Laser speed measuring device, speed measuring method thereof and laser radar

Abstract

The invention discloses a laser speed measuring device, a speed measuring method thereof and a laser radar, the laser speed measuring device comprises a transmitting module, a transmission module, a receiving module and a processing module, the transmission module receives echo light and then divides the echo light into frequency discrimination light and to-be-measured light; the transmission module further transmits the frequency discrimination light to form speed measurement comparison light. The processing module obtains an echo frequency according to the collected speed measurement comparison light and the to-be-measured light, obtains a speed frequency shift according to the working frequency and the echo frequency, and further obtains the radial speed of the obstacle according to the speed frequency shift, and the echo frequency is the frequency of the echo light. According to the technical scheme, speed detection can be achieved, the requirement for a light source can be effectively lowered, the control complexity of the transmitting module is lowered, and the detection reliability is improved.

Description

Technical Field

[0001] The present disclosure relates to laser detection, and in particular to a laser speed measuring device and a speed measuring method thereof, and a laser radar. Background Art

[0002] LiDAR is a commonly used distance measurement sensor with the characteristics of long detection distance, high resolution, and low environmental interference. It is widely used in intelligent robots, drones, unmanned driving and other fields. In recent years, autonomous driving technology has developed rapidly, and LiDAR, as its core sensor for distance perception, has become indispensable.

[0003] Among the existing laser radars that can measure the speed of obstacles, one is the frequency modulated continuous wave coherent laser radar, which uses the coherent beat frequency of the echo light and the local oscillator light to analyze the distance and speed information of the target based on the spectrum of the beat frequency signal. However, due to the time delay of the echo light relative to the local oscillator light, the triangular wave frequency modulation method commonly used in the frequency modulated continuous wave coherent laser radar cannot handle the measurement of close-range high-speed moving obstacles.

[0004] Moreover, the frequency modulated continuous wave coherent lidar uses linear frequency modulated continuous light, which makes it difficult to control the light source. The linearity of the linear frequency modulated light generated by the light source is prone to deviations, which will directly affect the detection effect and even make it impossible to measure. Summary of the invention

[0005] The problem solved by the present disclosure is to realize the detection of the speed of an obstacle by using a relatively simple light source and detection light.

[0006] In order to solve the above problems, the present disclosure provides a laser speed measuring device, comprising:

[0007] A transmitting module, wherein the transmitting module is suitable for generating light to form detection light, the light generated by the transmitting module has an operating frequency, and the detection light forms echo light after being reflected by an obstacle; a transmission module, wherein the transmission module is suitable for receiving the echo light and dividing the echo light into a discrimination light and a light to be measured; the transmission module is also suitable for transmitting the discrimination light to form a speed measurement comparison light; a receiving module, wherein the receiving module is suitable for receiving the speed measurement comparison light and the light to be measured; a processing module, wherein the processing module is suitable for obtaining an echo frequency based on the received speed measurement comparison light and the light to be measured, and obtaining a speed frequency shift based on the operating frequency and the echo frequency; the processing module is also suitable for obtaining a radial speed of the obstacle based on the speed frequency shift, wherein the echo frequency is the frequency of the echo light.

[0008] Optionally, the transmission module outputs a speed measurement contrast light of corresponding light intensity based on the discrimination light and according to the echo frequency; the receiving module is suitable for receiving the speed measurement contrast light to obtain the light intensity of the speed measurement contrast light, and the receiving module is also suitable for receiving the light to be measured to obtain the light intensity of the light to be measured; the processing module obtains the echo signal power of the echo light according to the light intensity of the speed measurement contrast light and the light intensity of the light to be measured; the processing module obtains the echo frequency according to the echo signal power combined with the frequency intensity curve.

[0009] Optionally, the transmission module includes: a first spectroscopic unit, which is suitable for dividing the echo light into discrimination light and light to be measured; a discrimination unit, which is located in the optical path of the discrimination light downstream of the first spectroscopic unit, and transmits the discrimination light to form the speed measurement comparison light.

[0010] Optionally, the frequency discrimination unit includes: a frequency discriminator, and the frequency discriminator includes at least one of a fiber Bragg grating frequency discriminator and a Mach-Zehnder interferometer frequency discriminator.

[0011] Optionally, the splitting ratio of the first splitting unit is 1:N; the ratio of the intensity of the discrimination light split by the first splitting unit to the intensity of the light to be measured split by the first splitting unit is N:1, where N is greater than 1.

[0012] Optionally, the receiving module includes: a first detection unit, which is located in the optical path downstream of the frequency discrimination unit of the transmission module, and is suitable for receiving the speed measurement contrast light to obtain the light intensity of the speed measurement contrast light; and a second detection unit, which is located in the optical path of the light to be measured downstream of the first spectroscopic unit, and is suitable for receiving the light to be measured to obtain the light intensity of the light to be measured.

[0013] Optionally, the processing module is suitable for obtaining the echo signal power of the echo light based on the light intensity of the speed measurement comparison light and the light intensity of the light to be measured, combined with the splitting ratio of the first splitting unit of the transmission module; the processing module is also suitable for obtaining the echo frequency based on the echo signal power, combined with the frequency intensity curve of the discrimination unit of the transmission module.

[0014] Optionally, the transmitting module includes: a light generating unit, the light generating unit is suitable for generating initial light, the initial light is suitable for forming detection light, and the initial light has a preset light intensity; the transmission module is also suitable for separating feedback light from the initial light; the transmission module is also suitable for transmitting the feedback light to form locking contrast light; the receiving module is also suitable for receiving the locking contrast light; the processing module is also suitable for obtaining an initial frequency based on the received locking contrast light, the initial frequency being the frequency of the initial light; the laser speed measuring device also includes: a feedback module, the feedback module is suitable for controlling the transmitting module based on the initial frequency so that the operating frequency is locked at a preset value.

[0015] Optionally, the transmission module further includes: a second light splitting unit, the second light splitting unit is located in the optical path of the initial light downstream of the light generating unit, and the second light splitting unit is suitable for separating feedback light from the initial light.

[0016] Optionally, the transmission module further includes: a selection unit, the selection unit is located in the optical path upstream of the discrimination unit of the transmission module, and the selection unit is suitable for selecting one of the discrimination light and the feedback light for transmission.

[0017] Optionally, the selection unit includes an optical switch; when the optical switch conducts the optical path between the first optical splitting unit and the discrimination unit, it disconnects the optical path between the second optical splitting unit and the discrimination unit; when the optical switch conducts the optical path between the second optical splitting unit and the discrimination unit, it disconnects the optical path between the first optical splitting unit and the discrimination unit.

[0018] Optionally, the optical switch has a first input end, a second input end and an output end, the first input end of the optical switch is suitable for inputting the feedback light, the second input end of the optical switch is suitable for inputting the discrimination light, and the output end of the optical switch is connected to the discrimination unit.

[0019] Optionally, the light generating unit generates continuous initial light; the light emitting module further includes: a pulse generating unit, the pulse generating unit is located in the optical path downstream of the light generating unit, and the pulse generating unit is suitable for converting the continuous initial light into pulsed initial light.

[0020] Optionally, the pulse generating unit is located in the optical path between the light generating unit and the second spectroscopic unit; the second spectroscopic unit is suitable for dividing the pulsed initial light into pulsed feedback light and pulsed detection light; the transmission module also includes: a delay unit, which is located in the optical path of the detection light downstream of the second spectroscopic unit, and the delay unit is suitable for delaying the emission of the pulsed detection light.

[0021] Optionally, the delay unit delays the emission of the pulsed detection light so that the moment when the discrimination unit of the transmission module receives the pulsed feedback light is different from the moment when the discrimination unit of the transmission module receives the pulsed discrimination light.

[0022] Optionally, the pulse generating unit includes: a semiconductor optical amplifier.

[0023] Optionally, the preset value locked by the operating frequency is the Q point of the discriminator of the frequency discrimination unit in the transmission module.

[0024] Optionally, the transmission module further includes: a three-terminal transmission unit, wherein the three-terminal transmission unit is suitable for transmitting the detection light to achieve the emission of the detection light, and the three-terminal transmission device is also suitable for receiving the echo light to separate the optical path of the echo light from that of the detection light.

[0025] Optionally, the transmission module also includes: a lens unit, which is located in the optical path downstream of the three-terminal transmission unit, the lens unit receives the detection light transmitted by the three-terminal transmission unit to emit it, and the lens unit also receives echo light and transmits it to the three-terminal transmission unit.

[0026] Accordingly, the present disclosure also provides a laser velocity measurement method, comprising:

[0027] Generate light to form detection light, the generated light has an operating frequency, and the detection light forms echo light after being reflected by an obstacle; receive the echo light and divide the echo light into frequency discrimination light and light to be measured; transmit the frequency discrimination light to form speed measurement comparison light; receive the speed measurement comparison light and the light to be measured; obtain the echo frequency according to the received speed measurement comparison light and the light to be measured, wherein the echo frequency is the frequency of the echo light; obtain the velocity frequency shift according to the operating frequency and the echo frequency; and obtain the radial velocity of the obstacle according to the velocity frequency shift.

[0028] Optionally, in the step of transmitting the demodulation light to form a speed measurement contrast light, based on the echo frequency, a speed measurement contrast light of corresponding light intensity is output; the step of receiving the speed measurement contrast light and the light to be measured includes: receiving the speed measurement contrast light to obtain the light intensity of the speed measurement contrast light; receiving the light to be measured to obtain the light intensity of the light to be measured; the step of obtaining the echo frequency includes: obtaining the echo signal power of the echo light according to the light intensity of the speed measurement contrast light and the light intensity of the light to be measured; and obtaining the echo frequency according to the echo signal power in combination with the frequency intensity curve.

[0029] Optionally, in the step of separating the echo light into frequency discrimination light and light to be measured, the ratio of the intensity of the separated frequency discrimination light to the intensity of the separated light to be measured is N:1, where N is greater than 1.

[0030] Optionally, the step of generating light to form detection light includes: generating initial light, the initial light is suitable for forming detection light, and the initial light has a preset light intensity; the laser speed measurement method also includes: separating feedback light from the initial light; transmitting the feedback light to form locking contrast light; receiving the locking contrast light; obtaining an initial frequency based on the received locking contrast light, the initial frequency being the frequency of the initial light; and locking the operating frequency at a preset value based on the initial frequency.

[0031] Optionally, the method further includes: selecting one of the discrimination light and the feedback light for transmission.

[0032] Optionally, in the step of dividing the echo light into discrimination light and light to be measured, the echo light is divided into discrimination light and light to be measured by a first spectroscopic unit; in the step of separating feedback light from the initial light, the feedback light is separated from the initial light by a second spectroscopic unit; the step of selectively transmitting one of the discrimination light and the feedback light includes: when the optical path of the discrimination light downstream of the first spectroscopic unit is connected, the optical path of the feedback light downstream of the second spectroscopic unit is disconnected; when the optical path of the feedback light downstream of the second spectroscopic unit is connected, the optical path of the discrimination light downstream of the first spectroscopic unit is disconnected.

[0033] Optionally, in the step of generating the initial light, continuous initial light is generated; and the step of generating light to form the detection light further includes: converting the continuous initial light into pulsed initial light.

[0034] Optionally, in the step of separating the feedback light from the initial light, the pulsed initial light is separated into pulsed feedback light and pulsed detection light; the laser speed measurement method further comprises: delaying the emission of the pulsed detection light.

[0035] Optionally, in the step of delaying the emission of the pulsed detection light, the emission of the pulsed detection light is delayed so that the timing of executing the step of forming the locking contrast light according to the feedback light is different from the timing of executing the step of forming the speed measurement contrast light according to the frequency discrimination light.

[0036] Optionally, in the step of locking the operating frequency at a preset value according to the initial frequency, the operating frequency is locked at a Q point of a frequency discriminator according to the initial frequency.

[0037] In addition, the present disclosure also provides a laser radar, including:

[0038] A transmitting module, wherein the transmitting module is suitable for generating light to form detection light, the light generated by the transmitting module has an operating frequency, and the detection light forms echo light after being reflected by an obstacle; a transmission module, wherein the transmission module is suitable for receiving the echo light and dividing the echo light into a discrimination light and a light to be measured; the transmission module is also suitable for forming a speed measurement comparison light according to the discrimination light based on the echo frequency, and the echo frequency is the frequency of the echo light; a receiving module, wherein the receiving module is suitable for receiving the speed measurement comparison light and the light to be measured; a processing module, wherein the processing module is suitable for obtaining the echo frequency according to the received speed measurement comparison light and the light to be measured, and obtaining a speed frequency shift according to the operating frequency and the echo frequency; the processing module is also suitable for obtaining a radial speed of the obstacle according to the speed frequency shift; the processing module is also suitable for obtaining a distance of the obstacle according to the collected light to be measured.

[0039] Compared with the prior art, the technical solution disclosed in the present invention has the following advantages:

[0040] In the disclosed technical solution, the frequency discrimination light and the light to be measured are separated from the echo light, and the frequency discrimination light is transmitted to form the speed measurement comparison light; the echo frequency is obtained according to the collected speed measurement comparison light and the light to be measured, so as to obtain the speed frequency shift, and then obtain the radial speed of the obstacle. The disclosed technical solution can realize speed detection, and can effectively reduce the requirements for the light source, reduce the control complexity of the transmitting module, and improve the detection reliability.

[0041] In the optional solution disclosed in the present invention, feedback light is further separated from the initial light; the feedback light is transmitted to form locking contrast light; an initial frequency is obtained according to the collected locking contrast light, and the initial frequency is the frequency of the initial light; the transmitting module is controlled according to the initial frequency so that the operating frequency is locked at a preset value. The technical solution disclosed in the present invention can lock the operating frequency at a preset value, can effectively ensure the stability of the frequency of the generated detection light, and can effectively ensure the accuracy of the detection result. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work. The drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. They are used together with the embodiments of the present disclosure to explain the present disclosure and do not constitute a limitation on the present disclosure. In the drawings:

[0043] Figure 1 is a functional block diagram of the first embodiment of the laser speed measuring device disclosed in the present invention;

[0044] Figure 2 yes Figure 1 The frequency intensity curve of the frequency discriminator of the frequency discriminator unit in the transmission module in the embodiment of the laser speed measuring device shown;

[0045] Figure 3 is a functional block diagram of the second embodiment of the laser speed measuring device disclosed in the present invention;

[0046] Figure 4 Shows Figure 3 The intensity frequency curve of the frequency discriminator of the frequency discriminator unit in the transmission module in the embodiment of the laser speed measuring device shown;

[0047] Figure 5 is a functional block diagram of the third embodiment of the laser speed measuring device disclosed in the present invention;

[0048] Figure 6 It is a flow chart of an embodiment of the laser velocity measurement method disclosed in the present invention. DETAILED DESCRIPTION

[0049] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0050] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0051] In the description of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0052] In the present disclosure, unless otherwise expressly specified and limited, a first feature being “above” or “below” a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being “above”, “above”, and “above” a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0053] The disclosure below provides many different embodiments or examples to realize different structures of the present disclosure. In order to simplify the disclosure of the present disclosure, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present disclosure. In addition, the present disclosure can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present disclosure provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0054] As can be seen from the background technology, the laser radar in the prior art has the problem of being unable to measure the target speed.

[0055] In order to solve the technical problem, the present disclosure provides a laser speed measuring device, comprising:

[0056] A transmitting module, wherein the transmitting module is suitable for generating light to form detection light, the light generated by the transmitting module has an operating frequency, and the detection light forms echo light after being reflected by an obstacle; a transmission module, wherein the transmission module is suitable for receiving the echo light and dividing the echo light into a discrimination light and a light to be measured; the transmission module is also suitable for transmitting the discrimination light to form a speed measurement comparison light; a receiving module, wherein the receiving module is suitable for collecting the speed measurement comparison light and the light to be measured; a processing module, wherein the processing module is suitable for obtaining an echo frequency based on the collected speed measurement comparison light and the light to be measured, and obtaining a speed frequency shift based on the operating frequency and the echo frequency; the processing module is also suitable for obtaining a radial speed of the obstacle based on the speed frequency shift, wherein the echo frequency is the frequency of the echo light.

[0057] In the disclosed technical solution, the frequency discrimination light is transmitted to form a speed measurement contrast light; the echo frequency is obtained according to the collected speed measurement contrast light and the light to be measured, thereby obtaining the speed frequency shift, and then obtaining the radial speed of the obstacle. The disclosed technical solution can realize speed detection, and can effectively reduce the requirements for the light source, reduce the control complexity of the transmitting module, and improve the detection reliability.

[0058] In order to make the above-mentioned objects, features and advantages of the present disclosure more obvious and easy to understand, the specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0059] refer to Figure 1 , showing a functional block diagram of an embodiment of the laser speed measurement device disclosed in the present invention.

[0060] The laser speed measuring device comprises:

[0061] A transmitting module 110, wherein the transmitting module 110 is suitable for generating light to form detection light, the light generated by the transmitting module 110 has an operating frequency, and the detection light forms echo light after being reflected by an obstacle; a transmission module 120, wherein the transmission module 120 is suitable for receiving the echo light and dividing the echo light into a discrimination light and a light to be measured; the transmission module 120 is also suitable for transmitting the discrimination light to form a speed measurement comparison light; a receiving module 130, wherein the receiving module 130 is suitable for collecting the speed measurement comparison light and the light to be measured; a processing module 140, wherein the processing module 140 is suitable for obtaining an echo frequency based on the collected speed measurement comparison light and the light to be measured, and obtaining a speed frequency shift based on the operating frequency and the echo frequency; the processing module 140 is also suitable for obtaining a radial speed of the obstacle based on the speed frequency shift, wherein the echo frequency is the frequency of the echo light.

[0062] The transmission module 120 separates the frequency discrimination light and the light to be measured from the echo light, and transmits the frequency discrimination light to form the speed measurement comparison light; the processing module 140 obtains the echo frequency according to the collected speed measurement comparison light and the light to be measured, thereby obtaining the speed frequency shift, and then obtaining the radial speed of the obstacle. The laser speed measurement device can realize speed detection, and can effectively reduce the requirements for the light source, reduce the control complexity of the transmitting module, and improve the detection reliability.

[0063] The technical solution of the laser speed measuring device embodiment is described in detail below with reference to the accompanying drawings.

[0064] The transmitting module 110 as a light source is suitable for generating light to form detection light.

[0065] In some embodiments of the present disclosure, the transmitting module 110 includes: a light generating unit 111, wherein the light generating unit 111 is suitable for generating initial light, wherein the initial light is suitable for forming detection light, and wherein the initial light has a preset light intensity.

[0066] Specifically, the initial light generated by the light generating unit 111 has the same frequency as the detection light, and the frequency of the initial light and the frequency of the detection light are both the operating frequency f 0 The initial light intensity is I 0 .

[0067] The light generating unit 111 is a light source for generating light. Specifically, the light generating unit 111 may include a laser, wherein the light generating unit 111 may include a distributed feedback laser (DFB), a vertical cavity surface emitting laser (VCSEL), an edge emitting laser (Edge-emitting Laser, EEL) and other lasers, or other light-emitting components capable of generating lasers.

[0068] In some specific embodiments, the light generating unit 111 generates continuous initial light, and the initial light is direct current light; the laser speed measuring device uses a pulse signal to measure the speed, so the light transmitting module 110 also includes: a pulse generating unit 112, and the pulse generating unit 112 is located in the optical path downstream of the light generating unit 111, and the pulse generating unit 112 is suitable for converting the continuous initial light into a pulsed initial light.

[0069] The pulse generating unit 112 includes a semiconductor optical amplifier (Semi-conductor Optical Amplifier, SOA). The pulse generating unit 112 is formed by using a semiconductor optical amplifier, which can convert continuous initial light into pulsed initial light and amplify the optical signal at the same time.

[0070] Specifically, in the pulse generating unit 112, a pulse signal is used to drive the semiconductor optical amplifier. When the driving pulse is at a high level, the pulse generating unit 112 amplifies the optical signal. When the driving pulse is at a low level, the pulse generating unit 112 reduces the optical loss to zero, thereby converting the input continuous initial light into a pulsed initial light, and the initial light has a greater light intensity.

[0071] The transmission module 120 transmits the detection light to realize the emission of the detection light; the transmission module 120 also receives and transmits the echo light formed by the detection light being reflected by an obstacle.

[0072] Specifically, the transmission module 120 receives and transmits the detection light generated by the transmission module 110 to realize the emission of the detection light to the external space.

[0073] like Figure 1 In some specific embodiments shown, the laser speed measuring device is arranged using a coaxial optical path. In the laser speed measuring device, the optical path of the emitted detection light and the optical path of the received echo light partially overlap. The transmission module 120 also includes: a three-terminal transmission unit 125, which is suitable for transmitting the detection light to achieve the emission of the detection light, and the three-terminal transmission device is also suitable for receiving the echo light to separate the optical path of the echo light from the detection light.

[0074] The three-terminal transmission unit 125 is used to separate the optical path of the detection light and the optical path of the echo light. Specifically, the three-terminal transmission unit 125 includes a circulator. Figure 1 As shown, the three-terminal transmission unit 125 has a first end, a second end and a third end; the first end of the three-terminal transmission unit 125 is connected to the transmitting module 110, and the three-terminal transmission unit 125 transmits the detection light input from the first end to the second end for output; the three-terminal transmission unit 125 is also suitable for transmitting the echo light input from the second end to the third end.

[0075] In other embodiments, the three-terminal transmission unit 125 includes a polarizing beam splitter (PBS) or a semi-transparent and semi-reflective mirror or other optical splitting elements that can separate the optical paths of the detection light and the echo light.

[0076] In addition, in some embodiments, the transmission module 120 also includes: a lens unit 126, which is located in the optical path downstream of the three-port transmission unit 125, and the lens unit 126 receives the detection light transmitted by the three-port transmission unit 125 to emit it, and the lens unit 126 also receives the echo light and transmits it to the three-port transmission unit 125.

[0077] Specifically, the lens unit 126 includes at least one lens. The lens unit 126 includes a collimating lens. Figure 1 As shown, the lens unit 126 corresponds to the second end of the three-terminal transmission unit 125. The lens unit 126 receives the detection light output from the second end of the three-terminal transmission unit 125, and shapes or collimates it to emit it to the external space; the lens unit 126 receives the echo light formed by reflection in the external space, and focuses it to input it to the second end of the three-terminal transmission unit 125.

[0078] The transmission module 120 also receives and transmits the echo light, and divides the echo light into frequency discrimination light and light to be measured, and forms speed measurement comparison light according to the frequency discrimination light. In some specific embodiments, the transmission module 120 outputs speed measurement comparison light of corresponding light intensity according to the echo frequency based on the frequency discrimination light.

[0079] In some specific embodiments, the transmission module 120 includes: a first spectroscopic unit 121, wherein the first spectroscopic unit 121 is suitable for dividing the echo light into discrimination light and light to be measured; a discrimination unit 122, wherein the discrimination unit 122 is located in the optical path of the discrimination light downstream of the first spectroscopic unit 121, and the discrimination unit 122 transmits the discrimination light to form the speed measurement contrast light.

[0080] The first light splitting unit 121 is used to split light according to its splitting ratio. Specifically, the first light splitting unit 121 includes: a beam splitter. The first light splitting unit 121 has an input end and two output ends; the input end of the first light splitting unit 121 is suitable for inputting echo light, such as Figure 1 As shown, the input end of the first optical splitter unit 121 is connected to the third end of the three-end transmission unit 125 to receive the echo light output from the third end; the two output ends of the first optical splitter unit 121 are suitable for outputting the demodulation light and the light to be measured respectively.

[0081] In some specific embodiments, the first light splitting unit 121 includes a coupler.

[0082] In some embodiments of the present disclosure, the splitting ratio of the first splitting unit 121 is 1:N, and the ratio of the intensity of the discrimination light separated by the first splitting unit 121 to the intensity of the light to be measured separated by the first splitting unit 121 is N:1, where N is greater than 1; the intensity of the discrimination light separated by the first splitting unit 121 is greater than the intensity of the light to be measured separated by the first splitting unit 121.

[0083] If the obstacle has radial velocity, the movement of the obstacle will cause the echo light to produce a Doppler frequency shift relative to the outgoing detection light. The echo light formed by the obstacle reflection has a working frequency f of the outgoing detection light. 0 are not the same, the frequencies of the discrimination light and the light to be measured are the same as the working frequency f of the emitted detection light. 0 Specifically, the radial velocity of the obstacle may be the relative velocity between the obstacle and the laser velocity measuring device in the direction of the line connecting the obstacle and the laser velocity measuring device.

[0084] The frequency discrimination unit 122 is used to form the speed measurement contrast light, and the intensity of the speed measurement contrast light formed by the frequency discrimination unit 122 is related to the frequency of the frequency discrimination light. The frequency discrimination unit 122 changes the intensity of the transmitted light based on the frequency of the transmitted light, thereby outputting light whose intensity is related to the frequency of the transmitted light. The intensity of the speed measurement contrast light is related to the frequency of the frequency discrimination light, so when the obstacle has a radial velocity, the intensity of the speed measurement contrast light is not equal to the intensity of the frequency discrimination light, the intensity of the speed measurement contrast light is greater than the intensity of the frequency discrimination light, or the intensity of the speed measurement contrast light is less than the intensity of the frequency discrimination light.

[0085] Specifically, the frequency discriminator 122 includes: a frequency discriminator, which includes at least one of a fiber Bragg grating frequency discriminator and a Mach-Zehnder interferometer frequency discriminator. The frequency discriminator is an optical frequency discriminator, which refers to an optical component whose light intensity of an output light signal corresponds to the frequency of an input light signal, wherein a relationship curve between the light intensity of an output light signal of the optical frequency discriminator and the frequency of an input light signal is a frequency intensity curve f(p) of the frequency discriminator.

[0086] Figure 1 In some specific embodiments shown, the frequency discriminator is a frequency discriminator based on the fiber Bragg Grating (FBG) principle; Figure 2 Shows Figure 1 The frequency intensity curve f(p) of the frequency discriminator of the frequency discriminator unit 122 in the transmission module 120 in the embodiment of the laser speed measuring device is shown.

[0087] like Figure 2As shown, the discriminator has a Q point. When the frequency of the input optical signal is at the Q point, the intensity of the output optical signal of the discriminator is equal to the intensity of the input optical signal. In some embodiments of the present disclosure, the Q point of the discriminator of the discriminator unit 122 matches the operating frequency of the light generated by the transmitting module 110, and the operating frequency of the light generated by the transmitting module 110 is close to the Q point of the discriminator of the discriminator unit 122.

[0088] Continue to refer Figure 1 The laser speed measuring device also has a receiving module 130, which collects optical signals and performs photoelectric conversion to generate corresponding electrical signals according to the collected optical signals.

[0089] The receiving module 130 is connected to the transmission module 120 to receive the light to be measured and the speed measurement comparison light separated by the transmission module 120. The intensity of the speed measurement comparison light formed by the discrimination unit 122 is related to the frequency of the discrimination light; and the discrimination light and the light to be measured are obtained by splitting the echo light by the first light splitting unit 121, so the relationship between the intensity of the discrimination light and the intensity of the light to be measured is related to the splitting ratio of the first light splitting unit 121.

[0090] In some embodiments of the present disclosure, the receiving module 130 is suitable for collecting the speed measurement contrast light to obtain the light intensity I of the speed measurement contrast light. 1 The receiving module 130 is also suitable for collecting the light to be measured to obtain the light intensity I of the light to be measured. 2 .

[0091] Specific as Figure 1 As shown, the receiving module 130 includes: a first detection unit 131, the first detection unit 131 is located in the optical path downstream of the frequency discrimination unit 122 of the transmission module 120, and the first detection unit 131 is suitable for collecting the speed measurement contrast light to obtain the light intensity I of the speed measurement contrast light. 1 A second detection unit 132, the second detection unit 132 is located in the optical path of the light to be measured downstream of the first light splitting unit 121, and the second detection unit 132 is suitable for collecting the light to be measured to obtain the light intensity I of the light to be measured 2 .

[0092] In some embodiments of the present disclosure, at least one of the first detection unit 131 and the second detection unit 132 includes a photodetector; the photodetector may include a photodiode (PD), a silicon photomultiplier (SiPM), an avalanche photodiode (APD), or a single photon avalanche photodiode (SPAD) and other components that can realize photoelectric conversion.

[0093] It should be noted that at least one of the first detection unit 131 and the second detection unit 132 further includes circuit components such as a sampling circuit.

[0094] The processing module 140 processes the electrical signal generated by the receiving module 130 to obtain the radial velocity of the obstacle.

[0095] The processing module 140 is connected to the receiving module 130 , and receives the electrical signal generated after the receiving module 130 collects the speed measurement comparison light and the light to be measured.

[0096] Specifically, the processing module 140 includes: a first processing unit, the first processing unit is suitable for obtaining the echo frequency f' according to the collected speed measurement contrast light and the light to be measured; a second processing unit, the second processing unit is suitable for obtaining the speed frequency shift f according to the working frequency and the echo frequency. v ; A third processing unit, wherein the third processing unit is suitable for obtaining the radial velocity v of the obstacle by the velocity frequency shift.

[0097] In some embodiments of the present disclosure, the processing module 140 processes the light intensity I of the speed measurement comparison light according to the light intensity I 1 and the light intensity I of the light to be measured 2 , obtaining the echo signal power P of the echo light; the processing module 140 obtains the echo frequency f' according to the echo signal power P in combination with the frequency intensity curve f(p).

[0098] Specifically, the first processing unit includes: a first processor, the first processor is suitable for processing the light intensity I of the speed measurement comparison light according to the light intensity I of the speed measurement comparison light. 1 and the light intensity I of the light to be measured 2 , obtaining the echo signal power P of the echo light; a second processor, wherein the second processor is suitable for obtaining the echo frequency f' according to the echo signal power P in combination with the frequency intensity curve f(p).

[0099] The frequency discrimination light and the light to be measured that form the speed measurement contrast light are formed by the echo light being split according to the splitting ratio 1:N of the first light splitting unit 121. In some specific embodiments, the processing module 140 is suitable for processing the speed measurement contrast light according to the light intensity I 1 and the light intensity I of the light to be measured 2 , combined with the splitting ratio 1:N of the first splitting unit 121 of the transmission module 120, the normalized echo signal power P of the echo light is obtained; the processing module 140 is also suitable for obtaining the echo frequency f' according to the echo signal power, combined with the frequency intensity curve f(p) of the discrimination unit 122 of the transmission module 120.

[0100] In some embodiments, the first processor pre-stores a light splitting ratio of 1:N of the first light splitting unit 121, and the first processor calculates the light intensity I of the speed measurement comparison light according to the light intensity I of the speed measurement comparison light. 1 and the light intensity I of the light to be measured 2 , combined with the splitting ratio 1:N of the first splitting unit 121 of the transmission module 120, the echo signal power P of the echo light is obtained. Specifically, the echo signal power of the echo light obtained by the first processor of the processing module is the normalized echo signal power P,

[0101] The second processor has a pre-stored frequency intensity curve f(p), which is a normalized frequency intensity curve f(p). Therefore, the second processor obtains the echo frequency f' based on the normalized echo signal power P obtained by the first processor and the pre-stored normalized frequency intensity curve f(p).

[0102] The second processing unit of the processing module 140 obtains the echo frequency f' according to the second processor of the first processing unit, combined with the working frequency f 0 , get the velocity frequency shift f v , f v =f'-f 0 The third processing unit of the processing module 140 obtains the speed frequency shift f according to the second processing unit v , obtain the radial velocity v of the obstacle,

[0103] refer to Figure 3 , shows a functional block diagram of another embodiment of the laser speed measuring device disclosed in the present invention.

[0104] The same as the above embodiment, the present disclosure will not repeat it here. The difference from the above embodiment is that: Figure 3In some of the embodiments shown, the laser speed measuring device can also lock the operating frequency of the light generated by the transmitting module 110.

[0105] Figure 3 In some embodiments shown, the transmitting module 210 includes: a light generating unit 211, wherein the light generating unit 211 is suitable for generating initial light, wherein the initial light is suitable for forming a detection light, and wherein the initial light has a preset light intensity I 0 ; The transmission module 220 is also suitable for separating feedback light from the initial light; the transmission module 220 is also suitable for transmitting the feedback light to form locking contrast light; the receiving module 230 is also suitable for collecting the locking contrast light; the processing module 240 is also suitable for obtaining an initial frequency based on the collected locking contrast light, and the initial frequency is the frequency of the initial light; the laser speed measuring device also includes: a feedback module 250, and the feedback module 250 is suitable for controlling the transmitting module 210 according to the initial frequency so that the working frequency is locked at a preset value.

[0106] The feedback module 250 can lock the initial frequency of the initial light at a preset value to prevent the operating frequency of the light generated by the transmitting module 210 from drifting, and can effectively ensure the stability of the frequency of the generated detection light, and can effectively ensure the accuracy of the detection result.

[0107] In order to separate the feedback light from the initial light, in some embodiments, the transmission module 220 further includes: a second splitting unit 223, which is located in the optical path of the initial light downstream of the light generating unit 211, and the second splitting unit 223 is suitable for separating the feedback light from the initial light.

[0108] The second light splitting unit 223 includes a beam splitter. The second light splitting unit 223 includes an input end and two output ends. The input end of the second light splitting unit 223 is suitable for inputting the initial light. The two input ends of the second light splitting unit 223 output detection light and feedback light respectively.

[0109] In some specific embodiments, the second light splitting unit 223 includes a coupler.

[0110] Specifically, according to the preset light intensity I of the initial light 0 The intensity of the feedback light can be determined by the splitting ratio of the light splitting unit 221 and the second light splitting unit 223 .

[0111] It should be noted that the light generating unit 211 generates continuous initial light, which is direct current light; the light transmitting module 210 further includes a pulse generating unit 212 for converting the continuous initial light into pulsed initial light. Figure 3In some of the embodiments shown, the second light splitting unit 223 is located in the optical path between the light generating unit 221 and the pulse generating unit 212, and the second light splitting unit 223 separates continuous feedback light from the continuous initial light, and the feedback light is also direct current light.

[0112] An input end of the second spectroscopic unit 223 is connected to the light generating unit 211 to input the initial light generated by the light generating unit 211; an output end of the second spectroscopic unit 223 is connected to the pulse generating unit 212 to transmit part of the initial light to the pulse generating unit 212 as detection light, which is output after being transmitted through the three-terminal transmission unit 225 and the lens unit 226; another output end of the second spectroscopic unit 223 transmits the remaining part of the initial light to the demodulation unit 222 of the transmission module 220.

[0113] In order to achieve multiplexing of the discrimination unit 222, in some embodiments, the transmission module 220 also includes: a selection unit 224, which is located in the optical path upstream of the discrimination unit 222 of the transmission module 220, and the selection unit 224 is suitable for selecting one of the discrimination light and the feedback light for transmission.

[0114] The selection unit 224 selects the optical signal input to the discrimination unit 222 to switch the laser speed measuring device between the speed measuring mode and the frequency locking mode. In some specific embodiments, the selection unit 224 includes an optical switch; when the optical switch conducts the optical path between the first optical splitter unit 221 and the discrimination unit 222, the optical switch disconnects the optical path between the second optical splitter unit 223 and the discrimination unit 222; when the optical switch conducts the optical path between the second optical splitter unit 223 and the discrimination unit 222, the optical switch disconnects the optical path between the first optical splitter unit 221 and the discrimination unit 222.

[0115] like Figure 3 As shown, the optical switch has a first input end, a second input end and an output end. The first input end of the optical switch is suitable for inputting the feedback light, the second input end of the optical switch is suitable for inputting the discrimination light, and the output end of the optical switch is connected to the discrimination unit 222.

[0116] The first input end of the optical switch is connected to an output end of the second optical splitting unit 223 to receive the feedback light split by the second optical splitting unit 223, and the second input end of the optical switch is connected to the first optical splitting unit 221 to receive the discrimination light split by the first optical splitting unit 221; the optical switch selectively connects one of the optical path between the first input end and the output end and the optical path between the second input end and the output end to realize the selective transmission of the discrimination light and the feedback light.

[0117] The optical switch conducts the optical path between the second input end and the output end, and disconnects the optical path between the first input end and the output end; the optical path between the first optical splitter 221 and the discrimination unit 222 is conducted, and the optical path between the second optical splitter 223 and the discrimination unit 222 is disconnected; the selection unit 222 transmits the discrimination light to the discrimination unit 222; the laser speed measuring device is in speed measuring mode, and the discrimination light separated from the echo light is input to the discrimination unit 222; the first detection unit 231 collects speed measuring contrast light formed according to the discrimination light; the processing module 240 obtains the echo frequency, that is, the frequency of the echo light, and thus the radial velocity v of the obstacle can be obtained.

[0118] The optical switch conducts the optical path between the first input end and the output end, and disconnects the optical path between the second input end and the output end; the optical path between the second optical splitter 223 and the frequency discrimination unit 222 is conducted, and the optical path between the first optical splitter 221 and the frequency discrimination unit 222 is disconnected; the selection unit 222 transmits the feedback light to the frequency discrimination unit 222; the laser speed measuring device is in a frequency locking mode, and the frequency discrimination unit 222 inputs the feedback light separated from the initial light; the first detection unit 231 collects the locking contrast light formed according to the feedback light; the processing module 240 obtains the initial frequency, that is, the frequency of the initial light generated by the light generating unit 211.

[0119] The feedback module 250 is connected to the processing module 240 to obtain the initial frequency; the feedback module 250 is also connected to the light generating unit 211 to control the light generating unit 211 to lock the operating frequency according to the initial frequency.

[0120] Specifically, the processing module 240 obtains the normalized optical power of the locking contrast light according to the intensity of the feedback light, the splitting ratio of the second splitting unit 223, and the intensity of the locking contrast light, and then obtains the initial frequency according to the frequency intensity curve f(p).

[0121] Specifically, the feedback module 250 changes the current of the light generating unit 211 according to the difference between the initial frequency and the operating frequency, so that the frequency of the light generated by the light generating unit 211 is locked at a preset value.

[0122] In some embodiments of the present disclosure, the preset value to which the working frequency is locked is the Q point of the frequency discriminator of the frequency discrimination unit 222 in the transmission module 220 . Figure 3In the laser speed measuring device shown, the frequency discriminator of the frequency discriminator unit 222 in the transmission module 220 is a Mach-Zehnder Interferometer (MZI); Figure 4 Shows Figure 3 The intensity frequency curve of the frequency detector of the frequency detector unit 222 in the transmission module 220 in the embodiment of the laser speed measuring device is shown. Figure 4 As shown, the intensity of the optical signal output by the Mach-Zehnder interferometer discriminator varies periodically with the frequency of the input light.

[0123] Specifically, the discriminator of the discriminator unit 222 in the transmission module 220 has a Q point, and the preset value locked by the working frequency is the frequency corresponding to the Q point of the discriminator. When the frequency of the light input to the discriminator unit 222 is the preset value, the light intensity of the light output by the discriminator unit 222 is equal to the light intensity of the light input to the discriminator unit 222. When the laser speed measuring device is in the frequency locking mode, when the frequency of the initial light generated by the light generating unit 211 is the preset value, the light intensity of the feedback light is equal to the light intensity of the locking contrast light; when the frequency of the initial light generated by the light generating unit 211 deviates from the preset value, the light intensity of the locking contrast light will deviate from the light intensity of the feedback light, and the feedback module 250 adjusts the current of the light generating unit 211 based on the deviation of the light intensity of the locking contrast light relative to the feedback light to change the frequency of the initial light generated by the light generating unit 211 so as to return it to the preset value.

[0124] In the above-mentioned embodiment, the output light intensity of the Mach-Zehnder interferometer discriminator changes periodically with the frequency of the input light, that is, the Mach-Zehnder interferometer discriminator has multiple Q points, and the multiple Q points correspond to different operating frequencies. During the feedback process, the working point of the Mach-Zehnder interferometer discriminator can be locked at any Q point. Specifically, when the frequency of the initial light shifts, the working point of the Mach-Zehnder interferometer discriminator can be locked at the Q point closest to the initial light frequency after the shift through feedback, so as to reduce the feedback adjustment cycle and improve the feedback efficiency and effectiveness.

[0125] It should be noted that, in some embodiments, the pulse generating unit 212 includes a semiconductor optical amplifier, and the pulse generating unit 212 is driven by a pulse signal. When the laser speed measuring device is in the speed measuring mode, the driving pulse of the pulse generating unit 212 is at a high level, and the light generated by the light generating unit is amplified to form a pulsed detection light; when the laser speed measuring device is in the frequency locking mode, the pulse generating unit 212 consumes the light generated by the light generating unit to avoid light emission.

[0126] It should also be noted that, in the aforementioned embodiment, the second optical splitter unit 223 is located in the optical path between the light generating unit 211 and the pulse generating unit 212, and the selection unit 224 is provided to realize the selection of the optical signal input to the discrimination unit 222. In other embodiments of the present disclosure, the second optical splitter unit may also be provided in the optical path downstream of the pulse generating unit, and the feedback light and the discrimination light may be prevented from being coherent in the discrimination unit by delaying the emission of the pulsed detection light.

[0127] refer to Figure 5 , shows a functional block diagram of another embodiment of the laser speed measurement device disclosed in the present invention.

[0128] The same as the above embodiment, the present disclosure will not repeat it here. Figure 5 As shown, the pulse generating unit 312 is located in the optical path between the light generating unit 311 and the second light splitting unit 323; the second light splitting unit 323 is suitable for splitting the pulsed initial light into pulsed feedback light and pulsed detection light; the transmission module 320 also includes: a delay unit 328, the delay unit 328 is located in the optical path of the detection light downstream of the second light splitting unit 323, and the delay unit 328 is suitable for delaying the emission of the pulsed detection light.

[0129] The continuous initial light generated by the light generating unit 311 is converted into a pulsed initial light by the pulse generating unit 312; the second spectroscopic unit 323 divides the pulsed initial light output by the pulse generating unit 312 into a pulsed feedback light transmitted to the discrimination unit 322 and a pulsed detection light transmitted to the three-terminal transmission unit 325; wherein part of the pulsed feedback light is transmitted to the discrimination unit 322 by the first spectroscopic unit 321 for feedback control of the light source.

[0130] On the other hand, after the pulsed detection light is delayed by the delay unit 328, it is transmitted through the three-terminal transmission unit 325 and the lens unit 326 to be emitted; the formed pulsed echo light is transmitted to the first spectroscopic unit 321 by the lens unit 326 and the three-terminal transmission unit 325, and the first spectroscopic unit 321 divides the pulsed echo light into a pulsed discrimination light transmitted to the discrimination unit 322 and a pulsed light to be measured transmitted to the second detection unit 332 for speed measurement.

[0131] In some embodiments of the present disclosure, the delay unit 328 delays the emission of the pulsed detection light so that the moment when the discrimination unit 322 of the transmission module 320 receives the pulsed feedback light is different from the moment when the discrimination unit 322 of the transmission module 320 receives the pulsed discrimination light.

[0132] The delay unit 328 makes the emission of the pulsed detection light and the reception of the pulsed echo light staggered in time. The feedback module 350 locks the light feedback generated by the light generating unit 311 at a preset value, and the pulsed detection light emitted to the external space is delayed by the delay unit 328, so that the time when the discrimination light formed by the echo light is transmitted to the discrimination unit 322 is staggered with the time when the feedback light formed by the initial light is transmitted to the discrimination unit 322, for example, the time when the discrimination light is transmitted to the discrimination unit 322 is later than the time when the feedback light is transmitted to the discrimination unit 322, so as to avoid interference between the discrimination light and the feedback light, realize time division multiplexing of the frequency locking mode and the speed measurement mode, and effectively reduce costs and improve reliability.

[0133] Correspondingly, the present disclosure also provides a laser radar.

[0134] The laser radar includes: a transmitting module 110, wherein the transmitting module 110 is suitable for generating light to form detection light, the light generated by the transmitting module 310 has an operating frequency, and the detection light forms an echo light after being reflected by an obstacle; a transmission module 120, wherein the transmission module 120 is suitable for receiving the echo light and dividing the echo light into a discrimination light and a light to be measured; the transmission module 120 is also suitable for forming a speed measurement comparison light according to the discrimination light based on the echo frequency, and the echo frequency is the frequency of the echo light; a receiving module 130, wherein the receiving module 130 is suitable for collecting the speed measurement comparison light and the light to be measured; a processing module 140, wherein the processing module 140 is suitable for obtaining the echo frequency according to the collected speed measurement comparison light and the light to be measured, and obtaining the speed frequency shift according to the operating frequency and the echo frequency; the processing module 140 is also suitable for obtaining the radial speed of the obstacle according to the speed frequency shift; the processing module 140 is also suitable for obtaining the distance of the obstacle according to the collected light to be measured.

[0135] In some specific embodiments, the transmitting module 110, the transmission module 320, the receiving module 330 and the processing module 340 of the laser radar are suitable for constituting the laser speed measuring device of the present disclosure. The specific technical scheme of the transmitting module 110, the transmission module 320, the receiving module 330 and the processing module 340 of the laser radar refers to the specific embodiment of the aforementioned laser speed measuring device. The present disclosure will not be repeated here.

[0136] Correspondingly, the present disclosure also provides a laser speed measurement method.

[0137] refer to Figure 6 , showing a flow chart of an embodiment of the laser velocity measurement method disclosed in the present invention.

[0138] The laser speed measurement method comprises:

[0139] Execute step S110 to generate light to form detection light, the generated light has an operating frequency, and the detection light forms echo light after being reflected by an obstacle; execute step S120 to receive the echo light and divide the echo light into frequency discrimination light and light to be measured; execute step S130 to transmit the frequency discrimination light to form speed measurement contrast light; execute step S140 to collect the speed measurement contrast light and the light to be measured; execute step S150 to obtain an echo frequency based on the collected speed measurement contrast light and the light to be measured, wherein the echo frequency is the frequency of the echo light; execute step S160 to obtain a velocity frequency shift based on the operating frequency and the echo frequency; execute step S170 to obtain a radial velocity of the obstacle based on the velocity frequency shift.

[0140] In some embodiments of the present disclosure, the laser speed measurement method is the laser speed measurement method adopted by the laser speed measurement device of the present disclosure. The specific technical scheme of the laser speed measurement method can refer to the embodiment of the aforementioned laser speed measurement device.

[0141] like Figure 6 As shown, step S110 is first performed to generate light to form detection light, the generated light has a working frequency, and the detection light forms echo light after being reflected by an obstacle.

[0142] Specifically, executing step S110, the step of generating light to form detection light includes: generating initial light, wherein the initial light is suitable for forming detection light, and the initial light has a preset light intensity.

[0143] The initial light and the detection light have the same frequency, and the frequency of the initial light and the frequency of the detection light are both the operating frequency f 0 The initial light intensity is I 0 The initial light may be generated by a laser, and the laser may be a distributed feedback laser (DFB), such as a vertical cavity surface emitting laser (VCSEL), an edge emitting laser (Edge-emitting Laser, EEL), or other light-emitting components capable of generating laser light.

[0144] In some specific embodiments, in the step of generating initial light, continuous initial light is generated, and the initial light is direct current light; executing step S110, the step of generating light to form detection light also includes: converting the continuous initial light into pulsed initial light.

[0145] The continuous initial light can be converted into the pulsed initial light by the semiconductor optical amplifier, and the optical signal can be amplified while the continuous initial light is converted into the pulsed initial light. Specifically, the semiconductor optical amplifier is driven by a pulse signal, and when the driving pulse is at a high level, the optical signal is amplified, and when the driving pulse is at a low level, the optical loss is zero, thereby converting the input continuous initial light into the pulsed initial light, and the initial light has a greater light intensity.

[0146] The detection light is emitted to the external space after being transmitted, and forms echo light after being reflected by obstacles in the external space.

[0147] Continue to refer Figure 6 Then, step S120 is performed to receive the echo light and divide the echo light into frequency discrimination light and light to be measured.

[0148] Specifically, the echo light is divided into the discrimination light and the light to be measured based on a preset splitting ratio. In some embodiments, step S120 is executed, and in the step of dividing the echo light into the discrimination light and the light to be measured, the ratio of the intensity of the separated discrimination light to the intensity of the separated light to be measured is N:1, where N is greater than 1. Step S120 is executed, and in the step of dividing the echo light into the discrimination light and the light to be measured, the intensity of the separated discrimination light is greater than the intensity of the separated light to be measured.

[0149] In some embodiments, step S120 is performed, in which the echo light is divided into the discrimination light and the light to be measured by a first light splitting unit including a beam splitter, and the splitting ratio of the beam splitter used is a preset splitting ratio.

[0150] If the obstacle has radial velocity, the movement of the obstacle will cause the echo light to produce a Doppler frequency shift relative to the outgoing detection light. The echo light formed by the obstacle reflection has a working frequency f of the outgoing detection light. 0 are not the same, the frequencies of the discrimination light and the light to be measured are the same as the working frequency f of the emitted detection light. 0 Specifically, the radial velocity of the obstacle may be the relative velocity between the obstacle and the laser velocity measuring device in the direction of the line connecting the obstacle and the laser velocity measuring device.

[0151] After the discrimination light is separated, step S130 is performed to transmit the discrimination light to form speed measurement comparison light.

[0152] In some embodiments, step S130 is executed, in the step of transmitting the discrimination light to form the speed measurement contrast light, based on the echo frequency, the speed measurement contrast light of the corresponding light intensity is output. Specifically, based on the frequency of the transmitted light, the light intensity of the transmitted light is changed, so as to output light whose light intensity is related to the frequency of the transmitted light. The light intensity of the speed measurement contrast light is related to the frequency of the discrimination light, so when the obstacle has a radial velocity, the light intensity of the speed measurement contrast light is not equal to the light intensity of the discrimination light, the light intensity of the speed measurement contrast light is greater than the light intensity of the discrimination light, or the light intensity of the speed measurement contrast light is less than the light intensity of the discrimination light.

[0153] Specifically, the frequency discriminator can be transmitted through a frequency discriminator to form the speed measurement comparison light. The frequency discriminator includes at least one of a fiber Bragg grating frequency discriminator and a Mach-Zehnder interferometer frequency discriminator. The frequency discriminator is an optical frequency discriminator, which refers to an optical component whose light intensity of the output light signal corresponds to the frequency of the input light signal, wherein the relationship curve between the light intensity of the light signal output by the optical frequency discriminator and the frequency of the input light signal is the frequency intensity curve f(p) of the frequency discriminator.

[0154] The frequency discriminator may be a frequency discriminator based on the principle of fiber Bragg grating (FBG); Figure 2 Shows Figure 6 The frequency intensity curve f(p) of the frequency discriminator used in the embodiment of the laser speed measurement method is shown.

[0155] like Figure 2 As shown, the discriminator has a Q point, and when the frequency of the input optical signal is at the Q point, the intensity of the output optical signal of the discriminator is equal to the intensity of the input optical signal. In some embodiments of the present disclosure, the Q point of the discriminator matches the operating frequency, and the operating frequency is close to the Q point of the discriminator.

[0156] The laser speed measurement method further includes: executing step S140 to collect the speed measurement comparison light and the light to be measured.

[0157] In some embodiments of the present disclosure, step S140 is performed, and the step of collecting the speed measurement contrast light and the light to be measured includes: collecting the speed measurement contrast light to obtain the light intensity I of the speed measurement contrast light. 1 ; Collect the light to be measured to obtain the light intensity I of the light to be measured 2 .

[0158] The intensity of the speed measurement contrast light is related to the frequency of the discrimination light; and the discrimination light and the light to be measured are obtained by splitting the echo light with a preset splitting ratio, so the relationship between the intensity of the discrimination light and the intensity of the light to be measured is related to the preset splitting ratio.

[0159] Specifically, the speed measurement comparison light and the light to be measured can be collected by a photodetector. The photodetector can be a photodiode (PD), a silicon photomultiplier (SiPM), an avalanche photodiode (APD), or even a single photon avalanche diode (SPAD) or other components capable of photoelectric conversion.

[0160] Obtain the light intensity I of the speed measurement contrast light 1 and the light intensity I of the light to be measured 2 Afterwards, step 150 is executed to obtain an echo frequency according to the collected speed measurement comparison light and the light to be measured, wherein the echo frequency is the frequency of the echo light.

[0161] In some embodiments of the present disclosure, step S140 is performed, and the step of obtaining the echo frequency includes: according to the light intensity I of the speed measurement contrast light 1 and the light intensity I of the light to be measured 2 , obtain the normalized echo signal power P of the echo light; according to the echo signal power P, combined with the frequency intensity curve f(p), obtain the echo frequency f'.

[0162] The frequency discrimination light and the light to be measured that form the speed measurement contrast light are obtained by splitting the echo light according to a preset splitting ratio. In some specific embodiments, in the step of obtaining the echo signal power P of the echo light, according to the light intensity I of the speed measurement contrast light, 1 and the light intensity I of the light to be measured 2 , combined with the splitting ratio 1:N of the first splitting unit 121 of the transmission module 120, the echo signal power P of the echo light is obtained. Specifically, the echo signal power of the echo light obtained is the normalized echo signal power P,

[0163] Then, the echo frequency f' is obtained according to the echo signal power and the frequency intensity curve f(p) of the frequency discrimination unit 122 of the transmission module 120; then, according to the echo frequency f', the working frequency f 0 , get the velocity frequency shift f v , f v =f'-f 0 ; According to the speed frequency shift f v , obtain the radial velocity v of the obstacle,

[0164] It should be noted that in some embodiments of the present disclosure, the laser velocity measurement method can also lock the operating frequency of the detection light. The initial frequency of the initial light is locked at a preset value to prevent the operating frequency of the light generated by the transmitting module 210 from drifting, which can effectively ensure the stability of the frequency of the generated detection light and the accuracy of the detection result.

[0165] Specifically, the step of generating light to form the detection light includes: generating initial light, the initial light is suitable for forming the detection light, and the initial light has a preset light intensity I 0 The laser speed measurement method also includes: after generating initial light, separating feedback light from the initial light; transmitting the feedback light to form locking contrast light; collecting the locking contrast light; obtaining an initial frequency based on the collected locking contrast light, the initial frequency being the frequency of the initial light; and then locking the operating frequency at a preset value based on the initial frequency.

[0166] Wherein, in the step of separating the feedback light from the initial light, the feedback light is separated from the initial light by a second light splitting unit including a beam splitter.

[0167] In some embodiments, in the step of generating initial light, continuous initial light is generated, and the initial light is direct current light; the step of generating light to form detection light also includes: converting the continuous initial light into pulsed initial light; therefore, after generating the continuous initial light and before converting the continuous initial light into pulsed initial light, continuous feedback light is separated from the continuous initial light, and the feedback light is also direct current light.

[0168] In some embodiments, the laser speed measurement method further includes: selectively transmitting one of the discrimination light and the feedback light to enable the laser speed measurement device to switch between a speed measurement mode and a frequency locking mode to avoid mutual interference between the discrimination light and the feedback light.

[0169] Specifically, in the step of dividing the echo light into the discrimination light and the light to be measured, the echo light is divided into the discrimination light and the light to be measured by the first spectroscopic unit; in the step of separating the feedback light from the initial light, the feedback light is separated from the initial light by the second spectroscopic unit; therefore, the step of selecting one of the discrimination light and the feedback light for transmission includes: when the optical path of the discrimination light downstream of the first spectroscopic unit is connected, the optical path of the feedback light downstream of the second spectroscopic unit is disconnected; when the optical path of the feedback light downstream of the second spectroscopic unit is connected, the optical path of the discrimination light downstream of the first spectroscopic unit is disconnected.

[0170] When the optical path of the discrimination light downstream of the first spectroscopic unit is turned on, the optical path of the feedback light downstream of the second spectroscopic unit is turned off, and the radial velocity v of the obstacle is obtained; when the optical path of the feedback light downstream of the second spectroscopic unit is turned on, the optical path of the discrimination light downstream of the first spectroscopic unit is turned off, and the initial frequency, that is, the frequency of the initial light generated, is obtained.

[0171] After obtaining the initial frequency, the laser speed measurement method further includes: locking the operating frequency at a preset value according to the initial frequency. Specifically, the difference between the initial frequency and the operating frequency changes the current of the laser in the light generating unit so that the frequency of the generated light is locked at the preset value.

[0172] In some embodiments of the present disclosure, in the step of locking the operating frequency at a preset value according to the initial frequency, the operating frequency is locked at a Q point of a frequency discriminator according to the initial frequency.

[0173] In some specific embodiments, the frequency discriminator is a Mach-Zehnder Interferometer (MZI); Figure 4 FIG. 2 shows the frequency intensity curve f(p) of the frequency discriminator used in the embodiment of the laser speed measurement method. Figure 4 As shown, the frequency discriminator is a Mach-Zehnder interferometer, and the intensity of the optical signal output by the Mach-Zehnder interferometer frequency discriminator varies periodically with the frequency of the input light.

[0174] Specifically, the discriminator has a Q point, and the preset value locked by the working frequency is the frequency corresponding to the discriminator Q point. When the frequency of the light input to the discriminator is the preset value, the intensity of the light output by the discriminator is equal to the intensity of the light input to the discriminator.

[0175] When the frequency of the initial light is a preset value, the intensity of the feedback light is equal to the intensity of the locking contrast light; when the frequency of the initial light deviates from the preset value, the intensity of the locking contrast light will deviate from the intensity of the feedback light, and then, based on the deviation of the intensity of the locking contrast light relative to the feedback light, the current of the laser is adjusted to change the frequency of the initial light so that it returns to the preset value.

[0176] In the above-mentioned embodiment, the output light intensity of the Mach-Zehnder interferometer discriminator changes periodically with the frequency of the input light, that is, the Mach-Zehnder interferometer discriminator has multiple Q points, and the multiple Q points correspond to different operating frequencies. During the feedback process, the working point of the Mach-Zehnder interferometer discriminator can be locked at any Q point. Specifically, when the frequency of the initial light shifts, the working point of the Mach-Zehnder interferometer discriminator can be locked at the Q point closest to the initial light frequency after the shift through feedback, so as to reduce the feedback adjustment cycle and improve the feedback efficiency and effectiveness.

[0177] It should be noted that, in the aforementioned embodiment, the laser velocity measurement method avoids the coherent influence of the feedback light and the discrimination light by selecting one of the discrimination light and the feedback light for transmission. In some embodiments, in the step of generating the initial light, a continuous initial light is generated, and the initial light is a direct current light; the step of generating light to form the detection light also includes: converting the continuous initial light into a pulsed initial light; therefore, in other embodiments, the coherent influence of the feedback light and the discrimination light can also be avoided by delaying the emission of the pulsed detection light.

[0178] In some embodiments, in the step of generating initial light, continuous initial light is generated, and the initial light is direct current light; the step of generating light to form detection light also includes: converting the continuous initial light into pulsed initial light; therefore, after converting the continuous initial light into pulsed initial light, separating the feedback light from the initial light; therefore, in the step of separating the feedback light from the initial light, the pulsed initial light is separated into pulsed feedback light and pulsed detection light; the laser speed measurement method also includes: delaying the emission of the pulsed detection light.

[0179] Specifically, in the step of delaying the emission of the pulsed detection light, the emission of the pulsed detection light is delayed so that the timing of executing the step of forming the locking comparison light according to the feedback light is different from the timing of executing the step of forming the speed measurement comparison light according to the discrimination light.

[0180] The emission of the pulsed detection light and the reception of the pulsed echo light are staggered in time. The generated light feedback is locked at a preset value, and the pulsed detection light emitted to the external space is emitted after a delay, so that the time of executing the step of forming the locking contrast light according to the feedback light and the time of executing the step of forming the speed measurement contrast light according to the discrimination light are staggered, for example, the time of executing the step of forming the speed measurement contrast light according to the discrimination light is later than the time of executing the step of forming the locking contrast light according to the feedback light, thereby avoiding interference between the discrimination light and the feedback light, which can effectively reduce costs and improve reliability.

[0181] In summary, the frequency discrimination light and the light to be measured are separated from the echo light, and the frequency discrimination light is transmitted to form the speed measurement comparison light; the echo frequency is obtained according to the collected speed measurement comparison light and the light to be measured, so as to obtain the speed frequency shift, and then obtain the radial speed of the obstacle. The disclosed technical solution can realize speed detection, and can effectively reduce the requirements for the light source, reduce the control complexity of the transmitting module, and improve the detection reliability.

[0182] Moreover, feedback light is separated from the initial light; the feedback light is transmitted to form locking contrast light; an initial frequency is obtained according to the collected locking contrast light, and the initial frequency is the frequency of the initial light; the transmitting module is controlled according to the initial frequency so that the operating frequency is locked at a preset value. The disclosed technical solution can lock the operating frequency at a preset value, can effectively ensure the stability of the frequency of the generated detection light, and can effectively reduce the requirements for the light source.

[0183] Although the disclosure is disclosed as above, the disclosure is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the disclosure, so the protection scope of the disclosure should be based on the scope defined by the claims.

Claims

1. A laser speed measuring device, characterized in that: include: A transmitting module, wherein the transmitting module is suitable for generating light to form detection light, the light generated by the transmitting module has an operating frequency, and the detection light forms an echo light after being reflected by an obstacle; A transmission module, wherein the transmission module is suitable for receiving the echo light and dividing the echo light into a frequency discrimination light and a light to be measured; the transmission module is also suitable for transmitting the frequency discrimination light to form a speed measurement comparison light; A receiving module, wherein the receiving module is adapted to receive the speed measurement comparison light and the light to be measured; A processing module, wherein the processing module is adapted to obtain an echo frequency according to the received speed measurement comparison light and the light to be measured, and to obtain a speed frequency shift according to the working frequency and the echo frequency; the processing module is also adapted to obtain a radial speed of the obstacle according to the speed frequency shift, The echo frequency is the frequency of the echo light.

2. The laser speed measuring device according to claim 1, characterized in that: The transmission module outputs a speed measurement comparison light of corresponding light intensity based on the frequency discrimination light and the echo frequency; The receiving module is suitable for receiving the speed measuring contrast light to obtain the light intensity of the speed measuring contrast light, and the receiving module is also suitable for receiving the light to be measured to obtain the light intensity of the light to be measured; The processing module obtains the echo signal power of the echo light according to the light intensity of the speed measurement comparison light and the light intensity of the light to be measured; the processing module obtains the echo frequency according to the echo signal power in combination with the frequency intensity curve.

3. The laser speed measuring device according to claim 2, characterized in that: The transmission module comprises: a first light splitting unit, wherein the first light splitting unit is suitable for splitting the echo light into a frequency discrimination light and a light to be measured; A frequency discrimination unit is located in the optical path of the frequency discrimination light downstream of the first light splitting unit, and the frequency discrimination unit transmits the frequency discrimination light to form the speed measurement comparison light.

4. The laser speed measuring device according to claim 3, characterized in that: The frequency discrimination unit comprises: a frequency discriminator, and the frequency discriminator comprises at least one of a fiber Bragg grating frequency discriminator and a Mach-Zehnder interferometer frequency discriminator.

5. The laser speed measuring device according to claim 3, characterized in that: The splitting ratio of the first splitting unit is 1:N; the ratio of the intensity of the discrimination light split by the first splitting unit to the intensity of the light to be measured split by the first splitting unit is N:1, where N is greater than 1.

6. The laser speed measuring device according to claim 2, characterized in that: The receiving module comprises: A first detection unit, the first detection unit is located in the optical path downstream of the frequency discrimination unit of the transmission module, and the first detection unit is suitable for receiving the speed measurement contrast light to obtain the light intensity of the speed measurement contrast light; The second detection unit is located in the optical path of the light to be measured downstream of the first light splitting unit, and the second detection unit is suitable for receiving the light to be measured to obtain the light intensity of the light to be measured.

7. The laser speed measuring device according to claim 3, characterized in that: The processing module is adapted to obtain the echo signal power of the echo light according to the light intensity of the speed measurement comparison light and the light intensity of the light to be measured, combined with the splitting ratio of the first splitting unit of the transmission module; The processing module is also adapted to obtain the echo frequency according to the echo signal power in combination with a frequency intensity curve of a frequency discrimination unit of the transmission module.

8. The laser speed measuring device according to claim 1, characterized in that: The transmitting module comprises: a light generating unit, the light generating unit is suitable for generating initial light, the initial light is suitable for forming detection light, and the initial light has a preset light intensity; The transmission module is also suitable for separating feedback light from the initial light; the transmission module is also suitable for transmitting the feedback light to form locking contrast light; The receiving module is also suitable for receiving the locking contrast light; The processing module is also adapted to obtain an initial frequency according to the received locking contrast light, wherein the initial frequency is the frequency of the initial light; The laser speed measuring device further comprises: a feedback module, which is suitable for controlling the transmitting module according to the initial frequency so that the operating frequency is locked at a preset value.

9. The laser speed measuring device according to claim 8, characterized in that: The transmission module also includes: A second light splitting unit is located in the optical path of the initial light downstream of the light generating unit, and the second light splitting unit is suitable for separating feedback light from the initial light.

10. The laser speed measuring device according to claim 9, characterized in that: The transmission module also includes: A selection unit is located in the optical path upstream of the frequency discrimination unit of the transmission module, and is suitable for selecting one of the frequency discrimination light and the feedback light for transmission.

11. The laser speed measuring device according to claim 10, characterized in that: The selection unit includes an optical switch; The optical switch disconnects the optical path between the second optical splitter unit and the frequency discrimination unit when conducting the optical path between the first optical splitter unit and the frequency discrimination unit; The optical switch disconnects the optical path between the first optical splitting unit and the frequency discrimination unit when connecting the optical path between the second optical splitting unit and the frequency discrimination unit.

12. The laser speed measuring device according to claim 11, characterized in that: The optical switch has a first input end, a second input end and an output end. The first input end of the optical switch is suitable for inputting the feedback light, the second input end of the optical switch is suitable for inputting the discrimination light, and the output end of the optical switch is connected to the discrimination unit.

13. The laser speed measuring device according to claim 8 or 9, characterized in that: The light generating unit generates continuous initial light; The optical transmission module also includes: A pulse generating unit is located in the optical path downstream of the light generating unit, and is suitable for converting the continuous initial light into a pulsed initial light.

14. The laser speed measuring device according to claim 13, characterized in that: The pulse generating unit is located in the optical path between the light generating unit and the second light splitting unit; The second light splitting unit is suitable for splitting the pulsed initial light into pulsed feedback light and pulsed detection light; The transmission module further comprises: a delay unit, which is located in the optical path of the detection light downstream of the second light splitting unit, and is suitable for delaying the emission of the pulsed detection light.

15. The laser speed measuring device according to claim 14, characterized in that: The delay unit delays the emission of the pulsed detection light so that the time when the discrimination unit of the transmission module receives the pulsed feedback light is different from the time when the discrimination unit of the transmission module receives the pulsed discrimination light.

16. The laser speed measuring device according to claim 13, characterized in that: The pulse generating unit includes: a semiconductor optical amplifier.

17. The laser speed measuring device according to claim 8, characterized in that: The preset value to which the working frequency is locked is the Q point of the frequency discriminator of the frequency discrimination unit in the transmission module.

18. The laser speed measuring device according to claim 1, characterized in that: The transmission module also includes: A three-terminal transmission unit, wherein the three-terminal transmission unit is suitable for transmitting the detection light to realize the emission of the detection light, and the three-terminal transmission device is also suitable for receiving the echo light to separate the optical path of the echo light from that of the detection light.

19. The laser speed measuring device according to claim 18, characterized in that: The transmission module also includes: a lens unit, which is located in the optical path downstream of the three-terminal transmission unit, and receives the detection light transmitted by the three-terminal transmission unit to emit it, and also receives the echo light and transmits it to the three-terminal transmission unit.

20. A laser speed measurement method, characterized in that: include: Generating light to form detection light, the generated light having an operating frequency, and the detection light forming an echo light after being reflected by an obstacle; receiving the echo light and dividing the echo light into frequency discrimination light and light to be measured; Transmitting the frequency discrimination light to form speed measurement contrast light; receiving the speed measurement comparison light and the light to be measured; Obtaining an echo frequency according to the received speed measurement comparison light and the light to be measured, wherein the echo frequency is the frequency of the echo light; Obtaining a velocity frequency shift according to the operating frequency and the echo frequency; The radial velocity of the obstacle is obtained according to the velocity frequency shift.

21. The laser velocity measurement method according to claim 20, characterized in that: In the step of transmitting the frequency discrimination light to form the speed measurement contrast light, based on the echo frequency, the speed measurement contrast light of corresponding light intensity is output; The step of receiving the speed measurement contrast light and the light to be measured comprises: receiving the speed measurement contrast light to obtain the light intensity of the speed measurement contrast light; receiving the light to be measured to obtain the light intensity of the light to be measured The step of obtaining the echo frequency includes: obtaining the echo signal power of the echo light according to the light intensity of the speed measurement contrast light and the light intensity of the light to be measured; and obtaining the echo frequency according to the echo signal power in combination with a frequency intensity curve.

22. The laser velocity measurement method according to claim 21, characterized in that: In the step of dividing the echo light into frequency discrimination light and light to be measured, the ratio of the intensity of the separated frequency discrimination light to the intensity of the separated light to be measured is N:1, where N is greater than 1.

23. The laser velocity measurement method according to claim 20, characterized in that: The step of generating light to form the detection light includes: generating initial light, the initial light being suitable for forming the detection light, the initial light having a preset light intensity; The laser speed measurement method also includes: separating feedback light from the initial light; transmitting the feedback light to form locking contrast light; receiving the locking contrast light; Obtaining an initial frequency according to the received locking contrast light, wherein the initial frequency is the frequency of the initial light; The operating frequency is locked at a preset value according to the initial frequency.

24. The laser velocity measurement method according to claim 23, characterized in that: Also includes: One of the discrimination light and the feedback light is selected for transmission.

25. The laser velocity measurement method according to claim 23 or 24, characterized in that: In the step of dividing the echo light into the frequency discrimination light and the light to be measured, the echo light is divided into the frequency discrimination light and the light to be measured by a first light splitting unit; In the step of separating the feedback light from the initial light, the feedback light is separated from the initial light by a second light splitting unit; The step of selecting one of the discrimination light and the feedback light for transmission comprises: When the optical path of the discrimination light downstream of the first optical splitting unit is turned on, the optical path of the feedback light downstream of the second optical splitting unit is turned off; When the optical path of the feedback light downstream of the second optical splitter unit is opened, the optical path of the discrimination light downstream of the first optical splitter unit is disconnected.

26. The laser velocity measurement method according to claim 23, characterized in that: In the step of generating the initial light, continuous initial light is generated; The step of generating light to form detection light also includes: converting the continuous initial light into pulsed initial light.

27. The laser velocity measurement method according to claim 26, characterized in that: In the step of separating the feedback light from the initial light, the pulsed initial light is separated into the pulsed feedback light and the pulsed detection light; The laser velocity measurement method further includes: delaying the emission of the pulsed detection light.

28. The laser velocity measurement method according to claim 27, characterized in that: In the step of delaying the emission of the pulsed probe light, the emission of the pulsed probe light is delayed so that the timing of executing the step of forming the locking comparison light based on the feedback light is different from the timing of executing the step of forming the speed measurement comparison light based on the discrimination light.

29. The laser velocity measurement method according to claim 23, characterized in that: In the step of locking the operating frequency at a preset value according to the initial frequency, the operating frequency is locked at a Q point of a frequency discriminator according to the initial frequency.

30. A laser radar, characterized in that: include: A transmitting module, wherein the transmitting module is suitable for generating light to form detection light, the light generated by the transmitting module has an operating frequency, and the detection light forms an echo light after being reflected by an obstacle; A transmission module, wherein the transmission module is adapted to receive the echo light and divide the echo light into a frequency discrimination light and a light to be measured; the transmission module is also adapted to form a velocity measurement contrast light according to the frequency discrimination light based on the echo frequency, wherein the echo frequency is the frequency of the echo light; A receiving module, wherein the receiving module is adapted to receive the speed measurement comparison light and the light to be measured; A processing module, wherein the processing module is suitable for obtaining the echo frequency according to the received speed measurement comparison light and the light to be measured, and obtaining the speed frequency shift according to the working frequency and the echo frequency; the processing module is also suitable for obtaining the radial speed of the obstacle according to the speed frequency shift; the processing module is also suitable for obtaining the distance of the obstacle according to the collected light to be measured.

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