CN112924953A - Light detection system and method and laser radar system - Google Patents
Light detection system and method and laser radar system Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
- G01S7/4817—Constructional features, e.g. arrangements of optical elements relating to scanning
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
- G01S17/32—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/50—Systems of measurement based on relative movement of target
- G01S17/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/491—Details of non-pulse systems
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
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Abstract
The invention discloses a light detection method and a system, and a laser radar system, wherein the light detection system comprises: an array of coherent pixels; an FMCW operator array; an optical emission module; an optical receiving module; a light emitter; a controller; the optical emission module is connected with the light emitter, the controller is connected with the FMCW operator array and the light emitter, the light emitter is used for generating frequency modulation continuous waves, the frequency modulation continuous waves are used for detecting a target object, the optical receiving module is installed on the coherent pixel array and used for receiving optical reflection signals of the target and generating mixing signals through the coherent pixel array, and the FMCW operator array is used for analyzing the mixing signals to obtain detection data. The optical detection system and the method adopt Frequency Modulated Continuous Wave (FMCW) signals for detection, and can obviously improve the signal-to-noise ratio of the received weak signals, thereby obviously improving the sensitivity of distance detection.
Description
Technical Field
The invention relates to the field of optics, in particular to an optical detection system and method and a laser radar system.
Background
Currently, a LiDAR (LiDAR) system is a common prior art means in the field of optical detection technology, and the LiDAR system generally emits pulse or modulated laser, calculates the depth (i.e., distance) of one or more directions in a two-dimensional scene by using related information of reflected light, and generates a cloud point image to visually represent the depth information of the scene. The existing laser radar system irradiates the whole scene through a divergent light beam and then obtains reflected light for depth analysis, however, the reflected light has certain power to be received by a detector, and the larger the power of the reflected light is, the smaller the influence of external noise is, namely the higher the signal-to-noise ratio is, the more accurate the calculated distance is. On the other hand, the farther the distance is, the smaller the reflected light power is, and thus the laser emission power must be increased for long-distance detection. However, high-power laser light is very easy to damage human eyes, the safety problem of human eyes must be considered in practical application, and the high-power emitted light signal has poor energy-saving effect, is limited by the current battery storage technology, and is not beneficial to the application on devices such as electric vehicles and mobile phones.
In other prior art schemes, a photodiode or a photogate is used to detect received photons in a voltage mode or a charge mode for detection over a distance, and a scheme for detection by a photosensor needs to consider photocurrent shot noise and circuit noise, which limit the theoretical sensitivity of the photosensor and easily cause a large error.
In addition, in the prior art, sensing is performed based on transmitting and receiving optical signals at one time, so that a sensing result is integrally fixed, and dynamic local sensing cannot be realized.
Disclosure of Invention
One of the objectives of the present invention is to provide an optical detection system and method, and a lidar system, wherein the optical detection system and method employs a coherent pixel array composed of a plurality of coherent pixel sensors, and employs a Frequency Modulated Continuous Wave (FMCW) Signal for detection, and mixes a frequency modulated source Signal (LO Signal) and a reflected frequency modulated continuous wave Signal, so as to significantly improve a Signal-to-Noise Ratio (SNR) of a detected weak Signal, thereby significantly improving sensitivity of optical detection.
One of the objectives of the present invention is to provide an optical detection system and method, and a laser radar system, where the optical detection system and method need to acquire a frequency modulated continuous wave signal received by each coherent pixel, and detection and analysis can be performed only after a weak frequency modulated continuous wave signal and a small amount of frequency modulated source signals are acquired and mixed, so that a high-power emission source is not needed, energy consumption is reduced, and applicability of the system is improved.
One of the objectives of the present invention is to provide an optical detection system and method, and a lidar system, where the optical detection system and method control signal emission and signal detection of different coherent pixel arrays formed by a coherent pixel sensor, where the coherent pixel includes an optical phased array chip (OPA chip) based on a silicon PIC, and the optical phased array chip can externally emit a signal beam with a specific shape or a specific direction, so as to perform dynamic local detection, and different detection positions in the whole process are in different states, thereby effectively solving the defect of only overall fixed sensing in the prior art.
One of the objectives of the present invention is to provide an optical detection system and method, and a lidar system, where the optical detection system and method can use a line-by-line emission detection optical signal and a line-by-line scanning mode to perform detection, and illuminate a part of an area at the same time, so as to avoid the excessive optical signal power caused by one-time emission of the detection signal, and reduce the damage to human eyes while saving the optical power of the system.
One of the objectives of the present invention is to provide a light detection system and method, and a lidar system, wherein the light detection system and method distributes a frequency-modulated source signal by means of a multi-stage optical switch, and an optical switch controller dynamically switches an LO signal into a row optical waveguide corresponding to a currently selected pixel row for reading, so that the LO signal is not transmitted to other inactive (unselected) pixel rows, thereby reducing the optical power of the required LO signal.
To achieve at least one of the above-mentioned objects, the present invention further provides a light detection system, comprising:
an array of coherent pixels;
an FMCW operator array;
an optical emission module;
an optical receiving module;
a light emitter;
a controller;
the optical emission module is connected with the light emitter, the controller is connected with the FMCW operator array and the light emitter, the light emitter is used for generating frequency modulation continuous waves, the frequency modulation continuous waves are used for detecting a target object, the optical receiving module is installed on the coherent pixel array and used for receiving optical reflection signals of the target and generating mixing signals through the coherent pixel array, and the FMCW operator array is used for analyzing the mixing signals to obtain detection data.
According to one of the preferred embodiments of the present invention, the coherent pixel array comprises a silicon material-based optical waveguide or a silicon nitride-based optical waveguide.
According to another preferred embodiment of the present invention, the coherent pixel array comprises a plurality of coherent pixels, each coherent pixel comprises a coherent receiving unit and an optical conversion unit, and the coherent receiving unit and the optical conversion unit respectively form a coherent receiving array and an optical conversion array, and each coherent receiving unit is connected with a corresponding optical conversion unit and is used for receiving the optical reflection signal and processing and converting the optical reflection signal.
According to another preferred embodiment of the present invention, each coherent receiving unit includes a receiving antenna and an optical mixer, which respectively form a receiving antenna array and an optical mixer array, the receiving antenna is connected to the optical mixer, the optical mixer is connected to the optical transmitting module, and is configured to mix an optical reflection signal received by the receiving antenna with a source signal, and input the mixed optical signal to the optical converting unit, and the optical converting unit includes an optical detector, and the optical detector is configured to convert the mixed optical signal into an electrical signal.
According to another preferred embodiment of the present invention, each of the receiving antennas is connected to a corresponding optical waveguide, and is configured to receive the optical reflection signal and couple the optical reflection signal to the optical waveguide connected to the corresponding optical mixer.
According to another preferred embodiment of the invention, the array of coherent pixels comprises a row and column grid, each row of the row and column grid connecting a corresponding pixel and an array of FMCW operators, each column grid of the row and column grid connecting a corresponding pixel and a corresponding FMCW operator unit.
According to another preferred embodiment of the present invention, the optical emission module is connected to a beam splitter, the beam splitter is connected to the optical transmitter, the beam splitter is connected to each coherent pixel, and the beam splitter is configured to transmit an optical signal to the target space and simultaneously transmit an optical signal to the array of coherent pixels.
According to another preferred embodiment of the present invention, the optical emission module includes at least one of an optical lens, an optical diffuser, or an optical phased array for beam shaping.
According to another preferred embodiment of the present invention, after the beam splitter is connected to the coherent pixel array, the beam splitter cascade-arranged on the coherent pixel array forms a routing optical path, and the beam splitter cascade-arranged is connected to an optical switch, the optical switch is connected to the controller, each optical switch is provided with at least two optical branches, the end of each optical branch is connected to a coherent pixel, and the routing optical path is configured to controllably send a source signal to the corresponding coherent pixel.
According to another preferred embodiment of the invention, the optical emission module comprises an optical phased array chip, integrated on or present independently of the coherent pixel array, for emitting the source signal and emitting the collimated or desired beam to the target space.
According to another preferred embodiment of the present invention, the FMCW operator array is used for reading row-column grid data in a row-by-row manner, and sequentially acquiring detection data of different target spaces.
To achieve at least one of the above objects, the present invention further provides a light detection method, comprising the steps of:
generating frequency modulation continuous waves, and splitting the frequency modulation continuous waves into source signals and detection signals;
controlling the detection signals in a grading way, and sending the detection signals to a specified direction or position according to a control rule;
transmitting source signals to the designated coherent pixels according to the control rule;
receiving an optical reflection signal and a source signal and mixing the source signal and the optical reflection signal;
and analyzing the mixed signal to acquire the detection information.
According to one of the preferred embodiments of the present invention, the generated frequency-modulated continuous wave is acquired by an optical phased array, a detection signal of a linear collimated light beam or a linear desired light beam is further generated, and a split source signal is generated, the detection signal is used for emitting towards a specified direction or a specified position, and the source signal is input into a corresponding coherent pixel.
According to another preferred embodiment of the present invention, the light reflection signals on the coherent pixels are read line by line, and the light reflection signals and the source signals are mixed and then analyzed line by line, so as to obtain the detection information line by line or in a fixed area.
According to a preferred embodiment of the present invention, one or more optical lenses are disposed on the coherent pixels to form a light receiving module for receiving at least one light reflection signal in a specified direction, and the light reflected by the target is imaged on the coherent pixel array to form the light reflection signal.
In accordance with one of the preferred embodiments of the present invention, an array of coherent pixels is used to receive a reflected signal from a target area illuminated by a uniformly diverging beam of light or from a target point illuminated by a collimated emitted beam of light.
To achieve at least one of the above objects, the present invention further provides a lidar system employing a light detection system as described above.
To achieve at least one of the above objects, the present invention further provides a lidar system that employs the above-described light detection method.
Drawings
FIG. 1 is a schematic diagram of a preferred embodiment of an optical detection system according to the present invention;
FIG. 2 is a schematic diagram of another preferred embodiment of an optical detection system according to the present invention;
FIG. 3 is a schematic diagram showing the structure of a coherent pixel array and an FMCW operator array in an optical detection system according to the present invention;
FIG. 4 is a schematic diagram showing an internal structure of a coherent pixel in an optical detection system according to the present invention;
fig. 5 is a flow chart illustrating a light detection method according to the present invention.
Detailed Description
The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.
It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced devices or components must be in a particular orientation, constructed and operated in a particular orientation, and thus the above terms are not to be construed as limiting the present invention.
It is understood that the terms "a" and "an" should be interpreted as meaning that a number of one element or element is one in one embodiment, while a number of other elements is one in another embodiment, and the terms "a" and "an" should not be interpreted as limiting the number.
Referring to fig. 1-5, the present invention discloses a light detection system and method, wherein the light detection system comprises a light emitter, a coherent pixel array; an FMCW operator array; an optical emission module; an optical receiving module; and a controller, wherein the optical transmitter is preferably a single-mode laser transmitter in the present invention, and the single-mode laser transmitter may be a semiconductor diode laser, a diode-pumped solid-state laser or a fiber laser, and the single-mode laser transmitter may emit any wavelength from 800nm to 1600nm to the outside. In order to solve the problem of phase noise in FMCW (frequency modulated continuous wave), lasers with narrow linewidths are required, for example, the linewidth required for a detection distance of about 100m is generally less than 500kHz, and a laser with a linewidth less than 500kHz is required for a detection distance longer than that required for detection, and a diode-pumped solid-state laser or a fiber laser in the existing laser can meet the linewidth requirement. In another preferred embodiment of the present invention, an external cavity or filter can be provided on a laser with a relatively large linewidth to meet the linewidth requirement.
The optical transmitter transmits a corresponding light beam to the optical transmitter module, in a preferred embodiment of the present invention, the optical transmitter module is connected to a beam splitter, and the beam splitter is disposed on the optical transmitter and configured to split the light beam transmitted by the optical transmitter into at least one probe signal beam and a source signal beam, wherein the probe signal beam is configured to transmit a probe signal in an external or external designated direction, the source signal is a Local Oscillator (LO) signal from a Local light source, the source signal beam is split and then transmitted to the coherent pixels, each coherent pixel includes a coherent receiving unit and an optical conversion unit, a coherent receiving array and an optical conversion array are formed on a coherent pixel array of a plurality of coherent pixels, each coherent receiving unit includes a receiving antenna and an optical mixer, each optical conversion unit comprises an optical detector, a corresponding beam splitter is connected to each coherent pixel in Shanghai mode, the receiving antenna can be made of a waveguide grating coupler or a micro reflector, and receives optical reflection signals from a target detection space, a mixer is further arranged in each coherent pixel, the mixer receives a source signal from the beam splitter and optical reflection signals from the receiving antenna, the source signal is a mixed local oscillation frequency, the local oscillation frequency and the frequency of the optical reflection signals are mixed to form a mixed frequency, detection signals of the mixed frequency can be input into an existing FMCW arithmetic unit, and detected distance and position information can be calculated through existing arithmetic rules. The FMCW operation is a prior art, and the present invention is not described in detail herein.
It should be noted that the beam splitter connected to the coherent pixels is arranged in a cascade manner to form a routing optical path, where the routing optical path has a plurality of optical switches, each optical switch forms at least 2 optical branches, the end of each optical branch is connected to a corresponding coherent pixel, and the optical switch can control the on and off of any optical branch, where the optical switch is connected to a controller, and the on and off of the optical switch can be realized by the controller. In a preferred embodiment shown in fig. 3, the beam splitter forms a 3-stage connection structure under the arrangement of the optical switch, and one end of the left side of the beam splitter is connected to an input coupler, which may be a surface-incident grating coupler or a side-incident edge coupler, through which the source signal can be coupled into the coherent pixel array. The receiving antenna also couples the reflected light detection signal to the coherent pixel corresponding to the coherent pixel array, and further supplies the mixer to carry out frequency mixing, the mixer is connected with the photoelectric detector, the optical signal of the mixer after the frequency mixing is completed is converted into an electric signal through the photoelectric detector, and further one or more specific FMCW arithmetic units are appointed through the controller to obtain appointed detection information, wherein the controller comprises a central processing unit and an optical switch controller, and the central processing unit is used for overall work of the whole optical detection system. The light switch controller is used for controlling a specified row or a specified position in the coherent pixel array to carry out light detection. Optionally, the optical detection system further includes a power management module, an I/O communication module, and a memory, which are respectively used for supporting the operation of the optical detection system.
It should be noted that the optical detection system comprises a row-column electrical network consisting of row conductors and column conductors, wherein the column conductors connect the coherent pixels of one column, each row conductor connects the coherent pixels of a corresponding row, and all row conductors are connected to an array of FMCW operators, which can selectively read out data of a specific row or rows, each FMCW operator processes the detection data converted into electrical signals of a corresponding column, and each column conductor structurally extends to the FMCW operator of the corresponding column. Each FMCW arithmetic device is connected with a central processing unit, the FMCW arithmetic devices input detection data converted into electric signals into the central processing unit for analysis and processing, due to the structural relationship between the FMCW arithmetic devices and pixels, detection information on coherent pixels can be read line by line under the control of the controller, FMCW detection light beams are irradiated in a specified direction under the control of the optical emitting module, reflected light is acquired by the optical receiving module and then input into the coherent pixel array for optical detection to generate optical reflection signals, and the optical reflection signals are converted into electric signals line by line to be processed by the central processing unit. In other preferred embodiments of the present invention, since the optical switch controller controls the beam splitting direction of the light in a step-by-step manner, the source signal can be dynamically switched into the optical waveguide of the selected pixel row which is read, so that the source signal can be prevented from being fed into the inactive pixel, and the waste of power can be avoided.
After receiving the mixed signal, the FMCW operator performs distance and speed calculations based on an FMCW signal analysis algorithm, and the calculation method is the prior art, which is not described herein again. The object and the speed of the space corresponding to the row of pixels can be detected, the detection can be carried out line by line under the control of the controller in a local or line by line mode to transmit detection signals, and after signal identification or processing is completed, the rest rows or positions receive the detection signals transmitted to other directions, so that the damage of one-time strong detection light to human eyes can be effectively avoided, and meanwhile, the energy consumption can be effectively saved. Secondly, after the distances and the speeds of the detected objects of all the coherent pixels are read, the distances and the speeds of the detected objects of the whole coherent pixel array can be acquired, and the detection operation is continuously repeated at a constant or variable frame rate, so that the video detection information of the depth or the speed can be acquired.
It should be noted that, the frequency of the control signal required in the FMCW signal detection process may be used, and the frequency modulation may be achieved by modulating the current injected into the optical transmitter or heating the emitted optical beam, or modulating the physical size and refractive index of the laser cavity, and the invention is not limited thereto. The beam splitter can be selectively adjusted according to the property of the light beam emitted by the light emitter, if the light emitter outputs free space light, the beam splitter can adopt free space optical writing components including but not limited to a prism, a semi-transparent mirror and the like to perform optical beam splitting, and if the emitted light beam of the light emitter is based on optical fiber coupling, the corresponding beam splitter can adopt a beam splitter based on optical fiber. The optical emission module can be used for shaping and adjusting the orientation of the emitted light beam, wherein the optical emission module comprises one or more lenses, which can be convex lenses or concave lenses, for increasing or decreasing the divergence angle of the emitted light beam. The optical receiving module includes at least one lens, it should be noted that the coherent array may be provided in multiple numbers, at least one lens, such as a convex lens, is provided on each coherent pixel array, and the optical lens above each coherent pixel array may acquire a reflected light detection signal in a specified direction, so that each pixel may acquire detection information in different directions and positions.
With continued reference to the silicon PIC based coherent pixel array shown in fig. 4, the splitter may be made of a directional coupler or Multi-Mode Interference (MMI) including an optical waveguide based for distributing a portion of the LO signal light from the optical waveguide into a single pixel for local optical mixing and passing the rest to the next pixel; the optical mixer may be made of a waveguide-based directional coupler or MMI, and is configured to mix the LO optical signal with the received optical signal in the optical domain and output the mixed optical signal to the photodetector; the photodetector may be made of a waveguide type germanium (Ge) photodiode (suitable wavelength less than 1600nm) or a silicon (Si) photodiode (suitable wavelength less than 1100nm) for converting the mixed optical signal into an electrical signal. Wherein the photodetector has an anode connected to the row conductors of the row and column power grids and a cathode connected to the column conductors of the row and column power grids, wherein the conductors may be made of relevant metals including but not limited to copper, aluminum, and alloys.
Referring to fig. 2, in another preferred embodiment of the present invention, the Optical emission module can be replaced by an existing Optical Phased Array (OPA) chip based on silicon PIC, and the OPA chip can be integrated on a coherent pixel Array chip or implemented on a separate chip. It should be noted that, the OPA chip can output a collimated light beam and a light beam with a desired shape to the outside, and the OPA chip can be manipulated to emit a linear light beam to a specific position, the linear light beam has a large divergence angle in the row direction of the coherent pixel array and a narrow divergence angle in the column direction of its pixels, that is, is nearly collimated, and forms an imaging region on the coherent pixels of a specific row or a specific region through the optical receiving module, and after reading row by row, the linear light beam is converted into an electrical signal by the photodetector row by row through the mixing of the mixer and the source signal, and then the electrical signal is processed by the FMCW operator, and each FMCW operator inputs the processed data to the central processor to acquire the detection data of all the coherent pixels.
In particular, according to the embodiments of the present disclosure, the processes described above with reference to the flowcharts may be implemented as computer software programs. For example, embodiments of the present disclosure include a computer program product comprising a computer program embodied on a computer readable medium, the computer program comprising program code for performing the method illustrated in the flow chart. In such an embodiment, the computer program may be downloaded and installed from a network via the communication section, and/or installed from a removable medium. The computer program, when executed by a Central Processing Unit (CPU), performs the above-described functions defined in the method of the present application. It should be noted that the computer readable medium mentioned above in the present application may be a computer readable signal medium or a computer readable storage medium or any combination of the two. The computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples of the computer readable storage medium may include, but are not limited to: an electrical connection having one or more wire segments, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the present application, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. In this application, however, a computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: wireless section, wire section, fiber optic cable, RF, etc., or any suitable combination of the foregoing.
The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
It will be understood by those skilled in the art that the embodiments of the present invention described above and illustrated in the drawings are given by way of example only and not by way of limitation, the objects of the invention having been fully and effectively achieved, the functional and structural principles of the present invention having been shown and described in the embodiments, and that various changes or modifications may be made in the embodiments of the present invention without departing from such principles.
Claims (18)
1. A light detection system, the system comprising:
an array of coherent pixels;
an FMCW operator array;
an optical emission module;
an optical receiving module;
a light emitter;
a controller;
the optical emission module is connected with the light emitter, the controller is connected with the FMCW operator array and the light emitter, the light emitter is used for generating frequency modulation continuous waves, the frequency modulation continuous waves are used for detecting a target object, the optical receiving module is installed on the coherent pixel array and used for receiving optical reflection signals of the target and generating mixing signals through the coherent pixel array, and the FMCW operator array is used for analyzing the mixing signals to obtain detection data.
2. A light detection system according to claim 1, wherein the coherent pixel array comprises a silicon-based material optical waveguide or a silicon nitride-based optical waveguide.
3. An optical detection system according to claim 1, wherein the coherent pixel array comprises a plurality of coherent pixels, each coherent pixel comprises a coherent receiving unit and an optical conversion unit, which form a coherent receiving array and an optical conversion array, respectively, and each coherent receiving unit is connected to the corresponding optical conversion unit for receiving the optical reflection signal and processing and converting the optical reflection signal.
4. The optical detection system of claim 3, wherein each coherent receiving unit comprises a receiving antenna and an optical mixer, which respectively form a receiving antenna array and an optical mixer array, the receiving antenna is connected to the optical mixer, the optical mixer is connected to the optical transmitting module, and is configured to mix the optical reflection signal received by the receiving antenna with the source signal, and input the mixed optical signal into the optical conversion unit, and the optical conversion unit comprises an optical detector, and the optical detector is configured to convert the mixed optical signal into an electrical signal.
5. An optical detection system as claimed in claim 2, wherein each receiving antenna is connected to a corresponding optical waveguide for receiving the optical reflection signal and coupling the optical reflection signal to the optical waveguide connected to the corresponding optical mixer.
6. An optical detection system according to claim 1 wherein the array of coherent pixels comprises a row and column electrical network, each row of the row and column electrical network connecting a corresponding pixel and the array of FMCW operators, each column electrical network of the row and column electrical network connecting a corresponding pixel and a corresponding FMCW operator unit.
7. An optical detection system as claimed in claim 1 wherein the optical emission module is connected to a beam splitter, the beam splitter being connected to the optical emitter, the beam splitter being connected to each coherent pixel, the beam splitter being arranged to transmit optical signals to the target space and simultaneously transmit optical signals to the array of coherent pixels.
8. A light detection system according to claim 7 wherein the optical emission module comprises at least one of an optical lens, an optical diffuser or an optical phased array for beam shaping.
9. An optical detection system according to claim 7, wherein after the beam splitter is connected to the coherent pixel array, the beam splitter cascade-connected to the coherent pixel array forms a routing optical path, and the beam splitter cascade-connected to the optical switch, the optical switch is connected to the controller, each optical switch is provided with at least two optical branches, each optical branch is connected to a coherent pixel at its end, and the routing optical path is configured to controllably send a source signal to the corresponding coherent pixel.
10. An optical detection system according to claim 8, wherein the optical emission module comprises an optical phased array chip integrated on or present independently of the coherent pixel array for emitting the source signal and emitting the collimated or desired beam of light to the target space.
11. An optical detection system as claimed in claim 1, wherein the FMCW operator array is configured to read row-column grid data in a row-by-row manner for sequentially acquiring detection data of different target spaces.
12. A method of light detection, the method comprising the steps of:
generating frequency modulation continuous waves, and splitting the frequency modulation continuous waves into source signals and detection signals;
controlling the detection signals in a grading way, and sending the detection signals to a specified direction or position according to a control rule;
transmitting source signals to the designated coherent pixels according to the control rule;
receiving an optical reflection signal and a source signal and mixing the source signal and the optical reflection signal;
and analyzing the mixed signal to acquire the detection information.
13. An optical detection method according to claim 12, characterized in that the generated frequency-modulated continuous wave is acquired by an optical phased array, a detection signal of a linear collimated light beam or a linear desired light beam is further generated, and a split source signal is generated, the detection signal is used for emitting to a specified direction or a specified position, and the source signal is input to a corresponding coherent pixel.
14. An optical detection method according to claim 12, wherein the optical reflection signals on the coherent pixels are read line by line, and the optical reflection signals and the source signal are mixed and then analyzed line by line to obtain the detection information line by line or in a fixed area.
15. A method as claimed in claim 12, wherein one or more optical lenses are disposed on the coherent pixel array to form a light receiving module for receiving at least one light reflection signal from a specified direction, and the light reflected from the target is imaged on the coherent pixel array to form the light reflection signal.
16. A method of optical detection as claimed in claim 12 wherein the coherent pixel array is adapted to receive a reflected signal from a target area illuminated by a uniformly diverging beam of light or from a target point illuminated by a collimated emitted beam of light.
17. A lidar system configured to employ a light detection system according to any of claims 1 to 11.
18. A lidar system configured to employ a light detection method according to any of claims 12 to 16.
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