Signal processing circuit module, frequency-modulated continuous wave radar and radar system control method

Abstract

The application is suitable for the field of radar technology, and provides a signal processing circuit module, a frequency-modulated continuous wave radar and a radar system control method.The signal processing circuit module comprises a signal branching module, the signal branching module comprising a wave divider; a first photoelectric detection module connected with the signal branching module; a second photoelectric detection module connected with the signal branching module; and a calculation module connected with the first photoelectric detection module and the second photoelectric detection module respectively, the calculation module comprising an adding unit, an analog-to-digital conversion unit and a digital processing unit.The wave divider is used for processing echo signals corresponding to two detection signals of different wavelengths, distinguishing the echo optical signals of the two different wavelengths, and calculating the Doppler velocity frequency and the distance-based frequency when the Doppler velocity frequency is greater than the distance-based frequency based on the frequency of the first beat frequency signal and the frequency of the second beat frequency signal, so as to realize the decoupling of the velocity measurement and the distance measurement of the target object.

Description

Technical Field

[0001] This application belongs to the field of radar technology, and in particular relates to a signal processing circuit module, a frequency modulated continuous wave radar system, a radar system control method, a terminal device, and a computer-readable storage medium. Background Technology

[0002] Frequency modulated continuous wave (FMCW) radar systems are ranging devices that have been widely used in intelligent transportation and autonomous driving fields because they can quickly and accurately detect road conditions and the environment around vehicles.

[0003] FMCW radar systems typically generate frequency-modulated radio frequency or laser signals (hereinafter referred to as frequency-modulated signals), then split the frequency-modulated signals into two signals. One signal is used as a local oscillator signal, and the other signal is emitted to the target object and reflected by the surface of the target object to form an echo signal. The echo signal is received and mixed with the aforementioned local oscillator signal to generate a beat frequency signal. The speed and distance of the target object can be calculated based on the frequency of the beat frequency signal. Summary of the Invention

[0004] With the development of FMCW radar detection technology, researchers have begun to explore schemes that use dual lasers to simultaneously emit laser signals, with both signals transmitted and received along the same optical path, to calculate the distance and velocity of a target object relative to the FMCW radar. However, current lidar systems cannot distinguish between the two types of echo signals when receiving the echo signals, thus preventing the calculation of distance and velocity.

[0005] This application provides a signal processing circuit module, a frequency modulated continuous wave radar, a radar system control method, a terminal device, and a computer-readable storage medium to improve the current situation where FMCW lidar using dual lasers cannot distinguish between two echo light signals.

[0006] In a first aspect, embodiments of this application provide a signal processing circuit module, including:

[0007] The signal splitting module includes a wavelength divider, which is used to receive the original echo optical signal including a first echo optical signal and a second echo optical signal, and perform wavelength division processing to obtain the first echo optical signal and the second echo optical signal with different wavelengths.

[0008] The first photoelectric detection module is used to receive the first echo light signal and the first local oscillator light signal corresponding to the first echo light signal, and output the first beat frequency electrical signal.

[0009] The second photoelectric detection module is used to receive the second echo optical signal and the second local oscillator optical signal corresponding to the second echo optical signal, and output a second beat frequency electrical signal; and

[0010] The calculation module includes an addition unit, an analog-to-digital conversion unit, and a digital processing unit. The addition unit is connected to the first photoelectric detection module and the second photoelectric detection module respectively to receive the first beat frequency electrical signal and the second beat frequency electrical signal, and superimpose them to output a first addition electrical signal. The analog-to-digital conversion unit is connected to the addition unit and is used to perform analog-to-digital conversion on the first addition electrical signal to output a first digital electrical signal. The digital processing unit is connected to the analog-to-digital conversion unit and is used to determine the distance and velocity of the target object relative to the radar based on the first digital electrical signal.

[0011] In one implementation of the first aspect, the signal splitting module further includes:

[0012] A first polarization beam splitter is disposed between the wave splitter and the first photoelectric detection module. The first polarization beam splitter receives the first echo light signal and outputs two first echo sub-signals with the same polarization direction as the first local oscillator signal; and

[0013] The second polarization beam splitter is located between the wave splitter and the second photoelectric detection module. The second polarization beam splitter is used to receive the second echo light signal and output two second echo sub-signals with the same polarization direction as the second local oscillator light signal.

[0014] The first photoelectric detection module is used to receive the first local oscillator light signal and one first echo sub-signal, and the second photoelectric detection module is used to receive the second local oscillator light signal and one second echo sub-signal.

[0015] In one implementation of the first aspect, the signal processing circuit module includes two first photoelectric detection modules, each of which is used to receive the first local oscillator light signal and one first echo sub-signal.

[0016] The signal processing circuit module includes two second photoelectric detection modules, each of which is used to receive the second local oscillator signal and a second echo sub-signal.

[0017] The calculation module includes two addition units, each of which is connected to a first photoelectric detection module and a second photoelectric detection module.

[0018] In one implementation of the first aspect, the computing module includes:

[0019] The first photoelectric detection module includes:

[0020] A first mixer is configured to receive the first local oscillator optical signal and the first echo optical signal, and to cause the first local oscillator optical signal and the first echo optical signal to beat at a frequency to generate a first beat frequency optical signal; and

[0021] A first balanced photodetector is connected to the first mixer and is used to perform balanced detection on the first beat frequency optical signal output by the first mixer in order to generate the first beat frequency electrical signal.

[0022] The second photoelectric detection module includes:

[0023] A second mixer is configured to receive the second local oscillator signal and the second echo signal, so that the second local oscillator signal and the second echo signal beat at a frequency to generate a second beat-frequency optical signal; and

[0024] A second balanced photodetector, connected to the second mixer, is used to perform balanced detection on the second beat frequency optical signal output by the second mixer to generate the second beat frequency electrical signal.

[0025] In one implementation of the first aspect, the computing module further includes:

[0026] The first signal amplification unit is connected between the first photoelectric detection module and the addition unit, and is used to amplify the first beat frequency electrical signal to output the amplified first beat frequency electrical signal.

[0027] The second signal amplification unit is connected between the second photoelectric detection module and the addition unit, and is used to amplify the second beat frequency electrical signal to output the amplified second beat frequency electrical signal.

[0028] In one implementation of the first aspect, the computing module further includes:

[0029] The first shaping unit is connected between the first signal amplification unit and the digital processing unit, and is used to shape the amplified first beat frequency electrical signal to obtain a first square wave signal.

[0030] The second shaping unit is connected between the second signal amplification unit and the digital processing unit, and is used to shape the amplified second beat frequency electrical signal to obtain a second square wave signal.

[0031] The digital processing unit determines the frequency of the first beat frequency electrical signal based on the first square wave signal, and determines the frequency of the second beat frequency electrical signal based on the second square wave signal.

[0032] In one implementation of the first aspect, the digital processing unit includes:

[0033] A first time gate circuit, connected to a first shaping unit, is used to acquire the frequency of the first square wave signal; and

[0034] The second time gate circuit is connected to the second shaping unit and is used to obtain the frequency of the second square wave signal.

[0035] Secondly, embodiments of this application provide a frequency-modulated continuous wave, including:

[0036] The signal transmitting end is used to generate a first detection light signal, a first local oscillator light signal corresponding to the first detection light signal, a second detection light signal, and a second local oscillator light signal corresponding to the second detection light signal, and to transmit the first detection light signal and the second detection light signal through the same transmission optical path, wherein the wavelengths of the first detection light signal and the second detection light signal are different;

[0037] A signal receiving end is used to receive raw echo light signals, the raw echo light signals including a first echo light signal and a second echo light signal, wherein the first echo light signal is formed by the reflection of the first detection light signal by the target object, and the second echo light signal is formed by the reflection of the second detection light signal by the target object; and

[0038] The signal processing circuit module as described in the first aspect or any alternative method of the first aspect is connected to the signal transmitting end and the signal receiving end respectively.

[0039] In the first implementation of the second aspect, the aforementioned signal transmitting end includes:

[0040] The frequency modulation signal generation module is used to generate first and second frequency modulation signals of different wavelengths.

[0041] A splitter, connected to the frequency modulation signal generation module, is used to split the first frequency modulation signal to obtain a first probe light signal and a first local oscillator light signal corresponding to the first probe light signal, and to split the second frequency modulation signal to obtain a second probe light signal and a second local oscillator light signal corresponding to the second probe light signal; and

[0042] The transmitting optical path is used to receive and transmit the first detection optical signal and the second detection optical signal output by the splitter.

[0043] Thirdly, embodiments of this application provide a radar system control method, applied to a frequency-modulated continuous wave radar as described in the second aspect and any optional method of the second aspect, the radar system control method comprising:

[0044] The control signal transmitting end generates a first detection light signal, a first local oscillator light signal corresponding to the first detection light signal, a second detection light signal, and a second local oscillator light signal corresponding to the second detection light signal, and transmits the first detection light signal and the second detection light signal through the same transmission optical path to detect the target object;

[0045] The original echo light signal is processed by the signal processing circuit module to determine the direction and distance of the target object's motion.

[0046] Fourthly, embodiments of this application provide a terminal device, the terminal device including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the radar system control method as described in the third aspect or any optional method of the third aspect.

[0047] Fifthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the radar system control method as described in the third aspect or any alternative method of the third aspect.

[0048] Sixthly, embodiments of this application provide a computer program product that, when run on a terminal device, causes the terminal device to execute the radar system control method described in the third aspect or any optional method of the third aspect.

[0049] The beneficial effects of the embodiments in this application compared with the prior art are:

[0050] Implementing the signal processing circuit module, frequency-modulated continuous wave radar, radar system control method, terminal equipment, and computer-readable storage medium provided in this application has the following beneficial effects:

[0051] The signal processing circuit module provided in this application embodiment processes the echo signals corresponding to two detection signals of different wavelengths by a wave demultiplexer, which can distinguish the echo light signals of two different wavelengths. Furthermore, the signal processing circuit can also calculate the Doppler velocity-based frequency and the distance-based frequency when the Doppler velocity frequency is greater than the distance-based frequency based on the frequency of the first beat frequency signal and the frequency of the second beat frequency signal, thereby calculating the speed and distance of the target object and realizing the decoupling of speed and distance measurement of fast-moving target objects. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of the structure of a frequency-modulated continuous wave radar system provided in an embodiment of this application;

[0054] Figure 2 This is a schematic diagram of the circuit structure of a signal processing circuit module provided in one embodiment of this application;

[0055] Figure 3 This is a schematic diagram of the circuit structure of the computing module in a signal processing circuit module according to an embodiment of this application;

[0056] Figure 4 This is a schematic diagram of the two-dimensional time spectrum of the echo signal after beat frequency in the embodiments of this application;

[0057] Figure 5 This is a schematic diagram of the circuit structure of a signal processing circuit module provided in another embodiment of this application;

[0058] Figure 6 This is a schematic diagram of the circuit structure of a signal processing circuit module provided in another embodiment of this application;

[0059] Figure 7 This is a schematic diagram of the circuit structure of a signal processing circuit module provided in another embodiment of this application;

[0060] Figure 8 This is a schematic diagram of the circuit principle of a signal processing circuit module provided in an embodiment of this application;

[0061] Figure 9 This is a schematic diagram illustrating the implementation process of a radar system control method provided in an embodiment of this application;

[0062] Figure 10 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application. Detailed Implementation

[0063] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0064] It should be understood that the term "and / or" as used in this application specification and the appended claims refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations. Furthermore, in the description of this application specification and the appended claims, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0065] It should also be understood that references to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include the specific features, structures, or characteristics described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0066] The following will provide a detailed description of the signal processing circuit module, frequency modulated continuous wave radar, radar system control method, terminal equipment, and computer-readable storage medium provided in the embodiments of this application:

[0067] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a frequency-modulated continuous wave radar provided in an embodiment of this application.

[0068] like Figure 1 As shown, the frequency modulated continuous wave radar mentioned above may include a signal transmitter 11, a signal receiver 12, and a signal processing circuit module 20.

[0069] The aforementioned signal transmitter 11 is used to generate a first detection light signal, a first local oscillator light signal corresponding to the first detection light signal, a second detection light signal, and a second local oscillator light signal corresponding to the second detection light signal. The first detection light signal and the second detection light signal have different wavelengths.

[0070] The aforementioned signal receiver 12 is used to receive the original echo light signal, which may include a first echo light signal and a second echo light signal. The first echo light signal is formed by the target object reflecting the first detection light signal, and the second echo light signal is formed by the target object reflecting the second detection light signal.

[0071] The signal processing circuit module 20 is connected to the signal transmitting terminal 11 and the signal transmitting terminal 12, respectively.

[0072] In one embodiment, the signal transmitting end 11 may include an FM signal generation module 111, a splitter 112, and a transmitting optical path 113, and the signal receiving end 12 may include a receiving optical path 121.

[0073] In practical applications, the frequency modulation signal generation module 111 is used to generate a first frequency modulation signal and a second frequency modulation signal with different wavelengths.

[0074] The splitter 112 is connected to the frequency modulation signal generation module 111 and is used to split the first frequency modulation signal to obtain a first probe light signal and a first local oscillator light signal corresponding to the first probe light signal; and to split the second frequency modulation signal to obtain a second probe light signal and a second local oscillator light signal corresponding to the second probe light signal.

[0075] The transmitting optical path 113 is used to receive and transmit the first and second probe optical signals output by the splitter 112.

[0076] In this embodiment, the wavelength of the first frequency modulation signal is not equal to the wavelength of the second frequency modulation signal, the sweep period of the first frequency modulation signal is the same as the sweep period of the second frequency modulation signal, the sweep slope of the first frequency modulation signal is equal to the sweep slope of the second frequency modulation signal, and the sweep direction of the first frequency modulation signal is opposite to the sweep direction of the second frequency modulation signal.

[0077] For example, the first frequency-modulated signal can be a triangular wave signal with a wavelength of λ1 and a sweep slope of K1, and correspondingly, the second frequency-modulated signal can be a triangular wave signal with a wavelength of λ2 and a sweep slope of K1; wherein, when the first frequency-modulated signal is in the upper sweep phase, the second frequency-modulated signal is in the lower sweep phase. Generally, the first wavelength λ1 and the second wavelength λ2 differ by 0.1 to 0.3 nm.

[0078] Accordingly, the sweep slope of the first detection optical signal is equal to the sweep slope of the second detection optical signal, and the sweep direction of the first detection optical signal is opposite to that of the second detection optical signal.

[0079] In one embodiment of this application, the frequency modulation signal generation module 111 may include a first laser and a second laser. The first laser and / or the second laser may be a DFB laser or a DBR laser, and this application does not limit this to either.

[0080] The first laser and the second laser are used to perform up and down frequency sweeps at the same time. That is, the first laser generates a first frequency modulation signal in the up frequency sweep phase and the second laser generates a second frequency modulation signal in the down frequency sweep phase, or the first laser generates a first frequency modulation signal in the down frequency sweep phase and the second laser generates a second frequency modulation signal in the up frequency sweep phase.

[0081] In practical applications, after the frequency modulation signal generation module 111 generates the first frequency modulation signal, it can be input to the splitter 112 for splitting. The splitter 112 divides the first frequency modulation signal into two signals, one of which serves as the first local oscillator signal of the first frequency modulation signal, and the other as the first detection signal. The first detection signal is then emitted through the transmission optical path 113 to detect the target object. After the frequency modulation signal transmission module 111 generates the second frequency modulation signal, it is input to the splitter 112 for splitting. The splitter 112 similarly divides the second frequency modulation signal into two signals, one of which serves as the second local oscillator signal of the second frequency modulation signal, and the other as the second detection signal. The second detection signal is then emitted through the transmission optical path 113 to detect the target object.

[0082] In specific applications, the aforementioned splitter 112 may include a first beam splitter and a second beam splitter. The first beam splitter is connected to the first laser and splits the first frequency-modulated signal generated by the first laser into two signals. One signal is emitted as a first probe light signal through the transmit optical path 113 to detect a target object. The other signal serves as a first local oscillator light signal for coherent detection of the first echo light signal corresponding to the first probe light signal. Similarly, the second beam splitter is connected to the second laser and splits the second frequency-modulated signal generated by the second laser into two signals. One signal is emitted as a second probe light signal through the same transmit optical path 113 as the first probe light signal to detect the same target object. The other signal serves as a second local oscillator light signal for coherent detection of the second echo light signal corresponding to the second probe light signal.

[0083] It should be noted that the first and second probe light signals are emitted using the same optical path to ensure that the same target object is detected and that the received echo light signals are echo light signals reflected from the same target object.

[0084] After the first detection light signal is emitted to the surface of the target object, the surface of the target object reflects the light to form a first echo light signal. After the second detection light signal is emitted to the surface of the target object, the surface of the target object reflects the light to form a second echo light signal. The signal receiving end 12 receives the light beam reflected from the surface of the target object (i.e., the original echo light signal) based on the receiving optical path 121.

[0085] In practical applications, the signal processing circuit module 20 can be connected to the signal transmitting end and the signal receiving end 12 respectively, and is used to process the first local oscillator light signal and the second local oscillator light signal generated by the signal transmitting end and the original echo light signal received by the signal receiving end 12.

[0086] In practical applications, the signal processing circuit module 20 processes the received raw echo light signal as follows: The signal processing circuit module 20 uses a wavelength demultiplexer to demultiplex the obtained raw echo light signal according to different wavelengths, obtaining a first echo light signal and a second echo light signal. The first echo light signal is formed by the reflection of a first detection light signal from the target object, and the second echo light signal is formed by the reflection of a second detection light signal from the target object. The signal processing circuit module 20 can also determine the direction of motion of the target object (rapidly approaching, rapidly moving away, or stationary) based on the frequency of the beat frequency signal (first beat frequency light signal) between the first echo light signal and the first local oscillator light signal, and the frequency of the beat frequency signal (second beat frequency light signal) between the second echo light signal and the second local oscillator light signal.

[0087] The signal processing circuit module provided in the embodiments of this application will be described below:

[0088] Please see Figure 2 , Figure 2 This is a circuit structure diagram of a signal processing circuit module provided in an embodiment of this application.

[0089] like Figure 2 As shown, a signal processing circuit module 20 provided in this application embodiment may include a signal splitting module 21, a first photoelectric detection module 22, a second photoelectric detection module 23, and a computing module 24.

[0090] The aforementioned signal splitting module 21 includes a wavelength divider 211, which is used to receive the original echo optical signal including the first echo optical signal and the second echo optical signal, and perform wavelength division processing to obtain the first echo optical signal and the second echo optical signal with different wavelengths.

[0091] Specifically, the aforementioned wavelength divider 211 performs wavelength demultiplexing processing on the received original echo optical signal to obtain the first echo optical signal and the second echo optical signal.

[0092] In specific applications, the first echo signal is the echo signal formed by the reflection of the target object surface after the first detection light signal detects the target object based on the above-mentioned transmission light path; the second echo signal is the echo signal formed by the reflection of the target object surface after the second detection light signal detects the target object based on the above-mentioned transmission light path; the wavelength of the first detection light signal is different from the wavelength of the second detection light signal, therefore the wavelength of the obtained first echo signal is different from the wavelength of the second echo signal.

[0093] In practical applications, the frequency of the first beat frequency electrical signal is the same as the frequency of the first beat frequency optical signal obtained by beating the first echo optical signal and the first local oscillator optical signal. The first beat frequency optical signal obtained by beating the first echo optical signal and the first local oscillator optical signal is converted into the first beat frequency electrical signal through photoelectric conversion.

[0094] The frequency of the second beat frequency electrical signal is the same as the frequency of the second beat frequency optical signal obtained by beating the second echo optical signal and the second local oscillator optical signal. The second beat frequency optical signal obtained by beating the second echo optical signal and the second local oscillator optical signal is converted into the above-mentioned second beat frequency electrical signal through photoelectric conversion.

[0095] The first photoelectric detection module 22 is connected to the signal transmitting end and the signal splitting module 21 respectively, and is used to receive the first echo optical signal and the first local oscillator optical signal corresponding to the first echo optical signal, and output the first beat frequency electrical signal.

[0096] It should be noted that, in the embodiments of this application, receiving a certain optical signal refers to receiving at least one part or all of the optical signal, such as receiving the original echo optical signal, which means receiving the original echo optical signal without beam splitting, or receiving the echo optical signal after beam splitting.

[0097] In specific applications, the aforementioned first photoelectric detection module 22 may include a first mixer and a first balanced photodetector (BPD). The first mixer receives the first local oscillator signal and the first echo signal, causing them to beat to generate a first beat frequency optical signal. Optionally, the mixer is a 180-degree mixer, such as a 3dB coupler; the mixer can then output two first beat frequency optical signals with a phase difference of 180 degrees. The first balanced photodetector is connected to the first mixer and receives the two first beat frequency optical signals, performing balanced detection to output an electrical signal related to the first beat frequency optical signal, i.e., a first beat frequency electrical signal.

[0098] It should be noted that the aforementioned photoelectric detection module 22 can also utilize other devices capable of frequency mixing to achieve frequency mixing. Correspondingly, the first balanced photodetector can also be adaptively adjusted to other photodetectors, and this application does not impose any limitations on this. Furthermore, the first photoelectric detection module 22 may also not include the first mixer; for example, it can receive the first beat frequency signal generated by the beat frequency of the first local oscillator light signal and the first echo light signal in free space through a photodetector, and perform photoelectric conversion to obtain the first beat frequency electrical signal.

[0099] The second photoelectric detection module 23 is connected to the signal transmitting end and the signal splitting module 21 respectively, and is used to receive the second echo optical signal and the second local oscillator optical signal corresponding to the second echo optical signal, and output the second beat frequency electrical signal.

[0100] In specific applications, the aforementioned second photoelectric detection module 23 also includes a second mixer and a second balanced photodetector (BPD). The second mixer receives the second local oscillator signal and the second echo signal, causing them to beat to generate a second beat frequency optical signal. Optionally, the second mixer is a 180-degree mixer, such as a 3dB coupler; the second mixer can then output two second beat frequency optical signals with a phase difference of 180 degrees. The second balanced photodetector is connected to the second mixer and receives the two second beat frequency optical signals, performing balanced detection to output an electrical signal related to the second beat frequency signal, i.e., a second beat frequency electrical signal.

[0101] It should be noted that the second photoelectric detection module 23 described above can also utilize other devices capable of frequency mixing to achieve frequency mixing. Correspondingly, the second balanced photodetector can also be adaptively adjusted to other photodetectors, and this application does not impose any limitations on this. In addition, the second photoelectric detection module 22 may also not include a second mixer; for example, it can receive the second beat frequency optical signal generated by the beat frequency of the second local oscillator light signal and the second echo light signal in free space through a photodetector, and perform photoelectric conversion to obtain the second beat frequency electrical signal.

[0102] In this embodiment of the application, the above-mentioned calculation module 24 is connected to the first photoelectric detection module 22 and the second photoelectric detection module 23 respectively.

[0103] Please see Figure 3 The aforementioned calculation module 24 includes an addition unit 241, an analog-to-digital conversion unit 242, and a digital processing unit 243.

[0104] The addition unit 241 is connected to the first photoelectric detection module 22 and the second photoelectric detection module 23 respectively to receive the first beat frequency electrical signal and the second beat frequency electrical signal, and superimpose the first beat frequency electrical signal and the second beat frequency electrical signal to output the first addition electrical signal.

[0105] The analog-to-digital conversion unit 242 is connected to the addition unit 241. The analog-to-digital conversion unit 242 is used to perform analog-to-digital conversion on the first addition electrical signal to output the first digital electrical signal.

[0106] The digital processing unit 243 is connected to the analog-to-digital conversion unit 242 and is used to determine the distance and speed of the target object relative to the radar based on the first digital electrical signal.

[0107] In this embodiment, the aforementioned FMCW lidar system can be applied to calculate the distance and velocity of a target object relative to the radar in scenarios where the Doppler beat frequency is higher than the range beat frequency.

[0108] Define the distance-based frequency f of the first local oscillator signal. R1 for:

[0109] f R1 =f r =k1*τ (1)

[0110] Define the distance-based frequency f of the second local oscillator signal. R2 for:

[0111] f R2 =f r =k1*τ (2)

[0112] Define the smaller frequency value of the first beat frequency optical signal and the second beat frequency signal as the first frequency f1, and the larger frequency value as the second frequency f2. Therefore:

[0113] f1=|k1*τ-f d | (3)

[0114] f2=|k1*τ+f d | (4)

[0115] The relationship between the beat frequency based on Doppler velocity and the velocity of the target object can be expressed as:

[0116]

[0117] Among them, f d It refers to the frequency based on Doppler velocity, where f0 is the center frequency of the first / second local oscillator optical signal, and τ is the time of flight.

[0118] The aforementioned digital processing unit 243 may include a Fast Fourier Transform module, which is used to obtain the frequencies corresponding to the peak values ​​of the two amplitudes based on the first additive electrical signal obtained by the aforementioned addition unit 241, wherein the smaller of the two frequencies is the aforementioned first frequency, and the other is the second frequency. For scenarios where the frequency based on Doppler velocity is greater than the frequency based on distance, the aforementioned formula (3) represents f1 = (f d -k1*τ), formula (4) is expressed as f2=(k1*τ+f d Adding the first frequency to the second frequency gives 2f. d Therefore, the frequency based on Doppler velocity can be calculated, and further, the frequency based on distance can be calculated. This allows for the decoupling of the target object's velocity and distance by combining the aforementioned center frequency and sweep slope. The inclusion of the adder unit 241 helps reduce the number of ADCs, thereby saving on the hardware size and cost of the signal processing module.

[0119] Therefore, based on the first frequency f1 and the second frequency f2, the above-mentioned calculation module 24 can calculate the Doppler velocity-based frequency and the distance-based frequency in a scenario where the Doppler velocity-based frequency is greater than the distance-based frequency. Finally, it can calculate the speed and distance of the target object, thereby achieving decoupling of velocity and distance measurement for fast-moving target objects. This solves the problem that FMCW lidar cannot decouple the speed and distance of target objects when detecting fast-moving target objects at close range because the Doppler velocity-based frequency is greater than the distance-based frequency.

[0120] Please see Figure 4 , Figure 4 A two-dimensional time-frequency spectrum diagram after the echo signal beats is shown. The first laser and the second laser perform up-scan and down-scan frequencies, respectively. Regardless of whether it is the first or second local oscillator signal, the third frequency f_ is defined as the frequency of the beat signal between the echo signal and the local oscillator signal corresponding to the up-scan frequency, and the fourth frequency f+ is defined as the frequency of the beat signal between the echo signal and the local oscillator signal corresponding to the down-scan frequency. When the target object's motion direction is such that the target object rapidly approaches the lidar, in the same half-scan period, the third frequency f_... - Less than the fourth frequency f + When the target object moves rapidly away from the lidar in the same half-scan period, the third frequency f - Greater than the fourth frequency f + When the target object is stationary relative to the lidar, in the same half-scan period, the third frequency f - Equal to the fourth frequency f +Therefore, based on the first and second local oscillator signals, frequency up or down can be processed to determine the beat frequency corresponding to the first local oscillator signal as the third frequency f. - Or the fourth frequency f + Then, by combining the size relationship between the two, the direction of motion of the target object relative to the lidar is determined.

[0121] In practical applications, the aforementioned computing module 24 can detect the frequencies of the first and second beat frequency electrical signals based on a field-programmable gate array (FPGA) or application-specific integrated circuits (ASICs). Alternatively, a high-speed parallel analog-to-digital converter (ADC) can be used to acquire the frequencies of the first and second beat frequency electrical signals. Since the FPGA can clearly define the sweep direction of the first and second local oscillator signals, it can further determine that the beat frequency corresponding to the first local oscillator signal is the third frequency f. - Or the fourth frequency f + One of them, the beat frequency corresponding to the second local oscillator signal is the third frequency f. - Or the fourth frequency f + The other one; then, by judging the size relationship between the two, the direction of motion of the target object relative to the lidar can be determined.

[0122] Please see Figure 5 , Figure 5 A schematic diagram of the circuit structure of a signal processing circuit module provided in another embodiment of this application is shown. Please refer to [link / reference]. Figure 5 In one embodiment of this application, the signal splitting module 21 may further include a first polarization beam splitter 212 and a second polarization beam splitter 213.

[0123] Along the propagation direction of the first echo light signal, the first polarization beam splitter 212 is disposed between the wave splitter 211 and the first photodetector module 22. The first polarization beam splitter 212 is used to receive the first echo light signal and output two first echo sub-signals with the same polarization direction as the first local oscillator light signal.

[0124] The first echo signal is input to the first polarization beam splitter 212 for polarization splitting, resulting in two signals with the same and orthogonal polarization directions as the first local oscillator signal. Then, the signal with the same polarization direction as the first local oscillator signal maintains its polarization direction and is output to obtain a first echo sub-signal. The other signal, with a polarization direction orthogonal to the first local oscillator signal, undergoes polarization rotation to obtain another first echo sub-signal with the same polarization direction as the first local oscillator signal. That is, the first echo signal can be split into two first echo sub-signals via the first polarization beam splitter. In some embodiments, both the first and second local oscillator signals are TE mode signals, so both first echo sub-signals are TE mode signals.

[0125] Along the propagation direction of the second echo light signal, the second polarization beam splitter 213 is disposed between the wave splitter 211 and the second photoelectric detection module. The second polarization beam splitter 213 is used to receive the second echo light signal and output two second echo sub-signals with the same polarization direction as the second local oscillator light signal.

[0126] The aforementioned second echo signal is input to the second polarization beam splitter 213 for polarization splitting, thereby obtaining two signals with the same and orthogonal polarization directions as the second local oscillator signal. Then, the signal with the same polarization direction as the second local oscillator signal maintains its polarization direction and is output to obtain one second echo sub-signal. The other signal with the orthogonal polarization direction to the second local oscillator signal undergoes polarization rotation to obtain another second echo sub-signal with the same polarization direction as the second local oscillator signal. That is, the second echo signal can obtain two second echo sub-signals via the second polarization beam splitter. In some embodiments, both the first and second local oscillator signals are TE mode signals, then both second echo sub-signals are TE mode signals.

[0127] Accordingly, the first photoelectric detection module 22 is used to receive the first local oscillator light signal and one of the first echo sub-signals, and the second photoelectric detection module 23 is used to receive the second local oscillator light signal and one of the second echo sub-signals.

[0128] Please continue reading. Figure 5 The aforementioned signal processing circuit module may include two first photoelectric detection modules 22, each of which is used to receive a first local oscillator light signal and one of the aforementioned first echo sub-signals.

[0129] The aforementioned signal processing circuit module may further include two second photoelectric detection modules 23, each of which is used to receive the second local oscillator light signal and one of the aforementioned second echo sub-signals.

[0130] The aforementioned calculation module 24 includes two addition units 241, each of which is connected to a first photoelectric detection module 22 and a second photoelectric detection module 23.

[0131] A first photoelectric detection module 22 receives a first local oscillator light signal and a first echo sub-signal, so that the first local oscillator light signal and the first echo sub-signal beat at a frequency to generate a first beat frequency light signal, and performs balanced detection on the first beat frequency light signal to generate a first beat frequency electrical signal.

[0132] Another first optical detection module 22 receives the first local oscillator optical signal and another first echo sub-signal, so that the first local oscillator optical signal and the other first echo sub-signal beat at the same frequency to generate another first beat frequency optical signal, and performs balanced detection on the first beat frequency optical signal to generate another first beat frequency electrical signal.

[0133] A second photodetector 23 is used to receive a second local oscillator optical signal and a second echo sub-signal, so that the second local oscillator optical signal and the second echo sub-signal beat at a frequency to generate a second beat frequency optical signal, and to perform balanced detection on the second beat frequency optical signal to generate a second beat frequency electrical signal.

[0134] Another second photodetector 23 is used to receive the second local oscillator light signal and another second echo sub-signal, so that the second local oscillator light signal and the other second echo sub-signal beat frequency to generate another second beat frequency light signal, and to perform balanced detection on the second beat frequency light signal to generate another second beat frequency electrical signal.

[0135] In one embodiment of this application, the above-mentioned calculation module 24 may include a first signal amplification unit 244 and a second signal amplification unit 245.

[0136] The first signal amplification unit 244 is connected between the first photoelectric detection module 22 and the addition unit 241, and is used to amplify the first beat frequency electrical signal to output the amplified first beat frequency electrical signal.

[0137] The second signal amplification unit 245 is connected between the second photoelectric detection module 23 and the addition unit 241, and is used to amplify the second beat frequency electrical signal to output the amplified second beat frequency electrical signal.

[0138] Please continue reading. Figure 6 In one embodiment of this application, the above-mentioned calculation module 24 may include two first signal amplification units 244. One first signal amplification unit 244 amplifies one first beat frequency electrical signal generated by a first photoelectric detection module 22, and the other first signal amplification unit 244 amplifies another first beat frequency electrical signal generated by another first photoelectric detection module 22.

[0139] The aforementioned calculation module 24 may also include two second signal amplification units 245. One second signal amplification unit 245 amplifies one second beat frequency electrical signal generated by one second photoelectric detection module 23, and the other second signal amplification unit 245 amplifies another second beat frequency electrical signal generated by another second photoelectric detection module 23.

[0140] The aforementioned analog-to-digital conversion unit may include a high-speed analog-to-digital conversion device.

[0141] This application embodiment also provides another calculation module 24, which uses a shaping unit to shape the signal output by the signal amplification unit to obtain square wave signals corresponding to each beat frequency signal. Then, it calculates the number of square waves per preset unit time to determine the frequency of each beat frequency signal. In this way, on the one hand, the direction of motion of the target object relative to the lidar can be determined based on the frequency of the first beat frequency electrical signal and the magnitude of the frequency of the second beat frequency electrical signal; on the other hand, the aforementioned distance-based beat frequency and velocity-based beat frequency can also be directly obtained through the frequency of the first beat frequency electrical signal and the magnitude of the frequency of the second beat frequency electrical signal.

[0142] Please see Figure 7 , Figure 7 A schematic diagram of the circuit structure of a signal processing circuit module according to another embodiment of this application is shown. Figure 7 As shown, unlike the previous embodiment, the calculation module 24 of the signal processing circuit module provided in this application embodiment further includes a first shaping unit 246 and a second shaping unit 247.

[0143] In a specific application, the first shaping unit 246 is connected between the first signal amplification unit 244 and the digital processing unit 243, and is used to shape the amplified first beat frequency electrical signal to obtain the first square wave signal.

[0144] The second shaping unit 247 is connected between the second signal amplification unit 245 and the digital processing unit 243, and is used to shape the amplified second beat frequency electrical signal to obtain the second square wave signal.

[0145] The digital processing unit 243 determines the frequency of the first beat frequency electrical signal based on the first square wave signal, and determines the frequency of the second beat frequency electrical signal based on the second square wave signal.

[0146] The aforementioned signal processing circuit may include two first shaping units 246 and two second shaping units 247. One first shaping unit 246 is used to shape the electrical signal output by a first signal amplification unit 244 to obtain a corresponding first square wave signal; the other first shaping unit 246 is used to shape the electrical signal output by another first signal amplification unit 244 to obtain another first square wave signal; one of the aforementioned second shaping units 247 is used to shape the electrical signal output by a second signal amplification unit 245 to obtain a second square wave signal; the other second shaping unit 247 is used to shape the electrical signal output by another second signal amplification unit 245 to obtain another second square wave signal.

[0147] In this embodiment of the application, the digital processing unit includes: a first time gate circuit and a second time gate circuit.

[0148] The first time gate circuit is connected to the first shaping unit to obtain the frequency of the first square wave signal.

[0149] The second time gate circuit is connected to the second shaping unit and is used to obtain the frequency of the second square wave signal.

[0150] By using the first and second time gate circuits, the frequencies of the first and second square wave signals at the same moment can be determined. By comparing the magnitudes of the frequencies of the first and second square wave signals, the direction of motion of the target object can be determined. By superimposing the first and second beat frequency electrical signals, the frequencies of the first and second beat frequency electrical signals can be obtained using the Fast Fourier Transform or the time gate circuit, thereby achieving decoupling of the target object's distance and velocity measurement.

[0151] It should be noted that after shaping each beat frequency signal into a square wave signal, a frequency-to-voltage conversion circuit can be used to convert the square wave signal into a current / voltage signal. Then, a voltage comparator / current comparator can be used to compare the magnitudes of the two signals to determine the direction of motion of the target object. Alternatively, a slow ADC can be used to acquire the converted voltage of each channel, and then the direction of motion of the target object can be determined in the digital domain.

[0152] It is worth mentioning that the first and second time gate circuits are low-cost, and obtaining the aforementioned frequencies through them can save ADC hardware resources, thereby reducing the hardware cost of the signal processing circuit module. Furthermore, for close-range detection, since the echo light signal has high energy, obtaining the first beat frequency electrical signal (and second beat frequency electrical signal) through the first (and second) time gate circuits is sufficient, and the overall structure of the processing circuit is simple. However, for medium- and long-range detection, since the echo light signal has low energy, obtaining the first beat frequency electrical signal (and second beat frequency electrical signal) through the first (and second) time gate circuits is insufficient. In this case, the first summed electrical signal can be transmitted to the digital processing module through two ADCs. After the digital processing module performs a Fast Fourier Transform on the two first summed electrical signals to obtain the frequency domain signal, it can also superimpose the two frequency domain signals, thereby nearly doubling the peak value of each amplitude in the frequency domain signal. This allows the lidar to achieve detection at longer distances.

[0153] For example, please refer to Figure 8 , Figure 8 A schematic diagram of the circuit principle of the signal processing circuit module provided in an embodiment of this application is shown.

[0154] like Figure 8 As shown, the signal splitting module 21 in this embodiment may include a demultiplexer DEMUX, a first polarization splitter and rotato (PSR) PSR1, and a second polarization splitter and rotato (PSR2).

[0155] The demultiplexer (DEMUX) separates the input raw echo optical signal into a first echo optical signal and a second echo optical signal. The first echo optical signal is polarized and rotated by a first polarization beam splitter (PSR1) to obtain two TE mode first echo sub-signals. The second echo optical signal is polarized and rotated by a second polarization beam splitter (PSR2) to obtain two TE mode second echo sub-signals.

[0156] Each first photodetector module 22 includes an optical mixer and a balanced photodetector BPD, and each second photodetector module 22 also includes an optical mixer and a balanced photodetector BPD.

[0157] In one first photoelectric detection module 22, the optical mixer 1 mixes one first echo sub-signal output from the first polarization beam splitter rotator PSR1 with the first local oscillator signal, and then performs photoelectric conversion through the balanced photodetector BDP1 connected to the optical mixer 1 to obtain one first beat frequency electrical signal. In another photoelectric detection module 22, the optical mixer 2 mixes another first echo sub-signal output from the first polarization beam splitter rotator PSR1 with the first local oscillator signal, and then performs photoelectric conversion through the balanced photodetector BDP2 connected to the optical mixer 2 to obtain another first beat frequency electrical signal. In one second photoelectric detection module 23, the optical mixer 3 mixes the second echo sub-signal output by the second polarization beam splitter rotator PSR2 with the second local oscillator signal, and then performs photoelectric conversion through the balanced photodetector BPD3 connected to the optical mixer 3 to obtain a second beat frequency electrical signal. In another second photoelectric detection module 23, the optical mixer 4 mixes another second echo sub-signal output by the second polarization beam splitter rotator PSR2 with the second local oscillator signal, and then performs photoelectric conversion through the balanced photodetector BDP4 connected to the optical mixer 4 to obtain another second beat frequency electrical signal.

[0158] The signal processing circuit may include two first signal amplification units and two second signal amplification units.

[0159] Each first signal amplification unit 244 includes a transimpedance amplifier TIA, which amplifies the first beat frequency electrical signal output by the balanced photodetector BDP. Similarly, each second signal amplification unit 245 may include a transimpedance amplifier TIA, which amplifies the second beat frequency electrical signal output by the balanced photodetector BDP.

[0160] The signal processing circuit may include two first shaping units 246 and two second shaping units 247. The first shaping unit 246 includes a first shaping circuit, and the second shaping unit 247 includes a second shaping circuit. That is, the signal processing circuit includes two first shaping circuits and two second shaping circuits.

[0161] A first shaping circuit is used to shape the electrical signal output by the transimpedance amplifier TIA1 in a first signal amplification unit to obtain a corresponding first square wave signal; another first shaping circuit is used to shape the electrical signal output by the transimpedance amplifier TIA2 in another first signal amplification unit to obtain another first square wave signal; a second shaping circuit is used to shape the electrical signal output by the transimpedance amplifier TIA3 in a second signal amplification unit to obtain a second square wave signal; another second shaping circuit is used to shape the electrical signal output by the transimpedance amplifier TIA4 in another second signal amplification unit to obtain another second square wave signal.

[0162] The signal processing circuit may also include two adding units 241. Each adding unit 241 includes an adding circuit; wherein, one adding circuit superimposes the electrical signal output by transimpedance amplifier TIA1 with the electrical signal output by transimpedance amplifier TIA3, and the other adding circuit is used to superimpose the electrical signal output by transimpedance amplifier TIA2 with the electrical signal output by transimpedance amplifier TIA4.

[0163] The aforementioned analog-to-digital conversion unit 242 includes a high-speed parallel ADC.

[0164] The aforementioned digital processing unit 243 includes a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC).

[0165] The following will combine Figure 8 The working principle of the signal processing circuit module provided in the embodiments of this application is explained as follows:

[0166] When the radar system's receiving optical path receives the original echo signals from the first and second detection optical signals reflected by the target object, the signal processing circuit module separates the original echo signals into a first echo signal and a second echo signal using a demultiplexer (DEMUX). The first echo signal is then polarized and rotated using a first polarization splitter (PSR1) to obtain two first echo sub-signals in TE mode. Similarly, the second echo signal is polarized and rotated using a second polarization splitter (PSR2) to obtain two second echo sub-signals in TE mode. One first echo sub-signal is input to optical mixer 1 and mixed with the first local oscillator signal. This mixture is then photoelectrically converted by a balanced photodetector (BDP1) connected to optical mixer 1 to obtain a first beat frequency electrical signal. The other first echo sub-signal is input to optical mixer 2 and mixed with the first local oscillator signal. This mixture is then photoelectrically converted by a balanced photodetector (BDP2) connected to optical mixer 2 to obtain another first beat frequency electrical signal. A second echo sub-signal is input to optical mixer 3 and mixed with the second local oscillator signal. Then, it is photoelectrically converted by balanced photodetector BPD3 connected to optical mixer 3 to obtain a second beat frequency electrical signal. Another second echo sub-signal is input to optical mixer 4 and mixed with the second local oscillator signal. Then, it is photoelectrically converted by balanced photodetector BDP4 connected to optical mixer 4 to obtain another second beat frequency electrical signal. The first beat frequency signal generated by the balanced photodetector BPD1 is amplified by transimpedance amplifier TIA1 and then shaped in the first shaping circuit to obtain a first square wave signal. The first beat frequency signal generated by the balanced photodetector BPD2 is amplified by transimpedance amplifier TIA2 and then shaped in the first shaping circuit to obtain another first square wave signal. The second beat frequency signal generated by the balanced photodetector BPD3 is amplified by transimpedance amplifier TIA3 and then shaped in the second shaping circuit to obtain a second square wave signal. The second beat frequency signal generated by the balanced photodetector BPD4 is amplified by transimpedance amplifier TIA4 and then shaped in the second shaping circuit to obtain another second square wave signal. The frequency of the first beat frequency signal is determined by calculating the number of square waves in the first square wave signal within a preset unit time using a field-programmable gate array (FPGA) or dedicated integrated circuit (ASIC) chip. The frequency of the second beat frequency signal is determined by calculating the number of square waves in the second square wave signal within a preset unit time. By comparing the magnitudes of the frequencies of the first and second beat frequency signals, the direction of motion of the target object can be determined.The electrical signals output from transimpedance amplifier TIA1 and TIA3 are superimposed using an adder circuit, and the outputs from transimpedance amplifier TIA2 and TIA4 are superimposed using another adder circuit. A high-speed parallel ADC performs analog-to-digital conversion, and the two converted first digital signals are transmitted to the FPGA / ASIC. A Fast Fourier Transform (FFT) module performs a Fourier transform on the first digital signals to obtain the frequencies corresponding to the peak values ​​of the two amplitudes, yielding the first frequency f1 and the second frequency f2. Then, in scenarios where the Doppler velocity frequency is greater than the distance-based frequency, the Doppler velocity-based frequency and the distance-based frequency can be calculated. Finally, the velocity and distance of the target object can be calculated.

[0167] It should be noted that the above signal processing circuit module can be integrated into a silicon photonic waveguide chip, and the signal processing process can be realized through this silicon photonic waveguide chip.

[0168] As can be seen from the above, the signal processing circuit module provided in this application embodiment can distinguish between two echo light signals of different wavelengths. Furthermore, the signal processing circuit can calculate the Doppler velocity frequency and the distance-based frequency when the Doppler velocity frequency is greater than the distance-based frequency, based on the frequency of the first beat frequency signal and the frequency of the second beat frequency signal. This allows for the calculation of the target object's speed and distance, achieving decoupling of velocity and distance measurement for fast-moving target objects. This solves the problem that FMCW lidar cannot decouple the speed and distance of target objects when detecting fast-moving target objects at close range because the Doppler velocity frequency is greater than the distance-based frequency.

[0169] It should be noted that the information interaction and execution process between the above-mentioned units are based on the same concept as the method embodiments of this application. Their specific functions and technical effects can be referred to the method embodiments section, and will not be repeated here.

[0170] Based on the radar system and signal processing circuit module provided in the above embodiments, the present invention further provides a radar control method embodiment applied to the above radar system embodiment and signal processing circuit module embodiment.

[0171] Please see Figure 9 , Figure 9 This is a schematic flowchart illustrating a radar system control method provided in an embodiment of this application. The execution entity of the radar system control method provided in this embodiment is the aforementioned frequency-modulated continuous wave lidar, specifically, it can be the control system inside the lidar.

[0172] like Figure 9As shown, the radar system control method provided in this application embodiment may include S11 to S12, which are detailed below:

[0173] S11: The control signal transmitting end generates a first detection light signal, a first local oscillator light signal corresponding to the first detection light signal, a second detection light signal, and a second local oscillator light signal corresponding to the second detection light signal, and transmits the first detection light signal and the second detection light signal through the same transmitting optical path.

[0174] In practical applications, when a radar system needs to detect a target object, it can send a control command to the signal transmitter to control the transmitter to emit a first detection light signal and a second detection light signal through the same transmission optical path. Upon receiving the control command from the radar system, the signal transmitter generates a first frequency-modulated signal and a second frequency-modulated signal based on the command. Then, it splits the first frequency-modulated signal to obtain a first local oscillator light signal and a first detection light signal, and splits the second frequency-modulated signal to obtain a second local oscillator light signal and a second detection light signal.

[0175] In practical applications, the wavelength of the first frequency modulation signal is not equal to the wavelength of the second frequency modulation signal, the sweep slope of the first frequency modulation signal is equal to the sweep slope of the second frequency modulation signal, and the sweep direction of the first frequency modulation signal is opposite to the sweep direction of the second frequency modulation signal.

[0176] Therefore, the wavelength of the first detection light signal is not equal to that of the second detection light signal, the sweep slope of the first detection light signal is equal to that of the second detection light signal, and the sweep direction of the first detection light signal is opposite to that of the second detection light signal.

[0177] After obtaining the first and second detection light signals, the first and second detection light signals can be emitted through the same transmission optical path to detect the target object.

[0178] S12: The original echo light signal is processed by the signal processing circuit module to determine the speed and distance of the target object relative to the radar.

[0179] In practical applications, when the first detection light signal detects a target object, the target object's surface reflects an echo signal. Similarly, when the second detection light signal detects a target object, the target object's surface also reflects an echo signal. The radar system can receive the original echo light signals returned from the target object's surface through the receiving optical path of the signal receiver. Once the radar system receives the original echo light signals returned from the target object's surface through the signal receiver, it can analyze the target object's speed and distance based on the received original echo light signals.

[0180] In practical applications, the original echo light signal can be processed based on the signal processing circuit module to separate the first echo light signal and the second echo light signal from the original echo light signal. The first echo light signal is mixed with the first local oscillator light signal and then photoelectrically converted to obtain the first beat frequency electrical signal. The second echo light signal is mixed with the second local oscillator light signal and then photoelectrically converted to obtain the second beat frequency electrical signal. Based on the first beat frequency electrical signal and the second beat frequency electrical signal, the frequency based on Doppler velocity and the frequency based on distance are further determined, thereby enabling the calculation of the target object's speed and distance.

[0181] It should be noted that the processing procedure of the signal processing circuit module for the original echo optical signal can be found in the description of the signal processing circuit module embodiment. To avoid repetition, it will not be repeated here.

[0182] As can be seen from the above, the radar system control method provided in this application embodiment can also detect the same target object by emitting two sets of linear frequency sweep signals with different wavelengths and opposite sweep directions. By processing the echo signals corresponding to the two detection signals with different wavelengths, the echo light signals of the two different wavelengths can be distinguished. Furthermore, the above signal processing circuit can also calculate the frequency based on Doppler velocity and the frequency based on distance when the frequency of Doppler velocity is greater than the frequency based on distance, based on the frequency of the first beat frequency signal and the frequency of the second beat frequency signal, thereby calculating the speed and distance of the target object. This achieves decoupling of speed and distance measurement for fast-moving target objects and solves the problem that FMCW lidar cannot decouple the speed and distance of the target object when detecting fast-moving target objects at close range because the frequency of Doppler velocity is greater than the frequency based on distance.

[0183] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0184] Figure 10 This is a schematic diagram of the structure of a terminal device provided in one embodiment of this application. For example... Figure 10 As shown, the terminal device 9 provided in this embodiment includes: a processor 90, a memory 91, and a computer program 92 stored in the memory 91 and executable on the processor 90, such as an image segmentation program. When the processor 90 executes the computer program 92, it implements the steps in the various radar system control method embodiments described above, for example... Figure 9 S11 to S12 are shown.

[0185] For example, the computer program 92 can be divided into one or more modules / units, which are stored in the memory 91 and executed by the processor 90 to complete this application. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 92 in the terminal device 9. For example, the computer program 92 can be divided into multiple units; please refer to the specific functions of each unit. Figure 5 The relevant descriptions in the corresponding embodiments are not repeated here.

[0186] The terminal device may include, but is not limited to, a processor 90 and a memory 91. Those skilled in the art will understand that... Figure 9 This is merely an example of terminal device 9 and does not constitute a limitation on terminal device 9. It may include more or fewer components than shown, or combine certain components, or different components. For example, the terminal device may also include input / output devices, network access devices, buses, etc.

[0187] The processor 90 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0188] The memory 91 can be an internal storage unit of the terminal device 9, such as a hard disk or memory of the terminal device 9. The memory 91 can also be an external storage device of the terminal device 9, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the terminal device 9. Furthermore, the memory 91 can include both internal and external storage units of the terminal device 9. The memory 91 is used to store the computer program and other programs and data required by the terminal device. The memory 91 can also be used to temporarily store data that has been output or will be output.

[0189] This application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, can implement the aforementioned radar system control methods S11 to S12.

[0190] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the aforementioned radar system control method.

[0191] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the terminal device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0192] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, refer to the relevant descriptions of other embodiments.

[0193] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0194] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A signal processing circuit module, characterized in that, include: The signal splitting module includes a wavelength divider, which is used to receive the original echo optical signal including a first echo optical signal and a second echo optical signal, and perform wavelength division processing to obtain the first echo optical signal and the second echo optical signal with different wavelengths. The first photoelectric detection module is used to receive the first echo light signal and the first local oscillator light signal corresponding to the first echo light signal, and output the first beat frequency electrical signal. The second photoelectric detection module is used to receive the second echo light signal and the second local oscillator light signal corresponding to the second echo light signal, and output the second beat frequency electrical signal. as well as The calculation module includes an addition unit, an analog-to-digital conversion unit, and a digital processing unit. The addition unit is connected to the first photoelectric detection module and the second photoelectric detection module respectively to receive the first beat frequency electrical signal and the second beat frequency electrical signal, and superimpose them to output a first addition electrical signal. The analog-to-digital conversion unit is connected to the addition unit and is used to perform analog-to-digital conversion on the first addition electrical signal to output a first digital electrical signal. The digital processing unit is connected to the analog-to-digital conversion unit and is used to determine the distance and velocity of the target object relative to the radar based on the first digital electrical signal.

2. The signal processing circuit module according to claim 1, characterized in that, The signal splitting module also includes: A first polarization beam splitter is disposed between the wave splitter and the first photoelectric detection module. The first polarization beam splitter receives the first echo light signal and outputs two first echo sub-signals with the same polarization direction as the first local oscillator light signal; and The second polarization beam splitter is located between the wave splitter and the second photoelectric detection module. The second polarization beam splitter is used to receive the second echo light signal and output two second echo sub-signals with the same polarization direction as the second local oscillator light signal. The first photoelectric detection module is used to receive the first local oscillator light signal and one first echo sub-signal, and the second photoelectric detection module is used to receive the second local oscillator light signal and one second echo sub-signal.

3. The signal processing circuit module according to claim 2, characterized in that: The signal processing circuit module includes two first photoelectric detection modules, each of which is used to receive the first local oscillator light signal and one first echo sub-signal. The signal processing circuit module includes two second photoelectric detection modules, each of which is used to receive the second local oscillator light signal and one second echo sub-signal. The calculation module includes two addition units, each of which is connected to a first photoelectric detection module and a second photoelectric detection module.

4. The signal processing circuit module according to claim 1, characterized in that, The first photoelectric detection module includes: A first mixer is configured to receive the first local oscillator optical signal and the first echo optical signal, and to cause the first local oscillator optical signal and the first echo optical signal to beat at a frequency to generate a first beat frequency optical signal; and A first balanced photodetector is connected to the first mixer and is used to perform balanced detection on the first beat frequency optical signal output by the first mixer in order to generate the first beat frequency electrical signal. The second photoelectric detection module includes: A second mixer is configured to receive the second local oscillator signal and the second echo signal, so that the second local oscillator signal and the second echo signal beat at a frequency to generate a second beat-frequency optical signal; and A second balanced photodetector, connected to the second mixer, is used to perform balanced detection on the second beat frequency optical signal output by the second mixer to generate the second beat frequency electrical signal.

5. The signal processing circuit module according to claim 1, characterized in that, The computing module also includes: The first signal amplification unit is connected between the first photoelectric detection module and the addition unit, and is used to amplify the first beat frequency electrical signal to output the amplified first beat frequency electrical signal. The second signal amplification unit is connected between the second photoelectric detection module and the addition unit, and is used to amplify the second beat frequency electrical signal to output the amplified second beat frequency electrical signal.

6. The signal processing circuit module according to claim 5, characterized in that, The computing module also includes: The first shaping unit is connected between the first signal amplification unit and the digital processing unit, and is used to shape the amplified first beat frequency electrical signal to obtain a first square wave signal. The second shaping unit is connected between the second signal amplification unit and the digital processing unit, and is used to shape the amplified second beat frequency electrical signal to obtain a second square wave signal. The digital processing unit determines the frequency of the first beat frequency electrical signal based on the first square wave signal, and determines the frequency of the second beat frequency electrical signal based on the second square wave signal.

7. The signal processing circuit module according to claim 6, characterized in that, The digital processing unit includes: A first time gate circuit, connected to a first shaping unit, is used to acquire the frequency of the first square wave signal; and The second time gate circuit is connected to the second shaping unit and is used to obtain the frequency of the second square wave signal.

8. A frequency-modulated continuous wave radar, characterized in that, include: The signal transmitting end is used to generate a first detection light signal, a first local oscillator light signal corresponding to the first detection light signal, a second detection light signal, and a second local oscillator light signal corresponding to the second detection light signal, and to transmit the first detection light signal and the second detection light signal through the same transmission optical path, wherein the wavelengths of the first detection light signal and the second detection light signal are different; The signal receiving end is used to receive the original echo light signal, which includes a first echo light signal and a second echo light signal. The first echo light signal is formed by the target object reflecting the first detection light signal, and the second echo light signal is formed by the target object reflecting the second detection light signal. as well as The signal processing circuit module as described in any one of claims 1 to 7, wherein the signal processing circuit module is connected to the signal transmitting end and the signal receiving end respectively.

9. The frequency-modulated continuous wave radar as described in claim 8, characterized in that, The sweep slope of the first detection optical signal is equal to the sweep slope of the second detection optical signal, and the sweep direction of the first detection optical signal is opposite to the sweep direction of the second detection optical signal.

10. The frequency-modulated continuous wave radar as described in claim 8, characterized in that, The signal transmitting end includes: The frequency modulation signal generation module is used to generate first and second frequency modulation signals of different wavelengths. A splitter, connected to the frequency modulation signal generation module, is used to split the first frequency modulation signal to obtain a first probe light signal and a first local oscillator light signal corresponding to the first probe light signal, and to split the second frequency modulation signal to obtain a second probe light signal and a second local oscillator light signal corresponding to the second probe light signal; and The transmitting optical path is used to receive and transmit the first detection optical signal and the second detection optical signal output by the splitter.

11. A radar system control method, applied to a frequency-modulated continuous wave radar as described in any one of claims 8 to 10, characterized in that, include: The control signal transmitting end generates a first detection light signal, a first local oscillator light signal corresponding to the first detection light signal, a second detection light signal, and a second local oscillator light signal corresponding to the second detection light signal, and transmits the first detection light signal and the second detection light signal through the same transmission optical path to detect the target object; The signal processing circuit module processes the original echo light signal to determine the direction and distance of the target object relative to the radar.

12. A terminal device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the radar system control method as described in claim 11.

13. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the radar system control method as described in claim 11.

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