CN113050071A - Laser radar data processing method, device, equipment and storage medium - Google Patents

本发明实施例提供一种激光雷达数据处理方法、装置、设备及存储介质，通过激光雷达当前通道采集回波信号；判断回波信号是否处于目标检测窗口内；目标检测窗口为激光雷达的探测范围内存在噪点的区间对应的检测窗口或预设探测范围对应的检测窗口；若回波信号处于目标检测窗口内，则根据预先获取的当前通道目标检测窗口内的干扰信号，对回波信号进行还原，得到真实信号。在激光雷达的探测范围内存在干扰信号的情况下根据预先获取的当前通道目标检测窗口内的干扰信号对激光雷达当前通道采集回波信号进行还原，得到真实信号，提高激光雷达测距的准确性，并且本方法能够在激光雷达前端处理器实现，相比于常规的后端处理算法实时性好，稳定性强。

Embodiments of the present invention provide a laser radar data processing method, device, equipment, and storage medium, which collect echo signals through a current channel of the laser radar; determine whether the echo signals are within a target detection window; the target detection window is the detection range of the laser radar The detection window corresponding to the interval in which the noise exists or the detection window corresponding to the preset detection range; if the echo signal is within the target detection window, the echo signal is restored according to the pre-obtained interference signal in the target detection window of the current channel , get the real signal. When there is an interference signal in the detection range of the lidar, the echo signal collected by the current channel of the lidar is restored according to the interference signal in the target detection window of the current channel acquired in advance, so as to obtain the real signal and improve the accuracy of the lidar ranging. , and the method can be implemented in the laser radar front-end processor, and compared with the conventional back-end processing algorithm, the real-time performance is good and the stability is strong.

Laser radar data processing method, device, equipment and storage medium

Technical Field

The invention relates to the technical field of laser radars, in particular to a laser radar data processing method, a laser radar data processing device, laser radar data processing equipment and a storage medium.

Background

The laser radar is a radar system for detecting the position, speed and other characteristic quantities of a target by emitting a laser beam, and in terms of working principle, the laser radar emits a detection signal to the target, then compares a received echo signal reflected from the target with the emission signal, and after appropriate processing, can obtain relevant information of the target, such as target distance, strength, azimuth angle and the like, so as to detect, track and identify the target.

The conventional laser radar generally comprises a circuit part, a light path part and a mechanical structure, and due to the particularity of the light path and the complexity of the structure, interference signals cannot be avoided in the design and application process of the laser radar, for example, a detection signal emitted by the laser radar at one time may hit on a plurality of target objects, and a plurality of waveforms may be superimposed on a reflected echo signal, so that a noise problem is caused. In the application process of the laser radar, due to the existence of interference signals, the accuracy of laser radar ranging is greatly influenced.

Disclosure of Invention

The invention provides a laser radar data processing method, a device, equipment and a storage medium, which are used for improving the accuracy of laser radar ranging.

The first aspect of the present invention provides a laser radar data processing method, including:

collecting echo signals through a current channel of a laser radar;

judging whether the echo signal is in a target detection window; the target detection window is a detection window corresponding to an interval in which a noise point exists in a detection range of the laser radar or a detection window corresponding to a preset detection range;

and if the echo signal is in the target detection window, restoring the echo signal according to the interference signal in the current channel target detection window acquired in advance to obtain a real signal.

A second aspect of the present invention provides a laser radar data processing apparatus, including:

the acquisition module is used for acquiring echo signals through the current channel of the laser radar;

the judging module is used for judging whether the echo signal is in a target detection window; the target detection window is a detection window corresponding to an interval in which a noise point exists in a detection range of the laser radar or a detection window corresponding to a preset detection range;

and the processing module is used for restoring the echo signal according to the interference signal in the current channel target detection window acquired in advance to obtain a real signal if the echo signal is in the target detection window.

A third aspect of the present invention is to provide a lidar data processing apparatus comprising:

a memory;

a processor; and

a computer program;

wherein the computer program is stored in the memory and configured to be executed by the processor to implement the method of the first aspect.

A fourth aspect of the present invention is to provide a computer-readable storage medium having stored thereon a computer program;

which when executed by a processor implements the method according to the first aspect.

The invention provides a laser radar data processing method, a device, equipment and a storage medium, wherein echo signals are collected through a current channel of a laser radar; judging whether the echo signal is in a target detection window; the target detection window is a detection window corresponding to an interval in which a noise point exists in a detection range of the laser radar or a detection window corresponding to a preset detection range; and if the echo signal is in the target detection window, restoring the echo signal according to the interference signal in the current channel target detection window acquired in advance to obtain a real signal. According to the method and the device, under the condition that the interference signal exists in the detection range of the laser radar, the echo signal collected by the current channel of the laser radar can be restored according to the interference signal in the pre-acquired target detection window of the current channel, so that a real signal is obtained, the accuracy of laser radar distance measurement is improved, the method can be realized in a front-end processor of the laser radar, and compared with a conventional back-end processing algorithm, the method and the device are good in real-time performance and strong in stability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a flowchart of a laser radar data processing method according to an embodiment of the present invention;

FIG. 2 is a flowchart of a lidar data processing method according to another embodiment of the present invention;

fig. 3 is a schematic waveform diagram of an interference signal in a laser radar data processing method according to an embodiment of the present invention;

fig. 4 is a schematic waveform diagram of a superimposed signal in a laser radar data processing method according to an embodiment of the present invention;

fig. 5 is a schematic diagram of a process of acquiring a waveform of a real signal in a laser radar data processing method according to an embodiment of the present invention;

fig. 6 is a structural diagram of a lidar data processing apparatus according to an embodiment of the present invention;

fig. 7 is a block diagram of a lidar data processing apparatus according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The existing laser radar transmits a detection signal, the detection signal is reflected by a target object, the laser radar acquires an echo signal, the echo signal contains a real signal obtained by reflecting the detection signal by the target object, and may also contain some interference signals, for example, the target object is located in a detection range of the laser radar (outside a near-end detection blind area and within a farthest detection distance), the detection signal transmitted by the laser radar at one time may be hit on a plurality of target objects, so that the reflected echo signal may have a plurality of waveforms superimposed, which may also cause the spot to be inaccurate in distance measurement, and the problem of laser radar data noise spots occurs. In view of the above problems, embodiments of the present invention provide a laser radar data processing method, which can improve accuracy of laser radar ranging when an interference signal (noise point) exists in a detection range of a laser radar, reduce an echo signal acquired by a current channel of the laser radar according to a pre-acquired interference signal in a target detection window of the current channel to obtain a real signal, and introduce a laser radar data processing process in detail with reference to specific embodiments below.

Fig. 1 is a flowchart of a laser radar data processing method according to an embodiment of the present invention. The embodiment provides a laser radar data processing method, which comprises the following specific steps:

and S101, acquiring an echo signal through a current channel of the laser radar.

In this embodiment, the lidar may be a single line lidar or a multi-line lidar, that is, the lidar of this embodiment may have at least one channel; for any one of the channels, after the channel transmits the detection signal, the channel acquires the echo signal.

S102, judging whether the echo signal is in a target detection window; the target detection window is a detection window corresponding to an interval in which a noise point exists in the detection range of the laser radar or a detection window corresponding to a preset detection range.

In this embodiment, the target detection window may be a detection window corresponding to an interval in which a noise point exists in a detection range of the laser radar or a detection window corresponding to a preset detection range. Further, the target detection window may be acquired in advance.

Specifically, whether an interval with signal intensity exceeding a preset signal intensity threshold exists in an echo signal acquired by the current channel of the laser radar can be judged according to the preset signal intensity threshold, and if the interval exists, the interval is used as a detection window corresponding to an interval with noise points in the detection range of the laser radar, for example, the interval can be judged according to a preset signal intensity threshold V_gJudging whether the signal intensity of the echo signal acquired by the current channel of the laser radar exceeds the preset signal intensity threshold value V or not_gThe interval of (1); if so, the interval (t0 to t3) is used as a detection window corresponding to an interval where noise exists in the detection range of the current channel of the laser radar, that is, the current channel is based on a preset signal intensity threshold V in the embodiment_gAnd identifying the echo signal of the current channel at the angle alpha at the moment, and acquiring a detection window theta (t 0: t3) corresponding to the interval with the noise point]。

Or, a preset detection range input by a user may also be obtained, and a detection window corresponding to the preset detection range is obtained according to the preset detection range, for example, when the user focuses on an interference signal of the laser radar in a certain detection range, the setting may be performed through the process of this embodiment, specifically, if the preset detection range input by the user is 5 to 8m, a time range of an echo signal corresponding to 5 to 8m is obtained, so as to obtain the detection window corresponding to the preset detection range.

In addition, the interference signal of the current channel in the target detection window can be acquired, wherein the interference signal can be acquired in advance through any existing means and is stored in the storage unit in advance.

In this embodiment, the echo signal collected by the current channel of the laser radar may specifically include the following conditions: the real signal reflected by the object is superposed with the interference signal in the target detection window, and the echo signal is in the target detection window at the moment; of course, the echo signal is in the target detection window, and not necessarily all real signals reflected by the object are superposed with the interference signal in the target detection window, or the laser radar does not detect the object, the echo signal only includes the interference signal, and at this time, the echo signal is also in the target detection window; in addition, the real signal reflected by the object is not superposed with the interference signal in the target detection window, that is, the interference signal exists in the target detection window, and the real signal exists outside the target detection window, in this case, the echo signal is not considered to be in the target detection window.

In this embodiment, the echo signal collected by the current channel of the laser radar may be first judged, whether the echo signal is in the target detection window is judged, and then different processing modes are adopted according to different judgment results.

In one possible embodiment, if the echo signal includes a first echo signal within a target detection window and a second echo signal outside the target detection window, determining that the echo signal is not within the target detection window; that is, in this case, the real signal reflected by the object is not superimposed on the interference signal in the target detection window, that is, the interference signal exists in the target detection window, and the real signal exists outside the target detection window. Further, a real signal can be obtained according to a second echo signal outside the target detection window.

In another possible embodiment, if it is determined whether the echo signal is in the target detection window, that is, the real signal possibly reflected by the object is superimposed on the interference signal in the target detection window, the step S103 may be performed.

S103, if the echo signal is in the target detection window, restoring the echo signal according to the interference signal in the current channel target detection window acquired in advance to obtain a real signal.

In this embodiment, when determining whether the echo signal is in the target detection window, it may be that the real signal reflected by the object is superimposed with the interference signal in the target detection window, so that the echo signal may be restored according to the interference signal in the current channel target detection window acquired in advance.

In an alternative embodiment, as shown in fig. 2, the restoring the echo signal according to the pre-obtained interference signal in the current channel target detection window to obtain a real signal in S103 may include:

s1031, acquiring the time corresponding to the starting point and the time corresponding to the peak point of the echo signal in the target detection window;

s1032, acquiring the number of rising edges included by the echo signal between the time corresponding to the starting point and the time corresponding to the peak point;

in this embodiment, the time corresponding to the start point to the time corresponding to the peak point of the echo signal in the target detection window is a waveform leading edge interval of the echo signal, then the number of rising edges in the waveform leading edge interval is counted, if the number of rising edges exceeds one, it indicates that at least one inflection point appears in the echo signal in the leading edge interval, and S1033 is executed if the echo signal in the target detection window is considered to be a superimposed signal of an interference signal and a real signal; if the number of the rising edges is one, it indicates that no inflection point occurs in the echo signal in the leading edge interval of the waveform, and it may be that the real signal intensity in the target detection window is weak, the echo signal superimposed with the interference signal does not generate an inflection point, or it may be that the echo signal does not have a real signal, and is only an interference signal (for example, the laser radar does not detect an object), then S1034 is performed.

Of course, the above process may also be performed by using a waveform trailing edge interval, that is, the time from the time corresponding to the peak point of the echo signal in the target detection window to the end point of the echo signal is obtained as the waveform trailing edge interval, and the number of falling edges in the waveform trailing edge interval is determined.

More specifically, assuming that a target detection window is Θ ═ t0: t3, if an echo signal acquired by a current channel of the laser radar is within the target detection window Θ ═ t0: t3, a time t1 corresponding to a starting point and a time t2 corresponding to a peak point of the echo signal within the target detection window Θ can be obtained, and a waveform leading edge interval epsilon [ t1, t2] of the echo signal within the target detection window Θ is obtained. Then, the number of rising edges included in the waveform leading edge interval ∈ is obtained, in this embodiment, sampling may be performed at a preset sampling frequency fs in the waveform leading edge interval ∈, so as to obtain a sampling signal sequence a, where the depth of the sampling signal sequence a is m ═ t2-t1) × fs, and the number n of rising edges included in the waveform leading edge interval ∈ may be determined by the following formula:

wherein, A [ i ]]For sampling data of the ith sample point in the signal sequence A, V_thThe value is the preset threshold value, that is, the above formula can determine that if the (i + 1) th sampling point data is lower than the ith sampling point data, and the descending amplitude is larger than V_thAnd then, the waveform is shown to have an inflection point at the ith sampling point, so that the number of rising edges is increased by 1. Further, if it is determined that the number n of rising edges included in the waveform leading edge interval epsilon exceeds one, S1033 is performed, and if it is determined that the number n of rising edges included in the waveform leading edge interval epsilon is one, S1034 is performed.

And S1033, if the number of the rising edges exceeds one, performing difference on the echo signal and the interference signal, and taking the difference result as a real signal.

In this embodiment, if the number of the rising edges exceeds one, it is determined that the echo signal is a superposition of the real signal and the interference signal in the target detection window, and then the echo signal and the interference signal may be subtracted, so as to obtain the real signal.

Specifically, the echo signal and the interference signal may be sampled at the preset sampling frequency respectively to obtain a sampling signal sequence of the echo signal and a sampling signal sequence of the interference signal; and subtracting corresponding data in the sampling signal sequence of the echo signal and the sampling signal sequence of the interference signal.

For example, fig. 3 is a waveform of an interference signal in a current channel target detection window acquired in advance, fig. 4 is a waveform of an echo signal after superposition of the interference signal and a real signal, and fig. 5 is a waveform of the real signal obtained by subtracting the waveforms of the echo signal and the target interference signal.

S1034, if the number of the rising edges is one, subtracting the echo signal from the interference signal, and determining that the signal intensity of the subtraction result exceeds a preset intensity threshold value, then taking the subtraction result as a real signal.

In this embodiment, the number of the rising edges is one, and may be that the real signal strength in the target detection window is weak, an inflection point is not generated in the echo signal after being superimposed with the interference signal, or that the echo signal does not have a real signal and is only the interference signal (for example, the laser radar does not detect an object). Therefore, in this embodiment, the echo signal and the interference signal may be subtracted first, and which of the above-mentioned situations is determined according to the signal strength of the subtraction result, and if the signal strength of the subtraction result exceeds the preset strength threshold, the first situation is determined, that is, the real signal strength is weaker, and at this time, the subtraction result may be used as the real signal; if the signal intensity of the difference result exceeds the preset intensity threshold, the second condition is that the echo signal has no real signal and is only an interference signal, and the result that the object is not detected can be output.

The echo signal and the interference signal are subjected to difference, and the echo signal and the interference signal can be respectively sampled at the preset sampling frequency to obtain a sampling signal sequence of the echo signal and a sampling signal sequence of the interference signal; and subtracting corresponding data in the sampling signal sequence of the echo signal and the sampling signal sequence of the interference signal.

It should be noted that, in this embodiment, the lidar may be a multi-line lidar, that is, the lidar has a plurality of channels, and interference signals between each channel are independent from each other, so that the lidar data processing may be performed on each channel through the process in the above embodiment. The interference signals in the target detection window can be stored respectively according to the channel, the scanning period and the scanning angle in advance, and then the required interference signals can be acquired from the storage unit according to the channel, the scanning period and the scanning angle. In addition, the interference signal can be updated once in one scanning period of the laser radar, and it is considered that the interference signal may change waveform characteristics such as amplitude and pulse width along with changes of environmental factors such as weather and temperature, but one scanning period of the laser radar is generally short, and the environmental factors are not mutated, so that the target interference signal can be updated once in one scanning period, which can approximately represent the condition of the interference signal in the whole scanning period, and further the latest interference signal can be obtained when the required interference signal is obtained.

In the laser radar data processing method provided by the embodiment, echo signals are collected through a current channel of a laser radar; judging whether the echo signal is in a target detection window; the target detection window is a detection window corresponding to an interval in which a noise point exists in a detection range of the laser radar or a detection window corresponding to a preset detection range; and if the echo signal is in the target detection window, restoring the echo signal according to the interference signal in the current channel target detection window acquired in advance to obtain a real signal. Under the condition that interference signals exist in the detection range of the laser radar, echo signals collected by the current channel of the laser radar can be restored according to the interference signals in the current channel target detection window acquired in advance, real signals are obtained, the accuracy of laser radar distance measurement is improved, the method can be realized by a laser radar front-end processor, and compared with a conventional back-end processing algorithm, the method is good in real-time performance and strong in stability.

acquiring the time corresponding to the starting point and the time corresponding to the peak point of the echo signal in the target detection window;

acquiring the number of rising edges included between the time corresponding to the starting point and the time corresponding to the peak point of the echo signal;

if the number of the rising edges exceeds one, the echo signal and the interference signal are subjected to difference, and the difference result is used as a real signal;

and if the number of the rising edges is one, subtracting the echo signal from the interference signal, and judging that the signal intensity of the subtraction result exceeds a preset intensity threshold value, and taking the subtraction result as a real signal.

sampling the echo signal and the interference signal at the preset sampling frequency respectively to obtain a sampling signal sequence of the echo signal and a sampling signal sequence of the interference signal;

and subtracting corresponding data in the sampling signal sequence of the echo signal and the sampling signal sequence of the interference signal.

the acquisition module is used for judging whether an interval with signal intensity exceeding a preset signal intensity threshold exists in an echo signal acquired by a current channel of the laser radar according to the preset signal intensity threshold, and if the interval exists, the interval is used as a detection window corresponding to an interval with noise points in a detection range of the laser radar; or acquiring a preset detection range input by a user, and acquiring a detection window corresponding to the preset detection range according to the preset detection range; and acquiring an interference signal of the current channel in the target detection window.

The lidar data processing apparatus provided in the embodiment of the present invention may be specifically configured to execute the method embodiments provided in fig. 1-2, and specific functions are not described herein again.

The laser radar data processing device provided by the embodiment of the invention collects echo signals through the current channel of the laser radar; judging whether the echo signal is in a target detection window; the target detection window is a detection window corresponding to an interval in which a noise point exists in a detection range of the laser radar or a detection window corresponding to a preset detection range; and if the echo signal is in the target detection window, restoring the echo signal according to the interference signal in the current channel target detection window acquired in advance to obtain a real signal. Under the condition that interference signals exist in the detection range of the laser radar, echo signals collected by the current channel of the laser radar can be restored according to the interference signals in the current channel target detection window acquired in advance, real signals are obtained, the accuracy of laser radar distance measurement is improved, the method can be realized by a laser radar front-end processor, and compared with a conventional back-end processing algorithm, the method is good in real-time performance and strong in stability.

The lidar data processing apparatus of the embodiment shown in fig. 7 may be configured to implement the technical solution of the above method embodiment, and the implementation principle and the technical effect are similar, which are not described herein again.

In addition, the present embodiment also provides a computer-readable storage medium on which a computer program is stored, the computer program being executed by a processor to implement the laser radar data processing method described in the above embodiment.

In the embodiments provided in the present invention, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.

The integrated unit implemented in the form of a software functional unit may be stored in a computer readable storage medium. The software functional unit is stored in a storage medium and includes several instructions to enable a computer device (which may be a personal computer, a server, or a network device) or a processor (processor) to execute some steps of the methods according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

It is obvious to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional modules is merely used as an example, and in practical applications, the above function distribution may be performed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to perform all or part of the above described functions. For the specific working process of the device described above, reference may be made to the corresponding process in the foregoing method embodiment, which is not described herein again.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.