based on the actually measured reflection value, calculating to obtain an estimated distance value corresponding to any accurate calibration point, and continuously calculating other accurate calibration points until the estimated distance values corresponding to all the accurate calibration points are calculated.

Optionally, the correction module 113 is further configured to:

And forming input data of the third fitting model based on the original ranging value, and calculating an estimated deviation value corresponding to the target object.

Optionally, the correction module 113 is further configured to:

If the inclination degree coefficient is larger than a preset inclination degree value, and the original ranging value is larger than the estimated deviation value corresponding to the target object and the estimated deviation value corresponding to the target object is larger than 0, the corrected ranging value of the target object is the difference between the original ranging value and the estimated deviation value corresponding to the target object;

and if the inclination degree coefficient is larger than a preset inclination degree value and the original ranging value is not larger than the estimated deviation value corresponding to the target object, taking the original ranging value as a corrected ranging value of the target object.

Optionally, the correction module 113 is further configured to:

acquiring a first accurate positioning interval, and acquiring a first estimated reflection value and a first estimated target distance value corresponding to the target object based on the first accurate positioning interval;

acquiring a second accurate positioning interval, and acquiring a second estimated reflection value and a second estimated target distance value corresponding to the target object based on the second accurate positioning interval;

Fitting by using a first estimated reflection value and a first estimated target distance value corresponding to the target object and a second estimated reflection value and a second estimated target distance value corresponding to the target object to obtain a fourth fitting model, wherein the fourth fitting model represents the relation between the reflection intensity and the target distance;

And forming input data of the fourth fitting model based on the actually measured reflection value, calculating an output distance value, and taking the output distance value as a corrected distance measurement value of the target object.

Optionally, the correction module 113 is further configured to:

Comparing the fitting target distance value with the fitting distance value of the calibration target with middle reflectivity in the calibration table, wherein the lowest reflectivity is smaller than the middle reflectivity, the middle reflectivity is smaller than the highest reflectivity, a first target calibration point position is determined, and the first accurate positioning interval is determined based on the first target calibration point position;

Fitting by using the reflection value and the fitting distance value corresponding to the middle reflectivity calibration target of each calibration point in the first accurate positioning interval to obtain a fifth fitting model; wherein the fifth fitting model represents the relationship between the reflection intensity and the fitting distance;

Forming input data of the fifth fitting model based on the fitting target distance value, and outputting a first estimated reflection value corresponding to the target object;

fitting is carried out according to the fitting distance value and the calibration distance corresponding to the calibration target of the middle reflectivity of each calibration point in the first accurate positioning interval, so as to obtain a sixth fitting model, wherein the sixth fitting model represents the fitting model of the relation between the fitting distance and the calibration distance;

And forming input data of the sixth fitting model based on the fitting target distance value, and outputting a first estimated target distance value corresponding to the target object.

Optionally, the correction module 113 is further configured to:

Determining a second target calibration point based on the actually measured reflection value and a first estimated reflection value corresponding to the target object, determining a second accurate positioning interval based on the second target calibration point, and determining reflection values and fitting distance values corresponding to the calibration points of the second accurate positioning interval;

Fitting by using the reflection values and the fitting distance values corresponding to the calibration points of the second accurate positioning interval to obtain a seventh fitting model, wherein the seventh fitting model represents the relation between the reflection intensity and the fitting distance;

Forming input data of the seventh fitting model based on the fitting target distance value, and outputting a second estimated reflection value corresponding to the target object;

Fitting is carried out according to fitting distance values and calibration distances corresponding to all calibration points in the second accurate positioning interval, so as to obtain an eighth fitting model, wherein the eighth fitting model represents the relation between the fitting distance and the estimated distance;

And forming input data of the eighth fitting model based on the fitting target distance value, and outputting a second estimated target distance value corresponding to the target object.

Optionally, the correction module 113 is further configured to:

It will be appreciated by those skilled in the art that the configuration of the ranging apparatus of fig. 11 is not limiting and that the various modules may be implemented in whole or in part by software, hardware, or a combination thereof. The above modules may be embedded in hardware or independent of a controller in a computer device, or may be stored in software in a memory in the computer device, so that the controller may call and execute operations corresponding to the above modules. In other embodiments, more or fewer modules than shown may be included in the ranging device.

Referring to fig. 12, in another aspect of the embodiment of the present application, there is further provided a lidar, which includes a memory 3011 and a processor 3012, wherein the memory 3011 stores a computer program, and the computer program when executed by the processor causes the processor 3012 to perform the steps of the ranging method provided by any of the above embodiments of the present application. Where the processor 3012 is a control center, various interfaces and lines are utilized to connect various portions of the overall computer device, perform various functions of the computer device and process data by running or executing software programs and/or modules stored in the memory 3011, and invoking data stored in the memory 3011. Optionally, the processor 3012 may include one or more processing cores; preferably, the processor 3012 may integrate an application processor and a modem processor, wherein the application processor primarily handles operating systems, user pages, applications, etc., and the modem processor primarily handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 3012.

The memory 3011 may be used to store software programs and modules, and the processor 3012 executes various functional applications and data processing by executing the software programs and modules stored in the memory 3011. The memory 3011 may mainly include a storage program area that may store an operating system, application programs required for at least one function (such as a sound playing function, an image playing function, etc.), and a storage data area; the storage data area may store data created according to the use of the computer device, etc. In addition, memory 3011 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid-state storage device. Accordingly, the memory 3011 may also include a memory controller to provide access to the memory 3011 by the processor 3012.

In another aspect of embodiments of the present application, there is also provided an autonomous mobile apparatus, which is an apparatus mounted on any type of mobile body capable of autonomous movement, such as a vehicle, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobile apparatus, an airplane, an unmanned aerial vehicle, a ship, or a robot.

In another aspect of the embodiments of the present application, there is further provided a storage medium storing a computer program, where the computer program when executed by a processor causes the processor to perform the steps of the ranging method provided in any of the foregoing embodiments of the present application.

Those skilled in the art will appreciate that implementing all or part of the processes of the methods provided in the above embodiments may be accomplished by computer programs stored on a non-transitory computer readable storage medium, which when executed, may comprise processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in embodiments provided herein may include non-volatile and/or volatile memory. The nonvolatile memory can include Read Only Memory (ROM), programmable ROM (PROM), electrically Programmable ROM (EPROM), electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double Data Rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (SYNCHLINK) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), among others.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. The scope of the invention is to be determined by the appended claims.

Claims

1. A ranging method, applied to a lidar, comprising:

Establishing a calibration table for distance calibration, wherein the calibration table comprises calibration data under a plurality of different calibration distances, the calibration data under each calibration distance comprises a calibration point position, a calibration distance, measurement distances and reflection values of calibration targets with different reflectivities, and fitting distance values of the calibration targets, wherein the measurement distances and the reflection values are data output by the laser radar under the calibration distances, and the fitting distance values are calculated based on the measurement distances and the reflection values of the calibration targets;

2. The ranging method of claim 1, wherein correcting the original ranging value based on the calibration table and the measured reflection value to obtain the corrected ranging value for the target object comprises:

3. The ranging method as claimed in claim 2, wherein if the inclination degree coefficient is greater than a preset inclination degree value, performing a correction strategy corresponding to a normal inclination degree comprises:

4. The ranging method of claim 3, wherein the obtaining the precise location interval closest to the target object based on the fitted target distance value and based on the calibration table comprises:

5. The ranging method according to claim 4, wherein comparing the fitting target distance value with the fitting distance value corresponding to the calibration target with the lowest reflectivity and the fitting distance value corresponding to the calibration target with the highest reflectivity in the calibration table, respectively, and determining the coarse positioning interval corresponding to the target object includes:

6. The ranging method according to claim 3, wherein calculating the estimated distance value corresponding to each accurate calibration point based on the original ranging value, the measured reflection value, and the calibration data corresponding to each accurate calibration point in the accurate positioning interval comprises:

7. The ranging method according to claim 3, wherein calculating the estimated deviation value corresponding to the target object based on the original ranging value, the estimated distance value corresponding to each accurate calibration point, and the estimated deviation value corresponding to each accurate calibration point comprises:

8. The ranging method of claim 3, wherein correcting the original ranging value based on the estimated offset value corresponding to the target object to obtain the corrected ranging value for the target object comprises:

9. The ranging method as claimed in claim 2, wherein if the inclination degree coefficient is not greater than a preset inclination degree value, performing the correction strategy corresponding to the abnormal inclination degree comprises:

10. The ranging method of claim 9, wherein the obtaining a first precise positioning interval, and obtaining a first estimated reflection value and a first estimated target distance value corresponding to the target object based on the first precise positioning interval comprises:

fitting is carried out according to the fitting distance value and the calibration distance corresponding to the calibration target of the middle reflectivity of each calibration point in the first accurate positioning interval, so as to obtain a sixth fitting model, wherein the sixth fitting model represents a fitting model of the relation between the fitting distance and the calibration distance;

11. The ranging method of claim 10, wherein the obtaining a second precise positioning interval, and obtaining a second estimated reflection value and a second estimated target distance value corresponding to the target object based on the second precise positioning interval comprises:

12. The ranging method according to claim 3 or 10, wherein calculating a fitted target distance value corresponding to the target object based on the measured reflection value and the calibration table comprises:

13. A laser radar which comprises a laser beam source, characterized by comprising the following steps:

At least one processor; and

A memory communicatively coupled to the at least one processor; wherein,

The memory stores instructions executable by the at least one processor to enable the at least one processor to perform the ranging method of any of claims 1-12.

14. An autonomous mobile device, comprising: the lidar of claim 13.

15. A computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, computer executable instructions for causing a computer device to perform the ranging method of any of claims 1 to 12.