CN114938662B

CN114938662B - Laser radar and control method of laser radar

Info

Publication number: CN114938662B
Application number: CN202180007911.5A
Authority: CN
Inventors: 汪敬
Original assignee: Suteng Innovation Technology Co Ltd
Current assignee: Suteng Innovation Technology Co Ltd
Priority date: 2021-10-13
Filing date: 2021-10-13
Publication date: 2023-04-04
Anticipated expiration: 2041-10-13
Also published as: CN114938662A; WO2023060473A1

Abstract

The application discloses a laser radar and a control method thereof, wherein the laser radar comprises a frequency modulation light source, a beam splitting module, a target detection module, a polarization beam splitting rotator and a balance detection module, wherein the frequency modulation light source generates an input light beam; the beam splitting module splits an input light beam into a detection light beam and a local oscillation light beam; the target detection module transmits a detection light beam to a target object and receives a reflected light beam reflected by the target object; the polarization beam splitting rotator converts the polarization state of the reflected light beam to obtain a signal light beam, and the polarization state of the signal light beam is consistent with that of the local oscillation light beam; the balance detection module carries out balance detection on the local oscillator light beam and the signal light beam and outputs a first detection signal, and the first detection signal is used for acquiring position information of a target object. By adopting the laser radar detection device, the polarization state of the reflected light beam reflected by the target object is adjusted through the polarization beam splitting rotator, the situation of detection failure caused by inconsistent polarization states is avoided, and the detection success rate of the laser radar is improved.

Description

Laser radar and control method of laser radar

Technical Field

The application relates to the technical field of radars, in particular to a laser radar and a control method of the laser radar.

Background

Currently, common vehicle-mounted laser radars include a Frequency Modulated Continuous Wave (FMCW) based laser radar. The laser beam emitted by the FMCW radar is frequency-modulated continuous laser, the laser beam is divided into two beams, one beam is used as local oscillation light, the other beam is used as emission light to be emitted to a detection area, the emission light is reflected after meeting a target object in the detection area, and the distance of the target object is calculated through the reflected emission light and the local oscillation light.

The reflected emitted light and the local oscillator light need to be processed by the balance detector first, and then the distance of the target object can be calculated based on the output signal of the balance detector, it should be noted that the balance detector requires that the polarization states of the local oscillator light and the reflected emitted light are consistent, and the material forming the target object is unknown, which means that the polarization state of the emitted light reflected by the target object is random, and the detection failure condition is easily caused, so that the detection success rate of the FMCW laser radar is too low.

Disclosure of Invention

The application provides a laser radar and a control method of the laser radar, which can solve the technical problem of how to improve the detection success rate of the laser radar.

In a first aspect, an embodiment of the present application provides a lidar, including: the device comprises a frequency modulation light source, a beam splitting module, a target detection module, a polarization beam splitting rotator and a balance detection module;

the frequency modulation light source is used for generating an input light beam and transmitting the input light beam to the beam splitting module;

the beam splitting module is used for receiving an input light beam, splitting the input light beam into a detection light beam and a local oscillation light beam, transmitting the detection light beam to the target detection module, and transmitting the local oscillation light beam to the balance detection module;

the target detection module is used for receiving the detection light beam, transmitting the detection light beam to a target object, receiving a reflected light beam reflected by the target object, and transmitting the reflected light beam to the polarization beam splitting rotator;

the polarization beam splitting rotator is used for receiving the reflected light beam, converting the polarization state of the reflected light beam to obtain a signal light beam and transmitting the signal light beam to the balance detection module, wherein the polarization state of the signal light beam is consistent with that of the local oscillator light beam, and the polarization state of the signal light beam is a transverse electric mode polarization state or a transverse magnetic mode polarization state;

the balance detection module is used for receiving the local oscillator light beam and the signal light beam, carrying out balance detection on the local oscillator light beam and the signal light beam, and outputting a first detection signal, wherein the first detection signal is used for acquiring the position information of the target object.

In a second aspect, an embodiment of the present application provides a method for controlling a laser radar, where the method includes:

generating an input light beam, and dividing the input light beam into a detection light beam and a local oscillator light beam;

emitting a detection light beam to a target object, and receiving a reflected light beam reflected by the target object;

converting the polarization state of the reflected light beam to obtain a signal light beam, wherein the polarization state of the signal light beam is consistent with that of the local oscillation light beam, and the polarization state of the signal light beam is a polarization state of a transverse electric mode or a polarization state of a transverse magnetic mode;

carrying out balance detection on the local oscillator light beam and the signal light beam to obtain a first detection signal;

position information of the target object is acquired based on the first detection signal.

In an embodiment of the present application, a lidar includes: the device comprises a frequency modulation light source, a target detection module, a polarization beam splitting rotator, a beam splitting module and a balance detection module; the frequency modulation light source is used for generating an input light beam and transmitting the input light beam to the beam splitting module; the beam splitting module is used for receiving an input light beam, splitting the input light beam into a detection light beam and a local oscillation light beam, transmitting the detection light beam to the target detection module, and transmitting the local oscillation light beam to the balance detection module; the target detection module is used for receiving the detection light beam, transmitting the detection light beam to a target object, receiving a reflected light beam reflected by the target object and transmitting the reflected light beam to the polarization beam splitting rotator; the polarization beam splitting rotator is used for receiving the reflected light beam, converting the polarization state of the reflected light beam to obtain a signal light beam and transmitting the signal light beam to the balance detection module, wherein the polarization state of the signal light beam is consistent with that of the local oscillator light beam; the balance detection module is used for receiving the local oscillator light beam and the signal light beam, carrying out balance detection on the local oscillator light beam and the signal light beam, and outputting a first detection signal, wherein the first detection signal is used for acquiring the position information of the target object. Therefore, the polarization state of the reflected light beam reflected by the target object is adjusted through the polarization beam splitting rotator so as to convert the polarization state of the reflected light beam to be consistent with the polarization state of the local oscillation light beam, the condition of detection failure caused by inconsistent polarization states is avoided, and the detection success rate of the laser radar is improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of a laser radar according to an embodiment of the present disclosure;

fig. 2 is a schematic detection diagram of a lidar according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a laser radar according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a laser radar according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a laser radar according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of a laser radar according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of a laser radar according to an embodiment of the present disclosure;

fig. 8 is a schematic flowchart of a control method of a laser radar according to an embodiment of the present disclosure;

fig. 9 is a schematic flowchart of a control method for a laser radar according to an embodiment of the present disclosure;

fig. 10 is a schematic flowchart of a control method for a laser radar according to an embodiment of the present disclosure;

fig. 11 is a schematic flowchart of a control method of a laser radar according to an embodiment of the present disclosure;

fig. 12 is a schematic flowchart of a control method for a laser radar according to an embodiment of the present disclosure;

fig. 13 is a schematic structural diagram of a computer device according to an embodiment of the present application.

Detailed Description

In order to make the features and advantages of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments obtained by a person skilled in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the application, as detailed in the appended claims. The flow diagrams depicted in the figures are merely exemplary and need not be performed in the order of the steps shown. For example, some steps are parallel, and there is no strict sequence relationship in logic, so the actual execution sequence is variable. In addition, the terms "first", "second", "third", "fourth", "fifth", "sixth", "seventh", "eighth" are for purposes of distinction only and should not be construed as limiting the present disclosure.

As shown in fig. 1, fig. 1 is a schematic structural diagram of a laser radar provided in an embodiment of the present application, where the laser radar 1 includes: a frequency-modulated light source 11, a beam splitting module 12, an object detection module 13, a polarization beam splitting rotator 14 and a balance detection module 15.

The beam splitting module 12 has at least two output ends; the object detection module 13 has at least two input terminals, a first input terminal for receiving the detection beam and a second input terminal for receiving the reflected beam; the balance detection module has at least two input ends; the output end of the frequency modulation light source 11 is connected with the input end of the beam splitting module 12; a first output end of the beam splitting module 12 is connected with a first input end of the target detection module 13, and a second output end of the beam splitting module 12 is connected with a first input end of the balance detection module 15; the output end of the target detection module 13 is connected with the input end of the polarization beam splitting rotator 14; the output end of the polarization beam splitter rotator 14 is connected to a second input end of the balance detection module 15.

As shown in fig. 2, fig. 2 is a schematic detection diagram of a laser radar provided in this embodiment of the present application, a Frequency Modulated light source 11 generates an input light beam, where the input light beam refers to a Frequency Modulated Continuous Wave signal (FMCW), that is, a Continuous signal whose emission Frequency is Modulated by a specific signal, and the Frequency Modulated light source 11 transmits the input light beam to a beam splitting module 12 connected to the Frequency Modulated light source 11 after generating the input light beam. The beam splitting module 12 receives the input light beam output by the frequency modulation light source 11, then splits the input light beam into a local oscillator light beam and a detection light beam according to a preset splitting ratio, transmits the local oscillator light beam to the balanced detection module 15, and transmits the detection light beam to the target detection module 13. The object detection module 13 receives the probe beam output by the beam splitting module 12, and then emits the probe beam toward the object 00.

It should be noted that the probe light beam enters the detection range of the object detection module 13 through the light beam emitting port of the object detection module 13 (i.e. the second input end of the object detection module 13, which is both the light exit port and the light entrance port), and when encountering the object 00, the probe light beam is reflected by the object 00 to form a reflected light beam, and the reflected light beam is reflected to the object detection module 13.

The object detection module 13 receives the reflected light beam reflected by the object 00 and transmits the reflected light beam to the polarization beam splitter rotator 14. The polarization beam splitter rotator 14 receives the reflected light beam, converts the polarization state of the reflected light beam to obtain a signal beam, and transmits the signal beam to the balance detection module 15. It should be noted that the polarization state of the signal light beam is consistent with the polarization state of the local oscillator light beam, when the frequency modulation light source 11 generates the input light beam, the frequency modulation light source 11 generates the light beam according to the preset polarization state that is preset by the frequency modulation light source 11, the polarization state of the input light beam is known and is fixed to the preset polarization state, and the polarization beam splitter rotator 14 adjusts the polarization state of the reflected light beam to the preset polarization state when converting the polarization state of the reflected light beam; for example, the predetermined polarization state may be a horizontal polarization state, a vertical polarization state, and the like, which is not limited herein. Based on the characteristics of a Polarization beam Splitter rotator (PSR), the predetermined Polarization state is one of a Polarization state of a Transverse Electric (TE) mode or a Polarization state of a Transverse Magnetic (TM) mode; accordingly, the polarization state of the local oscillator beam is also one of the polarization states of the TE mode and the TM mode, and is the same as the polarization state of the signal beam.

The balance detection module 15 receives the local oscillator light beam output by the beam splitting module 12 and the signal light beam output by the polarization beam splitting rotator 14, performs balance detection on the local oscillator light beam and the signal light beam, and outputs a first detection signal, where the first detection signal is used to obtain the position information of the target object 00.

Optionally, the laser radar 1 further includes a processing module, where the processing module is configured to obtain a first detection signal output by the balanced detection module 15, and obtain position information of the target object 00 based on the first detection signal, where the position information may be a distance between the target object 00 and the laser radar 1, a direction of the target object 00 relative to the laser radar 1, speed information of the target object 00, and the like.

In the embodiment of the application, the polarization state of the reflected light beam reflected by the target object is adjusted through the polarization beam splitting rotator so as to convert the polarization state of the reflected light beam to be consistent with the polarization state of the local oscillator light beam, thereby avoiding the situation of detection failure caused by inconsistent polarization states and improving the detection success rate of the laser radar.

As shown in fig. 3, fig. 3 is a schematic structural diagram of a laser radar provided in an embodiment of the present application, where the laser radar 1 includes: the system comprises a frequency modulation light source 11, a beam splitting module 12, an object detection module 13, a polarization beam splitting rotator 14, a balance detection module 15 and an optical mixing module 16.

The optical frequency mixing module 16 includes at least two input terminals, a first input terminal for receiving the local oscillator beam and a second input terminal for receiving the signal beam, and the optical frequency mixing module 16 further includes at least two output terminals. The output end of the frequency modulation light source 11 is connected with the input end of the beam splitting module 12; a first output end of the beam splitting module 12 is connected with a first input end of the target detection module 13, and a second input end of the beam splitting module 12 is connected with a first input end of the optical mixing module 16; the output end of the target detection module 13 is connected with the input end of the polarization beam splitting rotator 14; the output end of the polarization beam splitting rotator 14 is connected with the second input end of the optical mixing module 16; a first output terminal of the optical mixing module 16 is connected to a first input terminal of the balanced detection module 15, and a second output terminal of the optical mixing module 16 is connected to a second input terminal of the balanced detection module 15.

The frequency modulated light source 11 generates an input beam and then transmits the input beam to a beam splitting module 12 connected to the frequency modulated light source 11. The beam splitting module 12 receives the input light beam output by the frequency modulation light source 11, then splits the input light beam into a local oscillator light beam and a probe light beam according to a preset splitting ratio, transmits the local oscillator light beam to the optical frequency mixing module 16, and transmits the probe light beam to the target detection module 13. The object detection module 13 receives the probe beam output from the beam splitting module 12, and then emits the probe beam toward the object 00. The object detection module 13 receives the reflected light beam reflected by the object 00 and transmits the reflected light beam to the polarization beam splitter rotator 14. The polarization beam splitter rotator 14 receives the reflected light beam, converts the polarization state of the reflected light beam to obtain a signal light beam, the polarization state of the signal light beam is consistent with the polarization state of the local oscillator light beam, and transmits the signal light beam to the optical frequency mixing module 16.

The optical frequency mixing module 16 receives the local oscillator beam output by the beam splitting module 12 and the signal beam output by the polarization beam splitting rotator 14, and then performs optical frequency mixing, such as frequency subtraction, frequency addition, frequency superposition, and other frequency mixing operations on the received local oscillator beam and the signal beam to obtain a first frequency mixing signal, where the first frequency mixing signal is a differential signal.

Illustratively, if there are two ports in the optical mixer module 16, the mixing operations are adding and subtracting, respectively, the first output outputs the mixed signal with the frequencies subtracted, the second output outputs the mixed signal with the frequencies added, the first input of the balance detection module 15 receives the mixed signal with the frequencies subtracted from the first output of the optical mixer module 16, and the second input of the balance detection module 15 receives the mixed signal with the frequencies added from the second output of the optical mixer module 16.

The balance detection module 15 receives each first mixed signal, performs balance detection based on each first mixed signal, and outputs a first detection signal, where the first detection signal is used to obtain position information of the target object 00.

It should be noted that the optical mixing module is composed of at least two optical mixers.

In this application embodiment, obtain enough big difference signal, first mixing signal promptly through the optical mixing module to improve the detection accuracy of balanced detection module, and then improved laser radar's detection success rate.

As shown in fig. 4, fig. 4 is a schematic structural diagram of a laser radar provided in an embodiment of the present application, where the laser radar 1 includes: the system comprises a frequency-modulated light source 11, a beam splitting module 12, an object detection module 13, a polarization beam splitting rotator 14, a balance detection module 15, a first mode converter 171, a second mode converter 172 and a mode conversion module 173.

The input end of the first mode converter 171 is connected with the output end of the frequency-modulated light source 11, and the output end of the first mode converter 171 is connected with the input end of the beam splitting module 12; the input end of the second mode converter 172 is connected with the first output end of the beam splitting module 12, and the output end of the second mode converter 172 is connected with the first input end of the target detection module 13; the input end of the mode conversion module 173 is connected to the output end of the object detection module 13, and the output end of the mode conversion module 173 is connected to the input end of the polarization beam splitter rotator 14.

The frequency modulated light source 11 generates an input beam and then transmits the input beam to a first mode converter 171 connected to the frequency modulated light source 11; the first mode converter 171 receives the input light beam output by the frequency-modulated light source 11, adjusts the beam diameter of the input light beam to a first predetermined diameter, obtains a target input light beam with the beam diameter of the first predetermined diameter, and transmits the target input light beam to the beam splitting module 12. The beam splitting module 12 receives the target input light beam output by the first mode converter 171, then splits the target input light beam into a local oscillator light beam and a probe light beam according to a predetermined splitting ratio, transmits the local oscillator light beam to the balanced detection module 15, and transmits the probe light beam to the second mode converter 172. The second mode converter 172 receives the probe beam output by the beam splitting module 12, adjusts the beam diameter of the probe beam to a second preset diameter, obtains a target probe beam with the beam diameter of the second preset diameter, and transmits the target probe beam to the target probe module 13. Wherein the second predetermined diameter is greater than the first predetermined diameter. The object detection module 13 receives the object detection beam output by the second mode converter 172 and then emits the object detection beam toward the object 00.

The object detection module 13 receives the reflected light beam reflected by the object 00 and transmits the reflected light beam to the mode conversion module 173. The mode conversion module 173 receives the reflected light beam output from the object detection module 13, adjusts the beam diameter of the reflected light beam to a third predetermined diameter, obtains an object reflected light beam having a beam diameter of the third predetermined diameter, and transmits the object reflected light beam to the polarization beam splitter rotator 14. Wherein the second predetermined diameter is greater than the third predetermined diameter. The polarization beam splitter rotator 14 receives the target reflected light beam, converts the polarization state of the target reflected light beam to obtain a signal beam, and transmits the signal beam to the balance detection module 15. It should be noted that the polarization state of the signal light beam is consistent with the polarization state of the local oscillator light beam, when the frequency modulation light source 11 generates the input light beam, the frequency modulation light source 11 generates the light beam according to the preset polarization state that is preset by the frequency modulation light source 11, the polarization state of the input light beam is known and is fixed to the preset polarization state, and the polarization beam splitter rotator 14 adjusts the polarization state of the target reflected light beam to the preset polarization state when converting the polarization state of the target reflected light beam; for example, the predetermined polarization state may be a horizontal polarization state, a vertical polarization state, and the like, which is not limited herein.

The balanced detection module 15 receives the local oscillator light beam output by the beam splitting module 12 and the signal light beam output by the polarization beam splitting rotator 14, performs balanced detection on the local oscillator light beam and the signal light beam, and outputs a first detection signal, where the first detection signal is used to obtain position information of the target object 00.

In the embodiment of the application, because the beam diameter of the input beam that the frequency modulation light source generated is great, and the beam splitting module, polarization beam splitting converter, balanced detection module and target detection module require different to beam diameter, switch over the beam diameter of light beam through first mode converter, second mode converter and mode conversion module to make each module normally work, avoided causing the too big problem of beam loss because beam diameter is too big/undersize, avoided the problem that the detection accuracy descends or detects the inefficacy because of beam loss, laser radar's detection success rate has been improved.

As shown in fig. 5, fig. 5 is a schematic structural diagram of a laser radar provided in an embodiment of the present application, where the laser radar 1 includes: the system comprises a frequency-modulated light source 11, a beam splitting module 12, an object detection module 13, at least one polarization beam splitting rotator 14, a balance detection module 15, a first mode converter 171, a second mode converter 172 and a mode conversion module 173, wherein the object detection module 13 comprises an optical amplifier 131, at least one circulator 132 and at least one beam steering module 133, and the mode conversion module 173 comprises at least one third mode converter 174; the circulators 132 correspond to the third mode converters 174 one to one, the circulator 132 corresponds to the beam steering module 133 one to one, and the third mode converter 174 corresponds to the polarization beam splitter rotator 14 one to one.

The output end of the second mode converter 172 is connected to the input end of the amplifier 131, the amplifier 131 has at least two output ends, the number of the output ends of the amplifier 131 is the same as the number of the circulators 132, each output end of the amplifier 131 is connected to the first end of each circulator 132, the second end of each circulator 132 is connected to the first end of the corresponding beam steering module 133, the third end of each circulator 132 is connected to the input end of the corresponding third mode converter 174, the output end of each third mode converter 174 is connected to the corresponding polarization beam splitting rotator 14, and the output end of each polarization beam splitting rotator 14 is connected to the input end of the balance detection module 15.

The frequency modulated light source 11 generates an input beam and then transmits the input beam to a first mode converter 171 connected to the frequency modulated light source 11; the first mode converter 171 receives the input light beam output by the frequency-modulated light source 11, adjusts the beam diameter of the input light beam to a first predetermined diameter, obtains a target input light beam with the beam diameter of the first predetermined diameter, and transmits the target input light beam to the beam splitting module 12. The beam splitting module 12 receives the target input light beam output by the first mode converter 171, and then splits the target input light beam into a preset number of local oscillator light beams and probe light beams according to a preset splitting ratio, where it should be noted that the preset number is the number of all the circulators 132, and transmits each local oscillator light beam to the balanced probe module 15, and transmits the probe light beam to the second mode converter 172. The second mode converter 172 receives the probe beam output by the beam splitting module 12, adjusts the beam diameter of the probe beam to a second preset diameter, obtains a target probe beam with the second preset diameter, and transmits the target probe beam to the amplifier 131. Wherein the second predetermined diameter is greater than the first predetermined diameter. The amplifier 131 receives the target probe beam output by the second mode converter 172, then gains the optical power of the target probe beam to obtain a predetermined number of actual probe beams, and transmits each actual probe beam to each circulator 132. Each circulator 132 receives the actual probe beam output from the amplifier 131 through a first end and transmits the actual probe beam to the beam steering module 133 through a second end. Each beam steering module 133 receives the actual probe beam output by the corresponding circulator 132 through the first end, then processes the actual probe beam, such as shaping, collimating, and scanning, and emits the processed actual probe beam through the second end, so as to detect the target object 00 in the corresponding detection range. It should be noted that different beam steering modules 133 correspond to different detection angles, and when the actual detection beam encounters the target object 00, the actual detection beam is reflected by the target object 00 to form a reflected beam, and the reflected beam is reflected to the second end of the beam steering module 133.

The beam steering module 133 transmits the reflected beam to the circulator 132 through the first end. The second end of the circulator 132 receives the reflected beam output by the circulator and transmits the reflected beam through the third end to a corresponding third mode converter 174. Each third mode converter 174 receives the reflected beam output from the corresponding circulator 132, adjusts the beam diameter of the reflected beam to a third predetermined diameter, obtains a target reflected beam having a beam diameter of the third predetermined diameter, and transmits the target reflected beam to the corresponding polarization beam splitting rotator 14. Wherein the second predetermined diameter is greater than the third predetermined diameter. Each polarization beam splitter rotator 14 receives the target reflected light beam, then converts the polarization state of the target reflected light beam to obtain a signal beam, and then transmits the signal beam to the balance detection module 15. The balance detection module 15 receives the local oscillator light beams output by the beam splitting module 12 and the signal light beams output by the polarization beam splitting rotators 14, performs balance detection on the local oscillator light beams and the signal light beams, and outputs first detection signals, it should be noted that the balance detection module 15 performs balance detection on one signal light beam and one local oscillator light beam in sequence to obtain corresponding first detection signals, and all the first detection signals are used for obtaining the position information of the target object 00.

In this application embodiment, through setting up multiunit circulator, beam manipulation module and third mode converter, increase laser radar's detectable angle to improve laser radar's detection scope.

As shown in fig. 6, fig. 6 is a schematic structural diagram of a laser radar provided in an embodiment of the present application, where the laser radar 1 includes: the system comprises a frequency-modulated light source 11, a beam splitting module 12, an object detection module 13, at least one polarization beam splitting rotator 14, a balance detection module 15, a first mode converter 171, a second mode converter 172, a mode conversion module 173 and at least two optical mixers 161, wherein the object detection module 13 comprises an optical amplifier 131, at least one circulator 132 and at least one beam steering module 133, the mode conversion module 173 comprises at least one third mode converter 174, and the balance detection module 15 comprises at least two first balance detectors 151; the circulators 132 correspond to the third mode converters 174 one to one, the circulator 132 corresponds to the beam steering module 133 one to one, the third mode converters 174 correspond to the polarization beam splitting rotators 14 one to one, the polarization beam splitting rotators 14 correspond to two optical mixers 161, the optical mixers 161 correspond to one polarization beam splitting rotator 14, and the optical mixers 161 correspond to the first balanced detector 151 one to one.

The polarization beam splitting rotator 14 has two outputs, and the optical mixer 161 has two inputs; the first output end of the polarization splitting rotator 1 is connected to the first input end of the corresponding optical mixer 161, the second output end of the polarization splitting rotator 14 is connected to the first input end of the other corresponding optical mixer 161, and the second input end of each optical mixer 161 is connected to one output end of the splitting module 12. A first output of the optical mixer 161 is connected to a first input of a corresponding first balanced detector 151 and a second output of the optical mixer 161 is connected to a second input of a corresponding first balanced detector 151.

The frequency modulated light source 11 generates an input beam and then transmits the input beam to a first mode converter 171 connected to the frequency modulated light source 11; the first mode converter 171 receives the input light beam output by the frequency-modulated light source 11, adjusts the beam diameter of the input light beam to a first predetermined diameter, obtains a target input light beam with the beam diameter of the first predetermined diameter, and transmits the target input light beam to the beam splitting module 12. The beam splitting module 12 receives the target input light beam output by the first mode converter 171, and then splits the target input light beam into a preset number of local oscillator light beams and probe light beams according to a preset splitting ratio, where it should be noted that the preset number is the number of all the circulators 132, and transmits each local oscillator light beam to each optical mixer 161, and transmits the probe light beam to the second mode converter 172. The second mode converter 172 receives the probe beam output by the beam splitting module 12, adjusts the beam diameter of the probe beam to a second preset diameter, obtains a target probe beam with the second preset diameter, and transmits the target probe beam to the amplifier 131. Wherein the second predetermined diameter is greater than the first predetermined diameter. The amplifier 131 receives the target probe beam output by the second mode converter 172, and then gains the optical power of the target probe beam to obtain a predetermined number of actual probe beams, and transmits each actual probe beam to each circulator 132. Each circulator 132 receives the actual probe beam output from the amplifier 131 through a first end and transmits the actual probe beam to the beam steering module 133 through a second end. Each beam steering module 133 receives the actual probe beam output by the corresponding circulator 132 through the first end, then processes the actual probe beam, such as shaping, collimating, and scanning, and emits the processed actual probe beam through the second end, so as to detect the target object 00 in the corresponding detection range. It should be noted that different beam steering modules 133 correspond to different detection angles, and when the actual detection beam encounters the target object 00, the actual detection beam is reflected by the target object 00 to form a reflected beam, and the reflected beam is reflected to the second end of the beam steering module 133.

The beam steering module 133 transmits the reflected beam to the circulator 132 through the first end. The second end of the circulator 132 receives the reflected beam output by the circulator and transmits the reflected beam through the third end to a corresponding third mode converter 174. Each third mode converter 174 receives the reflected beam output from the corresponding circulator 132, adjusts the beam diameter of the reflected beam to a third predetermined diameter, obtains a target reflected beam having a beam diameter of the third predetermined diameter, and transmits the target reflected beam to the corresponding polarization beam splitting rotator 14. Wherein the second predetermined diameter is greater than the third predetermined diameter. Each polarization beam splitting rotator 14 receives the target reflected light beam, then converts the polarization state of the target reflected light beam to obtain a signal beam, and then transmits the signal beam to the corresponding two optical mixers 161.

The optical mixer 161 receives the local oscillator beams and the signal beams output by the beam module 12 and the polarization beam splitting rotator 14, performs optical frequency mixing, such as frequency subtraction, frequency addition, frequency superposition, and other frequency mixing operations on the received local oscillator beams and signal beams, and obtains at least two different first frequency mixing signals based on different optical frequency mixing operations, where the first frequency mixing signals are differential signals. The optical mixer 161 transmits each first mixed signal to the corresponding first balanced detector 151 through the first output terminal and the second output terminal, respectively. The first balanced detector 151 receives each first mixed signal output by the corresponding optical mixer 161, performs balanced detection on each first mixed signal, and outputs first detection signals, which are all used to acquire position information of the target object 00.

In the embodiment of the application, the optical mixer is used for optically mixing the local oscillator light beam and the signal light beam, so that a sufficiently large differential signal is obtained, the accuracy of the balance detector is improved, and the detection success rate of the laser radar is improved.

As shown in fig. 7, fig. 7 is a schematic structural diagram of a laser radar provided in an embodiment of the present application, where the laser radar 1 includes: the system comprises a frequency modulation light source 11, a beam splitting module 12, an object detection module 13, a polarization beam splitting rotator 14, a balance detection module 15, an optical delay line 18, a coupler 19 and a second balance detector 20.

The coupler 19 comprises a first input, a second input and at least two outputs. The input end of the optical delay line 18 is connected with the output end of the light beam module 12, the output end of the optical delay line 18 is connected with the first input end of the coupler 19, the second input end of the coupler 19 is connected with the other output end of the light beam module, the first output end of the coupler 19 is connected with the first input end of the second balanced detector 20, and the second output end of the coupler 19 is connected with the second input end of the second balanced detector 20.

The frequency modulated light source 11 generates an input beam and transmits the input beam to a beam splitting module 12 connected to the frequency modulated light source 11. The beam splitting module 12 receives the input beam output by the frequency modulation light source 11, then divides the input beam into a local oscillator beam, a probe beam and two beams of calibration beams according to a preset splitting ratio, namely a first calibration beam and a second calibration beam, transmits the local oscillator beam to the balance detection module 15, transmits the probe beam to the target detection module 13, transmits the first calibration beam to the optical delay line 18, and transmits the second calibration beam to the coupler 19.

The object detection module 13 receives the probe beam output from the beam splitting module 12, and then emits the probe beam toward the object 00. The object detection module 13 receives the reflected light beam reflected by the object 00 and transmits the reflected light beam to the polarization beam splitter rotator 14. The polarization beam splitter rotator 14 receives the reflected light beam, converts the polarization state of the reflected light beam to obtain a signal beam, and transmits the signal beam to the balance detection module 15. The balance detection module 15 receives the local oscillator light beam output by the beam splitting module 12 and the signal light beam output by the polarization beam splitting rotator 14, performs balance detection on the local oscillator light beam and the signal light beam, and outputs a first detection signal, where the first detection signal is used to obtain the position information of the target object 00.

The optical delay line 18 receives the first calibration light beam output by the beam splitting module 12, the first calibration light beam is transmitted through the optical delay line 18 to obtain a delay light beam, and the delay light beam is transmitted to the coupler 19. The coupler 19 receives the delayed light beam output by the light extension line 18, receives the second calibration light beam output by the beam splitting module 12, then performs optical mixing, such as frequency subtraction, frequency addition, frequency superposition, and the like, on the currently received delayed light beam and the second calibration light beam, and obtains at least two different second mixed signals based on different optical mixing operations, where the second mixed signals are differential signals. The coupler 19 transmits the second mixed signals to the second balanced detector 20 via a first output terminal and a second output terminal, respectively.

The second balanced detector 20 receives the second mixed signals output by the coupler 19, performs balanced detection on the second mixed signals, and outputs second detection signals, where the second detection signals are all used to obtain an adjustment value of the frequency-modulated light source 11.

Optionally, the laser radar 1 further includes a processing module, configured to acquire a second detection signal output by the second balanced detector 20, and acquire an adjustment value of the frequency-modulated light source 11 based on the second detection signal, where the adjustment value may be a light frequency of the output light beam, or the like.

In the embodiment of the application, the adjustment value of the frequency modulation light source is obtained through the calibration light path (namely, the line composed of the beam splitting module, the optical delay line, the coupler and the second balanced detector), and the light beam output by the frequency modulation light beam is adjusted in time to obtain the local oscillator light beam and the detection light beam with higher linearity and obtain the signal light beam with higher linearity, so that the signal quality of the laser radar is improved.

Optionally, the beam splitting module 12, the polarization beam splitting rotator 14, the balance detection module 15, the first balance detector 151, the optical mixing module 16, the optical mixer 161, the first mode converter 171, the second mode converter 172, the mode conversion module 173, the third mode converter 174, the optical delay line 18, the coupler 19, and the second balance detector 20 may be integrated on a detection chip, and the detection chip may be processed by a mature semiconductor processing technology, so as to avoid the situation of discrete devices, improve the integration level of the lidar, and reduce the complexity, the production cost, and the product volume of the lidar.

The control method of the laser radar according to the embodiment of the present application will be described in detail below with reference to fig. 8 to 11.

Please refer to fig. 8, which is a flowchart illustrating a method for controlling a laser radar according to an embodiment of the present disclosure. As shown in fig. 8, the method may include the following steps S101 to S105.

The method is applied to the laser radar, and the specific connection mode of the laser radar can be referred to the foregoing embodiments, which are not described herein again.

S101, generating an input light beam, and dividing the input light beam into a detection light beam and a local oscillator light beam.

S102, emitting a detection beam to the target object, and receiving a reflected beam reflected by the target object.

And S103, converting the polarization state of the reflected light beam to obtain a signal light beam, wherein the polarization state of the signal light beam is consistent with that of the local oscillation light beam.

And S104, carrying out balance detection on the local oscillator light beam and the signal light beam to obtain a first detection signal.

And S105, acquiring the position information of the target object based on the first detection signal.

Specifically, the input light beam refers to a Frequency Modulated Continuous Wave (FMCW) signal, that is, a Continuous signal whose transmission Frequency is Modulated by a specific signal, and the transmission Frequency of the laser radar is an adjustable value; the target object is an object within the detection range of the lidar.

After receiving the detection instruction, the laser radar generates a continuous frequency modulation continuous wave signal, namely an input light beam, according to a preset transmitting frequency and a preset polarization state, and then divides the input light beam into a detection light beam and a local oscillator light beam according to a preset splitting ratio. The laser radar emits the probe beam toward the target object. It should be noted that when the probe beam encounters a target object within the detection range of the laser radar, the probe beam is reflected by the target object and is reflected back to the laser radar as a reflected beam. The laser radar receives the reflected light beam reflected by the target object, converts the polarization state of the received reflected light beam into a preset polarization state, and uses the reflected light beam after the polarization state conversion as a signal light beam, so that it can be understood that the polarization state of the signal light beam is consistent with the polarization state of the local oscillation light beam. The laser radar carries out balance detection on the local oscillator light beam and the signal light beam to obtain a first detection signal, then carries out signal processing processes such as signal sampling and filtering on the first detection signal, and calculates position information of a target object based on the signal data obtained through processing.

In the embodiment of the application, the polarization state of the reflected light beam reflected by the target object is adjusted to be converted to be consistent with the polarization state of the local oscillator light beam, so that the situation of detection failure caused by inconsistent polarization states is avoided, and the detection success rate of the laser radar is improved.

Fig. 9 is a schematic flow chart of a laser radar control method according to an embodiment of the present disclosure. As shown in fig. 9, the method may include the following steps S201 to S205.

S201, generating an input light beam, and dividing the input light beam into a detection light beam and a local oscillation light beam;

s202, emitting a detection light beam to a target object, and receiving a reflected light beam reflected by the target object;

s203, converting the polarization state of the reflected light beam to obtain a signal light beam, wherein the polarization state of the signal light beam is consistent with the polarization state of the local oscillator light beam;

s204, carrying out frequency mixing processing on the local oscillator light beam and the signal light beam to obtain a first frequency mixing signal;

s205, perform balance detection on the first mixed signal to obtain a first detection signal.

Specifically, after receiving a detection instruction, the laser radar generates a continuous frequency modulation continuous wave signal, i.e., an input light beam, according to a preset emission frequency and a preset polarization state, and then divides the input light beam into a detection light beam and a local oscillator light beam according to a preset splitting ratio. The laser radar transmits the detection beam to a target object, receives a reflected beam reflected by the target object, converts the polarization state of the received reflected beam into a preset polarization state, and uses the reflected beam with the converted polarization state as a signal beam.

The laser radar firstly carries out optical frequency mixing on a local oscillator light beam and a signal light beam, wherein the optical frequency mixing can be frequency mixing operations such as frequency subtraction, frequency addition and frequency superposition to obtain a first frequency mixing signal, then carries out balance detection on the basis of the first frequency mixing signal to obtain a first detection signal, then carries out signal processing processes such as signal sampling and filtering on the first detection signal, and calculates the position information of a target object on the basis of the processed signal data.

Optionally, the laser radar may perform optical frequency mixing on the local oscillator light beam and the signal light beam based on the first frequency mixing operation to obtain a first frequency mixing sub-signal, perform optical frequency mixing on the local oscillator light beam and the signal light beam based on the second frequency mixing operation to obtain a second frequency mixing sub-signal, perform balance detection based on the first frequency mixing sub-signal and the second frequency mixing sub-signal to obtain a first detection signal, perform signal processing processes such as signal sampling and filtering on the first detection signal, and calculate the position information of the target object based on the signal data obtained by the processing.

In the embodiment of the application, the detection accuracy of the balance detection is improved by acquiring the sufficiently large differential signal, namely the first mixing signal, and the detection success rate of the laser radar is further improved.

Referring to fig. 10, a schematic flow chart of a laser radar control method is provided in an embodiment of the present application. As shown in fig. 10, the method may include the following steps S301 to S309.

S301, generating an input light beam;

s302, adjusting the beam diameter of the input beam to a first preset diameter to obtain a target input beam;

s303, dividing the target input light beam into a detection light beam and a local oscillation light beam;

s304, adjusting the beam diameter of the detection beam to a second preset diameter to obtain a target detection beam, wherein the second preset diameter is larger than the first preset diameter;

s305, emitting a target detection beam to the target object and receiving a reflected beam reflected by the target object;

s306, adjusting the beam diameter of the reflected beam to a third preset diameter to obtain a target reflected beam, wherein the second preset diameter is larger than the third preset diameter.

S307, converting the polarization state of the reflected light beam to obtain a signal light beam, wherein the polarization state of the signal light beam is consistent with the polarization state of the local oscillator light beam;

s308, carrying out balance detection on the local oscillator light beam and the signal light beam to obtain a first detection signal;

s309, position information of the target object is acquired based on the first detection signal.

Specifically, the first predetermined diameter refers to a maximum beam diameter of a light beam transmittable by an integrated chip of the laser radar, and may also be an optimal beam diameter, which is not limited herein, but the first predetermined diameter is certainly less than or equal to the maximum beam diameter of the light beam transmittable by the integrated chip; the second predetermined diameter is a maximum beam diameter of a non-integrated chip of the lidar, and may be an optimal beam diameter, which is not limited herein. The third predetermined diameter may be the same as the first predetermined diameter, and the third predetermined diameter is necessarily smaller than or equal to the maximum beam diameter of the integrated chip capable of transmitting the beam.

After receiving the detection instruction, the laser radar generates a continuous frequency modulation continuous wave signal, namely an input light beam, according to a preset emission frequency and a preset polarization state, and then adjusts the beam diameter of the input light beam to a first preset diameter to obtain a target input light beam. The laser radar divides the target input light beam into a detection light beam and a local oscillator light beam according to a preset splitting ratio, then adjusts the light beam diameter of the detection light beam to a second preset diameter, and transmits the target detection light beam to the target object. The laser radar receives a reflected light beam reflected by a target object, then adjusts the beam diameter of the received reflected light beam to a third preset diameter to obtain a target reflected light beam, converts the polarization state of the target reflected light beam to a preset polarization state, and uses the reflected light beam with the converted polarization state as a signal beam. The laser radar carries out balance detection on the local oscillator light beam and the signal light beam to obtain a first detection signal, then carries out signal processing processes such as signal sampling and filtering on the first detection signal, and calculates position information of a target object based on the signal data obtained through processing.

In the embodiment of the application, because the beam diameter of the input beam is larger, and the requirements of the integrated chip and the non-integrated chip component on the beam diameter are different, by switching the beam diameter of the beam, errors caused by overlarge/undersize beam diameters are avoided, and the detection success rate of the laser radar is improved.

Referring to fig. 11, a schematic flow chart of a laser radar control method is provided in an embodiment of the present application. As shown in fig. 11, the method may include the following steps S401 to S411.

S401, generating an input light beam, dividing the input light beam into a detection light beam and at least two local oscillator light beams, wherein the number of the local oscillator light beams is twice of the number of emission angles, and the emission angles are at least one;

s402, adjusting the beam diameter of the input beam to a first preset diameter to obtain a target input beam;

s403, dividing the target input light beam into a detection light beam and a local oscillation light beam;

s404, adjusting the beam diameter of the detection beam to a second preset diameter to obtain a target detection beam, wherein the second preset diameter is larger than the first preset diameter;

s405, gaining the optical power of the target detection beam to obtain an actual detection beam;

s406, emitting actual detection beams to the target object through each emission angle;

s407, receiving reflected light beams reflected by the target object at all emission angles;

s408, adjusting the beam diameter of each reflected beam to a third preset diameter to obtain a target reflected beam;

s409, converting the polarization state of each target reflected light beam, splitting the beams to obtain at least two signal light beams, and splitting one target reflected light beam into two signal light beams;

s410, acquiring each first detection signal based on each local oscillator light beam and each signal light beam;

s411, position information of the target object is acquired based on each of the first detection signals.

Specifically, the emission angle refers to the emission angle of laser when the laser radar emits the emission laser for detection, the emission angle is at least one, if the number of the emission angles of the laser radar is a first preset number, the number of the local oscillator beams is a second preset number, and the second preset number is twice of the first preset number.

After receiving the detection instruction, the laser radar generates a continuous frequency modulation continuous wave signal, namely an input light beam, according to a preset transmitting frequency and a preset polarization state, and then adjusts the light beam diameter of the input light beam to a first preset diameter to obtain a target input light beam. The laser radar divides the target input light beam into the detection light beam and the local oscillator light beams with a second preset number according to the preset splitting ratio, then adjusts the light beam diameter of the detection light beam to a second preset diameter, and transmits the target detection light beam to the target object. The laser radar receives a reflected light beam reflected by a target object, the beam diameter of the received reflected light beam is adjusted to a third preset diameter to obtain a target reflected light beam, the polarization state of the target reflected light beam is converted into a preset polarization state, and laser beam splitting is performed on the reflected light beam after the polarization state conversion to obtain a second preset number of signal light beams. It should be noted that, if there is no difference between the local oscillator light beams, one signal light beam and one local oscillator light beam are used as a group of detection signals, and the signal light beam corresponds to the local oscillator light beam one to one.

The laser radar carries out balance detection on the local oscillator light beams and the signal light beams in the same group to obtain each first detection signal, then signal processing processes such as signal sampling and filtering are carried out on each first detection signal, and position information of a target object is measured and calculated based on each signal data obtained through processing.

It should be noted that, if a certain emission angle of the laser radar cannot detect the target object, the laser radar cannot receive the reflected light beam corresponding to the emission angle, and then the balanced detection process corresponding to the emission angle does not exist subsequently.

In the embodiment of the application, the detection range of the laser radar is improved by increasing the detectable angle of the laser radar.

Referring to fig. 12, a schematic flow chart of a laser radar control method is provided in an embodiment of the present application. As shown in fig. 12, the method may include the following steps S501 to S509.

S501, generating an input light beam, and dividing the input light beam into a detection light beam, a local oscillation light beam, a first calibration light beam and a second calibration light beam;

s502, emitting a detection light beam to a target object, and receiving a reflected light beam reflected by the target object;

s503, converting the polarization state of the reflected light beam to obtain a signal light beam, wherein the polarization state of the signal light beam is consistent with the polarization state of the local oscillation light beam;

s504, carrying out balance detection on the local oscillator light beam and the signal light beam to obtain a first detection signal;

and S505, acquiring the position information of the target object based on the first detection signal.

S506, prolonging the transmission time of the first calibration light beam to obtain a delay light beam;

s507, carrying out frequency mixing processing on the delayed light beam and the second calibration light beam to obtain a second frequency mixing signal;

s508, performing balance detection on the second mixing signal and outputting a second detection signal;

and S509, acquiring an adjustment value of the frequency modulation light source of the laser radar based on the second detection signal.

Specifically, after receiving a detection instruction, the laser radar generates a continuous frequency modulation continuous wave signal, i.e., an input light beam, according to a preset emission frequency and a preset polarization state, and then divides the input light beam into a detection light beam, a local oscillation light beam, a first calibration light beam and a second calibration light beam according to a preset splitting ratio, it should be noted that the preset splitting ratio is only used for splitting the input light beam, the specific size can be defined by a user, and the laser splitting only changes the size of the laser beam. The laser radar emits the probe beam toward the target object. It should be noted that when the detection light beam encounters a target object in the detection range of the laser radar, the detection light beam is reflected by the target object and is reflected back to the laser radar as a reflected light beam. The laser radar receives the reflected light beam reflected by the target object, converts the polarization state of the received reflected light beam into a preset polarization state, and uses the reflected light beam after the polarization state conversion as a signal light beam, so that it can be understood that the polarization state of the signal light beam is consistent with the polarization state of the local oscillator light beam. The laser radar carries out balance detection on the local oscillator light beam and the signal light beam to obtain a first detection signal, then carries out signal processing processes such as signal sampling and filtering on the first detection signal, and calculates position information of a target object based on the signal data obtained through processing.

Meanwhile, the laser radar prolongs the transmission time of the first calibration signal to obtain a delayed beam, then performs optical mixing on the delayed beam and the second calibration beam, wherein the optical mixing may be frequency subtraction, frequency addition, frequency superposition and other mixing operations to obtain a second mixed signal, then performs signal processing processes such as signal sampling and filtering on the second detection signal, calculates an adjustment value of a preset transmitting frequency based on the processed signal data and the original preset transmitting frequency, then obtains a target preset transmitting frequency based on the adjustment value and the preset transmitting frequency, and then replaces the preset transmitting frequency stored in the memory with the target preset transmitting frequency.

In the embodiment of the application, the adjusting value of the frequency modulation light source is obtained, and the preset transmitting frequency is adjusted in time, so that the output light beam is adjusted, the local oscillator light beam and the detection light beam which are higher in reliability are obtained, the signal light beam with high reliability is obtained, and the effect of improving the detection success rate of the laser radar is achieved.

The embodiment of the present application further provides a storage medium, where the storage medium may store a plurality of program instructions, and the program instructions are suitable for being loaded by a processor and executing the method steps in the embodiments shown in fig. 8 to 12, and a specific execution process may refer to specific descriptions of the embodiments shown in fig. 8 to 12, which is not described herein again.

Referring to fig. 13, a schematic structural diagram of a computer device is provided in an embodiment of the present application. As shown in fig. 13, the computer apparatus 1000 may include: at least one processor 1001, at least one memory 1002, at least one network interface 1003, at least one input/output interface 1004, at least one communication bus 1005, and at least one display unit 1006. Processor 1001 may include one or more processing cores, among other things. Processor 1001 interfaces with various parts throughout computer device 1000 using various interfaces and lines to perform various functions of terminal 1000 and process data by executing or executing instructions, programs, code sets, or instruction sets stored in memory 1002, and invoking data stored in memory 1002. The memory 1002 may be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory. The memory 1002 may optionally be at least one memory device located remotely from the processor 1001. The network interface 1003 may optionally include a standard wired interface or a wireless interface (e.g., WI-FI interface). A communication bus 1005 is used to enable the connection communication between these components. As shown in fig. 13, the memory 1002, which is a storage medium of a terminal device, may include therein an operating system, a network communication module, an input-output interface module, and a control program of a laser radar.

In the computer device 1000 shown in fig. 13, the input/output interface 1004 is mainly used for providing an input interface for a user and an access device, and acquiring data input by the user and the access device.

In one embodiment.

Processor 1001 may be configured to invoke a control program for the lidar stored in memory 1002 and to perform the following operations:

generating an input light beam, and dividing the input light beam into a detection light beam and a local oscillation light beam;

converting the polarization state of the reflected light beam to obtain a signal light beam, wherein the polarization state of the signal light beam is consistent with that of the local oscillation light beam;

Optionally, when the processor 1001 performs balanced detection on the local oscillator beam and the signal beam to obtain the first detection signal, the following operations are specifically performed:

carrying out frequency mixing processing on the local oscillator light beam and the signal light beam to obtain a first frequency mixing signal;

and carrying out balance detection on the first mixing signal to obtain a first detection signal.

Optionally, when the processor 1001 generates the input light beam and divides the input light beam into the probe light beam and the local oscillator light beam, the following operations are specifically performed:

generating an input light beam;

adjusting the beam diameter of the input beam to a first preset diameter to obtain a target input beam;

the target input light beam is split into a probe light beam and a local oscillator light beam.

Optionally, when the processor 1001 executes the steps of emitting the probe beam to the target object and receiving the reflected beam reflected by the target object, the following operations are specifically executed:

adjusting the beam diameter of the detection beam to a second preset diameter to obtain a target detection beam, wherein the second preset diameter is larger than the first preset diameter;

transmitting a target detection beam to a target object, and receiving a reflected beam reflected by the target object;

and adjusting the beam diameter of the reflected beam to a third preset diameter to obtain a target reflected beam, wherein the second preset diameter is larger than the third preset diameter.

Optionally, when the processor 1001 executes the steps of emitting the target detection beam to the target object and receiving the reflected beam reflected by the target object, the following operations are specifically executed:

the optical power of the target detection beam is gained to obtain an actual detection beam;

the actual probe beam is emitted toward the target object and the reflected beam reflected by the target object is received.

the method comprises the steps of generating an input light beam, dividing the input light beam into a detection light beam and at least two local oscillator light beams, wherein the number of the local oscillator light beams is twice of the number of emission angles, and the emission angles are at least one.

Optionally, when the processor 1001 executes the steps of emitting the actual probe beam to the target object and receiving the reflected beam reflected by the target object, specifically:

emitting actual detection beams to the target object through each emission angle;

receiving reflected light beams reflected by the target object at all emission angles;

optionally, when the processor 1001 adjusts the beam diameter of the reflected beam to a third preset diameter to obtain the target reflected beam, the following operations are specifically performed:

adjusting the beam diameter of each reflected beam to a third preset diameter to obtain a target reflected beam;

optionally, when the processor 1001 performs the conversion of the polarization state of the reflected light beam to obtain the signal light beam, the following operations are specifically performed:

converting the polarization state of each target reflected light beam, splitting the beams to obtain at least two signal beams, and splitting one target reflected light beam into two signal beams

acquiring first detection signals based on local oscillator light beams and signal light beams

Optionally, when the processor 1001 obtains the position information of the target object based on the first detection signal, it specifically performs the following operations:

acquiring position information of a target object based on each of the first detection signals

Optionally, when the processor 1001 performs splitting of the input light beam into the probe light beam and the local oscillator light beam, the following operation is specifically performed:

splitting an input beam into a probe beam, a local oscillator beam, a first calibration beam, and a second calibration beam

Optionally, after the processor 1001 performs splitting the input light beam into the probe light beam and the local oscillator light beam, the following operations are further performed:

prolonging the transmission time of the first calibration light beam to obtain a delayed light beam;

performing frequency mixing processing on the delayed light beam and the second calibration light beam to obtain a second frequency mixing signal;

performing balance detection on the second mixing signal and outputting a second detection signal;

and acquiring an adjustment value of the frequency modulation light source of the laser radar based on the second detection signal.

It should be noted that, for the sake of simplicity, the above-mentioned method embodiments are described as a series of acts or combinations, but those skilled in the art should understand that the present application is not limited by the described order of acts, as some steps may be performed in other orders or simultaneously according to the present application. Further, those skilled in the art will appreciate that the embodiments described in this specification are presently considered to be preferred embodiments and that acts and modules are not required in the present application.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

In view of the above description of the laser radar, the control method of the laser radar, the storage medium and the device provided by the present application, those skilled in the art will recognize that changes may be made in the specific implementation and application scope according to the concepts of the embodiments of the present application.

Claims

1. A lidar, characterized in that the lidar comprises: the device comprises a frequency modulation light source, a beam splitting module, a target detection module, a polarization beam splitting rotator and a balance detection module;

the polarization beam splitting rotator is used for receiving the reflected light beam, converting the polarization state of the reflected light beam to obtain a signal light beam, and transmitting the signal light beam to the balance detection module, wherein the polarization state of the signal light beam is consistent with the polarization state of the local oscillator light beam, and the polarization state of the signal light beam is a transverse electric mode polarization state or a transverse magnetic mode polarization state;

the balance detection module is used for receiving the local oscillator light beam and the signal light beam, carrying out balance detection on the local oscillator light beam and the signal light beam and outputting a first detection signal, wherein the first detection signal is used for acquiring the position information of the target object.

2. The lidar of claim 1, further comprising: an optical mixing module;

the beam splitting module is used for transmitting the local oscillation light beam to the optical frequency mixing module;

the polarization beam splitting rotator is used for transmitting the signal light beam to the optical mixing module;

the optical frequency mixing module is configured to receive the local oscillator light beam and the signal light beam, perform frequency mixing processing on the received local oscillator light beam and the received signal light beam to obtain a first frequency mixing signal, and transmit the first frequency mixing signal to the balance detection module;

the balance detection module is configured to receive the first mixed signal, perform balance detection on the first mixed signal, and output a first detection signal, where the first detection signal is used to obtain position information of the target object.

3. The lidar of claim 2, further comprising: a first mode converter, a second mode converter and a mode conversion module;

the frequency modulated light source to transmit the input beam to the first mode converter;

the first mode converter is used for receiving the input light beam, adjusting the beam diameter of the input light beam to a first preset diameter to obtain a target input light beam, and transmitting the target input light beam to the beam splitting module;

the beam splitting module is used for receiving the target input light beam, splitting the target input light beam into a detection light beam and a local oscillation light beam, transmitting the detection light beam to the second mode converter, and transmitting the local oscillation light beam to the balance detection module;

the second mode converter is used for receiving the detection beam, adjusting the beam diameter of the detection beam to a second preset diameter to obtain a target detection beam, and transmitting the target detection beam to the target detection module, wherein the second preset diameter is larger than the first preset diameter;

the target detection module is used for receiving the target detection light beam, transmitting the target detection light beam to a target object, receiving a reflected light beam reflected by the target object and transmitting the reflected light beam to the mode conversion module;

the mode conversion module is used for receiving the reflected light beam, adjusting the beam diameter of the reflected light beam to a third preset diameter to obtain a target reflected light beam, and transmitting the target reflected light beam to the polarization beam splitting rotator, wherein the second preset diameter is larger than the third preset diameter.

4. The lidar of claim 3, wherein the object detection module comprises: the laser radar further comprises at least one polarization beam splitting rotator, wherein the circulators correspond to the third mode converters one by one, the circulators correspond to the beam steering modules one by one, and the third mode converters correspond to the polarization beam splitting rotators one by one;

the second mode converter is used for transmitting the target detection beam to the optical amplifier;

the optical amplifier is used for receiving the target detection beam, gaining the optical power of the target detection beam to obtain an actual detection beam, and transmitting the actual detection beam to each circulator;

the circulator is used for receiving the actual detection light beam and transmitting the actual detection light beam to the corresponding light beam control module;

the light beam control module is used for receiving the actual detection light beam, transmitting the actual detection light beam to the target object, receiving a reflected light beam reflected by the target object and transmitting the reflected light beam to the corresponding circulator;

the circulator is further used for receiving the reflected light beams and transmitting the reflected light beams to the corresponding third mode converter;

and the third mode converter is used for receiving the reflected light beam, adjusting the beam diameter of the reflected light beam to be the third preset diameter to obtain a target reflected light beam, and transmitting the target reflected light beam to the corresponding polarization beam splitting rotator.

5. The lidar of claim 4, further comprising: the balance detection module comprises at least two first balance detectors, the polarization beam splitting rotators correspond to the two optical mixers, the optical mixers correspond to one polarization beam splitting rotator, and the optical mixers correspond to the first balance detectors one by one;

the polarization beam splitting rotator is further configured to receive the target reflected light beam, convert the polarization state of the target reflected light beam, split the beam to obtain two signal light beams, and transmit each signal light beam to the two corresponding optical mixers, where the polarization state of each signal light beam is consistent with the polarization state of the local oscillator light beam;

the beam splitting module is further configured to split the target input light beam into a detection light beam and at least two local oscillator light beams, and transmit each local oscillator light beam to each optical mixer;

the optical mixer is configured to receive the local oscillator light beam and the signal light beam, perform frequency mixing processing on the local oscillator light beam and the signal light beam to obtain a first frequency mixing signal, and transmit the first frequency mixing signal to the corresponding first balanced detector;

the first balanced detector is configured to receive the first mixed signal, perform balanced detection on the first mixed signal, and output a first detection signal, where the first detection signal is used to obtain position information of the target object.

6. The lidar of claim 5, further comprising: the optical delay line, the coupler and the second balanced detector;

the beam splitting module is further configured to split the input light beam into a probe light beam, a local oscillator light beam and two calibration light beams, and transmit each of the calibration light beams to the optical delay line and the coupler respectively;

the optical delay line is used for receiving the calibration light beam, prolonging the transmission time of the calibration light beam to obtain a delayed light beam and transmitting the delayed light beam to the coupler;

the coupler is used for receiving the calibration light beam and the delay light beam, mixing the calibration light beam and the delay light beam to obtain a second mixed signal, and transmitting the second mixed signal to the second balanced detector;

the second balanced detector is configured to receive the second mixed signal, perform balanced detection on the second mixed signal, and output a second detection signal, where the second detection signal is used to obtain an adjustment value of the frequency-modulated light source.

7. The lidar of claim 6, wherein the lidar further comprises an integrated chip;

the polarization beam splitting rotator, the beam splitting module, the balance detection module, the optical mixing module, the first mode converter, the second mode converter, the mode conversion module, the optical delay line, the coupler and the second balance detector are integrated inside the integrated chip.

8. A method of controlling a lidar, the method comprising:

emitting the detection light beam to a target object, and receiving a reflected light beam reflected by the target object;

converting the polarization state of the reflected light beam through a polarization beam splitting rotator to obtain a signal light beam, wherein the polarization state of the signal light beam is consistent with the polarization state of the local oscillator light beam, and the polarization state of the signal light beam is a polarization state of a transverse electric mode or a polarization state of a transverse magnetic mode;

carrying out balance detection on the local oscillator light beam and the signal light beam through a balance detection module to obtain a first detection signal;

9. The method of claim 8, wherein the performing balanced detection on the local oscillator beam and the signal beam to obtain a first detection signal comprises:

performing frequency mixing processing on the local oscillator light beam and the signal light beam to obtain a first frequency mixing signal;

10. The method of claim 8, wherein generating the input beam and splitting the input beam into a probe beam and a local oscillator beam comprises:

generating an input light beam;

dividing the target input light beam into a detection light beam and a local oscillation light beam;

the emitting the probe beam to the target object and receiving the reflected beam reflected by the target object comprise:

transmitting the target detection light beam to a target object, and receiving a reflected light beam reflected by the target object;

11. The method of claim 10, wherein said emitting the target probe beam toward the target object and receiving the reflected beam reflected by the target object comprises:

gaining the optical power of the target detection beam to obtain an actual detection beam;

and emitting the actual detection light beam to the target object, and receiving a reflected light beam reflected by the target object.

12. The method of claim 11, wherein generating the input beam and splitting the input beam into a probe beam and a local oscillator beam comprises:

generating an input light beam, and dividing the input light beam into a detection light beam and at least two local oscillator light beams, wherein the number of the local oscillator light beams is twice of the number of emission angles, and the emission angles are at least one;

the emitting the actual detection beam to the target object and receiving the reflected beam reflected by the target object comprises:

emitting the actual detection light beams to the target object through each emission angle;

receiving reflected light beams reflected by the target object at each of the emission angles;

adjusting the beam diameter of the reflected beam to the third preset diameter to obtain a target reflected beam comprises:

adjusting the beam diameter of each reflected beam to the third preset diameter to obtain a target reflected beam;

the converting the polarization state of the reflected light beam to obtain the signal light beam includes:

converting the polarization state of each target reflected light beam, splitting the beams to obtain at least two signal light beams, and splitting one target reflected light beam into two signal light beams;

the performing balanced detection on the local oscillator light beam and the signal light beam to obtain a first detection signal includes:

acquiring each first detection signal based on each local oscillator light beam and each signal light beam;

the acquiring of the position information of the target object based on the first detection signal includes:

and acquiring the position information of the target object based on each first detection signal.

13. The method of claim 8, wherein splitting the input optical beam into a probe beam and a local oscillator beam comprises:

splitting the input light beam into a probe light beam, a local oscillator light beam, a first calibration light beam and a second calibration light beam;

after splitting the input light beam into a probe light beam and a local oscillator light beam, the method further comprises:

mixing the delayed light beam and the second calibration light beam to obtain a second mixing signal;

and acquiring an adjustment value of a frequency modulation light source of the laser radar based on the second detection signal.