CN110716193B

CN110716193B - Signal generation method and device

Info

Publication number: CN110716193B
Application number: CN201911270451.6A
Authority: CN
Inventors: 骆龙; 侴智; 陈培
Original assignee: MILESEEY TECHNOLOGY Inc
Current assignee: MILESEEY TECHNOLOGY Inc
Priority date: 2019-12-12
Filing date: 2019-12-12
Publication date: 2020-05-08
Anticipated expiration: 2039-12-12
Also published as: CN110716193A

Abstract

The application provides a signal generation method, which comprises the following steps: generating at least one set of synchronization signals by a synchronization signal generation module; generating at least one set of source signals from at least one signal source; and controlling at least three sets of frequency dividers by the at least one set of synchronization signals such that the at least three sets of frequency dividers frequency-divide the at least one set of source signals, respectively, to generate phase-synchronized first, second, and third signals, wherein frequency division coefficients of the at least three sets of frequency dividers are set such that a frequency of the first signal is different from a frequency of the second signal, and a frequency of the third signal is a difference between the frequencies of the first and second signals.

Description

Signal generation method and device

Technical Field

The present application relates to the field of signal generation, and in particular, to a method and an apparatus for generating a low-frequency reference signal in laser ranging.

Background

Laser ranging is widely applied to a plurality of fields such as industry, building industry, safety monitoring and the like. The phase type distance measuring device sends a high-frequency measuring signal to a target to be measured, receives a measuring signal reflected by the target to be measured, and calculates the phase difference of the reflected signal relative to the measuring signal to obtain the distance from the target to be measured to the distance measuring device. Since the measurement signal is a high frequency signal, it is difficult to directly measure the signal difference between the two signals, and usually, the phase difference is indirectly measured by using a frequency reduction method. The frequency-reducing method is to generate another local high-frequency signal which has a small frequency difference (such as 1 KHZ) with the measuring signal while transmitting the measuring signal, mix (electrically or photoelectrically) the measuring signal reflected by the target to be measured with the local high-frequency signal to obtain a low-frequency signal (such as 1 KHZ) related to the distance, and compare the phase of the low-frequency signal with the initial phase to obtain the phase difference related to the distance. However, because of the randomness of the initial phase between the measurement signal and the other local high frequency signal, the initial phase of the obtained indirect low frequency signal will also have a randomness. Therefore, in practical applications, another low frequency reference signal needs to be obtained locally as a reference for the initial phase.

The traditional distance measurement method mainly generates a low-frequency reference signal by means of electrical mixing or optical mixing. This is generally achieved in several ways: (1) direct electrical mixing. I.e. the measurement signal to be transmitted and the local high frequency signal are directly electrically mixed to obtain a low frequency signal. (2) Two laser transmitters are adopted, wherein one laser transmitter transmits light which passes through a fixed reference light path in the machine to reach a photoelectric receiver, echo on the fixed light path is obtained, and the low-frequency reference signal is generated. (3) Two receivers are used. Light emitted by the laser transmitter is split, and one split light reaches one of the receivers through a fixed reference light path in the machine to generate an echo signal of the fixed light path, so that the low-frequency reference signal is obtained. On the other hand, when generating the reference signal by electrical mixing, two sets of high-frequency electrical signals (e.g., a high-frequency measurement signal and a high-frequency local oscillator signal) need to be input to the electrical mixer for mixing. And the interaction of two sets of high-frequency electric signals can interfere with the signal or other signals in the circuit, and bring adverse effect to the whole ranging process. And the added electrical mixer also adds some complexity to the circuit. On the other hand, when the reference signal is generated by optical mixing, a set of reference optical signals and the local oscillator signal need to be mixed. In this case, in addition to the optical path for normally emitting the measuring beam outwards, an additional optical path for transmitting the reference beam needs to be built in the distance measuring device to generate the reference optical signal. And additionally setting up the light path can make the structure of the distance measuring device more complicated, can also improve the difficulty of subsequent treatment simultaneously, have higher requirement to the distance measuring device, and introduce extra interference easily, lead to the accuracy of finding distance to reduce. Therefore, it is desirable to provide a signal generation method with convenient implementation and strong anti-interference capability to improve the accuracy of the laser ranging method and realize accurate ranging of different distances.

Disclosure of Invention

One of the embodiments of the present application provides a signal generation method, including: generating at least one set of synchronization signals by a synchronization signal generation module; generating at least one set of source signals from at least one signal source; and controlling at least three sets of frequency dividers by the at least one set of synchronization signals such that the at least three sets of frequency dividers frequency-divide the at least one set of source signals, respectively, to generate phase-synchronized first, second, and third signals, wherein frequency division coefficients of the at least three sets of frequency dividers are set such that a frequency of the first signal is different from a frequency of the second signal, and a frequency of the third signal is a difference between the frequencies of the first and second signals; the first signal is used for modulating a laser emission module to generate a laser beam so as to emit the laser beam to a target to be measured; the second signal is used for mixing with the laser beam which is received by the laser receiving module and reflected by the target to be measured so as to generate a measuring signal; the third signal is used for comparing the signal processing module with the measurement signal so as to calculate the distance from the ranging device to the target to be measured.

In some embodiments, the at least one set of synchronization signals generated by the synchronization signal generation module is a periodic signal and the at least one set of source signals generated by the at least one signal source is a periodic signal.

In some embodiments, said generating at least one set of source signals by at least one signal source comprises: controlling the at least one signal source by the at least one set of synchronization signals to cause the at least one signal source to generate at least one set of source signals, the at least one set of source signals being phase synchronized.

In some embodiments, the controlling at least three sets of frequency dividers by the at least one set of synchronization signals, causing the at least three sets of frequency dividers to divide the at least one set of source signals to generate the phase synchronized first, second, and third signals, respectively, comprises: the at least one signal source and the at least three sets of frequency dividers are respectively controlled by the same set of synchronization signals to enable the at least one signal source to generate at least one set of source signals, and the at least three sets of frequency dividers are respectively used for frequency dividing the at least one set of source signals to generate a first signal, a second signal and a third signal which are synchronous in phase.

In some embodiments, the controlling at least three sets of frequency dividers by the at least one set of synchronization signals, causing the at least three sets of frequency dividers to divide the at least one set of source signals to generate the phase synchronized first, second, and third signals, respectively, comprises: the at least one signal source is controlled by one of the at least one set of synchronization signals to cause the at least one signal source to generate at least one set of source signals, and the at least three sets of frequency dividers are controlled by another of the at least one set of synchronization signals to cause the at least three sets of frequency dividers to frequency divide the at least one set of source signals, respectively, to generate phase synchronized first, second, and third signals.

In some embodiments, the controlling at least three sets of frequency dividers by the at least one set of synchronization signals, causing the at least three sets of frequency dividers to divide the at least one set of source signals to generate the phase synchronized first, second, and third signals, respectively, comprises: and controlling at least three groups of frequency dividers by the at least one group of synchronous signals, so that the at least three groups of frequency dividers respectively divide the frequency of the same group of source signals to generate the first signal, the second signal and the third signal which are synchronous in phase.

In some embodiments, the controlling at least three sets of frequency dividers by the at least one set of synchronization signals, causing the at least three sets of frequency dividers to divide the at least one set of source signals to generate the phase synchronized first, second, and third signals, respectively, comprises: and controlling at least three groups of frequency dividers by the at least one group of synchronous signals, so that the at least three groups of frequency dividers respectively divide at least two groups of source signals to generate the first signal, the second signal and the third signal which are synchronous in phase.

In some embodiments, at least one fractional divider of the at least three sets of dividers is included.

One of the embodiments of the present application provides a signal generating apparatus, including: a synchronization signal generation module configured to generate at least one set of synchronization signals; and a modulation signal generation module including a source signal generation unit and a divided signal generation unit, wherein the source signal generation unit includes at least one signal source for generating at least one set of source signals, the divided signal generation unit includes at least three sets of frequency dividers configured to divide the frequency of the at least one set of source signals, respectively, under the control of the at least one set of synchronization signals, to generate phase-synchronized first, second, and third signals, wherein division coefficients of the at least three sets of frequency dividers are set such that the frequency of the first signal is different from the frequency of the second signal, and the frequency of the third signal is a difference between the frequencies of the first and second signals; the laser emission module is configured to generate a laser beam under the modulation of the first signal and emit the laser beam to a target to be measured; the laser receiving module is configured to receive the laser beam reflected by the target to be measured and perform frequency mixing with the second signal to generate a measuring signal; and a signal processing module configured to calculate a distance from a ranging device to the target to be measured based on the measurement signal and the third signal.

In some embodiments, the modulation signal generation module is configured to: controlling the at least one signal source by the at least one set of synchronization signals such that the at least one signal source generates at least one set of source signals, the at least one set of source signals being phase synchronized.

In some embodiments, the modulation signal generation module is configured to: the at least one signal source and the at least three groups of frequency dividers are respectively controlled by the same group of synchronous signals, so that the at least one signal source generates at least one group of source signals, and the at least three groups of frequency dividers respectively divide the at least one group of source signals to generate a first signal, a second signal and a third signal which are synchronous in phase.

In some embodiments, the modulation signal generation module is configured to: the at least one signal source is controlled by one of the at least one set of synchronization signals to cause the at least one signal source to generate at least one set of source signals, and the at least three sets of frequency dividers are controlled by another of the at least one set of synchronization signals to cause the at least three sets of frequency dividers to frequency divide the at least one set of source signals, respectively, to generate phase synchronized first, second, and third signals.

In some embodiments, the modulation signal generation module is configured to: and controlling at least three groups of frequency dividers by the at least one group of synchronous signals, so that the at least three groups of frequency dividers respectively divide the frequency of the same group of source signals to generate the first signal, the second signal and the third signal which are synchronous in phase.

In some embodiments, the modulation signal generation module is configured to: and controlling at least three groups of frequency dividers by the at least one group of synchronous signals, so that the at least three groups of frequency dividers respectively divide at least two groups of source signals to generate the first signal, the second signal and the third signal which are synchronous in phase.

One of the embodiments of the present application provides a signal generating apparatus, which includes a processor and a memory; the memory for storing computer instructions, wherein the computer instructions, when executed by the processor, cause the apparatus to implement a method of signal generation as in any one of the above.

One of the embodiments of the present application provides a computer-readable storage medium storing computer instructions, at least a portion of which, when executed by at least one processor, implement a method of signal generation as described in any one of the above.

Drawings

The present application will be further explained by way of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals are used to indicate like structures, wherein:

FIG. 1 is a schematic diagram of an application scenario of a signal generation apparatus according to some embodiments of the present application;

FIGS. 2A-2D are schematic diagrams illustrating exemplary applications of a laser ranging device according to further embodiments of the present disclosure;

FIG. 3 is a block diagram of a signal generation apparatus according to some embodiments of the present application;

FIG. 4 is a schematic diagram of an internal structure of an exemplary signal generating device according to some embodiments of the present application;

FIG. 5 is an exemplary flow chart of a signal generation method according to some embodiments of the present application;

FIG. 6 is a schematic block diagram of an exemplary modulated signal generating module according to some embodiments of the present application;

FIG. 7 is a block diagram illustrating an exemplary modulated signal generating module according to further embodiments of the present application;

FIG. 8 is a block diagram illustrating an exemplary modulated signal generating module according to further embodiments of the present application;

FIG. 9 is a block diagram illustrating an exemplary modulated signal generating module according to further embodiments of the present application;

fig. 10 is a schematic diagram of an exemplary phase-locked loop structure according to some embodiments of the present application.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only examples or embodiments of the application, from which the application can also be applied to other similar scenarios without inventive effort for a person skilled in the art. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

It should be understood that "system", "device", "unit" and/or "module" as used herein is a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, other words may be substituted by other expressions if they accomplish the same purpose.

As used in this application and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

Flow charts are used herein to illustrate operations performed by systems according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in the exact order in which they are performed. Rather, the various steps may be processed in reverse order or simultaneously. Meanwhile, other operations may be added to the processes, or a certain step or several steps of operations may be removed from the processes.

Fig. 1 is a schematic diagram of an application scenario of a signal generation apparatus 100 according to some embodiments of the present application.

The signal generating device 100 may be a device having both a signal generating function and a laser ranging function, or may be a part integrated in a laser ranging device (e.g., the laser ranging device 200) to generate an electrical signal for the laser ranging device. As shown in fig. 1, the signal generating apparatus 100 may generate a signal and be used to measure a distance to at least one object to be measured (e.g., objects to be measured 121, 122, 123, 124, etc.). In some embodiments, the distance to be measured may be one or more distances, such as

distances

131, 132, 133, 134, and so forth. The target to be measured may include a spatial point located on one or more object surfaces (e.g., an outer surface, an inner surface), an edge line, or any other position. For example, the target to be measured may be a vertex, a center of gravity, a center point, or other spatial point of an object. The spatial point may be located in any direction of the signal generating means.

In some embodiments, the signal generating device may be used to measure the distance between a plurality of points on an object. For example, the signal generating device may obtain the distances between the plurality of spatial points on the object based on the distance analysis between the plurality of points and the ranging device by measuring the distances between the ranging device and the plurality of spatial points.

Fig. 2A-2D are schematic diagrams illustrating application scenarios of a laser ranging device 200 according to other embodiments of the present application.

In fig. 2A-2D, the signal generating apparatus 100 may be a part integrated in the laser ranging apparatus 200, and is used for generating an electrical signal for the laser ranging apparatus 200 to measure the distance from the target to be measured to the laser ranging apparatus 200 in any scene, such as land, air, water, etc. For example, fig. 2A-2D provide illustrative four exemplary applications of the laser ranging device integrated with the signal generating device 100. These four application scenarios are only used as examples and do not limit the application range of the present laser ranging apparatus.

As shown in fig. 2A, the laser ranging device 200 may be mounted on an aircraft 210 for measuring an object to be measured in the air. In some embodiments, the aerial vehicle 210 may include one or any combination of a drone, an Unmanned Aerial Vehicle (UAV), an airship, an airplane, a helicopter, a hot air balloon, a satellite, a manned spacecraft, a space probe, a space shuttle, a rocket, and the like. In some embodiments, laser ranging device 200 and/or aerial vehicle 210 may perform ranging operations in the air according to user controls or self-settings. For example, the aircraft 210 may fly with the laser ranging device 200 to the vicinity of a target to be measured in the air. Then, the laser ranging device 200 may emit a laser signal and detect the laser signal reflected by the target to be measured, so as to estimate the distance from the laser ranging device 200 to the target to be measured. In some embodiments, one or more image sensors (e.g., a camera) may be included on the aerial vehicle 210 and/or the laser ranging device 200. The image sensor may be used to capture image information about the aircraft 210, such as images of the front, back, below, or any other direction of the aircraft 210. The aircraft 210 or its remote control terminal may control the aircraft 210 based on the image acquired by the image sensor. Additionally or alternatively, the user may analyze the acquired image through a remote control terminal (e.g., a computer device) and remotely control the movement of the aircraft 210 based on the analysis result so as to locate the laser ranging device 200 at the optimal ranging position. In some embodiments, the laser ranging device 200, the aircraft 210, and the remote terminal may each include a communication interface. Commands and data may be exchanged between the laser ranging device 200, the aerial vehicle 210, and the remote terminal via the communication interface. In some embodiments, one or more components of laser ranging device 200 may be integrated into aircraft 210.

As shown in fig. 2B, the laser ranging device 200 can perform ranging under the control of the hand 220. In some embodiments, laser ranging device 200 may include an interface or interfaces, such as a user interface, touch screen, control device, etc., that facilitate operation by hand 220. Alternatively, the laser ranging device 200 may include a device that is convenient for holding by hand, such as a handle, a groove, etc. The hand 220 may be in a fixed position or may be moved arbitrarily while the hand-held laser ranging device 200 is taking measurements.

As shown in fig. 2C, the laser ranging device 200 may be mounted on a support 230 for ranging. The bracket 230 may be used to support the laser ranging device 200 so that it can be stable during measurement. In some embodiments, the carriage 230 may drive the laser ranging device 200 to move, such as up, down, flip, and the like. Movement of the carriage 230 and/or the laser ranging device 200 may be controlled by a user manually, by a user remotely, or automatically by the carriage 230 (e.g., the carriage 230 may be automatically controlled according to a program stored therein). In some embodiments, the cradle 230 may include one or more measurement aids, such as a microphone, remote control, sight, camera, and the like. Optionally, cradle 230 may include a communication module that may be configured to provide communication support for laser ranging device 200 and a remote device. In some embodiments, one or more components of laser ranging device 200 may be integrated into cradle 230.

As shown in fig. 2D, the laser ranging device 200 may be mounted on a movable apparatus 240 for measuring targets to be measured in water and/or on land. The mobile device 240 may include, but is not limited to, one or any combination of a remote control car, a non-powered cart, an automobile, a probe (e.g., a Mars probe, a moon probe, a sea-bottom probe), and any other mobile device. In some embodiments, the movable apparatus 240 may be moved in any direction (e.g., horizontal, vertical, etc.) above ground, above water, below water, etc., by a pulley, a robotic arm, a suspension device, or the like. The removable device 240 may move autonomously, for example, detecting movement itself based on instructions or data stored in the device. The removable device 240 may also be moved by manual control, for example, a person moving a remote control device at a remote control. In some embodiments, one or more components of laser ranging apparatus 200 may be integrated into removable device 240.

It should be understood that although only four application scenarios are listed in fig. 2A-2D, the laser ranging device disclosed herein may be applied in a variety of other scenarios without departing from the spirit of the present application, and is not limited thereto.

FIG. 3 is a block diagram of a signal generation apparatus according to some embodiments of the present application.

As shown in fig. 3, the signal generating apparatus 300 may include a synchronization signal generating module 310 and a modulation signal generating module 320.

The synchronization signal generation module 310 may be used to generate a synchronization signal. In some embodiments, the synchronization signal generation module 310 may generate one or more sets of synchronization signals. The multiple groups of synchronization signals may be completely same periodic signals or different periodic signals. For example, the synchronization signal generation module 310 may generate two sets of synchronization signals with identical phase, frequency, period and shape. In some embodiments, the synchronization signal generated by the synchronization signal generation module 310 may be used to control the modulation signal generation module 320 to generate multiple sets of signals that are phase synchronized. Phase synchronization as used herein may refer to the exact same phase between different signals or a particular phase difference between different signals. For example, the synchronization signal may trigger the modulation signal generation module 320 to generate multiple sets of periodic signals with identical phases. In some embodiments, the modulated signal generation module 320 may include various signal generation structures and/or software programs. For example, the modulation signal generation module 320 may be a control circuit capable of generating a periodic signal.

The modulation signal generation module 320 may generate phase-synchronized sets of signals based on the synchronization signals. The signal in the embodiment of the present application refers to a periodic signal, and the periodic signal is a signal having a waveform with a certain periodicity in a time domain. For example, the modulation signal generation module 320 may generate a first signal, a second signal, and a third signal that are phase-synchronized under the modulation of the synchronization signal, and the first signal, the second signal, and the third signal are all periodic signals. For convenience of description, the subsequent first, second and third signals will be described as first, second and third periodic signals, respectively. In some embodiments, the periodic signal generated by the modulation signal generation module 320 may be a continuous signal with a continuously changing signal intensity with time or a pulse signal with a signal appearing at intervals in the time domain, according to different application scenarios.

In some embodiments, the modulation signal generation module 320 may include a source signal generation unit 324 and a divided signal generation unit 326. The source signal generating unit 324 may be used to generate at least one set of source signals. In some embodiments, the source signal generating unit 324 may include at least one signal source for generating one or more sets of source signals having a periodicity. In some embodiments, the source signal generation unit 324 may include one or more signal sources of the same or different types. For example, the phase locked loop and the RC oscillator circuit may be used as two different types of signal sources, respectively for generating source signals of the same or different frequencies. As another example, two or more phase-locked loops may be used as the same type of signal source, and may be used to generate source signals of the same or different frequencies, respectively. As used herein, two signal sources, if they are of the same type, means that they are made up of the same or similar electronic components. If the two signal sources are of different types, this means that at least one of the electronic components forming the two signal sources is different. In some embodiments, the signal source in the source signal generating unit 324 may generate one or more sets of phase-synchronized source signals under the control of the synchronization signal.

The divided signal generation unit 326 may be used to divide (or down) the source signal to obtain periodic signals of one or more desired frequencies. For example, assuming that the frequency of a source signal generated by one signal source is 20MHz and the division factor of the frequency divider is 4, the frequency of a periodic signal output after passing through the frequency divider is 5 MHz. In some embodiments, the divided signal generation unit 326 may include one or more dividers (or downconverters, such as low pass filters). In some embodiments, the frequency-divided signal generation unit 326 may include at least three sets of frequency dividers that may frequency-divide one or more sets of source signals, respectively, under control of one or more sets of synchronization signals to generate one or more sets of phase-synchronized periodic signals, e.g., a first periodic signal, a second periodic signal, and a third periodic signal. In some embodiments, the three sets of frequency dividers may have different division factors. In some embodiments, at least one of the three sets of dividers may be a fractional divider. In some embodiments, multiple frequency dividers may divide the same source signal simultaneously or may divide different source signals separately. The number of signal sources, the frequency of the source signal, the frequency division coefficient of the frequency divider, etc. can be determined according to actual requirements. For more details regarding the signal generator, reference may be made to fig. 6-9 and their associated description.

If the signal generating apparatus 300 is an apparatus having both a signal generating function and a laser ranging function, the signal generating apparatus may further include a laser emitting module 330, a laser receiving module 340 and a signal processing module 350, in which case, the signal generating apparatus 300 may also be referred to as a laser ranging apparatus.

As shown in fig. 3, the laser emitting module 330 may generate a laser beam under modulation of a periodic signal. For example, the laser emitting module 330 may generate a continuous wave laser beam under modulation of a continuous signal or a pulsed laser beam under modulation of a pulsed signal. In some embodiments, the laser emitting module 330 may emit the generated laser beam to the target to be measured, and the laser beam is reflected by the target to be measured and then transmitted to the laser receiving module. In some embodiments, the laser emitting module 330 may directly emit the generated laser beam to the laser receiving module along the inner optical path. In the embodiment of the present application, the laser emitting module 330 may generate a laser beam under modulation of a first signal (i.e., a first periodic signal) and emit the laser beam to the target to be measured.

In some alternative embodiments, the signal generating apparatus 300 may include a plurality of sets of laser emission modules 330. For example, a first laser emission module and a second laser emission module. The two groups of laser emission modules can be respectively used for generating two laser beams based on the same group of periodic signal modulation. For example, the first laser emitting module may modulate and generate a first laser beam based on the first periodic signal, and the first laser beam may form a measurement optical signal after being transmitted along the first path; the second laser emitting module may generate a second laser beam based on the first periodic signal modulation, and the second laser beam may be emitted to the laser receiving module 340 along a second path inside the apparatus to form a reference light signal. The measurement optical signal and the reference optical signal may be converted into a measurement signal and a first reference signal of a medium-low frequency, respectively, by one or more mixing operations. In this case, in some embodiments, the signal processing module 350 may calculate the distance from the signal generating device to the object to be measured by comparing the measurement signal with the first reference signal.

The laser receiving module 340 may convert the received laser beam into an electrical signal. In some embodiments, the laser receiving module 340 may receive the laser beam reflected by the target to be measured, and mix the laser beam with the second periodic signal to generate a middle-low frequency measurement signal. In some embodiments, the laser receiving module 340 may receive the laser beam emitted by the laser emitting module 330 along the internal optical path, and mix the laser beam with the second periodic signal to generate the first reference signal with a middle-low frequency.

The signal processing module 350 may be used to calculate the distance from the ranging device (or signal generating device) to the target to be measured. For example, the signal processing module 350 may receive the measurement signal processed by the laser receiving module 340, and calculate and obtain the distance from the ranging device (or the signal generating device) to the target to be measured according to the third periodic signal and the measurement signal.

It should be understood that the apparatus shown in fig. 3 and its modules may be implemented in various ways. For example, in some embodiments, an apparatus and its modules may be implemented by hardware, software, or a combination of software and hardware. Wherein the hardware portion may be implemented using dedicated logic; the software portions may be stored in a memory for execution by a suitable instruction execution system, such as a microprocessor or specially designed hardware. Those skilled in the art will appreciate that the methods and apparatus described above may be implemented using computer executable instructions and/or embodied in processor control code, such code being provided for example on a carrier medium such as a diskette, CD-or DVD-ROM, a programmable memory such as read-only memory (firmware) or a data carrier such as an optical or electronic signal carrier. The apparatus and its modules of the present application may be implemented not only by hardware circuits such as very large scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., but also by software executed by various types of processors, for example, or by a combination of the above hardware circuits and software (e.g., firmware).

It should be noted that the above description of the signal generating apparatus and the modules thereof is only for convenience of description, and the present application is not limited to the scope of the illustrated embodiments. It will be appreciated by those skilled in the art that, given the teachings of the present system, any combination of modules or sub-system configurations may be used to connect to other modules without departing from such teachings. For example, in some embodiments, for example, the synchronization signal generation module 310, the modulation signal generation module 320, the laser emission module 330, the laser reception module 340 and the signal processing module 350 disclosed in fig. 3 may be different modules in a system, or may be a module that implements the functions of two or more modules described above. For example, the synchronization signal generation module 310 and the modulation signal generation module 320 may be two modules, or one module may have both the synchronization signal generation function and the modulation signal generation function. For example, each module may share one memory module, and each module may have its own memory module. Such variations are within the scope of the present application.

FIG. 4 is a schematic diagram of an internal structure of an exemplary signal generation apparatus according to some embodiments of the present application. In fig. 4, the signal generating apparatus (e.g., the signal generating apparatus 100, the signal generating apparatus 300) may be a schematic diagram of an internal structure corresponding to a signal generating apparatus having both a signal generating function and a ranging function.

As shown in fig. 4, the signal generating apparatus 400 may include a control circuit 410, a signal generating unit 420, a laser driver 430, a laser module group 440, a light detector 450, a signal preprocessing unit 460, and a digital signal processor 470. The connections between the different components in the signal generation apparatus 400 may be wired connections or wireless connections. For example, the control circuit 410 may send a signal to the signal generation unit 420 by means of wired transmission or wireless transmission.

The control circuit 410 may be used to generate one or more sets of synchronization signals. The multiple groups of synchronization signals may be completely same periodic signals or different periodic signals. In some embodiments, the control circuit 410 may include various signal generating structures and/or software programs. In the embodiment of the present application, the control circuit 410 is functionally equivalent to the synchronization signal generation module 310 in the signal generation apparatus 300.

The signal generation unit 420 may generate a plurality of sets of signals that are phase-synchronized under the control of the synchronization signal. For example, the signal generation unit 420 may be configured to generate phase-synchronized first, second, and third periodic signals under control of the synchronization signal. In some embodiments, the signal generation unit 420 may include one or more signal generators. For example, as shown in fig. 4, the signal generation unit 420 may include a signal generator 1, a signal generator 2, a signal generator 3, … …, and a signal generator N. The first, second, and third periodic signals may be generated by at least one signal generator in the signal generation unit 420. For example, the first, second, and third periodic signals may be generated by the signal generator 1, the signal generator 2, and the signal generator 3, respectively. For another example, the first periodic signal and the second periodic signal may be generated by the signal generator 1, and the third periodic signal may be generated by a signal generator other than the signal generator 1. As another example, the first periodic signal, the second periodic signal, and the third periodic signal may be generated by the same signal generator (e.g., signal generator 1). In this application, a signal generator refers to a signal source that includes a signal source that generates an electrical signal (e.g., a pulse signal) at a particular frequency. Additionally or alternatively, the signal generator may comprise one or more components for post-processing the electrical signal, e.g. components for frequency dividing, filtering, etc. the electrical signal.

In the embodiment of the present application, the signal generation unit 420 is functionally equivalent to the modulation signal generation module 320 in the signal generation apparatus 300. Further description of the signal generator can be found in relation to the modulated signal generating module 320 in fig. 3, and corresponding descriptions in fig. 6-9.

The laser driver 430 may drive the laser module assembly 440 to generate a laser beam 445 under the first periodic signal, and the laser module assembly 440 may emit the laser beam 445 to the target to be measured along the outer optical path 447 and reflect the laser beam to the optical detector 450 through the target to be measured to form a measuring optical signal.

In some alternative embodiments, the laser beam generated by the laser module set 440 may be split into multiple laser beams that travel along different paths. For example, a first laser beam, i.e., laser beam 345, may be transmitted along a first path (i.e., outer optical path 447) to form a measurement optical signal. The other laser beam, reflected by one or more optical structures, may be transmitted along a second path (i.e., inner optical path 443) internal to signal generation apparatus 400 to light detector 450. In some embodiments, the distance of the inner optical path 443 is known, so the optical signal received by the light detector 450 after being transmitted along the inner optical path 443 is also referred to as a reference optical signal. The measurement optical signal and the reference optical signal may be converted into a measurement signal and a first reference signal of a medium-low frequency, respectively, by one or more mixing operations. In this case, in some embodiments, the digital signal processor 470 may calculate the distance from the signal generating device 400 to the target to be measured by comparing the measurement signal with the first reference signal. Additionally or alternatively, the digital signal processor 470 may use a third periodic signal synchronized with the first periodic signal as a second reference signal, and calculate the distance from the signal generating apparatus 400 to the object to be measured in combination with the measurement signal, the first reference signal, and the second reference signal. Specifically, the digital signal processor 470 may calculate a first distance from the signal generating device 400 to the object to be measured according to the measurement signal and the first reference signal, calculate a second distance from the signal generating device 400 to the object to be measured according to the measurement signal and the second reference signal, and obtain a final distance from the signal generating device 400 to the object to be measured according to the first distance and the second distance. More particularly, the digital signal processor 470 may determine the reliability of the measurement result by comparing the first reference signal and the second reference signal. The digital signal processor 470 may determine that the measurement is invalid when the phase difference between the first reference signal and the second reference signal exceeds a certain threshold.

In some embodiments, the laser driver 430 may include a dc constant current source drive circuit, an automatic power control drive circuit, or the like. In some embodiments, the set of laser modules 440 may include any combination of one or more elements of laser diodes, photodiodes, and the like. In the embodiment of the present application, the laser driver 430 and the laser module group 440 in combination function equivalently to the laser emission module 330 in the signal generation apparatus 300.

The light detector 450 may be used to convert the received optical signal into an electrical signal. In some embodiments, the light detector 450 may down convert the received signal. For example, the optical detector 450 may receive the laser beam reflected by the target to be measured and mix with the second periodic signal to generate a measurement signal of a middle-low frequency. In some embodiments, the light detector 450 may be a single point detector or an array detector. In some embodiments, the photodetector may include one or any combination of Avalanche Photodiodes (APDs), Single Photon Avalanche photodiodes (Single Photon Avalanche diodes), silicon photomultipliers (MPCCs), PIN photodiodes, and the like.

In some alternative embodiments, the light detector 450 may be used only to convert the received laser beam reflected by the target to be measured into an electrical signal. In this case, the signal generating apparatus 400 may be connected to a mixing unit after the optical detector 450, and is configured to mix the electrical signal output by the optical detector 450 with the second periodic signal to generate the middle-low frequency measurement signal. For example, a mixing subunit may be accessed in the signal preprocessing unit 460 for mixing the electrical signal output by the light detector 450 with the second periodic signal to generate the middle and low frequency measurement signal.

In some embodiments, the signal generation apparatus 400 may be comprised of one or more photodetectors. For example, in the case that the outer optical path 447 and the inner optical path 443 exist at the same time, one optical detector may receive two laser beams transmitted through the outer optical path 447 and the inner optical path 443 at the same time, and mix with the second periodic signal to generate a middle-low frequency signal, where the generated middle-low frequency signal may include the measurement signal and the first reference signal at the same time. For another example, in the case where the outer light path 447 and the inner light path 443 exist at the same time, two photodetectors may be used to receive two laser beams transmitted through the outer light path 447 and the inner light path 443, respectively. It should be noted that, the number and the type of the optical detectors are not specifically limited in the present application, and the corresponding optical detectors may be selected according to the actual application requirements.

The signal preprocessing unit 460 may be used to preprocess, e.g. filter, amplify, etc., the measurement signal. In some embodiments, the signal preprocessing unit 460 may down-convert the electrical signal converted by the photodetector 450. For example, when the photodetector has only a photoelectric conversion function, the electrical signal may be down-converted by the signal preprocessing unit 460. In some embodiments, the signal preprocessing unit 460 may include one or any combination of a signal amplifier, a low pass filter, a mixer, and the like.

In the embodiment of the present application, the combined functions of the light detector 450 and the signal preprocessing unit 460 may be equivalent to the laser receiving module 340 in the signal generating apparatus 300.

The digital signal processor 470 may receive the preprocessed measurement signal, and calculate the distance between the signal generating device 400 and the target to be measured according to the third periodic signal and the preprocessed measurement signal. In some embodiments, the digital signal processor 470 may receive the pre-processed measurement signal and a first reference signal (i.e., a reference signal generated by the laser beam transmitted through the internal optical path 443), and calculate a distance between the signal generating device 400 and the target to be measured based on the measurement signal and the first reference signal. In some embodiments, the digital signal processor 470 may include a smart oscilloscope, a computer, or the like, as computing-capable electronic device. In an embodiment of the present application, the digital signal processor 470 is functionally equivalent to the signal processing module 350 in the signal generating apparatus 300.

It should be noted that the above description of the signal generating apparatus 400 and its components is merely for convenience of description and should not limit the present application to the scope of the illustrated embodiments. It will be understood by those skilled in the art that, having the benefit of this disclosure, any combination of elements or sub-structure may be made with other elements without departing from the spirit and scope of the present disclosure. For example, the laser driver 430 and the laser module group 440 may be different parts of one module structure, or may be two or more separate unit structures. For another example, the signal preprocessing unit 460 may include one structure capable of simultaneously performing the amplifying and filtering functions, or may include two separate structures having the filtering and amplifying functions. As another example, the signal generating apparatus 400 may include two different components having optical-to-electrical conversion and frequency mixing functions, respectively, in which case the light detector 450 may be used only to convert an optical signal (e.g., a laser beam) into an electrical signal. As another example, one or more components in the signal generating device 400 may be spatially remote from other components, which may form a laser ranging system therebetween. Such variations are within the scope of the present application.

Fig. 5 is an exemplary flow chart of a signal generation method according to some embodiments of the present application.

In some embodiments, the process 500 may be implemented by a signal generation apparatus (e.g., the signal generation apparatus 100, the signal generation apparatus 300, the signal generation apparatus 400) disclosed herein. The order in which the process operations shown in FIG. 5 and described below are performed is not intended to be limiting. For illustrative purposes, the following description will mainly use the signal generating apparatus 300 as an example to describe the implementation of the flow 500.

At 510, at least one set of synchronization signals is provided by the synchronization signal generation module 310.

In this application, a synchronization signal refers to a signal that can provide the same reference (time) to a component that needs to process information or data synchronously. For example, the synchronization signal may be used to control the modulation signal generation module 320 to generate one or more synchronous periodic signals. Specifically, the modulation signal generating module 320 may generate one or more clock signals synchronized with the Phase of the synchronization signal by adjusting the Phase Time (Phase Time) between the clock signal and the synchronization signal based on the synchronization signal. The phase time refers to a delay time of the clock signal and the synchronization signal at a corresponding valid instant (e.g., a rising edge or a falling edge of the signal), and is simply referred to as "phase". In some embodiments, phase synchronization may include the exact same phase and/or a particular phase difference between different signals. For example, when the rising edges and/or the falling edges of the multiple signals generated by the modulation signal generation module 320 at the same time are completely consistent, the multiple signals are completely synchronized in phase. For another example, when the delay time of the rising edge and/or the falling edge between the multiple signals generated by the modulation signal generation module 320 at the same time is kept unchanged, the multiple signals have a fixed phase difference therebetween. For example only, the phase delay time between the signals may be 5 nanoseconds, 10 nanoseconds, 0.1 microseconds, 0.5 microseconds, or the like. The periodic signal referred to in this application is a signal having various shapes and a waveform having a certain periodicity in the time domain. For example, the periodic signal may be a sine wave signal, a pulse signal (e.g., a sawtooth wave signal, a square wave signal, a triangular wave signal), or the like.

In some embodiments, the synchronization signal generation module 310 may generate one or more sets of synchronization signals. The multiple groups of synchronization signals may be completely same periodic signals or different periodic signals. For example, the synchronization signal generated by the synchronization signal generation module 310 may be two sets of periodic signals with identical phase, period, frequency, signal shape, and the like. In this case, a group of synchronization signals may be used to control at least one signal source to generate one or more groups of source signals with consistent signal parameters; another set of synchronization signals may be used to control at least one frequency divider to generate phase-synchronized sets of periodic signals based on at least one set of source signals.

In some embodiments, the synchronization signal may include periodic signals of various shapes, such as a sine wave signal, a sawtooth wave signal, a rectangular wave (e.g., square wave) signal, a triangular wave signal, and the like. In some embodiments, the synchronization signal generation module 310 may include various signal generation structures and/or software programs that may generate a particular type of synchronization signal by setting signal parameters. For example, the synchronization signal generation module may include one or any combination of a signal generation function, a sinusoidal signal generator, a function generator, a pulse signal generator, a high frequency signal generator, a low frequency signal generator, etc. of MATLAB software.

In 520, the modulation signal generation module 320 may generate at least one set of source signals.

The source signal may be divided to produce a periodic signal of one or more desired frequencies. In some embodiments, the modulated signal generation module 320 may generate one or more sets of source signals by one or more signal sources. For example, the source signal generating unit 324 may generate one or more sets of source signals by one signal source, or generate two or more sets of source signals by two signal sources, and the like. In some embodiments, the modulation signal generation module 320 may generate phase-synchronized sets of source signals, e.g., a first source signal, a second source signal, a third source signal, and so on, based on the synchronization signal. In some embodiments, dividing based on one or more sets of source signals that are phase synchronized may generate periodic signals that are more similar (e.g., the same signal shape, phase, etc.), such as the phase synchronized first, second, and third signals.

In 530, the modulation signal generation module 320 may frequency divide at least one set of source signals under control of the synchronization signal to produce phase synchronized first, second, and third signals.

In some embodiments, the modulation signal generation module 320 may control the at least three sets of frequency dividers based on the at least one set of synchronization signals, respectively, such that the at least three sets of frequency dividers frequency-divide the at least one set of source signals to produce the phase-synchronized first, second, and third periodic signals. The frequency division coefficients of the three sets of frequency dividers may be positioned such that the frequency of the first periodic signal is different from the frequency of the second periodic signal and the frequency of the third periodic signal is the difference between the frequencies of the first and second periodic signals. For example, frequency divider 1 (which may also be referred to as a first frequency divider) may generate a first periodic signal having a frequency of 5MHz, frequency divider 2 (which may also be referred to as a second frequency divider) may generate a second periodic signal having a frequency of 4.999MHz, and frequency divider 3 (which may also be referred to as a third frequency divider) may generate a third periodic signal having a frequency of 1 KHz. It should be appreciated that in a scenario where the first periodic signal, the second periodic signal, and the third periodic signal are used for laser ranging, when the frequency of the third periodic signal is equal to the difference between the frequencies of the first periodic signal and the second periodic signal, the calculation process of ranging can be simplified and more accurate ranging results can be provided. Specifically, in laser ranging, a first periodic signal may be used to modulate a laser emission module to generate a laser beam, so as to emit the laser beam to a target to be measured; the second periodic signal can be used for mixing with the laser beam received by the laser receiving module and reflected by the target to be measured so as to generate a measuring signal; the third periodic signal can be used for comparing with the measurement signal to calculate the distance from the ranging device to the target to be measured. It should be noted that the frequency of the measurement signal generated after the laser beam reflected by the target to be measured is mixed with the second periodic signal is equal to the difference between the frequency of the first periodic signal and the frequency of the second periodic signal. When the frequency divider is used for generating the third periodic signal, the frequency of the third periodic signal is the difference between the frequencies of the first periodic signal and the second periodic signal, namely the frequency of the third periodic signal is the same as that of the measuring signal, the phase change caused by the propagation of the measuring signal between the laser ranging device and the object to be measured can be directly reflected by comparing the phase difference between the third periodic signal and the measuring signal, and the distance from the ranging device to the object to be measured can be directly calculated and obtained. In addition, because the problem of mutual comparison among signals with different frequencies does not exist in the calculation process, the finally obtained measurement result is more accurate.

In some embodiments, at least one of the three sets of dividers may be a fractional divider. In some alternative embodiments, the coefficients of the three sets of frequency dividers may be set to other applicable coefficients, which is not limited in this application. In some embodiments, the coefficients of the frequency divider may be set manually and/or by machine, etc. In some embodiments, three sets of frequency dividers may divide one or more sets of source signals to generate a first periodic signal, a second periodic signal, and a third periodic signal, respectively. For example, frequency dividers 1, 2, 3 may divide a set of source signals to generate a first periodic signal, a second periodic signal, and a third periodic signal, respectively. For another example, frequency dividers 1 and 2 may divide a first source signal to generate a first periodic signal and a second periodic signal, and frequency divider 3 may divide a second source signal to generate a third periodic signal. For another example, the frequency dividers 1, 2, 3 may divide the frequency of the first, second, and third source signals to generate the first, second, and third periodic signals, respectively.

In some alternative embodiments, the first periodic signal, the second periodic signal, and the third periodic signal may be divided by the same frequency divider. For example, the first periodic signal, the second periodic signal, and the third periodic signal may all be generated by the frequency divider 1. Alternatively, at least two of the first periodic signal, the second periodic signal, and the third periodic signal may be generated by different frequency dividers. For example, the first and second periodic signals may be generated by frequency divider 1 and the third periodic signal may be generated by frequency divider 2.

In some embodiments, the modulation signal generation module 320 may control the frequency division signal generation unit 326 to generate the first, second, and third periodic signals that are phase-synchronized based on the synchronization signal. For example, the frequency-divided signal generation unit 326 may maintain phase synchronization of the first, second, and third periodic signals by adjusting phase times between the first, second, and third periodic signals and the synchronization signal. For example, the frequency-divided signal generating unit 326 may adjust the phase times of the first, second, and third periodic signals and the synchronization signal, respectively, such that the rising edges (or falling edges) of the first, second, and third periodic signals completely coincide with the rising edges (or falling edges) of the synchronization signal, respectively. At this time, the first periodic signal, the second periodic signal and the third periodic signal realize complete phase synchronization, and the phase difference is 0. For another example, the frequency-divided signal generating unit 326 may respectively adjust the phase times of the first periodic signal, the second periodic signal, and the third periodic signal and the synchronization signal, so that the rising edge (or the falling edge) of the first periodic signal and the second periodic signal respectively coincides with the delay time of the rising edge (or the falling edge) of the synchronization signal (e.g., each is 5 ns), and the delay time of the rising edge (or the falling edge) of the third periodic signal and the delay time of the rising edge (or the falling edge) of the synchronization signal are kept unchanged (e.g., 10 ns). At this time, the first/second periodic signals and the third periodic signal have a fixed phase difference therebetween.

In some embodiments, the modulation signal generation module 320 may control the source signal generation unit 324 and the frequency-divided signal generation unit 326, respectively, based on a set of synchronization signals to generate phase-synchronized first, second, and third periodic signals. In some embodiments, the modulation signal generation module 320 may control the source signal generation unit 324 and the frequency-divided signal generation unit 326, respectively, based on two different sets of synchronization signals to generate the phase-synchronized first, second, and third periodic signals. Further details regarding the generation of the synchronized periodic signal by the modulated signal generation module 320 can be found elsewhere in this application (e.g., in fig. 6-10 and their associated descriptions). When the first periodic signal, the second periodic signal and the third periodic signal are controlled to be generated in phase synchronization based on the synchronization signal, the phase difference between the first periodic signal, the second periodic signal, and the third periodic signal (e.g., a phase difference of 0) can be unambiguously known, therefore, in the subsequent ranging process, when the phase of the first periodic signal changes (for example, the laser corresponding to the first periodic signal needs to propagate between the laser ranging device and the object to be measured, and a phase change occurs), the phase of the third periodic signal is taken as a reference (i.e., since the third periodic signal is synchronized with the first periodic signal at the beginning, the phase of the third periodic signal can be regarded as the initial phase of the first periodic signal before the phase change occurs), the change value of the first periodic signal phase and the corresponding measuring distance can be directly calculated, so that the measuring precision of the target to be measured in the laser ranging is improved. Specifically, in the laser ranging, the laser beam generated under the modulation of the first periodic signal has an unchanged frequency and a shifted phase after being reflected by the target to be measured, and the laser beam reflected by the target to be measured and the second periodic signal are mixed to obtain a measurement signal with an unchanged phase shift and a reduced frequency.

In some embodiments, the first periodic signal and the second periodic signal may be high frequency signals, and the frequencies between the two signals are close (e.g., the frequency difference is less than a frequency threshold). Two high-frequency signals with close frequencies can obtain a signal with a medium-low frequency through mixing. The third periodic signal is a medium-low frequency signal, and the frequency is a difference between the frequency of the first periodic signal and the frequency of the second periodic signal. In this application, a high frequency signal refers to a signal having a frequency exceeding a first frequency threshold, and a medium and low frequency signal refers to a signal having a frequency below a second frequency threshold. The first and second frequency thresholds may be any value. The first and second frequency thresholds may be equal or unequal. For example only, the first periodic signal may have a frequency of 5MHz, the second periodic signal may have a frequency of 4.999MHz, and the third periodic signal may have a frequency of 1 KHz.

The first signal, the second signal and the third signal generated by the modulation signal generation module 320 may be used in a method for measuring a distance to a target to be measured by using a laser. For example, the first signal may be used to modulate the intensity of a laser signal emitted by the laser emission module 330, and the laser signal may be emitted to and reflected by a target to be measured; the reflected signal is received by the laser receiving module 340 and then mixed with a second signal to generate a measurement signal, where the measurement signal may be a medium-low frequency signal generated by performing frequency conversion on the reflected signal; the third signal may be used for comparison with the measurement signal, thereby calculating the distance from the signal generating apparatus 300 to the object to be measured. In the present application, the first signal corresponds to a laser signal emitted by the signal generating apparatus 300, the second signal may also be called a local oscillator signal, and the third signal may also be called a reference signal (e.g., similar to the second reference signal described above). The first signal, the second signal and the third signal generated by the modulation signal generation module 320 are used for laser ranging, so that the structure of the ranging device can be simplified, the signal processing difficulty can be reduced, the extra circuit structure interference can be reduced, and the ranging accuracy can be improved. For example, the third signal (electrical signal) is directly used as the reference signal in laser ranging, so that a circuit or optical path structure that a laser signal (i.e. the first signal) is mixed with a local oscillator signal (i.e. the second signal) to generate a low-frequency reference signal is avoided, the requirement on a ranging device is reduced, and extra circuit interference is reduced. For another example, the laser receiving module receives the laser signal reflected by the target to be measured, converts the laser signal into an electrical signal, and mixes the electrical signal with a second signal which is also the electrical signal to generate a measurement signal with a medium-low frequency, so that the difficulty in processing the signal is reduced.

Specifically, in 540, the laser emitting module 330 may emit a laser beam generated under modulation of the first signal to the target to be measured.

In some embodiments, the first periodic signal may modulate the intensity of the laser beam generated by the laser emission module 330 at a stable frequency. For example, the laser emitting module 330 may convert the high and low of the first periodic signal into the light and dark of the laser beam and the rate of the light and dark change under the modulation of the first periodic signal, thereby generating the laser beam. In some embodiments, the laser emitting module 330 may emit the generated laser beam to the target to be measured.

In 550, the laser receiving module 340 may receive the laser beam reflected by the object to be measured and mix with the second signal to generate a measurement signal.

The laser beam emitted by the laser emitting module 330 is reflected by the target to be measured and transmitted to the laser receiving module 340, and the laser receiving module 340 converts the received optical signal into an electrical signal and mixes the electrical signal with the second periodic signal to generate a measurement signal. In some embodiments, the measurement signal may be a medium to low frequency signal. As described above, the first periodic signal is a high-frequency signal, and the electrical signal generated after the laser beam generated by the modulation of the first periodic signal is reflected by the target to be measured is still a high-frequency signal. The high-frequency signal has high difficulty, large calculation amount and long time consumption in signal processing, so that the high-frequency signal needs to be converted into a medium-low frequency signal so as to reduce the calculation amount of signal processing and improve the measurement accuracy. Since the frequency of the second periodic signal is similar to the frequency of the first periodic signal, the high frequency signal can be converted into a medium-low frequency signal after being mixed with the second periodic signal by the laser receiving module 340. For example, assuming that the frequency of the first periodic signal generated by the modulation signal generation module 320 is 5MHz, and the frequency of the second periodic signal is 4.999MHz, the laser beam generated by the modulation of the first periodic signal is reflected by the target to be measured and then transmitted to the laser receiving module 340, and the medium-low frequency measurement signal with the frequency of 1KHz can be obtained by mixing the laser beam with the second periodic signal in the laser receiving module 340.

In some other variable embodiments, the signal generating apparatus 300 may convert the high frequency signal to the medium and low frequency signal in any other feasible manner (e.g., low pass filtering), which is not limited in this application. In some embodiments, the laser receiving module 340 may further perform post-processing on the measurement signal obtained by mixing, such as frequency-selective amplification, low-pass filtering, and the like, to improve the quality of the measurement signal.

In 560, the signal processing module 350 may calculate a distance from the ranging device to the target to be measured based on the measurement signal and the third signal.

The laser emitting module 330 emits a laser beam to the target to be measured, and the laser beam is reflected by the target to be measured to generate a delay, so that the phase of the laser beam is shifted. And the third periodic signal is synchronized with the phases of the first periodic signal and the second periodic signal, so that the third periodic signal can be used as a reference signal of the measuring signal. The distance information from the signal generating device 300 to the target to be measured can be obtained by comparing the phase difference between the measurement signal and the third periodic signal.

By controlling the frequency divider to generate the phase-synchronized first, second, and third signals with the synchronization signal, it can be ensured that the first, second, and third signals have a fixed phase difference (e.g., a phase difference of 0 or other fixed value). Compared with the method of generating the reference signal by electrical mixing or optical mixing, the method of directly using the third signal generated by the control of the synchronization signal as the reference signal can avoid the interference of other electronic structures, circuit transmission and the like on the reference signal, and keep the initial phase difference between the reference signal (i.e. the third signal) and the first signal and the second signal unchanged. In this case, since the phase difference between the modulation signal of the reference signal and the laser beam and the local oscillator signal remains unchanged, the laser beam is reflected by the target to be measured and mixed with the local oscillator signal, and the generated measurement signal retains the phase offset of the signal, and since the frequency of the third signal is the difference between the frequencies of the first signal and the second signal, and the frequency of the measurement signal is the same as that of the reference signal (i.e., the third signal), a more accurate phase offset value caused by the reflection of the target to be measured can be calculated when the phase difference between the reference signal and the measurement signal is calculated, and the accuracy of laser ranging can be effectively improved.

For example, the frequency of the first periodic signal may be 5MHz, the frequency of the second periodic signal may be 4.999MHz, and the frequency of the third periodic signal may be 1 KHz. The frequency of the measurement signal is the frequency of the mixed reflected laser beam and the second periodic signal, i.e. 1 KHz. If the phases of the first periodic signal, the second periodic signal and the third periodic signal are phi 1 and the phase of the measurement signal is phi 2, the distance between the signal generation device 300 and the target to be measured can be calculated based on the phase change of the measurement signal and the third periodic signal in the same period. For example only, the distance of the signal generating device 300 to the object to be measured may be determined based on the following formula (1):

L=1/2*c*φ/2π，（1）

wherein, L is the distance from the signal generating device 300 to the target to be measured, c is the speed of light, and Φ is the phase difference between the measurement signal and the reference signal (i.e. the third period signal) in the same period, i.e. (Φ 2- Φ 1).

In a specific embodiment, the signal generating apparatus 400 may obtain a set of synchronization signals from the control circuit 410, and the signal generating unit 420 may generate the first pulse signal, the second pulse signal, and the third pulse signal that are phase-synchronized based on the synchronization signals. The laser driver 430 may drive the laser module group 440 to generate a laser beam 445 under modulation of the first pulse signal, and emit the laser beam 445 to the target to be measured along the external light path 447, the laser beam 445 is reflected by the target to be measured and then transmitted to the optical detector 450, the optical detector 450 mixes the received laser signal with the second pulse signal to generate a measurement signal in the process of converting the received laser signal into an electrical signal, the signal preprocessing unit 460 performs preprocessing such as filtering and amplifying on the measurement signal, and the digital signal processor 470 calculates and obtains the distance from the signal generating device 400 to the target to be measured based on the preprocessed measurement signal and the third pulse signal.

In another specific embodiment, the signal generating apparatus 400 may obtain a set of synchronization signals from the control circuit 410, and the signal generating unit 420 may generate the first pulse signal, the second pulse signal, and the third pulse signal that are phase-synchronized based on the synchronization signals; the first laser emission module can generate a first path of laser beam (such as the laser beam 445 in fig. 4) under modulation of a first pulse signal, and emit the first path of laser beam to a target to be detected along a first path (such as the external optical path 447 in fig. 4), the first path of laser beam is transmitted to the optical detector 1 after being reflected by the target to be detected, and the optical detector 1 mixes the received laser signal with a second pulse signal to generate a middle-low frequency measurement signal in a process of converting the received laser signal into an electric signal; the second laser emitting module may generate a second laser beam under the modulation of the first pulse signal, and emit the second laser beam to the optical detector 2 along a second path (e.g., the inner optical path 443 in fig. 4), and the optical detector 2 mixes the received laser signal with the second pulse signal to generate a first reference signal with a medium-low frequency in the process of converting the received laser signal into an electrical signal; the signal preprocessing unit 460 performs preprocessing such as filtering and amplifying on the measurement signal and the first reference signal, at this time, the digital signal processor 470 may use the third pulse signal as the second reference signal, calculate a first distance from the signal generating device 400 to the target to be measured according to the preprocessed measurement signal and the first reference signal, calculate a second distance from the signal generating device 400 to the target to be measured according to the measurement signal and the second reference signal, and obtain a final distance from the signal generating device 400 to the target to be measured based on the first distance and the second distance.

It should be noted that the above description related to the flow 500 is only for illustration and explanation, and does not limit the applicable scope of the present application. Various modifications and changes to flow 500 may occur to those skilled in the art upon review of the present application. However, such modifications and variations are intended to be within the scope of the present application. For example, in 530, the signal generating apparatus may synchronize the three signals by adjusting a phase difference between each of the first periodic signal, the second periodic signal, and the third periodic signal. For another example, in 530, the signal generating device may generate two phase-synchronized signals based on the synchronization signal: a first periodic signal and a second periodic signal. In this case, the signal generating means may divide the laser beam generated under the modulation of the first periodic signal into two groups in a certain (energy) ratio (e.g., 1:2, 1:1, 2:5, etc.), one of which is transmitted in the outer optical path as the measurement optical signal and the other of which is transmitted in the inner optical path as the reference optical signal.

Fig. 6 is a block diagram of an exemplary modulated signal generating module according to some embodiments of the present application.

The modulation signal generation module 320 (or the signal generation unit 420) may include one or more signal generators. In some embodiments, a signal generator may include a signal source that may generate an electrical signal (e.g., a pulse signal) at a particular frequency, which may correspond to the source signal generation unit 324. In some embodiments, each signal generator may further include one or more frequency dividers (or down converters, such as low pass filters), which may correspond to the divided signal generation unit 326, for dividing (or down converting) the generated source signal to obtain periodic signals of one or more desired frequencies.

As shown in fig. 6, the modulation signal generation module 320 may include a signal source 605 and three

frequency dividers

610, 620, and 630. Wherein the signal source 605 corresponds to the source signal generating unit 324, and the three

frequency dividers

610, 620, and 630 correspond to the divided frequency signal generating unit 326. The signal source 605 may generate a source signal (e.g., a pulsed source signal) at a particular frequency. Signal source 605 may be any signal source that can generate a periodic signal. For example, signal source 605 may include one or more circuit devices in a phase locked loop, an RC oscillation circuit, an LC oscillator, an astable multivibrator, a venturi bridge oscillator, a difference frequency oscillator, a function generator, and so forth. The first frequency divider 610, the second frequency divider 620, and the third frequency divider 630 may divide the frequency of the source signal output by the signal source 605 to generate three sets of periodic signals, e.g., a first periodic signal, a second periodic signal, and a third periodic signal, respectively, as described above. In some embodiments, the first frequency divider 610, the second frequency divider 620, and the third frequency divider 630 may be frequency dividers having division coefficients different from each other, and at least one of the first frequency divider 610, the second frequency divider 620, and the third frequency divider 630 is a fractional frequency divider. For example, assuming that the frequency of the source signal is 20MHz, the frequency division coefficient of the second frequency divider 620 may be set to be a small number such that the frequency of the second periodic signal generated after frequency division by the second frequency divider 620 is 4.999 MHz. In some embodiments, the division scaling coefficients of the first divider 610, the second divider 620, and the third divider 630 may be adjusted based on actual needs, which is not limited in this application. In some embodiments, the frequency divider may include a frequency dividing element and/or a sub-signal source. For example, the frequency divider may be a simple frequency divider having only a frequency slicing function. For another example, the frequency divider may include a complex frequency divider composed of a sub-signal source (such as a phase-locked loop, an RC oscillator, etc.) having a signal generation function and a sub-frequency divider having a frequency slicing function.

In the modulation signal generation module shown in fig. 6, the first frequency divider 610, the second frequency divider 620, and the third frequency divider 630 may be simultaneously controlled to divide the frequency of the source signal based on a set of synchronization signals generated by the signal generation apparatus (e.g., the signal generation apparatus 100, the signal generation apparatus 300, and the signal generation apparatus 400), so as to obtain three sets of periodic signals synchronized in phase. For example, a first periodic signal, a second periodic signal, and a third periodic signal.

Fig. 7 is a block diagram illustrating an exemplary modulated signal generating module according to further embodiments of the present application.

As shown in fig. 7, the modulation signal generation module 320 may include two signal sources of the same type (i.e., phase locked loops 1000, 1002) and three

frequency dividers

710, 720, and 730. The

signal sources

1000, 1002 correspond to the source signal generating unit 324, that is, the source signal generating unit 324 includes two signal sources, and the three

frequency dividers

710, 720, and 730 correspond to the frequency-divided signal generating unit 326. In some embodiments, the first phase locked loop 1000, the first frequency divider 710, and the second frequency divider 720 may form a first signal generator (e.g., signal generator 1 in fig. 4); the second phase locked loop 1002 and the third frequency divider 730 may form a second signal generator (e.g., signal generator 2 in fig. 4).

The first phase locked loop 1000 may generate a first source signal, and the first frequency divider 710 and the second frequency divider 720 may divide the first source signal to generate, for example, a first periodic signal and a second periodic signal, respectively. The second phase locked loop 1002 may generate a second source signal and the third frequency divider 730 may divide the second source signal to generate, for example, a third periodic signal.

In some embodiments, the first source signal and the second source signal are periodic signals having the same shape. For example, the first source signal and the second source signal are both triangular pulse signals. In some embodiments, the first source signal and the second source signal may have the same signal parameters (e.g., period, amplitude, phase, etc.). In some embodiments, the first source signal and the second source signal may have different signal parameters. For example, the first source signal is a high frequency triangular wave signal (e.g., 100 MHz) and the second source signal is a low frequency triangular wave signal (e.g., 1 MHz). In some embodiments, the first frequency divider 710, the second frequency divider 720, and the third frequency divider 730 may be frequency dividers having different division coefficients, respectively. The first, second, and

third frequency dividers

710, 720, and 730 may be fractional and/or integer dividers, respectively. For example, the division factor of the first divider 710 is 2, the division factor of the second divider 720 is 4, and the division factor of the third divider 730 is 10. For another example, the frequency division factor of the first frequency divider 710 is 1.5, the frequency division factor of the second frequency divider 720 is 1.3, and the frequency division factor of the third frequency divider 730 is 3.

In the modulation signal generation module shown in fig. 7, the synchronization signal may control the signal source and the frequency divider, respectively. For example, the synchronization signal may simultaneously control the first phase-locked loop 1000 and the second phase-locked loop 1002 to generate the first source signal and the second source signal that are phase-synchronized, and the synchronization signal may also simultaneously control the first frequency divider 710, the second frequency divider 720, and the third frequency divider 730 to divide the frequency of the first source signal and the frequency of the second source signal, respectively, to obtain three sets of periodic signals that are phase-synchronized. In different embodiments, the synchronization signal for controlling the signal source and the synchronization signal for controlling the frequency divider may be the same synchronization signal, or may be different synchronization signals, which is not limited herein. For example, the signal generating apparatus or the laser ranging apparatus may generate two sets of synchronization signals with the same phase, wherein one set is used for controlling the first phase-locked loop 1000 and the second phase-locked loop 1002 to generate the first source signal and the second source signal with phase synchronization, respectively, and the other set is used for controlling the first frequency divider 710, the second frequency divider 720 and the third frequency divider 730 to divide the frequency of the first source signal and the second source signal, respectively, to obtain three sets of periodic signals with phase synchronization. In some embodiments, when the synchronization signal for controlling the signal source and the synchronization signal for controlling the frequency divider are different synchronization signals, the different synchronization signals may be generated by the same synchronization signal generation module (e.g., the synchronization signal generation module 310 or the control circuit 410) or may be generated by two synchronization signal generation modules independent from each other.

It should be understood that the signal sources depicted in fig. 7 are for illustrative purposes only and that those skilled in the art may substitute other signal sources or combinations of signal sources that can generate the target frequency and still be within the scope of the present application. For example, in addition to a phase-locked loop, the signal source may be one or more circuit devices of an RC oscillator circuit, an LC oscillator, an astable multivibrator, a venturi bridge oscillator, a difference frequency oscillator, a function generator, and the like.

Fig. 8 is a block diagram illustrating an exemplary modulated signal generating module according to further embodiments of the present application.

As shown in fig. 8, the modulation signal generation module 320 may include two different types of signal sources (a phase locked loop 1000, an RC oscillator 810) and three

frequency dividers

820, 830, and 840. In this case, the source signal generating unit 324 in the modulation signal generating module 320 includes two signal sources, which are a phase locked loop 1000 and an RC oscillator 810, respectively, and the divided frequency signal generating unit 326 includes three

frequency dividers

820, 830, and 840. In some embodiments, the phase locked loop 1000, the first frequency divider 820, and the second frequency divider 830 may form a first signal generator (e.g., signal generator 1 in fig. 4); RC oscillation circuit 810 and third frequency divider 840 may form a second signal generator (e.g., signal generator 2 in fig. 4). The phase locked loop 1000 generates a first source signal, and the first frequency divider 820 and the second frequency divider 830 divide the first source signal to generate, for example, a first periodic signal and a second periodic signal, respectively. The RC oscillating circuit 810 generates a second source signal, and the third frequency divider 840 divides the second source signal to generate, for example, a third periodic signal.

In the modulation signal generation module shown in fig. 8, the synchronization signal may control the signal source and the frequency divider, respectively. For example, the synchronization signal may simultaneously control the phase-locked loop 1000 and the RC oscillating circuit 810 to generate the first source signal and the second source signal that are phase-synchronized, and the synchronization signal may also simultaneously control the first frequency divider 820, the second frequency divider 830, and the third frequency divider 840 to divide the frequency of the first source signal and the frequency of the second source signal, respectively, to obtain three sets of periodic signals that are phase-synchronized. In different embodiments, the synchronization signal for controlling the signal source and the synchronization signal for controlling the frequency divider may be the same synchronization signal, or may be different synchronization signals, which is not limited herein.

It should be understood that the signal sources depicted in fig. 8 are for illustrative purposes only and that those skilled in the art may substitute other signal sources or combinations of signal sources that can generate the target frequency and still be within the scope of the present application. For example, in addition to the phase-locked loop and the RC oscillation circuit, the signal source may be one or more circuit devices of an LC oscillator, an astable multivibrator, a venturi bridge oscillator, a difference frequency oscillator, a function generator, and the like.

Fig. 9 is a block diagram illustrating an exemplary modulated signal generating module according to further embodiments of the present application.

As shown in fig. 9, the modulation signal generation module 320 may include three

signal sources

910, 920, 930 and three

frequency dividers

940, 950, 960. In this case, the source signal generating unit 324 may include three signal sources. In some embodiments, first signal source 910 and first frequency divider 940 may form a first signal generator (e.g., signal generator 1 in fig. 4), second signal source 920 and second frequency divider 950 may form a second signal generator (e.g., signal generator 2 in fig. 4), and third signal source 930 and third frequency divider 960 may form a third signal generator (e.g., signal generator 3 in fig. 4). The first signal source 910 may generate a first source signal, and the first frequency divider 940 may divide the first source signal to generate, for example, a first periodic signal. Second signal source 920 may generate a second source signal and second frequency divider 950 may divide the frequency of the second source signal to generate, for example, a second periodic signal. Third signal source 930 may generate a third source signal and third frequency divider 960 may divide the third source signal to generate, for example, a third periodic signal.

In some embodiments, the first source signal, the second source signal, and the third source signal may be periodic signals having the same shape. For example, the first source signal, the second source signal, and the third source signal are all sawtooth pulse signals. In some embodiments, at least two of the first, second and third source signals have the same signal parameters (e.g., period, amplitude, phase, etc.). For example, the first source signal and the second source signal are both high frequency pulse signals (e.g., 100 MHz), and the third source signal is a medium and low frequency pulse signal (e.g., 10 kHz). In some embodiments,

signal sources

910, 920, and 930 may include three different types of signal sources, or three same types of signal sources, or at least two of the three are the same type of signal source. For example, the first signal source 910, the second signal source 920, and the third signal source 930 are all phase-locked loops. For another example, the first signal source 910 and the second signal source 920 are phase-locked loops, and the third signal source 930 is an RC oscillation circuit. For another example, the first signal source 910 is a phase-locked loop, the second signal source 920 is an LC oscillating circuit, and the third signal source 930 is an RC oscillating circuit. It should be understood that the above description of three signal sources is for illustrative purposes only, and that one skilled in the art may replace any signal source with another signal source or combination of signal sources that can generate the target frequency and that such modifications are still within the scope of the present application. For example, one or more of the three signal sources described above may be replaced with one or more circuit devices in an LC oscillator, astable multivibrator, venturi bridge oscillator, difference frequency oscillator, function generator, or the like.

In the modulation signal generation block shown in fig. 9, the synchronization signal controls three signal sources and three frequency dividers at the same time. For example, the synchronization signal may simultaneously control the

signal sources

910, 920, and 930 to generate the phase-synchronized first, second, and third source signals, respectively. The synchronization signal may also simultaneously control the first frequency divider 940, the second frequency divider 950, and the third frequency divider 960 to divide the frequency of the first source signal, the second source signal, and the third source signal, respectively, to obtain three sets of periodic signals (e.g., a first periodic signal, a second periodic signal, and a third periodic signal) synchronized in phase. In different embodiments, the synchronization signal for controlling the signal source and the synchronization signal for controlling the frequency divider may be the same synchronization signal, or may be different synchronization signals, which is not limited herein. In some embodiments, when the synchronization signal for controlling the signal source and the synchronization signal for controlling the frequency divider are different synchronization signals, the different synchronization signals may be generated by the same synchronization signal generation module (e.g., the synchronization signal generation module 310) or may be generated by two synchronization signal generation modules independent of each other.

It should be noted that the descriptions of the modulation signal generation modules in fig. 6-9 are only examples and should not limit the scope of the present application. It will be understood by those skilled in the art that, having the benefit of the teachings of this disclosure, various components may be combined in any suitable manner or replaced with components having the same functionality without departing from such teachings. For example, the modulation signal generation module 320 may also use other signal sources (e.g., LC tank circuit) instead of the phase locked loop or RC tank circuit to generate the source signal. As another example, one or more frequency dividers in the modulated signal generation module 320 may not be necessary. In some cases, a source signal generated by one of the signal sources (e.g., the second phase locked loop 1002, the RC oscillation circuit 810) in the modulation signal generation module 320 has a frequency equal to a frequency of the desired third periodic signal. In particular, the RC oscillating circuit 810 may generate a sine wave having the same middle or low frequency as the required third periodic signal, and may directly output the third periodic signal after the waveform conversion.

Fig. 10 is a schematic diagram of an exemplary phase-locked loop structure according to some embodiments of the present application. A phase-locked loop is a feedback synchronization signal generation module, referred to as a phase-locked loop (PLL) for short, and can be used to synchronize an external input signal with an internal oscillation signal. As shown in fig. 10, the phase locked loop 1000 may include a phase detector, a loop filter, a voltage controlled oscillator, and a frequency divider.

In one embodiment, the phase detector may compare the frequency and/or phase of the input signal with the feedback signal from the vco output and generate an error signal ve (t) if any phase (or frequency) difference is detected within the operating range of the pll 1000. The error signal ve (t) is proportional to the phase difference between the input signal and the output signal of the voltage controlled oscillator. In some embodiments, the phase difference may be a dc level modulated with an ac component. The loop filter filters out the ac component of the error signal ve (t) and generates a signal vd (t) to control the voltage controlled oscillator so that the voltage controlled oscillator changes its frequency in a direction of decreasing phase or frequency error, thereby gradually decreasing the frequency difference or phase difference between the input signal and the output signal of the voltage controlled oscillator until it is 0.

It should be noted that the above description of a phase locked loop architecture is by way of example only and is not intended to limit the present application to the scope of the illustrated embodiments. It will be understood by those skilled in the art that, having the benefit of the teachings of this disclosure, various components may be combined in any suitable manner or replaced with components having the same functionality without departing from such teachings. For example, the phase-locked loop circuit structure may include only a phase detector and a voltage controlled oscillator. As another example, a phase-locked loop structure may include a phase detector, a charge pump, a loop filter, a voltage-controlled oscillator, and a frequency divider.

The beneficial effects that may be brought by the embodiments of the present application include, but are not limited to: (1) the periodic signal generated by the signal source is directly subjected to frequency division to obtain the reference signal (namely, the third signal) with the frequency being the difference between the frequencies of the ranging signal (namely, the first signal) and the local oscillator signal (namely, the second signal), so that the reference signal with the frequency equal to that of the measuring signal can be directly and effectively obtained. On the basis, the distance to be measured is calculated by comparing the phases of the measuring signal and the reference signal, and a more accurate calculation result can be obtained. Meanwhile, as the reference signal is generated without a signal mixing process, the additional signal interference generated by high-frequency signal mixing can be avoided, and the error in the final measurement result is reduced; (2) different from the process of additionally arranging a reference light path to obtain a reference signal, the electric signal generated by frequency division is directly used as the reference signal for laser ranging in the application, so that the light path structure in the ranging device can be reduced, the ranging device is simplified, and the signal processing difficulty is reduced; (3) the first signal, the second signal and the third signal generated by the signal generator are controlled by the synchronizing signal, the phase between every two signals keeps synchronous (or the phase difference is known), so that the third signal can be directly used as a reference signal in laser ranging, the phase synchronism of the measuring signal and the reference signal can be ensured, more accurate phase deviation difference can be obtained when the measuring signal and the reference signal are compared, the complexity of comparison between signals with different frequencies is eliminated, and the accuracy of the laser ranging is improved. It should be noted that different embodiments may generate different advantages, and in different embodiments, the possible generated advantages may be any one or combination of the above, and any other possible obtained advantages.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing detailed disclosure is to be considered merely illustrative and not restrictive of the broad application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Also, this application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Moreover, those skilled in the art will appreciate that aspects of the present application may be illustrated and described in terms of several patentable species or situations, including any new and useful combination of processes, machines, manufacture, or materials, or any new and useful improvement thereon. Accordingly, various aspects of the present application may be embodied entirely in hardware, entirely in software (including firmware, resident software, micro-code, etc.) or in a combination of hardware and software. The above hardware or software may be referred to as "data block," module, "" engine, "" unit, "" component, "or" system. Furthermore, aspects of the present application may be represented as a computer product, including computer readable program code, embodied in one or more computer readable media.

The computer storage medium may comprise a propagated data signal with the computer program code embodied therewith, for example, on baseband or as part of a carrier wave. The propagated signal may take any of a variety of forms, including electromagnetic, optical, etc., or any suitable combination. A computer storage medium may be any computer-readable medium that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code located on a computer storage medium may be propagated over any suitable medium, including radio, cable, fiber optic cable, RF, or the like, or any combination of the preceding.

Computer program code required for the operation of various portions of the present application may be written in any one or more programming languages, including an object oriented programming language such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C + +, C #, VB.NET, Python, and the like, a conventional programming language such as C, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, a dynamic programming language such as Python, Ruby, and Groovy, or other programming languages, and the like. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any network format, such as a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet), or in a cloud computing environment, or as a service, such as a software as a service (SaaS).

Additionally, the order in which elements and sequences of the processes described herein are processed, the use of alphanumeric characters, or the use of other designations, is not intended to limit the order of the processes and methods described herein, unless explicitly claimed. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

The entire contents of each patent, patent application publication, and other material cited in this application, such as articles, books, specifications, publications, documents, and the like, are hereby incorporated by reference into this application. Except where the application is filed in a manner inconsistent or contrary to the present disclosure, and except where the claim is filed in its broadest scope (whether present or later appended to the application) as well. It is noted that the descriptions, definitions and/or use of terms in this application shall control if they are inconsistent or contrary to the statements and/or uses of the present application in the material attached to this application.

Finally, it should be understood that the embodiments described herein are merely illustrative of the principles of the embodiments of the present application. Other variations are also possible within the scope of the present application. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the present application can be viewed as being consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to only those embodiments explicitly described and depicted herein.

Claims

1. A method of signal generation, the method comprising:

generating at least one set of synchronization signals by a synchronization signal generation module;

generating at least one set of source signals from at least one signal source; and

controlling at least three sets of frequency dividers by the at least one set of synchronization signals such that the at least three sets of frequency dividers frequency-divide the at least one set of source signals, respectively, to generate phase-synchronized first, second, and third signals, wherein division coefficients of the at least three sets of frequency dividers are set such that a frequency of the first signal is different from a frequency of the second signal, and a frequency of the third signal is a difference between the frequencies of the first and second signals; and

the first signal is used for modulating a laser emission module to generate a laser beam so as to emit the laser beam to a target to be measured; the second signal is used for mixing with the laser beam which is received by the laser receiving module and reflected by the target to be measured so as to generate a measuring signal; the third signal is used for comparing the signal processing module with the measurement signal so as to calculate the distance from the ranging device to the target to be measured.

2. The method of claim 1, wherein the at least one set of synchronization signals generated by the synchronization signal generation module are periodic signals and the at least one set of source signals generated by the at least one signal source are periodic signals.

3. The method of claim 1, wherein the generating at least one set of source signals by at least one signal source comprises: controlling the at least one signal source by the at least one set of synchronization signals to cause the at least one signal source to generate at least one set of source signals, the at least one set of source signals being phase synchronized.

4. The method of claim 3, wherein the controlling at least three sets of frequency dividers by the at least one set of synchronization signals such that the at least three sets of frequency dividers divide the at least one set of source signals to generate phase synchronized first, second, and third signals, respectively, comprises:

the at least one signal source and the at least three sets of frequency dividers are respectively controlled by the same set of synchronization signals to enable the at least one signal source to generate at least one set of source signals, and the at least three sets of frequency dividers are respectively used for frequency dividing the at least one set of source signals to generate a first signal, a second signal and a third signal which are synchronous in phase.

5. The method of claim 3, wherein the controlling at least three sets of frequency dividers by the at least one set of synchronization signals such that the at least three sets of frequency dividers divide the at least one set of source signals to generate phase synchronized first, second, and third signals, respectively, comprises:

the at least one signal source is controlled by one of the at least one set of synchronization signals to cause the at least one signal source to generate at least one set of source signals, and the at least three sets of frequency dividers are controlled by another of the at least one set of synchronization signals to cause the at least three sets of frequency dividers to frequency divide the at least one set of source signals, respectively, to generate phase synchronized first, second, and third signals.

6. The method of claim 1, wherein the controlling at least three sets of frequency dividers by the at least one set of synchronization signals such that the at least three sets of frequency dividers divide the at least one set of source signals to generate phase synchronized first, second, and third signals, respectively, comprises:

and controlling at least three groups of frequency dividers by the at least one group of synchronous signals, so that the at least three groups of frequency dividers respectively divide the frequency of the same group of source signals to generate the first signal, the second signal and the third signal which are synchronous in phase.

7. The method of claim 1, wherein the controlling at least three sets of frequency dividers by the at least one set of synchronization signals such that the at least three sets of frequency dividers divide the at least one set of source signals to generate phase synchronized first, second, and third signals, respectively, comprises:

and controlling at least three groups of frequency dividers by the at least one group of synchronous signals, so that the at least three groups of frequency dividers respectively divide at least two groups of source signals to generate the first signal, the second signal and the third signal which are synchronous in phase.

8. The method of claim 1, wherein at least one of the at least three sets of frequency dividers includes at least one fractional divider.

9. A signal generation apparatus, characterized in that the apparatus comprises:

a synchronization signal generation module configured to generate at least one set of synchronization signals;

a modulation signal generation module including a source signal generation unit and a frequency-divided signal generation unit, wherein,

the source signal generating unit comprises at least one signal source, and the signal source is used for generating at least one group of source signals;

the frequency-divided signal generation unit includes at least three sets of frequency dividers configured to frequency-divide the at least one set of source signals, respectively, under control of the at least one set of synchronization signals to generate phase-synchronized first, second, and third signals, wherein frequency-division coefficients of the at least three sets of frequency dividers are set such that a frequency of the first signal is different from a frequency of the second signal, and a frequency of the third signal is a difference between the frequencies of the first and second signals;

the laser emission module is configured to generate a laser beam under the modulation of the first signal and emit the laser beam to a target to be measured;

the laser receiving module is configured to receive the laser beam reflected by the target to be measured and perform frequency mixing with the second signal to generate a measuring signal; and

a signal processing module configured to calculate a distance from a ranging device to the target to be measured based on the measurement signal and the third signal.

10. The apparatus of claim 9, wherein the at least one set of synchronization signals generated by the synchronization signal generation module are periodic signals and the at least one set of source signals generated by the at least one signal source are periodic signals.

11. The apparatus of claim 9, wherein the modulation signal generation module is configured for:

controlling the at least one signal source by the at least one set of synchronization signals such that the at least one signal source generates at least one set of source signals, the at least one set of source signals being phase synchronized.

12. The apparatus of claim 11, wherein the modulation signal generation module is configured for:

the at least one signal source and the at least three groups of frequency dividers are respectively controlled by the same group of synchronous signals, so that the at least one signal source generates at least one group of source signals, and the at least three groups of frequency dividers respectively divide the at least one group of source signals to generate a first signal, a second signal and a third signal which are synchronous in phase.

13. The apparatus of claim 11, wherein the modulation signal generation module is configured for:

14. The apparatus of claim 9, wherein the modulation signal generation module is configured for:

15. The apparatus of claim 9, wherein the modulation signal generation module is configured for:

16. The apparatus of claim 9, wherein at least one of the at least three sets of frequency dividers comprises a fractional divider.

17. A signal generating apparatus, the apparatus comprising a processor and a memory; the memory for storing computer instructions, wherein the computer instructions, when executed by the processor, cause the apparatus to perform a method of signal generation as claimed in any one of claims 1 to 8.

18. A computer-readable storage medium storing computer instructions, wherein at least a portion of the computer instructions, when executed by at least one processor, implement a method of signal generation according to any one of claims 1-8.