A laser ranging and velocity measurement method, device, terminal equipment, and storage medium

Abstract

This application relates to the field of laser ranging and velocimetry technology, providing a laser ranging and velocimetry method, device, system, and storage medium. It involves emitting a linearly swept-frequency optical signal towards a target object during the i-th sweep time of each measurement cycle; emitting a pulsed optical signal towards the target object during the i-th pulse time of each measurement cycle; obtaining the distance of the target object during the i-th pulse time of each measurement cycle based on the flight time of the pulsed optical signal emitted during the i-th pulse time of each measurement cycle; and obtaining the velocity of the target object during the i-th sweep time of each measurement cycle based on the flight time of the pulsed optical signal emitted during the i-th pulse time of each measurement cycle and the beat frequency of the beat frequency signal corresponding to the linearly swept-frequency optical signal emitted during the i-th sweep time. This method enables rapid detection of the distance and velocity of the target object and achieves decoupling of the distance and velocity of nearby targets.

Description

Technical Field

[0001] This application belongs to the field of frequency modulated continuous wave (FMCW) laser radar (LiDAR) technology, and particularly relates to a laser ranging and velocimetry method, device, terminal equipment and storage medium. Background Technology

[0002] Frequency-modulated continuous wave (FM-WW) lidar can simultaneously measure distance and velocity, and is widely used in fields such as intelligent transportation and autonomous driving. It can provide safer and more reliable distance and speed information for autonomous or assisted driving. Compared to time-of-flight (TOF) ranging technology alone, FM-WW lidar can quickly detect the distance and velocity of a target object, thus enabling faster target identification and facilitating early avoidance actions.

[0003] Existing frequency-modulated continuous wave (FM-CW) lidar typically employs two modulation methods. The first is internal modulation, which adjusts the wavelength of the laser's output light signal by regulating the laser's operating current. The second is an external electro-optic modulator, which indirectly modulates the laser's output light signal into a linear frequency-modulated continuous wave by adjusting the phase or intensity of the output light signal. The first modulation method suffers from range-velocity coupling when measuring close-range targets. The second modulation method can resolve this range-velocity coupling issue when measuring close-range targets, but the addition of an external electro-optic modulator increases hardware costs. Summary of the Invention

[0004] In view of this, embodiments of this application provide a laser ranging and velocity measurement method, device, terminal equipment, and storage medium, which can achieve decoupling of distance and velocity when measuring close-range target objects without increasing hardware costs.

[0005] The first aspect of this application provides a laser ranging and velocimetry method, including:

[0006] A linear sweep frequency optical signal is emitted toward the target object during the i-th sweep frequency time of each measurement cycle;

[0007] A pulsed light signal is emitted toward the target object during the i-th pulse time of each measurement cycle;

[0008] The distance of the target object at the i-th pulse time of each measurement cycle is obtained based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle.

[0009] Based on the flight time of the pulsed light signal emitted at the i-th pulse time of each measurement cycle and the beat frequency of the beat frequency signal corresponding to the linear sweep frequency light signal emitted at the i-th sweep frequency time, the velocity of the target object at the i-th sweep frequency time of each measurement cycle is obtained.

[0010] Each measurement cycle includes m alternating sweep times and m pulse times, i = 1, 2, ..., m, where m is a positive integer.

[0011] A second aspect of this application provides a laser ranging and velocimetry device, comprising:

[0012] A linear sweep frequency optical signal transmitting unit is used to transmit a linear sweep frequency optical signal to the target object during the i-th sweep frequency time of each measurement cycle;

[0013] The pulsed light signal transmitting unit is used to transmit a pulsed light signal to the target object during the i-th pulse time of each measurement cycle;

[0014] The ranging unit is used to obtain the distance of the target object at the i-th pulse time of each measurement cycle based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle.

[0015] The velocity measurement unit is used to obtain the velocity of the target object at the i-th sweep time of each measurement cycle based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle and the beat frequency of the beat frequency signal corresponding to the linear sweep frequency light signal emitted at the i-th sweep time.

[0016] Each measurement cycle includes m alternating sweep times and m pulse times, i = 1, 2, ..., m, where m is a positive integer.

[0017] A third aspect of this application provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the laser ranging and velocimetry method as described in the first aspect of this application.

[0018] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the laser ranging and velocimetry method as described in the first aspect of this application.

[0019] The laser ranging and velocimetry method provided in the first aspect of this application involves emitting a linearly swept-frequency optical signal to the target object during the i-th sweep time of each measurement cycle; emitting a pulsed optical signal to the target object during the i-th pulse time of each measurement cycle; obtaining the distance of the target object during the i-th pulse time of each measurement cycle based on the flight time of the pulsed optical signal emitted during the i-th pulse time of each measurement cycle; and obtaining the velocity of the target object during the i-th sweep time of each measurement cycle based on the flight time of the pulsed optical signal emitted during the i-th pulse time of each measurement cycle and the beat frequency of the beat frequency signal corresponding to the linearly swept-frequency optical signal emitted during the i-th sweep time. This method can quickly detect the distance and velocity of the target object and achieve decoupling of the distance and velocity of nearby target objects.

[0020] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is a schematic diagram of the first process of the laser ranging and velocimetry method provided in the embodiments of this application;

[0023] Figure 2 This is the first time-frequency diagram of pulsed optical signal and linearly swept frequency optical signal provided in the embodiments of this application;

[0024] Figure 3 This is a second time-frequency diagram of pulsed optical signals and linearly swept optical signals provided in the embodiments of this application;

[0025] Figure 4 This is a third time-frequency diagram of pulsed optical signals and linearly swept optical signals provided in the embodiments of this application;

[0026] Figure 5 This is the fourth time-frequency diagram of pulsed optical signals and linearly swept optical signals provided in the embodiments of this application;

[0027] Figure 6 This is the fifth time-frequency diagram of pulsed optical signals and linearly swept optical signals provided in the embodiments of this application;

[0028] Figure 7 This is an amplitude-frequency diagram of the pulsed optical signal and the linearly swept optical signal provided in the embodiments of this application;

[0029] Figure 8 This is a time-frequency diagram of the beat frequency signal and the pulse light signal provided in the embodiments of this application;

[0030] Figure 9 This is an amplitude-frequency diagram of the beat frequency signal and the pulse light signal provided in the embodiments of this application;

[0031] Figure 10 This is a schematic diagram of the second process of the laser ranging and velocimetry method provided in the embodiments of this application;

[0032] Figure 11 This is a schematic diagram of the structure of the laser ranging and velocimetry device provided in the embodiments of this application;

[0033] Figure 12 This is a schematic diagram of the first structure of the terminal device provided in the embodiments of this application;

[0034] Figure 13 This is a schematic diagram of a second structure of the terminal device provided in the embodiments of this application;

[0035] Figure 14 This is a schematic diagram of the third structure of the terminal device provided in the embodiments of this application. Specific implementation methods

[0036] 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 the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0037] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0038] It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0039] As used in this specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0040] Furthermore, in the description of this invention and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0041] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of the invention include a specific feature, structure, or characteristic 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. The terms "a plurality of," and variations thereof mean "at least two."

[0042] This application provides a laser ranging and velocity measurement method, which can be executed by the processor of a terminal device when running a computer program with corresponding functions. The method obtains the distance of the target object at the i-th pulse time of each measurement cycle based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle. It obtains the velocity of the target object at the i-th sweep time of each measurement cycle based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle and the beat frequency of the beat frequency signal corresponding to the linear sweep frequency signal emitted at the i-th sweep frequency time. By using time-division multiplexing of pulse light signals and linear sweep frequency signals, the distance and velocity of the target object are detected separately. Compared to using time-of-flight ranging technology alone, this method can detect the distance and velocity of near-range or far-range targets more quickly. Compared to existing frequency-modulated continuous wave lidar, it can decouple the distance and velocity of near-range targets.

[0043] In applications, the close range is generally 30m to 50m. The laser ranging and velocity measurement method provided in this application is not only suitable for fast, efficient and accurate ranging and velocity measurement of close targets, but also suitable for fast, efficient and accurate ranging and velocity measurement of distant targets. It can be applied to any field that requires ranging and velocity measurement, such as intelligent transportation, aerospace, resource exploration, urban planning, agricultural development, water conservancy projects, land use, environmental monitoring, metallurgical manufacturing, and textile manufacturing. Specifically, it can be applied to unmanned vehicles, drones, robots, positioning systems, navigation systems, loading and unloading and handling equipment, metallurgical process control equipment, and non-contact measurement equipment.

[0044] In applications, the terminal device can be a lidar, a signal processing device within a lidar, or any device with ranging and velocity measurement functions, such as a ranging and velocity sensor or a ranging and velocity meter. The terminal device includes a laser, a scanning system, a photodetector, and a signal processing device. It may also include optical multiplexers, optical amplifiers, optical couplers, optical circulators, optical collimators, optical beam splitters, optical beam combiners, interferometers, power modules, communication modules, etc. The specific structure of the terminal device can be configured according to actual needs; this application embodiment does not impose any restrictions on the specific structure of the terminal device.

[0045] In applications, lasers can be implemented using any laser capable of time-division multiplexing between linear frequency modulation (LFM) mode and pulsed mode, emitting linearly swept-frequency optical signals in LFM mode and pulsed optical signals in pulsed mode. Examples include semiconductor lasers such as Distributed Bragg Reflector (DBR) lasers and Distributed Feedback Laser (DFB) lasers. A lidar system can also include multiple lasers, with one laser operating in pulsed mode to emit pulsed optical signals and the remaining lasers operating in LFM mode to emit linearly swept-frequency optical signals; or, all lasers can operate in time-division multiplexing between pulsed and LFM modes, emitting linearly swept-frequency optical signals in LFM mode and pulsed optical signals in pulsed mode.

[0046] In applications, the photodetector can be a balanced photodetector (BPD).

[0047] In applications, the optical amplifier can be an erbium-doped fiber application amplifier (EDFA).

[0048] In applications, the interferometer can be a Mach-Zehnder interferometer (MZI).

[0049] In applications, signal processing devices may include a processor, and may also include at least one stage of amplifier circuit, analog-to-digital converter (ADC), time-to-digital converter (TDC), memory, etc. The processor may also have its own internal storage space and analog-to-digital conversion function to replace the analog-to-digital converter and memory.

[0050] In applications, the processor can 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. General-purpose processors can be microprocessors or any conventional processor.

[0051] In applications, the memory may be an internal storage unit of the terminal device in some embodiments, such as the hard drive or RAM of the terminal device. In other embodiments, the memory may be an external storage device of the terminal device, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, the memory may include both internal and external storage units of the terminal device. The memory is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of a computer program. The memory can also be used to temporarily store data that has been output or will be output.

[0052] In applications, the amplifier circuit can be implemented using a trans-impedance amplifier (TIA).

[0053] In applications, power modules may include power management devices, power interfaces, etc.

[0054] In applications, the communication module can be configured as any device capable of direct or indirect wired or wireless communication with other devices, depending on actual needs. For example, the communication module can provide solutions for communication on network devices, including communication interfaces (e.g., Universal Serial Bus (USB)), wired local area networks (LANs), wireless local area networks (WLANs) (e.g., Wi-Fi networks), Bluetooth, Zigbee, mobile communication networks, Global Navigation Satellite System (GNSS), Frequency Modulation (FM), Near Field Communication (NFC), and Infrared (IR) technologies. The communication module can include an antenna, which can have a single element or be an antenna array with multiple elements. The communication module can receive electromagnetic waves through the antenna, frequency-modulate and filter the electromagnetic wave signal, and send the processed signal to the processor. The communication module can also receive signals to be transmitted from the processor, frequency-modulate and amplify them, and then convert them into electromagnetic waves for radiation via the antenna.

[0055] like Figure 1 As shown, the laser ranging and velocimetry method provided in this application includes the following steps S101 to S104:

[0056] Step S101: At the i-th sweep time of each measurement cycle, a linear sweep frequency optical signal is emitted to the target object, and then proceed to step S104;

[0057] Step S102: At the i-th pulse time of each measurement cycle, a pulse light signal is emitted to the target object, and then proceed to step S103.

[0058] In applications, a linearly swept optical signal refers to an optical signal whose frequency changes linearly from the initial frequency to the final frequency within the sweep time, and whose rate of frequency change (i.e., sweep slope) remains constant within the sweep time. The initial frequency is the center frequency of the laser emitting the linearly swept optical signal, and the center frequency of the laser can be set according to actual needs, for example, 192.3 THz. The final frequency is equal to the product of the sweep time and the sweep slope plus the initial frequency.

[0059] In the application, each measurement cycle can include m alternating frequency sweep times and m pulse times, i = 1, 2, ..., m, where m is a positive integer. That is, each measurement cycle includes at least one alternating frequency sweep time and at least one pulse time, with the number of frequency sweep times and pulse times being equal. Each frequency sweep time is preceded by a corresponding pulse time. The terminal device controls the laser to emit a linearly swept frequency optical signal towards the target object during each frequency sweep time to measure the target object's velocity relative to the lidar; and to emit a pulse optical signal towards the target object during each pulse time to measure the distance between the target object and the lidar. The number of pulse optical signals emitted during each pulse time can be multiple (e.g., any value between 10 and 30), and these multiple pulse optical signals constitute a pulse sequence.

[0060] In one embodiment, m = 1, and the sweep slope of the linear sweep optical signal emitted during the sweep time of each measurement cycle is positive or negative;

[0061] Alternatively, m = 2, where the signs of the sweep slopes of the linear sweep optical signals emitted during the first and second sweep times of each measurement cycle are opposite.

[0062] In applications, the number of pulse times and sweep times included in each measurement cycle can be set according to actual needs, as long as the number of both is equal and alternates. For example, each measurement cycle can include only one pulse time and one sweep time, during which the sweep slope of the linear sweep optical signal emitted can be positive or negative. Each measurement cycle can also include two pulse times and two sweep times, during which the sweep slope of the linear sweep optical signal emitted can be positive and negative, respectively. When the sweep slope of the linear sweep optical signal is positive, the corresponding sweep time can be defined as the upper sweep time; when the sweep slope of the linear sweep optical signal is negative, the corresponding sweep time can be defined as the lower sweep time.

[0063] like Figure 2 As shown, an exemplary illustration is provided, illustrating the time-frequency diagrams of the pulsed optical signal and the linearly swept optical signal when m=1 and the sweep slope of the linearly swept optical signal is positive within each measurement cycle; wherein, each measurement cycle includes an up-sweep time.

[0064] like Figure 3 As shown, an exemplary time-frequency diagram of the pulsed optical signal and the linearly swept optical signal is presented when m=1 and the sweep slope of the linearly swept optical signal is negative in each measurement cycle; wherein each measurement cycle includes a downsweep time.

[0065] like Figure 4As shown, an exemplary diagram illustrates the time-frequency graphs of the pulsed optical signal and the linearly swept optical signal when the sweep slope of the linearly swept optical signal is positive in the first sweep time and negative in the second sweep time within each measurement cycle, where m=2. Each measurement cycle includes two sweep times set sequentially, the first sweep time being the upper sweep time and the second sweep time being the lower sweep time.

[0066] like Figure 5 As shown, an exemplary example is presented, where m=2, and the sweep slope of the linear sweep optical signal in each measurement cycle is negative in the first sweep time and positive in the second sweep time, and the time-frequency diagrams of the pulse optical signal and the linear sweep optical signal are shown. Each measurement cycle includes two sweep times set sequentially, the first sweep time being the lower sweep time and the second sweep time being the upper sweep time.

[0067] like Figure 6 As shown, an exemplary case is illustrated where m=2, and the sweep slope of the linear sweep light signal emitted by one part of the lasers in each measurement cycle is positive in the first sweep time and negative in the second sweep time, while the sweep slope of the linear sweep light signal emitted by the other part of the lasers in each measurement cycle is negative in the first sweep time and positive in the second sweep time. The time-frequency diagrams of the pulse light signal and the linear sweep light signal are shown. Specifically, each measurement cycle of one part of the lasers includes two sequentially set sweep times: the first sweep time is the upper sweep time, and the second sweep time is the lower sweep time. Similarly, each measurement cycle of the other part of the lasers also includes two sequentially set sweep times: the first sweep time is the lower sweep time, and the second sweep time is the upper sweep time.

[0068] In one embodiment, the duty cycle of the m pulse times in each measurement cycle is less than or equal to 1 / 3, and the duty cycle of the m sweep times is greater than or equal to 2 / 3.

[0069] Alternatively, the duty cycle of the m pulse times in each measurement cycle is less than or equal to 1 / 5, and the duty cycle of the m sweep times is greater than or equal to 4 / 5.

[0070] In application, the duty cycle of the total pulse time in each measurement cycle should be set to be less than the duty cycle of the total sweep time. The specific setting can be made according to actual needs. For example, the duty cycle of the total pulse time is less than or equal to 1 / 3 and the duty cycle of the total sweep time is greater than or equal to 2 / 3, or the duty cycle of the total pulse time is less than or equal to 1 / 5 and the duty cycle of the total sweep time is greater than or equal to 4 / 5.

[0071] In one embodiment, the duration of each measurement cycle is greater than or equal to 5 µs, and the value of each pulse time ranges from 2 ns to 5 ns.

[0072] In applications, the duration of each measurement cycle, as well as the duration of the pulse time and sweep time within each measurement cycle, can be set according to actual needs. The duration of each measurement cycle can be set to the order of 10µs, specifically any value greater than or equal to 5µs, for example, any value between 5µs and 1ms. The duration of each pulse time can be set to a duration much shorter than the measurement cycle, for example, any value between 2ns and 5ns.

[0073] In one embodiment, the pulse power of the pulsed optical signal emitted during the i-th pulse time of each measurement cycle is constant and ranges from 1W to 1000W.

[0074] In applications, the terminal device controls the laser to emit a pulsed light signal with a constant pulsed power within each pulse time of each measurement cycle. The pulsed power is positively correlated with the light intensity of the pulsed light signal and can be set according to actual needs. The pulsed power of the pulsed light signal emitted within each pulse time of each measurement cycle can be set to any value greater than or equal to 1W, for example, any value between 1W and 1000W.

[0075] like Figure 7 As shown, the amplitude-frequency diagrams of pulsed optical signals and linearly swept optical signals are illustrated for m=1 or 2.

[0076] In application, for any two different measurement cycles, the duration of the measurement cycle, the value of m, the duration of the pulse time and the sweep frequency time, and the sweep frequency slope can all be set to be different and can be adjusted according to actual needs. For example, for any measurement cycle, the value of m is positively correlated with the measurement frequency of the target object's distance and velocity. The larger m is, the more times the target object's distance and velocity are measured in a measurement cycle; the smaller m is, the fewer times the target object's distance and velocity are measured in a measurement cycle.

[0077] In applications, the number of channels in a LiDAR system can be set according to actual needs. The terminal device can control the laser to emit beams equal to the number of channels towards the target object. When the number of channels is 1, single-point scanning of the target object can be achieved. When the number of channels is greater than 1×1 and the beams are arranged in a one-dimensional array, one-dimensional scanning of the target object can be achieved, obtaining the one-dimensional contour of the target object's surface and improving the resolution of the LiDAR in the horizontal or vertical direction. When the number of channels is greater than 2×2 and the beams are arranged in a two-dimensional array, two-dimensional scanning of the target object can be achieved, obtaining the two-dimensional contour of the target object's surface and improving the resolution of the LiDAR in both the horizontal and vertical directions.

[0078] Step S103: Based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle, obtain the distance of the target object at the i-th pulse time of each measurement cycle, and proceed to step S104.

[0079] In application, after the terminal device controls the laser to emit a pulsed light signal towards the target object, the photodetector receives the pulsed light signal reflected by the target object and converts it into a first electrical signal. The analog-to-digital converter samples the first electrical signal and converts it into a first digital signal. The processor obtains the reception time of the pulsed light signal reflected by the target object based on the first digital signal, calculates the time difference between the emission time and the reception time of the pulsed light signal, and obtains the flight time of the pulsed light signal. Since the speed of light in the air is constant, the propagation distance of the pulsed light signal from emission to reception can be calculated based on the flight time and propagation speed. The distance between the target object and the lidar is equal to half the propagation distance of the pulsed light signal.

[0080] In applications, since the time when the terminal device controls the laser to emit a pulsed light signal towards the target object is known, the time when the terminal device controls the laser to emit a pulsed light signal towards the target object can be used as the emission time of the pulsed light signal.

[0081] In one embodiment, before step S103, the following is included:

[0082] Receives the pulsed light signal reflected by the target object;

[0083] The flight time of the pulse light signal emitted at the i-th pulse time in each measurement cycle is obtained based on the pulse light signal emitted at the i-th pulse time in each measurement cycle and the pulse light signal reflected by the target object.

[0084] Step S104: Based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle and the beat frequency of the beat frequency signal corresponding to the linear sweep frequency light signal emitted at the i-th sweep frequency time, obtain the velocity of the target object at the i-th sweep frequency time of each measurement cycle.

[0085] In application, the terminal device controls the laser to directly transmit a portion of the linearly swept optical signal (referred to as the local oscillator linearly swept optical signal) to the photodetector via an optical beam splitter, and emits another portion of the linearly swept optical signal (referred to as the probe linearly swept optical signal) to the target object. After the probe linearly swept optical signal is emitted to the target object, the photodetector receives the probe linearly swept optical signal reflected by the target object. The local oscillator linearly swept optical signal and the probe linearly swept optical signal reflected by the target object interfere at the receiving surface of the photodetector, generating a beat frequency signal. The photodetector converts the first beat frequency signal into a second electrical signal. The analog-to-digital converter samples the second electrical signal and converts it into a second digital signal. The processor processes the second digital signal using algorithms such as Fast Fourier Transform to obtain the beat frequency of the beat frequency signal. Then, based on the beat frequency and flight time, the speed of the target object relative to the lidar is further calculated.

[0086] In one embodiment, before step S103, the following is included:

[0087] Receive the linearly swept frequency optical signal reflected by the target object;

[0088] Based on the linear sweep frequency light signal emitted at the i-th sweep frequency time in each measurement cycle and the linear sweep frequency light signal reflected by the target object, the beat frequency signal corresponding to the linear sweep frequency light signal emitted at the i-th sweep frequency time in each measurement cycle is obtained.

[0089] Based on the beat frequency signal corresponding to the linear sweep frequency optical signal emitted at the i-th sweep frequency time in each measurement cycle, the beat frequency of the corresponding beat frequency signal is obtained.

[0090] In applications, the beat frequency of the beat signal corresponding to the linear sweep optical signal emitted during the upper sweep time is defined as the upper sweep frequency, and the beat frequency of the beat signal corresponding to the linear sweep optical signal emitted during the lower sweep time is defined as the lower sweep frequency.

[0091] like Figure 8 As shown, an exemplary example is illustrated where m=2, and the sweep slope of the linear sweep optical signal in each measurement cycle is positive in the first sweep time and negative in the second sweep time, along with the time-frequency diagrams of the beat frequency signal and the pulse optical signal. Each measurement cycle includes two sequentially set sweep times: the first sweep time is the upper sweep time, and the second sweep time is the lower sweep time. The beat frequency of the beat signal corresponding to the first sweep time is the upper sweep frequency, and the beat frequency of the beat signal corresponding to the second sweep time is the lower sweep frequency.

[0092] like Figure 9As shown, an exemplary diagram illustrates the amplitude-frequency diagrams of the beat frequency signal and the pulsed optical signal when the sweep slope of the linear sweep frequency optical signal is positive in the first sweep frequency time and negative in the second sweep frequency time within each measurement cycle (m=2). Each measurement cycle includes two sweep frequency times set sequentially: the first sweep frequency time is the upper sweep frequency time, and the second sweep frequency time is the lower sweep frequency time.

[0093] In applications, when a lidar system includes multiple lasers, by having all the lasers operate in linear frequency modulation mode to emit linearly swept frequency optical signals, multiple velocities of the target object at the i-th sweep time in each measurement cycle can be obtained. The average, median, or root mean square of these multiple velocities can be taken as the actual velocity of the target object at the i-th sweep time in each measurement cycle to improve the accuracy of the velocity measurement results. The number of multiple velocities is equal to the number of lasers operating in linear frequency modulation mode.

[0094] like Figure 10 As shown, in one embodiment, step S104 includes the following steps S201 to S203:

[0095] Step S201: Based on the flight time of the pulsed optical signal emitted at the i-th pulse time of each measurement cycle and the sweep slope of the linear sweep optical signal emitted at the i-th sweep time, obtain the distance beat frequency of the linear sweep optical signal emitted at the i-th sweep time of each measurement cycle.

[0096] In applications, the sweep slope of the linear sweep optical signal emitted by the laser in each sweep time of each measurement cycle is known, and the distance beat frequency of the linear sweep optical signal can be calculated by combining the flight time and the sweep slope.

[0097] In one embodiment, the formula for calculating the distance beat frequency of the linear sweep optical signal emitted during the i-th sweep time of each measurement cycle is:

[0098] f ri =k i *t i / 2; (Formula 1)

[0099] Among them, f ri k represents the distance beat frequency of the linear sweep optical signal emitted during the i-th sweep time in each measurement cycle. i t represents the sweep slope of the linear sweep optical signal emitted during the i-th sweep time in each measurement cycle. i This represents the flight time of the pulsed light signal emitted during the i-th pulse time of each measurement cycle.

[0100] In application, using Formula 1 above, the distance beat frequency of the linear swept-frequency optical signal emitted at each sweep time in each measurement cycle is calculated based on the sweep slope of the linear swept-frequency optical signal emitted at each sweep time in each measurement cycle and the flight time of the pulse optical signal emitted at each corresponding pulse time. For example, when each measurement cycle includes only one sweep time and one pulse time, the formula for calculating the distance beat frequency of the linear swept-frequency optical signal emitted at each sweep time in each measurement cycle is as follows:

[0101] f r = k*t / 2;

[0102] Among them, f r denoted by , k represents the distance beat frequency of the linear sweep optical signal emitted during the sweep time of each measurement cycle, k represents the sweep slope of the linear sweep optical signal emitted during the sweep time of each measurement cycle, and t represents the flight time of the pulse optical signal emitted during the pulse time of each measurement cycle.

[0103] When each measurement cycle includes two sweep times and two pulse times, the formula for calculating the distance beat frequency of the linear sweep optical signal emitted during the first sweep time of each measurement cycle is:

[0104] f r1 =k1*t1 / 2;

[0105] Among them, f r1 denoted by k1, the distance beat frequency of the linear sweep optical signal emitted during the first sweep time of each measurement cycle; k1 represents the sweep slope of the linear sweep optical signal emitted during the first sweep time of each measurement cycle; and t1 represents the flight time of the pulse optical signal emitted during the first pulse time of each measurement cycle.

[0106] The formula for calculating the distance beat frequency of the linear sweep frequency optical signal emitted during the second sweep time of each measurement cycle is as follows:

[0107] f r2 = k2*t2 / 2;

[0108] Among them, f r2 t2 represents the distance beat frequency of the linear sweep optical signal emitted during the second sweep time of each measurement cycle, k2 represents the sweep slope of the linear sweep optical signal emitted during the second sweep time of each measurement cycle, and t2 represents the flight time of the pulse optical signal emitted during the second pulse time of each measurement cycle.

[0109] Step S202: Based on the distance beat frequency of the linear sweep frequency optical signal emitted during the i-th sweep time of each measurement cycle and the beat frequency of the corresponding beat frequency signal, obtain the velocity beat frequency of the linear sweep frequency optical signal emitted during the i-th sweep time of each measurement cycle.

[0110] In applications, the beat frequency of the linear sweep frequency optical signal emitted by the laser in each sweep time of each measurement cycle is calculated based on the beat frequency signal. The velocity beat frequency of the linear sweep frequency optical signal can be calculated by combining the distance beat frequency and the beat frequency.

[0111] In one embodiment, the formula for calculating the velocity beat frequency of the linear sweep optical signal emitted during the i-th sweep time of each measurement cycle is:

[0112] f vi =f i -f ri ; (Formula 2)

[0113] Among them, f vi f represents the velocity beat frequency of the linear sweep optical signal emitted during the i-th sweep time in each measurement cycle. i This represents the beat frequency of the beat frequency signal corresponding to the linear sweep frequency optical signal emitted during the i-th sweep frequency time in each measurement cycle.

[0114] In application, using Formula 2 above, the velocity beat frequency of the linear swept-frequency optical signal emitted at each sweep time in each measurement cycle is calculated based on the distance beat frequency and the corresponding beat frequency of the beat frequency signal of the linear swept-frequency optical signal emitted at each sweep time in each measurement cycle. For example, when each measurement cycle includes only one sweep time, the formula for calculating the velocity beat frequency of the linear swept-frequency optical signal emitted at each sweep time in each measurement cycle is:

[0115] f v =ff r ;

[0116] Among them, f v The speed beat frequency of the linear sweep optical signal emitted during the sweep time of each measurement cycle is denoted by f, and f represents the beat frequency of the corresponding linear sweep optical signal emitted during each sweep time of each measurement cycle.

[0117] When each measurement cycle includes two sweep times, the formula for calculating the velocity beat frequency of the linear sweep optical signal emitted in the first sweep time of each measurement cycle is:

[0118] f v1 =f1-f r1 ;

[0119] Among them, f v1 f1 represents the beat frequency of the linear sweep optical signal emitted during the first sweep time of each measurement cycle, and f1 represents the beat frequency of the beat signal corresponding to the linear sweep optical signal emitted during the first sweep time of each measurement cycle.

[0120] The formula for calculating the velocity beat frequency of the linear sweep optical signal emitted during the second sweep time of each measurement cycle is:

[0121] f v2 =f2-f r2 ;

[0122] Among them, f v2 f1 represents the velocity beat frequency of the linear sweep optical signal emitted during the second sweep time of each measurement cycle, and f2 represents the beat frequency of the beat signal corresponding to the linear sweep optical signal emitted during the second sweep time of each measurement cycle.

[0123] Step S203: Based on the velocity beat frequency and initial frequency of the linear sweep frequency light signal emitted during the i-th sweep frequency time in each measurement cycle, obtain the velocity of the target object during the i-th sweep frequency time in each measurement cycle.

[0124] In applications, the initial frequency of the linear sweep light signal emitted by the laser in each sweep time of each measurement cycle is known, and the speed of the linear sweep light signal can be calculated by combining the velocity beat frequency and the initial frequency.

[0125] In one embodiment, the formula for calculating the velocity of the target object at the i-th sweep time in each measurement cycle is:

[0126] v i =f vi *c / 2f oi ; (Formula 3)

[0127] Among them, v i Let f represent the velocity of the target object during the i-th sweep time in each measurement cycle, c represent the speed of light in air, and f represent the speed of light. oi This represents the initial frequency of the linear sweep optical signal emitted during the i-th sweep time of each measurement cycle.

[0128] In application, using Formula 3 above, the velocity of the target object in each sweep time of each measurement cycle is calculated based on the velocity beat frequency and initial frequency of the linear sweep optical signal emitted in each sweep time of each measurement cycle. For example, when each measurement cycle includes only one sweep time, the formula for calculating the velocity of the target object in each sweep time of each measurement cycle is:

[0129] v = fv *c / 2f o ;

[0130] Where v represents the velocity of the target object during the frequency sweep time in each measurement cycle, c represents the speed of light propagation in air, and f o This represents the initial frequency of the linearly swept optical signal emitted during the sweep time of each measurement cycle;

[0131] When each measurement cycle includes only two sweep times, the formula for calculating the velocity of the target object during the first sweep time of each measurement cycle is:

[0132] v1 = f v1 *c / 2f o1 ;

[0133] Where v1 represents the velocity of the target object during the first sweep time of each measurement cycle, c represents the speed of light in air, and f o1 This represents the initial frequency of the linearly swept optical signal emitted during the first sweep time of each measurement cycle;

[0134] The formula for calculating the velocity of the target object during the second sweep time of each measurement cycle is:

[0135] v2 = f v2 *c / 2f o2 ;

[0136] Where v2 represents the velocity of the target object during the second sweep time in each measurement cycle, c represents the speed of light in the air, and f o2 This represents the initial frequency of the linearly swept optical signal emitted during the second sweep time of each measurement cycle.

[0137] 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.

[0138] This application also provides a laser ranging and velocimetry device for performing the steps described in the above-described laser ranging and velocimetry method embodiments. The laser ranging and velocimetry device can be a virtual appliance within a terminal device, run by the terminal device's processor, or it can be the terminal device itself.

[0139] like Figure 11 As shown, the laser ranging and velocimetry device 100 provided in this application embodiment includes:

[0140] The linear sweep frequency optical signal transmitting unit 101 is used to transmit a linear sweep frequency optical signal to the target object during the i-th sweep frequency time of each measurement cycle, which then enters the velocity measuring unit 104.

[0141] The pulse light signal transmitting unit 102 is used to transmit a pulse light signal to the target object during the i-th pulse time of each measurement cycle, which then enters the ranging unit 103.

[0142] The ranging unit 103 is used to obtain the distance of the target object at the i-th pulse time of each measurement cycle based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle.

[0143] The speed measurement unit 104 is used to obtain the speed of the target object at the i-th sweep time of each measurement cycle based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle and the beat frequency of the beat frequency signal corresponding to the linear sweep frequency light signal emitted at the i-th sweep time.

[0144] Each measurement cycle includes m alternating sweep times and m pulse times, i = 1, 2, ..., m, where m is a positive integer.

[0145] In one embodiment, the laser ranging and velocimetry device further includes:

[0146] An optical signal receiving unit is used to receive pulsed light signals reflected by a target object;

[0147] The time-of-flight acquisition unit is used to acquire the time of flight of the pulse light signal emitted at the i-th pulse time in each measurement cycle based on the pulse light signal emitted at the i-th pulse time in each measurement cycle and the pulse light signal reflected by the target object.

[0148] In one embodiment, the laser ranging and velocimetry device further includes:

[0149] An optical signal receiving unit is used to receive linearly swept frequency optical signals reflected by a target object;

[0150] The beat frequency signal acquisition unit is used to acquire the beat frequency signal corresponding to the linear sweep frequency light signal emitted at the i-th sweep frequency time in each measurement cycle based on the linear sweep frequency light signal emitted at the i-th sweep frequency time in each measurement cycle and the linear sweep frequency light signal reflected by the target object.

[0151] The signal processing unit is used to obtain the beat frequency of the beat frequency signal corresponding to the linear sweep frequency optical signal emitted at the i-th sweep frequency time based on the beat frequency signal corresponding to the linear sweep frequency optical signal emitted at the i-th sweep frequency time in each measurement cycle.

[0152] In applications, the units in a laser ranging and velocimetry device can be software program units, implemented through different logic circuits integrated in a processor, or implemented through two or more distributed processors. When the terminal device is a lidar, the pulsed light signal transmitting unit and the linear sweep light signal transmitting unit can be the same or different lasers, the ranging unit and the velocimetry unit can be processors, the light signal receiving unit can be a photodetector, the time-of-flight acquisition unit can be a time-to-digital converter, a processor, or a combination of an analog-to-digital converter and a processor, the beat frequency signal acquisition unit can be an interferometer or a photodetector, and the signal processing unit can be a processor or a combination of an analog-to-digital converter and a processor.

[0153] like Figure 12 As shown, this application embodiment also provides a terminal device 200, including: at least one processor 201 ( Figure 12 The diagram shows only one processor, memory 202, and computer program 203 stored in memory 202 and executable on at least one processor 201. When processor 201 executes computer program 203, it implements the steps in the various laser ranging and velocimetry method embodiments described above.

[0154] like Figure 13 and 14 As shown, in one embodiment, the terminal device 200 further includes: a first-stage amplifier circuit 204, a second-stage amplifier circuit 205, a third-stage amplifier circuit 206, an analog-to-digital converter 207, and a time-to-digital converter 208;

[0155] The first-stage amplifier circuit 204, the second-stage amplifier circuit 205, the third-stage amplifier circuit 206, the analog-to-digital converter 207, and the processor 201 are connected in sequence. The first-stage amplifier circuit 204 is connected to the photodetector 300.

[0156] Figure 13 The example shows a time-to-digital converter 208 connected between a second-stage amplifier circuit 205 and a processor 201;

[0157] Figure 14 An exemplary illustration shows a time-to-digital converter 208 connected between a third-stage amplifier circuit 206 and a processor 201.

[0158] In applications, terminal devices may include, but are not limited to, analog-to-digital converters, time-to-digital converters, memory, processors, etc., and may also include at least one stage of amplifier circuitry, for example... Figure 13 and Figure 14 The three-stage amplifier circuit shown is illustrated. Those skilled in the art will understand that... Figures 12 to 14The examples provided are merely illustrations and do not constitute a limitation on the terminal devices. They may include more or fewer components than shown, or combine certain components, or different components. For example, a time-to-digital converter may also be connected between the first-stage amplifier circuit and the processor.

[0159] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0160] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units is used as an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the device can be divided into different functional units to complete all or part of the functions described above. The functional units 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 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 in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0161] This application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the laser ranging and velocimetry method of any of the above embodiments.

[0162] This application provides a computer program product that, when run on a terminal device, causes the terminal device to execute the laser ranging and velocimetry method of any of the above embodiments.

[0163] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying the computer program code to a terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks.

[0164] 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, please refer to the relevant descriptions of other embodiments.

[0165] 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.

[0166] In the embodiments provided in this application, it should be understood that the disclosed apparatus, terminal devices, and methods can be implemented by other methods. For example, the apparatus and terminal device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, two or more units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0167] The above 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 laser ranging and velocimetry method, characterized in that, include: A linear sweep frequency optical signal is emitted toward the target object during the i-th sweep frequency time of each measurement cycle; A pulsed light signal is emitted toward the target object during the i-th pulse time of each measurement cycle; The distance of the target object at the i-th pulse time of each measurement cycle is obtained based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle. Based on the flight time of the pulsed light signal emitted at the i-th pulse time of each measurement cycle and the beat frequency of the beat frequency signal corresponding to the linear sweep frequency light signal emitted at the i-th sweep frequency time, the velocity of the target object at the i-th sweep frequency time of each measurement cycle is obtained. Each measurement cycle includes m frequency sweep times and m pulse times that are set alternately, i = 1, 2, ..., m, where m is a positive integer; The step of obtaining the velocity of the target object at the i-th sweep time of each measurement cycle based on the flight time of the pulsed light signal emitted at the i-th pulse time and the beat frequency of the beat frequency signal corresponding to the linear sweep frequency signal emitted at the i-th sweep time includes: Based on the flight time of the pulsed optical signal emitted at the i-th pulse time in each measurement cycle and the sweep slope of the linear sweep optical signal emitted at the i-th sweep time, the distance beat frequency of the linear sweep optical signal emitted at the i-th sweep time in each measurement cycle is obtained. Based on the distance beat frequency of the linear sweep frequency optical signal emitted at the i-th sweep time in each measurement cycle and the beat frequency of the corresponding beat frequency signal, the velocity beat frequency of the linear sweep frequency optical signal emitted at the i-th sweep time in each measurement cycle is obtained. Based on the velocity beat frequency and initial frequency of the linear sweep frequency light signal emitted at the i-th sweep time in each measurement cycle, the velocity of the target object at the i-th sweep time in each measurement cycle is obtained.

2. The laser ranging and velocimetry method as described in claim 1, characterized in that, The formula for calculating the distance beat frequency of the linear sweep frequency optical signal emitted during the i-th sweep time of each measurement cycle is: f ri =k i *t i / 2; The formula for calculating the velocity beat frequency of the linear sweep optical signal emitted during the i-th sweep time of each measurement cycle is: f vi =f i -f ri ; The formula for calculating the velocity of the target object during the i-th sweep time in each measurement cycle is: v i =f vi *2c / f oi ; Among them, f ri k represents the distance beat frequency of the linear sweep optical signal emitted during the i-th sweep time in each measurement cycle. i t represents the sweep slope of the linear sweep optical signal emitted during the i-th sweep time in each measurement cycle. i f represents the flight time of the pulsed light signal emitted at the i-th pulse time in each measurement cycle. vi f represents the velocity beat frequency of the linear sweep optical signal emitted during the i-th sweep time in each measurement cycle. i v represents the beat frequency of the beat signal corresponding to the linear sweep frequency optical signal emitted during the i-th sweep time of each measurement cycle. i Let f represent the velocity of the target object during the i-th sweep time in each measurement cycle, c represent the speed of light in air, and f represent the speed of light. oi This represents the initial frequency of the linear sweep optical signal emitted during the i-th sweep time of each measurement cycle.

3. The laser ranging and velocimetry method as described in claim 1 or 2, characterized in that, m=1, where the sweep slope of the linear sweep optical signal emitted during the sweep time of each measurement cycle is positive or negative; Alternatively, m = 2, where the signs of the sweep slopes of the linear sweep optical signals emitted during the first and second sweep times of each measurement cycle are opposite.

4. The laser ranging and velocimetry method as described in claim 1 or 2, characterized in that, In each measurement cycle, the duty cycle of m pulse times is less than or equal to 1 / 3, and the duty cycle of m sweep times is greater than or equal to 2 / 3. Alternatively, the duty cycle of the m pulse times in each measurement cycle is less than or equal to 1 / 5, and the duty cycle of the m sweep times is greater than or equal to 4 / 5.

5. The laser ranging and velocimetry method as described in claim 4, characterized in that, The duration of each measurement cycle is greater than or equal to 5µs, and the value of each pulse time ranges from 2ns to 5ns.

6. The laser ranging and velocimetry method as described in claim 1 or 2, characterized in that, The pulse power of the pulsed optical signal emitted during the i-th pulse time of each measurement cycle is constant and ranges from 1W to 1000W.

7. A laser ranging and velocimetry device, characterized in that, include: A linear sweep frequency optical signal transmitting unit is used to transmit a linear sweep frequency optical signal to the target object during the i-th sweep frequency time of each measurement cycle; The pulsed light signal transmitting unit is used to transmit a pulsed light signal to the target object during the i-th pulse time of each measurement cycle; The ranging unit is used to obtain the distance of the target object at the i-th pulse time of each measurement cycle based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle. The velocity measurement unit is used to obtain the velocity of the target object at the i-th sweep time of each measurement cycle based on the flight time of the pulse light signal emitted at the i-th pulse time of each measurement cycle and the beat frequency of the beat frequency signal corresponding to the linear sweep frequency light signal emitted at the i-th sweep time. Each measurement cycle includes m pulse times and m frequency sweep times that are set alternately, i = 1, 2, ..., m, where m is a positive integer; The step of obtaining the velocity of the target object at the i-th sweep time of each measurement cycle based on the flight time of the pulsed light signal emitted at the i-th pulse time and the beat frequency of the beat frequency signal corresponding to the linear sweep frequency signal emitted at the i-th sweep time includes: Based on the flight time of the pulsed optical signal emitted at the i-th pulse time in each measurement cycle and the sweep slope of the linear sweep optical signal emitted at the i-th sweep time, the distance beat frequency of the linear sweep optical signal emitted at the i-th sweep time in each measurement cycle is obtained. Based on the distance beat frequency of the linear sweep frequency optical signal emitted at the i-th sweep time in each measurement cycle and the beat frequency of the corresponding beat frequency signal, the velocity beat frequency of the linear sweep frequency optical signal emitted at the i-th sweep time in each measurement cycle is obtained. Based on the velocity beat frequency and initial frequency of the linear sweep frequency light signal emitted at the i-th sweep time in each measurement cycle, the velocity of the target object at the i-th sweep time in each measurement cycle is obtained.

8. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the laser ranging and velocimetry method as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the laser ranging and velocimetry method as described in any one of claims 1 to 6.

Images