Laser radar chip, laser radar and data processing method of laser radar chip

Abstract

The invention relates to the technical field of photoelectricity, and discloses a laser radar chip, a laser radar and a data processing method of the laser radar chip. The laser radar chip comprises an analog-to-digital converter, a memory, a first detection module and a second detection module. The first detection module is used for detecting the sampling signal generated by the analog-to-digital converter when the signal acquired by the analog-to-digital converter is a beat frequency signal, and the second detection module is used for detecting the sampling signal generated by the analog-to-digital converter when the signal acquired by the analog-to-digital converter is an echo signal. The laser radar chip not only can be applied to a receiving end signal processing circuit of an FMCW laser radar, but also can be applied to a receiving end signal processing circuit of a ToF laser radar, and also can be applied to a receiving end signal processing circuit of an FMCW and ToF combined laser radar, and the compatibility is stronger.

Description

Technical Field

[0001] The present application relates to the field of optoelectronic technology, and in particular to a laser radar chip, a laser radar, and a data processing method for the laser radar chip. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect target characteristics such as position and speed. Its working principle is to first emit a detection laser beam to the target, and then compare the received signal reflected from the target with the transmitted signal. After appropriate processing, relevant information about the target can be obtained, such as target distance, direction, altitude, speed, attitude, and even shape parameters.

[0003] Most of the laser radars in the related art are time of flight (ToF) laser radars and frequency modulated continuous wave (FMCW) laser radars. ToF laser radars generally include structures such as a light source module, a photoelectric detection module, an analog-to-digital conversion module, a detection module, and a calculation module. Among them, the light source module is used to emit detection light so that the detection light detects the target object. The photoelectric detection module is used to receive the echo light formed by the target object reflecting the detection light, and perform photoelectric conversion to obtain an echo signal, which is an electrical signal. The analog-to-digital conversion module is used to collect the above-mentioned electrical signal to obtain a sampling signal. The detection module is used to detect the sampling signal to determine the time of receiving the echo signal. The calculation module of the laser radar can determine the distance of the target object relative to the laser radar based on the time information of the light source module emitting the detection light and the time information of the echo signal obtained by the detection module; and can determine the movement speed of the target object relative to the laser radar based on multiple distance detections.

[0004] FMCW laser radar generally includes structures such as a light source module, a photoelectric detection module, an analog-to-digital conversion module, a detection module and a calculation module. Among them, the light source module is used to emit detection light and local oscillator light, the detection light is used to detect the target object, and the local oscillator light is used as a reference signal for the detection light. The photoelectric detection module is used to receive the beat frequency light signal formed by mixing the local oscillator light and the echo light reflected by the target object, and perform photoelectric conversion on the beat frequency light signal to obtain the beat frequency signal, which is an electrical signal. The analog-to-digital conversion module is used to collect the above-mentioned beat frequency signal to obtain a sampling signal. The detection module is used to detect the sampling signal to determine the frequency information corresponding to the beat frequency signal. The calculation module of the laser radar can determine the distance of the target object relative to the laser radar and the movement speed of the target object relative to the laser radar based on the frequency information of the beat frequency signal obtained by detection. Summary of the invention

[0005] The inventor of this application found that the signal processing circuit of the receiving end of the laser radar in the related art is designed for either FMCW radar or ToF radar, and it can only be applied to one of the radars and perform signal detection processing. The compatibility of such receiving end signal processing circuit is poor. For example, manufacturers in the related field need to purchase or manufacture receiving end signal processing circuits of different specifications when producing FMCW laser radar and ToF laser radar; for another example, in the laser radar that needs to combine the FMCW solution with the ToF solution, the above-mentioned receiving end signal processing circuit cannot meet the requirements.

[0006] The embodiments of the present application aim to provide a laser radar chip, a laser radar, and a data processing method for a laser radar chip, so as to improve the poor compatibility of the receiving-end signal processing circuit of the current laser radar.

[0007] The first aspect of the present application provides a laser radar chip, which includes an analog-to-digital converter, a memory, a first detection module and a second detection module. The analog-to-digital converter is used to perform analog-to-digital conversion on an input signal to obtain a sampling signal; wherein the input signal is a beat frequency signal, and the beat frequency signal is a signal generated based on the local oscillator light of the laser radar and the echo light received by the laser radar, or the input signal is an echo signal. The memory is connected to the downstream of the analog-to-digital converter along the transmission direction of the sampling signal, and the memory is used to store the sampling signal. The first detection module is connected to the downstream of the memory along the transmission direction of the sampling signal, and the first detection module is used to extract at least one data window from the sampling signal and detect the data window when the input signal is a beat frequency signal. The second detection module is connected to the downstream of the memory along the transmission direction of the sampling signal, and the second detection module is used to detect the sampling signal when the input signal is an echo signal.

[0008] The second aspect of the present application provides a laser radar, which includes a housing, a light source module, a photoelectric detection module and the above-mentioned laser radar chip. The light source module is accommodated in the housing. The photoelectric detection module is accommodated in the housing. The laser radar chip is connected downstream of the photoelectric detection module.

[0009] A third aspect of the present application provides a data processing method for a laser radar chip, wherein the laser radar chip is the above-mentioned laser radar chip, and the method comprises:

[0010] Performing analog-to-digital conversion on the beat frequency signal to obtain a sampling signal, wherein the beat frequency signal is a signal generated based on the local oscillator light of the laser radar and the echo light received by the laser radar;

[0011] Extracting a plurality of data windows in a signal interval of the sampling signal corresponding to the same up-sweep time interval or the same down-sweep time interval of the local oscillator light in the time domain, wherein the plurality of data windows are arranged in sequence in the time domain, and any two adjacent data windows in the plurality of data windows have an overlapping area in the time domain;

[0012] A detection step is performed on each of the data windows.

[0013] The technical solution provided by this application may have the following beneficial effects:

[0014] The laser radar chip provided by the present application includes an integrated analog-to-digital converter, a memory, a first detection module and a second detection module. Among them, the first detection module is used to detect the sampling signal generated by the analog-to-digital converter when the signal acquired by the analog-to-digital converter is a beat frequency signal, and the second detection module is used to detect the sampling signal generated by the analog-to-digital converter when the signal acquired by the analog-to-digital converter is an echo signal. The laser radar chip can be applied to the receiving end signal processing circuit of the FMCW laser radar, the receiving end signal processing circuit of the ToF laser radar, and the receiving end signal processing circuit of the laser radar combining FMCW and ToF, and its compatibility is stronger.

[0015] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present application will become more apparent by describing in more detail exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0017] Figure 1 Schematic diagram of a lidar chip in some embodiments of the present application.

[0018] Figure 2 This is a schematic diagram of a laser radar chip in another embodiment of the present application.

[0019] Figure 3 Schematic diagram of the laser radar chip in some other embodiments of the present application.

[0020] Figure 4 Schematic diagram of a laser radar chip in some further embodiments of the present application.

[0021] Figure 5 Schematic diagram of the laser radar in some embodiments of the present application.

[0022] Figure 6This is a schematic block diagram of the process of the data processing method of the laser radar chip in some embodiments of the present application.

[0023] In the figure:

[0024] 1. LiDAR chip;

[0025] 100. Analog-to-digital converter;

[0026] 200, memory;

[0027] 300, first detection module; 310, windowing circuit module; 320, Fourier transform circuit module; 330, first detection circuit module; 340, first filtering module;

[0028] 400, second detection module; 410, second detection circuit module; 420, time determination circuit module; 430, second filtering module;

[0029] 500, high pass filter;

[0030] 2. Laser radar; 21. Shell; 22. Light source module; 23. Photoelectric detection module. DETAILED DESCRIPTION

[0031] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0032] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0033] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0034] In the related art, the signal processing circuit of the receiving end of the laser radar is designed for either FMCW radar or ToF radar. It can only be applied to one of the radars and perform signal detection processing. The compatibility of such receiving end signal processing circuit is poor. For example, manufacturers in the related field need to purchase or manufacture receiving end signal processing circuits of different specifications when producing FMCW laser radar and ToF laser radar; for another example, in the laser radar that needs to combine the FMCW solution with the ToF solution, the above-mentioned receiving end signal processing circuit cannot meet the requirements.

[0035] Based on this, the present application provides a laser radar chip to improve the above-mentioned deficiencies. Figure 1 , which shows a schematic diagram of the laser radar chip 1 in this embodiment, the laser radar chip 1 is configured downstream of the photoelectric detection module (not shown in the figure) in the laser radar to receive the electrical signal output by the photoelectric detection module; in other words, the electrical signal is the input signal of the laser radar chip 1, and the laser radar chip 1 is used to perform detection based on the input signal. The laser radar chip 1 includes an analog-to-digital converter 100, a memory 200, a first detection module 300 and a second detection module 400 integrated in the same substrate. The analog-to-digital converter 100 is used to perform analog-to-digital conversion on the above input signal to obtain a sampling signal; wherein the input signal is a beat signal, which is a signal generated based on the local oscillator light of the laser radar and the echo light received by the laser radar, or the sampling signal is an echo signal, which is a signal generated based on the echo light of the laser radar. The memory 200 is connected to the downstream of the analog-to-digital converter 100 along the transmission direction of the sampling signal, and the memory 200 is used to store the above sampling signal. The first detection module 300 is connected to the downstream of the memory 200 along the transmission direction of the sampling signal, and is used to extract at least one data window from the sampling signal and perform detection on the data window when the input signal is a beat signal. The second detection module 400 is also connected to the downstream of the memory 200 along the transmission direction of the sampling signal, and is used to perform detection on the sampling signal when the input signal is an echo signal. Next, the above results are described in detail in turn.

[0036] For the above analog-to-digital converter 100, please refer to Figure 1, from the flow direction of the electrical signal, the analog-to-digital converter 100 is located downstream of the photoelectric detection module in the laser radar, so as to receive the electrical signal output by the photoelectric detection module, that is, the input signal mentioned above. In the application, the upstream of the analog-to-digital converter 100 can be connected to the first photoelectric detection module for realizing FMCW photoelectric detection and / or the second photoelectric detection module for realizing ToF photoelectric detection. Specifically, the first photoelectric detection module is used to receive the local oscillator light of the laser radar and the echo light formed by the reflection of the detection light by the target object in the FMCW detection scene, so that the two beat to form a beat frequency light signal, and the first photoelectric detection module is used to photoelectrically convert the above-mentioned beat frequency light signal into the above-mentioned input signal. It should be noted that the local oscillator light and the detection light can be obtained by splitting the light beam generated by the light source in the laser radar by a spectrometer, or they can be obtained by emitting separately from two different light sources; the local oscillator light and the detection light have the same time-frequency characteristics, and the "same time-frequency characteristics" described in this application document means that the frequency of the local oscillator light and the detection light at the same time point in the time domain is consistent. The second photoelectric detection module is used to receive the echo light in the ToF detection scenario, and perform photoelectric conversion on the echo light into the above-mentioned input signal.

[0037] For the above memory 200, please continue to refer to Figure 1 , the memory 200 is connected to the downstream of the analog-to-digital converter 100 along the transmission direction of the sampling signal, and is used to store the sampling signal obtained after the analog-to-digital converter 100 samples, so as to facilitate the call of the first detection module 300 and the second detection module 400. In this embodiment, the memory 200 is a cache; a cache is a high-speed memory, and its read and write speed is faster than that of a general random access memory. It should be noted that the "downstream" described in the embodiment of the present application means the position at the rear along the transmission direction of the sampling signal in the laser radar chip 1; for example, "the memory is connected to the downstream of the analog-to-digital converter" means that the sampling signal first passes through the analog-to-digital converter 100 and then reaches the memory 200.

[0038] For the first detection module 300, please refer to Figure 2, which shows a schematic diagram of a laser radar chip 1 in another embodiment of the present application, and the first detection module 300 is used to detect the above-mentioned sampling signal in the FMCW detection scenario. In this embodiment, the first detection module 300 includes a windowing circuit module 310, a Fourier transform circuit module 320 and a first detection circuit module 330. Among them, the windowing circuit module is used to extract at least one data window from the sampling signal (i.e., the beat frequency signal) in the signal interval corresponding to the same upper frequency sweep time interval or the same lower frequency sweep time interval of the local oscillation light in the time domain. The windowing circuit module can adopt a digital circuit module that can realize data windowing in the relevant technology, and the present application does not make specific limitations on this. The Fourier transform circuit module 320 is connected to the downstream of the windowing circuit module 310, and is used to perform Fourier transform, such as fast Fourier transform, on the data window extracted by the windowing circuit module 310 to obtain a signal spectrum. The Fourier transform circuit module 320 can adopt any circuit that can realize Fourier transform, for example, the Fourier transform circuit module can be a digital signal processor or a customized Fourier transform electronic device. The first detection circuit module 330 is connected to the downstream of the Fourier transform circuit module 320, and is used to detect the signal spectrum output by the Fourier transform circuit module 320. The first detection circuit module 330 can also adopt any circuit module that can perform detection. The method adopted for detection can be dynamic threshold detection, and accordingly, the first detection circuit module 330 can be a dynamic threshold detection circuit module. For example, the dynamic threshold detection circuit module can use a constant false alarm detection method for detection, which performs detection by dynamically estimating noise, so the detection rate of the spectrum peak corresponding to the beat frequency signal can be improved to a certain extent.

[0039] Further, the first detection module 300 also includes a first filtering module 340. The above-mentioned Fourier transform circuit module 320, the first detection circuit module 330 and the first filtering module 340 correspond one to one; the first filtering module 340 is connected between the Fourier transform circuit module 320 and the first detection circuit module 330, and the setting of the first filtering module 340 is intended to filter the spectrum output by the Fourier transform circuit module 320 to improve the signal detection rate. In this embodiment, the first filtering module 340 is a digital filter, and a bandpass filter, and the upper and lower limits of its passband can be matched and designed with the frequency range of the beat frequency signal, for example, the lower limit value of the passband of the digital filter is configured as the lower limit value of the frequency of the beat frequency signal, and the upper limit value of the passband of the digital filter is configured as the upper limit value of the frequency of the beat frequency signal. It should be noted that the "passband of the bandpass filter" described in this application document means the passband corresponding to the -3db bandwidth of the bandpass filter. Of course, in other embodiments, the first filtering module 340 may also include a matched filter to improve the signal-to-noise ratio of the detection.

[0040] Please read further Figure 3 , which shows a schematic diagram of a laser radar provided by another embodiment of the present application. In this embodiment, the first detection module 300 includes a windowing circuit module 310, a plurality of Fourier transform circuit modules 320 and a plurality of first detection circuit modules 330. The windowing circuit module 310 is used to extract a plurality of data windows from the sampling signal (i.e., the signal after the beat frequency signal is sampled) in the time domain corresponding to the same up-sweep time interval or the same down-sweep time interval of the local oscillator light; wherein the plurality of data windows are arranged in sequence in the time domain, and any two adjacent data windows in the plurality of data windows have an overlapping area in the time domain. Each Fourier transform circuit module 320 in the same first detection module 300 is connected to the above-mentioned windowing circuit module 310. The data windows corresponding to each Fourier transform circuit module 320 are arranged in sequence in the time domain, and as described above, there is an overlapping area between two adjacent data windows. Each first detection circuit module 330 is correspondingly connected to a Fourier transform circuit module 320.

[0041] In this embodiment, the sampling signal has multiple data windows in the signal interval corresponding to the same up-sweep time interval or the same down-sweep time interval of the local oscillator light. For example, the sweep waveform of the local oscillator light is a triangular wave, and the triangular wave has an up-sweep time interval and a down-sweep time interval, and the opening positions of the above-mentioned data windows correspond to the same up-sweep time interval or the same down-sweep time interval of the triangular wave in the time domain. For another example, the sweep waveform of the local oscillator light is a sawtooth wave, and the sawtooth wave has an up-sweep time interval, and the opening positions of the above-mentioned data windows correspond to the same up-sweep time interval of the sawtooth wave in the time domain. It is worth mentioning that those skilled in the art can understand that each data window corresponding to the same up-sweep or the same down-sweep of the local oscillator light should be opened in the time interval where the frequency of the beat signal is constant.

[0042] In this embodiment, in the signal interval of the same up-sweep time interval or the same down-sweep time interval of the local oscillator light in the time domain, any two adjacent data windows have an overlapping area in the time domain. For example, in two data windows, the end of the first data window and the beginning of the second data window have an overlapping time period in the time domain. The specific position of the overlapping area can be an area between one-third and two-thirds of the length of the data window time domain. Generally, the larger the overlapping area, the more data windows can be opened in a unit time domain. The number of data windows opened can be set according to actual needs, and the width corresponding to each data window can be set according to actual needs. By setting adjacent data windows to have overlapping areas, on the one hand, the number of data windows that can be opened can be increased within a limited time, thereby increasing the point frequency of the point cloud, and the resolution of the laser radar; on the other hand, each data window is very close in the time domain, and each data window theoretically has a high probability of corresponding to the same target object. Therefore, after each data window is detected, the real signal can be judged based on the similarity of the spectrum peaks found from each data window to improve the accuracy of signal detection.

[0043] It is worth mentioning that in this embodiment, the windowing circuit module 310, the Fourier transform circuit module 320, the first detection circuit module 330 and the first filtering module 340 in the above-mentioned first detection module are all implemented by hardware, and each module can adopt a circuit module that can realize the corresponding function in the relevant technology; but it should be understood that the present application is not limited to this. In other embodiments of the present application, the windowing circuit module 310 can be replaced by software implementation. For example, the windowing function can be configured based on the digital signal processor to realize the softening of the hardware of the windowing circuit module 310; similarly, the Fourier transform circuit module 320, the first detection circuit module 330 and the first filtering module 340 are also the same. In other words, as long as it is ensured that the first detection module 300 can perform detection processing based on the beat signal data stored in the memory 200; the present application does not specifically limit the implementation of windowing, Fourier transform and detection by hardware circuits and / or software algorithms.

[0044] For the second detection module 400, please continue to refer to Figure 2In this embodiment, the second detection module 400 is used to detect the above-mentioned sampling signal in the ToF detection scenario. In this embodiment, the second detection module 400 includes a second detection circuit module 410 and a time determination circuit module 420. Among them, the second detection circuit module 410 is used to receive the sampling signal after analog-to-digital conversion, and perform detection based on the sampling signal to obtain the target signal. The second detection circuit module 410 can adopt the detection circuit in the related art. Similar to the first detection circuit module 330, the second detection circuit module 410 can also use dynamic threshold detection for detection, that is, the second detection circuit module 410 is a dynamic threshold detection circuit module, so as to improve the reliability of echo signal detection to a certain extent.

[0045] The time determination circuit module 420 is used to determine the corresponding time corresponding to the echo signal according to the target signal determined by the detection, so that the processing module inside the laser radar can determine the flight time of the detection light based on the sending time of the detection light, thereby determining the distance of the target object. In some embodiments, the time determination circuit module 420 includes a constant ratio timing circuit module. Specifically, the constant ratio timing circuit module includes a delayer, an attenuator and a comparator; the delayer is used to delay the sampling signal, and the attenuator is connected in parallel with the delayer, which is used to attenuate the sampling signal. One of the in-phase input terminal and the inverting input terminal of the comparator is connected to the delayer, and the other is connected to the attenuator, so that constant ratio timing identification can be achieved.

[0046] Furthermore, the second detection module 400 also includes a second filtering module 430. The second filtering module 430 is connected to the upstream of the second detection circuit module 410, and is used to receive the sampling signal and filter the sampling signal to improve the signal detection rate. In this embodiment, the first filtering module 340 is a matched filter, and the matched filter can filter in a manner that ensures a high signal-to-noise ratio, thereby facilitating the improvement of the signal detection rate of the downstream second detection module 410.

[0047] In some embodiments, the laser radar chip 1 also includes a high-pass filter 500, which is connected downstream of the memory 200 and located upstream of the first detection module 300 and the second detection module 400; the high-pass filter is used to perform initial filtering on the above-mentioned sampling signal to filter out the DC component.

[0048] The above description is based on an example in which the laser radar chip 1 includes an analog-to-digital converter 100 and its corresponding first detection module 300 and second detection module 400, but it should be understood that the present application is not limited thereto. For example, please refer to Figure 4, which shows a schematic diagram of a laser radar chip 1 in some other embodiments of the present application, the laser radar chip 1 includes multiple analog-to-digital converters 100, multiple memories 200, multiple first detection modules 300 and multiple second detection modules 400; each analog-to-digital converter 100, memory 200, first detection module 300 and second detection module 400 corresponds to each other. The laser radar chip 1 includes multiple signal acquisition and detection channels, each channel can be used for signal acquisition and processing in FMCW detection scenarios, or for signal acquisition and processing in ToF detection scenarios, or part of each channel is used for FMCW detection scenarios, and part is used for signal acquisition and processing in ToF detection scenarios. This laser radar chip 1 has a wide range of application scenarios and strong compatibility.

[0049] In summary, the laser radar chip 1 provided in the present application includes an integrated analog-to-digital converter 100, a memory 200, a first detection module 300 and a second detection module 400. Among them, the first detection module 300 is used to detect the sampling signal generated by the analog-to-digital converter 100 when the signal acquired by the analog-to-digital converter 100 is a beat frequency signal, and the second detection module 400 is used to detect the sampling signal generated by the analog-to-digital converter 100 when the signal acquired by the analog-to-digital converter 100 is an echo signal. The laser radar chip 1 can be applied to the receiving end signal processing circuit of the FMCW laser radar, the receiving end signal processing circuit of the ToF laser radar, and the receiving end signal processing circuit of the laser radar combining FMCW and ToF, and its compatibility is stronger.

[0050] In addition, the present application improves the integration of the laser radar by integrating the device modules such as the analog-to-digital converter 100, the memory 200, the first detection module 300 and the second detection module 400 into the same chip. In addition, the first detection module 300 is used to detect the data window with overlapping areas, which can improve the resolution of the laser radar.

[0051] Based on the same inventive concept, the present application embodiment also provides a laser radar 2, see Figure 5 The laser radar comprises a housing 21, a light source module 22, a photoelectric detection module 23 and the above-mentioned laser radar chip 1. The housing 21 is a mounting base for the remaining structures, and the above-mentioned structures are all accommodated in the housing 21.

[0052] In some embodiments, the laser radar 2 is a ToF laser radar. The housing 21 is a mounting base for the above-mentioned components. The light source module 22 is used to generate detection light. The photoelectric detection module 23 is used to receive echo light. The laser radar chip 1 is used to receive the signal output by the photoelectric detection module, and realizes signal detection through the analog-to-digital converter 100, the memory 200 and the second detection module 400.

[0053] In some embodiments, the laser radar 2 is a FMCW laser radar. The housing 21 is a mounting base for the above-mentioned components. The light source module 22 is used to generate detection light and local oscillator light. The photoelectric detection module 23 is used to receive the local oscillator light and the echo light, and generate the above-mentioned beat signal. The laser radar chip 1 is used to receive the signal output by the photoelectric detection module, and realizes the signal detection through the analog-to-digital converter 100, the memory 200 and the first detection module 300.

[0054] In some embodiments, the laser radar 2 is a laser radar that combines FMCW detection with ToF detection. The housing 21 is a mounting base for the above-mentioned devices. The laser radar 2 includes a plurality of light source modules 22, and the plurality of light source modules 22 are divided into a first light source module and a second light source module; wherein the first light source module is used to generate detection light for ToF detection, and the second light source module is used to generate detection light and local oscillation light for FMCW detection. The photoelectric detection module 23 corresponds one-to-one to the above-mentioned light source modules, and some photoelectric detection modules are used to receive echo light, and some photoelectric detection modules are used to receive local oscillation light and echo light, and generate the above-mentioned beat frequency signal. The laser radar chip 1 includes a multi-channel analog-to-digital converter 100, and multiple memories 200, multiple first detection modules 300, and multiple second detection modules 400 respectively corresponding to the analog-to-digital converters 100; wherein, part of the analog-to-digital converters 100 corresponds to the first light source module, so that the second detection module 400 corresponding to the analog-to-digital converter 100 performs detection, and part of the analog-to-digital converters 100 corresponds to the second light source module, so that the first detection module 300 corresponding to the analog-to-digital converter performs detection. The laser radar can realize a solution combining ToF and FMCW detection through the laser radar chip 1.

[0055] To sum up, the laser radar 2 provided in the embodiment of the present application includes the above-mentioned laser radar chip 1. Therefore, the laser radar chip 1 in the laser radar 2 also has the characteristic of strong compatibility. Correspondingly, the laser radar also has the characteristic of more flexible application scenarios.

[0056] Based on the same inventive concept, the present application also provides a laser radar chip data processing method, which is applied to the FMCW signal processing channel of the laser radar chip in any of the above embodiments. Figure 6 , Figure 6 It is a flow chart of a data processing method of a laser radar chip in some embodiments of the present application. The method is applied to the laser radar chip 1 mentioned in any of the above embodiments, and includes the following steps S100 to S200.

[0057] S100: Perform analog-to-digital conversion on the beat signal to obtain a sampling signal; wherein the beat signal is a signal generated based on the local oscillator light of the laser radar and the echo light received by the laser radar. The data processing method of the laser radar chip of this embodiment can be applied to FMCW laser radar (or FMCW and ToF combined laser radar). FMCW laser radar transmits continuous detection light to the target object, and then receives the local oscillator light with the same time-frequency characteristics as the detection light signal and the echo light formed by the target object reflecting the detection light, so as to detect the target object. The local oscillator light and the echo light coherently beat in the photoelectric detection module to generate a beat signal. In step S100, the beat signal can be converted into a digital signal by an analog-to-digital converter, so that the sampling of the beat signal can be achieved.

[0058] S200: extract multiple data windows in a signal interval of the sampling signal corresponding to the same up-sweep time interval or down-sweep time interval of the local oscillator light in the time domain; wherein the multiple data windows are arranged in sequence in the time domain, and any two adjacent data windows have an overlapping area in the time domain. The windowing step can be implemented by a windowing circuit or a windowing function.

[0059] S300: Perform a detection step on each data window, wherein the detection step may include the following steps S310 to S320.

[0060] S310: Perform Fourier transform on the data window to obtain the corresponding signal spectrum. In this embodiment, the data window obtained after the above windowing is extracted by the Fourier transform circuit module, and Fourier transform is performed, so as to obtain the signal spectrum corresponding to the data window. The number of Fourier transform circuit modules is consistent with the number of data windows in the above time interval. Each Fourier transform circuit module extracts a data window to perform the above operation, that is, multiple signal spectra can be quickly obtained through multiple Fourier transform circuit modules. Among them, the signal spectrum can be an amplitude spectrum or a power spectrum; the following is an example of the signal spectrum being a power spectrum, that is, the horizontal axis of the signal spectrum is the frequency axis, and the vertical axis is the power axis.

[0061] S320: According to preset conditions, a preset number of spectrum peaks are determined in the signal spectrum. For example, a preset number of spectrum peaks can be determined in the signal spectrum according to a dynamic threshold detection method. In some embodiments, a preset number of spectrum peaks can be determined in the signal spectrum according to the signal estimation spectrum; wherein the signal estimation spectrum is the difference between the signal spectrum and the noise estimation spectrum. Specifically, the noise estimation spectrum can be estimated first, and then the signal estimation spectrum can be determined based on the difference between the signal spectrum and the noise estimation spectrum, and then a preset number of spectrum peaks with the largest power can be determined based on the signal estimation spectrum, such as 5 spectrum peaks can be determined. In other embodiments, a preset number of spectrum peaks can be determined in the signal spectrum according to the signal-to-noise ratio estimation value of each point in the signal spectrum; wherein the signal-to-noise ratio estimation value is the difference between the power value of the sample point in the signal spectrum and the noise power estimation value, and the quotient of the noise power estimation value. Specifically, the noise power estimation spectrum can be estimated first, and then the signal power estimation spectrum can be determined based on the difference between the signal spectrum and the noise power estimation spectrum, and then the signal-to-noise ratio of each sample point can be determined based on the quotient of the signal power estimation spectrum and the noise power estimation spectrum, and finally the preset number of spectrum peaks with the largest signal-to-noise ratio can be determined, such as 5 spectrum peaks. The number of spectrum peaks determined can be adjusted according to the specific computing power of the laser radar, and can be any number of more than 2; of course, only one can be determined.

[0062] It should be noted that, in this embodiment, the "spectral peak" described in this application document includes at least three sample points, and the at least three sample points include a first sample point, at least one second sample point, and at least one third sample point. The power of the first sample point is the maximum point in the spectrum peak, the power of the second sample point and the third sample point is lower than that of the first sample point, the second sample point and the third sample point are arranged on both sides of the first sample point along the frequency axis, the horizontal axis of the signal spectrum is the frequency axis, and the vertical axis of the signal spectrum is the power axis.

[0063] It is understandable that the detection can also be based on fixed threshold detection to determine a preset number of spectrum peaks in the signal spectrum; the main difference between it and the aforementioned implementation is that the noise estimation is flat, and the rest is roughly the same and will not be repeated here. In addition, a combination of fixed threshold and dynamic threshold detection can also be adopted to determine a preset number of spectrum peaks in the signal spectrum.

[0064] In some embodiments, the above-mentioned preset number is greater than or equal to 2. After the above-mentioned step S300, the data processing method of the above-mentioned laser radar chip also includes steps S400 to S500, which are specifically as follows.

[0065] S400: Determine the echo signal spectrum peak corresponding to the current signal spectrum based on the frequency of each spectrum peak in the current signal spectrum and the frequency of each spectrum peak in the remaining signal spectra. In this embodiment, when judging whether a target spectrum peak in a target signal spectrum is a signal, the target spectrum peak can be compared with each spectrum peak in other signal spectra, such as the spectrum peaks in the neighboring signal spectrum of the target signal spectrum. If there are spectrum peaks with similar frequencies in other signal spectra, the count value corresponding to the confidence of the target spectrum peak is increased, such as by adding one. After performing the above operation on all the determined spectrum peaks in the target signal spectrum, the spectrum peak with the highest confidence in the target signal spectrum can be obtained, and the spectrum peak with the highest confidence is determined as the echo signal spectrum peak.

[0066] S500: Determine the frequency of the echo signal spectrum peak. After determining the echo signal spectrum peak, the horizontal coordinate of the spectrum peak, that is, the frequency, can be output for subsequent solution of distance and speed. In addition, the signal strength of the echo signal can also be determined. In this embodiment, the signal spectrum is a power spectrum, and the vertical coordinate of the echo signal spectrum peak is power, which can characterize the strength of the echo signal; in other embodiments, when the signal spectrum is an amplitude spectrum, the vertical coordinate of the echo signal spectrum peak is amplitude, which can also characterize the signal strength.

[0067] It should be understood that even if the present embodiment determines the echo signal spectrum peak in a confidence manner, the present application is not limited thereto, and in the embodiments of the present application, the echo signal spectrum peak may also be determined in other ways from multiple spectrum peaks of the signal spectrum. For example, in some embodiments, the signal power estimation of each spectrum peak may be determined, and the spectrum peak with the largest signal power estimation may be determined as the echo signal spectrum peak, wherein the signal power estimation is the difference between the power of the spectrum peak in the signal spectrum and the noise power estimation of the spectrum peak. For example, in other embodiments, the signal-to-noise ratio of each spectrum peak may be determined, and the spectrum peak with the largest signal-to-noise ratio may be determined as the echo signal spectrum peak.

[0068] In some embodiments, after step S100 and before step S200, the data processing method of the laser radar chip also includes step S110, as follows.

[0069] S110: Filter the sampled signal obtained after analog-to-digital conversion to obtain a filtered sampled signal. A filter can be used to filter the sampled signal after analog-to-digital conversion to remove noise present in the digital signal. In this embodiment, the filter is a digital filter. Of course, in other embodiments, the filter can also be other forms of filters, which are not limited here. Optionally, the filter for filtering the beat frequency signal after analog-to-digital conversion is a bandpass filter, then the above step S100 is: bandpass filter the beat frequency signal after analog-to-digital conversion to obtain a filtered beat frequency signal.

[0070] Further, based on the above step S110, in some embodiments, the step of performing a detection step on each data window in the above step S300 includes: performing a detection step on the signal spectrum corresponding to each data window in the frequency band corresponding to the passband of the sampling signal. Specifically, it can be that in step S320, a preset number of spectrum peaks are determined in the frequency band corresponding to the passband of the beat frequency signal. Since the passband of the filter is designed to adapt to the frequency band of the sampling signal, in other words, the frequency of the sampling signal must be within the passband of the filter. Therefore, the signal can be detected by performing a detection step in the frequency band corresponding to the passband, so as to avoid the false detection of the spectrum peak outside the above frequency band as the signal when detecting on the entire frequency axis of the signal spectrum.

[0071] In addition, it is considered that a small amount of detection light may not be emitted from the window of the laser radar, but may be reflected by the internal components such as the window to form echo light and reach the photoelectric detection module, which may cause the laser radar to misjudge the presence of a target object at a very close distance. For the convenience of explanation, this signal is referred to as a leading signal below. In order to overcome the deficiency of misjudgment caused by the leading signal, in some embodiments, the above-mentioned step of detecting each data window includes: performing a detection step on the signal spectrum corresponding to each data window in a frequency band greater than the first frequency threshold.

[0072] Specifically, the frequency of the sampling signal, that is, the frequency of the beat signal, is actually the coupling of the distance beat frequency and the speed beat frequency. Since the leading signal is not outside the laser radar, the frequency of the beat signal corresponding to the leading signal is actually the distance beat frequency. The distance beat frequency is related to the distance, so a smaller distance threshold can be set according to the optical path of the detection light from the light source module to the window, and the distance threshold can be equal to twice the above optical path, or a preset multiple of the above optical path; and the corresponding first frequency threshold is determined based on the distance threshold. When the frequency of the spectrum peak determined from the signal spectrum is less than the first frequency threshold, it can be considered that the spectrum peak is caused by the leading signal and should be filtered out; when the frequency of the spectrum peak determined from the signal spectrum is greater than the first frequency threshold, the spectrum peak can be excluded as the spectrum peak caused by the leading signal. That is, the detection step can be performed in a frequency band greater than the first frequency threshold. It is worth noting that the selection of the first frequency threshold is not necessarily based on the optical path from the light source module to the window, but can also be converted according to a specific distance, such as 20 cm, 30 cm or 50 cm.

[0073] To sum up, the data processing method of the laser radar chip provided in the embodiment of the present application detects the sampling signal by means of stacked window detection, that is, multiple data windows are opened in the signal interval corresponding to the same upper sweep time (or the same lower sweep time) of the local oscillator signal in the time domain of the sampling signal, and detection is performed; in this way, the number of point frequencies of the laser radar point cloud can be increased to improve the resolution of the laser radar.

[0074] In addition, the method according to the present application may also be implemented as a computer program or a computer program product, which includes computer program code instructions for executing some or all of the steps in the above method of the present application.

[0075] Alternatively, the present application can also be implemented as a non-temporary machine-readable storage medium (or computer-readable storage medium, or machine-readable storage medium) on which executable code (or computer program, or computer instruction code) is stored. When the executable code (or computer program, or computer instruction code) is executed by a processor of an electronic device (or electronic device, server, etc.), the processor executes part or all of the steps of the above-mentioned method according to the present application.

[0076] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the application herein may be implemented as electronic hardware, computer software, or combinations of both.

[0077] The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system and method according to multiple embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a part of a module, a program segment or a code, and the part of the module, the program segment or the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or the flow chart, and the combination of the square boxes in the block diagram and / or the flow chart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0078] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

[0079] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated again here.

[0080] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A laser radar chip, characterized in that: include: An analog-to-digital converter, used for performing analog-to-digital conversion on an input signal to obtain a sampling signal; wherein the input signal is a beat frequency signal, which is a signal generated based on the local oscillator light of the laser radar and the echo light received by the laser radar, or the input signal is an echo signal, which is a signal generated based on the echo light; A memory connected downstream of the analog-to-digital converter along a transmission direction of the sampling signal, the memory being used to store the sampling signal; a first detection module connected to the downstream of the memory along the transmission direction of the sampling signal, the first detection module being used for extracting at least one data window from the sampling signal and detecting the data window when the input signal is a beat frequency signal; and The second detection module is connected to the downstream of the memory along the transmission direction of the sampling signal, and the second detection module is used to detect the sampling signal when the input signal is an echo signal.

2. The laser radar chip according to claim 1, characterized in that: The first detection module comprises: A Fourier transform circuit module, connected to the downstream of the memory along the transmission direction of the beat frequency signal, and configured to perform Fourier transform on the data window to obtain a signal spectrum; and The first detection circuit module is connected to the downstream of the Fourier transform circuit module, and is used for detecting the signal spectrum.

3. The laser radar chip according to claim 2, characterized in that: The first detection module is used to extract multiple data windows from the sampling signal in a signal interval corresponding to the same up-sweep time interval or the same down-sweep time interval of the local oscillator light in the time domain, wherein the multiple data windows are arranged in sequence in the time domain, and any two adjacent data windows in the multiple data windows have an overlapping area in the time domain; The first detection module includes a plurality of the Fourier transform circuit modules and a plurality of first detection circuit modules, each of the Fourier transform circuit modules is connected downstream of the memory, and each of the first detection circuit modules corresponds one-to-one to each of the Fourier transform circuit modules.

4. The laser radar chip according to claim 3, characterized in that: The first detection module includes a windowing circuit module; The windowing circuit module is used to extract multiple data windows within a signal interval of the sampling signal corresponding to the same up-sweep time interval or the same down-sweep time interval of the local oscillator light in the time domain, wherein the multiple data windows are arranged in sequence in the time domain, and any two adjacent data windows among the multiple data windows have an overlapping area in the time domain.

5. The laser radar chip according to claim 2, characterized in that: The first detection circuit module is a dynamic threshold detection circuit module.

6. The laser radar chip according to claim 2, characterized in that: The first detection module also includes a first filtering module; The first filtering module is connected between the Fourier transform circuit module and the first detection circuit module.

7. The laser radar chip according to claim 1, characterized in that: The second detection module comprises: a second detection circuit module, configured to receive the sampled signal and perform detection based on the sampled signal; and The time determination circuit module is used to determine the corresponding time corresponding to the echo signal according to the target signal determined by the detection.

8. The laser radar chip according to claim 7, characterized in that: The second detection circuit module is a dynamic threshold detection circuit module; The time determination circuit module is a constant ratio timing circuit module.

9. The laser radar chip according to claim 7, characterized in that: The second detection module also includes a second filtering module; The second filtering module is located between the memory and the second detection circuit module.

10. The laser radar chip according to claim 1, characterized in that: The laser radar chip includes a plurality of analog-to-digital converters, a plurality of memories, a plurality of first detection modules and a plurality of second detection modules; There is a one-to-one correspondence between the analog-to-digital converter, the memory, the first detection module and the second detection module.

11. A laser radar, characterized in that: include: case; A light source module is housed in the housing; A photoelectric detection module is housed in the housing; as well as The laser radar chip as described in any one of claims 1 to 10, wherein the laser radar chip is connected downstream of the photoelectric detection module.

12. A method for processing data of a laser radar chip, wherein the laser radar chip is the laser radar chip according to any one of claims 1 to 10, characterized in that: The method comprises: Performing analog-to-digital conversion on the beat frequency signal to obtain a sampling signal, wherein the beat frequency signal is a signal generated based on the local oscillator light of the laser radar and the echo light received by the laser radar; Extracting a plurality of data windows in a signal interval of the sampling signal corresponding to the same up-sweep time interval or the same down-sweep time interval of the local oscillator light in the time domain, wherein the plurality of data windows are arranged in sequence in the time domain, and any two adjacent data windows in the plurality of data windows have an overlapping area in the time domain; A detection step is performed on each of the data windows.

13. The method according to claim 12, characterized in that The detection step comprises: Performing Fourier transform on the data window to obtain a corresponding signal spectrum; According to preset conditions, a preset number of spectrum peaks are determined in the signal spectrum, wherein each of the spectrum peaks includes at least three sample points, the at least three sample points include a first sample point, at least one second sample point and at least one third sample point, the vertical axis coordinate of the first sample point is a maximum point in the spectrum peak, the vertical axis coordinates of the second sample point and the third sample point are lower than the first sample point, the second sample point and the third sample point are arranged on both sides of the first sample point along the horizontal axis, the horizontal axis of the signal spectrum is the frequency axis, and the vertical axis of the signal spectrum is the power axis or the amplitude axis.

14. The method according to claim 13, characterized in that The preset number is greater than or equal to 2, and the method further includes: Determining the echo signal spectrum peak corresponding to the signal spectrum according to the frequency of each spectrum peak in the signal spectrum and the frequency of each spectrum peak in the remaining signal spectra; The frequency of the echo signal spectrum peak is determined.

15. The method according to claim 12, characterized in that The detection step is performed in the form of dynamic threshold detection.

16. The method according to claim 12, characterized in that After the step of performing analog-to-digital conversion on the beat frequency signal to obtain a sampling signal, and before the step of extracting a plurality of data windows in a signal interval of the sampling signal corresponding to the same up-sweep time interval or the same down-sweep time interval of the local oscillator light in the time domain, the method further includes: The sampled signal is filtered to obtain a filtered sampled signal.

17. The method according to claim 16, characterized in that: The step of detecting each of the data windows comprises: performing a detection step on each of the data windows within a frequency band greater than a first frequency threshold; and / or, The filtering of the sampling signal includes: performing bandpass filtering on the sampling signal; the detection step of each data window includes: performing a detection step on each data window within a frequency band corresponding to a passband of the bandpass filtering of the sampling signal.

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